Bus type energy storage element equalization circuit, system and method based on zero-current PWM bidirectional DC-DC CUK converter

Abstract

The invention provides a bus type energy storage element equalization circuit, system and method based on a zero-current PWM bidirectional DC-DC CUK converter, and the circuit is characterized in that the anode output end of a first equalization circuit is connected with the anode end of an equalization bus, the cathode output end of the first equalization circuit is connected with the cathode end of the equalization bus, and the anode output end of a second equalization circuit is connected with the anode end of the equalization bus; the negative output end of the second equalization circuit is connected with the equalization bus negative terminal, the positive output end of the Nth equalization circuit is connected with the equalization bus positive terminal, the negative output end of the Nth equalization circuit is connected with the equalization bus negative terminal, and N is a positive integer. By using the equalization circuit in the equalization bus, the balance of energy in the bus is realized, so that the equalization bus system operates more stably and smoothly, and the energy loss is smaller.

Description

technical field [0001] The invention relates to the field of electronic circuits, in particular to a bus-type energy storage element equalization circuit, system and method based on a zero-current PWM bidirectional DC-DC CUK converter. Background technique [0002] The DC converter generally adopts the PWM control mode, and the switching tube works in the hard switching state. The bidirectional DC-DC CUK converter is a typical DC converter, which is widely used in the balance circuit of the bus type energy storage element. Its structure is as follows: Figure 10 shown. Since the actual switching tube is not an ideal device, the voltage of the switch does not drop to zero immediately when it is turned on, but has a falling time, and its current does not immediately rise to the load current, but also has a rising time. During this time, the current and voltage have an overlapping region, resulting in loss, which is called turn-on loss. When the switch tube is turned off, the ...

AI Technical Summary

Problems solved by technology

Turn-on loss and turn-off loss are collectively referred to as switching loss. Under certain conditions, the switching loss of the switch tube in each switching cycle is constant, and the total switching loss of the converter is proportional to the switching frequency. The higher the switching frequency, the total The greater the switching loss, the lower the efficiency of the converter, which in turn leads to the lower equalization efficiency of the bus-type energy storage element equalization system

Therefore, the existence of the switch limits the increase of the switching frequency of the converter, thereby limiting the miniaturization and weight reduction of the converter and the equalization system

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