Controlled Shunt Reactor Research Articles

A Study of the Operating Modes of Controlled Shunt Reactors in Electrical Networks of 330 kV and Higher Rated Voltages

A Study of the Operating Modes of Controlled Shunt Reactors in Electrical Networks of 330 kV and Higher Rated Voltages

Analysis of DC Bias in Magnetic Controlled Shunt Reactor and Its Influence on Interturn Protection

Abstract Magnetic controlled shunt reactor is widely used in new energy transmission, and its special operation characteristics provide dynamic reactive power compensation for the power system, while the reactive power capacity can be continuously adjusted, solving the problem that conventional fixed reactance cannot be applied to reactive power demand fluctuations. This paper briefly introduces the structure and working principle of a magnetic controlled shunt reactor, analyzes the relationship between core magnetic saturation and control current in a magnetic controlled reactor under different DC bias conditions, and the reliability of interturn protection under different working conditions is studied and a feasible scheme is proposed, provides a certain reference for the design and operation and maintenance of magnetic controlled shunt reactor.

Placement of controlled shunt reactors in 330 kV electrical networks and study of their operating modes

The improvement of the method for selecting shunt reactors based on instantaneous power in order to eliminate a surplus of reactive power created by the charging capacities of power transmission lines in 330-500 kV elelctrical networks of the power system is considered. Based on the proposed method, the performance of controlled shunt reactors located in priority 330 kV nodes of a real power system is superficially described and their operating modes are studied. As a result of the study, in accordance with changes in the modes of shunt reactors in real time, the voltage in the 330 kV buses is maintained in a stable and acceptable range, as well as the increase in the voltage stability of the power system.

Modeling and simulation of extra high voltage magnetically controlled shunt reactor based on PSCAD

For the two typical topologies of the extra high voltage magnetically controlled shunt reactor (MCSR), this study introduces its specific wiring methods and working principles. It conducts an analysis of the change characteristics and response characteristics of the core magnetic flux under different wiring modes of the controlled shunt reactor body. Based on PSCAD, two typical structures are used to model the body of the first 500 kV MCSR put into operation in a provincial power grid and perform steady-state and dynamic simulations. The results of field experiments are compared and analyzed. The winding connection mode of the device’s body electromagnetic transient model is determined, which lays a foundation for the follow-up research.

Study on the effect of different pre-excitation factors on the output characteristics of MCSR

This paper takes the BKFSZT-30000/400 three-phase eight-limb magnetically controlled shunt reactor as the research object. Firstly, an electromagnetic transient simulation model is established based on the parity principle to verify the operating characteristics of the MCSR during direct energization and pre-excitation energization. On this basis, the influence of the pre-excitation capacity and the target capacity on the output characteristics of the MCSR is investigated. The results show that during the pre-excitation process the currents of working and control winding produce a DC component and a harmonic component dominated by the second harmonic, with the size of both DC components mainly influenced by the pre-excitation capacity and the attenuation determined by MCSR; the variation of the working harmonics is mainly influenced by the target capacity, while the size and attenuation of the control harmonics are determined by the pre-excitation capacity and the target capacity respectively. The results of the study clarify the output characteristics of the MCSR when energization with pre-excitation and provide a reference for further analysis of the interaction with the grid. Finally, to solve the problem of no reliable external power supply for pre-excitation, a fast excitation energization method with short-connected of the compensation winding is provided and verified by simulation.

Designing a Reactor for Use in High Voltage Power Systems and Performing Experimental and Simulation Analysis

Today, magnetically controlled shunt reactors are widely used in solving power quality problems. These reactors are designed to reduce system reactive power, control high super/special high voltage grid voltage, suppress power frequency, regulate overvoltage, eliminate generator excitation, dynamically compensate transmission line power charge, suppress secondary arc current, suppress system resonance. By using suitably designed silica plate core reactors at the input of the frequency converters in the electrical distribution system, the level of harmonic currents drawn from the electrical power distribution system can be reduced to certain rates. The core material, the air-gapped nature of the reactor core, and the sizing of the reactor have a great influence on the harmonic level of the current and its ability to reduce losses in the reactor. In this study, three reactors with different core materials and different air gap gaps are designed for a certain voltage value. Parametric analysis of the reactors designed to see the changes in inductance values depending on the load level has been made both theoretically and experimentally and using the Finite Element Method. As a result of the analysis, the inductance stability, losses and compliance of the reactors with the standards are presented. The reactor's magnetic circuit is modeled with ANSYS@Maxwell, realizing a solution based on this method. The magnetic circuit is simulated to see the behavior of the reactor. In addition, real-time verification of the designed alternating current reactor has been made. Optimum design was obtained by using different core materials and different core air-gaped tested experimentally. The effect of the air gap distance in the core on the magnetic field and inductance value was also obtained.

Control strategy of controllable shunt reactors (CSR) in Zhangbei substation of Zhangbei-Xiongan UHV project

Based on the incremental control method of reactive power demand, this paper considers accessing the status information of low-voltage reactive power compensation devices and the reactive power exchange information of the medium-voltage side of the main transformer, so as to realize the reactive power balancing of the partition system, which is composed of the substation and half the length of substation outlets. Aiming at the actual situation of Zhangbei UHV substation interconnected with wind farms, this paper further considers the constraint of reactive power flow ride-through, so as to generate an inner-layer control strategy, which comprehensively considers the reactive power balancing of partition system and reactive power flow exchange. This inner-layer control strategy and the outer-layer control strategy of voltage boundary emergency control together constitute double-layer control strategy of controllable shunt reactors in Zhangbei UHV substation. This control strategy has passed the thematic review conference organized by the State Grid UHV Department, and has been applied to Zhangbei UHV substation.

Research on the protection strategy of open-circuit fault of controllable wiring in 1000kV switching-type controllable shunt reactor

In term of switching-type controllable shunt reactor of ZHANGBEI to XIONG'AN ultra-high voltage (UHV) power transmission system, this paper study the character of open-circuit fault of controllable wiring in UHV switching-type controllable shunt reactor, the volt-ampere characteristic of open-circuit fault of controllable wiring is provided. Furthermore, this paper provided a method of the calculation of fault protection in open-circuit fault of controllable wiring, the simulation of RTDS is completed to prove its reliability effectiveness and accuracy.

ТЕХНІЧНІ ЗАСОБИ ПОДАВЛЕННЯ РЕЗОНАНСНИХ ЯВИЩ В ЕЛЕКТРИЧНИХ МЕРЕЖАХ

The self-excitation phenomenon of generators connected to an unloaded power line is considered. Accordingly, the selected values of the conductivity of the controlled shunt reactors, following the control range (especially in the overload mode), avoid the occurrence of self-excitation of the generators. The physical analysis of the processes occurring at self-excitation of the synchronous generator is given, and the calculated models are developed. It is established that in the case of artificial support along the entire length of the voltage line at the nominal value using controlled compensating devices, the transmission will have properties characteristic of relatively short lines (up to 500 km) regardless of its geometric length. It is determined that the length of the line section at the ends of which the DC voltage is maintained is much less than 500 km. Therefore, less than the natural voltage along the section length will exceed the nominal value at the transmitted power, and the line will have excess reactive power. Consumption in intermediate compensation devices (compensation current must be inductive). Ref.8, fig. 4, tables 4.

Investigation of GIS enclosure circulating current in UHV substation with hybrid reactive power compensation

There are typically large circulating current losses when such a current is produced in a gas-insulated switchgear (GIS). An excessive circulating current also causes a heating phenomenon and insulation aging, as well as hidden dangers and adverse effects on the normal operations of power systems. In addition, the installation of hybrid reactive power compensation (HRPC) may increase the complexity of the circulating current. Thus, a detailed investigation of GIS enclosure circulating current on an ultra-high-voltage (UHV) substation with HRPC is imperative. Here, the mechanism of the enclosure circulating current is thoroughly discussed, and models of the GIS busbar, and enclosure are established based on the partial element equivalent circuit (PEEC) method. Combined with HRPC equivalent circuit model, the equivalent calculation model for the GIS enclosure circulating current with HRPC equipment is established. The influence of the structural parameters on the circulating current, such as the inlet capacitance of the stepped controlled shunt reactor (SCSR), enclosure radius, enclosure height from the earth, and distance between earthing points, are considered in terms of the simulation model as built using transient simulation software. The factors that influence the enclosure circulating current and their associated rules are used to develop suppression measures.

DC Bias Characteristics Analysis of CSR of TCT Type in the Thyristor Abnormal Operation State

In order to obtain DC bias characteristics of controlled shunt reactors (CSRs) of thyristor controlled transformer (TCT) type in the thyristor abnormal operation state, a DC bias characteristics analysis model for the CSR based on Jiles-Atherton(J-A) theory is proposed. A single-phase prototype for the CSR is developed and tested. The coil currents and magnetic flux densities of the iron core are calculated in time domain and frequency domain based on the model. The experimental results agree well with the calculated results. The DC bias characteristics of the CSR are analyzed.

ПАРАМЕТРИЧНА ОПТИМІЗАЦІЯ РЕЖИМІВ РОБОТИ МАГІСТРАЛЬНИХ ЕЛЕКТРИЧНИХ МЕРЕЖ ЗА КРИТЕРІЄМ ВТРАТ АКТИВНОЇ ПОТУЖНОСТІ

It is shown that the use of controlled shunt reactors enables, based on ultra-high voltage transmission lines, to create a controlled generation of new generation FACTS types that meet the requirements of modern power systems and combinations. Typical modes of operation of the high-voltage power line with installed controlled shunt reactors are analyzed. The efficiency of the use of controlled shunt reactors as measures of transverse compensation in ultrahigh voltage transmission lines is shown. The article shows that due to a smooth change in the consumption of excess reactive power of the transmission line, the normalization of the voltage values is achieved, and, accordingly, the total power losses are reduced. Ref. 9, fig. 3, tables 3.

Magnetic Circuit Model of Magnetic Valve Controllable Reactor Considering Magnetic Flux Leakage Effect

The magnetic circuit model of the magnetic saturation characteristic magnetoresistance of the magnetically controlled shunt reactor (MCSR) nonlinear core is proposed by using the magnetic field division method, combining with the geometric parameters and working principle of the prototype. The magnetic circuit structure and working characteristics are analyzed. The calculation formula of the magnetic potential node of the magnetically controlled shunt reactor is derived by improving the node analysis method, and the simulation calculation and analysis of the working current of the magnetic control reactor under no-load and different DC bias are carried out. The conclusion shows that the accuracy of the magnetic circuit model can meet the needs of engineering, and the modeling method has the characteristics of clear principle, simple modeling, accurate model and engineering applicability, which can provide guidance for designers.

Simplified Modelling of Transient Ground Potential Rise of GIS in Ultra-high-voltage Substations with Hybrid Reactive Power Compensation

The application of hybrid reactive power compensation (HRPC) in ultra-high-voltage substations has a nonnegligible impact on the characteristics of transient ground potential rise (TGPR) in the gas-insulated switchgear (GIS) enclosure. In this paper, according to the principle of series compensation and stepped controlled shunt reactors under a very fast transient overvoltage, a simplified model of an HRPC device is established. Based on the generation mechanism of TGPR and the theory of transmission lines, the equivalent simulation circuit of GIS in a substation is designed under the occurrence of TGPR. Simulation experiments comparing the characteristics of TGPR with and without HRPC are conducted to explore the factors that influence TGPR. This paper proposes specific methods of reducing TGPR, and provides a theoretical basis for the construction of GIS protection devices for ultra-high-voltage substations.

On the issue of improving the efficiency of power systems and substantiation of reactive power compensation in electric networks

Reactive power in the power system negatively affects the operating mode of the electric network, additionally loading high-voltage lines and transformers, which leads to an increase in power losses, as well as to an increase in voltage drops. The influence of active and reactive power components of voltage in the network nodes is different and is overwhelmingly determined by the ratio of active and reactive components of the resistance elements of the electric system. In high-voltage networks, the reactive component of the resistance significantly exceeds the active component, and therefore the flow of reactive current through the network leads to a greater voltage drop than the flow of the active component of the current. The transfer of reactive power can lead to exceeding the normalized voltage range in the load nodes. To reduce power losses and voltage drop in the elements of the electric network, synchronous compensators (SC), static capacitor banks (SCB), static thyristor compensators (STC), controlled shunt reactors (CSR) can be used. The cost of production and transmission of active and reactive power are different, and when choosing the power of reactive power compensation means, it is necessary to take into account the costs and compare them with the resulting effect, which differs for large and small values of reactive power when this is reduced by the same amount. To assess the feasibility of application of compensatory devices, and to choose their type and locations of installation, relevant calculations are required. An empirical criterion is proposed for preliminary assessment of the technical feasibility of reactive power compensation. It enables to identify the network sections and nodes, which require reactive power compensation and should be considered in greater detail.

ЗАСТОСУВАННЯ КЕРОВАНИХ ПРИСТРОЇВ КОМПЕНСАЦІЇ ЗАРЯДНОЇ ПОТУЖНОСТІ ЛЕП НВН В ЕЛЕКТРИЧНИХ МЕРЕЖАХ

It is shown that the use of controlled shunt reactors allows you to create FACTS-controlled power lines based on extra-high voltage power lines that meet the necessary requirements of modern energy systems to control normal conditions. The typical modes of operation of an ultra-high voltage power line with installed controlled shunt reactors are analyzed. The efficiency of using controlled shunt reactors to increase the reliability of single-phase auto-reclosing is shown. The issues of the appearance of an aperiodic component in the current when disconnecting the line of SF6 circuit breakers are considered. It is shown that the presence of a ferromagnetic core in controlled shunt reactors causes the appearance of transition resonance, which must be taken into account when designing the FACTS. References 10, figures 1, tables 1.

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.

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.

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.

Modelling and Design of a Low-Level Turn-to-Turn Fault Protection Scheme for Extra-High Voltage Magnetically Controlled Shunt Reactor

The objective of this paper is to model and design a low-level turn-to-turn fault (T2TF) protection scheme for a magnetically controlled shunt reactor (MCSR), during incipient stage under 10% to 100% operating capacity. Due to the structural and functional differences of all the three windings in extra-high voltage (EHV) MCSR, a separate mechanism of detecting a T2TF in each winding is necessary. For this purpose, a detailed mathematical and structural analysis of the model is performed, and a comprehensive protection scheme based on the internal changes in magnetic and electric parameters of the windings is formulated to detect 3% T2TF in power windings (PWs), control windings (CtrWs), compensation windings (CpWs), and to differentiate it from other abnormalities. The main idea of the scheme is to perform the currents magnitude comparison of respective winding with the predefined settings values and decide necessary action. The proposed scheme is also capable of identifying the faulty winding along with faulty phase. The scheme is tested under different operating capacities (10%, 50%, 100%), and other types of unusual conditions, i.e., direct energization, pre-excited energization, power regulation, internal and external faults. The results demonstrate the effectiveness of the proposed scheme. The work of this paper is applicable in the areas of power system transmission and power system protection. The simulations are carried out on MATLAB/Simulink-based models.