STABILITY INSPECTING METHOD FOR TYING INVERTER TO GRID, AND INVERTER

摘要

The present invention relates to the field of inverters, and specifically, to a method for detecting grid connection stability of an inverter and an inverter. The method includes: injecting, by an inverter, a first-sequence disturbance current into the power grid, and while the first-sequence disturbance current is injected, detecting a line voltage and a current of the alternating current port to obtain a first group of line voltage values and a first group of current values; injecting a second-sequence disturbance current into the power grid, and while the second-sequence disturbance current is injected into the power grid, detecting the line voltage and the current of the alternating current port to obtain a second group of line voltage values and a second group of current values; obtaining an equivalent impedance matrix of the power grid according to the first group of line voltage values, the first group of current values, the second group of line voltage values, and the second group of current values; and determining, by the inverter according to an equivalent admittance matrix and the equivalent impedance matrix, whether a stability requirement of the inverter is met. According to the method, impact of a power grid on an inverter can be determined when measurement costs are reduced.