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VOLTAGE ORIENTED CONTROL – SIMULATION

(3.14) (3.15)

Reference voltages

Figure 3.9 : Current controller block diagram

Comments : In our system, the line current

is split into a q component

and a d component

.

determines the active power flow whereas

the reactive power. The unit power factor (UPF)

condition is met when the line current vector

is aligned with line voltage

. In this case, we have

to set

to zero in our controller (

).

Figure 3.10 : Vector diagram of VOC – Line current and voltage [9]

3

3

3

2 3

2 3

2 3

2

2

2

Furthermore, we can write down the equation for power and see that the reactive power is set to zero. From the power equations established in section “2.2.2 Mathematical model” we can write

(3.16)

(3.17)

Now if we set the reference

to zero and we know that the line voltage vector is aligned with the d

axis, so

. Finally, we get

3

2

(3.18)

3.4.4 Active damping, voltage saturation, anti windup ACTIVE DAMPING

As it’s fully explained in [4] (section 1.4–p24), the current control error

could be decrease

be increasing R. Therefore, we can add a inner feedback loop which add Ra (just using signal, there is no energy transfer or more losses). This method improve disturbance rejection capability because

25

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