Attachment 2 SOW_2.9_DECS 250N Manual.pdf

INSTRUCTION MANUAL

FOR

DIGITAL EXCITATION CONTROL SYSTEM

DECS-250N

Publication: 9440500990 Revision: B 05/14

9440500990 Rev B i

Preface This instruction manual provides information about the installation and operation of the DECS-250N Digital Excitation Control System. To accomplish this, the following information is provided:

• General Information

• Human-Machine Interface

• Functional Description

• Installation

• BESTCOMSPlus® Software

• Setup

• Communication Protocols

• Maintenance

• Specifications

• Expansion Modules

Warning!

To avoid personal injury or equipment damage, only qualified personnel should perform the procedures in this manual.

NOTE

Be sure that the device is hard-wired to earth ground with no smaller than 12 AWG (3.3 mm2) copper wire attached to the case ground terminal. When the device is configured in a system with other devices, a separate lead should be connected from the ground bus to each device.

Current transformer (CT) grounding should be applied in accordance with local codes and conventions.

DECS-250N Preface ii 9440500990 Rev B

12570 State Route 143

Highland IL 62249-1074 USA www.basler.com, info@basler.com

Tel: +1 618.654.2341, Fax: +1 618.654.2351

© 2014 by Basler Electric All rights reserved

First printing: January 2014

Confidential information of Basler Electric. It is loaned for confidential use, subject to return on request, and with the mutual understanding that it will not be used in any manner detrimental to the interests of Basler Electric.

It is not the intention of this manual to cover all details and variations in equipment, nor does this manual provide data for every possible contingency regarding installation or operation. The availability and design of all features and options are subject to modification without notice. Over time, improvements and revisions may be made to this publication. Visit www.basler.com to obtain the latest version. Should further information be required, contact Basler Electric.

For terms of service relating to this product and software, see the Commercial Terms of Products and Services document available at https://www.basler.com/terms.

The English-language version of this manual serves as the only approved manual version.

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This product contains, in part, open source software (software licensed in a way that ensures freedom to run, copy, distribute, study, change, and improve the software) and you are granted a license to that software under the terms of either the GNU General Public License or GNU Lesser General Public License. The licenses, at the time of sale of the product, allow you to freely copy, modify, and redistribute that software and no other statement or documentation from us, including our End User License Agreement, places any additional restrictions on what you may do with that software.

For at least three (3) years from the date of distribution of this product, a machine-readable copy of the complete corresponding source code for the version of the programs distributed to you will be sent upon request (contact information is provided above). A fee of no more than our cost of physically performing the source code distribution is charged.

The source code is distributed in the hope that it will be useful, but WITHOUT ANY REPRESENTATION or WARRANTY or even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Refer to the source code distribution for additional restrictions regarding warranty and copyrights.

For a complete copy of GNU GENERAL PUBLIC LICENSE Version 2, June 1991 or GNU LESSER GENERAL PUBLIC LICENSE Version 2.1, February 1999 refer to www.gnu.org or contact Basler Electric. You, as a Basler Electric Company customer, agree to abide by the terms and conditions of GNU GENERAL PUBLIC LICENSE Version 2, June 1991 or GNU LESSER GENERAL PUBLIC LICENSE Version 2.1, February 1999, and as such hold Basler Electric Company harmless related to any open source software incorporated in this product. Basler Electric Company disclaims any and all liability associated with the open source software and the user agrees to defend and indemnify Basler Electric Company, its directors, officers, and employees from and against any and all losses, claims, attorneys' fees, and expenses arising from the use, sharing, or redistribution of the software. Review the software website for the latest version of the software documentation.

Preface DECS-250N http://www.basler.com/ mailto:info@basler.com http://www.basler.com/ https://www.basler.com/terms

9440500990 Rev B iii

Contents Introduction

Features and Functions Application Package Optional Features and Capabilities Storage

Controls and Indicators Front Panel Illustration and Description Menu Navigation Adjusting Settings Display Setup

Power Inputs Control Power Operating Power

Power Stage Field Transient Protection Inverting Style Excitation System Compatibility

Voltage and Current Sensing Generator Voltage Generator Current Bus Voltage

Synchronizer Generator Synchronization Voltage Matching Breaker Hardware Configuration Generator and Bus Condition Detection Generator Governor Control

Regulation Regulation Modes Pre-Position Setpoints Transient Boost Operation with Paralleled Generators Autotracking Setpoint Configure

Auxiliary Control Auxiliary Control Input Type Auxiliary Control Input Function Auxiliary Control Gains Summing Type

Contact Inputs and Outputs Contact Inputs Contact Outputs

Protection Voltage Protection Frequency Protection Power Protection Field Protection Sync-Check Protection Generator Frequency Less Than 10 Hertz Configurable Protection iv 9440500990 Rev B

Limiters Overexcitation Limiter Underexcitation Limiter Stator Current Limiter Var Limiter Limiter Scaling Underfrequency Limiter

Metering Metering Explorer Metered Parameters Status Indication Auto Export Metering

Event Recorder Sequence-of-Events Recording Data Logging Trending

Power System Stabilizer Supervisory Function and Setting Groups Theory of Operation

Stability Tuning AVR Mode FCR and FVR Modes Other Modes and Functions

Mounting Mounting Considerations Projection Mounting Behind-the-Panel Mounting

Terminals and Connectors Overview Terminal Types

Typical Connections

BESTCOMSPlus® Software General Description Installation Activation of the DECS-250N Plugin for BESTCOMSPlus® Menu Bars Settings Explorer Metering Explorer Settings File Management Automatic Metering Export Firmware Updates BESTCOMSPlus® Updates

BESTlogic™Plus Introduction Overview of BESTlogic™Plus Logic Schemes Programming BESTlogic™Plus BESTlogic™Plus File Management BESTlogic™Plus Examples

Communication Local Communication Communication with a Second DECS

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Modbus™ Communication CAN Communication Ethernet Communication PROFIBUS Communication

Configuration Generator, Field, and Bus Ratings Sensing Transformer Ratings and Configuration Bridge Operating Power Configuration Startup Functions Device Information Display Units

Security Password Access Port Security Login and Access Controls

Timekeeping Time and Date Format Daylight Saving Time Adjustments Network Time Protocol (NTP)

IRIG

Testing Real-Time Metering Analysis Frequency Response Time Response Step Response Analysis Analysis Options

CAN Communication Introduction CAN Parameters

Modbus™ Communication Introduction Modbus Modes of Operation Detailed Message Query and Response for RTU Transmission Mode Data Formats Secure DECS-250N Login via Modbus Modbus Parameters

PROFIBUS Communication Data Types Setup PROFIBUS Parameters

Maintenance Storage Preventive Maintenance Cleaning the Front Panel Troubleshooting Support

Specifications Operating Power Control Power Generator and Bus Voltage Sensing Generator Current Sensing Accessory Inputs Contact Inputs vi 9440500990 Rev B

Communication Ports IRIG Time Synchronization Input Contact Outputs Field Power Output Regulation Parallel Compensation Generator Protection Functions Field Protection Functions Synchronism Check (25) Protection Startup Voltage Matching On-Line Overexcitation Limiting Off-Line Overexcitation Limiting Sequence of Events Recording (SER) Data Logging (Oscillography) Environment Type Tests Patent Physical Regulatory Standards

Analog Expansion Module General Information Features Specifications Installation Communications Functional Description Metering Maintenance

Contact Expansion Module General Information Features Specifications Installation Communications Functional Description Metering Maintenance

Revision History

9440500990 Rev B 1

Introduction DECS-250N Digital Excitation Control Systems offer precise excitation control and machine protection in a compact package. DECS-250N adaptability to many applications is assured through configurable contact inputs and outputs, flexible communication capabilities, and programmable logic implemented with the provided BESTCOMSPlus® software.

Features and Functions

DECS-250N features and functions include:

• Five excitation control modes:

o Automatic Voltage Regulation (AVR) o Field Current Regulation (FCR) o Field Voltage Regulation (FVR) o Power Factor Regulation (PF) o Var Regulation (var)

• Three pre-position setpoints for each excitation control mode

• Internal tracking between operating mode setpoints and external tracking of a second DECS excitation setpoint

• Two PID stability groups with Auto Tune feature

• Remote setpoint control input accepts analog voltage or current control signal

• Real-time metering

• Optional automatic synchronizer

• Optional integrated power system stabilizer (PSS) o Generator or motor control modes, accommodates phase rotation changes between modes o Speed and power sensing or speed-only sensing o Two wattmeter or three-wattmeter methods of power measurement

• Soft start and voltage buildup control

• Five limiting functions:

o Overexcitation: summing point and takeover o Underexcitation o Stator current o Reactive power (var) o Underfrequency

• Twenty protection functions:

o Generator undervoltage (27) o Generator overvoltage (59) o Loss of sensing (LOS) o Overfrequency (81O) o Underfrequency (81U) o Reverse power (32R) o Loss of excitation (40Q) o Field overvoltage o Field overcurrent o Loss of PMG o Exciter diode failure o Sync-check (25) o Eight configurable protection elements

• IRIG or network time synchronization

• Sixteen contact sensing inputs o Two fixed-function inputs: Start and Stop o Fourteen programmable inputs

DECS-250N Introduction

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• Twelve contact outputs o One, fixed-function output: Watchdog (SPDT configuration) o Eleven programmable outputs

• Flexible communication o Serial communication through front-panel USB port o Modbus communication through RS-485 port or Modbus TCP o Ethernet communication through an optional copper or fiber optic port o CAN communication with an ECU (engine control unit), optional AEM-2020 Analog

Expansion Module, or optional CEM-2020 Contact Expansion Module o Optional PROFIBUS communication protocol

• Data logging, sequence of events recording, and trending

• Optional CEM-2020 Contact Expansion Module provides:

o Ten contact inputs o Eighteen contact outputs (CEM-2020H) or 24 contact outputs (CEM-2020) o Customizable input and output functions assigned through BESTlogic™Plus programmable logic o Communication via CAN protocol

• Optional AEM-2020 Analog Expansion Module provides:

o Eight analog inputs o Eight resistive thermocouple device (RTD) inputs o Two thermocouple inputs o Four analog outputs o Customizable input and output functions assigned through BESTlogicPlus programmable logic o Communication via CAN protocol

Application

The DECS-250N is intended for synchronous generator applications where the DECS-250N controls the generator output through the application of regulated excitation power to the field. It provides regulated dc excitation power based on the monitored generator voltage and current and a regulation setpoint established by the user.

Excitation power is supplied from the DECS-250N by means of a six-SCR, full-wave bridge. It is capable of two-quadrant operation; it can produce negative as well as positive output power. With nominal operating voltage applied, the DECS-250N is capable of supplying 20 Adc continuously at a nominal voltage of 32, 63, or 125 Vdc.

Package

A single, compact package contains all excitation control and power components.

A front panel HMI provides local annunciation and control through a backlit liquid crystal display (LCD), light-emitting diodes (LEDs), and pushbuttons. Remote annunciation and control is provided through a flexible communication interface which accommodates Ethernet, Modbus, optional PROFIBUS, and the optional Interactive Display Panel (IDP-800).

Optional Features and Capabilities

DECS-250N optional features and capabilities are defined by a combination of letters and numbers that make up the style number. The model number and style number describe options and characteristics in a specific device and appear on a label affixed to the device.

Introduction DECS-250N

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Style Number The style number identification chart in Figure 1 defines the electrical characteristics and operational features available in the DECS-250N.

Figure 1. DECS-250N Style Chart

Storage

If a DECS-250N will not be placed in service right away, store it in the original shipping carton in a moisture- and dust-free environment. The temperature of the storage environment must be within the range of –40 to 85°C (–40 to 185°F).

Electrolytic Capacitor Considerations The DECS-250N contains long-life aluminum electrolytic capacitors. For a DECS-250N kept in storage as a spare, the life of these capacitors can be maximized by energizing the device for 30 minutes once per year. Refer to the energizing procedures provided in Maintenance.

DECS-250N Introduction

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Introduction DECS-250N

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Controls and Indicators All controls and indicators are located on the front panel and consist of pushbuttons, LED indicators, and a liquid-crystal display (LCD).

Front Panel Illustration and Description

DECS-250N controls and indicators are illustrated in Figure 2 and described in Table 1. The locators and descriptions of Table 1 correspond to the locators shown in Figure 2.

Figure 2. Front Panel Controls and Indicators

DECS-250N Controls and Indicators

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Table 1. Front Panel Control and Indicators Descriptions

Locator Description A Display. The liquid crystal display (LCD) serves as a local source of information provided by the DECS-250N. The LCD displays operating setpoints, loop gains, metering, protection functions, system parameters, and general settings. The 128 by 64 dot pixel, backlit LCD displays white characters on a blue background.

B Pre-Position Indicator. This red light emitting diode (LED) lights when the active mode setpoint is at any of the three pre-position (predefined) settings.

C Limit Indicators. Two red LEDs indicate when the active mode setpoint reaches the minimum or maximum value.

D Scrolling Pushbuttons. These four buttons are used to scroll up, down, left, and right through the menus displayed on the LCD (locator A). During an editing session, the left and right scrolling pushbuttons select the variable to be changed and the up and down scrolling pushbuttons change the value of the variable.

E Reset Pushbutton. This button cancels editing sessions, resets alarm annunciations and latched alarm relays, and can be used for quick access to the metering screen.

F Communication Port. This type B USB jack connects the DECS-250N with a PC operating BESTCOMSPlus® for local communication. BESTCOMSPlus is supplied with the DECS-250N.

Caution In accordance with the guidelines defined in USB standards, the USB port on this device is not isolated. To prevent damage to a connected PC or laptop, the DECS-250N must be properly tied to ground.

G Edit Pushbutton. Pressing this button starts an editing session and enables changes to DECS-250N settings. At the conclusion of the editing session, the Edit pushbutton is pressed to save the settings changes.

H Null Balance Indicator. This green LED lights when the setpoint of the inactive operating modes (AVR, FCR, FVR, var, and PF) match the setpoint of the active mode.

I PSS Active Indicator. This red LED lights when the integrated power system stabilizer is enabled and can generate a stabilizing signal in response to a power system disturbance.

J Internal Tracking Indicator. This red LED lights when any inactive mode (AVR, FCR, FVR, Var, or Power Factor) is tracking the setpoint of the active mode to achieve a “bumpless” transfer when changing active modes.

Menu Navigation The DECS-250N provides local access to DECS-250N settings and metering values through a menu structure displayed on the front panel LCD. An overview of the menu structure is illustrated in Figure 3.

Movement through the menu structure is achieved by pressing the four scrolling pushbuttons.

Controls and Indicators DECS-250N

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Figure 3. Menu Structure Overview

Adjusting Settings

A setting adjustment is made at the front panel by performing the following steps.

1. Navigate to the screen listing the setting to be changed.

2. Press the Edit button and enter the appropriate username and password to gain the needed level of security access. (Information about implementing and using username and password protection is provided in the Security section of this manual.)

3. Highlight the desired setting and press the Edit button to view the setting editing screen. This screen lists the setting range or the permissible setting selection.

4. Use the scrolling pushbuttons to select the setting digits/selections and adjust/change the setting.

5. Press the Edit button to save the change.

Display Setup

BESTCOMSPlus® Navigation Path: Settings Explorer, General Settings, Front Panel HMI

HMI Navigation Path: Settings, General Settings, Front Panel HMI

Front panel display appearance and behavior can be customized to meet user preferences and site conditions. These BESTCOMSPlus settings are illustrated in Figure 4.

LCD

LCD setup includes a contrast adjustmentA to suit the viewing angle used or compensate for environmental conditions. The ability to reverse the display colorsB is provided to accommodate lighting conditions and user preferences.

Sleep Mode Sleep modeC reduces the demand on control power by turning off the LCD backlight when no pushbutton activity is seen for the duration of the LCD Backlight Timeout settingD.

Language Language modules are available for the DECS-250N. Once a language module is implemented it can be enabled via the Language Selection settingE.

DECS-250N Controls and Indicators

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Screen Scrolling The display can be set to automatically scroll through a user-selected listF of metered values. This feature is enabled and disabled with the Enable Scroll settingG. The rate at which scrolling occurs is configured with the Scroll Time Delay settingH.

Figure 4. Front Panel HMI Settings

A Contrast Value (%): Adjustable from 0 to 100 in 1% increments.

B Invert display: Deselect for white characters on a blue background. Select for blue characters on a white background.

C Sleep Mode: Enable or disable.

D LCD Backlight Timeout: Adjustable from 0 to 120 seconds in 1 second increments.

E Language Selection: Select English, Russian, Spanish, or German.

F Scrollable Metering Settings: Select from main categories of GV Primary, GC Primary, CC Primary, Frequency, Power Primary, PF Primary, Energy Primary, BV Primary, Field Primary, PSS Primary, Synchronization Primary, Aux Input, Tracking, Real Time Clock, Contact Inputs, Contact Outputs, or Device ID. Follow this selection by the desired parameters within each category.

G Enable Scroll: Enable or disable.

H Scroll Time Delay (s): Adjustable from 1 to 600 seconds in 1 second increments.

Controls and Indicators DECS-250N

9440500990 Rev B 9

Power Inputs Power is applied to two separate inputs: control power and operating power. The control power input supplies power to an internal power supply that provides power for logic, protection, and control functions.

The power stage uses the operating power input as the source for the converted excitation power that it applies to the field.

Control Power Two inputs supply the DECS-250N with control power. One input accepts dc control power and the other input accepts ac control power. The level of acceptable control power voltage is determined by the style number. One of two levels is possible. Style Lxxxxxx indicates a nominal voltage of 24 or 48 Vdc and accepts a voltage range of 16 to 60 Vdc. Style Cxxxxxx indicates a nominal voltage of 120 Vac/125 Vdc and accepts a voltage range of 90 to 150 Vdc and 82 to 132 Vac (50/60 Hz). One input (either dc or ac) is sufficient for operation but two inputs provide redundancy (for style Cxxxxxx only). When both control power inputs are used, an isolation transformer is required for the ac input. DC control power is applied at terminals BATT+ and BATT–. AC control power is applied at terminals L and N.

Operating Power Operating power is applied at terminals A, B, and C. To achieve the desired level of excitation, the appropriate operating power input voltage must be applied. Table 2 lists the acceptable operating power voltage ranges for the DECS-250N. The operating power frequency range for the DECS-250N is listed in Table 3.

Table 2. DECS-250N Operating Power Specifications

Desired Nominal Excitation Power Voltage

Applied Operating Power Voltage Range

63 Vdc 100 to 139 Vac

125 Vdc 190 to 277 Vac

250 Vdc 380 to 528 Vac, 50/60 Hz (style xx3xxxx)

Table 3. DECS-250N Operating Power Frequency Specifications

DECS-250N

Style Number

Operating Power Frequency Range xx1xxxx 50/60 Hz xx2xxxx 61 to 420 Hz xx3xxxx 50/60 Hz (480 Vac input, 250 Vdc output)

DECS-250N Power Inputs

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Power Inputs DECS-250N

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Power Stage The power stage supplies regulated dc excitation power to the field of a brushless exciter. Excitation power is supplied at terminals F+ and F–.

DECS-250N power stage operating power accepts single- or three-phase ac power from a transformer or PMG. Power Stage operating power is applied at terminals A, B, and C. The GND terminal serves as a ground connection.

The DECS-250N power stage employs a six-SCR, full-wave bridge that converts the ac operating power input into dc excitation power. It is capable of two-quadrant operation; it can produce negative as well as positive output power as long as positive current is flowing in the machine field (in excess of the minimum holding current required for the SCRs). The DECS-250N power stage is capable of supplying 20 Adc continuously at nominal voltages of 63, 125, or 250 Vdc.

Nominal DECS-250N operating power levels include 480 Vac for a 250 Vdc continuous exciter field requirement (style XX3XXXX), 240 Vac for a 125 Vdc requirement, or 120 Vac for a 63 Vdc requirement.

The frequency range of the operating power voltage is determined by the DECS-250N style number. Style XX1XXXX indicates an operating power frequency of 50 to 60 hertz, style XX2XXXX indicates a frequency of 61 to 420 hertz, and style XX3XXXX limits the frequency to 50 or 60 hertz (for an operating voltage of 480 Vac).

Field Transient Protection

Fault conditions such as generator overloading or loss of synchronism can induce transients into the field circuit. If this energy is not dissipated, it has the potential to damage the power stage SCRs. The DECS-250N has two modes of field transient protection.

Most voltage transients are less than 150 microseconds in duration and are limited to a safe level by internal DECS-250N components.

During major system faults, an SCR crowbar circuit protects the DECS-250N power stage. When field overvoltage is detected, the power stage SCR firing pulses are blocked, the crowbar circuit is energized, and a crowbar annunciation is made. During a normal shutdown, the same actions are taken but no crowbar annunciation is made.

Inverting Style Excitation System Compatibility

The DECS-250N power stage can be configured for operation in the negative direction to supply the control windings of an inverting style excitation system.

DECS-250N Power Stage

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Power Stage DECS-250N

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Voltage and Current Sensing The DECS-250N senses generator voltage, generator current, and bus voltage through dedicated, isolated inputs.

Generator Voltage

Three-phase generator sensing voltage is applied to DECS-250N terminals E1, E2, and E3. This sensing voltage is typically applied through a user-supplied voltage transformer, but may be applied directly.

These terminals accept three-phase, three-wire connections at terminals E1 (A), E2 (B), and E3 (C) or single-phase connections at E1 (A) and E3 (C).

The generator voltage sensing input accepts a maximum voltage of 600 Vac and has a burden of less than 1 VA.

The transformer primary and secondary winding voltages are entered in settings that the DECS-250N uses to interpret the applied sensing voltage and calculate system parameters. The phase rotation of the generator sensing voltage can be configured as ABC or ACB. Information about configuring the DECS-250N for the generator sensing voltage is provided in the Configuration chapter of this manual.

Typical generator voltage sensing connections are illustrated in Figure 5.

Figure 5. Typical Generator Voltage Sensing Connections

Generator Current

Generator current sensing inputs consist of three phase-sensing inputs and a sensing input for cross-current compensation.

Current transformer (CT) grounding should be applied in accordance with local codes and conventions.

Phase Sensing Three-phase generator sensing current is applied to DECS-250N terminals CTA+ and CTA–, CTB+ and CTB–, and CTC+ and CTC– through user-supplied current transformers (CTs). Single-phase generator sensing current is applied to DECS-250N terminals CTB+ and CTB–. The DECS-250N is compatible with CTs having 5 Aac or 1 Aac nominal secondary ratings. The DECS-250N uses this secondary rating, along with the CT nominal primary ratings to interpret the sensed current and calculate system parameters.

DECS-250N Voltage and Current Sensing

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Information about configuring the DECS-250N for the generator sensing voltage is provided in the Configuration chapter of this manual. Typical generator phase-current sensing connections are shown in Figure 6.

Figure 6. Typical Generator Current Sensing Connections

Cross-Current Compensation Cross-current compensation (reactive differential) mode allows two or more paralleled generators to share a common load. As shown in Figure 7, each generator is controlled by a DECS-250N using the DECS-250N cross-current compensation input (terminals CCCT+ and CCCT–) and a dedicated, external current transformer (CT) to sense generator current. The resistors shown in Figure 7 are used to set the burden and may be adjusted to suit the application. Ensure that the power rating of the resistors is adequate for the application.

Figure 7. Connections for Cross-Current Compensation

Voltage and Current Sensing DECS-250N

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If a machine is taken offline, then the secondary winding of that machine’s cross-current compensation CT must be shorted.

Otherwise, the cross-current compensation scheme will not function.

Bus Voltage

Bus voltage monitoring enables bus failure detection, generator and bus voltage matching, and synchronization of the generator with the utility/bus. These features are discussed in the Synchronizer chapter of this manual. Three-phase bus sensing voltage is applied to DECS-250N terminals B1, B2, and B3. This sensing voltage is typically applied through a user-supplied voltage transformer, but may be applied directly. These terminals accept three-phase, three-wire connections at terminals B1 (A), B2 (B), and B3 (C) or single-phase connections at B3 (C) and B1 (A).

The bus voltage sensing input accepts a maximum voltage of 600 Vac and has a burden of less than 1

VA.

The transformer primary and secondary winding voltages are entered in settings that the DECS-250N uses to interpret the applied sensing voltage. Information about configuring the DECS-250N for the bus sensing voltage is provided in the Configuration section of this manual.

Typical bus voltage sensing connections are illustrated in Figure 8.

Figure 8. Typical Bus Voltage Sensing Connections

DECS-250N Voltage and Current Sensing

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Voltage and Current Sensing DECS-250N

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Synchronizer DECS-250N controllers with a style number of xxxxAxx are equipped with an automatic synchronizer that acts to align the voltage, phase angle, and frequency of the generator with the bus. The synchronizer function includes compensation settings for the generator breaker and bias control settings for the generator governor. Related synchronizer features include voltage matching and bus condition detection.

Generator Synchronization

BESTCOMSPlus® Navigation Path: Settings Explorer, Synchronizer/Voltage Matching, Synchronizer HMI Navigation Path: Settings, Sync/Voltage Matching, Synchronizer

Two modes of generator synchronization are available: phase lock loop and anticipatoryA. In either mode, the DECS-250N matches the voltage, phase angle, and frequency of the generator with the bus and then connects the generator to the bus by closing the generator breaker. Anticipatory mode has the added capability of compensating for the breaker closing time. (Breaker closing time is the delay between the issuance of a breaker close command and closure of the breaker contacts.) The DECS-250N compensates for the breaker closure time by monitoring the frequency difference between the generator and bus and calculating the advance phase angle required to close the breaker at a zero-degree phase angle.

Frequency Correction Generator frequency correction is defined by the slip frequency and further refined by the breaker closing angle. The slip frequency settingB establishes the maximum allowable deviation of the generator speed (frequency) from the bus frequency. The Min Slip Control Limit settingC and Max Slip Control Limit settingD are used to calculate the slip frequency error and to provide continuous slip frequency control while in phase lock synchronization. If the slip frequency magnitude is above the Max Slip Control Limit, the error is set equal to the Max Error in the opposite polarity. If the slip frequency magnitude is below the Min Slip Control Limit, the slip frequency error is 0. When it is between the two limits, the error is calculated internally by the DECS-250N. Slip frequency error is shown in Figure 9.

To minimize the impact on the bus during synchronization, the generator frequency can be forced to exceed the bus frequencyE at the moment of breaker closure. If this is the case, the DECS-250N will drive the generator frequency higher than the bus frequency before closing the breaker. The breaker closing angle settingF defines the maximum allowable phase angle difference between the generator and bus.

For breaker closure to be considered, the slip angle must remain within this setting for the duration of the sync activation delayG.

Figure 9. Slip Frequency Error

Voltage Correction Voltage correction is initiated when the generator voltage is outside the defined voltage window. The voltage window settingH is expressed as a percentage of the bus voltage and determines the band of generator voltage surrounding the bus voltage where breaker closure will be considered. Enabling the Vgen>Vbus settingI causes the DECS-250N to drive the generator voltage higher than the bus voltage prior to synchronizing. A generator to bus PT matching levelJ setting is provided to compensate for step-up or step-down transformers in the system. The DECS-250N adjusts the sensed generator voltage by

Slip Error = Max (-)

Slip Error = Max (+)Slip Error = 0

P0064-49

DECS-250N Synchronizer

18 9440500990 Rev B this percentage. This setting also appears on the Voltage Matching screen, below. When the value is changed, it is reflected in both places.

Angle Compensation An angle compensationK setting is provided to offset phase shift caused by transformers in the system.

The angle compensation value is added only to the bus angle. For example, it is given that the generator and bus are synchronized but the DECS-250N metered slip angle reads –30°. Equation 1, below, illustrates the DECS-250N slip angle calculation. This means that the generator angle is lagging behind the bus angle by 30° due to transformer phase shift. To compensate for this phase shift, the angle compensation setting should contain a value of 330°. This value is added to the metered bus angle resulting in an adjusted slip angle of zero degrees. Only the metered bus angle is affected by the angle compensation setting, the metered generator angle is not biased by the DECS-250N.

𝐺 − (𝐵 + 𝐴) = 𝑆𝑙𝑖𝑝 𝐴𝑛𝑔𝑙𝑒

Equation 1. DECS-250N Metered Slip Angle

Where:

G = metered generator angle B = metered bus angle A = angle compensation value

Failure of Synchronization Generator synchronization is aborted if generator synchronization fails to occur within a timeframeL established by the user.

BESTCOMSPlus generator synchronization settings are illustrated in Figure 10.

Figure 10. Generator Synchronizer Settings

A Sync Type: Select Anticipatory or Phase Lock Loop.

B Slip Frequency: Adjustable from 0.1 to 0.5 Hz in 0.05 Hz increments.

C Min Slip Control Limit: Adjustable from 0.1 to 2.0 Hz in 0.1 Hz increments.

D Max Slip Control Limit: Adjustable from 0.1 to 2.0 Hz in 0.1 Hz increments.

E Fgen>Fbus: Select Enable or Disable.

F Breaker Closing Angle: Adjustable from 3 to 20° in 0.5° increments.

G Sync Activation Delay: Adjustable from 0.1 to 0.8 s in 0.1 s increments.

H Voltage Window: Adjustable from 2 to 15% in 0.5% increments.

I Vgen>Vbus: Select Enable or Disable.

J Gen to Bus PT Match Level: Adjustable from 0 to 700% in 0.1% increments.

Synchronizer DECS-250N

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K Angle Compensation (°): Adjustable from 0.0 to 359.9° in 0.1° increments.

L Sync Fail Activation Delay: Adjustable from 0.1 to 0.8 s in 0.1 s increments.

Voltage Matching

BESTCOMSPlus® Navigation Path: Settings Explorer, Synchronizer/Voltage Matching, Voltage Matching HMI Navigation Path: Settings, Sync/Voltage Matching, Voltage Matching

When enabledA, voltage matching is active in AVR control mode and automatically adjusts the AVR mode setpoint to match the sensed bus voltage. Voltage matching is based on two parameters: band and matching level.

The voltage matching bandB defines the window in which the generator voltage must be for voltage matching to occur.

The generator to bus PT matching levelC defines the percentage of the sensed bus voltage to which the generator sensed voltage will be adjusted.

Voltage matching settings are illustrated in Figure 11.

Figure 11. Voltage Matching Settings

A Voltage Matching: Select Enabled to enable function.

B Band: Adjustable from 0 to 20% in 0.1% increments.

C Gen to Bus PT Match Level: Adjustable from 0 to 700% in 0.1% increments.

Breaker Hardware Configuration

BESTCOMSPlus Navigation Path: Settings Explorer, Synchronizer/Voltage Matching, Breaker Hardware HMI Navigation Path: Settings, Sync/Voltage Matching, Breaker Hardware

The DECS-250N can control and monitor a generator breaker. Breaker hardware settings are illustrated in Figure 12.

Breaker Failure When a close command is issued to the breaker, the DECS-250N monitors the breaker status and annunciates a breaker failure if the breaker does not close within the time defined by the breaker close wait delayA. Typically, the wait delay is set to be longer than the actual breaker closing time.

Generator Breaker The DECS-250N must be configuredB with the generator breaker characteristics before the breaker can be controlled by the DECS-250N. Breakers controlled by pulse or continuous control inputsC are supported. During anticipatory-mode synchronization, if the generator breaker is serving to tie the generator to the bus, the DECS-250N uses the breaker closing timeD to calculate the optimum time to

20 9440500990 Rev B close the breaker. For a pulse-controlled generator breaker, the breaker openE and closeF pulse times are used by the DECS-250N when issuing open and close commands to the breaker. When setting the pulse times, the open and close times should be set at or longer than the breaker closing time setting.

If desired, breaker closure is possible during a dead bus conditionG and/or dead generator conditionH.

Caution Use caution when connecting a “dead” generator to a “dead” bus.

Undesired system damage can occur if the bus becomes energized while a “dead” generator is connected to it.

Figure 12. Breaker Hardware Configuration Settings

A Breaker Close Wait Time: Adjustable from 0.1 to 600 s in 0.1 s increments.

B Gen Breaker: Select Configured or NOT Configured.

C Contact Type: Select Pulse or Continuous.

D Breaker Closing Time: Adjustable from 0 to 800 ms in 5 ms increments.

E Open Pulse Time: Adjustable from 0.01 to 5 s in 0.01 s increments. Setting is available only when Contact Type is Pulse.

F Close Pulse Time: Adjustable from 0.01 to 5 s in 0.01 s increments. Setting is available only when Contact Type is Pulse.

G Dead Bus Close: Select Disabled or Enabled.

H Dean Gen Close Enable: Select Disabled or Enabled.

Generator and Bus Condition Detection

BESTCOMSPlus® Navigation Path: Settings Explorer, Synchronizer/Voltage Matching, Bus Condition Detection

HMI Navigation Path: Settings, Sync/Voltage Matching, Bus Condition Detection

The DECS-250N monitors the voltage and frequency of the generator and bus for determining when a breaker closure is appropriate. Generator and bus condition detection settings are illustrated in Figure 13.

9440500990 Rev B 21

Generator Condition A dead generator is recognized by the DECS-250N when the generator voltage decreases below the dead generator thresholdA for the duration of the dead generator activation delayB.

A failed generator is recognized when the generator voltage or frequency does not meet the established generator stability criteria for the duration of the failed generator activation delayC. Generator stability parameters are described in Generator Stability.

Generator Stability Before initiating a breaker closure (tying the generator to a stable or dead bus), the generator voltage must be stable. Several settings are used to determine generator stability. These settings include pickup and dropout levels for overvoltageD, undervoltageE, overfrequencyF, and under-frequencyG. Recognition of generator stability is further controlled by a generator stability activation delayH. Breaker closure is not considered if the voltage conditions are not within the stability pickup and dropout settings for the duration of the stability activation delay.

Bus Condition A dead bus is recognized by the DECS-250N when the bus voltage decreases below the dead bus thresholdI for the duration of the dead bus activation delayJ.

A failed bus is recognized when the bus voltage or frequency does not meet the established stability criteria for the duration of the failed bus activation delayK. Bus stability parameters are described in Bus Stability.

Bus Stability Before initiating a breaker closure (tying the generator to a live bus), the bus voltage must be stable.

Several settings are used to determine bus stability. These settings include pickup and dropout levels for overvoltageL, undervoltageM, overfrequencyN, and underfrequencyO. Recognition of bus stability is further controlled by a bus stability activation delayP. Breaker closure is not considered if the voltage conditions are not within the stability pickup and dropout settings for the duration of the stability activation delay.

22 9440500990 Rev B

Figure 13. Generator and Bus Condition Detection Settings

A Dead Gen Threshold: Adjustable from 0 to 600,000 Vac in 1 Vac increments.

B Dead Gen Activation Delay: Adjustable from 0.1 to 600 s in 0.1 s increments.

C Gen Failed Activation Delay: Adjustable from 0.1 to 600 s in 0.1 s increments.

D Generator Stability Overvoltage Pickup and Dropout: Adjustable from 10 to 600,000 Vac in 1 Vac increments.

E Generator Stability Undervoltage Pickup and Dropout: Adjustable from 10 to 600,000 Vac in 1 Vac increments.

F Generator Stability Overfrequency Pickup and Dropout: Adjustable from 46 to 64 Hz in 0.05 Hz increments.

G Generator Stability Underfrequency Pickup and Dropout: Adjustable from 46 to 64 Hz in 0.05 Hz increments.

H Generator Stability Activation Delay: Adjustable from 0.1 to 600 s in 0.1 s increments.

9440500990 Rev B 23

I Dead Bus Threshold: Adjustable from 0 to 600,000 Vac in 1 Vac increments.

J Dead Bus Activation Delay: Adjustable from 0.1 to 600 s in 0.1 s increments.

K Bus Failed Activation Delay: Adjustable from 0.1 to 600 s in 0.1 s increments.

L Bus Stability Overvoltage Pickup and Dropout: Adjustable from 10 to 600,000 Vac in 1 Vac increments.

M Bus Stability Undervoltage Pickup and Dropout: Adjustable from 10 to 600,000 Vac in 1 Vac increments.

N Bus Stability Overfrequency Pickup and Dropout: Adjustable from 46 to 64 Hz in 0.05 Hz increments.

O Bus Stability Underfrequency Pickup and Dropout: Adjustable from 46 to 64 Hz in 0.05 Hz increments.

P Bus Stable Activation Delay: Adjustable from 0.1 to 600 s in 0.1 s increments.

Generator Governor Control

BESTCOMSPlus Navigation Path: Settings Explorer, Synchronizer/Voltage Matching, Governor Bias Control Settings

HMI Navigation Path: Settings, Sync/Voltage Matching, Governor Bias Control Settings

During synchronization, the DECS-250N adjusts the generator voltage and frequency by issuing speed correction signals to the speed governor. Correction signals are issued in the form of DECS-250N output contact closures. These correction signals may be either continuous or proportionalA. When proportional correction is selected, the correction pulses are of varying widthsB and intervalsC. Initially, long pulses are issued when the frequency difference between the generator and bus is large. As the correction pulses take effect and the frequency difference becomes smaller, the correction pulse widths are proportionally decreased.

Governor bias control settings are illustrated in Figure 14.

Figure 14. Generator Governor Control Settings

A Bias Control Contact Type: Select Continuous Pulse or Proportional Pulse.

B Correction Pulse Width: Adjustable from 0 to 99.9 s in 0.1 s increments.

C Correction Pulse Interval: Adjustable from 0 to 99.9 s in 0.1 s increments.

24 9440500990 Rev B

9440500990 Rev B 25

Regulation The DECS-250N precisely regulates the level of supplied excitation power in each of the five available regulation modes. Stable regulation is enhanced by the automatic tracking of the active-mode setpoint by the inactive regulation modes. Pre-position setpoints within each regulation mode enable the DECS-250N to be configured for multiple system and application needs.

BESTCOMSPlus® Navigation Path: Settings Explorer, Operating Settings, AVR/FCR/FVR and VAR/PF HMI Navigation Path: Settings, Operating Settings, AVR/FCR/FVR and VAR/PF

Regulation Modes The DECS-250N provides five regulation modes: Automatic Voltage Regulation (AVR), Field Current Regulation (FCR), Field Voltage Regulation (FVR), var, and Power Factor (PF).

AVR

When operating in AVR (Automatic Voltage Regulation) mode, the DECS-250N regulates the excitation level in order to maintain the generator terminal voltage setpointA despite changes in load and operating conditions. AVR setpoint (or operating point) adjustment is made through:

• Application of contacts at DECS-250N contact inputs configured for raising and lowering the active setpoint

• Application of an analog control signal at the DECS-250N Auxiliary Control input.

• The BESTCOMSPlus Control Panel screen (available in the BESTCOMSPlus Metering Explorer)

• A raise or lower command transmitted through the DECS-250N Modbus port

The range of adjustment is defined by MinimumB and MaximumC settings that are expressed as a percentage of the rated generator voltage. The length of time required to adjust the AVR setpoint from one limit to the other is controlled by a Traverse Rate settingD. These settings are illustrated in Figure 15.

FCR

When operating in FCR (Field Current Regulation) mode, the DECS-250N regulates the level of current it supplies to the field based on the FCR setpointE. The setting range of the FCR setpoint depends on the field rated data and other associated settings. FCR setpoint adjustment is made through:

• Application of contacts at DECS-250N contact inputs configured for raising and lowering the active setpoint

• Application of an analog control signal at the DECS-250N Auxiliary Control input

• The BESTCOMSPlus® Control Panel screen (available in the BESTCOMSPlus Metering Explorer)

• A raise or lower command transmitted through the DECS-250N Modbus port

The range of adjustment is defined by MinimumF and MaximumG settings that are expressed as a percentage of the rated field current. The length of time required to adjust the FCR setpoint from one limit to the other is controlled by a Traverse Rate settingH. These settings are illustrated in Figure 15.

FVR

FVR (Field Voltage Regulation) mode enables generator modeling and validation testing in accordance with WECC testing requirements. FVR mode can also be used to smooth the transfer from the active DECS-250N to a secondary DECS.

When operating in FVR mode, the DECS-250N regulates the level of field voltage it supplies to the field based on the FVR setpointI. The setting range of the FVR setpoint depends on the field rated data and other associated settings. FVR setpoint adjustment is made through:

• Application of contacts at DECS-250N contact inputs configured for raising and lowering the active setpoint

• Application of an analog control signal at the DECS-250N Auxiliary Control input

• The BESTCOMSPlus Control Panel screen (available in the BESTCOMSPlus Metering Explorer)

• A raise or lower command transmitted through the DECS-250N Modbus port

DECS-250N Regulation

26 9440500990 Rev B

The range of adjustment is defined by MinimumJ and MaximumK settings that are expressed as a percentage of the rated field voltage. The length of time required to adjust the FVR setpoint from one limit to the other is controlled by a Traverse RateL setting. These settings are illustrated in Figure 15.

Figure 15. AVR, FCR, and FVR Regulation Settings

A AVR Setpoint: Range of adjustment is based on the rated generator voltage and limited by the AVR Min

(B) and Max (C) settings.

B Min (% of rated): Adjustable from 70 to 120% in 0.1% increments.

C Max (% of rated): Adjustable from 71 to 120% in 0.1% increments.

D Traverse Rate (s): Adjustable from 10 to 200 seconds in 1 second increments.

E FCR Setpoint: Range of adjustment is based on the rated field current and limited by the FCR Min (F) and Max (G) settings.

F Min (% of rated): Adjustable from 0 to 120% in 0.1% increments.

G Max (% of rated): Adjustable from 0 to 120% in 0.1% increments.

H Traverse Rate (s): Adjustable from 10 to 200 seconds in 1 second increments.

I FVR Setpoint: Range of adjustment is based on the rated field voltage and limited by the FCR Min (J) and Max (K) settings.

J Min (% of rated): Adjustable from 0 to 150% in 0.1% increments.

K Max (% of rated): Adjustable from 0 to 150% in 0.1% increments.

L Traverse Rate: Adjustable from 10 to 200 seconds in 1 second increments.

Var When operating in var mode, the DECS-250N regulates the reactive power (var) output of the generator based on the var setpointA. The setting range of the var setpoint depends on the generator ratings and other associated settings. Var setpoint adjustment is made through:

• Application of contacts at DECS-250N contact inputs configured for raising and lowering the active setpoint

• Application of an analog control signal at the DECS-250N Auxiliary Control input

• The BESTCOMSPlus® Control Panel screen (available in the BESTCOMSPlus Metering Explorer)

• A raise or lower command transmitted through the DECS-250N Modbus port

The range of adjustment is defined by MinimumB and MaximumC settings that are expressed as a percentage of the generator rated kVA output. The length of time required to adjust the Var setpoint from one limit to the other is controlled by a Traverse Rate settingD. A Fine Voltage Adjustment Band settingE defines the upper and lower boundaries of voltage correction when operating in var or power factor regulation modes. Var mode settings are illustrated in Figure 16.

Power Factor When operating in Power Factor (PF) mode, the DECS-250N controls the var output of the generator to maintain the Power Factor setpointF as the kW load on the generator varies. The setting range of the PF setpoint is determined by the PF – LeadingG and PF – LaggingH settings. The length of time required to adjust the PF setpoint from one limit to the other is controlled by a Traverse Rate settingI. A Fine Voltage

Regulation DECS-250N

9440500990 Rev B 27

Adjustment Band settingE defines the upper and lower boundaries of voltage correction when the DECS-250N is operating in Var or Power Factor regulation modes. PF Active Power LevelJ establishes the level of generator output power (kW) where the DECS-250 switches to/from Droop Compensation/Power Factor mode. If the level of power decreases below the setting, the DECS-250 switches from Power Factor mode to Droop Compensation mode. Conversely, as the level of power increases above the setting, the DECS-250 switches from Droop Compensation mode to Power Factor mode. A setting of 0 to 30% may be entered in 0.1% increments.

Power Factor mode settings are illustrated in Figure 16.

Figure 16. Var and Power Factor Regulation Settings

A Setpoint: Range of adjustment is based on the generator ratings and limited by the Var Minimum (B) and Var Maximum…