57results about How to "Fast protection" patented technology

The invention provides an SIC (Silicon Carbide) MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) over-current short-circuit detection circuit and detection protection system. The SIC MOSFET over-current short-circuit detection circuit comprises a first resistor, a second resistor, a sixth resistor, a seventh resistor, an eighth resistor, a ninth resistor, a tenth resistor, a 29th resistor, a 30th resistor, a third capacitor, a first diode, a second diode, a fourth diode, a fifth diode, a second triode and a switch current extending device. For the SIC MOSFET over-current short-circuit detection circuit, the switch current extending device is used, and the switching speed of the switch current extending device is higher than the switching speed of a SiC MOSFET; when the SiC MOSFET is completely turned on, the switch current extending device can be quickly turned on so that the detection circuit can quickly give a response and quickly enter into the detection stage and quickly detect whether over-current short circuit occurs in the SiC MOSFET. Therefore, the detection speed is improved so that the speed for the over-current short-circuit protection circuit to protect the SiC MOSFET is improved.

The invention relates to an over-current or short-circuit state detection circuit of an insulated gate bipolar transistor (IGBT), which comprises a branch circuit, a capacitor, a transistor, a resistor R1, a resistor R2 and a resistor R3, wherein one end of the branch circuit and a negative pole of a power voltage source are electrically connected at a node A, and the other end of the branch circuit, an emitter of a lower bridge arm of a power conversion circuit and a signal grounding terminal of an IGBT driving circuit are electrically connected at a node B; a switching control pole of the transistor and one end of the capacitor are electrically connected at the node B; one end of the resistor R1 is electrically connected at the node A; the other end of the capacitor and the other end of the resistor R1 are electrically connected with a second pole of the transistor; a third pole of the transistor is electrically connected with one end of the resistor R2 and one end of the resistor R3 respectively; the other end of the resistor R2 is connected with high-level chlorinated polyvinyl chloride (PVCC); and the other end of the resistor R3 outputs a guard signal OC. The detection circuit provided by the invention has the advantages of few used elements, low cost, small occupied area of a printed circuit board (PCB) and quick and reliable response, the reduced pressure of the branch circuit does not have disturbance to the IGBT driving circuit, and the power conversion can not influence the reliability and stability of operation.