Mitsubishi Denki Kabushiki Kaisha

Other

Yasuhiko Hosokawa

Masahiko Akamatsu

Kanji Katsuki

Shotaro Murakami

Toshio Suzuki

Naoki Morishima

Masao Yano

Susumu Matsumura

Shunichiro Onishi

A compensation control device for a power system includes a switched capacitor connected in series with a transmission line, a voltage applying control connected in series with the transmission line, and a ganged control for controlling on/off operation of the switched capacitor and a linearizing voltage generated by the voltage applying control. The control ensures that a sum voltage of a stepped voltage generated across the switched capacitor and the linearizing voltage produced by the voltage applying control and that is applied to the transmission line is continuous. The control device realizes controllability of the total impedance of the transmission line and reduces the capacitance of the parts employed in the ganged control.

Compensation control device for a power system

A power system compensator apparatus comprising a power converter unit that works in series with the transmission of a power system and switching control means for controlling the link voltage (V.sub.LINK) of the non-power system side. The switching control means controls the phase of, at least, the fundamental frequency of the power system. The power converter unit contains a static power converter transformer with phase differences taking place the secondary windings of the power converter unit. The static power converter unit is operated in non-PWM or fixed pulse width ratio. Switching rate is minimized. Loss is lowered while economy of operation is improved. Since the voltage that works in series with the power transmission line is controlled, direct compensation of system reactance voltage and direct control of line current are performed. Improved performance thus results.

Power system compensator apparatus and power converter apparatus

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 control apparatus for thyristor motor comprises a voltage detector (27), a speed detecting circuit (600) and a correction circuit (800). The voltage detector (27) detects DC voltage (E.sub.d) supplied to an inverter circuit (200). The speed detecting circuit (600) detects the rotational speed of a synchronous motor (3) and provides speed voltage (E.omega.) proportional thereto. The correction circuit (800) detects a difference between the detected DC voltage (E.sub.d) and the speed voltage (E.omega.) and provides a correction signal to an excitation circuit (700) when a difference is detected. The excitation circuit (700) corrects field current in response to the correction signal so that the DC voltage (E.sub.d) and the speed voltage may be equal. Thus, a proportional relation can be maintained between the instructed torque and the generated torque.

Control apparatus for thyristor motor

A gate pulse phase shifter is designed so as to generate pulses at intervals of 60.degree. regardless of distortions in the AC power supply voltage, and so that, for linearity in control, the phase reference signal and the DC output voltage of AC-DC converters connected to the device are proportionally related.

Gate pulse phase shifter

The disclosed inverter system comprises three three-phase inverters connected in parallel across a positive and a negative terminal of a DC source including a negative terminal, and two three-phase transformers each including star-connected primary windings connected at one end to three AC outputs of the mating inverter and at the other ends connected to the neutral source terminal. Three secondary windings of each transformer are serially connected to those of the other transformer across three star-connected phase windings of a synchronous motor and three AC output of that inverter not connected to the transformer. The motor includes a neutral terminal connected to the neutral source terminal.

Growing community of inventors

Kobe, Japan

Yasuhiko Hosokawa