Besides the commonly used alternating current (AC), direct current (DC) also plays a pivotal role in emerging application scenarios. Though DC power supply accounts for a relatively small share in traditional power distribution, it fulfills an irreplaceable role in specific fields thanks to its unique advantages. The main DC power supply modes include:
Two-wire system
It transmits electrical energy via two positive and negative conductors, with no grounding required. Characterized by a simple structure, it is suitable for short-distance, high-current transmission. Its key applications include urban trolleybuses, subway locomotives, and mining traction systems.
Three-wire system
A neutral wire is added to the positive and negative conductors to form a bipolar power supply system. It enables flexible voltage adjustment to meet the demands of precision processes. It is mainly applied in auxiliary power systems of power plants and substations, as well as industrial scenarios like electrolysis and electroplating.
High-Voltage Direct Current (HVDC) Transmission
It converts AC to DC through converter stations to realize long-distance, large-capacity power transmission. Boasting advantages such as low line loss, high safety, and strong economic efficiency, it is primarily used for cross-regional power transmission (e.g., submarine cables, transnational power grid interconnection).
The Synergistic Future of AC and DC Power Supply
With the advancement of smart grid and new energy technologies, AC and DC power supply modes are not mutually exclusive but show a complementary trend:
Traditional fields: AC power supply remains the preferred option for high-voltage transmission and low-voltage distribution, as its technical maturity and economic efficiency are irreplaceable.
Emerging fields: DC power supply is accelerating its penetration in rail transit, data centers, and distributed energy systems, driving the evolution of power systems toward an "AC-DC hybrid" mode.
As a leading enterprise in the electrical equipment industry, PEOPLE has always been committed to delivering efficient and reliable electrical solutions to customers. Our product portfolio covers full-scenario needs—whether it is transformers and switchgear for AC distribution, or inverters for DC power supply.
Post time: Feb-07-2026
