- Synchronous reactor
- Series inductor
- Synchronous condenser
- Series capacitor
Answer: 3. Synchronous condenser
Explanation:
Which device is used in substations to improve the power factor?
A synchronous condenser is a type of synchronous machine that is used in electrical power systems to provide reactive power support and improve the power factor. It is essentially a large rotating mass with a small amount of winding that is connected to the grid through a switchgear.
When a power system has a low power factor, it means that there is a large amount of reactive power flowing in the system, which can result in inefficient use of the available power. A synchronous condenser is designed to provide a leading reactive power, compensating for the system's lagging reactive power, thus improving the power factor.
A synchronous condenser operates in a manner similar to a synchronous motor, but without a connected mechanical load. The rotor of the synchronous condenser is connected to the grid, and the stator windings are connected to a voltage source. When the voltage source is connected to the stator windings, a magnetic field is produced that rotates the rotor. This rotation of the rotor generates a leading reactive power, which is fed back into the grid.
The leading reactive power generated by the synchronous condenser reduces the overall reactive power demand from the power supply, improving the system's power factor. By controlling the output of the synchronous condenser, the reactive power demand of the system can be managed, ensuring that the power factor remains at an optimal level.
Synchronous condensers are often used in large power systems, such as power grids and industrial plants, where the power factor is critical for efficient operation. They are also used to support voltage stability and improve the system's dynamic response during transient conditions.
Which device is used to improve the overvoltage condition at the receiving end of the transmission line?
A synchronous reactor is a synchronous machine operating as a pure inductive load. It is designed to absorb or generate reactive power in an electrical power system. Reactive power is required in an AC power system to establish and maintain the magnetic fields in transformers and motors.
In an electrical power system, when the reactive power demand is more than the reactive power supplied by the power generators, it causes the voltage level at the receiving end to increase, leading to an overvoltage condition. The overvoltage condition can cause insulation failure, equipment damage, and system instability.
A synchronous reactor can help in improving the overvoltage condition by absorbing the excess reactive power available in the system. The synchronous reactor is connected to the system in such a way that it absorbs the reactive power when the voltage level is high and releases the reactive power when the voltage level is low. This helps to maintain a constant voltage level at the receiving end of the transmission line.
Which devices are used as current limiting reactors to increase the impedance of a system?
A series inductor, also known as a series reactor, is a type of inductor that is placed in series with a circuit or load. It is designed to increase the impedance of the system, which in turn limits the flow of current through the circuit. This is useful in a number of applications, including electrical power systems, where it can be used to protect against voltage surges and other electrical disturbances.
Current limiting:
One of the primary uses of a series inductor is to limit the flow of current through a circuit. By adding an inductor in series with the load, the effective impedance of the circuit is increased, which in turn limits the flow of current. This can be useful in a variety of applications where it is important to limit the amount of current flowing through a circuit, such as in electrical power systems or in motor control applications.
Increased impedance:
The addition of a series inductor increases the impedance of the circuit or system. Impedance is a measure of the opposition to the flow of electrical current and is typically measured in ohms. By increasing the impedance of the system, the series inductor can help to reduce the effects of voltage surges and other electrical disturbances. This can be particularly important in applications where the circuit or system is exposed to high levels of electrical noise or other types of interference.
Protection against voltage surges:
Series inductors can also be used to protect a circuit or system against voltage surges. When a voltage surge occurs, it can cause a sudden increase in the amount of current flowing through the system. This can be dangerous, as it can damage sensitive electronic components or even cause a fire. By adding a series inductor, the surge current is limited, which can help to protect the system from damage.
Power System MCQs With Explanation
The advantages of high transmission voltage are
The charging current drawn by the cable is
The fact that current density is higher at the surface when compared to the center is known as
In which of the following transmission lines capacitance effect is negligible?
The distribution constant of the transmission line is
Proximity effect is more in case of
If the frequency is increased, then the skin effect will
Bundled conductors in EHV transmission lines help in
Which of the following produces radio interference in communication lines?
Telecommunication lines are transposed to reduce the
What is the function of economizer in Thermal Power Plant
Which of the following effects are associated with transmission line
The insulator thickness on the conductor, in cables, depends upon
By using a guard ring in a transmission line, its string efficiency
If sag in an overhead line increase, the tension in the line
Corona is accompanied by
The conductor carries more current on the surface as compared to the core. This is called as
Critical disruptive voltage is a voltage at which
Bundled conductors are used for EHV transmission lines primarily for reducing the
Low power factor is usually not due to
Bonding is done at both ends of the cable to reduce the
For Improving power factor
Stock bridge dampers are used to
Which of the following insulator is practically used for railway crossings?
Which of the following decides the insulation level of 400 kV, EHV line?
When earth fault occurs
The minimum length of pipe electrode used for earthing should not be less than
A ground wire is used to
Earth resistance in typical domestic wiring is
By which of the following systems electric power may be transmitted?
Which of the following equipment will be most economical for regulating the voltage in the distribution feeder?
Transformer MCQs With Explanation
In a transformer the primary flux is
The noise of the transformer is mainly due to
Buchholz relay is used for the protection
Iron loss in a transformer can be determined by
Oil is provided in an oil-filled transformer for
In a star-delta transformer, the delta side phase voltage leads the star sides phase voltage by an angle
Minimum voltage regulation occurs in transformer when the power factor of the load is
The chemical used in the breather of a transformer should have the property of
The power transformer can be termed as a constant
In a transformer, which of the following losses are zero?
Which of the following Transformer can have a tap changer?
If the supply frequency (f) of a transformer decreases, the effect of frequency on the transformer's secondary output voltage?
The primary winding of a transformer has a 120 V ac supply. What is the value of secondary voltage if the turn ratio is 10?
The efficiency of a power transformer is _____ at full load.
In a transformer the relation between the input frequency and the output voltage on secondary winding is _____.
In a current transformer, _____ winding is closed.
A transformer is a _____ device.
A step-down transformer has _____ number of turns on primary winding and _____ number of turns on the secondary winding.
A step-up transformer has _____ number of turns on primary winding and _____ number of turns on the secondary winding.
Transformer works on ______ principle.
Shell Type Transformer is mainly used for
A Magnetic Oil level Guage (MOG) is used in the Transformer to
The Function Of Power Transformer is/are
The Radiators are used in transformers for
The noise of the transformer is mainly due to
Buchholz relay is used for the protection
Iron loss in a transformer can be determined by
Oil is provided in an oil-filled transformer for
In a star-delta transformer, the delta side phase voltage leads the star sides phase voltage by an angle
Minimum voltage regulation occurs in transformer when the power factor of the load is
The chemical used in the breather of a transformer should have the property of
The power transformer can be termed as a constant
In a transformer, which of the following losses are zero?
Which of the following Transformer can have a tap changer?
If the supply frequency (f) of a transformer decreases, the effect of frequency on the transformer's secondary output voltage?
The primary winding of a transformer has a 120 V ac supply. What is the value of secondary voltage if the turn ratio is 10?
The efficiency of a power transformer is _____ at full load.
In a transformer the relation between the input frequency and the output voltage on secondary winding is _____.
In a current transformer, _____ winding is closed.
A transformer is a _____ device.
A step-down transformer has _____ number of turns on primary winding and _____ number of turns on the secondary winding.
A step-up transformer has _____ number of turns on primary winding and _____ number of turns on the secondary winding.
Transformer works on ______ principle.
Shell Type Transformer is mainly used for
A Magnetic Oil level Guage (MOG) is used in the Transformer to
The Function Of Power Transformer is/are
The Radiators are used in transformers for
Synchronous Motor MCQs With Explanation
In 3 -Φ synchronous motor if one of the phases is short-circuited the motor will
The speed regulation of a synchronous motor is
The negative phase sequence in a three-phase synchronous motor exists when the motor is
What happens if the field winding of the synchronous motor is short-circuited?
For power factor correction, synchronous motors operate at
The speed regulation of a synchronous motor is
The negative phase sequence in a three-phase synchronous motor exists when the motor is
What happens if the field winding of the synchronous motor is short-circuited?
For power factor correction, synchronous motors operate at
Induction Motor MCQs With Explanation
Electrical Interesting Questions | All Posts
Will a D.C Shunt Motor operate on an A.C Supply?What is Load Shedding Transformer? Applications of Load Shedding Transformers
What is XLPE Cables? Applications of XLPE cables
What is Silicon Rubber Insulator? Where Silicon Rubber Insulator is used?
What is a voltage detecting insulator? Where voltage detecting insulators are used?
What Is Vacuum Interrupter? How Vacuum Interrupters Work in Circuit Breaker?
What is Arc Chutes or Arc Divider or Arc Splitters In Circuit Breaker?
What is a High Voltage Detector? Where High Voltage Detector is Used?
What is Wave Trap? Where it is Used?
why generation is 11kv in the power stations?
Why Earth Pin is Thicker and Longer in a 3-Pin Plug?
Why are Bundle Conductors used in Transmission Lines?
What are the Colored Aerial Marker Balls on Power Lines For?
Why is Electric Power Transmission is Multiple of 11 i.e 11kV, 22kV, 66kV, etc?
Why Tertiary Winding is used in transformers?
Why PT and CT Terminals are Star Connected?
What is Oil Surge Relay in Transformer?
What is Stockbridge Vibration Damper In Transmission Line?
Why Stones are used in Sub-Station Switchyard?
Why Arc Horn is used in High Voltage Transmission Line?
Why tester does not work on DC?
What is Auto-Recloser In-Transmission System? How its Works?
What is Aviation Light? Why it is used?
Why Transformer Taps On High Voltage Side?
Why Earthing Transformer is used?
Why does a humming sound occur in high voltage transmission lines?
Why is shunt capacitor bank used in substation?
Why do the positive and negative wires spark when touched?
Why reactors are used in substations?