# How to solve algebraic loop error??

200 views (last 30 days)

Show older comments

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 Comments

Jim Riggs
on 2 Dec 2019

Malaiyappan M
on 17 Aug 2020

in MPPT Buck/Boost Converer try adjust the Inductor Value to resolve this error

### Accepted Answer

Azzi Abdelmalek
on 23 Nov 2012

Edited: Azzi Abdelmalek
on 23 Nov 2012

##### 15 Comments

NING XUE
on 10 Mar 2020

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?

### More Answers (5)

Ahmed
on 19 Jun 2019

##### 2 Comments

Akash maheshwari
on 3 Oct 2019

Gert Kruger
on 27 Jun 2019

##### 2 Comments

ayachi amor
on 14 Jun 2021

Click on the PV panel itself, go to ' Advanced', then click on 'Break algebaic loop in internal model'.

hope to be solved.

##### 1 Comment

Zachary Naidoo
on 14 Apr 2022

### See Also

### Products

### Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!