A controllable voltage source type sub-module protection method

[0068] Such as Figure 1-9 As shown, the invention of this example provides a controllable voltage source type sub-module protection method. The method of the present invention measures the temperature of the key position of the sub-module, and at the same time inverts the internal junction temperature of the power electronic device through the thermal circuit model, thereby obtaining the key position of the sub-module and the thermal stress state of the components; The key positions in the sub-module are compared with the temperature of the components, and the protection against overheating faults of the controllable voltage source sub-module is realized.

[0069] The invention provides a typical half-bridge sub-module based on IGBT devices. The electrical diagram of the half-bridge submodule 1 is attached figure 1 As shown, it contains the secondary board 2, the IGBT module 3, the discharge resistor 4 and the DC capacitor 5. Among them, the IGBT module 3 and the secondary bo...