ABSTRACT

This study provides designing and techno-economic analysis of a low voltage (48 V) DC microgrid for domestic load application. In present DC microgrid, photovoltaic (PV) is considered as main power generator to deliver the load demand while fuel cell (FC) and battery are considered as backup power sources. To establish a 48 V DC bus, suitable DC-DC converter having wide input voltage range (22–65 V) is designed to stabilize the variable output voltage of PV and FC generators. The converter efficiency was found to be ≈ 87%. A techno-economic study is also carried out to assess the levelized cost of electricity in microgrid using different energy storage systems, i.e. battery and hydrogen. Lead-acid and lithium-ion are considered as battery storages while high-pressure cylinder and metal hydride storages are considered for hydrogen storage. It is found that PV-battery is most economical configuration; however, PV-FC-battery is better choice for high reliability of overall system. PV-FC-battery configuration has lower cost of electricity as compared to PV-FC alone system. In battery storage system, lithium-ion battery shows faster charging/discharging and efficient operation as compared to lead-acid battery application. In hydrogen storage system, if high-pressure hydrogen is considered, the levelized cost of electricity is reduced significantly as compared to metal hydride storage. However, metal hydride is much better choice for hydrogen storage as compared to the high pressure considering the safety concern.

摘要

这项研究为家用负载应用提供了低压（48 V）直流微电网的设计和技术经济分析。在当前的DC微电网中，光伏（PV）被认为是满足负载需求的主要发电机，而燃料电池（FC）和电池被认为是备用电源。为了建立48 V DC总线，设计了合适的具有宽输入电压范围（22–65 V）的DC-DC转换器，以稳定PV和FC发电机的可变输出电压。发现转换器效率约为87％。还进行了一项技术经济研究，以评估使用不同的储能系统（即电池和氢气）的微电网中的平均电费。铅酸和锂离子被视为电池存储，而高压钢瓶和金属氢化物被视为氢气存储。发现光伏电池是最经济的配置。但是，PV-FC电池对于整个系统的高可靠性是更好的选择。与单独使用PV-FC的系统相比，PV-FC电池配置具有较低的电力成本。在电池存储系统中，与铅酸电池相比，锂离子电池显示出更快的充电/放电和高效的操作。在氢存储系统中，如果考虑使用高压氢，则与金属氢化物存储相比，可显着降低电力平准化成本。但是，考虑到安全性，与高压相比，金属氢化物是更好的储氢选择。与单独使用PV-FC的系统相比，PV-FC电池配置具有较低的电力成本。在电池存储系统中，与铅酸电池相比，锂离子电池显示出更快的充电/放电和高效的操作。在氢存储系统中，如果考虑使用高压氢，则与金属氢化物存储相比，可显着降低电力平准化成本。但是，考虑到安全性，与高压相比，金属氢化物是更好的储氢选择。与单独使用PV-FC的系统相比，PV-FC电池配置具有较低的电力成本。在电池存储系统中，与铅酸电池相比，锂离子电池显示出更快的充电/放电和高效的操作。在氢存储系统中，如果考虑使用高压氢，则与金属氢化物存储相比，可显着降低电力平准化成本。但是，考虑到安全性，与高压相比，金属氢化物是更好的储氢选择。与金属氢化物存储相比，平均成本降低了。但是，考虑到安全性，与高压相比，金属氢化物是更好的储氢选择。与金属氢化物存储相比，平均成本降低了。但是，考虑到安全性，与高压相比，金属氢化物是更好的储氢选择。