Design Of Electrical Power System Research Articles

Application of functional safety to electrical power equipment and systems in process industries

In process industries, the application of functional safety in preventing major incidents is a well-established practice. The functional safety standard IEC 61511 (IEC, 2016) is applied to the safety instrumented system (SIS) protection layers to avoid the undesired events or reduce the likelihood of the events or impacts due to failures in the process, process equipment, or its control system including human interactions. However, there are risks of catastrophic incidents due to electrical equipment failures as well. Therefore, one should not underestimate the importance of the management, design, installation, operation, and maintenance of electrical power systems and protection devices. Regulatory authorities, in some countries, require the owners or operators to address the risks that arise from electrical equipment failure.The risk-based assessment, allocation of safety functions to protection devices, the establishment of integrity requirements, design, installation, operation, and maintenance of electrical protection devices must be managed like the protection layers for the process units. This paper focusses on the application of IEC 61511 to the protection of electrical equipment and systems, available industry guidelines, and the unique challenges in implementing the functional safety standards. The paper guides the electrical engineers with an example risk assessment, identification of protection device and its safety integrity level (SIL), verification of the reliability of the protection device and establishing a maintenance and operation program.

Design and Implementation of Effective Electrical Power System for Surya Satellite-1

Surya Satellite-1 is a nanosatellite developed by students of Surya University. The subject of this paper is the design and implementation of effective electrical power system for Surya Satellite 1. The electrical power system role is to supply other systems of the satellite with appropriate electrical power. First, the requirements of the electrical power system are defined. The architecture of the electrical power system is then designed to build the prototype. The orbit simulation is calculated to predict the power production. When prototype test and simulation data is gained, we make an operation scenario to keep the produced power and the consumed power in balance. The design of the modules of the electrical power system is carried out with triple junction solar cells, lithium ion batteries, maximum power point trackers, charging controllers, power distributions, and protection systems. Finally, the prototypes of the electrical power system are presented.

A Study on an Electric Power System Design of a Small Electric Vehicle

The electric power system design of the electric vehicle are required to improve the performance. The electric power system on the electric vehicle are consist of a battery, a pedal sensor, an electric motor and a controller. In this paper, Automotive manufacture's various electric vehicle models ar...

Analysis, Comparison and Study on Mitigation of Harmonics by using Active and Passive Harmonics Filters by using MATLAB Simulation

In this Paper Harmonics Distortion problems counter many of the conventional rules of Electric power system design and operation that consider only the fundamental frequency. The engineer is faced with unfamiliar phenomena that require their unfamiliar tools to analyse, study and unfamiliar equipment to solve. This paper is basically concerned with the Analysis and Study of Harmonics generated and Destroyed by Power Electronic Converters. The investigation and analysis of harmonics has been carried out using Fast Fourier Transform (FFT) to evaluate the Total Harmonic Distortion (THD) of the converters with and without filters. MATLAB/SIMULINK have been employed for their presenting the simulation results because it is well established and recognized simulation software for the power system. Next, the designing of Passive Filter (Single tuned), is carried out after a literature review and have been applied to the converters for harmonics mitigation. In the future, we would proceed to work on Active as well as Passive (combination types) Filters for Harmonics Mitigation. The harmonic distortion solution chosen was to design a passive filter to decrease the distortion by shifting the resonance point of the network. This Paper includes the method to design the passive filter and its impact on efficiency and energy usage.

Control Design and Voltage Stability Analysis of a Droop-Controlled Electrical Power System for More Electric Aircraft

This paper focuses on the analysis of a single dc bus multigenerator electrical power system (EPS) for future more electric aircraft. Within such a single bus paradigm, the paper proposes a detailed control design procedure and provides a stability analysis based on the derivation of the output impedance of the source subsystem and input impedance of the load subsystem, including control dynamics. The single bus characteristic is analyzed and the stability properties of the EPS are investigated when supplying constant power loads. In addition, the paper highlights the impact on stability of the number of parallel sources and of the power sharing ratio. The theoretical analysis is instrumental in designing an optimally stable single dc bus EPS. The key findings are validated by experimental results.

Experimental investigation into the fault response of superconducting hybrid electric propulsion electrical power system to a DC rail to rail fault

Hybrid electric propulsion aircraft are proposed to improve overall aircraft efficiency, enabling future rising demands for air travel to be met. The development of appropriate electrical power systems to provide thrust for the aircraft is a significant challenge due to the much higher required power generation capacity levels and complexity of the aero-electrical power systems (AEPS). The efficiency and weight of the AEPS is critical to ensure that the benefits of hybrid propulsion are not mitigated by the electrical power train. Hence it is proposed that for larger aircraft (~200 passengers) superconducting power systems are used to meet target power densities. Central to the design of the hybrid propulsion AEPS is a robust and reliable electrical protection and fault management system. It is known from previous studies that the choice of protection system may have a significant impact on the overall efficiency of the AEPS. Hence an informed design process which considers the key trades between choice of cable and protection requirements is needed. To date the fault response of a voltage source converter interfaced DC link rail to rail fault in a superconducting power system has only been investigated using simulation models validated by theoretical values from the literature. This paper will present the experimentally obtained fault response for a variety of different types of superconducting tape for a rail to rail DC fault. The paper will then use these as a platform to identify key trades between protection requirements and cable design, providing guidelines to enable future informed decisions to optimise hybrid propulsion electrical power system and protection design.

Design and performance evaluation of a hybrid electric power system for multicopters

The aim of the proposed investigation is to design and analyze the performance of a hybrid electric power system for multicopter and to evaluate its performance. To this, the overall power request was assumed to be satisfied in three possible ways: a battery (electric power system), a generator powered by a two-stroke internal combustion engine (thermal power system), and both battery and engine (hybrid power system). The fuel stored on board was calculated for each configuration by keeping constant the overall mass. In the hybrid case, the engine also allows the battery to be recharged during the flight with an on/off behavior of the engine. Electric mode is started when the batteries are sufficiently charged and can produce the required propulsive power. This mode goes on as long as the state of charge (SOC) is above a minimum value. When the SOC is lower than this value, the batteries let the engine be restarted by the generator. Then, the engine generates both the power for propulsion and to recharge the battery. After a sensitivity analysis, an optimization has been performed by considering different thresholds for the battery state of charge to shift from electric to recharge mode and by taking into account different values of the recharge current. The methodology was applied to two different multicopters and the proposed powertrains were simulated with a backward approach starting from experimental time histories of required electric power.

A novel software package for the robust design of off-grid power systems

Off-grid power systems represent one of the key solutions for rural electrification. Most of the analyses or tools already present in literature do not consider the final users' energy needs as the starting point of the process nor they consider the inherent uncertainties about loads and resources. Comprehensive stochastic procedures that look at the atypical features of rural contexts and include estimation errors into the design phase are strongly required. In this paper, we present Poli. NRG (POLItecnico di Milano - Network Robust desiGn): a novel software package for the robust design of off-grid electric power systems. Poli. NRG is composed of four blocks which separately face the different design phases: (i) the data inputs gathering block provides a methodology to collect field data as regards weather condition and load demand; (ii) the inputs processing block elaborates the inputs to obtain load and sources profiles over the entire lifetime of the plant; (iii) the system modelling and simulation block simulates different off-grid system configurations and evaluates the related techno-economic performances; (iv) the output formulation block finds the most robust design for the targeted context through specific optimization methods. After a comprehensive description of the software, we have applied it to size a PV + BESS microgrid system to supply power to a peri-urban area of Uganda. The results confirm that parameters' uncertainties deeply affect the design of the system and motivate the robust design approach proposed. Poli. NRG is devoted to map those uncertainties and provide information for decision makers.

Coordinated Distributed MPC for Load Frequency Control of Power System With Wind Farms

Load frequency control (LFC) is crucial for the operation and design of modern electric power systems. This becomes quite challenging, as more wind power is included into the power system. This paper proposes a coordinated distributed model predictive control (DMPC) for the LFC of a power system that includes inherently variable wind-power generations. This DMPC communicates power system measurement and prediction data, and considers the information of other controllers for their local objective to realize effective coordination. The controllers solve the optimization problem while considering given constraints, e.g., generation rate constraints, wind speed, pitch angle, and load input constraints for each area. Since the wind-power output depends largely on the wind speed, different optimization modes for the DMPC were used. Both simulation and experimental tests of a four-area interconnected power system LFC, which consists of thermal plants, hydro units, and a wind farm, demonstrate the improved efficiency of the coordinated DMPC.

ОБЗОР ИСТОЧНИКОВ ЭЛЕКТРИЧЕСКОЙ ЭНЕРГИИ БЕЗЭКИПАЖНЫХ НАДВОДНЫХ АППАРАТОВ

The article deals with small unmanned surface vehicles (USV), which main objective is exploration of seas and oceans as well as use for military purposes. The subject matter of this study is to analyze power sources providing power supply for all USVs power consuming units. There has been offered a review of actual-to-date USVs both of Russian and foreign manufacturing, which autonomous operation can last up to 3 months. The author has analyzed general characteristics of USVs, and paid special attention to the power sources and to consuming energy by the vehicles. Approximate total power obtained from USV electric sources makes 300-1000 W. It should be noted that USV electric power sources are not only accumulators and generators, but solar batteries and wind power generators. To save power USVs use sailing rigging, or apply wave glider’s technology where wave power is harvested to increase mobility of the vehicle. A distinctive feature of some USVs structure is placing solar batteries both on deck and on sales. A significant advantage of this structure is less power consumption at sufficient wind velocity and strengthening USV power system. There are considered not only single-hulled USVs, but also catamaran types (for gaining effective area to place additional solar batteries). Using data of USV structural features analysis, the author has inferred the factors influencing USV’s electric power system design, as well as perspectives of development of new types of unmanned crafts.

Optimal Design of Electric Vehicle Power System with the Principle of Minimum Curb Mass

With the lightweight idea, an optimal design is developed for the powertrain of electric vehicles (EVs) to reduce the power consumption while maintaining excellent performance. Based on a prototype EV, the paper takes minimum curb mass as design principle, a single charge trip range mileage and whole life cycle of battery as constraints. The uniqueness of the design is the consideration in the selection of base speed and the associated change of motor and battery mass. The design is developed in two stages. With power and torque demand ensured, the first carries on the calculation and configuration of dynamic parameters to minimize curb mass for energy saving. The second stage verified the depth of discharge to guarantee good durability. The superiority of the design is demonstrated by comparing optimization results with original values.

Analysis of Open-Phase Conditions in Korean Standard Nuclear Power Plants and Fault Detection Scheme

Because of partial losses of power known as “open-phase faults”, controlled reactor shutdown has occurred in nuclear power plants around world. Depending on transformer wiring and loading, such conditions can be difficult to detect, because phase voltage measurements can appear to be normal. Many of the identified events went undetected for several weeks. These findings were sufficient for staff to conclude that an open phase condition is a credible event having safety significance and must be considered in the electric power system design for nuclear power plants. This paper elaborates the processes and results of the open-phase fault studies on the standard nuclear power plants in Korea. The ETAP unbalanced load flow module is used for the system analysis. The analysis described in this paper has been performed to determine the response of unit auxiliary transformers and standby auxiliary transformers during open-phase conditions to aid in the development of system protection schemes designed to detect such conditions.

Distributed model predictive load frequency control of multi-area power system with DFIGs

Reliable load frequency control U+0028 LFC U+0029 is crucial to the operation and design of modern electric power systems. Considering the LFC problem of a four-area interconnected power system with wind turbines, this paper presents a distributed model predictive control U+0028 DMPC U+0029 based on coordination scheme. The proposed algorithm solves a series of local optimization problems to minimize a performance objective for each control area. The generation rate constraints U+0028 GRCs U+0029, load disturbance changes, and the wind speed constraints are considered. Furthermore, the DMPC algorithm may reduce the impact of the randomness and intermittence of wind turbine effectively. A performance comparison between the proposed controller with and without the participation of the wind turbines is carried out. Analysis and simulation results show possible improvements on closed–loop performance, and computational burden with the physical constraints.

3 tons pure electric vehicles power system design based on Cruise

The pure electric minivan is different from electric car. Combined with a given vehicle, vehicle simulation model established in Cruise software, complete simulation by setting tasks for the selected models designed drivetrain. Simulation results show that: The design of the transmission ratio can best meet the performance requirements of the matching target power analysis and simulation of electric minivan provides a new way, with practical guidance.

Exomars 2016 Mission Electrical Power System

ExoMars is the first step of the European Space Agency’s Aurora Exploration Programme. Comprising two missions [ 1], the first one launched in 2016 and the second one to be launched in 2020, ExoMars is a joint ESA-Roscosmos program that will address the scientific question of whether life ever existed on Mars and demonstrate key technologies for entry, descent, landing, drilling and roving on the Martian surface [ 2]. The Spacecraft Composite (SCC), consisting of a Trace Gas Orbiter (TGO) and an EDL (Entry Descend and Landing) Demonstrator Module (EDM) named Schiaparelli, has been launched on 14 March 2016 from the Baikonur Cosmodrome by a Proton Launcher. The two modules will separate on 16 October 2016 after a seventh-months cruise. The TGO will search for evidence of methane and other atmospheric gases that could be signatures of active biological or geological processes on Mars and will provide communications relay for the 2020 mission surface assets. The Schiaparelli module will prove the technologies required to safely land a payload on the surface of Mars, with a package of sensors aimed to support the reconstruction of the flown trajectory and the assessment of the performance of the EDL subsystems. Following separation, the EDM will undergo a threedays coasting phase to reach the Mars atmospheric Entry Interface Point, complete the Entry Descent and Landing phases in six minutes and perform surface science operations for a duration of up to four Martian sols, with data transmission to TGO and to other ESA and NASA orbiters.This paper outlines the Exomars 2016 Electrical Power System (EPS) design, providing a description of the major design drivers and resulting configuration, with a view to highlight aspects that could be considered for future designs.

Impact of Distributed Generation on the Reliability of Local Distribution System

With the growth of distributed generation (DG) and renewable energy resources the power sector is becoming more sophisticated, distributed generation technologies with its diverse impacts on power system is becoming attractive area for researchers. Reliability is one of the vital area in electric power system which defines continuous supply of power and customer satisfaction. Around the world many power generation and distribution companies conduct reliability tests to ensure continues supply of power to its customers. Uttermost reliability problems in power system are due to distribution network. In this research reliability analysis of distribution system is done. The interruption frequency and interruption duration increases as the distance of load points increase from feeder. Injection of single DG unit into distribution system increase reliability of distribution system, injecting multiple DG at different locations and near to load points in distribution network further increases reliability of distribution system, while introducing multiple DG at single location improves reliability of distribution system. The reliability of distribution system remains unchanged while varying the size of DG unit. Different reliability tests were done to find the optimum location to plant DG in distribution system. For these analyses distribution feeder bus 2 of RBTS is selected as case study. The distribution feeder is modeled in ETAP, ETAP is software tool used for electrical power system modeling, analysis, design, optimization, operation, control, and automation. These results can be helpful for power utilities and power producer companies to conduct reliability tests and to properly utilize the distributed generation sources for future expansion of power systems.

Robust distributed MPC for load frequency control of uncertain power systems

Reliable Load frequency control (LFC) is crucial to the operation and design of modern electric power systems. However, the power systems are always subject to uncertainties and external disturbances. Considering the LFC problem of a multi-area interconnected power system, this paper presents a robust distributed model predictive control (RDMPC) based on linear matrix inequalities. The proposed algorithm solves a series of local convex optimization problems to minimize an attractive range for a robust performance objective by using a time-varying state-feedback controller for each control area. The scheme incorporates the two critical nonlinear constraints, e.g., the generation rate constraint (GRC) and the valve limit, into convex optimization problems. Furthermore, the algorithm explores the use of an expanded group of adjustable parameters in LMI to transform an upper bound into an attractive range for reducing conservativeness. Good performance and robustness are obtained in the presence of power system dynamic uncertainties.

Introducing LQR-Fuzzy Technique with Dynamic Demand Response Control Loop to Load Frequency Control Model

Abstract The present paper indicates a novel approach of LQR-Fuzzy controller to stabilize the frequency in all (normal and emergency) conditions under micro grid environment. Load Frequency Control (LFC) model plays a vital role in electric power system design and operation. From the literature, it is proven that the implementation of DR (Demand Response) is a key to the future micro grid. In practice, LFC-DR model is tuned by conventional controllers like PI, PD, PID controllers, with their fixed gains. However, they are incapable of obtaining good dynamic performance over a wide range of operating conditions and load changes. This paper presents an idea of introducing a DR control loop in the traditional LFC model (called LFC-DR) using Intelligent Controller for a power system. DR communication delay latency in the controller design is considered and is linearized using Pade approximation. The addition of DR control loop guarantees stability of the overall closed-loop system and effectively improves the system dynamic performance. Simulation results show that LQR- Fuzzy Logic Controller based LFC-DR single-area power system have better performance and superiority over a classical controller under any operating scenarios.

실용적인 원전공학 교육을 위한 시스템즈 엔지니어 프로그램

KEPCO International Nuclear Graduate School (KINGS) is dedicated to nurturing leadership-level professionals in nuclear power plant (NPP) engineering. KINGS have designed curriculum based on two philosophies. First, we balance aspects of discipline engineering, specialty engineering, and management engineering in the framework of systems engineering. Second, KINGS have designed the curriculum so that students can learn and experience the know-what, know-how and know-why level knowledge of NPP engineering and management. The specialization programs are opened during the 2nd year for 3 trimesters and those are a process of learning through practical project courses. The objectives of the specialization programs are to help students to learn the NPP life cycle technologies in highly structured and systematic ways. The systems engineer program (SEP) is one of the specialization programs. A practical case of the SEP which was applied to the project course for the NPP electric power system design education will be elaborated in this paper.

Development and testing of an energy saving tool – Suitability analysis with case study

Abstract The increasing demand for electrical energy, the depletion of fossil fuel based resources and environmental constraints have made it mandatory for the efficient use of electrical energy, energy saving applications and implementing an energy management program. In this paper, a user-friendly tool for tracking and analyzing the electric bills, suggesting the best electricity tariff, controlling the active and reactive power rates, increasing energy efficiency, allowing the consumer to compare the alternatives and avoiding any penalties is presented step by step. The proposed energy saving tool will also help the electrical and more particularly power engineers and consumers in industrial sector to reduce electricity consumption while maintaining the quality of service. The developed tool is applied and tested to determine the optimal design of electrical power system in a university hospital. Test results reveal the performance of the developed tool for an optimization of commercial and industrial plants under different scenarios of power consumption and load demand. The program is written in the Delphi programming environment XE3 to provide enhanced flexibility and runs on Windows.