Abstract
本論文之主要目的在於應用電力電子切換技術，智慧型調控單相感應 馬達之輔助繞組電流，以改善其整體操作性能。文中首先推導單相感應馬 達之主導方程式，以利於操作特性之分析與模擬。其次探究在將輔助繞組 之電流相角維持與主繞組者互差90度下，調控輔助繞組電流之大小對單相 感應馬達啟動及穩態運轉性能之影響，並據以擬定輔助繞組電流之調控法 則。在啟動時，調控輔助繞組電流大小可直接控制啟動轉矩，非常易於在 配備之電流額定內，滿足不同負載所需之啟動特性。在穩態運轉時，分析 顯示馬達吸收功率最小與理想兩相安匝平衡之工作點相當接近，因兩相安 匝平衡之判定不易，故在本論文以追蹤輸入功率最小化為調整輔助繞組電 流大小之智慧型電力電子切換調控法則。在輸入功率最小化之工作情況下 ，雖然兩相安匝平衡並非理想，但脈動轉矩已很小，故馬達亦具有較平順 之運轉特性。所提單相感應馬達之切換機構，不需啟動電容、運轉電容、 離心開關及馬達參數。實測結果顯示在各負載情況下，輔助繞組之電流之 相角常保與主繞組者互差90度，具有維持吸收功率最小、繞組及電源電流 之諧波失真降低、及功因提高等之整體操作性能改善。 The major purpose of this thesis is to study the operating per- formance of a single-phase induction motor by switching controlling its auxiliary winding current. First, the governed equations, equi- valent circuits and steady-state operating characteristics of a single-phase induction motor are derived and simulated. Then accordingly, the intelligent switching control strategy is developed. In the proposed switching controlled single-phase induction motor, while the main winding is permenantly connected accross the AC grid, its auxiliary winding is fed by a current-controlled switching mode inverter. The phase of auxiliary winding current is kept in quadra- ture with those of main winding, but its magnitude is independently controlled by the current- controlled inverter. At starting, within the current ratings of system components, the starting torque can be directly controlled to meet the load requirements. On the other hand, the magnitude of auxiliary winding current is regulated toward the condition of minimum input power at running case using the pro- posed intelligent switching controller. Although the actual ampere- turn balanced can not be achieved simultaneously at this condition, the pulsating torque is neglighly small and thus the mechanical run- ning characteristic can also be improved. For further improving the line drawn current quality, a power factor correction switching con- troller, which is located at the ac source side, is also implemented in the thesis. Through which, the line drawn curent is regulated to be low-distorted, and the power factor is much improved. The proposed switching-controlled single- phase induction motor has the adventages that the starting and running capacitors, the centrifugal switch and the motor parameters are not needed. The overall performance improve- ment of the single-phase induction motor via the proposed controlled stratgies are demonstrated experimentally.