Thyristor controllied series capacitor adapted to damp sub synchronous resonances
AssigneeABB Research Ltd.
InventorsGunnar Asplund, Changchun Zhou, Quianjin Liu
Life of this patent
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Abstract
An apparatus for controlling a thyristor controlled series capacitor connected to a power transmission line. A thyristor firing control includes a unit for effectuating a desired capacitor voltage zero crossing in dependence of a line current and a capacitor voltage in response to a command signal. A command control provides the command signal to the thyristor firing control. The command control includes a damping control including a damper configured to damp at a least one discrete frequency.
Claims14
A control apparatus for controlling a thyristor controlled series capacitor connected to a power transmission line, the control apparatus comprising:
- a thyristor firing control comprising means for effectuating a desired capacitor voltage zero crossing in dependence of a line current and the capacitor voltage in response to a command signal, and
- a command control for providing the command signal to the thyristor firing control, wherein the command control comprises a damping control comprising a frequency damper configured to damp at a least one discrete frequency.
A method for providing a positive damping of a discrete frequency oscillation present on a power transmission line, the power transmission line comprising a thyristor controlled series capacitor comprising a thyristor firing control, the method comprising:
- providing a signal representing the oscillation present on a power transmission line,
- filtering the signal,
- sensing a presence of the discrete frequency,
- phase shifting the signal, and
- sending a command signal to the thyristor firing control for effectuating the damping.
A computer program product, comprising:
- a computer readable medium;
- and
- computer program instructions recorded on the computer readable medium and executable by a processor to carryout a method comprising providing a signal representing an oscillation present on a power transmission line, filtering the signal, sensing a presence of a discrete frequency, phase shifting the signal, and sending a command signal to a thyristor firing control for effectuating a damping.
Dependencies are inferred from the claim text.