Low switching frequency model prediction power control algorithm of single-phase pulse rectifier

Abstract

The invention discloses a low switching frequency model prediction power control algorithm of a single-phase pulse rectifier. Under the low switching frequency, power prediction values of active power and reactive power are calculated through a model prediction power algorithm; then the component of the minimal optimal control quantity of an evaluation function is calculated under a rotating coordinating system; regulating waves subjected to volt-second compensation is acquired through the volt-second balancing compensation algorithm; and finally an on-off control signal is generated by combining a pulse width modulating strategy, and the control of the single-phase pulse rectifier is finished. According to the invention, the control precision of the low switching frequency model prediction power control algorithm of the single-phase pulse rectifier is improved with no need to repeatedly calculate the evaluation function, so the complexity of the algorithm is reduced; control and sampling efficiency is improved; the algorithm has good dynamic and stable-state performance, and high in flexibility; and different modulating strategies and control can be adopted to cooperate with the control algorithm so that requirements in different application occasions are met.

Description

technical field [0001] The invention relates to the technical field of single-phase PWM converter control systems in the field of power electronics and electric transmission, in particular to a low switching frequency model predictive power control algorithm for single-phase pulse rectifiers. Background technique [0002] Single-phase pulse rectifiers have the advantages of bidirectional energy flow, grid side voltage and current maintain unity power factor, and DC side voltage is constant, so they are widely used in high-power railway traction drive systems, UPS power supplies, etc. At present, the control algorithm of single-phase rectifier mainly includes indirect current control, hysteresis current control, transient current control and dq axis current decoupling control. [0003] In order to improve the control accuracy and dynamic performance of the rectifier, the direct power control algorithm suitable for the three-phase rectifier is based on the instantaneous power ...

AI Technical Summary

Problems solved by technology

The traditional direct power control algorithm uses a hysteresis switch table to control active and reactive power, and the response speed is fast, but the switching frequency is not fixed, the harmonic distribution is wide, and it is not conducive to the design of the grid side filter, so it is rarely used in the actual system. In this regard, a power control algorithm based on model prediction is proposed. The traditional model predictive power control algorithm repeatedly calculates and compares the evaluation function corresponding to each switching state, selects the appropriate switching state, and then generates the gate control signal of the rectifier. ; However, the switching frequency of traditional model predictive control is uncertain and the harmonics are widely distributed, which restricts its application in practical engineering

[0004] In order to solve the problem that the model predicts the switching fre

Images