Switching control method based on discrete Lyapunov function

Abstract

The invention discloses a switching control method based on a discrete Lyapunov function, and belongs to the field of power electronic conversion technique and intelligent control. The method comprises: according to a discrete mathematical model of a converter, defining a discrete Lyapunov function based on an error term of a controlled variable and a reference variable, obtaining a control law by a Lyapunov stability second theorem, selecting different defined variables [alpha] in a dynamic response phase and a steady state phase, then through PWM, outputting a switching signal. The method comprises a feedback term of the controlled variable, an error value compensation term of the controlled variable and the reference variable, and a feedforward compensation term input by future reference. The control method is simple in principle and easy in digital realization, and is combined with advantages of no-beat control and characteristics of feedforward-feedback of model prediction control, and has advantages of fast dynamic response, good control performance, and good 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 power electronic conversion. Background technique [0002] With the development of the economy, the demand for high-power DC power supplies is increasing year by year. The input current harmonics of traditional uncontrolled and phase-controlled power supplies are large, and the low power factor has a greater impact on the power grid, and the slow current response cannot meet the needs of production and life; Voltage-type PWM rectifiers can eliminate input current harmonics from the source, and have unit power factor, so they are currently focused on in the field of power electronics. [0003] Based on the control method of discrete lyapunov function, when the defined variable α is zero, that is, the traditional deadbeat control, and deadbeat control depends o...

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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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