[Instrument Introduction] The relay protection tester is a new type of intelligent testing instrument. Previous relay protection test tools mainly consisted of voltage regulators and phase shifters, which were bulky, heavy, and had low accuracy, unable to meet the calibration needs of modern microcomputer-based relay protection. With the continuous development of science and technology, microcomputer-based relay protection has been widely applied in various fields such as line protection, main transformer differential protection, and excitation control. Substation integrated automation has become the mainstream. Modern relay protection testers can be divided into two types: one uses traditional OCL power amplifiers, which are large and weigh about 25kg, making them relatively bulky. The power amplifier tubes operate in the amplification region and are prone to damage over time, with a narrow dynamic range and low accuracy. The other type uses switching power supplies and digital power amplifiers, which are compact, lightweight, and efficient, representing the development direction of relay protection testers. It can test various types of relays such as voltage, current, frequency, power, impedance, harmonic, differential, and synchronizing relays, either manually or automatically. It can simulate various fault types for distance and zero-sequence protection device setting verification and complete group testing of protection devices. It can automatically scan the ratio restraint curves of microcomputer and digital transformers and generator-transformer unit differential protection, and has GPS triggering function. [Instrument Features] 1. Intelligent host: The host uses DSP chip control with 16-bit DAC output, capable of generating a high-density sine wave of 2000 points per cycle for the fundamental wave, representing the highest level among domestic testers. This greatly improves waveform quality and enhances the tester's accuracy. 2. Standalone operation: The device is operated via a rotary mouse through a large LCD screen, with full Chinese display. It can calibrate various on-site relays, protections, and safety automatic devices, and can simulate various large and complex transient, permanent, and conversion faults for complete group testing. 3. Computer connection: When connected to a computer, it can perform various large-scale, complex, and highly automated calibration tasks. It can conveniently test and scan various protection settings, store test data in real-time, display vector diagrams, plot fault waveforms, and print reports via the computer. 4. "Foolproof" operation: It uses an advanced "photoelectric rotary mouse" controller, eliminating complex keyboard operations. No computer knowledge is required to operate it; it is simple and easy to learn. 5. Modular design: All plug-ins are completely independent. 6. With six-phase current and six-phase voltage outputs, it can conveniently test backup auto-switching devices and microcomputer differential protection devices. 7. Standalone operation: It has a built-in high-performance industrial computer with a main frequency of 300-600MHz, 128M memory, 12G hard drive, running Windows XP operating system. The panel is equipped with a high-grade stainless steel keyboard, trackball mouse, and an 8.4-inch TFT true color LCD display. [Instrument Characteristics] 1. The relay protection tester meets all on-site test requirements. It has standard four-phase voltage and three-phase current outputs, with voltage of 125V per phase and current of 30A per phase. Three phases can be connected in parallel to achieve 90A. It can test both traditional relays and protection devices, as well as various modern microcomputer protections. Especially for transformer differential protection and backup auto-switching devices, testing is more convenient and perfect. 2. All technical specifications fully meet the standard DL/T624-1997 "Technical Conditions for Microcomputer-Based Relay Protection Test Devices" issued by the Ministry of Electric Power. 4. It is the first in the domestic industry to adopt imported brushed stainless steel panels and stainless steel keyboards, and uses a touch mouse, overcoming the disadvantages of trackball mice being inflexible and prone to damage. It also features an 8.4-inch TFT true color display with a resolution of 800*600, making the overall operation of the standalone device convenient and durable. 5. The main control board adopts DSPFPGA structure with 16-bit DAC output, capable of generating a high-density sine wave of 2000 points per cycle for the fundamental wave, greatly improving waveform quality and enhancing the tester's accuracy. 6. The current and voltage outputs of the relay protection tester use high-performance linear amplifiers with direct coupling output, allowing the current and voltage sources to directly output AC and DC waveforms. It can also output various waveforms such as square waves, superimposed harmonic waveforms, and fault transient waveforms through software calculation, effectively simulating current and voltage characteristics during various short-circuit faults. The power amplifier circuit uses imported high-power, high-fidelity modular power devices for the output stage, combined with carefully designed heat dissipation structures, providing sufficient power redundancy and thermal capacity. The power amplifier circuit has complete overheat, overcurrent, overvoltage, and short-circuit protection, and the current loop allows open circuit without damaging the device. [Performance Specifications] 1. Ten channels output simultaneously, i.e., three voltage and three current channels with different frequencies and phases, plus one 3U0 channel. Voltage range: 0-120V, current range: 0-40A per three phases. 2. The relay protection tester uses an 8.4-inch TFT (800*600) true color LCD display, with interface colors adjustable according to on-site lighting conditions, providing intuitive image display for easy observation. 3. The lower computer uses a streamlined and stable Windows CE embedded operating system with a Windows interface style. The application is compact, runs fast, and the system is stable with a friendly and quick interface. 4. The relay protection tester is the first in the industry to use shortcut key operation for experiments. It has an integrated design with a built-in mouse and keyboard, and can also connect external mouse and keyboard for user convenience. 5. It uses the latest American TI DSP and large-scale programmable device FPGA, with 1448-point waveform simulation, providing better transient response and amplitude-frequency characteristics. It is the only one in China to use 16-bit serial DA, further improving output accuracy. 6. It can test various types of relays such as voltage, current, frequency, power, impedance, harmonic, differential, and synchronizing relays for relay protection testers, either manually or automatically. It can simulate various fault types for distance and zero-sequence protection device setting verification and complete group testing of protection devices. It can test high-voltage line protection (single and double end testing), automatic reclosing, intermediate relays, synchronizing relays, overexcitation protection, inverse-time positive and negative sequence overcurrent protection, definite-time positive and negative sequence overcurrent protection, compound voltage blocking overcurrent protection, frequency and under-frequency load shedding protection, reverse power protection, out-of-step protection, stator ground protection, negative sequence, zero sequence, and phase-to-phase power protection, and fault replay. It has GPS triggering function. Keywords: relay protection tester