| 摘要 |
PROBLEM TO BE SOLVED: To enable always exhibiting excellent harmonic absorbing effect, when frequency of a power system is changed and a capacitor and a reactor are changed by condition change with time or the like. SOLUTION: A capacitor and a reactor which are connected with a power system, a matching transformer which is connected in series with the capacitor and the reactor, an inverter connected with the secondary side of the matching transformer, a current transformer detecting a current flowing into the capacitor and the reactor, a transformer detecting a voltage of the power system, and a control equipment 8 into which these current.voltage signals are inputted and which controls an output voltage of the inverter are installed. The control equipment consists of the following; a circuit 8a detecting the harmonic component of a voltage, a circuit 8b detecting the harmonic component of a current, a circuit 8c detecting the difference of phases between the harmonic voltage and the harmonic current, an operating circuit 8d which increases and decreases a coefficient L corresponding to the difference of phases, a circuit 8e differentiating a detected current, a circuit 8f which forms an output voltage reference of the inverter by multiplying a differentiated value of current by the coefficient L, and a circuit 8g which drives a switching element of the inverter in accordance with the output voltage reference. |
