Design, Operation, Control, and Economics of a Photovoltaic/Fuel Cell/Battery Hybrid Renewable Energy System for Automotive Applications

Abstract

Abstract:Meeting rapidly growing global energy demand-without producing greenhouse gases or further diminishing the availability of non-renewable resources-requires the development of affordable low-emission renewable energy systems. Here, we develop a hybrid renewable energy system (HRES) for automotive applications-specifically, a roof-installed photovoltaic (PV) array combined with a PEM fuel cell/NiCd battery bus currently operating shuttle routes on the University of Delaware campus. The system's overall operating objectives-meeting the total power demand of the bus and maintaining the desired state of charge (SOC) of the NiCd battery-are achieved with appropriately designed controllers: a logic-based "algebraic controller" and a standard PI controller. The design, implementation, and performance of the hybrid system are demonstrated via simulation of real shuttle runs under various operating conditions. The results show that both control strategies perform equally well in enabling the HRES to meet its objectives under typical operating conditions, and under sudden cloud cover conditions; however, at consistently high bus speeds, battery SOC maintenance is better, and the system consumes less hydrogen, with PI control. An economic analysis of the PV investment necessary to realize the HRES design objectives indicates a return on investment of approximately 30% (a slight, but nonetheless positive, ~$550 profit over the bus lifetime) in Newark, DE, OPEN ACCESSProcesses 2015, 3 453 establishing the economic viability of the proposed addition of a PV array to the existing University of Delaware fuel cell/battery bus.

Sliding-Mode Control of a Charger/Discharger DC/DC Converter for DC-Bus Regulation in Renewable Power Systems

“…Then, H is calculated from Equation 56to limit the switching frequency to the value achievable by the MOSFET used in the implementation, it also depending on the inductance and capacitance of the charger/discharger, the maximum voltage supported by the ESD, the minimum voltage allowed to the DC-bus, and the maximum current injected from the DC-bus, i.e., negative i DC . The last condition is due to, for a constant H value, f sw is higher for negative bus currents as concluded from Equation (56).…”

“…In addition, the MPPT controller acting on the DC/DC converter is designed to optimize the operation of the renewable generator: for example, if a PV generator is used as the main source, the MPPT controller defines the duty cycle d of the DC/DC converter to increment the PV power p g generated [43,54]. Similarly, if a fuel cell is used as main generator, the MPPT controller regulates the DC/DC converter to decrement the input current i g , which is proportional to the hydrogen consumption [56][57][58]. Note that, in both cases, the output of the unidirectional DC/DC converter is not regulated, hence it provides a power profile p s with a non-regulated current i s .…”

“…Moreover, to simulate the processing of the SMC into a real digital device, the interaction of the C-block with the DC/DC converter and the hysteresis comparator was performed by means of Analog-to-Digital Converters (ADC) and a Digital-to-Analog Converter (DAC), which were simulated using quantization blocks of 12 bits with a sampling frequency of 1 MHz. In addition, the hysteresis band was designed using Equation (56) to ensure a switching frequency lower than 95 kHz, obtaining H = 1.9605. A slightly higher H = 2 was used to include a small safe margin.…”

Economic Dispatching Strategy of Double Lead-acid Battery Packs Considering Various Factors

“…Ref. [22,23] develop a hybrid renewable energy system (HRES) for automotive applications. But in the specific characteristics of the battery did not take into account the impact of service life.…”

Design and Concept of an Energy System Based on Renewable Sources for Greenhouse Sustainable Agriculture

“…They are working together and their integration into the energy market can improve the sustainability and the reliability of the power systems [45].…”