Reduce common-mode voltage in cascaded multilevel inverter based on artificial neural network

Abstract

Common-mode voltages are associated to shaft voltages and Abstract-Common-mode voltage due to different circulating leakage currents through parasitic capacitances modulation in power converters has introduced between the motor windings, the rotor, and the frame. The numerous problems in electrical systems. This paper amplitude and number of these current spikes is determined reviewed a Space Vector PWM (SVM), which can get rid by the and the number of commutations present in the of the common-mode voltage in multilevel inverters with common-mode voltage. These current spikes can cause fundamental switching frequency. But for difficulty of premature motor bearings failures and electromagnetic implement SVM algorithm, which requires complex and interference (EMI) [11]. Some solutions are based on time-consuming online computation, a feedforward additional hardware, like filters [10], [12], and other methods artificial neural network (ANN) with four-layer based on more advanced modulation strategies which avoid configuration is proposed, which receives angle command the generation of common-mode voltages are applicable in and modulation index as input and generate desirable the area of multilevel inverters [2], [13]. However, these PWM pattern for the three-phase cascaded multilevel methods work with high switching frequency. In addition, the inverter. The data derived from simulating of SVM-based modulation technique used is characterized by a low scheme is employed to train the proposed ANN with switching frequency, witch also helps to reduce the MATLAB/Neural Network Toolbox offline. The common-mode current spikes problem. The author in [14] performance of the trained ANN-based modulator is presents a control scheme, based on the space vector investigated in the 11-level cascaded inverters prototype, modulation (SVM) theory, which has been shown to operate and the results of the experiment appear to be wonderful with almost fundamental switching frequency, maintaining that common-mode voltage is reduced drastically and the good quality voltage and current waveforms in a cascaded power semiconductors operate with fundamental multilevel inverter. Nevertheless, the scheme effectively switching frequency.eliminates the common-mode voltages. In practice, a difficulty of SVM is that it requires complex and time-consuming online computation by DSP [15]. Online I.