Research on Control Strategy of Power Grid Analog Device for Voltage Adaptability Test of New Energy Transmission Terminal

With the development of new energy in China, UHV AC-DC hybrid cross-region transmission has become a typical feature of China's power grid. When continuous commutation failure occurs in the DC transmission system, it will cause serious fluctuations in the voltage and frequency of the new energy transmission grid, and even lead to the collapse of the power grid. Therefore, the voltage adaptability test of the new energy transmission terminal grid is an important index of access to the grid. In order to meet the needs of the voltage adaptability test of the new energy transmission terminal grid, a power grid simulation device is proposed to simulate the phenomenon of voltage and frequency fluctuations, so as to realize the continuous crossing of high and low voltage and frequency disturbance test. By adopting the double closed-loop control scheme of instantaneous value of voltage and current, and introducing negative feedback current feedforward into the inner current loop, the dynamic response of the inverter is accelerated, and the response of voltage disturbance and frequency disturbance is realized quickly, and the voltage can be accurately controlled from 0.2p.u to 1.3p.u within 10ms. In this paper, by using PSIM simulation system, a power grid simulation device model is built to verify the feasibility of the control strategy, and the field test in Golmud new energy power Station in Qinghai province further verifies the reliability of the simulation device.