diff --git a/main.py b/main.py
index 8c50902..dd3cb34 100644
--- a/main.py
+++ b/main.py
@@ -858,8 +858,9 @@ def evaluate_design(
         total_cost += cable["cost"]
 
         # 计算I²R损耗 (简化版)
-        loss = (cable["current"] ** 2) * cable["resistance"] * 3  # 三相
-        total_loss += loss
+        loss_w = (cable["current"] ** 2) * cable["resistance"] * 3  # 三相，单位：W
+        loss_kw = loss_w / 1000  # 转换为 kW
+        total_loss += loss_kw
 
     return {
         "total_cost": total_cost,
@@ -1551,7 +1552,7 @@ def compare_design_methods(
     if comparison_results:
         # 计算每个方案的总费用（净现值）
         comparison_results = total_investment(comparison_results, system_params)
-        
+
         export_all_scenarios_to_excel(comparison_results, excel_out_filename)
 
         if not interactive:
@@ -1680,21 +1681,23 @@ def total_investment(results, system_params):
         更新后的results列表，每个结果新增 'total_cost_npv' 字段（总费用净现值，元）
     """
     # 获取系统参数，使用默认值
-    discount_rate_percent = system_params.get('discount_rate', DISCOUNT_RATE)
-    electricity_price = system_params.get('electricity_price', ELECTRICITY_PRICE)
-    project_lifetime = system_params.get('project_lifetime', PROJECT_LIFETIME)
-    annual_loss_hours = system_params.get('annual_loss_hours', ANNUAL_LOSS_HOURS)
+    discount_rate_percent = system_params.get("discount_rate", DISCOUNT_RATE)
+    electricity_price = system_params.get("electricity_price", ELECTRICITY_PRICE)
+    project_lifetime = system_params.get("project_lifetime", PROJECT_LIFETIME)
+    annual_loss_hours = system_params.get("annual_loss_hours", ANNUAL_LOSS_HOURS)
 
     # 将折现率转换为小数
     r = discount_rate_percent / 100.0
 
     for result in results:
-        cable_cost = result['cost']  # 电缆总投资（元）
-        loss_power = result['loss']  # 线损功率（kW）
+        cable_cost = result["cost"]  # 电缆总投资（元）
+        loss_power = result["loss"]  # 线损功率（kW）
 
         # 1. 计算电缆投资的净现值（2年分期）
         # 第1年支付50%，第2年支付50%
-        npv_cable = (cable_cost * 0.5) / ((1 + r) ** 1) + (cable_cost * 0.5) / ((1 + r) ** 2)
+        npv_cable = (cable_cost * 0.5) / ((1 + r) ** 1) + (cable_cost * 0.5) / (
+            (1 + r) ** 2
+        )
 
         # 2. 计算电费损耗的净现值（生命周期内）
         # 年损耗费用 = 损耗功率(kW) * 年损耗小时数 * 电价(元/kWh)
@@ -1713,10 +1716,10 @@ def total_investment(results, system_params):
         total_cost_npv = npv_cable + npv_loss
 
         # 将结果添加到字典中
-        result['total_cost_npv'] = total_cost_npv
-        result['npv_cable'] = npv_cable
-        result['npv_loss'] = npv_loss
-        result['annual_loss_cost'] = annual_loss_cost
+        result["total_cost_npv"] = total_cost_npv
+        result["npv_cable"] = npv_cable
+        result["npv_loss"] = npv_loss
+        result["annual_loss_cost"] = annual_loss_cost
 
     return results