Three Phases Synchronous Machine Cutaway Models AC Machine Trainer Teaching Model

ASR6108E Three Phases Synchronous Machine Cutaway Models AC Machine Trainer Teaching Model
1 Introduction
Synchronous motor is an AC motor with the same rotating speed as the stator rotating field. The rotation speed of the rotor is n=60f/p with the logarithmic p and the power frequency f. The speed n depends on the power frequency f, so the power supply frequency must be constant, the speed is constant, and it has nothing to do with the load. It has the characteristics of high operation stability and overload capacity. It is often used in multi-machine synchronous transmission system, precision speed control system and large equipment.
2 Synchronous machine structure
The structure of synchronous motor is varied, and the rotor structure has hidden pole type and salient pole type. The installation methods include horizontal, suspension, semi-suspension and vertical. The synchronous motor is usually composed of stator, rotor, bearing, baseplate, end cover, collector ring and brush frame, and the motor with the protection grade of AIP44 is also included in the cooler. A brief description of the above components is given below:
1. Stator
The stator is composed of a stand, a stator coil and an end collar and supporting part of the stator coil.
1.1 stand
The frame has round stand and square frame (box structure), all welded by steel plate. The motor of the round machine seat of the large horizontal installation, the center of the machine can sink, and the lower part of the seat sometimes sinks to the pit below the installation plane, so the center of the motor is not limited by the outer circle size. Square base are commonly used in protective higher grade of motor, more than the air – air cooling or air – cooled, cooler on the top of the frame, general motors by the center core diameter high limit, lower frame is generally not below the installation plane.
1.2 stator core.
The stator core is composed of a frame and a silicon steel plate in the frame. The core is divided into internal pressure and external pressure mounting: the inner pressure is positioned inside the machine seat, and then the silicon steel sheet is pressed into the seat, and then the tension screw and the pressure ring are pressed and fixed on the machine seat. The outer pressure installation is to make the core frame first, the silicon steel sheet is pressed into the frame, and the embedded wire is then put into the frame by the vacuum pressure immersion treatment.
1.3 stator coil
The stator coil is made of an electromagnetic wire with the corresponding insulation and voltage grade, and the coil can be inserted into the stator core trough through the turns and the coils of the ground resistance test. The linear part of the coil is pressed tightly with the slot wedge. The end part is tightly bound together with the polyester sleeve coil, the end hoop and the supporting part. After the coating is processed, the whole stator becomes a solid whole. The stator coils can be insulated with class B and F, and the special case is H – class insulation. F is used for the above 10KV. Stator coil is the key part of the motor. It is easy to burn the motor due to damage of dirt, moisture and insulation.
The stator lead wire usually has 6 outlet heads and is marked with AU1, AV1, AW1 and AU2, AV2 and AW2. If it is connected with “Y”, then AU2, AV2 and AW2 will be joined together. If it is connected with “delta”, namely, AU2-AV1, AV2-AW1, AW2-AU1, three wiring heads, the high voltage motor is usually connected with Y.
2 Rotor
The rotor of the synchronous motor can be divided into two types: the hidden pole type and the convex one, which are generally made up of magnetic poles, magnetic yoke, rotating shaft and collector ring. 2.1 the magnetic poles are divided into implicit and salient poles. Non-salient pole type magnetic pole is the circumference of a circle is not evenly in rotor slot, made concentric rotor winding coil, embedded in the groove, using metal slot wedge, fixed coil two ends with ring guard banding, the structure of high mechanical strength, good coil heat dissipation, multi-purpose in 1500 turn above the motor. Most of the motors under 1500 RPM are of a convex type magnetic pole.
2.2 the salient pole is composed of magnetic pole, pole coil and pole screw, and the excitation lead is marked as AF1 and AF2.
2.2.1 pole core is the use of end plate, rod, rivet pole to pole plate riveting pressure into the whole, the pole shoe mount damper bar (starting winding), welding on damping rings on both ends, and notches in playing the punching core at both ends and the damper bar clamping to prevent axial moving, can also be used on the damping of the stretched out on both ends of the core set of brass to fixed
2.2.3 yoke and axis.
Most of the magnetic yoke is made of cast steel, which is also welded with steel plates. The diameter is small, and the magnetic yoke is directly connected with the shaft. The rotating shaft material is generally made of 45 steel and 35 steel, and the special case is made of alloy steel.
2.2.4 rotor assembly:
Yoke thermal set on the rotating shaft first, in the pole core pole wrapping package good insulation, good insulation gasket, set into the pole coil, mount pole bolt, can be installed on the yoke. Note when assembling, insulation gasket can’t more mat, also cannot little cushion, cushion the impact more air gap, less cushion may not tightly on the pole coil. In the case of pole to tighten bolts, general control pole core and the clearance between the yoke within 0.15 mm, at the same time to pay attention to the distance between the poles boots to uniform, the axial location to the end of the pole core level. Spoon fan. Overall varnished, in order to improve the mechanical strength, moisture and heat dissipation performance.
The rotor is the heart of the machine, is made up of many parts assembled, under the effect of electromagnetic force and centrifugal force at high speed, all the parts and fasteners loose easily, cause mechanical accident, therefore, all fastener must be tight when the assembly, and a locking measures, please assemble and maintenance workers should pay attention to check, found that the problem should be handled in a timely manner.