摘要:
A power fluctuation monitoring unit which monitors and detects the power fluctuation at a receiving point 9 by means of the measurement results of the voltage at injection point 14 of an intermediate-order harmonic current and the current at incoming line 10, a power compensation unit which forms the compensation power injection signal for canceling out the power fluctuation based on the detection results of the power fluctuation, and an inverter device 18 which is driven and controlled by the signal resulting from the addition of the intermediate-order harmonic current injection signal and the compensation power injection signal and injects the intermediate-order harmonic current and the compensation power into the injection point, are equipped.
摘要:
A problem to be solved by the present invention is to eliminate variation in potential in a turn-off time period of each GTO element, and to stabilize a gate drawing current by surely performing the turn-off of the GTO element. In an inverter apparatus (11) having a three-phase inverter (14) configured to include paired GTO elements UP, UN, VP, VN, WP, and WN connected in a bridge configuration and to convert a power supply voltage, which is supplied from a dc power supply (13), by the GTO elements UP, UN, VP, VN, WP, and WN into an ac voltage, an inverter control portion has a simultaneous switching prevention function of delaying a turn-on operation of each of the GTO elements VN and WN, which correspond to phases other than a phase corresponding to an optional one of the GTO elements and also correspond to an electrode opposite to an electrode corresponding to the optional one of the GTO elements, for example, the GTO element UP, by a predetermined time in a case where a turn-on command signal for turning on each of the GTO elements VN and WN, which correspond to the other phases, is generated within a predetermined time period since the turn-off of the optional one of the GTO elements.
摘要:
A problem to be solved by the present invention is to eliminate variation in potential in a turn-off time period of each GTO element, and to stabilize a gate drawing current by surely performing the turn-off of the GTO element. In an inverter apparatus having a three-phase inverter configured to include paired GTO elements an inverter control portion has a simultaneous switching prevention function of delaying a turn-on operation of each of the GTO elements which correspond to phases other than a phase corresponding to an optional one of the GTO elements and also correspond to an electrode opposite to an electrode corresponding to the optional one of the GTO elements by a predetermined time in a case where a turn-on command signal for turning on each of the GTO elements is generated within a predetermined time period since the turn-off of the optional one of the GTO elements.
摘要:
A harmonic injection point a is set on a power line extending downstream from a harmonic measuring point b in an electric power system. The currents of interharmonics are injected to the harmonic injection point a by a current injection device. The frequencies of the interharmonics are located on both sides of the frequency of an n-th targeted harmonic in frequency spectrum and each of the frequencies is a nonintegral multiple of the frequency of a fundamental wave of an electric power transmitted by the electric power system. The current values and voltage values of the interharmonics at the harmonic measuring point are detected to thereby obtain admittance values of an equivalent circuit of a power line extending upstream from the harmonic measuring point b when the interharmonics flow therethrough. An admittance value of the equivalent circuit of the power line when the targeted harmonic flows therethrough is determined by interpolating the admittance values for the interharmonics. Measurement is made of a harmonic characteristic of the power line extending upstream from the harmonic measuring point b, which is set at a point located upstream from the harmonic injection point a.