Bidirectional direct-current converter feedback linearized back-stepping sliding-mode control mode

Abstract

The invention discloses a bidirectional direct-current converter feedback linearized back-stepping sliding-mode control mode. The bidirectional direct-current converter feedback linearized back-stepping sliding-mode control method comprises steps of using a filtering capacitance voltage and inductive current as control variables to establish a mathematic model of a bidirectional direct-current converter, performing feedback linearization on an original state variable to form a new linearized state equation, tracking an error with a new state variable as an input of a controller, combining a back-stepping method with a sliding-mode variable structure and designing a feedback control rule of a converter system, wherein the feedback control rule of the inverter system is performed on pulse width modulation and controls the bidirectional direct-current converter. The bidirectional direct-current converter feedback linearized back-stepping sliding-mode control mode combines the feedback linearization with the back-stepping sliding mode control to apply to the bidirectional direct-current converter, solves a non-minimum phase characteristic and a variable structure characteristic of the converter, greatly reduces fluctuation of bus voltage, expands a stable area of a system and has a good engineering application prospect.

Description

technical field [0001] The invention belongs to the technical field of smart grids, in particular to a bidirectional DC converter feedback linearization backstepping sliding mode control method. Background technique [0002] In recent years, microgrids integrating various distributed power systems and power electronic technologies have received more and more attention and research. By combining relatively mature distributed power supply technology, advanced control devices and various types of loads into a new power supply system, connecting it to the large power grid in the form of a micro-grid, and using flexible control strategies, the power supply capacity of the power grid can be improved. and power quality purposes. Compared with the AC microgrid, the DC microgrid has only one-stage voltage conversion device between each distributed power supply and the DC bus, which reduces the system construction cost; the DC bus voltage is the only standard to measure the balance o...

AI Technical Summary

Problems solved by technology

At present, scholars at home and abroad have made considerable achievements in the field of DC / DC converter control. It is relatively mature in the field of traditional linear control, such as PID control and optimal control, but its control accuracy is low and it is sensitive to system parameter changes. , less robust

With the in-depth study of nonlinear control theory, the precise linearization method based on differential geometry theory has been widely used in converters. However, this method is based on the precise mathematical model of the controlled object and does not consider the actual System uncertainty problem, so the robustness is not strong, the calculation expression is complicated, and the engineering realization is more difficult

The sliding mode variable structure control is highly valued for its strong robustness to system parameter perturbations and external disturbances. In the past two decades, breakthroughs have been made in the field of nonlinearity. However, the current sliding mode Most variable structure control designs use the error between the control variable and the reference quantity as the switching function, which cannot optimize the dynamic quality of the sliding mode.

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