Three-phase voltage type PWM inverter control method

Abstract

The invention provides a three-phase voltage type PWM inverter control method. The three-phase voltage type PWM inverter control method includes following steps: firstly, a three-phase voltage type PWM inverter mathematical model is established; secondly, the three-phase voltage type PWM mathematical model is analyzed based on a synthetic vector via the introduction of the thought of the synthetic vector; thirdly, a control strategy obtained by analysis based on the synthetic vector is converted to a synchronous rotation d-q coordinate system, and a decoupling control method of a current inner loop of the three-phase voltage type PWM inverter without inductance parameters is obtained; and fourthly, a voltage outer loop control strategy of the three-phase voltage type PWM inverter is designed. According to the three-phase voltage type PWM inverter control method, no-inductance-parameter complete decoupling of the current inner loop is realized, and the control performance is guaranteed.

Description

technical field [0001] The invention relates to the field of electrical engineering, in particular to a control method for a three-phase voltage type PWM inverter. Background technique [0002] With the development of power electronics technology, three-phase voltage-type PWM inverters that can realize two-way flow of energy, unit power inverter operation, and low output current harmonic function have been widely used. With the diversification of applications, the requirements for its dynamic and static performance are getting higher and higher, and the control strategy to improve the control performance of the three-phase voltage PWM inverter has become a research hotspot. At present, the voltage and current double closed-loop control strategy is widely used in three-phase voltage-type PWM inverters. Because in the synchronous coordinate system, AC variables are decomposed into active variables and reactive variables, and in steady state, they are all DC components, and ac...

AI Technical Summary

Problems solved by technology

However, the current state feedback decoupling control item commonly used in the traditional double closed-loop control strategy must know the exact value of the AC side inductance. Due to the influence of the inductance measurement error, the system will not be completely decoupled, which will affect the control performance of the entire system.

Generally speaking, the double closed-loop control strategy adopted by the three-phase voltage-type PWM inverter has the following disadvantages: first, the precise value of the AC side inductance needs to be known when designing the current inner loop controller; second, the measured value of the inductance and the precise value of the inductance There is inevitably an error between them; Third, when there is an error in the inductance parameter, the current inner loop will not be completely decoupled, and the control performance will deteriorate. This phenomenon is particularly obvious as the synchronization frequency increases.

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