Induction Machine Field-Oriented Control

Per-unit discrete-time induction machine FOC

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Libraries:
Simscape / Electrical / Control / Induction Machine Control

Description

The Induction Machine Field-Oriented Controller block implements an induction machine field-oriented control (FOC) structure using the per-unit system. To decouple the torque and flux, FOC uses the rotor d-q reference frame. The figure shows the control structure.

In the diagram:

• ω_r is the measured angular velocity.

• ω_ref is the reference angular velocity.

• i_d and i_q are the d- and q-axis stator currents.

• i_a, i_b, and i_c are the a-, b- and c-phase stator winding currents.

• i_{mr_ref} is the reference magnetizing current.

• i_mr is the magnetizing current.

• v_d and v_q are the d- and q-axis stator voltages.

• v_a, v_b, and v_c are the a-, b- and c-phase stator winding voltages.

• θ_e is the rotor electrical angle.

• G_AH, G_AL, G_BH, G_BL, G_CH, and G_CL are the a-, b- and c-phase high (H) and low(L) gate pulses.

Assumptions and Limitations

• The machine parameters are known.

• The implementation uses the per-unit system.

• The control structure implementation uses a single sample rate.

Examples

Electric Engine Dyno

Model an electric vehicle dynamometer test. The test environment contains an asynchronous machine (ASM) and an interior permanent magnet synchronous machine (IPMSM) connected back-to-back through a mechanical shaft. Both machines are fed by high-voltage batteries through controlled three-phase converters. The 164 kW ASM produces the load torque. The 35 kW IPMSM is the electric machine under test. The Control Machine Under Test (IPMSM) subsystem controls the torque of the IPMSM. The controller includes a multi-rate PI-based control structure. The rate of the open-loop torque control is slower than the rate of the closed-loop current control. The task scheduling for the controller is implemented as a Stateflow® state machine. The Control Load Machine (ASM) subsystem uses a single rate to control the speed of the ASM. The Visualization subsystem contains scopes that allow you to see the simulation results.

• Open Model

Ports

Input

imRef — Current

scalar

Magnetizing reference current in the per-unit system.

Data Types: single | double

wrRef — Velocity

scalar

Rotor reference velocity in per-unit system.

Data Types: single | double

iabc — Current

vector

Measured phase currents in the per-unit system.

Data Types: single | double

wr — Velocity

scalar

Measured angular velocity in per-unit system.

Data Types: single | double

Vdc — Voltage

scalar

Measured dc-link voltage, in V.

Data Types: single | double

Output

G — Gate pulses

vector | 0 or 1

Inverter gate pulses. The block does not consider any dead time.

Data Types: single | double

Visualization — Visualization signals

vector

Bus containing signals for visualization.

Data Types: single | double | bus

Parameters

General

Rated voltage, rms line-to-line (V) — Voltage

550 (default)

Nominal voltage.

Rated electrical frequency (Hz) — Frequency

60 (default)

Nominal electrical frequency.

Rotor resistance, referred to the stator side (pu) — Resistance

0.01 (default)

Rotor, stator-side resistance in the per-unit system.

Rotor leakage inductance, referred to the stator side (pu) — Inductance

0.06 (default)

Rotor stator-side leakage inductance, in the pu-unit system.

Magnetizing inductance (pu) — Inductance

2.7 (default)

Magnetizing inductance in the per-unit system.

Time constant for dq currents filters (s) — Time constant

1e-4 (default)

Time constant for filtering the d and q currents.

Inverter dc-link voltage threshold (V) — Voltage

500 (default)

Voltage threshold to activate the power inverter.

Fundamental sample time (s) — Time

5e-6 (default) | positive scalar less than the control sample time

Fundamental sample time must be less than the control sample time.

Control sample time (s) — Time

5e-5 (default) | positive scalar greater than the fundamental sample time

Control sample time must be greater than the fundamental sample time.

Outer Loop

Magnetizing current controller proportional gain — Gain

10 (default)

Proportional gain for the magnetizing current controller.

Magnetizing current controller integral gain — Gain

1000 (default)

Integral gain for the magnetizing current controller.

Magnetizing current controller integral anti-windup gain — Gain

1000 (default)

Integral anti-windup gain for the magnetizing current controller.

Speed controller proportional gain — Gain

10 (default)

Proportional gain for the speed controller.

Speed controller integral gain — Gain

1000 (default)

Integral gain for the speed controller.

Speed controller integral anti-windup gain — Gain

1000 (default)

Integral anti-windup gain for the speed controller.

Maximum d-axis current [pu] — Current

2 (default)

Maximum current for the d-axis.

Maximum q-axis current [pu] — Current

2 (default)

Maximum current for the q-axis.

Inner Loop

Phase-a axis alignment — dq0 reference frame alignment

Q-axis (default) | D-axis

Align the a-phase vector of the abc reference frame to the d- or q-axis of the rotating reference frame.

D-axis current proportional gain — D-axis proportional gain

1 (default) | positive number

Proportional gain of the PI controller used for direct-axis current control.

D-axis current integral gain — D-axis integral gain

100 (default) | positive number

Integrator gain of the PI controller used for direct-axis current control.

D-axis current anti-windup gain — D-axis anti-windup gain

1 (default) | positive number

Anti-windup gain of the PI controller used for direct-axis current control.

Q-axis current proportional gain — Q-axis proportional gain

1 (default) | positive number

Proportional gain of the PI controller used for quadrature-axis current control.

Q-axis current integral gain — Q-axis integral gain

100 (default) | positive number

Integrator gain of the PI controller used for quadrature-axis current control.

Q-axis current anti-windup gain — Q-axis anti-windup gain

1 (default) | positive number

Anti-windup gain of the PI controller used for quadrature-axis current control.

Axis prioritization — Axis prioritization for voltage limiter

Q-axis (default) | D-axis | D-Q equivalence

Prioritize or maintain ratio between d- and q-axes when block limits voltage.

PWM

PWM method — Pulse width modulation method

SVM: space vector modulation (default) | SPWM: sinusoidal PWM

Specify the waveform technique.

Sampling mode — Wave-sampling method

Natural (default) | Asymmetric | Symmetric

The sampling mode determines whether the block samples the modulation waveform when the waves intersect or when the carrier wave is at one or both of its boundary conditions.

Switching frequency (Hz) — Switching rate

1000 (default) | positive integer

Specify the rate at which you want the switches in the power converter to switch.

Extended Capabilities

C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.

Version History

Introduced in R2017b