直流电机双闭环调速系统MATLAB仿真

Chopper-Fed DC Motor Drive
This example shows a Chopper-Fed DC Motor Drive.

Description
The DC motor is fed by the DC source through a chopper which consists of GTO thyristor and free-wheeling diode D1. The motor drives a mechanical load characterized by inertia J, friction coeficient B, and load torque TL.
The hysteresis current controller compares the sensed current with the reference and generates the trigger signal for the GTO thyristor to force the motor current to follow the reference. The speed control loop uses a proportional-integral controller which produces the reference for the current loop. Current and Voltage Measurement blocks provide signals for visualization purpose.
Simulation
Motor starting
Start the simulation. Observe the motor current, voltage, and speed during the starting on the scope. At the end of the simulation time (1.5 s), the system has reached its steady-state.
Response to a change in reference speed and load torque
The initial conditions state vector ‘xInitial’ to start with wm = 120 rad/s and TL = 5 N.m has been saved in the ‘power_dcdrive_init.mat’ file. This file is automatically loaded in your workspace when you start the simulation (see Model Properties). In order to use these initial conditions you have to enable them. Check the Simulation/Configuration Parameters menu , then select “Data Import/Export” and check “Initial state”.
Now, double click the two Manual Switch blocks to switch from the constant "Ref. Speed (rad/s) " and “Torque (N.m)” blocks to the Step blocks. (Reference speed wref changed from 120 to 160 rad/s at t = 0.4 s and load torque changed from 5 to 25 N.m at t= 1.2s). Restart the simulation and observe the drive response to successive changes in speed reference and load torque.
在此基础上修改测试

Chopper-Fed DC Motor Drive (Discrete)
his example shows a Chopper-Fed DC Motor Drive.
H. LeHuy (Universite Laval, Quebec) and G. Sybille (Hydro-Quebec)

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Description
Simulation

Description
A DC motor is fed by a DC source through a chopper which consists of GTO thyristor and a free-wheeling diode.
The motor drives a mechanical load characterized by inertia J, friction coeficient B, and load torque TL. The motor uses the discrete DC machine provided in the Machines library.
The hysteresis current controller compares the sensed current with the reference and generates the trigger signal for the GTO thyristor to force the motor current to follow the reference. The speed control loop uses a proportional-integral controller which produces the reference for the current loop.
Simulation
Start the simulation and observe the motor voltage (Va), current (Ia) and speed (wm) on the scope. The following observations can be made:
0 < t < 0.8 s: Starting and Steady State Operation
During this period, the load torque is TL = 5.N.m and the motor reaches the reference speed (wref = 120 rad/s) given to the speed controller . The initial values of reference torque and speed are set in the two Step blocks connected to the TL torque input of the motor. Notice that during the motor starting the current is maintained to 30 A, according to the current limit set in the speed regulator. Zoom in the motor current Ia in steady state. Observe the current triangular waveshape varying between 5 A and 7 A, corresponding to the specified hysteresis of 2 A. The commutation frequency is approximately 1.5 kHz.
t = 0.8 s: Reference Speed Step
The reference speed is increased from 120 rad/s to 160 rad/s. The speed controller regulates the speed in approximately 0.25 s, and the average current stabilizes at 6.6 A. During the transient period, current is still limited at 30 A.
t = 1.5 s: Load Torque Step
The load torque is suddenly increased from 5 N.m to 25 N.m. The current increases to 23 A, while speed is maintained at the 160 rad/s set point.