scholarly journals Method of Switching on and Off a Power Transformer with a Capacitor Bank in an Electrothermal Installation

2021 ◽  
Vol 2096 (1) ◽  
pp. 012196
Author(s):  
V S Klimash ◽  
B D Tabarov
Keyword(s):  
Energy Efficiency ◽  
Steady State ◽  
Reactive Power ◽  
Power Transformer ◽  
Capacitor Bank ◽  
Steady State Mode ◽  
Operating Modes ◽  
Switching Losses ◽  
Full Compensation ◽  
Special Control

Abstract The article is devoted to issues related to increasing the energy efficiency of industrial electrothermal installations, both in starting and stationary operating modes due to the use of capacitors and thyristor starters with special control. The results of a significant reduction in the duration of the transient process, elimination of surges and asymmetry of starting currents and voltage drawdowns are presented. The results of full compensation of the reactive power of the network in the steady-state mode are also presented. It is shown that the starting currents do not exceed their steady-state values and that the shutdown of the electrothermal installation is performed without the occurrence of an arc and switching losses at the contacts of the switches. Researches of an electrothermal installation with a capacity of 750 kV⋅A and a voltage of 380 / 80 V are made on the model in the Matlab environment.

scholarly journals The Principle of Construction of Capacitive Reactive Power Compensators with Three-Stage Regulation

2021 ◽  
Vol 2096 (1) ◽  
pp. 012195
Author(s):  
V S Klimash ◽  
B D Tabarov ◽  
E G Antonov
Keyword(s):  
Steady State ◽  
Reactive Power ◽  
Control Method ◽  
Electronic Device ◽  
Operation Mode ◽  
Power Circuit ◽  
Capacitor Discharge ◽  
Switching Losses ◽  
Steady State Operation ◽  
Power Regulation

Abstract It is proposed to reduce the number of electrical and electronic devices by 1.5 times in three-stage capacitor installations by changing the connections in the power circuit and using a special control method. The new principle of construction of reactive power compensators will allow, with minimal changes and additions to existing installations, to reduce the costs of their production and the cost of finished products. The existing installations contain three blocks of the same type of capacitors, each of which is equipped with an electrical and electronic device and resistors for their discharge. It is proposed to connect two of these three blocks in parallel without changing the design of the products, using a common electronic device for connecting and disconnecting the resulting block of capacitors with double capacity and a common electrical device in the capacitor discharge circuit of this block. A model is presented in the Matlab environment for the study of dynamic and stationary processes of three-stage reactive power regulation in a new scheme of a capacitor plant. Numerical experiments have shown that when the installation is switched on and off, as well as when switching from one stage of reactive power regulation to another, the proposed device does not create bursts of starting currents. After starting, it almost immediately enters the steady-state operation mode and when switching stages, it also immediately passes from one level of the steady-state values of such to another level of their steady-state values. The installation is switched off without switching losses and without arcing on the mechanical contacts, since thyristor switches with natural switching are switched off first, and then the de-energized mains switch.

Study of power transformer loading in rural power supply systems

2021 ◽  
Vol 13 (4) ◽  
pp. 282-289
Author(s):  
I. V. Naumov ◽  
D. N. Karamov ◽  
A. N. Tretyakov ◽  
M. A. Yakupova ◽  
E. S. Fedorinovа
Keyword(s):  
Energy Efficiency ◽  
Power Supply ◽  
Rural Areas ◽  
Power Transformer ◽  
Electric Energy ◽  
Power Transformers ◽  
Electric Networks ◽  
Load Factors ◽  
Optimal Load ◽  
Supply Systems

The purpose of this study is to study the effect of loading power transformers (PT) in their continuous use on their energy efficiency on a real-life example of existing rural electric networks. It is noted that the vast majority of PT in rural areas have a very low load factor, which leads to an increase in specific losses of electric energy when this is transmitted to various consumers. It is planned to optimize the existing synchronized power supply systems in rural areas by creating new power supply projects in such a way as to integrate existing power sources and ensure the most efficient loading of power transformers for the subsequent transfer of these systems to isolated ones that receive power from distributed generation facilities. As an example, we use data from an electric grid company on loading power transformers in one of the districts of the Irkutsk region. Issues related to the determination of electric energy losses in rural PT at different numerical values of their load factors are considered. A computing device was developed using modern programming tools in the MATLAB system, which has been used to calculate and plot the dependence of power losses in transformers of various capacities on the actual and recommended load factors, as well as the dependence of specific losses during the transit of 1 kVA of power through a power transformer at the actual, recommended and optimal load factors. The analysis of specific losses of electric energy at the actual, recommended and optimal load factors of PT is made. Based on the analysis, the intervals of optimal load factors for different rated power of PT of rural distribution electric networks are proposed. It is noted that to increase the energy efficiency of PT, it is necessary to reduce idling losses by increasing the load of these transformers, which can be achieved by reducing the number of transformers while changing the configuration of 0.38 kV distribution networks.

Research on Multi-Mode Controller of Switching Power Supply

2014 ◽  
Vol 568-570 ◽  
pp. 1217-1220
Author(s):  
Shu Lin Liu ◽  
Li Li Qi
Keyword(s):  
Power Supply ◽  
Switching Frequency ◽  
Switching Power Supply ◽  
Load Range ◽  
Heavy Load ◽  
Operating Modes ◽  
Switching Power ◽  
Advantages And Disadvantages ◽  
Switching Losses ◽  
Light Load

In order to improve the efficiency of the switching power supply in whole load range, the controller with PWM, PFM and BURST operating modes is designed in this paper, which changes the operation mode automatically according to the load. The operating principle and the advantages and disadvantages of the three operating modes are analyzed and compared. PWM mode is used in heavy load; PFM mode is used in light load to reduce switching losses by reducing the switching frequency and BURST mode is used at the standby time to further reduce switching losses. The main control module is designed and simulation results verify the feasibility of the designed circuit.

Performance Analysis on Transmission Line for Improvement of Load Flow

2012 ◽  
Vol 433-440 ◽  
pp. 7208-7212
Author(s):  
Ya Min Su Hlaing ◽  
Ze Ya Aung
Keyword(s):  
Steady State ◽  
Power System ◽  
Transmission Line ◽  
Power Flow ◽  
Reactive Power ◽  
Load Flow ◽  
Electric Power System ◽  
Steady State Condition ◽  
Newton Raphson ◽  
Raphson Method

This thesis implements power flow application, Newton-Raphson method. The Newton-Raphson method is mainly employed in the solution of power flow problems. The network of Myanma electric power system is used as the reference case. The system network contains 90 buses and 106 brunches. The weak points are found in the network by using Newton-Raphson method. Bus 16, 17, 85 and 86 have the most weak bus voltages. The medium transmission line between bus 87 and bus 17 is compensated by using MATLAB program software. The transmission line is compensated with shunt reactors, series and shunt capacitors to improve transient and steady-state stability, more economical loading, and minimum voltage dip on load buses and to supply the requisite reactive power to maintain the receiving end voltage at a satisfactory level. The system performance is tested under steady-state condition. This paper investigates and improves the steady–state operation of Myanma Power System Network.

scholarly journals Hybrid Converter to Supply DC and AC Loads Using Tapped Boost Topology

2018 ◽  
Vol 7 (3.8) ◽  
pp. 48
Author(s):  
Goutham Menon ◽  
Mahesh Ratheesh ◽  
Gopikrishna S Menon ◽  
Gautham S ◽  
P Kanakasabapathy
Keyword(s):  
Steady State ◽  
Power Systems ◽  
Boost Converter ◽  
Voltage Source ◽  
Electronic Systems ◽  
Power Electronic ◽  
Voltage Source Inverter ◽  
Smart Power ◽  
Steady State Analysis ◽  
Operating Modes

Advancements in power electronic systems has brought forth the modernization of residential power systems exponentially. The interfacing of AC and DC loads with various kinds of resources of energy has been achieved with the help of modern nanogrid architectures. This paper brings into depiction a Tapped Boost derived hybrid converter that can be used to meet the demands of both AC and DC loads having a solitary DC input. A voltage source inverter (VSI) bridge network is used instead of the single switch of a Tapped Boost converter. The VSI bridge has shoot-through protection in the inverter stage increasing its importance for smart power systems. The Tapped Boost derived converter also borrows the advantages provided by the Tapped Boost converter. The paper covers topics like the operation, steady-state analysis and operating modes of the proposed Tapped Boost-DHC. The output and input characteristics has also been tested and verified through simulatio

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