Model Predictive Control Methods to Reduce Common-Mode Voltage for Three-Phase Voltage Source Inverters

Abstract

In this paper, we propose model predictive control methods to reduce the common-mode voltage of three-phase voltage source inverters (VSIs). In the reduced common-mode voltage-model predictive control (RCMV-MPC) methods proposed in this paper, only nonzero voltage vectors are utilized to reduce the common-mode voltage as well as to control the load currents. In addition, two nonzero voltage vectors are selected from the cost function at every sampling period, instead of using only one optimal vector during one sampling period. The two selected nonzero vectors are distributed in one sampling period in such a way as to minimize the error between the measured load current and the reference. Without utilizing the zero vectors, the common-mode voltage controlled by the proposed RCMV-MPC algorithms can be restricted within ±V dc /6. Furthermore, application of the two nonzero vectors with optimal time sharing between them can yield satisfactory load current ripple performance without using the zero vectors. Thus, the proposed RCMV-MPC methods can reduce the common-mode voltage as well as control the load currents with fast transient response and satisfactory load current ripple performance compared with the conventional model predictive control method. Simulation and experimental results are included to verify the effectiveness of the proposed RCMV-MPC methods.Index Terms -Predictive control, common-mode voltage, current control, voltage source inverter. 0885-8993 (c) reference, the current controller evaluates all the predicted current values obtained by the seven possible states to select one optimal switching state with the smallest cost value. Finally, the VSI with the model predictive controller applies the optimal switching state during the entire sampling period of the controller. Because of its simplicity with no requirement of individual PWM blocks as well as its control flexibility, the model predictive control scheme has been employed to control the load currents of power converters other than VSIs, such as multilevel inverters, multiphase inverters, active power filters, and matrix converters [14][15][16][17][18][19][20][21][22][23][24][25][26].This paper proposes two reduced common-mode voltage-model predictive control (RCMV-MPC) methods to reduce the common-mode voltage of three-phase VSIs on the basis of the model predictive control method. In the proposed RCMV-MPC methods, only six nonzero VSI states are considered to perform model predictive control to reduce the common-mode voltage by avoiding the zero vectors. Furthermore, the proposed methods utilize two nonzero voltage states in one sampling period in order to compensate for the reduced number of voltage states, instead of using only one optimal vector during one sampling period as in the conventional method. The two selected active vectors are distributed within the sampling period in such a way as to minimize the squared current errors between the reference and actual future load currents in the proposed methods. Therefore, the common-mode volta...

Dual carrier based PWM strategy for common-mode voltage reduction of three-phase voltage source inverters

“…However, pulse-width modulation (PWM) applied in VSI tends to cause the high frequency common-mode voltage (CMV), as one of the side effects of PWM techniques [3]. Furthermore, the CMV will produce electro-magnetic interference (EMI) and even shaft current to reduce the lifetime of motor bearing [4,5]. Therefore, when considering the reduction of CMV, the conventional PWM strategies need to be improved.…”

Common Mode Voltage Suppression Method Based on Model Predictive Control for a Permanent Magnet Synchronous Motor Considering Current Error Limit

“…Although this method can reduce the computational burden, but the differential part will produce a lot of noise. Reference [8] designed the voltage suppression algorithm using two non-zero voltage vectors during each sampling period to achieve CMV suppression and to reduce total harmonic distortion (THD) of the current. However, the algorithm needs to optimize the selection of two vectors, which leads to computational complexity and high switching frequency.…”

Near State Vector Selection-Based Model Predictive Control with Common Mode Voltage Mitigation for a Three-Phase Four-Leg Inverter

“…Thus, four-leg inverters have been introduced v dc 6 by utilizing six non-zero voltage vectors in the three-phase three-leg inverter [28]. The FCS-MPC method can reduce the CMV and control the load current for the three-phase three-leg inverter, as mentioned in [28][29][30]. Meanwhile, in [29], the load current ripple and CMV are reduced, but the process of selecting two non-zero voltage vectors in each sampling period and determining each vector duration is very complex.…”

“…The FCS-MPC method can reduce the CMV and control the load current for the three-phase three-leg inverter, as mentioned in [28][29][30]. Meanwhile, in [29], the load current ripple and CMV are reduced, but the process of selecting two non-zero voltage vectors in each sampling period and determining each vector duration is very complex. This greatly increases the computation complexity.…”