Help required for designing a HVDC circuit breaker using LTSPICE

[siddiqui]

I am designing a one stage HVDC circuit breaker using LTSPICE software. Basically it consists of a circuit breaker (solid state like thyristor, IGBT etc) and a current commutation circuit in parallel which consist of a capacitor, inductor and energy absorbing circuit (a varistor or high resitor). I have a design based on theoretical model which I am trying to simulate in LTSPICE but it does not work. I am not sure how to control switching. I can attach the .asc file if required.

Thanks in advance.

 

[MikeMl]

Are you asking how to model a switch? A circuit breaker? What, exactly.

 

[siddiqui]

Are you asking how to model a switch? A circuit breaker? What, exactly.

Hello Mike,

I meant the complete model. I am using thyristor as the switch but it does not work. I have also tried using SW and NMOS switches as well but no still does not work. However, the working of the model completely depends on the timing and control of switches. When a fault current is sensed the commutation circuit produces a reverse current (Ic)and which opposes the main current (Ib). At the point when the current reaches zero crossing the main breaker S1 (also S2) is opened. The energy stored in Cc is absorbed by the varistor. All these require a precise coordination of all the switches which I am trying to implement.

 

[ronv]

It might be better if you describe the parts that make up your system... Voltage, load, etc. and then describe what you want the circuit breaker to do.

 

[MikeMl]

Hello Mike,

I meant the complete model...

Then zip up the .asc and all of its library elements, and post it.