Electrical Scheme Design for Thermal Power Units Coupled with Molten Salt Thermal Energy Storage System

In response to the challenge that coal-fired cogeneration units in the new power system struggle to reconcile deep peak shaving with industrial heat supply due to the "heat-led power generation" constraint, this study conducts research on the electrical scheme design for a molten salt thermal storage system coupled with a thermal power unit, based on a 50 MW molten salt thermal storage project for industrial heating peak shaving. The paper discusses the design of the plant"s main electrical wiring and auxiliary power systems, compares three power supply schemes involving connection to the 220 kV side, the 110 kV side, and the generator outlet, and recommends adopting the scheme of connecting a 63 MVA high-voltage molten salt transformer from the 220 kV side. Furthermore, the results of the 10 kV single-bus sectionalized wiring for molten salt electric heaters, the load calculation and equipment selection for the 0.4 kV auxiliary power system, as well as the cable laying and grounding systems are presented. The designed electrical system ensures the safe and stable operation of the molten salt thermal storage device, providing a technical reference for similar retrofitting projects of thermal power units.