【作者】 崔学深；

【导师】 罗应立；

【作者基本信息】 华北电力大学（北京） ， 电机与电器， 2009， 博士

【摘要】 本文根据抽油机电动机的周期性变工况负载特性,提出断续供电节能控制新原理,并结合调压和无功补偿等技术研究综合节能控制方法,对采油工业的能源高效利用和节能减排工作有重要意义。为消除断续供电控制中通电时的冲击电流,提出了感应电机电源快速软投入方法及控制策略。对晶闸管一电动机系统建立了综合描述电源快速软投入过程的数学模型,并通过解析方法研究主要影响因素,最终得到快速软投入触发角序列的实用计算方法。具体研究工作包括以下几个方面:1)针对快速软投入两相与三相通电交替的过渡过程,分别建立有利于解析分析的不对称瞬态和对称瞬态的降阶数学模型。在不对称瞬态模型的解析研究中,利用卡丹公式法解决了三次特征根的求解问题,最终求得初始两相通电的定子瞬态电流时域解析表达式;对空间向量复数坐标系下的对称数学模型进行解析,得到第三相投入后的定子瞬态电流解析表达式;将不对称瞬态也用空间向量来表示,建立与与对称瞬态相关联的模型,用以实现两相到三相通电状态交替过程的连接。2)研究快速软投入触发角序列等控制参数,揭示了电源快速软投入过程的控制规律,并对其影响因素进行分析。通过解析方法找到快速软投入初始触发角与瞬态电流首半波峰值之间的基本关系,进而提出了由限流值和空间向量轨迹确定初始两相和第三相触发角的方法,并以固定步长均匀递减的方式由投入时转速计算出其它后续触发角;结合仿真和实验验证了快速软投入对冲击电流的抑制作用,并分析了不同转速下投入时对电源快速软投入过程的影响。3)对典型周期性变工况负载特性进行能耗分析,深入研究断续供电节能机理和控制模式,并进一步发展了以断续供电为主的综合节能控制新技术。在研究断续供电与最优调压相结合的节能途径过程中,提出一种周期性变工况条件下新的异步电机损耗理论计算方法,可通过测量数据辨识计算转矩和最优电压;对传统的星角变换与无功补偿进行改造,使之与断续供电相协调,得到的综合节能控制技术对变工况负载的综合节电率有很大的提高。更多还原

【Abstract】 According to the periodically variable running load of the motors working in the oil pumping machines,a novel energy saving control principle of intermittent power supply is put forward in this paper.The integrated energy saving control method is studied combined with voltage regulation and reactive power compensation techniques,which is of great significance to the energy saving,emission reduction and the efficient use of energy source for oil extraction industry.A rapid soft re-switching approach of power supply for induction motors and its control strategy are put forward here in order to avoid the inrush current at the time of re-switching in the course of the intermittent power supply control.The transient mathematical models are established for thyristor-motor system to describe rapid soft re-switching course comprehensively.The main influnce factor of rapid soft re-switching course is studied by means of analytical method and the practicable calculating method of series of firing angles is obtained finally.The concrete research work includes the following aspects:1) Aiming at the alternating transient between two-phase and three-phase switching-on of rapid soft re-switching of the induction motors,the reduced order mathematical models for asymmetrical transient and symmetrical transient are established respectively.For the analytical research of asymmetrical transient model,the problem of extracting three-order eigenvalue is solved by using the Cardannao formula method.Futhermore,the transient stator current of initial two-phase switching-on can be expressed in time domain.By means of the analytical method in space vector complex coordinate for the symmetrical mathematical model,the analytical expression of transient stator current is got when the third phase switching on.The asymmetrical transient model can also be expressed with space vector, which is associated with the symmetrical transient to realize the connecting of the alternating course between two-phase and three-phase switching-on.2) The control parameters such as firing angles of rapid soft re-switching control are studied to reveal the control rules and analyze the influnce factors.The basic relationship between the the first half-wave peak value of transient current and the initial firing angles is found by means of analytical method.The practical method is put forward to determine the initial two-phase and the third phase firing angles with the limiting value and the space vector varying track of transient current.And then the subsequent series of firing angles with the even step are calculated by using the speed at the time of re-switching.The suppressive effect to the inrush current is verified with simulation and experiment of rapid soft re-switching control,by which the influence of different speed to rapid soft re-switching course is analyzed besides.3) To analyze the power loss for typical periodically variable running load and deeply study the energy-saving principle and control mode of the intermittent power supply approach. Futhermore,the novel integrated energy-saving control technique is developed on base of the intermittent power supply approach.In the course of studying the energy saving approach of the voltage regulation optimization in association with the intermittent power supply,a new loss calculation method of asynchronous motor is put forward under the condition of periodically changing load,which can be used to calculate the torque and optimal voltage with the measured data.The traditional energy saving approaches of wye-delta transform and reactive power compensation are restructured and made it to associate with the intermittent supply control to form the integrated energy-saving control technique,by which the comprehensive energy saving rate is improved greatly.更多还原