Abstract:

Taking the field test of injection stator grounding protection of a 1008MW steam turbine generator set in a power plant as an example,combining its protection principle,methods for the influencing factors of accuracy, phase compensation test,impedance compensation test,parallel resistance compensation test,resistivity correction factor test and dynamic simulation test are introduced in detail.At the same time,suggested setting values for grounding zerosequence current and the loop monitoring are given.The error of the test data is below 5%, which verifies the rationality of compensation tests.In addition, targeted approach for loop inspection are give for solving anomalies in 20Hz voltage signal,20Hz current signal,phase angle difference and grounding resistance during the field test.Analysis on failure startup of the injection stator grounding protection,blocking during startstop process,multiphase angle compensation and the influence on synchronous and speed measuring device are made.And the recommendations for action delay setting,frequency blocking, timing for multiphase angle compensation and synchronous voltage selection are made.

Key words:

font-size: 10.5pt, mso-spacerun: 'yes', mso-font-kerning: 1.0000pt">generator;injection stator grounding protection;field test;setting