University of South Wales Master of Sciences Thesis
Standalone hybrid generation system for the remote area of Thar, Pakistan
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- Figure 2-19
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Standalone hybrid generation system for the remote area of Thar, Pakistan Fig. 2.17. The d-axis current vs output electric power. Fig. 2.18. Machine side controller. 2.5. Energy Storage System There is currently considerable interest in electrical energy storage technologies, for a variety of reasons. These include changes in the worldwide utility regulatory environment, an ever-increasing reliance on electricity in industry, commerce and the home, the growth of renewable energy sources to meet the growing demand for electricity, and all combined with ever more stringent environmental requirements. The need of energy storage is to transfer the excess power during weak loads or excess supply from RESs to the peak periods [14, 15]. The energy from the RESs has to be transformed into a storable energy form first and then transformed when storing is needed. This can be shown by the following block diagram. Figure 2-19: Energy storage with distributed energy generation system [14] The energy storage techniques with hybrid power systems applied to the electrification of remote rural areas will be discussed in this section. The HPSs in this thesis consists of PV-array system, wind turbines and diesel Genset. The solar irradiation varies with time and so does the wind speed, throughout the day. Thus, in a HPS, both the RESs and the load are fluctuating throughout the day. Standalone hybrid generation system for the remote area of Thar, Pakistan These fluctuations may result in imbalances in power distribution (energy sources are not equal to energy sinks). As a result, the voltage and frequency in the power system will be affected. The addition of energy storage will assist balancing the distribution of power in the power network. The energy storage behaves like a large buffer to accommodate the unequal instantaneous energy in the power system. The energy storage element can act as a load or a generator depending on the supply to demand ratio. Ideally, at any instant of time, there should be a zero net exchange between the energy sources and the energy sinks (both real and reactive power) [14-16]. If this balance is not achieved, the voltage and frequency of the system changes to maintain equilibrium. There are many energy storage techniques. To mention some [6, 14]: - Battery Energy Storage System (BESS) - Pumped Hydroelectric Storage System (PHSS) - Superconducting Magnetic Energy Storage System (SMESS) - Ultra-capacitors - Flywheel Energy Storage Systems (FESS), etc. The different energy storage techniques have different applications in power systems. Some of them are [14]: i. Rapid reserve, ii. Area control and frequency responsive reserve, iii. Commodity storage iv. Transmission system stability, v. Transmission voltage regulation, vi. Transmission and Distribution facility deferral, vii. Renewable energy management, viii. Customer energy management, ix. Power quality and reliability. Each technology has its own particular strengths and operational characteristics. In this thesis, the battery bank as energy storage device is only considered. tải về 6.62 Mb. Chia sẻ với bạn bè của bạn:
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