| 摘要 |
A voltage limiter for protecting the thyristors of a current source inverter, also known as a controlled current inverter, wherein the limiter includes a circuit for sensing the respective voltages directly across at least one but preferably across each of the thyristors in the inverter and generating a signal corresponding to the highest value and a regulator circuit which is operable in response to the difference between the highest value signal and a reference signal corresponding to a safe operating voltage for the thyristors in the inverter, to modify the thyristor gating angle of those thyristors which control the current in the inverter. The voltage limiter thus reduces the current carried by the inverter thyristors when the highest voltage across the inverter thyristors exceeds the reference signal, and thereby reduces the amplitude of any commutating spike voltage in the voltage applied across the thyristors. This permits full utilization of the inverter rating while requiring no adjustment for source impedance, line voltage, or commutating capacitance. |
