Dual-zero vector model forecasting control method applicable for three-phase grid-connected inverter

Abstract

The invention discloses a dual-zero vector model forecasting control method applicable for a three-phase grid-connected inverter. The method comprises the following steps of (1) forecasting a system state by a forecast model; (2) sieving an optimal switching vector according to a value function; (3) using a control signal corresponding to the optimal switching vector if the optimal switching vector is a non-zero vector, and selecting a certain zero vector and using a corresponding control signal according to an inequality criterion if the optimal switching vector is a zero vector; and (4) forwarding to the step (1) after entering a next sampling period. According to the method, the two zero vectors are selected and adopted by building a new criterion; and compared with the traditional model forecasting control, the method has the advantages that the switching loss of an upper bridge arm and a lower bridge arm can be effectively balanced, and the switching frequency is reduced.

Description

technical field [0001] The invention relates to a double zero vector model predictive control method suitable for a three-phase grid-connected inverter. Background technique [0002] Model predictive control is a computer control method with a profound background in practical engineering applications. It adopts real-time prediction, rolling optimization and feedback correction mechanism, has good adaptability to disturbance and uncertain factors, and can achieve good control effect. The basic process of model predictive control is to first sample the system state variables and use the system model to predict, and then use the value function to calculate the optimal control signal online. [0003] Suppose the system variable is at t k The sampling value at time is x(k), and the prediction model of the controlled system can be described as: [0004] x(k+1)=f(x(k),u(k))(1) [0005] In the formula, x(k+1) is the predicted value of the system state variable, and x(k) and u(k)...

AI Technical Summary

Problems solved by technology

Therefore, using only one zero vector will cause the loss imbalance of the upper and lower bridge arm switches, cause uneven heating, and affect the service life of the entire inverter

Images