How to solve algebraic loop error??

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Vidya
Vidya 2012-11-23
评论： Zachary Naidoo 2022-4-14
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.
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Jim Riggs
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
Malaiyappan M 2020-8-17
in MPPT Buck/Boost Converer try adjust the Inductor Value to resolve this error

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采纳的回答

Azzi Abdelmalek
Azzi Abdelmalek 2012-11-23
编辑：Azzi Abdelmalek 2012-11-23
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
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NING XUE
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?

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更多回答（5 个）

Walter Roberson
Walter Roberson 2017-5-6
Kalyani Dhawad
Kalyani Dhawad 2018-9-6
I have same problem in pv system
Ahmed
Ahmed 2019-6-19
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.
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Akash maheshwari
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.

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Gert Kruger
Gert Kruger 2019-6-27
ayachi amor
ayachi amor 2021-6-14
Click on the PV panel itself, go to ' Advanced', then click on 'Break algebaic loop in internal model'.
hope to be solved.
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Zachary Naidoo
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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