Yilin Hu¹, Yan Xie², Bo Li^3,*, Yiqiang Jiang¹, Fu Bao¹

Energy Engineering, Vol.118, No.4, pp. 911-929, 2021, DOI:10.32604/EE.2021.014759

Abstract Wind turbine employs pitch angle control to maintain captured power at its rated value when the wind speed is higher than rated value. This work adopts a perturbation observer based sliding-mode control (POSMC) strategy to realize robust variable-pitch control of permanent magnet synchronous generator (PMSG). POSMC combines system nonlinearities, parametric uncertainties, unmodelled dynamics, and time-varying external disturbances into a perturbation, which aims to estimate the perturbation via a perturbation observer without an accurate system model. Subsequently, sliding mode control (SMC) is designed to completely compensate perturbation estimation in real-time for the sake of achieving a global consistent control performance and… More >

Xiaojuan Lu, Zeping Liang^*

Energy Engineering, Vol.118, No.4, pp. 1171-1183, 2021, DOI:10.32604/EE.2021.014724

Abstract There are two prominent features in the process of temperature control in solar collector field. Firstly, the dynamic model of solar collector field is nonlinear and complex, which needs to be simplified. Secondly, there are a lot of random and uncontrollable, measurable and unmeasurable disturbances in solar collector field. This paper uses Taylor formula and difference approximation method to design a dynamic matrix predictive control (DMC) by linearizing and discretizing the dynamic model of the solar collector field. In addition, the purpose of controlling the stability of the outlet solar field salt temperature is achieved by adjusting the mass flow… More >

Wenhui Zhao¹, Yibo Yin^1,*, Lu Mao², Konglu Zhong³, Guanghui Yuan⁴, Hai Huang⁵, Yige Yang⁶

Energy Engineering, Vol.118, No.4, pp. 1009-1026, 2021, DOI:10.32604/EE.2021.014650

Abstract Changes in the energy price system will determine the direction of evolution of the energy industry structure. As a country where coal is the dominant energy source, what is the effect of coal price fluctuations on China’s industry development costs and energy consumption structure? To investigate this problem, this paper utilized an economy–energy–environment computable general equilibrium model. In this study, four aspects were analyzed: Energy supply side, proportion of renewable energy consumption, macroeconomy, and changes in CO₂ emissions. The results of this study show that an increase of 10%–20% in coal prices contributes to a shift into using renewable energy,… More >

Xinhong Xue¹, Zhongcheng Wang^2,*

Energy Engineering, Vol.118, No.4, pp. 995-1008, 2021, DOI:10.32604/EE.2021.014613

Abstract Electricity shortages present a significant constraint on manufacturers, who rely on electricity as an important input into production. In China, electricity supply has been growing rapidly. However, the rapid industrialization sometimes makes the power supply still unable to meet the demand. Using a survey of 1673 Chinese manufacturing firms, this paper explores how firms response to electricity shortages and its impact on productivity. We find that self-generation of electricity and investment in Research and Development (R&D) have significant positive relationships with electricity shortages. Further investigations reveal that self-generation is the most common way to deal with electricity shortages. However, it… More >

Weifeng Gong^1,2, Baoqing Zhu³, Chuanhui Wang^1,*, Zhenyue Fan¹, Mengzhen Zhao¹, Liang Chen⁴

Energy Engineering, Vol.118, No.4, pp. 981-994, 2021, DOI:10.32604/EE.2021.014554

Abstract An in-depth study of the energy related carbon emissions has important practical significance for carbon emissions reduction and structural adjustment in Shandong Province and throughout China. Based on the perspective of industrial structure, the expanded KAYA equation to measure the energy related carbon emissions of the primary industries (Resources and Agriculture) and secondary industries (Manufacturing and Construction) and tertiary industries (Retail and Service) was utilized in Shandong Province from 2011 to 2017. The carbon emissions among industries in Shandong Province were empirically analyzed using the Logarithmic Mean Divisia Index decomposition approach. The results were follows: (1) Under the three industrial… More >

Lei Zhang^*, Dejian Yang, Lei Ren, Yun Cheng, Qiufeng Yan, Yinlong Yuan

Energy Engineering, Vol.118, No.4, pp. 1155-1170, 2021, DOI:10.32604/EE.2021.014549

Abstract As a wide bandgap power electronics device, the SiC MOSFET has a lot of advantages over the traditional Si IGBT. Replacing the Si IGBT with the SiC MOSFET in the existing power electronics converter is an effective means to improve the performance and promote the upgrading of the traditional converter. Generally, in order to make full use of its advantages of the SiC MOSFET, the Si IGBT in the traditional power electronics circuit cannot be simply replaced by the SiC MOSFET, but the main circuit and the driver circuit need to be redesigned because the oscillation problem and the cross-talk… More >

Jiangyong Bao¹, Jianjun He^1,*, Biao Chen², Kaijun Yang¹, Jun Jie², Ruifeng Wang¹, Shihao Zhang²

Energy Engineering, Vol.118, No.4, pp. 947-959, 2021, DOI:10.32604/EE.2021.014535

Abstract As a surface functional material, super-hydrophobic coating has great application potential in wind turbine blade anti-icing, self-cleaning and drag reduction. In this study, ZnO and SiO₂ multi-scale superhydrophobic coatings with mechanical flexibility were prepared by embedding modified ZnO and SiO₂ nanoparticles in PDMS. The prepared coating has a higher static water contact angle (CA is 153°) and a lower rolling angle (SA is 3.3°), showing excellent super-hydrophobicity. Because of its excellent superhydrophobic ability and micro-nano structure, the coating has good anti-icing ability. Under the conditions of −10°C and 60% relative humidity, the coating can delay the freezing time by 1511S,… More >

Duojin Fan¹, Chengji Shi², Kai Sun², Xiaojuan Lu^2,*

Energy Engineering, Vol.118, No.4, pp. 1197-1221, 2021, DOI:10.32604/EE.2021.014532

Abstract This paper proposed a new type of combined cooling heating and power (CCHP) system, including the parabolic trough solar thermal (PTST) power generation and gas turbine power generation. The thermal energy storage subsystem in the PTST unit provides both thermal energy and electrical energy. Based on the life cycle method, the configuration optimization under eight operation strategies is studied with the economy, energy, and environment indicators. The eight operation strategies include FEL, FEL-EC, FEL-TES, FEL-TES&EC, FTL, FTL-EC, FTL-TES, and FTL-TES&EC. The feasibility of each strategy is verified by taking a residential building cluster as an example. The indicators under the… More >

Quan Min¹, Min Deng¹, Zichen Zheng^2,*, Shu Wang², Xianyong Gui³, Haichuan Zhang²

Energy Engineering, Vol.118, No.4, pp. 853-874, 2021, DOI:10.32604/EE.2021.014515

Abstract Combined with the characteristics of the distributed-drive electric vehicle and direct yaw moment control, a double-layer structure direct yaw moment controller is designed. The upper additional yaw moment controller is constructed based on model predictive control. Aiming at minimizing the utilization rate of tire adhesion and constrained by the working characteristics of motor system and brake system, a quadratic programming active set was designed to optimize the distribution of additional yaw moments. The road surface adhesion coefficient has a great impact on the reliability of direct yaw moment control, for which joint observer of vehicle state parameters and road surface… More >

Jin Zhang¹, Youliang Tang¹, Feng Yu^2,*

Energy Engineering, Vol.118, No.4, pp. 1083-1094, 2021, DOI:10.32604/EE.2021.014482

Abstract In this paper, position sensorless control system of permanent magnet synchronous linear motor (PMSLM) based on sliding mode observer (SMO) with an improved phase-locked loop (PLL) is studied. Firstly, according to the mathematical model, a SMO is designed for sensorless control PMSLM drive. Thereafter, an improved PLL is proposed to tackle the imperfection of data overflow existed in the traditional PLL. The designed SMO incorporating with the improved PLL can be effectively suppress the pulsation of the estimated position and hence the chattering of the derived electrical angular velocity. At last, simulated and experimental results are presented to verify the… More >