Integrated panoramic topology diagram of PV side of photovoltaic power station
Photovoltaic power station PV side topology module
"Photovoltaic power station PV side system equipment level operation and maintenance manual" complete chapter outline
1. Part 0: Project Acceptance and Early Handover Specifications (Basic General Outline)
(1) Cold static acceptance: component open-circuit voltage (Voc) and short-circuit current (Isc) spot test, square array insulation resistance test (≥ 2 MΩ), high-voltage cable and box transformer withstand voltage test, bolt tightening torque review (M6~M16), lightning protection grounding grid impedance (< 4 Ω).
(2) Hot charging acceptance and trial operation: power-on logic sequence, SCADA/inverter P2P sampling verification, 72-hour continuous trial operation assessment (PR performance ratio ≥ 82%).
(3) Delivery documents and spare parts handover: IV curve factory report, infrared hot spot detection report, module/inverter spare parts inventory.
2. Part 1: Photovoltaic modules and array system equipment-level inspection and operation and maintenance SOP (corresponding to topology module 1)
(1) Physical appearance and structural inspection of photovoltaic modules: Inspection of tempered glass bursts, backplane scratches/yellowing/degumming, aluminum alloy frame deformation, and EVA film bubbles.
(2) Component hot spots (Hotspots) and junction box diodes: Infrared thermal imaging camera scans hot spots (temperature difference ΔT ≥ 20 ℃ or local temperature > 80 ℃ must be replaced within 48 hours), junction box bypass diode breakdown and short circuit test.
(3) Crack test (EL) and PID effect prevention: portable EL crack detector operation, PID effect (potential induced decay) diagnosis and Anti-PID nighttime reverse pressure repair SOP (500 ~ 1000V DC).
(4) Component specification cleaning SOP: cleaning period control (cleaning during high temperature periods at noon is strictly prohibited and must be done before sunrise/evening), water quality requirements (pH 6.0~8.0, hardness < 100 mg/L), and water pressure control (< 0.4 MPa).
3. Part 2: Equipment-level inspection and operation and maintenance SOP for photovoltaic brackets and tracking transmission systems (corresponding to topology module 2)
(1) Maintenance of fixed brackets: inspection of anti-corrosion layer of hot-dip galvanized/aluminum alloy brackets, tightening torque of anchor bolts and diagonal brace bolts (M10/M12), settlement and pull-out force test of bracket foundation (cast-in-place piles/bolt piles).
(2) Tracking bracket transmission mechanism (flat single shaft/double shaft): replenishing and replacing the lubricating oil of the reduction gearbox, testing the current of the drive motor, and troubleshooting the jamming of the rotating bearing and coupling.
(3) Tracking electronic control system and strong wind/snow Stow protection: Tracking angle deviation calibration (error < 1.5°), anemometer/snow load sensor linkage strong wind tiling (Stow) protection mode actual measurement (response time < 30 s).
4. Part 3: Photovoltaic inverter (string/centralized) system equipment-level inspection and operation and maintenance SOP (corresponding to topology module three)
(1) Inverter cabin/cabinet dustproof and AC/DC channels: cabin door sealing, air inlet dust screen cleaning/replacement, waterless dry purge SOP (0.20 ~ 0.30 MPa), AC/DC circuit breaker and terminal infrared temperature measurement (< 65 ℃).
(2) IGBT power module and filter circuit: IGBT junction temperature monitoring (full load < 85 ℃), thermal grease overcoating SOP (performed every 3 years, thickness 50~100 μm), DC bus support capacitance/ESR test, filter inductor insulation (≥ 100 MΩ) and noise (< 75 dB).
(3) Sampling, phase locking and adaptive protection: sampling accuracy verification (error ≤ ± 0.5%), anti-islanding protection (Anti-Islanding) measured SOP (≤ 2.0 s cut-off), low/high voltage ride-through (LVRT/HVRT) logic, cooling fan array maintenance.
5. Part 4: Convergence and low-voltage distribution system equipment-level inspection and operation and maintenance SOP (corresponding to topology module four)
(1) AC/DC combiner box cabinet and sampling: The combiner box cabinet is sealed and moisture-proof, Hall string current sampling module (extreme value deviation < 5%), string open circuit voltage (Voc) and operating current (Isc) are tested.
(2) Fuse and Surge Protector (SPD): aR-class fast fuse striker/damage inspection, contact resistance test (≤ 0.1 mΩ); SPD window color (green for normal, red for failure).
(3) MC4 terminals and DC cables are protected against arcing: check for blackening/melting of the MC4 interface (infrared temperature rise < 15°C), and lay the DC cable along the bracket to prevent wear and arcing.
6. Part 5: High-voltage power transformation, distribution and booster station system equipment-level inspection and operation and maintenance SOP (corresponding to topology module 5)
(1) 35kV/10kV high-voltage switch cabinet: SF6 gas pressure (0.35 ~ 0.45 MPa), vacuum circuit breaker spring energy storage, mechanical five-proof locking.
(2) On-site box-type transformer (box-type transformer): oil-immersed box-type transformer oil level gauge/oil color (DGA chromatographic analysis), respirator color-changing silica gel (dark blue); dry-type box-type transformer winding temperature and fan start and stop (100 ℃ start, 130 ℃ alarm, 150 ℃ trip).
(3) High-voltage cable heads and arresters: Infrared temperature measurement of high-voltage cable terminal heads (full load < 70 ℃), partial discharge (PD) ultrasonic testing (< 20 pC), zinc oxide arrester leakage current (< 1.0 mA).
(4) Station main grounding grid: power frequency grounding resistance test (< 4 Ω or < 1 Ω), corrosion inspection and repair welding of grounding flat steel.
7. Part 6: Station environment and station auxiliary system equipment level inspection and operation and maintenance SOP (corresponding to topology module 6)
(1) Station area perimeter and flood control: security infrared radiation, flood control drainage ditch, flood control water retaining board (≥ 500 mm), vegetation cover and clearing.
(2) Station AC power distribution panel and ATS: station variable winding temperature, AC 380V power distribution cabinet bolt tightening and temperature measurement, ATS dual power automatic switching test (< 100 ms).
(3) Station DC panel and UPS: battery cell float voltage (13.50 V ~ 13.80 V), internal resistance test, UPS inverter status check.
(4) Station-level fire control main screen: Fire control main screen (FACP) self-test, smoke/temperature sensor probe test.
8. Part 7: Meteorological Monitoring and Intelligent Environment System Equipment Level Inspection and Operation and Maintenance SOP (corresponding to Topology Module 7)
(1) Total radiation and scattered irradiance meter: cleaning of the pyranometer glass cover, level bubble calibration, desiccant discoloration inspection, and irradiance sampling error calibration (≤ ± 2%).
(2) Ambient temperature and humidity meter and component board temperature sensor: calibration of the shutter ambient temperature and humidity meter, inspection of the attachment status of the patch type component board temperature sensor and temperature measurement accuracy calibration (error ≤ ± 1.0 ℃).
(3) Wind speed and direction meter and sunshine meter: ultrasonic/mechanical wind speed and direction meter rotation sensitivity test, sunshine meter photoelectric sensor cleaning.
9. Part 8: Secondary System and Power Prediction Scheduling SOP (corresponding to Topology Module 8)
(1) Photovoltaic SCADA monitoring background and database: SCADA main/standby server dual-machine hot backup switching (< 1.0 s), time series database disk space and historical curve retrieval.
(2) Photovoltaic power prediction system (short-term/ultra-short-term): Numerical Weather Prediction (NWP) data reception, power prediction model calibration, short-term (072h) and ultra-short-term (04h) prediction accuracy calculation (must be ≥ 85%).
(3) AGC/AVC power control and grid dispatch: AGC automatic power generation control active power derating/power limiting response (response < 1.0 s), AVC reactive power voltage regulation, inverter PR energy efficiency ratio calculation.
(4) Comprehensive troubleshooting SOPs for typical faults: SOPs for segmented positioning of strings with too low insulation resistance (Riso Low) in the entire station, SOPs for overvoltage/undervoltage/overfrequency trip recovery on the grid side of the inverter, and SOPs for zero-current/low-current cascade troubleshooting of photovoltaic array strings.
10. Part 9: Full-cycle inspection and maintenance plan matrix (day/week/month/quarter/year)
(1) Day/week/month/quarter/year five-level inspection and maintenance nodes and technical requirements.
(2) Closed-loop management of full-cycle operation and maintenance of the entire power station.
Full-cycle inspection and maintenance plan matrix for PV side of photovoltaic power station (day/week/month/quarter/year)
This part stipulates the time nodes and operating specifications for daily routine inspections, weekly inspections, monthly maintenance, quarterly inspections and annual overhaul (preventive testing) of all photovoltaic power station equipment throughout the life cycle.
1. Daily inspection plan (daily inspection: SCADA 7×24h online monitoring + on-site inspection)
(1) Daily online SCADA monitoring (completed before 09:00)
Energy efficiency ratio (PR) and power accounting: retrieve the PR (energy efficiency ratio, standard PR ≥ 82%) and power generation capacity of the entire station on the previous day, and analyze the matching between lighting and power generation.
String current dispersion rate monitoring: Comparing the operating current of each string under the same combiner box or inverter, the extreme value dispersion rate must be < 5%. If the current of a certain string is 0 A, immediately issue a work order for troubleshooting.
Meteorological data verification: Check that the weather station irradiance data (W/m²) and plate temperature data are collected normally.
Alarm log retrieval: Search SCADA alarm logs for the past 24 hours to confirm that there are no unreset low insulation or grid-side trip alarms.
(2) Daily on-site inspection (completed before 14:00)
Station area environment and flood control: The security fence is not damaged; the flood control drainage channel is smooth, and the water retaining board (≥ 500 mm) is in place.
Station power and fire main screen: The station transformer makes no abnormal noise; the station DC panel/UPS operates normally; the fire main screen (FACP) operating light is always on.
High-voltage switch and box transformer: The SF6 air pressure of the 35kV switch cabinet is in the green zone (0.35 ~ 0.45 MPa); the oil level of the box transformer is at the 25°C scale, and the respirator silica gel is dark blue.
Inverter and combiner box: The inverter fan runs smoothly and makes no abnormal noise; the combiner box indicator light is normal and the cabinet door is locked tightly.
2. Weekly inspection plan (weekly inspection: on-site in-depth inspection and thermal imaging temperature measurement)
Full-load infrared thermal imaging temperature measurement: Use an infrared thermal imaging camera to scan when there is sufficient sunlight (irradiance ≥ 700 W/m²) and the power station is running at full power:
35kV cable terminal and switch cabinet busbar (maximum temperature must be < 70 ℃, phase-to-phase temperature difference ΔT ≤ 5 ℃);
Inverter AC/DC side circuit breaker and wiring terminals (maximum temperature must be < 65 ℃);
Fuses and DC circuit breaker terminals inside the combiner box (maximum temperature must be < 60°C).
Tracking bracket rotation and Stow protection check: Spot check the flat single-axis/double-axis tracking bracket, the tracking angle error must be < 1.5°; test the strong wind sensor (>17.2 m/s) linkage to the strong wind tiling Stow protection response.
Measurement of DC screen battery float charge voltage: Use a digital multimeter to measure the DC screen lead-acid/gel battery cell float charge voltage. The qualified range is 13.50 V ~ 13.80 V.
3. Monthly inspection and maintenance plan (monthly maintenance: cleaning, water quality analysis and vegetation clearing)
(1) Component dust assessment and standardized cleaning
Dust shielding evaluation: Compare the power generation of components in the clean test area and the contaminated area. When dust obstruction causes power generation loss ≥ 3%, start the cleaning plan.
Standard cleaning execution: avoid high temperature periods at noon (must be carried out before sunrise or in the evening), cleaning water quality pH 6.0~8.0, hardness < 100 mg/L, water pressure < 0.4 MPa.
Weeds and tree blocking and clearing: Cut and clear the weeds and trees in front of the photovoltaic array to ensure that there is no shadow on the array (to avoid causing hot spots).
(2) Cleaning of the inverter dust filter and analysis of liquid cooling water quality
Inverter dust filter: Remove the dust filter from the inlet of the inverter, rinse and dry it completely and then reinstall it.
Liquid-cooled inverter coolant detection: measure the coolant conductivity (must be < 5.0 μS/cm, if ≥ 10.0 μS/cm, the resin filter must be replaced), pH value (7.0 ~ 8.5) and freezing point (≤ -35.0 ℃), and clean the Y-type filter.
4. Quarterly inspection and maintenance plan (quarterly inspection: mechanical fastening, protection measurement and hot spot scanning)
Random test of the tightening torque of the bracket bolts (sampling test rate 20%): Use an insulated torque wrench to randomly test the anchor bolts and diagonal support bolts of the fixed bracket (M10 torque: 3842 N·m, M12 torque: 8085 N·m). After the random test, re-spray the anti-loosening marking line.
Anti-islanding measured SOP: When the inverter is connected to the grid and discharging (50% power), manually disconnect the grid-side analog circuit breaker. The inverter must cut off the AC current output within ≤ 2.0s (actual measurement < 200ms) measured by the oscilloscope.
Full square array infrared hot spot scanning: Use a drone or handheld infrared thermal imaging camera to conduct infrared scanning of the entire station components. Severe hot spot components with a single point temperature higher than the surrounding cell ΔT ≥ 20 ℃ or a local temperature > 80 ℃ must be replaced within 48 hours.
MC4 terminal temperature rise and fuse spot test: spot test the MC4 connector temperature rise (must be < 15 ℃); use a microohmmeter to test the DC fuse contact resistance (must be ≤ 0.1 mΩ).
5. Annual overhaul and preventive test plan (annual maintenance: station-wide power outage overhaul and EL/PID repair)
Waterless dry purging in the cabin/cabinet: Use 0.20 ~ 0.30 MPa dry waterless compressed air (with insulated nozzle hose) to purge the dust accumulated inside the inverter, switch cabinet and combiner box.
Component EL crack testing and Anti-PID night repair:
Randomly test 5% of the components for portable EL (electroluminescence) crack detection to check for cracks and weak soldering;
For square arrays with power attenuation, start the Anti-PID generator at night and apply 500 ~ 1000V DC reverse high voltage for PID repair.
AC/DC high voltage preventive test:
High-voltage switchgear and cable withstand voltage test and ultrasonic partial discharge test (partial discharge pulse < 20 pC);
Box-type transformer oil dissolved gas analysis (DGA chromatography analysis) and winding insulation testing;
Lightning arrester (SPD) continuous leakage current test (must be < 1.0 mA).
Impedance test 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 < 4.0 Ω (or < 1.0 Ω).
Photovoltaic power prediction model calibration: Calibrate short-term (072h) and ultra-short-term (04h) power prediction models, and the prediction accuracy must be ≥ 85%.
Time synchronization accuracy and network packet loss rate of the whole station: GPS/Beidou time synchronization error of the whole station must be ≤ 1.0 ms; 24-hour Ping test LAN packet loss rate of the whole station must be < 0.01%.
CoreTect power station PV side operation and maintenance engineering department operation and maintenance plan execution table