Kabushiki Kaisha Toshiba

The Tokyo Electric Power Company, Incorporated

Naomi Nakamura

Haruhisa Inokuchi

Syunichi Hirose

Fumitoshi Ichikawa

Yukio Tokiwa

A power conversion system has a control circuit constituted by a dual system. The control circuit of each system is equipped with a current control circuit. The current control circuit has a selection circuit that, after determining the magnitude of the output of an integrating amplifier of its own system and the output of an integrating amplifier of the other system, selects one of the outputs of the two integrating amplifiers. The selection circuit applies a signal responsive to a difference between the output of the integrating amplifier of its own system and the output of the selection circuit of its own system as correction signal to the input of the integrating amplifier of its own system. Accordingly, when the power conversion system is utilizes a dual control system, even when the current control circuit includes an integration algorithm, control can be performed by the two systems without saturation due to the integration algorithm.

Power conversion control apparatus

There is disclosed an apparatus for detecting a short-circuit of a bi-polar d.c. transmission system in which one end of a neutral line is ground and the other end thereof is not ground. This short-circuit detecting apparatus is adapted to detect a short-circuit between d.c. transmission lines on conditions that a current flowing in the neutral line is below a predetermined value, that a ground current at the ground point of the neutral line is below a predetermined value, and that a difference between bi-polar current command values is above a predetermined value.

Apparatus for detecting short-circuit for use in bi-polar d.c.

A coupling system in which power converters are coupled through a DC circuit to exchange active power between the converters comprises a control apparatus for controlling active power exchanged between each converter and its AC system. The control apparatus includes an automatic active power regulator for regulating active power exchanged between the converters and the AC system to be equal to be predetermined active power reference value, and an automatic DC voltage regulator for regulating a DC voltage of the DC circuit to be equal to a predetermined DC voltage reference value. When an output signal from the automatic active power requlator of each converter is input as an upper limit value of an output signal from the automatic DC voltage regulator, a DC voltage reference value of one converter is set to be equal to or larger than a DC voltage reference value of the remaining power converter.

Growing community of inventors

Tokorozawa, Japan

Naomi Nakamura