A sliding-mode power offset direct power control method for a three-phase voltage-type pwm converter

Abstract

The invention discloses a sliding mode power cancellation direct power control method of a three-phase voltage type PWM converter, The actual value of the active pow decreases and the actual value ofthe reactive pow increases and the actual value of the reactive power of the active power decreases, an another non-zero voltage vector is looked for, An improved vector table is obtained, At that same time, according to the sector where the grid voltage position angle is located, Actual value of active power and reactive power and reference value of active power and reactive power, three optimalvoltage vectors are selected from the improved vector table, which can reduce the error between the actual value of active power and reactive power and reference value at the same time, and calculatethe action time of each vector according to the reference value of active power and reactive power. The control algorithm of the method is simple and easy to realize, the approach speed of the arrivalstage can be improved, the output chattering of the system can be suppressed, the steady-state ripple of the active power and the reactive power can be suppressed at the same time, and the current distortion rate is low, so that the system has excellent dynamic and static performance.

Description

technical field [0001] The invention relates to the control field of power electronic power conversion devices, in particular to a sliding mode power offset direct power control method of a three-phase voltage type PWM converter. Background technique [0002] With the continuous development of power electronics technology and control technology, the performance of power converters has been continuously improved, and has been widely used in rectification, AC speed regulation, active filtering, reactive power compensation and new energy grid-connected power generation and other fields. After rapid development in recent years, more and more control methods have been proposed and applied to the control of PWM power converters. The control methods of power converters mainly include grid voltage oriented control (VOC), virtual flux oriented control (VFOC), sliding mode control (sliding mode control, SMC), model predictive control ( model predictive control, MPC) and direct power ...

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Problems solved by technology

In order to suppress the steady-state ripple of active power and reactive power at the same time, and further improve the dynamic response of the system, the patent No. CN201510097432.3 discloses a three-phase voltage-type PWM converter three-vector direct power control method, which is When reducing the active power and increasing the reactive power and reducing the active power and reducing the reactive power, approximate the target (increase the active power smaller but increase the reactive power larger and increase the active power smaller but increase the reactive power Power reduction is large) choose another non-zero voltage vector, the ripple of active power and reactive power obtained by this method is unstable, and the dynamic response of the system is poor

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