For a long time, the customization of switchgear has suffered from a common industry-wide problem: even slight variations in project requirements necessitate redrawing schematics, modifying molds, and debugging production-resulting in long lead times, high costs, and poor versatility, as well as a proliferation of non-standard equipment and cumbersome after-sales maintenance. With the standardization of power distribution equipment and the evolution of modularization technology, the design barriers of traditional monolithic switchgear have been completely broken down, ushering in a new
"Lego-style" assembly model for the industry. By breaking down complex cabinet structures, electrical circuits, and protective functions into standardized, universal modules-and freely combining them to adapt to different operational conditions-customized power distribution solutions have become simple and efficient. All types of switchgear can be adapted to this modular retrofitting logic. Among them, 24 kV switchgear-the mainstay of industrial and mining distribution networks-and highly versatile air-insulated switchgear (AIS) are currently the two most mature categories for modular implementation, completely revolutionizing the traditional design and delivery models of switchgear.
Many customers have a core question: After breaking down switchgear into standard functional blocks, can non-specialists independently assemble their own customized solutions? The answer is: While standardized modules can be freely combined, professional power distribution solutions require the support of standardized logic. This article will break down the design logic, module classification, and adaptation advantages of "Lego-style" modular switchgear. By integrating the adaptation characteristics of various switchgear types, it will provide a detailed explanation of the modular implementation scenarios for 24 kV switchgear and air-insulated switchgear (AIS), thereby addressing the core questions surrounding modular customization in the industry.
I. Pain Points of Traditional Switchgear: Customization = Redesigning the Entire Process
Before the widespread adoption of modular technology, switchgear relied on monolithic, custom designs. Since each project had different load parameters, installation environments, and functional requirements, the cabinet dimensions, circuit layout, protection configurations, and secondary logic all required tailored modifications. This non-standard design approach resulted in extremely poor equipment versatility; components from different projects or batches were not interchangeable. Consequently, in the event of equipment failure, procuring spare parts was difficult and time-consuming.
At the same time, the design systems for different types of switchgear were independent of one another, making it impossible to share or reuse components. Traditional 24 kV switchgear typically featured a monolithic armored structure, requiring the entire unit to be disassembled or even replaced for capacity expansion, retrofitting, or functional upgrades. Conventional air-insulated switchgear (AIS) had a fragmented structure; after non-standard modifications, issues such as reduced protection levels and logic mismatches were highly likely to occur, significantly increasing project retrofitting and O&M costs. Under the traditional model, customized solutions rely heavily on the manufacturer's technical team, leaving customers with no ability to participate independently and resulting in extremely low flexibility.
II. The Core Logic of "Lego-Style" Modularization: Decomposing Complex Equipment into Standardized Functional Units
The essence of "Lego-style" modularization for switchgear lies in eliminating non-standardization, standardizing decomposition, and enabling universal assembly. The technical team breaks down the entire switchgear system into six standard functional blocks: busbar modules, circuit breaker operating modules, insulation protection modules, secondary control modules, environmental monitoring modules, and feeder modules. All modules feature uniform dimensions, standardized interfaces, and consistent wiring logic, allowing them to be freely disassembled, arbitrarily combined, and stacked as needed-much like LEGO bricks.
This modular design offers exceptional equipment compatibility and can be adapted to the retrofitting and upgrading of mainstream switchgear types on the market. For 24 kV switchgear used in medium-voltage power distribution scenarios, the modular design separates the high-voltage busbar, switching mechanisms, and protection systems into independent blocks. Modules can be freely added or removed based on load levels and the number of circuits to accommodate plant expansion and load upgrade requirements. For air-insulated switchgear (AIS) used in general applications, the insulation modules, ventilation and heat dissipation modules, and operating modules are standardized, allowing for flexible configuration of protective and functional components based on the installation environment and O&M requirements.
III. Can Customers Independently Assemble Customized Solutions? Practical Limits and Rules
Let's return to the core question: Once standardized functional blocks are in place, can customers independently assemble their own customized switchgear solutions? From a practical perspective, basic configurations can be assembled independently, while complex configurations require professional verification. This means assembly is not entirely barrier-free, nor is it entirely dependent on the manufacturer.
In standard power distribution scenarios, standardized modules feature fixed parameters, universal interfaces, and clearly defined functions. Customers can independently combine feeder modules, monitoring modules, and protection modules based on their load requirements, installation space, and functional needs to quickly build a basic customized solution. Whether it's a 24 kV switchgear undergoing capacity expansion or routine maintenance of air-insulated switchgear (AIS), the assembly logic for standardized modules is simple and intuitive. Basic solution configurations can be completed without requiring in-depth electrical design expertise.
However, in extreme operating conditions-such as high temperatures, extreme cold, strong seismic activity, or high corrosion-as well as in complex scenarios involving multi-circuit interlocking and multi-level protection coordination, simple "Lego-style" assembly alone cannot meet safety standards. A professional technical team is required to verify module parameter compatibility, insulation coordination, protection logic interlocking, and system compatibility to avoid electrical hazards caused by improper module combinations. This is also the core limitation of modular applications for various types of switchgear: simplifying the customization process without compromising safety standards.
IV. Core Advantages of Modular Switchgear: Cost Reduction, Faster Implementation, and Ease of Operation and Maintenance
Compared to traditional, non-standard, monolithic switchgear, the advantages of the "Lego-style" modular design extend across the entire lifecycle of the equipment-from design and production to installation, operation, maintenance, and retrofitting-completely resolving the industry's customization challenges.
First, delivery cycles are significantly shortened. Standard modules can be prefabricated in bulk and kept in stock, eliminating the need for custom tooling. Once the customer finalizes the solution, assembly and production can begin quickly, reducing delivery cycles by more than 50%. Second, retrofitting and capacity expansion incur zero waste costs. When upgrading plant capacity or expanding circuits later on, there is no need to replace the entire cabinet; simply add or remove the corresponding functional modules to accommodate medium- to long-term load upgrade requirements for 24 kV switchgear.
At the same time, operational and maintenance convenience is greatly enhanced. Faulty modules can be removed and replaced individually without disassembling the entire unit, and with 100% parts interchangeability, the problem of scarce spare parts for non-standard equipment is completely resolved. For commonly used equipment such as air-insulated switchgear (AIS), modular replacement enables maintenance without downtime, greatly enhancing the stability of the power distribution system. Furthermore, standardized modules simplify equipment iteration and technical upgrades across various types of switchgear; there is no need to reconstruct the overall structure-upgrades can be completed by simply iterating a single functional module.
Conclusion
The "Lego-style" modular transformation of switchgear represents an inevitable trend in the evolution of power distribution equipment from non-standard customization toward standardization and intelligence. It addresses industry pain points such as rigid traditional equipment design, high retrofitting costs, and difficult operation and maintenance, making switchgear customization more streamlined, flexible, and versatile. The modular upgrades of mainstream 24 kV switchgear, general-purpose air-insulated switchgear (AIS), and all other types of switchgear not only give customers the freedom to configure their own solutions and customize them as needed, but also ensure the safe operation of power distribution systems, providing a new technological pathway for improving the quality and efficiency of industrial power distribution and enabling flexible upgrades.
About us
Established in 2018, Zhejiang Lvma Electric Co., Ltd. leverages 17 years of hands-on electrical engineering expertise. As an ISO 9001:2015-certified enterprise, our main product lines include advanced switchgear systems and both oil-immersed and dry-type distribution transformers, exported widely to Europe, the Middle East, South America, Southeast Asia, and Africa.
Our R&D team possesses more than 40 patents, empowering us to pioneer intelligent and sustainable power infrastructure. Through digital manufacturing and continuous condition monitoring, we guarantee stable performance and uncompromising safety in every unit.