Frequency converting control method appropriate for charging process of electric automobile

Abstract

The invention discloses a frequency converting control method appropriate for a charging process of an electric automobile. The frequency converting control method appropriate for the charging process of the electric automobile includes the following steps of fitting a charging power curve in a controller of a battery charger of the electric automobile, and obtaining P 0, P max, P min, and deltaP according to the charging power curve; working out present charging power P d; determining a range which the charging power P d is within; outputting the present frequency conversion operation power P out and obtaining present switching frequency value; judging a range of the frequency conversion operation power P out, wherein the charging time quantum t1-t2 ends; judging a range of present charging power P d in the time quantum t1-t2; outputting present frequency conversion operation power P out and obtaining present switching frequency value; and finishing the charging process when value of the P d is less than charging-stopping power P min. The frequency converting control method appropriate for the charging process of the electric automobile reduces power loss of a system when the vehicle-mounted battery charger charges a storage battery, improves charging efficiency, reducing battery disturbance in the charging process, and improves stability and capacity of resisting disturbance of the system.

Description

technical field [0001] The invention relates to the field of electric vehicle charging, in particular to a frequency conversion control method in the charging process of electric vehicle batteries. Background technique [0002] In today's world, the two major problems of environment and energy are becoming increasingly prominent, and electric vehicles have developed rapidly due to their superior environmental protection and energy-saving characteristics. As an important part of the electric vehicle, the on-board digital charger provides an external power supply to charge the vehicle battery. The efficiency of the charger has become an important criterion for measuring the technical level of electric vehicles. In order to reduce its proportion in the weight and volume of the vehicle, its volume is usually relatively small, but the volume decreases, which promotes an increase in the frequency during the charging process. The increase in frequency leads to an increase in the sw...

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Problems solved by technology

However, the method described in this patent has the following disadvantages: 1. The system makes the frequency of the switching power supply vary with the change of the load. This is a hysteresis compensation control method. If the frequency of the charging system lags behind the load change in real time, the system will appear abnormal. Stabilization phenomenon, leading to the destruction of the entire charging system

2. Electric vehicle battery charging is a process in which the charging power is constantly changing. The frequency of the switching power supply changes in real time according to the change of the load. When a disturbance occurs, the frequency of the switching power supply may change drastically, causing system instability and EMI problems

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