**4.1. CAD design of controller parameters for DC motor drive in frequency domain**

The DC drive controllers in the *frequency domain* are calculated mostly by using the following criteria:

	- 1. The current controller of the PI type is calculated on basis of the *Optimum Modulus Criterion* (OMC) from the drive system parameters:

$$F\_{Rl} = K\_{Rl} + \frac{1}{sT\_{ll}}\tag{16}$$

2. After calculation of the current controller parameters and current control loop simplification, the speed controller is calculated based on the *Symmetrical Optimum Criterion* (SOC). It is again of PI type having the transfer function:

$$F\_{R\_{\alpha\nu}} = \mathbf{K}\_{R\_{\alpha\nu}} + \frac{1}{sT\_{i\alpha}}\tag{17}$$

Fig. 22 shows the principal block diagram of the system and in Fig. 23 there is view on the virtual GUI model of speed controlled DC drive.

**Figure 21.** Control circuit of DC motor drive with current and speed controllers

Virtual model features

The user has a possibility to tune controller parameters in each design step according to displayed time response. The GUI screen consists of several panels:


Before starting the model, implicit parameters are set up, but they can be changed later. After pushing the button *Computed value* the parameters of controllers are calculated from the actual values of parameters. Simultaneously a small window appears there with a question whether the calculated values of controller parameters are acceptable or not (if not, user can set up own parameters and can to tune them according to the time responses of the drive). To return to starting values, the user pushes the button *Default* (similar to the system restart).

Dynamic Simulation of Electrical Machines and Drive Systems Using MATLAB GUI 337

**Figure 22.** GUI screen for designing DC motor drive controllers in the frequency domain

*Criterion* (SOC). It is again of PI type having the transfer function:

**Figure 21.** Control circuit of DC motor drive with current and speed controllers

displayed time response. The GUI screen consists of several panels:

starts and new time responses are drawn (like in a real drive).

*System parameters* are changed by sliders or inserting values into the boxes.

starting values, the user pushes the button *Default* (similar to the system restart).

*Block diagram* - displays the block diagram of the system

 = *KR* + 1 *<sup>i</sup> sT*

*Criterion* (OMC) from the drive system parameters:

 *FRI* = *KRI* +

 *FR*

Virtual model features

virtual GUI model of speed controlled DC drive.

1. The current controller of the PI type is calculated on basis of the *Optimum Modulus* 

2. After calculation of the current controller parameters and current control loop simplification, the speed controller is calculated based on the *Symmetrical Optimum* 

Fig. 22 shows the principal block diagram of the system and in Fig. 23 there is view on the

The user has a possibility to tune controller parameters in each design step according to

 *Time response* - the graph with time courses of the motor current and speed. Immediately after change of any system parameter (motor -, drive -, or controller parameters) by a slider or inserting a numeric value into editable box the simulation

Before starting the model, implicit parameters are set up, but they can be changed later. After pushing the button *Computed value* the parameters of controllers are calculated from the actual values of parameters. Simultaneously a small window appears there with a question whether the calculated values of controller parameters are acceptable or not (if not, user can set up own parameters and can to tune them according to the time responses of the drive). To return to

1

*iI sT* (16)

(17)
