The Design Of Electroplating Current-sharing Control System Of Digital Power Supply

With the increasing output current of the switch-mode power supply, compared to the single large module, paralleled power modules have significant advantages in supplying large output current. A flexible and economic distributed power system becomes a trend, and the current balance is one of the key issues during the design of a paralleled power system. This paper focuses on a new current-sharing control system used in an ultra-heavy current electroplating power system.An overall plan of the modularized electroplating power system is introduced in this paper. The power section consists of several paralleled power module with an current-sharing controller to every module. Besides, the paper also discusses several popular current-sharing schemes, and then puts forward a new kind of active current-sharing scheme based on the digital communication which shows excellent performance.This paper takes the paralleling of the electroplating power as an example to tell the digital realization of the paralleled current-sharing system. At first it introduces the realization of the single module, such as the topology of the main circuit, the choice of the component, the IGBT driver, the design of the outer ring control circuit and the interface circuit of the External Controller which contains the pin-settings of the voltage or current, the voltage feedback and the current feedback and so an. After that, it tells the design scheme of the current-sharing controller, which takes the PIC18F66J10 as the main control chip and the CAN bus as the communication medium to connect every single module together, and realizes the constant current and voltage stabilizing mode paralleled current-sharing via algorithm. What's more, the controller also supplies friendly Human Machine Interface so that the user could observe the working state and the output current of every module and measure the real time voltage as well as change the setting value at any moment conveniently.At last, the paper analyses the measured real time data and gets the performance of the paralleled system, which proves the excellent stability and current-sharing.