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What should be paid attention to in the AC withstand voltage test
2025-09-05Wuhan UHV specializes in producing series resonance (also known as AC withstand voltage test equipment). Next, we will share with you what to pay attention to in AC withstand voltage testing.The AC withstand voltage test is conducted to check the insulation performance of electrical equipment by applying high voltage at the operating frequency. In the power system, such as transformer main withstand voltage test, AC withstand voltage test of power cables, insulation test of insulation equipment, etc., AC withstand voltage test can be conducted before power system debugging or regular inspection. So, what should be paid attention to when conducting AC withstand voltage test? We should pay attention to the following matters during the withstand voltage testBefore communicating the withstand voltage, the tested product should be wiped clean. If it is an oil filled device, letting the oil sit for a period of time to eliminate residual bubbles inside can effectively improve the pressure re
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Comprehensive Introduction to AC withstand voltage
2025-09-05Wuhan UHV specializes in producing series resonance (also known as AC withstand voltage test device), and now we will share a comprehensive introduction to AC withstand voltage with you.AC voltage withstand test is used to check the insulation performance of electrical equipment by applying high-frequency high voltage. AC voltage withstand test is a common item in power systems. So why not use DC voltage measurement? Below, we will briefly explain the significance of using AC voltage withstand test!Why not use DC withstand voltageCompared with DC voltage, the voltage, waveform, frequency, and electric field state inside the insulation of the tested object in AC testing are consistent with the actual operating conditions, and the test voltage is higher than the value of the internal overvoltage. Therefore, it can effectively detect the main insulation defects of electrical equipment, especially for the insulation defects of the stator winding slot, which is more effective than DC withst
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A comprehensive explanation of series resonance for you
2025-09-05A comprehensive explanation of series resonance (also known as variable frequency series resonance device) will be introduced to you. Firstly, whether it is series resonance or parallel resonance, they belong to the structural branches of series resonance testing devices, but there is a slight difference in their names. Next, let's take a detailed look.What is series resonanceWith the preventive testing of large capacity and high voltage electrical engineering equipment in China, it is recommended to use power frequency withstand voltage to analyze the performance of insulation materials, which eliminates the management requirements for insulation performance testing of electrical technology equipment using DC high-voltage generators. Although both belong to destructive tests, after long-term research by enterprises, the use of power frequency withstand voltage method has better stability and safety compared to DC withstand voltage. Due to the large capacity and high voltage of ele
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On site testing of series resonance test equipment
2025-09-04Wuhan UHV specializes in producing series resonance (also known as series resonance test equipment). Next, we will share with you the on-site testing of the series resonance test equipment.The variable frequency series resonance test device is a high-capacity high-voltage sample withstand voltage test equipment that adopts the principle of LCR series resonance circuit. For a high-voltage equipment enterprise such as a test transformer, there are strict technical development requirements in its application, but its completion time is generally limited by the test transformer, which cannot meet the high-voltage requirements of large capacity test samples. The inverter series vibration testing device generally consists of an inverter source, excitation variables, resistors (multiple), voltage molecules, and may also have compensating capacitors under special conditions. The on-site management and use of the variable frequency series resonance test device requires students to follow thei
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How to operate the power frequency withstand voltage test device
2025-09-04Wuhan UHV specializes in producing series resonance (also known as power frequency withstand voltage test device). Next, we will share with you how to operate the power frequency withstand voltage test device.Operation guide for power frequency withstand voltage test deviceBefore operating the system, we should grade it according to the capacity and voltage of different test samples, calculate the maximum operating current, and adjust the economic current protector. Power frequency withstand voltage test device1. Connect a power supply (box type refers to socket type power supply, desktop type refers to terminal type power supply), and automatically control the voltage reduction through a voltage regulator to zero position. The zero position switch is closed, and the zero position indicator light (red light) is on (also known as the zero position balance output working status of the voltage regulator can be indicated); 2. Press the start button (green light), the contactor draws in a
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Precautions for using variable frequency series resonant device
2025-09-04Wuhan UHV specializes in producing series resonance (also known as power frequency withstand voltage test equipment). Next, we will share with you the precautions for using variable frequency series resonance devices.The variable frequency series resonant device utilizes the principle of series resonance and the output characteristics of the excitation transformer to excite the series resonant circuit. By adjusting the output frequency of the variable frequency controller, the inductance L in the circuit resonates with the sample C. The resonant voltage is the voltage applied to the sample. On site inspection of the laying quality of cross-linked cables and the installation quality of accessories is an effective means. By connecting series and parallel reactors, the AC withstand voltage requirements of 10kV-500kV high-voltage cross-linked cables can be met.The variable frequency series resonant device is suitable for AC withstand voltage testing of various large power transformers, pow
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How to select a complete set of equipment for power frequency withstand voltage test
2025-09-03Wuhan UHV specializes in the production of series resonance (also known as power frequency withstand voltage test equipment). Next, we will share with you how to select the power frequency withstand voltage test equipment.Overview of Series Resonance Test DeviceThe series resonance test device is a series resonance test device that uses tuned inductors and load capacitors to generate power frequency series resonance and obtain power frequency test voltage. A resonant series is composed of isolation and transformer, frequency and voltage regulation system power supply, excitation for transformer, reactor, and capacitive voltage divider. The capacitors and resistors of the subjects form a series resonant connection, and the voltage molecules are connected in series with the main body to measure the resonant voltage on the main body and provide overvoltage protection signals. The frequency modulation power output is coupled with the excitation transformer and the series resonant circuit t
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Guidelines for Safe Operation of AC Withstand Voltage Test Equipment
2025-09-03Wuhan UHV specializes in producing series resonance (also known as AC withstand voltage test equipment). Next, we will share with you the safety operation guidelines for AC withstand voltage test equipment.1. It is not allowed to suddenly cut off the system power during testing. Before performing the series resonance test, the test state must be exited before the power can be cut off. 2. After the host malfunctions, do not open the chassis for maintenance, otherwise the consequences will be borne by yourself. 3. Do not store or use the instrument in high temperature, high humidity, flammable, explosive, or strong magnetic fields. 4. Use a damp cloth and neutral cleaning agent to clean the instrument casing for maintenance and upkeep. Do not use abrasives and solvents. 5. Before testing, please check whether the series resonant instrument is intact, whether the connecting wires are intact, ensure power output, whether the signal sampling cable is firmly connected, and whether the co
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The reason why the series resonance test equipment cannot be improved
2025-09-03Wuhan UHV specializes in producing series resonance (also known as series resonance test equipment). Next, we will share with you the reasons why series resonance test equipment cannot be improved.There are two main reasons why series resonance testing equipment does not boost voltage when understanding voltage. For example, whether the boost point did not rise after finding the resonance point, or whether the boost did not rise during the search for the resonance point. By analyzing these two situations, determine whether there is a problem with the series resonance testing device itself or whether the insulation of the test item is damaged.For example, the first scenario is damage to the cable insulation layer (this possibility is very small, and if it is damaged, the resonance point cannot be found).The second scenario is that the reactor you are using is damaged. This kind of hardware damage will definitely not increaseUsually, series resonance does not enhance. In most cases, prob
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Characteristics of Variable Frequency Series Resonant Device
2025-09-02Wuhan UHV specializes in producing series resonant devices (also known as variable frequency series resonant devices). Next, we will share with you the characteristics of variable frequency series resonant devices.The main characteristics of series resonance are:1. Easy to operate: Two modes of automatic testing (automatic search for resonance point and automatic boost) and manual testing (manual search for resonance point and manual boost) are suitable for different testing requirements. 2. Can set the test voltage, frequency range, protection current, and pressurization time.3. Automatic mode: only need to set the test voltage and time; Automatic precision of equipment Quasi frequency regulation and voltage regulation; Complete the experiment and save the data. 4. It has grounding and flashover protection functions. In the event of flashover of the test sample or sudden loss of resonance in the resonant circuit caused by other reasons, the variable frequency control power supply wi
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Do you understand all these principles of series resonance
2025-09-02Wuhan UHV specializes in producing series resonance (also known as series resonance test device). Next, we will share with you the principles of series resonance. Are you clear about them.Resonance is a physical harmonic vibration in which the acceleration of an object is proportional to the displacement from the equilibrium position, and always points towards the restoring force at the equilibrium position. Its dynamic equation is f=- KX. The resonance phenomenon occurs when the current increases, the voltage decreases, and the closer it is to the resonance center, the faster the power meter rotates. However, the difference between short circuit and short circuit is not a zero order quantity. resonant circuitA circuit composed of inductance L and capacitance C can resonate at one or more frequencies, known as a resonant circuit. In electronic and wireless engineering, it is often necessary to select the electrical signals we need from many electrical signals, while suppressing or fil
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Introduction to the New Series Resonant Withstand Voltage Device
2025-09-02A newly disclosed series resonant voltage withstand device (also known as series resonant). The capacitors and reactors of the test object are connected in series resonant connection, the high-voltage discharge device is connected in parallel with the test object, and the output of the variable frequency power supply is coupled to the series resonant circuit through a driving transformer. The lower output voltage of the variable frequency power supply can generate a higher test voltage on the test object through circuit resonance.technical fieldThis utility model relates to an electric power testing device, particularly to a testing unit that uses the principle of circuit resonance to obtain the required high voltage test. Background technologyAt present, due to the large capacitance of general test specimens or high expectations for test voltage, there are higher requirements for the power supply capacity of test specimens. For traditional industrial grade withstand voltage devices,
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Characteristics of using power frequency withstand voltage test equipment
2025-09-01Wuhan UHV specializes in producing series resonance (also known as power frequency withstand voltage test equipment). Next, we will share with you the characteristics of using power frequency withstand voltage test equipment.Variable frequency series resonance consists of a variable frequency control power supply, excitation system transformer, reactor, and capacitive voltage divider. The test object forms a series resonant connection with the capacitor of the reactor; The voltage divider is connected in parallel with the test object to measure the resonant voltage on the test object and issue an overvoltage protection signal; The frequency modulation power output is coupled to the series resonant circuit through an excitation transformer to provide excitation power for series resonance. The test and detection device for frequency conversion series resonance structure is based on the working principle of knowledge series resonance. The excitation transformer can be used to excite the s
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When LC parallel circuit resonates, it is equivalent to an open circuit, and when connected in series, resonance is equivalent to a short circuit
2025-09-01Wuhan UHV specializes in producing series resonance (also known as series resonance withstand voltage equipment). Next, we will share with you that LC parallel circuit resonance is equivalent to an open circuit, and series resonance is equivalent to a short circuit.When in parallel resonance, there are currents on both L and C components, which are equal in magnitude and opposite in phase. Combining L and C together as a whole, this whole has a current of '0' and no current exchange with the external circuit, so it is considered an open circuit. At this point, the resonant circuit can be seen as a two terminal component with infinite impedance. On the contrary, when connected in series, the resonant impedance is 0, which is equivalent to a short circuit.The essence of resonance is the mutual conversion between the electric field energy in the capacitor and the magnetic field energy in the inductor, which completely compensates for each other. The sum of electric field energy an
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A Brief Analysis of the Principle of Series Resonance
2025-09-01Wuhan UHV specializes in producing series resonance devices (also known as variable frequency series resonance devices). Next, we will share with you an analysis of the principle of series resonance.Definition of series resonanceIn an AC circuit containing resistor, inductor, and capacitor elements in series, when the power supply voltage U is in phase with the circuit current I, it is called resonance. Since the elements are connected in series, it is called series resonance.Circuit current: l=U/Z Circuit equivalent impedance: Z=R+J (XL-XC)According to the definition of series resonance, when a circuit resonates, the circuit current 1 is in phase with the power supply voltage U. According to the basic knowledge of electrical engineering, only when the AC circuit load is purely resistive, the power supply voltage and current are in phase.As can be seen from the above, circuit resonance has the following obvious characteristics:(1) The equivalent impedance of the circuit reaches its min
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Do you know about series resonance and parallel resonance
2025-08-29Wuhan UHV specializes in producing series resonance (also known as cable withstand voltage test equipment). Now, we will share with you the series resonance and parallel resonance. Do you know about themCharacteristics of parallel resonance and series resonanceParallel resonance refers to the phenomenon in which the resistance, capacitance, and inductance in a parallel resonance circuit have the same phase as the circuit terminal voltage and total current. We call it a parallel resonance circuit. In the parallel resonance test, when the voltage remains constant and the current is added, the corresponding parallel resonance is series resonance. The characteristic of series resonance is to form a series connection between the capacitance of the test object and the reactor to generate resonance. The electrical characteristic of voltage addition and current remains constant is called series resonance, which can also be called a series circuit.Composition of parallel resonance and series re
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What are the hazards of non sinusoidal waves on AC withstand voltage testing?
2025-08-29Wuhan UHV specializes in producing series resonance (also known as series resonance test withstand voltage device). Next, we will share with you the hazards of non sinusoidal waves on AC withstand voltage testing?1. When conducting AC withstand voltage tests, some voltage measuring instruments measure the effective value of the voltage. Power frequency discharge or breakdown generally determines the amplitude of the voltage. When the test voltage waveform is non sinusoidal, the ratio of the amplitude of the voltage to the effective value (i.e. the crest factor) is not √ 2. When the waveform is severely distorted, a large third harmonic component is mainly superimposed on the sinusoidal fundamental component, resulting in a crest factor of 1.45-1.55. At this time, if the amplitude is calculated by multiplying the effective value by √ 2, it will cause significant test errors.2. The waveform of the power frequency test voltage also has a certain impact on the insulation test results of ce
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Precautions for AC withstand voltage test
2025-08-29Wuhan UHV specializes in producing series resonance (also known as AC voltage withstand test device). Next, we will share with you the precautions for AC voltage withstand test.Precautions for communication withstand voltage test:1. Before conducting the AC withstand voltage test, the outer insulation surface of the test object should be wiped clean. For oil filled equipment, the oil should be allowed to stand still for a period of time according to regulations to eliminate any residual air inside.2. The AC withstand voltage test is a destructive test that must be conducted only after all insulation test items have passed the test. 3. During the boosting process, the voltage rises slowly while the current rises sharply. This may be due to the presence of a short circuit or similar situation in the tested equipment, or it may be due to the tested equipment having a large capacity or approaching resonance. 4. During the boosting process, the current decreases while the voltage remains
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Do you know the conditions for resonance in series and parallel circuits
2025-08-28Wuhan UHV specializes in producing series resonance (also known as power frequency withstand voltage test equipment). Next, we will share with you the conditions for resonance in series and parallel circuits. Do you know.1. In a series resonant circuit of resistors, capacitors, and inductors, the phenomenon of power supply, voltage, and current being in phase occurs, which is called series resonance. Its characteristics are: the circuit is purely resistive, the power supply, voltage, and current are in phase, the reactance X is equal to 0, and the impedance Z is equal to the resistance R. At this time, the impedance of the circuit is the smallest and the current is the largest. High voltages that are many times larger than the power supply voltage may be generated on the inductor and capacitor, so series resonance is also known as voltage resonance. 2. Parallel resonance refers to the phenomenon in which the voltage at the circuit end and the total current are in phase in a resistor,
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Calculation of series resonant withstand voltage frequency and current
2025-08-28Wuhan UHV specializes in producing series resonance (also known as power frequency withstand voltage test equipment). Next, we will share with you the frequency and current calculation of series resonance withstand voltage.At present, there are three common types of communication testing devices:1. Power frequency AC withstand voltage device. 2. Inductive series resonant withstand voltage device.3. Frequency modulation series resonant withstand voltage test device. Due to its large and bulky size, the power frequency AC withstand voltage device is rarely used on site and is only used during the withstand voltage test of electrical equipment at a voltage level of 10kV. The inductive type has been abandoned due to its use of adjustable iron core air gap reactors, which have disadvantages such as high noise, complex structure, and bulky equipment. IEC517 and GB7674 consider that the test frequency in the range of 10-300Hz is basically equivalent to the power frequency voltage test, so c
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