Fuel cells are used as a power generator in distributed generation and aircrafts applications. This paper proposes a new high step-up DC-DC converter with zero-voltage switching (ZVS) of switches and zero current switching (ZCS) of diodes, to be used as fuel cell's power conditioner. To have a ripple free input current, a coupled inductor can be used at the input side of the converter. The voltage gain of the converter is calculated and required conditions for soft switching have been presented. The voltage stress of elements of the proposed converter is discussed, the efficiency of converter is derived and finally experimental results have been used to validate the properties of the converter.

No abstract

Distribution network reconfiguration (DNR) is capable to improve indices of power systems by changing the distribution network (DN) topology under normal conditions. Here, DNR is implemented to improve the power quality (PQ) and power losses of DN. Furthermore, to achieve better optimum in DNR, discrete particle swarm optimization (DPSO) algorithm is equipped with a smart radial method. The proposed algorithm is faster than other metaheuristic methods due to the prevention of regeneration non-radial configurations. In addition, the algorithm increases the probability of finding the optimal configurations using the mutation function. The results clearly demonstrated the positive effect of DNR in improving harmonic losses, total harmonic distortion (THD), and power losses. Furthermore, the proposed method is compared with other metaheuristic algorithms in IEEE 33 bus DN, IEEE 69 bus DN, and real 95-bus DN in presence of photovoltaic (PV). The results show that the developed algorithm leads to the better or same accuracy and speed in all comparisons. In addition, results indicated that considering the summation of fundamental and harmonic losses compared to only fundamental losses in DNR can lead to further energy saving in DNs.