Bbc Brown, Boveri & Company, Limited

Bbc Aktiengesellschaft Brown, Boveri & Cie

Karl-Werner Kanngiesser

Michael Hausler

Dietrich Kluge

In the high voltage d-c transmission (HGU) power station in a block circuit, a three-phase generator feeds a 12-pulse high voltage d-c transmission (HGU) short coupler through at least one shifting transformer which serves for forming voltages of two three-phase voltage systems phase-shifted relative to each other by 30.degree. el. As compared to a full transformer, the shifting transformer can be constructed for substantially less power, which reduces the cost and the losses of the station. While the voltages of the two phase-shifted voltage systems can be taken off at the external terminals of the secondary windings of the shifting transformer, the center taps of the secondary windings are acted upon by the generator voltage. Advantageously, the high voltage d-c transmission short coupler is formed of a multiplicity of parallel, electrically separate d-c circuits which can be fed by separate shifting transformers.

High voltage D-C transmission power station with a generator transformer

In order to place into operation a group of power converters which are connected in series as concerns the direct-current mode and in parallel as concerns the alternating-current mode, of a power or current converter operating in a rectifying mode of a high-voltage direct-current transmission installation, the control pulses of the group of power converters to be placed into operation are set at a range of approximately 100 to 115 electrical degrees. The bypass or shunt switch of such group of power converters subsequently receives an opening command. The control pulses, after accomplishment of opening of the bypass or shunt switch are shifted in accordance with a predetermined linear ramp function in the rectifying range and thereafter the control pulses are delivered by means of a pole current regulator. The placement into operation of a power converter operating in the inverting mode is accomplished in a similar fashion. Reactive power swings or fluctuations between the network and the power converters are avoided.

Method for placing into operation a series connected group of static

A method and apparatus for controlling the real and reactive power behavior of a high voltage transmission (HDT) system characterized by a rectifier station connected to a first three phase network and an inverter station connected to a second three phase network. The rectifier and inverter stations have positive and negative station-halves connected to each other over positive and negative D.C. transmission lines to form positive and negative poles, each station having a common ground or return wire. Each station is equipped with current and voltage regulators, as well as control angle and quenching angle regulators whereby in case of the tripping of line protective devices monitoring line current in a faulty pole, and the consequent unloading of the faulty pole, the regulation of the intact pole assumes control for a short time to protect against network transients resulting from the load drop. In the event of a line disturbance, both the current set point for the current regulator and the control angle set point for the control angle regulator of the intact station-half of the intact pole are increased according to preset functions, with the control angle set point subordinated to the magnitude of the current angle set point.

Method and apparatus for controlling the real and reactive power

A method and apparatus for regulation of the power factor of a 3-phase network fed with power from another 3-phase network via a short high-voltage direct current transmission link interconnecting the two networks. The d.c. transmission link includes rectifier and inverter stations connected at opposite ends of the link and the inverter station is controlled in such manner as to supply power to the fed network at a variable leading power factor in dependence upon the actual power factor of the fed network.

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Viernheim, Germany

Karl-Werner Kanngiesser