Transient analysis - modelling.

[mukhriz]

To all experts.
Can anyone guide me in the event we do not have the actual governor and exciter models/ function, what is the rule and how does we select the various models from the library ( regardless the program used).?

Specifically for SKM, to create an event where the load tripped by UF or UV - how do we implement this as I cant find UV ir UF relays from the library.

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[BabyBear]

Mukhriz,

PSS/E provides information on how to use exciter/governor models. The model of exciters/governors sometimes depends on the generator manufacturer/supplier and or prime mover fuel types. Two options are available. First, select an exciter/governor model from the PSS/E dynamic model library and fill out the required data. Second, create a dynamic model for exciter and governor (only for model writers). You can check also IEEE Guide for Excitation System models for further information.

For transient stability studies, the benchmark is in favor of PSS/E while some engineers prefer PowerFactory. It's still up to the engineer on which software should be used depending on the standard (American/European) and the method of calculations adopted.

[mukhriz]

I just wondering, in literature we learn about synch machine modelling.From this we have many complex equations describing the voltage,fluxes,rotor voltage etc and transformed into dqo axes via Park Transformation. But where do we use all of these equation in load flow, transient etc?

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[surgeArrester]

It depends on the type of study mukhriz, d-q axes are well explained in a book by reinmart..(if im not mistaken)..

In the book, he applied the equation in generator fault at terminals and then calculated the resultant current.

This may not be much, my knowledge on transient stability is limited.


Sent from Mars

[BabyBear]

Mukhriz,

What you have said forms the foundation of synchronous machine modeling theory. The stator quantities are transformed via dq0 transformation in order to establish equations relating to machine rotor quantities. From these modeling theory, several synchronous machine models were developed e.g. two-axis model, flux decay model, classical model, etc. following some certain assumptions like neglecting or considering magnetic saturation. These models are used in transient stability studies. However, due to intricacy of the models being translated into computer models, several models, which are now known as industrial synchronous machine models such as GENROU, GENROE, GENSAL, etc. were developed approximately resembling the behaviour of the original models. These are now used in computer simulations such as the well renowned PSS/E, DigSilent, and GE PSLF.

In general, the engineer has no direct interaction with these machine equations when dealing with power system studies. The engineer just need to select proper generator model (which resembles a synchronous machine model from machine equations) for stability studies.

[mukhriz]

Mukhriz,

What you have said forms the foundation of synchronous machine modeling theory. The stator quantities are transformed via dq0 transformation in order to establish equations relating to machine rotor quantities. From these modeling theory, several synchronous machine models were developed e.g. two-axis model, flux decay model, classical model, etc. following some certain assumptions like neglecting or considering magnetic saturation. These models are used in transient stability studies. However, due to intricacy of the models being translated into computer models, several models, which are now known as industrial synchronous machine models such as GENROU, GENROE, GENSAL, etc. were developed approximately resembling the behaviour of the original models. These are now used in computer simulations such as the well renowned PSS/E, DigSilent, and GE PSLF.

In general, the engineer has no direct interaction with these machine equations when dealing with power system studies. The engineer just need to select proper generator model (which resembles a synchronous machine model from machine equations) for stability studies.

have you ever seen a complete hand calculation/ example for min 2 synch machines ( not SMIB system) from pre,during and post transient event?

Most literatures only give SMIB example,and multimachine system only on the theoretical aspect or the example is solved by simulation.

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[mukhriz]

It depends on the type of study mukhriz, d-q axes are well explained in a book by reinmart..(if im not mistaken)..

In the book, he applied the equation in generator fault at terminals and then calculated the resultant current.

This may not be much, my knowledge on transient stability is limited.


Sent from Mars

If you can remember the name of the book,let me know.
I used Saadat but that only on the basic, Fouad ,Kimbark are the best plus few author from India.

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[surgeArrester]

Its protective relaying on generation systems by donald reimert... I think its chapter 1 or 2..


Sent from Mars

[fgf]

Babybear gave a great answer,

I'd also like to add that , remenber , it 's all math, governor and exciter models are just REALLYＲＥＡＬＬＹ　 ｒｅａｌｌｙ　ï� �Œï½ï½Žï½‡ and repetitive math that simulates behaviour.

So to your original question " what is the rule?"

Start with the basics Governor IEEEST and exciter EXAC1
you can simplify everything to these 2 models if you ignore alot of stuff and you really wanted to

A analogy i like to use is , say i want to model your net worth
If you really wanted to you could sell everything you own and convert it to cash (if you really wanted to!!! )
however that is the worst way to do it.

REMEMBER IT"S ALL MATH!!

[nafamesaoud@hotmail.fr]

why not use mathlab?

[surgeArrester]

why not use mathlab?

Its matlab, not mathlab.. And yes, if his using saadat as reference then he maybe have the m-files associated with it.

[BabyBear]

have you ever seen a complete hand calculation/ example for min 2 synch machines ( not SMIB system) from pre,during and post transient event?

Most literatures only give SMIB example,and multimachine system only on the theoretical aspect or the example is solved by simulation.

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Try looking for Power System Stability Volumes I-III by Kimbark. There is a portion in the book that treats multimachine stability calculation. However, the machines here are treated to be classical models, not the detailed models i mentioned before. Here's the general idea: multimachine stability calculation is just done to give an idea on how an interconnected power system works.

Why do you want to look for multimachine stability calculation? As mentioned before, it only considers elementary machine model, not the detailed one. So if you are trying to be familiar with the multimachine stability analysis, a simulation is best to start with.