The Study Of Medium-frequency Inverter And Digital Control Technology Applied In Armored Equipment

With the rapid development of military equipment today, armored equipment is still an important support of the national military strategy. The power supply system of the armored equipment is responsible for providing the high quality electrical energy to the electronic equipment of the whole vehicle, ensuring the normal operation of the equipment. At present, the kinetic energy of the armored equipment were provided by the gasoline engine, by the engine driven rotary AC machine to generate electrical energy, the energy conversion is simple and direct, low failure rate. But it is lack of, such as mobile training wasting energy seriously, and the harmonic content of the output voltage higher. Therefore, it is significant to study a static inverter system which uses the city power supply in the absence of motor training. It can extend the life of the fuel engine and save energy. In this paper, a static inverter is designed, its parameters and performance meet the needs of a certain type of armored equipment power supply system.In this paper, research on unbalanced load based on intermediate frequency three-phase four wire system, adhering to the modular design ideas, the use of combined three-phase inverter topology and double closed-loop PI control strategy with effective value feedback, the use of unipolar double frequency SPWM control and the intersection of asymmetric SPWM sampling algorithm design. System consists of main circuit, control circuit, sampling circuit, protection circuit and auxiliary power supply circuit composition, main control chip for TI TMS320F28069, it mainly responsible for sampling, calculation, output drive pulse and protective pulse etc.In this paper, we first make the topology selection, the advantages and disadvantages of several common three-phase four wire inverter topologies are analyzed in detail, and calculate the power loss in the same output power, and analysis of its reliability, according to the design index of this paper, we choose the optimal topology combined three-phase inverter topology; Then analyze the control strategy, choose double closed loop PI control strategy, the inductor current and capacitor current are used as the control object of the current inner loop, and make comparative analysis from the transfer function, amplitude frequency characteristic, MATLAB simulation, draw a conclusion that the effect of capacitive current control is better than that of inductor current, however, due to the capacitive current control of the double closed loop PI control strategy is still not enough, in this paper, an improved double closed loop PI control strategy with an effective value ring is introduced; Finally, by doing experiments, the rationality of the design is verified, experimental platform output voltage amplitude is stable,the waveform quality is good, the harmonic content is low, the conversion efficiency is high, the system band is not balanced load ability is strong, meet the design requirements.