Abstract:Microgrid is aimed at achieving the coexistence of flexibility and reliability on the power generation side, giving consideration to the forth putting of renewable energy and the stability of energy use. Based on this purpose, a microgrid with multi-energy, multi-energy storage structure and multi-type load is constructed. A multi-objective optimization model that considers microgrid compensation costs, abandonment costs, and operating income is proposed, and a demand response model to optimize energy storage and user participation in peak shaving are introduced. In order to deal with the uncertainty of wind and photovoltaic output, the WPP and PV output scenarios are reduced, the multi-objective model is transformed into a single - objective model through the decision analysis table, and the rough set theory is used to calculate the objective function weight. The analysis results of the calculation ex-ample show that scenario reduction can overcome the impact of uncertainty on system scheduling and demand response can solve the problem of poor matching between source and load. The interaction of DR and ESS can improve system sustainability.

Abstract:The increasing use of distributed generation（DG）in power systems can result in frequent online voltage problems.In case of large prediction error of DG, the requirement of online volt-age regulation can not be met by limited voltage regulation devices.In order to solve this problem, a flexible topology control method is proposed, and a deep reinforcement learning algorithm is used to model and solve it. The action mechanism in this algorithm combines the branch exchange concept in graph theory, and effectively simplifies the action dimension and action space. The analysis of the calculation examples on the standard IEEE 14 node system shows that the algorithm has excellent generalization ability. Compared with the previous methods, the proposed algorithm can obtain the closest optimal solution, improve the performance of the calculation significantly and meet the needs of online voltage regulation.

Abstract:Load aggregators can aggregate users’loads,achieve demand response, and ease grid pressure. To lessen the effects of the different users’demand response capability and the uncertainty of users’response behavior on the response characteristics of load aggregators, a potential assessment model is built and a load aggregator optimal dispatching model based on refined potential evaluation is proposed. Firstly, four indicators are designed, an accurate potential assessment model based on the users’historical power consumption data is established, the assessment of demand response potential is accurated to the device level,and then demand response potential of users and devices under different economic incentives are studied. Next, the demand potential assessment model and load aggregator optimal dispatching model are combined and optimal dispatching results are solved. The simulation results show that the model can accurately reflect demand response potential of users and devices. Combining this model with the optimal dispatching of the load aggregator can give full play to users’ability to participate in demand response, improve users’satisfaction and mobilize the enthusiasm of users, thereby improving the reliability and overall economy of the load aggregator.

Abstract:Intermittent power sources such as photovoltaic power and wind turbine are used as the power supply for recovery of distribution system. Firstly, an operating criterion for the complementary joint operation of power supply systems is proposed to combine the complementary power supply systems. Then, a method of island division is proposed, which combines Floyd algorithm and Prim algorithm and considers the shortest path of power supply. On this basis, the fault recovery process considering the complementary characteristics of multi-source islands is designed. The results of calculation examples show that the proposed power supply fault recovery method considering the complementary characteristics of multi-source islands can not only effectively reduce the impact of intermittent power output fluctuations on the recovery capacity of the island, but also recover more loads and improve the recovery effect.

Abstract:With the increasing number of temperature sensitive load such as air conditioning, electric heaters has become available, the relationship between temperature and power load is more and more significant and complex. An example is given to illustrate the effect of temperature accumulation effect on load change. On this basis, the influence of temperature on load on the day to be analyzed and its premier two days is also considered, and a modified temperature model considering temperature accumulation effect is proposed. Based on Sigmoid curve and quantization of date type, date serial number, a load-temperature fitting mathematical model is established. The undetermined coefficients in the two models are solved by simulated annealing with the maximum load-temperature similarity and the minimum global fitting error as the objective functions. The actual load and temperature data of some cities in a province are used for testing and verification. The results prove that the load - temperature fitting model proposed can have good fitting accuracy in the whole temperature range, and the fitting error is further reduced after the modified temperature is adopted. Sensitivity curve of temperature to load change has been obtained respectively through the load-temperature fitting model using the actual temperature and the corrected temperature, including the sensitivity of the modified temperature curve for more comprehensive quantitative history two adjacent temperature change on the influence of load, research results for more sophisticated,more accurate quantitative temperature change on the influence of load change provides a sufficient theoretical basis.

Abstract:The central air-conditioners（CAC）in commercial buildings is an important kind of demand response（DR）resources.Taking peak-shaving in summer as the case, three DR strategies for CAC based on global temperature adjustment（GTA）are proposed,and two evaluation indicators are designed：interactive capability and user net income considering the loss of productivity.In order to achieve accurate DR prediction, EnergyPlus physical modeling method is used to build energy consumption prediction model. Simulation results of a commercial building in Shanghai show that：the proposed DR strategies can provide different interactive capabilities for the grid under the premise of comfort level. Using the pro-posed user net income model considering the productivity loss, the grid can analysis the impact of the compensation price on the CAC users, while users can choose the best DR strategy and optimal interactive power to obtain maximum net income.

Abstract:Aiming at the problem of high energy consumption and low energy efficiency of commercial buildings in summer, energy-saving renovation schemes with rooftop photovoltaic and different energy storage equipment are proposed. Firstly, the mathematical models of several core equipment to be used in the renovation of the refrigeration system are established, including photovoltaic modules, refrigeration units, batteries and ice thermal storage. Secondly,the mixed-integer linear programming（MILP）model with economic objectives is established. Thirdly, the typical daily electricity and cooling load data of commercial buildings in summer are used to optimize the configuration of the three energy - saving renovation schemes. Finally, the energy - saving renovation schemes are optimized. The results of the three schemes are compared and analyzed which show that the economic efficiency of the system will be greatly improved by the configuration of photovoltaic hybrid energy storage in commercial buildings. And the results provide theoretical and data support for the selection of energy - saving renovation schemes of commercial buildings.

Abstract:A multi-parameter economic analysis model is established and the influence degree of parameters is analyzed for optimal design of air conditioning terminal system. The results show that the proportion of operation and maintenance costs is not high,the difference in labor costs does not affect the trend of cost changes, but the duration of operation has a greater impact on operation costs. The longer the operation time, the greater the impact on the unit efficiency. Distributed terminal units with small air volume are economical and energy-saving, and the control strategy is flexible.The integral air conditioning unit has wide adaptability and is the optimal solution for the air conditioning terminal system of most terminals. For the complex situation of electricity price policy, specific problems should be analyzed in detail, and an accurate optimization plan should be obtained by substituting into the model. The research provides a reference for the optimal operation and design of the air-conditioning terminal system in traffic buildings.

Abstract:The construction and development of integrated energy system have become an important direction for the future transformation of China’s energy system. The development of inte-grated energy system with electricity as the center is conducive to improve user energy efficiency and optimize energy structure. The construction and optimization of low-carbon / near zero carbon rural community integrated energy system is studied. Firstly, the specific research object is determined, and the resource endowment and energy consumption status of the research object are analyzed.Then the carbon emission boundary is combed and the carbon emission is calculated. Finally, combined with the short-term and long-term development master plan of the studied area, the optimization suggestions of low-carbon / near zero carbon community integrated energy system matching with the local status and development plan are further provided, and reference and suggestions for other areas to build low-carbon / near zero carbon rural communities with significant local characteristics are provided.

Abstract:In recent years, the rapid growth of building electricity load mainly by air conditioning has become an important reason for the widening of peak valley gap between summer and winter. Therefore, incorporating the adjustable load into the peak load regulation system can effectively improve the load characteristics of buildings and reduce the contradiction between supply and demand of the power grid. Firstly, in the framework of Sino-US cooperation on smart grid, the system platform architecture of sino-american cooperative demand response project is proposed, and the deployment plan from the main station of automatic demand response to the terminal is designed. Secondly, the two-way adaptive device for automatic demand response is developed. Then, the global control strategy of controllable load is proposed. Finally, an empirical verification of Sino-US cooperative automatic demand response is carried out in the old and new office buildings of Shenzhen Luohu power supply company. The empirical results show that the participation of building load in demand response has great regulatory potential, can achieve good economic and social benefits, and has broad prospects for promotion.

Abstract:Arming at the problem of not considering meteorological factors when the trend change method is used to forecast power load, a weighted method of load forecasting based on change trend and meteorological factors is proposed, which is modified the power load forecasting method based on the change trend by considering the three meteorological factors of temperature, humidity and weather type. Two problems of the power load forecasting method based on the change trend including failure to consider the influence of external factors and cumulative error by trend forecasting method are analyzed. The detailed calculation steps are given based on fully studying the daily average load change rate and the average load change rate between points, which is applied to an ex-ample of power load forecasting in a certain area of northern Jiangsu. Finally, the results show that the average relative error of the method is 3.42% with high forecasting accuracy and small data fluctuating, which verifies its validity and feasibility.

Abstract:During the 14th Five-Year Plan period，Guangxi will have a surplus of electricity after receiving the electricity from Udongde；Yunnan, Guizhou and Guangdong which are adjacent to Guangxi have their own characteristics. In order to promote the optimal allocation of energy resources in the Southern Power Grid and fully absorb clean energy，take advantage of Guangxi’s location and combine with the relevant policies of the current electric power system reform, the possible trading model is analyzed, the feasibility of the trading electricity price is studied and a benefit distribution mechanism is given, followed the principle that the sending and receiving ends both have a reasonable benefits.

Abstract:In the domestic and foreign electricity spot markets with LMP mechanism, there is a risk that units cannot recover their operating cost or achieve the expected revenue due to the change of supply and demand, load forecasting deviation, emergency situation and other factors. In order to tackle this problem, compensation mechanisms have been established in various power markets to ensure the revenue of power generation units when operating according to the safe dispatch requirements of the transmission system operator. However, it also leads to the risk of power generation groups manipulating the compensation mechanism to exercise market power. Based on the uplift mechanism of PJM market in the United States, the impact of market participants’bidding strategies on their total revenue are studied through a three-node electrical grid example. The revenue gained in the market with uplift mechanism is compared with the revenue gained in the market without uplift mechanism. The manifestation of market power in the bidding compensation market is analyzed. In order to reduce the market power risk caused by the uplift payment, the monitoring methods of market power and the optimization methods of the compensation mechanism are proposed.

Abstract:In the context of deepening electricity market re-form in China, Guangxi speedes up with the construction of the electricity spot market. The actual situation of Guangxi electricity market is analyzed while summarizing the key issues in Guangxi.In response to the key issues raised, the market deregulation path is proposed for both demand and supply sides in Guangxi and designs bidding strategies for generating units with different cost in order to survive. Moreover, a cohesive mechanism between regulated and deregulated parts of the market is also proposed, along with subsidy principles for electricity users in the market environment,providing a reference for the subsequent construction of the power spot market in Guangxi.

Abstract:Faced with the more insidious electricity stealing methods of high-frequency pulsed magnetic field, anti-theft detection based on magnetic field signals would fail due to noise. Aiming at this problem, a method combining SVD and wavelet transform is applied to anti-theft devices and proposed to remove noise and separate stolen electricity signal in detection. Firstly, the noisy magnetic field mixed signal is transformed by FFT to obtain the power spectrum, and the classical threshold is introduced to determine the number of narrow-band noises and the effective rank order of the SVD.Then the mixed signal is SVD decomposed, the singular value corresponding to the narrow-band noise is reset to zero, and then the signal is reconstructed. Finally, wavelet transform is used to remove the influence of random noise. Simulation and experimental results show that, this method can be effectively applied to the detection of electrical stealing. Compared with FFT threshold filtering method and EMD method, the suppression effect of the proposed method is more prominent.

Abstract:Through the classification and analysis of load data, the behavior characteristics of power users can be obtained,which provides support for the formulation of demand response strategies and effect evaluation. Firstly, the load data is preprocessed including identifying and processing abnormal numbers,and smoothing to remove burr data. Secondly, with the reason that the fuzzy C-means clustering algorithm is sensitive to the initial cluster center, easy to fall into local optimality, and is greatly affect-ed by noise, the shortest distance clustering method is proposed to provide the initial clustering center for fuzzy C clustering. The efficiency index is used to select the best clustering results of different categories, and the data density is used to identify and eliminate noise points.Finally, through comparison with other methods and cluster analysis of a certain hemp spinning enterprise’s load, the correctness and effectiveness of the improved algorithm is verified.

Abstract:In the park energy Internet, in order to realize the real-time control of the charging and discharging process of the energy storage elements, the 2V, 200 Ah valve-regulated lead acidbattery is taken as the research object. According to the supply side environment, experimental data and existing data of the energy system, a nonlinear dynamic equivalent circuit model is established, which takes into account electricity, heat, nonlinear behavior and temperature estimation. Through the model, the influence of different discharge rates on the capacity of energy storage equipment, the function of the nonlinear parameters of the battery related to the current and open circuit voltage, and the influence of the battery temperature on the internal parameters are studied. The model results match the experimental results completely, which provides a certain reference value for improving the energy storage configuration.

Abstract:Since China stepped on a new stage of power market reform, the scale of electricity transaction has grown steadily,and the complexity of the power market and the degree of strict supervision have continued to increase. In order to test the efficiency of the power market operation and promote market competition, it is necessary to establish a sound monitoring mechanism for the operation of market entities. The practical experience of typical foreign power markets is investigated, combined with the current market status and deficiencies in China, and the development direction of the market entity management monitoring system is proposed, aiming at provide a valuable reference for the design of market rules and ensure the health and stability of the market development.