一、问题描述
在33节点配电网系统中,确定分布式发电(DG)单元的最优位置和容量,以最小化系统网损、改善电压分布并提高供电可靠性。这是一个典型的非线性优化问题,涉及潮流计算、约束处理和智能优化算法。
二、系统建模
2.1 IEEE 33节点系统参数
matlab
% IEEE 33节点系统参数
bus_data = [
1 0 0 0 1.00 0.00; % 节点1: 平衡节点
2 1 100 60 1.00 0.00; % 节点2: PQ节点
3 1 90 40 1.00 0.00;
4 1 120 80 1.00 0.00;
5 1 60 30 1.00 0.00;
6 1 60 20 1.00 0.00;
7 1 200 100 1.00 0.00;
8 1 200 100 1.00 0.00;
9 1 60 20 1.00 0.00;
10 1 60 20 1.00 0.00;
11 1 45 30 1.00 0.00;
12 1 60 35 1.00 0.00;
13 1 60 35 1.00 0.00;
14 1 120 80 1.00 0.00;
15 1 60 10 1.00 0.00;
16 1 60 20 1.00 0.00;
17 1 60 20 1.00 0.00;
18 1 90 40 1.00 0.00;
19 1 90 40 1.00 0.00;
20 1 90 40 1.00 0.00;
21 1 90 40 1.00 0.00;
22 1 90 40 1.00 0.00;
23 1 90 50 1.00 0.00;
24 1 420 200 1.00 0.00;
25 1 420 200 1.00 0.00;
26 1 60 25 1.00 0.00;
27 1 60 25 1.00 0.00;
28 1 60 20 1.00 0.00;
29 1 120 70 1.00 0.00;
30 1 200 600 1.00 0.00;
31 1 150 70 1.00 0.00;
32 1 210 100 1.00 0.00;
33 1 60 40 1.00 0.00;
];
branch_data = [
1 2 0.0922 0.0470;
2 3 0.4930 0.2511;
3 4 0.3660 0.1864;
4 5 0.3811 0.1941;
5 6 0.8190 0.7070;
6 7 0.1872 0.6188;
7 8 0.7114 0.2351;
8 9 1.0300 0.7400;
9 10 1.0440 0.7400;
10 11 0.1966 0.0650;
11 12 0.3744 0.1238;
12 13 1.4680 1.1550;
13 14 0.5416 0.7129;
14 15 0.5910 0.5260;
15 16 0.7463 0.5450;
16 17 1.2890 1.7210;
17 18 0.7320 0.5740;
2 19 0.1640 0.1565;
19 20 1.5042 1.3554;
20 21 0.4095 0.4784;
21 22 0.7089 0.9373;
3 23 0.4512 0.3083;
23 24 0.8980 0.7091;
24 25 0.8960 0.7011;
6 26 0.2030 0.1034;
26 27 0.2842 0.1447;
27 28 1.0590 0.9337;
28 29 0.8042 0.7006;
29 30 0.5075 0.2585;
30 31 0.9744 0.9630;
31 32 0.3105 0.3619;
32 33 0.3410 0.5302;
];
2.2 系统参数
matlab
% 系统参数
baseMVA = 10; % 基准功率 (MVA)
baseKV = 12.66; % 基准电压 (kV)
Z_base = (baseKV*1000)^2 / (baseMVA*1e6); % 基准阻抗 (Ω)
V_min = 0.95; % 最小允许电压 (p.u.)
V_max = 1.05; % 最大允许电压 (p.u.)
max_DG = 500; % 单个DG最大容量 (kW)
三、优化算法实现
3.1 遗传算法优化框架
matlab
function [best_DG, best_loss] = dg_optimization()
% 参数设置
pop_size = 50; % 种群大小
max_gen = 100; % 最大迭代次数
pc = 0.8; % 交叉概率
pm = 0.1; % 变异概率
% 初始化种群
population = initialize_population(pop_size);
% 进化过程
for gen = 1:max_gen
% 计算适应度
fitness = evaluate_fitness(population);
% 选择
parents = selection(population, fitness);
% 交叉
offspring = crossover(parents, pc);
% 变异
offspring = mutation(offspring, pm, max_DG);
% 更新种群
population = [parents; offspring];
% 保留最优个体
[min_loss, idx] = min(fitness);
best_individual = population(idx, :);
% 显示进度
fprintf('Generation %d: Min Loss = %.4f kW\n', gen, min_loss);
end
% 返回最优解
best_DG = best_individual;
best_loss = min_loss;
end
3.2 初始化种群
matlab
function population = initialize_population(pop_size)
% 每个个体代表33个节点的DG容量 (kW)
population = randi([0, 500], pop_size, 33);
end
3.3 适应度评估(含潮流计算)
matlab
function losses = evaluate_fitness(population)
n = size(population, 1);
losses = zeros(n, 1);
for i = 1:n
DG_capacities = population(i, :); % DG容量 (kW)
[losses(i), ~, ~] = power_flow_analysis(DG_capacities);
end
end
3.4 潮流计算(前推回代法)
matlab
function [total_loss, voltages, branch_flows] = power_flow_analysis(DG_capacities)
global bus_data branch_data baseMVA Z_base;
n_bus = size(bus_data, 1);
n_branch = size(branch_data, 1);
% 初始化
P_load = bus_data(:, 3)/1000; % kW -> MW
Q_load = bus_data(:, 4)/1000; % kVar -> MVAr
P_DG = DG_capacities/1000; % kW -> MW
Q_DG = zeros(1, n_bus); % 假设DG不提供无功
V = ones(n_bus, 1); % 初始电压 (p.u.)
V(1) = 1.0; % 平衡节点电压
% 构建节点-父节点关系
parent = zeros(n_bus, 1);
children = cell(n_bus, 1);
for i = 1:n_branch
from = branch_data(i, 1);
to = branch_data(i, 2);
parent(to) = from;
if isempty(children{from})
children{from} = to;
else
children{from} = [children{from}, to];
end
end
% 确定节点处理顺序(广度优先)
order = zeros(n_bus, 1);
queue = 1;
order(1) = 1;
front = 1; rear = 1;
while front <= rear
node = queue(front);
front = front + 1;
if ~isempty(children{node})
for child = children{node}
rear = rear + 1;
queue(rear) = child;
order(rear) = child;
end
end
end
% 迭代计算
max_iter = 100;
tolerance = 1e-6;
for iter = 1:max_iter
V_prev = V;
% 回代过程(计算支路电流)
I_branch = zeros(n_bus, 1);
for i = n_bus:-1:2
node = order(i);
S = (P_DG(node) - P_load(node)) + 1j*(Q_DG(node) - Q_load(node));
I_node = conj(S / (V(node) * baseMVA)); % 节点电流
% 累加子节点电流
if ~isempty(children{node})
for child = children{node}
I_node = I_node + I_branch(child);
end
end
I_branch(node) = I_node;
end
% 前推过程(计算节点电压)
for i = 2:n_bus
node = order(i);
par = parent(node);
% 查找支路参数
for br = 1:n_branch
if branch_data(br, 1) == par && branch_data(br, 2) == node
R = branch_data(br, 3) / Z_base; % 标幺值
X = branch_data(br, 4) / Z_base;
Z = R + 1j*X;
break;
end
end
V(node) = V(par) - I_branch(node) * Z;
end
% 检查收敛
if max(abs(V - V_prev)) < tolerance
break;
end
end
% 计算网损
total_loss = 0;
branch_flows = zeros(n_branch, 1);
for i = 1:n_branch
from = branch_data(i, 1);
to = branch_data(i, 2);
R = branch_data(i, 3); % 欧姆
% 计算支路电流
I = abs(I_branch(to)); % 简化计算
branch_flows(i) = 3 * (I^2) * R; % 三相功率损耗 (W)
total_loss = total_loss + branch_flows(i);
end
total_loss = total_loss / 1000; % 转换为kW
% 电压结果
voltages = V;
end
3.5 选择操作(轮盘赌选择)
matlab
function parents = selection(population, fitness)
n = size(population, 1);
inv_fitness = 1./(fitness + eps); % 损失越小适应度越高
prob = inv_fitness / sum(inv_fitness);
% 轮盘赌选择
selected = randsample(1:n, n, true, prob);
parents = population(selected, :);
end
3.6 交叉操作(算术交叉)
matlab
function offspring = crossover(parents, pc)
n = size(parents, 1);
offspring = zeros(n, size(parents, 2));
for i = 1:2:n-1
if rand < pc
alpha = rand;
p1 = parents(i, :);
p2 = parents(i+1, :);
offspring(i, :) = alpha*p1 + (1-alpha)*p2;
offspring(i+1, :) = (1-alpha)*p1 + alpha*p2;
else
offspring(i, :) = parents(i, :);
offspring(i+1, :) = parents(i+1, :);
end
end
end
3.7 变异操作(随机重置)
matlab
function offspring = mutation(offspring, pm, max_DG)
[n, m] = size(offspring);
for i = 1:n
for j = 1:m
if rand < pm
% 随机重置变异
offspring(i, j) = randi([0, max_DG]);
end
end
end
end
四、结果分析与可视化
4.1 主程序
matlab
% 主程序
clear; clc; close all;
% 运行优化
[best_DG, min_loss] = dg_optimization();
% 计算优化后系统状态
[total_loss, voltages, branch_flows] = power_flow_analysis(best_DG);
% 显示结果
fprintf('\n===== 优化结果 =====\n');
fprintf('最小网损: %.2f kW\n', min_loss);
fprintf('节点电压范围: [%.4f, %.4f] p.u.\n', min(voltages), max(voltages));
% 显示DG配置
fprintf('\n===== DG配置 =====\n');
for i = 1:33
if best_DG(i) > 10 % 忽略小容量DG
fprintf('节点 %2d: %5.1f kW\n', i, best_DG(i));
end
end
% 可视化
visualize_results(best_DG, voltages, branch_flows);
4.2 结果可视化
matlab
function visualize_results(DG_capacities, voltages, branch_flows)
% DG配置柱状图
figure;
bar(DG_capacities);
title('DG容量分布');
xlabel('节点编号');
ylabel('DG容量 (kW)');
grid on;
% 电压分布图
figure;
plot(1:33, voltages, 'bo-');
hold on;
plot([1, 33], [0.95, 0.95], 'r--');
plot([1, 33], [1.05, 1.05], 'r--');
title('节点电压分布');
xlabel('节点编号');
ylabel('电压 (p.u.)');
legend('电压', '允许下限', '允许上限');
grid on;
% 网损分布图
figure;
stem(1:length(branch_flows), branch_flows);
title('支路网损分布');
xlabel('支路编号');
ylabel('网损 (W)');
grid on;
% 系统拓扑图
figure;
draw_system_topology(DG_capacities, voltages);
end
function draw_system_topology(DG_capacities, voltages)
% 绘制33节点系统拓扑
figure;
hold on;
axis equal;
grid on;
% 节点位置 (简化布局)
angles = linspace(0, 2*pi, 33);
radius = 10;
x = radius * cos(angles);
y = radius * sin(angles);
% 绘制支路
for i = 1:size(branch_data, 1)
from = branch_data(i, 1);
to = branch_data(i, 2);
plot([x(from), x(to)], [y(from), y(to)], 'k-');
end
% 绘制节点
for i = 1:33
if i == 1
% 平衡节点
plot(x(i), y(i), 'ro', 'MarkerSize', 8, 'MarkerFaceColor', 'r');
else
% 普通节点
if DG_capacities(i) > 0
% 有DG的节点
plot(x(i), y(i), 'go', 'MarkerSize', 8, 'MarkerFaceColor', 'g');
else
% 无DG的节点
plot(x(i), y(i), 'bo', 'MarkerSize', 6, 'MarkerFaceColor', 'b');
end
end
% 标注节点编号
text(x(i)+0.3, y(i)+0.3, num2str(i), 'FontSize', 8);
% 标注电压
text(x(i)-0.5, y(i)-0.5, sprintf('%.3f', voltages(i)), 'FontSize', 7);
end
% 添加图例
legend('平衡节点', '有DG节点', '无DG节点', 'Location', 'Best');
title('33节点系统拓扑与电压分布');
xlabel('X坐标');
ylabel('Y坐标');
end
五、性能评估与比较
5.1 不同DG数量的影响
matlab
function compare_dg_numbers()
dg_counts = [1, 2, 3, 4, 5];
results = zeros(length(dg_counts), 3); % [DG数量, 网损(kW), 电压偏差]
for i = 1:length(dg_counts)
n_dg = dg_counts(i);
[DG_config, loss] = optimize_with_fixed_dg_count(n_dg);
[~, voltages, ~] = power_flow_analysis(DG_config);
voltage_deviation = max(abs(voltages - 1.0));
results(i, :) = [n_dg, loss, voltage_deviation];
end
% 显示结果
disp('DG数量 | 网损(kW) | 电压偏差(p.u.)');
disp(results);
% 绘图
figure;
subplot(2,1,1);
bar(results(:,1), results(:,2));
title('不同DG数量下的系统网损');
xlabel('DG数量');
ylabel('网损 (kW)');
grid on;
subplot(2,1,2);
bar(results(:,1), results(:,3));
title('不同DG数量下的电压偏差');
xlabel('DG数量');
ylabel('最大电压偏差 (p.u.)');
grid on;
end
5.2 不同优化算法比较
matlab
function compare_algorithms()
algorithms = {'GA', 'PSO', 'SA'};
results = zeros(length(algorithms), 2); % [算法, 网损(kW), 计算时间(s)]
for i = 1:length(algorithms)
algo = algorithms{i};
tic;
[~, loss] = run_optimization(algo);
time = toc;
results(i, :) = [i, loss, time];
end
% 显示结果
disp('算法 | 网损(kW) | 计算时间(s)');
for i = 1:length(algorithms)
fprintf('%s\t%.2f\t%.2f\n', algorithms{i}, results(i,2), results(i,3));
end
% 绘图
figure;
subplot(1,2,1);
bar(results(:,1), results(:,2));
set(gca, 'XTickLabel', algorithms);
title('不同算法的网损结果');
ylabel('网损 (kW)');
grid on;
subplot(1,2,2);
bar(results(:,1), results(:,3));
set(gca, 'XTickLabel', algorithms);
title('不同算法的计算时间');
ylabel('时间 (s)');
grid on;
end
参考代码 33节点DG最优分布 www.youwenfan.com/contentcss/78649.html
六、工程应用与扩展
6.1 考虑多种DG类型
matlab
function [best_DG, best_loss] = dg_optimization_multi_type()
% 三种DG类型: 光伏、风电、燃气轮机
n_types = 3;
pop_size = 30;
max_gen = 50;
% 初始化种群: 每种DG在每个节点的容量
population = zeros(pop_size, 33*n_types);
for i = 1:pop_size
for j = 1:33
for k = 1:n_types
% 不同类型DG容量范围不同
if k == 1 % 光伏
cap = randi([0, 300]);
elseif k == 2 % 风电
cap = randi([0, 400]);
else % 燃气轮机
cap = randi([0, 500]);
end
population(i, (j-1)*n_types + k) = cap;
end
end
end
% 进化过程 (类似单类型优化)
% ...
end
6.2 考虑储能系统
matlab
function [best_DG, best_ES, best_loss] = dg_es_optimization()
% 同时优化DG和储能系统(ES)
n_vars = 33 * 2; % 33个节点,每个节点有DG和ES容量
% 初始化种群
population = zeros(pop_size, n_vars);
for i = 1:pop_size
% DG容量 (0-500kW)
population(i, 1:33) = randi([0, 500], 1, 33);
% ES容量 (0-200kWh)
population(i, 34:66) = randi([0, 200], 1, 33);
end
% 适应度函数考虑储能充放电策略
function loss = es_fitness(individual)
DG = individual(1:33);
ES_capacity = individual(34:66);
ES_soc = 0.5 * ES_capacity; % 初始SOC
% 简化的充放电策略
[loss, ~, ~] = power_flow_analysis(DG);
% 考虑储能对网损的改善
loss = loss * (1 - 0.1*mean(ES_capacity)/200);
end
% 进化过程
% ...
end
七、结论与建议
7.1 优化结果分析
-
DG最优位置:通常位于线路中部或负荷中心附近
-
DG最优容量:单个DG容量在200-400kW之间效果最佳
-
网损降低:优化后网损可降低30-50%
-
电压改善:节点电压偏差控制在±0.03p.u.以内
7.2 实施建议
-
分阶段部署:优先在网损降低显著的节点安装DG
-
考虑经济性:结合当地能源价格和补贴政策
-
运行策略:根据负荷变化调整DG出力
-
保护配合:校核DG对继电保护的影响
7.3 扩展方向
-
多目标优化:同时考虑网损、电压质量、投资成本
-
动态优化:考虑负荷和可再生能源的时序特性
-
鲁棒优化:应对负荷和可再生能源的不确定性
-
智能算法改进:结合深度学习优化算法参数