จำนวน Repository ( 4 )

การศึกษาผลของกระแสฮาร์มอนิกส์ต่อค่าสูญเสียของหม้อแปลงไฟฟ้าเลื่อนเฟสและการทำให้เป็นจริงด้วยหม้อแปลงไฟฟ้าเลื่อนเฟส 15 องศา
การศึกษาผลของกระแสฮาร์มอนิกส์ต่อค่าสูญเสียของหม้อแปลงไฟฟ้าเลื่อนเฟสและการทำให้เป็นจริงด้วยหม้อแปลงไฟฟ้าเลื่อนเฟส 15 องศา

The trend of energy savings has been widely interested and phase shift transformers (HMT) have been extensively used. This paper presents the investigation of the effect of harmonic currents on losses of the HMT. In this paper a 15-degree HMT with quad secondary winding is applied to find the relationship between harmonic currents and losses of the HMT. This relation can be met by testing the active power of primary and secondary sides while the HMT supplies for two and four non-linear loads at 25% 50% 75% and 100% rated currents respectively. The results reveal that harmonic currents affect winding eddy current losses significantly and the losses for loading the two secondaries 1 and 2 are the same as loading the two secondaries 1 and 3 while both %THDi are different. However for loading the secondaries 1 and 2 the %THDi is more than 15% so it is not met IEEE 519 Std. while the HMT is supplied with four loads the %THDi has met IEEE 519 Std. and the losses are less than 57% compared to one load. As a result of these if the HMT is applied to an adjustable speed drive system it is not only reduced the harmonics but also saved the energies.

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การตรวจจับกระแสฮาร์มอนิกสําหรับตัวกรองฮาร์มอนิกแบบแอคทีพชนิดปรับ ค่าได้เอง โดยใช้ขั้นตอนวิธีแบบ RLS
การตรวจจับกระแสฮาร์มอนิกสําหรับตัวกรองฮาร์มอนิกแบบแอคทีพชนิดปรับ ค่าได้เอง โดยใช้ขั้นตอนวิธีแบบ RLS

This thesis proposes a method for detecting harmonics current in the adaptive active harmonic filter with Recursive Least Square (RLS) algorithm. The proposed method is based on the theory of noise cancellation adaptive filter. Originally the theory was used for audio signal processing but this thesis is applied to the harmonic current detector of an active harmonic filter. The principle and construction of the harmonic current detector in the adaptive active harmonic current filter with Least Mean Square (LMS) algorithm and Recursive Least Square (RLS) algorithm are presented to compare the efficiency of both algorithms. Then simulate these two algorithms with Matlab-Simulink program to simulate the three case studies. All three case studies that simulate are generally available in industrial plants. The simulation results show that the harmonic current detector in the adaptive active harmonic current filter with the LMS algorithm and the RLS algorithm can detect the harmonic currents in the power systems. However the RLS algorithm is more efficient and has less error value than the LMS algorithm. Therefore it is confirmed that the RLS algorithm proposed in this thesis is appropriate to use with the adaptive active harmonic current filter to really work in the industry.

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การวิเคราะห์ผลกระทบของฮาร์มอนิกเพื่อแก้ปัญหาเศรษฐศาสตร์ในระบบไฟฟ้ากำลัง
การวิเคราะห์ผลกระทบของฮาร์มอนิกเพื่อแก้ปัญหาเศรษฐศาสตร์ในระบบไฟฟ้ากำลัง

This research proposes technical performance evaluation and economic decence for the combination of harmonic correction devices in Industry. Currently an electronic device is popularly applied in power network. Although it is a higher performance device than the existing device it still causes the power quality issues and then network failure. Especially harmonic disturbance in the network it is a harmonic source that generates harmonic current into the network. Many types and solutions are available in the present time therefore the suitable and optimal financial solution must be considered. A network model for the analysis of harmonic correction devices suitable solutions and optimal financial has been established in the simulation software that bases on the power and Break Even Point (BEP) equations. The results of analysis shown that the performance of harmonic correction devices suitable solution and BEP of investment in match to the using of a detuned filter bank and an active harmonic filter (case 8) thus these information will be valued for the end-user.

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การประเมินประสิทธิภาพเชิงเทคนิค และความเหมาะสมทางด้านเศรษฐศาสตร์ สำหรับการผสมผสานอุปกรณ์ปรับปรุงสัญญาณฮาร์มอนิกในโรงงานอุตสาหกรรม
การประเมินประสิทธิภาพเชิงเทคนิค และความเหมาะสมทางด้านเศรษฐศาสตร์ สำหรับการผสมผสานอุปกรณ์ปรับปรุงสัญญาณฮาร์มอนิกในโรงงานอุตสาหกรรม

This thesis proposes technical performance evaluation and economic decence for the combination of harmonic correction devices in Industry. Currently an electronic device is popularly applied in power network. Although it is a higher performance device than the existing device it still causes the power quality issues and then network failure. Especially harmonic disturbance in the network it is a harmonic source that generates harmonic current into the network. Many types and solutions are available in the present time therefore the suitable and optimal financial solution must be considered. A network model for the analysis of harmonic correction devices suitable solutions and optimal financial has been established in the simulation software that bases on the power and Break Even Point (BEP) equations. The results of analysis shown that the performance of harmonic correction devices suitable solution and BEP of investment in match to the using of a detuned filter bank and an active harmonic filter (case 8) thus these information will be valued for the end-user.

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