When the voltage rises due to a fault or disturbance in the power grid, within a certain voltage increase range and time interval, the photovoltaic power station can ensure continuous operation without off-grid. PA series power analyzers have real-time wave recording as fast as 200KS / s, and can detect the dynamic grid-connected voltage in high-voltage ride-through. The detection of the high-voltage ride-through capability of the photovoltaic power station shall include the test of the high-voltage ride-through capacity of the photovoltaic power generation unit and the verification of the high-voltage ride-through capacity of the photovoltaic power station. The basic requirements include the following aspects. Basic requirements for voltage rise generators Using passive equipment as shown in the principle of Figure 1 to simulate the voltage rise of the power grid, the device should meet the following requirements: The device should be able to simulate three-phase symmetrical voltage rise; At least one of the current-limiting reactance L and the boost capacitor C is adjustable, and the device should be able to generate voltage rises of different amplitudes at point A; The ratio of the reactance value of the current limiting reactance to the resistance value should be at least greater than 10; The current-limiting reactance should meet the short-circuit capacitance of test point A after being connected is more than 3 times the total rated power of the inverter equipped with the photovoltaic power unit under test; The boost switch S_2 should be able to accurately control the input and cut-off time of the boost capacitor C and damping resistor R in all three-phase circuits, and the resulting voltage rise time error should be within the allowable error range shown in Figure 2; The voltage step time generated by the device should be less than 20ms, and no overshoot should occur during the voltage rise; When the no-load test is carried out by the voltage rise generating device, the tolerance of the voltage rise is shown in Figure 2. measuring equipment Measurement equipment includes voltage transformers, current transformers and data acquisition devices. The accuracy of the measurement equipment should at least meet the requirements of Table 1, and the bandwidth of the data collection device should not be less than 10 kHz. Table 1 Measurement equipment accuracy requirements Test case Examples of high-voltage ride-through tests for photovoltaic power plants are shown in Table 2. The test should select at least 5 rise points. The voltage rise amplitude and high voltage duration are shown in Table 3. The photovoltaic power generation unit should be between 0.1Pn, d ～ 0.3Pn, d and not less than 0.7Pn. d Test under two working conditions, and all test points should be repeated once. test program 1. Test wiring Before conducting the high voltage ride-through test, the inverter of the photovoltaic power generation unit should work in the same control mode as when it is actually put into operation. Connect the photovoltaic power generation unit, voltage rise generating device and other related equipment according to Figure 3. 2. No-load test Before the photovoltaic power generation unit is put into operation, an empty test should be carried out. The test should be carried out as follows: Make sure that the inverter of the photovoltaic power unit under test is out of service; Adjust the voltage rise generating device to simulate three-phase symmetrical faults, and the voltage rise point meets the test case requirements; Measure and adjust the parameters of the detection device so that the amplitude and duration of the voltage rise meet the tolerance requirements of Figure 2. 3. Load test Under the condition that the no-load test results meet the requirements, the photovoltaic power generation unit should be tested for high-voltage ride through load under two working conditions of 0.1Pn, d ～ 0.3Pn, d and not less than 0.7Pn, d The current-limiting impedance, boosting impedance, boosting damping resistance and voltage rise time setting during the test should be consistent with the no-load test; Put the photovoltaic power generation unit into operation; Control voltage rise generating device to conduct three-phase symmetrical voltage rise test; On the step-up transformer side or the low-voltage side, record the waveforms of the voltage and current of the measured photovoltaic power generation unit through the data acquisition device, and record the data from at least 10s before the voltage rises to 6s after the voltage returns to normal. Note: Pn and d are the total rated power of the inverter equipped with the photovoltaic power unit under test. Use PA as data acquisition device for high voltage ride-through test The PA series power analyzer has the fastest real-time recording of up to 200KS / s, supports various crossover tests such as 50Hz / 60Hz, single-phase / three-phase systems, and can detect the dynamic grid-connected voltage in high-voltage crossover as data The collection device is tested for high voltage ride through. The specific process is as follows: 1. Connect the device and set the parameters First open the PA management software PAM, then search for the device (or manually add the device), select the industry test in the device list-> voltage ride-through test view, select the high voltage ride-through test as the test type, select the online test, unit 1, unit 2, Unit 3 is set to wiring unit 3V3A (in single test, click single test and select test unit) 2. Test process After completing the settings, click the Apply button, and then click the Start Test button. The PA enters the data acquisition process as shown in Figure 6. At this time, the operating voltage raising device raises the voltage, and after a period of time according to Table 3, it drops to the normal. If the test has been completed within the set time, you can manually click the Stop Test button on the menu bar, otherwise the test will be automatically stopped after the time is up, and the data will be automatically retrieved for analysis. After the data analysis and calculation are completed, the final test result is displayed, and the crossing time button can be automatically found by clicking the crossing time button, as shown in Figure 9.
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Figure 3 Schematic diagram of high voltage ride through capability test 
Figure 9 High-voltage ride-through test results
High voltage ride-through test in photovoltaic power generation