Motor drive unit (MDU) component

This folder contains a few models of motor drive unit (MDU), which is a system consisting of an electric motor and a controller. The MDU models in this component are all abstract and simulate the high-level behavior of conversion between electric and mechanical powers by considering power conversion efficiency or losses.

MDU models

This component provides the following MDU models.

Basic model (MotorDriveUnit_Basic_refsub) is the simplest model with the fewest parameters among the provided models. It uses Motor & Drive block from Simscape Driveline. This model takes torque command and computes electrical and mechanical power conversion using the single efficiency measurement model to compute copper loss coefficient. Irons loss and fixed loss are not modeled. This model does not simulate temperature dynamics. Below is an example plot of efficiency contour of the Basic model.

Basic thermal model (MotorDriveUnit_BasicThermal_refsub) uses Motor & Drive block, which is the same block as the above Basic model uses, but with thermal model enabled to simulate motor temperature dynamics.

System-level thermal model (MotorDriveUnit_System_refsub) uses Motor & Drive (System-Level) block from Simscape Electrical to compute power conversion between electrical and mechanical powers. Thermal model is enabled too. Power conversion model is the same as the Basic model, which is the single efficiency measurement model, but irons loss and fixed loss are also considered in this model. Below is an example plot of efficiency contour of the System-level model.

System-level model with tabulated losses (MotorDriveUnit_SystemTable_refsub) uses Motor & Drive (System-Level) block from Simscape Electrical. It takes torque command and computes motor speed which is the same as the other models above, but for power conversion efficiency or losses, this model uses tabulated parameter data as a function of motor speed and torque. Thermal model is disabled, but you can enable it if you have two data sets of efficiency or losses measured at two different temperatures.

Harness model

To run simulation with the above models, use the harness model.

• HarnessModel_MotorDriveUnit.mdl

Simulation Cases

For each model, there is SimulationCases folder containing Live Scripts that are used to visually inspect the simulation behaviors of the models in various simulation scenarios as follows.

• Constant ... All inputs are constant. This is used to check that the test model runs.

• Drive ... MDU drives axle by consuming electric power.

• Regenerative braking ... Axle drives motor, and MDU generates electric power.

• Random .... Input signals for motor torque command and axle load torque are randomly generated.

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