The dual-loop control method, in which inner-loop is the current and outer-loop is the voltage, is proposed to design a high-efficient precise numerical control parallel power supply system, it operates at input voltage of 24V, output voltage of 6-12V and output current of 0-4A. The current ratio of the parallel circuits can be set arbitrarily. Precise adjustment of output current and improvement of efficiency are realized by width modulation and synchronous buck-topology switching power supply, the output current error is smaller than 20mA and DC-DC conversion efficiency is up to 90%; to make output voltage error smaller than 30 mV and the current-sharing error smaller than 0.5%, digital calibration technology and PID control algorithm are used. In addition, this system is equipped with the function of overload protection, double-source redundant heat standby and turn-off, etc.
Intelligent numerical control power supply system design
