Other

Mitsubishi Denki Kabushiki Kaisha

Susumu Jatsumura

Susumu Matsumura and Mitsubishi Denki Kabushiki Kaisha

Susumu Matsumura

Masao Yano

Nobuo Sashida

Yasuhiko Hosokawa

Yoshihiko Yamamoto

Mitsumasa Imataki

Kanji Katsuki

This invention relates to an apparatus for controlling a D.C. power transmission system having a line-commutated converter which is connected between a first A.C. system and D.C. power transmission lines and which performs power conversion between A.C. power and D.C. power, and a forced-commutated converter which is connected between the D.C. power transmission lines and having a second A.C. system and which performs power conversion between A.C. power and D.C. power. In order to control transmission power in the two-terminal D.C. power transmission system wherein the two A.C. systems are associated by direct current, a control apparatus for a D.C. power transmission system according to this invention includes a voltage detector which detects a D.C. voltage of the D.C. power transmission lines, a first control circuit for comparing the output of the voltage detector with a voltage reference signal and for controlling ignition of the self-excited converter in accordance with the comparison, a detector which detects a current which is proportional to the conversion power of the line-commutated converter, and a second control circuit for comparing the output of the current detector with a power reference signal and for controlling ignition of the line-commutated converter in accordance with the comparison.

Control apparatus for D.C. power transmission system

A thyristor apparatus employing light-triggered thyristors comprises forward voltage detecting circuits (15) and a thyristor number detecting circuit (17). The forward voltage detecting circuits (15) detect forward voltages applied to light-triggered thyristors (13) to provide detected signals. The thyristor number detecting circuit (17) is responsive to the detected signals to cause light-triggered thyristors in a thyristor arm (U) to be turned on simultaneously in the case where the number of the light-triggered thyristors being supplied with forward voltages is one or more but not more than a predetermined number. Accordingly, if and when an overvoltage is applied to the thyristor arm (U), overvoltage suppressing elements (14) are prevented from being damaged even if partial commutation failure occurs in the light-triggered thyristors.

Thyristor apparatus employing light-triggered thyristors

A power converter adapted for use in a high-voltage circuit and equipped with a plurality of arms each comprising a plurality of thyristor elements connected in series, wherein an overvoltage limiter having an overvoltage limiting element and means for short-circuiting the ends of the overvoltage limiting element in response to flow of a load current therein are connected between the anode and the cathode of each thyristor element. The short-circuiting means has a gap between the two electrodes connected respectively to the anode and the cathode of each thyristor element, and also a metal layer of a low melting point which is molten by heat generated due to the flow of a load current in the overvoltage limiting element to fill the gap.

Power converter

A transmission line interconnecting system including an AC-DC converter connected to a first transmission line; and a forced-commutated type inverter connected to a second transmission line. DC terminals of the AC-DC converters and the forced commutated type inverter are connected and the output voltage of the forced commutated type inverter is varied by controlling DC voltage to feed a reactive power to the second transmission line in a normal state and to feed an active power from the first transmission line through the AC-DC converter and the forced excited type inverter to the second transmission line in an emergency state.

Growing community of inventors

Kyotoshi, Japan

Susumu Matsumura