Power Maximization in Standalone Photovoltaic System: An Adaptive PSO Approach

A control strategy for power maximization which is an important mechanism to extract maximum power under changing environmental conditions using Adaptive Particle Swarm Optimization (APSO) is proposed in this paper. An Adaptive Inertia Weighting Factor (AIWF) is utilised in the velocity update equation of traditional PSO for the improvement in speed of convergence and precision in tracking Maximum Power Point (MPP) in standalone Photovoltaic system. Adaptation of weights based on the success rate of particles towards maximum power extraction is the most promising feature of AIWF. The inertia weight is kept constant in traditional PSO for the complete duration of optimization process. The MPPT in PV system poses a dynamic optimization problem and the proposed APSO approach paves way not only to track MPP under uniform irradiation conditions, but also to track MPP under non uniform irradiation conditions. Simulations are done in MATLAB/Simulink environment to verify the effectiveness of proposed technique in comparison with the existing PSO technique. With change in irradiation and temperature, the APSO technique is found to provide better results in terms of tracking speed and efficiency. Hardware utilizing dSPACE DS1104 controller board is developed in the laboratory to verify the effectiveness of APSO method in real time.

Implementation and Validation of Hybrid Control for a DFIG Wind Turbine Using an FPGA Controller Board

In this study, a novel control approach for a doubly-fed induction generator (DFIG) is developed and applied to improve the system’s dynamic response and performance for providing high energy quality while avoiding harmonic accumulations. Because of its ease of implementation, field-oriented control (FOC) is frequently used. This control has great sensitivity to the machine’s parametric variations. For this reason, adaptive Backstepping control (ABC) is capable of preserving almost all of the performance and robustness properties. However, its analytical formulation has a problem. To overcome these disadvantages, the hybrid control (HC) is developed and verified to enable rapid response, complete reference tracking, and appropriate dynamic behavior with a low ripple level. This control is a combination of FOC’s and ABC’s control laws. The prepared control is explored by simulation testing using Matlab/Simulink and practical implementation using an FPGA board with actual turbine settings and a real wind profile of Dakhla City, Morocco. The results of hardware simulation show the efficacy of the HC in terms of speed and robustness, with a total harmonic distortion THD = 0.95, a value of THD that reveals the quality of the energy injected into the grid.

Implementation on the dSPACE 1104 of VOC-SVM based anti-windup PI Controller of a three-phase PWM rectifier

<p><span>The study made in this paper concerns the use of the voltage-oriented control (VOC) of three-phase pulse width modulation (PWM) rectifier with constant switching frequency. This control method, called voltage-oriented controlwith space vector modulation (VOC-SVM). The proposed control scheme has been founded on the transformation between stationary (α-β) and and synchronously rotating (d-q) coordinate system, it is based on two cascaded control loops so that a fast inner loop controls the grid current and an external loop DC-link voltage, while the DC-bus voltage is maintained at the desired level and ansured the unity power factor operation. So, the stable state performance and robustness against the load’s disturbance of PWM rectifiers are boths improved. The proposed scheme has been implemented and simulated in MATLAB/Simulink environment. The control system of the VOC-SVM strategy has been built based on dSPACE system with DS1104 controller board. The results obtained show the validity of the model and its control method. Compared with the conventional SPWM method, the VOC-SVM ensures high performance and fast transient response.</span></p>

A Simple Low-Cost Electrocardiogram Synchronizer

Electrocardiogram (ECG) synchronization is useful to avoid the effects of cardiac motion in medical measurements, and is widely used in standard medical imaging. A number of medical equipment include embedded commercial synchronizers. However, the use of independent synchronization modules is sometimes needed when several non-integrated instruments are used, or in the development of new medical instruments and procedures. We present a simple low-cost ECG synchronizer module based on an Arduino controller board that converts the ECG signal into a transistor-transistor-logic (TTL) one, allowing real-time medical measurements triggered at specific phases of the cardiac cycle. The device and conversion algorithm developed is optimized in vitro using synthetic and human ECG signals, and tested in vivo on three swine specimens. Error rates during the in vivo testing stage remain below the 2% of the cycles in all animals and critical false positives are less than 1%, which is sufficient for most applications. Possible algorithm updates are discussed if its performance needs to be improved.

PrintrLab incubator: A portable and low-cost CO2 incubator based on an open-source 3D printer architecture

Growth in open-source hardware designs combined with the decreasing cost of high-quality 3D printers have supported a resurgence of in-house custom lab equipment development. Herein, we describe a low-cost (< $400), open-source CO2 incubator. The system is comprised of a Raspberry Pi computer connected to a 3D printer controller board that has controls for a CO2 sensor, solenoid valve, heater, and thermistors. CO2 is supplied through the sublimation of dry ice stored inside a thermos to create a sustained 5% CO2 supply. The unit is controlled via G-Code commands sent by the Raspberry Pi to the controller board. In addition, we built a custom software application for remote control and used the open-source Grafana dashboard for remote monitoring. Our data show that we can maintain consistent CO2 and temperature levels for over three days without manual interruption. The results from our culture plates and real-time PCR indicate that our incubator performed equally well when compared to a much more expensive commercial CO2 incubator. We have also demonstrated that the antibiotic susceptibility assay can be performed in this low-cost CO2 incubator. Our work also indicates that the system can be connected to incubator chambers of various chamber volumes.

Implementation of reduced induction machine fuzzy logic control based on dSPACE-1104 R&D controller board

In this paper, we present our contribution in Induction Machine control field. The control we designed is based on fuzzy logic theory, this choice is motivated by the fact that this technique of control is suitable for the control of systems characterized by its parameters uncertainties and variations. The proposed control is optimized by using a genetic algorithm for fuzzy logic controller (FLC) gains tuning and by a good choice of calculation techniques used in FLC. Three versions of IM fuzzy logic control were validated by simulation. After that in order to be able to experimentally implement this control on dSPACE-1104, we proposed an optimized and reduced structure of the control. The experimental results proof the effectiveness and the satisfied performance of the proposed IM fuzzy control.

Seven-level grid-connected packed U-cells inverter using photovoltaic generators system

In this article, one of the most recent multilevel converter topologies named packed U-cells is developed for three-phase grid-connected inverter mode using photovoltaic input voltage sources. This topology makes a very important research subject in what concerns the adaptation of multilevel inverters with photovoltaic systems. According to the literature, it is well applicable with the string type and suitable for high-voltage applications because the number of switches is less than conventional topology and maximum blocking voltage is Udc and 2 Udc; however, it is not applicable for multistring type and unsuitable for the central type because it is based on isolated DC source. The packed U-cells topology is highly optimized from the point of view of the number of passive and active components. The output voltages of our converter are composed by seven levels obtained by the auxiliary buses voltages regulation. In order to obtain the DC input voltages of 120 V for the inverter, photovoltaic generators are connected to a boost converters. The maximum power point tracking method based on the Perturb and Observe was used to improve and optimize the performance of the photovoltaic system control in the simulation part. The grid-connected PUC7 inverter operates with a unit power factor and injects active power into the grid. The control is configured to make the current waveform in phase with the AC voltage waveform. Reference angle variations have been made to operate with different power factors to test the performance of the applied control and the influence of these variations on the auxiliary buses voltages regulation. The simulations were done under Matlab/Simulink platform and have been experimentally verified using dSpace 1104 controller board and three-phase packed U-cells inverter composed by nine half-bridge insulated-gate bipolar transistor modules.

Arduino based control of the Food and Water Conveyance Systems of a Refractance Window Dryer

A refractance window dryer with a 14.5kg/hr throughput capacity was developed to effectively dry food product of 3mm on the conveyor belt. For efficient dryer performance an automated system for the conveyor belt movement and water conveyance system was designed. The automated system comprised of an ARDUINO centered control system, an arrangement of sensors, water pump and the conveyor motor. A computer program was written in Arduino environment, successfully compiled and uploaded on to the controller board to process all commands. The system was first simulated successfully in ISIS Proteus environment and connected onto a bread board for testing before attaching the motor onto the main circuit board. Performance tests done at 85°C revealed that there was no movement of the belt as temperature built steadily from 31.19°C until it reached a temperature of 92.0°C in the boiler. The maximum recorded water temperature was 98.06°C and the system had an operating range of 95±3°C. Achieving this led to an automated food conveyance system that was reliable and ensured high product quality. The Arduino based system worked well and is recommended for the refractance window dryer and can be up scaled to a bigger similar machine.