How to solve algebraic loop error??
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Hii....I came across this error while making a model..
Simulink cannot solve the algebraic loop containing 'trial_3/PV panel/PV module' at time 0.0 using the TrustRegion-based algorithm due to one of the following reasons: the model is ill-defined i.e., the system equations do not have a solution; or the nonlinear equation solver failed to converge due to numerical issues. To rule out solver convergence as the cause of this error, either a) switch to LineSearch-based algorithm using set_param('trial_3','AlgebraicLoopSolver','LineSearch') b) reducing the VariableStepDiscrete solver RelTol parameter so that the solver takes smaller time steps. If the error persists in spite of the above changes, then the model is likely ill-defined and requires modification.
I am using coding to make photovoltaic panel and MPPT P&O algorithm.
Please help me to solve this error.
4 个评论
ahmed altaee
2017-1-27
i have the same problem!! :(
Rajesh Laguri
2018-4-2
Have you done this, can you please suggest how you solved this issue.I am also coding for same.
Jim Riggs
2019-12-2
It's true that you can break algebraic loops using a unit delay as Azzi Abdelmalek says, but judging by the comments, people are not reviewing the link provided by Walter Roberson, below. This article contains some important information and considerations on the effect of using a unit delay and provides an alternative solution.
Malaiyappan M
2020-8-17
in MPPT Buck/Boost Converer try adjust the Inductor Value to resolve this error
采纳的回答
Azzi Abdelmalek
2012-11-23
编辑：Azzi Abdelmalek
2012-11-23
19 个投票
Algebraic loop occurs often, when you have a feedback through a constant block or equivalent, which means your signal y(t0)=constant * y(t0) , you should have y(t0+1)=constant*y(t0) which you can get with a unit delay block
15 个评论
billel madridi
2013-3-25
it's useful your answer, i just added a unit delay and it works thanks
Walter Roberson
2014-3-15
编辑：Walter Roberson
2017-5-6
Divyasri Venkat commented, "Thanks sir even i got the same error"
Ahmed Badie
2015-4-7
It works, thanks
tahahmady@gmail.com
2015-7-13
thank you , after all this time , its works finally by your answer
Ibrahim Banat
2016-2-17
where can I add this block in my system?
Azzi Abdelmalek
2016-2-17
just before the feedback
Ibrahim Banat
2016-2-17
firstly, thanks for reply. but I don't know the exact location to insert the block.. my system consists of 72 cells PV panel and I'm studying the shading effect and the same problem appear every time. Can I send you my system to see whats I mean?
Ibrahim Banat
2016-2-18
Any help Mr. Azzi Abdelmalek
lukemya fabien
2016-7-29
I have the same error but in the PV array block, I don't see where I can place the unity delay. Please help me to solve this problem. Thanks.
Mohamed Yousry
2017-5-6
Thanks Dear Azzi, this answer surely solved my problem.
Om Krishan
2018-11-1
Thanks@VAzzi Abdelmalek it works
Praveen Kumar
2018-11-7
Same issue. Where should I place the unit delay? Someone, please comment. Thank you.
Lukas Kretzschmar Waeny
2019-3-12
Same issue, thanks for helping ...
Sudhanshu Telrandhe
2019-11-8
thanks for helping ...
NING XUE
2020-3-10
Simulink cannot solve the algebraic loop containing 'partial_shading_conditions2/PV_SERIES2/Subsystem/Divide2' at time 0.039814999999999996 using the LineSearch-based algorithm due to one of the following reasons: the model is ill-defined i.e., the system equations do not have a solution; or the nonlinear equation solver failed to converge due to numerical issues. To rule out solver convergence as the cause of this error, either a) switch to TrustRegion-based algorithm using set_param('partial_shading_conditions2','AlgebraicLoopSolver','TrustRegion') b) reducing the VariableStepDiscrete solver RelTol parameter so that the solver takes smaller time steps. If the error persists in spite of the above changes, then the model is likely ill-defined and requires modification.
The same issue,but I have place the unit delay before the feedback,can't solve this problem
can you help me?
更多回答（5 个）
Walter Roberson
2017-5-6
1 个投票
Kalyani Dhawad
2018-9-6
0 个投票
I have same problem in pv system
Ahmed
2019-6-19
0 个投票
I've faced the same problem before, it can be solved by adding a unit delay block and type "set_param('trial_3','AlgebraicLoopSolver','LineSearch') " in the command prombit window of MATLAB.
2 个评论
matham kiran kumar
2019-8-3
Thank you. Its working for me too.
Akash maheshwari
2019-10-3
can you pleasse explain set_param('trial_3','AlgebraicLoopSolver','LineSearch'). i did that in my matlab command window but window show me that algebraic loop parameter did not found.
Gert Kruger
2019-6-27
0 个投票
PV panel model with fixed algebraic loop: https://www.mathworks.com/matlabcentral/fileexchange/71682-pv-array-with-algebraic-loop-broken
2 个评论
PIRC
2019-12-2
same problem. you model not helpful.
Malaiyappan M
2020-8-17
Inductor is not designed properly
ayachi amor
2021-6-14
0 个投票
Click on the PV panel itself, go to ' Advanced', then click on 'Break algebaic loop in internal model'.
hope to be solved.
1 个评论
Zachary Naidoo
2022-4-14
Hi, I have tried this by my displays for voltage and current show nan when for this. However if I don't click it then it displays the result with an error
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