Development Of DSP-based High Power Switching Power Amplifier

With the development of the electric vibration test system, the requirement of the power amplifier with high performance and high efficiency is urgent. is popularly used because of its virtues of its high efficiency, small volume and high frequency bandwidth. The switching power amplifier is gradually replacing the linear amplifier and has become a hotspot of research now.With the development of the digital dignal processing technology, TMS320C24x series of DSPs (Digital Signal Processor) perform fast and accurate calculations, flexible program capability, and abundant peripheral functions. The high performance of DSPs allows real-time execution of complex control algorithms and single-chip solution for switching power amplifier control system. Benefiting from high performance and low system loss, applications of the TMS320C24x in the control system of switching power amplifiers extensively.How to digitize the control system of switching power amplifier is the focus point in the study.Firstly, the thesis researches the principle, control strategy and classification of the switching power amplifier, and analyses some main parameters. Later, it makes some comparison with four kinds of modulation technique, and finally, it implements the three-level PWM switching power amplifier with the PWM technique. The power of the amplifier is 2kVA, and the frequency bandwidth is 10～3kHz.In the thesis, the author designs and makes the hardwares of the switching power amplifier. The hardwares contain power inverter rank circuit, control system circuit based on DSP, drive and isolation circuit, and protective circuit. The thesis also analyses the potential safety problems and put forward some solutions for the problems. Furthermore, the thesis accomplishes the software design of the control system, and successfully debugs it. The methods of designing higher power ampilfier are also discussed in the thesis. It analyses the feasibility of the methods, outlines the way of how to design higher power switching power amplifier, and does some experiments with the method of switches-parallelling.At last, the hardware and the control strategy are tested by emulation and experiments. A series of waveforms of the whole system are given.