A cascaded hybrid inverter with improved dc-link voltage control for grid connected systems
- Authors: Wanjekeche, T. , Jimoh, A. A. , Nicolae, Dan-Valentin
- Date: 2012
- Subjects: Voltage-frequency converters , Converters , Electronic circuits
- Language: English
- Type: Conference proceedings
- Identifier: http://hdl.handle.net/10210/17312 , uj:15870 , ISBN: 9781467301589 , Ciatation: Wanjekeche, T.,Jimoh, A.A. & Nicolae, D.V. 2012. A cascaded hybrid inventer with improved dc-link voltage control for grid connected systems IEEE – ISIE 2012, 28–31 May, Hangzhou, China:1950-1956. DOI:10:1109/ISIE.2012.6237391
- Description: Abstract: This paper presents investigation of a new Phase shifted PWM technique with improved harmonic suppression. A novel balance circuit for DC – link voltage balance of two three level legs connected back – to back is designed and tested. Combined with the individual voltage control, a complete voltage controller is developed for a cascaded nine level hybrid model with two cells. Robustness of the proposed algorithm under varying operating conditions and modulation indices is verified by simulation.
- Full Text:
Design and implementation of an integrated coupling circuit for power line communication
- Authors: Wright, James Adriaan
- Date: 2019
- Subjects: Electronic circuits , Digital integrated circuits , Digital communications
- Language: English
- Type: Masters (Thesis)
- Identifier: http://hdl.handle.net/10210/481948 , uj:43686
- Description: Abstract: It is predicted that in 2025 there would be 75 billion devices connected to the Internet of Things. With this immense growth, radio frequency communication will not have the required bandwidth to keep abreast. Power Line Communication allows a communication signal to be transmitted on any electrical infrastructure. The communication signal is connected to the electrical infrastructure using a coupling circuit. This coupling circuit galvanically isolates the communication signal from the power line voltage. By implementing Power Line Communication, the strain on radio frequency communication can be relieved. The purpose of this research is to design and implement an improved coupling circuit. The improved coupling circuit is required to be easily manufactured, be reliable and more cost effective than traditional coupling circuits. Power Line Communication will be used to complement radio frequency communication, thus a considerable number of coupling circuits will be manufactured. A quantitative experimental research method was used. A traditional coupling circuit was characterised with the aim to improve on it. A method to integrate the coupling circuit was proposed and implemented. The performance of the improved coupling circuit was compared to a study in 2008. The traditional coupling circuit operated between 90 kHz to 150 kHz, CENELEC D band. Whereas the improved coupling circuit operates at 1MHz to 100 MHz, G.9960/G.9961. The two Power Line Communication couplers cannot be directly compared to one another; however the frequency response can be juxtaposed. The integrated coupling circuit is compared to a commercial coupling circuit in size and cost. The equations used to design the traditional coupling circuit at a lower frequency holds for coupling circuits designed to operate at a higher frequency. For a coupling circuit to be valid the operating frequency should conform to standard, block the power line voltage and allow the communication signal to pass through the coupling circuit with minimum attenuation. The implementation of an improved coupling circuit was found to be successful. The improved coupling circuit is easily manufactured, reliable and cost effective. Further studies are needed to decrease the size of the improved coupling circuit. , M.Ing.
- Full Text: