The reduction of the electromagnetic interference by using chaotic and random modulation methods in the electric drive systems

The Reduction of The Electromagnetic Interference by using Chaotic and Random Modulation Methods in the Electric Drive Systems Electromagnetic Interference (EMI) is a serious threat to human health as well as electrical appliances. On the electric driver system EMI that is transferred by transmission is originated on the Common Mode Voltage (CMV) and Differential Mode Voltages (DMV). This noise occurs on the current and voltage due to sudden changes that are caused by the short-term switching of switching equipment. Therefore CMV and DMV harmonics are occurred in switching frequency and its multiples. These harmonics have higher amplitude on the interval of 9-150 kHz and that means EMI value is higher. On the other hand the noises are caused by switching frequency and they are also known as disturbance. The frequencies that are below 20 kHz can be heard by human ears, especially the frequency which is below 12 kHz is very noisy for human ears. In that research, various methods such as voltage controlled PMSM driver systems as vector control and Direct Torque Control of Space Vector Modulation (SV-DTC) are proposed to reduce the EMI and acoustic noise. Although the methods mentioned above have been developed recently years, researchers are focused on chaotic system. Especially closed loop application in terms of applicable fixed switching frequency is an important parameter. In addition, security of equipment and clearness of switching equipment losses are also important. To reduce EMI and acoustic noises, novel methods are developed based on fixed switching. Especially two methods that are effective on CMV are proposed. The first method is a New Random Pulse Position Modulation (CS-NRPPM) that is developed by help of Chaotic Signal, the other one is a novel method known as Random Switching Modulation method (CS-RSM). Then, chaotic switching frequency mixed methods affected on both CMV and DMV are developed. Finally chaotic switching frequency, Chaotic Space Vector Modulated Direct Torque Control (CSV-DTC) method was performed. Key Words: Vector Control, Space Vector-Direct Torque Control, Electromagnetic Compatibility, Electromagnetic Interference, Chaos, Chaotic Switching frequency, Chaotic Switching, Random Modulation, Chaotic Modulation