GB/T 42315-2023Code of maintenance for electrochemical energy storage station (English PDF)

Foreword

This document was issued on 17 March 2023 by the State Administration for Market Regulation; Standardization Administration of the PRC and takes effect on 1 October 2023.

It is a GB/T standard: recommended rather than compulsory, but it is the text a Chinese reviewer applies when assessing a submission.

1 Scope

GB/T 42315-2023 covers the maintenance of an electrochemical energy storage station - the items to be worked, the methods used and the quality each job has to reach across the battery arrays, the power conversion system, the monitoring and control system, and the auxiliary facilities. Before any of it begins, the general requirements call for a maintenance schedule, a maintenance plan and an emergency plan, so that work on a live installation is planned rather than improvised. The battery array clauses carry the bulk of the document and open with the isolation sequence: the primary AC and DC circuit breakers and the isolating switch opened, and a grounding wire fitted, before anyone reaches into a rack. The power conversion clauses do the same on their side, opening the AC and DC side switches and then measuring the residual voltage at the ports rather than assuming it has decayed. That distinction is why the document exists. A battery stores its energy chemically and cannot be switched off, so a string sits at full voltage with every breaker open, and a converter holds charge after disconnection; maintenance written for a substation does not transfer to a storage hall. Written for station operators, maintenance contractors and the engineers who draft site work instructions and permits.

This document specifies the items, methods and quality requirements for battery arrays,

power conversion systems, monitoring and control systems and auxiliary facilities of

the electrochemical energy storage station.

This document is applicable to electrochemical energy storage stations - with a power

of 500 kW and an energy of 500 kW.h and above - that use lithium ion batteries, lead-

carbon batteries, flow batteries, and fuel cells as energy storage carriers. It also applies

as a reference to other electrochemical energy storage stations.

2 Normative references

The following documents are referred to in the text in such a way that some or all of

their content constitutes requirements of this document. For dated references, only the

version corresponding to that date is applicable to this document; for undated references,

the latest version (including all amendments) is applicable to this document.

GB/T 1094.6, Power transformers - Part 6: Reactors

GB/T 1094.11, Power transformers - Part 11: Dry-type transformers

GB 4962, Technical safety regulation for gaseous hydrogen use

GB/T 12706 (all parts), Power cables with extruded insulation and their accessories

for rated voltages from 1 kV (Um = 1.2 kV) up to 35 kV (Um = 40.5 kV)

GB/T 17702, Capacitors for power electronics

GB/T 20840.2, Instrument transformers - Part 2: Additional requirements for current

transformers

GB/T 20840.3, Instrument transformers - Part 3: Additional requirements for

inductive voltage transformers

GB/T 24499, Technology glossary for gaseous hydrogen, hydrogen energy and

hydrogen energy system

GB 32311, Minimum allowable values of energy efficiency and energy efficiency

grades for hydrogen producing systems by water electrolysis

3 Terms and definitions

Terms and definitions determined by DL/T 2528 and GB/T 24499 are applicable to this

document.

4 General requirements

4.1 Before the maintenance of the electrochemical energy storage station, a

maintenance schedule shall be formulated; also, a maintenance plan and an emergency

plan shall be compiled.

4.2 The maintenance of the electrochemical energy storage station includes scheduled

maintenance and troubleshooting; also, a condition-based maintenance should be

carried out according to the operation of the equipment. The cycle of scheduled

maintenance - which should be 1 year - can be adjusted according to the assessment

results. The condition-based maintenance should be determined according to the

comprehensive assessment results of equipment operating status, fault location, fault

type and severity based on operating data.

4.3 The maintenance operation shall be carried out in the aspects of appearance

inspection, inspection test, repair, post-repair test, etc. in combining with equipment

status. An overall performance test of the energy storage system shall be carried out

after the replacement of main components such as battery arrays, power conversion

systems, and monitoring and control systems.

4.4 The maintenance of primary equipment such as voltage transformers, switches,

surge arresters, and transformers shall be carried out in accordance with the provisions

of DL/T 573, DL/T 727, DL/T 1686, DL/T 1689, DL/T 1700, and DL/T 1702; the

maintenance of secondary equipment such as AC-DC system for station, relay

protection and automation, and metering shall be carried out in accordance with the

regulations of DL/T 724, DL/T 995, and DL/T 1664.

4.5 Maintenance personnel shall be trained regularly to be familiar with the design

requirements, running conditions and equipment technical requirements of the power

station, and to master the maintenance skills and quality requirements of the power

station equipment.

4.6 Maintenance tools and appliances shall be inspected and calibrated regularly, and

used within the inspection and calibration date.

4.7 Maintenance personnel shall prepare spare parts in advance according to the

maintenance schedule and order cycle time.

4.8 The maintenance safety of the electrochemical energy storage station shall meet the

requirements of GB/T 42288.

4.9 The electrochemical energy storage station shall formulate environmental

protection measures during the maintenance process. Waste batteries and electrolytes

shall be recycled.

4.10 After the maintenance is completed, a maintenance assessment of the energy

storage station shall be carried out, and a maintenance report shall be compiled.

5 Maintenance of battery arrays

5.1 General provisions

5.1.1 Before the maintenance of battery arrays, the primary circuit AC/DC circuit

breaker and isolating switch shall be disconnected, a grounding wire shall be installed

on the AC side of the power conversion system, and a safety warning sign shall be hung.

5.1.2 During battery maintenance, the positive and negative poles of battery cells,

battery modules, battery clusters, and stacks shall not be short-circuited or reversed.

5.1.3 After the maintenance of lithium ion batteries, lead-carbon batteries, flow batteries

and fuel cell arrays, the total voltage balance among battery clusters of the same battery

array should be adjusted. The total voltage range between lithium ion battery and lead-

carbon battery clusters shall not be greater than 2% of the average value; the total

voltage range between flow battery clusters shall not be greater than 4% of the average

value; the total voltage range between fuel cell clusters shall not be greater than 5% of

the rated value.

5.2 Maintenance of lithium ion battery arrays

5.2.1 Appearance inspection

5.2.1.1 Check the appearance of the battery module, including deformation, cracking,

leakage, corrosion and tightness of electrical connections.

5.2.1.2 Check the deformation, damage, corrosion of the battery bracket and the

tightness of connection of the grounding wire.

5.2.1.3 Check the air-cooling system of the battery array, including fan rotation and

abnormal noise.

5.2.1.4 Check the liquid cooling system of the battery array, including liquid cooling

system liquid level, temperature, circulating pump rotation, flow rate, abnormal noise,

liquid cooling system circulating pump, pipes, valves, flange connection circuit leakage,

damage, cracking and valve switch.

5.2.1.5 Check the connection tightness of power lines and communication lines of the

battery management system, as well as the working voltage of the battery management

system, and the display of the work indicating lamp.

5.2.3.5 Before replacing battery cells and modules, new battery cells and modules shall

be tested for voltage and insulation resistance, where the test results shall meet the

requirements of GB/T 36276.

5.2.3.6 When the voltage and temperature data of battery cells and modules is abnormal,

the battery cell or battery module shall be replaced.

5.2.3.7 If the charge and discharge energy of the lithium ion battery energy storage

system does not meet the requirements of GB/T 36558, and the battery voltage range

after offline equalization does not meet the requirements, the battery modules in the

same battery array shall be replaced by those of the same specifications and parameters.

5.2.3.8 The battery holder - which is deformed, damaged or corroded - shall be

replaced. The grounding wire shall be tightened or replaced in the case of loose

connection or damage.

5.2.3.9 If the insulation resistance of the fan of the battery array air-cooling system is

unqualified or the rotation is abnormal, the fan shall be repaired or replaced.

5.2.3.10 When the insulation resistance of the circulating pumps of the battery array

liquid cooling system is unqualified, the rotation is abnormal, and the temperature and

flow sensors are faulty, the circulating pumps and sensors shall be repaired or replaced

with the circulating pumps and sensors of the same specification.

5.2.3.11 In the case of leakage, damage or cracking of circulating pumps, pipelines,

valves and flanges of the battery array liquid cooling system, they shall be replaced

with circulating pumps, pipelines, valves and flanges of the same specification. When

the circulating pump and flange bolts are loose, they shall be tightened. When the

position of the valve switch is incorrect or jammed, it shall be adjusted.

5.2.3.12 When the battery voltage, temperature and current sensors of the battery

management system fail, the sensors shall be replaced.

5.2.3.13 When the voltage and temperature acquisition lines and communication lines

of the battery management system are loose or fall off, the wiring shall be restored;

when broken, they shall be replaced.

5.2.3.14 When the measured values of battery voltage, temperature and current of the

battery management system are abnormal, the battery management system and sensors

shall be repaired or replaced.

5.2.4 Post-repair test

5.2.4.1 After the battery management system is repaired or replaced, the measured

values of cell voltage, temperature and current of the battery management system shall

be checked, and the protection function simulation test and communication function

test shall be carried out.

5.2.4.2 After the cells of the battery array have been balanced offline and replaced, it is

advisable to carry out voltage range and temperature range tests of cells within the

battery cluster and voltage range tests between battery clusters.

5.2.4.3 After the cells of the battery array have been balanced off-line and replaced, it

is advisable to carry out the charge-discharge energy and efficiency tests of the lithium

ion battery energy storage system.

5.2.4.4 After the fan of the battery array air-cooling system and the circulating pump of

the liquid-cooling system are repaired or replaced, various performance tests shall be

carried out.

5.3 Maintenance of lead-carbon battery arrays

5.3.1 Appearance inspection

5.3.1.1 Check the appearance of the battery, including deformation, cracking, acid

leakage, liquid leakage, corrosion, safety valve action and electrical connection

tightness.

5.3.1.2 Check the battery electrolyte level.

5.3.1.3 Check the deformation, damage, corrosion of the battery bracket and the

tightness of connection of the grounding wire.

5.3.1.4 Check the air-cooling system of the battery array, including fan rotation and

abnormal noise.

5.3.1.5 Check the connection tightness of power lines and communication lines of the

battery management system, as well as the working voltage of the battery management

system, and the display of the work indicating lamp.

5.3.1.6 Check the human-machine interface of the battery management system,

including the display and refresh of data such as battery voltage, temperature, battery

cluster voltage, current and system time, as well as alarm information records.

5.3.2 Inspection test

5.3.2.1 Test the internal resistance of the cell, and verify the corresponding measured

values of the battery management system.

5.3.2.2 Verify the cell voltage sensor, temperature sensor and current sensor of the

battery management system.

5.3.2.3 Test the battery voltage, temperature and current, and verify the corresponding

measured values of the battery management system.

5.3.2.4 Test the voltage range and temperature range of cells in the battery cluster.

5.3.3.11 When the battery voltage, temperature and current sensors of the battery

management system fail, the sensors shall be replaced.

5.3.3.12 When the voltage and temperature acquisition lines and communication lines

of the battery management system are loose or fall off, the wiring shall be restored;

when broken, they shall be replaced.

5.3.3.13 When other abnormalities occur in the battery management system, the battery

management system shall be repaired or replaced.

5.3.4 Post-repair test

5.3.4.1 After the battery management system is repaired or replaced, the measured

values of battery voltage, temperature and current of the battery management system

shall be checked, and the protection function simulation test and communication

function test shall be carried out.

5.3.4.2 After the cells of the battery array have been balanced offline and replaced, it is

advisable to carry out voltage range and temperature range tests of cells within the

battery cluster and voltage range tests between battery clusters.

5.3.4.3 After the cells of the battery array have been balanced off-line and replaced, it

is advisable to carry out the charge-discharge energy and efficiency tests of the battery

energy storage system.

5.3.4.4 After the fan of the battery array air-cooling system is repaired or replaced,

various performance tests shall be carried out.

5.4 Maintenance of flow battery arrays

5.4.1 Appearance inspection

5.4.1.1 Check the deformation, damage, leakage, corrosion and compression bolts,

positive and negative connection tightness of the stack.

5.4.1.2 Check the deformation, cracking, leakage, inclination, liquid level indication,

etc. of the electrolyte storage tank.

5.4.1.3 Check the deformation, damage, corrosion of the battery holder and the

tightness of connection of the grounding wire.

5.4.1.4 Check the electrolyte circulating pump, including rotation, abnormal noise,

damage, leakage, etc., and the tightness of bolt connections.

5.4.1.5 Check the pipes, flanges, and valves, including deformation, damage, cracking,

leakage, bolt connection tightness, and valve switch conditions.

5.4.1.6 Check the connection tightness of sensors such as voltage, current, temperature,

pressure, flow rate and leakage.

5.4.1.7 Check the connection tightness of power lines and communication lines of the

battery management system, as well as the working voltage of the battery management

system, and the display of the work indicating lamp.

5.4.1.8 Check the human-machine interface of the battery management system,

including the display and refresh of data such as electrolyte temperature, stack voltage,

battery array current, pressure, flow rate, and system time, as well as alarm information

records.

5.4.2 Inspection test

5.4.2.1 Detect the concentration of electrolyte components, the valence state of active

substances, and the content of impurity elements.

5.4.2.2 Check the temperature, voltage, current, pressure and flow sensors of the battery

management system.

5.4.2.3 Detect the insulation resistance, charging and discharging power of the stack.

5.4.2.4 Detect the insulation resistance and flow rate of the electrolyte circulating pump.

5.4.2.5 Detect the pipeline pressure resistance of the electrolyte circulation system of

the flow battery.

5.4.2.6 Detect the electrolyte temperature, stack voltage and battery array current,

pressure and flow of the battery management system, and verify the corresponding

measured values of the battery management system.

5.4.2.7 Carry out the charge-discharge energy and efficiency test of the flow battery

energy storage system, and carry out the calibration of the charge-discharge energy of

the energy storage system.

5.4.3 Repair

5.4.3.1 Before repairing, the electrolyte in the repairing part shall be drained.

5.4.3.2 The compression bolts shall be tightened when the stack is not compressed, and

shall be fastened when the positive and negative connections are loose.

5.4.3.3 If the stack is deformed, damaged, leaking, corroded, etc., the insulation

resistance is less than 1 Mohm, and the rated energy efficiency of the stack is lower than

75%, it shall be repaired or replaced with a stack of the same specifications and

parameters. The new stack shall be tested for insulation resistance, stack voltage range,

stack efficiency, and electrolyte circuit withstand voltage.

5.5.1 Appearance inspection

5.5.1.1 Check the deformation, damage, leakage, corrosion, displacement of the

electrode plate, color of the battery tab, tightness of the compression bolt, and

connection of the positive and negative electrodes of the electrolytic cell.

5.5.1.2 Check the deformation, damage, leakage of the stack and the tightness of the

positive and negative wiring connections.

5.5.1.3 Check the appearance of the circulating pump, hydrogen compressor, air

compressor, and water pump, including deformation, damage, abnormal rotation noise,

etc., as well as the tightness of bolt connections and the turbidity and odor of the oil

medium.

5.5.1.4 Check the appearance and connection tightness of sensors such as voltage,

current, temperature, pressure, liquid level, flow, and hydrogen monitoring.

5.5.1.5 Check the appearance of pipes, flanges, valves and connectors, including

deformation, damage, cracking, corrosion, leakage, etc., as well as the tightness of bolt

connections and the status of valve switches.

5.5.1.6 Check the appearance of the electrolyzer and stack support frame, including

deformation, damage, corrosion and the tightness of the connection of the grounding

wire.

5.5.1.7 Check the tightness of the power line and communication line of the fuel cell

array automatic control device, the working voltage of the fuel cell array automatic

control device, and the display of the working indicator light.

5.5.1.8 Check the human-machine interface of the fuel cell array automatic control

device, including the display and refresh of data such as pressure, temperature, voltage,

current, flow and system time, and alarm information records.

5.5.2 Inspection test

5.5.2.1 Detect the grounding resistance of hydrogen pipelines and containers.

5.5.2.2 Carry out the airtightness test of the hydrogen production system, hydrogen

storage system, fuel cell system and piping.

5.5.2.3 Check the sensors such as voltage, current, temperature, pressure, flow,

hydrogen/oxygen content, moisture content, conductivity, etc., as well as thermometers,

pressure gauges, and safety valves.

5.5.2.4 Carry out pneumatic and electric valve transmission tests.

5.5.2.5 Carry out the inspection of pressure vessels of hydrogen production system and

hydrogen storage system.

5.5.2.6 Detect the outlet water quality of external water supply and pure water system.

5.5.2.7 Detect the cooling water quality of the cooling system.

5.5.2.8 Detect the composition of the electrolyte in the alkaline water electrolyzer.

5.5.2.9 Detect the output voltage, power and capacity of the starting power supply.

5.5.2.10 Carry out the protection function tests of the fuel cell array control system

voltage, current, temperature, pressure, liquid level, etc.

5.5.2.11 Carry out control function tests such as start-up and emergency shutdown of

the fuel cell array control system and communication function test.

5.5.2.12 Carry out the start/shutdown test of the hydrogen production system, and test

the purity of hydrogen and oxygen.

5.5.2.13 Carry out the hydrogen discharge capacity test of the hydrogen storage system.

5.5.2.14 Carry out start/shutdown test and efficiency test of the fuel cell system.

5.5.3 Repair

5.5.3.1 Before repairing, the shut-off valve connected to the repaired part shall be

switched off, and the repaired part shall be replaced with nitrogen no less than 3 times.

The repair operation shall meet the safety requirements of GB 4962.

5.5.3.2 When the electrolyzer, electric stack pressing bolts, and positive and negative

wires are loose, they shall be tightened. If the electrolyzer and electric stack are

deformed, damaged, leaked, corroded, plate shifted, the color of the tab is abnormal, or

the air tightness test fails, they shall be repaired or replaced.

5.5.3.3 When the rated power and efficiency of the fuel cell stack do not meet the

requirements, the stack shall be replaced.

5.5.3.4 When the purity of the hydrogen/oxygen at the outlet of the electrolyzer is

unqualified, the electrolyte or the electrolyzer shall be replaced. When the hydrogen

purity at the outlet of the hydrogen purification system does not meet the design

requirements, the purification system shall be repaired or replaced.

5.5.3.5 When the hydrogen discharge capacity of the hydrogen storage system is lower

than 80% of the design capacity, the hydrogen storage alloy container shall be activated.

When the hydrogen discharge capacity after activation is still lower than 90% of the

design capacity, it shall be repaired or replaced.

5.5.3.6 When the electrolyte of the alkaline water electrolyzer does not meet the

requirements of GB/T 37562, the electrolyte shall be replaced.

5.5.4 Post-repair test

5.5.4.1 The hydrogen pipelines and containers, repaired or replaced electrolyzers and

stacks shall be tested for air tightness, and the pipelines and containers shall be replaced

with hydrogen after the test.

5.5.4.2 The electric and pneumatic valves after repair or replacement shall be tested for

transmission.

5.5.4.3 After the fuel cell array control system is repaired, the protection function test,

emergency shutdown function test and communication function test shall be carried out.

5.5.4.4 The hydrogen discharge capacity test shall be carried out after the hydrogen

storage container of the hydrogen storage system is repaired or replaced.

5.5.4.5 After the water electrolysis hydrogen production system is repaired, the

start/shutdown test shall be carried out; after the electrolyzer is replaced, the hydrogen

production energy efficiency test shall be carried out according to the test method

specified in GB 32311.

5.5.4.6 After the hydrogen storage system or fuel cell system is repaired, the

start/shutdown test and efficiency test of the fuel cell system shall be carried out.

6 Maintenance of power conversion system

6.1 General provisions

6.1.1 Before the power conversion system is overhauled, the AC and DC side switches

shall be disconnected, and the port residual voltage shall be measured. When the DC

port voltage is less than 50 V and the AC port voltage is less than 36 V, the case (door)

can be opened for maintenance operation.

6.1.2 During the maintenance of the power conversion system, anti-static measures

shall be taken, and energy storage components such as reactors and capacitors shall be

fully discharged.

6.1.3 After the overall replacement of the power conversion system or the replacement

of important components such as controllers, power modules, capacitors, reactors, and

isolation transformers, corresponding functional and performance tests shall be carried

out.

6.2 Appearance inspection

6.2.1 Check the appearance of the power conversion system, including deformation,

corrosion, damage and the fastening of the ground wire connection.

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