Finite Control Set-Model Predictive Control of a Flying Capacitor Multilevel Chopper Using Petri Nets

Abstract

This paper presents a control scheme based on predictive control theory and Petri nets (PNs) formalism to control a flying capacitor multilevel converter. The proposed scheme takes advantage of the benefits offered by the Finite Control Set -Model Predictive Control (FCS-MPC) methodology and the versatility of PNs to regulate the capacitor voltages and output current, simultaneously. The inclusion of PNs allows to simplify the control scheme. A first PN is used to select, from a subset of switching states, the switching state that accomplishes both control objectives. This approach reduces the computational burden if compared with a typical predictive control scheme. Furthermore, a PN based prediction scheme is used to predict the capacitor voltages. This prediction scheme uses only measurements of output voltage and current, which reduces the number of required sensors. This approach allows to implement the internal capacitor voltages control independently if a multi-leg configuration is needed. The scheme is experimentally validated in a 5-level flying capacitor multilevel converter.

Hybrid Control Strategy of MPC and DBC to Achieve a Fixed Frequency and Superior Robustness

“…Because of the computational burden of the conventional FCS-MPC, the simplified FCS-MPC was proposed in [35], the predicted model of which could also be described as Equation (11). Hence, according to Equations (11) and (12), the improved FCS-MPC with error correction can be calculated as follows:…”

“…Compared to continuous control set MPC (CCS-MPC), the outstanding merit of FCS-MPC is that, on the one hand, it directly applies the control action to the converter without a modulation stage, which results in a fast dynamic response. On the other hand, FCS-MPC presents a simple formulation of MPC problems [9][10][11][12]. However, FCS-MPC has not yet been applied widely due to certain problems, such as the variable switching frequency leading to electromagnetic interference (EMI) problems, and model mismatch, which causes unstable systems.…”

Comprehensive study of finite control set model predictive control algorithms for power converter control in microgrids

“…where i o is the output current of the inverter, L and R are the inductance and resistance of the filter, respectively, and v grid is the main grid voltage [50]. As for FC converters, the topology is mainly similar to the NPC converter topology, except that, instead of clamping via diodes, the FC converters use clamping capacitors [51][52][53]. For high power applications, adding more voltage levels to the converter can be practical such as four-level NPC [54,55] and five-level NPC [56] converters.…”

Asymmetrical Multi-Step Direct Model Predictive Control of Nine-Switch Inverter for Dual-Output Mode Operation

“…The major drawback of model predictive control method in power electronics is high computational burden since corresponding objective function needs to be solved for each possible control actuation. In literature, several different approaches have been presented to handle this high computational demand [16]- [19]. Among these methods, an FPGA-based model predictive control approach is more promising solution due to its flexibility.…”