外文文獻(xiàn)及翻譯--三相異步電動機(jī)的幾種調(diào)速方式-其他專業(yè)-全文預(yù)覽
【正文】 發(fā)熱形式消耗在轉(zhuǎn)子電阻中，效率較低。 電磁轉(zhuǎn)差離合器由電樞、磁極和勵磁繞組三部分組成。當(dāng)電樞隨拖動電動機(jī)旋轉(zhuǎn)時，由于電樞與磁極間相對運(yùn)動，因而使電樞感應(yīng)產(chǎn)生渦流，此渦流與磁通相互作用產(chǎn)生轉(zhuǎn)矩，帶動有磁極的轉(zhuǎn)子按同一方向旋轉(zhuǎn)，但其轉(zhuǎn)速恒低于電樞的轉(zhuǎn)速 N1，這是一種轉(zhuǎn)差調(diào)速方式，變動轉(zhuǎn)差離合器的直流勵磁電流，便可改變離合器的輸出轉(zhuǎn)矩和轉(zhuǎn)速。殼中充入一定量的工作液體，當(dāng)泵輪在原動機(jī)帶動下旋轉(zhuǎn)時，處于其中的液體受葉片推動而旋轉(zhuǎn)，在離心力作用下沿著泵輪外環(huán)進(jìn)入渦輪時，就在同一轉(zhuǎn)向上給渦輪葉片以推力，使其帶動生產(chǎn)機(jī)械運(yùn)轉(zhuǎn)。 4 The threephase induction motor speed control method Threephase asynchronous motor speed formula: N = 60f / p (1s) Can be seen from the above formula, change the power supply frequency f, motor pole number p and the slip s may be too much to change the speed of purpose. From the speed of the essence of view, is simply a different way to change speed synchronous AC motor does not change the sync transfer speed or two. Widespread use in production machines without changing the synchronous speed of motor speed control method Wound Rotor Series Resistance Speed, chopper speed control, cascade control, and application of electromagic slip clutch, fluid couplings, clutches and other film speed. Change the synchronous speed of change on the number of stator pole multispeed motor to change the stator voltage and frequency to frequency conversion with no change to the motor speed and so on. Energy from the speed point of view when, with high speed method and inefficient methods of two kinds of speed: high speed when the slip refers to the same, so no slip losses, such as multispeed motors, Slip frequency control and loss can speed recovery methods (such as cascade control, etc.). A deteriorating loss of speed control methods are inefficient speed, such as series resistance of the rotor speed method, the energy loss in the rotor circuit on。 A level speed, differential large, can not get smooth speed control。 Technical plexity, high cost, difficult maintenance and overhaul. This method is suitable for the high accuracy, good speed performance occasions. 3. Cascade Speed Regulation Method Cascade control method Cascade control is wound into the rotor circuit in the series of additional potential can be adjusted to change the motor39。 Thyristor cascade speed low power factor, harmonics greater impact. This method is suitable for fans, pumps and rolling mills, mine hoist, extrusion machines. 4. Wound Rotor Motor Speed Control Method of Series Resistance Wound Rotor Motor additional resistance in series, so that the motor slip up, motor running at low speed. Th
環(huán)評公示相關(guān)推薦
鄂ICP備17016276號-1