This paper describes the implementation of a hybrid energy storage system (HESS) using ultracapacitors (UCs) to protect the batteries of an electrical vehicle (EV) from high-peak currents and therefore extend their lifetime. A field-programmable gate array (FPGA) controlled interleaved bidirectional buck-boost converter working in a discontinuous conduction mode, has been designed to transfer the energy between the batteries and the UCs. The FPGA is responsible of generating all the converter gate signals and implements the control stage needed to smooth the battery current peaks. The control strategy is based on dividing the current demand of the motor into two parts (high-frequency current and low-frequency current), the batteries supply the low frequency part and the UCs supply the high-frequency part. Experimental tests have been carried out driving the EV under different scenarios. Experimental results demonstrate the good behavior of the proposed HESS, although the potential battery life extension is still under quantification. The consumption of the EV has been increased due to the converter losses, this increase is minimum under typical driving scenarios, but is quite important in start-stop driving cycles.

This paper presents a practical implementation of a photovoltaic I-V curves and maximum power point estimation algorithm (IVMPPE). The IVMPPE estimates the I-V curve and sets the operation of the solar panels at a voltage that extracts the maximum available power without tracking. The operation is based on solving the parameters of the solar array equivalent electrical model, in real time, only with the measurements of six voltage and current coordinates near the operating point. Moreover, the strategy for selecting the measured points and the discard procedures for incorrect estimated curves are also detailed. To validate the IVMPPE, it has been tested under different operating conditions, and its accuracy has been compared with the classical perturb and observe (P&O) technique. The distinguishing feature of the IVMPPE is that complete I-V model is obtained, not only the MPP, enlarging the capabilities to other fields, e.g., real-time monitoring and prediction.

This article presents a new ultrafast DC Solid State Circuit Breaker (SSCB) that uses a Silicon Carbide (SiC) cascode as the main switching and limiting semiconductor and an isolated photovoltaic driver to control it. The proposed topology is self-powered and fully implemented with discrete parts.