A short circuit and overcurrent protection device and method

Abstract

The present application discloses a short circuit and overcurrent protection device, including: a detection circuit for detecting the absolute value of the magnetic field; and, for the preset N switching tubes in the protected circuit, if the positive If the direction current is the same, the magnetic field vectors generated by each switch tube at the detection position of the detection circuit are the same, and N is a positive integer not less than 2; the shut-off circuit connected with the detection circuit is used for when the absolute value of the magnetic field detected by the detection circuit When the preset magnetic field strength threshold is reached, at least one switch tube in the N switch tubes is turned off. By applying the solution of the present application, the short-circuit and over-current protection of the switching tube can be realized quickly and accurately at low cost, and the short-circuit situation can be predicted to a certain extent, and the short-circuit protection can be performed in advance. The application also discloses a short circuit and overcurrent protection method, which has corresponding technical effects.

Description

technical field [0001] The invention relates to the technical field of circuits, in particular to a short circuit and overcurrent protection device and method. Background technique [0002] Reliable short-circuit and overcurrent protection is critical to the reliability of power electronics. Especially compared to Si IGBT (Silicon Insulated Gate Bipolar Transistor, Silicon Insulated Gate Bipolar Transistor), SiCMOSFET (Silicon Carbide Metal-Oxide-Semiconductor Field-Effect Transistor, Silicon Carbide Metal-Oxide-Semiconductor Field-Effect Transistor) short-circuit current The rising speed and peak value are much larger, so the short-circuit current can withstand a shorter time, and it is more necessary to perform fast and accurate short-circuit protection. The implementation of short-circuit and over-current protection is mainly divided into two steps. The first step is to detect a short-circuit or over-current of the device, thereby sending out a fault signal. Step 2: The...

AI Technical Summary

Problems solved by technology

A typical approach is to use figure 1 The RC integrator circuit shown, the Kelvin inductor's information into a voltage, the Short-circuit faults can be judged by comparing with the threshold, but for slow-changing over-current faults, the detection time will be significantly longer, or even undetectable

SiC MOSFET chips integrated with sense electrodes can use part of the unit cell exclusively for current detection, but the cost is high and it is not universal

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