Tubular PECVD (Plasma-Enhanced Chemical Vapour Deposition) is a kind of equipment used for surface coating of solar cells
which may have short circuit faults or circuit overload during operation. Firstly
the bidirectional thyristor control circuit model was established
and the magnitude of the conduction angle was changed through the opening and shutdown time of the bidirectional thyristor control circuit
so as to adjust the output power. Secondly
according to the possible overcurrent multiple
the inverse-time overcurrent protection circuit is designed. Finally
a simulation model was built in the Matlab/Simulink platform to verify the feasibility of the circuit design.The simulation results show that this model can realize inverse-time overcurrent protection and solve the safety problems of tubular PECVD equipment.