A novel control method for grid side inverters under generalized unbalanced operating conditions

2013 ◽  
Author(s):  
Ana V. Stankovic ◽  
Yaroslav Rutkovskiy
Keyword(s):  
Control Method ◽  
Operating Conditions ◽  
Grid Side

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.

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.

scholarly journals Emulation of grid-forming inverters using real-time PC and 4-quadrant voltage amplifier

2021 ◽  
Author(s):  
Wolf Schulze ◽  
Maurizio Zajadatz ◽  
Michael Suriyah ◽  
Thomas Leibfried
Keyword(s):  
Real Time ◽  
Control Method ◽  
Current Control ◽  
Control Methods ◽  
Test Bed ◽  
Test Scenario ◽  
Power Semiconductors ◽  
Voltage Amplifier ◽  
Grid Side ◽  
Virtual Synchronous Machine

AbstractA test bed for the evaluation of novel control methods of inverters for renewable power generation is presented. The behavior of grid-following and grid-forming control in a test scenario is studied and compared.Using a real-time capable control platform with a cycle time of 50 µs, control methods developed with Matlab/Simulink can be implemented. For simplicity, a three-phase 4‑quadrant voltage amplifier is used instead of an inverter. Thus, the use of modulation and switched power semiconductors can be avoided. In order to show a realistic behavior of a grid-side filter, passive components can be automatically connected as L‑, LC- or LCL-filter. The test bed has a nominal active power of 43.6 kW and a nominal voltage of 400 V.As state-of-the-art grid-following control method, a current control in the d/q-system is implemented in the test bed. A virtual synchronous machine, the Synchronverter, is used as grid-forming control method. In combination with a frequency-variable grid emulation, the behavior of both control methods is studied in the event of a load connection in an island grid environment.

scholarly journals Assessment of vehicle brake control functional stability

2021 ◽  
Vol 12 (2) ◽  
pp. 33-44
Author(s):  
Volodymyr Volkov ◽  
◽  
Igor Gritsuk ◽  
Tetiana Volkova ◽  
Volodymyr Kuzhel ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Control Method ◽  
Operating Conditions ◽  
National Standards ◽  
Passenger Vehicles ◽  
The Difference ◽  
Braking Control ◽  
The Stability ◽  
Friction Surfaces

The article is devoted to the study of the influence of the brake control elements of passenger vehicles on the stability of their braking properties. The analysis of the influence of uneven braking forces on the wheels of one axle of vehicles on the deviation of the distribution of braking forces between the axles from its calculated value is carried out. When assessing the error in regulating the distribution of braking forces between the axles of vehicles, three components were taken into account: the theoretical error due to the imperfection of the selected control method (the difference between the actual calculated control characteristic from the ideal), the error created due to the instability of the ratio of the braking forces on the front and rear wheels, an additional error caused by the unevenness of the braking forces on the wheels of individual axles, since the fulfillment of the most stringent requirements of international and national standards for the efficiency of braking of vehicles and is inextricably linked with the need to increase the energy consumption of brake mechanisms. The energy consumption of braking mechanisms is understood as the ability of the latter to dissipate the greatest amount of energy of the braking machine without reducing the braking efficiency indicators to the minimum permissible level. Excessive heating of the braking mechanisms leads to a decrease in the friction coefficient μ of the friction surfaces and increased wear of the friction linings, and the brakes are the most unstable element of the braking control, which ensures the absorption and dissipation of the vehicle's energy during braking. The instability of the braking torques on the front and rear wheels, caused by a change in the coefficients of friction of friction pairs, leads not only to a change in the distribution of braking forces between the axles and individual wheels, but also to a decrease in the braking efficiency of vehicles under operating conditions. A method is proposed that makes it possible to assess the quality of regulation of the distribution of braking forces between the axles of a car, taking into account the instability of the braking forces on the wheels.

scholarly journals Simulation of reactive power regulation of DFIG

2021 ◽  
Vol 233 ◽  
pp. 01025
Author(s):  
Yingfeng Zhu ◽  
Xiaosu Xie ◽  
Dong Yang ◽  
Song Gao ◽  
Weichao Zhang ◽  
...  
Keyword(s):  
Wind Farm ◽  
Reactive Power ◽  
Control Method ◽  
Power Regulation ◽  
Working Principle ◽  
Power Limit ◽  
Doubly Fed ◽  
Grid Side ◽  
Grid Side Converter ◽  
And Control

Doubly fed induction generator (DFIG) wind power generation system is widely used in wind farm all over the world. Reactive power can be generated both in grid-side converter and generator-side converter of DFIG. In this paper, working principle and control method of DFIG are introduced, and the reactive power limit of DFIG is derived, finally reactive power regulation is simulated in Simulink.

Application of Blow-off Wind Tunnel Control Based on Genetic Algorithm Optimized BP-Neural Network PID Neural Network

2013 ◽  
Vol 310 ◽  
pp. 557-559 ◽  
Author(s):  
Li Ji ◽  
Xiao Fei Lian
Keyword(s):  
Neural Network ◽  
Genetic Algorithm ◽  
Wind Tunnel ◽  
Bp Neural Network ◽  
Control Method ◽  
Network Control ◽  
Operating Conditions ◽  
Algorithm Optimization ◽  
Large Delay ◽  
Neural Network Pid

For a blow-off tunnel running, there is the large delay and lag issues. We build a mathematical model of the wind tunnel Mach number control by the test modeling method, then analyse the pros and cons of various control methods based on BP neural network control algorithm. Put forward genetic algorithm optimization neural network adaptive control method to solve the large inertia of the wind tunnel system, and large delay. A large number of simulation studies, run a variety of operating conditions for the wind tunnel simulation proved that the improved adaptive neural network PID control method is reasonable and effective.

scholarly journals A Robust Maximum Power Point Tracking Control Method for a PEM Fuel Cell Power System

2018 ◽  
Vol 8 (12) ◽  
pp. 2449 ◽  
Author(s):  
Mohamed Derbeli ◽  
Oscar Barambones ◽  
Lassaad Sbita
Keyword(s):  
Proton Exchange Membrane ◽  
Control Method ◽  
Rapid Change ◽  
Proton Exchange ◽  
Operating Conditions ◽  
Maximum Power ◽  
Backstepping Technique ◽  
Maximum Power Point ◽  
Power Point ◽  
Efficient Power

Taking into account the limited capability of proton exchange membrane fuel cells (PEMFCs) to produce energy, it is mandatory to provide solutions, in which an efficient power produced by PEMFCs can be attained. The maximum power point tracker (MPPT) plays a considerable role in the performance improvement of the PEMFCs. Conventional MPPT algorithms showed good performances due to their simplicity and easy implementation. However, oscillations around the maximum power point and inefficiency in the case of rapid change in operating conditions are their main drawbacks. To this end, a new MPPT scheme based on a current reference estimator is presented. The main goal of this work is to keep the PEMFCs functioning at an efficient power point. This goal is achieved using the backstepping technique, which drives the DC–DC boost converter inserted between the PEMFC and the load. The stability of the proposed algorithm is demonstrated by means of Lyapunov analysis. To verify the ability of the proposed method, an extensive simulation test is executed in a Matlab–Simulink T M environment. Compared with the well-known proportional–integral (PI) controller, results indicate that the proposed backstepping technique offers rapid and adequate converging to the operating power point.

Model-based model predictive control for a direct-driven permanent magnet synchronous generator with internal and external disturbances

2019 ◽  
Vol 42 (3) ◽  
pp. 586-597 ◽  
Author(s):  
Li Shengquan ◽  
Li Juan ◽  
Tang Yongwei ◽  
Shi Yanqiu ◽  
Cao Wei
Keyword(s):  
Permanent Magnet ◽  
Control Method ◽  
Synchronous Generator ◽  
Critical Issue ◽  
Operating Conditions ◽  
Maximum Power ◽  
External Disturbances ◽  
Permanent Magnet Synchronous Generator ◽  
Model Based ◽  
Wide Range

This paper deals with the critical issue in a direct-driven permanent magnet synchronous generator (PMSG)-based wind energy conversion system (WECS): the rejection of internal and external disturbances, including the uncertainties of external environment, rapid wind speed changes in the original parameters of the generator caused by mutative operating conditions. To track the maximum power, a maximum power point tracking strategy based on model predictive controller (MPC) is proposed with extended state observer (ESO) to attenuate the disturbances and uncertainties. In real application, system inertia and the system parameters vary in a wide range with variations of wind speeds and disturbances, which substantially degrade the maximum power tracking performance of wind turbine. The MPC design should incorporate the available model information into the ESO to improve the control efficiency. Based on this principle, a model-based MPC with ESO control structure is proposed in this paper. Simulation study is conducted to evaluate the performance of the proposed control strategy. It is shown that the effect of internal and external disturbances is compensated in a more effective way compared with the ESO-based MPC approach and traditional proportional integral differential (PID) control method.

Control for Dc-Bus Voltage Using Grid Voltage Feed-Forward and Crowbar Circuit

2013 ◽  
Vol 448-453 ◽  
pp. 1727-1731
Author(s):  
Xi Yun Yang ◽  
Li Xia Li ◽  
Ya Min Zhang
Keyword(s):  
Power System ◽  
Wind Power ◽  
Output Power ◽  
Control Method ◽  
Direct Drive ◽  
Grid Voltage ◽  
Wind Power System ◽  
Dc Bus ◽  
Bus Voltage ◽  
Grid Side

The DC bus voltage is key variable for the operation of converter system in a wind power system. When grid voltage drops, a control of the DC bus voltage is needed to keep the smoothness of DC bus voltage for avoiding generator cutting off grid. A combined control method based on the grid voltage information feedforward with a crowbar circuit is proposed for a direct-drive wind power system in the paper. The unbalanced energy of the DC bus can be unleashed by the crowbar circuit during the dropping of grid voltage. At the same time, the output power of motor-side converter can be controlled to decrease according to the grid-side voltage information, and the mechanical speed of wind turbine and generator can be suppressed by the pitch angle regulation when the output power reduces. Thus, the DC-bus voltage can keep smooth. Results based on Matlab/Simulink simulation shows that this method not only improves dynamic response performance of DC bus voltages control, but also reduces the action time of crowbar circuit. It is benefit to the ability of the wind power system riding through the grid fault.

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