Введение в продукт
The series resonance test device is a specialized equipment that obtains the test voltage by adjusting the power frequency series resonance between the reactor and the sample capacitor. It consists of a variable frequency power supply, excitation transformer, reactor, capacitive voltage divider, and compensation capacitor. This device measures the voltage of the test object through a voltage divider and provides overvoltage protection. It is mainly used for AC withstand voltage testing and partial discharge detection of power cables, generators, GIS switches, transformers and other equipment.
Main components of the device
Serial number | Имя устройства | Specification and model | Единица | Quantity |
1 | Variable frequency power supply | UHV-15kW | Tower | 1 |
2 | Трансформатор возбуждения | UHV-4kVA/1.5/3/6kV/0.4kV | Tower | 1 |
3 | High voltage reactor | UHV-67.5kVA/27kV | Section | 4 |
4 | Capacitive voltage divider | UHV-1500pF/110kV | Набор | 1 |
Main technical parameters and functions
Номинальная мощность | 270kVA |
Номинальное напряжение | 27kV；54kV；108kV |
Номинальный ток | 10A；5A；2.5A |
Точность измерения | System RMS level 1.5 |
Operating frequency | 30-300Hz |
Device output waveform | Sinusoidal wave |
Фактор качества | Device Q≥30(f=45Hz) |
Коэффициент искажения формы сигнала | Output voltage waveform distortion ≤1% |
Входной источник питания | Single-phase 220 or three-phase 380V voltage, frequency 50Hz |
Working hours | Allow continuous 60min under rated load; Overpressure 1.1 times 1 minute |
Повышение температуры | 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 |
Температура окружающей среды | －20℃-55℃ |
Относительная влажность | ≤90% относительной влажности |
Высота | ≤3000m |
Product Features:
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.
Product Comparison
Comparing dimensions | Series resonance | Power frequency transformer | Very low frequency (0.1Hz) |
Core Advantages | Lightweight power supply, no impact during breakdown, good equivalence | Absolute frequency, pure waveform | Extremely lightweight and safe for low voltage operation |
Fatal weakness | High equipment cost and high requirements for variable frequency power supply | Extremely bulky, breakdown can burn the test sample | Long testing time and not recognized by all standards |
Who is most suitable for | 220kV and above cables, GIS switches | Transformers and insulators below 10kV | Quick troubleshooting of medium and low voltage cables (length ≤ 5km) |
Application Areas
1. High voltage power test (core): Conduct a "voltage withstand test" on equipment such as power cables, GIS switches, transformers, etc., using resonant boosting to detect insulation defects, especially suitable for on-site testing of long cables.
2. Industrial heating: used for metal melting, hot forging, and surface quenching.
3. Electronics and Communication: Used for frequency selective filtering in radio and mobile RF front-end, and also for wireless charging of electric vehicles.
4. New energy and transportation: Cable withstand voltage testing for offshore wind power cables, photovoltaic power stations, and high-speed rail traction power supply systems.
FAQ
Q1: What factors will affect the results of the series resonant cable withstand voltage test? A2: Mainly includes cable parameters (length, capacitance), test voltage, environmental conditions (temperature, humidity), and stability of testing equipment.
Q2: Apart from voltage withstand testing, what other methods can be used to evaluate cable insulation? A3: Partial discharge detection, dielectric loss testing, DC withstand voltage testing, and other commonly used methods can reflect insulation status from different dimensions.
Q3: How to ensure the accuracy of the series resonant cable withstand voltage test? A5: It is necessary to accurately measure cable parameters, select appropriate test frequencies and voltages, use high-precision testing equipment, and strictly follow operating procedures.
