最新刊期
卷 46 ， 期 6 ， 2025
- 摘要：The grading rings，as a key part for electric field homogenization in high-voltage transmission equipment，often experience vibrations induced by wind loads，leading to structural fatigue or even fracture. In this paper a wind-induced vibration suppression method by optimizing the dynamic characteristics of grading rings through counterweight addition is proposed. First，a dynamic model of the grading ringcounterweight system is set up to analyze the regulatory mechanism of counterweights on natural frequencies and vibration modes. Then，finite element simulation is used to verify the vibration suppression effect of the counterweight-enhanced scheme on wind-induced frequencies. Finally，the engineering applicability of the counterweight optimization scheme is verified through a case study of wind-induced vibrations in grading rings installed on capacitor banks at a converter station in Hami，Xinjiang.关键词：grading rings;vortex shedding frequency;wind-induced vibration suppression;counterweight optimization;natural frequency0|0|0更新时间：2026-01-23
- 摘要：Under lightning strike conditions，direct current transmission lines can cause overvoltage in the neutral area of converter station，greatly affecting and threatening the safe and stable operation of equipment（with DC filters in particular）of neutral area. In this paper an electromagnetic transient simulation model is set up to investigate overvoltage characteristics，fousing on a typical fault overvoltage event and its properties in the pole II HP12/36DC filter in the full-voltage operation mode of the DC bipolar ground return system at a ±500 kV converter station. It is concluded that the overvoltage is a non-standard type of power frequency overvoltage between power frequency overvoltage and operating overvoltage. Based on this conclusion，the influence of such factors as creepage distance calculated voltage，lightning withstand voltage and operating withstand voltage on overvoltage is analyzed，The type selection requirements for DC filters and their supporting insulator are proposed. This has reference and inspiration value for the selection of transient rated values and key parameter optimization of filters and lightning arresters.关键词：DC filter;lightning overvoltage;operating overvoltage;power frequency overvoltage;transient parameters0|0|0更新时间：2026-01-23
Reactive Power Compensation and Filter
- 摘要：Oil-immersed capacitors are widely used in power systems for reactive power compensation and filtering due to their advantages of high reliability and low cost. With the increasing demand of energy storage density of capacitors in power systems，the energy storage performance of traditional biaxially oriented polypropylene（BOPP）film has gradually been unable to meet the demand. Although the research of materials with high energy storage density has achieved remarkable results，yet the prerequiste for developing high property oil-immersed capacitors is to reveal the aging characteristics of dielectric materials in actual condition of oil-immersed capacitors. Therefore，in this paper a systematic study on the aging characteristics of BOPP film under electric-thermal-oil coupling condition is proposed. The electric-thermal aging experiment for 1000 hours is performed by way of setting up electric-thermal-oil coupling aging experimental platform and the The BOPP film samples immersed in benzyl toluene impregnating agent（M/DBT）are obtained. Such tests as Fourier transform infrared spectrometer（FTIR），differential scanning calorimetry（DSC），dynamic thermomechanical analysis（DMA）and direct current breakdown are performed on the BOPP film before and after aging. The results show that small molecules of impregnating agent enter into the molecular gap of BOPP which，on the one hand，plays the role of softening molecular chain and reduces the activation energy of molecular chain segments and，on the other hand，the coupling effect of the electric-thermal-oil destroys the regularity of molecular chain segment，resulting in the decrease of the breakdown strength of the films by 14.85% . The study provides data support and theoretical foundation for the development of dielectric materials and impregnating agent for oil-immersed capacitors.关键词：oil-immersed capacitors;polypropylene;M/DBT;electric and thermal aging;insulating properties0|0|0更新时间：2026-01-23
- 摘要：As for the the operation conditions of high-voltage shunt capacitors in harmonic environments，in this paper the influence of harmonic voltage amplitude on the thermal stablility temperature rise characteristics of capacitors is studied. Through setting up thermal stability test platform and at the condition of constant ambient temperature at 30℃，a voltage combination of undamental waves superimposed with 3rd-order harmonics at different phases is applied to the capacitors.While maintaining constant current RMS value and harmonic frequency，the synthetized voltage amplitude is adjusted by varying the harmonic phases，thereby decoupling the influence of voltage on dielectric loss. The temperature measurement data is filtered by using a Kalman filter algorithm，and the thermal stability temperature rise value is extracted based on the temperature rise variation rate. The test result shows that in case of harmonic phase at 180°，the amplitude of synthetized voltage is maximum and the temperature rise of the capacitors is the highest. While in case of phase at 0°，the the amplitude of synthetized voltage is minimum and the temperature rise of the capacitors is the lowest. The findings confirm the influence of voltage amplitude on dielectric loss and temperature rise. The research in this paper provides both theoretical base and experimental support for assessing thermal stability performance of high-voltage shunt capacitors in harmonic conditions.关键词：power capacitor;Harmonic phase;voltage amplitude;dielectric loss;thermal stability and temperature0|0|0更新时间：2026-01-23
- 摘要：The reliability of VSC-HVDC DC capacitors directly affects operation reliability of the converter valve. It is necessary to study their steady and transient operating characteristics so to provide a basis for the full-condition equivalent test of theVSC-HVDC DCcapacitors. In this paper the actual parameters of the Wudongde project system is taken as an input，an electromagnetic transient simulation model of VSCHVDC DC system containing real sub-modules is set up，and the steady and transient operating characteristics of theVSC-HVDC DCcapacitors is analyzed. The simulation results show that under steady conditions，theVSC-HVDC DCcapacitors are subjected to a step-shaped AC voltage biased by DC，regardless of whether there is a negative switching condition. Under steady conditions，the current on the VSC-HVDC DC capacitors is a superposition of the power frequency AC current and the impulse current. In case of no negative switching，only a positive impulse current is existed on the capacitors. While，in case negative switching，both positive and negative impulse currents are existed on the capacitors. Under transient condition，the peak of current of theVSC-HVDC DCcapacitors is the highest under a single-phase grounding fault on the valve side of high valve group converter transformer，and the peak of transient voltage of the capacitors is the highest under a single-phase grounding fault on the valve side of low valve group converter transformer.关键词：VSC-HVDC transmission;capacitor;steady-state;transient;voltage and current characteristics0|0|0更新时间：2026-01-23
- 摘要：In the VSC-HVDC transmission system，metallized film capacitors serve as core energy storage components，and their reliability directly affects safe operation of the power grid. As for the the failure issues due to manufacturing defects in projects，in this paper the failure mechanisms of such four typical defects as winding，metallization，casting and impurity intrusion are systematically studied. Through such multidimensional tests as inter-electrode voltage withstand，impulse discharge，and accelerated aging under AC and DC conditions and also in combination with capacitance degradation as well as dielectric loss characteristic analysis，the failure of defects under different stress conditions are revealed. The capacitance sensitivity factor is used to quantify the defect sensitivity of different tests. The results show that inter-electrode voltage withstand is most sensitive to metallization defects，the impulse discharge is most sensitive to the winding defects，the DC voltage accelerated aging is most sensitive to casting defects，the DC superimposed power frequency AC is most sensitive to casting defects，and the DC durability is most sensitive to the winding defects. The defect protection strategies are proposed based on the defect mechanism，providing theoretical and technical support for enhancing capacitor reliability.关键词：metallized film;VSC-HVDC transmission;capacitor;aging;lifespan0|0|0更新时间：2026-01-23
- 摘要：Aiming at the key process defects in the production process of VSC-HVDC capacitors，in this paper the types of defects due to soldering and casting and their impact on the performance of the prototype are systematically studied，and the characteristic parameters corresponding to different defects are clarified. By artificially setting such typical defects as cold solder joints，sharp angle soldering，non-vacuum casting and case separation，defective components and test samples are designed and produced，and corresponding process quality control measures are proposed. Based on such characteristic parameters as capacitance，loss tangent，partial discharge and also in combination with such test methods as withstand voltage of pole to case，partial discharge，inter-pole withstand voltage，and DC aging，the influence of different defects on the performance of capacitors is analyzed. The research results show that the cold solder joints defects significantly increase the partial discharge，the non-vacuum casting defects are prone to cause self-healing failure in AC/DC superimposed aging tests，while the non-injection defects accelerate the degradation process of capacitors. The defect characterization parameters and test methods proposed in this paper provide theoretical basis and test method support for process optimization and quality improvement of VSC-HVDC capacitors.关键词：VSC-HVDC capacitors;process defects;performance characterization;partial discharge;aging test0|0|0更新时间：2026-01-23
Capacitor
- 摘要：In this paper，such drawbacks as the frequent modification of the test circuit and manual installation and disassembly of the oil cup in the common delivery test of capacitive divider，and the basic principle，hardware structure and control system of the automatic wiring test device for the capacitive divider is analyzed in detail. The use of the equipment developed by such devices as a live-line changing devices，pneumatic wiring devices，and standard capacitor adapter transfer box and through the programmable logic control，can significantly reduce the number of wiring connections while ensuring safety，thereby enhancing the testing efficiency.关键词：capacitive voltage divider;test;automatic wiring;Safety;efficiency0|0|0更新时间：2026-01-23
- 摘要：The high-precision，low-temperature coefficient resistors in resistive capacitive DC voltage divider for DC converter station are used for voltage division. High frequency harmonics can cause heat of the internal capacitors of the voltage divider，rise of insulation oil temperature，and dissolution of polypropylene film in the capacitor element in the high temperature insulation oil，reducing the surface insulation strength of the insulation material of capacitor element and causing breakdown of capacitor element. In this paper the fault phenomenon and heat development process of the resistive capacitive DC voltage divider due to high-frequency harmonics in a VSC-HVDC power grid project is analyzed. The fault mechanism is analyzed through the disassembly，harmonic monitoring，decomposition and simulation of the voltage divider. The influence of high-frequency harmonics on the edge flashover and insulation performance of the capacitive elements inside the voltage divider is studied，and the influencing factors of the insulation performance of the resistive capacitive voltage divider are verified. The specific improvement measures are proposed from the aspects of structural process，design selection，and resistive capacitive performance，providing the theoretical support and technical reference for improving the intrinsic safety level of the resistive capacitive voltage divider.关键词：VSC-HVDC engineering;DC voltage divider;resistive capacitive type;high frequency harmonics;breakdown strength0|0|0更新时间：2026-01-23
- 摘要：Capacitive voltage transformer（CVT）is an important electrical equipment in power system for measurement，protection and metering，and is widely used in substations at 110 kV and above. Its insulation condition has a significant impact on the stable operation of power system. In on-site tests，the dielectric loss factor（tan δ）is often used as the base for judging the insulation condition of CVT. However，in some CVT with film-paper composite insulation structure the Garton effect is existed. Sometimes，such abnormal data as high tan δ may occur in the dielectric loss test at 10 kV and below，which cannot reflect the real insulation condition of the equipment. In this paper a case of abnormally high dielectric loss in the lower section capacitor of a 330 kV film-paper insulated CVT due to the Garton effect is analyzed，the determination and handling methods of the Garton effect in on-site tests of CVT are proposed，providing a scientific reference for the dielectric loss measurement and insulation condition judgment of CVT. This is of great significance for maintaining the operation reliability of power grid and improving economic benefits.关键词：capacitive voltage transformer;film-paper composite insulation structure;Garton effect;dielectric loss factor2|0|0更新时间：2026-01-23
Instrument Transformer
- 摘要：In this paper，the complex domain averaging modeling method is adopted to model the threephase LCL grid-connected inverter，simplifying the complex three-phase multi-input and multi-output（MIMO）system into a single-input and single-output（SISO）system. On this basis，the state equation of the three-phase LCL grid-connected inverter system in the complex domain is derived，and the control strategy for the grid-connected current based on the complex domain model is designed. Secondly，the stability of the control system of the three-phase LCL grid-connected inverter is analyzed by using the complex Hurwitz criterion and the control parameter range for stable operation of the system is obtained. The effectiveness and correctness of the method are verified by both simulation and experimental results.关键词：complex domain;three-phase grid-connected inverter;complex Hurwitz criteria;multi-input and multi-output;single-input and single-output2|0|0更新时间：2026-01-23
- 摘要：Ultra wideband（UWB）method is used to achieve personnel positioning in thermal power plants. However，due to the complex environment of thermal power plants，issues of multipath reflection and non Line of sight（NLoS）occlusion are existed，resulting in significant fluctuations in positioning results. A novel UWB personnel positioning system，which integrates random forest classification，neural network error compensation，and Q-learning dynamic anchor point selection，is proposed so to achieve the Line of Sight（LoS）/Non Line of Sight（NLoS）link state recognition，ranging error correction and dynamic optimization of base station subsets，which significantly improve positioning stability without the need for additional hardware deployment. The simulation results show that after adopting the new UWB personnel positioning system，the maximum jump error of personnel positioning is reduced to 0.4 m，and the Root mean squared error（RMSE）can be reduced by 85%，which effectively improve the stability and accuracy of personnel positioning in complex industrial environments of thermal power plants.关键词：UWB;Q-learning;random forest;dynamic anchor point selection;error suppression2|0|0更新时间：2026-01-23
Research on System Application
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