Multi-vector fast model predictive control method under non-ideal power grid condition

Abstract

The invention provides a multi-vector fast model predictive control method under a non-ideal power grid condition. The three-phase voltage on the grid side, the three-phase current on the grid side and the capacitor voltage on the direct-current side are collected, and the abc coordinate system of the three-phase voltage on the grid side and the three-phase current on the grid side is converted into an alpha-beta coordinate system through Clarke conversion, so as to obtain the voltage and the current under a two-phase static coordinate system; a grid side complex power vector is defined basedon the instantaneous power theory; derivation conducting is carried out on the grid side complex power vector; derivation conducting is carried out by taking a negative conjugated complex power vectoras a control variable; discretizing is carried out on the formula of the change rate of the negative conjugated complex power vector, and the power error is obtained; the phase angle and the amplitude value of the error vector caused by the zero voltage vector are calculated; the power size needing to be compensated is calculated; and the action time under each voltage vector is calculated separately, and the operation of a PWM rectifier is controlled under a non-ideal power grid condition according to a switch signal. The method disclosed by the invention has the advantages that the calculation complexity is relatively low, the calculation speed is relatively high, and the control precision is high.

Description

technical field [0001] The invention belongs to the technical field of operation and control of converters in flexible direct current transmission systems, and in particular relates to a multi-vector fast model predictive control method under non-ideal grid conditions. Background technique [0002] With the vigorous development of renewable energy in my country, different power electronic converters are used more and more, especially in wind power generation, photovoltaic power generation, and flexible direct current transmission systems. Due to the increasing penetration of renewable energy in my country, different from the stability of traditional power generation methods, this type of renewable energy will inevitably generate low-order harmonics in the process of power generation, which seriously affects the operating characteristics of the power grid. Coupled with the impact of factors such as grid voltage phase loss operation and nonlinear loads on the grid, it will not ...

AI Technical Summary

Problems solved by technology

For fast model predictive control methods, mainly including single-vector fast model predictive control, double-vector fast model predictive control and three-vector fast model predictive control, the current research is mainly based on the operation and control of the converter under ideal grid conditions. For non-ideal There is little research on the stability control of converters under grid conditions, especially in multi-vector based low-complexity fast model predictive control

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