Zhijie Zheng¹, Song Zhang¹, Xiaolei Zhang², Bo Yang¹, Fang Yan³, Xiaoning Ge^3,*

Energy Engineering, Vol.120, No.3, pp. 633-647, 2023, DOI:10.32604/ee.2022.024081 - 03 January 2023

Abstract The DC distribution network system equipped with a large number of power electronic equipment exhibits weak damping characteristics and is prone to low-frequency and high-frequency unstable oscillations. The current interpretation of the oscillation mechanism has not been unified. Firstly, this paper established the complete state-space model of the distribution system consisting of a large number of electric vehicles, characteristic equation of the distribution network system is derived by establishing a state-space model, and simplified reduced-order equations describing the low-frequency oscillation and the high-frequency oscillation are obtained. Secondly, based on eigenvalue analysis, the oscillation modes and More >

Jiulong Sun¹, Yanbo Che^1,*, Ting Yang¹, Jian Zhang², Yibin Cai¹

Energy Engineering, Vol.120, No.2, pp. 367-384, 2023, DOI:10.32604/ee.2023.023661 - 29 November 2022

Abstract As the number of electric vehicles (EVs) continues to grow and the demand for charging infrastructure is also increasing, how to improve the charging infrastructure has become a bottleneck restricting the development of EVs. In other words, reasonably planning the location and capacity of charging stations is important for development of the EV industry and the safe and stable operation of the power system. Considering the construction and maintenance of the charging station, the distribution network loss of the charging station, and the economic loss on the user side of the EV, this paper takes… More > Graphic Abstract

Mehrdad Ahmadi Kamarposhti^1,*, Ilhami Colak², Phatiphat Thounthong³, Kei Eguchi⁴

CMC-Computers, Materials & Continua, Vol.74, No.2, pp. 4547-4570, 2023, DOI:10.32604/cmc.2023.034082 - 31 October 2022

Abstract The present study suggests that series voltage injection is more effective than parallel current injection to improve voltage quality on the load side. The line voltage can be accurately symmetrized at the connection point by creating and controlling a series voltage component in each phase. This is more reliable and effective than parallel current injection. A dynamic voltage restorer (DVR) and a distribution static synchronous compensator (DSTATCOM) were utilized to provide the required power. The DVR is an effective and modern device utilized in parallel within the grid and can protect sensitive loads from voltage More >

Chao Zhu¹, Lei Wang¹, Dai Pan¹, Zifei Wang², Tao Wang², Licheng Wang^2,*, Chengjin Ye³

CMES-Computer Modeling in Engineering & Sciences, Vol.134, No.1, pp. 599-609, 2023, DOI:10.32604/cmes.2022.021052 - 24 August 2022

Abstract In this paper, a model free volt/var control (VVC) algorithm is developed by using deep reinforcement learning (DRL). We transform the VVC problem of distribution networks into the network framework of PPO algorithm, in order to avoid directly solving a large-scale nonlinear optimization problem. We select photovoltaic inverters as agents to adjust system voltage in a distribution network, taking the reactive power output of inverters as action variables. An appropriate reward function is designed to guide the interaction between photovoltaic inverters and the distribution network environment. OPENDSS is used to output system node voltage and More >

S. Arun Kumar^*, S. Padma, S. Madhubalan

Intelligent Automation & Soft Computing, Vol.33, No.2, pp. 777-789, 2022, DOI:10.32604/iasc.2022.023702 - 08 February 2022

Abstract Energy management carried in a power system by configuration process is a difficult activity. So, reconfiguration has been introduced to solve this problem. Numerous optimization topologies have been utilized to solve this problem so far. However, they exhibit some drawbacks such as convergence, etc. Hence to overcome this issue, this work formulated a new hybrid optimization topology Genetic Algorithm Enabled Particle Swarm Optimization (PSOGA) to solve the energy configuration problem with low power loss in the Distribution System (DS). The proposed topology’s effectiveness was evaluated on the IEEE 33 bus Distribution System, and the results More >

Min Liu^*

Energy Engineering, Vol.119, No.2, pp. 781-800, 2022, DOI:10.32604/ee.2022.016657 - 24 January 2022

Abstract With the application of phasor measurement units (PMU) in the distribution system, it is expected that the performance of the distribution system state estimation can be improved obviously with the PMU measurements into consideration. How to appropriately place the PMUs in the distribution is therefore become an important issue due to the economical consideration. According to the concept of efficient frontier, a value-at-risk based approach is proposed to make optimal placement of PMU taking account of the uncertainty of measure errors, statistical characteristics of the pseudo measurements, and reliability of the measurement instrument. The reasonability More >

Van-Phuong Ta^*, Dinh-Nhon Truong, Nguyen-Thanh Nhan

Intelligent Automation & Soft Computing, Vol.32, No.3, pp. 1605-1615, 2022, DOI:10.32604/iasc.2022.022374 - 09 December 2021

Abstract Water Distribution System (WDS) is one of the important phases of the Water Treatment Plant (WTP) and plays a crucial role in plant, animal, and human life. The WDS aims not only to supply a continuous, stable water amount but also to reduce energy consumption as little as possible during operation. To keep the continuous, stable water amount, the water pressure in the pipe network of the WDS must be maintained at desired set points under the effecting of uncertainties, disturbances, and noises. For saving the energy requirement, a Variable Frequency Driver (VFD) was utilized More >

Bo Zeng^*, Yixian Liu, Yangfan Luo

Energy Engineering, Vol.118, No.6, pp. 1713-1728, 2021, DOI:10.32604/EE.2021.016678 - 10 September 2021

Abstract In the future smart cities, parking lots (PLs) can accommodate hundreds of electric vehicles (EVs) at the same time. This trend creates an opportunity for PLs to serve as a potential flexibility resource, considering growing penetration of EVs and integration of distributed energy resources DER (such as photovoltaic and energy storages). Given this background, this paper proposes a comprehensive evaluation framework to investigate the potential role of DER-integrated PLs (DPL) with the capability of vehicle-to-grid (V2G) in improving the reliability of the distribution network. For this aim, first, an overview for the distribution system with… More >

Neil Stephen Lopez^1,*, Selena Kay Galeos¹, Brian Raphael Calderon¹, David Roy Dominguez¹, Bryan Joseph Uy¹, Rupesh Iyengar²

FDMP-Fluid Dynamics & Materials Processing, Vol.17, No.2, pp. 333-347, 2021, DOI:10.32604/fdmp.2021.011213 - 02 April 2021

Abstract The underfloor air distribution (UFAD) system has not been able to penetrate the residential and commercial air conditioning industry significantly until now. To date, the most notable applications are found in datacenters because of their more demanding thermal stratification and cooling requirements. In addition to highlighting the advantages of the UFAD system over the traditional overhead (OH) system, this study compares various ventilation layouts for a UFAD system. Four different UFAD ventilation layouts are compared and one OH layout. The results show that using multiple swirl-type diffusers creates a more uniform floor-to-knee temperature and less More >