when i am removing the parallel RLC load connected between synchronous machine, as shown in image below, it says u can't connect synchronous machine with transformer? why i cant connect an inductive load directly with current source? model is attached below
The synchronous generator is modeled as a current source in Simulink/Matlab, and so it cannot be connected in series with the inductive element ( three phase transformer) . to avoid this problem, you must place a parallel resistance element. to avoid bad effect of parallel resistance on simulated systems, a high-value resistance must be added in parallel with synchronous generator.
Dear Tohid, thanx
what should be the value of resistance? how should i decide the value for parallel RLC load? whatever the value of parallel RLC load connected between synchronous machine and transformer will be considered load? for example i am coonecting 70% load will it incorporated in 70% load?
Dear Farhan A. Larik
you can insert any % load in parallel with synchronous generator. if you decide to do not insert any load parallel with synchronous generator, to avoid bad effect of parallel resistance on simulated systems, a high-value resistance (example: 100 k ohm) must be added in parallel with synchronous generator. (if my answer was helpfull, please like my first and secondary answers)
best regard
Ya I faced the same problem previously. I did same like Tohid mentioned. Put very high value of resistance which does not effect your power flows but help back ground equations and matrices to be well conditioned during the simulation.
Any Load Element connected across the Voltage Source and any Load Element connected in Series with a Current Source are considered to be Redundant Elements.
Irrespective of the Value of the Parallel Element, the Voltage Supplied by the Voltage Source will be the same as without it. Similarly irrespective of the value of the Series Element, the Current supplied by the Current Source after that Series element will be the same as without it.
The Impedance across a Current Source has to be very High so as not to reduce the Current supplied by that Current source.The Impedance connected in Series with a Voltage Source has to be very small so as not to Cause any Voltage drop across it and Full voltage is supplied to the Load Connected to the Voltage source.That is why the internal impedance of a Current Source is very high and the internal impedance of a Voltage source very low.
Synchronous generator is a Voltage Source with very low internal impedance and to represent it as a Current Source the impedance connected across it has to be very high.
P.S.
Load connected across the Voltage Source and any connected which is in Series with a Current Source are considered to be no longer a working Elements
Non working Elements - in the case of Current Source passes the Current through it.
Redundant element means an element that can be ignored in Analysis.
P.S.
Thanks a lot guys on this conversation, because I had the same problem.
Now, what should I tell my professor because he refused the idea of having a load connected to the generator terminals directly.
Dharini Govindaraj it was not my issue that's why I asked the person who posted above. In my case, I also added parallel load to avoid this issue and it worked.
I am also having problems combining wind turbine and PMSG generator with rectifier as shown in the picture. If the load R is removed to connect to the rectifier controller, the system will report an error.
This is a wind energy power system (wind turbine + PMSG generator + MPPT algorithm) connecting a controlled rectifier. But it seems that the system cannot work when unloading R. Because the voltage and current signal after the PMSG generator cannot be obtained. Matlab simulink software always reports an error. Hope you can help me understand the above issue. And how to fix that error. Sincere thanks.
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