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As a kind of renewable energy, wind power generation not only has low cost of power generation, but also does not cause environmental pollution. However, wind power has strong randomness and volatility, and it is difficult to predict wind speed and wind power, which has a serious impact on the safe operation and economic scheduling of the system. In this paper, based on the traditional economic dispatching of power system, clean energy wind energy is added. Considering the fluctuation of wind power output and the large prediction error of wind power output, the influence of wind power grid connection and the upper and lower rotation reserve constraints of the system are considered, an economic dispatching model coordinated with environmental protection is established to ensure the stable operation of the system. Then, it introduces an improved differential evolution algorithm which combines the differential evolution algorithm and the artificial bee colony algorithm. This algorithm can improve the search performance of the algorithm and reduce the population size required by the algorithm. Finally, the algorithm is used to solve the model, and the effectiveness and feasibility of the model are verified by simulation.

The globalized stone energy crisis and the climate and environmental crisis have promoted the adjustment and transformation of the energy industry structure worldwide. As a key area of the energy development strategy, the power industry will develop towards clean and efficient renewable energy. With the development of new material technology and control technology, the construction of micro-grid is bound to become a trend, and the large-scale development of micro-grid will affect the operation of the power grid, so the use of advanced control strategies and energy management technologies to improve the performance of micro-grid imperative. This paper first establishes the mathematical model of the independent micro-grid operation mode, and establishes the objective function from the constructed mathematical model. Then, through the improved genetic algorithm to coordinate and optimize the multi-objective. Finally, a micro-grid structure is built on the MATLAB platform to simulate the control strategy of the independent operation mode of the micro-grid. The experimental results show that the strategy proposed in this paper is feasible and correct for energy optimization of the independent micro-grid containing photovoltaic power generation Grid energy coordination and optimization improves the utilization rate of energy, maximizes the consumption of renewable energy, reduces the operating costs of micro-grids, and improves the comprehensive economic benefits of micro-grids.

With the development of modern industrial high and new technology, users have higher and higher requirements for power supply quality. Therefore, the power quality problem of micro grid cannot be ignored. In this paper, the power quality of micro grid is taken as the research object. Through understanding the basic structure of micro grid, the power quality of micro grid is analyzed, and the impact of voltage sag on micro grid is obtained. Based on the characteristics of power transmission, the difference between droop control in micro grid and that in traditional large power grid is analyzed. Because the droop control has the problem of voltage and frequency offset, especially in the isolated operation of micro grid, over migration directly affects the stability of the system. In this paper, the restoration control of voltage and frequency is adopted to guarantee the stability of the whole system. Then, the simulation of the control strategy studied in this paper was completed based on MATLAB/Simulink simulation software, which verified the feasibility of the control method studied.

An online calculation method for emerging decision-making of static voltage stability based on severe fault set is proposed, which is of great significance for ensuring the safe operation of the power grid. The method aims to select the reactive power control measure based on the voltage modal analysis result; when the reactive power control is insufficient, the active power control measure is added based on the active comprehensive sensitivity information; when the fault comprehensive control measure causes the normal operation mode When the bus voltage is upper limit, the reactive power distribution is re-adjusted by solving the reactive voltage comprehensive sensitivity. The application effect in Liaoning network has proved the practicality of assistant decision-making.

The large-scale integration of distributed PV into the distribution network will pose challenges to grid security. How to dissipate distributed PV power generation is particularly important. Aiming at the incomplete information of distribution network, a distributed generation grid-connected method based on big data analysis is proposed. The historical data of each link in the grid system is integrated, and the distributed power grid-connected capability analysis model is proposed. Considering the adjustment ability of different grid configuration modes, the voltage deviation and voltage fluctuation index are taken as the target value for quantitative calculation, and the safety indexes such as short-circuit current and branch current-carrying flow are taken as constraints, and the acceptance ability is analyzed. Finally, the effectiveness and feasibility of the proposed method are verified by the actual distribution network. The results show that the energy storage configuration is more obvious on the grid side than on the distributed generation side. Distributed PV consumption capacity can be greatly improved.

In the power system, transmission line as a guarantee for effective power supply, takes charge of the transmission from output power of substation to the consumers. The present study mainly focuses on the fault of transmission line resulted from external uncertainties, such as lightning, wind age yaw, ice coating and bird damage, as well as internal factors of high-voltage transmission line, including the grounding and short circuit. Accordingly, fault diagnosis and protecting measures on the high-voltage transmission line are proposed with advices on the improvement of operation and maintenance management of the line to reduce the fault frequency of the transmission line in the process of operation at a greater extent and to ensure the power supply stability of the whole power grid system to the user.

Existing personal and network encryption application modes are summarized, and a new kind of offline team confidential document application mode is defined and analyzed for satisfying special confidential demand in practical. In this mode, confidential electronic documents are classified by team’s role. Team is the smallest unit of key distribution, and access authority is allowed to be delivered between teams. PKI system dependable on Intranet or Internet is forbidden to use in this mode. In response, a cross-access method based on offline key management for this new mode is proposed, algorithms for authorization, encryption, authentication, and decryption in this method are described in detail through an implement example of transparent encryption system using Microsoft Office plug-in technology.

In the power system, transmission line as a guarantee for effective power supply, takes charge of the transmission from output power of substation to the consumers. The present study mainly focuses on the fault of transmission line resulted from external uncertainties, such as lightning, windage yaw, ice coating and bird damage, as well as internal factors of high-voltage transmission line, including the grounding and short circuit..

The optical performance of Parabolic Trough Collectors (PTCs) for various tracking modes in sub-tropical area (for latitude of 25.02°) were investigated with Hottel model, incidence angle and daily irradiation during equinoxes and solstices, as well as annual incident irradiation were all compared. Results show that, the mode of tracking affects the amount of incident radiation falling on the collector surface, for four tracking modes, PTCs obtain much more irradiation in summer and much less in winter, and the optimum period for solar thermal application is between March and October. Besides, for two axes rotating tracking, polar E-W tracking, horizontal E-W tracking and horizontal N-S tracking, the relative proportion of yearly irradiation yield are 100%, 95.93%, 91.32% and 73.67% respectively. The selection of tracking mode for PTCs should not only take into consideration of temperature delivered, heat demand level, but also all the costs for manufacture, the auxiliary energy required for tracking drive, and other overheads.

Existing personal and network encryption application modes are summarized, and a new kind of offline team confidential document application mode is defined and analyzed for satisfying special confidential demand in practical. In this mode, confidential electronic documents are classified by team's role. Team is the smallest unit of key distribution, and access authority is allowed to be delivered between teams. PKI system dependable on Intranet or Internet is forbidden to use in this mode. In response, a cross-access method based on offline key management for this new mode is proposed, algorithms for authorization, encryption, authentication, and decryption in this method are described in detail through an implement example of transparent encryption system using Microsoft Office plug-in technology.

This paper is concerned with control synthesis of uncertain Roesser-type discrete-time two-dimensional (2D) systems. The mathematical model of the 2D system’s parameter uncertainty, which may appear typically in many actual environment, is modeled as a convex bounded uncertain domain. By using the Lyapunov stability theory, stabilization conditions is proposed in with the purpose of ensuring the robust asymptotical stability of the underlying closed-loop uncertain Roesser-type discrete-time 2D systems. Furthermore, the obtained result of this paper is formulated in the form of linear matrix inequalities (LMIs), which can be easily solved via standard numerical software. Finally, a numerical example is also provided to demonstrate the effectiveness of the proposed result.

The adding medicament control of water treatment is an important step of the whole precess of generating power in a thermal power plant. In the light of the limitation of the conventional Smith predictive control, the fuzzy set theory is inroduced in this paper to keep the PH value of the circulating water in a predetermined range by regulating the amount of adding acid. In the end, an illustrative example of is presented to verify the effectiveness of the proposed intelligent control scheme.

This paper investigates the asymptotical synchronization problem of a class of novel uncertain chaotic systems with channel delay. Furthermore, the parameters of the chaotic system in the synchronization systems are assumed to be fully unknown. It is reasonable since the sending end usually is located on the remote site. By virtue of the definition of lag synchronization and adaptive control idea, the asymptotical synchronization for a novel type chaotic systems is implemented. The above results will provide theoretical foundation for the secure communication applications based on chaotic synchronization. Simulation results are given to verify the effectiveness of the proposed adaptive synchronization method.

In this paper, the delay-dependent non-fragile robust H ∞ control for a class of fuzzy descriptor time-delay systems with norm-bounded parameter uncertainties is investigated. First, a new delay-dependent non-fragile H ∞ stabilization method is proposed via a state feedback fuzzy controller, which guarantees the closed-loop nominal system to be regular, impulse free, asymptotically stable. Then, sufficient conditions for the solvability of the controller design problems of different gain cases are presented in terms of linear matrix inequalities (LMIs) and satisfies an H ∞ -norm condition for all admissible uncertainties. Finally, a numerical example is provided to demonstrate the application of the proposed method.

Chaotic synchronization is the key technique in secure communication systems. This paper proposes a novel control method to synchronize two nonidentical discrete-time hyperchaotic maps based on T-S fuzzy models. Firstly, a universal fuzzy modeling process is presented for most discrete-time hyperchaotic maps. Then, a simple fuzzy controller is designed based on the PDC technique. The asymptotic stability criteria of the fuzzy synchronization error system is derived by applying linear system theory. Finally, simulation results are given to demonstrate the effectiveness of the proposed fuzzy synchronization scheme for two nonidentical discrete-time hyperchaotic maps. Because a linear closed-loop synchronous error system can be obtained by the proposed fuzzy synchronous controller design method in this paper, many satisfactory performance indices can be achieved, such as rapid response and short transient time, etc.