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The lower the impedance, the lower the voltage drop across the transformer as it is loaded. This means regulation is better, since voltage variance is smaller.
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What effect does low impedance have on voltage regulation?
raised voltage output
What effect does transformer has a very low impedance on short circuit current?
the short ckt curent will be very high.
How do you convert percent impedance of transformer to impedance value?
The apparent impedance looking into a transformer from one side will not be the same as looking in it from the other, which is why percent impedance is used. If you are looking from the high voltage winding (I'm labeling #1) to the low voltage winding (#2), you must scale the percent impedance as follows: (% impedance) x (Winding #1 nominal voltage)^2 / (transformer base VA)
Why low power factor wattmeter is used for open circuit test of transformer?
For open circuit test of transformer, the secondary is open circuit and the circuit impedance is largely inductive due to the core impedance having high L as compared to R. hence the power factor is reduced, thus , we use low power factor wattmeters.
More the transformer impedance less the fault current... so is a high value of transformer impedance good for it?
It depends a lot on the application, i would go with low impedance transformers if am using the transformers for distribution as it will really increase the the maximum fault current. If am using the transformers as step up specially for generators or to charge capacitors, using a high impedance transformer is a good idea as it will decrease the inrush current of the system. you have to see your application and decide what fit that best. Mohammad Jaradat Power Generation Project Manager
What effect does low impedance have on voltage regulation?
raised voltage output
What effect does transformer has a very low impedance on short circuit current?
the short ckt curent will be very high.
What type of transformer configuration will you select to design a high input impedance and low output impedance amplifier?
main volage
How do you convert percent impedance of transformer to impedance value?
The apparent impedance looking into a transformer from one side will not be the same as looking in it from the other, which is why percent impedance is used. If you are looking from the high voltage winding (I'm labeling #1) to the low voltage winding (#2), you must scale the percent impedance as follows: (% impedance) x (Winding #1 nominal voltage)^2 / (transformer base VA)
What happens if dc supply is connected to incomer of transformer?
If a DC supply is connected to the incomer of a transformer, you effectively have a short circuit, because the DC impedance of a transformer (actually, any inductor) is quite low. You will blow something.
What is the difference between Ohm and Ohm CT in impedance of an audio transformer?
The side of the transformer that has the ohm CT which translates into a winding on the transformer that has a center tap . This side of the transformer was likely attached directly to the audio output transistors set up in push pull configuration. This is what the center tap is for. This side of the transformer would have a higher impedance and is directly driven by the power supply to provide amplification The transformer also isolates the amplifier voltage from the other side which is of low impedance. This may be in the range of 8 to to 16 ohms which would be directly tied to a speaker.
Why low power factor wattmeter is used for open circuit test of transformer?
For open circuit test of transformer, the secondary is open circuit and the circuit impedance is largely inductive due to the core impedance having high L as compared to R. hence the power factor is reduced, thus , we use low power factor wattmeters.
More the transformer impedance less the fault current... so is a high value of transformer impedance good for it?
It depends a lot on the application, i would go with low impedance transformers if am using the transformers for distribution as it will really increase the the maximum fault current. If am using the transformers as step up specially for generators or to charge capacitors, using a high impedance transformer is a good idea as it will decrease the inrush current of the system. you have to see your application and decide what fit that best. Mohammad Jaradat Power Generation Project Manager
What is percentage impedance?
In electrical engineering, the percentage impedance of a transformer is the voltage drop on a full load, which is expressed as a percentage of the specified rated voltage. It's measured by conducting a short circuit test.
In a multistage amplifier input impedance is high and output impedance is low justify the statement?
no. input impedance is low & output impedance is high
Effect of winding resistance with respect to EHV transformers voltage levels and their MVA rating?
The MVA rating will have an effect on the winding resistance - the higher the rating, the bigger current flows, thus the larger winding wire must be, which lowers the resistance. Generally, EHV transformers impedance (the resistance value you're thinking of) is specified when ordering the transformer, and can range from 4-20% (on the transformer base rating). When heavily loaded, on a weak system (high source impedance), the impedance of the transformer can impact the voltage level negatively (cause the voltage level, typically on the low side, to be less than desirable. I don't believe this is a serious concern, or the main reason to specify one impedance value versus another. Usually they are specified for cost, and other reasons (lower impedance must be able to withstand much more mechanical stress, while very high impedance may not provide enough fault current). On the EHV system, loads are typically "a ways away", and capacitor banks, inductor banks, and generators can be used to get the power to where it needs to go. Usually when it gets down to the loads that use it, it must go through at least one transformer that has an LTC (load tap changer) that can make corrections for any degradation in voltage. Often transformers with LTC's on the low sides have multiple taps on the high side as well to accommodate location in electrically weak locations. Furthermore, recently I've seen a lot of "musical transformers" activities going on (moving one transformer from one site to another); these transformers have different impedances, and are put in drastically different locations (electrically). I have not heard anyone scream foul based on the transformer impedance causing voltage issues. Disclaimer: My experience with transformer impedance choosing is not from a transmission planning perspective; my job does not usually entail dealing with voltage regulation. The planning people may do modelling that I do not know about to help in specification of impedance values.
How you can eliminate loading effect in amplifiers?
By increasing the input impedance of amplifier.
