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Series Resonance Test Device

LHV-270kVA/108kV High Voltage Resonant Test System for Cable & Transformer Testing

Professional 270kVA/108kV resonant test system for large capacity cable (up to 3km) and transformer testing. Complies with GB 50150-2016 standards, features DSP technology and multi-protection functions.


  • US$1.00; Negotiated Price
  • Lead time: 90days

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Product Details

Product Tags

LHV-270kVA/108kV High Voltage Resonant Test System

Product Overview

The LHV-270kVA/108kV Resonant Test System delivers industry-leading capacity for high-voltage cable and transformer testing. Engineered for field use with DSP-controlled precision, this system meets strict Chinese standards including GB 50150-2016 and DL/T 849.6-2016 for preventive maintenance testing.

Key Advantages:

  • 270kVA/108kV maximum output

  • 3km cable testing capacity (10kV/300mm²)

  • 1/Q power efficiency (up to 90% energy saving)

  • DSP-based automatic frequency sweep (30-300Hz)

  • Modular design for field deployment

Technical Specifications

ParameterSpecification
Rated Capacity270kVA
Output Voltage0-108kV AC
Frequency Range30-300Hz (45-65Hz optimized)
Waveform DistortionTHD ≤3%
Protection ClassIP54 (field environment)

Standard Test Applications

1. Cable Testing Solutions

Cable TypeLengthCapacitanceTest VoltageDuration
10kV/300mm²3km≤1.1265μF22kV5min
35kV/300mm²1km≤0.1945μF52kV60min

2. Electrical Equipment Testing

EquipmentCapacitanceTest VoltageDuration
35kV/31500kVA Transformer≤0.02μF68kV1min
35kV Switchgear-≤95kV1min

Advanced Protection System

Overvoltage Protection

Automatic shutdown at 110% rated voltage with <1ms response

Flashover Management

Records breakdown voltage while limiting current to 1/Q value

Zero-start Interlock

Prevents improper energization sequences

System Detuning

Instant response to resonance condition changes

DSP Control Platform Features

  • Automatic Frequency Sweep: Bidirectional scanning with visual resonance curve display

  • Three Operation Modes: Full-auto, semi-auto, and manual control

  • Data Management: Stores 1000+ test records with digital timestamps

  • Upgradable Firmware: Field-update capability for future enhancements

Field Efficiency Advantages

MetricLHV-270 SystemConventional Test Sets
Power Consumption≈30kW≈300kW
Total Weight≈1200kg≈5000kg
Crew Required2-3 technicians5-6 technicians

Compliance Standards

  • GB 50150-2016: Electrical equipment installation engineering handover standards

  • DL/T 849.6-2016: Technical conditions for resonant test devices

  • DL/T 474.4-2018: Preventive test procedures for power equipment

Main components of the device

Serial numberDevice nameSpecification and modelUnitQuantity
1Variable frequency power supplyLHV-15kWTower1
2Excitation transformerLHV-4kVA/1.5/3/6kV/0.4kVTower1
3High voltage reactorLHV-67.5kVA/27kVSection4
4Capacitive voltage dividerLHV-1500pF/110kVSet1

Main Functions and Features

UHV-135kVA/108kV series resonance scheme, using the way to adjust the frequency of the power supply, so that the reactor and the tested capacitor achieve resonance, so as to obtain high voltage and high current on the test product, because of its small power supply required, light weight and small volume of the equipment, has been widely praised and applied at home and abroad, is the current high voltage test of the new method and trend.

The main functions and technical characteristics of the frequency-modulation resonance device of our company:

1, the device has overvoltage, overcurrent, zero start, system mismatch (flashover) and other protection functions, overvoltage and overcurrent protection value can be adjusted according to user needs, flashover protection action when the test product flashover and can record the flashover voltage value for test analysis.

2, the whole device single weight is very light, easy to use on site.

3, the device has three working modes: automatic mode, manual mode, automatic tuning manual boost mode; Convenient for users to flexibly choose according to the field situation, improve the test speed.

4, can store and remote print data, stored data number is a number, easy for users to identify and find.

5, when the device automatically sweeps the frequency starting point can be arbitrarily set within the specified range, the scanning direction can be selected up and down, and the LCD large screen displays the scanning curve, which is convenient for users to intuitively understand whether to find the resonance point.

6, the use of DSP platform technology, according to user needs to increase or decrease the function and upgrade, human-machine exchange interface is more humane.

7, the required power capacity is greatly reduced. Series resonant power supply is the use of resonant reactor and the test product capacitor resonance to produce high voltage and high current, in the whole system, the power supply only needs to provide the active power consumption of the system, so the power required for the test is only 1/Q of the test capacity.

8, the weight and volume of the equipment are greatly reduced. In the series resonant device, the bulky high-power voltage regulator and the ordinary high-power power frequency test transformer are omitted, and the resonant excitation power supply only needs 1/Q of the test capacity, which greatly reduces the weight and volume of the system, generally 1/10-1/30 of the ordinary test device.

9, effectively improve the output voltage waveform. The resonant power supply is a resonant filter circuit, which can improve the waveform distortion of the output voltage, obtain a good sinusoidal waveform, and effectively prevent the harmonic peak to the test product.

10, prevent large short circuit current burn fault point. In the series resonance state, when the insulation weakness of the test product is broken down, the circuit is immediately detuned, the loop current rapidly drops to 1/Q of the normal test current, and when the parallel resonance or test transformer is used for voltage resistance test, the breakdown current immediately rises dozens of times, compared with the two, the short circuit current and the breakdown current are hundreds of times different. The series resonance can effectively find the insulation weakness, and there is no large short-circuit current burn fault point worry.

11, No recovery overvoltage will occur. When the test product breaks down, due to the loss of resonance conditions, the high voltage also immediately disappears, the arc is immediately extinguished, and the re-establishment process of the recovery voltage is very long, it is easy to disconnect the power supply before reaching the flashover voltage again, the recovery process of this voltage is a kind of intermittent oscillation process of energy accumulation, its process is long, and there will be no recovery overvoltage.

Main technical parameters and functions

Rated capacity270kVA
Rated voltage27kV;54kV;108kV
Rated current10A;5A;2.5A
Measurement accuracySystem RMS level 1.5
Operating frequency30-300Hz
Device output waveformSinusoidal wave
Quality factorDevice Q≥30(f=45Hz)
Waveform distortion rateOutput voltage waveform distortion ≤1%
Input power supplySingle-phase 220 or three-phase 380V voltage, frequency 50Hz
Working hoursAllow continuous 60min under rated load; Overpressure 1.1 times 1 minute
Temperature riseTemperature rise ≤65K after continuous operation under rated load for 60 minutes
Protection functionOvervoltage, overcurrent, zero start, system mismatch (flashover) and other protection functions
Ambient temperature-20℃-55℃
Relative humidity≤90%RH
Altitude≤3000m

Device capacity verification (device capacity is set at 135kVA, divided into four reactors, reactor single section is 33.75kVA/27kV/1.25A/100H)

Serial numberTestTest FrequencyTest Current
110kV/300mm² cable 3km AC voltage withstand test, capacitance ≤1.1265μF, test frequency 30-300Hz, test voltage 22kV, test time 5min. Use four reactors in parallel, L=100/4=25Hf=1/2π√(LC)=1/(2×3.14×√(25×1.1265×10⁻⁶))=30HzI=2πfCU=2π×30×1.1265×10⁻⁶×22×10³=4.67A
235kV/300mm² cable 1km AC voltage withstand test, capacitance ≤0.1945μF, test frequency 30-300Hz, test voltage 52kV, test time 60min. Use two reactors in series (mutual inductance coefficient 1.15) two groups in parallel, L=100×2×1.15/2=115Hf=1/2π√(LC)=1/(2×3.14×√(115×0.1945×10⁶))=33.65HzI=2πfCU=2π×33.65×0.1945×10⁻⁶×52×10³=2.14A
3Ac voltage withstand test of 35kV/31500kVA main transformer, capacitance ≤0.02μF, test frequency 45-65Hz, test voltage 68kV, test time 1min. Use four reactors in series (mutual inductance coefficient 1.25), L=100×4×1.25=500Hf=1/2π√(LC)=1/(2×3.14×√(500×0.02×10⁻⁶))=50.33HzI=2πfCU=2π×50.33×0.02×10⁻⁶×68×10³=0.43A

Equipment combination method during testing

Test Object
Combination Method

Reactor Selection
(33.75kVA/27kV Four Sections)
Excitation Transformer
Output Selection
Test Voltage
(kV)
10kV/300mm2
Cable 3km
Use four reactors in parallel1.5kV≤22kV
10kV switch and other substation equipmentUse three reactors in series3kV≤42kV
35kV/300mm2
Cable 1km
Use two reactors in series and two groups in parallel3kV≤52kV
35kV/31500kVA main transformerUse four reactors in series6kV≤68kV
35kV switch and other electrical equipmentUse four reactors in series6kV≤95kV

System Configuration Parameters

(一) Variable Frequency Power Supply UHV-15kW (1 unit)

Rated Output Capacity15kW
Power Supply220/380±10%V (Single/Three Phase), Power Frequency
Output Voltage0-400V
Rated Input Current37.5A
Rated Output Current37.5A
Voltage Resolution0.01kV
Voltage Measurement Accuracy1.5%
Frequency Adjustment Range30-300Hz
Frequency Adjustment Resolution≤0.1Hz
Frequency Stability0.1%
Operating TimeContinuous 60min at Rated Capacity
Maximum Component Temperature at Continuous 60min Operation at Rated Capacity≤65K
Noise Level≤50dB
Dimensions (L×W×H mm)460×340×420
WeightApproximately 15kg

(二) Excitation Transformer UHV-15kVA/1.5/3/6kV/0.4kV (1 unit)

Rated Capacity15kVA
Input Voltage0-400V
Output Voltage1.5/3/6kV
StructureDry Type
Dimensions (L×W×H mm)520×520×460
WeightApproximately 85kg

(三) High Voltage Reactor UHV-67.5kVA/27kV (4 units)

Rated Capacity67.5kVA
Rated Voltage27kV
Rated Current2.5A
Inductance50H/unit
Quality FactorQ≥30(f=45Hz)
StructureDry Type
Dimensions (Inner Diameter×Height mm)382×435
WeightApproximately 90kg

(四) Capacitive Voltage Divider UHV-1500pF/110kV (1 set)

Rated Voltage110kV
High Voltage Capacitance1500pF
Dielectric Losstgσ≤0.5%
Voltage Division Ratio1500:1
Measurement AccuracyEffective Value 1.5 Grade
Dimensions (Inner Diameter×Height mm)140×1000
WeightApproximately 8kg

Delivery List

No.Equipment NameModel and SpecificationsUnitQuantity
1Variable Frequency Power SupplyLHV-15kWUnit1
2Excitation TransformerLHV-15kVA/1.5/3/6kV/0.4kVUnit1
3High Voltage ReactorLHV-67.5kVA/27kVSection4
4Capacitive Voltage DividerLHV-1500pF/110kVSet1
5Internal Connection Cables
Set1
6Factory Inspection Report
Copy1
7User Manual
Copy1
8Product Certificate
Copy1
9Packing List
Copy1

Reference Test Standards

DL/T 596-1996"Preventive Test Code for Electric Power Equipment"
GB50150-2016"Standard for Handover Testing of Electrical Equipment in Electrical Installation Engineering"
GB10229-88"Reactors"
GB1094"Power Transformers"
GB1094.1-GB1094.6-96"Degrees of Protection Provided by Enclosures"
GB2900"Electrotechnical Terminology"
GB/T16927.1~2-1997"High Voltage Test Techniques"
DL/T474.4-2006"Guide for Insulation Test Implementation on Site - AC Withstand Voltage Test"
DL/T1015"Guide for the Use of Voltage Measurement Systems for On-site DC and AC Withstand Voltage Tests"
GB/T311.1-1997"Insulation Coordination and Insulation of High Voltage Power Transmission and Transformation Equipment"
GB191-2000"Pictorial Markings for Packaging and Storage"
JB/T9641-1999"Test Transformers"
IEC358(1990)"Coupling Capacitors and Capacitor Dividers"
GB4793-1984"Safety Requirements for Electronic Measuring Instruments"
GB/T3859.2-1993"Application Guide for Semiconductor Converters"
GB/T2423.8-1995"Basic Environmental Testing Procedures for Electrical and Electronic Products"
DL/T849.6-2004"General Technical Specifications for Special Test Instruments for Power Equipment Part 6: High Voltage Frequency Tuning Test Devices"

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