The article discusses the impact of charging plug-in hybrid electric vehicles (PHEVs) on a residential distribution grid. PHEVs, which can be charged at home or in corporate parking, are becoming more popular, and their charging can significantly affect the grid due to increased electrical demand. Uncoordinated charging, where vehicles are charged immediately upon plugging in or after a fixed delay, can lead to grid problems such as power losses and voltage deviations. To mitigate these issues, coordinated charging is proposed to minimize power losses and maximize grid load factor. The optimal charging profile for PHEVs is determined by minimizing power losses, using stochastic programming to account for uncertain household loads. Two main techniques are analyzed: quadratic programming and dynamic programming. The study shows that coordinated charging significantly reduces power losses and voltage deviations compared to uncoordinated charging. For example, during peak hours, coordinated charging reduces voltage deviations, which are critical for power quality. The research also considers the impact of PHEV penetration on the grid. With a 30% penetration level, the grid must be upgraded to handle increased loads. The study compares different charging periods and shows that coordinated charging during off-peak hours reduces voltage deviations and power losses. The results indicate that coordinated charging can lead to a more efficient grid operation, with lower power losses and better voltage stability. The article also discusses the use of smart metering systems to enable coordinated charging, which allows for better grid management and reduces the need for grid reinforcements. However, implementing smart metering requires investment and may involve additional costs. The study concludes that coordinated charging can lower power losses and voltage deviations, but the implementation of such systems requires careful planning and investment. The research highlights the importance of coordinated charging in improving the efficiency and reliability of the distribution grid.The article discusses the impact of charging plug-in hybrid electric vehicles (PHEVs) on a residential distribution grid. PHEVs, which can be charged at home or in corporate parking, are becoming more popular, and their charging can significantly affect the grid due to increased electrical demand. Uncoordinated charging, where vehicles are charged immediately upon plugging in or after a fixed delay, can lead to grid problems such as power losses and voltage deviations. To mitigate these issues, coordinated charging is proposed to minimize power losses and maximize grid load factor. The optimal charging profile for PHEVs is determined by minimizing power losses, using stochastic programming to account for uncertain household loads. Two main techniques are analyzed: quadratic programming and dynamic programming. The study shows that coordinated charging significantly reduces power losses and voltage deviations compared to uncoordinated charging. For example, during peak hours, coordinated charging reduces voltage deviations, which are critical for power quality. The research also considers the impact of PHEV penetration on the grid. With a 30% penetration level, the grid must be upgraded to handle increased loads. The study compares different charging periods and shows that coordinated charging during off-peak hours reduces voltage deviations and power losses. The results indicate that coordinated charging can lead to a more efficient grid operation, with lower power losses and better voltage stability. The article also discusses the use of smart metering systems to enable coordinated charging, which allows for better grid management and reduces the need for grid reinforcements. However, implementing smart metering requires investment and may involve additional costs. The study concludes that coordinated charging can lower power losses and voltage deviations, but the implementation of such systems requires careful planning and investment. The research highlights the importance of coordinated charging in improving the efficiency and reliability of the distribution grid.