A switching control method based on discrete lyapunov function

Abstract

The invention discloses a switching control method based on a discrete Lyapunov function, which belongs to the field of power electronic conversion technology and intelligent control. According to the discrete mathematical model of the converter, the present invention defines a discrete Lyapunov function based on the error term of the controlled quantity and the reference quantity, obtains the control law from the second theorem of Lyapunov stability, and selects different definition variables α in the dynamic response stage and the steady state stage , and then output switching signals through PWM modulation; this method includes the feedback item of the controlled quantity, the error value compensation item of the controlled quantity and the reference quantity, and the feedforward compensation item of the future reference input. The control method of the invention is simple in principle, easy to implement digitally, combines the advantages of deadbeat control and the "feedforward-feedback" feature of model predictive control, and has the advantages of fast dynamic response, good control performance and strong robustness.

Description

technical field [0001] The invention relates to a single-phase voltage-type PWM rectification technology, in particular to a switching control method based on a discrete Lyapunov function, and belongs to the technical field of electric current conversion. Background technique [0002] With the development of the economy, the demand for high-power DC power supply is increasing year by year. The traditional uncontrolled and phase-controlled power supplies have large input current harmonics, low power factor has a great impact on the power grid, and the slow current response cannot meet the needs of production and life; and The voltage-type PWM rectifier can eliminate the harmonics of the input current from the source, and has a unit power factor, so it is the focus of attention in the field of power electronics. [0003] The control method based on the discrete lyapunov function, when the defined variable α is zero, it is the traditional deadbeat control, and the deadbeat cont...

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Problems solved by technology

[0002] With the development of the economy, the demand for high-power DC power supply is increasing year by year. The traditional uncontrolled and phase-controlled power supplies have large input current harmonics, low power factor has a great impact on the power grid, and the slow current response cannot meet the needs of production and life; and The voltage-type PWM rectifier can eliminate the input current harmonics from the source, and has a unit power factor, so it is currently the focus of attention in the field of power electronics

[0003] The control method based on the discrete lyapunov function, when the defined variable α is zero, it is the traditional deadbeat control, and the deadbeat control depends on the mathematical model of the controlled object, so the accuracy of the parameters of the controlled object has a great influence on the control The performance has a great impact. In the application of single-phase PWM rectifier, the drift of inductance parameters and inaccurate sampling may make the current unstable and distorted, so the robustness is poor; when the defined variable α is not zero, the stability of the system The dynamic control performance is better and the robustness is stronger, but there is a problem of slow dynamic response

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