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Records with Subject: Energy Management
Showing records 1 to 25 of 241. [First] Page: 1 2 3 4 5 Last
The Development of a Waste Tyre Pyrolysis Production Plant Business Model for the Gauteng Region, South Africa
Nhlanhla Nkosi, Edison Muzenda, Tirivaviri A. Mamvura, Mohamed Belaid, Bilal Patel
October 6, 2020 (v1)
Keywords: batch pyrolysis, business model, South Africa, waste tyres
Some of today’s modern life challenges include addressing the increased waste generation and energy deficiencies. Waste tyres have been identified as one of the key environmental concerns due to their non-biodegradable nature and bulk storage space demand. Pyrolysis is a thermochemical process with the potential to address the growing waste tyre problem, energy deficits, and material recovery by converting waste tyres to pyrolysis oil that can be used as a fuel. This study seeks to critically evaluate the feasibility of constructing and operating a waste tyre processing facility and then subsequently marketing and selling the pyrolysis secondary end products by developing a financial business model. The model encompasses costing, procurement, installation, commissioning, and operating a batch pyrolysis plant in Gauteng, South Africa. To achieve the study objectives, an order of magnitude costing method was used for model construction. The results showed the feasibility and sustainabili... [more]
Automatic Implementation of a Self-Adaption Non-Intrusive Load Monitoring Method Based on the Convolutional Neural Network
Xin Wu, Dian Jiao, Yu Du
September 23, 2020 (v1)
Keywords: convolutional neural network, load identification, non-intrusive load monitoring
Non-intrusive load monitoring (NILM) is an effective way to achieve demand-side measurement and energy efficiency optimization. This paper studies a method of non-intrusive on-line load monitoring under a high-frequency mode of electric data acquisition, which enables the NILM to be automated and in real-time, including the short-term construction of a dynamic signature library and continuous on-line load identification. Firstly, in the short initial operation phase, load separation and category determination are carried out to construct the load waveform library of the monitoring user. Then, the continuous load monitoring phase begins. Based on the data of each user’s signature library, the decomposition waveforms are classified by convolutional neural network models that are constructed to be suitable for each signature library in order to realize load identification. The real-time power consumption status of the load can be obtained continuously. In this paper, the electricity data... [more]
Adaptive Control Strategy of Energy Storage System Participating in Primary Frequency Regulation
Chaoxiong Fang, Yuchen Tang, Rong Ye, Zhangsui Lin, Zhenshan Zhu, Buying Wen, Chengtao Ye
September 15, 2020 (v1)
Keywords: drop control, Energy Storage, primary frequency regulation, virtual inertial control
In order to solve the capacity shortage problem in power system frequency regulation caused by large-scale integration of renewable energy, the battery energy storage-assisted frequency regulation is introduced. In this paper, an adaptive control strategy for primary frequency regulation of the energy storage system (ESS) was proposed. The control strategy combined virtual droop control, virtual inertial control, and virtual negative inertial control. The virtual inertial control was used to reduce the frequency change rate, and the virtual droop control was used to reduce the steady-state frequency deviation. The virtual droop control and the virtual inertia control were adopted in the frequency deterioration stage to slow down the frequency drop. While in the frequency recovery stage, the virtual negative inertia control worked together with the virtual droop control to accelerate the frequency recovery. Besides, the coefficients of the control methods were related to the state of ch... [more]
A 140 MW Solar Thermal Plant in Jordan
Wael Al-Kouz, Ahmad Almuhtady, Nidal Abu-Libdeh, Jamal Nayfeh, Alberto Boretti
August 29, 2020 (v1)
Keywords: concentrated solar power, Energy Storage, Jordan, molten salt, solar energy
This paper aims to compute the performances of a smaller version of Solana power plant, with half the solar field, and 1 of 2 turbines in the power cycle, that can be built in Amman or Ma’an in Jordan. The climate conditions for both Amman and Ma’an are discussed thoroughly in the paper. Furthermore, a preliminary validation exercise performed by using measured monthly average values of electricity production from existing plants, a system advisor model (SAM) is used to predict the performances of the proposed Solana-like plants in Ma’an and Amman. The validation shows a good agreement with the measured data for different existing power plants. The simulation results including the monthly capacity factors suggest the annual operation in Ma’an maybe even better than the operation in Gila Bend, for an annual average capacity factor of about 41% for Ma’an vs. a capacity factor of about 39% for Gila Bend. This is mainly due to the best combination of direct normal irradiance (DNI) and the... [more]
Assessment and Prediction of Complex Industrial Steam Network Operation by Combined Thermo-Hydrodynamic Modeling
Kristián Hanus, Miroslav Variny, Peter Illés
July 17, 2020 (v1)
Keywords: bottleneck, cold spot, heat losses, operation optimization, steam network
Steam network operation stability and reliability is vital for any industrial branch. A combined steam network model comprising a balance and a coupled thermo-hydrodynamic model, including seasonal variations impact and system specificities, is presented. A balance model can readily be used by a refinery’s operators. The thermo-hydrodynamic model identifies system bottlenecks and cold spots and evaluates proposed operation and investment measures including heat loss reduction. A three-pressure levels refinery steam network served for model testing and validation. Balance model results reveal significant misbalance in steam production and consumption, reaching 30.5% in the low-pressure steam system, and heat balance differences in the range of 9.2% to 29.5% on individual pressure levels, attributable both to flow measurement accuracy issues and to heat losses. The thermo-hydrodynamic model results differ from the measured steam parameters by less than 5% (temperature) and by less than 4... [more]
Single Inductor-Multiple Output DPWM DC-DC Boost Converter with a High Efficiency and Small Area
Young Jun Park, Zaffar Hayat Nawaz Khan, Seong Jin Oh, Byeong Gi Jang, Nabeel Ahmad, Danial Khan, Hamed Abbasizadeh, Syed Adil Ali Shah, Young Gun Pu, Keum Cheol Hwang, Youngoo Yang, Minjae Lee, Kang Yoon Lee
June 23, 2020 (v1)
Keywords: DC-DC converter, digital pulse width modulation, interlaced hysteresis delay cells (IHDCs)
In this paper, a small-area and high-efficiency single-inductor multiple output (SIMO) boost converter with digital pulse-width modulation (DPWM) is proposed. The DPWM comprises a delay line using interlaced hysteresis delay cells (IHDCs) that occupy a small area while consuming a low power amount. These proposed IHDCs are applied to replace the conventional delay cells of the prior works for both the power and area reductions. Regarding the DC-DC converter, this technique comprises fewer digital blocks in the feedback path compared with the conventional DC-DC converter, and the DPWM architecture uses IHDCs. The purpose of the digital limiter block is to concede some helpful code for the DPWM. The IHDC topology used for delay in DPWM is of the simplest architecture. The high-side power switch gate drivers need individual phases which are generated by phase control. The Complementary Metal Oxide Semiconductor (CMOS)-fabrication process is 55 nm, with a standard supply voltage of 1.8 V a... [more]
Power Management of the DC Bus Connected Converters in a Hybrid AC/DC Microgrid Tied to the Main Grid
Robert Antonio Salas-Puente, Silvia Marzal, Raúl González-Medina, Emilio Figueres, Gabriel Garcera
June 23, 2020 (v1)
Keywords: communication with power converters, microgrid, power management algorithm
In this paper, a centralized control strategy for the efficient power management of power converters composing a hybrid AC/DC microgrid is explained. The study is focused on the converters connected to the DC bus. The proposed power management algorithm is implemented in a microgrid central processor which is based on assigning several operation functions to each of the generators, loads and energy storage systems in the microgrid. The power flows between the DC and AC buses are studied in several operational scenarios to verify the proposed control. Experimental and simulation results demonstrate that the algorithm allows control of the power dispatch inside the microgrid properly by performing the following tasks: communication among power converters, the grid operator and loads; connection and disconnection of loads; control of the power exchange between the distributed generators and the energy storage system and, finally, supervision of the power dispatch limit set by the grid ope... [more]
A Case Study of Control and Improved Simplified Swarm Optimization for Economic Dispatch of a Stand-Alone Modular Microgrid
Xianyong Zhang, Wei-chang Yeh, Yunzhi Jiang, Yaohong Huang, Yingwang Xiao, Li Li
June 23, 2020 (v1)
Keywords: control, diesel generator, economic dispatch, simplified swarm optimization, solar power, stand-alone modular microgrid, storage battery, three-port converter, wind power
Due to the complex configuration and control framework, the conventional microgrid is not cost-effective for engineering applications with small or medium capacity. A stand-alone modular microgrid with separated AC bus and decentralized control strategy is proposed in this paper. Each module is a self-powered system, which consists of wind and solar power, a storage battery, load and three-port converter. The modules are interconnected by three-port converters to form the microgrid. Characteristics, operation principle, control of the modular microgrid and the three-port converter are analyzed in detail. Distributed storage batteries enable power exchanges among modules to enhance economic returns. Economic dispatch of the stand-alone modular microgrid is a mixed-integer programming problem. A day-ahead operation optimization model including fuel cost, battery operation cost, and power transmission cost is established. Because there are so many constraints, it is difficult to produce a... [more]
An Improved Wireless Battery Charging System
Woo-Seok Lee, Jin-Hak Kim, Shin-Young Cho, Il-Oun Lee
June 23, 2020 (v1)
Keywords: series-series compensated circuit, wireless battery charging system, wireless power transfer
This paper presents a direct wireless battery charging system. The output current of the series-series compensated wireless power transfer (SS-WPT) system is used as a current source, and the output voltage of AC-DC converter controls the current source. Therefore, the proposed wireless battery charging system needs no battery charging circuit to carry out charging profiles, and can solve space constraints and thermal problems in many battery applications. In addition, the proposed wireless battery charging system can implement easily most other charging profiles. In this paper, the proposed wireless battery charging system is implemented and the feasibility is verified experimentally according to constant-current constant-voltage charging profile or multi-step current charging profile.
Frequency Response Analysis of a Single-Area Power System with a Modified LFC Model Considering Demand Response and Virtual Inertia
Muhammad Saeed Uz Zaman, Syed Basit Ali Bukhari, Khalid Mousa Hazazi, Zunaib Maqsood Haider, Raza Haider, Chul-Hwan Kim
June 23, 2020 (v1)
Keywords: demand response, load-frequency control, steady-state error, system frequency response, virtual inertia, virtual synchronous generator
The modern electric power system is foreseen to have increased penetration of controllable loads under demand response programs and renewable energy resources coupled with energy storage systems which can provide virtual inertia. In this paper, the conventional model of an electric power system is appended by considering, individually and collaboratively, the role of demand response and virtual inertia for the purpose of frequency analysis and control. Most existing literature on this topic either considers one of these two roles or lacks in providing a general model of power system with demand response and virtual inertia. The proposed model is presented in general form and can include/exclude demand response and/or virtual inertia. Further, power system operator can opt the power shares from conventional, demand response, and virtual inertia loops for frequency regulation and can also evaluate the impact of other parameters such as time delays and frequency deadbands on system freque... [more]
An Original Transformer and Switched-Capacitor (T & SC)-Based Extension for DC-DC Boost Converter for High-Voltage/Low-Current Renewable Energy Applications: Hardware Implementation of a New T & SC Boost Converter
Sanjeevikumar Padmanaban, Mahajan Sagar Bhaskar, Pandav Kiran Maroti, Frede Blaabjerg, Viliam Fedák
June 23, 2020 (v1)
Keywords: DC-DC boost converter, high-voltage, low current, maximum power point tracking, Renewable and Sustainable Energy, switched capacitor, transformer
In this article a new Transformer and Switched Capacitor-based Boost Converter (T & SC-BC) is proposed for high-voltage/low-current renewable energy applications. The proposed T & SC-BC is an original extension for DC-DC boost converter which is designed by utilizing a transformer and switched capacitor (T & SC). Photovoltaic (PV) energy is a fast emergent segment among the renewable energy systems. The proposed T & SC-BC combines the features of the conventional boost converter and T & SC to achieve a high voltage conversion ratio. A Maximum Power Point Tracking (MPPT) controller is compulsory and necessary in a PV system to extract maximum power. Thus, a photovoltaic MPPT control mechanism also articulated for the proposed T & SC-BC. The voltage conversion ratio (Vo/Vin) of proposed converter is (1 + k)/(1 − D) where, k is the turns ratio of the transformer and D is the duty cycle (thus, the converter provides 9.26, 13.88, 50/3 voltage conversion ratios at 78.... [more]
A Stackelberg Game Approach for Energy Outage-Aware Power Distribution of an Off-Grid Base Station over Multiple Retailers
Seung Hyun Jeon, Joohyung Lee, Hong-Shik Park
June 23, 2020 (v1)
Keywords: energy outage (EO), multi-leader single-follower Stackelberg game, multiple retailers, off-grid base station (BS), power distribution, unit power price
This paper investigates the problem of power distribution for an off-grid base station (BS) that operates sustainably without an electrical grid. We consider that multiple retailers with heterogeneous renewable energy sources (RESs) compete to maximize their revenues by individually setting the unit power price. Energy outages (EOs), which cause the power supply to fall below that which is sufficient for ensuring the traffic arrival rate required for the off-grid BS, critically affect the users’ service quality. To minimize EOs and operational expenditure (OPEX), the off-grid BS manages the power supply by reacting to the retailers’ pricing decisions. We analyze the economic benefits of power distribution to the off-grid BS from the perspective of the retailers’ pricing competition, by designing a hierarchical decision-making scheme as a multi-leader single-follower Stackelberg game. We derive a closed form expression for the optimal behavior of the off-grid BS and retailers, based on... [more]
On the Distribution of Lightning Current among Interconnected Grounding Systems in Medium Voltage Grids
Guido Ala, Salvatore Favuzza, Elisa Francomano, Graziella Giglia, Gaetano Zizzo
June 23, 2020 (v1)
Keywords: bare buried rope, full-wave, grounding, lightning current, Lightning Protection System (LPS), lightning stroke, metal shields
This paper presents the results of a first investigation on the effects of lightning stroke on medium voltage installations’ grounding systems, interconnected with the metal shields of the Medium Voltage (MV) distribution grid cables or with bare buried copper ropes. The study enables us to evaluate the distribution of the lightning current among interconnected ground electrodes in order to estimate if the interconnection, usually created to reduce ground potential rise during a single-line-to-ground fault, can give place to dangerous situations far from the installation hit by the lightning stroke. Four different case studies of direct lightning stroke are presented and discussed: (1) two secondary substations interconnected by the cables’ shields; (2) two secondary substations interconnected by a bare buried conductor; (3) a high voltage/medium voltage station connected with a secondary substation by the medium voltage cables’ shields; (4) a high voltage/medium voltage station connec... [more]
Impact Analysis of Customized Feedback Interventions on Residential Electricity Load Consumption Behavior for Demand Response
Fei Wang, Liming Liu, Yili Yu, Gang Li, Jessica Li, Miadreza Shafie-khah, João P. S. Catalão
June 23, 2020 (v1)
Keywords: consumption behavior, customized feedback, demand response, energy policy, questionnaire design, residential electricity load
Considering the limitations of traditional energy-saving policies, a kind of energy conservation method called the Information Feedback to Residential Electricity Load Customers, which could impact the demand response capacity, has increasingly received more attention. However, most of the current feedback programs provide the same feedback information to all customers regardless of their diverse characteristics, which may reduce the energy-saving effects or even backfire. This paper attempts to investigate how different types of customers may change their behaviors under a set of customized feedback. We conducted a field survey study in Qinhuangdao (QHD), China. First, we conducted semi-structured interviews to classify four groups of customers of different energy-saving awareness, energy-saving potential, and behavioral variability. Then, 156 QHD households were surveyed using scenarios to collect feedback of different scenarios. Social science theories were used to guide the discuss... [more]
Symmetric Fuzzy Logic and IBFOA Solutions for Optimal Position and Rating of Capacitors Allocated to Radial Distribution Networks
Chandan Kishore, Smarajit Ghosh, Vinod Karar
June 23, 2020 (v1)
Keywords: capacitor placement, fuzzy modeling, improved bacterial foraging algorithm, load flow, loss sensitivity factor, voltage stability index
This paper suggests an innovative approach for the ideal placement and categorization of capacitors in radial distribution networks (RDNs) by applying symmetric fuzzy and improved bacterial foraging optimization algorithm (IBFOA) solutions. The reactive power reimbursement significantly enhances the function of the power system, and capacitor placement is an impressive technique used to reduce loss of the system. The capacitor allocation for distribution system problems involves determining the ideal location and size of the capacitor. In this work, load flow is performed at first to compute actual losses and voltages at different nodes without compensation. In the planned technique, the loss sensitivity factor (VSF) and voltage stability index (VSI) are utilized to determine the optimal location of capacitors in RDNs. Here, the IBFOA is used to determine the proper rating of the capacitor. The suggested scheme is applied on three different types of RDNs.
Identification of the Most Effective Point of Connection for Battery Energy Storage Systems Focusing on Power System Frequency Response Improvement
Thiago Pieroni, Daniel Dotta
June 23, 2020 (v1)
Keywords: battery energy storage systems (BESS), controllability, frequency control, frequency regulation mode, wind generation
With the massive penetration of intermittent generation (wind and solar), the reduction of Electrical Power Systems’ (EPSs) inertial frequency response represents a new challenge. One alternative to deal with this scenario may be the application of a Battery Energy Storage System (BESS). However, the main constraint for the massive deployment of BESSs is the high acquisition cost of these storage systems which in some situations, can preclude their use in transmission systems. The main goal of this paper is to propose a systematic procedure to include BESSs in power system aiming to improve the power system frequency response using full linear models and geometric measures. In this work, a generic battery model is developed in a two-area test system with assumed high wind penetration and full conventional generators models. The full power system is linearized, and the geometric measures of controllability associated with of the frequency regulation mode are estimated. Then, these resul... [more]
Identification and Evaluation of Cases for Excess Heat Utilisation Using GIS
Fabian Bühler, Stefan Petrović, Torben Ommen, Fridolin Müller Holm, Henrik Pieper, Brian Elmegaard
June 23, 2020 (v1)
Keywords: district heating, Energy Efficiency, excess heat, heat recovery, industry, power generation, utility
Excess heat is present in many sectors, and its utilization could reduce the primary energy use and emission of greenhouse gases. This work presents a geographical mapping of excess heat, in which excess heat from the industry and utility sector was distributed to specific geographical locations in Denmark. Based on this mapping, a systematic approach for identifying cases for the utilization of excess heat is proposed, considering the production of district heat and process heat, as well as power generation. The technical and economic feasibility of this approach was evaluated for six cases. Special focus was placed on the challenges for the connection of excess heat sources to heat users. To account for uncertainties in the model input, different methods were applied to determine the uncertainty of the results and the most important model parameters. The results show how the spatial mapping of excess heat sources can be used to identify their utilization potentials. The identified ca... [more]
Flexible Biogas in Future Energy Systems—Sleeping Beauty for a Cheaper Power Generation
Markus Lauer, Daniela Thrän
June 23, 2020 (v1)
Keywords: biogas, flexibility options, system integration, total system costs
The increasing proportion of intermittent renewable energies asks for further technologies for balancing demand and supply in the energy system. In contrast to other countries, Germany is characterized by a high installed capacity of dispatchable biogas plants. For this paper, we analyzed the total system costs varying biogas extension paths and modes of operation for the period of 2016⁻2035 by using a non-linear optimization model. We took variable costs of existing conventional power plants, as well as variable costs and capital investments in gas turbines, Li-ion batteries, and pumped-storage plants into account. Without the consideration of the costs for biogas plants, an increasing proportion of biogas plants, compared to their phase out, reduces the total system costs. Furthermore, their flexible power generation should be as flexible as possible. The lowest total system costs were calculated in an extension path with the highest rate of construction of new biogas plants. However... [more]
Impact of Conductor Temperature Time⁻Space Variation on the Power System Operational State
Yanling Wang, Yang Mo, Mingqiang Wang, Xiaofeng Zhou, Likai Liang, Pei Zhang
June 23, 2020 (v1)
Keywords: conductor temperature, maximum transmission power, power flow, time–space variation, transmission line
The conductor temperature of an overhead transmission line varies with time and space, which has an important impact on the system operation. In this paper, the conductor temperature is solved iteratively by the CIGRE heat balance equation. The time⁻space variation of conductor temperature of a 220-kV transmission line is analyzed using real meteorological data from Weihai. Considering the temporal distribution characteristics, the seasonal model of the conductor temperature is given. Considering the spatial distribution, the mean value model, the weight average model, and the segmentation model are established. The system power flow involving the conductor temperature is established based on the relationship between conductor temperature and transmission line parameters. Through the calculation of power flow and the analysis of the maximum power transmission capability, the accuracy of the segmentation model is verified. The results show that the conductor temperature of overhead line... [more]
A Method for Increasing the Operating Limit Capacity of Wind Farms Using Battery Energy Storage Systems with Rate of Change of Frequency
Dae-Hee Son, Muhammad Ali, Sang-Hee Kang, Jae-Haeng Heo, Soon-Ryul Nam
June 23, 2020 (v1)
Keywords: battery energy storage system (BESS), blade pitch angle, kinetic energy, operating limit capacity, rate of change of frequency (ROCOF)
In this paper, the appropriate rated power of battery energy storage system (BESS) and the operating limit capacity of wind farms are determined considering power system stability, and novel output control methods of BESS and wind turbines are proposed. The rated power of BESS is determined by correlation with the kinetic energy that can be released from wind turbines and synchronous generators when a disturbance occurs in the power system. After the appropriate rated power of BESS is determined, a novel control scheme for quickly responding to disturbances should be applied to BESS. It is important to compensate the insufficient power difference between demand and supply more quickly after a disturbance, and for this purpose, BESS output is controlled using the rate of change of frequency (ROCOF). Generally, BESS output is controlled by the frequency droop control (FDC), however if ROCOF falls below the threshold, BESS output increases sharply. Under this control for BESS, the power s... [more]
Optimization of Energy Management Strategy and Sizing in Hybrid Storage System for Tram
Yu Wang, Zhongping Yang, Feng Li
June 23, 2020 (v1)
Keywords: energy management strategy, hybrid storage system, sizing
In order to design a well-performing hybrid storage system for trams, optimization of energy management strategy (EMS) and sizing is crucial. This paper proposes an improved EMS with energy interaction between the battery and supercapacitor and makes collaborative optimization on both sizing and EMS parameters to obtain the best working performance of the hybrid storage system. This paper demonstrates the whole process of the improvement of the EMS, the traction calculation, the parameter optimization, and the sizing optimization based on real tram and line conditions. The improved strategy is proven to be superior as it guarantees normal operation and avoids shutdown conditions when the supercapacitor is at a low voltage. Furthermore, the optimized sizing result largely decreases the weight of the storage system and obtains a long battery lifespan.
Reliability Equivalence to Symmetrical UHVDC Transmission Systems Considering Redundant Structure Configuration
Xing Jiang, Chengjin Ye, Yi Ding, Ruipeng Guo
June 23, 2020 (v1)
Keywords: redundant configure configuration, reliability equivalence, sensitivity analysis, UHVDC transmission system
In recent years, the ultra-high voltage direct current (UHVDC) transmission system has been developed rapidly for its significant long-distance, high-capacity and low-loss properties. Equipment failures and overall outages of the UHVDC system have increasingly vital influence on the power supply of the receiving end grid. To improve the reliability level of UHVDC systems, a quantitative selection and configuration approach of redundant structures is proposed in this paper, which is based on multi-state reliability equivalence. Specifically, considering the symmetry characteristic of an UHVDC system, a state space model is established as a monopole rather than a bipole, which effectively reduces the state space dimensions to be considered by deducing the reliability merging operator of two poles. Considering the standby effect of AC filters and the recovery effect of converter units, the number of available converter units and corresponding probability are expressed with in universal ge... [more]
A Comprehensive Strategy for Accurate Reactive Power Distribution, Stability Improvement, and Harmonic Suppression of Multi-Inverter-Based Micro-Grid
Henan Dong, Shun Yuan, Zijiao Han, Zhiyuan Cai, Guangdong Jia, Yangyang Ge
June 23, 2020 (v1)
Keywords: droop control, harmonic suppression, micro-grid, power quality, virtual impedance
Among the issues of accurate power distribution, stability improvement, and harmonic suppression in micro-grid, each has been well studied as an individual, and most of the strategies about these issues aim at one inverter-based micro-grid, hence there is a need to establish a model to achieve these functions as a whole, aiming at a multi-inverter-based micro-grid. This paper proposes a comprehensive strategy which achieves this goal successfully; since the output voltage and frequency of micro-grid all consist of fundamental and harmonic components, the strategy contains two parts accordingly. On one hand, a fundamental control strategy is proposed upon the conventional droop control. The virtual impedance is introduced to solve the problem of accurate allocation of reactive power between inverters. Meanwhile, a secondary power balance controller is added to improve the stability of voltage and frequency while considering the aggravating problem of stability because of introducing vir... [more]
Multi-Objective Optimal Energy Management for the Integrated Electrical and Natural Gas Network with Combined Cooling, Heat and Power Plants
Yanbo Chen, Yangzi Wang, Jin Ma
June 23, 2020 (v1)
Keywords: CCHP, energy management, integrated electrical and natural gas network, linepack reserve, Optimization
This paper proposes a multi-objective optimal energy management framework for the integrated electrical and natural gas network (IEGN) with combined cooling, heat, and power (CCHP) plants. Various energy conversion devices that are installed in the CCHP plant provide redundant generation options and energy pathways, which could be optimally chosen and shifted with given objectives, while meeting the multi-energy (ME) demands. However, this flexible energy dispatch manners may frequently change the energy distribution in the IEGN and challenge their mutual accommodation. In particular, the linepack reserve in the natural gas network, which supports the ramping capabilities of both the gas turbines and the flexible energy dispatch of the gas-dependent ME devices, is highly influenced. Without enough linepack reserve, not only will the flexible operation of the CCHP plants be hindered, but also the gas turbines will be prevented from balancing the supply and the demand in the electrical n... [more]
An Adaptive Grid Voltage/Frequency Tracking Method Based on SOGIs on a Shipboard PV⁻Diesel-Battery Hybrid Power System
Guoling Wang, Xu Liu, Zhenyu Li, Shunxiao Xu, Zhe Chen
June 23, 2020 (v1)
Keywords: droop control, phase-locked loop (PLL), PV–diesel-battery, shipboard power system (SPS), SOGI, SOGI-FDE, SOGI-FLL, vessel
This paper addresses the unbalanced voltage, subharmonic/dc-offset voltage, and low-frequency (LF)/high-frequency (HF) harmonics of a grid voltage tracking method based on second-order generalized integrators (SOGIs) in high voltage/frequency swing on a shipboard photovoltaic (PV)-diesel-battery hybrid power system. To perform this work, a kind of shipboard PV⁻diesel-battery hybrid power system structure was first analyzed, emphasizing both the active and reactive power (PQ) control strategy and the sensitivity of the phase-locked loop (PLL) that is crucial to the vessel’s electrical networks. Then, the effect of grid voltage harmonics in SOGIs and of voltage/frequency swing on SOGI frequency-locked loop (SOGI-FLL) was studied. Meanwhile, aiming to the adverse power qualities of a shipboard power system (SPS), a SOGI-based structure with prefilter, a dc-offset block, and a positive sequence extractor (SOGI-FDE) was proposed. Finally, to overcome all of the vessel’s grid problems, a new... [more]
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