In today's rapidly developing smart substations, relay protection devices serve as the "safety guards" of the power grid, and their accuracy and reliability are directly related to the stable operation of the power system. Traditional testing tools have long faced pain points such as bulky size, narrow dynamic range, and poor protocol compatibility.
The integration application of optical digital relay protection tester and three-phase/six phase microcomputer relay protection tester is breaking this deadlock and reshaping the technical standards and workflow of the industry.
01 Noun analysis: Technological leap of the three core testing instruments
Optical digital relay protection tester
This type of equipment is a revolutionary tool designed specifically for smart substations. It uses high-performance PowerPC processors and large-scale FPGA chips, and is directly connected to the protection device through fiber optic Ethernet.
Supports IEC61850-9-1/9-2, FT3 protocol, and GOOSE communication, enabling closed-loop testing of merging units (MU), intelligent terminals, and protection devices that support the IEC61850 standard.
For example, the TPJBC-S model of Wuhan Ultra High Voltage Power Technology Co., Ltd. has built-in IEEE1588 precision network timing with an error of less than 1 microsecond, providing critical support for multi station joint debugging.
Three phase microcomputer relay protection tester
As a basic testing platform, its advantages lie in multifunctional integration and high-precision output. Typical equipment such as a 320 × 240 dot matrix LCD screen paired with a rotating mouse controller, supports 4-phase voltage (120V/phase) and 3-phase current (up to 120A when connected in triplicate) output.
The key breakthrough lies in the use of true 16 bit DAC modules and digital power amplifier technology, which enables AC current output accuracy to reach level 0.5 and can superimpose 1-20 harmonics, perfectly simulating power grid distortion conditions.
Six phase microcomputer relay protection tester
It is irreplaceable in complex protection testing. Taking LDJB-712 as an example, its 6-phase voltage+6-phase current output capability can simulate multiple circuit faults simultaneously.
For example, when testing bus differential protection, six current signals can be injected synchronously to accurately verify the protection logic. Its core lies in the DSP digital signal processor and modular linear power amplifier, achieving 1200Hz high-frequency response and 0.2ms level instantaneous fault simulation.
02 Industry Transformation: Four Dimensions of Redefining Testing Standards
Testing accuracy changes from "quantitative change" to "qualitative change"
The accuracy of traditional simulation testers is generally around level 1, while new generation equipment such as the six phase tester from Wuhan Ultra High Voltage Power Technology Co., Ltd. improves the accuracy of DC voltage output to ± 0.1% and controls harmonic distortion below 0.1%.
This has continuously broken through the error limit defined in the "DL/T 1153-2012 Calibration Specification for Relay Protection Testers", forcing the standard to be upgraded.
Protocol compatibility becomes a hard threshold
State Grid Q/GDW 11016-2013 "Regulations for Relay Protection Inspection of Intelligent Substations" clearly requires that testing equipment must support IEC61850-9-2 sampling values and GOOSE message parsing.
The optical digital tester directly decodes the MU data stream through the FT3 protocol parsing module, replacing traditional secondary conversion and avoiding signal attenuation. For example, in the merging unit test, digital signals can be directly injected to verify the sampling synchronization accuracy, with an error detection sensitivity of 0.01 °.
Significant improvement in the ability to simulate complex faults
In the debugging of new energy stations, the state sequence testing function of the six phase tester can construct composite fault scenarios including frequency fluctuations, power reversal, and harmonic superposition. When simulating a 35kV line fault in a photovoltaic power station:
First output 20ms symmetrical short-circuit current
Second stage cut in attenuation current containing 15% second harmonic
Permanent fault after triggering reclosing in three stages
The entire process automatically records the protection action time, with an error controlled within 1ms. This has exceeded the testing depth of traditional 'whole group experiments'.
Workflow Refactoring
Traditional testing requires carrying multiple devices such as relay protectors, DC high-voltage generators, and switch characteristic meters, while modern six phase testers integrate:
Adjustable DC power supply (0-300V independent output)
7-way switch quantity contact detection
GPS trigger module
Analog injection for insulation resistance testing
A single machine can complete 90% of on-site verification, increasing efficiency by over 200%. Engineers from Wuhan Ultra High Voltage Power Technology Co., Ltd. used a single device to complete the full station protection verification in three days for the Zhangbei flexible project, shortening the construction period by five days compared to traditional methods.
03 Landing scenario: Comprehensive coverage from substations to new energy
Intelligent substation full chain verification
Merge unit: Inject IEC61850-9-2 sampling values through an optical digital tester to verify synchronization accuracy and timekeeping errors
Line protection: Use a six phase tester to simulate conversion faults (such as AB phase → ABC phase grounding) and verify the distance protection action sequence
Intelligent terminal: GOOSE subscription/release test, check the transmission delay of switch trip command
Special testing for new energy stations
In the high cycle cutting machine protection test of wind farms, the six phase tester can construct:
Frequency 52Hz for 5 seconds (verify protection activated)
Overlay ± 10% voltage fluctuation (simulating wind turbine disconnection disturbance)
Output harmonic coverage 2-50 times (testing PLC logic)
Addressing pain points in the renovation of old stations
In the digital transformation of 110kV traditional stations, the FT3/GOOSE conversion module of the optical digital tester has become a key tool. For example, when integrating the electromagnetic protection of Tongling Substation into the new system:
Output analog current (0-120A) through the tester
Converted into digital signals through merging units
Verify the mapping accuracy of sampling values on the digital side
Realize lossless transition from cable wiring to fiber optic communication.
04 Selection Guide: Four dimensional indicators determine the ceiling of testing capability
Core parameter baseline
|Device Type | Output Channel | Protocol Support | Accuracy Level | Special Features|
|----------------|---------------|----------------------------|----------|-----------------------|
|Three phase tester | 4V3A | IEC60044-8 | Level 0.5 | Harmonic superposition|
|Six phase tester | 6V6A | IEC61850-9-1 | Level 0.2 | State sequence testing|
|Optical digital tester | Optical port × 4 | IEC61850-9-2/GOOSE/FT3 | Class 0.1 | IEEE1588 timing|
Selection decision tree
A [type of tested device] -->B {including merging unit/intelligent terminal? }
B -->| Yes | C [Select Optical Digital Tester]
B -->| No | D {Do you need to simulate complex faults? }
D -->| Yes | E [Select Six Phase Tester]
D -->| No | F [Select three-phase tester]
As the scale of * * ultra-high voltage power grid * * and * * new energy grid integration * * continues to expand, relay protection testing equipment is evolving towards three directions: * * "multi protocol integration" * *, * * "high dynamic response" * *, and * * "AI analysis" * *. The integrated testing platform launched by Wuhan Ultra High Voltage Power Technology Co., Ltd. has achieved:
-Automatically generate test reports that comply with * * GB/T 7261-2016 * *
-Built in * * cable fault testing * * algorithm library
-Support * * partial discharge testing * * data correlation analysis
This cross-border integration is blurring the boundary between relay protection testers and online monitoring devices, promoting a comprehensive upgrade of preventive maintenance standards. In the next three years, testers that support digital twin interfaces may redefine industry benchmarks.
Five common questions and answers on relay protection testing technology
**Q1: Can the optical digital tester be compatible with traditional electromagnetic protection devices? **
A: It can be connected to traditional devices by configuring * * analog output modules * * (such as 0~120V voltage/0~120A current), and combined with FT3 protocol converters to achieve hybrid system testing.
**Q2: What are the core advantages of a six phase tester compared to a three-phase model? **
A: In addition to differences in the number of channels, the six phase equipment has stronger * * state sequence testing capabilities * * and * * harmonic superposition depth * * (up to 50 times), making it particularly suitable for complex logic verification such as bus differential protection and main transformer differential.
**Q3: How does the tester ensure the accuracy of GOOSE message testing? **
A: It is necessary to confirm that the device supports MMS protocol parsing and message injection timing detection. It is recommended to choose a model with IEEE1588 precise timing function, and the time synchronization error should be ≤ 1 μ s.
**Why modern testers must support harmonic output? **
A: The fault current of new energy power plants contains a large amount of harmonics. For example, when testing the harmonic braking characteristics of transformer differential protection, it is necessary to inject a current containing 2-5 harmonics to verify the reliable blocking threshold of the protection.
**Q5: How to verify the accuracy of the equipment when making a purchase? **
A: Request the manufacturer to provide a calibration report issued by a provincial metrology institute, with a focus on checking whether the three key indicators of DC resistance testing, AC harmonic distortion, and time synchronization accuracy comply with the DL/T 1153-2012 standard.
