Shunt Reactor Research Articles

A typical dry-type iron core reactor failure and its treatment measures

Dry-type iron core reactors frequently have various insulation faults due to their own process defects and operating environment impacts, which pose a certain threat to the safe and stable operation of the power grid. In this paper, the technicians conducted overall tests, on-site analysis, and comprehensive judgment on a 220kV dry-type iron-core shunt reactor, and proposed solutions on this basis, which have certain guiding significance for solving the insulation failure of the iron-core shunt reactor.

SHORT CIRCUIT CURRENT CONTROL DEVICE TO INCREASE THE EFFICIENCY OF POWER SUPPLY SYSTEMS

Amid growing levels of short-circuit currents, issues related to increasing the efficiency of methods and means of limiting short-circuit currents are central in the context of development of Ukraine’s energy sector. A key factor here is intensifying pace of decreasing electricity losses in power supply production systems (PSPS), which could be achieved through implementation of new and improved efficiency of existing methods and means of limiting short circuit currents. The scientific and practical relevance of improving the functioning of credit limit short – circuit (short circuit), formulated the goal and objectives of research. As a solution proposed research and the way to manage complex limitation of short circuit currents in electricity supply production systems under the reactor – controlled shunt. The algorithm of the system reactor – controlled shunt. For the first time the schemes cause – effect relationships occurrence of short – circuit currents – Figure Ysikavy according to ISO 9004. The proposed method of limiting short circuit currents in the PSPS and the suite for its implementation under the controlled shunt reactor scheme fully compensates for all the disadvantages that occur when limiting short circuit currents in the PSPS under the unregulated shunt reactor scheme. It should also be noted that the limitation of short circuit currents in the PSPS under the controlled shunt reactor scheme has certain advantages over other means of limiting short circuit currents.

Air‐core dry‐type shunt reactor protection based on an alternative current alpha plane

Air‐core dry‐type shunt reactor protection based on an alternative current alpha plane

Simulation Analysis of Vibration and Noise Characteristics of High Voltage Shunt Reactor Based on Multi-physical Field Coupling

In order to study the vibration characteristics of the high-voltage shunt reactor, a finite element model of the single-phase reactor was established based on the analysis of the vibration mechanism of the reactor body, by using COMSOL multi-physical field coupling simulation software. The magnetic flux density distribution of reactor core, windings, stress distribution and vibration displacement of iron core were analysed by simulation. The sound pressure distribution of the iron core was analysed based on the pressure sound field model. The results indicate that the magnetostrictive effect of the iron core reactor, the electromagnetic attraction between the iron core cakes and the ampere force on the winding are the main factors for its vibration. In addition, the reactor vibration to be mainly concentrated at the core air gap. The results obtained by multi-physics simulation are basically consistent with the measured data, which verifies the effectiveness of the simulation method. The conclusions can provide theoretical basis for the analysis and monitoring of reactor vibration and noise.

Adaptive Overhead Transmission Lines Auto-Reclosing Based on Hilbert–Huang Transform

This paper presents a reliable and fast index to detect the instant of arc extinction for adaptive single-pole automatic reclosing (ASPAR). The proposed method is a simple technique for ASPAR on shunt compensated transmission lines using the Hilbert–Huang Transform (HHT). The HHT method is a combination of the empirical mode decomposition (EMD) and the Hilbert transform (HT). The first intrinsic mode function (IMF1) decomposed by EMD, which contains high frequencies of the faulty phase voltage, was used to calculate the proposed index. HT calculates the first IMF spectrum in the time-frequency domain. The presented index is the sum of all frequency contents below 55 Hz, which remains very low until the fault clearance. The proposed method uses a global threshold level and therefore no adjustment is needed for different transmission systems. This method is effective for various system configurations including different fault locations, line loading, and various shunt reactor configurations, designs, compensation rates, and placement. The performance of the method was verified using 324 test cases simulated in electromagnetic transient program (EMTP) related to a 345 kV transmission line. For all the test cases, the algorithm successfully operated with an average reclosing time delay of 32 ms.

The Magnetically Controlled Reactor Applied to Peruvian Power System

Nowadays, the electrical systems require new flexible AC transmission systems; they allow the implementation of new reactive control and flexibility with the short circuit currents, with modern control systems. This paper develops the design of a magnetically controlled reactor (MCR) system, with a case study for design and application in the Peruvian power system. The dynamics analysis and faults considerations are important points for new projects in a real power system. The MCR could be applied in the power systems, instead of a static var compensator (SVC) or static synchronous compensator (STATCOM), besides the Transient Restoration Voltage is eliminated in the case of shunt reactors in power lines for the circuit breakers degradation. The main characteristics, constraints and benefits are developed in this research.

Optimal Conditions for Controlled Switching of a Three-Phase Shunt Reactor

The switching of shunt reactors in an electrical network is in many cases accompanied by reignition of the arc in the circuit breaker and the occurrence of dangerous overvoltage in the network. To limit such overvoltage, controlled-switching devices are used to switch off the reactor in the optimal phase of the current. To select the optimal switching conditions, the switching processes are analyzed, taking into account the intuitively clear difference between the switching conditions for three-phase and single-phase shunt reactors due to the electrical and/or magnetic coupling between the phase windings. The proposed method of analysis is universal for all types of three-phase shunt reactors due to the use of a universal four-legged star equivalent circuit. The reactor phases are switched off, synchronized against the phase Avoltage curve, in the sequence A → C → B to minimize the total switching time.

Hardware Emulation of Energization of a Long Transmission Line by High-Frequency Power Electronic Converter

Hardware emulators, simulating a test environment in real time, are an essential tool in testing power system equipment. This article presents a hardware emulator of a programmable transmission line capable of simulating high-frequency transients. Emulation of, energization of long transmission line, requires the observer to solve transmission line or telegraphers equations in real time. This article identifies a continuous time model that captures the wave nature and suitable for real-time implementation. This article derives the discrete-time model to be solved in the observer of the hardware emulator. A step-by-step procedure is given to determine two key emulator parameters: observer sampling frequency, and switching frequency of the power amplifier considering different hardware, event, and software related constraints. For high bandwidth requirement, a high switching frequency, 100-kHz, 12-kVA silicon carbide (SiC) based voltage source converter is designed to operate under a current controller with a gain crossover frequency of 5 kHz. A system on chip that combines an Anvanced RISC Machine (ARM) processor along with an field programmable gate array (FPGA) is used to implement the observer. Experimental results verify accuracy of the designed emulator in the event of energization of a long transmission line. Though proposed transmission line emulator can only be used to study the energization of a long line with one end terminated with shunt reactor, the solution can be extended for emulation of a long line that links two sections of power grid.

Research on switching overvoltage suppression of 35 kV shunt reactor

In recent years, a number of equipment abnormal events caused by operating overvoltage have occurred during the interruption of 35 kV shunt reactors, which jeopardizes the safe and stable operation of the grid. In order to explore the mechanism of operating overvoltage when 35 kV shunt reactor is cut off and the effect of various suppression measures, this paper carries out simulation analysis and research, mainly considers several factors to the effect of overvoltage, such as bus outlet, circuit breaker switching position and overvoltage protector.

Investigation and Mitigation of Temporary Overvoltage Caused by De-Energization on an Offshore Wind Farm

The Ferranti effect could cause a rise in voltage along the cables on a wind farm if the circuit breakers at the receiving ends are switched off. Ferroresonance could also occur due to stuck pole(s) of the circuit breaker during de-energization. This paper reports on the temporary overvoltage (TOV) arising from the de-energization of the circuit breaker connecting the wind turbine to the feeder, the feeder breaker connecting an array of wind turbines to the point of common coupling (PCC), and the opening of the circuit breaker connecting the onshore to the offshore substation. Ferroresonance was characterized using a phase plane diagram and Poincaré map and was identified to be chaotic. The effect of the nonlinear characteristic of the wind transformer core on the ferroresonant overvoltage was examined and increased with the steepness of slope of the transformer curve. A damping resistor, shunt reactor and surge arrester were used to mitigate the overvoltage experienced during the ferroresonant event. The damping resistor was able to reduce the overvoltage to 1.24 P.U. and damped the ferroresonance from chaotic to fundamental mode.

A Procedure for Placing Shunt Reactors in High-Voltage Networks and Justification of its Efficiency

In recent years, the controlled shunt reactor (CSR), a type of FACTS device, has been widely used to regulate voltage and reactive power flows in the high-voltage electrical network. The selection of location and the determination of the law of CSR control under the stochastically variable operation of high-voltage power transmission lines are associated with numerous technical and economic factors. At the same time, one should take into account such limiting conditions as ease of use, performance, purpose, and location in the system, as well as the time of commissioning. In the proposed procedure, these factors are considered as fuzzy constraints. The paper proposes a procedure for CSR placement in the 330 kV electrical network of the “Azerenergy” system for control of reactive power flows, given the mentioned fuzzy constraints. The obtained simulation results demonstrate the advantage of the proposed procedure. The computational experiments confirm the CSR efficiency.

Analysis of the overvoltage cooperative control strategy for the small hydropower distribution network

AbstractIn general, the seasonal characteristics of small hydropower (SHP) especially the power transmission during the summer flood season would lead to the steady overvoltage of the distribution network. In order to suppress this steady overvoltage, a strategy for coordinated cooperation between generator phase-in operation and shunt reactors which can be called cooperative control is proposed. The distribution network of SHP stations connected to the 35 kV Bantao substation in southern Shaanxi is taken as an example to study the mechanism of overvoltage after the SHP is connected to the grid. A distribution network model with SHP units is established. Based on the model, the effect of separately installing shunt reactors on the node voltage is studied in the case of generator lag phase operation and the influence of the operation mode of SHP unit on the node voltage is also analyzed separately. Finally, the improvement measures of cooperative control between the generator phase-in operation and the parallel reactors are analyzed by simulation. Results are presented to verify the improvement measures that can effectively restrain the overvoltage of the distribution network in the SHP area.

Adaptive Single-Phase Auto-Reclosing Approach for Shunt Compensated Transmission Lines

Single-phase auto-reclosing (AR) scheme is widely employed in extra high voltage (EHV) transmission networks to quench transient faults without completely removing the faulted transmission line (TL). Long EHV TLs are commonly equipped with shunt reactors to reduce the Ferranti effect overvoltages. It is common practice to disconnect these reactors under the heavy load periods during the year. Considering this point, the AR technique should be able to work properly not only when the TL shunt reactors are in service, but also when they are disconnected. This paper puts forward a novel adaptive single-phase AR approach for shunt compensated TLs based on the general mathematical model of faulted phase voltage waveform after the line isolation, which is obtained by analytical analysis conducted on the TL's equivalent circuit. The effect of capacitor voltage transformer (CVT) on the voltage measurement is taken into account using a proper model for the CVT. Performing some data processing on the faulted phase measured voltage, useful features are extracted which are used by the support vector machine classifier to reliably detect the arc extinction instant. The proposed approach performance is evaluated by extensive simulation studies, accounting for different TL compensation schemes, transposition configurations, and arc conditions.

МОДЕЛИРОВАНИЕ РЕЖИМОВ ДАЛЬНИХ ЛЭП, ОСНАЩЕННЫХ УСТАНОВКАМИ ПРОДОЛЬНОЙ КОМПЕНСАЦИИ

The results of computer studies of long-distance transmission modes of 500 kV, equipped with a longitudinal compensation unit, shunt reactors and a controlled source of reactive power are presented. It is shown that in the presence of all of the above devices, the relative losses of active power at the main section of the power transmission line are reduced by half compared with situations of their absence.

Effects of 500 kV EHV Transmission Lines on Location Determination and Capacity of Shunt Reactor in South Sulawesi Systems

Electricity in South Sulawesi system is so extensive that it is necessary to construct a 500 kV Extra High Voltage (EHV) to avoid instability and waste of electricity during the distribution of electricity. need. Therefore, this paper describes the implementation of research on optimizing the electrical energy network system from renewable energy power plants in the form of the application of extra high voltage transmission. This research was carried out as an effort to implement a 500 kV extra high voltage transmission in South Sulawesi. The length of the 500 kV EHV to be installed includes an extra-long transmission, which is 365 kms which will produce more voltage on the network during light loads. So, it is necessary to make efforts to improve the electrical system to meet applicable standards, including the addition of the shunt reactor. The purpose of this study is to obtain conclusions about the effect of the shunt reactor on the South Sulawesi transmission system after the 500 kV EHV is applied. The research that has been carried out aims to obtain the optimal location and capacity of a shunt reactor. The results of this study will be very useful for electricity stakeholders, especially transmission companies in South Sulawesi.

Controlled Shunt Reactor for UHVAC System Reactive Power Control

Background: In this paper, a novel technique for reactive power management of the Ultra High Voltage (UHV) lines having voltage level of 1200 kV line and above is suggested. The UHV power grid has to frequently face the problems associated with the power- frequency and switching over-voltages. Methods: The technique involves the use of three-phase UHV Transformers as a Controlled Shunt Reactor (CSR) in combination with the use of a fixed reactor. The performance of the UHV AC transmission line is studied using PSCAD software and working of CSR is evaluated. Results: Standard parameters of the proposed Wardha-Aurangabad 1200 kV transmission line in India are considered for simulation model. The use of CSR has been found to be effective in mitigating system problems. Conclusion: The system can be used for maintaining voltage profile, resulting in enhancement of the reliability of the UHV transmission system.

Simulation of Temperature Field of Dry-Type Air-Core Shunt Reactor at Different Temperatures

Simulation of Temperature Field of Dry-Type Air-Core Shunt Reactor at Different Temperatures

Research on the Effect of Plant Boundary Conditions on Noise Attenuation in UHV Substations

Accurately analyzing the influence of the terrain environment of the plant boundary on noise transmission and attenuation can not only give guidance for the substation site selection and station layout optimization, but also provide theoretical basis for noise abatement after the substation has been put into operation. In this paper, by applying sound level meters to test the sound pressure of the main equipment in the substation and the noise around the plant boundary, the noise characteristics of main transformers and shunt reactors, as well as the noise distribution around the plant boundary were analyzed, thus concluding that the noise at the plant boundary is mostly derived from the main equipment within the substation. While taking the layout of the Zhebei UHV Substation as an example, this paper chose the SoundPLAN software to simulate and calculate the noise attenuation law under seven terrain conditions outside the plant boundary, and finally such a proposition as the low-lying terrain and the raised hilly terrain can best interrupt the noise transmission was made. The conclusions of this paper can provide a theoretical reference for site selection of new substations and optimizing the terrain structures of substations in operation.

A Fault Analysis of 750kV Shunt Reactor and Repair Program

Combined with an example of 750kV shunt reactor exception handling, the author used field test inspections and search methods to dismantle the plant and found that the cause of the reactor abnormality was an incident caused by impurities or foreign matter. Combining the historical operation data of the equipment, the analysis and comparison of the reactor’s routine inspections and test results are performed. Combined with the simulation calculation of the internal insulation margin of the reactor, the judgment methods and conclusions are given, and the troubleshooting method and flow of the reactor abnormality are proposed, and put forward specific measures to strengthen the state monitoring of the network operation reactor.

A new differential protection algorithm for power reactors based on the second central moment

Power shunt reactors are critical elements in electric power systems for controlling reactive power and maintaining voltage within a permissible range in transmission systems. Protection schemes for shunt reactors are similar to those used in power transformers, e.g., the differential, overcurrent, and distance protection schemes. However, these protection schemes may misoperate for several reasons such as a decaying DC component when the reactor is energized, or the occurrence of current transformer saturation when an external fault occurs. In this context, a novel differential protection algorithm for power shunt reactors is proposed. This algorithm uses the magnitude of the second central moment as a basis for identifying whether the event corresponds to an internal fault. The proposed algorithm was tested and implemented using PSCAD and the MATLAB software. Current transformer saturation and noise were considered in all the events evaluated. The results show that the proposed algorithm accurately discriminates between internal and external faults as well as transient events such as inrush currents. Furthermore, the algorithm exhibits a limited capability for detecting turn-to-turn faults until 2% of short-circuited turns.