Model-free neural network-based predictive control for robust operation of power converters

An accurate definition of a system model significantly affects the performance of model-based control strategies, for example, model predictive control (MPC). In this paper, a model-free predictive control strategy is presented to mitigate all ramifications of the model’s uncertainties and parameter mismatch between the plant and controller for the control of power electronic converters in applications such as microgrids. A specific recurrent neural network structure called state-space neural network (ssNN) is proposed as a model-free current predictive control for a three-phase power converter. In this approach, NN weights are updated through particle swarm optimization (PSO) for faster convergence. After the training process, the proposed ssNN-PSO combined with the predictive controller using a performance criterion overcomes parameter variations in the physical system. A comparison has been carried out between the conventional MPC and the proposed model-free predictive control in different scenarios. The simulation results of the proposed control scheme exhibit more robustness compared to the conventional finite-control-set MPC

Frequency-constrained energy and reserve scheduling in wind incorporated low-inertia power systems considering vanadium flow redox batteries

This paper proposes a novel energy and reserve scheduling model for power systems with high penetration of wind turbines (WTs). The objective of the proposed model is to minimize the total operation cost of the system while static and dynamic security is guaranteed by preserving the frequency nadir, RoCoF, and quasi-steady-state frequency in the predefined range. Likewise, a supervisory, control, and data acquisition (SCADA) system is developed which allows Vanadium Redox Flow Batteries (VRFBs) to continuously communicate and participate in the primary frequency response. To cope with the uncertainties, adaptive information gap decision theory is used that ensures a target operating cost for the risk-averse operator of the power system. The proposed scheduling model is applied on a modified IEEE 39 bus test system to verify the impacts of the fast reserve provided by the VRFBs in the dynamic frequency security enhancement of the power system with high penetration of WTs

Effects of Calendar and Cycle Ageing on Battery Scheduling for Optimal Energy Management: A Case Study of HSB Living Lab

This paper deals with the optimal scheduling of abuilding microgrid coupled with solar photovoltaic and batteryenergy storage (BES) considering battery degradation. The aim isto minimize the operation cost of the microgrid which includes thecost of imported electricity from the grid, the degradation cost ofthe battery, the cost for the peak power drawn from the grid, andthe revenue from selling electricity to the grid. The nonlinearmodels of calendar and cycle ageing are linearized to solve theoptimal scheduling as a mixed-integer linear programming(MILP) problem. The developed model is examined for a realresidential building microgrid (HSB Living Lab) in Gothenburg,Sweden. The results show that if the degradation of the BES isignored, the operation cost of the microgrid will increase by 1,394SEK per year, and the ageing cost of the BES will also rise by42.27%

Curcumin increases insulin sensitivity in C2C12 muscle cells via AKT and AMPK signaling pathways

Background: Diabetes is an enduring condition that causes impaired, peripheral insulin resistance. Curcumin was shown to exert notable anti-diabetic effects, which might be possible by overexpression of certain glucose transporter genes and glycoprotein content within the cells. Objectives: To investigate the effect of curcumin alone and in concomitant with insulin on glucose translocation from intracellular compartments of nuclear or endoplasmic reticulum membranes into the cytoplasmic membrane (CM) and key kinases involved in insulin signaling pathways. Materials and Methods: C2C12 myoblast cells were cultured and differentiated to the myotubes. Later, the cells were treated with curcumin alone or a combination of curcumin and insulin, so their viability was measured by MTT assay. The expression level of GLUT 4 gene was examined by Real Time-reverse Transcription Polymerase Chain Reaction (qRT-PCR). To evaluate the activity of curcumin and curcumin/insulin synergistic effect on stimulated GLUT4 translocation, kinases AKT, P-AKT, AMP-activated protein kinase (AMPK) and P-AMPK were assessed and detected via Western Blotting (WB). Results: Curcumin significantly induced GLUT 4 expression and its translocation from intra-cell space into the cell surface and showed a synergic effect on GLUT 4 translocation in presence of insulin. This synergistic effect was inhibited by the insulin receptor inhibitor AG1024 and the inhibitor of AMPK signaling, compound C. Conclusion: Curcumin demonstrated a synergistic effect with insulin and could be a choice of type 2 diabetes mellitus (T2DM) treatment, which may be affected by both AKT and AMPK signaling pathways, hereby facilitates glucose uptake into the cells