High withstand voltage power semiconductor device on-line voltage drop measurement circuit and system

Abstract

The present invention provides a high withstand voltage on-line measurement circuit and system for the conduction voltage drop of power semiconductor devices, including a withstand voltage circuit and a clamping circuit, one end of the withstand voltage circuit is connected to one end of the clamping circuit, the withstand voltage circuit and the The other end of the clamping circuit is respectively connected to any one of the two ends of the power semiconductor device under test. The withstand voltage circuit is composed of several withstand voltage units and a current limiting circuit. The two ends of the clamping circuit are the output terminals of the measuring circuit. The clamping voltage of the bit circuit is higher than the turn-on voltage drop of the power semiconductor device under test. When the power semiconductor device under test is turned off, the clamp circuit plays a clamping role; when the power semiconductor device under test is turned on, the clamp circuit The clamping effect fails. The present invention realizes the substantial improvement of the withstand voltage level of the measurement circuit through the series voltage division of multiple withstand voltage units, and can improve the transient performance of the measurement system by adjusting the device parameters in the current limiting circuit and the clamping circuit, and the measurement is accurate and applicable. wide and low cost.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a measurement circuit and system for conducting voltage drop of a power semiconductor device with high withstand voltage and adjustable transient performance. Background technique [0002] The power semiconductor device is an important component in the power electronic converter, and the power semiconductor device is the part with the highest failure probability and the highest cost in the power electronic converter. The conduction voltage drop is one of the important characteristic parameters of the power semiconductor device. It is related to the junction temperature of the power semiconductor device and the aging state of the bonding wire inside the device. Therefore, the conduction voltage drop can be used as a temperature sensitivity coefficient for monitoring the device The heating state can also be used to detect the aging state of the device. Accurate on-line m...

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Problems solved by technology

However, when the power semiconductor device is turned off under working conditions, its two ends need to withstand a high voltage of hundreds of volts or even thousands of volts, and when the device is turned on, its conduction voltage drop is only about 1V, so directly measure the voltage across the device The voltage will reduce the measurement accuracy of the conduction voltage drop due to the large range of the measurement system. It is necessary to clamp the voltage when the device is turned off to a lower value to accurately measure the conduction voltage drop when the device is turned on.

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