A tester for testing a transformer is provided. The tester comprises a primary voltmeter and a plurality of secondary voltmeters. The tester may also comprise an ammeter in series with a voltage source configured to apply voltage to the transformer. The primary voltmeter is configured to measure voltage induced across a primary winding of the transformer, while the secondary voltmeters may simultaneously measure voltage outputs at secondary windings of the transformer. The tester is configured to calculate ratios, saturation curves, and knee points for multiple winding combinations based on the measurements simultaneously obtained by the ammeter and the primary and secondary voltmeters.

A tester for testing a transformer is provided. The tester comprises a primary voltmeter and a plurality of secondary voltmeters. The tester may also comprise an ammeter in series with a voltage source configured to apply voltage to the transformer. The primary voltmeter is configured to measure voltage induced across a primary winding of the transformer, while the secondary voltmeters may simultaneously measure voltage outputs at secondary windings of the transformer. The tester is configured to calculate ratios, saturation curves, and knee points for multiple winding combinations based on the measurements simultaneously obtained by the ammeter and the primary and secondary voltmeters.

The embodiments relates to a stator used in resolvers, in which multiple slots are formed at constant intervals in the circumferential direction and have an excitation coil, a first output coil, and a second output coil are respectively wound around the multiple slots. The excitation coil is wound by a number of windings that is changed on the basis of a sinusoidal wave in accordance with the order of the multiple slots in the circumferential direction. After the first output coil is wound by a number of windings resulting from the division of the total number of windings by a constant ratio, the second output coil is wound, and then the rest of the first output coil is wound.

The embodiments relates to a stator used in resolvers, in which multiple slots are formed at constant intervals in the circumferential direction and have an excitation coil, a first output coil, and a second output coil are respectively wound around the multiple slots. The excitation coil is wound by a number of windings that is changed on the basis of a sinusoidal wave in accordance with the order of the multiple slots in the circumferential direction. After the first output coil is wound by a number of windings resulting from the division of the total number of windings by a constant ratio, the second output coil is wound, and then the rest of the first output coil is wound.

Systems, apparatuses, and methods are described for a transformer supporting two or more sets of windings electrically connected to different voltage levels. Use of stress control materials or composite materials (comprising a matrix and filler) may direct electrical fields caused by the different voltage levels to have a lowered electrical field amplitude.

Systems, apparatuses, and methods are described for a transformer supporting two or more sets of windings electrically connected to different voltage levels. Use of stress control materials or composite materials (comprising a matrix and filler) may direct electrical fields caused by the different voltage levels to have a lowered electrical field amplitude.

A turns ratio meter may be connected to each phase of each set of windings. The excitation voltage used in testing is a DC square wave. The excitation voltage is relatively low, between 1 and 48 volts. The step down and step up testing is performed several times with different voltages and/or frequencies. Excitation losses of the transformer are determined based upon the multiple step down and step up tests. The step down and step up testing can be performed without reconfiguring the test leads on the transformer. The testing is performed on a single phase of the transformer or all three phases of the transformer simultaneously. The turns ratio of the transformer is accurately determined using the results of the step down and step up testing and the calculated excitation losses.

A turns ratio meter may be connected to each phase of each set of windings. The excitation voltage used in testing is a DC square wave. The excitation voltage is relatively low, between 1 and 48 volts. The step down and step up testing is performed several times with different voltages and/or frequencies. Excitation losses of the transformer are determined based upon the multiple step down and step up tests. The step down and step up testing can be performed without reconfiguring the test leads on the transformer. The testing is performed on a single phase of the transformer or all three phases of the transformer simultaneously. The turns ratio of the transformer is accurately determined using the results of the step down and step up testing and the calculated excitation losses.

A method for performing diagnostics on a target transformer includes applying a voltage output of a voltage generator to a winding or phase of the target transformer; controlling the voltage generator to output an AC voltage at a first frequency and then a second frequency and measuring first and second excitation currents flowing into the target transformer associated with the first frequency and second frequency, respectively. The method further includes determining an actual excitation current of the target transformer as a function of both the first and second excitation currents, and comparing the actual excitation current of the target transformer to excitation currents associated with one or more benchmark transformers having known electrical characteristics. And when the actual excitation current of the target transformer matches an excitation current of one of benchmark transformers, determining the electrical characteristics of the target transformer to match electrical characteristics of the one benchmark transformer.

A system and a method for determining the power loss of a transformer. The method includes measuring voltage and current at the primary side of the transformer, calculating input power by multiplying the measured current and voltage on the primary side of the transformer; measuring voltage and current at the secondary side of the transformer, calculate a nominal error ratio, calculating output power by multiplying the measured current and voltage on the secondary side of the transformer. The method further involves calculating a first corrected power loss by means of multiplying the input power with the nominal error ratio and subtract the output power.