ACIM Rs Estimator
Estimate stator resistance (Rs) of AC induction motor (ACIM)
Motor Control Blockset / Parameter Estimation / ACIM Parameter Estimation
The ACIM Rs Estimator block computes the stator resistance of an induction motor using the phase currents, DC voltage across the motor, and the test configuration elements.
The block injects a voltage across the motor phases and measures the current response to estimate the motor resistance.
Iabc — Three-phase current response
The three-phase current response of the motor measured by the current sensors.
Providing phase-c current input is optional. The block functionality is not impacted if you do not provide the phase-c current input.
Vdc — DC link voltage
DC bus voltage that you provide to the inverter.
StartStop — Control signal for Rs estimation
Signal that either starts or stops Rs estimation:
1(rising edge of a pulse) — This signal initiates the Rs estimation process.
0(falling edge of a pulse) — This signal immediately stops the Rs estimation process. If you interrupt the estimation process abruptly before completion, the block does not compute or output the Rs value.
Config — Bus signal input
This table summarizes the expected configuration elements in the bus signal input.
Elements for motor and inverter hardware
Number of pole pairs
Nominal motor current
Maximum measurable inverter current
Current sense gain
Voltage sense gain
Elements for estimating magnetizing current Id0
Open-loop ramp time
Elements for estimating motor resistance (Rs)
Vd reference voltage 1
Vd reference voltage 2
Elements for estimating rotor resistance (Rr), magnetizing inductance (Lm), stator leakage inductance (Lls), and rotor leakage inductance (Llr)
Frequency 1 as a ratio of rated frequency
Frequency 2 as a ratio of rated frequency
|High frequency for Lm|
Start voltage for voltage sweep
Voltage step for voltage sweep
High-frequency injection voltage
Elements for estimating motor inertia (J) and friction constant (B)
Closed-loop speed duration
Iq Reference current for FOC
Lower speed limit for inertia estimation
Parameter estimation sample time
You can connect this input port to the
Config output port of
the ACIM Parameter Estimation Configurator block.
Vabc — a, b, and c-axis stator
reference voltage components
Stator reference voltage components along the a, b, and c axes of the abc reference frame.
Rs — Estimated stator resistance
Estimated stator resistance (in ohms) of the induction motor.
Log — Debug signals
Debug signals that the block provides for examination. The bus includes these debug signals.
|Did not complete Rs estimation|
|Rs estimation completed successfully|
C/C++ Code Generation
Generate C and C++ code using Simulink® Coder™.
Introduced in R2023a