Which electrical equipment can reduce the %VUF value to no more than 2%?

Good evening, I have some questions to ask. This circuit is three-phase circuit with Va=220, Vb=180, Vc=210 and have sliding window with Fourier Analysis for harmonic mitigate in the system.First I decide to create 25 order harmonics. The harmonics start at the 2nd order and drop down to get %THD at 5%. Then create a voltage imbalance by using a switch control , set time 0.3 to 0.5 second and finally I need to mitigate harmonic to become sin wave form. The value of %VUF(Voltage Unbalance Factor) 3-phase before mitigate is 7.5%. What equipment must be used and how should it be connected to mitigate %VUF to not exceed 2% according to international EN50160 standards?

the system

Va source that decide to have 25 order harmonics and control switch.

control switch in Va source set time 0.3 to 0.5 is the imbalance period.

Code for calculation the %VUF value in system.

[Shishir Reddy]

Could you share the .slx, .m files you have used to build the model?

[Thunchanok]

Here it is.

Answer 1

[Shivam Gothi]

Hello @Thunchanok,

As per my understanding, you are looking for a power system device that improves VUF (Voltage Unbalance Factor).

There is no such “device” present to achieve the above objective, but it can be done by using a properly designed DVR (Dynamic Voltage Regulator). It is a controlled voltage source inserted in between the network and the load through a transformer injecting voltage into the network to correct any unbalance in the line. It is a quite complex system consisting of transformers, DC link, controllers and IGBT switches.

Refer to the below cited IEEE conference paper. It focuses on mitigation of Sag/Swell by Dynamic Voltage Restorer using SPWM technique. The authors have also demonstrated it using Simulink model.

“P. B. Shendge and S. H. Pawar, "Simulink model for mitigation of Sag/Swell by Dynamic Voltage Restorer using SPWM technique," 2017 International Conference on Intelligent Sustainable Systems (ICISS), Palladam, India, 2017, pp. 747-750, doi: 10.1109/ISS1.2017.8389274”

Additionally, you can also refer to the below file exchanges that attempts to implement DVR.

https://www.mathworks.com/matlabcentral/fileexchange/162061-three-phase-dynamic-voltage-restorer-dvr-using-fuzzy-logic

https://www.mathworks.com/matlabcentral/fileexchange/51064-series-active-filter-dynamic-voltage-restorer-dvr

I am suggesting one of the possible configurations of DVR that you can use for your attached Simulink model in the below attached screenshot.

Note: The gate pulse signal “g1” will come from a properly designed control system. Refer to the above cited IEEE paper to design the required control system.

I hope you find the information useful!

[Thunchanok]

My sincere apologies for the late reply and thank you for your advice. This information was really helpful to me. I will continue to study and research the information you provided.