1．In the context of power systems, transformers serve as core components; consequently, their long-term, reliable operation is critical to the overall stability and reliability of the entire system.

2．Currently, DC resistance testing and turns ratio/vector group testing are mandatory procedures during the scheduled outage maintenance of distribution transformers. To perform these inspections and operations, it typically requires the separate deployment of a dedicated DC resistance tester and a dedicated turns ratio/vector group tester, necessitating the transport of two distinct instruments to the site for every testing session. Since these are two independent units—each equipped with its own set of specialized test leads—the testing process must be conducted in separate stages, involving frequent reconfiguration of the wiring connections. This results in a significant waste of manpower, material resources, and working hours.

3．Our "Two-in-One" Distribution Transformer Testing System (combining DC Resistance and Turns Ratio/Vector Group testing)—powered by a high-capacity lithium battery—streamlines this process. With just a single device, users can complete both sets of tests without the need for frequent disconnection and reconnection of test leads.

①　With a single connection, the device can perform both DC resistance and turns ratio tests.

②　DC Resistance Testing Function: Supports automatic three-phase testing for Yn, Y, and Δ-type windings, and calculates the three-phase unbalance rate. With a maximum output current of 20A, it is capable of accurately measuring the extremely low resistance values found in the low-voltage coils of distribution transformers.

③　Turns Ratio Testing Function: Features testing capabilities for three-phase, single-phase, and Z-type transformers; includes PT/CT ratio and polarity testing functions, as well as a "blind test" function.

④　Equipped with multiple wired and wireless communication interfaces to facilitate convenient expansion of the instrument's capabilities.

⑤　The instrument runs on an embedded Linux operating system, offering superior security, operational fluidity, and user-friendliness.

⑥　The instrument utilizes an A7+M4 dual-core architecture, ensuring both real-time measurement accuracy and smooth operational performance.

⑦　Features an industrial-grade 7-inch large-screen display with a clean, minimalist design style, creating a comfortable and convenient human-machine interaction experience.

⑧　The instrument is powered by a high-capacity lithium battery with a built-in charger.