Power Management Control Strategy Research Articles

Improved Adaptive Network-Based Fuzzy Inference System Approach for Power Flow Analysis in Interconnected DC Microgrid

High-performance power conversion needs are becoming more and more important for microgrid applications. In actuality, many contemporary DC distribution systems use isolated bidirectional dc-dc converters. Hence, in this paper, an Improved Adaptive Network-based Fuzzy Inference System (IANFIS)is developed to control the output power of the components and reduce the variation among the consumption and generation of the power while managing a constant DC bus voltage. This work proposes a power management control strategy that ensures the power balance of a stand-alone DC microgrid where DAB converters link the battery energy storage (BES) unit and the renewable energy source (RES). The generation side, or photovoltaic (PV) system and BES, is coupled to the storage systems and renewable energy sources. Furthermore, a DC microgrid is connected to the load demand. The load demand is compensated with the help of the storage and generation systems with the help of a dual active bridge converter. The DAB is connected with the dual DC microgrid system for managing power flow among the two DC microgrids. This dual active bridge converter is utilized to balance the power among Dual DC microgrids. The proposed methodology is developed to manage the power among generation and load demand management. The proposed method is evaluated on a dual active bridge converter connected microgrid system with the components of PV and BESS respectively.

A Decentralized Power Management and Sliding Mode Control Strategy for Hybrid AC/DC Microgrids including Renewable Energy Resources

This paper presents a new decentralized robust strategy to improve small and large-signal stability and power-sharing of hybrid AC/DC microgrids and improve its performance for nonlinear and unbalanced loads. In addition to the sliding mode controller for DC/DC converters, for the sake of improving power sharing and regulating active and reactive powers injected by distributed energy resources, and moreover, controlling harmonic and negative-sequence current in the presence of nonlinear and unbalanced loads, two separate controllers for positive sequence power control and negative sequence current control are designed based on the sliding mode control and Lyapunov function theory, respectively. The theoretical concept of the proposed robust control strategy, including mathematical modeling of microgrid components, basic theorems, controller design procedure, and robustness and closed loop stability analysis are outlined. Also, this direct power/current/voltage control scheme is governed by a new hybrid AC/DC hierarchical control scheme that exploits a harmonic virtual impedance loop and voltage compensation scheme. To show the effectiveness of the proposed robust control scheme, offline time-domain simulations are done on a hybrid AC/DC wind/photovoltaic/fuel-cell microgrid with nonlinear and unbalanced loads in MATLAB/Simulink environment, and the results are experimentally verified by OPAL-RT real-time digital simulator.

Implementation of hybrid optimized battery controller and advanced power management control strategy in a renewable energy integrated DC microgrid.

In Renewable Energy (RE) integrated DC Microgrid (MG), the intermittency of power variation from RE sources can lead to power and voltage imbalances in the DC network and have an impact on the MG's operation in terms of reliability, power quality, and stability. In such case, a battery energy storage (BES) technology is widely used for mitigating power variation from the RE sources to get better voltage regulation and power balance in DC network. In this study, a BES based coordinated power management control strategy (PMCS) is proposed for the MG system to get effective utilization of RE sources while maintaining the MG's reliability and stability. For safe and effective utilization of BES, a battery management system (BMS) with inclusion of advanced BES control strategy is implemented. The BES control system with optimized FOPI controllers using hybrid (atom search optimization and particle swarm optimization (ASO-PSO)) optimization technique is proposed to get improved overall performance in terms of control response and voltage regulation in DC network under the random change in load profile and uncertain conditions of RE sources in real time.

A robust control strategy for power management of a DC microgrid based on EVs in presence of energy storage battery

A robust control strategy for power management of a DC microgrid based on EVs in presence of energy storage battery

A study of power management approach in a grid connected hybrid renewable generation system

<p>Where sun irradiation is not continuous throughout the day, photovoltaic (PV) cells are used to supply solar power to the grid. A suitable power management plan is required to provide a steady power supply to the grid. The hybrid renewable generation system (HRGS) interconnected to the grid is the subject of this study, which provides a revolutionary power management method and control strategy. PV devices, a battery storage unit (BSU) charged by electricity generated from solar energy, and an auxiliary unit make up the HRGS concept (AU). Maximum power point tracking (MPPT) uses an improved perturb and observe (P&O) method to track maximal energy from solar irradiation. The peculiarity of this approach is that it uses a modified MPPT algorithm to handle power management throughout the process, allowing it to manage continuous power delivery to the grid based on load demand. It is capable of working under any load situation. The action of an L-C filter is utilized to decrease the total harmonic distortion (THD). The HRGS scheme's performance appraisals work correctly, achieve maximum productivity, and continually managing the power provided to the grid in a satisfactory way.</p>

A Comprehensive Review of Electric Vehicle Charging Stations with Solar Photovoltaic System Considering Market, Technical Requirements, Network Implications, and Future Challenges

Electric cars (EVs) are getting more and more popular across the globe. While comparing traditional utility grid-based EV charging, photovoltaic (PV) powered EV charging may significantly lessen carbon footprints. However, there are not enough charging stations, which limits the global adoption of EVs. More public places are adding EV charging stations as EV use increases. However, using the current utility grid, which is powered by the fossil fuel basing generating system, to charge EVs has an impact on the distribution system and could not be ecologically beneficial. The current electric vehicle (EV) market, technical requirements including recent studies on various topologies of electric vehicle/photovoltaic systems, charging infrastructure as well as control strategies for Power management of electric vehicle/photovoltaic system., and grid implications including electric vehicle and Plug-in hybrid electric vehicles charging systems, are all examined in depth in this paper. The report gives overview of present EV situation as well as a thorough analysis of significant global EV charging and grid connectivity standards. Finally, the challenges and suggestions for future expansion of the infrastructure of EV charging, grid integration, are evaluated and summarized. It has been determined that PV-grid charging has the ability to create a profit. However, due to the limited capacity of the PV as well as the batteries, the Power system may not be cost effective. Furthermore, since PV is intermittent, it is probable that it will not be able to generate enough electricity to meet consumer demand.

A novel digital control scheme for power management in a hybrid energy-source environment pertaining to electric vehicle applications

In electric vehicle, the utilization of various input power sources demand an appropriate integration. This integration inevitably questions the effectiveness of a suitable power management system. The integration of sources causes complexity in power conversion and programming errors while switching between the sources and brings difficulties in real-time implementation. This study presents a novel digital control scheme specific to the integration of solar, battery, and fuel cell to solve these issues and also explains the power management system in different controllers for electric vehicles. The proposed scheme checks the reference currents based on the power generated by the different sources needed to meet the instantaneous demand from the permanent magnet synchronous machine, which is widely used in electric vehicles. The methodology constitutes maximum power point tracking in solar panels at every second of the day, retaining constant voltage in the DC bus and managing the power flow from sources to the permanent magnet synchronous machine based on the power availability from different sources. The power flow to a control module dedicated to permanent magnet synchronous machine control is considered. The major contribution of the paper is the design and development of a power management system for an electric vehicle with a novel digital control scheme. Power management is achieved with the aid of a digital controller using real-time solar data for a periodically fluctuating load demand in MATLAB/Simulink and also in an experimental investigation, the results of which are discussed.

An Adaptive Multi Functional Control Strategy for Power Management and Voltage Frequency Regulation of PV, BESS, and Hybrid Units in a Microgrid

An Adaptive Multi Functional Control Strategy for Power Management and Voltage Frequency Regulation of PV, BESS, and Hybrid Units in a Microgrid

A Centralized Shifted Power Control Scheme for Isolated Bidirectional DC-DC Converter in Standalone DC Distribution System

When parallel converter structures are considered in modern DC distribution systems, several challenges are faced in the energy management system (EMS). For example, the circuit parameter mismatches of parallel isolated DC-DC converter modules will cause power imbalances, which is the most important concern in DC distribution system. To deal with this issue, this study presents a power management control scheme in the EMS to ensure the power balance of isolated DC-DC converters in DC distribution system. In the proposed method, the proposed shifted voltage is introduced at the output of each converter to compensate the output impedance mismatches. Especially, the shifted voltage is flexibly determined according to the output current sharing error to obtain a balanced output impedance among converters, and the balanced power sharing is achieved by means of the modified voltage reference. The simulation results with the stand-alone DC distribution system are carried out to verify the effectiveness of the proposed control scheme.

Optimized Power Management Control Scheme for Transportation System Electrified with High Voltage DC Microgrid

Optimized Power Management Control Scheme for Transportation System Electrified with High Voltage DC Microgrid

A power management control and optimization of a wind turbine with battery storage system

Battery storage systems are an important alternative to compensate for wind turbine irregularities. This paper contributes to the feasibility of a wind energy installation with battery storage. In order to manage these different power sources, a power management control (PMC) strategy is developed and connected to the proposed two-level MPPT controller. PMC provides an efficient optimal operation of two MPPT algorithms (torque and speed) and ensures minimal stress on the used storage batteries. A complete system with better performances is obtained by combining the advantages of both MPPT and PMC proposed methods. The obtained results highlight the positive impact of MPPT hybridization on the reduction of usage of battery storage system. The different wind turbine parameters were identified in our research laboratory. All these parameters have been used in simulation models in order to obtain more realistic mathematical models and the closest to the empirical data. The study was performed under Matlab/Simulink. The obtained results with the different comparisons are presented to show the best algorithm to be used in a wind energy system (WES) in terms of power, efficiency, response time, and effect on the battery state of charge.

Control of pico‐hydro‐PV‐based distributed generation with battery support for off‐grid electrification

This work presents the operation and control of a pico-hydro-solar photovoltaic (PV)-battery energy storage (BES)-based isolated renewable energy system (RES) feeding 3-phase 4-wire loads. For voltage regulation, to maintain frequency, and power quality improvement in this system, a 4-leg VSC is used. The BES is connected to the DC-link of the voltage source converter (VSC) through a bidirectional converter (BDC), which regulates the DC-link voltage and controls the charging and discharging current of the battery. An advanced perturb and observe (AP&O)-based MPPT control technique with drift free operation and capability to operate in the derated mode is adapted in this work. The VSC connected to PCC, injects or absorbs power from this system based on the difference of power between generation and the load. The modified complex co-efficient filter (MCCF)-based control technique monitors the power quality of this RES system and 4 leg VSC provides the source neutral current compensation. This control algorithm is used to extract the amplitude of the fundamental load current component with improved dynamic response, DC offset elimination and higher order harmonics removal capability. The ability of the presented control strategy for power quality improvement, power management, load balancing and neutral current compensation is reported in this work.

Dynamic Modelling and Control Analysis of a Fuel Cell Connected to Electric Vehicle

A fuel cell electric vehicle (FCEV) is an electric vehicle that uses a fuel cell to power an electric motor. FCEV aims to provide customers with the benefits of battery electric vehicles such as low-to-zero emissions, high efficiency and low maintenance, without compromising on range and recharge times. A novel power management control strategy is proposed to improve the fuel cell system simulation model that is easy to use and has acceptable accuracy at the same time. The simulation model is developed through MATLAB / Simulink software using the energy macroscopic representation method, the accuracy of this method is compared with an established model. Fuel cell integration simulation analysis is performed using experimental data from a real battery car.

Energy management and emission control for range extended electric vehicles

Range extended electric vehicles (REEVs), transition vehicles between combustion engine vehicles and electric vehicles, have been widely used due to their advantages of low fuel consumption and low emissions. By optimizing power management and after-treatment system control strategies, it is possible to achieve lower fuel consumption and emissions. This study proposes an integrated control method based on optimization strategies for the auxiliary power unit (APU) on/off system and energy management optimization for extended hybrid electric vehicles. The Elitist Nondominated Sorting Genetic Algorithm (NSGA-II) optimization method is used to determine the control parameters. In addition, considering the frequent start and stop characteristics of the APU caused by the optimization strategy, closed-loop control of the urea injection is established to solve the ammonia leakage problem. Due to their high computational efficiency, the proposed energy management and urea injection algorithms can be easily implemented in real time. The actual operating emissions of engines under the different strategies are tested on a semi-physical simulation platform, focusing on the analysis and comparison of NOx emissions. The conclusion has certain reference significance for vehicle production.

Shipboard Power Management for Failure Mode Using the Hybrid MPC Approach

Shipboard integrated power systems, the key technology of ship electrification, call for effective failure mode power management control strategy to achieve the safe and reliable operation in dynamic reconfiguration. Considering switch reconfiguration with system dynamics and power balance restoration after reconfiguration, in this paper, the optimization objective function of optimal management for ship failure mode is established as a hybrid model predictive control problem from the perspective of hybrid system. To meet the needs for fast computation, a hierarchical hybrid model predictive control algorithm is proposed, which divides the original optimization problem into two stages, and reduces the computation complexity by relaxing constraints and the minimum principle. By applying to a real-time simulator in two scenarios, the results verify the effectivity of the proposed method.

Bidirectional Power Sharing for DC Microgrid Enabled by Dual Active Bridge DC-DC Converter

Currently, high-performance power conversion requirements are of increasing interest in microgrid applications. In fact, isolated bidirectional dc-dc converters are widely used in modern dc distribution systems. The dual active bridge (DAB) dc-dc converter is identified as one of the most promising converter topology for the mentioned applications, due to its benefits of high power density, electrical isolation, bidirectional power flow, zero-voltage switching, and symmetrical structure. This study presents a power management control scheme in order to ensure the power balance of a dc microgrid in stand-alone operation, where the renewable energy source (RES) and the battery energy storage (BES) unit are interfaced by DAB converters. The power management algorithm, as introduced in this work, selects the proper operation of the RES system and BES system, based on load/generation power and state-of-charge of the battery conditions. Moreover, a nonlinear robust control strategy is proposed when the DAB converters are in voltage-mode-control in order to enhance the dynamic performance and robustness of the common dc-bus voltage, in addition to overcoming the instability problems that are caused by constant power loads and the dynamic interactions of power electronic converters. The simulation platform is developed in MATLAB/Simulink, where a photovoltaic system and battery system are selected as the typical RES and BES, respectively. Assessments on the performance of the proposed control scheme are conducted. Comparisons with the other control method are also provided.

Power Management, Voltage Control and Grid Synchronization of Microgrids in Real Time

This paper presents an efficient power management, voltage balancing and grid synchronization control strategy to increase the stability and reliability of distributed energy resources (DERs)-based microgrid. The microgrid is composed of Photovoltaic, Double Fed Induction Generator-based wind and diesel generator with critical and non-critical loads. The system model and the control strategy have been developed in Real Time Digital Simulator. The coordination and power management of the DERs in both grid connected and island operation modes is implemented. One distinct challenge of microgrid operation in island mode is the stable control of frequency. A controller is proposed and implemented in the island mode for the diesel generator equipped with the required inertia to maintain the microgrid rated frequency by operating in the isochronous mode. To restore the microgrid back to the utility, the voltage, frequency and phase angle of the islanded microgrid should match with that of the grid network within specified limits to avoid transient instability. Switched capacitor banks are connected at the point of common coupling to balance the voltage for microgrid synchronization. The CIGRE medium voltage test bench system is used to implement the DERs and their controller. The proposed control approach has potential applications for the complete operation of microgrids by properly controlling the power, voltage and frequency in both grid and island modes. The real time digital simulator results verify the effectiveness and superiority of the proposed control scheme in grid connected, island and grid resynchronization scenarios.

A Modulized Three-Port Interlinking Converter for Hybrid AC/DC/DS Microgrids Featured With a Decentralized Power Management Strategy

A compact interlinking converter modular (ICM) for hybrid ac/dc microgrids with a distributed storage (DS) bus for storage integration is proposed in this article. The advanced ICM for hybrid ac/dc/ds microgrids involves the nine-switch topology with compact configuration and decreased number of active operating switches, which structurally equivalents to afford a dc interconnection port for dc subgrid, an ac interconnection port for ac subgrid, a ds interconnection port for ds subgrid, and two dc–dc converters for the interconnection ports for parallel DSs. In addition to the popular advantage of component elements saving, the suggested ICM, aggregating various interlinking converter cells (ICCs) into an ICM, is also proficient of participating computations from all ICC sensors to enhance the overall modular performance without building extra communication connection links between ICCs. With this in mind, a decentralized power management control strategy is realized by employing a coordination power control methodology to systematically handle various distributed generations (DGs), DSs, and ICM in a decentralized manner with improved communication fault ride-through capability. The controller hardware-in-the-loop experiments on a real-time digital simulator platform validates the achievement of the advanced ICM application in hybrid ac/dc/ds microgrids and the effectiveness of the associated decentralized power management scheme.

Multiple parallel‐connected DAB‐based solid‐state transformer for hybrid DC/AC microgrid system

To cater unceasing supply to the modern AC and DC loads, renewable energy resources integrated hybrid DC/AC microgrid (HMG) are considered as a viable technological solution. In this study, a multiple parallel-connected bidirectional converter (MPBC) topology has been proposed to enhance the solid-state transformer (SST) power handling capability with flexible control of the HMG. To improve the high-frequency AC-link power quality and to control the power transfer through the SST in each dual active bridge a split-step phase shift (SSPS) control technique has been used. A power management control strategy has also been proposed for efficient power transfer between the sources and loads of the HMG. The proposed MPBC-based SST is suitable for interconnecting multiple utility feeders. Multiple redundant utility feeders ensure stiff bus voltages and omit the power supply reliability issues. The operation of the proposed MPBC-SST converter system with corresponding control algorithm is verified through the simulation results in both grid feeding and grid fetching operating modes. Furthermore, experimental results are presented to validate the performance of the proposed MPBC-SST converter along with its proposed controller strategy.

An integrated rule-based power management and dynamic feed-forward low voltage ride through scheme for a grid-connected hybrid energy system

Power generation from a grid-integrated renewable energy generator embedded with backup sources to form a hybrid energy system possesses convincing features of high efficiency and zero emissions. Control for felicitating apt power sharing and for providing ancillary services such as low voltage ride through (LVRT) is necessary for the compliance of grid codes. However, the simultaneous control coordination for meeting these control objectives is challenging due to the dynamic nature of renewable generators and utility grid. Hence, this paper proposes an integrated power management strategy (PMS) and LVRT control scheme for such systems. A wind energy conversion system backed up by a battery energy storage system, proton exchange fuel cell, and electrolyzer is considered in this work. A reduced rule-based power management control scheme is proposed for the considered system where the request made by the grid operator is kept in priority. Further, a dynamic current feed-forward based LVRT control scheme based on negative sequence current minimization is presented for the grid-interfaced inverter. The inverter control is coupled with an inherent mode selection capability between the grid feeding mode and LVRT mode in order to realize the proposed integrated control objectives. The validation of the proposed PMS and LVRT control is justified by detailing relevant mathematical control models and also by realizing practical case scenarios such as variable wind speed, load demand, grid power request, and occurrences of balanced and unbalanced voltage sag. The obtained simulation results show the cordial response of the system with the proposed control strategies.