Why is Single Phase Motor not suitable for high-power industrial applications?

Single-phase motors have low efficiency. Compared with three-phase motors, single-phase motors are usually only 78% efficient, which leads to higher energy consumption in high-power applications and cannot meet the energy efficiency requirements of industrial production. In addition, the output power density of single-phase motors is low and cannot provide high power output comparable to three-phase motors.
Single-phase motors have insufficient starting torque. Since single-phase motors cannot naturally generate a rotating magnetic field, their starting torque is much lower than that of three-phase motors, which requires additional starting devices such as capacitors or split-phase starters when starting single-phase motors. This additional starting device not only increases the cost, but may also cause unstable operation of the equipment, especially under high load conditions.
Single-phase motors have poor performance when running at low speeds. Due to their design characteristics, single-phase motors cannot run stably at low speeds and are prone to losing steps. This is a serious problem for industrial equipment that needs to run continuously, because low-speed operation may cause inefficiency or even damage to the equipment.
The high starting current of single-phase motors has a greater impact on the power grid. Single-phase motors generate high starting currents of 6 to 10 times the normal operating current when starting, which can burden the power grid, especially in areas with limited power supply. This high starting current can also cause the motor to burn out or shorten its service life.
Single-phase motors have limited application scope. Although single-phase motors perform well in low-power, low-load applications, their performance and reliability cannot meet the needs in high-power industrial applications. For example, industrial equipment generally requires higher output power and more stable operating performance, which are difficult for single-phase motors to provide.
Although single-phase motors have cost advantages in some scenarios, they have problems such as low efficiency, insufficient starting torque, poor low-speed performance, large grid impact, and limited application scope in high-power industrial applications. Therefore, for industrial equipment that requires high power and high efficiency, choosing a three-phase motor is a more appropriate choice.