As a power output device widely used in fan and water pump machinery manufacturing industries, variable frequency speed-regulating motors, the insulation life of variable-frequency speed-regulating motors often represents the life of variable-frequency motors, so variable-frequency motor manufacturers remind that the quality of the insulation materials of variable-frequency motors is very important. !

　　The following are the common reasons for the insulation damage of the inverter motor, which are sorted out by the inverter motor manufacturer.

　　XNUMX. Partial discharge is the main cause of premature crushing of the insulation of high-power and high-voltage variable frequency motors.

　　The pulse high-frequency voltage generated by the variable frequency power supply system causes the motor to produce corona, causing partial discharge, dielectric fever, and cracking of the organic high-resolution insulation material, which in turn leads to the insulation damage of the variable frequency motor. This environment is mostly high power at this moment. The use of high-voltage variable frequency motors is in progress.

　　When a pulse current passes through the insulated coil of a variable-tilt motor, the pulse wave with a short rising edge time causes the voltage to spread unevenly in the coil.The voltage waveform is measured by imitating the length of the stator winding of the motor, and the first few turns of the stator winding of the motor are covered by about 80% of the overvoltage amplitude, so that the inter-turn voltage experienced at the first turn of the winding is higher than the power frequency exchange voltage. Under the conditions, the average turn-to-turn voltage is more than 10 times, although it is still far below the breakdown voltage of the insulation (the variable frequency wire can withstand the power frequency voltage of 13000V), but it is already higher than the junction partial discharge initial voltage.It can be seen that partial discharge is the main cause of premature smashing of inverter motor insulation, and the existence of various factors such as dielectric loss, fever, space charge, electromagnetic excitation, and vibration accelerates the aging process of materials.

　　XNUMX. The insulation design of the frequency conversion motor is not suitable for the utilization situation

　　Powerful variable frequency motor manufacturers should be able to optimize the insulation design of variable frequency motors based on customer utilization.Therefore, inverter motor manufacturers, when designing the insulation layout of inverter motors, the insulation performance of inverter motors not only satisfies customers, but also meets the requirements of resistance to thermal aging and electrical aging in the traditional sense, but also to the requirements of resistance to high-frequency pulses and partial discharge.

　　XNUMX. Frequent start and stop affect the insulation life of the inverter motor

　　When the variable frequency motor is in the state of frequent starting and braking, the motor insulation is often affected by the alternating electromagnetic stress of the cycle.The shorter and more frequent the starting and braking time, the greater the attack force and the higher the probability of insulation breakdown.