Regulation and efficiencyWhat is voltage Regulation?The term voltage regulation identifies the characteristic of the voltage change in the transformer with loading. The voltage regulation of the transformer is defined as the arithmetical difference in the secondary terminal voltage between noload (I_{2}=0) and full rated load (I_{2} = I_{2fl}) at a given power factor with the same value of primary voltage for both rated load and noload. The numerical difference between noload and fullload voltage is called inherent voltage regulation. Inherent voltage regulation Where V_{2fl} = rated secondary terminal voltage at rated load. V_{2nl} = no load secondary terminal voltage with the same value of primary voltage for both rated load and no load. Per unit voltage regulation at full load is Percent voltage regulation at full load We can say that voltage regulation is an important measure for the performance of the transformer. We can specify the limits of the transformer in terms of voltage regulation. Voltage Regulation in terms of primary values: Per unit voltage regulation Calculation of Voltage RegulationWe can calculate the voltage regulation of a transformer in terms of circuit parameters. The equivalent circuit diagram of a transformer referred to secondary is shown below. Figure: Equivalent circuit of the transformer referred to the secondary By KVL, To calculate the voltage regulation we have to follow the steps given below: 1. We have to take V_{2} as the reference Phasor 2. Write I_{2} in Phasor form 3. Calculate Z_{e}_{2} ) 4. Calculate 5. Now we will calculate the voltage regulation Or we can say that it is the ratio of the difference between the voltages at no load and full load to the voltage at full load. What is Transformer Efficiency?Transformer efficiency (η) can be explained as the ratio of the output power to the input power. As we know that in a transformer there is no rotational part so there are no rotational losses such as windings and frictional losses in a rotating machine. Therefore, we can obtain a maximum efficiency as high as 99% in a welldesigned transformer. What is all day (or energy) efficiency of a transformer?The ratio of the energy output of 24hour to the energy input of a 24hour period is called the Allday efficiency of a transformer. If we know the load cycle of the transformer, then all day efficiency can easily be determined.
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