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To achieve accurate and fast fault location in the distribution network, this paper introduces chaos theory into PSO (Particle Swarm Optimization). It proposes a fault location method for distribution networks with distributed generation based on CPSO (Chaotic Particle Swarm Optimization). The IEEE14-node distribution network model with multiple power sources is established. Then, the coding mode, switching function, and fitness function of distribution network fault information is constructed. Finally, the location results of single-point fault, multi-point fault, and information distortion are analyzed, respectively. The results show that the chaotic particle swarm algorithm proposed in this paper can achieve accurate location and outperform the traditional particle swarm algorithm, genetic algorithm, and the recently proposed manta ray foraging algorithm in convergence, accuracy, and algorithm efficiency.

The practical application of wireless sensor networks (WSNs) in hot fields is summarized. It is found that compared with traditional monitoring methods, it has better adaptability to complex environments and low cost. It is suitable for monitoring power grid operation parameters. Therefore, this paper combines the above network and cascading failures, analyzes its 24-hour continuous and dynamic monitoring of the operation parameters of the power grid, and considers how to use the obtained parameters to analyze the disturbance of the remaining lines after the initial fault of the power grid. To prevent cascading failures in the power grid, a preventive control model considering safety and economy is proposed, and the model is solved by nondominated sorting genetic algorithm II and particle swarm optimization (NSGA2-PSO). Finally, the rationality of this method is verified in the IEEE39 node system.

This article introduces a method by which the power grid's security level can be observed in advance based on the expected initial failure. Firstly, based on the general form of cascading trip, this paper gives a mathematical expression of grid tripping based on cascading trip relay protection action behavior. According to the mathematical expression, the relationship between grid tripping and grid node injection power is discussed. According to this relationship, the distance between the node injection power under the current operation state and the nearest critical state node injection power is taken as the index to measure the power grid's security for cascading trip. According to this index, combined with various power grid constraints before and after the initial fault, a mathematical model for obtaining this safety index is given. This model is an optimized mathematical model. For the model, this paper gives a solution idea based on particle swarm. Finally, a few cases are performed in the IEEE-14 node system, and the calculations of the cases proved the accuracy of the proposed model and method.

The use of prepaid electricity meters appeared in many countries a few years ago and has been widely recognized by consumers and managed to find solutions to too many problems faced by distribution companies. But for traditional systems, users must purchase electricity and manually charge the meter. For example, if he is in the office and needs to charge the house electricity meter, then he must go home to do this, which is considered a waste of time and energy. However, the advanced low-cost smart prepaid electricity meter is a solution to the problem mentioned earlier. By sending GSM text messages to the Arduino as a microcontroller through the GSM module, consumers can use their mobile phones to charge the electricity meter anywhere. This is the main reason for the microcontroller. The control process is also connected to an electricity meter and also to a relay module to provide power for consumers or consumers when the balance is equal to zero.

In the case of power grid cascading trip, this study puts forward a strategy to prevent cascading trip by changing the output of generator set. Firstly, according to the specific performance of the power grid under the cascade tripping, combined with the action behavior of the line current-type backup protection, and an expression equation for measuring the safety level index between the power grid and the cascading trip failure is given. Secondly, the vulnerable branch is found out through the safety level index, the output of the key power generation nodes on the branch is taken as the optimization variable, and the optimization model is established to improve the safety level index under the chain trip of the power grid. Finally, a combination of sensitivity analysis and particle swarm optimization(PSO) was used to analyze an example on the IEEE-39 node system. The results demonstrate the feasibility and effectiveness of the model and method, and provide a reference for preventing chain trip accidents.

Short-term load forecasting can reasonably allocate power resources and keep modern power systems in a stable and reliable working state. Due to the increasing requirements of modern power systems in recent years and the close integration of computer technology and smart grids, artificial intelligence has been widely used in power load forecasting. The least-square support vector machine (LSSVM) model is used in It has good forecasting effect in short-term load forecasting. This article introduces several artificial intelligence algorithms that can be used to optimize model parameters and summarize methods to make model prediction results more accurate.

With the development of science and technology, many scholars study artificial intelligence technology in distribution network fault location. In recent times, there have been many achievements made by many researchers, of which some were the application of particle swarm optimization [1, 2], genetic algorithm [3, 4], ant colony algorithm [5]. This paper describes the application of a bi-state binary particle swarm optimization algorithm, multiple population genetic algorithm, and hybrid ant colony algorithm, the optimized intelligent algorithm in the distribution network's fault location. In distribution network fault location, traditional algorithms have more limitations, which need further improvement to make them more perfect—comparing the simulation data obtained before and after optimization shows that the optimized algorithm has faster convergence speed, higher accuracy, and higher fault location efficiency.

View of preventing cascading trips, this paper mainly studies the security level model of how to effectively prevent cascading failures in the system is studied. First of all, from the point of view of relay protection, we consider the case of backup protection for current protection, by judging the electrical distance between the operating parameters of the branch and the relay protection fixed value after the initial fault of the system, it can be judged whether the branch will undergo cascading trips or not. Then, considering the critical state of cascading trips in branch grids, a safety index is proposed to measure the shortest distance between the critical state of power grids and the current operation state, and the specific calculation method is given. Finally, an optimization model is given, which aims to find the nearest state on the boundary from the current operation state. Aiming at this model, this paper presents a solution method based on PSO algorithm, which is verified by simulation through an example analysis.

With the continuous development of the smart wireless communications, the importance of electric energy becomes increasingly evident. Intricately interconnected power grids will also suffer from the threats of blackouts caused by grid cascading failure while bringing convenience to the masses. The grid cascading trip is closely related to cascading failure. Generally, the cascading failure shows a cascading trip at early stage. Hence, the avoidance of occurrence of cascading trip at an early stage may restrain the occurrence of complex cascading failure, thereby avoiding the occurrence of the blackout. In this paper, the occurrence principle of the cascading trip is firstly analyzed from the perspective of relay protection. The output of the generator is taken as the optimization variable, and the optimization model for restraining the grid trip is presented. Finally, the example of IEEE14 node system is analyzed in this paper in combination with the particle swarm algorithm, which verifies the rationality of the proposed method.

This paper proposes a method to prevent cascading trip based on the action of relay protection and the output of generator as the optimization variable for aiming at the cascading trip in power grid. Firstly, the critical state of cascading trip is discussed, and the safety index of cascading trip in power grid is analyzed based on the analysis of the performance of cascading trip and the action of relay protection. On the basis of this index, a kind of optimized model of cascading trip prevention is given while considering the various constraints of power grid synthetically. This paper presents a complete algorithm flow for solving the optimized model combined with particle swarm optimization algorithm aiming at the proposed optimized model. Finally, on a IEEE39 system, an example is analyzed by the MATLAB program, which verifies the rationality of the proposed method.

In this paper, a grid security index considering cascade tripping is proposed, and an algorithm is proposed for this index combination with the operating behavior of relay protection so as to solve the cascading tripping problem of the power system. Firstly, according to the current behavior of branch cascading tripping and the action of line current-mode backup protection, the critical state of grid cascading trip is analyzed, and it is proved that the input power of grid nodes can be used to describe the security of grid. Then, based on the relationship between the input power of nodes and the security level of power grid, a model is presented to represent the security level of power system without cascading failures under the impact of initial faults, and the model is solved by particle swarm optimization. An example proves the validity of the algorithm.

Aiming at the phenomenon of the cascading trip in power system, this paper studies a calculation method of safety margin of power system considering the cascading trip. First, this paper analyses the behavior of cascading trip according to the action equation of relay protector, and proposes the concept of the critical state according to find out whether there are cascading trip events occurring in a power system. Then, this paper proposes an index for measuring the safety margin of power system in the case of considering a cascading trip, and proposes a model and an algorithm for calculating the safety margin. Finally, the rationality of the algorithm is demonstrated by the example of IEEE39 system.

A new method for calculating danger distance of cascading trips is proposed in this paper. The method is based on enhanced particle swarm optimization. An example on IEEE 39-system proves the effectiveness of the method.

The research object is aimed to the small power distribution underground system with 22.8 kV voltage level which consists of two feeders connected by a tie switch. According to the switches of the feeder adjacent to the formation of the segment is divided into the feeder section and each section has its own complex power with the load characteristics of the varying. Therefore, base on the changing of the complex power of the feeder outlet and the complex power of the segment load of the feeder to derive the all of power factor and the maximum power factor of each section of the feeder maximum power factor of each segments of the feeder line are deduced to find the compensation point of the best power factor. In order to improve the feeder output and feeder segments of the power factor. Due to the feeder segment by each adjacent two switch to investigate the load concentration, complex power, load changing trend for 24 h a day and the fuzzy theory derive the best in each segment of the feeder reactive power compensation point and compensation quantity. Based on result by the three-phase load flow program to reach the relative error of the power factor deduced from the fuzzy theory is discussed. The average relative error of the three-phase load current is 1.94%, but the three-phase load power consumption is large and the calculation time more than the fuzzy theory of reactive power compensation has a superior effect.

Reactive power optimization is an effective method for improving the electricity quality and reducing the power loss in power system, and it is a mixed nonlinear optimization problem, so the optimization process becomes very complicated. Genetic algorithm is a kind of adaptive global optimization search algorithm based on simulating biological genetic in the natural environment and evolutionary processes, can be used to solve complex optimization problems such as reactive power optimization. Genetic algorithm is used to solve reactive power optimization problem in this study, improved the basic genetic algorithm, included the select, crossover and mutation strategy, and proposed a individual fitness function with penalty factor. The proposed algorithm is applied to the IEEE9-bus system to calculate reactive power. The results show the superiority of the proposed model and algorithm.

Collecting data from spatially distributed sensor nodes is a generic form of sensor network applications. Multihop forwarding has been broadly used for this purpose, but it could be inefficient in terms of energy consumption.A downside of this approach is an increased data delivery latency, and thus we should optimize the motion of data mule so that we can minimize the latency. In this paper, we survey the existing work on the mobility-assisted data collection by classifying them into three categories based on the mobility exploited: the random mobility, the predictable mobility, and the controlled mobility. We also highlight several open problems on this topic.

Based on the method of direct current flow, this paper studies the limit conditions under which cascading overload events may happen in the power system in N-1 mode, and proposes a practical method for obtaining the limit power flow state. In this method, the limit power flow state can be directly obtained by the power increment equation after an initially faulted branch is removed, which helps to avoid a large amount of computations with special optimized techniques and searching methods that may need much time. An example in 22-bus system of Chinese Electric Power Research Institute proves that this method is reasonable.

For the shortages of the traditional flow program control and time program control in the process of sewage treatment, this paper adopts a Fuzzy programming method based on PLC. The PLC and its general I/O module are involved in forming the Module Controller in hardware. We use the DO and the sludge reflux ratio as the main control parameters, and infer the best control variables by PLC discrete calculation and look-up table on line. Not only can we ensure the quality of purified water, but also save energy by using this fuzzy controller in the process of sewage treatment.

Power flow transfer is one of main causes of cascading failures. It is important to evaluate power flow transfer phenomenon from the perspective of cascading failure. The authors propose a set of evaluation indexes based on the structure and operating features of the power networks and the consequence of power flow transfer. On this basis, the authors propose a comprehensive evaluation method which is based on variation coefficient method to evaluate power flow transfer phenomenon comprehensively and systematically. And an example in IEEE4 system proves that the evaluation method is reasonable.

The reductive alkylation of secondary lactams is an important transformation in the total synthesis of alkaloids and pharmaceuticals. Methods for this transformation are scarce. We report in this paper a versatile two-step approach consisting of N-benzylation and one-pot reductive alkylation–debenzylation. With suitably functionalized Grignard reagents, a formal [4 + 2] annulation reaction has been achieved. Using this method, we have successfully synthesized several N-α-alkyl and N-α,α′-dialkyl heterocycles, including (±)-coniine (7) and the ant venom alkaloids (2R,5S)-cis-2-butyl-5-propylpyrrolidine (8) and (+)-monomorine I (10) each in two steps starting from readily available secondary lactams.