A.N. Githiari

The series connection of IGBTs with active voltage sharing

This paper presents the reasons that make series operation of insulated gate bipolar transistors (IGBTs) attractive and challenging and reviews the methods that may be used. Then, a new approach, which uses the IGBTs gate-controlled active regime in place of large voltage-sharing snubbers, is proposed. Analytical and simulation techniques are used to study the performance and conditions for stability given. It is concluded that when making each IGBT voltage follow a reference input, with closed-loop voltage control, the IGBTs are able to share the transient turn-off voltage without turn-off snubbers. This technique may lead to more compact and efficient high-voltage-power modules.

The series connection of IGBTs with optimised voltage sharing in the switching transient

This paper reviews the reasons that make series operation of IGBTs attractive and challenging. Then, a new approach which uses the IGBTs gate controlled active regime in place of large series sharing snubbers is proposed. This technique is shown to improve the voltage sharing during switching transients and may lead to more compact and efficient high voltage power modules.<<ETX>>

High performance gate drives for utilizing the IGBT in the active region

The advantages of operating the IGBT in its active region for active snubbing and series operation have been established in the literature. In this paper we describe the implementation and performance of several gate drive circuits suitable for use in closed loop control of the IGBT voltage. The application of the gate drives to active control of a wide range of IGBT devices is demonstrated and discussed.

A comparison of IGBT models for use in circuit design

In choosing an accurate insulated gate bipolar transistor (IGBT) model for power electronic circuit design, physics-based models are frequently preferred due to their high accuracy and fast simulation speed in comparison to other types of models. In this paper, an experimental comparison of two such models is made, using parameters extracted from experimental measurements. The comparison focuses on two particular IGBTs-the BUP202 and the BUK854-representing the two common types of IGBT, respectively, the nonpunchthrough and the punchthrough IGBT. The models are investigated for the IGBTs operation in three situations typical of low-power (600 V, 10 A) applications.

Some scaling issues in the active voltage control of IGBT modules for high power applications

The operation of an IGBT in its active region is a well established technique for handling short circuits, and also for voltage and dv/dt control. One important application of this technique is in the series operation of IGBTs, where voltage controllers can automatically ensure voltage sharing. In this paper we address some specific issues encountered in extending the method to large IGBT modules for high power applications. In applying the method to high power circuits, the scaling of the IGBTs internal capacitances, and other parasitic components is the main aspect that must be given particular consideration.