Part 0: Acceptance and early handover specifications for PV side projects of photovoltaic power stations
This article stipulates the acceptance conditions, testing standards, defect rectification and delivery list from the completion of construction to the formal handover for operation and maintenance of photovoltaic power generation systems (including distributed and ground-based centralized photovoltaic power stations).
1. Cold-state static acceptance specifications for photovoltaic power station construction completion (uncharged state)
Cold acceptance is carried out before the system is powered on, and the core is to ensure that electrical insulation, mechanical connection torque, lightning protection grounding and pipe/structure sealing are up to standard.
(1) Cold test specifications for photovoltaic modules and arrays
100% blind test verification of string polarity and open circuit voltage (Voc) (CoreTect zero safety blind zone standard):
Test method: Disconnect the DC input switch of the combiner box/inverter, and the operation and maintenance engineer uses a calibrated DC multimeter (DC 1000V/1500V range) to measure 100% of the strings entering the inverter/combine box line by line. The red test lead is connected to the positive pole (PV+) of MC4, and the black test lead is connected to the negative pole (PV-).
合格标准：
Polarity determination (100% must check): The multimeter reading must show a positive value. If a negative number is displayed, it is judged to be a Class A fatal defect (reversed polarity). Closing is strictly prohibited and the construction party must be required to make rectifications immediately!
Voltage deviation (100% record): After the actual measured Voc is converted to standard test conditions (STC: 1000 W/m², 25 ℃), the deviation from the factory nameplate/design calculated value must be ≤ ± 3.0%. If the voltage is lower than the voltage of a single module, it means there is a missing connection or virtual connection.
String short-circuit current (Isc) and IV curve random test (≥ 10% random inspection quality control):
Test method: Randomly test no less than 10% of the strings in the photovoltaic array circuit, use a portable IV curve tester and a DC clamp meter to measure the string short-circuit current Isc and draw the IV curve.
Qualification standard: The deviation between the actual measured Isc and the nameplate after conversion to STC conditions must be ≤ ± 3.0%, and the IV curve should be smooth without step changes (no serious cracks or hot spots blocked).
Photovoltaic array DC insulation resistance impedance test:
Test method: Disconnect the DC switch of the combiner box/inverter, short-circuit the positive and negative poles of the string, and use a 1000V/2500V insulation megger to test the insulation resistance of the string to the ground (string frame/ground grid).
Qualification standard: DC-to-ground insulation resistance impedance must be ≥ 2.0 MΩ (1500V high-voltage system must be ≥ 5.0 MΩ). If the impedance is < 2.0 MΩ, closing is strictly prohibited.
(2) Mechanical connection and bolt tightening torque inspection
Use a calibrated torque wrench to conduct 100% bolt tightening inspections on photovoltaic brackets, module clamps, terminal blocks, etc. (the inspection rate shall not be less than 20%), and spray anti-loosening marking lines after tightening:
(3) Cable insulation, high voltage withstand and lightning protection grounding tests
DC/AC cable insulation resistance test:
The insulation resistance of the 1000V/1500V DC main cable between phases and to ground must be ≥ 10.0 MΩ (1000V megger test for 1 minute).
The insulation resistance of the 35kV high-voltage AC cable winding to ground must be ≥ 1000 MΩ (2500V megger test), and the absorption ratio K = R60s / R15s ≥ 1.3.
High voltage electrical withstand voltage test (Hip-Test):
When 1.5 Un + 1000V power frequency withstand voltage is applied to 35kV cables and high-voltage switch cabinets for 1 minute, the leakage current is < 5 mA, and there is no breakdown discharge flashover phenomenon.
Lightning protection grounding and equipotential jumper resistance test:
Use a ground resistance tester to measure the power frequency resistance of the main grounding network of the ground photovoltaic power station must be < 4.0 Ω (large booster stations must be < 1.0 Ω).
The equipotential cross-connection resistance between the component aluminum alloy frame and the bracket and the bracket and the main grounding grid must be ≤ 0.1 Ω.
2. Photovoltaic power station thermal live acceptance and trial operation specifications
(1) Logic sequence of receiving power and powering on
The system power receiving process must strictly follow the following safety logic steps:
Step 1: Close the AC 380V/220V auxiliary power supply for the station and check that the auxiliary voltage deviation is within ± 5% of the rated voltage range.
Step 2: Close the station DC panel/UPS AC incoming line and confirm that the control power supply DC 220V/110V outputs normally.
Step 3: Activate the fire main screen (FACP) and security monitoring system to confirm that there are no fire alarms or intrusion alarms.
Step 4: Start the SCADA background monitoring server and weather station sampling module to confirm data communication connectivity.
Step 5: Close the main circuit breaker of the 35kV booster station, receive power from the 35kV high-voltage busbar, and check the three-phase voltage balance.
Step 6: Close the load switch on the high-voltage side of the local box-type transformer step by step, perform impact power on the box-type transformer, and check that the voltage on the low-voltage side (such as 800V AC) of the box-type transformer is normal.
Step 7: Close the AC side circuit breaker of the string/centralized inverter, and the inverter completes AC adaptive phase locking.
Step 8: Close the DC side switch of the inverter or the main switch of the DC combiner box, and the inverter starts to connect to the grid to generate electricity.
(2) Point-to-point (P2P) sampling and verification between SCADA and inverter/combiner box
Telemetry sampling accuracy verification: Under full power generation, use Fluke's high-precision AC/DC clamp meter to measure the inverter's input DC voltage/current and output AC voltage/current, and compare with the SCADA monitoring interface. The voltage/current sampling error must be ≤ ± 0.5%.
Remote control derating and shutdown test: "Derate the inverter power by 50%" and "Emergency shutdown" commands are issued through SCADA, and the inverter must respond and accurately perform power derating or trip shutdown within < 100 ms.
(3) 72-hour continuous trial operation assessment standards
Before the power station is officially handed over to the operation and maintenance team, it must undergo a continuous 72-hour trouble-free trial operation:
Operational stability: No primary or secondary emergency protection tripped within 72 hours, and the inverter was only planned to be disconnected from the grid.
Overall site energy efficiency ratio (PR - Performance Ratio) assessment:
Calculation formula: PR = (actual output grid power kWh) / [nominal installed capacity kWp × (actual cumulative irradiance kWh/m² / 1 kW/m²)] × 100%.
Assessment standards: Under standard lighting conditions, the PR of the entire station during the trial operation must be ≥ 82.0%.
Protection function verification: During the trial operation, it successfully passed the anti-islanding protection (Anti-Islanding) and low voltage ride through (LVRT) simulated cut-off tests.
3. Photovoltaic power station handover defect order rectification and standard delivery list
(1) A/B/C three-level defect classification and closed-loop processing
Class A defects (fatal defects/strictly prohibited from receiving power): unqualified insulation impedance of the square array, failure to prevent false locking of the high-voltage switch cabinet, oil leakage from the box transformer, severe hot spots in the components (ΔT ≥ 20 ℃) ➔ Must be 100% rectified and eliminated before receiving power.
Class B defects (serious defects/time-limited rectification): string current deviation > 10%, abnormal noise of individual fans of the inverter, tracking angle deviation of the tracking bracket > 2.0° ➔ Derating operation is allowed, and the closed loop will be eliminated within 7 days.
Class C defects (minor defects/remaining rectification): local dust on the surface of the component glass, slight flaws in the paint on the bracket, and skewed nameplate logo ➔ Included in the defect elimination plan within 30 days.
(2) Operation and maintenance delivery documents and spare parts handover confirmation
When handing over the project, the construction unit must hand over a full set of engineering drawings, factory reports, spare parts and special tools to the CoreTect operation and maintenance team (see the printable form at the end for details).
Closed-loop table of completion acceptance and delivery of PV side project of photovoltaic power station
Power station name: _______________________________ Acceptance date: ____ month ____ day, 2026
Power plant scale: ______ MWp / ______ MW EPC construction unit: ____________________
1. Cold and hot key indicator acceptance confirmation form
2. Operation and maintenance delivery documents, drawings and spare parts inventory and handover confirmation form
3. Deadline for registration and rectification of defects left on site
4. Three-party signature confirmation and handover seal