Computation of the efficiency map with scalar control command

Overview

The aim of the test “Performance mapping – Sine wave – Motor – Efficiency map scalar” is to characterize the behavior of the machine in the "Torque-Speed" area.

Input parameters like “the maximum Line-Line voltage, the rated power supply frequency, the maximum line current and the maximum speed” of the machine are considered here.

One type of command mode is available: scalar command.

Input parameters define the torque-speed area in which the evaluation of the machine behavior is performed.

Performance mapping – Sine wave – Motor - Efficiency map - Motor - Illustration

The computations are based on the identification and the solving of a non-linear model which is built with maps. It considers the cross saturation and the eddy current effects in the squirrel cage.

The identification of the model (1st harmonic) is operated with the steady state AC application of Flux (Finite Elements).

All this allows getting a good compromise between accuracy of results and computation time.

Characterization – Model – Motor – Scalar - Model

In the results, the performance of the machine at the base point (base speed point) and at the maximum speed (maximum speed point) set by the user are presented.

User inputs and outputs

The main user input parameters are the maximum Line-Line voltage, the rated power supply frequency, the maximum line current and the maximum speed”. In addition, temperatures of winding, and squirrel cage must be set, and the power electronics data if needed.

The main outputs are displayed with data, curves, maps, and tables.

Among the main test results, there are data about the machine performance for both base speed point and maximum speed point (torque, speed, electrical power, power factor, power balance, efficiency etc.)

Curves that present machine quantities versus speed are computed and displayed (torque, efficiency, current, voltage, slip, frequency, powers, power factor, losses).

Mechanical torque versus speed - Example

There are also characteristic curves like, the normalized base point curves, the normalized torque-speed curves, and the voltage boost. versus speed (low speed between zero speed and base speed).

Such results help the user to understand the possible performance of the machine in its electric environment.

Characteristics curves - Normalized base point curves - Example

Characteristics curves - Normalized torque speed curves - Example

Efficiency in torque-speed area - Example