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The only difference between a synchronous motor and a synchronous condenser is the synchronous condenser shaft is not connected to anything—it simply spins unimpeded. The sole purpose of a synchronous condenser is to adjust conditions (power factor) on the electric power transmission grid.
What are advantages and disadvantages of synchronous condenser?
(i) By varying the field excitation, the magnitude of current drawn by the motor can be changed by any amount. This helps in achieving step less control of power factor. (ii) The motor windings have high thermal stability to short circuit currents. (iii) The faults can be removed easily.
Which of the following defines a synchronous condenser?
In electrical engineering, a synchronous condenser is a device identical to a synchronous motor, whose shaft is not connected to anything but spins freely. Its purpose is not to convert electric power to mechanical power or vice versa, but to adjust conditions on the electric power transmission grid.
Which among these is the advantage of synchronous condensers?
Helps in achieving the stepless control of power factor. b. The motor windings have a lower thermal stability.
Why Statcom is used?
The Static Synchronous Compensator (STATCOM) is used in an HVDC system to provide reactive power compensation. It makes use of the Voltage Source Converter (VSC) to synthesize a controllable sinusoidal voltage at the fundamental frequency.
What power factor means?
Power factor (PF) is the ratio of working power, measured in kilowatts (kW), to apparent power, measured in kilovolt amperes (kVA). PF expresses the ratio of true power used in a circuit to the apparent power delivered to the circuit. A 96% power factor demonstrates more efficiency than a 75% power factor.
What is synchronous condenser and hunting?
The word hunting is used because after the sudden application of load the rotor has to search or ‘hunt’ for its new equilibrium position. That phenomenon is referred to as hunting in a synchronous motor. In steady state, rotor runs at synchronous speed thereby maintaining a constant value of torque angle (δ).
What do you mean by synchronous speed?
: a definite speed for an alternating-current machine that is dependent on the frequency of the supply circuit because the rotating member passes one pair of poles for each alternation of the alternating current.
What is the application of synchronous motor?
Synchronous motors are normally used in applications in which a constant and precise speed is required. Typical applications of these low power motors are positioning machines. They are also used in robot actuators. Synchronous motors are also used in ball mills, watches, record players, and turntables.
What is the main disadvantage of phase advancer?
Disadvantage: Phase advancers are not economical for motors below 200 H.P.
Which device is used for improving the power factor of the system?
The most practical and economic power factor improvement device is the capacitor. Capacitors produce capacitive reactive power, which is the opposite of inductive reactive power that is the primary driver behind low power factor values.
What is consequence of low power factor?
Poor Voltage Regulation and Large Voltage Drop: Now in case of Low Power factor, Current will be increased. So the Larger the current, the Larger the Voltage Drop. In case of Low Power Factor (lagging Power factor) there would be large voltage drop which causes low voltage regulation.
How do Statcoms work?
STATCOM is connected parallel in power grid and works as reactive current source. Its reactive current can be flexibly controlled and compensate reactive power for system automatically. Its voltage output connects system by through reactor or transformer.
How does a SVC work?
In transmission applications, the SVC is used to regulate the grid voltage. If the power system’s reactive load is capacitive (leading), the SVC will use thyristor controlled reactors to consume VARs from the system, lowering the system voltage.
What is the reason for voltage collapse?
(b) If adjacent generators are overexcited and overloaded then it leads to voltage collapse due to increase in reactive power loss. (c) Due to large load demand or large rapid magnitude of power transfer, reactive power demand increases and voltage reduces.
What is 0.8 power factor?
Generator sets are rated in kVA at 0.8 power factor lagging. This 0.8 power factor is not the load power factor. It is a nominal power factor used to calculate the kW output of an engine to supply the power for a particular alternator kVA output.
What is a good power factor?
The ideal power factor is unity, or one. Anything less than one means that extra power is required to achieve the actual task at hand. All current flow causes losses both in the supply and distribution system. A load with a power factor of 1.0 results in the most efficient loading of the supply.
Why do we need power factor?
A lower power factor causes a higher current flow for a given load. As the line current increases, the voltage drop in the conductor increases, resulting in a lower voltage at the equipment. With an improved power factor, the voltage drop in the conductor is reduced, improving the voltage at the equipment.
Why synchronous motor is called a condenser?
Under excitation causes it to operate at a lagging power factor. When the motor is operated at no load with over-excitation, it takes a current that leads the voltage by nearly 90 degrees. Thus, it behaves like a capacitor and under such operating conditions, the synchronous motor is called a synchronous capacitor.
How the synchronous motor is used as asynchronous condenser?
Like capacitor bank, we can use an overexcited synchronous motor to improve the poor power factor of a power system. When a synchronous motor runs with over-excitation, it draws leading current from the source. We use this property of a synchronous motor for the purpose.
Why synchronous motors are not self starting?
Above a certain size, synchronous motors are not self-starting motors. This property is due to the inertia of the rotor; it cannot instantly follow the rotation of the magnetic field of the stator. Once the rotor nears the synchronous speed, the field winding is excited, and the motor pulls into synchronization.
