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Application of Box-Type Substations in New Energy (Photovoltaic/Wind Power) Projects

Release time:

2025-11-26

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Abstract

Application of Box-Type Substations in New Energy (Photovoltaic/Wind Power) Projects

Driven by the "Dual Carbon" goals, China's installed capacity of new energy continues to reach new milestones. By 2025, cumulative installations of photovoltaic and wind power have surpassed 800 million kilowatts and 500 million kilowatts, respectively. However, the intermittent and fluctuating nature of new energy sources poses significant challenges to the safe and stable operation of the power grid. As a critical hub in new-energy generation systems, modularly designed, intelligently integrated, and scenario-specific box-type substations are reshaping the fundamental principles of new-energy power conversion and transmission, emerging as an essential technological solution to tackle the growing challenges of new-energy consumption and integration.

1. Technological Iteration: From Single-Purpose Power Distribution to the Paradigm Shift of Photovoltaic-Storage Synergy

Traditional box-type substations primarily handle voltage transformation and power distribution functions, whereas in new energy scenarios, box-type substations have evolved into integrated, intelligent platforms. Take the Kunshan 3.555 MW distributed photovoltaic project as an example—this project employs customized photovoltaic step-up box transformers that utilize amorphous alloy core technology, reducing no-load losses by up to 70%. Paired with an IP54-rated enclosure design, these transformers maintain stable operation even in environments where humidity exceeds 90% during the plum rain season. More notably, the equipment features a built-in APF active filter, keeping harmonic distortion below 3%, effectively addressing the stringent power quality demands of precision manufacturing equipment.

In the wind power sector, Guizhou Engineering Company's innovative "Integrated Construction Method for Wind Turbine Generators with Top-Mounted Box Transformers" marks a significant milestone. By integrating the step-up transformer into the rear of the nacelle, the method eliminates the need for 35 armored cables and reduces reliance on ground-mounted transformer foundations, thereby cutting the construction cost of a single wind turbine by 110,000 yuan. This design also streamlines the internal cabling within the tower to just one power cable, shortening the electrical installation time from three days to a single day. Additionally, it mitigates operational risks such as blade icing and flooding, offering a practical solution for challenging scenarios like offshore wind farms and high-altitude wind projects.

II. Scenario Adaptation: Building Differentiated Technology Solutions

The regional characteristics and varying energy consumption demands of new energy projects have given rise to diverse technical approaches for modular substations. In the Yangtze River Delta region, where manufacturing is highly concentrated, photovoltaic box-type substations must balance both energy efficiency improvements and space optimization. The Pengchi Hardware project adopts a dual-capacity configuration: a 2000kVA main transformer handles 80% of the production’s electricity needs, while a 500kVA auxiliary transformer steps in to meet peak load demands. Paired with a smart monitoring system that tracks 128 string circuits, this setup enables seamless switching between power generation and consumption modes within just 0.2 seconds, ensuring uninterrupted power supply to the production line. This "main-plus-auxiliary transformer + intelligent management" model allows the project to recoup its investment within 4.2 years, while also cutting annual carbon dioxide emissions by 3,800 tons.

For urban distributed PV scenarios, dedicated box-type substations for charging piles demonstrate distinct advantages. These devices feature an "integrated + modular" design, consolidating high-voltage switching, transformers, low-voltage distribution, and other functions into a standardized cabinet—reducing the footprint by 50% compared to conventional solutions. In community-based charging stations, advanced multi-channel independent control technology enables the system to automatically adjust charging power based on residents' electricity usage patterns, facilitating seamless coordination among "vehicle-home-grid." When the grid load reaches peak levels, the system intelligently reduces charging power to 30 kW; meanwhile, during off-peak nighttime hours, it boosts output up to 120 kW. This dynamic adjustment capability enhances transformer utilization by as much as 40%.

III. System Breakthrough: Unlocking the Key Bottleneck in New Energy Integration

The high integration of new energy power sources places greater demands on the regulation capabilities of packaged substations. The growing popularity of box-type energy-storage substations marks a new stage in technological advancement. These devices incorporate energy storage systems into their conventional structures, creating a closed-loop "generation-storage-discharge" system. In a pilot project at the Jiuquan Wind Power Base in Gansu Province, a 2MWh energy-storage-equipped packaged substation was deployed. By leveraging intelligent algorithms to predict wind power output curves, the substation can store excess energy during periods of overproduction and release it when generation falls short, effectively reducing the curtailment rate from 12% to 3%. Additionally, by participating in grid frequency modulation services, the substation generates extra revenue.

More notably, there’s the innovative "integrated solar-storage-charging" model. In a Shenzhen industrial park, an intelligent box-type substation has been deployed, featuring monocrystalline silicon photovoltaic panels installed on its roof and lithium iron phosphate battery packs fitted along its sides—creating a microgrid system that operates on the principles of "self-generation for self-use, surplus power fed back to the grid, and energy storage for grid regulation." This system leverages an advanced Energy Management System (EMS) to achieve triple optimization: solar power is first prioritized for charging stations, with any excess energy stored in the battery pack. Once the battery reaches 80% capacity, the remaining electricity is sold back to the grid. As a result, the park has slashed its electricity costs by 35%, while simultaneously easing the burden on the grid during peak-demand periods.

IV. Future Outlook: The Directions of Intelligent and Platform-Based Development

With the penetration of technologies such as digital twins and artificial intelligence, box-type substations are evolving into "smart energy terminals." The State Grid's 2025 Technology Roadmap clearly outlines that the next-generation box-type substations will feature three core capabilities: first, comprehensive equipment condition sensing, achieved by deploying over 500 sensors to enable real-time monitoring of parameters like temperature, partial discharge, and mechanical characteristics; second, precise fault prediction, leveraging deep learning algorithms to model historical data and provide early warnings of equipment defects up to 72 hours in advance; and third, intelligent operation and maintenance decision-making, using digital twin technology to simulate the effectiveness of various O&M strategies, thereby optimizing maintenance cycles and resource allocation.

In terms of platformization, box-type substations are transitioning from standalone devices to becoming nodes within the energy internet. A pilot project by the Southern Power Grid demonstrates that integrating 5G communication modules and edge computing units into these substations enables real-time interaction with distributed photovoltaic systems, electric vehicles, and energy storage systems. When regional electricity demand surges unexpectedly, the system automatically aggregates nearby adjustable resources, effectively creating a virtual power plant that can participate in electricity market transactions. This transformation not only enhances the ability to integrate and consume new energy sources but also fosters innovative business models and a vibrant new value-chain ecosystem.

From the Gobi wind farms to rooftop photovoltaics in urban areas, and from coastal tidal flats to industrial parks, the technological evolution of modular substations reflects China's profound transformation in its new energy industry—from sheer scale expansion toward a focus on quality enhancement. As each modular substation becomes a vital nerve ending of the smart grid, and as every unit of green electricity carries the intelligent DNA of digital technology, new energy

Key words:

Smart City Development: The Path to Intelligent Upgrading of Ring Main Unit Switchgear

Industrial Power Distribution Equipment Selection: Energy-Saving Optimization Solutions for High-Energy-Consuming Factories

Hunan Chengyuan Electrical CO.,LTD

Application of Box-Type Substations in New Energy (Photovoltaic/Wind Power) Projects