The Research And Identify On Turbine Generator Rotor Windings Short-circuit Fault

With the rapid development of China’s economy, the power requirements are increasing, and the electricity demand is also growing. Now with the shortage of coal resources, the clean energy is advocated. As the leading military of clean energy, the hydropower plays an irreplaceable role. In the hydropower plant machinery is undoubtedly the most important hydroelectric, and therefore its security is particularly important, and the failure of a short circuit between the rotor windings often appears in hydro.This paper firstly introduces the research background of hydro-generator rotor winding interturn short circuit, and adopts the method of fault tree, and analyzes the causes of the formation of hydro-generator rotor winding interturn short circuit in detail, and illustrates the hydro-generator rotor winding interturn short circuit and the unbalanced magnetic pull research status at home and abroad. SF600-42/1308 type hydroelectric generating is set as the research object, and establish a model of hydro-generator, and from two aspects such as hydro-generator no-load curve method and the unbalanced magnetic pull method to study. Specifically, the main content and work are:(1) Introduce the structure of hydro-generator rotor, and establish the winding interturn short circuit model, and elaborate the hydro-generator no-load curve method and the unbalanced magnetic pull method of theoretical calculation method in detail. No load curve method expounds the voltage and flux linkage of hydro-generator loop equation in the first, and then tells the story of hydro-generator parker change and d, q, 0 under the system of electromagnetic flow. Unbalanced magnetic pull method deduces the unbalanced magnetic pull discretization expression in detail. These two methods provide a theoretical basis for the follow-up study.(2) The hydro-generator rotor winding interturn short circuit fault a detailed analysis of the failure mechanism, the concrete can be divided into normal and rotor winding interturn short circuit when the electromagnetic properties of the two cases. Rotor winding interturn short circuit, turn the short route between the magnetic potential, can be equivalent to a demagnetization magnetic potential superposition to normally turn magnetic potential, and the direction with the main magnetic potential in the opposite direction, thus reduces the size of the magnetic potential, effect is relatively reduced.(3) No-load curve method is proposed to solve the hydro-generator rotor winding interturn short circuit, and through the park change method, and the complex calculation simplification, so more conducive to study. Put forward to use the relative change rate of field current to distinguish the severity of the turn-to-turn short circuit, and the criterion is deduced. Establish simulation model, and come to the conclusion that with the increase of short circuit, the reactive power loss and images of the short-circuit current increase, also get the criterion of percentage interturn short circuit in the numerical value and turn said percentage interturn short circuit calculation of value tendency, the same numerical value is very close.(4) The unbalanced magnetic pull method is proposed for research hydro-generator rotor winding interturn short circuit, from three aspects such as the electromagnetic torque, reactive power, and electromagnetic force. Calculation and electromagnetic torque are obtained along with the change of rotor winding interturn short circuit level and location of the rule of change. Further study of reactive power with the characteristics of these two changes; finally, the hydro-generator rotor winding interturn short circuit unbalanced electromagnetic force characteristics analyzed.