Selection Of Inverter Power Devices

- Jan 15, 2019-

At present, the domestic photovoltaic power generation system (PhotoVoltaic Sys-tem, referred to as PVS) is mainly DC system, but the most common power load is AC load, which makes DC power supply photovoltaic power supply is difficult to popularize as a commodity. At the same time, because solar photovoltaic grid-connected power generation can not battery, and maintenance is simple, and saving investment is the development trend of photovoltaic power generation. All of these must be AC power supply, so the application of inverters in PVS is becoming more and more important. Inverter is a power transformation device which transforms DC into alternating current, and the inverter technology has been mature in power electronics technology.

For example: inverter in UPS power supply, inverter technology in frequency conversion technology, Inverter technology in special power supply and inverter technology in power regulator, these have been introduced to the market in the form of products, and widely recognized by the community. In small capacity, low pressure PVS, power devices use more metal-oxide-semiconductor FET (MOSFET). Because it has a low state pressure drop and a higher switching frequency at low pressure, its flux resistance increases with the increase of MOSFET voltage. Therefore, in the large capacity, high pressure PVS, the general use of insulated Gate transistor (IGBT) as a power device, in the 100kVA above the large capacity of the PVS, the general use of door pole can be shut down thyristor (GTO) as a power device. The inverter drive circuit in PVS is mainly aimed at the gate pole drive of the power switch tube. In order to get a good PWM pulse waveform, the design of the drive circuit is very important. In recent years, with the development of microelectronics and integrated circuit technology, a number of multi-functional special integrated chips have been introduced, such as: HIP4801,TLP520,IR2130,EXB841, they have brought great convenience to the design of application circuits [1,2]. The control circuit commonly used in inverter power supply is mainly to provide the required logic and waveform for the driving circuit, such as PWM,SPWM control signal and so on. At present, more commonly used chips have foreign production of 8XC196,MP16,PIC16C73 and domestic production of TMS320F206,TMS320F240, SG3525 and so on.