Six-phase intelligent substation electronic transformer integrated mu relay protection tester

Product DescriptionDescriptionMU(Merging Unit) is one of important devices used in smart substation, which is directly related to the safe operation of power grid. MU Test System DCU-500 can test Merging Unit comprehensively and systematically, which is applicable to various types of merging units, such as traditional instr

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Product Description

MU(Merging Unit) is one of important devices used in smart substation, which is directly related to the safe operation of power grid. 

MU Test System DCU-500 can test Merging Unit comprehensively and systematically, which is applicable to various types of merging units, such as traditional instrument transformers input type, electric instrument transformers input type, mixed input type etc.


Main Features
Full Test Functions: the tester can test ratio error, phase angle error, harmonic accuracy analysis, message time characteristics, packet loss rate, signal analysis, current/voltage phase verification and transient characteristic verification of merging unit. 

Multiple Test Objects: except merging unit test, the tester also can test traditional protection relays and intelligent protection devices based on IEC61850. 

Dual Operation Mode: embedded IPC is adopted for MU Test System. It can be used to do tests without external PC, also can be connected to external PC to do tests via PC. 

Unique Ethernet interface for Monitoring: 1 channel G-net interface (1000M net) output function with monitoring input and output data during testing, to realize digital multi-meter function via connecting G-net interface and PC. 

Various Standard Message: provide various standard messages which comply with IEC61850-9-1/9-2, GOOSE, IEC60044-7/8 FT3. 

Network Analyzer Function: grab IEC 61850 or FT3 packet, display data waveform, synchronization, total message count, message loss count, message disordering statistics etc., and simulate frame loss and unreadable code during the output. 

Completed Analysis Protection Modular Document: realize current/voltage channel selection, ratio coefficient, ASDU number, sampling rate, GOOSE message etc. configure, easy to connect all kinds of protection. 

Integrated High-precision Signal Source Inside: the integrated high-precision signal source is embedded into MU Tester, so don't need external signal source. MU Tester can complete MU tests independently, also is suitable for closed-loop automatic test. 


Perfect Self-check and Prompt: the system can run stably for a long time. Considering all possible test abnormal conditions, it can detect abnormal condition timely and send an alarm to alert. 

Precise Time Synchronization Performance: time synchronization performance is directly related to testing accuracy of amplitude, frequency and phase. CPU+FPGA framework is adopted for MU Tester, which can ensure precise time synchronization performance. 

Powerful Digital Fault Simulation Function: it can simulate the various messages abnormity in smart substation, such as SV frame loss, disordering, quality abnormity, synchronization abnormity, jitter, wrong values, GOOSE timeout, GOOSE chain scission, network storm etc.. 

Waveform Display and Waveform Record: display and record voltage/current waveform output by device and merging unit, and detect conformity and bit error rate of message. 

Punctual Function: the tester can trace and test message time drifting caused by PPS loss of MU, and monitor synchronization changes. 

Auto Test: users can set each check point before test, the tester will boost voltage/current automatically, then test at corresponding check point, and then save test result.


Technical Data
Ethernet Communication Interfaces


100/1000Base-Tx(100/1000Mbit, Twisted-Pair, Auto-Crossover)

Number Of Port


Type Of Interface


Status Indicator

LED Indicator(Green Light): Effective Link, LED Indicator(Yellow Light Flickers): Data Exchange


Optical Fiber Communication Interfaces


100Base-Fx(100Mbit, Optical Fiber, Full Duplex)

Number Of Port

8 Pairs

Type Of Interface


Fiber Type

62.5/125µm (Multi-Mode Fiber)



Status Indicator

LED Indicator(Red Light): Effective Link, LED Indicator(Red Light Flickers): Data Exchange


FT3 Interfaces

Number Of Port

9 (8 For Transmitter, 1 For Receiver)

Type Of Interface


Fiber Type

62.5/125µm (Multi-Mode Fiber)




Analog U/I Output

AC Current Output

Range: 6-Phase(L-N) 6x0…15A, Power: 6-Phase(L-N) 6x150VA@15A

AC Voltage Output

Range: 6-Phase(L-N) 6x0…120V, Power: 6-Phase(L-N) 6x80VA@120V

AC Output Accuracy

≤0.05%( Within Main Range)

DC Voltage Output

Range: 6-Phase(L-N) 6x0…±160V, Power: 6-Phase(L-N) 6x80VA@160V

DC Current Output

Range: 6-Phase(L-N):6x0…±10A, Power: 6-Phase(L-N) 6x120VA@10A

DC Output Accuracy

≤0.1%( Within Main Range)


Range: 0~360°, Accuracy:0.1°, Resolution: 0.01°


Superposition Order 0~13 Times, Distortion: ≤0.5%


Range: 0~650Hz, Accuracy:<1mHz(0~65Hz), <10mHz(65~450Hz), <20mHz(450~1600Hz), Resolution: 0.001Hz,


Binary Inputs




Potential-Free Contact Or Idle Contact (Automatic Identification)


Binary Outputs



Break Capacity

AC250V/0.2A, DC250V/0.5A


Power Supply

Nominal Input Voltage

Customized (AC 220V/230V/110V/120V±10%, 1-Phase)

Nominal Frequency

50/60 Hz

Rated Current

10A At 230V / 12A At 115V


Standard AC Socket (IEC 60320)


Environmental Conditions

Operation Temperature

0 ... +50 °C (+32 ... +122 °F)

Storage Temperature

-25 ... +70 °C (-13 ... +158 °F)

Humidity Range

Relative Humidity 5 ... 95 %, Non-Condensing


IEC 60068-2-6(20m/S2 At 10 ... 150 Hz)




21kg(46.30 Lb)

Dimensions (W X H X D, Without Handle)

378×260×100mm(15.94x7.28x11.81 In)


Safety Standards, Electromagnetic Compatibility


The Product Adheres To The Electromagnetic Compatibility (EMC) Directive 2004/108/EC(CE Conform).

IEC 61326-1; IEC 61000-6-4; IEC 61000-3-2/3


The Product Adheres To The Low Voltage Directive 2006/95/EC(CE Conform).

IEC 61010-1


MU Test System DCU-500 can output analog signal, SV message, GOOSE message, FT3 message to merging unit as standard channels, and acquire these standard channels inside. The tested Merging Unit receives standard channel output simultaneously, after processing it will be sent to Tester via SV or FT3 mode. MU Tester will compare tested channel and standard channel, then get amplitude, frequency and phase error of Merging Unit automatically. The main test modules are as following: 

Ratio Error & Phase Displacement Error Test:
Harmonic Accuracy Test
Time & Message Characteristic Test
SV Fault Test
GOOSE Edit Test

Company Profile

Six-Phase Smart Substation Electronic Transformer Comprehensive Mu Relay Protection TesterSix-Phase Smart Substation Electronic Transformer Comprehensive Mu Relay Protection TesterSix-Phase Smart Substation Electronic Transformer Comprehensive Mu Relay Protection Tester 
HAOMAI ELECTRIC POWER AUTOMATION is established in 1999 and located in Wuhan of China, which is specialized in developing and manufacturing electrical power test and measurement instruments. HAOMAI products are widely used in power grid, petrochemical, metallurgy, railway, coal mine, research institutes and all kinds of large-scale factories or enterprises.mainly focuses on the sales and services of Protection Relay Test System, CT/PT Analyzer, Battery Load Tester, Transformer Testing Equipment, Circuit Breaker Analyzer, Partial Discharge Detector etc. electrical power test and measurement instruments.
HAOMAI follows total quality criteria, and always maintains standardized process and procedures for continuous growth. HAOMAI has been certified by ISO 9001:2015, ISO 14001:2015 and OHSAS 18001:2007.
HAOMAI builds own RELAYSTAR laboratory and performance test laboratory, and possesses professional production equipment and testing instruments in factory, such as Agilent 34401A 6 1/2 High-precision Meter, FLUKE Multi-meter, EMH Standard Meter, CLOU Standard Power Source, Oscilloscope, Phase Meter, Insulation Test System, High Voltage Dividers, AC High Voltage Generator, Time Calibration Tester, Standard Micro-resistance etc.
HAOMAI is China well-known mark recognized and approved by State Administration for Industry & Commerce of People's Republic of China, and enjoys high reputation in domestic and foreign markets.
HAOMAI now is the key supplier for SGCC(State Grid Corporation of China) and CSG(China Southern Power Grid). Till 2018 HAOMAI products have been sold to 34 different countries. 
HAOMAI always sticks to the faith of "cooperation and sharing", takes the "technology and market" as the direction, "creation and innovation" as the soul, listens to clients carefully, and improves the technology, upgrades the products, optimizes the service and tries all to be the global leader in electrical power test and measurement instruments field.

Our Advantages

Six-Phase Smart Substation Electronic Transformer Comprehensive Mu Relay Protection Tester

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