Why are flat wire motors more suitable for new energy vehicles than round wire motors?

The difference between flat wire motors and round wire motors lies in the way the copper wire is formed. Flat wires are conducive to improving the motor slot full rate. Generally, the slot full rate of round wire motors is about 40%, while the slot full rate of flat wire motors can reach More than 60%. The increase in slot fullness means that more copper wires can be filled in while the space remains unchanged, generating stronger magnetic field strength and increasing power density. The flat wire motor conforms to the development needs and direction of the new energy automobile industry. It can provide more efficient, energy-saving, comfortable and environmentally friendly driving solutions for new energy vehicles.

Flat wire motors were initially mainly used in high-power motors and generator sets in the industrial field, because these occasions require high power and efficiency of the motor. With the gradual rise of the new energy automobile industry, flat wire motors have also begun to be applied to the vehicle field. Many application functions on vehicles use flat wire motors, such as automotive generators, starters, EPS (electric power steering) motors, main drive motors, P2 (parallel hybrid) system motors, etc.

1. Compared with round wire motors, flat wire motors have the advantages of high slot filling rate, high power density and efficiency, good noise and comfort.

1.1. The slot full rate refers to the filling ratio of copper conductors in the motor stator slots. Flat wire motors use copper strips instead of copper wires, allowing more copper conductors in the slots to wrap the stator teeth more tightly, thereby increasing the slot fill rate. This can reduce magnetic field leakage and reluctance, and increase the magnetic flux and torque of the motor.

1.2. Power density and efficiency refer to the power or effect output by the motor under unit volume or weight. Flat wire motors can output more power with the same or smaller volume and weight due to their high slot fill rate. This is very important for new energy vehicles because it means space and cost can be saved, and performance and mileage can be improved.

1.3. Noise and comfort refer to the impact of vibration generated by the motor on people's feelings during operation. Due to its high slot full rate, the flat wire motor works more efficiently under low speed and high torque conditions or high speed and low torque conditions. This means it can output more torque at lower rpm or less torque at higher rpm. This reduces noise or vibration caused by speed changes.

2. How does the flat wire motor achieve these advantages? How does it work?

2.1. There is essentially no difference in the working principles of flat wire motors and round wire motors. They both produce rotation through the force exerted by current in the magnetic field. The difference is that flat wire motors use flat rectangular wires instead of traditional round wires. If you use flat rectangular wires instead of round wires, you can increase the slot fullness ratio, which is the proportion of space occupied by the coil after being placed in the slot, because there are no gaps between flat wires, but there are gaps between round wires.

The high slot fill rate means that within the same volume, flat wire motors can be filled with 20-30% more conductors. This is equivalent to increasing the amount and strength of the magnetic field produced when current flows through the wire. The stronger the magnetic field, the greater the rotational torque (i.e. rotational capacity) generated by the motor. Therefore, under the same volume, flat wire motors have higher power density (i.e., output power per unit volume) and efficiency (i.e., the ratio of output power to input power) than round wire motors.

2.2. Flat wire can reduce Pierce loss in the winding (that is, eddy current loss caused by AC current in the winding). Because flat conductors have a smaller cross-sectional area and a larger circumference perpendicular to the winding axis than round conductors. In this way, when eddy currents are generated in an alternating magnetic field, the cross-sectional area required is smaller, the circumference is larger, the resistance is larger, and the eddy current is smaller; conversely, the cross-sectional area is larger, the circumference is smaller, and the resistance is smaller. Small, large eddy current. Therefore, under the same conditions, flat wires have lower Pierce losses than round wires.

3. Development potential of flat wire motors

The advantages of flat wire motors are not only reflected in theory, but also verified in practice. In the field of new energy vehicles, flat wire motors have become the drive motor of choice for many well-known brands, showing excellent performance and effects and becoming an important development direction of new energy vehicle drive technology. Flat wire motors can not only improve the performance and efficiency of automobiles, but also reduce their cost and environmental impact.

4. Difficulties faced by flat wire motors

Although flat wire motors have many advantages, they are not without shortcomings and difficulties. In actual production and application, flat wire motors still face some technical difficulties and challenges, which require continuous research and improvement.

4.1. The manufacturing process of flat wire motors is relatively complex. Since the conductor cross-section of flat wire motors is rectangular rather than circular, more precision and skill are required during the winding process to ensure uniform spacing and arrangement between conductors and to avoid wear and damage between conductors . In addition, the windings of flat wire motors also require more materials and time, thus increasing production costs and cycle times.

4.2. The heat dissipation problem of flat wire motors is quite prominent. Because the slot fill rate of the flat wire motor is higher, the air circulation inside the winding is not smooth, making it difficult to effectively dissipate heat. At the same time, due to the higher power density of flat wire motors, more heat will be generated under high load conditions, which may lead to excessive winding temperature, insulation aging, energy degradation and other problems. Therefore, flat wire motors need better heat dissipation designs and materials to ensure stable and reliable operation.

4.3. Flat wire motors also have some other challenges. For example, during use, it may be affected by external interference or its own failure, which affects its control accuracy and effect; there may be matching or compatibility problems when working with other components; it may encounter user awareness or acceptance during marketing Not a high-level question.

Ningbo Nide Machinery Equipment Co., Ltd., was committing to provide customers with highly automated, intelligent, and flexible production solutions, and focusing on the production line of stator, rotor and final assembly of various motors.

At present, the products cover the professional manufacture of new energy motor stator and rotor, hairpin motor, automatic aluminum casting rotor line, brushless motor/ BLDC motor, universal motor, wheel hub motor, etc., which are used in new energy vehicles, household appliances, industrial motors, water pump motors, servo motors, etc. If you want more details for flat wire motors for new energy vehicles,please contact us feel free.