Cross-linked polyethylene (XLPE) and polyethylene (PE) insulated cables are widely used in modern power transmission and distribution systems due to their excellent electrical and mechanical properties. These cables are designed for rated voltages ranging from low voltage to extra-high voltage, and are suitable for installation in power plants, industrial facilities, public utilities, and infrastructure projects such as urban distribution networks and transportation systems.XLPE insulated cables use cross-linked polyethylene as the insulating material. Through a cross-linking process, the linear molecular structure of polyethylene is transformed into a three-dimensional network structure, significantly improving the material’s thermal resistance, mechanical strength, and aging performance. XLPE insulation allows cables to operate continuously at higher conductor temperatures, typically up to 90°C in normal service, 130°C under emergency overload, and 250°C under short-circuit conditions, without loss of electrical integrity. This makes XLPE cables particularly suitable for high load density environments and applications requiring long service life and high reliability.PE insulated cables, using thermoplastic polyethylene as insulation, are characterized by low dielectric loss, good insulation resistance, and excellent moisture resistance. They are widely used in low and medium voltage systems, communication and control circuits, and in applications where cost-effectiveness and ease of processing are important. Although PE insulation has a lower maximum operating temperature compared with XLPE, it offers very good electrical performance and is suitable for many standard power and signal transmission applications.Both XLPE and PE insulated cables typically consist of a copper or aluminum conductor, an insulating layer, optional semi-conductive screens, metallic shielding or armoring, and various outer sheath materials depending on the installation environment. These cables can be installed in ducts, trenches, tunnels, on cable trays, or directly buried in soil when properly protected. They exhibit good resistance to moisture, certain chemicals, and environmental stress, and can be designed to meet flame-retardant, low-smoke, or halogen-free requirements according to project specifications and safety standards.In comparison with traditional paper-insulated or PVC-insulated cables, XLPE and PE insulated cables offer lower dielectric loss, lighter weight, easier installation, and reduced maintenance requirements. Their insulation systems show excellent resistance to partial discharge and electrical treeing when correctly manufactured and installed. As a result, XLPE and PE insulated cables have become preferred solutions for urban grid upgrades, renewable energy connections, industrial power distribution, and other critical applications that demand high performance, safety, and long-term operational stability.