scholarly journals Improved Dynamic Voltage Regulation in a Droop Controlled DC Nanogrid Employing Independently Controlled Battery and Supercapacitor Units

2018 ◽  
Vol 8 (9) ◽  
pp. 1525
Author(s):  
Ahmad M. A. Malkawi ◽  
Luiz A. C. Lopes
Keyword(s):  
Energy Storage ◽  
Storage System ◽  
Voltage Regulation ◽  
Potential Contribution ◽  
Pass Filter ◽  
Power Sources ◽  
Dynamic Voltage ◽  
Dc Bus ◽  
Bus Voltage ◽  
The Impact

DC bus voltage signaling (DBS) and droop control are frequently employed in DC nano and microgrids with distributed energy resources (DERs) operating in a decentralized way. This approach is effective in enforcing the desired contributions of power sources and energy storage systems (ESSs) in steady-state conditions. The use of supercapacitors (SCs) along with batteries in a hybrid energy storage system (HESS) can mitigate the impact of high and fast current variations on the losses and lifetime of the battery units. However, by controlling the HESS as a single unit, one forfeits the potential contribution of the SC and its high power capabilities to dynamically improve voltage regulation in a DC nanogrid. This paper discusses an approach where the SC interface is controlled independently from the battery interface, with a small droop factor and a high pass filter (HPF), to produce high and short current pulses and smooth DC bus voltage variations due to sudden power imbalances in the DC nanogrid. Experimental results are presented to show that, unlike in a conventional HESS, the SC unit can be used to improve the dynamic voltage regulation of the DC nanogrid and, indirectly, mitigate the high and fast current variations in the battery.

Performance of STATCOM-ES in Mitigating SSR

2017 ◽  
Vol 8 (4) ◽  
pp. 1822 ◽  
Author(s):  
Mala R.C ◽  
Nagesh Prabhu ◽  
Gururaja Rao H.V
Keyword(s):  
Energy Storage ◽  
Voltage Regulation ◽  
Storage Device ◽  
Energy Storage Device ◽  
Static Synchronous Compensator ◽  
Facts Controllers ◽  
Torque Analysis ◽  
Bus Voltage ◽  
Storage Technologies ◽  
The Impact

One of the advanced power applications using energy storage is the integration of energy storage technologies with VSC-based FACTS controllers. With the support of energy storage device, FACTS controllers will have the ability to exchange active power or energy with the ac network in steady state. This paper discusses the impact of Static Synchronous Compensator incorporating energy storage device (STATCOM-ES) on subsynchronous resonance (SSR). It also proposes the design of an auxiliary SSR damping controller (SSDC) for STATCOM-ES to damp the subsynchronous oscillations which the system is undergoing because of a series capacitor in the transmission system. The system under consideration is IEEE FBM which is modified to incorporate STATCOM-ES at the electrical midpoint. The investigation of SSR characteristics when a STATCOM - ES operating in bus voltage regulation mode is carried out by eigenvalue and damping torque analysis. Transient analysis based on the nonlinear model is also performed to validate the results obtained by conventional methods.

Based on the Hybrid Energy Storage System in the Application of Stable DC Bus Voltage

2014 ◽  
Vol 953-954 ◽  
pp. 765-770
Author(s):  
Yang Yang Wu ◽  
You Kuan Liu ◽  
Pei Tian
Keyword(s):  
Energy Storage ◽  
Storage System ◽  
Energy Storage System ◽  
Storage Unit ◽  
Hybrid Energy ◽  
Hybrid Energy Storage ◽  
Photovoltaic Array ◽  
Hybrid Energy Storage System ◽  
Dc Bus ◽  
Bus Voltage

Due to the large number of distributed power supply random connected to power grid, it has severely influenced on power quality of the grid. In the storage battery directly on the basis of the DC bus, adopting the method of hybrid energy storage system makes a research on the output characteristics of photovoltaic array and the charging and discharging of battery and super capacitor. Research results show that the hybrid energy storage system can take advantage of the DC/DC converter to coordinate photovoltaic array, energy storage unit and the energy flows among load, also that the stability of DC bus voltage can be ensured by the system switch from the different work patterns.

scholarly journals An Optimal Control Strategy for DC Bus Voltage Regulation in Photovoltaic System with Battery Energy Storage

2014 ◽  
Vol 2014 ◽  
pp. 1-16 ◽  
Author(s):  
Muhamad Zalani Daud ◽  
Azah Mohamed ◽  
M. A. Hannan
Keyword(s):  
Energy Storage ◽  
Optimization Technique ◽  
Current Mode ◽  
Voltage Regulation ◽  
Boost Converter ◽  
Pv System ◽  
Battery Energy Storage ◽  
Dc Bus ◽  
Bus Voltage ◽  
Battery Energy

This paper presents an evaluation of an optimal DC bus voltage regulation strategy for grid-connected photovoltaic (PV) system with battery energy storage (BES). The BES is connected to the PV system DC bus using a DC/DC buck-boost converter. The converter facilitates the BES power charge/discharge to compensate for the DC bus voltage deviation during severe disturbance conditions. In this way, the regulation of DC bus voltage of the PV/BES system can be enhanced as compared to the conventional regulation that is solely based on the voltage-sourced converter (VSC). For the grid side VSC (G-VSC), two control methods, namely, the voltage-mode and current-mode controls, are applied. For control parameter optimization, the simplex optimization technique is applied for the G-VSC voltage- and current-mode controls, including the BES DC/DC buck-boost converter controllers. A new set of optimized parameters are obtained for each of the power converters for comparison purposes. The PSCAD/EMTDC-based simulation case studies are presented to evaluate the performance of the proposed optimized control scheme in comparison to the conventional methods.

scholarly journals Control and Validation of a Reinforced Power Conversion System for Upcoming Bioelectrochemical Power to Gas Stations

Electronics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1470
Author(s):  
Mahdi Shahparasti ◽  
Amirhossein Rajaei ◽  
Andres Tarraso ◽  
Jose David Vidal Leon Romay ◽  
Alvaro Luna
Keyword(s):  
Energy Storage ◽  
Reactive Power ◽  
Voltage Regulation ◽  
Electrical Network ◽  
External Control ◽  
Gas Stations ◽  
Current Reference ◽  
Dc Bus ◽  
Bus Voltage ◽  
Power To Gas

This paper presents a proposal for potential bioelectrochemical power to gas stations. It consists of a two-level voltage source converter interfacing the electrical grid on the AC side and an electromethanogenesis based bioelectrochemical system (EMG-BES) working as a stacked module on the DC side. The proposed system converts CO2 and electrical energy into methane, using wastewater as the additional chemical energy input. This energy storage system can contribute to dampening the variability of renewables in the electrical network, provide even flexibility and grid services by controlling the active and reactive power exchanged and is an interesting alternative technology in the market of energy storage for big energy applications. The big challenge for controlling this system lays in the fact that the DC bus voltage of the converter has to be changed in order to regulate the exchanged active power with the grid. This paper presents a cascade approach to control such a system by means of combining external control loops with fast inner loops. The outer power loop, with a proportional-integral (PI) controller with special limitation values and anti-windup capability, is used to generate DC bus voltage reference. An intermediate loop is used for DC bus voltage regulation and current reference generation. A new proportional resonant controller is used to track the current reference. The proposed scheme has been validated through real-time simulation in OPAL OP4510.

scholarly journals A control strategy for battery/supercapacitor hybrid energy storage system

2021 ◽  
Vol 2108 (1) ◽  
pp. 012091
Author(s):  
Congzhen Xie ◽  
Jigang Wang ◽  
Bing Luo ◽  
Xiaolin Li ◽  
Lei Ja
Keyword(s):  
Energy Storage ◽  
Control Strategy ◽  
Renewable Energy Sources ◽  
Storage System ◽  
Energy Storage System ◽  
Hybrid Energy ◽  
Hybrid Energy Storage ◽  
Hybrid Energy Storage System ◽  
Dc Bus ◽  
Bus Voltage

Abstract In DC microgrid (MG), the hybrid energy storage system (HESS) of battery and supercapacitor (SC) has the important function of buffering power impact, which comes from renewable energy sources (RES) and loads. This paper proposes a HESS control strategy with DC bus voltage self-recovery function. High and low frequency power decomposition based on virtual droop control, and DC bus drop voltage is compensated by added proportional integral regulation. The relationship between DC bus voltage recovery and super-capacitor (SC) state of charge (SoC) recovery is analyzed. The system can realize stable energy storage, supply under frequent load power impact. The effectiveness of the proposed control strategy is verified by simulation in MATLAB/Simulink.

scholarly journals Research on Optical Energy Storage System Based on Rule Logic Control

2021 ◽  
Vol 237 ◽  
pp. 02003
Author(s):  
Lu Yan ◽  
Rui Xu ◽  
Xin Zhang
Keyword(s):  
Energy Storage ◽  
Energy Management ◽  
Control Strategy ◽  
Storage System ◽  
Energy Storage System ◽  
Power Balance ◽  
Storage Battery ◽  
Tracking Accuracy ◽  
Dc Bus ◽  
Bus Voltage

Photovoltaic energy storage system is composed of photovoltaic power generation, energy storage battery, load and power grid, it has researched on different modes of bi-directional DC/AC converter, taking into account a variety of photovoltaic output fluctuations, energy storage battery charging and discharging management, load increasing and decreasing, etc. Aiming at the energy management strategy, using DC bus voltage fluctuation as the basis of energy layer mobilization, the power balance control based on regular control is proposed. Compared with the DC bus voltage level energy management, the power tracking accuracy is further improved and energy loss is reduced. Finally, through MATLAB/Simulink being in off/connected model and the charging/discharging model, the effectiveness of the energy control strategy was verified separately by simulation. The simulation results show that: the proposed control strategy can improve the power tracking accuracy and reduce the energy loss of the system; the proposed strategy guarantees the bidirectional exchange of system energy and maintains the power balance in the network, the DC bus voltage is stable, and the energy storage battery achieves smooth power output and peak load shifting.

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