Improved passive control method for three-phase grid-connected inverter based on disturbance observer compensation

Abstract

The invention discloses an improved passive control method of a three-phase grid-connected inverter based on interference observer compensation, which relates to the technical field of grid-connectedinverters, comprising the following steps: (1) sampling the grid-connected current of the inverter and the PCC point voltage, and performing abc / dq conversion; (2) calculating d-axis and q-axis command values; (3) performing d-axis and q-axis current control by a current inner-loop passive controller; (4) obtaining the output voltage compensation value of the inverter by using an interference observer; (5) performing PWM driving pulse production. In this invention, the current tracking controller of grid-connected inverter is designed based on a passive control theory, the controller has strong robustness, fast dynamic response and simple design. The disturbance observer is used to compensate the output, which effectively suppresses the influence of uncertain factors such as parameter perturbation, unmodeled error and disturbance on the steady-state / dynamic response characteristics of the system, thus improving the robustness of the controller.

Description

technical field [0001] The invention belongs to the technical field of grid-connected inverters, and more specifically relates to an improved passive control method for three-phase grid-connected inverters based on disturbance observer compensation. Background technique [0002] As the penetration rate of distributed new energy such as photovoltaics and wind energy continues to increase, grid-connected inverters are necessary interface devices for distributed new energy power generation equipment to connect to the AC distribution network. In order to improve the quality of the grid-connected current, a filter is usually connected in series between the inverter and the distribution network, and a single-inductance L filter is often used. During the operation of the grid-connected inverter, the main task of the controller is to realize fast, stable and accurate tracking of the command signal. In addition, in order to meet the needs of different operating conditions, the contro...

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Problems solved by technology

[0004] Aiming at the above defects or improvement needs of the prior art, the present invention provides an improved passive control method for three-phase grid-connected inverters based on disturbance observer compensation, thereby solving the problem that the existing passive control technology relies on the controlled object Accurate mathematical model, under uncertain factors such as parameter perturbation, unmodeled error and disturbance, will affect the operating balance point of the system, thus affecting the technical problem of controller performance

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