imx METIS AC-PI
imx METIS for induction motors combines modular hardware, intelligent test bench software, and model-based test methods in one integrated electric motor testing platform.
The Head Unit handles measurement data acquisition and test sequence control, while the Control Unit provides the required control electronics and motor controllers for precise dynamic excitation of the motor under test. A safety PLC and power supply components complete the system.
The software platform is based on imx OMEGA, providing test control, automation, data acquisition, and analysis. Integrated into imx OMEGA, imx PI (Parameter Identification) enables model-based identification of relevant motor characteristics and parameters – fast, reproducible, and without the need for a mechanical load machine.
All components are combined into a fully integrated, ready-to-operate imx METIS test system.
Outstanding Features
Deep testing of induction motors
imx OMEGA AC-PI for induction motors
imx Parameter Identification is a model-based, fully automated test method for determining the physical parameters and characteristics of an electric motor – Deep Testing.
Instead of mechanically loading and measuring the motor at numerous operating points, imx AC-PI precisely measures current, voltage, and rotor angle during dynamic excitation of the motor under test.
Mathematical optimization methods are used to identify the motor model parameters from the acquired measurement data. These primary parameters are immediately available for motor assessment and are used to derive additional motor characteristics, as shown below.
Induction motors place specific demands on electric motor testing. Complete characteristic curves, thermally stabilized measurement conditions, and traceability to recognized standards are essential for reliable assessment of motor quality and performance.
imx OMEGA AC-PI is designed to meet these requirements. Using targeted electrical excitation and model-based parameter optimization, the key electromechanical parameters and characteristics of the motor are identified. The fast test method also provides results comparable to those obtained in accordance with DIN EN 60034-28.
From a single test sequence, efficiency, electrical and mechanical power, as well as speed-torque and current-torque characteristics can be determined – providing comprehensive Deep Testing within a very short test cycle.
The result is a complete, validated motor model with traceable results that can be directly compared with conventional test methods.
Test sequence
-
Phase I
Determination of line-to-line resistances -
Phase II
Identification of motor start-up behavior -
Phase III
No-load measurement -
Phase IV
Dynamic excitation is used to determine inductances and the moment of inertia -
Phase V
Coast-down from no-load speed to determine the friction parameters
Primary test results
- Stator resistance
- Iron-loss resistance
- Magnetizing inductance
- Leakage inductance
- Rotor resistance
- Sliding and static friction
- Moment of inertia
Derived motor characteristics
- Rated torque
- Rated current
- Rated efficiency
- Power factor at the rated operating point
- No-load speed
- Breakdown torque
- Speed at breakdown torque
- Starting torque
Fault detection
imx OMEGA AC-PI detects a wide range of motor-specific faults, including bearing defects as well as stator and rotor winding faults.
The identified parameters not only provide a comprehensive picture of the motor but also form the basis for reliable motor quality assessment. Combined with short test cycles and model-based Parameter Identification, imx AC-PI provides the high level of test depth required for production testing, end-of-line testing (EOL), incoming goods inspection, and quality assurance.
