How to evaluate the energy product and coercivity of motor magnets?
Publish Time: 2025-02-27
As a key component in the motor, the performance of motor magnets directly affects the efficiency, power density and service life of the motor. Energy product and coercivity are two important indicators to measure the performance of motor magnets, and are crucial to evaluating the quality of magnets.Magnetic energy product, also known as maximum magnetic energy product, is the maximum value of the product of magnetic induction intensity B and magnetic field intensity H at any point on the demagnetization curve, usually expressed as (BH)max, in units of mega-gauge oeres (MGOe) or joules per cubic meter (J/m³). It reflects the maximum magnetic energy that a magnet can store in a given volume. The larger the energy product, the higher the magnetic field intensity that the magnet can generate in the same volume, thereby improving the efficiency and power density of the motor.To evaluate the energy product of a motor magnet, professional magnetic measurement equipment such as a hysteresis loop instrument or a vibrating sample magnetometer (VSM) is usually required. These devices can measure the demagnetization curve of the magnet and calculate the value of the energy product. During the measurement process, it is necessary to ensure that the magnet is in a stress-free and impurity-free state to obtain accurate measurement results.Coercive force is an important indicator to measure the ability of a magnet to resist external magnetic field interference. It indicates how large a reverse magnetic field needs to be applied to reverse the magnetization direction of the magnet after it is completely demagnetized. The larger the coercive force, the stronger the magnet's ability to resist demagnetization, and the more severe the environment. The output of the magnetic field can be maintained.To evaluate the coercive force of a motor magnet, professional measuring equipment such as a fluxmeter or a Hall effect tester is also required. These devices can measure the hysteresis loop of the magnet during magnetization and demagnetization, and thus calculate the value of the coercive force. During the measurement process, it is necessary to pay attention to controlling the ambient temperature and magnetic field interference to ensure the accuracy of the measurement results.In summary, evaluating the magnetic energy product and coercive force of a motor magnet is a key step to ensure its stable and reliable performance. Through professional measuring equipment and rigorous measurement processes, we can accurately obtain the data of these two indicators, providing strong support for the design and optimization of motors. At the same time, for motor magnet manufacturers, continuously improving the magnetic energy product and coercive force is also an important way to enhance product competitiveness.
