High-power parallel switch power circuit capable of realizing adjustability and current equalization

Abstract

The invention discloses a high-power parallel switch power circuit capable of realizing adjustability and current equalization, and relates to a switch power circuit. By using a power supply expanded by parallel modules, the current equalization is realized by using a maximum current self-current-equalization method and an external current equalization controller mode, the structure is complicated, and the cost is high. The high-power parallel switch power circuit capable of realizing the adjustability and the current equalization is characterized by comprising a control circuit, wherein the control circuit comprises a current sampling unit, a voltage sampling unit, a current equalization bus unit connected with the current sampling unit, a current equalization control voltage acquisition unit, an adjustable external reference voltage unit, an adjustable external current-limiting reference voltage unit, a voltage error amplification unit and a current error amplification unit. The voltage error amplification unit comprises a first operational amplifier; and the first operational amplifier is connected with the voltage sampling unit, the current equalization bus unit, the adjustable external reference voltage unit and the current equalization control voltage acquisition unit. By adopting the technical scheme, the maximum current self current equalization can be realized by a pure hardware circuit, and a controller is not needed; furthermore, a practical circuit with adjustable output voltage can be achieved; and the high-power parallel switch power circuit is simple in structure and low in cost.

Description

technical field [0001] The invention relates to a switching power supply circuit. Background technique [0002] In the field of energy applications, high-power power supply systems are more and more widely used, but limited by the capacity of power devices, magnetic materials and heat dissipation, the maximum output power of a single switching power supply module can only be used for small and medium power, such as below 3KW. The development trend of power supply is to adopt modularization, expand capacity through parallel connection, and use relatively small power supply modules to form a building block, intelligent high-power power supply system. [0003] When the modules are used in parallel, due to the dispersion of the parameters of the electronic components, the open circuit voltage and internal resistance of each power supply will be different. Usually the internal resistance of the switching power supply is very small, so the small difference in the open circuit volt...

AI Technical Summary

Problems solved by technology

[0003] When the modules are used in parallel, due to the dispersion of the parameters of the electronic components, the open circuit voltage and internal resistance of each power supply will be different. Usually the internal resistance of the switching power supply is very small, so the small difference in the open circuit voltage will be large. The output current of each power supply has a large difference

This state will lead to the phenomenon of idle idleness and busy busyness: some modules are overloaded, and the loss and heat are severe, and the lifespan will be reduced; working status

At this time, it is necessary to introduce an effective load distribution or current sharing control strategy in the multi-module parallel operation system. At present, there are many current sharing schemes, such as output impedance method, master-slave setting method, average current method, maximum current autonomous current sharing method and external Current sharing controller, complex structure, high cost

In the absence of an external controller, in most cases, current sharing can only be achieved at a fixed voltage and power, and the current sharing effect is poor

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