Hybrid single and double‐voltage vector‐based model predictive common‐mode voltage reduction method for 2‐level voltage source inverters

Abstract

To reduce the common-mode voltage (CMV) as well as the current total harmonic distortions (THDs) of 2-level voltage source inverters (2L-VSIs), a hybrid single and double-voltage vector (VV)-based model predictive control (MPC) method is proposed. Firstly, a two non-zero VV-based MPC strategy is proposed to reduce the CMV as well as the current THDs. Secondly, the influences of the dead time on this method are analysed in detail, and an improved VV preselection method is further proposed to remove the dead time effects. Thirdly, considering the impacts of the control delay and the current ripples, a new current sector division method is presented, based on which a hybrid single and double-VV-based MPC strategy is finally proposed. Furthermore, the current variation per control period under the action of different VVs is also analysed indepth in this study to lay a solid theoretical foundation for dividing the current sector more properly. Both the simulation and experimental studies are carried out to verify the effectiveness of the proposed method.

A Dual-Vector Modulated Model Predictive Control Method for Voltage Source Inverters with a New Duty Cycle Calculation Method

“…To calculate the values of the twelve constructed hybrid voltage vectors, the duty cycles of the basic voltage vectors should be calculated first. Different from the methods in [22][23][24][25][26][27][28][29], which lack theoretical support, here a new duty cycle calculation method is proposed by assuming that it is inversely proportional to the square root of its cost function value, as shown in (11), where m is a positive coefficient. In Section 4, the effectiveness of this proposed hypothesis is verified in detail by a particular theoretical analysis.…”

“…An MPC strategy was designed to control the current of two-level voltage source inverters in [6] in 2007. From then on, many researchers began to study new MPC strategies to reduce the computational time [7,8], to lower the switching frequency [9,10], to suppress the common-mode voltage [11,12], to decrease the current ripples [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29], or to minimize the power ripples [30][31][32].…”

“…Additionally, as a flexible control method, MPC strategies are also studied in [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] to reduce the current ripples by using more voltage vectors instead of only one in every control cycle. In [13][14][15], dual-vector MPC strategies are studied.…”

“…Alternately, there is another way to determine the duty cycles, which is named modulated MPC [22][23][24][25][26][27][28][29]. In this type of method, the duty cycle of each voltage vector is deduced by assuming that it is inversely proportional to its cost function value.…”

“…In this type of method, the duty cycle of each voltage vector is deduced by assuming that it is inversely proportional to its cost function value. As it is simple but effective, many researchers have studied modulated MPC to control the cascaded H-bridge converter [22], the multilevel solid-state transformer [23], the direct and indirect matrix converter [24,25], the shunt active filter [26], the brushless doubly fed induction machine [27], the two-level three-phase inverter [28,29], and so on. However, although it is shown in [22][23][24][25][26][27][28][29] that the modulated MPC method can achieve current control, up to now, there still lacks a solid theoretical support for this kind of method, which hinders its popularization and application.…”