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Why Is The Motor's Speed Unstable
Edit: Wuxi Lanhai Electric Motor Co.,Ltd    Date: Sep 12, 2017



Why is the Motor's speed unstable

Standards in all of the parameters of the Motor has a rated speed, the rated speed is generally less than synchronous speed of the Motor (2 pole synchronous speed is 3000 RPM, 4 pole at 1500 RPM, 6 pole at 1000 RPM, eight pole is 750 RPM), but the Motor will often encounter in the actual running speed below or above this speed. Why is the Motor speed unstable? From the principle of analysis, the following situations can be:

The first, adjustable resistance is not good, because the adjustable resistor is installed on the control panel, because its use frequency is very high, the use time is long, the situation of contact is very ordinary.
Second, measure the other three diodes are normal but when comparing measurements, found that two types of diodes are positive and negative polarity opposite, so it is important to note that while installing had better use of the same model, with specifications of the yuan.
The third, the Motor rotor and commutator have the carbon powder or the carbon brush itself is not good.
If the Motor speed is unstable, this is probably the case.
Motor stator adjustment method: when changing the stator voltage of the Motor, a set of different mechanical characteristic curves can be obtained to obtain different speeds. Because the torque of the Motor is proportional to the square of the voltage, the maximum torque decreases a lot, and its speed range is smaller, making it difficult to apply the general cage Motor. In order to enlarge the speed range, regulating speed rotor resistance value should be adopted for the big cage Motor, such as torque Motor, USES for regulating speed or frequency on the wound rotor Motor series resistor. In order to expand the range of stable operation, the feedback control should be used to achieve the automatic adjustment of the rotating speed. The main device of regulating speed regulation is a power supply which can provide voltage change. Currently, there are several kinds of voltage regulating modes, such as series saturation reactor, autotransformer and thyristor. The thyristor is the best mode. The adjustment speed regulation generally applies to the production machinery under 100KW.
The characteristics of regulating speed adjustment:
1. The regulating speed regulating circuit is simple and easy to realize automatic control;
2. The transfer differential power of the pressure regulating process is consumed in the rotor resistance in the form of heat, and the efficiency is low
The change of times, everything has changed, people's thought, the demand is rising. In China, the demand for Motor use is becoming more and more strict. There is no doubt that China is a populous country and its natural demand for material is rising.
The Motor is mainly a power mechanical equipment, which consumes more than 50% of the electricity consumption in China every year. Under the condition of full load conditions, the Motor efficiency is generally higher, usually about 80 %. Once the load drops, the Motor's efficiency drops. Why is that? Must have at the moment all hearts full of doubt, because the Motor type selection is needed according to the largest possible load and the worst in the determination of the required power, most of the Motor is in in most of the running time of load rate is 50% ~ 60%, so the actual runtime efficiency is low. Therefore, it is of great economic and social benefit to improve the operation efficiency of this part of the Motor.
At the same time also is the need to remind, for Motor Motor power that the input power is not only used to drive the Motor, is part of this will be the loss inherent to the Motor. The Motor main loss for the copper loss and iron loss, copper loss of by electric current flows through the Motor winding, and is proportional to the square of the current.