Driver eletrônico com seis saídas isoladas para transistores de potência do tipo IGBT

Abstract

In this work, it was developed a driver for actuation of IGBT power transistors. the main characteristics of the developed prototype stand out the galvanic isolation between the pulse generator and the gate, the compatibility with circuits CMOS and TTL, a single source of 15V and the possibility of actuate until six transistors simultaneously. The circuit was developed with electronic components of low price and easy acquiring. The flexibility to update the electronic components also is a strong point. So, won't have great changes in the structure in case of some components becomes unavailable in the electronical industry. The proposal of the driver arose of the need of this kind of device with isolated outputs. This is required to some applications in power electronics. NPC inverters of three levels have four transistors connected in series. In this example, the drivers need isolated sources to operate on different reference points. Although this implementation be possible, the same raises the costs and the global size of the inverter. In this work, the 15V of a single source are converted to an alternated signal of high frequency and applied in the primary winding of a transformer. This transformer has six isolated secondary windings each other. Each of secondary windings have push-pull output stages, with bipolar transistors commanded by optical isolators. Experimental tests have shown that the times of rise and fall of the pulses in the output of the driver as well as the propagation times can compete with the commercial devices.