SubArray.m

%% SubArray Class
% Defines a group of series connected modules

classdef SubArray < handle

    properties
        id uint32               % SubArray identifier
        color                   % Subarray view color
        numModules = 0          % Number of objects in ModuleList
        moduleList Module       % Vector containing SolarModule objects

        viMatrix                % VI Matrix for storing VI curve
    end

methods

        % Appends module to end of moduleList
        function AddModule(obj, module)
            obj.numModules = obj.numModules + 1;
            obj.moduleList(obj.numModules) = module;
            obj.GenerateMatrix;
        end

        % Remove module from end of moduleList
        function RemoveModule(obj, idx)
            obj.moduleList(idx) = [];
            obj.numModules = obj.numModules - 1;
            obj.GenerateMatrix;
        end

        % Import VI matrix from file
        function ImportMatrix(obj, filename)
            obj.viMatrix = readmatrix("CurveData/" + filename);
        end

        % Returns subarray current given voltage and light intensity
        function I = GetCurrent(obj, V, li)
            [~, idx] = min(abs(obj.viMatrix(obj.liIndex(li), :) - V));
            I = obj.IndexCurrent(idx);
        end

        % Returns subarray voltage given current and light intensity
        function V = GetVoltage(obj, I, li)
            V = obj.viMatrix(obj.liIndex(li), obj.CurrentIndex(I));
        end

        % Returns open-circuit voltage based on light intensity
        function Voc = GetVoc(obj, li)
                Voc = obj.GetVoltage(0, li);
        end

        % Returns short-circuit current based on light intensity
        function Isc = GetIsc(obj, li)
            Isc = obj.GetCurrent(0, li);
        end

        % Returns power given voltage and light intensity
        function P = GetPowerV(obj, V, li)
            P = V .* obj.GetCurrent(V, li);
            P = P .* ~(isinf(P));
        end

        % Returns power given current and light intensity
        function P = GetPowerI(obj, I, li)
            P = I .* obj.GetVoltage(I, li);
            P = P .* ~(isinf(P));
        end

        % Returns electrical parameters at the maximum power point
        function [Vmpp, Impp, Pmpp] = GetMPP(obj, li)
            Impp = fminbnd(@(I)obj.GetPowerI(I, li) * (-1), 0, obj.moduleList(1).IoptMax);
            Vmpp = obj.GetVoltage(Impp, li);
            Pmpp = Impp * Vmpp;
        end

%         % Plot VI curve
%         function PlotVI(obj, li)
%             I = linspace(-1, 10, 1101);
%             y = obj.viMatrix(obj.liIndex(li), :);
% 
%             hold on
%             title('VI Characteristics of ' + obj.id)
%             plot(I, y);
%             plot([0 0], ylim, 'k-')         % plot y-axis
%             plot(xlim, [0 0], 'k-')         % plot x-axis
%             xlabel('Currnet (A)')
%             ylabel('Voltage (V)')
%             hold off
%         end
% 
%         % Plot IV curve
%         function PlotIV(obj, li)
%             V = obj.viMatrix(obj.liIndex(li), :);
%             I = linspace(-1, 10, 1101);
% 
%             hold on
%             title('IV Characteristics of ' + obj.id)
%             plot(V, I);
%             plot([0 0], ylim, 'k-')         % plot y-axis
%             plot(xlim, [0 0], 'k-')         % plot x-axis
%             xlabel('Voltage (V)')
%             ylabel('Currnet (A)')
%             hold off
%         end
% 
%         % Plot MPP curve with IV curve
%         function PlotMPP(obj, li)
%             V = obj.viMatrix(obj.liIndex(li), :);
%             I = linspace(-1, 10, 1101);
%             P = obj.GetPowerI(I, li);
%             [Vmpp, Impp, ~] = obj.GetMPP(li);
% 
%             hold on
%             title('IV Characteristics of ' + obj.id)
% 
%             yyaxis left
%             plot(V, I);                     % Plot current as a function of voltage
%             plot([Vmpp Vmpp], ylim, 'r-')   % plot MPP voltage
%             plot(xlim, [Impp Impp], 'r-')   % plot MPP current
%             plot([0 0], ylim, 'k-')         % plot y-axis
%             plot(xlim, [0 0], 'k-')         % plot x-axis
%             xlabel('Voltage (V)')
%             ylabel('Currnet (A)')
% 
%             yyaxis right
%             plot(V, P)                      % plot power as a function of voltage
%             ylabel('Power (W)')
%             hold off
%         end

    end

    methods (Access = private)

        % Generate VI matrix for subarray
        function GenerateMatrix(obj)
            if obj.numModules > 0
                obj.viMatrix = zeros(size(obj.moduleList(1).viMatrix));
                for i = 1:obj.numModules              % Sum the matricies of individual modules
                    if obj.moduleList(i).numCells > 0
                        obj.viMatrix = obj.viMatrix + obj.moduleList(i).viMatrix;
                    else
                        error('Modules must contain at least 1 cell');
                    end
                end

                % filename = "CurveData/" + obj.id + ".csv";
                % writematrix(obj.viMatrix, filename);
            end
        end
    end

    methods (Static)

        % Constructor function
        function obj = CreateModule(id, color, varargin)
            obj = Module;
            obj.id = id;
            obj.color = color;
            obj.numModules = nargin - 2;
            obj.shadeList = [];
            obj.bypassPresent = 0;

            for i = 1:(nargin - 2)
                obj.moduleList(i) = varargin{i};
            end
            obj.GenerateMatrix;
        end

        % Convert absolute current into matrix index
        function idx = CurrentIndex(I)
            idx = int32((I + 1) * 100 + 1);
        end

        % Convert matrix index into absolute current
        function I = IndexCurrent(idx)
            I = (idx - 1) / 100 - 1;
        end
    
        % Convert absolute light intensity into matrix index
        function idx = liIndex(li)
            idx = int32(li * 100 + 1);
        end

    end

end