Chai Chompoo-Inwai

System impact study for the interconnection of wind generation and utility system

Following in the steps of the gas industry, the traditional paradigm of the vertically integrated electric utility structure has begun to change. In the United States, the Federal Energy Regulatory Commission has issued several rules and Notices of Proposed Rulemaking to set the road map for the deregulated utility industry. The crisis in California has drawn great attention and sparked intense discussion within the utility industry. One general conclusion is to rejuvenate the idea of integrated resource planning and promote the distributed generation via traditional or renewable generation facilities for the deregulated utility systems. Wind generation is one of the most mature and cost-effective resources among different renewable energy technologies. Recently, several large-scale wind generation projects have been implemented in the U.S. and other parts of the world. Similar to other new generation facilities, the impacts of a large-scale wind generation on the system operation, voltage profile, and system security have to be investigated and studied. Remedies for possible operation issues have to be evaluated and implemented. This paper discusses the impact study of connecting a 120-MW wind farm into the transmission system of a utility company within the southwest power pool.

Reactive compensation techniques to improve the ride-through capability of wind turbine during disturbance

World wind energy capacity expanded at an annual rate of 25% during the 1990s. The total world wind turbine installation capacity was approximately 40 000 MW at the end of 2003. Germany has the highest installed capacity of over 10 000 MW, while Denmark, where the wind energy accounts for more than 13% of electricity consumed, has the highest wind energy level per capita. The United States is catching up in the development of wind farms, with several large-scale wind generation projects currently being materialized. Even though there is significant progress in the wind generation technology, most of the currently installed wind turbines utilize induction generators to produce the electricity. Since the induction generators do not perform voltage regulation and absorb reactive power from the utility grid, they are often the source of voltage fluctuations. It is necessary to examine their responses during the faults and possible impacts on the system stability when the percentage of the wind generation increases. This paper compares the steady-state voltage profile and the voltage ride-through capabilities of the induction-generator-based wind farms with different reactive compensation techniques.

Design Optimization of Wind Power Planning for a Country of Low-Medium Wind Speed Profile

The emerging energy crisis resulting from a high price of crude oil has drawn attention about renewable energy all over the world. Thailand is a developing country located at the heart of Southeast Asia, with about 66 million of population as of 2006. The electricity supply industry structure under the government of Thailand has been managed by the Electricity Generating Authority of Thailand, the Metropolitan Electricity Authority, and the Provincial Electricity Authority for almost 50 years. According to the 2004 Power Development Plan, the country would have generation reserve at a marginal of 15%. Due to the rapid economic growth and difficulty in building new centralized generating facilities, this has the potential to create a security issue of electricity energy shortage and may develop a severe system blackout. Renewable energy issues have been widely discussed and debated over the country. Although solar energy is the most prominent renewable energy source due to the appropriate geographic of Thailand, it is still considered as a low-density energy source which requires a large area of installation. Therefore, for the long-term investment, wind power seems to be a good candidate because it is quick to install, needs no fuel cost, and is environment friendly. Therefore, this paper investigates the impact of the penetration level of wind power generation to be integrated into the Thailand system. System stability has been observed in various system configuration changes due to different control strategies of wind farms. The economic analysis of wind-farm investment has been also considered.

Transmission Congestion Management During Transition Period of Electricity Deregulation in Thailand

Transmission congestion management (TCM) plays a significant role in power-system operation under todays deregulated environment. Its two major functions are to maintain power system within security limits and to collect money from market participants paying back to transmission-grid investors. The TCM issue has been widely debated during the past decade. It is still an extensively discussed opened issue in the current competitive environment. In the United States, Pennsylvania New Jersey Maryland (PJM) with nodal congestion management based on renowned locational marginal price and the Electric Reliability Council of Texas with zonal congestion management are two successful stories of TCM under different operation schemes. Although the PJM model is adopted in some developing countries where the processes of restructuring of Electricity Supply Industry is still under the beginning phase, many concerns, such as advances in an information technology, energy security, social equity, price volatility, and the need to subsidize poor consumers, are necessitate factors to be considered before the establishment of TCM and settlement processes. Taking into account the above concerns, this paper proposes a TCM model for the electrical utility industry in Thailand during the transition period to the deregulated environment.

Transmission congestion management during transition of electricity deregulation in Thailand

Transmission congestion management (TCM) plays a significant role in power system operation under todays deregulated environment. Its two major functions are maintaining power system within security limits and collecting money from market participants paying back to transmission grid investors. TCM issue has been widely debated during the past decade. It is still an extensively discussed opened issue in the current competitive environment. In the United States, PJM with nodal congestion management (NCM) base on renowned location marginal price (LMP) and the Electric Reliability Council of Texas (ERCOT) with zonal congestion management (ZCM), are two successful stories of TCM under different operation schemes. Though PJM model is adopted in some developing countries where the processes of restructuring is still at the beginning phase, many social economical issues, such as advance in an information technology, energy security, social equity, price volatility, and the need to subsidize poor consumers, are necessary to be addressed before the establishment of TCM and settlement processes. Taking into account the above mentioned concerns, this paper proposes a TCM model for the electrical utility industry in Thailand during the transition period to the deregulated environment.

Biomass power generation development in Thailand

The emerging global warming crisis results from carbon dioxide emission has drawn an attention about renewable energy all over the world. Thailand is a developing country located at the heart of Southeast Asia with almost 70 million of population as of 2008. The ESI structure under the government of Thailand has been managed by the Electricity Generating Authority of Thailand (EGAT), Metropolitan Electricity Authority (MEA), and Provincial Electricity Authority (PEA) for almost 50 years. According to the Power Development Plan (PDP 2007), during the year 2007–2021, the government of Thailand plan to have the most economic power generation resources yet reliable and least environmental impact. To achieve those goals, there are three strategic plans which are to import power from neighboring country, to promote the renewable power generation from the public power companies, and to have a variety on power generations resources. This paper discusses the biomass power generation development in Thailand. System overview processes and biomass fuel consumed for the electricity production process are also presented.

Closure to discussion of "Reactive compensation techniques to improve the ride-through capability of wind turbine during disturbance"

For original article by C. Chompoo-inwai et al. see ibid., vol.41, no.3, p.666-72, May/Jun. 2005 and for discussion by Shih-Min Hsu see ibid., vol.41, no.6, p.1483, Nov./Dec. 2005.

Development of an electronics ballast for a 250-watt high intensity discharge lamp

The main objective of this paper is to purpose the newly developed prototype of electronics ballast used for 250 watt high pressure sodium (HPS) lamp. In this paper, concept designs, circuit designs, and the implementation of the 250 watt prototype-ballast are presented. Test result shows that the newly developed model provides not only lower loss compares to the traditional core-coil ballast, but also give the higher system efficiency. Moreover, the overall system power factor is above 0.85 lagging with the expectation of percentage of total harmonics distortion less than 30 percent. All test procedures, and conditions are applied to employ with 250 high pressure metal halide (HPM) lamp as well.

Analysis of Winding Temperature and Design of Distribution Transformer for Improving Short Circuit Withstand Capability under Renewable Generations Mixed Environment

Under renewable generations mixed in today’s modern grid system, many of renewable generation resources tend to increase the fault level to an existing power system. Rules and regulation for power equipment and devices need to be revised and updated, of course, no exception for the distribution transformers. This article, therefore, presents the evaluation and analysis of the winding temperature on both loading and short circuit conditions of an oil-immersed distribution transformer and propose the novel transformer design method for improving short circuit withstand capability. In the study, the methodologies of measuring and estimating the winding temperature of the transformer during short circuited are presented and implemented. In the study, various winding parameters are analysed including: the winding temperature, the hottest temperature of the winding after a short circuit, the short circuit current, short circuit force and short circuit duration. The tested and analysed result are benefit for the newly proposed distribution transformer design of a 400 kVA 3 phases 50 Hz 22 kV-400/230 V, Dyn11. The new design approaches will enable designers to find a weak spot and proper selection of raw materials, such as winding size, insulation thickness and properties of the silicon steel for a better quality of distribution transformer. Moreover, the new design can offer lower winding temperature rise of transformer while loading or experiencing with short circuit conditions meaning that it can prolong transformer insulation and extend transformer lifetime.

Optimal Design of a Small Scale Wind Power Generation System for a Rural and Low Capacity Factor Area

In Thailand, according to the Power Development Plan (PDP 2007), during the year 2007-2021, the government of Thailand plan to have the most economic power generation resources yet reliable and least environmental impact. At the present time, in addition, the emerging energy crisis resulting from an uncertainty price of crude-oil and the emerging global warming crisis results from carbon dioxide emission have drawn an attention about renewable energy all over the world including Thailand (1-2). One of the most effective solutions for Thailand is to promote the renewable energy usage in the rural area especially from solar energy and wind generation system. However, with the fast growing in wind power technologies, many concerns and focuses pay to this type of renewable energy in the country. Unfortunately, Thailand is considered as a country of low to medium wind speed profile with approximately wind capacity factor close to 30 percent. Therefore, in order to obtain the most efficient and effective wind generation system for rural household usage, the optimal design for a household scale wind generation should be governmentally supported and implemented. This paper, therefore, addresses to this issue and study result shows that the optimal scale of household wind generation system is 5 kW. with a proposed cut-in speed at 2.5 m/s while the suggested rated power at wind speed of 8 m/s. This proposed wind generation system can offer an Optimal Annual Capacity Factor (OACF) close to 30 percent.