Study on an Evaluation Method for Voltage-Upgrade Retrofits in Medium-Voltage Mixed-Supply Areas under High-quality Distribution Network Development

Against the backdrop of advancing the construction goals of a high-quality distribution network, effectively enhancing the operational efficiency and asset utilization of medium-voltage (10 kV/20 kV) mixed-supply areas has become a pressing practical issue. For a long time, the approach of relying on natural equipment replacement to implement voltage-upgrade retrofits has lacked sufficient decision-making support, making it difficult to properly weigh the gap in long-term economic benefits relative to proactive upgrade strategies. Therefore, taking medium-voltage mixed-supply areas as the context, this paper constructs a suitability evaluation framework for voltage-upgrade retrofits based on life-cycle cost analysis. By establishing a conversion model between technical indicators and economic costs, key parameters such as equipment penetration level and service life are transformed into comparable economic data, thereby systematically identifying and accurately estimating the hidden costs inherent in mixed-supply configurations and the overall benefits brought by voltage upgrades. This research helps improve the scientific basis and execution efficiency of power-grid upgrade decision-making, providing a crucial technical reference for achieving efficient, reliable, and intelligent development of the distribution network.