Temperature protection circuit

A temperature protection circuit for a power converter, the power converter comprising a control circuit, a plurality of driving circuits, a plurality of power semiconductor switch blocks connected in series, and a heat sink, each of the power semiconductor switch blocks comprising at least one power semiconductor switch, wherein

• the power converter further comprises a voltage-withstanding clamping circuit connected between a potential midpoint of the power converter and the heat sink;
• the temperature protection circuit comprises a plurality of temperature protection branches, each of the temperature protection branches comprises a resistor, a voltage source, a temperature switch, and an isolation transformer, the temperature switch comprises a contact of the temperature switch and a base, and the base is disposed on the heat sink;
• and
• each of the temperature protection branches corresponds to one of the power semiconductor switch blocks, and a first end of the resistor of each of the temperature protection branches is coupled to an output electrode of the power semiconductor switch block, and a second end of the resistor is coupled to a first end of the voltage source and coupled to a first end of the contact of the temperature switch via a primary winding of the isolation transformer, a second end of the voltage source and a second end of the contact of the temperature switch are respectively coupled to the potential midpoint of the power converter, and two ends of a secondary winding of the isolation transformer are respectively coupled to the driving circuit corresponding to the corresponding power semiconductor switch or coupled to the control circuit.