Advanced Mode Control Strategies for Inverter Based Distributed Generators in Micro-Grids

2013 ◽  
Vol 284-287 ◽  
pp. 2210-2214
Author(s):  
Tsao Tsung Ma ◽  
Shun Yao Ho
Keyword(s):  
Control Algorithm ◽  
Control Method ◽  
Control Strategies ◽  
Operating Conditions ◽  
Digital Controllers ◽  
Software Environment ◽  
Practical Applications ◽  
Distributed Generators ◽  
Grid Side ◽  
Micro Grids

This paper describes a novel control algorithm for inverter-based distributed generators (DG) to maintain a continuous voltage and power supply for the critical and voltage sensitive loads in micro-grids when a serious fault on the grid side occurs. Based on a set of given system conditions, the proposed algorithm can automatically switch the DG inverter between the power-controlled and the voltage-controlled modes. In this paper, to develop a feasible control algorithm, some operating conditions are firstly assumed and the proposed control strategies are then addressed. The feasibility and effectiveness of the proposed control scheme are verified with comprehensive simulation studies carried out in the PSIM software environment. The simulation results confirm some merits of the proposed control method. It is worthwhile noting that the proposed control algorithm can easily be implemented using digital controllers for practical applications.

scholarly journals Overlapping Decentralized Control Strategies of Building Structures’ Vibration with Time Delay Based on H∞ Control Algorithms under Seismic Excitation

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Xiaofang Kang ◽  
Jian Wu ◽  
Yewei Zhang ◽  
Guoliang Liu ◽  
Suhui Zhang ◽  
...  
Keyword(s):  
Control System ◽  
Time Delay ◽  
Vibration Control ◽  
Decentralized Control ◽  
Control Strategy ◽  
Control Algorithm ◽  
Control Method ◽  
Control Strategies ◽  
Linear Matrix ◽  
Feedback Gain

A decentralized control strategy can effectively solve the control problem of the large-scale time delayed structures. In this paper, combining the overlapping decentralized control method, linear matrix inequality (LMI) method, and H∞ control algorithm, overlapping decentralized H∞ control approach of the time delayed structures has been established. The feedback gain matrixes of all subsystems are obtained by this method based on genetic algorithm optimization tools and the specific goal of optimization control. The whole vibration control system of the time delayed structures is divided into a series of overlapping subsystems by overlapping decentralized control strategy. The feedback gain matrixes of each subsystem can be obtained by using H∞ control algorithm to calculate each subsystem. The vibration control of a twenty layers’ antiseismic steel structure Benchmark model was analyzed with the numerical method. The results show that the proposed method can be applied to control system with time delay. The overlapping decentralized control strategies acquire the similar control effects with that of the centralized control strategy. Moreover, the flexibility of the controller design has been enhanced by using overlapping decentralized control strategies.

A nonlinear control algorithm for a wind turbine

2015 ◽  
Vol 34 (6) ◽  
pp. 1863-1878 ◽  
Author(s):  
Merzak Aimene ◽  
Alireza Payman ◽  
Brayima Dakyo
Keyword(s):  
Nonlinear Control ◽  
Wind Turbine ◽  
Control Algorithm ◽  
Control Method ◽  
Synchronous Generator ◽  
Maximum Power ◽  
Content Type ◽  
Point Tracking ◽  
Grid Side ◽  
Reference Trajectories

Purpose – The purpose of this paper is to propose a new nonlinear control algorithm to control a wind turbine based on permanent magnet synchronous generator (PMSG) connected to the grid via a back-to-back converter. The control algorithm is composed of a flatness-based method for the machine side convertor (MSC) and a voltage-oriented method for the grid side converter (GSC). Design/methodology/approach – For the MSC control, the output variable is chosen properly to prove that the system is flat at first. Then, the appropriate reference trajectories are planned on its components. The reference trajectories are such designed that the system operates in maximum power point tracking (MPPT) mode. Finally, state feedback regulators are used to force the system output to follow its reference. To control the GSC, a classical voltage-oriented control method is used. Findings – The simulation results obtained with a random wind speed are presented in order to prove the validity of the proposed control algorithm. These results show that the system is controlled successfully while it operates in the MPPT mode or in its maximum power limitation mode. Originality/value – In this paper, a new algorithm based on flatness property is presented to control a variable speed wind turbine based on a PMSG. The proposed control method allows the system to operate in optimal operating modes.

A New strategy for on- line Droop adjustment for Microgrid connected DGs

2018 ◽  
Vol 9 (1) ◽  
pp. 139
Author(s):  
Sathyaprabakaran B ◽  
Subrata Paul ◽  
Debashis Chatterjee
Keyword(s):  
Control Method ◽  
Load Capacity ◽  
Operating Conditions ◽  
Control Mode ◽  
Control Technique ◽  
Effective Control ◽  
Droop Control ◽  
Capacitor Voltage ◽  
Grid Side ◽  
Filter Capacitor

This paper proposes a simple and effective control technique for interconnection of DG resources to the power grid via interfacing converters based on Phase locked loop (PLL) and Droop control. The behaviour of a Microgrid (MG) system during the transition from islanded mode to grid-connected mode of operation has been studied. A dynamic phase shifted PLL technique is locally designed for generating phase reference of each inverter. The phase angle between filter capacitor voltage vector and d-axis is dynamically adjusted with the change in q-axis inverter current to generate the phase reference of each inverter. During fluctuations in load capacity, the grid-connected system must be able to supply balanced power from the utility grid side and micro-grid side. Therefore, droop control is implemented to maintain a balanced power sharing. The inverter operates in voltage control mode in order to control the filter capacitor voltage. An adjusted droop control method for equivalent load sharing of parallel connected Inverters, without any communication between individual inverters, has been presented. The control loops are tested with aid of MATLAB Simulink tool during several operating conditions.

A Target Voltage Control Method for Distribution Systems based on Nodal P&Q Prices for PV Distributed Generators

2020 ◽  
Vol 140 (6) ◽  
pp. 456-464
Author(s):  
Naoto Yorino ◽  
Tsubasa Watakabe ◽  
Ahmed Bedawy Khalifa ◽  
Yutaka Sasaki ◽  
Yoshifumi Zoka
Keyword(s):  
Distribution Systems ◽  
Control Method ◽  
Voltage Control ◽  
Distributed Generators

Infections of bean plant and field soil are linked to region, root rot pathogen, and agro-ecosystem

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
B. Naseri ◽  
M. Gheitury ◽  
M. Veisi
Keyword(s):  
Root Rot ◽  
Multivariate Analyses ◽  
Control Method ◽  
Control Strategies ◽  
Fusarium Species ◽  
Macrophomina Phaseolina ◽  
Soil Variables ◽  
Plant Infection ◽  
Pathogen Prevalence ◽  
Soil Infestation

SummaryUnderstanding pathogen-agrosystem interaction is particularly essential when applying a control method to minimize pathogen prevalence prior to plant infection. To meet this requirement, frequency of major root rot pathogens isolated from bean root and seed, and their soil populations were examined in farmers’ fields. Multivariate analyses evidenced more frequent isolations of Fusarium solani and Rhizoctonia solani from root and seed compared to Macrophomina phaseolina and Fusarium oxysporum. Two Fusarium species had denser soil populations than R. solani and M. phaseolina. More frequent isolations of pathogens were detected in root and seed collected from Abhar and Khodabandeh compared to Kheirabad region. Agronomic and soil variables corresponded less closely to root infections compared to soil infestation and seed infections. Bean market class, herbicide application, and planting depth were linked to root, seed and soil infestations. Such information provides a basis for increased confidence in choosing appropriate control strategies for a pathogen and region in sustainable agriculture.

Improved Oxygen Dissolution Control for Oxygen Activated Sludge

1988 ◽  
Vol 20 (4-5) ◽  
pp. 101-108 ◽  
Author(s):  
R. C. Clifft ◽  
M. T. Garrett
Keyword(s):  
Activated Sludge ◽  
Control Method ◽  
Control Strategies ◽  
Cost Savings ◽  
Utilization Efficiency ◽  
Oxygen Production ◽  
Oxygen Utilization ◽  
Potential Cost ◽  
Oxygen Dissolution ◽  
The City

Now that oxygen production facilities can be controlled to match the requirements of the dissolution system, improved oxygen dissolution control can result in significant cost savings for oxygen activated sludge plants. This paper examines the potential cost savings of the vacuum exhaust control (VEC) strategy for the City of Houston, Texas 69th Street Treatment Complex. The VEC strategy involves operating a closed-tank reactor slightly below atmospheric pressure and using an exhaust apparatus to remove gas from the last stage of the reactor. Computer simulations for one carbonaceous reactor at the 69th Street Complex are presented for the VEC and conventional control strategies. At 80% of design loading the VEC strategy was found to provide an oxygen utilization efficiency of 94.9% as compared to 77.0% for the conventional control method. At design capacity the oxygen utilization efficiency for VEC and conventional control was found to be 92.3% and 79.5%, respectively. Based on the expected turn-down capability of Houston's oxygen production faciilities, the simulations indicate that the VEC strategy will more than double the possible cost savings of the conventional control method.

A Review of Classical and Modern Control Techniques Utilized in Modern Microgrids

2021 ◽  
Vol 14 ◽  
Author(s):  
Muhammad Hamza Shahbaz ◽  
Arslan Ahmed Amin
Keyword(s):  
Control Strategies ◽  
Optimal Solution ◽  
Energy Resources ◽  
Control Methods ◽  
Research Gaps ◽  
Control Techniques ◽  
Micro Grid ◽  
Exciting Development ◽  
Micro Grids ◽  
Modern Control

: Because of the consistently expanding energy request, the introduction of a decentralized micro-grid based on energy resources will soon be the most exciting development in the power system. Micro-grids, which are mainly based on inverters, are becoming more popular as they can handle different forms of renewable energy effectively. However, one of the most challenging areas of research is their control. In the last few years, many control strategies have been developed. In this review, different control methods have been discussed that apply to the micro-grid system. Furthermore, the comparative analysis of classical and modern control strategies is also considered. This survey guides the new researchers about all available control strategies and room for improvement towards the optimal solution of the micro-grid control techniques. It also identifies several research gaps and future trends therein as well as provides a solution to manage problems in MGs. The strategies are then compared based on their applicability to different control requirements.

scholarly journals Power Hardware-in-the-Loop-Based Performance Analysis of Different Converter Controllers for Fast Active Power Regulation in Low-Inertia Power Systems

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3274
Author(s):  
Jose Rueda Torres ◽  
Zameer Ahmad ◽  
Nidarshan Veera Kumar ◽  
Elyas Rakhshani ◽  
Ebrahim Adabi ◽  
...  
Keyword(s):  
Performance Evaluation ◽  
Power Systems ◽  
Real Time ◽  
Control Strategies ◽  
Active Power ◽  
Power Electronic ◽  
Hardware In The Loop ◽  
Digital Controllers ◽  
Power Regulation ◽  
The Impact

Future electrical power systems will be dominated by power electronic converters, which are deployed for the integration of renewable power plants, responsive demand, and different types of storage systems. The stability of such systems will strongly depend on the control strategies attached to the converters. In this context, laboratory-scale setups are becoming the key tools for prototyping and evaluating the performance and robustness of different converter technologies and control strategies. The performance evaluation of control strategies for dynamic frequency support using fast active power regulation (FAPR) requires the urgent development of a suitable power hardware-in-the-loop (PHIL) setup. In this paper, the most prominent emerging types of FAPR are selected and studied: droop-based FAPR, droop derivative-based FAPR, and virtual synchronous power (VSP)-based FAPR. A novel setup for PHIL-based performance evaluation of these strategies is proposed. The setup combines the advanced modeling and simulation functions of a real-time digital simulation platform (RTDS), an external programmable unit to implement the studied FAPR control strategies as digital controllers, and actual hardware. The hardware setup consists of a grid emulator to recreate the dynamic response as seen from the interface bus of the grid side converter of a power electronic-interfaced device (e.g., type-IV wind turbines), and a mockup voltage source converter (VSC, i.e., a device under test (DUT)). The DUT is virtually interfaced to one high-voltage bus of the electromagnetic transient (EMT) representation of a variant of the IEEE 9 bus test system, which has been modified to consider an operating condition with 52% of the total supply provided by wind power generation. The selected and programmed FAPR strategies are applied to the DUT, with the ultimate goal of ascertaining its feasibility and effectiveness with respect to the pure software-based EMT representation performed in real time. Particularly, the time-varying response of the active power injection by each FAPR control strategy and the impact on the instantaneous frequency excursions occurring in the frequency containment periods are analyzed. The performed tests show the degree of improvements on both the rate-of-change-of-frequency (RoCoF) and the maximum frequency excursion (e.g., nadir).

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