Cleanliness of energy system requires both NO x reduction due to urgent air pollution control and CO 2 cutting due to long-term climate change pressure. In the urban heating sector, quick-win plans use to be popular...
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ISBN:
(数字)9781728155081
ISBN:
(纸本)9781728155098
Cleanliness of energy system requires both NO x reduction due to urgent air pollution control and CO 2 cutting due to long-term climate change pressure. In the urban heating sector, quick-win plans use to be popular that focus on the NO x reduction by replacing untreated scattered coal fired boilers to natural gas or combined heat and power generators (CHPs). Meanwhile, in the electrical sector, all these fossil fuel generators should be cut down in the long-term decarbonization process. There should be a need for coordination of short- and long-term targets, because two energy supply sectors are believed to work in a coupled way in the future. A three-layered collaborative planning model is proposed in this paper: the top layer focuses roadmap economic evaluation; the middle layer applies coupled production simulation aiming at verifying energy balance; and the bottom one checks real-time operational feasibility. Pathways are made from 2020 to 2040 based on Hebei, China. Results indicate that the pathway with quick win will have delayed construction of renewable power, resulting the slow process in emission control. The long-term strategy scheme greatly promotes the renewables for supply in both sectors, but the close operational link forces the decoupling, leading to rebound on emission and operation cost on decentralized heating for the long-term future. In conclusion, the tradeoff pathway, reducing CO 2 emission as much as possible with NO x emission controlled to acceptable level, is recommended with good performance on emission control and economy.
Electrical tree is one of the major issues for insulation failure in high-voltage direct current (HVDC) cable. In this paper, electrical tree initiation and growth characteristics of silicone rubber (SIR) are studied ...
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Electrical tree is one of the major issues for insulation failure in high-voltage direct current (HVDC) cable. In this paper, electrical tree initiation and growth characteristics of silicone rubber (SIR) are studied by optical tree observation system under DC and AC voltage with varied temperature. Moreover, tree channels are pictured and analyzed by 3D fluorescence imaging technology. Results show that the average tree initiation voltage, whether DC or AC, decreases exponentially with increasing temperature. However, the initiation voltage under positive DC voltages is much higher than that under AC voltages. AC tree growth pattern could be roughly divided into two modes: bush-like growing pattern and pine-like growing pattern, while DC trees stop growing after voltage stabilizes. 3D fluorescence tests show that DC tree branches are sparser and the channels are thinner. Based on the trap theory, mechanism of DC electrical tree in SIR is clarified. It is believed that different charge transport dynamics are the main reason for the differences in electrical tree behavior under DC and AC voltages.
In recent years, with the development of smart grid technologies, wind turbines, photovoltaics and other renewable energy sources as well as demand-side loads have participated in grid dispatching, resulting in increa...
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ISBN:
(数字)9781728191645
ISBN:
(纸本)9781728191652
In recent years, with the development of smart grid technologies, wind turbines, photovoltaics and other renewable energy sources as well as demand-side loads have participated in grid dispatching, resulting in increased complexity of energy flows in the grid. Distributed energy resources (DERs) differ in many dimensions, such as technical attributes, operating modes, and business objectives, and its management authority also belongs to different entities, making it more difficult for grids to manage DERs. A management mode, virtual power plant (VPP), being enabled by information and communication technology, could effectively overcome the challenges with decentralized DERs and help realize the aggregation of DERs. In this paper, the interaction between customers and VPP is modeled, where VPP divides the owners of DERs into three categories according to the willingness and responsiveness of customers and balances budget costs and risks based on the modern portfolio theory. simulation with the CIGRE 20kV distribution network benchmark demonstrates that VPP could greatly meet the power consumption demand of multiple participants during operation. This paper also provides a basis for the selection of DERs aggregated by VPP. 1 1This paper is sponsored by the National key Research and Development Program (No.2017YFB0903300) and National Natural Science Foundation of China (No.51807107) 2 2This paper is sponsored by the Young Talents Support Project of the Chinese Society for Electrical Engineering (CSEE) titled “Research on key technologies for optimal operation and control of transportation energy systems”.
The beat frequency characteristic of the recovery voltage of fault phase in the case of single-phase grounding transient fault happening to line with the shunt reactors is analyzed. Besides, the paper analyzes the rea...
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Large-scale power system transmission and transformation equipment operates in high-voltage environments, placing notable requirements on the insulation strength of polymers used in core insulation frameworks. Increas...
Large-scale power system transmission and transformation equipment operates in high-voltage environments, placing notable requirements on the insulation strength of polymers used in core insulation frameworks. Increasing the polymer insulation performance in high-voltage environments is crucial for protecting large-capacity and integrated power equipment and ensuring the safe and stable operation of electrical devices. Here, we discuss the phenomena and the underlying mechanisms of bulk breakdown and surface flashover that lead to insulation failure in polymers and present relative strategies to increasing the performance of the insulating materials. We analyse the challenges faced by polymeric insulating materials in various extreme environments and the strategies to address them. Finally, we identify key challenges and highlight future directions and opportunities for the development of reliable polymeric insulating materials.
Distance protection is widely applied in High/Ultra- High Voltage AC transmission system. Impedance relay, the core element of distance protection, may operate incorrectly under power swing, so a power swing blocking ...
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Oil-paper insulation bears AC/DC composite voltage in converter transformers. However, the AC/DC space charge behavior is still not clear, which will result in electric field distortion, material aging and even insula...
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ISBN:
(纸本)9781728195728;9781728195735
Oil-paper insulation bears AC/DC composite voltage in converter transformers. However, the AC/DC space charge behavior is still not clear, which will result in electric field distortion, material aging and even insulation failure. In this work, the space charge distribution of oil-paper under the AC/DC composite voltage with the AC/DC ratio of 1:1, 1:3, 1:5, and 1:7, is studied by pulse electroacoustic (PEA) method, respectively. It was found that as DC component increases, the accumulated charge near the electrode decreases, while the interior charge increases. It suggests that DC stress mainly influences the amount and the depth of space charge accumulation. AC component has a relatively significant impact on the injection and extraction behavior of space charge near the electrode. Furthermore, AC/DC composite voltage enhances the migration of space charge compared with that under DC voltage. This research contributes to the further understanding of the space charge characteristics of oil-paper under AC/DC composite voltage, which will benefit the safe and stable operation of converter transformers.
This study proposes a steady-state model of multi-port electric energy router (EER) and a power flow analysis method for AC/DC hybrid system considering control strategies. Firstly, a circuit topology model of EER is ...
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Hot dry rock is a new type of geothermal resource which has a promising application prospect in *** paper conducted a comparative research on performance evaluation of two eligible bottoming cycles for a hot dry rock ...
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Hot dry rock is a new type of geothermal resource which has a promising application prospect in *** paper conducted a comparative research on performance evaluation of two eligible bottoming cycles for a hot dry rock power plant in the Gonghe *** on the given heat production conditions,a Kalina cycle and three organic Rankine cycles were tested respectively with different ammonia-water mixtures of seven ammonia mass fractions and nine ecofriendly working *** results show that the optimal ammonia mass fraction is 82%for the proposed bottoming Kalina cycle in view of maximum net power *** analysis suggests that wet fluids should be supercritical while dry fluids should be saturated at the inlet of turbine,*** maximum net power output of the organic Rankine cycle with dry fluids expanding from saturated state is higher than that of the other organic Rankine cycle combinations,and is far higher than the maximum net power output in all tested Kalina cycle *** the given heat production conditions of hot dry rock resource in the Gonghe Basin,the saturated organic Rankine cycle with the dry fluid butane as working fluid generates the largest amount of net power.
Demand response(DR) is important to account for behaviors of the demand side to yield an optimal dispatch result. However, it is difficult for energy suppliers to collect customers' private information unless ther...
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Demand response(DR) is important to account for behaviors of the demand side to yield an optimal dispatch result. However, it is difficult for energy suppliers to collect customers' private information unless there is an incentive mechanism for customers to do so. Therefore,this paper proposes a new integrated generation–consumption dispatch based on compensation mechanism considering DR behavior. Firstly, in light of the dayahead load forecast data, we deduce the utility function model of different customers. By subtracting generating units' operation cost from consumers' total utility, the dispatch model has a decentralized demand participant structure based on this utility function. The utility function is used to describe consumers' preferences and energy consumption behaviors. Secondly, an effective compensation mechanism is designed to ensure customers to select the level of compensation appropriate to their willingness to curtail load. Finally, a new dispatch model is proposed that incorporates the DR compensation mechanism into the generation–consumption dispatch model. The new model can improve the interaction of generation and consumption,and benefit both the energy supplier and its customers. The proposed model is piecewise linearized and solved by a mixed-integer linear programming method. It is tested on a six-bus system and the IEEE 118-bus system. simulation results show that the proposed model can realize both maximum social welfare and Pareto optimal results.
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