Hybrid MANET-satellite network is a natural evolution in achieving ubiquitous communication. Their combination gives full play to respective advantages—autonomy and flexibility of MANET, wide coverage and resilience ...
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近年来,混合多端直流输电系统快速发展。但是,在混合直流系统中应用的电压源换流器(voltage-source converter, VSC)出口不再需要直流滤波器。此外,考虑到其直流故障电流可被换流器自身有效抑制,直流线路两端也不再需要安装限流电抗器。这意味着线路两端边界缺失,导致应用于常规高压直流输电(line commutated converter based high-voltage direct current, LCC-HVDC)系统和柔性直流(VSC-HVDC)电网的单端量保护均无法适用于混合多端直流输电系统。为此,本文提出了一种适用于混合多端直流输电系统的单端量保护新原理,该方法主要基于暂态信息和主动注入思想实现故障辨识。与应用于LCCHVDC和VSC-HVDC系统的单端量保护相比,所提方法无需依赖线路两端的边界元件,因此更加适用于混合多端直流系统。大量的仿真算例充分验证了所提方法的可行性和优越性。
The regional integrated energy system is an effective way to realize energy cascade utilization and improve the flexibility and economy of the load side operation. Combine cooling heating and power (CCHP) system is a ...
The regional integrated energy system is an effective way to realize energy cascade utilization and improve the flexibility and economy of the load side operation. Combine cooling heating and power (CCHP) system is a typical form of integrated energy systems. However, due to heat-load-based operation mode, the peak modulation capacity of CCHP units and the accommodation of renewable energy are limited. This paper explores methods of increasing the flexibility and economy of the system. An optimal scheduling model is proposed for integrated energy systems containing an electric heat pump, considering heating network characteristics. Simulation results show that the electric heat pump can help the system realize heat-and-power decoupling, improve the flexibility of the system and reduce the operating cost of the system.
Recently, new energy is conversely distributed and centralized grid connection which need transmit redundant power to other regions urgently by HVDC system. Based on the characteristics of new energy, this paper analy...
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Recently, new energy is conversely distributed and centralized grid connection which need transmit redundant power to other regions urgently by HVDC system. Based on the characteristics of new energy, this paper analyzes the correlation between sending end new energy and receiving end loads by person correlation coefficient method and proposes a correction method for HVDC transmission plan considering the correlation which promotes new energy penetration level and improves utilization of HVDC system. By taking a HVDC system as an example, the results of analyzing practical scheduling data in 2015 demonstrate the feasibility of the proposed method.
In combined cooling heating and power system, the gas-steam combined cycle is gradually used more and more. The common operation mode in CCHP is mainly to determine heat by electricity and heat by electricity. This pa...
In combined cooling heating and power system, the gas-steam combined cycle is gradually used more and more. The common operation mode in CCHP is mainly to determine heat by electricity and heat by electricity. This paper defines an index indicator and analyzes the difference between the two operating modes in different intervals through the system energy supply interval chart, finally analyzes the difference in the indicators between the two operating modes through the actual load method. It is concluded that in winter operating conditions, the following the thermal load (FTL) operation mode is better; in summer operating conditions, the indicator of following the electric load (FEL) is better; during the transition season, the value of PEC is better in the case of following the thermal load.
Power dispatching operators need to read a large number of power dispatching logs every day and arrange them into daily work reports. It takes them a lot of time to do information extraction and transfer that informat...
Power dispatching operators need to read a large number of power dispatching logs every day and arrange them into daily work reports. It takes them a lot of time to do information extraction and transfer that information into work reports. In order to reduce the workload of power dispatching operators, we propose an intelligent method for automatic generation of daily work reports in this paper by adopting RoBERTa, which is an improved version of BERT. With the outstanding performance of RoBERTa in semantic analysis and entity recognition, the workload of power dispatching operators is reduced approximately 50% through our proposed method, which means the efficiency is greatly improved.
In this paper, the non-intrusive monitoring and disaggregation method of industrial load based on Petri net theory is studied. First, the basic concepts of Petri nets are introduced. On the basis of prototype Petri ne...
In this paper, the non-intrusive monitoring and disaggregation method of industrial load based on Petri net theory is studied. First, the basic concepts of Petri nets are introduced. On the basis of prototype Petri nets, time factor is added. Then, the Petri net with time factor is combined with industrial load production process. Considering the production sequence, start-stop time and production time constraints of industrial load, a non-intrusive monitoring and disaggregation model of industrial load is constructed. Finally, according to the actual production process of industrial load, the electricity consumption situation of each production link is calculated, and the detailed analysis results of industrial user's electricity consumption behavior are obtained. The research could provide an important reference for realization of friendly interaction between industrial users and power grid.
The transmission capacity of ultra-high voltage direct current(UHVDC) transmission system is huge. Once a fault occurs, it will bring tremendous impact on the operation of the power grid, bring about a number of probl...
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The transmission capacity of ultra-high voltage direct current(UHVDC) transmission system is huge. Once a fault occurs, it will bring tremendous impact on the operation of the power grid, bring about a number of problems such as power flow overload, insufficient reserve, and frequency drop, and induce chain failure. Therefore, it is necessary to adopt a comprehensive Precautions. This article describes the specific ideas and implementation methods of solving problems from the overall solutions to the handling of UHVDC faults, the risk assessment and prevention in advance, the real-time monitoring of events, and the assistance in emergency recovery *** method mentioned above has been operated in some regional and provincial power companies for demo purpose, and has played an important role in the handling of DC blocking events many times.
In the large power grid dispatching and control system, the unmanned substations bring a large amount of graph drawing and model input work to the automation maintenance personnel. The complicated work increases the e...
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In the large power grid dispatching and control system, the unmanned substations bring a large amount of graph drawing and model input work to the automation maintenance personnel. The complicated work increases the error probability and hidden dangers, and it is difficult to adapt to the development of the large power grid. Therefore, it is very necessary to realize the quick generation method of power grid graphs and models in the large power grid dispatching and control system. This paper proposes a method for quick generation of graphs and models in SCADA system. This method is based on the design concept of object-oriented graph and model integration and realizes the quick generation of similar substations. This design has been used in real application widely and makes the maintenance of the automation system more conveniently, rapidly and accurately.
Directly scheduled unit, as a kind of excellent frequency regulation resource, plays an important role in the control of China's interconnected power grid. First of all, based on the regional control model, the th...
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ISBN:
(纸本)9781509064151;9781509064144
Directly scheduled unit, as a kind of excellent frequency regulation resource, plays an important role in the control of China's interconnected power grid. First of all, based on the regional control model, the theory of the "closed area" of the direct-dispatching generators is demonstrated, and the mechanism of suppressing the regional control error(ACE) by this method is revealed. Then, based on Virtual Partition(VP), the tie-line bias control(TBC) method for hierarchical control structure is designed. This method enables the power of each tie-line to reach the rated value. Finally, the correctness and feasibility of the proposed method are verified by the standard IEEE 10-unit 39-bus system.
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