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How do you counter the induced voltage spark during the generator?
Wiki User
∙ 11y ago
By creating a rotating electric field. The generator has two main sets of windings - the field windings (the spinning ones on the rotor usually) and the stator windings(the stationary part connected to the grid). The field windings are electrified to create an electromagnet out of the rotor. Spinning the rotor creates a rotating electric field, which induces a voltage on the stator windings.
Wiki User
∙ 13y ago
Wiki User
∙ 12y agoinduction motor is not self starting..it start with the use of dc motor. it couple with im. we 1st start dc motor.. it rotate the im.. when the im speed reaches 75% during excitation apply to it...now the im rotate full speed and cut the dc motor..
Wiki User
∙ 11y agomicroprocessor os that in which we read about various type of instruction
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What will happen to the transformer if double the rated voltage is applied to the winding during the open circuit test?
no voltage will be induced on the secondary side of the motor as the windings will become saturated.
What rule should you use in order to determine the direction of induced EMF in a coil?
The direction of an induced voltage is such that it always acts to oppose any change of current which causes it.So, for example, during the first quarter-cycle of a sine wave, when the current is increasing, the induced voltage acts oppose that change (increase) -in other words, it acts in the opposite direction to that current. During the second quarter-cycle of a sine wave, when the current is decreasing, the induced voltage again acts opposethat decrease that change (decrease) -in other words, it acts in the same direction to that current -trying to sustain that current.
How reverse power will occur during synchronizing?
Reverse power flow into a generator can occur during synchronization if the generator is spinning too slowly, or the voltage phase angle is lagging relative to the power system. If the generator is spinning too slowly, power from the system is used by the generator to increase its' speed. If the phase angle is lagging, an initial spike of power will flow into the generator to force it into sync with the system. Typically generator's will match system frequency very closesly, and force the phase angle to leading slightly between the generator and the system. When synchronized, an extra bump of power will flow out while the generator is torqued into phase with the system. This will avoid tripping any reverse power devices.
What happens during energy conversion?
There is no physical connection between the primary and secondary of a transformer. A transformer is essentially 2 laminated coils of wire interwoven with each other. The magnetic field created in the primary coil is induced into the secondary coil creating voltage on the secondary side.
What is the difference between a DC motor and a generator in terms of EMF?
During the operation of a DC motor, EMF is created across its terminals using an external source. Whereas, in a DC generator EMF is created across its terminal based on principle of dynamically induced EMF. So talking in terms of EMF, in DC motor EMF is consumed by the motor coil and utilized to rotate the axle. On the other hand, in DC generator EMF developed across coil is transfered to a load or a battery and consumed by them.
How does an induced voltage across a generator coil change during each revolution of the magnet?
sinusoidally
What will happen to the transformer if double the rated voltage is applied to the winding during the open circuit test?
no voltage will be induced on the secondary side of the motor as the windings will become saturated.
What rule should you use in order to determine the direction of induced EMF in a coil?
The direction of an induced voltage is such that it always acts to oppose any change of current which causes it.So, for example, during the first quarter-cycle of a sine wave, when the current is increasing, the induced voltage acts oppose that change (increase) -in other words, it acts in the opposite direction to that current. During the second quarter-cycle of a sine wave, when the current is decreasing, the induced voltage again acts opposethat decrease that change (decrease) -in other words, it acts in the same direction to that current -trying to sustain that current.
What is the difference between voltage restrained overcurrent protection and voltage controlled overcurrent protection?
The voltage-restrained overcurrent relay adjusts the pickup setting and characteristic curve of the overcurrent function based on the system voltage. The relay is set pickup greater than overload, and sensitivity increases as the voltage drops. The voltage-controlled overcurrent relay uses an undervoltage element to supervise the operation of the overcurrent element. When the voltage drops below a predetermined level, the undervoltage element permits the operation of the time overcurrent units. Voltage-restrained overcurrent relays can provide faster backup protection than voltagecontrolled overcurrent relays, particularly in cases where the generator voltage does not drop significantly below rated voltage during fault conditions. If the generator voltage always drops below a given voltage level for all faults in which operation is required, the voltage-controlled overcurrent unit may be set to provide faster overall clearing speed
How reverse power will occur during synchronizing?
Reverse power flow into a generator can occur during synchronization if the generator is spinning too slowly, or the voltage phase angle is lagging relative to the power system. If the generator is spinning too slowly, power from the system is used by the generator to increase its' speed. If the phase angle is lagging, an initial spike of power will flow into the generator to force it into sync with the system. Typically generator's will match system frequency very closesly, and force the phase angle to leading slightly between the generator and the system. When synchronized, an extra bump of power will flow out while the generator is torqued into phase with the system. This will avoid tripping any reverse power devices.
What is AVR generator?
AVR stands for Automatic Voltage Regulator for generator. Most AVR work by automatically comparing the sensed voltage with the reference setting generator output voltage then diverting the input current to the exciter circuit. Some AVR circuit are configured in parallel connection with the exciter stator winding, When it sense below rated set voltage, more current is feed to the exciter to catch up the voltage difference until it would reach equilibrium again, when it is within rated voltage less current is feed to the exciter or more current is diverted to the AVR circuit. Some AVR has manual remote voltage trim or control to manually raise or lower the set voltage. The AVR works also during parallel operation by regulating voltage and controlling load Ampere (load sharing capability), the power factor (PF) and VAR (Volt-Amps Reactive).
What happens during energy conversion?
There is no physical connection between the primary and secondary of a transformer. A transformer is essentially 2 laminated coils of wire interwoven with each other. The magnetic field created in the primary coil is induced into the secondary coil creating voltage on the secondary side.
An emotionally induced response during which air movement is similar to crying?
laughing
Emotionally-induced response during which air movement is similar to crying?
laughing
What is restriking voltage?
Restriking voltage is transient voltage. During the arcing time, at current zero, the voltage that shows up across the contacts is the restriking voltage.
What is the difference between a DC motor and a generator in terms of EMF?
During the operation of a DC motor, EMF is created across its terminals using an external source. Whereas, in a DC generator EMF is created across its terminal based on principle of dynamically induced EMF. So talking in terms of EMF, in DC motor EMF is consumed by the motor coil and utilized to rotate the axle. On the other hand, in DC generator EMF developed across coil is transfered to a load or a battery and consumed by them.
What does 50 hertz or 60 hertz mean in an electrical generator?
The unit hertz means "cycles per second" and is a measure of the frequency of variation of anything which changes during a set period of time, including electric current and voltage. Saying that a generator of electricity runs at 50 hertz means that its current and voltage changes regularly at a rate of 50 times per second. Saying that a generator of electricity runs at 60 hertz means that its current and voltage changes regularly at a rate of 60 times per second. The Hertz value can be changed on the generator by increasing or decreasing the speed (RPM) of the prime mover. The generator has a feed back unit that monitors the frequency and automatically applies more power to the prime mover if the load increases and the generator RPM starts to slow down. The reverse happens if the load drops off and the generator starts to speed up, the power to the prime mover will be reduced. On a diesel generator it is the fuel flow that is increased and decreased to keep the frequency at a constant value. On a water turbine it is the water flow that is increased and decreased to keep the frequency at a constant value.
