Electricity Generating Authority Of Thailand Research Articles

Optimal Power Flow for Enhance TTC with Optimal Number of SVC by using Improved Hybrid TSSA

In this paper, the hybrid tabu search and simulated annealing (TSSA) method are modified for improving. The main point of modification is to apply sine value into the value of the temperature of simulated annealing. This modification aims to reduce the disadvantage of the original hybrid TSSA. This disadvantage means the value of each parameter is only increased to the maximum value of the temperature of simulated annealing. The optimal number of flexible alternating current transmission system (FACTS) controller determining method is used to determine optimal number of FACTS. SVC is used as FACTS controller in this paper. The split search space method is integrated to manage search space of static var compensator (SVC) operating point. The allocations of SVCs are used to enhance total transfer capability (TTC). Test results on the IEEE 118-bus system and the practical Electricity Generating Authority of Thailand (EGAT) 58-bus system show that the proposed improved hybrid TSSA with optimal number determining method of SVC give higher TTC and less number of SVC than test results from evolutionary programming (EP) and original hybrid TSSA.

Neural network with genetic algorithm for forecasting short-term electricity load demand

Short-term load forecasting is to forecast the next day electricity demand for 48 periods and it is important to make decisions related to the electricity generation and distribution. Neural network (NN) is selected for forecasting the future electricity consumption since its ability of recognising and learning nonlinear patterns of data. This research proposes the combination usage of genetic algorithm (GA) to train the neural network and results are compared with the results from backpropagation. Data from the electricity generating authority of Thailand (EGAT) is used in this research to demonstrate the performance of the proposed technique. The dataset contains weekday (excluding Mondays) load demand from 1st of October to 30th of November 2013. November load is forecasted using an NN with 192 inputs and 48 outputs. Even though GA takes more time for training neural networks, it gives better results compared to backpropagation.

Neural network with genetic algorithm for forecasting short-term electricity load demand

Short-term load forecasting is to forecast the next day electricity demand for 48 periods and it is important to make decisions related to the electricity generation and distribution. Neural network (NN) is selected for forecasting the future electricity consumption since its ability of recognising and learning nonlinear patterns of data. This research proposes the combination usage of genetic algorithm (GA) to train the neural network and results are compared with the results from backpropagation. Data from the electricity generating authority of Thailand (EGAT) is used in this research to demonstrate the performance of the proposed technique. The dataset contains weekday (excluding Mondays) load demand from 1st of October to 30th of November 2013. November load is forecasted using an NN with 192 inputs and 48 outputs. Even though GA takes more time for training neural networks, it gives better results compared to backpropagation.

Classification of Lightning and Faults in Transmission Line Systems Using Discrete Wavelet Transform

In Thailand, electrical energy consumption has been rapidly increasing, following economic and population growth. In order to supply constant power to consumers, reliability is an important factor the electric utility needs to consider. Common disturbances that cause severe damage to transmission and distribution systems are lightning and faults. The system operator must deal with these two phenomena with speed and accuracy. Thus, this study aims to investigate the differential behaviour of transmission systems when disturbance such as lightning strikes and faults occurs in a 115-kV transmission line. The methodology consists of using the ATP/EMTP program to model the transmission system by the 115-kV Electricity Generating Authority of Thailand (EGAT) and simulate both lightning and fault signals in the system. The discrete wavelet transforms are then applied to obtain the signals in order to evaluate the characteristics and behaviour of both signals in terms of high-frequency components. The obtained data will then be used to construct the fault and lightning classification algorithm based on DWT and travelling wave theory. The proposed algorithm shows the effectiveness in classifying the fault and lightning based on the transmission system that was modelled after the actual system in Thailand. Thus, it can further improve the protection scheme and devices in terms of accuracy and reduce the response time for an operator to address the disturbance and ensure the reliability of the system in the future.

Short-term Electricity Load Forecasting in Thailand: an Analysis on Different Input Variables

This paper suggests a support vector regression model to make short-term load forecasting in Thailand by different training inputs. The primary objective of this paper is to describe the importance of data pre-processing and the external factors for accurate forecasting. The Electricity Generating Authority of Thailand (EGAT) provides the half-hourly electricity load demand. For numerical analysis, a dataset of net peak load of Thailand for a period of weeks from January 2016 to December 2017 is selected. The historical load demand is filtered for each day by Local regression filtering technique. After filtering the data, the effectiveness of input variables is important for accurate performance. Mean absolute percentage error (MAPE) is used to evaluate the model performance. By comparing the three models, model which considerate the temperature and seasonal factors enhances the model performance.

Assessment of ocean wave energy resource potential in Thailand

Currently, Thailand's energy consumption is increasing rapidly due to its economic expansion. The main source of energy production is still petroleum, accounting for 54% of all energy produced. Considering only electricity, the Electricity Generating Authority of Thailand (EGAT) is able to generate 44% of the demand, which is increasing every year. Ocean waves are an interesting source of alternative energy because ocean wave energy can produce electricity without the limitation of time. The technology that generates power from ocean wave energy can be placed on the surface of the ocean and can be designed to be environmentally friendly to the marine environment. Additionally, ocean wave energy can be predicted and is widely available. Before using ocean wave energy, an assessment of ocean wave energy resources is necessary. Since ocean wave energy converters are currently expensive and have low efficiency due to technical problems, an assessment of ocean wave energy resources is needed for decision making before the development of a project. In Thailand, ocean wave energy can be produced on both coasts because Thailand has the Gulf of Thailand (GOT) to the east and the Andaman Sea situated to the west. The numerical model used in this study is the Simulated WAves Nearshore (SWAN) model. This model, which is suitable for shallow waters, can be used to determine the characteristics of ocean waves, including ocean wave height. The significant wave height is evaluated to assess the natural potential of ocean wave energy in both the GOT and the Andaman Sea using data spanning a 10-year period from 2005 to 2015. Looking at the results for an overall average wave power for all seasons in the Gulf of Thailand, station P5 is the best station to provide wave power. The nearest mainland shore from this station is the nature recreation area in the Kui Buri district, Prachuap Khiri Khan Province. Stations P4 and P11 also provide high wave power. The nearest mainland shore from stations P4 and P11 are the Queen Sirikit Park in Samut Songkhram Province and the Muang-Ngam sub-district in Songkhla Province, respectively. As for the results regarding the Andaman Sea, the highest average significant wave height and wave power are found at station P12. The nearest mainland shore from this station is the nature recreation area in the Mueang Ranong District, Ranong Province.

Feasibility study of VLH hydro turbine installation at Nam Pung hydropower plant, Thailand

The aim of this research was to study the feasibility of installing a very low head (VLH) hydro turbine downstream of the Nam Pung hydropower plant thereby increasing the potential of renewable energy resources of the Electricity Generating Authority of Thailand (EGAT). The water head level was limited to less than 2 meters and the flow rate to below 5 m 3 / s due to site constraints. The selected hydro turbine was an axial flow turbine with an efficiency of 86.4%. The power output was 84.61 kW. Investment analysis was subsequently applied to estimate feasibility of the project. Analyses of results showed that the project is worthwhile in terms of investment. The payback period of actual price was 0.83 and 0.88 years and for the general price, it was 3.68 and 4.04 years, with annual interest rates of 6.75% and 12.625% respectively. The projected project lifespan is 25 years.

Hydrogenics for first renewable hydrogen-based energy storage, power plant in SE Asia

Canadian-based Hydrogenics, along with Phraram 2 Civil Engineering Co Ltd (PCE) in Bangkok, has been awarded the Lam Ta Khong Wind Hydrogen Hybrid Project by the Electricity Generation Authority of Thailand (EGAT). This will be the first MW-scale energy storage project in southeast Asia.

Analysis of Transient Signals in a Substation Capacitor Bank System Using an Experimental Setup

The capacitor bank system is one of the important systems in an electric utility, with the benefit of power factor correction and reactive power compensation for transmission and distribution systems. Installation of a capacitor bank system in a substation causes transient signals when switching occurs. The aim of this research is to study the transient signals that occur when the capacitor bank is switched in each step. A capacitor bank-switching experimental test unit has been built to create a downscale capacitor bank system in a distribution–level substation. This unit was modelled after the NongChok substation under the Electricity Generating Authority of Thailand (EGAT). The impact on the distribution system when the capacitor bank is switched has been studied, and phenomena such as inrush currents, voltage transience, and frequency oscillation are taken into consideration. A method to reduce transient issues has been discussed and implemented in the test unit to evaluate the performance impact of these methods on a switching capacitor bank system.

Development of a Novel Software to Identify the Real-Time Energy (kWh) Flows among Multiple Loads and Sources Including Renewables in a Smart Grid

An innovative software has been developed to measure and identify energy flow for multiple loads and sources like Grid and or other renewables. Algorithms have been developed to indicate status of energy used within a building unit and the Smart Gird as a whole. The software is developed on the AngularJS bases in the model-view-controller (MVC) platform using PHP language and MySQL is used as database for recording the data. The results of this research can support Electricity Generating Authority of Thailand (EGAT) for future grid planning and can be helpful for adaptive forcasting in connection with the consumption and generation. In the future, this software could be applied to improve the functions of energy management system (EMS) in the homes, buildings, and offices.

The association between mean platelet volume and cardiovascular risk factors

BackgroundMean platelet volume (MPV) correlates with platelet activation and has recently emerged as a potential marker of cardiovascular diseases. Previous publications also suggest possible association between MPV and some cardiovascular risk factors but the evidences are still conflicting and inconclusive. ObjectiveTo study the association between MPV and cardiovascular risk factors. MethodsThis is a cross-sectional study using data from the second survey of the Electricity Generating Authority of Thailand (EGAT) cohort. All participants of the survey who had results of MPV were included. Exclusion criteria included subjects with known hematologic disease or subjects with hematocrit <30% or platelet count <140,000/mm3. The details of cardiovascular risk factors were documented and the association between MPV and risk factors was analyzed using fractional polynomial regression analysis. ResultsThere were 2727 subjects with MPV results. After excluding those who had hematologic disease, 2642 subjects were included for analysis. Univariate analysis revealed that gender, diabetes, serum triglyceride, hypertension, and prehypertension were associated with MPV. Hematocrit, platelet count and fasting plasma glucose were inversely correlated with MPV. After adjusting with other variables, the risk factors that remained significantly associated with MPV included female gender, diabetes, metabolic syndrome, serum triglyceride, hypertension, and prehypertension. Platelet count and hematocrit were found to have significant inverse correlation with MPV. ConclusionAfter adjusting for other cardiovascular risk factors, the independent factors remain associated with MPV included female gender, diabetes, metabolic syndrome, serum triglyceride, hypertension and prehypertension. MPV has significant, but inverse association with platelet count and hematocrit.

The Effect of Controlling Stray and Disc Capacitance of Ceramic String Insulator in the Case of Clean and Contaminated Conditions

Due to their flexibility against the tension force and the easiness of maintenance characteristics of overhead transmission line, one of the biggest problems when using ceramic string insulator is the non-uniform voltage distribution on each insulator disc that connected on the string. This paper analyzes the effect of controlling stray capacitance (Kcsc), disc capacitance (Kcdc) and contaminated pollution (Kccp). In this paper research study considerations, the Electricity Generating Authority of Thailand (EGAT) 115kV overhead transmission line power towers are simulated in EMTP/ATP drawing and the results were analyzed. As it was found that in the clean condition, when the constant (Kcsc) was conducted and adjustment when Kcsc value has low value (decreases), the string efficiency would be high value (increases) for instances Kcsc=0.01 string efficiency=99%, Kcsc=0.50 string efficiency=64%. When the constant (Kcdc) was adjusted; if Kcdc is low, the string efficiency will also be low for instances at Kcdc=0.01 string efficiency=33%, Kcdc=0.50 string efficiency=40%. Nevertheless, Kcdc adjustment utilizes the appropriate value gained from factory that the k=0, so the value will be 90% higher. As for the contaminated condition, when the constant (Kcsc) was adjusted as shown in Fig.11, if Kcsc value is low, the string efficiency will be high for instances Kcsc=0.01 string efficiency=99%, Kcsc=0.05 string efficiency=65%. When the constant (Kcdc) was adjusted; if Kcdc is low, the string efficiency will also be low for instances at Kcdc=0.01 string efficiency=17%, Kcdc=0.50 string efficiency=40%. Considering on Kccp, for example Kccp=0.01 string efficiency=82% Kccp=0.50 string efficiency=55%.

Energy Storage System Sizing for Peak Shaving in Thailand

This paper presents a mathematical model of energy storage systems (ESSs) to minimise daily electrical peak power demand in Thailand. A daily electrical load curve on a peak day obtained from Electricity Generating Authority of Thailand (EGAT) is used to analyse the capability of energy storage system for electrical peak power demand reduction with different ESS sizes. It is found that with power rate of 50 percent of the difference between the minimum and the maximum demands of the daily load curve and with energy capacity of 50 percent of the sum of each time step absolute energy difference between the demand and the average demand of the daily load curve, ESS can decrease daily electrical peak demand approximately 7.4 percent and increase daily load factor approximately 9.9 percent.

Unit weight, strength and microstructure of a water treatment sludge–fly ash lightweight cellular geopolymer

A water treatment sludge–fly ash lightweight cellular geopolymer (WTS–FA LCG) is investigated in this research with the intention to develop an alternative green construction and building material, without using Portland cement as a cementing agent. Two waste by-products: WTS from the Bang Khen water treatment plants of the Metropolitan Water Work Authority of Thailand (MWA) and FA from the Mae Moh power plants of the Electricity Generating Authority of Thailand (EGAT) were used as an aggregate and a precursor, respectively. The liquid alkaline activator (L) used was a mixture of sodium silicate solution (Na2SiO3) and sodium hydroxide solution (NaOH). The unit weight and strength of WTS–FA LCG heated at 65°C for various influential factors are investigated and presented in this paper. The various influential factors studied include mixing ingredient (air content (Ac), liquid alkaline activator content (L) and Na2SiO3/NaOH), heat duration and curing time. Scanning electron microscopy (SEM) analysis was undertaken to investigate the role of influential factors on unit weight and strength. The test results indicate that the L content at liquid limit state (LL) is optimal for manufacturing WTS–FA LCG for all Na2SiO3/NaOH ratios, heat durations and air contents tested for which the highest strength is attained. Although the unit weight of WTS–FA LCG significantly reduces when L>LL, it is not economical to manufacture WTS–FA LCG at L>LL due to the drastic strength reduction. The addition of Ac at L=LL is found to be an appropriate means to reduce the unit weight and minimize the strength reduction. The maximum strengths at L=LL for various air contents are found at Na2SiO3/NaOH of 80:20 and heat duration of 72h. The longer heat durations of 96 and 120h cause the loss of moisture, thereby resulting in micro-cracks and strength reduction. The WTS was found to be viable alternative aggregate to develop WTS–FA LCG, thereby resulting in this waste material traditionally destined for landfills to be used sustainably as a valuable resource.

Compressive strength development in fly ash geopolymer masonry units manufactured from water treatment sludge

A novel water treatment sludge–fly ash geopolymer is investigated in this research with the intention to develop an alternative green construction and building materials, without the usage of Portland cement as a cementing agent. Two waste by-products namely water treatment sludge from the Bang Khen water treatment plants of the Metropolitan Waterworks Authority of Thailand (MWA) and fly ash (FA) from the Mae Moh power plants of the Electricity Generating Authority of Thailand (EGAT) were used in this research. The liquid alkaline activator, L used was a mixture of sodium silicate solution (Na2SiO3) and sodium hydroxide solution (NaOH). This article investigates the effect of the various influential factors on compressive strength of sludge–fly ash geopolymer. The various influential factors studied are mixing ingredient (L content and Na2SiO3/NaOH ratio), heat condition (temperature and duration) and curing time. Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analyses were undertaken to understand the role of influential factors on strength development. Test results show that the optimum ingredient providing maximum unit weight and strength is Na2SiO3/NaOH ratio of 80:20 and L/FA ratio of 1.3, irrespective of heat condition and curing time. The optimum heat temperature and duration for the optimum ingredient are 75°C and 72h, respectively. The higher heat temperature of 85°C causes the loss of moisture, which results in micro-cracks and strength reduction. The water treatment sludge traditionally destined for landfill can be used in a sustainable manner to develop geopolymer masonry units, with their compressive strengths comfortably meeting the Thailand Industrial Standards.

Vitamin D Binding Protein Gene Polymorphism as a Risk Factor for Vitamin D Deficiency in Thais

Vitamin D deficiency is related to increased risks for a number of diseases. To date, at least 3 candidate genes, vitamin D binding protein (VDBP) gene (GC), 25-hydroxylase (CYP2R1), and 7-dehydrocholesterol reductase/NAD synthetase 1 (DHCR7/NADSYN1), have been associated with serum 25-hydroxyvitamin D (25[OH]D) levels, but their influences on the prevalence of vitamin D deficiency in relation to other known risk factors have not been clearly defined. The study assessed 4,476 individuals aged 14 to 93 years from the Thailand 4th National Health Examination Survey (2008-2009) and the Electricity Generating Authority of Thailand (EGAT) (2008) cohorts. The GC rs2282679 polymorphism on chromosome 4q12-q13 was genotyped by real-time polymerase chain reaction (PCR). Serum 25(OH)D was measured by liquid chromatography/tandem mass spectrometry. Vitamin D deficiency was defined as a 25(OH)D concentration <20 ng/mL. Data were expressed as mean ± SD. There were 2,747 (61.4%) males and 1,729 (38.6%) females in the study, with an average body mass index (BMI) of 23.7 ± 4.2 kg/m2 and a mean total 25(OH)D of 28.9 ± 9.0 ng/mL. Serum 25(OH)D levels decreased progressively with the presence of the C allele. Using multiple logistic regression analysis, vitamin D deficiency was significantly associated with the GC rs2282679 genotype (odds ratio [OR] per C allele 1.80, 95% confidence interval CI 1.57-2.01), independent of established risk factors for vitamin D deficiency including age, sex, and BMI. A specific GC gene polymorphism is associated with lower 25(OH)D levels independent of age, sex, and adiposity in Thai subjects.

Smart Grid National Pilot Project in Mae Hong Son Province, Thailand

The system reliability is a main factor that affects on the growth of business in Mae Hong Son Province, which is located in the Northern region of Thailand. Mae Hong Son Province is far as deep valley hemmed in by the high mountain ranges of the Shan Hills. Since it is the mountainous province in the Northern part, the electricity is hardly supplied through the transmission line. There is no transmission line of the Electricity Generating Authority of Thailand (EGAT) linked from the main grid to Mae Hong Son Province due to the limitation of line routes passing prohibited areas, such as watershed area class 1 A and national park. The power is currently delivered through the distribution line of Provincial Electricity Authority (PEA) by receiving the electric power from EGAT at the Mae Tang Substation of EGAT through 115 kV and 22 kV distribution lines. Moreover, the demand consumption is fulfilled by very small power plants (VSPP) in Mae Hong Son Province. In case that the power demand of Mae Hong Son Province during the hot season is increased very much, the dispatching on diesel generators is required with high fuel cost. Sometimes, it also effects on the system reliability and power quality in Mae Hong Son Province EGAT is undertaking the study to develop the national pilot project with the collaboration of related organizations to improve the system reliability for Mae Hong Son Province. From the energy supply aspect, Mae Hong Son Province has several basic factors to enable the renewable energy generation, that is, high potential renewable energy including solar, hydro, biomass, and biogases. However, most renewable energy resources are intermittent, the smart grid technologies such as: energy storage and demand response shall be applied to handle the uncertainty of the power supply. The generation capacity in Mae Hong Son Province shall meet with the power demand in the province with sustainable and green power supply. From the operation point of view, the system reliability can be improved with the automatic control and operation, for example, self monitoring and self healing. The network can be automatically adapted and isolated when faults occur in the electrical system. With this concept, the power grid shall be smarter. This paper proposes the study of smart grid implementation in Mae Hong Son Province with three strategies, i.e. smarter grid, sustainable grid, and green grid, to improve the system reliability, promote the sustainability and green province policies in Mae Hong Son Province for micro grid system. In EGAT Smart Grid Roadmap Plan, EGAT plans to implement the Mae Hong Son Pilot Project as the national pilot project. This pilot project will be studied and demonstrate with smart grid, micro grid in order to find gab analysis especially renewable energy in Mae Hong Son Province. There is a need to appraise potential renewable energy to achieve goal. The policy on Smart Grid is being the main policy of all countries especially Thailand for supporting the green electricity concept. Many utilities/authorities in Thailand have established the working groups in order to determine the optimal framework to develop Smart Grid. In this paper, the feasibility study of Smart Grid Pilot Project in Mae Hong Son Province is investigated. Since Smart Grid concepts shall be applied to Mae Hong Son Province to propose to be the National Pilot Project of Thailand, the potential of renewable energy, demand response, and energy management system are reviewed. In additions, the gap analysis between the existing condition and the future goal to be determined as the key success factors of the National Pilot Project. From this study, it can be concluded that the Mae Hong Son Pilot Project can improve reliability indices, i.e. SAIFI, SAIDI as well as the concept of green province and sustainability development can be achieved.

Reliability evaluation of power systems with high short-circuit current reduction

Similar to other cities worldwide, the increasing amounts of short-circuit current in Bangkok (Thailand) and the vicinity areas are becoming higher than the interrupting capacity (IC) of circuit breakers. To cope with the problem, the Electricity Generating Authority of Thailand (EGAT) has come up with the solutions of network reconfiguration, e.g. bus splitting and transmission line disconnecting. These solutions help reduce effectively the amounts of short-circuit currents by increasing the equivalent system impedance. However, bus splitting and transmission line disconnecting tend to decrease the system reliability. One of the alternative approaches, the installation of high-voltage direct current (HVDC) can help reduce the amounts of short-circuit currents, while the system reliability is maintained. Therefore, this paper mainly presents the reliability evaluation method of the systems with HVDC installation, which requires AC/DC power flow calculation. To avoid system constraint violation, generation redispatch, load shedding, and DC power flow control are executed. The Monte Carlo simulation is used to repeatedly evaluate the system reliability until convergence. The proposed method is tested in (i) the IEEE Reliability Test System 79 (RTS79) to confirm the correctness of reliability evaluation and (ii) the system of EGAT Bangkok including its vicinity areas to show the readiness for real implementation. Comparison of reliability indices among all solutions of short-circuit current reduction is presented and discussed. The results show that the proposed method is effective and the HVDC installation can increase the system reliability, depending on its installation location and capacity. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

Causal relationship between the AHSG gene and BMD through fetuin-A and BMI: multiple mediation analysis

Using mediation analysis, a causal relationship between the AHSG gene and bone mineral density (BMD) through fetuin-A and body mass index (BMI) mediators was suggested. Fetuin-A, a multifunctional protein of hepatic origin, is associated with bone mineral density. It is unclear if this association is causal. This study aimed at clarification of this issue. A cross-sectional study was conducted among 1,741 healthy workers from the Electricity Generating Authority of Thailand (EGAT) cohort. The alpha-2-Heremans-Schmid glycoprotein (AHSG) rs2248690 gene was genotyped. Three mediation models were constructed using seemingly unrelated regression analysis. First, the ln[fetuin-A] group was regressed on the AHSG gene. Second, the BMI group was regressed on the AHSG gene and the ln[fetuin-A] group. Finally, the BMD model was constructed by fitting BMD on two mediators (ln[fetuin-A] and BMI) and the independent AHSG variable. All three analyses were adjusted for confounders. The prevalence of the minor T allele for the AHSG locus was 15.2%. The AHSG locus was highly related to serum fetuin-A levels (P < 0.001). Multiple mediation analyses showed that AHSG was significantly associated with BMD through the ln[fetuin-A] and BMI pathway, with beta coefficients of 0.0060 (95% CI 0.0038, 0.0083) and 0.0030 (95% CI 0.0020, 0.0045) at the total hip and lumbar spine, respectively. About 27.3 and 26.0% of total genetic effects on hip and spine BMD, respectively, were explained by the mediation effects of fetuin-A and BMI. Our study suggested evidence of a causal relationship between the AHSG gene and BMD through fetuin-A and BMI mediators.

Causal relationship between body mass index and fetuin‐A level in the asian population: a bidirectional mendelian randomization study

Fetuin-A is associated with body mass index (BMI) as well as components of the metabolic syndrome. However, it is unclear if fetuin-A affects BMI or the other way around. We therefore assessed the causal association between fetuin-A and BMI or vice versa, utilizing a bidirectional Mendelian randomization approach. This was a study of 2558 subjects from the Electricity Generating Authority of Thailand (EGAT) cohort. Two polymorphisms, that is, rs2248690 in the alpha2-Hereman-Schmid glycoprotein (AHSG) gene and rs9939609 in the fat mass and obesity-associated (FTO) gene were genotyped. Bidirectional causal models were constructed using a two-stage least-square instrumental variable (IV) regression. First, rs2248690 locus was used as the instrumental variable for the effect of circulating fetuin-A on BMI, and then, the FTO rs9939609 locus was used as the instrumental variable for the effect of BMI on circulating fetuin-A. Among the 2558 subjects, the prevalence of the minor AHSG (T) and FTO (A) alleles was 17.9% and 22.1%, respectively. The AHSG rs2248690 locus was highly related to serum fetuin-A levels (P < 0.001). Likewise, the FTO rs9939609 locus and BMI were highly associated (P < 0.001). Mendelian randomization analyses showed that circulating fetuin-A, instrumented by the AHSG rs2248690 locus, was associated with BMI (coefficient = 2.26; 95% CI: 0.39, 4.12). In contrast, BMI, instrumented by the FTO rs9939609 locus, was not associated with circulating fetuin-A (coefficient = 0.0007; 95% CI: -0.0242, 0.0256). Our findings suggest a causal association leading from circulating fetuin-A to BMI. There was no evidence of reverse causality from BMI to fetuin-A.