Method and apparatus for balancing the power losses in a number of parallel-connected cascode circuits

A method for balancing the power losses in at least two electrically parallel-connected cascode circuits, each of which have a low-blocking-capability semiconductor switch composed of silicon and a high-blocking-capability semiconductor switch composed of silicon carbide, said method comprising:

• linking one control connection of said high-blocking-capability semiconductor switch to a reference connection of its corresponding low-blocking-capability semiconductor switch by means of a controllable decoupling device;
• detecting an output voltage of each low-blocking-capability semiconductor switch in said parallel-connected cascode circuits;
• and
• establishing correction values as a function of said detected output voltages, and supplying said correction values to corresponding controllable decoupling devices.

An apparatus for balancing the power loss in at least two electrically parallel-connected cascode circuits, which each have a low-blocking-capability semiconductor switch composed of silicon and a high-blocking-capability semiconductor switch composed of silicon carbide, said apparatus comprising:

• a control connection of said high-blocking-capability semiconductor switches linked by means of a controllable decoupling device to a reference
• connection of its corresponding low-blocking-capability semiconductor switch;
• and
• a voltage measurement device for each cascode circuit and a device for establishing a correction value for each cascode circuit, wherein each voltage measurement device is linked on the input side to a main connection and to a reference connection of a low-blocking-capability semiconductor switch, and being linked on the output side to an input of a corresponding device, and wherein each device for establishing a correction value is connected on the output side to a control input of a corresponding controllable decoupling device.