Power distribution equipment is a collective term for the various devices within a power system used to receive, distribute, control, protect, and monitor electrical energy. Its primary function is to safely, reliably, and efficiently distribute power from the transmission grid or power plants to end-users, while simultaneously ensuring the safety of the connected electrical loads.
A power distribution system primarily consists of transformation and distribution equipment (such as transformers), distribution lines, switching and control devices (such as circuit breakers and disconnectors), and protective devices (such as relay protection units) [8]. Based on product form, distribution equipment can be categorized into complete distribution assemblies (such as switchgear and distribution boxes) and standalone components (such as transformers and instrument transformers). Complete distribution assemblies-specifically switchgear-are electrical systems centered around circuit breakers; manufacturers pre-assemble high- and low-voltage electrical components, busbars, current-carrying conductors, insulators, and other elements into enclosed or semi-enclosed metal cabinets, configured according to specific main circuit wiring diagrams to form distinct functional units.
Power distribution equipment is characterized by fundamental attributes such as stability and reliability, high energy efficiency, safety and ease of maintenance, intelligence, and green sustainability. Intelligence represents a core developmental trend in modern power distribution equipment, manifested through the automation, digitalization, and networking of functions such as monitoring, measurement, control, and protection. Complete distribution assemblies are distinguished by their high assembly quality and operational reliability; furthermore, they incorporate comprehensive protection features and safety designs-such as "Five-Prevention" interlocking mechanisms-to prevent operational errors. These assemblies feature compact structures and rational layouts, effectively minimizing overall volume and physical footprint while facilitating streamlined, standardized mass production. Driven by technological advancements, power distribution equipment is evolving toward greener, more eco-friendly, and energy-efficient solutions-examples include vegetable-oil-insulated transformers utilizing natural ester fluids, and solid-state transformers leveraging semiconductor technologies such as silicon carbide (SiC) and gallium nitride (GaN), which enable higher efficiencies (exceeding 98%) and significantly smaller dimensions. The electrical installation of complete assemblies can be conducted independently of civil engineering construction, thereby shortening the overall project timeline; moreover, their metal enclosures provide effective protection against dust and contamination, simplifying routine maintenance procedures.
