开关磁阻电机的前景一、开关磁阻电机发展简介 开关磁阻电机是80年代初随着电力电子、微电脑和控制技术的迅猛发展而发展起来的一种新型调速驱动系统,具有结构简单、运行可靠及效率高等突出特点,成为交流电机调速系统、直流电机调速系统和无刷直流电机调速系统的强有力的竞争者,引起各国学者和企业界的广泛关注跨国电机公司Emerson电气公司还将开关磁阻电机视为其下世纪调速驱动系统的新的技术、经济增长点目前开关磁阻电机已广泛或开始应用于工业、航空业和家用电器等各个领域 1970年,英国Leeds大学步进电机研究小组首创一个开关磁阻电机(Switched Reluctance Motor, SRM)雏形,这是关于开关磁阻电机最早的研究1972年,进一步对带半导体开关的小功率电动机(10w~1kw)进行了研究到了1975年有了实质性的进展,并一直发展到可以为50kw的电瓶汽车提供装置1980年在英国成立了开关磁阻电机驱动装置有限公司(SRD Ltd.),专门进行SRD系统的研究、开发和设计1983年英国(SRD Ltd.)首先推出了SRD系列产品,该产品命名为OULTON1984年TASC驱动系统公司也推出了他们的产品。
另外SRD Ltd. 研制了一种适用于有轨电车的驱动系统,到1986年已运行500km该产品的出现,在电气传动界引起不小的反响在很多性能指标上达到了出人意料的高水平,整个系统的综合性能价格指标达到或超过了工业中长期广泛应用的一些变速传动系统 从上世纪90年代国际会议的上有关SRD系统的文章来看,对SRD系统的研究工作已经从论证它的优点、开发应用阶段进入到设计理论、优化设计研究阶段对SR电机、控制器、功率变换器等的运行理论、优化设计、结构形式等方面进行了更加深入的研究 二、原理简介及优越性简介 开关磁阻电动机驱动系统(SRD)是较为复杂的机电一体化装置,SRD的运行需要实时检测的反馈量一般有转子位置、速度及电流等,然后根据控制目标综合这些信息给出控制指令,实现运行控制及保护等功能转子位置检测环节是SRD的重要组成部分,检测到的转子位置信号是各相主开关器件正确进行逻辑切换的根据,也为速度控制环节提供了速度反馈信号 开关磁阻电机具有再生的能力,系统效率高对开关磁阻电机的理论研究和实践证明,该系统具有许多显著的优点: (1)电机结构简单、坚固,制造工艺简单,成本低,可工作于极高转速;定子线圈嵌放容易,端部短而牢固,工作可靠,能适用于各种恶劣、高温甚至强振动环境。
(2)损耗主要产生在定子,电机易于冷却;转子无永磁体,可允许有较高的温升 (3)转矩方向与电流方向无关,从而可最大限度简化功率变换器,降低系统成本 (4)功率变换器不会出现直通故障,可靠性高 (5)起动转矩大,低速性能好,无感应电动机在起动时所出现的冲击电流现象 (6)调速范围宽,控制灵活,易于实现各种特殊要求的转矩-速度特性 (7)在宽广的转速和功率范围内都具有高效率 (8)能四象限运行,具有较强的再生制动能力 (9)容错能力强开关磁阻电机的容错体现在电机某一相损坏,电机照样可以运行 与当前广泛应用的变频调速感应电动机相比,开关磁阻电机在成本、效率、调速性能、单位体积功率、可靠性、散热性等都具有明显的优势或竞争力 如果说第一代开关磁阻电机(1983年研制)在小功率范围的效率比高效变频调速感应电动机低,第二代开关磁阻电机(1988年研制)的效率已全面超过了高效变频调速感应电动机更难得的是,开关磁阻电机在宽广的速度和功率范围内都能保持较高的效率,这是变频调速感应电动机难以比拟的感应电动机要取得与直流电机相近的调速特性需采用复杂的矢量控制系统,而开关磁阻电机通过调整开通角、关断角、电压和电流,可以得到不同负载要求的机械特性,控制简单、灵活,能容易地实现软启动和四象限运行,而且由于这是一种纯逻辑的控制方式,很容易智能化,通过修改软件调整电机工作特性满足不同应用要求。
由于开关磁阻电机固有的转矩波动,可能导致较大的噪声和振动,事实上这种情况的发生往往与电机设计和控制的不合理相关,通过优化电机设计和控制策略,转矩波动和噪声完全可以得到有效的抑制,正确认识到这一点对开关磁阻电机的开发和应用是很重要的SRD Ltd.公司开发的伺服应用开关磁阻电机,转矩波动仅为0.05%近年研究的最优励磁控制策略、两次换流控制策略、电机噪声根源、定子振动模态、定子固有频率计算等成果对降低电机噪声都有积极的促进作用随着设计和制造水平的提高,噪声必将进一步降低 The prospect of Switched Reluctance MotorFirst, the development of Switched Reluctance Motor Introduction Switched Reluctance Motor is the early 80s with the power electronics, micro-computer control technology and the rapid development and developed a new type of speed control drive system, with a simple structure, reliable and efficient operation of the prominent characteristics of higher has become AC motor speed control system , DC motor speed control system and the brushless DC motor speed control system of strong competitors, scholars and business caused by the extensive attention. Transnational Emerson Electric Co., Ltd. Electric Company will be regarded as one of the switched reluctance motor speed drive system the next century, new technologies, economic growth. Switched reluctance motor current or the beginning has been widely applied in industry, aviation industry and household appliances and other fields.In 1970, the United Kingdom University of Leeds research team first stepper motor of a switched reluctance motor (Switched Reluctance Motor, SRM) prototype, which is switched reluctance motor on the first study. In 1972, further semiconductor switches with low-power motor (10w ~ 1kw) were studied. By 1975, substantial progress has been and has been the development of the battery for cars 50kw device. In the United Kingdom in 1980 set up a Switched Reluctance Motor Drive Co., Ltd. (SRD Ltd.), Devoted to the SRD system research, development and design. In 1983 the United Kingdom (SRD Ltd.) First introduced the SRD Series products, the product named OULTON. TASC-driven system in 1984 also launched their products. In addition SRD Ltd. Developed a tram driver for the system to run in 1986 has 500km. The emergence of electric drive in the sector caused the reaction. In many performance indicators reached an unexpected high level of performance throughout the system meet or exceed the price indices of industrial long-term a number of widely used variable-speed drive system.90's from the last century of the International Conference on the SRD system, look at the article on the SRD system has its advantages from the demonstration, development and application of theory to the design stage, optimizing the design of a research stage. On the SR motor, controller, power converter, such as theory of operation, and optimize the design, structure and other aspects of the form of more in-depth research.Second, the principle of the superiority of a briefing and briefing Switched reluctance motor drive system (SRD) is a more complex integration of mechanical and electrical devices, SRD operational needs of online real-time feedback on the volume of a general rotor position, speed and current, etc., and then under the control objectives are given control of the information integrated command, to achieve operational control and protection functions. Rotor position detection is the SRD an important component of the rotor position detected signal is the right of the main switching device to switch to the logic of the basis for speed control provides a link speed feedback signal.Switched Reluctance Motor has a regeneration capacity, systems and high efficiency. Switched Reluctance Motor for the theoretical study and practice has proved that the system has many significant advantages: (1) motor structure is simple, robust, simple manufacturing process, low cost, can work in a high speed; release easily embedded stator coils, the ends of short and strong, reliable, able to apply to a variety of harsh, high temperature or strong vibration environment . (2) arising primarily from the loss in the stator, motor cooling is easy; free permanent magnet rotor can be allowed to have a higher temperature rise. (3) the direction of torque has nothing to do with the current direction, which can be simplified to maximize power converter, reducing system cost. (4) power converter does not arise through failure, and high reliability. (5) starting torque, and low-speed performance, non-induction motor in the start-up arising from the impact of current phenomena. (6) wide range speed control, control flexibility, easy to implement the special requirements of a variety of torque - speed characteristics.(7)In a broad range of speed and power efficiency are (8)To four-quadrant operation, has a strong capacity of regenerative braking. (9) Fault-tolerant capability. Fault-tolerant switched reluctance motor in the motor with a damaged motor can run the same.With the current extensive use of variable frequency induction motor speed compared to switched reluctance motor in terms of cost, efficiency, speed performance, power per unit volume, reliability, heat dissipation and so has the obvious advantage or competitive edge.If the first generation of switched reluctance motor (developed in 1983) in the scope of the efficiency of low-power efficient than the low-frequency induction motor speed control, second-generation switched reluctance motor (developed in 1988) the efficiency has been more than a high-performance VVVF induction motor. What is even more encouraging is that of switched reluctance motor in a broad range of speed and power to maintain high efficiency, this is the variable frequency induction motor speed can not match. Induction motor and DC motor to get close to the speed characteristics of the vector to be complex control systems, and switched reluctance motors by adjusting the opening angle, turn-off angle, voltage and current, you can load the requirements of different mechanical properties, control is simple, flexible and can be easier to achieve soft-start and four quadrant operation, and because it is a pure logic of control, it is easy to intelligent, by modifying the software to adjust properties of the electrical work to meet the requirements of different applications.Switched reluctance motor as a result of the inherent volatility of the torque may lead to a higher level of noise and vibration, in fact, the occurrence of such cases are often associated with the electrical design and control related to the irrational, by optimizing the motor design and control strategy, torque fluctuations and noise can be effectively inhibited this a correct understanding of Switched Reluctance Motor for the development and application is very important. SRD Ltd. Servo applications developed switched reluctance motor, torque fluctuation of only 0.05%. Research in recent years, the optimal excitation control strategy, two strategies for flow control, the source of electrical noise, vibration mode of the stator, the stator natural frequency calculation results in reducing the electrical noise has a positive role in promoting. With the design and manufacturing level, will further reduce noise.。