7.1. Glossary¶
- ADC
- analog-to-digital converter
- API
- Application Programming Interface
- BLDC
- brushless DC motor — generally used in six-step control. Also known as PMSM
- feedback path
- The section of the current control loop between ADC inputs and the current controllers, including Park and Clarke transforms. See also FOC block diagram.
- FOC
- field-oriented control — a type of control scheme for permanent-magnet synchronous motors or induction motors, where the stator field is controlled relative to the rotor field. It generally results in smoother torque, slightly higher efficiency, and higher torque-speed curve, compared to six-step control, but requires a measurement or estimate of rotor position, and is more computationally intensive.
- forward path
- The section of the current control loop between the output of the current controllers and the transistor gate drives, including inverse Park and Clarke transforms, DC link compensation, zero sequence modulation, and overmodulation. See also FOC block diagram.
- HAL
- Hardware Abstraction Layer
- IPM
- interior permanent-magnet motors (see rotor saliency)
- IPMSM
- interior permanent-magnet synchronous motors (see rotor saliency)
- ISR
- interrupt service routine
- MCAF
- Motor Control Application Framework
- MIMO
- Multi-input, multi-output systems, usually specified and analyzed with state-space equations. See also SISO.
- MCAPI
- Motion Control API
- MTPA
- Maximum Torque per Ampere
- PIM
- Plug-In Module — a small circuit board containing a processor and several passive components (such as bypass capacitors), meant to plug in to one of Microchip’s development boards.
- PLL
- phase-locked loop — see AN1292 for the Microchip Application Note covering the PLL-style sensorless estimator.
- PMSM
- permanent-magnet synchronous motor — generally used with FOC. Also known as BLDC.
- PWM
- pulse-width modulation
- QEI
- Quadrature Encoder Interface — the name of the hardware encoder counter peripheral in some Microchip devices.
- rotor saliency
Permanent magnet synchronous motors can be divided into two types, interior permanent-magnet synchronous motors (IPM or IPMSM) with magnets located inside the rotor, and surface permanent-magnet synchronous motors (SPM or SPMSM) with magnets placed evenly over the surface of the rotor.
These can be distinguished quantitatively through the ratio of the synchronous inductances \(\xi = L_q/L_d\), known as the saliency ratio.
The SPMSM has stator inductance which is independent of rotor position, and has no significant difference between the two synchronous inductances, so \(\xi = L_q/L_d \approx 1\).
The IPMSM has stator inductance which is dependent of rotor position, and has significant difference between the two synchronous inductances, typically with saliency ratio \(\xi = L_q/L_d > 1\).
- SISO
- Single-input, single-output systems, usually specified and analyzed with state-space equations. See also MIMO.
- SMO
- sliding-mode observer — see AN1078 for the Microchip Application Note covering the SMO-style sensorless estimator.
- SPM
- surface permanent-magnet motors (see rotor saliency)
- SPMSM
- surface permanent-magnet synchronous motors (see rotor saliency)