Online harmonic error compensation of Atan2 function for a low-cost automotive sensor application

A new compensation method of harmonic distortions by using Atan2 function is introduced in this paper. It provides a simple online calibration function to determine the parameters of harmonic distortions. Thus, it can be implemented in a microcontroller with less computational capacity and can increase the accuracy of a low-cost angle position sensor for automotive applications.

POWER QUALITY IMPROVEMENT USING CUCKOO SEARCH BASED MULTI-LEVEL FACTS CONTROLLER

Nowadays, the improvement of power quality is the major concern in power system scenario. These problems mainly caused due to utilization of different load conditions to the power system. To mitigate these problems different methods are implemented in literature. As per literature analysis the one of the Flexible AC Transmission System called as unified power quality conditioner (UPQC) plays a key role. The series and shunt controllers of UPQC designed with 9-level inverters to reduce the harmonic distortions. An instantaneous PQ theory is used to generate the reference signals required for series and shunt controllers along with dq-transformation analysis. A Cuckoo optimization technique is used to tune the parameters of PI controller in shunt controller to achieve better harmonic distortions and improve power quality. This proposed system is to be tested and verified in MATLAB/SIMULINK.

Finding the Best Programmable PWM Pattern for Three-Level Active Front-Ends at 18-Pulse Connection

The existing publications on the analysis of power quality indicators in modern electric power supply systems are void of a comprehensive approach to improving these indicators in power systems by implementing multipulse connections. To the authors’ knowledge, this paper is the first to analyze current harmonic distortions in an 18-pulse connection of three-level active front-ends (AFE) featuring a programmed PWM. Raw data were obtained from, and current quality was analyzed for the power circuit of the main electric drive actuating the rolls in the rolling stand of a plate mill. The key feature of such circuitry is that the synchronous motor of each work roll is connected to the grid with an 18-pulse connection that uses three phase-shift transformers, where the phase shifts are 0° (delta/delta), 20° (delta/polygon) and −20° (delta/polygon). The circuitry connects three frequency converters (FC) with the AFEs in parallel. Phase-shift transformers were found to periodically overheat in the process. When overheating occurred, a programmed PWM voltage waveform was applied where harmonics 17 and 19 were eliminated. The goal and objectives were to analyze why the transformer would overheat and to find out how the issue could be addressed. The authors developed a simulation model of the research object in order to assess power quality parameters. Simulation results obtained in Matlab/Simulink were used to estimate the total harmonic distortions (THD) and individual harmonic factors for up to the 50th secondary transformer winding and grid harmonic with four different programmed AFE PWM voltage waveforms. The results helped find the best such waveform to prevent phase-shift transformers from overheating; one with harmonics 5, 7, 17 and 19 eliminated. The experimental and mathematical modeling results in the paper were confirmed by positive effects after industrial implementation of the system. Research performed directly on the operating equipment has been classified by the company and is not publicly available. These results are highly versatile and could be used in similar research on other circuitries to ensure the electromagnetic compatibility of nonlinear power-consuming devices.

Implementation of a Hybrid ANN-Based Filter for the Reduction of Harmonic Currents

Harmonic distortions caused by non-linear loads (NLLs) affect the behavior of electrical systems, creating harmonics in the fundamental signal. As a result, this deteriorates the power quality. Therefore, this work proposes the implementation of a hybrid filter based on an artificial neural network (ANN) control system, focused on subharmonic, interharmonic and odd harmonic distortions generated by a three-pulse cycloconverter. In addition, a passive double tuned filter was implemented to damp even and odd harmonics. As a result, the simulation performed in MATLAB/SIMULINK showed that the responses produced by the ANN are approximate to the distortions present in the electrical system. Consequently, the levels of total voltage distortions (THDV) and total current distortions (THDI) are reduced. Therefore, the ANN control system improves the quality in the electrical network because the current and voltage harmonics comply with the electrical standards.

Analysis of Harmonic Distortion Reduction through Modular Multi-Level Inverter using Nearest Level Modulation (NLM) Control Strategy

The research paper presents the control strategy to reduce THD (Total Harmonic Distortions) losses by the implementation of the Nearest Level Modulation control technique in a Modular Multilevel Converter. Modular Multilevel Converter is found one of the leading technologies in Power Electronics & Control, its applications are very common in HVDC systems, FACTS (Flexible Alternating-current Transmission system), Variable frequency drives and Electric vehicles as well. The power quality of MMC is better and has lesser THD in comparison to conventional converters like 2-level converters with carrier-based modulation techniques. The MMC has been designed with high scalability and has high voltage and power capacity. Sub-module is an integral part of MMC which is built up as an identical and controllable part of it. This converter is also called a controllable voltage source (VSC). Researchers aim to come up with a detailed review of control methods and necessary operations applied to MMC-based systems for HVDC, particularly focusing to control the total harmonic distortions. Power converters use many modulation techniques, but the existing techniques contribute to a great part in switching losses. MMC up to 49 levels, by implementing the Nearest Level Modulation (NLM) technique, is robust and has less complexity for the systems like MMC-HVDC, and the levels control the total harmonic distortions. In this research paper, the reduction of THD by increasing the voltage levels in MMC is comprehensively evaluated. The simulation results in MATLAB/Simulink are used to examine and confirm the proposed control strategy for stable operation of MMC for HVDC application.