| 摘要 |
PROBLEM TO BE SOLVED: To connect a converter to an AC voltage network without using an intermediate individual winding transformer by a method, wherein a control signal is generated and supplied to a gate turn-off semiconductor valve, so as to make the time average of a voltage at a junction point equal to a voltage between two terminals of a capacitor. SOLUTION: A control signal -CS, by which one of the thyristors of valves V7 and V8 is electrically conducting for a time of half the period, while the respective thyristors are electrically conducting to make the time average of a voltage at a junction point J equal to the average of the terminal voltages of corresponding capacitors, i.e., zero. If a voltage +Ud is supplied to the neutral electrode of a single electrode power network, symmetrical DC voltages +UC and -UC are respectively supplied to the DC voltage terminals of a converter VC, and the voltages +UC and -UC are equal to +Ud/2 and -Ud/2. Therefore, the converter can be connected to an AC voltage network, without the use of an intermediate individual winding transformer. |
