Variable Frequency Resonance
Product Introduction
Capacitive equipment such as transformers, GIS systems, SF6 switches, CT/PT, insulators, busbars, cables, and bushings are the most common primary electrical equipment in substations. According to the test procedures for primary electrical equipment withstand voltage in substations at 220V and below, the corresponding AC/DC withstand test equipment must not only meet the test conditions of high voltage and low current but also low voltage and high current, requiring a wide range of applicability. Using the principle of series resonance, the main equipment consists of a variable frequency power supply control box (operating console), an excitation transformer, reactors, and a capacitive voltage divider. By connecting a rectifier stack and a microammeter to the capacitive voltage divider, DC withstand voltage tests can be completed. Due to the excellent filtering characteristics after system resonance, the DC voltage produced is comparable to that rectified from a conventional test transformer. It is an ideal withstand voltage device for high-voltage testing departments at prefecture, city, and county levels, as well as for power installation and repair engineering units.
Variable Frequency Resonance
Product Aliases
AC Withstand Voltage Resonance Device, Variable Frequency Series Resonance, Series Resonance, Series Resonance Transformer, Series Resonance Test Equipment
Product Features
1. Reactors of the same voltage level and capacity are smaller in size and lighter in weight; temperature rise is minimal under rated load; dry-type epoxy casting ensures high mechanical strength, excellent electrical insulation performance, and is aesthetically pleasing and reliable
2. The variable frequency power supply control box has ample capacity margin; strong protection functions; good output waveform; good stability; multiple operating modes for convenient operation; compatible with single-phase 220V or three-phase 380V input power, facilitating on-site power access
3. Flexible configuration. Different types of reactors can be selected to meet various test object requirements, achieving multi-purpose use with high cost-effectiveness
Technical Specifications:
| Rated Output Voltage |
0～1000kV and below |
| Output Frequency |
30～300Hz |
| Resonant Voltage Waveform |
Pure sine wave, waveform distortion rate ≤1.0% |
| Duty Cycle |
Continuous operation at full power for 60 minutes |
| Quality Factor |
30～90 |
| Frequency Adjustment Sensitivity |
0.1Hz |
| Instability |
＜0.05% |
| Working Power Supply |
Single-phase 220V or three-phase 380V±10% |
| Power frequency 50Hz±5% |
Series Product Configuration and Applicable Scope:
| Product Model and Name |
Applicable Scope (AC withstand voltage equipment for electrical equipment in substations with voltage levels from 10kV to 500kV, frequency 30～300Hz) |
| Variable Frequency Source |
Resonant Reactor |
Excitation Transformer |
Voltage Divider |
Applicable Scope |
| BPXZ-50/50/25 |
3kW |
25kV/1A Two units
(Dry-type) |
3kVA
(Dry-type) |
50kV |
10kV power transformers up to 1000kVA
10kV switches, busbars, PT, CT, etc.
10kV (300mm2) cables ≤1.0km |
| BPXZ-108/108/27 |
5kW |
27kV/1A Four units
(Dry-type) |
5kVA
(Dry-type) |
110kV |
35kV power transformers up to 31500kVA
35kV switches, busbars, PT, CT, etc.
10kV (300mm2) cables 2km
35kV (300mm2) cables 0.5km |
| BPXZ-200/200/50 |
10kW |
50kV/1A Four units
(Dry-type) |
10kVA
(Dry-type) |
200kV |
110kV power transformers up to 50000kVA
110kV GIS, PT, CT, etc. (preventive tests)
35kV (300mm2) cables ≤1.0km
10kV (300mm2) cables ≤2.0km |
| BPXZ-270/270/45 |
15kW |
45kV/1A Six units
(Dry-type) |
15kVA
(Dry-type) |
300kV |
110kV power transformers up to 50000kVA
110kV GIS, PT, CT, etc.
35kV (300mm2) cables ≤1.2km
10kV (300mm2) cables ≤3.0km |
| BPXZ-800/400/50 |
30kW |
50kV/2A Eight units
(Dry-type)
100kV/2A Four units
(Oil-immersed) |
30kVA
(Dry-type)
30kVA
(Oil-immersed) |
400kV |
220kV power transformers up to 80000kVA
110kV power transformers up to 50000kVA
110kV/220kV GIS, PT, CT, etc.
35kV (300mm2) cables ≤2.0km
110kV (300mm2) cables ≤0.7km |
| BPXZ-1600/800/200 |
60kW |
200kV/2A Four units
(Oil-immersed) |
60kVA
(Dry-type) |
800kV |
220kV power transformers up to 80000kVA
110kV power transformers up to 50000kVA
500kV GIS, PT, CT, etc.
220kV switches, GIS, PT, CT, etc.
110kV (400mm2) cables ≤1.5km
220kV (400mm2) cables ≤1.0km |
Note: Customized solutions can be provided based on the parameters of the test object
