| The multiphase machine with low phase capacity and high fault tolerance can constitute generation system or AC inverter driving system with low voltage and large capacity, which can improve the performance, efficiency and reliability of the system and reduce the level of system supporting equipment. The multiple three-phase windings synchronous machine is one important direction in the study of the multiphase machine, since it can be supplied with three-phase inverters used for industrial application widely, besides its high power density and controllable power factor. In this paper, its stator inductance and transient reactance algorithms were studied, and their variation regulations with winding structure and rotor eccentricity were analyzed.In order to analyze the stator inductances and give a reasonable transient reactance algorithm of the multiple three-phase windings synchronous machine, its time-domain mathematical model and complex mathematical model were analyzed successively. Firstly, the relationship between its stator inductances after dq0 transformation and vector space decomposition transformation was determined. Then, the flux linkage equations with no rotor current variables were deduced and their simplification conditions were given. Using the proposed definition method of the equivalent reactances based on the rate of phase currents, the equivalent circuit of simplified complex flux linkage equations was determined.When the stator inductance is determinated through improved winding function theory, the air-gap length function must be defined. Since this work for the salient synchronous machine with many poles and rotor eccentricity is difficult, a fast and accurate calculation method of the air-gap length during its rotor with different shape and different eccentricity condition was proposed, which is based on the finite element method and calculation process with the improved winding function calculated firstly and the air-gap length calculated later. Besides, the difference between winding function and improved winding function was defined as difference function, and its existence conditions during the rotor with different shape and different eccentricity condition were derived through analysis.The stator inductance algorithm of multiple three-phase windings synchronous machine must be both accurate and fast. In order to fast calculate the stator inductance related to the air-gap magnetic field, its integral formula was separated into the winding function together with the difference winding function rationally, through which, the calculation process can be simplified through the existence conditions of the difference winding function. Based on these integral formulas and the air-gap function characteristics, the series formulas of these inductances were deduced with different winding structure and different rotor eccentricity condition be considered, and their accuracy were proved through the finite element method.The stator inductance of the multiple three-phase windings synchronous machine is related to its winding structure. Therefore, the regulations of its stator inductance variation with its stator winding structure were studied, so as to provides some references related parameters for its stator winding design. Through the analysis, the features of stator inductances after dq0 transformation and vector space decomposition transformation with their harmonic components be considered, the cyclic characteristics of stator inductance matrix after dq0 transformation with DC components of inductances considered, the variation of d-q subspace inductances with winding structure, stator inductance characteristics during rotor being dynamic eccentricity and static eccentricity was derived respectively.For fast analyzing the transient reactance of the multiple three-phase windings synchronous machine, the algorithm of its operational reactance frequency characteristics was studied, and the pulsating currents loading method of the multiphase winding was proposed. Based on the algorithm and the transient reactance fitting equations, the transient reactances of a salient-pole synchronous machine with double three-phase windings were calculated, and the results were proved to be rational through the test. Besides, the variation regulations of the transient reactances with winding structure and rotor position were analyzed, and the frequency-domain algorithm characteristics of the transient reactance were proposed. |
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