User-defined constant switching frequency current control strategy for a four-leg inverter

2009 ◽  
Vol 2 (4) ◽  
pp. 335-345 ◽  
Author(s):  
V. George ◽  
M.K. Mishra
2017 ◽  
Vol 37 (1) ◽  
pp. 103-113 ◽  
Author(s):  
Xin Qi ◽  
Lin Wu ◽  
Xiaomin Zhou ◽  
Xianghua Ma

Purpose This study aims to drive the induction machine system with a low switching frequency. Design/methodology/approach An unconventional inverter control strategy – field-oriented predictive control (FOPC) – is presented. The strategy limits current distortion by setting a boundary circle. The voltage vector, which could keep current trajectories in boundary, is selected to obtain a low switching frequency. Findings A dual simulation step technique is developed to investigate the influence of sampling frequency on current distortion control and switching frequency. Current control distortion can be improved, i.e. reduced, by increasing the sampling frequency; however, the switching frequency will also increase. Such a law is discovered by the dual simulation step technique and finally verified by experiments. Originality/value A new predictive control method, FOPC, is derived from the rotor filed coordinate machine model and presented in this paper. FOPC circumvents derivative calculations, and thus avoids high-frequency noise amplification.


Energies ◽  
2019 ◽  
Vol 12 (12) ◽  
pp. 2294 ◽  
Author(s):  
Osvaldo Gonzalez ◽  
Magno Ayala ◽  
Jesus Doval-Gandoy ◽  
Jorge Rodas ◽  
Raul Gregor ◽  
...  

In applications such as multiphase motor drives, classical predictive control strategies are characterized by a variable switching frequency which adds high harmonic content and ripple in the stator currents. This paper proposes a model predictive current control adding a modulation stage based on a switching pattern with the aim of generating a fixed switching frequency. Hence, the proposed controller takes into account the prediction of the two adjacent active vectors and null vector in the ( α - β ) frame defined by space vector modulation in order to reduce the (x-y) currents according to a defined cost function at each sampling period. Both simulation and experimental tests for a six-phase induction motor drive are provided and compared to the classical predictive control to validate the feasibility of the proposed control strategy.


2021 ◽  
Vol 261 ◽  
pp. 01035
Author(s):  
kang Liu ◽  
Guige Gao

Modular Multilevel Converter (MMC) has the characteristics of high voltage level and low switching frequency. The traditional modular multilevel converter circulating current control strategy mostly adopts the PI control principle, and the parameter setting is complicated and the accuracy is not high, and the control process is more difficult. Model predictive control strategy is the optimal control method based on the model in the existing time domain. This paper proposes a Model Predictive Control (MPC) method based on carrier phase-shifted pulse width modulation (PSC-PWM) to suppress the circulating current, and output the optimal modulation wave through model prediction. Compared with the traditional control strategy, this strategy is simple to implement, does not require complex tuning calculations, and combines with the traditional capacitor voltage equalization strategy to obtain the output modulation wave. A 7-level MMC simulation control system is built in MATLAB / SIMLINK to verify the theory, comparing with existing control methods, it can be concluded that the proposed method has high calculation efficiency, good control accuracy and strong robustness.


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