High voltage energy storage battery system includes key systems such as battery system body, battery management system, energy storage inverter and monitoring system. Because the high-voltage system has far exceeded the safe voltage range of the human body, our high-voltage battery products follow strict safety technical requirements in system production, commissioning and operation and maintenance operations, which are shared as follows.

 

1. General regulations

1.1 Entering the operation site and test site of high-voltage energy storage battery system, labor protective equipment should be properly worn, all tools must be insulated and wrapped, and non-sparking tools should be used during operation.

1.2 When entering the high-voltage energy storage battery system to carry out testing work, the person in charge of the test should be clearly defined. Before the test starts, the person in charge of the test should give a test (safety technology) briefing to all the testers to clarify the work tasks, danger points and danger sources.

1.3 Testers should check the name, model and location of each product under test before testing, and should master the safety risk points in and around the equipment under test.

1.4 test power supply voltage, frequency, capacity should be able to meet the requirements of the test equipment, the test power switch protection parameters should be correctly adjusted.

1.5 The test site lighting, test power supply, test device should be available and ready for use, the site fire-fighting facilities should be complete or have effective temporary fire-fighting facilities, and the various technical documents and design drawings required for testing (including at least software threshold table, electrical schematic diagram, BMS upper computer, SOP, test procedure table or test ticket, etc.) are complete.

1.6 The testing process should strictly prevent personal and equipment risks, do a good job of personal and equipment protection, and work on high-voltage distribution lines and equipment should be done to prevent backfeeding measures.

 

2. Analysis and testing of high-voltage energy storage battery system. 

2.1 performance aspects: energy storage system capacity decay and charge/discharge cycle efficiency, power quality, battery charge state calibration, etc.

2.2 Protection function: battery management system and energy storage inverter relay protection operation, protection function reliability test, protection value reasonableness analysis, etc.

2.3 Safety: analysis of the temperature difference and maximum temperature difference between the battery modules in the battery compartment, analysis of the pressure difference between the battery cells in the battery cluster, analysis of the trend of the insulation resistance of the positive and negative terminals of the battery cluster to ground, fault analysis, etc.

2.4 Fire protection: combustible gas concentration, fire alarm signal, automatic fire extinguishing system operation, etc.

 

3. Battery and battery management system

3.1 The battery itself is charged and has a high voltage, it should be treated as a power source, and do a good job to prevent electrocution and prevent the battery from backfeeding to the power outage equipment.

3.2 After the energy storage battery is overhauled or replaced, the open circuit voltage of the battery should be measured before installation, so that the voltage of the battery module and the battery unit in the same battery cluster is consistent, and the new battery module should be tested for battery capacity, so that the capacity of the battery module in the same battery cluster is also consistent, and records should be kept.

3.3 After the battery management system is overhauled or replaced, it should be confirmed that the modules at all levels are correctly connected and displayed normally.

3.4 Lithium-ion batteries should be sampled for safety testing when first installed or replaced in large quantities, and the safety test should be conducted in a specific explosion-proof space, with good isolation and explosion-proof surrounding and personnel protection measures, and should be conducted in a qualified third-party laboratory.

3.5 battery test operation, it is prohibited not to wear insulation protection while touching the positive and negative battery poles, knocking, vibrating the battery, prohibit the placement of tools on the battery and its structure, etc., the whole process of testing should open the battery protection function, monitor each (string) battery voltage, do a good job to prevent the battery short circuit, overcharge, over discharge, over temperature, reverse connection measures, disassembly, moving the battery should do a good job of anti-vibration, anti-drop, anti Collision, short-circuit prevention measures, battery management system and energy storage inverter main board test should do a good job of anti-static measures.

 

4. High voltage system testing

4.1 High-voltage energy storage battery system testing must be reliably grounded.

4.2 High-voltage test equipment and test product discharge should use grounding rods, insulation length according to the requirements of safe operation to choose. When using the grounding rod, the hand shall not exceed the grip part of the guard ring. The distance between the grounding wire and the human body should be greater than the effective insulation length of the grounding rod. Before the high-voltage test, the discharge after the test, the grounding rod should be first grounding wire reliably connected to the grounding stake (with), and then use the grounding rod to contact the high-voltage test equipment and test products of the high-voltage end of the grounding discharge. After discharging the grounding rod hanging in the high-voltage end, keep the grounding state, and remove it before testing again. From the time when the grounding rod touches the high-voltage test equipment and the high-voltage end of the test article to the time when the tester can contact it, the discharge time should not be shorter than 3 min. The discharge time for large-capacity test products should be greater than 5 min.

4.3 High-voltage testing safety distance should meet the following requirements.

(a) high-voltage equipment work, regardless of whether the high-voltage equipment charged, testers should not move away from or over the fence alone to work; if there is a need to move away from the fence, there should be a guardian present, and in line with the schedule safety distance.

(b) direct contact with the equipment of electrical measurements, should be supervised. Measurement, the human body and high-voltage live parts shall not be less than the safe distance.

(c) staff in the normal work of the live conductor safety distance is less than 0.7 meters, the live part should be de-energized.

4.4 Before the charged test, the grounding network detection test is completed, and each cabin is connected to the grounding network intact. For all charged test areas, they must be clearly defined in the work ticket, and the isolation points must be clearly indicated.

4.5 Before the system test or the whole station test, the state of the protection parameters of the energy storage inverter, battery management system, switch, transformer and other equipment should be confirmed to be normal. During the test, the protection function of battery management system and energy storage inverter shall be turned on, and the operation status of test equipment, equipment under test and fire protection facilities shall be monitored.

4.6 The high-voltage test should use the standard short route, the high-voltage leads should be shortened as much as possible, and a special high-voltage test line should be used, supported firmly with insulators if necessary. Before adding voltage should check the test wiring, confirm that the meter multiplier, range, regulator zero and the initial state of the meter are correct, notify all personnel to leave the tested equipment (area), and obtain permission from the person in charge of the test before adding voltage. Pressurization process operators should stand on the insulating mat, should be supervised and call out, the test personnel should always be alert to abnormalities occur.

4.7 During the charged test, all personnel should stay in a zone that can prevent abnormal high-voltage discharge from endangering personal safety, such as the control room, observation room or outside the shielding shelter. Before cutting off the test power, no personnel should enter the test danger zone. In the battery room / cabin test should be to prevent personal injury due to battery explosion protection measures.

4.8 After the test is completed, the test power should be disconnected, the test equipment and test products for full discharge, installed after the ground wire, before disassembling the test wiring, remove the self-installed ground wire and short cable.

4.9 When resuming the test, the test wiring and safety measures should be re-checked.

4.10 After the test wiring removal is completed, the wiring before the test should be restored, check the equipment under test, the protection parameters back to the state before the test, and clean up the debris left at the scene.

 

5. Other equipment testing

5.1 Before power distribution cabinet and high-voltage box are serviced, confirm that no tools are left in the cabinet and high-voltage box, and close the cabinet door of the cabinet and high-voltage box in time, measure/verify whether the insulation of DC input and output side is normal and whether the polarity is correct. Before connecting the cables of the battery cluster sink in the battery sink box, confirm that the battery string and the DC side switch of the energy storage inverter are disconnected, and confirm that the positive and negative polarities of the cables are correct after connection.

5.2 Before the cable withstand voltage test, the pressurized end should be well secured to prevent personnel from entering the test site by mistake. The other end should have a railing and a warning sign.

 

6. Abnormal and accident handling

6.1 During the test, the whole process should be monitored. Whenever abnormalities are encountered, such as grounding of DC system, tripping of circuit breaker (switch), protection alarm, etc., regardless of whether they are related to the work, the testers should stop the test immediately under the premise of ensuring safety, maintaining the status quo, identifying the causes, isolating the fault site, and disposing of them according to the regulations.

6.2 During the test, if abnormal conditions such as smoke, discharge, rapid increase in current, sudden temperature rise, fire alarm or emergency situation that may cause a fire in the energy storage system are found in the battery room/compartment, the test should be stopped immediately, evacuate the operation site to a safe area, and report immediately, EMS staff on duty should first check the battery temperature, combustible gas concentration, smoke, flame, etc. through remote monitoring. The EMS duty personnel should first check the battery temperature, combustible gas concentration, smoke, flame and other information through remote monitoring, quickly determine the degree of urgency and danger of the accident, and dispose of it according to the corresponding emergency plan, and confirm that the battery temperature and combustible gas concentration have been reduced to a safe range before opening the battery room/compartment for inspection, if not, the battery compartment door should be opened only after 24h after the open fire has disappeared.

6.3 If a fire accident occurs during the test, the fire emergency plan should be started immediately, report to the higher management and report the fire alarm, the operator should immediately stop the operation of the equipment on fire and the threatened adjacent equipment, if there is an emergency that directly endangers personal safety, evacuate immediately to ensure personal safety, the battery room / cabin before and after fire extinguishing before opening the door should be strong exhaust to confirm that the concentration of combustible gas has been reduced to a safe range to prevent Explosion, after the completion of fire extinguishing measures should be done to prevent re-ignition.

6.4 In case of sudden power failure during the live test, the testers should treat the equipment as if it is still live and should not send power until the EMS regulator on duty has contacted the person in charge of the work.

6.5 Battery and Battery Management System

6.5.1 When a fire alarm occurs in the battery room/compartment, the monitoring personnel shall, based on the monitoring information such as battery temperature, combustible gas concentration, smoke and flame, quickly and remotely determine the degree of emergency and danger of the accident and start the corresponding fire emergency plan.

6.5.2 The total DC circuit breaker of the battery module should not be pulled open directly in the running state of the energy storage converter.

6.5.3 The cluster circuit breaker of the corresponding module shall be disconnected before the battery modules are connected in series and parallel.

6.5.4 Before charging and discharging the battery, make sure that the battery is protected by overvoltage, undervoltage, short circuit, high temperature and low temperature.

 

6.6 The energy storage battery shall be operated out of the energy storage system, disconnected from the electrical connection in the system and reported for overhaul treatment when the following conditions occur

 (a) battery single under-voltage, over-voltage, should be operated out of the energy storage system, cut off the system within the electric battery management system protection action.

 (b ) battery shell breakage, pressure relief valve rupture, electrolyte leakage.