*3.3.5. GUI of the BLDC motor*

334 MATLAB – A Fundamental Tool for Scientific Computing and Engineering Applications – Volume 1

The converter supplies the input voltage for three phases of the BLDC motor. Each phase leg comprises two power semiconductor devices. Fig. 18 shows the scheme of the considered

Appropriate pairs of the switches (S1 to S6) are driven based on the Hall sensors input. Three phases are commutated in every 60° (el. degrees). The model of the converter is

> ௗ ଶ െ ܵସ ௗ ଶ

> ௗ ଶ െ ܵ ௗ ଶ

> ௗ ଶ െ ܵଶ ௗ ଶ

where *Uan, Ubn, Ucn* are line-neural voltages, *Ud* – the DC link voltage, *Uf* – the forward diode

Fig. 19a shows the Simulink model of the three-phase converter block. In the simulation we assumed an ideal diode with neglected voltage drop *Uf*. The *Commutation sequences* block was developed based on the commutation sequence shown in Tab. 4. Converter voltage waveforms that are switched according to the commutation sequences in Tab. 4 are shown

**Figure 19.** Detailed overview of the three-phase converter (a) and voltage source waveforms (b)

(a) (b)



െ ܷ (13)

െ ܷ (14)

െ ܷ (15)

0 50 100 150 200 250 300 350

Ua [V] Ub [V] Uc [V]


ܷ ൌ ܵଵ

ܷ ൌ ܵଷ

ܷ ൌ ܵହ

*3.3.4. Mathematical and simulink model of the three-phase converter* 

three-phase converter.

**Figure 18.** Modelled three-phase converter

implemented using the equations:

voltage drop.

in Fig. 19b.

The simulated BLDC motor is presented in a graphical user interface GUI (Fig. 20).

By the buttons in the panel *Mode* we start the *Simulation* , put *Default* (original) values and show the Simulink *Model*.

**Figure 20.** GUI for the BLDC motor

The default parameters of the BLDC motor for simulation are: *Ud=*80 V*, Tl=*0,35 Nm*, R=*4,98 Ω*, L=*2,05 mH*, ψ=*56,23.10-3 Wb*, b=*0 Nm/rad.s-1*, J=*15,17.10-6 kgm2*, p=*4.
