I. Optimization of the motor Body design
Optimize the magnetic circuit structure
• High-grade silicon steel sheets: Low-loss, high-permeability silicon steel materials (such as 35W250) are adopted to reduce core eddy current loss and hysteresis loss.
• Magnetic steel performance upgrade: Utilizing permanent magnets with high residual magnetic density (Br) and high coercive force (Hc), such as N52 neodymium iron boron, to enhance the air-gap magnetic field strength and reduce excitation losses.
• Reasonable air gap length: The smaller the air gap, the lower the magnetic resistance. However, it is necessary to balance the processing accuracy and assembly difficulty to avoid friction between the rotor and the stator.
2. Winding design improvement
• Multi-pole number and short-pitch windings: Increasing the number of pole pairs can reduce the speed fluctuation. Using short-pitch windings (with the winding pitch less than the pole pitch) can reduce the end length and lower the copper loss (PCu=I ² R).
• High slot filling rate design: Optimize the wire diameter and winding process to increase the stator slot filling rate (target over 80%) and enhance the utilization rate of copper.
• Flat wire windings replace round wires: Use flat copper wires (Leeds wires) to reduce the skin effect, especially in high-frequency operating conditions, to reduce AC resistance losses.
3. Reduce mechanical losses
• Low-friction bearings: Ceramic bearings or high-precision ball bearings are adopted to reduce the coefficient of friction (such as changing grease lubrication to oil mist lubrication).
• Optimize rotor dynamic balance: Reduce vibration loss through dynamic balance correction, especially with significant effects during high-speed operation.
• Lightweight structure: Aluminum alloy or carbon fiber rotor brackets are adopted to reduce rotational inertia and centrifugal force loss.
Ii. Optimization of Drive and Control Strategies
1. Advanced control algorithm
• Field-oriented control (FOC) : Decoupling the three-phase current into excitation current (id) and torque current (iq) to achieve operation per unit power factor and reduce copper loss. For example, the control through id=0 can increase the efficiency by 3%-5%.
• Demagnetization control: In the high-speed zone, the magnetic field is weakened by a negative id to expand the constant power operation range and avoid efficiency decline caused by speed limitation.
• Adaptive control: Real-time monitoring of load and temperature, dynamic adjustment of PI parameters or current loop gain, and reduction of energy loss caused by control lag.
2. PWM modulation optimization
• Appropriate switching frequency: A switching frequency that is too high will increase the inverter's losses (such as the switching losses of IGBTs), while a frequency that is too low will lead to an increase in current ripple. The optimal frequency (usually 10-20kHz) should be selected based on the motor power.
• Space Vector Modulation (SVM) : Compared with traditional PWM, SVM has a higher DC voltage utilization rate (increased by 15%), which can reduce the peak phase current and copper loss.
3. High-efficiency power devices
Silicon carbide (SiC)/gallium nitride (GaN) devices: Replace traditional IGBTs or MOSFETs, reducing conduction losses and switching losses. For example, the on-resistance of SiC MOSFET is more than 50% lower than that of silicon-based devices.
• Low parasitic parameter design: Optimize the layout of the drive circuit, reduce line inductance and capacitance, and lower EMI interference and oscillation loss.
Iii. Thermal Management and Optimization of Operating Environment
Strengthen the heat dissipation design
• Integrated heat dissipation structure: The stator core and the housing are designed as an integrated unit to increase the heat dissipation area; Heat pipes or water cooling systems are adopted to reduce the winding temperature (for every 10℃ reduction, copper loss is reduced by approximately 4%).
• Insulation material upgrade: Use insulating varnish with high frequency resistance and high thermal conductivity (such as polyimide) to enhance heat conduction efficiency.
2. Work point matching
• Avoid light-load operation: The motor's efficiency drops significantly at low loads (<30% of the rated power). It can be made to operate in the high-efficiency zone (typically 60%-80% of the rated load) through load merging or variable frequency speed regulation.
• Rotational speed - Torque matching: Select an appropriate rotational speed range based on the load characteristics (such as constant torque and constant power) to avoid the phenomenon of "a big horse pulling a small cart".
3. Optimization of environmental conditions
• Cleaning and lubrication maintenance: Regularly clean the dust inside the motor to prevent the heat dissipation channels from being blocked; Insufficient or aged bearing grease will increase friction loss and needs to be replenished or replaced regularly.
• Voltage/frequency adaptation: Ensure that the supply voltage is consistent with the rated voltage of the motor. Overvoltage or undervoltage will both lead to increased iron loss or copper loss.
Iv. System-level Optimization
Energy recovery and utilization
Regenerative braking technology: When the motor decelerates or goes downhill, it converts kinetic energy into electrical energy and feeds it back to the power supply or energy storage device (such as a supercapacitor), enhancing the overall efficiency of the system.
• Multi-motor cooperative control: In multi-motor systems (such as robots and electric vehicles), the central controller coordinates the load distribution of each motor to prevent a single motor from being overloaded or underloaded.
2. Intelligent predictive maintenance
• Condition Monitoring (CBM) : By using sensors to monitor parameters such as motor temperature, vibration, and current in real time, it can provide early warnings of potential faults such as bearing wear and winding aging, thus avoiding efficiency decline caused by faults.
• Life management algorithm: By integrating data such as motor operation duration and load history, the control strategy is dynamically adjusted to extend the service life of key components (such as bearings and permanent magnets).
I. Optimization of the motor Body design
Optimize the magnetic circuit structure
• High-grade silicon steel sheets: Low-loss, high-permeability silicon steel materials (such as 35W250) are adopted to reduce core eddy current loss and hysteresis loss.
• Magnetic steel performance upgrade: Utilizing permanent magnets with high residual magnetic density (Br) and high coercive force (Hc), such as N52 neodymium iron boron, to enhance the air-gap magnetic field strength and reduce excitation losses.
• Reasonable air gap length: The smaller the air gap, the lower the magnetic resistance. However, it is necessary to balance the processing accuracy and assembly difficulty to avoid friction between the rotor and the stator.
2. Winding design improvement
• Multi-pole number and short-pitch windings: Increasing the number of pole pairs can reduce the speed fluctuation. Using short-pitch windings (with the winding pitch less than the pole pitch) can reduce the end length and lower the copper loss (PCu=I ² R).
• High slot filling rate design: Optimize the wire diameter and winding process to increase the stator slot filling rate (target over 80%) and enhance the utilization rate of copper.
• Flat wire windings replace round wires: Use flat copper wires (Leeds wires) to reduce the skin effect, especially in high-frequency operating conditions, to reduce AC resistance losses.
3. Reduce mechanical losses
• Low-friction bearings: Ceramic bearings or high-precision ball bearings are adopted to reduce the coefficient of friction (such as changing grease lubrication to oil mist lubrication).
• Optimize rotor dynamic balance: Reduce vibration loss through dynamic balance correction, especially with significant effects during high-speed operation.
• Lightweight structure: Aluminum alloy or carbon fiber rotor brackets are adopted to reduce rotational inertia and centrifugal force loss.
Ii. Optimization of Drive and Control Strategies
1. Advanced control algorithm
• Field-oriented control (FOC) : Decoupling the three-phase current into excitation current (id) and torque current (iq) to achieve operation per unit power factor and reduce copper loss. For example, the control through id=0 can increase the efficiency by 3%-5%.
• Demagnetization control: In the high-speed zone, the magnetic field is weakened by a negative id to expand the constant power operation range and avoid efficiency decline caused by speed limitation.
• Adaptive control: Real-time monitoring of load and temperature, dynamic adjustment of PI parameters or current loop gain, and reduction of energy loss caused by control lag.
2. PWM modulation optimization
• Appropriate switching frequency: A switching frequency that is too high will increase the inverter's losses (such as the switching losses of IGBTs), while a frequency that is too low will lead to an increase in current ripple. The optimal frequency (usually 10-20kHz) should be selected based on the motor power.
• Space Vector Modulation (SVM) : Compared with traditional PWM, SVM has a higher DC voltage utilization rate (increased by 15%), which can reduce the peak phase current and copper loss.
3. High-efficiency power devices
Silicon carbide (SiC)/gallium nitride (GaN) devices: Replace traditional IGBTs or MOSFETs, reducing conduction losses and switching losses. For example, the on-resistance of SiC MOSFET is more than 50% lower than that of silicon-based devices.
• Low parasitic parameter design: Optimize the layout of the drive circuit, reduce line inductance and capacitance, and lower EMI interference and oscillation loss.
Iii. Thermal Management and Optimization of Operating Environment
Strengthen the heat dissipation design
• Integrated heat dissipation structure: The stator core and the housing are designed as an integrated unit to increase the heat dissipation area; Heat pipes or water cooling systems are adopted to reduce the winding temperature (for every 10℃ reduction, copper loss is reduced by approximately 4%).
• Insulation material upgrade: Use insulating varnish with high frequency resistance and high thermal conductivity (such as polyimide) to enhance heat conduction efficiency.
2. Work point matching
• Avoid light-load operation: The motor's efficiency drops significantly at low loads (<30% of the rated power). It can be made to operate in the high-efficiency zone (typically 60%-80% of the rated load) through load merging or variable frequency speed regulation.
• Rotational speed - Torque matching: Select an appropriate rotational speed range based on the load characteristics (such as constant torque and constant power) to avoid the phenomenon of "a big horse pulling a small cart".
3. Optimization of environmental conditions
• Cleaning and lubrication maintenance: Regularly clean the dust inside the motor to prevent the heat dissipation channels from being blocked; Insufficient or aged bearing grease will increase friction loss and needs to be replenished or replaced regularly.
• Voltage/frequency adaptation: Ensure that the supply voltage is consistent with the rated voltage of the motor. Overvoltage or undervoltage will both lead to increased iron loss or copper loss.
Iv. System-level Optimization
Energy recovery and utilization
Regenerative braking technology: When the motor decelerates or goes downhill, it converts kinetic energy into electrical energy and feeds it back to the power supply or energy storage device (such as a supercapacitor), enhancing the overall efficiency of the system.
• Multi-motor cooperative control: In multi-motor systems (such as robots and electric vehicles), the central controller coordinates the load distribution of each motor to prevent a single motor from being overloaded or underloaded.
2. Intelligent predictive maintenance
• Condition Monitoring (CBM) : By using sensors to monitor parameters such as motor temperature, vibration, and current in real time, it can provide early warnings of potential faults such as bearing wear and winding aging, thus avoiding efficiency decline caused by faults.
• Life management algorithm: By integrating data such as motor operation duration and load history, the control strategy is dynamically adjusted to extend the service life of key components (such as bearings and permanent magnets).
