Finite Control Set Model Predictive Control of AC/DC Matrix Converter for Grid-Connected Battery Energy Storage Application

Abstract

This paper presents a finite control set model predictive control (FCS-MPC) strategy for the AC/DC matrix converter used in grid-connected battery energy storage system (BESS). First, to control the grid current properly, the DC current is also included in the cost function because of input and output direct coupling. The DC current reference is generated based on the dynamic relationship of the two currents, so the grid current gains improved transient state performance. Furthermore, the steady state error is reduced by adding a closed-loop. Second, a Luenberger observer is adopted to detect the AC input voltage instead of sensors, so the cost is reduced and the reliability can be enhanced. Third, a switching state pre-selection method that only needs to evaluate half of the active switching states is presented, with the advantages of shorter calculation time, no high dv/dt at the DC terminal, and less switching loss. The robustness under grid voltage distortion and parameter sensibility are discussed as well. Simulation and experimental results confirm the good performance of the proposed scheme for battery charging and discharging control.

Imposed Source Current Predictive Control for Battery Charger Applications with Active Damping

“…If an HPF with a sharper frequency response (with a stopband of 80 Hz and passband of 100 Hz) is used, a better active damping effect can be achieved to eliminate the third and fifth order components. The transfer function of the HPF in continuous time is given in (8) and discrete version of the filter is provided in (9). The filtered damping current term is then included in the modified cost function as given by ( 10) in order to inject damping current term into sinusoidal references.…”

“…In this strategy the control algorithm imposes the converter to draw a source current having a sinusoidal waveform and being in phase with its respective source voltage [7], [8]. In [9], an MPC approach whose cost function employs dc link current and the supply currents in αβ coordinates has been proposed. Since the cost function includes two objectives, the use of weighting factor is unavoidable.…”

“…A Phase Locked Loop (PLL) is employed to predict the supply voltages for next two sampling intervals. In [9], [10] active damping is not included in the proposed control techniques. In [11], a predictive control scheme for a CSR, that does not include output filter capacitor Co, has been proposed and the cost function involves two terms; the first one is for minimizing reactive power drawn from the grid in order to obtain unity power factor and second term is responsible for the reference load current.…”

A Model Predictive Current Control Method for Achieving a High Efficiency and High Robustness Boost PFC Converter Operation

“…Unlike conventional control methods, it adopts a variable switching frequency rather than a fixed switching frequency and does not require the design procedure for a current controller. It also has the advantage of fast dynamic response and does not require a separate pulse-width modulation (PWM) [28]- [32]. The MPCC method controls the current of the boost PFC converter by defining a cost function based on the system model [33].…”