Experimental Studies On The Three-winding Single-phase Motor For Agricultural Engineering

This paper firstly summarizes the the study history and ways of three-phase asynchronous motor applying single-phase power source. The sing-phase alternating current power supply is used by the urban resident and many countrysides. The small-capacity electric power motor with single-phase power supply has extensively adapted because of the development of frural economics and pervadeing of urban or rural household electrical appliances. Because of the structure restricted, adopting the single-phase asynchronous motor is not economical in the electric driving of big capacity with single-phase power supply. Three-phase symmetric asynchronous motor has the reliable performance, larger dragging power, high efficiency and fine starting property.Therefore, the study and exploitation of three-phase symmetric asynchronous motor at the symmetric or closely symmetric running with single-phase electric source have grand actual value.In normal conditions, the three-phase electrical motor supplied by the single-phase electric source is connected the suitable phase-spliting capacitor, if necessary the wiring type of the motor stator is changed. This type motor is called as Three-Winding Single-Phase Motor. Furthermore a variety of winding types have already been put forward in some published documents. In practical applications, such as the Triangle-connecting type in which the stator wirings are Triangle-wiring and the phase-spliting capacitors are connected to the different phase of the Triangle-connection stator to make the three-phase symmetric asynchronous motor starting and running with single-phase electric source. There are also Y-shaped winding type in which the phase-spliting capacitor in respective phases. Also SemihexTM and Smith connecting types in which the wirings are isolated and the phase-spliting capacitors are usedIn the past time, the investigating at the property of Three-Winding Single-Phase Motor is mainly based on the equivalent electrical circuit of the steady state about the motor and applies the symmetric components model in some conditions and counts the capacitance of the phase-spliting capacitor.But the literatures about the transient analysis are more rare. Although someone have studied the starting property by the simulation with the three phase coordinate system and the transient symmetrical component type at the three-phase Y and△stator wirings conecting a phase-spliting capacitor. Few people have investigated the starting process of Three-Winding Single-Phase Motor of SemihexTMand Smith winding connecting.Nobody studies the transient process such as malfunction operating, speed governing and braking process about the Three-Winding Single-Phase Motor.The regular connectors of the Three-Winding Induction Motors with single-phase or three-phase supply source are hardly researched.This paper studies thoroughly the transient and steady state properties of the four winding methods mentioned in the above, on account of the symmetrical component types and the transient mathematical model of the three-phase symmetrical asynchronous motor. It infers how to calculate the capacitance of the phase-spliting capacitor as Three-Winding Single-Phase Motor is normally running. It derives the constraint relations of the stator wiring terminal voltage in the condition of the smallest imbalance voltage and it makes a list of the voltage equations inα-βstationary frame of axes and it tests and verifies the starting and stable running process.It practically measures the transient property of Three-Winding Single-Phase Motor with Smith wiring ways, which demonstrates the correctness of the above mathematical model about Three-Winding Single-Phase Motor. It designs a simple starting winding way for Smith winding type and it is in the light of two phase-spliting capacitors starting.The article derives the constraint voltage of the stator wiring endpoint in the cutting-out and broken circuit for the four wirings mentioned above. The experimentations executes that the Three-Winding Single-Phase Motor with Triangle-winding,SemihexTM and Smith winding runs at these breakdown states, which verifies the upbuilt mathematical model is practicable.Finally, the regular connectors of the Three-Winding Induction Motors with single-phase or three-phase supply source are designed. The regular connector has the simple wiring, limited electrical equipments, minimum investment and easy operating.In this paper, starting and the fault operation state process about Three-Winding Single-Phase Motor has been made a deep investigation and study in the practice and thesis, and the regular connectors of the Three-Winding Induction Motor with single-phase or three-phase supply source are designed. and it obtains some theory and practical value in applied engineering and the thesis.