Decentralized active gate control for current balancing of parallel connected IGBT modules

In modern power converters operating at currents of few kA and voltages of several kV, Insulated Gate Bipolar Transistor (IGBT) modules are typically used. The increased power demand of modern inverters and rectifiers results in higher currents and voltages. Currents up to tens of kA and voltages up to tens of kV are required, which exceed the ratings of IGBT semiconductors currently available. Multiple IGBT modules can be connected in parallel or in series to provide the requested current or voltage rating. Depending on the interconnection of the switches, parameter variations in the semiconductors and in the system, as well as tolerances and delay times in the gate driving circuits, an unbalanced current or voltage distribution may occur. Therefore, the IGBT modules are generally derated, which results in an increased number of devices and volume being required. In this paper, a modular concept of a decentralized active gate control for current balancing of parallel connected IGBT modules is presented. It operates distributed to the gate drive units (GDU), the hardware and software configurations are independent of the system design and no restrictions on the number of parallel connected IGBT modules exist.