Kashif Ishaque

An Improved Particle Swarm Optimization (PSO)–Based MPPT for PV With Reduced Steady-State Oscillation

This paper proposes an improved maximum power point tracking (MPPT) method for the photovoltaic (PV) system using a modified particle swarm optimization (PSO) algorithm. The main advantage of the method is the reduction of the steady- state oscillation (to practically zero) once the maximum power point (MPP) is located. Furthermore, the proposed method has the ability to track the MPP for the extreme environmental condition, e.g., large fluctuations of insolation and partial shading condition. The algorithm is simple and can be computed very rapidly; thus, its implementation using a low-cost microcontroller is possible. To evaluate the effectiveness of the proposed method, MATLAB simulations are carried out under very challenging conditions, namely step changes in irradiance, step changes in load, and partial shading of the PV array. Its performance is compared with the conventional Hill Climbing (HC) method. Finally, an experimental rig that comprises of a buck-boost converter fed by a custom-designed solar array simulator is set up to emulate the simulation. The soft- ware development is carried out in the Dspace 1104 environment using a TMS320F240 digital signal processor. The superiority of the proposed method over the HC in terms of tracking speed and steady-state oscillations is highlighted by simulation and experimental results.

A Deterministic Particle Swarm Optimization Maximum Power Point Tracker for Photovoltaic System Under Partial Shading Condition

This paper proposes a deterministic particle swarm optimization to improve the maximum power point tracking (MPPT) capability for photovoltaic system under partial shading condition. The main idea is to remove the random number in the accelerations factor of the conventional PSO velocity equation. Additionally, the maximum change in velocity is restricted to a particular value, which is determined based on the critical study of P-V characteristics during partial shading. Advantages of the method include: 1) consistent solution is achieved despite a small number of particles, 2) only one parameter, i.e., the inertia weight, needs to be tuned, and 3) the MPPT structure is much simpler compared to the conventional PSO. To evaluate the idea, the algorithm is implemented on a buck-boost converter and compared to the conventional hill climbing (HC) MPPT method. Simulation results indicate that the proposed method outperforms the HC method in terms of global peak tracking speed and accuracy under various partial shading conditions. Furthermore, it is tested using the measured data of a tropical cloudy day, which includes rapid movement of the passing clouds and partial shading. Despite the wide fluctuations in array power, the average efficiency for the 10-h test profile reaches 99.5%.

Modeling and simulation of photovoltaic (PV) system during partial shading based on a two-diode model

This paper proposes accurate partial shading modeling of photovoltaic (PV) system. The main contribution of this work is the utilization of the two-diode model to represent the PV cell. This model requires only four parameters and known to have better accuracy at low irradiance level, allowing for more accurate prediction of PV system performance during partial shading condition. The proposed model supports a large array simulation that can be interfaced with MPPT algorithms and power electronic converters. The accurateness of the modeling technique is validated by real time simulator data and compared with the three other types of modeling, namely Neural Network, P&O and single-diode model. It is envisaged that the proposed work is very useful for PV professionals who require simple, fast and accurate PV model to design their systems.

Accurate MATLAB Simulink PV System Simulator Based on a Two-Diode Model

This paper proposes a MATLAB Simulink simulator for photovoltaic (PV) systems. The main contribution of this work is the utilization of a two-diode model to represent a PV cell. This model is known to have better accuracy at low irradiance levels which allows for a more accurate prediction of PV system performance. To reduce computational time, the input parameters are reduced to four and the values of Rp and Rs are estimated by an efficient iteration method. Furthermore, all of the inputs to the simulator are information available on a standard PV module datasheet. The simulator supports large array simulations that can be interfaced with MPPT algorithms and power electronic converters. The accuracy of the simulator is verified by applying the model to five PV modules of different types (multi-crystalline, mono-crystalline, and thin-film) from various manufacturers. It is envisaged that the proposed work can be very useful for PV professionals who require a simple, fast and accurate PV simulator to design their systems.

An improved two-diode photovoltaic (PV) model for PV system

This paper proposes a MATLAB Simulink simulator for photovoltaic (PV) system. The main contribution of this work is the utilization of the two-diode model to represent the PV cell. This model is known to have better accuracy at low irradiance level which allows for a more accurate prediction of PV system performance. To reduce computational time, the input parameters are reduced to four and the values of Rp and Rs are estimated by an efficient iteration method. Furthermore, all the inputs to the simulator are information available on standard PV module datasheet. The simulator supports large array simulation that can be interfaced with MPPT algorithms and power electronic converters. The accurateness of the simulator is verified by applying the model to two PV modules. It is envisaged that the proposed work can be very useful for PV professionals who require simple, fast and accurate PV simulator to design their systems.

A novel Maximum Power Point tracking control of photovoltaic system under partial and rapidly fluctuating shadow conditions using Differential Evolution

Photovoltaic (PV) system performance extremely depends on local insolation and temperature conditions. Under partial shading, P-I characteristics of PV systems are complicated and may have multiple local maxima. Conventional Maximum Power Point Tracking (MPPT) techniques can easily fail to track global maxima and may be trapped in local maxima under partial shading; this can be one of main causes for reduced energy yield for many PV systems. In order to solve this problem, this paper proposes a novel Maximum Power Point tracking algorithm based on Differential Evolution (DE) that is capable of tracking global MPP under partial shaded conditions. The ability of proposed algorithm and its excellent performances are evaluated with conventional and popular algorithm by means of simulation. The proposed algorithm works in conjunction with a Boost (step up) DC-DC converter to track the global peak. Moreover, this paper includes a MATLAB-based modeling and simulation scheme suitable for photovoltaic characteristics under partial shading.

Single Input Fuzzy Logic Controller for Unmanned Underwater Vehicle

This paper describes a control scheme that provides an efficient way to design a Fuzzy Logic Controller (FLC) for the unmanned underwater vehicle (UUV). The proposed method, known as the Single Input Fuzzy Logic Controller (SIFLC), reduces the conventional two-input FLC (CFLC) to a single input single output (SISO) controller. The SIFLC offers significant reduction in rule inferences and simplify the tuning of control parameters. Practically it can be easily implemented by a look-up table using a low cost microprocessor due its piecewise linear control surface. To verify its effectiveness, the control algorithm is simulated using the Marine Systems Simulator (MSS) on the Matlab/Simulink® platform. The result indicates that both the SIFLC and CFLC give identical response to the same input sets. However SIFLC requires very minimum tuning effort and its execution time is in the orders of two magnitudes less than CFLC.

Maximum Power Point Tracking for PV system under partial shading condition via particle swarm optimization

Performance of Photovoltaic (PV) system is greatly dependent on the solar irradiation and operating temperature. Due to partial shading condition, the characteristics of a PV system considerably change and often exhibit several local maxima with one global maxima. Conventional Maximum Power Point Tracking (MPPT) techniques can easily be trapped at local maxima under partial shading. This significantly reduced the energy yield of the PV systems. In order to solve this problem, this paper proposes a Maximum Power Point tracking algorithm based on particle swarm optimization (PSO) that is capable of tracking global MPP under partial shaded conditions. The performance of proposed algorithm is evaluated by means of simulation in MATLAB Simulink. The proposed algorithm is applied to a grid connected PV system, in which a Boost (step up) DC-DC converter satisfactorily tracks the global peak.

A Simple and Effective Method to Estimate the Model Parameters of Dielectric Barrier Discharge Ozone Chamber

This paper presents a simple yet effective method to determine the electrical model parameters of the dielectric barrier discharge (DBD) ozone chamber at frequencies above 20 kHz. The method is an alternative to the conventional Lissajous plot estimation method which appears to yield unsatisfactory results in this frequency range. Furthermore, the proposed technique allows for the chamber parameters to be determined at different frequencies-a flexibility which is not easily achievable using the typical Lissajous method. The measurement setup consists of a full-bridge inverter and a high-frequency variable inductor connected to the DBD chamber. The inductor can be adjusted to allow for parameter determination at different frequencies. The chamber parameters obtained from experimental results are validated by applying them in a high-voltage power supply for ozone generator.

Modeling and controller design of an industrial hydraulic actuator system in the presence of friction and internal leakage

This paper presents a robust controller scheme and its capabilities to control the position tracking performance of an electro-hydraulic actuator system. Sliding mode control with fixed and varying boundary layer is proposed in the scheme. It is aimed to compensate nonlinearities and uncertainties caused by the presence of friction and internal leakage. Its capabilities are verified through simulations in Matlab Simulink environment. The friction was represented by the LuGre model and the internal leakage was assumed to change. The results indicate that the scheme successfully improves the robustness and the tracking accuracy of the system. This improvement offers a significant contribution in the control of modern equipment positioning applications.