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Switch-capacitor battery equalizer (SCBE) is widely used because of its simple structure, small PCB area, and no inductance components. Its balance current is sawtooth or trapezoid waveform is significantly different from traditional charger’s DC waveform. From many non-DC charging literatures, it can be found that different frequency and waveform shape will cause the significantly different battery charging performance. Therefore, this paper explores the near-optimal balance current frequency and waveform shape of the SCBE from electrochemical impedance to optimize its battery balance performance. Further, the LC resonant battery equalizer (LC-RBE) is proposed to perform battery balancing with a sine wave. Experiments have shown that the better efficiency and lower battery temperature rise are obtained when the LC-RBE work with the battery minimum ac impedance frequency.

Battery cells connected in series have been widely used in high-voltage and high-power applications. In this paper, a single-phase battery energy storage system with battery balance charging, battery balance discharging, and power factor correction capabilities was developed. A prototype suitable for a single-phase 110V power supply was designed and implemented for verification. To verify its performance, three 48V/7 Ah battery modules were used as normal batteries, and a 48V/5Ah battery module was used as a retired battery. The experimental results showed that the battery energy storage system has excellent battery balancing capability. Compared with that of the conventional system without balanced control, the balancing performance of the proposed system is increased by about 15.25% and 26.92%, respectively, when the system was operated in the converter and rectifier modes. In addition, the proposed system also had battery fault tolerance, and was compatible with recycled batteries and an independent power supply.

With the development of the economy, the demands for food quality have gradually increased. Cold chain as a temperature-controlled supply chain has emerged to ensure the fresh goods. In recent years, the establishment and improvement of the cold chain logistics, as complex system engineering, is very important. While the cold chain logistics system has been vigorously developing, the common problems we face include: selection of suitable location for cold chain distribution center as well as optimization of distribution route. In this paper, we mainly focus on how to optimize the cold chain logistics distribution for a fresh processing factory M. We propose the methods to optimize the cold chain logistics distribution for M based on linear programming model. First, we adopt location set covering problem (LSCP) to model the location problem of cold chain logistics distribution center for Factory M, and use zero-one programming to solve the distribution center location. Then, we use transshipment problem, which is one of the transportation problem, to model and solve the distribution route for M. Experiments are conducted on IBM ILOG CPLEX Optimization platform, and the suitable plan of logistics distribution for Factory M is figured out at the end. The experiment result shows that the optimal solution using our optimization method can save about 15% of transportation cost compared to the result without any planning.

In smart factory, automatic processing mode with high-tech content has become the main method of the modern sorting system. In small manufacturing enterprises, most of the warehouse sorting system is not done with automation but by manual labor. However, along with the increase in demand for products and the expansion of production scale, an automated warehouse sorting system is necessary. Automated sorting system is a typical discrete logistics system. Applying modern logistics simulation technology can help to analyze and evaluate the actual systems. In this paper, we take a small scale bag manufacturing enterprise for example, to design an automated sorting system in the warehouse. Applying discrete event simulation, model and simulate the system with the Automod as one of the most popular logistics simulation tools. Through conducting the experiments and analyzing the experimental results, verify the feasibility of our design and put forward the improvement of the system. The proposed method can provide the references for other small manufacturing enterprises and help business managers to make decisions.

The distribution center plays an important role in modern supply chain. Choosing appropriate distribution center location can avoid many detrimental conditions. Distribution center location as optimization problems are widely studied and applied in a lot of fields. In this paper, we take selection of the tobacco distribution center in Area F as the research object. Based on capacitated facility location problem (CFLP) model, apply mathematical programming methods and analytic hierarchy process (AHP) to design the logistic distribution center location. Through the establishment of mathematical model of CFLP, use IBM ILOG CPLEX studio to calculate the optimized solutions, and further to analyze the results of the solution for candidates. Then use AHP method to find the better location among the candidates. The work provides a good way and ideas for the distribution center location.

A novel algorithm for maximum power point tracking (MPPT) in solar power-generating systems was proposed and compared with the conventional methods of hill climbing, perturbation and observation, and incremental conductance. The three conventional algorithms are prone to divergence under low irradiance levels (

In recent years, direct current power (DC) supply systems have been applied in various types of industrial equipment. As a common practice, an alternating current(AC)/DC converter will be introduced at the system front end to convert mains into DC power sources for system operation. However, when connecting to a power grid, under the influence of load-end characteristics, the phase difference between the voltage and current of the input AC power source will increase. This decreases the power factor (PF), reduces power quality, and affects the stability of system operation. In this paper, three types of circuit topologies (traditional, bridgeless, and interleaved boost) for power factor correction converters are compared and discussed. Moreover, features as well as pros and cons of these topologies are analysed. Finally, a prototype for each topology is studied and implemented. Further, the efficiency, PF, current harmonic distortion, and ripple are compared and examined based on experimental results.

In the electrical power system, there is a wide range of communication services and service needs, and the realization of differentiated services of different types is quite necessary. Thus, based on the combination of characters and requirements of electric power communication business, this paper makes an argument for a routing and wavelength assignment algorithm based on prediction and layered graph model (PLGMRWA). Through the wavelength number prediction mechanism, it realizes the distribution of wavelength resource according to the needs, and uses the layered graph model to wholly solve the problems of route and wavelength assignment in comprehensive considerations of hops and the usage of wavelength. The simulation results indicate that, algorithm PLGMRWA has advantages of blocking capacity and wavelength resource utilization over algorithms GWAS (Grouped wavelength assignment strategy) and DPWA (Dynamic and priority-based wavelength assignment algorithm) for all levels of business in electrical power communication network.

Since its introduction in the early 1960s, the inductive-loop detector has become the most utilized sensor in a traffic management system. It can obtain the data of traffic flow, occupancy and speed of the road. As a principal component, insulated loop wire is easy to be affected by pavement deformation and environment, so the health status and life of the equipment are easily affected. In order to study the health status of the lane detection devices, a single equipment health index model was proposed. The health status of the inductive loop wire is evaluated according to the results of health index calculation. So as to establish a set of management measures for the loop wire equipment. The health index is calculated by the basic data and the maintenance record of the lane detection equipment in the Beijing to Tibet freeway, so as to complete the health assessment of the loop wire, and make clear its actual operation. The results are in line with the actual situation of the equipment by the verification and evaluation.

In this paper, a multi-cluster-based particle swarm optimization (MC-PSO) algorithm for photovoltaic (PV) maximum power point tracking (MPPT) is proposed to promote the MPPT performance in the partial shading condition. During the tracking process, each PV module is viewed as a particle and the PV modules with similar characteristics are put into the same cluster. The particles in the same cluster can refer the information to each other to realize the MPPT in the partial shading condition. In addition, multiple sampling points can be obtained at the same time to avoid the misjudgement problem during insolation changing rapidly. Thus, the tracking speed is also improved. The simulation results used by MATLAB is done and compared with the perturbation and observation (P&O) MPPT algorithm. The accuracy of MPPT of the proposed MC-PSO is improved to 96.3% in the partial shading condition. Finally, a 2.1kW prototype is implemented to verify the feasibility. The generated energy using the proposed method compared to the conventional P&O method is increased about 13.3%.

The inter-turn insulation of stator winding for wind turbine generator (WTG) usually suffers the repetitive impulse over-voltages when the converter is connected to the winding terminals. The long-term effect of repetitive impulse over-voltages may lead to the development of inter-turn insulation defects and/or the occurrence of inter-turn insulation fault due to partial discharge (PD) activity. In this paper, the detecting method of inter-turn PD in the stator winding of WTG under the induced impulse voltage was investigated. A typical form-wound winding specimen for simulating the inter-turn insulation system of WTG was prepared. An exciting system for inducing high impulse voltage was established. The induced impulse voltage on inter-turn insulations of specimen can be with the peak value up to 1200 V and rise time less than 0.5 μs. The high frequency current sensor with the band width of 1.5∼ 45 MHz was designed for detecting PD activity in inter-turn insulation. The numerically simulating model for this test system was also provided. A series of tests under the different induced impulse voltage levels were carried out in the laboratory. Corresponding to the different induced inter-turn voltages, the output signal of the current sensors were recorded and analyzed. The presently test results indicate that the inducted impulse voltage can excite the PD activity in the inter-turn insulation of specimen.