Design Of A Digital PWM Controller Based On FPGA

With the rapid development of power electronics, control technique applied in the power electronic converters becomes more and more complex. Great progress of microprocessor and peripheral circuit causes distinct improvements in digital control techniques. Then, the digital control technique will gradually substitute analog in some aspect control technique for controlling power electronic system.Power semiconductor devices develop continuously for high frequency, high efficiency and intellectualization. It demands that power electronic control system has much higher real-time capability. With the demands of important departments and electric equipments for higher quality power supply ascending, high performance PWM controller are taken more and more attention. With its incomparable merits, digital control is gradually taking place of analog control in some aspect. On the one hand, digital PWM controllers gain more freedom for design, with which kinds of complicated and intelligent algorithms can be implemented easily; on the other hand, the traditional strategies are still playing an important pole in the digital control. The hybrid strategies of the advanced digital strategies and the traditional ones are now most accepted in the product application.In recent years, Programmable Logic Devices (PLD) stride continuously forward high integrity, high speed and lower price, which are applied more far and widely in signal processing. Compared with MCU, CPLD/FPGA has much higher speed. Aiming at the advantages of PLD such as high integrity, high speed, designed agility and short cycle of design, a new scheme that uses PLD in power electronic control technique for high real-time's capability is brought forward in this paper.In this paper, the principle and method that making use of FPGA to realize high accurate PWM controller are chiefly analyzed, A novel way of control circuit is mentioned for power electronics converters with FPGA. The units of A/D sampling control, realization of control arithmetic and generation of PWM waveforms are completely integrated in FPGA, which reduces the perplexity of circuit. Then, The digital controller based-on FPGA is applied in the Boost Converter. The emluation and experiment is performed. The results prove that the PLD have high speed processing capability interiorly and the digital controller based-on FPGA has a good performance.