Hydrogen production using variable and fixed speed wind farm topologies in a utility grid

Abstract

This paper presents hydrogen production in a utility grid that is composed of variable and fixed speed wind farms. The variable speed wind farm is made of Doubly Fed Induction Generator (DFIG) wind turbines, while the fixed speed wind farm is composed of only Induction Generator wind turbines. To achieve smoothening of the wind farm terminals, Flexible AC Transmission System devices of an Energy Capacitor System with a DC chopper type and Static Synchronous Compensator were used to stabilize the fixed speed wind farms. The power converters of the DFIGs were used to provide reactive power during dynamic periods to achieve stability of the variable speed wind farm. Since the amount of wind energy required producing hydrogen is insignificant and also by taking advantage of the smoothed terminal of the wind farms, a hydrogen generator composed of a rectifier and electrolyzer is connected to the wind farms to produce hydrogen. The produced hydrogen gas thereby acts as a means of transportation to power fuel cell cars. The cooperative control strategies of the system were developed in the visual simulation Power System Computer Aided Design/Electromagnetic Transient Including DC environment. The results obtained show that it is more cost effective to use the variable speed wind farm topology in hydrogen gas production. The effect of the low pass filter time constant in the electrolyzer circuitry was also investigated in the production of hydrogen gas. On the basis of the same grid energy in the utility network, the average time required to fill the hydrogen tanks using high pass filter time constant is shorter.