Series Resonance Test Device
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
Parameter | Specification |
---|---|
Rated Capacity | 270kVA |
Output Voltage | 0-108kV AC |
Frequency Range | 30-300Hz (45-65Hz optimized) |
Waveform Distortion | THD ≤3% |
Protection Class | IP54 (field environment) |
Standard Test Applications
1. Cable Testing Solutions
Cable Type | Length | Capacitance | Test Voltage | Duration |
---|---|---|---|---|
10kV/300mm² | 3km | ≤1.1265μF | 22kV | 5min |
35kV/300mm² | 1km | ≤0.1945μF | 52kV | 60min |
2. Electrical Equipment Testing
Equipment | Capacitance | Test Voltage | Duration |
---|---|---|---|
35kV/31500kVA Transformer | ≤0.02μF | 68kV | 1min |
35kV Switchgear | - | ≤95kV | 1min |
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
Metric | LHV-270 System | Conventional Test Sets |
---|---|---|
Power Consumption | ≈30kW | ≈300kW |
Total Weight | ≈1200kg | ≈5000kg |
Crew Required | 2-3 technicians | 5-6 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 number | Device name | Specification and model | Unit | Quantity |
1 | Variable frequency power supply | LHV-15kW | Tower | 1 |
2 | Excitation transformer | LHV-4kVA/1.5/3/6kV/0.4kV | Tower | 1 |
3 | High voltage reactor | LHV-67.5kVA/27kV | Section | 4 |
4 | Capacitive voltage divider | LHV-1500pF/110kV | Set | 1 |
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 capacity | 270kVA |
Rated voltage | 27kV;54kV;108kV |
Rated current | 10A;5A;2.5A |
Measurement accuracy | System RMS level 1.5 |
Operating frequency | 30-300Hz |
Device output waveform | Sinusoidal wave |
Quality factor | Device Q≥30(f=45Hz) |
Waveform distortion rate | Output voltage waveform distortion ≤1% |
Input power supply | Single-phase 220 or three-phase 380V voltage, frequency 50Hz |
Working hours | Allow continuous 60min under rated load; Overpressure 1.1 times 1 minute |
Temperature rise | Temperature rise ≤65K after continuous operation under rated load for 60 minutes |
Protection function | Overvoltage, 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 number | Test | Test Frequency | Test Current |
1 | 10kV/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=25H | f=1/2π√(LC)=1/(2×3.14×√(25×1.1265×10⁻⁶))=30Hz | I=2πfCU=2π×30×1.1265×10⁻⁶×22×10³=4.67A |
2 | 35kV/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=115H | f=1/2π√(LC)=1/(2×3.14×√(115×0.1945×10⁶))=33.65Hz | I=2πfCU=2π×33.65×0.1945×10⁻⁶×52×10³=2.14A |
3 | Ac 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=500H | f=1/2π√(LC)=1/(2×3.14×√(500×0.02×10⁻⁶))=50.33Hz | I=2πfCU=2π×50.33×0.02×10⁻⁶×68×10³=0.43A |
Equipment combination method during testing
Test Object | Reactor Selection (33.75kVA/27kV Four Sections) | Excitation Transformer Output Selection | Test Voltage (kV) |
10kV/300mm2 Cable 3km | Use four reactors in parallel | 1.5kV | ≤22kV |
10kV switch and other substation equipment | Use three reactors in series | 3kV | ≤42kV |
35kV/300mm2 Cable 1km | Use two reactors in series and two groups in parallel | 3kV | ≤52kV |
35kV/31500kVA main transformer | Use four reactors in series | 6kV | ≤68kV |
35kV switch and other electrical equipment | Use four reactors in series | 6kV | ≤95kV |
System Configuration Parameters
(一) Variable Frequency Power Supply UHV-15kW (1 unit)
Rated Output Capacity | 15kW |
Power Supply | 220/380±10%V (Single/Three Phase), Power Frequency |
Output Voltage | 0-400V |
Rated Input Current | 37.5A |
Rated Output Current | 37.5A |
Voltage Resolution | 0.01kV |
Voltage Measurement Accuracy | 1.5% |
Frequency Adjustment Range | 30-300Hz |
Frequency Adjustment Resolution | ≤0.1Hz |
Frequency Stability | 0.1% |
Operating Time | Continuous 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 |
Weight | Approximately 15kg |
(二) Excitation Transformer UHV-15kVA/1.5/3/6kV/0.4kV (1 unit)
Rated Capacity | 15kVA |
Input Voltage | 0-400V |
Output Voltage | 1.5/3/6kV |
Structure | Dry Type |
Dimensions (L×W×H mm) | 520×520×460 |
Weight | Approximately 85kg |
(三) High Voltage Reactor UHV-67.5kVA/27kV (4 units)
Rated Capacity | 67.5kVA |
Rated Voltage | 27kV |
Rated Current | 2.5A |
Inductance | 50H/unit |
Quality Factor | Q≥30(f=45Hz) |
Structure | Dry Type |
Dimensions (Inner Diameter×Height mm) | 382×435 |
Weight | Approximately 90kg |
(四) Capacitive Voltage Divider UHV-1500pF/110kV (1 set)
Rated Voltage | 110kV |
High Voltage Capacitance | 1500pF |
Dielectric Loss | tgσ≤0.5% |
Voltage Division Ratio | 1500:1 |
Measurement Accuracy | Effective Value 1.5 Grade |
Dimensions (Inner Diameter×Height mm) | 140×1000 |
Weight | Approximately 8kg |
Delivery List
No. | Equipment Name | Model and Specifications | Unit | Quantity |
1 | Variable Frequency Power Supply | LHV-15kW | Unit | 1 |
2 | Excitation Transformer | LHV-15kVA/1.5/3/6kV/0.4kV | Unit | 1 |
3 | High Voltage Reactor | LHV-67.5kVA/27kV | Section | 4 |
4 | Capacitive Voltage Divider | LHV-1500pF/110kV | Set | 1 |
5 | Internal Connection Cables | Set | 1 | |
6 | Factory Inspection Report | Copy | 1 | |
7 | User Manual | Copy | 1 | |
8 | Product Certificate | Copy | 1 | |
9 | Packing List | Copy | 1 |
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" |