In the field of new energy, as core control and protection equipment of power system, power switch plays a vital role in the fields of photovoltaic, wind power and energy storage. Their application scenarios and technical characteristics are closely related to system safety, efficiency and reliability. These three main areas were analysed as follows:
I. Photovoltaic Systems: Core Safeguards for safe access and fault isolation
PV systems convert solar energy into direct current through PV modules, and direct current converts direct current into alternating current through inverters and is integrated into the grid. In this process, the electrical switch has two core functions:
Security isolation and access control
DC Circuit Breaker: Used to cut the DC arc between inverter and PV assembly to prevent electrocution during maintenance. For example, Projoy Electric's DC disconnect switches are designed with physical distancing to ensure the safety of operators and have become a designated supplier to 80% of mainstream inverter manufacturers worldwide.
Grid-Connection Switchgear Cabinets: These integrated circuit breakers, circuit breakers and lightning protection modules provide overload, short-circuit protection and backflow protection as a connection hub between PV stations and the grid. Their airtight design withstands harsh environments, supports multiple PV module connections, and meets the expansion needs of residential rooftop installations and commercial/industrial distributed projects.
Rapid Fault Response and System Protection
Intelligent circuit breakers: real-time monitoring of current and voltage anomalies in response to the power output fluctuations of PV systems, automatically cutting circuits in the event of overflow, short-circuit circuit or leakage events to prevent equipment damage. For example, when a PV string branch circuit short-circuits, smart circuit breakers can swiftly isolate fault point and prevent system from collapsing.
ii. Wind Power Systems: Reliable Operation and Intelligent Maintenance in High-Voltage Environments
Wind power systems face challenges of high pressure, strong corrosion and extreme weather conditions. Technological upgrades to electrical switches focus on ocean adaptability, voltage tolerance and intelligence:
Offshore Wind Power High-Voltage Switchgear Solutions
72.5 kV GIS Switchgear: Fully enclosed metal construction, CX-grade anti-corrosion coating, an IP66 protection rating, high salt spray and humidity environments resistance. For example, XD Electric's low-frequency 72.5 kV GIS switchgear, designed with a common box circuit breaker, successfully completed a high-volume manufacturing/ damage test, making it the world's first application case.
550 kV DC GIS: for long distance transmission of offshore wind power transmission, reducing space requirements by 90% for offshore platforms and onshore converter stations. Its ±550 kV DC GIS has been put into operation in the Guangxi Guizhong Converter Station, which marks a technological breakthrough in China's high-voltage DC enclosed switchgear.
Smart Maintenance and Unmanned Operation Modes
The three-platform architecture consisting of equipment, station control and operation application layers enables联动 dynamic connection between local substation, remote monitoring and mobile operation platforms. XD Electric, for example, has deployed modular offshore substations to the Three Gorges New Energy A project, using a single-story layout to optimize space and support an "unmanned, remote monitoring" mode to reduce operating costs.
III. Energy Storage Systems: key support for power regulation and System Stability
Energy storage system adjusts the balance of supply anddemand through charging and discharging. Electrical switches must strike a balance between efficient energy conversion and safety protection:
Power Control in Battery Energy Storage Systems
Bidirectional Circuit Breakers: Supports a bidirectional power flow when battery is charged and discharged, allowing rapid response during active/ passive power regulation at access point. For example, when the system needs to absorb excess power, the circuit breaker adjusts the voltage phase angle of the BESS to inject active power. When the voltage fluctuates on the side of the load, the circuit breaker stabilizes power quality by adjusting voltage amplitude.
Superconducting magnetic energy storage: Utilizing the lossless energy storage characteristics superconducting coil, a millisecond response is achieved by electro electronic conversion technology. With more than 90% conversion efficiency and independent energy storage and storage design, it is suitable for high power applications such as damping low frequency oscillation.
Safety Protection of Integrated Photovoltaic EnergyStorage System
In a microgrid combining PV, energy storage and charging stations, intelligent circuit breakers must address the combined risks output power fluctuations, battery charge anddischarge, and charging station overload. For example, in response to high power charging demands of electric vehicles, circuit breakers can monitor current anomalies in real time and cut the circuit in 0.1 seconds during a short circuit to ensure system safety.
Technical Trends and Industry Outlook
High Voltage and Integration: With the expansion of wind power and photovoltaic (PV) installed capacity, demand for 72.5 kV and high voltage switchgear is increasing and equipment is moving towards compact and modular. For example, XD Electric's 72.5 kV tower switchgear reduces space occupancy through a single-story layout.
Intelligent and Digital: Integrated IoT technology, switchgear for condition monitoring, fault prediction and adaptive protection. Intelligent circuit breakers, for example, upload operational data to the cloud to optimize protection strategies through artificial intelligence algorithms.
Environmental protection and Reliability Enhancement: the use of SF6 gas usage can be reduced by the usage of vacuum interruption, air insulation and other environmental technologies, while enhanced anticorrosion design (e.g., CX-grade coating) and seismic structures can extend the lifespan of equipment to more than 30 years.
The application of electric switch in the field of new energy has been developed from single-function protection to system-level control, which drives the development of PV, wind power and energy storage systems to be more efficient, safe and intelligent. As the goal of the "dual carbon" goals, electrical switches will become the key infrastructure for the construction of new power systems.
