Static compensator and method for controlling thereof
First Claim
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1. A static compensator comprising:
- a transformer connected with a bus of a power system;
an inverter operating according to a control signal and connected to the transformer in series;
a tap changer changing turn ratio of the transformer;
a voltage controller controlling an output quantity of a reactive current according to a predetermined voltage control reference value;
a reactive current controller controlling a phase angle of an output voltage of the inverter using a difference in values between a reactive current inputted by the voltage controller and a reactive current measured by the inverter; and
a tap changer controller extracting an integrated value of a bus voltage if the bus voltage inputted from the bus and the reactive current controller is greater or smaller than a predetermined reference value, comparing the extracted integrated value with a predetermined excessive integration threshold value, and outputting any of a tap up signal or a tap down signal controlling the tap changer,wherein the voltage controller comprises;
a first D/Q changing unit receiving the bus voltage and converting the bus voltage into and outputting an active voltage of the bus voltage and a reactive voltage of the bus voltage;
an intensity calculating unit outputting a bus voltage by using an active power and a reactive power from the D/Q changing unit; and
a first PI controller controlling an output quantity of the reactive current by compensating a difference between the predetermined voltage control reference value and the bus voltage outputted from the intensity calculating unit, andwherein the tap changer controller comprises;
a first comparing unit generating an ON or OFF signal by comparing the bus voltage with the predetermined reference value;
an integrator extracting an integrated value of the bus voltage;
a timer placed between the integrator and the first comparing unit and transmitting a time delay signal to the integrator if the ON signal is received from the comparing unit; and
a second comparing unit outputting the tap up or tap down signal by comparing the integrated value with the excessive integration threshold value.
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Abstract
The present invention relates to a static compensator and a method for controlling thereof, more particularly, to a static compensator including a transformer connected with a bus of a power system; an inverter operating according to a control signal and connected to the transformer in series; a tap changer changing turn ratio of the transformer; and a controller generating the control signal to operate the inverter and generating a tap up or a tap down signal to provide to the tap changer and a method for controlling thereof.
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Citations
5 Claims
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1. A static compensator comprising:
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a transformer connected with a bus of a power system; an inverter operating according to a control signal and connected to the transformer in series; a tap changer changing turn ratio of the transformer; a voltage controller controlling an output quantity of a reactive current according to a predetermined voltage control reference value; a reactive current controller controlling a phase angle of an output voltage of the inverter using a difference in values between a reactive current inputted by the voltage controller and a reactive current measured by the inverter; and a tap changer controller extracting an integrated value of a bus voltage if the bus voltage inputted from the bus and the reactive current controller is greater or smaller than a predetermined reference value, comparing the extracted integrated value with a predetermined excessive integration threshold value, and outputting any of a tap up signal or a tap down signal controlling the tap changer, wherein the voltage controller comprises;
a first D/Q changing unit receiving the bus voltage and converting the bus voltage into and outputting an active voltage of the bus voltage and a reactive voltage of the bus voltage;
an intensity calculating unit outputting a bus voltage by using an active power and a reactive power from the D/Q changing unit; and
a first PI controller controlling an output quantity of the reactive current by compensating a difference between the predetermined voltage control reference value and the bus voltage outputted from the intensity calculating unit, andwherein the tap changer controller comprises;
a first comparing unit generating an ON or OFF signal by comparing the bus voltage with the predetermined reference value;
an integrator extracting an integrated value of the bus voltage;
a timer placed between the integrator and the first comparing unit and transmitting a time delay signal to the integrator if the ON signal is received from the comparing unit; and
a second comparing unit outputting the tap up or tap down signal by comparing the integrated value with the excessive integration threshold value. - View Dependent Claims (2, 3, 4, 5)
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Specification