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What should be noted for the series resonance withstand voltage test device?
2025-08-12Wuhan UHV specializes in producing series resonance (also known as series resonance withstand voltage test device). Next, we will share with you what to pay attention to for the series resonance withstand voltage test device?Attention to Series Resonance (GIS) Test:1. During the experiment, the high-voltage source should be connected to the test, and the high-voltage lead should use a dedicated non corona lead. Non test connections should be grounded to the GIS casing;2. The test must ensure that the SF6 gas in each chamber is at the rated pressure, and the gas content is within the qualified range after 4 hours of inflation. The GIS must be in an operational state and confirmed to be correct before the test can be conducted;3. Before the test pressurization, ensure that the voltage transformers inside the GIS are removed (if approved by the GIS manufacturer, the voltage transformers can be pressurized together, but the test resonance frequency must be greater than 100Hz), the CT is sh
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Why is power frequency withstand voltage testing equipment used?
2025-08-12Wuhan UHV specializes in producing series resonance (also known as power frequency withstand voltage test equipment). Next, we will share with you why power frequency withstand voltage test equipment is used?In practical work, power workers often hear about a high-voltage power testing equipment called series resonance. This device is widely used and well-known in the power industry. So why use the variable frequency series resonance testing device? Before putting high-voltage power cables into use, a resonance test needs to be conducted to find the resonance point of the cable. Therefore, a series resonance test device is needed at this time. This article will briefly introduce this equipment.The research on this device mainly focuses on the AC withstand voltage test of 220kV high-voltage bushings and isolation control switches, as well as the design and manufacturing of the AC withstand voltage test system for 220kV main transformers. There is a wide range of applicable laws, but the
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The difference between induction withstand voltage and power frequency withstand voltage
2025-08-12Wuhan UHV specializes in producing series resonance (also known as power frequency withstand voltage test device). Next, we will share the difference between induction withstand voltage and power frequency withstand voltage.In the power system, induction withstand voltage is an important functional test to assess the insulation strength of electrical equipment such as transformers, reactors, and voltage transformers. In DL/T474.4-2006 "Guidelines for the Implementation of On site Insulation Tests", it is clearly stipulated that in addition to the main insulation, transformers should also undergo insulation performance tests for longitudinal insulation such as turns, layers, and breaks, which can effectively check the integrity of winding coils!Induction voltage withstand test methodInductive withstand voltage is different from power frequency withstand voltage. Power frequency withstand voltage applies high-frequency high voltage on the primary side, while inductive withstand voltage a
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Application of Series Resonant withstand voltage Equipment in GIS System
2025-08-11Wuhan UHV specializes in producing series resonance (also known as series resonance withstand voltage equipment). Next, we will share with you the application of series resonance withstand voltage equipment in GIS systems.The method of measuring AC withstand voltage using a variable frequency series resonance test device is to change the inductance and frequency in the test circuit to make the circuit in a resonant state. This method can meet the requirements of high voltage and high current testing.When using a frequency conversion series resonant device for AC withstand voltage testing, the following points should be noted:1. Before the experiment, it is necessary to understand whether the non-destructive testing items of the tested equipment are qualified. If there are defects or abnormalities, the experiment should be carried out after cleaning;2. Adjust the gap between the protective balls to a discharge voltage of 105% to 110% of the test voltage, and conduct three consecutive te
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What are the possible overvoltages that may occur during power frequency withstand voltage testing and how can they be prevented?
2025-08-11Wuhan UHV specializes in the production of series resonance (also known as power frequency withstand voltage test equipment). Next, we will share with you the possible overvoltage that may occur during power frequency withstand voltage testing and how to prevent it?What are the possible overvoltages that may occur during the power frequency withstand voltage test?How to prevent this problem can be analyzed from two aspects: steady-state process and transition process. From a steady-state perspective, most of the tested objects are capacitive loads. The capacitive current of the load passes through the leakage reactance of transformers and voltage regulators, causing a voltage drop on the leakage reactance, resulting in the test voltage on the tested object being higher than the power supply voltage, known as the capacitance rise phenomenon. The method to overcome this phenomenon is to directly measure the voltage on the high-voltage side. If the leakage reactance of transformers and
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Calculation method for series resonance
2025-08-11Wuhan UHV specializes in producing series resonance (also known as series resonance withstand voltage equipment). Next, we will share with you the calculation method of series resonance.Variable frequency series resonance mainly refers to the voltage and current of the studied series circuit reaching the same phase, that is, the inductance reactance and capacitance reactance of the inductor in the circuit are equal in value and time, making the studied circuit exhibit pure resistance characteristics. At a given terminal voltage, the maximum current will occur in the studied circuit. The maximum active power is consumed in the circuit. Calculation method for frequency conversion series resonance:z=r+jx，x=0，z=r，i=u/z=u/r (1) Resonance definition: In a circuit, when the energy of two components is released by one reactive module and the other reactive module must absorb the same energy, the energy of the two components is equal, that is, there will be energy pulsation between the two re
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Protective measures for grounding arrangement of power frequency withstand voltage test equipment
2025-08-08Wuhan UHV specializes in producing series resonance (also known as power frequency withstand voltage test equipment). Next, we will share with you the protective measures for the grounding arrangement of power frequency withstand voltage test equipment.Variable frequency series resonance is mainly composed of variable frequency controller, excitation transformer, high-voltage reactor, high-voltage voltage divider, etc. During the frequency conversion series resonance test, the capacity of the excitation transformer should be greater than the active power P, and the transformation ratio of the excitation transformer should be reduced as much as possible on the premise that the minimum output voltage of the excitation transformer meets the test requirements, so as to correspondingly reduce the input current on the primary side of the excitation transformer. Due to the large capacitance of the tested cable, if the test sample breaks down or high-voltage leads discharge to ground during th
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Introduction to the characteristics of the variable frequency series resonance test device
2025-08-08Wuhan UHV specializes in producing series resonance (also known as variable frequency series resonance test device). Next, we will share with you the characteristics of the variable frequency series resonance test device.Series resonance testFirst of all, let's talk about the series resonance test, which is also commonly known as the AC withstand voltage test. It is the most effective and direct way to identify the insulation strength of power operating equipment before commissioning, and can play a decisive role in the pre commissioning process. Series resonance is a principle technology of electronic circuits, and it is a method or preventive test for insulation testing. Due to its large test capacity and high voltage, series resonance is widely used in power generation, power supply and other departments. The significance of series resonance testDuring the operation of power equipment, insulation will gradually deteriorate under the long-term effects of electric field, temperat
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Composition of variable frequency series resonance test device
2025-08-07Wuhan UHV specializes in producing series resonance (also known as variable frequency series resonance test device). Next, we will share with you the composition of the variable frequency series resonance test device.When we come into contact with the frequency conversion series resonance withstand voltage device, we will know that the power system and power engineering cannot do without the series resonance test device, because the series resonance withstand voltage test device is the most basic testing equipment for power safety. In the power industry, basic tools such as cables, transformers, and switches need to be tested for their voltage resistance performance using series resonance tests, in order to provide safety control for power equipment.So what are the components of the variable frequency series resonant withstand voltage device?The variable frequency series resonant withstand voltage device mainly consists of a variable frequency power supply, an excitation transformer, a
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Comprehensive answer on how to select series resonance
2025-08-07Wuhan UHV specializes in producing series resonance (also known as series resonance test device). Next, we will share with you a comprehensive answer on how to select series resonance.Introduction to series resonant deviceSeries resonance is a necessary test equipment for insulation inspection of large capacity and high voltage power equipment in power preventive testing projects. It achieves the functional requirements of resonant boosting by adjusting inductance and frequency in combination. Variable frequency series resonance is composed of a control power supply, excitation transformer, high voltage reactor, compensation capacitor, and capacitor divider.Selection requirements for series resonanceBefore purchasing a series resonance device, we need to understand the basic situation on site. Taking the voltage withstand test of power cables with many unknown parameters as an example, how to choose the capacity and maximum voltage of the series resonance test device based on the volta
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Analysis and Application of Series Resonant AC Voltage Test Device
2025-08-07Wuhan UHV specializes in producing series resonance (also known as AC/DC withstand voltage test device). Next, we will share with you the analysis and application of series resonance AC withstand voltage test device.In the debugging of power supply and distribution systems, it is necessary to inspect cross-linked polyethylene power cables (XLPE), high-voltage switchgear GIS、 High voltage and large capacity power equipment such as high-voltage motors, large generator sets, large power transformers, and transformers are subjected to insulation withstand voltage tests.The insulation withstand voltage test is divided into two types: DC withstand voltage test and AC withstand voltage test. In the past, DC voltage withstand test was used for cable voltage withstand test. Around 1980, foreign power departments discovered that DC withstand voltage testing was ineffective and harmful to rubber insulation. China began researching and practicing voltage withstand testing technology in the 1990s.
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Knowledge of series resonance withstand voltage test device
2025-08-06Wuhan UHV specializes in producing series resonance (also known as cable withstand voltage test equipment). Next, we will share with you the knowledge of series resonance withstand voltage test device.Knowledge of series resonance withstand voltage test deviceWhat is series resonance used for? The series resonance withstand voltage test device applies the principle of series resonance. By adjusting the output frequency of the variable frequency controller, the reactor inductance L and the sample capacitance C in the circuit undergo series resonance, and the resonance voltage is the voltage applied to the sample. The frequency conversion series resonance test device is widely used in industries such as power, metallurgy, petroleum, and chemical engineering. It is suitable for large capacity, high-voltage capacitive test samples, such as generators, power transformers, GIS and high cross-linking power cables, transformers, bushings, and other handover and preventive tests. The frequency
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A comprehensive introduction to the series resonance test device
2025-08-05The structure of variable frequency series resonance mainly consists of a variable frequency control power supply, excitation transformer, capacitor, and capacitor voltage divider. The application range of variable frequency series resonance: Suitable for various large power transformers, power cables, steam turbines, hydro generators, and other capacitive equipment. The AC withstand voltage test must be strictly conducted regularly according to the test regulations. Under power frequency conditions, due to the large capacitance of the test object or high requirements for the test voltage, there are also high requirements for the power capacity of the test device. Traditional power frequency withstand voltage devices often have large individual volumes, heavy weights, are not easy to transport on site, and are not easy to combine arbitrarily, resulting in poor flexibility.The principle of frequency conversion series resonance: When the circuit frequency f=1/2 π√ LC, the circuit resona
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What are the characteristics of the variable frequency series resonance withstand voltage test device?
2025-08-05The frequency conversion series resonance withstand voltage test device applies the principle of series parallel resonance. By adjusting the output frequency of the frequency conversion controller, the inductance L of the reactor in the circuit and the capacitance C of the test sample resonate, and the resonant voltage is the voltage applied to the test sample. Variable frequency series resonance provides power supply through a frequency modulation controller. The test voltage is initially boosted by an excitation transformer, and high voltage is applied to the reactor L and the test sample CX. By changing the output frequency of the frequency modulation controller, the circuit is in series resonance state; The resonant frequency of the circuit depends on the capacitance CX of the test sample and the inductance L of the reactor. Adjust the output voltage of the variable frequency controller to achieve the required voltage value on the high voltage of the variable frequency series reson
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What are the conditions for series resonance to occur? What are the factors involved?
2025-08-04What are the conditions for series resonance to occur? What are the factors involved? Series resonance is the combination of high current and high voltage, which has a significant impact on daily use and is also related to electrical safety. The occurrence of a series resonant circuit has certain conditions.In a series circuit composed of resistors, inductors, and capacitors, when the capacitive reactance XC is equal to the inductive reactance XL, i.e. XC=XL, the voltage U and current I in the circuit are in phase, and the circuit behaves as a pure resistor. This phenomenon is called series resonance. When the circuit has series resonance, the circuit impedance Z=√ R ^ 2+(XC-XL) ^ 2=R, the total impedance in the circuit is the smallest, and the current reaches the maximum value. Impedance condition, after resonance, the imaginary parts are equal and the signs are opposite. The series impedance is equal to 0, and the parallel impedance is equal to infinity. When resonating, the resonant
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The testing principle of series resonant withstand voltage tester
2025-08-04Fully utilizing the advantages of Wuhan UHV in electronic measurement technology and electromagnetic compatibility, we independently develop, design, and produce all components of this equipment, including high-voltage withstand voltage testing, variable frequency power supply, excitation transformer, cast high-voltage reactor, and high-precision capacitive voltage divider. Due to the widespread application of the method of generating high voltage through series resonance, problems may also be encountered when using this high-voltage method for withstand voltage testing on site. This article mainly analyzes the testing principle of the series resonant withstand voltage tester.The working principle of series resonance withstand voltage test is that the series resonance withstand voltage test device, also known as series resonance, is divided into frequency modulation type and inductance modulation type. It generally consists of a variable frequency power supply, excitation transformer,
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Application and precautions of frequency conversion series resonance withstand voltage test device
2025-08-01Years of practical experience in power testing and inspection have taught us that only variable frequency series resonant withstand voltage testing devices can meet the preventive testing of insulation performance for large capacity power equipment. Due to the high voltage level of large capacity power equipment and the need for large capacitors, general power frequency withstand voltage test devices are no longer able to meet the withstand voltage test requirements of large capacity power equipment. Due to the greatly reduced capacitance of the variable frequency series resonance, the required power supply for testing is only 1/Q of the testing capacity (q is the quality factor). Therefore, by using a variable frequency series resonance testing device, it is easier to increase the voltage to the required power level. It is safer and more reliable to use a variable frequency series resonant withstand voltage test device for the withstand voltage test of large capacity power equipment.
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Precautions for safe wiring of frequency conversion resonance withstand voltage test device
2025-08-01The frequency conversion resonance withstand voltage test device adopts a dedicated broadband voltage regulation power supply, with a voltage regulation range of ac0-400V, a frequency modulation range of 30-300Hz, and a frequency fineness of up to 0.1Hz. The output waveform in the entire frequency range is good, ensuring the stability and safety of the instrument at the minimum weight and volume. The device consists of a frequency and voltage regulating power supply, an excitation transformer, a reactor, and a capacitor voltage divider. The frequency conversion resonance withstand voltage test belongs to the high-voltage withstand voltage test. There are many things to pay attention to during the testing process. The circuit connection and precautions of the frequency conversion resonance withstand voltage test device are as follows:Through on-site testing of the full load wiring method of different specifications of frequency conversion resonance withstand voltage test devices, share
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How to choose series resonant equipment?
2025-07-311、 Power testing instruments, apparatus, and testing equipment for testing accuracyThe precision of an instrument is called accuracy, also known as precision. Accuracy and error can be said to be twin brothers, because there are errors, precise concepts. The accuracy of an instrument is only the precision with which the measured value is close to the true value, usually expressed as relative percentage error (also known as relative folding error). The formula for relative percentage error is as follows: δ - the relative percentage error during the detection process; (Proportional upper limit - Proportional lower limit) - Instrument measurement range; Δ x - Absolute error, the difference between the measured parameter value x1 and the measured parameter standard value x0. The so-called standard value is the value measured by a standard instrument, which is 3 to 5 times higher than the instrument being tested. The accuracy of the instrument is not only related to absolute error, but als
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Characteristics of series resonant reactor
2025-07-311、 Definition of ReactorThe main components of an electrical circuit are resistors, capacitors, and inductors. Inductance has the function of suppressing current changes and shifting the phase of alternating current. A wound type static induction device with inductive function is called a reactor. 2、 Characteristics of reactors1. Iron core reactorHigh noise, poor linearity of reactors, can cause magnetic leakage, local overheating, easy magnetic saturation, and coil burnout. The effects of system overvoltage, overcurrent, and harmonics cause a sharp decrease in the iron core's supersaturated reactance value, a decrease in the ability to suppress harmonics, and a low ability to withstand short-circuit currents. In addition to the above drawbacks, dry-type iron core reactors cannot operate outdoors. 2. Dry type air core reactorGood linearity, no noise, strong overcurrent ability, strong heat dissipation ability, simple and sturdy mechanical structure, suitable for indoor and outdoo
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