ACIM Rs Estimator

R2026b

Estimate stator resistance (R_s) of AC induction motor (ACIM)

Since R2023a

• 

ACIM Rs Estimator block

To add a block to a model, double-click the canvas and start typing the block name. Then, select the block from the list.

Libraries:
Motor Control Blockset / Control / Induction Machine / Parameter Estimation

Description

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.

Examples

Estimate Induction Motor Parameters Using Parameter Estimation Blocks

Uses the parameter estimation blocks provided by Motor Control Blockset™ to estimate these parameters of an AC induction motor (ACIM):

• Open Model

Ports

Input

Iabc — Three-phase current response

scalar

The three-phase current response of the motor measured by the current sensors.

Note

Providing phase-c current input is optional. The block functionality is not impacted if you do not provide the phase-c current input.

Data Types: single

Vdc — DC link voltage

scalar

DC bus voltage that you provide to the inverter.

Data Types: single

StartStop — Control signal for R_s estimation

logical

Signal that either starts or stops Rs estimation:

• 1 (rising edge of a pulse) — This signal initiates the R_s estimation process.

• 0 (falling edge of a pulse) — This signal immediately stops the R_s estimation process. If you interrupt the estimation process abruptly before completion, the block does not compute or output the R_s value.

Data Types: Boolean

Config — Bus signal input

bus

This table summarizes the expected configuration elements in the bus signal input.

Category	Configuration element			Units
Elements for motor and inverter hardware	Number of pole pairs			-
	Rated frequency			Hz
	Nominal motor current			A
	Nominal voltage			V
	Maximum measurable inverter current			A
	Board resistance			ohm
	Current sense gain			A/ADC Count
	Voltage sense gain			V/ADC Count
Elements for estimating magnetizing current Id0	Measurement time			seconds
	Open-loop ramp time			seconds
Elements for estimating motor resistance (Rs)	Estimation time			seconds
	Vd reference voltage 1			PU voltage
	Vd reference voltage 2			PU voltage
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			PU frequency
	Frequency 2 as a ratio of rated frequency			PU frequency
	High frequency for Lm			Hz
	Start voltage for voltage sweep			PU voltage
	Voltage step for voltage sweep			PU voltage
	High-frequency injection voltage			PU voltage
Elements for estimating motor inertia (J) and friction constant (B)	Closed-loop speed duration			seconds
	Closed-loop speed			RPM
	Iq Reference current for FOC			PU current
	Proportional gain			-
	Integral gain			-
	Lower speed limit for inertia estimation			RPM
-	Parameter estimation sample time			seconds

You can connect this input port to the Config output port of the ACIM Parameter Estimation Configurator block.

Data Types: single

Output

Vabc — a, b, and c-axis stator reference voltage components

scalar

Stator reference voltage components along the a, b, and c axes of the abc reference frame.

Data Types: single

Rs — Estimated stator resistance

scalar

Estimated stator resistance (in ohms) of the induction motor.

Data Types: single

Log — Debug signals

bus

Debug signals that the block provides for examination. The bus includes these debug signals.

Debug signal			Description	Units
Id			D-axis current	Amperes
Vd			D-axis voltage	Volts
status		0	Did not complete Rs estimation	-
		1	Rs estimation completed successfully	-

Data Types: single

Programmatic Use: Add Block

To add the block programmatically, use the add_block function with one of these library block paths as the source.

"mcblib/Control/Induction Machine/Parameter Estimation/Rs Estimator"

Example: add_block("mcblib/Control/Induction Machine/Parameter Estimation/Rs Estimator","myModel/myBlock",MakeNameUnique="on")

Extended Capabilities

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

Version History

Introduced in R2023a