Abstract
This article proposed and investigated a near-optimal finite-control-set model-predictive grid current control (NOP-MPGCC) for voltage source inverters (VSIs) with actively damped LCL filters. It carries three advantages: (i) the constant-frequency pulsewidth modulator produces regular switching spectrum - which can ease the LCL filter design process in grid current control applications with medium-to-high carrier ratio; (ii) it avoids the use of the usual first-order assumption in most PI-/PR-based control and the common simplifications adopted in some existing FCS-MPC schemes. This is achieved by considering the third-order behavior using long prediction horizon; and (iii) it can operate near and across the critical frequency, defined using the established classical control definition. Moreover, it retains the intuitive enumeration structure and maximizes the dc-bus utilization through the consideration of entire hexagonal vector space at every control cycle. The theoretical derivation, simulation, and experiment results verify that NOP-MPGCC is potentially a viable direct grid current control scheme for PWM-VSIs with actively damped LCL filters.
Original language | English |
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Article number | 9146179 |
Pages (from-to) | 2246-2257 |
Number of pages | 12 |
Journal | IEEE Transactions on Power Electronics |
Volume | 36 |
Issue number | 2 |
DOIs | |
Publication status | Published - Feb 2021 |
Externally published | Yes |
Keywords
- Cost function
- grid current
- model predictive control (MPC)
- near-optimal MPC
- optimal control