::: Dynamometer
::: CHALLENGE :::
Developing a system for performing fully automated testing of electric motors. We are looking for flexibility and standardization of the various trials, with the most important results sucha as the efficiency curve, the starting curve and tipping curve, which provide primary data for evaluation of the engines and constant improvement of the final product .
::: SOLUTION :::
Using a PC based architecture with a data acquisition board dedicated to the panel. The software used for acquisition, signal processing, communication with various instruments and selection and control of test steps. The development platform for the entire system was the LabVIEW software.
::: Description :::
Embraco, a Whirlpool’s compressor division company in Brazil, and world leader in the manufacture of compressors for refrigeration, needed a system for conducting electrical engine test, which evaluates, among other tests, the efficiency of the engines. This system is known in the company for Dynamometer panel. The main tests includes, gathering the engine efficiency curve (efficiency vs torque), starting curve (torque vs speed) and tipping curve (torque vs speed). As a result of these tests we aquire a large volume of information, which are used in various areas of research, as a form of feedback to design improvements which can be realized by optimizing the performance of electric motors.
For the tests, the engine is coupled to one of the bearing axis. Since there is a second motor (with power greater) coupled the other end used for imposition of torque, which is controlled by a frequency inverter and adjusted via a serial communication with the system. The selection and parameterization of the assay is performed by software, which communicates and adjusts the voltage supply via GPIB, according to the voltage and frequency of the selected motor. The electrical parameters are measured using a power meter and transmitted via GPIB, and acquired the speed signals (read the encoder through the counters), temperature (thermocouple for analog input), torque (analog input for load cell). During testing the software does the panel control, communication with instruments, speed control and torque control depending on the test configuration. This way it is possible to obtain accurate data on the engine load point and other areas of interest.
In addition to the standard methods, you can perform manual testing, where the operator has the freedom to customize the test for analysis of specific cases usually applied in new engines development.
The software was automatically developed to save form results in a hierarchical folder structure so that this way it was possible to generate a complete report containing information from different tests and different parts according to customer needs, maintaining product data in a standardized historical trend.
For more information about this application or others developed by DAQSYS, contact by phone +55 (41) 9967-6977 or info@daqsys.com.br.
