Capacitor compensated thyristor controlled braking resistor
A system ( 100 ) for stabilising a power grid ( 102 ), comprising a generator ( 104 ), configured to provide power to the power grid ( 102 ), the power having an active power component and a reactive power component, and a power line ( 106 ), configured to transmit power from the generator ( 104 ) to the power grid ( 102 ). The system ( 100 ) comprises a thyristor controlled braking resistor (TCBR) ( 108 ) arranged on the power line ( 106 ), and a capacitor ( 110 ) electrically connected in series with the TCBR ( 108 ). The TCBR ( 108 ) absorbs at least a portion of the reactive power component from the generator ( 104 ) during a fault on the power line ( 106 ) and the capacitor ( 110 ) is configured to compensate for the at least a portion of the reactive power component absorbed by the TCBR ( 108 ).
1. A system for stabilising a power grid, comprising:
a generator, configured to provide power to the power grid, the power having an active power component and a reactive power component;
a power line, configured to transmit power from the generator to the power grid;
a thyristor controlled braking resistor (TCBR) arranged on the power line and configured to control a power drawn from the generator; and
a capacitor electrically connected in series with the TCBR between the generator and the power grid;
wherein the capacitor is configured to compensate for at least a portion of a reactive power component absorbed by the TCBR.
2. The system according to claim 1 , further comprising:
a transformer connected on the power line between the generator and the power grid;
wherein: the capacitor is arranged between the transformer and the TCBR, or between the transformer and the power grid.
3. The system according to claim 1 , further comprising: a bypass switch configured to bypass the capacitor.
4. The system according to claim 1 , further comprising: a varistor electrically connected in parallel with the capacitor.
5. The system according to claim 1 , wherein the TCBR comprises:
a braking resistor configured to draw an electrical load from the generator;
a thyristor electrically connected in series with the resistor and configured to control the electrical load drawn by the braking resistor.
6. The system according to claim 5 , wherein: the thyristor is configured to be controlled by a control unit.
7. The system according to claim 5 , wherein:
the braking resistor is comprised of at least two resistors; and
the thyristor is arranged between the at least two resistors.
8. A power grid comprising the system of claim 1 .