Is the higher the height of the magnet, the greater the power of the electric vehicle motor?
In theory, according to newton’s second law, power P = force f * speed v. under the premise of maintaining the output torque of the motor, in order to improve the motor speed, we need to increase the motor power. So the higher the motor power, the faster the original electric vehicle will run. Of course, this is in the battery The supply of electricity to meet the premise of the realization.
Although there are differences in efficiency, load, tire pressure and wind resistance among different types of vehicles, the maximum speed that this electric vehicle can run can be basically determined when the motor power is determined. For example, with an 800W motor, the vehicle can run about 40km / h; with 1000W, it can run about 45km / h; with 1200W, it can run about 48km / h; with 1500W, it can run about 52km / h; with 2kW, it can It’s no problem to go up 58km / h, 3KW or above 65km / h.
Motor power = motor voltage * motor current. Under the premise of constant battery voltage, the higher the maximum current the motor winding can bear, the greater the power of the motor, and the larger the motor current means that the heat will also be large. Therefore, it is necessary to have a rough line diameter and a short line length to reduce the internal resistance. In this way, the motor can pass through a large current. Therefore, the motor has a high power, and the general line will be more than power The line with a small rate is a little thicker. A good motor should be in the premise of satisfying voltage and power, the less heat generated, the higher the efficiency.
Sometimes, the motor can be misleading when looking at the nominal power. The height of magnetic steel is a relatively important data. The large volume of magnetic steel determines the higher magnetic energy volume. For motors used in general electric vehicles, the thickness of magnetic steel is 3mm, and the width is only 13.65 and 14.2. The higher the height of magnetic steel, the larger the magnetic energy volume, the larger the space for motor power play. In the actual market, most 800W and 1000W motors have 30h magnetic steel height, and the torque difference between them is not big. If it is a 1000w30h motor and a 1000w35h motor, the torque of 35h is much larger, and the room for voltage rise is also much larger. Running at high speed 35h will save power, but if you run at a low speed of 30h, you can run a long distance.
If the number of turns is increased, the more turns each slot enters, it can also let multiple fine wires pass through a large current. However, with the increase of turns, the reverse emf will also increase. If the voltage is not increased, the current will decrease instead. The full slot rate is high, the width of magnetic steel is large, and the silicon steel sheet is thin and the label is small, and the motor power is relatively large. The motor power should be large, the current passing through is high, the coil is roughened, the turn number will be reduced correspondingly, the length will be shorter, the internal resistance will be reduced, and the magnetic steel will be increased. The transformer will increase the stator height, which in turn makes the coil grow, which offsets the impact of the decrease of turns. The coil length is constant, but the area increases, and the heat dissipation effect will be better. So the motor power up, the temperature can be balanced.
Although many people like the motor with higher power, the motor power is high and more energy will be consumed. At this time, the controller and battery capacity are required to be increased. At present, the national standard of electric bicycle requires that the motor power cannot exceed 400W, and you can not go on the road if you change it or drive on the road, which is a modification beyond the standard.
