In today's market, electric bikes (e-bikes) are becoming exceedingly popular due to their smaller size, ease of domestic charging and cost-friendly alternative in the category of electric vehicles. So, there is a need for the development of a power factor corrected (PFC) private off-board charger (OBC) to cater to the need of the domestic charging of e-bikes. Traditionally, e-bike chargers powered by a domestic meter are realised by a non-PFC OBC with a power rating of 500–700 W. Such converters draw harmonic currents at very high crest factor and affect the life and performance of other domestic appliances. A private OBC which derives its power from the domestic supply for charging the battery of an e-bike is proposed. The charger has two stages, i.e. the PFC stage for input current shaping and the DC–DC stage for regulating the battery charging voltage and charging current. The PFC stage is based on the single-ended primary inductance converter and the DC–DC stage is based on the inductor inductor capacitor (LLC) resonant converter. A 570 W, 57.6V, 10 A prototype is built using digital signal processor (TMS320F28035) to evaluate and validate its performance for charging a lithium-ion battery pack.

High efficiency, high power density and wide output voltage are required for on-board charger (OBC) applications. LLC resonant converter has the advantage of achieving zero-voltage switching for variable frequency and different load conditions. Compared with conventional fundamental harmonic approximation method, operation-mode analysis based on the time domain model provides an accurate description of resonant current, voltage and DC gain. In this study, the efficiency-oriented modified method is proposed based on the operation-mode analysis. The converter inductance ratio, characteristic impedance and transformer turns ratio are optimised and both-side soft switching can be achieved in the high output voltage region. Conduction loss can be minimised by optimising resonant parameters. Finally, a high-efficiency design method is proposed and validated through experiments on a 3.3 kW prototype applied in OBC. The prototype of the LLC resonant converter has been tested for dynamic charging voltage (230–430 V) with a peak efficiency value of 98.5%.

Lithium-ion battery is the most preferable type for hybrid electric vehicle due to their superior performance. The battery performances and safety factors are influenced by its operating temperature, hence it needs to be controlled carefully. Battery has a good performance at high temperature but this put it at risks of thermal runaway and explosion. This study presents a simulation model to predict battery's thermal behaviours during discharging and charging through regenerative braking in a series hybrid electric vehicle under various driving cycles. In total, five driving cycles are covered namely New European Driving Cycle (NEDC), Artemis cycle, Japanese 10-15 Mode cycle, FTP-75 cycle and worldwide harmonised light vehicles test procedure cycle. Validation of the model is performed using experimental results for NEDC cycle. Important results presented in this study focus on the battery temperature under different driving cycles and the impacts by considering thermal generation during charging process. Even though the temperature increase is relatively small, but the contribution of heat generation during charging is significant especially in an aggressive driving cycle. These results are very important in providing better understanding on the battery thermal behaviours so that a more effective battery management system can be developed (199/200).

Nowadays, running out of fossil fuels and more attention to reduce environmental pollutions are essential factors for the growing use of electric vehicles (EVs). Owing to these factors, it is important to present a method, which schedules charging or discharging of EVs and simultaneously considers economic and environmental aspects of the problem. This study proposes a multi-objective optimisation programme for charging or discharging of EVs in a smart distribution system by taking advantage of advanced metering infrastructure and uses a ɛ-constraint method for minimising operational costs and (CO₂) emissions. Simulating stochastic patterns of EV owner driving behaviour as well as considering different models and types of EVs with the help of trip planning algorithm are the main advantages of this study. Investigating the multi-objective problem in two cases shows the effectiveness and flexibility of this algorithm in real cases. Besides, vehicle-to-grid capability of EVs was also considered. This method was tested on a 33-bus distribution test system for over 24 h. As the results show, the total amount of scheduled power, the peak-to-valley difference of daily load, transmission power loss, CO₂ emission, and the total operational cost are reduced by the trip planning programme and EV owner revenue is increased.

Electric vehicles (EVs) battery has the ability to enhance the balance between the load demand and power generation units. Random behaviour of owners and EVs low capacity are some factors that develop the EV aggregator notion to increase the EV participation in the ancillary services market. In the presence of EVs aggregator, the frequency control service is capable of causing time-varying delay in load frequency control (LFC) systems. Owing to the dependency of controller effectiveness on its parameters, these parameters should be designed optimally in order to have a better result in an LFC system in the presence of time-varying delay. Therefore, a salp swarm algorithm (SSA) is utilised to adjust the fractional-order proportional integral derivative (PID) (FOPID) controller coefficients. Also, some evaluations are performed about the proposed LFC performance by an integral absolute error, integral time absolute error and mean absolute error indicators. In this study, both single and two-area LFC systems containing EVs aggregator with time-varying delay are simulated and analysed. The results indicate that the proposed controller has fewer frequency variations in contrast to other controllers presented in the case studies. Moreover, it is concluded that the FOPID controller could significantly decrease the overshoot and settling time of the frequency variation signal.