Masafumi Miyatake

Maximum Power Point Tracking of Multiple Photovoltaic Arrays: A PSO Approach

Multiple photovoltaic (PV) modules feeding a common load is the most common form of power distribution used in solar PV systems. In such systems, providing individual maximum power point tracking (MPPT) schemes for each of the PV modules increases the cost. Furthermore, its v-i characteristic exhibits multiple local maximum power points (MPPs) during partial shading, making it difficult to find the global MPP using conventional single-stage (CSS) tracking. To overcome this difficulty, the authors propose a novel MPPT algorithm by introducing a particle swarm optimization (PSO) technique. The proposed algorithm uses only one pair of sensors to control multiple PV arrays, thereby resulting in lower cost, higher overall efficiency, and simplicity with respect to its implementation. The validity of the proposed algorithm is demonstrated through experimental studies. In addition, a detailed performance comparison with conventional fixed voltage, hill climbing, and Fibonacci search MPPT schemes are presented. Algorithm robustness was verified for several complicated partial shading conditions, and in all cases this method took about 2 s to find the global MPP.

A Novel maximum power point tracker controlling several converters connected to photovoltaic arrays with particle swarm optimization technique

This paper deals with maximum power point tracking control of photovoltaic generators. Photovoltaic generation systems need maximum power point tracker because the PV power output depends on the operating terminal voltage and current. Further, the PV array exhibits two or more MPPs under partial shading condition and hence finding the MPP using conventional techniques is a difficult task. To overcome the difficulty, finding the MPP, the authors have proposed a novel MPPT algorithm by introducing Particle Swarm Optimization technique. Further, the proposed algorithm uses only one pair of sensors to control multiple PV arrays. This results in lower cost, higher overall efficiency and also the algorithm is simple. Proposed MPPT algorithm is verified through experimental studies. Several partial shading conditions were tested and in all these cases the algorithm takes about one second to reach the global MPP. The reachability to MPP is good in both shading and unshading.

A Stand-Alone Hybrid Generation System Combining Solar Photovoltaic and Wind Turbine with Simple Maximum Power Point Tracking Control

This paper proposes a hybrid energy system combing solar photovoltaic and wind turbine as a small-scale alternative source of electrical energy where conventional generation is not practical. A simple and cost effective control technique has been proposed for maximum power point tracking from the photovoltaic array and wind turbine under varying climatic conditions without measuring the irradiance of the photovoltaic or the wind speed. The proposed system is attractive owing to its simplicity, ease of control and low cost. A complete description of the proposed hybrid system along with detailed simulation results which ascertain its feasibility are given to demonstrate the availability of the proposed system in this paper. Simulation of the hybrid system under investigation was carried out using PSIM software

Hybrid Solar Photovoltaic/Wind Turbine Energy Generation System with Voltage-based Maximum Power Point Tracking

Abstract This article proposes a hybrid energy system combining solar photovoltaic and wind turbine as a small-scale alternative source of electrical energy where conventional generation is not practical. A simple and cost-effective control technique has been proposed for maximum power point tracking from the photovoltaic array and wind turbine under varying climatic conditions without measuring the irradiance of the photovoltaic or the wind speed. The proposed system is attractive because of its simplicity, ease of control, and low cost. A complete description of the proposed hybrid system, along with detailed simulation results that ascertain its feasibility, are given to demonstrate the availability of the proposed system in this article. Simulation of the hybrid system under investigation was carried out using PSIM software.

Improvement of the Maximum Power Point Tracker for photovoltaic generators with Particle Swarm Optimization technique by adding repulsive force among agents

This paper deals with Maximum Power Point Tracking (MPPT) control of photovoltaic generators. Photovoltaic (PV) generation systems need maximum power point tracker because the PV power output depends on the operating terminal voltage and current. Further, the PV array exhibits two or more MPPs under partial shading condition and hence finding the MPP using conventional techniques is a difficult task. To overcome the difficulty, finding the MPP, the authors improve the MPPT with Particle Swarm Optimization (PSO) technique by adding a kind of “repulsion term” to the equation of PSO algorithm. The term enables to improve the response to various types of insolation change. This results in lower cost, higher overall efficiency and also the algorithm is simple. The improved PSO-MPPT algorithm is verified through simulative and experimental studies. It is proved this algorithm is superior to the original PSO-MPPT methods by evaluating generated power and electrical energy.

Theoretical study on eco-driving technique for an Electric Vehicle considering traffic signals

Eco-driving technique for Electric Vehicle (EV) is investigated in this paper. Many works on EV were reported; however they did not deal with the eco-driving from the viewpoint of theoretical study. The authors have developed the energy-saving driving technique so-called “eco-driving” based on the dynamic programming (DP). Optimal speed profile of an EV, which minimizes the amount of total energy consumption has been decided under fixed origin and destination, running time, and road condition. DP algorithm can deal with such complicated conditions and also can derive the optimal solution. Using the proposed method, simulations were implemented in some cases. Especially the authors paid attention to the road with traffic signals and simulated it without increase of calculation time.

Numerical analyses of minimum energy operation of multiple trains under DC power feeding circuit

An algorithm optimizing total energy consumption of multiple inverter train operation considering DC feeding circuit is investigated in this paper. The proposed mathematical formulation can deal with several characteristics of trains, especially the effect of regenerative braking system. The developed optimization algorithm based on the gradient method is applicable to solve the formulated problems. The algorithm is ready to apply practical large-scale problems. The formulation and algorithm enables us to discuss energy-saving operation quantitatively. Several numerical analyses are demonstrated to verify the reliability and validity of the proposed method and clarify the energy-saving operation for two trains. The results shows that train speed profiles and control inputs strongly depend on the phase of departure times. The proposed algorithm can reduce energy consumption by 4.2~17.9% from that based on the conventional operation rule. These results indicates that the numerical analyses are significant to realize energy-saving operation. Furthermore, it is also demonstrated that the method can be applied to the optimal voltage control of a substation.

Application of unified power flow controller for improvement of power quality

The control scheme and characteristics of the unified power flow controller (UPFC) installed at the substation connecting the transmission system with the distribution network, are studied in relation with the power quality improvements for the loads. A simplified model of UPFC with network is introduced on the basis of the instantaneous power and reactive power function to design the control system and evaluate the effect to improve power quality in the load system. The effectiveness of UPFC is concluded for the power quality control in the substation connected to the distribution network both for the voltage dip and harmonics distortion. It would function with the same principle to suppress the interaction between the distant high power supply and the distributed small power generator in the load network.

Particle Swarm Optimization Based Solar PV Array Reconfiguration of the Maximum Power Extraction Under Partial Shading Conditions

For large photovoltaic power generation plants, number of panels are interconnected in series and parallel to form a photovoltaic (PV) array. In this configuration, partial shade will result in decrease in power output and introduce multiple peaks in the P–V curve. As a consequence, the modules in the array will deliver different row currents. Therefore, to maximize the power extraction from PV array, the panels need to be reconfigured for row current difference minimization. Row current minimization via Su Do Ku game theory do physical relocation of panels may cause laborious work and lengthy interconnecting ties. Hence, in this paper, an alternative to physical relocation based on particle swarm optimization (PSO) connected modules is proposed. In this method, the physical location of the modules remains unchanged, while its electrical connections are altered. Extensive simulations with different shade patterns are carried out and thorough analysis with the help of I–V, P–V curves is carried out to support the usefulness of the proposed method. The effectiveness of proposed PSO technique is evaluated via performance analysis based on energy saving and income generation. Further, a comprehensive comparison of various electrical array reconfiguration based is performed at the last to examine the suitability of proposed array reconfiguration method.

Optimization of speed profile and quick charging of a catenary free train with on-board energy storage

The optimal operation of a rail vehicle with onboard energy storage device minimizing energy consumption in catenary free mode is discussed in this paper. The Electric Double Layer Capacitor (EDLC) is assumed as an energy storage device because of its high power density, long lifetime and quick charge/discharge. The proposed method can determine the optimal acceleration/deceleration at each sampling point under fixed running time between stations taking state of charge of the EDLC into account. The model can be used for planning train schedule and evaluation of energy consumption. Using the methods, simulations for a Light Rail Vehicle (LRV) were implemented in some cases. From the simulation results, optimal distribution of running time through two sections with quick charging at the intermidiate station is clarified. The trend of optimal solutions such as values of control inputs and energy consumption is finally discussed qualitatively.