With the trend of electricity market deregulation for recent decades, the consumers at demand-side are progressively encouraged to trade the power in competitive market environment. Conventionally, only large-scale co...
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The further decarbonization of powersystems with high renewable energy penetration faces the problem of inter-day intermittence of renewable energy sources (RES) and the seasonal imbalance between RES and load demand...
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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.
Compared with large-scale physical batteries, aggregated and coordinated generic energy storage (GES) resources provide low-cost, but uncertain, flexibility for power grid operations. While GES can be characterized by...
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The uncertainty of renewable energy sources has aroused the interests in depicting the ability of powersystems to accommodate the variations. Loadability set is one of the typical methods to characterize the feasible...
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ISBN:
(纸本)9781839533914
The uncertainty of renewable energy sources has aroused the interests in depicting the ability of powersystems to accommodate the variations. Loadability set is one of the typical methods to characterize the feasible sets of powersystems with uncertainties. The existing literature on loadability set do not incorporate intertemporal constraints, while for some cases like security check, intertemporal constraints are necessary and important. This paper firstly adapts loadability set to security check, enabling it to depict the capability of powersystems to accommodate load variations. Singular value decomposition (SVD) and progressive vertex enumeration (PVE) are introduced to lighten the computational burden caused by multiple periods. The computational time can be traded off with the precision of approximation to the loadability set. Case studies verify that the loadability set can be approximated with proper precision.
Commutation failure (CF) is one of the major concerns in high-voltage direct current (HVDC) transmission system. Of many methods to mitigate CF, advancing firing angle is preferred one since it can be easily implement...
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Photovoltaic cells are being increasingly installed worldwide as a type of important renewable resource for powergeneration. Among the installed photovoltaic systems, data are collected from the control and monitorin...
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There may be complex interaction between the converter controlsystems of wind power and MMC-HVDC, which will lead to sub-/super-synchronous oscillation and threaten the safe and stable operation of the system. The re...
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There may be complex interaction between the converter controlsystems of wind power and MMC-HVDC, which will lead to sub-/super-synchronous oscillation and threaten the safe and stable operation of the system. The relevant events have been reported in Guangdong Nan'ao, Shanghai Nanhui and Zhangbei projects. Rudong offshore wind power project is the first offshore wind power transmission system in China, and it is still under construction. Therefore, it is of great significance to carry out the research on the risk analysis and suppression measures of sub-synchronous oscillation in Rudong wind power MMC-HVDC system. First, the time-domain simulation model of Rudong wind power MMC-HVDC system is built in the PSCAD/EMTDC simulation model. Then, the effects of the number of wind turbine generators, wind power output and the parameters of MMC-HVDC controller on the sub-/super-synchronous oscillation characteristics of the system are further analyzed. Finally, the suppression measures based on supplementary frequency dependent gain control are proposed, the application position of the controller is discussed, and the parameter optimization method of the controller is given. The research content provides a certain guiding significance for the operation and control of Rudong wind power MMC-HVDC.
The operation risk may increase with the high penetration of wind power, but the calculation of risk indices is complex and nonlinear, which makes it difficult to incorporate the risk constraints into the conventional...
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ISBN:
(数字)9781728177175
ISBN:
(纸本)9781728177182
The operation risk may increase with the high penetration of wind power, but the calculation of risk indices is complex and nonlinear, which makes it difficult to incorporate the risk constraints into the conventional unit commitment (UC) model. This paper focuses on accurately handling the risk constraints instead of approximate exponential decay rules, and proposes an iteration-correction methodology to solve risked-constrained UC of powersystems with wind power. The proposed method calculates the risk indices based on the PJM method, and modifies the minimum reserve demand in each iterative step if the risk indices exceed the limits. A dynamic iterative speed-up equation is given to decrease the elapsed time. The case studies based on the actual system of China are conducted to validate the effectiveness. Compared with the conventional reserve limit, the precise and optimal reserve decision is made under different risk levels, and the proposed UC has merits of less cost and lower risk.
Continuous-time random disturbances from the renewable generation pose a significant impact on power system dynamic behavior. In evaluating this impact, the disturbances must be considered as continuous-time random pr...
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ISBN:
(数字)9781728155081
ISBN:
(纸本)9781728155098
Continuous-time random disturbances from the renewable generation pose a significant impact on power system dynamic behavior. In evaluating this impact, the disturbances must be considered as continuous-time random processes instead of random variables that do not vary with time to ensure accuracy. Monte Carlo simulation (MCs) is a nonintrusive method to evaluate such impact that can be performed on commercial power system simulation software and is easy for power utilities to use, but is computationally cumbersome. Fast samplings methods such as Latin hypercube sampling (LHS) have been introduced to speed up sampling random variables, but yet cannot be applied to sample continuous disturbances. To overcome this limitation, this paper proposes a fast MCs method that enables the LHS to speed up sampling continuous disturbances, which is based on the Itô process model of the disturbances and the approximation of the Itô process by functions of independent normal random variables. A case study of the IEEE 39-Bus System shows that the proposed method is 47.6 and 6.7 times faster to converge compared to the traditional MCs in evaluating the expectation and variance of the system dynamic response.
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