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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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AC withstand voltage test overcurrent protection setting value
2025-08-28Wuhan UHV specializes in producing series resonance (also known as AC withstand voltage test equipment). Next, we will share with you the overcurrent protection setting values for AC withstand voltage test.The voltage, waveform, frequency, and distribution of the internal voltage of the tested insulation in the AC withstand voltage test all conform to the actual situation when operating under AC voltage, and can truly and effectively detect insulation defects. It is one of the methods to test the insulation withstand overvoltage ability of the tested insulation and has important significance for ensuring the safe operation of equipment.In the process of AC withstand voltage of electrical equipment, in order to ensure that the test power can be quickly and reliably cut off in case of short circuit and breakdown of the test object during the test, we must set the overcurrent protection setting in advance.According to engineering experience, the overcurrent protection setting is generally
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Series resonant harmonic control method
2025-08-27Wuhan UHV specializes in producing series resonance devices (also known as variable frequency series resonance devices). Next, we will share with you the methods for controlling series resonance harmonics.At present, there are four basic methods to deal with the problem of series resonant harmonic control. It is generally divided into two parts to focus on: unified centralized management of substations and on-site decentralized processing of nonlinear electrical equipment. We generally follow the principle of whoever pollutes controls it, and we need to handle non-linear electrical equipment in a decentralized manner on-site. Yes, a large number of scattered civilian equipment can only be centrally managed. 1、 Increase system capacityThis method improves the harmonic anti-interference performance of nonlinear electrical equipment by reducing the system impedance, popularizing the capacity of the power supply through series resonance, and then popularizing the level of the power supply
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Application of power cables in series resonant power systems
2025-08-27Wuhan UHV specializes in producing series resonance (also known as series resonance test device). Next, we will share with you the application of series resonance in power cables in power systems.As is well known, power cables are high-capacity electrical equipment in the power system. Before being laid and put into operation, power cables need to undergo voltage withstand tests to ensure their integrity. However, traditional voltage withstand equipment has a small capacity and cannot meet the requirements of long-distance cable voltage withstand tests. At this time, it is necessary to utilize resonance, which has both advantages and disadvantages in the power system.We know that when the circuit frequency, inductance, and capacitance satisfy the resonance condition, the circuit resonates, and the voltage on the test sample is Q times the output voltage of the excitation transformer high voltage end. Q is the system quality factor, which is the voltage resonance multiple, generally ran
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Common fault phenomena and diagnostic methods of series resonance
2025-08-27Wuhan UHV specializes in producing series resonance (also known as series resonance withstand voltage equipment). Next, we will share common fault phenomena and diagnostic methods of series resonance with you.1、 Instrument tuning failed1. Is the instrument and test sample reliably grounded2. Check if there are any broken wires in the reactor and transformer connections of this device. 3. Check the excitation transformer of this device: there are two methods of judgment① Measure the resistance of the transformer winding tap with a multimeter in 2k range. If there is an open circuit, it indicates a broken wire and a faulty transformer. ② After resonance, use a multimeter to measure whether there is voltage at the output tap of the excitation transformer. If not, it will cause tuning failure. 4. Check the reactor of this device:Use a multimeter to measure whether the resistance values at both ends of the reactor match the test report, and whether the resistance values between the react
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What are the characteristics of the AC/DC voltage withstand test device
2025-08-26Wuhan UHV specializes in producing series resonance (also known as AC/DC withstand voltage test device). Next, we will share with you the characteristics of the AC/DC withstand voltage test device.When the capacitance calculation reactance XC is equal to an inductance reactance XL, that is, the voltage U in XC=XL, the circuit and current pass through the same phase, and the circuit presents pure resistance This phenomenon is called series resonance. If a series system resonance occurs in a circuit, the impedance of circuit Z=√ R2XC-XL2=R, the minimum value of the total impedance in the circuit, and the current will reach this maximum value danger When resonance occurs, due to the presence of equivalent inductance and capacitance, the root mean square voltage across the inductance and capacitance is equal to ul=uc. High voltage wireless phase analyzer receiving system host safety check: Long press the "on/off" button to turn on the device, the screen displays normally, and the power co
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What should be noted for power frequency withstand voltage test equipment
2025-08-26Wuhan UHV specializes in producing series resonance (also known as power frequency withstand voltage test equipment). Next, we will share with you what to pay attention to for power frequency withstand voltage test equipment.1、 Preparation before the experiment1. There should be no less than 2 experimental researchers. Strictly follow the safety operating procedures for high-voltage testing when using2. In order to ensure the safety and correctness of the experiment, in addition to being familiar with the product design manual, we must also strictly follow the relevant technical standards and regulations developed by the country for analysis and testing operations; 3. When opening the packaging box, the tester should inspect the equipment according to the packing list. If the equipment is found to be inconsistent with the packing list, please contact Guodian Gaoxi immediately;4. The series resonance test device should be able to be used by professional technical personnel in high-volt
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Do you know the definitions of series resonant circuit and parallel resonant circuit
2025-08-26Wuhan UHV specializes in producing series resonance (also known as variable frequency series resonance withstand voltage device). Next, we will share with you the definitions of series resonance circuit and parallel resonance circuit. Do you know.The definitions of series resonant circuit and parallel resonant circuit are interpreted as follows:1. If the components in the road are connected sequentially one by one, then the circuit is a series circuit.The characteristic is that the current flowing through one component also flows through another. In a series circuit, due to the fact that there is only one path for current, the current flowing out of the positive pole of the power supply will flow through each appliance one by one, and then return to the negative pole of the power supply. Therefore, in a series circuit, if one of the appliances is damaged or disconnected at a certain point, the entire circuit will become broken, the circuit will have no current, and all appliances will
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The Current Status and Development of Series Resonant Power Supply
2025-08-25Wuhan UHV specializes in producing series resonant (also known as AC withstand voltage test device), and now we will share with you the current development of series resonant power supply.Development of series resonant power supplyEarly charging power sources used constant voltage DC charging, but their efficiency could not keep up with the design requirements. In order to achieve fast charging, power frequency resonance was developed, which linearly increased the voltage of the capacitor. However, the self-regulation ability of the current was too poor. With the change of load, the inductance and transformer volume under power frequency were large, and common mode interference was also serious, which could not achieve the required voltage accuracy and was inconvenient to carry. Therefore, inverter based circuits appeared. Although the weight and volume were reduced, the switching frequency of the thyristor was close to 10 Khz, and the triggering circuit of the thyristor was also very
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What should be noted for on-site testing of series resonance test device
2025-08-25Wuhan UHV specializes in producing series resonance (also known as series resonance test device). Next, we will share with you what to pay attention to during on-site testing of series resonance test device.1、 Preparation before the experiment1. The number of examiners shall not be less than 2. Strictly follow the national safety management and operation design regulations for high-voltage testing during use;2. In order to ensure the safety and correctness of the experiment, in addition to being familiar with the product specifications, it is also necessary to strictly follow the relevant national standards and regulations for experimental operations; 3. Experimental researchers can manage and check equipment information based on the packing list when opening the packaging box. If they find that the enterprise equipment does not match the packing list, they should immediately contact the manufacturer;4. The series resonance test device should be used by high-voltage testing profession
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Introduction to series resonance as a substitute for power frequency withstand voltage
2025-08-25Wuhan UHV specializes in producing series resonance (also known as variable frequency series resonance device). Next, we will share with you the introduction of series resonance as a substitute for power frequency withstand voltage.Series resonance can replace power frequency pressure. The corona sound and ozone odor of 7KV power frequency withstand voltage are very strong, which may be caused by the discharge of air from the test transformer casing. The low and odorless sound of the series resonance is due to the voltage distribution of the series resonance being distributed from bottom to top throughout the height of the reactor. So the creepage distance is different, so there is no ozone smell. Substation frequency converter series resonance tester, this series of voltage withstand devices is mainly designed and manufactured for AC voltage withstand testing of primary electrical appliances in substations of 220 kV and below. According to the requirements of the regulations, AC with
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The reason for the large series resonant current
2025-08-22Wuhan UHV specializes in producing series resonance (also known as series resonance withstand voltage equipment). Next, we will share with you the reasons for the large series resonance current.Principles of series resonance and parallel resonanceIn a series circuit of resistors, inductors, and capacitors, the phenomenon where the terminal voltage of some circuits is in phase with the total current of the circuit is called knowledge series resonance. A series resonant circuit is purely resistive, with terminal voltage and total current in phase. At this point, the impedance is low, the current is high, and high voltages many times greater than the power supply voltage may be generated on the inductance and capacitance. So series resonance is also called voltage resonance. In a circuit where the coil of an inductive sensor is connected in parallel with a capacitor, the phenomenon where the terminal voltage of a parallel control circuit is in phase with the total current of the circuit
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Purpose of AC withstand voltage test equipment testing
2025-08-22Wuhan UHV specializes in producing series resonance (also known as AC withstand voltage test equipment). Next, we will share with you the purpose of testing AC withstand voltage test equipment.Purpose of series resonant AC withstand voltage testSeries resonant AC pressure testing is the most effective and direct method for identifying the insulation strength of power equipment. However, non-destructive tests such as insulation resistance and absorption ratio tests, dielectric loss TG δ tests, and direct current leakage current tests can detect some insulation technical defects. However, due to the low voltage level of these tests, some local control defects may not be reflected clearly, and these local defects pose information security risks during operation. In order to effectively identify local control defects in certain enterprises, it is necessary to conduct information exchange withstand voltage tests on the test samples. The AC withstand voltage test will make the existing insu
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Introduction to series resonant voltage withstand device
2025-08-22Wuhan UHV specializes in producing series resonance (also known as cable withstand voltage test equipment). Next, we will share with you an introduction to the series resonance withstand voltage device.Composition of series resonant deviceSeries resonance is mainly composed of a frequency conversion series resonance test console, excitation transformer, high-voltage reactor, high-voltage voltage divider, etc. Principle of series resonant deviceSeries resonance is the application of the principle of variable frequency resonance, which uses an excitation transformer to excite a series resonant circuit, adjusts the output frequency of the variable frequency controller, and causes the circuit inductance L and the test sample C to resonate in series. The resonant voltage is the voltage applied to the test sample. Analysis of the principle of series resonance deviceIn an AC circuit with resistance R, inductance L, and capacitance C, the voltage at both ends of the circuit is generally diff
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Operation process of power frequency withstand voltage test equipment
2025-08-21Wuhan UHV specializes in producing series resonance (also known as power frequency withstand voltage test equipment). Next, we will share with you the operation process of power frequency withstand voltage test equipment.1. Check the connecting wires and confirm that they are correct;2. Power on: The voltage regulator console of the inductive series resonance test device starts the "power switch" after power on, the "power indicator" light is on, and the LCD lights up to display3. Increase the output voltage of the voltage regulator: generally increase it by 20V to 40V.4. Adjusting the gap of the reactor: (i.e. finding the resonance point) In general, the adjustable reactor core should be in the zero gap position after the last test and before the start of this series resonance test. Start pressing the "Increase Gap" button and pay attention to the value of the "Test Voltage". During the process of adjusting the gap, the test voltage increases with the increase of the iron core gap (be
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Operation steps of AC withstand voltage test device
2025-08-21Wuhan UHV specializes in producing series resonance (also known as AC withstand voltage test device). Next, we will share with you the operation steps of the AC withstand voltage test device.With the development of the power system, the capacity of operating equipment is increasing. For example, thermal power generation units have a single unit capacity of over 1000MW, and hydroelectric power generation units have a maximum single unit capacity of 800MW. Traditional testing equipment requires a large capacity for testing, and test transformers and voltage regulators are very bulky. Large capacity test power sources are also difficult to solve on site, making on-site testing extremely inconvenient. The series resonant AC withstand voltage test device has great advantages in terms of test power capacity, equipment weight, test waveform, and investment1. The overcurrent protection setting is set at 1.2 times the rated current on the high-voltage side of the test transformer.2. Overvoltage
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