Experimental determination of synchronous machine reactances from DC decay at standstill

Measurement of parameters of high-power synchronous machines from steady-state or transient AC operational tests requires a great deal of electrical power. This paper presents a new application of a floating-point analog-to-digital converter which is employed in a microcomputer-embedded system that implements a standstill time response method to measure synchronous machine parameters. Floating-point quantization of the stator current response of a locked-rotor synchronous machine to a step signal is used to find the direct-axis and quadrature-axis reactances. Compared to previous solutions, this testing technique is characterized by higher precision, while still reducing the required power and minimizing the testing time. Simulated and experimental results are finally presented to compare the precision of this system with current state-of-the-art solutions.