Capable of verifying various types of relays and microprocessor-based protection systems, as well as simulating a wide range of complex transient, permanent, and evolving faults for comprehensive system testing.

Intelligent main unit; supports standalone, independent operation.

Large-screen LCD display with an intuitive, user-friendly interface.

Features an independent, dedicated DC power supply output.

The LDJB-702B Microcomputer-based Relay Protection Tester is capable of verifying various types of relays—including current, voltage, inverse-time, directional power, impedance, differential, low-cycle, synchronization, frequency, DC, auxiliary, and time relays—as well as microcomputer-based protection systems. Furthermore, it can simulate a wide range of complex transient, permanent, and evolving faults to facilitate comprehensive system-level testing.

Product Aliases: Microcomputer-based Relay Protection Tester, Relay Protection Tester, Microcomputer-based Relay Protection Verifier

Product Features

Intelligent Main Unit:The main unit employs a high-speed, high-performance Digital Signal Processor (DSP). It features rapid processing speeds and a wide transmission bandwidth; via software, it utilizes double-precision algorithms to generate highly accurate, arbitrary waveforms for each phase. Thanks to its integrated structural design, all internal components are tightly coupled—minimizing data transmission distances—resulting in a highly compact and robust unit.

Standalone Operation:The device is operated via a large-screen LCD interface, controlled by a convenient and flexible "rotary mouse." The entire interface features full Chinese-language display. It is capable of performing the majority of on-site testing and verification tasks. It can verify various types of relays (including current, voltage, inverse-time, directional power, impedance, differential, low-cycle, synchronization, frequency, DC, auxiliary, and time relays) as well as microprocessor-based protection systems. Furthermore, it can simulate various complex transient, permanent, and evolving faults to conduct comprehensive system-wide testing.

Powerful Software Functionality:The device is capable of executing large-scale, complex verification tasks with a high degree of automation—such as differential protection testing, automatic transfer switching (ATS) testing, and line protection synchronization/reclosing verification. It allows for the convenient testing and scanning of various protection settings, real-time storage of test data, and the display of vector diagrams, among other functions.

Large-Screen LCD Display:The unit features a large, high-resolution graphical LCD display. All operational parameters are configured directly on the screen; both the user interface and test results are displayed in Chinese, offering a clear and intuitive visual experience.

"Foolproof" Operation: The device utilizes a new generation of advanced controllers—the "rotary mouse"—which incorporates multiple shortcut keys. This design significantly simplifies the operational structure, making the device easy, fast, and intuitive to operate—even for novices.

New High-Fidelity Power Amplifier: The output stage employs a new type of high-power, modular, high-fidelity amplifier component. It is capable of functioning as both a current source and a voltage source, delivering high output power with excellent accuracy and high reliability.

Direct Current and Voltage Output:The phase voltage and phase current outputs utilize a DC-coupled amplifier architecture. This allows for the direct output of AC voltage, AC current, DC voltage, and DC current. Furthermore, the angle and frequency can be adjusted, and harmonics ranging from the 1st to the 20th order can be superimposed onto the output signals.

Self-Protection Mechanisms:The device features a rationally designed heat dissipation structure, along with a comprehensive suite of reliable protection measures—including power supply "soft-start" functionality—as well as built-in fault self-diagnosis and interlocking capabilities.

Independent Dedicated DC Power Output:The unit is equipped with a dedicated, independent DC power output channel, providing a choice of either 110V or 220V DC supply. **Abundant Contact Points:** Features 8 contact inputs and 4 dry contact outputs. The input contacts support a dual-mode configuration—compatible with both dry contacts and 0–250V potential contacts—and are capable of intelligent automatic recognition.

Integrated Standalone Structure:** The main unit features a fully integrated, standalone design and operates on a standard AC 220V power supply. Its compact size, lightweight construction, and portability make it ideal for convenient field testing and mobile applications.

High Cost-Effectiveness:This product represents a collaborative, multi-disciplinary design effort, incorporating advanced technological achievements from various specialized fields. It combines the high-performance capabilities typically found in large-scale testing equipment with the affordable pricing of compact testers, offering an exceptional price-performance ratio.