Assessment of Operational Performance in a Power Generation/Selling Integrated Company Using a Dynamic Proportional Adjustment Coefficient

Currently,the operational performance assessment system in the power market primarily focuses on power generation and electricity retail companies,lacking a system tailored to the operational characteristics of power generation/selling integrated companies.Therefore,this article proposes an assessment index system for assessing the operational performance of a power generation/selling integrated company,encompassing three dimensions:basic capacity,development potential,and external environment.A dynamic proportional adjustment coefficient is designed,along with a subjective and objective weighting model for assessment indexes based on a combined weightingmethod.Subsequently,the operational performance of an integrated company is assessed using extension theory.The results in the case study demonstrate the feasibility and effectiveness of the proposed dynamic proportional adjustment coefficient.

Recent progress in integrated electro-optic frequency comb generation

Optical frequency combs have emerged as an important tool enabling diverse applications from test-and-measurement,including spectroscopy,metrology,precision distance measurement,sensing,as well as optical and microwave waveform synthesis,signal processing,and communications.Several techniques exist to generate optical frequency combs,such as mode-locked lasers,Kerr micro-resonators,and electro-optic modulation.Important characteristics of optical frequency combs include the number of comb lines,their spacing,spectral shape and/or flatness,and intensity noise.While mode-locked lasers and Kerr micro-resonators can be used to obtain a large number of comb lines compared to electro-optic modulation,the latter provides increased flexibility in tuning the comb spacing.For some applications in optical communications and microwave photonics,a high degree of integration may be more desirable over a very large number of comb lines.In this paper,we review recent progress on integrated electro-optic frequency comb generators,including those based on indium phosphide,lithium niobate,and silicon photonics.

Integrated Route Recovery of Aircraft and Aircrew Based on Column Generation Algorithm

The problem of abnormal flight recovery has always been the focus and difficulty in the field of civil aviation,and has important research significance. According to the recovery strategy,characteristics,and constraints of aircraft,aircrews and flights,this paper is based on the column generation algorithms. A mathematical optimization model for the integrated recovery of aircraft and aircrew in the case of temporary aircraft failures was established,and the corresponding solution algorithm was designed. At the same time,the influence of aircraft and aircrew on route selection was taken into account. Finally,the method of calling Cplex by Java was used. Part of the flight plan data actually operated by the company verifies the feasibility,accuracy and timeliness of the model and algorithm.

Current status of national integrated gasification fuel cell projects in China

Coal has been the main energy source in China for a long period.Therefore,the energy industry must improve coal power generation efficiency and achieve near-zero CO_(2) emissions.Integrated gasification fuel cell(IGFC)systems that combine coal gasification and high-temperature fuel cells,such as solid oxide fuel cells or molten carbonate fuel cells(MCFCs),are proving to be promising for efficient and clean power generation,compared with traditional coal-fired power plants.In 2017,with the support of National Key R&D Program of China,a consortium led by the China Energy Group and including 12 institutions was formed to develop the advanced IGFC technology with near-zero CO_(2) emissions.The objectives of this project include understanding the performance of an IGFC power generation system under different operating conditions,designing master system principles for engineering optimization,developing key technologies and intellectual property portfolios,setting up supply chains for key materials and equipment,and operating the first megawatt IGFC demonstration system with near-zero CO_(2) emission,in early 2022.In this paper,the main developments and projections pertaining to the IGFC project are highlighted.

α-times Integrated Cosine Operator Functions with Growth ω

For a continuous,increasing functionω:[0,∞)→C of finite exponential type,we establish a Hille-Yosida type theorem for strongly continuous α-times(α>0)integrated cosine operator functions with O(ω).It includes the corresponding results for n-times integrated cosine operator functions that are polynomially bounded and exponentially bounded.

Effects of Seed Viability and Number of Generations on Genetic Integrity of Soybean Germplasm Zhonghuang 18 by AFLP Markers

The seeds of a soybean cultivar Zhonghuang 18 were subjected to accelerated aging for 0(population G_0-1), 112(population G_0-2), 154(population G_0-3) and 196 d(population G_0-4), whose germination percentage was found to be 98.0%, 95.0%, 81.0%, and 79.0%, respectively. Then, the four populations were regenerated twice in the field. The first descendant populations were marked as G_1-1, G_1-2, G_1-3 and G_1-4, and the second were marked as G_2-1, G_2-2, G_2-3 and G_2-4, respectively. The genetic variation between the control population(G_0-1) and the experimental populations was analyzed using 12 AFLP primer combinations. The results showed that there was no significant difference in genetic similarity between the 11 experimental populations and the control population G_0-1. The genetic similarity between population G_2-4 and G_0-1 was still as high as 0.933 3, indicating that the F_2 generation of the population whose germination percentage was only 79.0% still had a high genetic similarity to the control population. The results of t-tests revealed that the populations G_1-1, G_2-1, G_1-2 and G_2-2 showed no significant difference from the control population G_0-1 in effective number of alleles per locus(Ae), genetic diversity index(H) and Shannon's diversity index(I), while these indices of populations G_0-3, G_0-4, G_1-3, G_1-4, G_2-3 and G_2-4 were significantly reduced. χ~2 tests indicated that the populations G_1-1 and G_2-1 showed little difference, and the populations G_0-2, G_0-3, G_0-4, G_1-2, G_1-3, G_1-4, G_2-2, G_2-3, and G_2-4 showed great difference in allele frequency distribution from the control population G_0-1, and the difference was greater when the seed viability was lower. Compared with the control population G_0-1, the number of rare alleles(Nr) of the populations G_0-2, G_1-1, G_2-1, G_1-2 and G_2-2 showed no significant difference, while that of the populations G_0-3, G_0-4, G_1-3, G_1-4, G_2-3 and G_2-4 declined obviously. These results revealed that compared with the control population, the genetic diversity and Nr for the descendant populations of the populations with 98.0% and 95.0% germination percentages did not change significantly, but declined greatly for the descendant populations of the populations with 81.0.% and 79.0% percentages. The results suggested that the decline in seed viability has a greater impact than the number of generations on genetic structure of soybean germplasm. So, it is suggested that soybean seed with an initial germination percentage of 98.0% should be regenerated before its germination percentage declines to 81.0%.

The Influence of Social Support and Psychological Capital Enhancement to the New Generation of Migrant Workers Integrating into the City

The new generation of migrant workers are the main urban construction team in China＇s economic development, they play an indispensable role.？However, the social integration of this group has been hampered by many factors. Views of this paper is that social support and psychological capital enhancement have a significant impact on the new generation of migrant workers integrated into the city. Finally, propose strategies to facilitate this group more easily integrate into city life.

Renewable energy power generation projects started construction in Tibet

On March 19, the construction of a 10-MW photovoltaic power plant and a 1 000-kW new type geothermal power generation project were started by Guodian Longyuan Group in Yanbajing Town, Dangxiong County of Tibet.

Effect of applied electric fields on supralinear dendritic integration of interneuron

Evidences show that electric fields(EFs)induced by the magnetic stimulation could modulates brain activities by regulating the excitability of GABAergic interneuron.However,it is still unclear how and why the EF-induced polarization affects the interneuron response as the interneuron receives NMDA synaptic inputs.Considering the key role of NMDA receptor-mediated supralinear dendritic integration in neuronal computations,we suppose that the applied EFs could functionally modulate interneurons’response via regulating dendritic integration.At first,we build a simplified multi-dendritic circuit model with inhomogeneous extracellular potentials,which characterizes the relationship among EF-induced spatial polarizations,dendritic integration,and somatic output.By performing model-based singular perturbation analysis,it is found that the equilibrium point of fast subsystem can be used to asymptotically depict the subthreshold input–output(sI/O)relationship of dendritic integration.It predicted that EF-induced strong depolarizations on the distal dendrites reduce the dendritic saturation output by reducing driving force of synaptic input,and it shifts the steep change of sI/O curve left by reducing stimulation threshold of triggering NMDA spike.Also,the EF modulation prefers the global dendritic integration with asymmetric scatter distribution of NMDA synapses.Furthermore,we identify the respective contribution of EF-regulated dendritic integration and EF-induced somatic polarization to an action potential generation and find that they have an antagonistic effect on AP generation due to the varied NMDA spike threshold under EF stimulation.

High-intensity spatial-mode steerable frequency up-converter toward on-chip integration

Integrated photonic devices are essential for on-chip optical communication,optical-electronic systems,and quantum information sciences.To develop a high-fidelity interface between photonics in various frequency domains without disturbing their quantum properties,nonlinear frequency conversion,typically steered with the quadratic(χ2)process,should be considered.Furthermore,another degree of freedom in steering the spatial modes during theχ2 process,with unprecedent mode intensity is proposed here by modulating the lithium niobate(LN)waveguide-based inter-mode quasi-phasematching conditions with both temperature and wavelength parameters.Under high incident light intensities(25 and 27.8 dBm for the pump and the signal lights,respectively),mode conversion at the sum-frequency wavelength with sufficient high output power(−7–8 dBm)among the TM01,TM10,and TM00 modes is realized automatically with characterized broad temperature(ΔT≥8°C)and wavelength windows(Δλ≥1 nm),avoiding the previous efforts in carefully preparing the signal or pump modes.The results prove that high-intensity spatial modes can be prepared at arbitrary transparent wavelength of theχ2 media toward on-chip integration,which facilitates the development of chip-based communication and quantum information systems because spatial correlations can be applied to generate hyperentangled states and provide additional robustness in quantum error correction with the extended Hilbert space.

Optimal Initialization and Starting Approach of Synchronous Condenser Integrated Power Grid

Synchronous condensers(SCs)are generally used at the receiving-end stations of ultra-high-voltage direct current(UHVDC)transmission systems due to their strong reactive power support and flexible regulation of reactive power according to the interconnected grids operating conditions.In this paper,different starting control schemes of a SC integrated power grid are investigated providing four main contributions:1)The principle of reactive power support of the SC on the interconnected power grid is analytically studied,providing the establishment of mathematical models.2)Four different starting control schemes are developed for the initialization and SC integration,i.e.in Scheme 1,a preset initial falling speed is directly utilized without initialization;in Scheme 2,a black start sequential control approach with a static frequency converter(SFC)is proposed;in Scheme 3,PI/PD/PID controllers are respectively applied for the excitation device at the speed-falling stage;in Scheme 4,a pre-insertion approach of an energy absorption component with R/L/RL is utilized to suppress the surges at the SC integration instant.3)The dynamic behaviors of four different starting schemes at specific operating stages are evaluated.4)The success rate of SC integration is analyzed to evaluate starting control performance.Performance of the SC interconnected system with four different starting control schemes is evaluated in the timedomain simulation environment PSCAD/EMTDC^(TM).The results prove the superiority of the proposed starting control approach in Scheme 4.

Optimal Operation Strategy Analysis with Scenario Generation Method Based on Principal Component Analysis,Density Canopy,and K-medoids for Integrated Energy Systems

The operation of integrated energy systems(IESs)is confronted with great challenges for increasing penetration rate of renewable energy and growing complexity of energy forms.Scenario generation is one of ordinary methods to alleviate the system uncertainties by extracting several typical scenarios to represent the original high-dimensional data.This paper proposes a novel representative scenario generation method based on the feature extraction of panel data.The original high-dimensional data are represented by an aggregated indicator matrix using principal component analysis to preserve temporal variation.Then,the aggregated indicator matrix is clustered by an algorithm combining density canopy and K-medoids.Together with the proposed scenario generation method,an optimal operation model of IES is established,where the objective is to minimize the annual operation costs considering carbon trading cost.Finally,case studies based on the data of Aachen,Germany in 2019 are performed.The results indicate that the adjusted rand index(ARI)and silhouette coefficient(SC)of the proposed method are 0.6153 and 0.6770,respectively,both higher than the traditional methods,namely K-medoids,K-means++,and density-based spatial clustering of applications with noise(DBSCAN),which means the proposed method has better accuracy.The error between optimal operation results of the IES obtained by the proposed method and all-year time series benchmark value is 0.1%,while the calculation time is reduced from 11029 s to 188 s,which verifies that the proposed method can be used to optimize operation strategy of IES with high efficiency without loss of accuracy.

Simulation study on starting of dual clutch transmission for tracked vehicles

In order to study the application of dual clutch transmission （DCT） on tracked vehicles, a simulation moclel and two control methods were performed for starting analysis. Based on a certain transmission of an existing tracked vehicle, a DCT structure was proposed. Matlab/Simulink was a dopted as a platform to develop the simulation model. The engine speed was controlled to follow the target speed as a launch strategy. Two control methods, a proportional integral derivative （ PID ） control method and a fuzzy control method, were proposed to control the engine throttle and oil pressure in order to track the target engine speed. Simulation results show that either the PID control or fuzzy control method can improve the starting performance compared with no loop control meth od. Fuzzy control method can lead a better starting quality compared with PID control method.

Multi-channel 28-GHz millimeter-wave signal generation on a silicon photonic chip with automated polarization control

We propose and experimentally demonstrate an integrated silicon photonic scheme to generate multi-channel millimeter-wave(MMW) signals for 5 G multi-user applications. The fabricated silicon photonic chip has a footprint of 1.1 × 2.1 mm^2 and integrates 7 independent channels each having on-chip polarization control and heterodyne mixing functions. 7 channels of4-Gb/s QPSK baseband signals are delivered via a 2-km multi-core fiber(MCF) and coupled into the chip with a local oscillator(LO) light. The polarization state of each signal light is automatically adjusted and aligned with that of the LO light, and then 7 channels of 28-GHz MMW carrying 4-Gb/s QPSK signals are generated by optical heterodyne beating. Automated polarizationcontrol function of each channel is also demonstrated with ～7-ms tuning time and ～27-dB extinction ratio.

A Novel Cascaded PID Controller for Automatic Generation Control Analysis With Renewable Sources

Present day power scenarios demand a high quality uninterrupted power supply and needs environmental issues to be addressed. Both concerns can be dealt with by the introduction of the renewable sources to the existing power system. Thus, automatic generation control(AGC) with diverse renewable sources and a modified-cascaded controller are presented in the paper.Also, a new hybrid scheme of the improved teaching learning based optimization-differential evolution(hITLBO-DE) algorithm is applied for providing optimization of controller parameters. A study of the system with a technique such as TLBO applied to a proportional integral derivative(PID), integral double derivative(IDD) and PIDD is compared to hITLBO-DE tuned cascaded controller with dynamic load change.The suggested methodology has been extensively applied to a 2-area system with a diverse source power system with various operation time non-linearities such as dead-band of, generation rate constraint and reheat thermal units. The multi-area system with reheat thermal plants, hydel plants and a unit of a wind-diesel combination is tested with the cascaded controller scheme with a different controller setting for each area. The variation of the load is taken within 1% to 5% of the connected load and robustness analysis is shown by modifying essential factors simultaneously by± 30%. Finally, the proposed scheme of controller and optimization technique is also tested with a 5-equal area thermal system with non-linearities. The simulation results demonstrate the superiority of the proposed controller and algorithm under a dynamically changing load.

Integration system research and development for three-dimensional laser scanning information visualization in goaf

An integration processing system of three-dimensional laser scanning information visualization in goaf was developed. It is provided with multiple functions, such as laser scanning information management for goaf, cloud data de-noising optimization, construction, display and operation of three-dimensional model, model editing, profile generation, calculation of goaf volume and roof area, Boolean calculation among models and interaction with the third party soft ware. Concerning this system with a concise interface, plentiful data input/output interfaces, it is featured with high integration, simple and convenient operations of applications. According to practice, in addition to being well-adapted, this system is favorably reliable and stable.

Hydro and Wind Power Integration: A Case Study of Dargai Station in Pakistan

Pakistan is facing acute energy crises since last few years. Due to shortage of fuel oil and its sky touching prices, it seems very uneconomical to generate electricity from fuel oil. In order to generate cheap electricity we have to rely on renewable energy resources. To address these challenges, wind power generation is among the popular options in the world which is now being considered in Pakistan as well. However unremitting change in wind speed from calm to stormy introduces real challenges. Storing wind energy in batteries during the periods of low demand seems an expensive option, especially when dealing with large scale power generation. Due to incessantly varying nature of wind speed, it is not feasible to rely only on wind power for cheap power production. Also, it is not thriftily possible to construct separate transmission line. However if we integrate wind power with hydro power, we can utilize the maximum possible transmission capacity. Existing hydro power station operating in that area or pumped storage scheme can be used. This paper is an attempt to analyze coordination of wind generation with hydro power in those areas of Pakistan where both wind and hydro power sources exist. In this paper, different issues have been analyzed taking case study of Dargai. This paper is first attempt in Pakistan about integration of wind and hydro power to draw some general conclusions and to point out some areas in which further research can be done.

Overview of Wind Power Integration in China

With the rapid development of wind power in China, the grid integration of wind energy systems has imposed lots of influences on the security and operation of power grids. This paper provides an overview of the characteristics of the wind power development in terms of distribution area, wind farm scale, integration voltage level and performance of wind turbines. The paper also presents an analysis of the problems and reasons emerging from the wind power integration in China and ends with putting forward some measures and suggestions about the wind power integration and operation for reference.

Investigation and Mitigation of Transformer Inrush Current during Black Start of an Independent Power Producer Plant

The energizing of large power transformers has long been considered a critical event in the operation of an electric power system. When a transformer is energized by the utility, a typical inrush current could be as high as ten times its rated current. This could cause many problems from mechanical stress on transformer windings to harmonics injection, and system protection malfunction. There have been numerous researches focusing on calculation and mitigation of the transformer inrush current. With the development of smart grid, distributed generation from independent power producers (IPPs) is growing rapidly. This paper investigates the inrush current due to black start of an IPP system with several parallel transformers, through a simulation model in DIgSILENT Power Factory software. The study demonstrates that a single genset is capable of energizing a group of transformers since the overall inrush current is slightly above the inrush of the transformer directly connected to the generator. In addition, a simple method is proposed to mitigate the inrush current of the transformers using an auxiliary transformer.

Efficiency analysis of trilateral-cycle power systems for waste heat recovery-to-power generation

Numerous innovative heat recovery-to-power technologies have been resourcefully and technologically exploited to bridge the growing gap between energy needs and its sustainable and affordable supply.Among them,the proposed trilateral-cycle(TLC) power system exhibits high thermodynamic efficiency during heat recovery-to-power from low-to-medium temperature heat sources.The TLCs are proposed and analysed using n-pentane as working fluid for waste heat recovery-to-power generation from low-grade heat source to evaluate the thermodynamic efficiency of the cycles.Four different single stage TLC configurations with distinct working principles are modelled thermodynamically using engineering equation solver.Based on the thermodynamic framework,thermodynamic performance simulation and efficiency analysis of the cycles as well as the exergy efficiencies of the heating and condensing processes are carried out and compared in their efficiency.The results show that the simple TLC,recuperated TLC,reheat TLC and regenerative TLC operating at subcritical conditions with cycle high temperature of 473 K can attain thermal efficiencies of 21.97%,23.91%,22.07% and 22.9%,respectively.The recuperated TLC attains the highest thermodynamic efficiency at the cycle high temperature because of its lowest exergy destruction rates in the heat exchanger and condenser.The efficiency analysis carried out would assist in guiding thermodynamic process development and thermal integration of the proposed cycles.