Automated electrical machine test facilities

Abstract

Testing electric machines during production and after overhauling is one of the basic production stages, which has a direct effect on the quality of the final products. Increasing the level of automation of the testing process to the point of total elimination of the human factor has been an unsolved problem until recently. On commission from ZAO Transmashkholding and OOO Novocherkassk Electric Locomotive Plant (NEVZ) and jointly with the latter, that task was accomplished for the entire range of the traction and auxiliary motors produced by this plant. The specifics of the methods for testing dc and ac electrical machines in accordance with the regulations of the normative documentation—in particular, those that concern the loading conditions—brings about difficulties in the creation of power static converters and automation equipment for test benches to test dc and ac electrical machines. The modes of loading the machines in accordance with a back-to-back diagram required tailored power transformers and converters. The creation of automatic control systems for power equipment—in particular, automated means for measuring the electric and the mechanic parameters of the testing process—necessitated development of complex systems that operate on the “conveyor belt” principle. All safety requirements were met, easy operation was ensured for personnel, the risk of committing errors was minimized, and an acceptable rate of the testing cycle was guaranteed. Operation of the electrical machine test facility at OOO NEVZ over a number of years has proven the effectiveness of the solutions that have been developed. This article describes the experience of developing and producing electrical equipment and automatic control systems for automated test benches to test electrical machines, methods for solving problems that arise when designing such equipment, and examples of different approaches to the design depending on production specifics. Circuit diagrams of the electrical equipment for industrial tests of traction electric motors are provided.