The Research And Application Design On Low-voltage And High-current Inverter

Since the birth of the inverter in1940s, the inverter has been experienced rapid development. Low-voltage and high-current inverter are widely used in low voltage and high-power field with the characteristic like low output voltage, high-current, etc. The research on low-voltage and high-current inverter is studied. The inverter by parallel power MOSFET and oriented control of rotor Magnetic field about induction motor and is designed by theoretical analysis, software simulation and experimental.The rotor flux model and the decoupling control is analysed and the indirect rotor field oriented control method by the space vector pulse width modulation for induction motor control is used, by changing the mathematical model of induction motor coordinate transformation to the two phase synchronous rotating coordinate system. Referring to the low-voltage high-current inverter for special requirements, the dead zone compensation has been taken. A low-voltage high-current inverter control system simulation models has been built, analyzing the waveform performance and low-voltage high-power motor drive of the system at rated speed and rated load conditions. Simulation results show that the dynamic performance of rotor field oriented control system is better, with a big load capacity to verify the correctness and effectiveness of control strategies.The inverter main circuit has been designed to meet the design requirements based on the principle of inverter. Power MOSFET devices in parallel programs is used by meeting the output requirements and economic conditions, according to the inverter topology, analysis of power MOSFET characteristics and working principle. For current imbalance of power MOSFET in parallel, analyzing the causes of power MOSFET in parallel uneven current distribution, the simulation of MOSFET in parallel is done and flow characteristics is studied, the gate way resistance compensation is used to solve the dynamic mode switch. The current of voltage spikes and current spikes are generated when the opening or closing, running from the system stability considerations, snubber circuit to suppress the power devices off when the opening of voltage spikes is designed. Mathematical model of the buffer circuit is set up, the buffer circuit and system main circuit are simulated, and the parameters of buffer circuit is optimized through theoretical analysis. The device is selected and the drive circuit is designed according to requirements of multiple power parallel MOSFET, analysis characteristics of drive chip common, calculation of parameters from drive circuit. The control circuit by the DSP and CPLD as the core has been designed finally.Finally, the analyses and experiments of the whole system are produced, by debugging the power circuit, driver circuit and control circuit. The experiments results show that low-voltage high-current inverter system meets the design requirements, the dynamic performance of the system is pretty well.