Attachment B- Technical Specification for the HSR Main Arc Dipole and Quadrupole Power Supplies.pdf

Electron-Ion Collider, Brookhaven National Laboratory

Doc No. [Insert here] Author: Dominic Prevosto Effective Date: [Insert here] Review Frequency: N/A

Specification: HSR Main Arc Dipole and Quadrupole Power Supplies Revision: 00

TECHNICAL SPECIFICATION

for the

HSR Main Arc Dipole and Quadrupole Power Supplies

Quality Classification: A-2

Prepared By:

__________________________________ Date: __________________

D. Prevosto, Electrical Engineer

Reviewed By:

K. Pandey, Electrical Engineer

S. Sankaran, Electrical Engineer

R.F. Lambiase, Principal Engineer

D. Bruno, Principal Electrical Engineer

C. Galdamez, EIC Procurement Liaison Engineer

C. Schaefer, EIC Environment Safety & Health Manager

C. Sullivan, EIC Quality Assurance

V. Ptitsyn, EIC HSR Performance Lead

_________________________________ Date: __________________

R. Feder, EIC TSD Deputy Director

J. Tuozzolo, EIC TSD Director

Approved By:

W. Halbig, EIC HSR Systems Manager, Deputy Division Director

This page intentionally left blank, to accommodate back-to-back printing.

REVISION HISTORY

Revision # Effective Date Summary of Change

00 Initial Release

Table of Contents

LIST OF ACRONYMS

1 SCOPE

1.1 Background

2 APPLICABLE DOCUMENTS

3 REQUIREMENTS

3.1 Technical/Performance Characteristics

3.1.1 Enclosure Configuration

3.1.2 Input Power Requirements

3.1.3 Output Requirements

3.1.4 Power Semiconductor Ratings

3.1.5 Acoustic Noise Requirements

3.1.6 Additional Features

3.1.7 Control States

3.1.8 Operating Modes

3.1.9 Local Instrumentation

3.1.10 Remote Interface

3.1.11 Oscilloscope Monitoring

3.1.12 PLC Interface

3.2 Materials

3.3 Construction/Layout/Location Requirements

3.4 Code/Standard Compliance

3.5 Environment, Safety and Health (ESH)

3.5.1 Material Handling and Electrostatic Discharge

3.5.2 Hazardous Materials

3.5.3 Electrical Safety

3.5.4 Lockout / Tagout

3.5.5 Stored Energy and Capacitor Safety

3.5.6 Pressure Safety

3.5.7 Acoustic Safety

3.6 Marking and Serialization

3.7 Packaging/Shipping

3.8 Storage

4 VERIFICATION

4.1 Classification of Inspections

4.2 Inspection/Testing Details/Requirements

4.2.1 Cooling Water Tests

4.2.2 High Potential Testing

4.2.3 Controls and Interlocks

4.2.4 Electrical Performance

4.2.5 Ramp Performance

4.2.6 Quench Protection Interface Verification

A1 Specification Data Sheet

A2 Model A Seller’s Proposal Data Sheet

A3 Model B Seller’s Proposal Data Sheet

Appendix A – Serial Link Interface

Appendix B – Figures

Appendix C – Waveforms

LIST OF ACRONYMS

AC Alternating Current

ACGIH American Conference of Governmental Industrial Hygienists

AHJ Authority Having Jurisdiction

ASME American Society of Mechanical Engineers

ASTM American Society for Testing and Materials

AWS American Welding Society

BIL Basic Insulation Level

BMC Biphase Mark Encoding

BNL Brookhaven National Laboratory

BSA Brookhaven Science Associates

CB Circuit Breaker

CT Current Transformer

DAQ Data Acquisition

DC Direct Current

DCCT Direct Current Current Transducer (zero-flux)

EIC Electron-Ion Collider

EMC Electromagnetic Compatibility

EMI Electromagnetic Interference

EPICS Experimental Physics and Industrial Control System

ESD Electrostatic Discharge

ESH Environment, Safety and Health

FCC Federal Communications Commission

FDR Final Design Review

HMI Human Machine Interface

HSR Hadron Storage Ring

IEC International Electrotechnical Commission

IEEE Institute of Electrical and Electronics Engineers

IGBT Insulated Gate Bipolar Transistor

LCW Low Conductivity Water

LOTO Lockout / Tagout

MADC Multiplexed Analog-to-Digital Converter

MCM Thousand Circular Mils

MTBF Mean Time Between Failure

NC Normally Closed

NEC National Electrical Code

NEMA National Electrical Manufacturers Association

NFPA National Fire Protection Association

NO Normally Open

NRTL Nationally Recognized Testing Laboratory

OSHA Occupational Safety and Health Administration

PFV Peak Forward Voltage

PID Proportional-Integral-Derivative

PIV Peak Inverse Voltage

PLC Programmable Logic Controller

PS Power Supply

PSC Power Supply Controller

QDS Quench Detection System

QPA Quench Protection Assembly

RFI Radio Frequency Interference

RMS Root Mean Square

RTD Resistance Temperature Detector

SC Superconducting

STBY Standby

TTL Transistor-Transistor Logic

TSD Technical Systems Division

UL Underwriters Laboratories

UPS Uninterruptible Power Supply

VAC Volts, Alternating Current

VDC Volts, Direct Current

VDRM Maximum Repetitive Peak Off-State Voltage

VRRM Maximum Repetitive Peak Reverse Voltage

HSR Main Arc Dipole and Quadrupole Power Supplies

1 SCOPE

This specification defines the technical requirements for the Hadron Storage Ring (HSR) Main

Arc Dipole and Quadrupole Power Supplies to be used at the Electron-Ion Collider (EIC) at

Brookhaven National Laboratory (BNL) managed by Brookhaven Science Associates (BSA).

1.1 Background

The EIC Project will design, build, and install the accelerator hardware for a new electron storage ring, an electron injector, and modifications to the hadron ring required to produce an electron-ion collider and infrastructure. It will include one interaction region, with an allowance for a second, and one detector. The facility is designed to meet requirements to ensure high reliability and availability for the user program.

The HSR is formed by modifying the existing hadron ring, and its main arc dipole and quadrupole magnets are superconducting elements connected in series strings around the ring. The two power supplies covered by this specification will be used to supply and precisely regulate ramped current into superconducting magnet loads. One supply, Model A, for the main arc dipole circuit and one supply, Model B, for the main arc quadrupole circuit.

2 APPLICABLE DOCUMENTS

The following specifications, standards and drawings form a part of this specification to the extent specified herein. Unless otherwise specified, the applicable revision level of these documents shall be that in effect on the date of the solicitation or contract. Exceptions must be approved in writing by BSA.

In the event of a conflict between the applicable documents and this specification, the Contractor shall immediately notify the BSA Contractual Representative who shall in each instance determine which document takes precedence and advise the Contractor accordingly. Failure to notify BSA of a document conflict shall not relieve the Contractor’s responsibility to ensure full compliance to all requirements.

Document Number Document Title

ASME B30.20-2018 Below-the-Hook Lifting Devices

ASME B31 Code for Pressure Piping

FCC Part 15 Class A Conducted line noise limits

IEC 60947-3 Low-voltage switchgear and control gear – Switches, disconnectors, switch-disconnectors and fuse-combination units

IEC 60947-4-1 Low-voltage switchgear and control gear – Contactors and motor-starters

IEC 60947-5-5 Low-voltage switchgear and control gear – Electrical emergency stop device with mechanical latching function

IEEE 383 Vertical flame test (cable qualification)

IEEE 519 Harmonic control in electrical power systems

IEEE 1202 Flame Testing of Cables for Use in Cable Tray

MIL-STD-217D Reliability Prediction

MIL-STD-461 EMI/EMC requirements

NEC / NFPA 70 /

NFPA 70E

National Electrical Code / Electrical Safety in the Workplace

NEMA SG5 Indoor Power Switchgear (referenced for cabinet construction)

NEMA 250 Enclosures for Electrical Equipment (1000 Volts Maximum) – Type 2 enclosure rating

UL 98 Enclosed and Dead-Front Switches

UL 60939-3 Passive filter units for electromagnetic interference suppression – Passive filter units for which safety tests are appropriate

3 REQUIREMENTS

Detailed requirements and parameters for these power supplies are specified in Attachment A1

Specification Data Sheet. The power supplies shall also meet the general electrical specifications, which are given here.

Each power supply shall function as a ramped, two-quadrant DC source, adjustable both remotely and locally. Each unit shall have a Contractor-provided current regulator with an inner voltage regulation loop.

This specification covers two (2) power supplies of two (2) voltage configurations, sharing a common maximum output current rating:

• Model A (HSR Main Arc Dipole): one (1) power supply

• Model B (HSR Main Arc Quad): one (1) power supply

The electrical parameters for each configuration are as follows:

Parameter HSR Main Arc Dipole HSR Main Arc Quad

Maximum Output Current 7000 A 7000 A

Maximum Output Voltage During Ramp ±400 V ±100 V

Maximum Output Voltage During Steady State 30 V 15 V

Ramp Rate 5-80 A/s 5-80 A/s

Load Inductance 4-4.5 H 0.5-0.7 H

This specification specifies the required maximum output voltage and current profiles, including the ramp and flat-top conditions, together with an operating duty of 4 consecutive cycles per hour for worst case scenario. The Contractor shall use these requirements to determine the necessary continuous power rating. The peak power requirement shall also be defined by the specified maximum voltage and current operating conditions.

The magnet loads are superconducting. The power supplies, together with quench protection and energy extraction provisions, shall safely manage the stored magnetic energy of the loads under both normal operation and quench events. Quench detection system is BNL scope and the power supply including the quench protection system (except energy extraction resistors) is Contractor scope.

These power supplies shall be a minimum of two-quadrant, operating in the +V/+I and −V/+I quadrants. Output current shall be sourced into the magnet load in a single polarity, with output voltage capable of reversing across the load during ramp-down. P[

These power supplies shall be modular. The design shall be conservative, using standard techniques and commercially available component parts that ensure high reliability and minimum maintenance. The power supplies shall be installed as part of the HSR accelerator system and shall operate continuously for long periods of time in an unmanned area. The power supplies shall exhibit a high level of reliability and be thoroughly interlocked. Each power supply shall be a completely assembled unit that shall be installed and interfaced to the EIC control system. Each shall include all the hardware, both analog and digital, and the appropriate water-cooling connections required for this interface.

3.1 Technical/Performance Characteristics

3.1.1 Enclosure Configuration

3.1.1.1 The power supply shall be partitioned into separate high current AC and DC compartments, as well as a separate low voltage control compartment. The purpose of these compartments is to ensure that electrically dangerous potentials are isolated.

3.1.1.2 The power supply shall have a control compartment which shall be used to enclose all of the power supply controls, over current devices, relays, protection, interlocks, system monitoring and status indications. There shall be a minimum 6U of height, 19” wide rack mountable, and 28” of depth to allow for BSA to install external equipment. This space shall be adjacent to the current regulator. This compartment shall be physically isolated from the high-power compartments and shall be behind an unlocked door. The door shall not be interlocked. This compartment shall not contain any voltages greater than 125 volts

AC rms or DC peak. Voltages greater than 50 volts AC rms or 50 volts DC peak shall be covered with barriers to prevent contact.

3.1.1.3 It is recommended that the Contractor provides the control compartment in a temperature-controlled environment to house the Contractor-supplied current regulator and Direct

Current Current Transducer (DCCT) electronics, as specified in the Attachment A1

Specification Data Sheet or an equivalent, subject to approval by the BSA Technical

Representative. The rack temperature shall be controlled to meet output current stability requirements.

3.1.1.4 Provisions shall be made for lifting the power supply cabinets by forklift (e.g. channels or I-beams). The frame shall be made sufficiently rigid so that lifting and relocation shall not cause deformation or misalignment of internal components or sealing surfaces. The frame shall provide all certified lifting points, eye bolts, shackles and lifting apparatus in compliance with The American Society of Mechanical Engineers (ASME) Standard

Below-the-Hook Lifting Devices B30.20-2018.

3.1.1.5 The equipment shall be constructed in an all-metal cabinet, which shall be in accordance with NEMA standards for Indoor Power Switch-gear as per publication SG5, latest edition. NEMA 2 cabinet.

3.1.1.6 The finish of all visible external cabinet parts shall consist of degreasing of the unit followed by powder coating. All internal aluminum cabinet metal work shall be clear iridite finish.

3.1.1.7 The power supply shall have a Mean-Time-Between-Failure (MTBF) rating of greater than 40,000 hours as determined by MIL-STD-217D for equipment with ground benign environment, or there shall be sufficient field experience with the design type to infer that the unit will meet the above MTBF rating.

3.1.1.8 Interchangeable, easily removable subassemblies shall be used where practical, to provide maximum flexibility of use and a minimum time for repairs. Interchangeability of replacement modules and subassemblies between the two power supplies, to the maximum extent practical given the different voltage configurations, is required to support spares strategy and minimize mean-time-to-repair. The power supply enclosure shall be modular in design such to allow for ease in transportation and installation.

3.1.1.9 All control and interlock relays shall be hermetically sealed or be of the sealed plastic-case variety and shall be socketed or mounted on a printed circuit board. Relays shall have clamping diodes or transient absorbers which protect external equipment from transients due to solenoid flyback voltages.

3.1.1.10 All parts used in the power supply should be listed by Underwriters Laboratory (UL) or equivalent nationally recognized testing laboratory (NRTL). If any unlisted parts are used, these should be specifically called out in the proposal. The complete power supply shall be NRTL/equivalent agency certified with a field evaluation.

3.1.1.11 Strain reliefs shall all be Roxtec Seals or equivalent, subject to approval by the BSA

Technical Representative.

3.1.2 Input Power Requirements

3.1.2.1 Input Power — The input power is described in the Attachment A1 Specification Data

Sheet. The input shall be filtered to prevent noise generated by the power supply from appearing on the AC lines. The filter shall have a cutoff frequency above the power line frequencies and attenuation extending to 1 MHz. The input line filter shall be a Corcom

FCD series or equivalent, subject to approval by the BSA Technical Representative.

3.1.2.2 There will be three (3) AC input power sources to the power supply.

AC source 1: There will be three phase, 480 VAC, 60 Hz to power the power supply DC output, or higher AC input voltage subject to approval by the BSA Technical Representative.

AC Source 2: AC Source-2 shall be a 120V, 60 Hz supply provided from an external

Uninterruptible Power Supply (UPS) during operation. This source shall supply power to critical components of the power supply unit, including but not limited to:

• Power supply controller

• DCCT-1 electronics

• Quench Protection Assembly (QPA) controller

• Gate drive circuits for the main output switch

• Gate drive circuits for Crowbar Circuit-2

AC Source 3: AC Source-3 shall be a 120V, 60 Hz supply provided from an independent external

UPS during operation at BNL. This source shall provide redundant AC power to safety-critical components, including but not limited to:

• DCCT-2 electronics

• Main output switch DC contactor drive circuit

• Gate drive circuits for Crowbar Circuit-1

Further details are provided in Figure 3 included in this specification. The above defines the preliminary AC power distribution scheme for critical systems to ensure redundancy and safe operation.

The Contractor may propose additional systems as needed and shall specify the required kVA capacity of the backup UPS to ensure safe magnet discharge and orderly shutdown of the power supply under all operating conditions.

3.1.2.3 The power supply shall be designed to operate from the following AC input characteristics:

• Voltage: 480 V, +10%, −10%

• Line Imbalance: ±5%, line-to-line

• Frequency: 60 Hz, ±3 Hz

3.1.2.4 Interrupting Capability — The incoming three-phase power shall connect directly to a circuit breaker, followed by an appropriate contactor for normal on/off operation and fault generated interlocks. The voltage ratings of these devices shall be 600 Volts AC. The circuit breaker shall have a minimum interrupting capacity rating of 65 kAIC. The contactor shall be rated for 2-3 million mechanical operations. The Contractor shall specify the manufacturer and the model number of the contactor chosen in their proposal.

A three phase, 3-pole contactor shall be used to turn the 480 V power to the main transformer on and off. An actuator operated circuit breaker is not an acceptable replacement for the contactor.

3.1.2.5 Current Inrush / Soft Start — A step start circuit shall be used to limit inrush current. If the Contractor proposes another type of limiter, its use must be approved by the BSA

Technical Representative in writing. The soft start circuit shall limit the output turn-on surge voltage to less than 5% of the rated output voltage, regardless of the reference command. The soft start circuit must limit the AC inrush current to less than 50% of the maximum steady state current.

3.1.2.6 Isolation / Rectifier Transformer — The power supply shall have a rectifier transformer to isolate the inverter from the three phase incoming AC line. The transformer shall be built with copper windings. The insulation shall be class H (Thermal Class 180). The transformer shall be braced for rectifier service and shall be able to withstand the worst-case fault currents available. The primary winding shall be delta connected.

3.1.2.7 A suitable Electromagnetic Interference (EMI) / Radio Frequency Interference (RFI) line filter shall be provided for 120 Volt AC line control power. Its ratings shall exceed the maximum voltage and current rating of the control circuit. EMI filters shall meet the UL

60939-3 or equivalent.

3.1.2.8 The circuit breaker shall have an operator lever with provisions for padlocking it in the

OFF position. This feature is required to meet Lockout and Tagout (LOTO) requirements of NFPA 70E. The switch must have a UL98 or equivalent approval rating.

3.1.2.9 The circuit breaker shall be covered in a separate enclosure and other 480 V components shall be mounted and covered so that there are no exposed terminals or conductors at this potential, even with the front or back doors of the power supply cabinet open.

3.1.2.10 The load side of the circuit breaker shall be monitored by an absence of voltage tester, to verify that turning the switch OFF has positively de-energized the unit. An absence of voltage tester, equivalent to Panduit Veri-safe series, shall be permanently installed on the load side of the circuit breaker. The Contractor shall add diagnostics in order to verify output or capacitors are at zero volts in each power supply.

3.1.2.11 AC source 2 must be monitored by an absence of voltage tester, to verify that turning the switch OFF has positively de-energized the unit. An absence of voltage tester, equivalent to Panduit Veri-safe series shall be used.

3.1.2.12 AC source 3 must be monitored by an absence of voltage tester, to verify that turning the switch OFF has positively de-energized the unit. An absence of voltage tester, equivalent to Panduit Veri-safe series shall be used.

3.1.2.13 The main contactor shall be operated by a nominal 120 VAC, 60 Hz, derived from the main 480 VAC power input. A set of four (4) auxiliary contacts mechanically linked to the main contactor shall be provided to monitor the status of the main contacts. The auxiliary contacts must meet IEC 60-947 specifications. Two of the contacts will be used for status and control and shall be of the normally open type. The other two contacts shall be of the normally closed type.

3.1.2.14 The power factor for the power supply shall be ≥0.9 or better at full rated power when line voltages are within ±5% of nominal. The Contractor shall state the expected power factor at 25%, 50%, 75%, and 100% of rated output power, and shall also state the power factor during ramping conditions.

3.1.2.15 Line harmonics generated by the power supply shall meet the limitations set by IEEE

519. The Contractor shall provide harmonic distortion analysis with their proposal, including harmonic content during both static and ramping operating conditions.

3.1.2.16 The power supply shall include AC line monitoring relays for phase sequence, loss of phase, and under voltage protection. Statuses shall be wired to the Programmable Logic

Controller (PLC) for interlock control and alarm indication.

3.1.2.17 Three phase AC over-current relays shall be provided to sense AC over current in the primary input of the power supply. The supplied current transformers shall be mounted in the power supply enclosure near the supplied contactor. The over current devices shall provide interlock contacts wired directly in series with the master interlock relay contacts.

The AC over current relays shall also provide status information to the PLC for other interlock control and alarm indication. The over-current relays shall have adjustable instantaneous and timed trip settings.

3.1.3 Output Requirements

3.1.3.1 General

The power supply shall be a ramped current source used to energize superconducting magnet loads in the Hadron Storage Ring (HSR). Ramping up and ramping down shall be controllable. Each power supply shall operate as a current-regulated power supply with an inner voltage loop provided by the Contractor. The power supply shall operate primarily in current regulation mode;

The Contractor shall allow for the power supply to run in voltage regulation mode for test and commissioning purposes. In addition, if BSA wants to add its own current loop, BSA shall have access to the voltage loop analog setpoint. The Contractor is responsible for the design, integration, and documentation of the complete power supply including the current loop, voltage loop, DCCT, and DCCT electronics.

This specification covers two (2) power supplies in two (2) voltage ratings as follows:

• Model A (HSR Main Arc Dipole): 7000 A maximum output current, ±400 V maximum output voltage

• Model B (HSR Main Arc Quad): 7000 A maximum output current, ±100 V maximum output voltage

Both power supplies share a common maximum output current of 7000 A. The detailed parameters for each configuration are given in the Attachment A1 Specification Data Sheet.

3.1.3.2 Voltage Regulation and Stability

For a constant control input, the output voltage shall not vary by more than the regulation limits specified in the Attachment A1 Specification Data Sheet.

The external analog voltage setpoint, when provided by the BSA Technical Representative as an interface for test or commissioning purposes, shall range from -10 to +10 V, with the output voltage following proportionally from zero voltage to positive full-scale voltage. For two-quadrant operation, voltage polarity control shall be internal to the Contractor-provided control architecture.

If a digital regulator is proposed, the Contractor shall provide means for this analog voltage setpoint to be introduced. This shall be agreed upon with the BSA technical representative.

3.1.3.3 Current Regulation — Contractor Supplied Current Regulator

The Contractor shall supply the current regulator (with an inner voltage loop) for each power supply. The regulator shall be analog or digital. The Contractor shall define the regulator architecture. If a digital regulator is proposed the Contractor shall provide suitable means for tuning the regulator loop coefficients by BSA through the digital interface via Experimental

Physics and Industrial Control System (EPICS). If an analog regulator is proposed the Contractor shall provide suitable means for adjusting the loop time constant. The regulator shall be designed, mounted, and shielded so that the required output current stability is maintained under the environmental conditions specified in the Attachment A1 Specification Data Sheet.

The output current shall meet the regulation limits at both steady state and ramping conditions as specified in the Attachment A1 Specification Data Sheet.

There will be two similar DCCTs required for this power supply and they shall be located at the output of the QPA as shown in Figure 1. One will be used for current feedback, and the other will be used for monitoring diagnostics and as a backup for the first DCCT. Both devices shall be a zero-flux DC current transducer (DCCT) specifications and manufacturers approved in writing by the BSA technical representative. Any other current measurement technique shall not be accepted as the current measuring device. The DCCT shall have sufficient resolution and bandwidth to support the required output current stability and ripple performance. The DCCT electronics shall be temperature stabilized using Peltier-based temperature stabilization, or an equivalent method subject to approval by the BSA Technical Representative, and shall be housed in the temperature-controlled compartment specified in the Enclosure Configuration subsection of this specification.

The DCCT bus bar shall be centered with respect to the sensor, and the layout shall minimize error due to return bus and shall adhere to the guidelines of the manufacturer.

The current setpoint interface shall be real time and of digital 24 bits which is as described in section 3.1.10 Remote Interface.

3.1.3.4 Ramping Requirements

The power supply shall operate as a ramped current source. The ramp rate, ramp linearity, and tracking error shall be as specified in the Attachment A1 Specification Data Sheet.

The power supply's control loops shall be dynamically stable across the full ramp range. The power supply's regulation controls shall be critically damped or overdamped, avoiding undershoot or overshoot during ramping.

3.1.3.5 Energy Absorption

The energy stored in the inductive superconducting magnet load is returned to the power supply when the power supply reduces the current in the load, or if the power supply shuts off due to command, fault, or power loss. The power supply and quench protection, together with the external energy extraction resistor (not under the Contractor’s scope) referenced in this specification, shall be capable of safely absorbing or dissipating this energy for the maximum time constant [L/R load] at the maximum operating current as specified in the Attachment A1 Specification Data Sheet. The

Contractor shall describe how the energy shall be safely stored or dissipated under all conditions, including but not limited to:

• Commanded ramp-down at maximum ramp rate

• Fault trip from maximum current

• Loss of AC input power at maximum current

• Quench event at maximum current

The Contractor shall coordinate the energy absorption design with the energy extraction architecture defined elsewhere in this specification.

3.1.3.6 Current Ripple

For the load impedances specified in the Attachment A1 Specification Data Sheet, the output current ripple shall not exceed the limits specified in the Attachment A1 Specification Data Sheet.

3.1.3.7 Ground Isolation

The power supply shall have 2200 Vrms ground isolation. The maximum total leakage current shall be 10 µA at the specified isolation voltage. The contractor shall state their expected leakage current in the proposal.

The power supply and its QPA shall contain a separate ground fault system to monitor the DC output of the power supply and the load. The power supply ground fault detection scheme shall be based on a current sensing circuit in series with a center tapped between the positive and negative terminals or by having a sense resistor current sensing circuit tied to the negative terminals.

Provisions for both shall be provided, however the grounding method shall be selected by BSA during power supply commissioning. There shall always be a ground detection scheme whether it is attached to the center tap or the negative terminal.

The QPA ground fault detection scheme shall be based on an isolated ground current sensing circuit in series with a center tap between the positive and negative terminals of the power supply.

This sensing device shall have the range of full operating current up to 7kA. Both ground fault detection systems shall provide two configurable levels, each with a configurable time qualifier and current setpoint. The Contractor shall provide suitable means for configuring these parameters through the digital interface via EPICS.

• Power Supply Ground Fault Warning: ±50 mA for more than 1 second. The warning shall latch and shall automatically unlatch after 20 seconds of continuous readings below the warning threshold.

• Power Supply Ground Fault Trip: ±500 mA for more than 2 seconds. The trip shall latch and shall require a manual or remote reset.

• QPA Ground Fault Warning: +/-86mA for more than 1 second. The warning shall latch and shall automatically unlatch after 20 seconds of continuous readings below the warning threshold.

Ground fault warning and trip statuses shall be reported to BSA Controls as defined in the

Protection and Interlocks subsection of this specification.

All power supplies shall have the ability to enable or disable a connection for a center-tapped resistor to ground or resistor from the negative terminal to the ground. The resistor to ground shall be used as part of a ground fault circuit, or another method for a ground fault circuit subject to approval by the BSA Technical Representative shall be provided.

3.1.3.8 Output Limiting

All output limiting features of this subsection shall be active in both current regulation mode and voltage regulation mode.

Current Limiting — The output current shall be limited to a value which is set as a configuration parameter during the power supply initialization process.

3.1.3.9 Voltage Loop Bandwidth

The power supply voltage loop 3 dB bandwidth measured on the output of the power supply shall be at least 200 Hz or to meet the specification requirements as specified in section 3.1.3.13, whichever is largest.

3.1.3.10 Power Supply Block Diagram

Each power supply shall have EMI input filtering, an input circuit breaker (CB), line contactor, minimum 12-pulse rectifiers, pre-regulator (if used), a linear output stage (if used), current measuring DCCT, regulation circuits, control and quench protection circuits. Active front ends are acceptable. The output filter shall be of LC/RC type which are designed minimum to meet the specifications mentioned in the document. However, the Contractor can provide an alternate filter type solution, approved by the BSA Technical Representative in writing, to meet the ripple requirements. There shall be a differential inductor at both legs and a common mode choke. The proposed block diagram is as shown in Figure 1.

3.1.3.11 Power Connections

Each phase of the AC input terminals shall be sized for at least 150% of rated current. The AC terminals shall be phased A-B-C, from left to right when facing the AC compartment door, and shall be clearly labeled.

The location of AC input is specified in the Attachment A1 Specification Data Sheet. The power supply shall have access doors for AC input hookups and for servicing. The rear door of the power supply shall be electrically interlocked with microswitches and be capable of being mechanically locked with Kirk-type locks. The Kirk-lock keys must be coordinated with BNL Kirk-lock keys.

The location of the high current DC output cables shall be as specified in the Attachment A1

Specification Data Sheet.

Any electrical cable and bus work used shall be made of Oxygen Free Electrolytic copper and of sufficient ratings and cross-section such that they shall not exhibit a temperature rise of greater than 50 °C at maximum load.

All low-level control wiring shall be twisted and rated for 600 volt, 105 °C, stranded copper conductor or approved (by the BSA technical representative) equivalent. All wires shall be labeled for circuit identification at all termination points. Appropriately voltage rated insulators and supports shall be used.

All cable insulation used in this system shall be of a self-extinguishing, low flame propagation, low smoke type and meet IEEE 1202 Flame Testing of Cables for Use in Cable Tray. All insulating material shall be reviewed and approved by the BSA technical representative in writing.

Strain reliefs shall be of Roxtec seal type or BSA technical representative approved equivalent.

3.1.3.12 Efficiency

Power losses from input to output shall not exceed >85% of the rated output power of the supply at full load. The Contractor shall state the expected efficiency at 25%, 50%, 75%, and 100% of rated output power in the proposal.

3.1.3.13 Output Current Settling After Line Disturbance

During power supply operation, if the input AC (grid) voltage varies by ±5% from its nominal value for a duration of up to 2 seconds, including the transition to the reduced voltage and the recovery to nominal voltage, the power supply shall maintain the output current regulation within the specified short-term stability limits. This input AC voltage sag is expected due to the simultaneous operation of other power supplies in the accelerator facility.

3.1.3.14 Quench Protection Interface

The magnet loads are superconducting. Quench-related functions are divided between the power supply (Contractor scope) and external BNL equipment as follows:

• BNL Quench detection is an external Quench Detection System (QDS). The power supply shall not include integral quench detection.

• Quench protection shall be provided by the power supply (Contractor scope) and shall interface with the BNL Quench Detection System. Quench protection consists of receiving the quench signal from the external BNL Quench Detection System, executing a coordinated fast shutdown of the power stage, initiating the energy extraction sequence defined elsewhere in this specification, latching the fault condition, and reporting status to the PLC and BNL control system. Interfaces are defined in sections 3.1.10 Remote

Interface and 3.1.12 PLC Interface.

The power supply shall accept a quench signal input from the external BNL Quench Detection

System. The quench signal interface shall be Transistor-Transistor Logic (TTL) logic level. The signal details are:

• Polarity: Positive

• Voltage level 5V

• 50 Ohm termination

Upon receipt of a quench signal, the power supply shall execute the quench protection sequence consistent with the energy extraction architecture defined below and align with Figure 2.

Step-1: The quench link is pulled down by the quench detectors.

Step-2: The QPA controller waits for 10ms (configurable) for the beam abort to be completed.

Step-3: The trigger pulse to power supply modules is removed and then the crowbar gates are triggered.

Step-4: After 1ms delay of crowbar triggered, Insulated Gate Bipolar Transistor (IGBT) Q3 and

Q4, triggers are removed. IGBT must interrupt the power supply current within 20ms.

Step-5: After 20ms (Configurable), the DC contactors are deenergized. If IGBT has interrupted the current, the DC contactor opens at near zero current.

Step-6: If IGBT’s did not interrupt the current, the DC contactors will interrupt the power supply full output current (Worst case. This time must be less than 70ms)

The quench-triggered fault condition shall latch in the power supply. Reset shall be possible only through a coordinated reset procedure consistent with the external BNL Quench Detection System reset and shall be remotely resettable through the PLC interface.

The crowbar system shall incorporate redundancy through two independent trigger circuits, each backed by an independent external UPS-supported AC power supply. Triggering shall be accomplished via either a quench link or a self-trigger mechanism. The self-trigger voltage shall be configurable in both hardware and software, with separate setpoints for the Model A dipole and

Model B quad. These voltage setpoints shall be selected to ensure that triggering does not occur during normal ramp up/down operation. As shown in Figure 3.

The QPA shall provide main power supply isolation via a dedicated disconnecting switch. The

IGBT shall serve as the primary disconnect mechanism, with a DC contactor serving as the secondary disconnect mechanism. If the IGBT fails to open, the DC contactor shall be designed with arc suppression systems capable of interrupting the power supply while operating at rated current. The DC contactor shall meet the specifications defined in the A1 Specification Data Sheet.

All IGBT currents and gate driver circuits shall be monitored and interlocked with the PS/QPA fault system. Failure of any individual gate driver shall raise a PS/QPA fault, causing the power supply to initiate a controlled shutdown sequence. The IGBTs shall be sized properly by the

Contractor to meet the redundancy and specification requirements. A typical four IGBT configuration is shown in Figure 4. In the case of one IGBT failure the other parallel IGBTs shall be able to carry the rated current for continuous operation.

3.1.3.15 Energy Extraction

The stored magnetic energy in the superconducting magnet load shall be safely removed during quench events and other fast-shutdown scenarios through an external energy extraction circuit.

The energy extraction resistors are external BNL equipment and are not within the Contractor scope of this procurement.

The energy extraction architecture for each configuration is a center-tapped resistor arrangement as specified in the Attachment A1 Specification Data Sheet (Model A — HSR Main Arc Dipole:

0.1 Ω + 0.1 Ω center-tapped; Model B — HSR Main Arc Quad: 0.048 Ω + 0.048 Ω center-tapped;

see Figure 3]). The maximum magnet discharge voltage is 700 V for Model A and 336 V for Model

B, as specified in the Attachment A1 Specification Data Sheet.

Because the energy extraction resistors are BNL equipment and will not be available at the

Contractor's facility, the Contractor shall propose a factory test method that demonstrates the power supply's quench protection response and energy extraction operation without the BNL energy extraction resistors present. The proposed test method shall be submitted for BSA

Technical Representative approval as part of the test plan review.

3.1.3.16 Protection and Interlocks

The following devices or systems shall be incorporated in the power supply and shall be used to interlock the power supply to internal and external control devices. All the interlocks and controls of each power supply shall be connected to the PLC. All faults shall latch until reset.

Some of the interlocks described below are required to be wired in series with the master interlock relay. The master interlock relay is defined as the relay that, when de-energized, will de-energize the main contactor regardless of any other state or condition, and shall do so without any semiconductor devices. De-energizing the main contactor shall remove line voltage from the power components, but not the control components.

Over temperature protection of power electronic components is required. The over temperature detection devices shall be thermostat type switches (or equivalent) with contacts that are electrically isolated from the heat sink and shall be capable of meeting the high potential test specified in Section 4. The thermostats shall be automatic reset type with normally closed contacts.

The trip point of the thermostat shall be set to protect the power electronic components from exceeding the manufacturer's recommended maximum safe operating case temperature.

A single water flow switch shall be provided at the output of each power supply. The power supply shall use the Proteus series 7000, series 8000, or the IFM Electronic SA5000 water flow switches, or BSA approved equivalent. In order to use any other water flow switches, they must first be approved by the BSA technical representative in writing. The water flow switches shall be wired to the PLC for interlock control and alarm indication.

The power supply shall have a DC over current sensing device that has an adjustable trip setting from 10 percent to 110 percent of rated DC output current. The over current device shall use an independent shunt or Hall Effect current sensor, such as a LEM (Liaisons Electroniques et

Mecaniques) unit, for current sensing. The DC over current device shall be wired directly in series with the master interlock relay coil, so that an over current condition shall open the master interlock relay contacts. The DC over current device shall also provide status information to the PLC for other interlock control and alarm indication.

Door interlock microswitches shall be mounted on all hinged doors of the power supply control cabinet that lead to high power AC and DC circuitry. The switches used shall be the type that have a bypass capability. The door switches shall be wired directly in series with the master interlock relay contacts. The door interlock microswitches shall provide status information to the PLC. The door switches to be used must be reviewed and approved by the BSA technical representative in writing.

The temperature of the power supply cabinet shall be monitored by Resistance Temperature

Detectors (RTDs), which shall report their temperatures back to the PLC for analysis and processing. An over temperature interlock shall be provided. The device shall be adjustable between 100 °F and 200 °F.

Control circuits shall be designed in a fail-safe manner so that loss of power does not result in a hazardous operating condition or cause any damage to the power supply. Protective interlock circuits and power supply controls shall be designed so that reactivation of the interlock circuit

(i.e., completing the circuit) will not result in an automatic restoration of power to the equipment.

The power supply shall have DC over-voltage protection and interlocking circuitry, which shall be capable of protecting the power supply from over-voltage conditions at the DC terminals. The over-voltage protection equipment shall also provide a detection circuit that will be wired directly to the master interlock relay contacts. Status information shall also be provided to the PLC.

Provisions shall be made for external BNL interlock inputs. At minimum, the following interlock inputs shall be provided:

• System security

• Machine protection / access interlock (from the HSR machine protection system)

• Quench link signal

The specific signal definitions, contact forms, voltage levels, and response times for all external interlock inputs shall be coordinated with the cognizant BSA engineer for each interfacing system.

Interlocks shall be wired directly in series with the master interlock relay through an appropriate terminal board. Status of the remote interlocks shall be monitored by the PLC and annunciated.

BSA will provide isolated contacts for these interlocks. The open circuit voltage seen by these contacts shall not exceed 26 VDC. The voltage the interlock inputs at the power supply shall not exceed 48 VDC in either the open or closed state.

The status of all interlocks shall be locally annunciated through the Human Machine Interface

(HMI). The following is a list of some of the statuses that shall be required at a minimum, with the capability to add more:

• Input AC line fault: Over-current, Over-voltage, phase loss, phase sequence

• DC Output fault: Over-current, Over-voltage

• Power supply over temperature: Cubicle, power electronic components, transformers

• Water fault: flow, pressure, over-temperature

• Blown fuse indication and location

• Door interlocks

• External interlocks (load, security, machine protection, quench link signal)

• Ground fault

• Power supply states: OFF, Standby, ON, FAULT

All cabinet temperatures shall have a temperature sensor with an analog output that shall be monitored for operating conditions and sent to the PLC for analysis and processing.

3.1.3.17 Safety Considerations for Capacitors

For capacitors with voltages above 50 V (DC) or stored energy greater than 10 Joules, fully visible, manual-grounding devices shall be provided to render the capacitors safe while they are being serviced. Capacitor discharge and grounding points shall be clearly marked, and the circuit shall prevent transferring charges to other capacitors.

Permanently connected bleeder resistors shall be used for all capacitors with working voltages greater than 50 V and stored energy greater than 10 Joules. Capacitors in series shall have separate bleeder resistors. Automatic-shorting devices that operate when the equipment is de-energized or the enclosure is opened shall be used where practical. The time required for a capacitor to discharge to safe voltage (50 V or less) shall be less than 1 minute. Bleeder resistor sizing must conform to the National Electrical Code (NEC).

Capacitors used in parallel shall be individually protected, where necessary, to prevent the stored energy from dumping into a faulted capacitor and causing the capacitor to overheat catastrophically. Care must be taken in placement of automatic-discharge safety devices with respect to fuses. If the discharge will flow through the fuses, a prominent warning sign must be placed at each entry indicating that each capacitor must be manually grounded before work can begin.

A fan shall be added for ventilation to cool the capacitor bank so the capacitor bank temperature does not rise above 45 °C.

3.1.4 Power Semiconductor Ratings

3.1.4.1 The peak inverse voltage (PIV) and peak forward voltage (PFV) rating of all power semiconductors shall be rated for two (2) times their peak circuit operating voltage or greater.

3.1.4.2 The continuous current rating of all power semiconductors shall be at least two (2) times greater than the maximum Root Mean Square (RMS) current the device will conduct during operation of the power supply.

3.1.4.3 The power supply shall limit on/off or other induced switching transients to 50 percent of the published inverse and forward voltage ratings of all power semiconductor devices.

3.1.4.4 The power semiconductors shall be water cooled. The units shall be mounted and clamped on water-cooled heat sinks according to the recommendations of the semiconductor manufacturer. The maximum junction temperature shall not exceed 100 °C under worst-case load conditions. Individually cooled power semiconductors heat sinks shall have an over-temperature protection scheme, such as thermostat-type switches, mounted close to the power semiconductor which shall be set to trip before the device junction temperature reaches 100 °C. The output of these switches shall interlock the power supply and give status to the PLC. The Contractor may elect to support over-temperature protection using an alternate procedure. The Contractor shall provide calculations showing the expected temperature rise with their proposed cooling and protection scheme. This shall be approved by a BSA technical representative in writing. The over-temperature monitoring circuitry shall meet the high potential test specified in Section 4. Deionized water is required and will be provided at the resistivity specified in the Attachment A1

Specification Data Sheet.

3.1.4.5 All power semiconductors shall be mounted with consideration for replacement and maintenance accessibility. The Contractor's preliminary drawings shall show their position in the power supply.

3.1.4.6 For any power switching elements used in hard turn-off or switching control, suitable snubber circuits shall be provided to protect from voltage spikes and to reduce the EMI generated. These shall conform to MIL-STD-461.

3.1.4.7 For personnel safety and to aid in troubleshooting, there shall be firing pulse transformers or drive optical isolation for any power switching elements so that the low-level pulse generation circuitry is isolated from the high-power circuitry. Isolation levels must be approved during by the BSA technical representative. Low-level control circuitry and components shall not have any exposed voltages greater than 50 V with reference to chassis ground.

3.1.5 Acoustic Noise Requirements

The noise level three feet away from the power supply from all sources within the cubicle, including cooling fans, shall be less than 70 dB when the unit is on and operating.

3.1.6 Additional Features

3.1.6.1 The main contactor shall provide a pair of auxiliary Normally Closed (NC) contacts to a power supply interface connector for the BNL safety system. These contacts shall open when the power supply goes to the ON state and the main contactor is closed.

3.1.6.2 An Emergency Off switch — red, "mushroom" style, twist to reset — shall be provided in an easily accessible location on the front and rear of the power supply. This switch shall meet the certification requirements of IEC 60947-5-5 or equivalent. Activating the

Emergency Off switch shall instantly de-activate the main contactor, remove power to any power conversion circuits, de-energize the output to zero volts, latch a fault, and indicate the fault to the remote communication interface and locally to the front panel.

3.1.6.3 Control and other auxiliary power shall come through a separate control power transformer which is connected to the load side of the 480 V line circuit breaker. When the circuit breaker from the 480 VAC line is in the OFF position, the control power must be able to be energized from an external 120 VAC molded case plug. Control power shall have a separate fuse or fast-acting circuit breaker. Presence of control power shall be indicated by a pilot light on the front panel. There shall be an isolated 24 VDC at 3 A control power available at a terminal strip in the rear of the enclosure for BSA use.

3.1.6.4 A diagnostic voltage monitor with a selector switch to…