The winding design of capacitor motor stator is one of the core factors affecting the motor starting performance. The rationality of its structure and parameters directly determines the performance of the motor at the moment of starting. The design of the winding is first reflected in the number of turns of the coil, and the number of turns will directly change the inductance of the winding. When the number of turns is large, the inductance of the winding is large, which will have a greater obstruction to the current at startup, resulting in a relatively slow increase in the starting current, but at the same time it can also suppress the impact current at startup to a certain extent, making the starting process relatively smooth; when the number of turns is small, the inductance is small, and the current rises faster, which may allow the motor to obtain a larger initial torque at startup, but it may also cause a greater impact on the motor and power supply due to a large current mutation.
The choice of winding wire diameter also has an important impact on the starting performance. The winding with a thicker wire diameter has a smaller DC resistance and can allow a larger current to pass through during startup, thereby providing a stronger starting torque for the motor, making it easier for the motor to overcome the static friction torque during startup and quickly enter the operating state; on the contrary, the winding with a thinner wire diameter has a larger resistance, and the starting current will be limited, which may lead to insufficient starting torque, especially when the load is large, it is easy to start difficult or even unable to start. Therefore, the design of the wire diameter needs to be accurately matched with the power, voltage and other parameters of the motor to balance the starting torque and current load.
The distribution of the winding is also a key link in the winding design. In the capacitor motor stator core, whether the arrangement of the winding is uniform and reasonable will affect the distribution of the magnetic field. Reasonable winding distribution can make the rotating magnetic field generated by the capacitor motor stator more symmetrical and stable, thereby forming a uniform electromagnetic force during startup and promoting the rotor to start smoothly. If the winding distribution is unreasonable, it may cause magnetic field distortion, generate unbalanced electromagnetic force, and cause the motor to vibrate and increase noise during startup. It may even affect the output of the starting torque due to the asymmetric magnetic field and reduce the starting performance.
The influence of the winding connection method on the motor starting performance cannot be ignored. Common connection methods include star connection and triangle connection, etc. Different connection methods will change the voltage and current relationship at both ends of the winding. In star connection, the voltage at both ends of the winding is low, and the starting current is relatively small, which is suitable for use in situations where the starting current needs to be limited; while in triangle connection, the winding withstands a higher voltage and a larger starting current, which can provide a larger starting torque and is suitable for situations where fast starting or load starting is required. Therefore, choosing the appropriate winding connection method according to the actual application scenario is an important means to optimize the motor starting performance.
In capacitor motor stator capacitor motors, the matching relationship between windings and capacitors is another key point of starting performance. The windings are connected in series or in parallel with capacitors to form different starting circuit structures. The capacitance of the capacitor will affect the phase difference of the current in the winding, thereby changing the strength and direction of the rotating magnetic field. When the capacitance and winding parameters match well, a strong rotating magnetic field can be generated at startup, so that the motor can obtain sufficient starting torque; if the capacitance is not properly selected, the current phase difference may be inappropriate, the rotating magnetic field is weak, and the starting effect may be affected, and even the motor may turn wrong or start slowly.
Although the insulation performance of the winding does not directly affect the size of the starting torque, it is related to the safety and reliability of the motor starting process. At the moment of starting, the current is large and the winding will generate more heat. If the performance of the insulation material is not good, it may age and break down at high temperature, resulting in a short circuit of the winding, so that the motor cannot start normally or even be damaged. Therefore, the insulation design of the winding needs to ensure that it can still maintain good insulation performance under the high current and high temperature environment at startup, so as to provide a guarantee for the stable starting of the motor.
The winding design also needs to consider the magnetic circuit characteristics of the iron core. The magnetic field generated by the capacitor motor stator winding needs to form a closed magnetic circuit through the iron core. Factors such as the material and cross-sectional area of the iron core will affect the magnetic resistance and flux density of the magnetic circuit. If the magnetic resistance of the iron core is large, it will lead to increased magnetic field energy loss, thereby reducing the electromagnetic force generated by the winding and affecting the starting performance; while a reasonable iron core design can effectively utilize the magnetic field energy, enhance the electromagnetic effect of the winding, and improve the starting ability of the motor. Therefore, the coordinated optimization of the winding design and the iron core structure is an important way to improve the starting performance of capacitor motors.
