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What is the variation of synchronous impedance with the state of magnetic saturation of machine?
in modern trend, synchronous impedance of alternator should be high. If impedance are more than voltage drop across its arm. Wdg. Is more .according to the phasor diagram of alternator if IaXs componant is more than magnitude of induced emf will also be increased.
What is Vector meter?
A vector impedance meter is used to measure impedance and phase angle, this is done by calculating voltage and current through an impedance and then calculating Z and phase angle with that, now there are two modes for operation i.e constant current mode and constant voltage mode.CONSTANT CURRENT MODERead more: What_is_vector_impedance_meter_explain_with_circuit_diagram
Which is better high input impedance or low input impedance and why?
That depends on the output impedance. In electronic we use voltage bridging, that is a relative low output impedance to a higher input impedance. Usualy the input impedance is more than ten times higher then the output impedance. An input impedance is called also a load impedance or an external impedance. An output impedance is called also a source impedance or an internal impedance.
Why 3 phase induction motor is self starting but synchronous motor is not?
the induction motor as soon as you turn on the power the rotating magnetic field is set up. the shorted winding in the squirrel cage see this and builds up a temporary magnet when its up to synchronous speed there is no longer current in the shorted winding in a single pole motor 60hz this speed is 3600 rpm depending on coupling and skew induction motor is always less than synchronous speed. the synchronous motor as soon as you turn on the power the rotating magnetic field is set up the permanent magnet 0 to 3600 rpm in 1/60th of a second this requires all the power you can deliver until you reach synchronous speed a bit hard on the power source smaller synchronous motors sometimes have a squirrel cage and permanent magnets and enough impedance so they dont put a heavy load on the power electric clocks have the shorted windings on the poles self starting hi impedance some older electric clocks didnt have the shorted windings and need to be nudged to get then spinning
How to distinguish between characteristic impedance and input impedance?
The characteristic impedance or surge impedance belongs to uniform transmission lines.In electronic gears we use voltage bridging, that is a relative low output impedance to a higher input impedance. Usualy the input impedance is more than ten times higher then the output impedance.An input impedance is called also a load impedance or an external impedance.An output impedance is called also a source impedance or an internal impedance.
What is synchronous impedance?
Synchronous impedance is also known as the EMF method. It is a ratio of open circuits to short circuits, when they both are referred to the same field excitation.
What is Regulation of alternator by synchronous impedance method?
It is conducting OC and SC tests on the given three phase alternator and determining the regulation by synchronous impedance method.
What is a synchronous motor?
Synchronous motors are those that run only at Synchronous speed ie.. constant speed.
What is the output impedance of a constant voltage source and constant current source?
The output impedance is z= V/I, the ratio of the constant voltage and the constant current source.
What is the variation of synchronous impedance with the state of magnetic saturation of machine?
in modern trend, synchronous impedance of alternator should be high. If impedance are more than voltage drop across its arm. Wdg. Is more .according to the phasor diagram of alternator if IaXs componant is more than magnitude of induced emf will also be increased.
Why is a synchronous speed motor considered a constant speed motor?
synchronous motor is a constant speed motor because it will only run at a synchronous speed or not at all.the speed can be changed by changiing the frequency only ns=120f/p
Why synchronous impedance method of determining voltage regulation is called as pessimistic method?
Because the saturation is not taken into consideration so the impedance calculated is more than the impedance that would have resulted once the saturation is taken into account.-- By Ankit(bigboss0086@gmail.com)
How the synchronous impedence and armature resistance can be determined in a synchronous generator?
synchronous impedance can be calculated by performing oc test and sc test. by oc test,since the armature current is zero Vt=Ef . in short circuit test ,entire emf is consumed in circulating the short circuit current Isc,through the synchronous impedance. Zs=Ef/Isc.= (open ckt. terminal voltage for a certain field current)/(short ckt. current at the same field current)
How armature resistance can be determined in a synchronous generator?
synchronous impedance can be calculated by performing oc test and sc test. by oc test,since the armature current is zero Vt=Ef . in short circuit test ,entire emf is consumed in circulating the short circuit current Isc,through the synchronous impedance. Zs=Ef/Isc.= (open ckt. terminal voltage for a certain field current)/(short ckt. current at the same field current)
What is the physical significance of the impedance?
Impedance may refer to: the ratio of the voltage phasor to the electric current phasor, as in Electrical impedance, a measure of opposition to time-varying electric current in an electric circuit. Characteristic impedance, a measure of opposition to electric current propagation in a transmission line. Impedance matching and Impedance mismatch. Vacuum impedance, a universal constant. Electromagnetic impedance, a constant related to electromagnetic wave propagation in a medium. Mechanical impedance, a measure of opposition to motion of a structure subjected to a force. Acoustic impedance, a constant related to the propagation of sound waves in an acoustic medium. Linear response function, a general way to represent the input-output characteristics of a system. Scroll down to related links and look at an example: "Interconnection of two audio units".
What is Vector meter?
A vector impedance meter is used to measure impedance and phase angle, this is done by calculating voltage and current through an impedance and then calculating Z and phase angle with that, now there are two modes for operation i.e constant current mode and constant voltage mode.CONSTANT CURRENT MODERead more: What_is_vector_impedance_meter_explain_with_circuit_diagram
What is synchronous reactance in alternator?
The overall reactance of the armature winding is the sum of its leakage reactance plus fictitious reactance, which is known as synchronous reactance (Xs).Xs=XL+Xarwhere XL and Xar are in Ω/phase. Therefore, Xs is in Ω/phase.The impedance of armature winding is obtained by combining its resistance and its synchronous reactance.
