Dq active and reactive power cross decoupling-based grid-connected control method of single-phase converter

Abstract

The invention discloses a dq active and reactive power cross decoupling-based grid-connected control method of a single-phase converter. The grid-connected control method comprises the steps of designing proportional integral (PI) controller to achieve active and reactive power cross control after a grid-connected control mathematical model of the single-phase converter is simplified; tracking andlocking a phase and amplitude of a power supply voltage by employing a single-phase locked loop (PLL) to obtain an angular frequency Omega(t) same as the frequency of the power supply voltage, a sinesignal sin(Omega)t and a cosine signal cos(Omega)t; processing an active component and a reactive component of a current by a lowpass filter (LPF) with a cutoff frequency being Omega / 2Phi to obtain Id and Iq; and finally, taking sum of an active transient AC voltage and a reactive transient AC voltage as a modulation wave, and selecting an appropriate modulation mode to obtain a switch signal forcontrolling on / off of a converter switch tube. By the control method, the controller structure is simplified, and the stability and the dynamic response of the system are improved.

Description

technical field The invention relates to the technical field of power electronics, in particular to a single-phase converter grid-connected control method based on dq active and reactive cross decoupling. Background technique With the development of power electronics technology, single-phase grid-connected converters have been widely used in various occasions. At present, most studies on the control strategy of single-phase grid-connected converters are direct control of transient current, which has the advantages of simple control, easy implementation, and good dynamic response. However, it cannot control the power factor of the grid side, nor can it provide reactive power to the grid side, and is not suitable for single-phase PWM grid-connected converters. The traditional dq decoupling control can better realize the power factor control and reactive power control when the single-phase PWM converter is connected to the grid, but its control algorithm contains differential ...

AI Technical Summary

Problems solved by technology

However, it cannot realize the control of the power factor of the grid side, nor can it provide reactive power to the grid side, and is not suitable for single-phase PWM grid-connected converters.

The traditional dq decoupling control can better realize the power factor control and reactive power control when the single-phase PWM converter is connected to the grid, but its control algorithm contains differential operators, and the control structure is relatively complicated, and the amount of calculation large, and therefore more complex to implement

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