Predictive power control method and system for pwm rectifier based on arbitrary period delay

Abstract

The present invention discloses a PWM rectifier prediction power control method based on any period delay. The method comprises a step of calculating the active power and novel reactive power of a current time and predicting the power value of a next time, a step of constructing a target function related to a current time power value and a next time power value, and solving an optimal voltage vector which allows a target function value to be minimum, a step of calculating the action time of the optimal voltage vector, emitting the optimal voltage vector according to the action time of the optimal voltage vector in a control period, and supplementing other times by a zero vector, and a step of obtaining the driving signal of a switch tube. The invention also discloses a PWM rectifier prediction power control system based on any period delay. The invention provides the PWM rectifier prediction power control method and system based on any period delay, the adding of an additional power compensation value is not needed, the amount of calculation is small, the delay period id short, the dynamic response of the system is fast, and the efficient working of a PWM rectifier in the condition of grid voltage balance or unbalance can be realized.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a PWM rectifier predictive power control method and system based on arbitrary period delay. Background technique [0002] Among the existing PWM rectifier control strategies, model predictive power control has attracted much attention due to its advantages of simple algorithm, fast dynamic response and flexible control. The definition of active power and reactive power in the traditional model predictive power control still uses the instantaneous power theory, that is, the instantaneous power theory under the ideal grid, but the actual grid voltage asymmetry will be caused by factors such as load imbalance and grid failure. If the traditional instantaneous power theory is still used for control, there will be large harmonics in the grid-side current, double-frequency fluctuations in power, and voltage fluctuations in the DC side, which seriously affect the control perfo...

AI Technical Summary

Problems solved by technology

The above methods are all based on the traditional instantaneous power theory and require the extraction of positive and negative sequence components, which not only increases the calculation amount of the system, but also inevitably brings a certain delay, usually at least 1 / 4 cycle delay, in the actual control system Followed by the software overhead will also become larger, these characteristics are not conducive to improving the real-time performance of the control system

Images