High-performance low-cost IGBT (Insulated Gate Bipolar Translator) negative pressure bootstrap drive circuit

Abstract

The invention provides a high-performance low-cost IGBT (Insulated Gate Bipolar Translator) negative pressure bootstrap drive circuit which comprises a direct-current power source, a lower-arm optocoupler, a gate resistor R3, a lower-arm insulated gate bipolar transistor Q2, a negative pressure capacitor C4 and a voltage stabilizing diode D5, as well as an upper-arm fast recovery diode D1, an upper-arm optocoupler, a bootstrap capacitor, a gate resistor R1, an upper-arm insulated gate bipolar transistor Q1, a negative pressure capacitor C3 and a voltage stabilizing diode D2. Improvements are achieved as follows: a branch is additionally arranged between the gate and emitter of the upper-arm Q1; one end of the branch is connected to the emitter of Q1, while the other end of the branch is connected to a circuit between the output pin of the upper-arm optocoupler and the gate of Q1; the branch is provided with a voltage stabilizing diode D6 and a fast recovery diode D7 connected in series reversely; and when Q1 is closed, the voltage between the gate and emitter of Q1 is the optimal drive voltage for the IGBT, which is negative pressure when the Q1 is opened; and therefore, Q1 can be opened reliably. The high-performance low-cost IGBT negative pressure bootstrap drive circuit can be used for solving the problems that the existing IGBT negative pressure bootstrap circuit cannot be recharged, the upper-arm IGBT cannot be opened reliably and the device is burnt out under large load. Besides, the high-performance low-cost IGBT negative pressure bootstrap drive circuit is rational in parameter and low in loss. The number of independent power sources is reduced so that the cost is reduced. Furthermore, the high-performance low-cost IGBT negative pressure bootstrap drive circuit is used for driving motors, inverted network access and frequency converters.

Description

[0001] (1) Technical field: The present invention relates to a driving circuit of an insulated gate bipolar transistor IGBT. Mainly used for driving motors, inverters and inverters. It belongs to DC and AC conversion power supply category (H02M), pulse technology category (H03K). (two) background technology: [0002] Insulated gate bipolar transistors (i.e. IGBTs) have the characteristics of both power field effect transistors (MOSFETs) and power transistors (BJTs), making them widely used in power electronics systems, especially in the frequency conversion technology industry. The key to the use of IGBT is to design a suitable drive circuit. [0003] In the frequency converter, the driving circuit of the IGBT is classified according to the driving power supply, which can be roughly divided into two categories: 1) The first category is that the upper arm IGBT in each bridge arm uses an independent low-voltage DC power supply (belonging to the control loop power supply): see ...

AI Technical Summary

Problems solved by technology

[0005] The high-performance and low-cost IGBT negative voltage bootstrap driving circuit provided by the present invention is to solve the problem that the negative voltage capacitor C3 in the existing IGBT negative voltage bootstrap driving circuit does not match the structure of the IGBT itself, and cannot be charged and the IGBT cannot be realized. Drive negative pressure, which causes the upper arm IGBT to be unable to be turned off reliably; when the load is heavy, the upper and lower arms are directly connected, which eventually burns down the device

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