Simulation Research For Operation Performance Of Tri-winding Single-phase Capacitance Motor

Since the limitation of power distribution system, the power consumption of urban resident, great majority of rural area and outlying district adopt the sing-phase AC power supply. With the popularizing of domestic appliances and development of rural economics, pint-sized electric motor with single phase power source has got extensive use. In the electric traction system with single phase power source, because of the structural restriction, adopting the single phase induction motor is uneconomical when the rated power is greater than 0.5 kw. Three-phase induction motor has the features of high material utilization, stable performance, high efficiency when symmetric operated , shorter development period and larger scale power, therefore, the development of three-phase induction motor at the nearly symmetric or symmetric operation with single-phase power supply is of great significance.Both of the connecting the appropriate phase-shifting components and changing the wiring mode of the motor stator is an effective way for the three-phase electrical motor supplied by the single-phase power. And using capacitor as the phase-shifting component is the most simple and practical method. When using capacitor as the phase-shifting component, it can be called as Tri-Winding Single-Phase Capacitance Motors. Also many wiring methods have already been put forward.Such as the "Steinmetz" wiring method. In this method the stator windings are Delta-wiring and the single-phase power and phase shifter are connected to the different phase of the stator Delta-connection to make the three-phase induction motor start-up and operating with single-phase power supply system. We used to call it Delta-wiring now; There are also Y-shaped connecting method with Y-shaped wiring for the stator windings, single-phase power and phase-shifting in different phases respectively and the Smith and Semihex connecting methods with the windings open and using the phase-shifting capacitor.The above four wiring method have more conspicuous advantages. They are common in practice and able to be promoted.The past performance studies on the Tri-Winding Single-Phase Capacitance Motor are primarily based on the steady-state electrical equivalent circuit using symmetric components in certain conditions to choice and calculate the numerical value of the phase-shifting components and other electrical properties of the steady-state. The papers on the of transient analysis are more rare. Literatures on the simulation of the starting performance with the instantaneous symmetrical component model, and the ABC model on the situation of a symmetrical three-phase Y andâ–³shaped stator windings with a phase-shifting capacitor have already existed. But the transient process of Tri-Winding Single-Phase Capacitance Motors with SemihexTM and Smith wiring methods are very few investigated. The studies on transient process like braking, reverse operation, fault running, load mutation, speed regulation and sharp fall of power supply voltage of the Tri-Winding Single-Phase Capacitance Motors are almost blank.This paper summarized the development of three-phase induction motor using single-phase power supply as well as the way to achieve and the purpose, methods and significance of the study. Based on the symmetrical component and the transient mathematical model of the three-phase induction motor, the comprehensive, in-depth study on the transient and steady-state performance of the model mentioned in the above four methods is explained in the paper. The main contents are as follows : As for the normal operation of a Tri-Winding Single-Phase Capacitance Motors, in the condition of the smallest imbalance voltage, the formula for calculating the phase-shifting capacitor is derived by using the symmetric component method and the three-phase induction motor equivalent circuit.Based on the stator winding endpoint equation, the constraint conditions of the stator winding terminal voltage is derived, the reunificated state equation in a stationary coordinate system is established, the computer program is organised, with actual applications, the starting operation and stable operation process is simulated and comparatively analyzed. The transient characteristic of Tri-Winding Single-Phase Capacitance Motors with Smith wiring methods is practically measured, and the correctness of the mathematical model is verified by the result. This paper introduces a simple starting wiring mode for the Tri-Winding Single-Phase Capacitance Motors with Smith wiring method, the simulation is executed in this research, and a comparison with a double-value capacitor starting is made. The starting process of the Tri-Winding Single-Phase Capacitance Motors with the double-cage rotor delta-wiring method and Semihex-wiring method are simulated.This paper presents several wiring modes of AC brake and DC brake for the Tri-Winding Single-Phase Capacitance Motors. According to the terminal voltage constraints conditions of the stator circuit and the mixed flux model of the three-phase induction motor in the stationary coordinate systems,the state equation on the AC brake,reverse operation, the DC brake and resistive and the capacitive brake for a Tri-Winding Single-Phase Capacitance Motors are established. By using the symmetrical component method, the mathematical expression of the brake capacitance calculation of AC brake and resistive and capacitive brake is derived.the computer simulation program is given, the transient process of AC brake,reverse operation, DC brake and resistor-capacitor brake for a Tri-Winding Single-Phase Capacitance Motors is overall simulated, and the results are given and analyzed.The correctness of the mathematical model is verified by the test result,which is given by the DC brake for a motor with SemihexTM-wiring method.The paper educes the stator windings terminal voltage constraints of the Tri-Winding Single-Phase Capacitance Motors with Wye-wiring method ,Delta-wiring method,SemihexTM and Smith wiring methods, which are in the fault state of stator windings in the open circuit, stator windings in the short-circuit, capacitors open and capacitors short-circuit,the unified mixed Flux type mathematical model is established under these faults.The simulation is executed through examples when the Tri-Winding Single-Phase Capacitance Motors with Delta-wiring method, SemihexTM and Smith cwiring methods are operating at the above four fault states,and the simulation results are analyzed. Two of these cases is practically measured, and the correctness of the established mathematical model is verified.Finally, apply the AC Chopper controller and electrical adjustable capacitor for the Tri-Winding Single-Phase Capacitance Motors, and its transient performance is calculated by simulation and also comparatively studied.Starting, braking, the breakdown operation and the velocity modulation transient state process of Tri-Winding Single-Phase Capacitance Motors has been further reseached in this thesis, and it obtained some to theory value and the project practical value conclusion in this thesis.