Date of publication xxxx 00, 0000, date of current version xxxx 00, 0000.

The normal life of a transformer is well above 25 years. The economical operation of the distribution system has its roots in the equipments being used. The economy being such, that it is financially advantageous to replace transformers with more than 15 years of service in the second perennial market. Testing of transformer is required, as its an indication of the extent to which a transformer can comply with the customers specified requirements and the respective standards (IEC 60076-3). In this paper, induced over voltage testing on transformers using enhanced Z source inverter is discussed. Power electronic circuits are now essential for a whole array of industrial electronic products. The bulky motor generator set, which is used to generate the required frequency to conduct the induced over voltage testing of transformers is nowadays replaced by static frequency converter. First conventional Z-source inverter, and second an enhanced Z source inverter is being used to generate the required voltage and frequency to test the transformer for induced over voltage test, and its characteristics is analysed.

AC voltage controller using PWM technique integrated with equal area digital modulation technique and connected to resistive loads is discussed in this paper. The proposed technique reduces the harmonics in the lower order significantly and improves the power factor compared to the existing conventional line commutated voltage controllers. The voltage and current waveforms are smoothened; therefore, a sinusoidal nature is achieved. The power factor is considerably improved at the low output voltage range when compared to existing methods. The capabilities of the proposed technique are computed mathematically and simulation results are compared with the existing methods.

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