IGBT Protection in AC or BLDC Motor Drives

In the last decade, industrial AC drives have become more advanced in performance and more compact in size. This is largely due to the rapid development of power silicon technology, including the enhancement of IGBTs and of High Voltage Integrated Circuits. Additionally, this technological growth has been particularly accelerated for low horsepower (< 5 Hp) AC Drives. Yet the ground fault protection, a feature sought increasingly in motor drives of all power levels, is available widely only in the high-end models due to the sensors and other circuitry involved. The market, however, continues to demand a fully protected, yet inexpensive, system. To meet this demand, International Rectifier has introduced the IR2137: a new generation 3-phase IGBT gate driver, featuring full IGBT protection and advanced soft shutdown features. To understand traditional methods of IGBT protection, read Section 2. To understand the working of the IR2137 skip to Section 3.