Optimal location of FACTS devices for damping oscillations

Damping of electromechanical oscillations between interconnected synchronous generators is necessary for a secure system operation. While local oscillations involving one or more generators swinging against the rest of the system are mainly influenced by a restricted number of local system parameter- the behavior of low frequency inter-area oscillations is generally determined by global parameters of larger parts of the power system. Power System Stabilizers (PSSs) applied on selected generators can effectively damp local oscillation modes; their limited influence on inter-area modes, however, lead to the fact that they may not be considered as the only solution to damp interarea oscillations. Flexible AC Transmission Systems are being increasingly used to better utilize the capacity of existing transmission systems. Flexible AC Transmission System (FACTS) is a technology based solution to help the utility industry deal with changes in the power delivery business. A major thrust of FACTS technology is the development of power electric based systems that provide dynamic control of the power transfer parameters transmission voltage, line impedance and phase angle [1]. The static var compensator (SVC), which is a shunt device, provides dynamically variable shunt impedance to regulate the series compensator (TCSC), which is a Series FACTS controller, is used to change the effective reactance of the line dynamically, thereby controlling the real power flow in the lines. The unified power flow controller (UPFC) is used to control the real and reactive powers simultaneously in a line by injecting a series voltage across the line. It also injects a shunt reactive current at one of the line-end buses to maintain the bus voltage at a specified value [2, 3]. FACTS devices are provided with supplementary controllers for damping out small signal oscillations [4-8], and the effectiveness of damping the oscillations depends on the location of FACTS controllers. Several methods [2–4] have been proposed for the placement of FACTS controllers. Previous studies [9–10] considered only static criterion like improving power transfer, available transfer capability (ATC), loss minimizations and did not consider any dynamic criteria for the placement of the FACTS controllers. A sensitivity based approach has been developed in some researches for determining the optimal placement of FACTS devices in electricity market having pool and contractual dispatches [11-13]. [11] Shows that few locations of FACTS devices can be decided based on sensitivity factors and then optimal dispatch problem must solved for finding suitable placement of UPFC in a congested system. [15] Implements Genetic Algorithm to finding the best location for TCSC to maximizing total transfer capacity. Tuning of FACTS parameters has been proposed for improving damping of weakly damped inter-area modes. [16-17] proposed a method for selecting suitable feedback signal to FACTS controllers for improving the damping. Sadikovic and Korba [18] used residue, called location index for effective damping, to find suitable location for damping inter-area mode of oscillations, also in the work of [14] and [19], the method used only UPFC placement based on only single operating condition. No consideration of other FACTS devices

On the policy of photovoltaic and diesel generation mix for an off-grid site: east malaysian perspectives

The recent policy of the Malaysian government to promote use of renewable, especially photovoltaic, energy has warranted a feasibility study on supplementing diesel generation in off-grid sites by solar (photovoltaic) electricity to be done in the Malaysian context. This paper addresses the technical viability and economy of using a photovoltaic (PV) system to supplement an existing diesel generator-based supply in a typical secondary school located at an interior, off-grid and rural site of Sarawak state in East Malaysia. The findings of the present study, would therefore, help the Government with a realistic picture of the techno-economic aspects in implementing its vision regarding renewable energy. Presently, a 150kW diesel generator supplies electricity to the considered school. The study required simulation of the load sharing pattern of the PV-diesel hybrid system taking into account varied weather and insolation conditions of the chosen site. Also, the purchase price as well as the size of the supplementing PV system that would give the lowest life cycle cost have been determined. The PV system was considered in both forms, i.e. with and without battery back-up. It has been found that if the market price for purchasing a PV system would drop to RM 11.02/WP (Ringgit Malaysia; US$1.00=RM 3.80) i.e. US$2.90/WP, a 35>kWP PV system without battery back-up in conjunction with the diesel generator would be able to supply the selected school's demand at a marginally lower energy cost than the existing diesel-only system. With continuous research and developments, PV price would keep falling in the near future so that a PV-diesel hybrid system with a higher sized PV is expected to be economically more viable. The reported feasibility study can serve as a guideline for making similar studies in the context of another off-grid site

SPS-2000 Demonstration of Energy Reception by Microwave Rectennas in Malaysia

As the worlds' population increases, the demand for energy, particularly electrical energy also increases. However, due to the depletion of energy in particular the hydrocarbons with time, an alternative sources is needed. Solar energy is one of the safest to be explored. This paper presents an approach in using solar power to generate electrical energy in the future using an SPS 2000 (solar power satellite) rectenna. The suitable location of the rectenna in Malaysia has been identified. Spherical rectenna is chosen for optimized reception area and for ease of analysis. The amount of energy received by this rectenna is simulated using Visual Basic V.5.0. The latitude of the rectenna, rectenna radius, earth inclination, distance between rectenna and satellite and the time of the year of inception determine energy reception. The program also estimates the price per kWh of energy generated. However, this is not the real of electricity as the satellite and the transmitting costs were not considered in the calculation

Optimization of biomass usage for electricity generation with carbon dioxide reduction in Malaysia

Electricity and energy sector are identified as the major carbon dioxide emitter. Coal, natural gas, diesel, oil and hydro are the sources to generate electricity in Malaysia. In the 9th Malaysia Plan, government of Malaysia encourage power producer shift from heavy reliance on natural gas and enhance use of biomass. Agriculture residue; palm oil residue, rice processing residue and wood processing residue were considered as fuel sources to generate electricity in this study. An MILP model has been developed to optimize fuel mix and meet CO2 emission target. The model was developed and implemented in General Algebraic Modeling System (GAMS) for the fleet of electricity generation in Peninsular Malaysia only. In order to reduce the CO2 emissions by 35% from current CO2 emission level, the optimizer has specified to switch from coal to natural gas and biomass from palm oil residues as a fuel. Therefore, agriculture residue is a promising fuel sources for electricity generation at the same time reduce CO2 emissions