| 摘要 |
A control system (1) for control or active power in a first electric power network (A) which obtains power from a second network (B) e.g. when electric supply for railway traffic is fed from a general electric network. The networks operate at different frequencies and this is accommodated by frequency converters (11,12). There will be a phase angle difference, or transfer angle, between the second network frequency at one point and that at another, depending upon the prevailing impedance and the actual power exchange in the second electric power network. The frequency converters are arranged to co-operate using a phase measuring device (21,22) with a common time reference (31,32). The arrangement enables fast and simple use of set value for the phase ratio in respective frequency converters, achieved with high-precision and, if desired, very short time intervals. The set of values are calculated to either minimize power flow or to control the flow so that power is obtained from specific connection points. |
