# Brushed Motors Design and Analysis

Motors & Generators with MotorSolve

The MotorSolve DCM module provides finite element based analysis for the design of DC brushed motors. The versatility of the DCM module is in its ability to create motors from templates and its advanced electromagnetic analysis capability. The analysis can be used to get standard DC motor characteristics or to get more advanced quantities such as waveforms, harmonic analysis of the waveforms, time-averaged quantities, Field distributions and many more.

## EXAMPLE of a TEMPLATE

MotorSolve is capable of handling the most popular brushed motor types including wound stator machines, as well as permanent magnet stators. For this example we shall use a permanent magnet brushed motor.

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## ARMATURE WINDING DESIGN

In MotorSolve the armature winding is displayed graphically and changes to the winding parameters are immediately reflected in the view. Both the graphical and physical parameter values are displayed in this view.

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## COMMUTATOR DESIGN

In the same way as windings are defined through parameters and displayed in the view, the commutator can be designed in the same way. Changes to the parameters are immediately reflected in the design view.

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## COGGING TORQUE

One of the areas where MotorSolve is very powerful is in the area of analysis of a given design. This area is divided into 3 sections: 1) Pre-defined performance charts, 2) General purpose analysis, and, 3) Field distribution display and data extraction. The performance charts are pre-defined analysis modes which are designed to be very simple to use. There are only a few parameters to set and the accuracy/speed tradeoff can be assigned.

One of the performance charts that is availabe in MotorSolve is the cogging torque.

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## MOTOR CONSTANTS

Under the performance charts option of the Results section MotorSolve calculates 3 of the basic motor constants. These are: 1) Back EMF value, 2) Back EMF constant, and, 3) Torque constant. These 3 quantities are often used to characterize a motor and the user simply has to click to view the result.

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## SPEED vs. TORQUE

One of the most common charts required for brushed DC motors is the Speed vs. Torque curve. There are more variables when working with this curve, therefore there are a lot more parameters that can be changed. The default curve is based on the design information provided as part of the general parameter information.

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## AIR GAP FLUX

The last performance curve in the list is the Air Gap Flux waveform.

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## MOTION ANALYSIS RESULTS

The motion analysis is currently the only option in the Analysis charts section of the Results. This is the general purpose mode where the designer can get all kinds of information about the motor. This analysis includes some of the charts available under the performance charts analysis. The user can view either time-averaged results, waveforms or the harmonics of a waveform.

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## FIELDS & FIELD CHARTs

MotorSolve is based on finite element analysis and therefore it also has to provide the option to the user of displaying field distributions. This is done through the Fields option and data can also be extracted from the field display using the Field Charts which are field probes along contours defined graphically or through parameters.

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