The Design Of SPWM Inverter Based On MCU PIC In Car

With the increasing of the vehicle electrical appliance dependent to people gradually, the design of a high efficiency, good stability, good safety power supply is very important. In order to meet the electricity needs of vehicle electrical equipment, Vehicle-borne power supply realizes the conversion of12V DC vehicular battery to220V/50HZ AC frequency,. Currently on the market, most Vehicle-borne power supplies are the correction of square wave power supply. This kind of Vehicle-borne power supplies can satisfy the demand of resistive load, but it is not applicable to the inductive load, greatly restricting its scope of application. Pure sine wave inverter power supply not only can realize demand of the resistive load, but also satisfy the demand of the inductive load, effectively widening the using range of the vehicle electrical appliances. Therefore, the design of a pure sine wave inverter power supply design appears extremely urgent.First of all, this paper make investigation of the status and the research significance of Vehicle-borne power supply, putting forward the design goal of a digital SPWM Vehicle-borne power supply.Secondly, through undertaking an analysis of application environment and technology design index to the vehicle of sine wave inverter, this paper designs main circuit topology of a Vehicle-borne power supply of300W12VDC-220VAC/50HZ power converter, i.e. former level converter circuit structure and the level of full bridge inverter two circuit structure, and front and rear stage adopt electromagnetic isolation mode. The advantage of thsis circuit structure largely improves the system’s stability and security.Again, this paper analysis and selects each subsystem and makes specific hardware circuit design, including DC-DC high frequency link main loop, frequency of DC-AC inverter main circuit,former stage of PWM control circuit, back stage of SPWM control circuit, voltage feedback circuit and undervoltage/over-voltage protection, Short circuit/overload protection and temperature protection five protection circuit.In addition, this paper makes the process design based on the software portion of the system, and makes the specific programmings of system initialization and interrupt service routine. Thus completing digital control of the system, so as to realize the system debugging, but also improve the adaptability of system.Finally, based on simulation and experimental circuit structures of the proposed scheme and debugging and testing of the few functions of the system, it is shown that the system has feasibility and implementation.In this paper, the design of a car inverter power supply meets the requirements of the current market car inverter design, and it provides a certain reference value.to the digital inverter power.