System Outline

The system is designed to drive a 3-phase permanent magnet synchronous motor (PMSM). The application meets the following performance specification:

• Vector Control of PMSM Motor
  
• Targeted at PowerArchitecture MPC5554 Controller Board (MPC5554CB), 3-phase Power Stage with MC33937 and TG Drives PMSM motor TGT2-0032-30-24
  
• Control technique incorporates:
  
  • Torque Vector control or Speed Vector Control
    
  • Both directions of rotation
    
  • Four-quadrant operation
    
  • Rotor alignment to the start position
    
  • Maximal speed 3500 RPM
    
  • Maximal torque 3 Nm
    
  • DC-Bus break
    
• Manual interface (Start/Stop switch, Up/Down push button control, LED indication)
  
• FreeMaster control interface (speed set-up)
  
• FreeMaster monitor
  
• DC Bus over-current fault protection
  

Application Description

A standard system concept is chosen for the drive. The system incorporates the following hardware:

• MPC5554 Controller Board (MPC5554CB)
  
• 3-phase Power Stage with MC33937
  
• Permanent Magnet Synchronous Motor (TGT2-0032-30-24)
  
• Resolver
  
• Power Supply 18V DC, 4Amps
  
  

The eTPU module runs the main control algorithm, independently on the CPU. PWM output signals for a 3-phase inverter are generated according to the input variable values, provided by the microcontroller CPU.
The microcontroller processing is allocated between the CPU and the eTPU, which run in parallel.

The CPU performs the following tasks:

• Periodically scans the user interface (ON/OFF switch, Up and Down buttons, FreeMaster). Based on the user moves it handles the application state machine and calculates the required speed, that is passed to the eTPU.
  

The eTPU performs the following tasks:

• Six eTPU channels (PWMF) are used to generate PWM output signals.
  
• One eTPU channel (RSLV) are used to generate Resolver excitation signal.
  
• One eTPU channel (PWMMAC) is internally used to perform selected modulation and synchronously update the PWM duty-cycles.
  
• One eTPU channel (PMSMVC) is internally used to perform vector control. The PMSMVC calculates applied voltage vector components alpha & beta based on measured phase currents and required values of phase currents in 2-phase orthogonal rotating reference frame (D-Q). The PMSMVC outputs (alpha & beta vector components) are passed to the PWM generator.
  
• One eTPU channel (SC) is internally used to close the speed loop. The actual motor speed is read from the Resolver (RSLV) and compared with the required speed, provided by the CPU and passed through a ramp. A speed PI control algorithm processes the error between the required and the actual speed. The PI controller output is passed to the PMSMVC eTPU function as a new corrected value of desired q-current.
  
• One eTPU channel (BC) generates the DC-bus break control signal, based on the actual DC-bus voltage, in order to protect DC-bus from over-voltage.
  
• One eTPU channel (ASAC) preprocess four analog values that are measured by an AD converter and transferred to the eTPU data memory by DMA transfer. The ASAC also triggers the AD converter and synchronize other eTPU functions.