Phobia Motor Controller

PMC is an open project that aims to build the quality permanent magnet synchronous motor (PMSM) controller for use in a variety of scopes like RC or electrotransport.

ATTENTION: the repository is moving to sf.net.

Hardware specification (rev4c)

• Dimension: 90mm x 50mm x 15mm.

• Weight: 40g (PCBs) or 230g (with 20cm wires and heatsink).

• Wires: 10 AWG.

• Connector: XT90-S and bullet 5.5mm.

• Supply voltage from 5v to 50v.

• Phase current up to 120A (IPT007N06N, 60v, 0.75 mOhm).

• Light capacitor bank (3 x 2.2uF + 3 x 680uF).

• PWM frequency from 20 to 80 kHz.

• STM32F405RG microcontroller (Cortex-M4F at 168 MHz).

• Onboard sensors:

  • Two current shunts (0.5 mOhm) with amplifiers (AD8418) give a measuring range of 150A.
  • Supply voltage from 0 to 60v.
  • Three terminal voltages from 0 to 60v.
  • Temperature of PCB with NTC resistor.

• Motor interfaces:

  • Hall Sensors or Quadrature Encoder (5v pull-up).
  • External NTC resistor (e.g. motor temperature sensing).

• Control interfaces:

  • CAN transceiver with optional termination resistor on PCB (5v).
  • USART to bootload and configure (3.3v).
  • Pulse input control: RC servo pulse width, STEP/DIR, QEP (5v-tolerant).
  • Two analog input channels (from 0 to 6v).

• Auxiliary interfaces:

  • Two combined ports with: SPI, I2C, USART, ADC, DAC, GPIO (3.3v).
  • BOOT and RESET pins to use embedded bootloader.
  • SWD to hardware debug.
  • External FAN control (5v).

• Power conversion:

  • Supply voltage to 5v buck (up to 1A).
  • 5v to 12v boost (up to 100 mA).
  • 5v to 3.3v linear (up to 400 mA).
  • 5v to 3.3vREF optional reference voltage (accuracy 0.2%, 25 mA).

Look into phobia-pcb repository for PCB design source files.

Software features

• Sensorless vector control of PMSM based on two inline current measurements.

• Advanced PWM scheme to reduce switching losses and fully utilise DC link voltage.

• Fast and robust multi-hypothesis flux observer (MHFO) with gain scheduling.

• Terminal voltage sensing to reduce the effect of Dead-Time.

• Automated motor parameters identification with no additional tools.

• Self test of hardware integrity to diagnose troubles.

• Flux weakening control (EXPERIMENTAL).

• Terminal voltage tracking to get smooth start when motor is already running (EXPERIMENTAL).

• Two phase machine support (e.g. bipolar stepper) (EXPERIMENTAL).

• Advanced command line interface (CLI) with autocompletion and history.

• Non critical tasks are managed by FreeRTOS.

• Flash storage for all of configurable parameters.

• Operation at low or zero speed:

  • Forced control that applies a current vector without feedback to force rotor turn.
  • High frequency injection (HFI) based on magnetic saliency (EXPERIMENTAL).
  • Hall Sensors or Quadrature Encoder (TODO).

• Control loops:

  • Current control is always enabled.
  • Speed control loop.
  • Servo operation (EXPERIMENTAL).
  • Battery charger (TODO).
  • Voltage rectifier (TODO).

• Adjustable limits:

  • Phase current (with adjustable derate from overheat).
  • Source current (or power) consumption and regeneration.
  • DC link overvoltage and undervoltage.
  • Maximal speed and acceleration (as part of speed control loop).

• Control inputs:

  • CAN bus (TODO).
  • RC servo pulse width.
  • STEP/DIR (TODO).
  • Analog input with brake signal.
  • Manual control through CLI.
  • Custom embedded application can implement any control strategy.

• Available information:

  • Total distance traveled.
  • Source energy (Wh) and charge (Ah) consumed (or reverted).
  • Fuel gauge percentage.
  • Peak values.

TODO

• Analyse HFI operation on large current values.

• Make a detailed documentation.

• FIX: add detached motor Kv probing

Current Status

Now we can declare that PMC is ready to use in most applications. But there is still a lot of unresolved issues. It may be difficult to configure the PMC for a specific motor.

There are a few videos that show the operation of the prototypes (may be outdated).

Read more in Getting Started.