Multi-source grid-connected inverter harmonic suppression method based on H-infinity composite control

Abstract

The invention discloses an H-infinity composite control-based multi-source grid-connected inverter harmonic suppression method, and an LCL filter, a photovoltaic system, an energy storage system, a local load and a grid-connected inverter are included, wherein the grid-connected inverter provides direct current through the mixing of the energy storage system and the photovoltaic system; the grid-connected inverter adopts a double-loop control strategy, the double-loop control strategy comprises grid-connected inner loop control and outer loop control, the grid-connected inner loop control comprises H-infinity control and voltage feedforward control, and the outer loop control is PQ power control; the grid-connected inverter suppresses the resonance peak of the LCL filter by adopting an active damping control strategy; the grid-connected inverter suppresses local load harmonics while transmitting power. According to the invention, the steady-state error of the output current of the grid-connected inverter is further reduced, meanwhile, the inverter is powered by multiple direct-current sources, when the external environment of the photovoltaic system changes, the influence of the photovoltaic system on the inverter can be weakened, the working reliability and stability of the inverter are improved, and the electric energy quality of the grid-connected current is better improved.

Description

technical field [0001] The invention relates to a method for suppressing harmonics of a multi-source grid-connected inverter based on H∞ compound control, and belongs to the technical field of new energy power generation and micro-grid. Background technique [0002] Due to the gradual scarcity of fossil energy, the development and utilization of renewable energy has become the key to alleviating the energy crisis, and the concept of microgrid has been proposed. The microgrid is composed of distributed power sources, energy storage systems, loads, electronic converters connected to the grid, and control systems. The microgrid is easy to control and can flexibly adjust power generation according to changes in loads. Can run independently. When nonlinear loads are connected to the power grid, nonlinear currents will be generated, which is very harmful to the stability and safe operation of the power system. At present, most of the control equipment used is based on the invert...

AI Technical Summary

Problems solved by technology

Non-linear loads connected to the power grid will generate non-linear currents, which are very harmful to the stability and safe operation of the power system

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