I have design the system in Matlab simulink, but when i start the current injection in the grid, my Source current become doubled also load current become less. I dont know this is active filtering or not.
Second, I am confuse about the PCC, when we inject current why the amplitude of the Source current changes,
Third, Can i keep the Vdc voltage of the capacitor initial voltage constant before start the simulation.
Hello Mr. Tareen,
Actually, this kind of operation can't be called as active filtering, instead you are amplifying the source harmonic currents. An ideal filtering should supress the source side current harmonics while load harmonics are kept constant, the main aim is to supress source current harmonics down to allowable limits in IEEE standards.
Let me clear a point, source means supply of electrical energy. Load means a nonlinear load that sink harmonic currents from source.
Basicly, at point of common coupling, Iload + Isource + Ifilter = 0 (Kirchoff's Current Law), But this sum is vectorial, not in magnitude. For effective filtering, Ifilter should be anti-phase (180 degrees apart for each harmonic frequency) with Iload so that you can supress load harmonics as much as possible. Your problem may be your filter current's phase. If you are sure that your filter current's phase is correct, the problem may be due to the passive components in your circuit, if there are passive filters in your topology (i.e. hybrid filter model), they may cause parallel resonance with source impedences or transformers so that the source harmonic components may be amplified. The last and less likely reason for the problem may be the source side modelling (an ideal source can be infinite bus Zs = 0 or such a very small series inductor), if your source impedence is modelled as high impedence, filter current may choose to flow load side depending on your load model, please check your source model.
Yes, you can start with constant initial dc link voltage in simulation start, but precharging is also a concern for practical system.
Please give extra information about Single Line Diagram showing all the passive components, transformers and your converter. Also detailed information about the topology and control method of your converter.
Best Regards
Hi Wajahat,
In addition with Erme's point, you can check the following paper for your design parameters selection process and also check your controller step by step. Hope it will help you a lot.
S K Khadem, M Basu and M F Conlon, Harmonic Power Compensation Capacity of Shunt APF and its Relationship to Design Parameters, IET Power Electronics, 2014, Vol 7(2), pp. 418 - 430
Regards,
Shafi
hi i have simulation model for that if u want i will send to u
yes sure, Mr Yonis. Kindly forward me on my email: [email protected]
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