Technological advances, environmental awareness and, in several countries (including the UK), financial incentives lead to the adoption of PV (photovoltaic) systems. Economic viability, an important ...consideration for investment in residential PV, is dependent on the annual energy yield which is affected by distribution network based factors such as point of connection to network, network hosting capacity, load profiles etc. in addition to the climate of the location. A computational algorithm easy on resources is developed in this work to evaluate the effects of distribution network on the annual energy yield of residential PV systems under scenarios of increasing PV penetration. A case study was conducted for residential PV systems in Newcastle upon Tyne with a generic UK distribution network model. Results identified penetration levels at which PV generation curtailment would occur as a consequence of network voltage rise beyond grid limits and the variation in the percentage of annual energy yield curtailed among the systems connected to the network. The volatility of economic performance of the systems depending on its location within the network is also analysed. The study also looked at the impact of the resolution of PV generation profiles on energy yield estimates and consequently economic performance.
•Development of a post curtailment energy yield estimation algorithm.•Analysis of the effect of the grid on energy yield under increasing PV penetration.•Consideration of a case study using a UK generic urban distribution network.•Evaluation of the impact of PV output profile resolution on energy yield estimates.•At high penetration levels some prosumers’ investments were more at risk than others.
•Development of a generic dynamic PV model including under/over voltage protection.•Analysis of the impact of fault on the performance of single-phase PV systems.•Analysis of the impact of PV systems ...on the dynamic performance of DN.•Implications of the adoption of different standards on unwanted tripping of PV systems.•Analysis of the impact of PV systems on the protective mechanisms in DN.
Faults are a major concern to the dynamic performance of distribution networks. With the predicted increase in PV contribution, it is vital to understand the impact of PV on the distribution network. However, there is very little work published that address the impact of PV systems on the dynamic performance of distribution networks. Most PV systems connected at the distribution level are single-phase in nature. A generic single-phase dynamic PV model, including the protection mechanism, is presented in this paper. This enables the evaluation of the dynamic performance of distribution networks with multiple single-phase PV systems. The paper analyses the impact of faults on the PV inverter output using the models developed. The impact of PV on the network performance during fault is then analysed. The implications of the adoption of different regulations, viz. G-83, IEEE 1547:2018, IEC 61727 and VDE 0126-1-1, are also discussed. The results show that the presence of PV systems does not significantly affect the performance of the distribution network during faults. Also, the usual concern of loss of protection co-ordination does not occur at this voltage level. Faults that are far from the PV terminals would be cleared within 0.2 s. This indicates that the disconnection delay of 0.5 s as stipulated by G-83 is appropriate. However, a lower cut-off voltage for under-voltage disconnection than the current value stipulated in G-83 would enable more PV systems to stay connected during fault and avoid unnecessary loss of generation. The network used in this work is a representative of distribution networks and protection schemes in the UK. The results of this analysis are therefore extendable to any radial distribution network that uses standard protection, e.g. fuses and relays in low voltage distribution networks.
In order to obtain maximum power output of a Wind Energy Conversion System (WECS), the rotor speed needs to be optimised for a particular wind speed. However, due to inherent inertia, the rotor of a ...WECS cannot react instantaneously according to wind speed variations. As a consequence, the performance of the system and consequently the wind energy conversion capability of the rotor are negatively affected. This study considers the use of a time series Adaptive Linear Prediction (ALP) technique as a means to improve the performance and conversion efficiency of wind turbines. The ALP technique is introduced as a real time control reference to improve optimal control of wind turbines. In this study, a wind turbine emulator is developed to evaluate the performance of the predictive control strategy. In this regard, the ALP reference control method was applied as a means to control the torque/speed of the emulator. The results show that the employment of a predictive technique increases energy yield by almost 5%.
•A representation of the performance of a real wind turbine subjected to variable wind.•Adaptive Linear Prediction to improve performance and conversion efficiencies of WECS.•Wind turbine emulator as a means to evaluate time series linear prediction.•Wind sensor method offers an optimal power mapping technique.
•Develop a simplified fault tolerance finite control set model predictive control of a five-phase BLDC motor drive for application in electric vehicles Propose a fault detection method capable of ...detection and localization of both open switch and short circuit faults in voltage source inverter.•Analyse the effect of parameters uncertainty on controller performance.•Validate the theory with experimental results.
Multiphase brushless direct current (BLDC) motors can meet the increasing demand for higher reliability in motor drives applicable in electric vehicles by integrating fault diagnosis to a fault-tolerant (FT) control method. To achieve this goal, a modified FT finite control set model predictive control (FCS–MPC) is proposed in this paper. The dead beat control is used to predict the reference voltage applied by the inverter. A sensitivity analysis is done to show the effect of model uncertainty on the controller performance. In addition, a simple, fast and general open switch and short circuit fault detection (FD) method in voltage source inverter (VSI) is presented. The FD method is capable of detecting open switch, open phase, and short circuit faults without any auxiliary variable. Moreover, it is robust to both speed and load transients in a motor drive. To validate the presented theory, experimental results are conducted on a five-phase BLDC motor drive with outer rotor in wheel structure.
National targets for increased renewable energy are common-place internationally and small/micro-generation may help achieve such goals. Energy yields from such technologies however, are very ...location and site specific. In rural environments, the average wind speed is relatively high and the homogeneous landscape promotes laminar air flow and stable (relatively) wind direction. In urban environments however, the wind resource has lower mean wind speeds and increased levels of atmospheric turbulence due to heterogeneous surface forms. This paper discusses the associated costs per unit of electricity generated by micro wind energy conversion systems from the perspective of both urban and rural locations, with three case studies that consider the potential and financial viability for such systems. The case studies ascertain the cost of energy associated with a standard HAWT (horizontal axis wind turbine), in terms of exemplar rural and urban locations. Sri Lanka, Ireland and the UK, are prioritised as countries that have progressive, conservative and ambitious goals respectively towards the integration of micro-generation. LCOE (Levelized cost of energy) analyses in this regard, offers a contextualised viability assessment that is applicable in decision making relating to economic incentive application or in the determination of suitable feed-in tariff rates.
•Levelized cost of energy analysis of rural/urban wind energy systems is presented.•Progressive, conservative and ambitious wind energy case studies are compared.•Design of Experiments analysis (DOE) considers LCOE parameter intra-dependencies.•Urban wind energy harvesting for each case proved to be a cost preclusive option.
In the rapidly evolving electric vehicle industry, the reliability of electronic systems is critical to ensuring vehicle safety and performance. Printed circuit boards (PCBs), serving as a ...cornerstone in these systems, necessitate efficient and accurate surface defect detection. Traditional PCB surface defect detection methods, like basic image processing and manual inspection, are inefficient and error-prone, especially for complex, minute, or irregular defects. Addressing this issue, this study introduces a technology based on the YOLOv5 network structure. By integrating the Convolutional Block Attention Module (CBAM), the model’s capability in recognizing intricate and small defects is enhanced. Further, partial convolution (PConv) replaces traditional convolution for more effective spatial feature extraction and reduced redundant computation. In the network’s final stage, multi-scale defect detection is implemented. Additionally, the normalized Wasserstein distance (NWD) loss function is introduced, considering relationships between different categories, thereby effectively solving class imbalance and multi-scale defect detection issues. Training and validation on a public PCB dataset showed the model’s superior detection accuracy and reduced false detection rate compared to traditional methods. Real-time monitoring results confirm the model’s ability to accurately detect various types and sizes of PCB surface defects, satisfying the real-time detection needs of electric vehicle production lines and providing crucial technical support for electric vehicle reliability.
•Propose a new concept for smart charging of electric vehicles (EV).•The charger satisfies EV user, extends battery life and reduces impact on grid.•Develop a battery aging model to simulate the ...aging process.•Develop computer and experimental models of EV charger.•Results presented demonstrate the effectiveness of the proposed controller.
Existing commercial battery charging posts for electric vehicles (EV) offer limited controllability and flexibility. These chargers are not designed to allow users to specify important criteria such as desired energy for next trip and waiting time whilst charging. In addition, the charging regime is not set to take into consideration the impact of charging (e.g. rate of charge) on the battery cycle life and the grid supply.
With increased penetration of EVs and distributed generators (DG), complying with grid regulations will become more challenging, e.g. network voltage levels may deviate from the statutory limits. Moreover, as the battery is the most expensive part of an EV, consideration should be given to extending battery life and reduce the effective EV cost. Therefore, there is a need to develop a smart EV charge controller that can meet users’ requirements, extend battery cycle life and have minimum impact on the grid supply.
In this paper, a smart controller is proposed which determines the optimal charging current based on grid voltage, battery state of health and user’s trip requirements. Models of a typical UK power distribution network and an EV battery (that allows simulation of battery aging process) are developed to investigate the performance of the “smart” charging system. Simulation and experimental results are presented to demonstrate the effectiveness of the proposed controller.
To enhance the stability and disturbance rejection of wireless charging systems for electric vehicles, we designed a bilateral collaborative control strategy based on BP neural networks, achieving ...closed-loop constant voltage control for the secondary rectification circuit. Integrating BP neural network adaptive PID parameters with dual-phase-shift control, this strategy outperforms conventional incremental PID controllers in terms of response time and overshoot. Validated on an 11 kW experimental platform, our approach demonstrated efficient response under disturbances; with a load switch from 10 Ω to 12 Ω, the system exhibited a mere 5% fluctuation rate and an impressive efficiency of up to 92.96%.
The lithium-ion battery is the most expensive part of the electric vehicle (EV). Improving battery performance is one of the most important factors in promoting the EV market by prolonging battery ...life, reducing the cost of ownership and giving confidence in the product to potential customers. This paper considers a method of improving battery performance that extends the life of the battery and increases holding capacity. This will be realized by finding the best charging profile for an EV battery by identifying, the time that battery can accept charging and the charging profile with minimum effect on battery life. The analysis presented shows that including rest periods during battery charging reduces battery degradation in two ways. Firstly, it reduces the rate of change in battery internal resistance. Secondly, it slows down the rate of capacity fade. Moreover, it reduces the average battery temperature through charging.
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