Constant voltage and constant current dual-mode buck DC power supply circuit based on compensation topology

Abstract

The invention provides a constant-voltage and constant-current dual-mode BUCK type direct-current power circuit on the basis of compensation topology. The constant-voltage and constant-current dual-mode BUCK type direct-current power circuit comprises a first capacitor, a second capacitor, a first resistor, a second resistor, an inductor, a first diode, a second diode, a third diode, a fourth diode, a fifth diode, a sixth diode, a first power electronic switch device, a second power electronic switch device, a third power electronic switch device, a fourth power electronic switch device, a fifth power electronic switch device, a first current sensor, a second current sensor, a voltage sensor, a first input wiring terminal, a second input wiring terminal, a third input wiring terminal and a fourth input wiring terminal. The constant-voltage and constant-current dual-mode BUCK type direct-current power circuit has the advantages that the problems that most traditional BUCK type direct-current power sources only can work in constant-voltage modes, are long in dynamic regulation time under the condition of sudden change of load, are high in voltage fluctuation amplitude in the constant-voltage modes and are high in current fluctuation amplitude in constant-current modes can be solved; voltages can be reduced on the premise that currents of input direct-current voltages are basically stable, stable direct-current voltages can be provided for load in constant-voltage modes by topological structures of a direct-current power main circuit and corresponding control strategies, and stable direct currents can be provided for the load in constant-current modes by the topological structures of the direct-current power main circuit and the corresponding control strategies.

Description

technical field [0001] The invention relates to a DC constant voltage / constant current power supply circuit. Background technique [0002] In actual engineering, both constant voltage mode power supply and constant current mode power supply are required in many occasions, such as battery charging and so on. Because of its simple structure and easy control, the BUCK circuit is often used as the main circuit of a step-down constant voltage or constant current power supply (the DC power supply mentioned below, unless otherwise specified, refers to a DC power supply with a BUCK circuit structure). Under the action of a reasonable control strategy (such as PI control of output voltage closed-loop in constant voltage mode, and PI control of inductor current closed-loop in constant current mode), this kind of DC power supply has high accuracy of output voltage and current in steady state. Good stability. However, when the load changes suddenly (the load suddenly increases or decr...

AI Technical Summary

Problems solved by technology

However, when the load changes suddenly (the load suddenly increases or decreases), the energy storage of the inductance and capacitance cannot meet the needs of the load instantly, so the circuit generates a large dynamic adjustment process under the adjustment of the controller, and the constant voltage mode The lower voltage fluctuation amplitude is larger, the current amplitude fluctuation is larger in constant current mode, and the adjustment time is longer in both cases

This seriously affects the output power quality of the DC power supply, and may even cause great harm to the entire system

For the problem of how to improve the dynamic response of DC power supply, researchers have proposed many solutions, but most of the solutions are only limited to improving the dynamic response of DC power supply constant voltage mode, and cannot be applied to both constant voltage and constant current modes at the same time.

Images