It is reported that permanent magnet synchronous motors (PMSMs) are being increasingly adopted, with continuous improvements in voltage ratings and rotational speeds. According to statistics, in the first batch of recommended vehicle catalogs in 2017, 150 models were equipped with PMSMs, accounting for 81% of the total, while 33 models were equipped with AC asynchronous motors, making up 18%.
The advantages of PMSMs over AC asynchronous motors include: (1) higher efficiency and greater energy savings; (2) higher power factor; (3) simpler and more flexible motor structure; (4) higher reliability; (5) smaller size and greater power density; and (6) higher starting torque, lower noise, and reduced temperature rise.
Compared to DC motors, PMSMs also offer distinct benefits. They lack components such as commutators and brushes found in DC motors, require less maintenance, and do not present the inconveniences associated with these parts. In contrast to asynchronous motors, PMSMs have a relatively simpler structure, reduced stator current and stator resistance losses, and offer measurable rotor parameters along with superior control performance. However, they also have limitations, such as maximum torque being constrained by permanent magnet demagnetization, relatively poor vibration resistance, speed limitations at high rotations, lower power capacity, higher costs, and difficulties in starting.
PMSMs feature high power density, reliability, and power factor, along with a broad operational speed range and excellent speed control performance, enabling wide调速范围. Without the need for excitation losses or complex heat dissipation systems, PMSMs boast a simple structure and are more compact than asynchronous motors of equivalent power.
Therefore, PMSMs have emerged as a critical development direction in motor drive technology.