Relay Protection Test
Previously, relay protection test tools mainly consisted of voltage regulators and phase shifters, which were bulky and imprecise, and could no longer meet the calibration requirements of modern microprocessor-based relay protection. With the continuous development of science and technology, microprocessor-based relay protection has been widely applied in various fields such as line protection, main transformer differential protection, and excitation control. Substation comprehensive automation has become the mainstream. Modern microprocessor-based 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 heavy. The amplifier tubes operate in the amplification region and are prone to damage over time, with a narrow dynamic range and low precision. The other type uses switching power supplies and digital power amplifiers, which are small, lightweight, and efficient, representing the development direction ofrelay protection testers. It can test various types of relays such as voltage, current, frequency, power, impedance, harmonic, differential, and synchronism relays, either manually or automatically. It can simulate various fault types for distance and zero-sequence protection device calibration and complete group tests of protection devices. It can automatically scan the ratio restraint curves of microprocessor-based and digital transformer and generator-transformer differential protection, and has GPS trigger function. The microprocessor-based relay protection test device is an important testing tool to ensure the safe and reliable operation of power systems. With the rapid development of computer technology, microelectronics, and power electronics, applying the latest technological achievements to continuously introduce new high-performance microprocessor-based relay protection test devices is an inevitable trend of technological progress. The relay protection test device is an important testing tool to ensure the safe and reliable operation of power systems. With the continuous expansion of modern power systems and the increasing requirements for reliability and efficiency in power system operation and management, the testing work of relay protection personnel has become more frequent and complex. Today, with the rapid development of computer technology, microelectronics, and power electronics, it is an inevitable trend of technological progress to apply the latest technological achievements to continuously introduce new high-performance relay protection testers, and it is also our responsibility given by the times. The relay protection tester is a new type of miniaturized microprocessor-based relay protection tester developed based on the People's Republic of China electric power industry standard "Technical Conditions for Microprocessor-based Relay Protection Test Devices" (DL/T 624 ─ 1997), fully utilizing modern advanced microelectronics technology and devices. It adopts an advanced structure that can operate independently as a single unit or connect to other computers. The host is equipped with a built-in high-performance industrial computer and high-speed digital signal processor, true 16-bit DAC modules, new modular high-fidelity high-power amplifiers, and comes with a TFT true color LCD display and embedded microcomputer keyboard. It can operate independently or connect to a laptop for operation. It has powerful functions, small size, and high precision. It not only has the superior performance and advanced functions of large testers, but also the compactness, flexibility, ease of operation, and high reliability of small testers.
1. The microprocessor-based relay protection tester meets all on-site test requirements. It has standard four-phase voltage, three-phase current output, with voltage of 125V per phase and current of 30A per phase. Three phases in parallel can reach 90A. It can test various traditional relays and protection devices, as well as various modern microprocessor-based protections. Especially for transformer differential protection and standby power supply automatic switching devices, testing is more convenient and perfect.
2. All technical indicators fully meet the standard of DL/T624-1997 "Technical Conditions for Microprocessor-based Relay Protection Test Devices" issued by the Ministry of Electric Power.
4. In the domestic industry, it is the first to adopt imported brushed stainless steel panels and stainless steel keyboards, and uses a touch mouse, overcoming the disadvantages of trackball mice that are not flexible 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 single unit convenient and durable.
5. The main control board adopts DSP+FPGA structure with 16-bit DAC output, which can generate a high-density sine wave of 2000 points per cycle for the fundamental wave, greatly improving the waveform quality and increasing the accuracy of the tester.
6. The microprocessor-based relay protection tester uses high-performance linear amplifiers with direct coupling output for current and voltage, allowing the current and voltage sources to directly output AC and DC waveforms. It can also output various combined waveforms such as square waves and superimposed harmonics through software calculation, as well as fault transient waveforms, effectively simulating the current and voltage characteristics of various short-circuit faults. The power amplifier circuit uses imported high-power high-fidelity modular power devices as 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.
