The power quality testing conducted in accordance with GB/T 29319-2012 "Technical Regulations for Connecting Photovoltaic Power Generation Systems to Distribution Networks" includes voltage transformers, current transformers, and data acquisition devices. The accuracy of measurement equipment requires that the channel bandwidth of the data acquisition device should not be less than 10MHz.Power quality monitoringdeviceThe flicker algorithm of the measuring device should comply with the requirements of GB/T 17626. 30 15.

For the power quality testing conducted in accordance with Q/GDW 617 "Technical Regulations for Connecting Photovoltaic Power Stations to the Grid" and Q/GDW 618 "Testing Regulations for Connecting Photovoltaic Power Stations to the Grid", the power quality testing device should meet the technical requirements of GB 19862 and DL/T1028, and meet the measurement accuracy requirements of IEC 61000-4-30 Class A.

When the photovoltaic power generation system stops operating, the relevant technical indicators at the grid connection point should meet the following requirements:The root mean square value of the total distortion rate of voltage harmonics measured within 10 minutes should meet the provisions of GB/T 14549;The deviation of the average value of the 10s measurement of the power grid frequency should meet the provisions of GB/T 15945;The deviation of the root mean square value of the grid voltage for 10 minutes should meet the provisions of GB/T 12325;The three-phase imbalance of power grid voltage should meet the provisions of GB/T 15543.

Steps for detecting three-phase voltage imbalance:Connect the power quality measurement device at the public connection point of the photovoltaic power generation system.Operate the photovoltaic power generation system, starting from the continuous normal operation of the photovoltaic power generation system, with 10% of the total rated power of the inverter equipped in the photovoltaic power generation station as a range, and continuously measure for 10 minutes in each range. Starting from the range, calculate the root mean square value every 3 seconds, and calculate a total of 200 3 seconds of root mean square root;Record the 95% probability value of the measured weight value of the negative sequence voltage imbalance separately.

Connect the power quality measurement device at the public connection point of the photovoltaic power generation system, and the cut-off frequency for measuring voltage and current should not be less than 400Hz. Starting from the continuous normal operation of the photovoltaic power generation system, 10% of the total rated power of the inverter in the photovoltaic power generation system is used as a range, and two 10min short-term flicker values (Psto) are measured within each range. The long-term flicker value of the photovoltaic power generation system should be calculated through the short-term flicker value Pst, and the detection method should meet the requirements of GB/T 12326.