Earticle

The variable integral gain voltage and current double closed-loop control technique based on a PWM inverter is studied in this paper. To improve the response speed and steady-state accuracy of the system, the voltage and current double closed-loop control model is established at first, and then the fixed integral of double closed-loop control strategy is analyzed based on this model. Because variable integral gain control method can improve the control precision based on the double closed loop, the voltage and current double closed-loop control strategy with variable integral gain is proposed. Finally, a series of simulation and experiment results are accomplished to verify the validity of this method. It is shown that the dynamic response time is 2ms and the maximum voltage change rate is only at 0.5%, and the steady-state accuracy can reach 99.55%.

The solar cell research has experienced more than half a century. The black silicon solar cells have the advantages of low cost, low reflectivity. Due to the very large surface state density of Black silicon solar cells, the surface passivation effect directly affects its efficiency. Since the Surface photo voltage technology is very sensitive to surface states, three kinds of black silicon solar cells: no surface passivation and SiO2 passivation were tested and analyzed by this technology. The electrical characteristics of the solar cells were tested. The passivation effects were studied using surface photo voltage technology. We found that the recombination in the bulk and on the surface dominated at shorter times and at longer times respectively from the transient photo voltage results. Surface photo voltage can reveal the generation and recombination mechanisms of light-induce charge carriers, it provides the theoretical guidance to improve the efficiency of the solar cells.

This paper first presents how to create a data stream of solar power generation from the climate archive open to the public as well as the operation logs accumulated for internal use. Then, a daily prediction model is built to forecast the amount of the future electricity generation according to the weather parameters such as wind speed, temperature, insolation, and sunshine hours in Jeju City. For the regression model built upon the identification of linear dependency of most parameters to the generated solar energy, its fitting accuracy is evaluated in terms of absolute residuals, standardized residuals, Cook’s distance, and error probability distribution. The prediction result shows that the absolute residual stays below 30 kwh and the average at 15.8 kwh, while maximum generation reaching 148 kwh. The prediction model will not only evolve with more record collections, possibly averaging out the effect of some abnormal points, but also make it possible for consumers like electric vehicles to select an energy source out of solar, wind, and legacy grid-providing energies.

This paper presents a speed sensorless control strategy for full-scale converter of wind turbine with the squirrel-cage induction generator (SCIG) based on a Model Reference Adaptive System (MRAS) method. The full-scale converter wind turbine has many advantages, such as simple structure, high reliability, low maintenance cost. However, there are still some drawbacks in its traditional control strategy, such as control stability, system performance, efficiency and reliability. The project implementation about generator speed estimation based on MRAS method is studied, and DC bias suppression is described completely based on the characteristics of SCIG. The Simulation experimental results show a consistency that is mainly in the correctness of flux observer design, the effectiveness of speed sensorless implementation strategy and good static and dynamic properties in the system.

The Cutting stock problem is an important problem that arises in a variety of industrial applications. The problem includes a grouping phase (the grouping problem). This research adopts a novel grouping particle swarm optimization approach for grouping problem. In this article, new particle position and velocity updating equations are developed according to the structure of grouping problem for cutting stock problem. The approach works with groups of items instead of items exclusively, compared with conventional method for cutting stock problem. The proposed approach is tested on a set of real instances from the ship building industry with very good results. Moreover, the efficacy and efficiency of the proposed approach are indicated on a set of randomly generated instances.

The patrol robot needs pollution free and efficient power source. The power source, introduced in this paper, can solve this problem. The power source adopted solar battery and super capacitors as the main module. Super capacitors were divided into two groups, in order to ensure that a group of capacitors charging and another group of capacitors power supply. The voltage of super capacitors needed to be balanced in case the super capacitors were damaged. In order to ensure the quality of the output power of the power source, DC-DC converter was adopted. The experimental results validate that the power take-off of robot is enhanced, and the voltage of super capacitors is balanced, and the power requirement from the power system is reduced.

As it is well aware, one of the major aspects of Ad Hoc networks is the randomized movement of nodes. In order for this to take place, the routing protocols in the Ad Hoc network have to quickly respond to the network topology change with the purpose of guaranteeing successful data packet delivery. This involves multiples routing pathways being established in order to improve on reliability and on limited bandwidth. The main idea behind the proposed algorithm is to apply the fuzzy modified Bee-MANET routing protocol on a simulated network and compare its efficiency with respect to Bee-MANET and AODV. Normally, the entire concept of the Bee-MANET routing protocol works on Swarm intelligence for choosing a path to send a packet from one node to another. The swarms of bees act as agents that communicate with each other via a ‘dance’, to select the shortest path i.e. the path that takes the least time based on the number of hops. However, a small modification has been made by applying fuzzy logic to alter the Bee-MANET routing protocol. Due to recurrent node movements, the topologies of mobile Ad-hoc networks keep changing rapidly. The fuzzy rules applied will dynamically decide upon the best path for the packet to be sent across. The swarm rules depend only upon the number of hops while the fuzzy rules consider a number of factors, including the number of hops as well as the energies of the nodes, bandwidth and data traffic. Ultimately, the aim of this work is to increase the Quality of Service (QoS) of the mobile Ad-hoc network by developing the efficiency with respect to latency and stability of the route.

An intuitionistic hesitant fuzzy set (IHFS) consists of hesitancy function intuitionistic fuzzy elements, which consists the membership degree and the non membership degree, supporting a more exemplary and flexible access to assign values for each element in the domain, and can handle this kind of hesitancy in this situation. It can be seen as a powerful tool to express uncertain information in the process of group recommendation. Therefore, we propose a correlation coefficient between IHFSs as a further extension of existing correlation coefficients for hesitant fuzzy sets and intuitionistic fuzzy sets and apply it to group recommendation under intuitionistic hesitant fuzzy environments. Through the weighted correlation coefficient between each item and the ideal item, the ranking order of all items can be identified and the best item can be easily identified as well. Finally, a practical example of a movie recommendation is given to demonstrate the practicality and effectiveness of the developed approach.

A modified MPPT control method which introduces the rapidity of the CVT method and the precision of the IncCond method, and combines the subregional variable duty cycle to optimize the photovoltaic array. To verify and analyze on basis of the setting up of the variable duty cycle ΔD and the time parameter of the power/hour Ta, and verify the method proposed in this paper on the experimental platform, In different areas of photovoltaic power generation using different duty cycle control method, Optimization of the target area using constant voltage method, Reached quickly determine the maximum power point (MPP) when light mutations.