A grid-connected control method for inverters based on virtual synchronous generator technology

Abstract

The invention discloses an inverter grid-connected control method based on the virtual synchronous generator technology and belongs to the field of distributed power generation system grid-connected researches. According to the technical scheme, the method includes the steps that a grid-connected inverter phase voltage phase value is obtained through calculation by simulating a conventional synchronous generator unit active power control method; a grid-connected inverter phase voltage amplitude value is obtained through calculation by simulating a conventional synchronous generator unit reactive power control method; a three-phase voltage reference value is worked out according to the inverter phase voltage phase value and the inverter phase voltage amplitude value, a three-phase modulated wave is figured out according to direct current side voltage obtained through detection, and the three-phase modulated wave is compared with a carrier wave to obtain six switching signals to control turn-off and turn-on of switching devices in a main circuit. System damping and active power-frequency droop control are achieved by means of control link signals, and power grid frequency does not need to be detected. The method simplifies a control structure and avoids the problems caused by a frequency detection link. Effectiveness of the method is verified through simulation and experiment results.

Description

technical field [0001] The invention belongs to the technical field of grid-connected research on renewable energy and distributed power generation systems, and in particular relates to an inverter grid-connected control method based on virtual synchronous generator technology. Background technique [0002] Since the 1970s, energy and environmental protection have gradually become one of the world's mainstream concerns. With the continuous increase of energy consumption and the continuous reduction of traditional energy sources, the development of new energy has attracted widespread attention and promotion from the whole society. Among them, photovoltaic power generation and wind power generation have the advantages of easy large-scale utilization and low cost, so It has developed rapidly in recent years. [0003] However, based on the existing control methods, the stable operation of new energy power generation equipment depends on the strong power grid, and the large-scal...

AI Technical Summary

Problems solved by technology

[0004] The existing virtual synchronous generator control methods all need to design a phase-locked loop to detect the grid frequency to realize the damping torque and active power-frequency droop control, which increases the control complexity. At the same time, the grid frequency detection error will cause active power reference value and actual active power Output error, large active power output error may cause grid frequency deviation, which is not conducive to frequency stability

Images