Current sharing circuit and current sharing system when inverters are connected in parallel at high frequency

Abstract

The present application discloses a current sharing circuit and a current sharing system when inverters are connected in parallel at high frequency, which are used to realize current sharing between inverters, and can be applied to wireless charging scenarios in the field of electric vehicles. Applied to at least the following two inverters: the first inverter and the second inverter; the output terminals of the first inverter and the output terminals of the second inverter are connected in parallel at a common parallel point; the current sharing circuit includes: The first inductance component, the second inductance component and the capacitor component; the first inductance component is connected between the output end of the first inverter and the common parallel point, and the second inductance component is connected between the output end of the second inverter and the common Between the parallel points; the capacitor component is connected between the common parallel point and the subsequent equipment connected to the current sharing circuit; the first inductance component and the second inductance component are connected in parallel to form an equivalent inductance; the capacitor component and the equivalent inductance form a series resonance , and the frequency of the series resonance is the same as the switching frequency of the inverter. The circuit ensures current sharing when the inverters are connected in parallel, and the heat distribution of each inverter is even, which improves the power density and work efficiency.

Description

technical field [0001] This application relates to the technical field of power electronics, in particular to a current sharing circuit and a current sharing system when inverters are connected in parallel at high frequency. Background technique [0002] With the depletion of energy and the increasingly serious environmental pollution, the application of new energy vehicles is becoming more and more popular, such as electric vehicles. However, the charging problem of electric vehicles has become an urgent problem to be solved. At present, the development of wired charging piles is very fast, but one problem faced by charging is that the charging time of low power is relatively long. If electric vehicles can be charged as fast as gasoline vehicles, it must Increase charging power. Therefore, wired charging has been developed in the direction of 350kW and 500kW. [0003] However, the problem faced by wired charging is that wired charging requires the operator to manually plu...

AI Technical Summary

Problems solved by technology

[0008] When multiple modules are connected in parallel for power supply, the parallel connection between high-frequency modules may cause uneven output current of each parallel module due to parameter differences and drive delays of each parallel module, and some modules have large output currents. , and some output currents are small, which leads to inconsistent heat generation among inverters, and in severe cases, it may even cause an explosion.

[0009] The traditional technology is to reserve a larger design margin so that the module with the most serious heat generation can also meet the temperature rise requirements, but too large a redundant design will lead to a reduction in the power density and reliability of the system

Images