20161011_MIL-STD-1399-LVDC-a.pdf

NOTE: This draft, dated 11 October 2016, prepared by Naval Sea Systems Command, has not been approved and is subject to modification. DO NOT USE PRIOR TO APPROVAL. (Project xxx-xxx-xxx-xxx)

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Distribution is unlimited

METRIC

MIL-STD-1399(NAVY)

SECTION LVDC

DRAFT

DEPARTMENT OF DEFENSE

INTERFACE STANDARD

SECTION LVDC

ELECTRIC POWER,

LOW VOLTAGE AND 1000 VOLTS DIRECT CURRENT

MIL-STD-1399-LVDC(NAVY)

DRAFT DATED 11 OCTOBER 2016

ii

FOREWORD

1. This standard is approved for use by the Department of the Navy and is available for use by all Departments and Agencies of the Department of Defense.

2. This section defines the standard interface requirements and verification methods for the design of shipboard sources and loads that will utilize shipboard direct current (DC) electric power at 375, 650 and 1000 volts. Sources are power conversion equipment within the electric power system. Loads are user equipment and power conversion equipment within the electric power system.

3. Comments, suggestions, or questions on this document should be addressed to Commander, Naval Sea

Systems Command, ATTN: SEA 05S, 1333 Isaac Hull Avenue, SE, Stop 5160, Washington Navy Yard DC 20376-

5160 or emailed to CommandStandards@navy.mil, with the subject line “Document Comment”. Since contact information can change, you may want to verify the currency of this address information using the ASSIST Online database at https://assist.dla.mil.

mailto:CommandStandards@navy.mil https://assist.dla.mil/ iii

CONTENTS

PARAGRAPH PAGE

1. SCOPE

1.1 Scope

1.2 Classification

1.3 Electrical interface

1.4 Nominal voltage recommendations

2. APPLICABLE DOCUMENTS

2.1 General

2.2 Government documents

2.2.1 Specifications, standards, and handbooks

2.2.2 Other Government documents, drawings, and publications

2.3 Order of precedence

3. DEFINITIONS

4. GENERAL REQUIREMENTS

4.1 Interface requirements

4.2 Loads

4.3 Sources

4.4 Equipment acting as both sources and loads

4.5 Distribution Equipment

4.6 Steady-State Measurements

4.7 Deviations

5. DETAILED REQUIREMENTS

5.1 Electrical power system characteristics

5.1.1 System grounding

5.1.2 Voltage spike waveform

5.2 Load requirements

5.2.1 Load Interface

5.2.2 Power Interruptions

5.2.3 Grounding

5.2.4 Human body leakage current limits for personnel safety

5.2.5 Pulse load

5.2.6 Voltage Spikes

5.3 Load Verification Methods

5.3.1 Load Normal Service Test

5.3.2 Load Abnormal Service Test

5.3.3 Load Voltage Offset Test

5.3.4 Load Transient Tolerance Test

5.3.5 Load Interruption Tolerance Test

5.3.6 Load Voltage Spike Test

5.3.7 Load Personnel Shock Hazard Test

5.3.8 Pulse Load Test

5.4 Source Requirements

5.4.1 Source Interface

5.4.2 Source maximum current ripple

5.4.3 Grounding

5.4.4 Human body leakage current limits for personnel safety

5.4.5 Pulse Support

5.4.6 Voltage Spikes

5.5 Source Verification Methods

5.5.1 Source Voltage Regulation Test

5.5.2 Source Current Limit Test

5.5.3 Source Voltage Offset Test

5.5.4 Source Transient Tolerance Test

5.5.5 Source Voltage Spike Test

iv

CONTENTS

PARAGRAPH PAGE

5.5.6 Source Personnel Shock Hazard Test

5.5.7 Source Pulse Test

6. NOTES

6.1 Intended use

6.2 Acquisition requirements

6.3 Tailoring guidance for contractual application

6.4 Subject term (key word) listing

FIGURES

Figure 1: DC interfaces Figure 2: Voltage Spike Waveform Figure 3: Simulated human body leakage current test setup for load Figure 4: Metering circuits for high and low frequency simulated human body leakage current tests Figure 5: Simulated human body leakage current test setup for source

TABLES

Table 1: Nominal DC system voltages Table 2: Nominal voltage recommendations based on load Table 3: Load Interface requirements Table 4: Source Interface requirements

EQUATIONS

No table of figures entries found.

DRAFT DATED 22 SEPTEMBER 2016

1. SCOPE

1.1 Scope. This military standard section establishes electrical interface characteristics for shipboard equipment utilizing DC electric power at 375, 650 or 1000 volts to ensure compatibility between electrical sources and loads. Characteristics of the electrical interfaces, as well as requirements and verification methods for electrical sources and loads are provided. Electrical interface characteristics for DC interfaces above 1000 volts are defined in

MIL-STD-1399 section MVDC. Electrical interface characteristics for 28 volt and 270 volt DC interfaces are defined in MIL-STD-704. Electrical interface characteristics for 155 volt DC interfaces are defined in MIL-STD-

1399 section 390.

1.2 Classification: This standard defines nominal voltages of shipboard DC electric power as listed in Table 1.

Table 1: Nominal DC system voltages

Nominal System Voltage Class

375 Volts DC Type 1

650 Volts DC Type 1

1000 Volts DC Type 1 and Type 2

1.3 Electrical interface. The basic characteristics and constraints categories concerned with this interface are shown symbolically in Figure 1. The source interface [1], as it concerns the characteristics of DC electric power, is located at the output terminals of the electric power source(s). The load interface [2], as it concerns the characteristics of DC electric power, is located at the input terminals of the electrical load(s).

Figure 1: DC interfaces

1.4 Nominal voltage recommendations. (Informative) Selection of which nominal voltage to utilize for a given load is application specific. Table 2 provides guidance to select nominal voltages based on electrical load.

Table 2: Nominal voltage recommendations based on load

Voltage

(VDC)

Recommended amperage range

(A)

Maximum recommended electrical load

(MW)

375 0 - 1,000 0.38 650 0 - 4,000 2.60

1,000 0 - 4,000 4.00

2. APPLICABLE DOCUMENTS

2.1 General. The documents listed in this section are specified in sections 3, 4, or 5 of this standard. This section does not include documents cited in other sections of this standard or recommended for additional information or as examples. While every effort has been made to ensure the completeness of this list, document users are cautioned that they must meet all specified requirements of documents cited in sections 3, 4, or 5 of this standard, whether or not they are listed.

2.2 Government documents.

2.2.1 Specifications, standards, and handbooks. The following specifications, standards, and handbooks form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract.

DEPARTMENT OF DEFENSE HANDBOOKS

MIL-HDBK-2036 - Preparation of Electronic Equipment Specifications

DEPARTMENT OF DEFENSE STANDARDS

MIL-STD-461 - Requirements for the Control of Electromagnetic Interference Characteristics of

Subsystems and Equipment

MIL-STD-1399 - Interface Standard for Shipboard Systems

(Copies of these documents are available online at http://quicksearch.dla.mil.)

2.2.2 Other Government documents, drawings, and publications. The following other Government documents, drawings, and publications form a part of this document to the extent specified herein. Unless otherwise specified, the issues of these documents are those cited in the solicitation or contract.

NAVAL SEA SYSTEMS COMMAND (NAVSEA) PUBLICATIONS

T9300-AF-PRO-020 - Electrical Systems Design Criteria and Practices (Surface Ships) For

Preliminary and Contract Design

(Copies of this document are available online at https://nll.ahf.nmci.navy.mil, may be requested by phone at

215-697-2626, or may be requested by email at nllhelpdesk@navy.mil. This publication can be located by searching the Navy Publications Index for the TMIN without the suffix.)

2.3 Order of precedence. Unless otherwise noted herein or in the contract, in the event of a conflict between the text of this document and the references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained.

http://quicksearch.dla.mil./ https://nll.ahf.nmci.navy.mil/ mailto:nllhelpdesk@navy.mil

3. DEFINITIONS

3.1. Commanded reference voltage: The voltage set point a source is regulating the output to. This set point is often a function of the steady-state current in the form of a droop characteristic.

3.2. Load abnormal service steady state voltage range: The range of steady state DC voltage that when applied to loads (with voltage ripple ranging from 0 to the source maximum steady state voltage ripple) the loads are not damaged. Loads may lose functionality as long as the loss of functionality does not directly result in damage to other equipment or injury to personnel.

3.3. Load maximum current rate of change (control negotiation): The maximum rate of change of the current waveform for a load that can be negotiated between the load and the electric plant control system. The rate of change is calculated using the same method as for the “load maximum current rate of change (no control negotiation).”

3.4. Load maximum current rate of change (no control negotiation): The maximum rate of change of the current waveform for a load if a larger value has not been pre-negotiated between the load and the electric plant control system. The change is calculated as the difference between the average value of the current measurements over the first half of a window and the average value of the current measurements over the second half of a window divided by half the time window duration. The maximum window duration is 10 ms and should consist of a minimum of forty current measurement samples. The time interval between the starts of successive time windows shall not exceed 20% of the time window duration.

3.5. Load maximum current ripple: The maximum root mean square magnitude of the steady state non-DC component of the current waveform of a load.

3.6. Load maximum inrush current: The peak instantaneous current which flows upon energizing the load or part thereof.

3.7. Load maximum pulse load (control negotiations): The maximum change in current allowable for a load that can be negotiated between the load and the electric plant control system. The change is calculated using the same method as for the Load maximum pulse load (no control negotiations)

3.8. Load maximum pulse load (no control negotiations): The maximum change in current allowable for a load if a larger value has not been pre-negotiated between the load and the electric plant control system. The change is calculated as the difference between the minimum and maximum load current over a moving time window of 1 second in duration. The time interval between the starts of time windows for calculating the difference shall not exceed 50 ms. The 1s time window is divided into 200 equal sub-windows of 5 ms each. The average load is calculated for each sub-window using a minimum of 20 samples. The minimum load is that of the sub-window with the lowest average load and the maximum load is that of the sub-window with the highest average load.

3.9. Load maximum steady state voltage ripple: The maximum root mean square value of the non-DC component of the voltage measured at the input of a load.

3.10. Load normal service steady state voltage range: The range of steady state DC voltage that when applied to loads (with the source maximum steady state voltage ripple), the loads are required to work properly. This range accounts for potential voltage drop in the distribution system as well as the Source steady-state voltage range.

3.11. Load voltage interruption Tolerance time: The duration of power interruption that a load can tolerate without any change in operation and without damage.

3.12. Load Voltage transient Recovery Time: The maximum time for the voltage waveform at the load to return to the range specified by the Load steady-state voltage range (0 to rated power) and Load maximum steady state voltage ripple.

3.13. Load Voltage transient Tolerance: Maximum permitted departure from the final steady-state voltage during transient conditions for which the load must remain fully operational.

3.14. Mission Critical Equipment: Equipment that is part of mission critical systems and required to operate through emergency conditions. See T9300-AF-PRO-020.

3.15. Nominal System Voltage: The design system DC voltage. Used as a reference for establishing other power quality requirements.

3.16. Source maximum current ripple: The ripple current a source can provide while still meeting voltage power quality requirements

3.17. Source maximum steady state current limit: The maximum steady-state current a source will provide.

3.18. Source maximum steady state current ripple: The maximum root mean square value of the non-DC component of the current measured at the output of an online source for which a source must be able to maintain voltage power quality.

3.19. Source maximum steady state voltage ripple: The maximum root mean square value of the non-DC component of the voltage measured at the output of an online source.

3.20. Source steady-state voltage range (0 to rated power): The allowable variation in the system DC voltage measured at the output of an online source under normal droop operation and constant power mode. This range does not account for potential voltage loss in the distribution system.

3.21. Source steady-state voltage range (constant current): The allowable variation in the system DC voltage measured at the output of an online source under current limit operation. This range does not account for potential voltage loss in the distribution system. The current is limited to the rated power divided by the upper limit of the source steady-state voltage range.

3.22. Source steady-state voltage tolerance: The maximum deviation of the steady-state voltage measured at the output of an online source from the commanded reference voltage.

3.23. Source Voltage transient Recovery Time: The maximum time for the voltage waveform at the source to return to the range specified by the Source steady-state voltage range (0 to rated power) and Source maximum steady state voltage ripple. The Voltage transient recovery time is characterized by the time constants associated with voltage regulation of the sources.

3.24. Source Voltage transient Tolerance: Maximum permitted departure from the final steady-state voltage during transient conditions for a single source with the sudden application of load, and with the sudden removal of load.

3.25. Temperature Stability: Temperature stability is achieved when the variation between successive temperature measurements at the same location does not exceed 1° C after 30 minutes.

3.26. Voltage Spike Waveform: A description of the shape and magnitude of a voltage spike

3.27. Worst Case voltage offset from Negative Terminal to Ground: In the case that the Positive Terminal experiences a ground-fault, or in the case of a ground fault in a power source, the maximum magnitude steady-state (negative) DC voltage with respect to ground expected on the Negative Terminal.

3.28. Worst Case voltage offset from Positive Terminal to Ground: In the case that the Negative Terminal experiences a ground-fault, or in the case of a ground fault in a power source, the maximum magnitude steady-state DC voltage with respect to ground expected on the Positive Terminal.

4. GENERAL REQUIREMENTS

4.1 Interface requirements. The specific interface requirements and constraints established herein are mandatory and shall be adhered to regarding any aspect of shipboard electrical power systems or user equipment designs to which these requirements and constraints apply, including systems and equipment design, production, and installation. The policies and procedures established by MIL-STD-1399 are mandatory. This section and the basic standard are to be viewed as an integral single document for use in the design and testing of electric power systems and user equipment. MIL-HDBK-2036 may be used as a guide for tailoring of requirements.

4.2 Loads. Loads shall adhere to the interfaces specified in section 5.2. As specified in acquisition documentation (see 6.2) loads shall be verified to adhere to the interface through the verification methods specified in section 5.2. For loads that have multiple applicable interfaces, the requirements specified in section 5.2 shall apply to each interface individually.

4.3 Sources.Sources shall adhere to the interfaces specified in section 5.4. As specified in acquisition documentation (see 6.2) sources shall be verified to adhere to the interface through the verification methods specified in section 5.4. For sources that have multiple applicable interfaces, the requirements specified in section

5.4 shall apply to each interface individually.

4.4 Equipment acting as both sources and loads. Some equipment, such as energy storage modules, may at times act as sources and at other times act as loads. When acting as a source, the source interface requirements apply. When acting as a load, the load interface requirements apply.

4.5 Distribution Equipment. The design of the distribution equipment in Figure 1 is governed by T9300-AF-

PRO-020. The impedance, switching, and fault clearing capability of the distribution equipment shall be designed to ensure that the power quality provided to the loads at the load interface and the source current characteristics at the source interface are in accordance with this standard if the load current characteristics at the load interface and the power quality provided by the source at the source interface are also in accordance with this standard.

4.6 Steady-State Measurements. The steady-state DC component is the average value over a 100 ms moving time window. The time interval between the starts of time windows shall not exceed 20 ms. Steady-state ripple / non-DC component is calculated using the same time windows by subtracting the steady-state DC component from the waveform and calculating the root mean square value. The sampling rate shall be sufficient to accurately measure the highest significant frequency component.

4.7 Deviations. The interfaces in this standard are based on a power electronics based DC electric power system. To meet the intent of this section for non-traditional electric power systems, deviation of requirements will be considered. The deviation provisions in MIL-STD-1399 shall be adhered to during the early development stage of equipment, as specified (see 6.2). Requests for deviation shall be submitted for approval to NAVSEA 05Z3.

5. DETAILED REQUIREMENTS

5.1 Electrical power system characteristics.

5.1.1 System grounding. The system grounding for the interfaces applicable to this standard shall be in accordance with T9300-AF-PRO-020. The grounding scheme (unless ungrounded) shall be implemented within the boundaries of the distribution equipment.

5.1.2 Voltage spike waveform. The voltage spike waveform is depicted in Figure 2. The voltage spike waveform is added to the steady-state voltage.

Figure 2: Voltage Spike Waveform

5.2 Load requirements.

5.2.1 Load Interface. Table 3 defines interface requirements and verification method requirements for loads.

Table 3: Load Interface requirements

Characteristic Value

Type 1

Value

Type 2

Verification

Method

Nominal System Voltage (Volts Direct Current) 375

N/A

Load normal service steady state voltage range

(percent of Nominal System Voltage)

84% to 106% 64% to 106% 5.3.1

Load abnormal service steady state voltage range

(percent of Nominal System Voltage)

0% to 84%

106% to 110%

0% to 64%

106% to 110%

5.3.2

Load maximum steady-state voltage ripple

(percent of Nominal System Voltage)

TBD (1.5% to

15%)

TBD (1.5% to

15%)

5.3.1

Worst Case voltage offset from Positive Terminal to

Ground: (percent of Nominal System Voltage)

110% 110% 5.3.3

Worst Case voltage offset from Negative Terminal to Ground: (percent of Nominal System Voltage)

-110% -110% 5.3.3

Load Voltage transient Tolerance: (% of Nominal

System Voltage)

TBD (±10.0% to

(±12.0%)

TBD (±10.0% to

(±12.0%)

5.3.4

Load Voltage transient Recovery Time (ms) TBD (15 to 100) TBD (15 to 100) 5.3.4

Load voltage interruption Tolerance Time (ms) TBD (5 to 20+) TBD (5 to 20+) 5.3.5

Voltage Spike Waveform Figure 2 with peak voltage equal to nominal system voltage times 1.5.

Figure 2 with peak voltage equal to nominal system voltage times 1.5.

5.3.6

Load maximum current ripple

(percent of steady-state current)

TBD (10% to

50%)

TBD (10% to

50%) 5.3.1

Load maximum current ripple frequency limits TBD (MIL-STD-

461 CE101 limit for surface ships and submarine applications, DC)

TBD (MIL-STD-

461 CE101 limit for surface ships and submarine applications, DC)

(MIL-STD-

461)

Load maximum inrush current (percent of rated current)

TBD (150%) TBD (150%) 5.3.1

Load maximum pulse load (no control negotiation)

(A)

See section 5.2.5 See section 5.2.5 5.3.8

Load maximum current rate of change (no control negotiation) (A / ms)

TBD (63) TBD (125) 5.3.8

Load maximum pulse load (control negotiation) See section 5.2.5 See section 5.2.5 5.3.8

Load maximum current rate of change (control negotiation) (A / ms)

TBD (125) TBD (250) 5.3.8

5.2.2 Power Interruptions. Loads not designated as Mission Critical Equipment (MCE) (see 6.2) may require a manual restart, but shall not be damaged due to power interruptions. Loads designated as MCE shall operate through power interruptions of duration up to the Load voltage interruption Tolerance time without damage or operational interruption, suffer any loss of data, or require a restart or reboot. Loads designated as MCE shall not be damaged due to power interruptions of duration greater than the Load voltage interruption Tolerance time and shall restart without operator intervention after the restoration of power.

5.2.3 Grounding. With the exception of power line filters, load electrical circuits sharing a ground reference with the DC electric power system shall not connect to the DC electric power system ground within the system boundary of the load. Where power line filters are required in the user equipment, a line-to-line configuration is preferred. If a line-to-ground configuration is used for filtering, then the value of the filter capacitance shall limit the rms line to ground current (for each line conductor) through the filter capacitance to less than 30 mA. Filters, if provided, shall use balanced capacitance per line-to-ground with a tolerance value not exceeding 10 percent.

5.2.4 Human body leakage current limits for personnel safety. Loads shall not pose a shock hazard to personnel. Section 5.3.7 provides a verification test using an impedance network simulating human body impedance. The test simulates the worst case current path through the human body to a neutral point ground if the equipment ground connection is opened.

5.2.4.1 Low frequency human body leakage current limits for personnel safety. Low frequencies include frequencies up to 700 Hz. The current limit through the impedance network simulating the human body for the test in 5.3.7 for the low frequency range is 5 milliamperes.

5.2.4.2 High frequency human body leakage current limits for personnel safety. High frequencies include those greater than 700 Hz and less than 100 kHz. The current limit through the impedance network simulating the human body for the test in 5.3.7 for the high frequency range is 70 milliamperes.

5.2.5 Pulse load. The load maximum pulse load (no control negotiation) shall be as specified in acquisition documentation (see 6.2). Pulse loads that do not exceed both the load maximum pulse load (no control negotiation) and the load maximum current rate of change (no control negotiation) are not required to coordinate with the control system for the electrical power system. Pulse loads that exceed either the load maximum pulse load (no control negotiations) or the load maximum current rate of change (no control negotiation) shall negotiate the maximum pulse load (up to the Load maximum pulse load (control negotiations) and maximum current rate of change (up to the Load maximum current rate of change (control negotiations) with the control system for the electrical power system. The protocols for conducting the negotiations shall be as specified in the acquisition documentation (see

6.2), or if not specified, in a manner approved by NAVSEA. The load maximum pulse load (control negotiation) shall be as specified in the acquisition documentation. (see 6.2)

5.2.6 Voltage Spikes. Loads shall remain operational before, during, and after being subjected to voltage spikes with the waveform specified in section 5.1.2. The waveform is applied line-to-line and line to ground for each conductor. When subjected to a voltage spike, loads shall not experience any operational interruption, suffer any loss of data, or require a restart or reboot. Loads shall be designed to be subjected on average to a spike once every

4 operating hours over the load’s design life.

5.3 Load Verification Methods: This section provides load verification procedures to verify compliance to the load interface requirements specified in this standard. For loads verified through testing, the hardware and software of a Unit Under Test (UUT) shall be representative of production. Verification / test procedure and Verification / test report requirements may be tailored in acquisition documentation (see 6.2) as approved by NAVSEA.

5.3.1 Load Normal Service Test. A load’s performance shall be verified through testing when provided steady-state power having a steady-state voltage within the range specified in Table 1 for Load normal service steady state voltage range.

5.3.1.1 Apparatus. The following apparatus is recommended for performing this test:

a. Power source able to achieve required capacity, specified voltage ripple, and range of voltage adjustment.

b. Voltmeters (true rms) capable of measuring DC and AC components with ±0.5 percent accuracy

c. Temperature meter with ±0.5° C accuracy

d. Digital storage oscilloscope having ≥ 500 kHz response per channel and wide-band current sensors capable of capturing the current waveform for inrush current measurement, current measurement, and current ripple measurement with ±0.5 percent accuracy. Voltage probes capable of measurement with ±0.5 percent accuracy.

5.3.1.2 Procedure. The UUT shall be operated in all normal operating modes with the following steady-state voltages applied from a powered down condition until the UUT has achieved Temperature stability:

a. Nominal System Voltage ±1%, minimal voltage ripple

b. Upper limit of the Load normal service steady state voltage range (or greater), minimal voltage ripple.

c. Lower limit of the Load normal service steady state voltage range (or less), minimal voltage ripple.

d. Nominal System Voltage ±1%, voltage ripple set at or greater than the Load maximum steady-state voltage ripple.

e. Upper limit of the Load normal service steady state voltage range (or greater), voltage ripple set at or greater than Load maximum steady-state voltage ripple.

f. Lower limit of the Load normal service steady state voltage range (or less), voltage ripple set at or greater than Load maximum steady-state voltage ripple.

The voltage ripple shall consist of a 1000 ±100 Hz square wave unless otherwise specified in acquisition documentation (see 6.2).

Voltage, voltage ripple, current, current inrush, current ripple, and internal equipment temperatures shall be measured and recorded at 10-minute intervals. During testing, the UUT shall be verified to operate normally with a stable temperature and with no operational degradation.

5.3.2 Load Abnormal Service Test. A load’s performance shall be verified through testing when provided steady-state power having a steady-state voltage within the ranges specified in Table 1 for Load abnormal service steady state voltage range

5.3.2.1 Apparatus. The following apparatus is recommended for performing this test:

a. Power source of required capacity and range of voltage adjustment.

b. Voltmeters (true rms) capable of measuring DC and AC components with ±0.5 percent accuracy

c. Temperature meter with ±0.5° C accuracy

d. Digital storage oscilloscope having ≥ 500 kHz response per channel and voltage probes with ±0.5 percent accuracy

5.3.2.2 Procedure. The UUT shall be operated with the following steady-state voltages until the UUT has achieved Temperature stability:

a. 8 to 12% of nominal system voltage, minimal voltage ripple

b. 48 to 52% of nominal system voltage, minimal voltage ripple

c. 78 to 82% of nominal system voltage, minimal voltage ripple

d. 110% (or greater) of nominal system voltage, minimal voltage ripple

Voltage, voltage ripple, and internal equipment temperatures shall be measured and recorded at 10-minute intervals. During testing, the UUT shall be verified to achieve a stable temperature, without damage, not cause damage to other equipment, and to not create a hazardous condition for personnel.

Following completion of the above cases, the UUT shall be operated in all normal operating modes until the

UUT has achieved Temperature stability when provided nominal system voltage. Voltage, voltage ripple, and internal equipment temperatures shall be measured and recorded at 10-minute intervals. During this portion of testing, the UUT shall be verified to operate normally with a stable temperature and with no operational degradation

5.3.3 Load Voltage Offset Test A load’s performance shall be verified through testing when provided steady-state power having a steady-state voltage within the range specified in Table 1 for Load normal service steady state voltage range and with one of the two conductors at ground potential.

5.3.3.1 Apparatus. The following apparatus is recommended for performing this test:

a. Power source of required capacity and range of voltage adjustment.

b. Voltmeters (true rms) capable of measuring DC and AC components with ±0.5 percent accuracy

c. Temperature meter with ±0.5° C accuracy

d. Means of Grounding each conductor

e. Digital storage oscilloscope having ≥ 500 kHz response per channel and voltage probes with ±0.5 percent accuracy

5.3.3.2 Procedure. The UUT shall be operated in all normal operating modes with the Upper limit of the

Load normal service steady state voltage (or greater) for the following conditions until the UUT has achieved

Temperature stability:

a. Positive conductor grounded

b. Negative conductor grounded

Voltage, voltage ripple, and internal equipment temperatures shall be measured and recorded at 10-minute intervals. During testing, the UUT shall be verified to operate normally with a stable temperature and with no operational degradation.

5.3.4 Load Transient Tolerance Test

5.3.4.1 Apparatus. The following apparatus is recommended for performing this test:

a. Power source of required capability, range of voltage adjustment, and programmability to create transient waveform

b. Digital storage oscilloscope having ≥ 500 kHz response per channel and voltage probes with ±0.5 percent accuracy

c. Temperature meter with ±0.5° C accuracy

5.3.4.2 Procedure.

The UUT shall be operated in the following manner for all normal operating modes. Record transient voltage waveforms and whether UUT continues to function normally or not.

a. Supply the UUT with the upper limit of the Load normal service steady state voltage (or greater).

b. Wait until the UUT has achieved Temperature stability

c. Increase the voltage by the maximum positive Load Voltage transient Tolerance (or greater) as quickly as possible, but no longer than 0.5 ms.

d. Wait for a period of time between 100 and 120% of the Load Voltage transient Recovery Time

e. Decrease the voltage to the upper limit of the Load normal service steady state voltage as quickly as possible, but no longer than 0.5 ms.

f. Verify that the UUT continues to function normally

g. Decrease the voltage to the lower limit of the Load normal service steady state voltage over a period of no less than 2 seconds.

h. Wait for 2 minutes.

i. Decrease the voltage by maximum negative Load Voltage transient Tolerance as quickly as possible, but no longer than 0.5 ms.

j. Wait for a period of time between 100 and 120% of the Load Voltage transient Recovery Time

k. Increase the voltage to the lower limit of the Load normal service steady state voltage as quickly as possible, but no longer than 0.5 ms

l. Verify that the UUT continues to function normally

m. Turn off the power supply.

5.3.5 Load Interruption Tolerance Test

5.3.5.1 Apparatus. The following apparatus is recommended for performing this test:

a. Power source of required capability, range of voltage adjustment, and programmability to create power interruptions of specified duration

b. Digital storage oscilloscope having ≥ 500 kHz response per channel and voltage probes with ±0.5 percent accuracy

c. Temperature meter with ±0.5° C accuracy

5.3.5.2 Procedure.

The UUT shall be operated in the following manner for all normal operating modes. Record temperatures, duration of power interruption, whether UUT continues to function normally or not and voltage waveforms for a 500 ms period centered on the interruption time period.

a. Supply the UUT with the nominal system voltage.

b. Wait until the UUT has achieved Temperature stability

c. Interrupt the power for a duration equal to or greater than the Load voltage interruption tolerance time.

d. Resume supplying the UUT with the nominal system voltage

e. Verify that the UUT continues to function normally

5.3.6 Load Voltage Spike Test

5.3.6.1 Apparatus. The following apparatus is recommended for performing this test:

a. Power source of required capability and ability to withstand voltage spikes

b. Voltage spike attenuation circuit – if necessary, to reduce the magnitude of voltage spikes imposed on the power source

c. Spike Generator and associated components capable of imposing a spike with the characteristic of Figure 2 on the load. The peak voltage shall be between 95% and 100% of the peak value depicting in Figure 2.

d. Digital storage oscilloscope having ≥ 500 kHz response per channel and voltage probes with ±0.5 percent accuracy

5.3.6.2 Procedure. With power disconnected, connect the power source, voltage spike attenuation circuit (if necessary), spike generator, measurement equipment, and UUT in accordance with the spike generator’s manufacturer’s instructions. Apply five voltage spikes at the rate of two per minute between the following conductors:

a. Line-to-line

b. Positive conductor to ground

c. Negative conductor to ground

Verify equipment remains operational before, during, and after each application of the series of five voltage spikes. See 5.2.6 for criteria for required load operability.

5.3.7 Load Personnel Shock Hazard Test

5.3.7.1 Apparatus. The following apparatus is recommended for performing this test:

a. Operational circuit configuration defined by Figure 3.

b. Metering circuit defined by Figure 4 for low or high frequency operation.

c. Power source.

d. Voltmeter should be true rms of +0.5 percent accuracy; the frequency response should be within measurement requirements.

e. Insulated probe, such as an oscilloscope probe.

5.3.7.2 Procedure. With power disconnected, place the UUT on an isolated surface. The UUT shall be isolated from any earth, power, or instrument ground. UTT shall be connected as in Figure 3. The appropriate metering circuit shall be used for the intended frequency range, shown in Figure 4. The current shall be determined by measuring the voltage drop across the metering circuit. The voltage measured across the metering circuit, when equal to 1.0 Vrms, represents 2.0 milliamperes of current. The overall measurement error shall not exceed 5 percent.

Where there is risk for current paths to any control or external surface component, the insulated probe shall be used on all control or external surface components such as case, connector housings, recessed calibration or adjustment controls and control shafts with knobs removed. The safety ground conductor shall not carry load current. The steps for conducting the test are:

a. The power source shall be de-energized. Connect the UUT as in figure XX utilizing the low or high frequency metering circuit as required. Leave the power source unconnected.

b. Place the UUT ON-OFF switch in the OFF position.

c. Place the SAFETY GROUND switch in the CLOSED or GROUND position.

d. Connect and energize the power source.

e. Observe the WARNING. Place the SAFETY GROUND switch in the OPEN or UNGROUNDED position.

f. Place the UUT ON-OFF switch in the ON position

g. Record the voltmeter reading.

h. Place the UUT ON-OFF switch in the OFF position

i. Place the SAFETY GROUND switch in the CLOSED or GROUND position.

j. Repeat steps e through i for each and every mode of operation

Figure 3: Simulated human body leakage current test setup for load

Figure 4: Metering circuits for high and low frequency simulated human body leakage current tests

5.3.8 Pulse Load Test

5.3.8.1 Apparatus. The following apparatus is recommended for performing this test:

a. Power source of required capability, range of voltage adjustment, and ability to implement control negotiations (if required).

b. Digital storage oscilloscope having ≥ 500 kHz response per channel and voltage/current probes with ±0.5 percent accuracy

5.3.8.2 Procedure. The load UUT shall be operated in all pulse modes of operation with the following steady-state voltages applied.

a. Nominal System Voltage ±1%, minimal voltage ripple

b. Upper limit of the Load normal service steady state voltage range (or greater), minimal voltage ripple.

c. Lower limit of the Load normal service steady state voltage range (or less), minimal voltage ripple.

Verify UUT does not exceed Load maximum pulse load (no control negotiations) and Load maximum current rate of change (no control negotiations) without first negotiating with the source. If negotiations have taken place, verify UUT has not exceeded the negotiated values for Load maximum pulse load and Load maximum current rate of change. Record control negotiations, voltage and current waveforms. The procedure should be repeated for different sets of source limitations to ensure robustness in the negotiation process and to verify the UUT does not exceed the negotiated values.

5.4 Source Requirements

5.4.1 Source Interface: Table 4 defines interface requirements and verification method requirements for sources.

Table 4: Source Interface requirements

Characteristic Value

Type 1

Value

Type 2

Verification

Method

Nominal System Voltages (Volts Direct Current) 375

N/A

Source steady-state voltage range: 0 to rated power

(percent of Nominal System Voltage) 90% to 105% 70% to 105% 5.5.1

Source steady-state voltage range: constant current

(percent of Nominal System Voltage) 0% to 90% 0% to 70% 5.5.2

Source steady-state voltage tolerance

(percent of Nominal System Voltage)

TBD (0.25% to

1%)

TBD (0.25% to 1%) 5.5.1

Source maximum steady-state voltage ripple

(percent of Nominal System Voltage)

TBD (3.5% to

10%)

TBD (3.5% to 10%) 5.5.1

Worst Case voltage offset from Positive Terminal to Ground: (percent of Nominal System Voltage) 110% 110% 5.5.3

Worst Case voltage offset from Negative Terminal to Ground: (percent of Nominal System Voltage) -110% -110% 5.5.3

Source Voltage transient Tolerance:

(percent of Nominal System Voltage)

TBD (±10.0% to

(±12.0%)

TBD (±10.0% to

(±12.0%) 5.5.4

Source Voltage transient Recovery Time (ms) TBD (15 to 100) TBD (15 to 100) 5.5.4

Voltage Spike Waveform Figure 2 with peak voltage equal to nominal system voltage times 2.5.

Figure 2 with peak voltage equal to nominal system voltage times 2.5.

5.5.5

Source maximum current ripple (rms A) TBD (between 0.10 and 0.50) x Rated

Power

Nominal System

Voltage

(See 5.4.2 for frequency limits)

TBD (between 0.10 and 0.50) x Rated

Power

Nominal System

Voltage

(See 5.4.2 for frequency limits)

5.5.1

Source maximum steady state current limit (A) Rated Power .

0.90 x Nominal System

Voltage

Rated Power .

0.70 x Nominal System

Voltage 5.5.2

Source maximum pulse (no control negotiation) (A) See section 5.4.5 See section 5.4.5 5.5.7

Source maximum current rate of change (no control negotiation) (A / ms)

See section 5.4.5 See section 5.4.5 5.5.7

Source maximum pulse (control negotiation) See section 5.4.5 See section 5.4.5 5.5.7

Source maximum current rate of change (control negotiation) (A / ms)

See section 5.4.5 See section 5.4.5 5.5.7

5.4.2 Source maximum current ripple: Frequency limits for the source maximum current ripple are the MIL-

STD-461 CE-101-1 limit for surface ships and submarine applications, DC, calculated at 3 amps, then increased by

20 log ( Rated Power / (3 x Nominal System Voltage)),

5.4.3 Grounding. With the exception of power line filters, source electrical circuits sharing a ground reference with the DC electric power system shall not connect to the DC electric power system ground within the system boundary of the source. Where power line filters are required in the source, a line-to-line configuration is preferred.

If a line-to-ground configuration is used for filtering, then the value of the filter capacitance shall limit the rms line to ground current (for each line conductor) to less than 30 mA. Filters, if provided, shall use balanced capacitance per line-to-ground with a tolerance value not exceeding 10 percent.

5.4.4 Human body leakage current limits for personnel safety. Sources shall not pose a shock hazard to personnel. Section 5.5.6 provides a verification method for sources through a test using an impedance network simulating human body impedance. The test simulates the worst case current path through the human body to a neutral point ground if the equipment ground connection is opened.

5.4.4.1 Low frequency human body leakage current limits for personnel safety. Low frequencies include frequencies up to 700 Hz. The current limit through the impedance network simulating the human body for the test in 5.5.6 for the low frequency range is 5 milliamperes.

5.4.4.2 High frequency human body leakage current limits for personnel safety. High frequencies include those greater than 700 Hz and less than 100 kHz. The current limit through the impedance network simulating the human body for the test in 5.5.6 for the high frequency range is 70 milliamperes.

5.4.5 Pulse Support. The source maximum pulse load (no control negotiation) and source maximum current rate of change (no control negotiation) shall be as specified in acquisition documentation (see 6.2). Sources shall be capable of maintaining power quality when providing pulses that do not exceed both the source maximum pulse load

(no control negotiation) and the source maximum current rate of change (no control negotiation) without control negotiations. Before a pulse is applied to a source that exceeds either the source maximum pulse load (no control negotiations) or the source maximum current rate of change (no control negotiation), the electrical power system control system shall negotiate the maximum pulse load (up to the Source maximum pulse load (control negotiations) and maximum current rate of change (up to the Source maximum current rate of change (control negotiations) with the source. The protocols for conducting the negotiations shall be as specified in the acquisition documentation (see

6.2), or if not specified, in a manner approved by NAVSEA. The source maximum pulse load (control negotiation) and source maximum current rate of change (control negotiation) shall be as specified in the acquisition documentation. (see 6.2)

5.4.6 Voltage Spikes. Sources shall remain operational before, during, and after being subjected to voltage spikes with the waveform specified in section 5.1.2. The waveform is applied line-line and line to ground for each conductor. When subjected to a voltage spike, sources shall not experience any operational interruption, suffer any loss of data, or require a restart or reboot. Sources shall be designed to be subjected on average to a spike once every

4 operating hours over the source’s design life.

5.5 Source Verification Methods. This section provides source verification procedures to verify compliance to the source interface requirements specified in this standard. For sources verified through testing, the hardware and software of a Unit Under Test (UUT) shall be representative of production. Verification / test procedure and

Verification / test report requirements may be tailored in acquisition documentation (see 6.2) as approved by

NAVSEA.

5.5.1 Source Voltage Regulation Test

5.5.1.1 Apparatus. The following apparatus is recommended for performing this test:

a. Programmable Load with sufficient capability and able to inject ripple current.

b. Voltmeter should be true rms of ±0.5 percent accuracy; the frequency response should be within

c. Temperature meter with ±0.5° C accuracy

d. Digital storage oscilloscope having ≥ 500 kHz response per channel and voltage/current probes with ±0.5 percent accuracy.

5.5.1.2 Procedure The UUT shall be operated with the following Commanded reference voltage and load until the UUT has achieved Temperature stability

a. Nominal system voltage and 8 to 12% load with minimal current ripple

b. Lower limit of source steady-state voltage range: 0 to rated power and 8 to 12% load with minimal current ripple

c. Upper limit of source steady-state voltage range: 0 to rated power and 8 to 12% load with minimal current ripple

d. Nominal system voltage and 95 to 100% load with minimal current ripple

e. Lower limit of source steady-state voltage range: 0 to rated power and 95 to 100% load with minimal current ripple

f. Upper limit of source steady-state voltage range: 0 to rated power and 95 to 100% load with minimal current ripple

g. Nominal system voltage and 8 to 12% load with source maximum current ripple

h. Lower limit of source steady-state voltage range: 0 to rated power and 8 to 12% load with source maximum current ripple

i. Upper limit of source steady-state voltage range: 0 to rated power and 8 to 12% load with source maximum current ripple

j. Nominal system voltage and 95 to 100% load with source maximum current ripple

k. Lower limit of source steady-state voltage range: 0 to rated power and 95 to 100% load with source maximum current ripple

l. Upper limit of source steady-state voltage range: 0 to rated power and 95 to 100% load with source maximum current ripple

The current ripple shall consist of a 1000 ±100 Hz square wave unless otherwise specified in acquisition documentation (see 6.2).

Voltage, voltage ripple, current, current ripple, and internal equipment temperatures shall be measured and recorded at 10-minute intervals. During testing, the UUT shall be verified to operate normally with a stable temperature and with no operational degradation.

5.5.2 Source Current Limit Test

5.5.2.1 Apparatus. The following apparatus is recommended for performing this test:

a. Programmable Load with sufficient range of capability.

b. Voltmeter should be true rms of ±0.5 percent accuracy; the frequency response should be within measurement requirements.

c. Temperature meter with ±0.5° C accuracy

d. Digital storage oscilloscope having ≥ 500 kHz response per channel and voltage/current probes with ±0.5 percent accuracy

5.5.2.2 Procedure The UUT shall be operated with the following load until the UUT has achieved Temperature stability

a. Load adjusted to result in a voltage equal to 98 to 100% of the upper limit of the Source steady-state voltage range: constant current.

b. Load adjusted to result in a voltage equal to 48 to 52% of nominal system voltage

c. Load adjusted to result in a voltage equal to 8 to 12% of nominal system voltage

Voltage, voltage ripple, current, current ripple, and internal equipment temperatures shall be measured and recorded at 10-minute intervals. During testing, the UUT shall be verified to operate normally with a stable temperature and with no operational degradation.

5.5.3 Source Voltage Offset Test

5.5.3.1 Apparatus. The following apparatus is recommended for performing this test:

a. Programmable Load with sufficient capability

b. Voltmeter should be true rms of ±0.5 percent accuracy; the frequency response should be within measurement requirements.

c. Temperature meter with ±0.5° C accuracy

d. Digital storage oscilloscope having ≥ 500 kHz response per channel and voltage/current probes with ±0.5 percent accuracy.

5.5.1.2 Procedure The UUT shall be operated with the following Commanded reference voltage, grounding, and load until the UUT has achieved Temperature stability

a. Upper limit of source steady-state voltage range: 0 to rated power and 9 to 11% load with positive conductor grounded

b. Upper limit of source steady-state voltage range: 0 to rated power and 95 to 100% load with positive conductor grounded

c. Upper limit of source steady-state voltage range: 0 to rated power and 9 to 11% load with negative conductor grounded

d. Upper limit of source steady-state voltage range: 0 to rated power and 95 to 100% load with negative conductor grounded

Voltage, voltage ripple, current, current ripple, and internal equipment temperatures shall be measured and recorded at 10-minute intervals. During testing, the UUT shall be verified to operate normally with a stable temperature and with no operational degradation.

5.5.4 Source Transient Tolerance Test.

5.5.4.1 Apparatus. The following apparatus is recommended for performing this test

a. Programmable Load with sufficient range of capability. The programmable load shall regulate to a commanded power set point.

b. Digital storage oscilloscope having ≥ 500 kHz response per channel and voltage probes with ±0.5 percent accuracy

5.5.4.2 Procedure. The maximum transient test load and the minimum transient test load are as specified in acquisition documentation (see 6.2) or if not specified, set the maximum transient test load to the rated load of the UUT and set the minimum transient test load to “no load”. The UUT shall be operated with the following conditions:

a. Command reference voltage set at upper limit of source steady-state voltage range: 0 to rated power and no load.

b. Wait at least 2 minutes

c. Command reference voltage set at upper limit of source steady-state voltage range: 0 to rated power and apply the maximum transient test load as quickly as possible (no more than 0.5 ms).

d. Wait at least 2 minutes

e. Command reference voltage set at upper limit of source steady-state voltage range: 0 to rated power…