MOSFET (Metal-Oxide -Semiconductor Field Effect Transistor) parallel current-sharing circuit based on fault diagnosis

Abstract

The invention provides an MOSFET (Metal-Oxide -Semiconductor Field Effect Transistor) parallel current-sharing circuit based on fault diagnosis. The MOSFET parallel current-sharing circuit comprises a main control unit and at least two paths of MOSFET parallel branch circuits, wherein the main control unit is connected with each path of MOSFET parallel branch circuit through a fault detection unit; each MOSFET parallel branch circuit is used for finishing signal acquisition of each branch circuit; the main control unit is used for judging whether the working of the branch circuits is normal or not according to an acquired signal and sending a corresponding driving signal to each branch circuit; the fault detection unit is used for carrying out overcurrent judgment according to a received current signal, and determining a finally output driving signal according to an overcurrent judgment result, a received driving under-voltage signal and a driving signal integrity detection signal. According to the MOSFET parallel current-sharing circuit, each MOSFET parallel branch circuit has the independent driving signal and the independent fault detection unit, and whether branch circuit voltage, temperature and gate driving are under-voltage and the driving signal is complete or not can be detected. By adopting the MOSFET parallel current-sharing circuit, parallel branch circuits current sharing is realized and fault detection of the parallel branch circuits is also realized; the reliability is higher when the plurality of parallel branch circuits works.

Description

technical field [0001] The invention relates to the technical field of power electronics, in particular to a parallel current sharing circuit including a fault detection unit. Background technique [0002] Parallel current sharing circuits are mainly used in motor drives. The current motor driver mainly uses IGBT or MOSFET as the main power device. Compared with IGBT, MOSFET has the advantages of lower price and smaller volume. Especially in the equal power and low voltage system, MOSFET is easier to achieve low voltage and high current through parallel connection than IGBT. power drive mode. [0003] While multiple MOSFETs are connected in parallel to meet the high-current power drive, the current sharing of the parallel branch is also particularly important. Most of the existing parallel current sharing circuits are passive current sharing methods, that is, the driving signal of each parallel circuit is shared, and the current sharing effect is achieved according to the ...

AI Technical Summary

Problems solved by technology

Most of the existing parallel current sharing circuits are passive current sharing methods, that is, the driving signal of each parallel circuit is shared, and the current sharing effect is achieved according to the self-regulating characteristics of the power device and the corresponding circuit, but due to the parameters of the power device itself and the circuit The difference in parameters will lead to the problem of uneven current distribution when devices are connected in parallel

And when the parallel branch fails, it cannot be judged and isolated in time. In severe cases, the related parallel power device will be overloaded and damaged

Images