Converter valve

摘要

A converter valve unit including a plurality of parallel connected controllable semiconducting elements. A free-wheeling diode is connected in anti-parallel with each semiconducting element. A control unit is configured to control each semiconducting element. A current sensor is connected to each of the parallel connected semiconducting elements. The current sensor is configured to sense a current of each semiconducting element by measuring a voltage over the current sensor. A differentiator is configured to compare the currents of the semiconducting elements by comparing the voltages. Upon detecting an unbalance in the currents the differentiator sends a turn-on signal to all control units to control all the semiconducting elements of the valve unit into a conducting stage.

主权项

1. A converter valve unit, comprising:
a plurality of parallel connected controllable semiconducting elements; a plurality of free-wheeling diodes, each of the free-wheeling diodes being connected in anti-parallel with a corresponding one of the semiconducting elements; a plurality of control units, each of the control units being configured to control a corresponding one of the semiconducting elements; a plurality of current sensors, each of the current sensors being connected to a corresponding one of the parallel connected semiconducting elements, wherein each of the current sensors is configured to sense a current of the corresponding one of the semiconducting elements by measuring a voltage over the corresponding current sensor; and a differentiator configured to compare the currents of the semiconducting elements by comparing the voltages, wherein upon detecting an unbalance between the current of any one of the semiconducting elements and the current of another one of the semiconducting elements, the differentiator sends a turn-on signal to all of the control units to control all the semiconducting elements of the converter valve unit into a conducting stage.