A two-stage MPPT controller for PV system based on the improved artificial bee colony and simultaneous heat transfer search algorithm.

The maximum power point tracking (MPPT) controller can monitor the voltage and current of photovoltaic (PV) array in real-time to acquire the maximum power output for battery charging in PV system. In order to improve the accuracy and rapidity of tracking process, a bionic two-stage MPPT control strategy composed of fast positioning stage and precise determination stage is proposed in this paper for optimizing the duty cycle d of DC-DC converter. Firstly, an improved artificial bee colony algorithm with simplified probability selection mechanism and novel employed bee phase is presented to balances exploration and exploitation for excellent rapidity in positioning rough search region around global peak.

Fast frequency recovery-oriented distributed optimal load frequency control: An active disturbance rejection control approach.

With high penetration of renewable energy sources in nested multiple-microgrids, conventional solutions for the integration of load frequency control and economic dispatch may degrade frequency control performance and decrease operational economy. In this paper, a fast frequency recovery-oriented distributed optimal control strategy is proposed to deal with these problems. Firstly, a partial primal-dual gradient algorithm is dynamically integrated with an active disturbance rejection control algorithm (instead of conventional Proportional-Integral (PI) controller) to realize the fast frequency recovery and enhance anti-disturbance capability.

Stability Analysis for Delayed Neural Networks via Improved Auxiliary Polynomial-Based Functions.

This brief is concerned with stability analysis for delayed neural networks (DNNs). By establishing polynomials and introducing slack variables reasonably, some improved delay-product type of auxiliary polynomial-based functions (APFs) is developed to exploit additional degrees of freedom and more information on extra states. Then, by constructing Lyapunov-Krasovskii functional using APFs and integrals of quadratic forms with high order scalar functions, a novel stability criterion is derived for DNNs, in which the benefits of the improved inequalities are fully integrated and the information on delay and its derivative is well reflected.

Novel fuzzy modeling and energy-saving predictive control of coordinated control system in 1000 MW ultra-supercritical unit.

In order to satisfy the growing demands of control performance and energy conservation in power generation process, a novel T-S fuzzy modeling method combined with the quantum artificial bee colony (QABC) algorithm is proposed and applied to the coordinated control system (CCS) of ultra-supercritical unit in 1000MW power plant. The T-S fuzzy modeling consists of the identifications of premise part and consequence part. In the premise part identification, the cluster number and initial cluster centers are obtained at first by using entropy-based clustering method.

Performance optimization of linear active disturbance rejection control approach by modified bat inspired algorithm for single area load frequency control concerning high wind power penetration.

The linear active disturbance approach is employed to deal with the load frequency control issue of a single area wind power system based on doubly fed induction generator, and the performance of the control law is optimized by using the bat-inspired algorithm. The load frequency control issue has become more challenging in a complex power system based on wind energy conversion system due to the varying feature of the wind penetration, and sustaining the balance between the power generation and demand by rejecting the internal uncertainties in the process model and the external disturbances simultaneously. In the framework of the presented linear active disturbance rejection control approach, by constructing an extended state observer, the total disturbance, including all the unmodelled dynamics in the process model and the external disturbances, can be estimated in real time and then compensated by a simple linear PD control law.

Improved Stability Analysis for Delayed Neural Networks.

In this brief, by constructing an augmented Lyapunov-Krasovskii functional in a triple integral form, the stability analysis of delayed neural networks is investigated. In order to exploit more accurate bounds for the derivatives of triple integrals, new double integral inequalities are developed, which include some recently introduced estimation techniques as special cases. The information on the activation function is taken into full consideration.

Coordinated control system modelling of ultra-supercritical unit based on a new T-S fuzzy structure.

The thermal power plant, especially the ultra-supercritical unit is featured with severe nonlinearity, strong multivariable coupling. In order to deal with these difficulties, it is of great importance to build an accurate and simple model of the coordinated control system (CCS) in the ultra-supercritical unit. In this paper, an improved T-S fuzzy model identification approach is proposed.

The four-tank control problem: Comparison of two disturbance rejection control solutions.

The paper aims to compare and prove a pair of disturbance/uncertainty rejection control laws for the well-known four-tank control problem. The control requirements are expressed in terms of a set point sequence as usual in the literature. The uncertainty class is defined as the union of four sub-classes: unknown disturbance, parametric uncertainty, measurement errors and neglected dynamics.

Further results on stabilization for interval time-delay systems via new integral inequality approach.

This paper investigates the stability and stabilization problems for interval time-delay systems. By introducing a new delay partitioning approach, various Lyapunov-Krasovskii functionals with triple-integral terms are established to make full use of system information. In order to reduce the conservatism, improved integral inequalities are developed for estimation of double integrals, which show remarkable outperformance over the Jensen and Wirtinger ones.

New H control approaches for interval time-delay systems with disturbances and their applications.

In this paper, the H performance and control problems for linear systems with interval state or input delays and disturbances are investigated. In order to exploit more information on the delay range, the quadruple -integral terms and quadratic forms of triple integrals are introduced into the Lyapunov-Krasovskii functional (LKF). Particularly, an improved integral inequality is developed for estimation of the cross terms in triple-integral type, which displays significant improvement over the Wirtinger inequality.

Novel delay-partitioning stabilization approach for networked control system via Wirtinger-based inequalities.

This paper studies the problems of stability analysis and state feedback stabilization for networked control system. By developing a novel delay-partitioning approach, the information on both the range of network-induced delay and the maximum number of consecutive data packet dropouts can be taken into full consideration. Various augmented Lyapunov-Krasovskii functionals (LKFs) with triple-integral terms are constructed for the two delay subintervals.