The variation of the electrical distance and the complexity of the electric network lead to the variations of feeder impedances between distributed generation units and load points. It is determined that conventional droop control has drawbacks in achieving accurate power sharing due to the effects of mismatched impedance. Therefore, this study proposes an enhanced proportional power sharing strategy based on adaptive virtual impedance in a low‐voltage networked microgrid. The improved R–L type droop control can effectively prevent the coupling between real and reactive powers. Furthermore, an adaptive virtual impedance loop is introduced to counteract the feeder voltage drop. The method utilises real and reactive power mismatching which were fed into integral controllers, and then generates the virtual inductive and resistive components, respectively. This proposed strategy is able to enhance power sharing accuracy without requiring the knowledge of feeder impedance, and it is more adaptive to the complex impedance. The simulation experiments carried out under the environment of MATLAB/Simulink, and results verify the effectiveness of the proposed strategy.

As the quantity of DC load and distributed generation system increases in China, AC/DC distribution system is arousing more and more research interest for its high‐efficiency distribution ability. In this study, the optimal size and location of renewable energy source (RES) and energy storage in a medium‐ and low‐voltage distributed AC/DC system is studied. A modelling method for the optimisation of such hybrid AC/DC system is developed. The objective of the proposed optimisation method is to minimise the life cycle cost of the system with consideration of the life span of RES. The planning method is based on energy balances and constraints of system operation. The utility requirements and subsidy in China for such system are also considered in the planning process. The method is demonstrated in a 10 kV and low‐voltage distributed AC/DC system considering installing photovoltaic system, wind turbines, and electric storage system. The provided results indicate that the method is effective and applicable for the optimisation of the size and location of RES in distributed AC/DC system. The life cycle cost of such system is significantly reduced with the subsidy of the Chinese government compared with the system without RES.

This paper proposes a maximum power point tracking (MPPT) method with partial shading (PS) detection based on modified PI incremental conductance (IC) for photovoltaic inverters. To accurately trigger the algorithm, a PS detecting approach based on voltage deviation is derived through the comparison of voltage and current characteristics under uniform and non‐uniform insolation. To track the global maximum power point (GMPP) precisely and fast, a global search scheme considering appropriate voltage reference, search direction and termination criteria is presented. The modified PI‐based IC method is implemented in the local search process. In order to verify the effectiveness of the algorithm, the proposed method is utilised in the two‐stage grid‐connected photovoltaic inverters built in MATLAB/Simulink. The performance of the scheme is compared with the traditional IC method under step‐changing and gradual‐changing insolation and various temperature. In all simulation cases, the proposed approach can identify the PS with multiple local maxima, accurately trigger the global search process and track the GMPP. The search periods are around 0.1–0.2 s, and the efficiencies of PV generation under steady state are normally above 99.5%. The presented method can improve the efficiency of distributed and centralised PV system.

This paper studies the influence of additional clutches on the fuel saving performance of a hybrid electric vehicle with a double-rotor electrical variable transmission. One clutch (C1) is introduced on the engine shaft to fix it to the ground, which enables two extra pure electric driving modes. The other (C2) is placed between the two rotors of the EVT to connect them together, resulting in the parallel hybrid and engine directly driving mode. To compare with the no-clutch EVT powertrain, a computationally efficient optimization framework, which combines dynamic programming and Pontryagin’s minimum principle, is employed to search the optimal fuel economy and mode controls under 15 various driving cycles. A bi-level formulation, containing a lower level that solves the underlying static optimization problems of components operation in combined driving modes and an upper level minimizes the Hamiltonian values, is incorporated into the optimization framework to further decrease the computation burden. The comparative analysis on three EVT powertrains, one without any clutches, one with two clutches and one with only C1, demonstrates that C1 could gain at most 5.66% of fuel saving under urban cycles, while the contribution of C2 is trivial to whichever driving conditions.

Cu/Mn co-doped Co₃O₄ catalysts with controlled doping ratios synthesized via co-precipitation exhibit enhanced CO oxidation activity.