Panoramic view of integrated photovoltaic power station energy storage side equipment topology and inspection SOP training
Full-cycle inspection and maintenance plan matrix for the energy storage side of photovoltaic power stations (day/week/month/quarter/year)
This article stipulates the time nodes, technical requirements and division of responsibilities for daily inspections, regular maintenance, quarterly inspections and annual overhauls of all energy storage power station equipment throughout the life cycle.
1. Daily inspection plan (daily inspection: online SCADA monitoring + on-site inspection)
Daily inspections are divided into "online 7×24h real-time monitoring" and "on-site routine inspections", with the core being the timely discovery of abnormal alarms and environmental hazards.
(1) Daily online SCADA/EMS monitoring (completed before 09:00)
Charge and discharge efficiency and energy calculation: retrieve the RTE (charge and discharge efficiency) of the entire station on the previous day, and the entire liquid-cooled station must be ≥ 85%.
Extreme value data and pressure difference/temperature difference troubleshooting:
Cell extreme voltage and voltage difference: the static voltage difference must be < 20 mV, and the voltage difference at the end of charge and discharge must be < 50 mV.
Single unit extreme temperature and temperature difference: the maximum operating temperature must be < 40.0 ℃, and the extreme temperature difference within the cluster must be ≤ 3.0 ℃.
Insulation resistance trace: Check the insulation monitor data. The DC-to-ground insulation resistance must be ≥ 1000 Ω/V.
Alarm log review: Search the SCADA system alarm logs for the past 24 hours to confirm that there are no primary or secondary unreset alarms.
(2) Daily on-site inspection (completed before 14:00)
Station environment and perimeter: The perimeter fence is not damaged and the electronic fence is normal; the flood control drainage channel is smooth and the water retaining board (≥ 500 mm) is in place; the explosion-proof pressure relief valve outside the cabin is intact and unobstructed.
Station power and fire protection main screen: The station AC power distribution cabinet has no abnormal tripping; the station DC panel/UPS is running normally; the fire control main screen (FACP) operating light is always on, and there is no fire alarm/fault alarm.
High-voltage switch and box transformer: The SF6 pressure gauge of the 35kV switch cabinet is in the green zone (0.35 ~ 0.45 MPa); the vacuum circuit breaker shows "energy stored"; the oil level of the booster box transformer is at the 25°C scale line, and the moisture absorber silica gel is dark blue.
PCS variable flow chamber and temperature control: The PCS fan runs smoothly without abnormal noise; the liquid cooling unit circulating water pump pressure is between 0.15 ~ 0.30 MPa, and the expansion tank liquid level is at 1/2 ~ 2/3, with no leakage.
2. Weekly inspection plan (weekly inspection: on-site in-depth inspection and functional self-inspection)
Weekly inspections focus on in-depth functional testing of auxiliary systems, safety protection devices and electrical connection points.
Explosion-proof exhaust and gas probe test: Press the "forced exhaust button" outside the cabin on site to test the explosion-proof exhaust fan forced start time (must be < 2s) and wind speed (must be ≥ 8 m/s). Spot check the CO/H2/VOC probe communication is normal.
Battery pack float voltage measurement: Use a digital multimeter to measure the DC screen lead-acid/gel battery cell float voltage. The qualified range is 13.50 V ~ 13.80 V.
Infrared thermal imaging temperature rise scanning: Use an infrared thermal imaging camera to scan when the power station is charging and discharging at 0.5C full power:
35kV cable terminals and high-voltage switch cabinet busbars (maximum temperature must be < 70 ℃, temperature difference ΔT ≤ 5 ℃); PCS incoming and outgoing circuit breaker terminals (maximum temperature must be < 65 ℃); battery cluster high-voltage box (BDU) terminals and main connecting copper bars (maximum temperature must be < 60 ℃, temperature difference ΔT ≤ 5 ℃).
Inspection of water marks and filter screen in liquid cooling pipes: Check the self-sealing liquid cooling quick-change joint inside the Pack. Use a water mark test paper close to the joint gap to confirm that there is no trace leakage; check the pressure difference between the inlet and outlet of the Y-type filter.
3. Monthly inspection and maintenance plan (monthly maintenance: cleaning, water quality analysis and strategic alignment)
Monthly maintenance focuses on physical cleaning of equipment, chemical analysis of coolant water quality, and calibration of control strategies.
(1) Monthly equipment cleaning and physical maintenance
Disassembly and cleaning of PCS and air-conditioning dust filter: Remove the PCS air inlet and air-cooled air-conditioning primary filter cotton, clean and dry them completely and then reinstall them.
Hatch door sealing and anti-condensation: Check the EPDM strip of the door and add anti-rust grease; test the automatic start-up function of the anti-condensation heater when the humidity is > 70% RH.
(2) Coolant water quality chemical analysis and filter cleaning SOP
Water quality index testing: sampling and measuring coolant:
Conductivity: must be < 5.0 μS/cm (when the conductivity is ≥ 10.0 μS/cm, the resin filter element must be replaced or the fluid must be changed);
pH value: must be maintained between 7.0 ~ 8.5; freezing point: must be ≤ -35.0 ℃.
Y-type filter cleaning: stop the water pump to release the pressure, remove the 100-mesh stainless steel filter of the Y-type filter, clean the scale and impurities, replace the fluororubber sealing ring and put it back, refill and exhaust to the water pressure of 0.18 ~ 0.22 MPa.
(3) Strategy alignment and passive balancing resistance check
Alignment of peak and valley arbitrage strategies: Check the EMS internal charge and discharge clock to be 100% aligned with the latest peak and valley electricity price period of the local power grid.
Passive equalization resistor infrared temperature measurement: When passive equalization is started, use an infrared thermal imager to scan the BMU board discharge resistor. The heating temperature must be < 60.0 ℃, and there should be no burnt open circuit.
4. Quarterly inspection and maintenance plan (quarterly inspection: mechanical fastening, actual protection measurement and capacity depth balancing)
Quarterly maintenance focuses on bolt tightening torque verification, safety protection function logic testing and battery depth equalization.
Random test of high-voltage bolt tightening torque (executed during power outage): Use a calibrated insulated torque wrench to randomly test the bolt tightening torque at a ratio of 20%: M6 pole bolts: 6.0 ~ 8.0 N·m; M8 copper bar bolts: 18.0 ~ 20.0 N·m; M10 BDU terminals: 38.0 ~ 42.0 N·m; M12 PCS busbar: 80.0 ~ 85.0 N·m; re-mark the anti-loosening marking line after random testing.
Actual measured SOP for anti-islanding protection: In the PCS grid-connected discharge (50% power) state, manually disconnect the grid-side analog circuit breaker. The oscilloscope measured the PCS to cut off the AC current output within < 200 ms and report a grid-side power loss alarm.
Fire-extinguishing cylinder weighing and drive valve self-inspection: weigh and recheck the heptafluoropropane fire-extinguishing cylinder, the mass reduction must be ≤ 5% of the nominal net weight; check the pressure of the nitrogen-driven small cylinder (6.0 ± 0.2 MPa); check that the mechanical safety pin of the electromagnetic drive valve is in the pulled out/unlocked state.
Artificial offline power supply and depth equalization: When the extreme voltage difference of a certain cluster of cells is > 100 mV and automatic equalization fails, use a portable power supply instrument to perform 20A limited power supply on the low-voltage Pack. After power supply, the extreme voltage difference must be < 15 mV after leaving it alone for 1 hour.
5. Annual overhaul and preventive test plan (annual maintenance: station-wide power outage maintenance and drill)
The annual overhaul is the highest-level comprehensive overhaul of the entire power station. It is usually arranged to carry out power outage overhaul during the power grid maintenance window period.
Waterless dry purge in the cabin: Use 0.20 ~ 0.30 MPa dry waterless compressed air (equipped with insulated nozzle hose) to purge the dust accumulated on the PCS, high-voltage cabinet and BMS control board in a "top-down" order.
Test the different-frequency resistance of the station's main grounding network: Use a different-frequency grounding resistance tester to measure. The power-frequency resistance of the entire station's main grounding network must be < 0.5 Ω. Check the corrosion of underground flat steel (corrosion rate > 30% requires repair welding).
AC/DC high voltage preventive test:
High voltage switch cabinet and cable withstand voltage test;
Box-type transformer oil dissolved gas analysis (DGA) and winding insulation testing;
Lightning arrester (SPD) continuous leakage current test (must be < 1.0 mA).
Protection setting sheet 100% aligned: Export the setting value of the microcomputer protection device and check it word for word with the latest setting notice from the power grid dispatching department. The error must be 0.0%.
Accurate time synchronization and network packet loss rate of the whole station: GPS/Beidou dual-mode time synchronization, the clock error of the whole station equipment must be ≤ 1.0 ms; the packet loss rate of the whole station LAN in the 24-hour Ping test must be < 0.01%.
Full-station RTE efficiency calibration and capacity degradation assessment: Carry out 100% DoD full-capacity charge and discharge, calculate the whole-station RTE efficiency and battery SOH health (SOH < 70%, apply for decommissioning).
Thermal runaway level three fire emergency drill: Cooperate with the local fire department to conduct a full-process practical drill including thermal runaway warning, gas extinguishing release, strong exhaust air cutoff and water spray cooling.
CoreTect photovoltaic power station energy storage side operation and maintenance engineering department operation and maintenance plan execution table