Wei Shi¹, Shusheng Xiong^1,*, Wei Li², Bohao Zhang³

Energy Engineering, Vol., , DOI:10.32604/EE.2021.014643

Abstract 48 V lithium battery micro hybrid system is the most fuel economy vehicle which can be mass produced at present. However, with the irreversible internal resistance increase of the key component 48 V lithium battery, and the capacity continues to decline, the system performance deteriorate. Worst case could be the system not functional in the middle and later age of vehicle life cycle. This paper studies the feasibility of using 48 V super capacitor as the replacement to 48 V lithium battery, and uses a 12 V module of 48 V super capacitor as the traditional 12 V power supply,… More >

Haibo Liu^1,*, Yujie Dong², Fuzhong Wang¹

Energy Engineering, Vol., , DOI: 10.32604/EE.2021.014630

Abstract For the problems of nonlinearity, uncertainty and low prediction accuracy in the gas outburst prediction of coal mining face, the least squares support vector machine (LSSVM) is proposed to establish the prediction model. Firstly, considering the inertia coefficients as global parameters lacks the ability to improve the solution for the traditional particle swarm optimization (PSO), an improved PSO (IPSO) algorithm is introduced to adjust different inertia weights in updating the particle swarm and solve the fitness to stagnate. Secondly, the penalty factor and kernel function parameter of LSSVM are searched automatically, and the regression accuracy and generalization performance is enhanced… More >

Lian Zhang^1,2,3,*, Linjun Fan⁴, Xin Xu⁵, Baowen Cao¹, Heng Zhang², Lihong Song³

Energy Engineering, Vol., , DOI:10.32604/EE.2021.012647

Abstract Radiator thermal performance test equipment plays a key role in the processing of developing a new type of heat radiator and its application products. The precise of temperature controlling, temperature measuring and flow measuring are the vital factors for a radiator thermal performance test equipment. Based on the above background, this paper improves the measurement and control system of radiator thermal performance test equipment, which improves the accuracy of the radiator thermal performance test equipment. This paper also optimizes the software and hardware system simultaneously so as to improve the precision of the auto-test system of test equipment. The flow… More >

Chi Zhang, Yong Shi^*, Xuwei Gui

Energy Engineering, Vol., , DOI:10.32604/EE.2021.014229

Abstract To realize effective utilization of renewable energy sources, a novel polymorphic topology with hybrid control strategy based LLC resonant converter was analyzed and designed in this paper. By combining the merits of a full bridge LLC resonant converter, three-level half bridge LLC resonant converter, and variable frequency control mode, the converter realizes an intelligent estimation of input voltage by automatically changing its internal circuit topology. Under this control strategy, different input voltages determine different operation modes. This is achieved in full bridge LLC mode when the input voltage is low. If the input voltage rises to a certain level, it… More >

Yu Liu¹, Ruiting Jiao¹, Liyao Zhao¹, Kai Liu^1,2,*

Energy Engineering, Vol., , DOI:10.32604/EE.2021.013472

Abstract The impact of greenization on the marginal utility of the intensity of carbon emissions in China and factors influencing this relationship are explored in this study. China’s level of greenization is evaluated by using an index system developed based on the comprehensive index method. The intensity of carbon emissions is determined by using the standards for the coefficients of conversion of coal equivalent and coefficients of carbon emission. The impact of greenization on the marginal utility of the intensity of carbon emissions is then evaluated by using an elastic formula and factors affecting this relationship are verified by regression analysis.… More >

Fenwicks Shombe Musonye^1,*, Hiram Ndiritu², Robert Kinyua³

Energy Engineering, Vol., , DOI:10.32604/EE.2021.013890

Abstract Pinch Analysis is an attractive solution for reduction of thermal energy costs in thermo-chemical industries. In this approach, maximum internally recoverable heat is determined and a heat exchange network is designed to meet the recovery targets. The thermal performance of a heat exchanger over its lifetime is however a concern to industries. Thermal performance of a heat exchanger is affected by many factors which include the physical properties of the shell and tube materials, and the chemical properties of the heat transfer fluid. In this study, thermal performance of shell and tube heat exchangers designed to meet heat recovery targets… More >

Bilin Xu, Mei Han^*

Energy Engineering, Vol., , DOI:10.32604/EE.2021.013384

Abstract Based on the theory of ecological organization, this paper analyzes the operation mechanism of chemical industry park (CIP) ecosystem by means of dynamic simulation. The research shows that the CIP ecosystem is a complex ecological system whose operation mechanism includes two levels, namely individual enterprises and ecosystem. At the level of individual enterprise, there are competition, symbiosis, invasion and other interactions between enterprises in the CIP ecosystem. Through the pre-determined judgment of the competition effect coefficient and the symbiosis effect coefficient, we calculate how the enterprises influence each other, and then generate their respective operation paths, and finally realize the… More >

G. Indira Kishore¹, M. Premkumar^1,*, Ramesh Kumar Tripathi², Chandra Sekhar Nalamati²

Energy Engineering, Vol., , DOI:10.32604/EE.2021.014079

Abstract Renewable energy with sources such as photovoltaic (PV) or fuel cells can be utilized for the generation of electrical power. But these sources generate fewer voltage values and therefore require high gain converters to match with DC bus voltage in microgrids. These high gain converters can be implemented with switched capacitors to meet the required DC bus voltage. Switched capacitors operate in a series and parallel combination during switching operation and produce high static gain, limits reverse voltage that appears across the components. A novel converter is proposed that satisfies all the features such as high voltage gain, only one… More >

D. Menaga¹, M. Premkumar², R. Sowmya^1,*, S. Narasimman³

Energy Engineering, Vol., , DOI:10.32604/EE.2020.013282

Abstract The proposed controller accompanies with different sliding surfaces. To understand maximum power point extraction as opposed to nonlinear uncertainties and unknown disturbance of a grid-connected photovoltaic system to various control inputs (u_d, u_q) is designed. To extract maximum power from a solar array and maintain unity power flow in a grid by controlling the voltage across the dclink capacitor (V_pvdc) and reactive current (i_q). A multiple input-output with multiple uncertainty constraints have considered designing proposed sliding mode controllers to validated their robustness performance. An innovative controller verifies uncertain inputs, constant and changes in irradiances, and temperature of the photo-voltaic system.… More >

Tanzhong Fu^1,2,3, Yu Xue^1,*, Tancai Xia¹, Wang Jing¹, De Gejirifu¹

Energy Engineering, Vol., , DOI:10.32604/EE.2020.011633

Abstract To further study the impact of renewable energy penetration on the technical transformation of distribution networks. Based on the output power characteristics of wind power and photovoltaics, a renewable energy grid-connected capacity model and a distribution network full cost-benefit model were constructed. Based on this, to maximize the comprehensive income of the distribution network and the renewable energy penetration rate, to establish the technical reform optimization model and search for the optimal solution through the improved NSGA-II algorithm. Finally, the effectiveness of the proposed model was verified by setting up three scenarios of simultaneous wind power, grid-connected wind power, grid-connected… More >