A Digital IGBT Driver. Control Algorithms and Emergency Modes Detection Methods

Effective control of IGBT power transistors and their protection from emergency modes are crucial for securing reliable and efficient operation of modern power electronics systems used in various fields: traction applications, mining equipment, petroleum production and pumping stations, and environmentally friendly electric transport. To control a power transistor, driver boards are used, which control the transistor module gate. Such board should secure reliable switching and integrity of the transistor module. The driver board receives a signal from the upper level and converts it into a transistor gate control voltage, while in an emergency, the driver must itself turn off the transistor and produce the relevant alarm signal to the upper level. Transistor driver boards can perform IGBT protection functions using both hardware and software approaches. The article describes the control and protection algorithms that have been implemented in an intelligent IGBT driver based on an inexpensive microcontroller. The use of a microcontroller makes the gate control design more flexible and allows the protection thresholds to be accurately adjusted. The driver protects the IGBT from short circuits, current overload, overvoltage; it monitors the voltage supply and controls the transistor turn-on and turn-off processes. To fulfill these tasks, both hardware solutions with a description of the critically important driver board components and software solutions with a description of the implementation of the embedded algorithms are considered. The efficiency of the designed circuit and the developed protection algorithms was tested experimentally using a dedicated test bench. The obtained oscillograms of the study results are presented.