1、直流电梯拖动系统通常分为二种：一是用发电机组构成的可控硅励磁的发电机-电动机驱动系统；二是可控硅直接供电的可控硅-电动机系统。Currently, electrical driving system is classified into two types, i.e. DC driving system and AC driving system. DC driving system has two types, one is driven by controllable silicon excitation multiple dynamos motor, the other by contr
2、ollable silicon motor. 交流拖动系统又可分为三种：交流变极调速系统、交流变压调速系统和变频变压调速系统。AC driving system includes three types: AC polar-speed-variable system, AC voltage-speed-variable system and frequency-voltage-speed-variable system.8-2 直流拖动系统DC driving system直流电梯速度快、舒适感好、平层精度高。但由于其对电网的影响较大，所以在2m/s速度以下的电梯已不再应用，但目前在2m/s速
3、度以上的电梯仍有应用（包括有齿轮的和无齿轮的）。Featuring high running speed, good riding comfort and high leveling accuracy, DC lift has a great influence on electrical network, therefore, lift with speed of less than 2m/s is not out of use, but lift with speed of more than 2m/s is still in use （including geared and gearl
4、ess）. 直流电动机的转速可由下式表示：DC motor speed is indicated as follows: 8-1？式中： Where:Ua 电机进线端的电压 Ua Inlet voltage of motor Ia 电枢电流 Ia Armature current Ra 电枢电阻 Ra Armature resistance Rt 外接调整电阻 Rt Varistor Ce 电势常数 Ce Potential constant 励磁磁通 Excitation flux由上式可知，直流电机的转速主要与输入电机的端电压、外接调整电阻及励磁磁通有关，只要改变其中的某个参数，均可改变电
5、机转速。其中改变端电压Ua比较理想，因为在不同电压下的特性曲线均是平行的，即在同一电压下负载变化时，其转速变化不大。直流电梯的两种拖动系统都是利用调整电动机端电压Ua的方法进行调速。发电机-电动机组是通过调节发电机的励磁改变发电机的输出电压（即电动机的端电压）进行调速，故称可控硅励磁系统。可控硅-电动机系统是利用三相可控硅整流器，把交流电变为可控的直流电，供给直流电动机的调速系统，省去了发电机组，因此降低了能耗和造价，使结构更加紧凑。图8-1为可控硅励磁的发电机-电动机拖动系统示意图；图8-2为可控硅直接供电的电机拖动系统。From the above formula, we learn th
6、at DC motor speed is mainly related to inlet voltage of motor, varistor and excitation flux, therefore, changing one of the three factors will alter motor speed. It is preferable to change Ua, i.e. inlet voltage of motor, since character curve is parallel under different voltages, i.e. motor speed d
7、oes not change noticeably under the same voltage when load varies. Both two driving systems of DC lift change speed by adjusting Ua, i.e. inlet voltage of motor. Dynamo-motor changes speed by adjusting excitation of motor to change outlet voltage of dynamo, i.e. inlet voltage of motor, and this proc
8、ess is called silicon excitation system. By means of three-phase controllable rectifier, controllable silicon motor system converts AC to DC, providing speed-adjusting system of DC motor, sparing dynamo, reducing power consumption and cost, making structure more compact. In figure 8-1 is shown contr
9、ollable silicon excitation dynamo-motor driving system, while in figure8- 2 controllable silicon motor driving system.lge of motor, since ehree facotrs r speed is mainly related to motor speed of more than 2m/s is still in use （）etwor8-2-1 可控硅励磁的发电机-电动机组拖动系统Controllable silicon excitation dynamo mot
10、or driving system图8-3为快速直流电梯拖动系统原理图Figure 8-3 is a sketch of the mechanism of high-speed DC driving system.给定电源经积分转换变成梯形信号。测速发电机取与电梯速度成正比的电压信号。速度给定信号与测速反馈信号相比较后得到的误差信号，加到具有比例积分的速度调节器进行放大调节，然后输出加到反并联的两组可控硅触发器上，使两组触发器同时得到两个符号相反、大小相等的控制信号，控制两组触发器的输出脉冲同时向相反方向作相等角度的移动，用以控制可控硅整流器的输出电压的大小和极性。可控硅整流器的输出电压控制直
11、流发电机的励磁磁通，使发电机电枢输出电压随之变化，电动机转速随发电机输出电压而变化，最终使速度跟随给定的速度曲线变化，达到速度自动调节的目的。Given power is converted to trapezoid signal after integration. Tachogenerator selects voltage signal in directly proportional to lift speed. Comparing given speed signal and feedback signal will produce a error signal, which is
12、added to PI speed controller to be amplified, then the outlet is added to two counter-parallel controllable silicon triggers, which can obtain two control signals that are equal in magnitude but have opposite codes. Outlet pulse controlling two triggers moves toward opposite directions simultaneousl
13、y at equal angle degree, so as to control the outlet voltage and polarity of controllable silicon rectifier. The outlet voltage of controllable silicon rectifier controls the excitation flux of DC dynamo, changing dynamo armature outlet voltage and motor speed. Consequently, speed will vary accordin
14、g to given speed curve, achieving the goal of speed self-adjusting. 当给定正电压与测速反馈电压相比较使速度调节器输出一个负电压给触发器，使正向组可控硅工作在整流状态，反向组可控硅工作在待逆变状态，供给发电机正的励磁电流，从而输出正电压，电动机正转，电梯上升运行。反之，则电动机反转，电梯下行。After given positive voltage compares with feedback voltage, speed controller will output a negative voltage to trigger,
15、 enabling positive controllable silicon to work at rectification state,negativeat ready-to-convert state, providing dynamo with positive excitation current, outputting positive voltage, rotating motor, moving lift upwards; otherwise, rotating motor reversely and moving lift downwards. 图8-4为直流高速电梯拖动系
16、统原理图Figure8- 4 is the sketch of mechanism of DC high-speed driving system. 与快速梯相比增加了电流调节器、电流检测、预负载信号和电平检测等环节。电流调节器可以提高系统的动态品质，使电梯起、制动更平稳。外在调节器的同相输入端还加进轿厢的预负载信号，以反映轿厢内的重量，使主回路产生一个预负载力矩，避免抱闸打开瞬间产生溜车。Compared with fast-speed lift, high-speed lift is equipped with current controller, current test, pre-l
17、oad signal and level test. Current controller is used to improve systems mobile quality, enabling lift to start up and decelerate more smoothly. Output of identical phase of exterior adjuster is added to pre-load signal of car, so as to reflect load in car, making main circuit produce pre-load torqu
18、e and preventing car from slipping when the moment brake opens. 8-2-2 可控硅直接供电的直流拖动系统Controllable silicon DC driving system 图8-5所示是一种可控硅直接供电的直流快速电梯拖动系统原理图，它主要由两组可控硅取代了传统驱动系统中的直流发电机组。两组可控硅可以进行相位控制，或处于整流或处于逆变状态。当控制电路对给定的速度指令信号与速度反馈信号、电流反馈信号进行比较运算后，就决定了两组可控硅整流装置中哪一组应该投入运行，并根据运算结果，控制可控硅整流装置的输出电压，即曳引电动机的电
19、枢电压，使电梯跟随速度指令信号运行常用的可控硅整流电路是将电源变压器接成三角形-星形，副边有中心抽头。正反向可控硅分别把电源变压器三相的正半波或负半波换成直流电，正向或反向加于直流电动机的电枢端，使电机正转或反转。而电枢端电压的大小变化，则由控制可控硅的脉冲相位移动所决定。Figure 8-5 is a sketch of mechanism of controllable silicon DC driving system for DC high-speed lift. In this driving system, replacing DC dynamo of conventional d
20、riving system, two groups of controllable silicon can perform phase control or be in the state of rectification and reverse change. After comparing given speed signal and feedback signal, current feedback signal and computing, control circuit will determine which group is to be put into operation, a
21、nd according to the computing result, control output voltage, i.e. armature voltage of traction machine, enabling lift to run by following speed signal. Common controllable silicon rectifier circuit is used to connect power voltage transformer into star-delta, with sideline having central terminal.
22、Positive and negative controllable silicon can convert positive semi-wave or negative semi-wave of power voltage transformer to DC, direct or reverse armature side applied on DC motor can make motor rotate directly or reversely. Armature side voltage magnitude is determined by pulse phase displaceme
23、nt of controllable silicon. 8-3 交流拖动系统AC driving system8-3-1 交流变极调速系统AC variable- polarity-adjusting - speed system由电机学原理可知。三相异步电动机的转速可由下式表示：Based on motor mechanism, the speed of three-phase asynchronous motor is indicated by the following formula:60fn （1s） 8-2 pn 电动机转速（r/min）； n Motor speed（r/min）
24、；f 电源频率 （Hz）； f Power frequency （Hz）； p 电机定子绕组的极对数； p Polarity pair of motor stator winding s 转差率。 s Rotation error rate从8-2式可以看出，交流异步电动机的转速是与其极对数成反比的。改变电动机的极对数就可以改变电动机的同步转速，因此，改变电动机的极对数是变速最简单的方法。It is indicated from the formula 8-2 that the speed of AC asynchronous motor is reversely proportional t
25、o its polarity pair. The simplest way to change synchronous rotating speed of motor is to change polarity pair of motor. 电梯用交流电动机有单速、双速及三速。单速仅用于速度较低的杂物梯。双速电机的定子绕组一般采用416极或624极，少数也有424极或636极。极数少的绕组称为快速绕组，极数多的绕组成为称为慢速绕组。三速电机的定子绕组一般采用6824极，它比双速电机多3个8极，这一绕组主要用于电梯在减速制动时的附加制动绕组，使减速开始的瞬间具有较好的舒适感，有了8极绕组就可以不
26、要在减速时串入附加的电阻或电抗器。另一种三相交流电动机的极对数为6418极，6极绕组作为起动绕组以限制起动电流，使起动电流小于2.5倍额定电流，4级绕组作为正常稳速运行用，18极绕组作为制动减速和平层停车用。AC motor used in lift has single-speed, double-speed and triple-speed. Single-speed motor is used in low-speed lift. Stator windings of double-speed motor usually adopts 4/16 polarity or 6/24 pola
27、rity, occasionally, 4/24 polarity or 6/36 polarity is used too. Winding with fewer polarity is called fast winding, while winding with more polarity slow one. Stator winding of triple-speed motor usually adopts 6/8/24 polarity, which has 3 sets of 8 polarity more than double-speed motor and is used
28、as additional winding when lift is decelerating, so that good riding comfort is provided when deceleration begins; besides, this 8-polarity winding can obviate additional resistance or resistor. An alternative triple-speed motor has polarity pair of 6/4/18 polarity, 6-polarity winding is used to res
29、trict start-up current, enabling start-up current less than 2.5 rated current, 4-polarity winding for normal operation, 18 polarity winding for deceleration and leveling before stop. 图8-6是交流双速电梯的主驱动系统的结构原理图。Figure 8-6 is a sketch of mechanism of main drive system of double speed lift. 从图中可以看出电动机为624极。为了限制起动电流，以减小对电网电压波动的影响，起动时，一般按时间原则，串电阻、电抗一级加速或二级加速；减速制动是在慢速绕组中按时间原则进行二级或三级再生发电制动减速，以慢速绕组进行低速稳定运行直至平层停车。变极调速是一种有级调速，调速范围不大。这种系统大多采用开环控制方式，线路简单，价格低，乘坐舒适感差，一般用于货梯。The figure shows that motor is 6/24 polarity. To restrict start-up current and reduce the influence on voltage fluctuation
