when i tried to runpf matpower 33 bus program, it shows this problem

Error using loadcase (line 199)

loadcase: syntax error or undefined data matrix(ices) in the file

Undefined function 'feval_w_path' for input arguments of type 'char'.

Error in runpf (line 101)

mpc = loadcase(casedata);

Answer 1

[Namnendra]

Hi Fausta,

The error you're encountering indicates that there is a problem with the syntax or content of the case file you're trying to load in MATPOWER, a power system simulation package in MATLAB. The `loadcase` function is used to load the case data, and it seems like there's a syntax error or an undefined variable in your case file.

Here's a step-by-step guide to troubleshoot and resolve this issue:

Steps to Troubleshoot and Resolve the Error

1. Check the Case File Syntax:

- Ensure that the case file (e.g., `case33.m`) follows the correct MATPOWER case file format.

- The case file should define a MATLAB struct with fields such as `mpc.version`, `mpc.baseMVA`, `mpc.bus`, `mpc.gen`, `mpc.branch`, etc.

2. Verify Variable Definitions:

- Check that all required matrices (`bus`, `gen`, `branch`, etc.) are defined and populated correctly.

- Ensure there are no syntax errors or undefined variables in the case file.

3. MATPOWER Path Configuration:

- Ensure that MATPOWER is correctly installed and its path is added to MATLAB's search path.

- You can add the MATPOWER path using the `addpath` function:

 addpath('path_to_matpower');

4. Example Case File:

- Compare your case file with an example case file provided by MATPOWER (e.g., `case9.m`) to ensure the structure and syntax are correct.

- Here is an example structure of a MATPOWER case file:

function mpc = case33
     %CASE33    Power flow data for 33 bus distribution system.
     
     %% MATPOWER Case Format : Version 2
     mpc.version = '2';

     %%-----  Power Flow Data  -----%%
     %% system MVA base
     mpc.baseMVA = 1;

     %% bus data
     % bus_i type    Pd   Qd    Gs   Bs area Vm Va baseKV zone Vmax Vmin
     mpc.bus = [
         1    1   0.0  0.0  0.0  0.0   1  1.00  0.0  12.66  1  1.05  0.95;
         2    1   0.1  0.06 0.0  0.0   1  1.00  0.0  12.66  1  1.05  0.95;
         % more bus data...
     ];

     %% generator data
     % bus Pg Qg Qmax Qmin Vg mBase status Pmax Pmin Pc1 Pc2 Qc1min Qc1max Qc2min Qc2max ramp_agc ramp_10 ramp_30 ramp_q apf
     mpc.gen = [
         1   0.0 0.0 10.0 -10.0 1.00 1.0  1  10.0 -10.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0;
         % more generator data...
     ];

     %% branch data
     % fbus tbus r x b rateA rateB rateC ratio angle status angmin angmax
     mpc.branch = [
         1  2 0.0922 0.0470 0.0 100.0 100.0 100.0 0.0 0.0 1 -360.0 360.0;
         % more branch data...
     ];

     %%-----  OPF Data  -----%%
     %% generator cost data
     % 1 startup shutdown n x1 y1 ... xn yn
     % 2 startup shutdown n c(n-1) ... c0
     mpc.gencost = [
         2 0.0 0.0 3 0.0 20.0 0.0;
         % more cost data...
     ];
end

5. Run the Power Flow Analysis:

- Once the case file is correctly formatted and saved, you can run the power flow analysis using the `runpf` function:

 mpc = loadcase('case33');
     results = runpf(mpc);

I hope the above information helps.

Thank you.

Answer 2

[Walter Roberson]

You appear to have a corrupted version of matpower .

feval_w_path is defined for at least MATPOWER 5, MATPOWER 6, MATPOWER 7, and MATPOWER 8

It is possible that your version of MATPOWER has the function but that somehow the function is not on the MATLAB path.

Answer 3

[Izhar]

Lab2Code.m

% =============================================================== % LAB 2: Load Flow Analysis of IEEE 9-Bus System (Newton-Raphson) % =============================================================== % Author: Muhammad Haris % Tool: MATLAB + MATPOWER % =============================================================== clc; clear; close all; define_constants; disp('==============================================='); disp(' LOAD FLOW ANALYSIS USING NEWTON-RAPHSON '); disp('==============================================='); %% Step 1: Load IEEE 9-Bus System mpc = loadcase('case9'); disp('✅ IEEE 9-Bus Test Case Loaded Successfully'); disp(['Total Buses: ', num2str(size(mpc.bus,1))]); disp(['Total Generators: ', num2str(size(mpc.gen,1))]); disp(['Total Branches: ', num2str(size(mpc.branch,1))]); disp('-----------------------------------------------'); %% Step 2: Run Power Flow using Newton-Raphson Method mpopt = mpoption('pf.alg','NR','verbose',1,'out.all',0); tic; results = runpf(mpc, mpopt); elapsed_time = toc; if results.success disp('✅ Power Flow Converged Successfully'); else disp('❌ Power Flow Did Not Converge'); end disp(['Computation Time: ', num2str(elapsed_time), ' seconds']); disp(['Iterations Taken: ', num2str(results.iterations)]); disp('-----------------------------------------------'); %% Step 3: Display Bus Results disp('========= BUS VOLTAGE RESULTS ========='); BusData = table(results.bus(:,BUS_I), results.bus(:,VM), results.bus(:,VA), ... 'VariableNames', {'Bus','Voltage_pu','Angle_deg'}); disp(BusData); %% Step 4: Display Line Flow Results disp('========= BRANCH FLOW RESULTS ========='); BranchData = table(results.branch(:,F_BUS), results.branch(:,T_BUS), ... results.branch(:,PF), results.branch(:,QF), results.branch(:,PT), results.branch(:,QT), ... 'VariableNames', {'From_Bus','To_Bus','P_from_MW','Q_from_Mvar','P_to_MW','Q_to_Mvar'}); disp(BranchData); %% Step 5: Calculate Total System Losses total_loss_P = sum(results.branch(:,PF) + results.branch(:,PT)); total_loss_Q = sum(results.branch(:,QF) + results.branch(:,QT)); disp('========= SYSTEM LOSSES ========='); fprintf('Total Real Power Loss = %.4f MW\n', abs(total_loss_P)); fprintf('Total Reactive Power Loss = %.4f Mvar\n', abs(total_loss_Q)); %% Step 6: Plot Voltage Profile figure('Color','w'); plot(results.bus(:,BUS_I), results.bus(:,VM), 'o-b','LineWidth',1.8); xlabel('Bus Number'); ylabel('Voltage Magnitude (p.u.)'); title('Voltage Profile - IEEE 9-Bus System (Newton-Raphson)'); grid on; %% Step 7: Plot Bus Voltage Angles figure('Color','w'); plot(results.bus(:,BUS_I), results.bus(:,VA), 's-r','LineWidth',1.8); xlabel('Bus Number'); ylabel('Voltage Angle (degrees)'); title('Bus Voltage Angles - IEEE 9-Bus System'); grid on; %% Step 8: Heavy Load Case (Optional) % Increase load at Bus 5 by 50% mpc.bus(5, PD) = 1.5 * mpc.bus(5, PD); disp('⚙️ Increasing load at Bus 5 by 50%...'); results_heavy = runpf(mpc, mpopt); % Compare voltage profile figure('Color','w'); plot(results.bus(:,BUS_I), results.bus(:,VM),'o-b','LineWidth',1.8); hold on; plot(results_heavy.bus(:,BUS_I), results_heavy.bus(:,VM),'s--r','LineWidth',1.8); xlabel('Bus Number'); ylabel('Voltage (p.u.)'); legend('Base Case','Heavy Load Case'); title('Voltage Profile Comparison under Load Variation'); grid on; disp('-----------------------------------------------'); disp('Simulation Completed Successfully ✅'); disp('-----------------------------------------------');

[Izhar]

Warning: runpf (MATPOWER) not found on MATLAB path. Either install MATPOWER or add it to your path.

> In untitled (line 22)

Warning: Could not load case9 with loadcase. Make sure MATPOWER is installed or provide case9 path.

> In untitled (line 32)

Unrecognized function or variable 'loadcase'.

Error in untitled (line 30)

mpc = loadcase('case9');

^^^^^^^^^^^^^^^^^^^^^^^^

>>

[Izhar]

mMake sure MATPOWER is installed for runpf to work (see guidance above).

[Walter Roberson]

Please format this as code.

First click on the '>' button in the CODE portion of the tool ribbon. Then paste your code into the area that gets opened.