Series Resonance Test Device

LHV-75kVA/75kV AC Resonant Test System for Cable & Transformer Testing

Professional LHV-75kVA/75kV resonant test system for large capacity HV testing. Complies with GB 50150-2016 standards, features DSP technology, and lightweight field operation.

US$1.00; Negotiated Price
Lead time: 90days

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Product Details

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LHV-75kVA/75kV AC Resonant Test System for High Voltage Applications

Product Introduction

The LHV-75kVA/75kV AC Resonant Test System is engineered for preventive testing and quality assurance of high-voltage electrical equipment. Utilizing advanced DSP platform technology, this lightweight solution meets stringent Chinese standards including GB 50150-2016 and DL/T 849.6-2016 for field testing applications.

Main components of the device

Serial number	Device name	Specification and model	Unit	Quantity
1	Variable frequency power supply	LHV-4kW	Tower	1
2	Excitation transformer	LHV-4kVA/1.5/3/6kV/0.4kV	Tower	1
3	High voltage reactor	LHV-25kVA/25kV	Section	3
4	Capacitive voltage divider	LHV-1000pF/80kV	Set	1

Main technical parameters and functions

Rated capacity	75kVA
Rated voltage	25k；75kV
Rated current	3A；1A
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 75kVA, divided into three reactors, reactor single section is 25kVA/25kV/1A/110H)

Serial number	Test	Test Frequency	Test Current
1	AC withstand voltage test for 10kV/300mm² cable 1.5km, capacitance ≤0.5632μF, test frequency 30-300Hz, test voltage 22kV, test time 5min, using three reactors in parallel, then L=110/3=36.7H	f=1/2π√(LC)=1/(2×3.14×√(36.7×0.5632×10⁻⁶))=35.01Hz	I=2πfCU=2π×35.01×0.5632×10⁻⁶×22×10³=2.73A
2	AC withstand voltage test for 35kV/300mm² cable 0.35km, capacitance ≤0.0681μF, test frequency 30-300Hz, test voltage 52kV, test time 60min, using three reactors in series (mutual inductance coefficient 1.2), L=110×3×1.2=396H	f=1/2π√(LC)=1/(2×3.14×√(396×0.0681×10⁻⁶))=30.65Hz	I=2πfCU=2π×30.65×0.0681×10⁻⁶×52×10³=0.68A
3	AC withstand voltage test for 35kV main control, capacitance ≤0.02μF, test frequency 45-65Hz, test voltage not exceeding 68kV, test time 1min, using three reactors in series (mutual inductance coefficient 1.2), then L=110×3×1.2=396H	f=1/2π√(LC)=1/(2×3.14×√(396×0.02×10⁻⁶))=55.55Hz	I=2πfCU=2π×55.55×0.02×10⁻⁶×68×10³=0.48A

Equipment combination method during testing

Test Object Combination Method	Reactor Selection (25kVA/25kV Three Sections)	Excitation Transformer Output Selection	Test Voltage (kV)
10kV/300mm² Cable 1.5km	Use three reactors in parallel	1.5kV	≤22kV
35kV/300mm² Cable 0.35km	Use three reactors in series	3kV	≤52kV
35kV Transformer Multiple Current Withstand Test	Use three reactors in series	6kV	≤68kV
10kV Switch and Other Electrical Equipment	Use three reactors in series	3kV	≤42kV

System Configuration Parameters

(一) Variable Frequency Power Supply UHV-4kW (1 unit)

Rated Output Capacity	4kW
Power Supply	220/380±10%V (Single/Three Phase), Power Frequency
Output Voltage	0-400V
Rated Input Current	10A
Rated Output Current	10A
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)	400×280×400
Weight	Approximately 10kg

(二) Excitation Transformer UHV-4kVA/1.5/3/6kV/0.4kV (1 unit)

Rated Capacity	4kVA
Input Voltage	0-400V
Output Voltage	1.5/3/6kV
Structure	Dry Type
Dimensions (L×W×H mm)	450×330×430
Weight	Approximately 45kg

(三) High Voltage Reactor UHV-25kVA/25kV (3 units)

Rated Capacity	25kVA
Rated Voltage	25kV
Rated Current	1A
Inductance	110H/unit
Quality Factor	Q≥30(f=45Hz)
Structure	Dry Type
Dimensions (Inner Diameter×Height mm)	282×435
Weight	Approximately 45kg

(四) Capacitive Voltage Divider UHV-1000pF/80kV (1 set)

Rated Voltage	80kV
High Voltage Capacitance	1000pF
Dielectric Loss	tgσ≤0.5%
Voltage Division Ratio	1000:1
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-4kW	Unit	1
2	Excitation Transformer	LHV-4kVA/1.5/3/6kV/0.4kV	Unit	1
3	High Voltage Reactor	LHV-25kVA/25kV	Section	3
4	Capacitive Voltage Divider	LHV-1000pF/80kV	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"

Core Features:

75kVA/75kV testing capacity
DSP-controlled precision measurement
Multi-stage protection (overvoltage, overcurrent, flashover)
30-300Hz adjustable test frequency
Field-portable design

Technical Specifications

Parameter	Specification
Rated Capacity	75kVA
Output Voltage	0-75kV AC
Frequency Range	30-300Hz (45-65Hz optimized)
Waveform Distortion	THD ≤3%
Protection Class	IP54 (field deployment)

Standard Test Applications

1. Cable Testing

Cable Type	Length	Capacitance	Test Voltage	Duration
10kV/300mm²	1.5km	≤0.5632μF	22kV	5min
35kV/300mm²	0.35km	≤0.0681μF	52kV	60min

2. Electrical Equipment Testing

Equipment	Capacitance	Test Voltage	Duration
35kV Transformer	≤0.02μF	≤68kV	1min
10kV Switchgear	-	≤42kV	1min

Safety Protection System

Comprehensive safeguards ensure operator and equipment protection:

Overvoltage Protection: Automatic shutdown at 110% rated voltage
Overcurrent Protection: Current limiting at 120% rated value
Zero-start Interlock: Prevents improper energization
System Mismatch Detection: Instant response to flashover events
Emergency Stop: Manual override capability

Compliance Standards

GB 50150-2016: Electrical equipment handover standards
DL/T 849.6-2016: Special technical conditions for resonant test devices
DL/T 474.4-2018: Preventive test procedures for power equipment

Field Operation Advantages

Weight Reduction

60% lighter than conventional test transformers of equivalent capacity

Power Efficiency

Requires only 20-30% of the power needed by traditional methods

Quick Deployment

Modular components enable setup in under 30 minutes

Typical Test Configurations

For 10kV Cable Testing (1.5km):

Connect resonant reactor in parallel configuration
Set frequency to 45Hz ±5%
Ramp voltage to 22kV over 60 seconds
Maintain for 5 minutes while monitoring leakage current