Читать книгу Analysis and Control of Electric Drives - Ned Mohan - Страница 15

Nearly 99% of electricity is produced through electric machines. This percentage was nearly the same, approximately 98.6%, in the United States in 2018. According to the US Energy Information Administration [3], about 4171 billion kWh (or 4.17 trillion kWh) of electricity was generated at utility‐scale electricity generation facilities in the United States in 2018. About 64% of this electricity generation was from fossil fuels (coal, natural gas, petroleum, and other gases). About 19% was from nuclear energy, and approximately 17% was from renewable energy sources. Out of the renewable energy sources, only 1.4% of the total electricity generated was by photovoltaic systems (PVs) that do not use electric machines, whereas all other sources of electricity generation use electric machines. Therefore, any improvement in increasing the efficiency of machines and electric drives will be very consequential.