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This paper presents a remote renewable plant with hydro-pump station as energy storage that will also compensate main utility voltage sag. The hydro-pump station receives mechanical power from the water flow between the upper and lower reservoirs. This network-connected plant has a local 9 MW wind farm which uses doubly-fed induction generators (DFIG) as well as a critical load. The hydro pump station...
Fractional frequency transmission system (FFTS) is utilized to transmit large-scale and remote wind power. By adopting a lower frequency (50/3 Hz), FFTS could reduce the electric distance of transmission lines, thus lowering the transmission loss. In order to analyze the interconnected system of FFTS and main grid, the power flow calculation should be conducted. This paper introduces a new method...
Thyristor controlled transformer (TCT) is a kind of static VAR compensator (SVC). It is mainly used to solve the power quality (PQ) problems of low power factor (PF) and three-phase unbalance. However, it pollutes the power system by producing harmonic currents during normal operation. This paper proposed a multi-objective optimal control strategy to improve the comprehensive PQ. Firstly, the total...
This paper studies the Australian market conditions and subsidies in place to promote the growth of wind power through the use of a stochastic linear programming model. This model optimizes the profit obtained for a static investment based on a variety of wind and price scenarios. It is subject to different constraints which focus on the amount of initial capital injected by an investor, selling power...
This paper presents the modeling of the wind power system and low voltage ride through (LVRT) techniques for doubly-fed induction generator (DFIG) wind energy system. Firstly the equivalent circuit and power transfer principle of DFIG are reviewed. A simulation model of DFIG system has been constructed in PSCAD, where the gird-side double closed loop vector control strategy is used to maintain a constant...
In this study, we determine the suitable method and timing for the renewal of the voltage control method using voltage control performance evaluated by the maximum photovoltaic (PV) installation rate possible without voltage deviation. The voltage control method is renewed when the voltage of a distribution system deviates with an existing voltage control method. We determine the most suitable voltage...
The unified power flow controller (UPFC) can be applied in the four-wire low voltage (LV) distribution networks for voltage regulation and phase current balancing. Instantaneous reactive power theory shows that DC-bus capacitor power will fluctuate at twice mains frequency during any unbalanced operation. The DC bus voltage fluctuation is controlled by forcing the power balance between series and...
Power system dynamic models are the foundation for transient stability simulations which are usually part of transmission planning studies. Accurate dynamic simulations are crucial for reliable and secure operation of a transmission system and the precision of power system stability analysis depends on the accuracy of the models used to represent system equipment. Therefore, the validation of power...
Based on characteristics investigation of reactive power dispatch conditions of present high-voltage distribution networks (HVDNs) in China, a two layer optimal reactive power dispatch (ORPD) model has been proposed in which all the decision variables are discrete types in order to reduce the combination decision space; open-source MATPOWER procedure is taken as the power flow calculation module after...
This paper present new voltage instability detection index (QLVIDI) based on reactive power loss using Synchrophasor technology. The proposed index is fast as compare to the already existing Voltage Instability Monitoring Index (VIMI) and Improved Voltage Instability Monitoring Index (IVIMI). The proposed scheme utilizes reactive power losses in the lines in consideration with direction of active...
Electrical distributors in Australia are experiencing high penetration levels of small scale distributed generation, such as solar photovoltaic systems, particularly being installed on houses that are connected to the Low Voltage network. Distributed generation is challenging the traditional operating paradigm and can result in occurrences of voltage rising to the point where it goes above safe limits,...
Distributed renewable generation is increasing all over the world. The effect of Distributed Generation (DG) on system voltage profile can be examined through sensitivity studies. The sensitivity matrix depicts variations in the voltage magnitude with respect to changes in active and reactive power associated with loads and local generation at different buses in the system. This sensitivity matrix...
Recent tendencies indicate that new and reconductored power lines are declining from the traditional cross arm mounted overhead connection types. Instead of the traditional connections, underground cables are increasing as it is one of the most popular choices. At the same time, LVABC is another type of overhead cable spreading in distribution networks, which has a bundled property similar to the...
High-voltage DC (HVDC) system based on line- commutated converter (LCC) is widespread technology around the world. Reactive power absorption of LCC-HVDC is always problem of the installation in weak system. Because of it, in general, reactive power compensation devices are installed together. If the space where the devices are planned to be installed is not sufficient, it is impossible to install...
Aurizon, Australia's largest freight railway operator, is investigating the use of Rail Power Conditioner (RPC) technology for load balancing, reactive power compensation and harmonic filtering. The new technology has the capability of replacing Static VAr Compensators (SVC) and Harmonic Filters, and is expected to have a significant impact on the overall costs of railway electrification. This paper...
Within active distribution network management, distributed generations, which are contracted by the non-firm connection method, can be directly controlled by the distribution network operator to adjust their power factor and the active power output level. This is called an output curtailment of distributed generation. Although the purpose of the output curtailment is to stably operate the distribution...
The frequent incident of voltage collapse in the modern power system due to incessant increase in load demand has posed a great challenge to power system utilities. This paper demonstrates the concept of inherent structural characteristics and the traditional approach of voltage collapse proximity index (VCPI) in predicting the collapse point in the power system network. The conventional technique...
Recently, researches on microgrids have attracted more and more attention all over the world. Numerous studies and experiments about microgrid converters have been done. This paper presents a method to improve the power quality by controlling the real and reactive power flow between the main grid and the microgrid through the grid-interfaced inverter. Firstly, the desired values of Id and Iq can be...
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