Synchronous Motor Working Principle . Based on the type of input we have classified it into single phase and 3 phase motors. Among 3 phase induction motors and synchronous motors are more widely used. When a 3 phase electric conductors are placed in a certain geometrical positions (In certain angle from one another) then an electrical field is generated. Now the rotating magnetic field rotates at a certain speed, that speed is called synchronous speed. Now if an electromagnet is present in this rotating magnetic field, the electromagnet is magnetically locked with this rotating magnetic field and rotates with same speed of rotating field. Synchronous motors is called so because the speed of the rotor of this motor is same as the rotating magnetic field. It is basically a fixed speed motor because it has only one speed, which is synchronous speed and therefore no intermediate speed is there or in other words it. Synchronous speed is given by. Now, let us first go through the basic construction of this type of motor. From the above picture, it is clear that how this type of motors are designed. The stator is given is given three phase supply and the rotor is given dc supply. They require some external means to bring their speed close to synchronous speed to before they are synchronized. The speed of operation of is in synchronism with the supply frequency and hence for constant supply frequency they behave as constant speed motor irrespective of load condition This motor has the unique characteristics of operating under any electrical power factor. This makes it being used in electrical power factor improvement. Principle of Operation Synchronous Motor. ![]() As with a three -phase induction motor, synchronous motor rotation is changed by reversing any. Figure 3: Effect of field. For the correct design and specification of a synchronous motor. Download and Read Ac Synchronous 3 Phase Generators Diagram. Title Type wiring diagram three phase generator PDF 3 phase solar schematic diagram PDF wiring diagram for 3 phase motor PDF wiring diagram three phase motor PDF 3. Synchronous Machine and Winding Models. Vector diagrams that describe operation as a motor and as a generator are shown in Figures 3. Synchronous motor is a doubly excited machine i. The 3 phase stator winding carrying 3 phase currents produces 3 phase rotating magnetic flux. The rotor carrying DC supply also produces a constant flux. Considering the frequency to be 5. Hz, from the above relation we can see that the 3 phase rotating flux rotates about 3. ![]() At a particular instant rotor and stator poles might be of same polarity (N- N or S- S) causing repulsive force on rotor and the very next second it will be N- S causing attractive force. But due to inertia of the rotor, it is unable to rotate in any direction due to attractive or repulsive force and remain in standstill condition. Hence it is not self starting. After some time magnetic locking occurs and the synchronous motor rotates in synchronism with the frequency. ![]() It could be either 3 phase induction motor or DC shunt motor. DC excitation is not fed initially. ![]() It is rotated at speed very close to its synchronous speed and after that DC excitation is given. After some time when magnetic locking takes place supply to the external motor is cut off. Damper winding : In case, synchronous motor is of salient pole type, additional winding is placed in rotor pole face. Initially when rotor is standstill, relative speed between damper winding and rotating air gap flux in large and an emf is induced in it which produces the required starting torque. As speed approaches synchronous speed , emf and torque is reduced and finally when magnetic locking takes place, torque also reduces to zero. Hence in this case synchronous is first run as three phase induction motor using additional winding and finally it is synchronized with the frequency. Application of Synchronous Motor. Synchronous motor having no load connected to its shaft is used for power factor improvement. Owing to its characteristics to behave at any electrical power factor, it is used in power system in situations where static capacitors are expensive. Synchronous motor finds application where operating speed is less (around 5. For power requirement from 3. W to 2. 50. 0 KW, the size, weight and cost of the corresponding three phase induction motor is very high. Hence these motors are preferably used. If there are 3 wire terminals led out from the motor in which 3 phase windings are already connected internally.Rab). Three Phase A Synchronous Motor. Www.nfphampden.com electrical advice 3 Phase AC Motor Theory 2 The frequency of the applied voltage, and the number of poles, determines the 'synchronous speed' of the rotating magnetic field in the stator of a motor. Synchronous Motor Working Principle Phasor Diagram for Synchronous Motor Synchronous Motor Excitation Hunting in Synchronous Motor AC Series Motor. Among 3 phase induction motors and synchronous motors are more widely used. Peripheral Description 3-Phase PMSM Motor Vector Control, Rev. 3 Freescale Semiconductor 5 Preliminary The Analog-to-Digital Converter (ADC) consists of a digital control module and two analog Sample and Hold (S/H) circuits. Ex- Reciprocating pump, compressor, rolling mills etc. Video Working Principle of Synchronous Motor. ![]()
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