High-Performance Motor Drive Solution for Industrial Applications

The maximum motor power depends on the external power stage: MCU capabilities - The HS32M200RGT6 can control motors up to 2kW with appropriate external IGBTs

PWM frequency up to 100kHz

Gate drive current of 500mA suitable for large IGBT modules. Power stage considerations - Voltage: Limited by IGBT rating (typically 600V-1200V)

Current: Limited by IGBT and thermal management

Switching: Gate drive capability affects switching speed. Typical power ranges: 24-48V systems: Up to 500W

310V systems (1-phase AC): Up to 1kW

540V systems (3-phase AC): Up to 2kW. The solution scales by selecting appropriate IGBT modules and heatsinking. For higher power, consider parallel IGBT configurations or contact BeiLuo for custom solutions.

Select IGBT module based on voltage/current requirements; ensure adequate heatsinking; size DC bus capacitors for ripple current.

Sensorless control estimates rotor position without mechanical sensors: Principle - Back EMF is proportional to rotor speed and position

Observer algorithms estimate position from voltage and current

Works above minimum speed where BEMF is detectable. Advantages - Lower cost (no encoder)

Higher reliability (no mechanical sensor)

Reduced wiring

Smaller motor size. Limitations - Poor performance at very low speed (<5% rated)

Requires accurate motor parameters

May lose sync on sudden load changes. Best for: Applications where low-speed torque is not critical

High-speed operation

Cost-sensitive designs

Harsh environments where encoders fail. Not recommended for: Zero-speed holding

Very low-speed operation

High-precision positioning without encoder. The HS32M200RGT6 includes sliding mode observer and extended Kalman filter options.

Use sensorless for cost reduction and reliability; add encoder if zero-speed operation or high-precision positioning required.

Field weakening extends motor speed beyond base speed: Base speed - Maximum speed at rated voltage with rated flux

Above base speed, BEMF would exceed supply voltage

Field weakening reduces flux to allow higher speed. Implementation - Reduce Id (flux current) in FOC

Maintain Iq (torque current) within limits

Automatic transition at configurable speed. Trade-offs - Reduced torque at high speed (constant power region)

Increased copper losses

Potential demagnetization risk. Applications: Machine tool spindles requiring wide speed range

Fans and pumps with variable speed

Electric vehicles for highway speeds. Typical speed extension: 1.5x to 3x base speed. The HS32M200RGT6 FOC library includes field weakening with automatic transition and protection against over-weakening.

Implement field weakening when speed range >1.5x base speed needed; monitor motor heating; set appropriate limits.

FOC tuning involves current and speed loops: Current loop (inner) - Start with Ki=0, increase Kp until oscillation

Set Kp to 50% of oscillation value

Add Ki to eliminate steady-state error

Typical bandwidth: 1-5kHz

Tune d-axis and q-axis similarly. Speed loop (outer) - Much slower than current loop (10:1 ratio)

Start conservative, increase gradually

Add integral term for load rejection

Filter speed feedback to reduce noise. Auto-tuning - Hangshun library includes auto-tuning wizard

Measures motor parameters automatically

Sets initial PI values

Requires manual fine-tuning for specific load. Tuning tips - Use scope to monitor step response

Target <10% overshoot

Check stability across speed range

Verify under load transients. Common issues: Oscillation → Reduce gains

Slow response → Increase gains

Overshoot → Add damping

Noise → Add filtering.

Use auto-tuning wizard first; fine-tune with actual load; verify across full operating range.

Motor drive protection is critical for reliability: Overcurrent protection (OCP) - Fast analog comparator (<1μs response)

Shutdown PWM immediately

Set threshold above max normal current but below damage level. Overvoltage protection (OVP) - Detects regenerative braking overvoltage

Triggers braking resistor or shutdown

Protects DC bus capacitors. Undervoltage protection (UVP) - Prevents operation with insufficient gate drive

Safe shutdown sequence

Prevents unexpected restart. Overtemperature protection - Monitor IGBT and motor temperature

Derate or shutdown on overtemp

Thermal modeling for prediction. Additional protections - Over-speed protection

Stall detection

Open-phase detection

Ground fault protection. Implementation: Hardware comparators for fast OCP

Software monitoring for other protections

Safe state configuration on fault

Fault logging for diagnostics. The HS32M200RGT6 integrates most protection features, reducing external component count.

Implement hardware OCP for power stage protection; add software monitoring for other faults; configure safe states; log faults for diagnostics.

Dual-axis control allows two motors from single MCU: Resource allocation - PWM: 4 channels per axis (8 total)

ADC: 3 channels per axis for current sensing

Timers: Independent control loops

CPU: FOC algorithm for both axes. Implementation - Independent FOC instances for each motor

Shared DC bus consideration

Synchronized or independent operation

Cross-coupling compensation if needed. Timing considerations - FOC execution: ~1.5μs per axis at 168MHz

PWM period: 50-100μs typical

CPU load: ~30% for dual axis

Plenty of time for communication and diagnostics. Applications: CNC machines (X/Y or Z/spindle)

Robot joints (adjacent axes)

Dual-spindle drives

Coordinated motion systems. Configuration: Set motor parameters for each axis

Configure control modes independently

Set synchronization if required

Implement appropriate protection for each axis. The FOC library includes dual-axis examples for common configurations.

Allocate 4 PWM + 3 ADC per axis; use synchronized PWM if needed; verify CPU load with both axes running.