scholarly journals Research on Improved Droop Control Strategy of Microsource Inverter Based on Internet of Things

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Di Bai ◽  
Tieyan Zhang ◽  
Zheng Yang

Microgrid connects the distributed power supply with the assistance of power electronic devices. Power electronic devices, especially in the inversion link, play a crucial role in the access of distributed power to microgrid. Whether in grid-connected mode or island mode, the control method of inverters is related to the stable operation of distributed power supply and plays an important role in the control strategy of microgrid. In this paper, by adding the drop control of controllable virtual impedance, the power coupling problem caused by resistive line impedance is reduced, and virtual impedance key points such as voltage feedback and frequency compensation are added. By optimizing the power reference value, the parallel operation stability of the control strategy is improved. The experimental results show that the proposed method improves not only the stability of the system and the power quality but also the accuracy of reactive power distribution.

2021 ◽  
Vol 2083 (2) ◽  
pp. 022099
Author(s):  
Chengyi Yue ◽  
Binbin Bei

Abstract Reducing the dependence of microgrid upon the communication system and realizing the efficient control of multiple distributed generation of the microgrid are problems that need to be solved urgently. Through the research, based on multiple microgrid operation modes, the peer-to-peer control strategy in microgrid is investigated, and the peer-to-peer control strategy method of microgrid is given for a variety of complex control problems of distributed power According to the peer-to-peer control strategy method, distributed power supply adopts droop control in adjusting distributed power supply in output voltage and frequency; the droop controller has P-f and Q-U droop characteristics. This paper establishes a peer-to-peer control microgrid simulation model, adopts the droop controller designed in this paper to island mode and grid-connected mode, and investigates how the microgrid switches between the two modes. In accordance with Matlab/Simulink simulation outcomes, the research examines frequency, voltage and power changes in distributed generation in the microgrid, and verifies the validity and feasibility of microgrid peer-to-peer control strategy.


2012 ◽  
Vol 516-517 ◽  
pp. 1722-1727 ◽  
Author(s):  
Wei Jun Yun ◽  
Gang Yao ◽  
Li Dan Zhou ◽  
Chen Chen ◽  
Jun Min Pan

Nowadays Static Synchronous Compensator (STATCOM) has gradually become one of the representative techniques in the field of dynamic reactive power compensation in the power distribution system. This paper analyzed the topology and the voltage imbalance problem of the up and down capacitors on DC side of the three-phase four-wire STATCOM. In allusion to the imbalance problem of neutral point, a novel control strategy based on the control of zero-sequence current was proposed. By the triple close-loop control strategy, the STATCOM can achieve great control accuracy and dynamic performance. Simulation result proves that the proposed control method is effective.


Energies ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 2223 ◽  
Author(s):  
Haifeng Liang ◽  
Yue Dong ◽  
Yuxi Huang ◽  
Can Zheng ◽  
Peng Li

The stable operation of a microgrid is crucial to the integration of renewable energy sources. However, with the expansion of scale in electronic devices applied in the microgrid, the interaction between voltage source converters poses a great threat to system stability. In this paper, the model of a three-source microgrid with a multi master–slave control method in islanded mode is built first of all. Two sources out of three use droop control as the main control source, and another is a subordinate one with constant power control which is also known as real and reactive power (PQ) control. Then, the small signal decoupling control model and its stability discriminant equation are established combined with “virtual impedance”. To delve deeper into the interaction between converters, mutual influence of paralleled converters of two main control micro sources and their effect on system stability is explored from the perspective of control parameters. Finally, simulation and analysis are launched and the study serves as a reference for parameter setting of converters in a microgrid.


2013 ◽  
Vol 433-435 ◽  
pp. 1263-1270
Author(s):  
Guo Wen Hu ◽  
Lin Wang ◽  
Yin Jie Wang

Abstract: The point of the micro-grid distributed power's control is grid-connected inverter. The flexible grid-connection control technology provided an optimizing control method between distributed power and micro-grid and between micro-grid and power system. The flexible grid-connection control strategy includes flexible grid-connection control and flexible islanding control. The flexible grid-connection control achieves the good performance by means of regulation of the active and reactive power of micro-grid, while inhibiting the impact of impulse current, smooth power output, forecasting load and micro-grid power capacity. Based on the flexible grid-connection technology research of distributed power in micro-grid, the flexible master-slave method was presented based on PQ control, and the balance of power and the flexible control in micro-grid has been reached by it. The emulation and experiment results verify that the flexible master-slave method is effective; the balance of power, the flexible control when micro-grid is in islanding mode has been reached; the feasibility of the flexible master-slave method to stabilize the system was showed.


Author(s):  
Xin Shen ◽  
Hongchun Shu ◽  
Min Cao ◽  
Nan Pan ◽  
Junbin Qian

In distribution networks with distributed power supplies, distributed power supplies can also be used as backup power sources to support the grid. If a distribution network contains multiple distributed power sources, the distribution network becomes a complex power grid with multiple power supplies. When a short-circuit fault occurs at a certain point on the power distribution network, the size, direction and duration of the short-circuit current are no longer single due to the existence of distributed power, and will vary with the location and capacity of the distributed power supply system. The change, in turn, affects the current in the grid, resulting in the generation and propagation of additional current. This power grid of power electronics will cause problems such as excessive standard mis-operation, abnormal heating of the converter and component burnout, and communication system failure. It is of great and practical significance to study the influence of distributed power in distributed power distribution networks.


2020 ◽  
Vol 2 (58) ◽  
pp. 28-32
Author(s):  
A. Gapon ◽  
O. Grib ◽  
S. Kozlov ◽  
O. Yevseienko ◽  
O. Levon

The work is devoted to solving an urgent problem - the development of a computer model of the energy consumption system of the Institute of the ionosphere of the National Academy of Sciences and the Ministry of Education and Science of Ukraine in order to solve the problem of increasing the energy efficiency of the measuring complex. The power supply system of the complex is described, a generalized structural diagram of the loads - powerful consumers of electricity is presented. The graphs characterizing the energy consumption of individual powerful loads are presented, the problem of compensating the reactive power of loads is shown. The adequacy of the developed model is confirmed by the coincidence of the shape and values of the experimentally obtained characteristics on loads with the characteristics of the model. The model adequacy was assessed by the variance of feedback deviations from the system mean. The results obtained confirmed the possibility of using the developed Matlab-model of the energy consumption system of the measuring complex for creating and testing on the model of an energy-efficient power supply system, which will ensure the stable operation of scientific equipment for the implementation of research programs of the NAS of Ukraine.


Electronics ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1264 ◽  
Author(s):  
Fatemeh Shahnazian ◽  
Ebrahim Adabi ◽  
Jafar Adabi ◽  
Edris Pouresmaeil ◽  
Kumars Rouzbehi ◽  
...  

This paper presents a dynamic model of modular multilevel converters (MMCs), which are considered as an effective interface between energy sources and the power grid. By improving the converter performance, appropriate reactive power compensation is guaranteed. Modulation indices are calculated based on detailed harmonic evaluations of both dynamic and steady-state operation modes, which is considered as the main contribution of this paper in comparison with other methods. As another novelty of this paper, circulating current control is accomplished by embedding an additional second harmonic component in the modulation process. The proposed control method leads to an effective reduction in capacitor voltage fluctuation and losses. Finally, converter’s maximum stable operation range is modified, which provides efficiency enhancements and also stability assurance. The proficiency and functionality of the proposed controller are demonstrated through detailed theoretical analysis and simulations with MATLAB/Simulink.


2019 ◽  
Vol 136 ◽  
pp. 01024
Author(s):  
Jinghong Zhao ◽  
Xing Huang ◽  
Honghao Zhao ◽  
Xin Hong

In order to achieve flexible and efficient operation of intelligent power distribution, solving the problems of traditional distribution transformer such as large volume and weight, easy to generate harmonics when overload, and need supporting protection equipment to protect it when failure, etc. We propose a power electronic transformer structure based on modular multilevel converter (MMC). Firstly, we consider the multi-dimensional control target of MMC converter to establish a mathematical model. Then a virtual submodule predictive control method is proposed. The method introduces the concept of virtual submodule to realize the optimal switching state rapid mapping and reduce the switching loss of MMC. Finally, the experimental results show that the mmc-based power electronic transformer has excellent dynamic steady-state performance and can effectively overcome the high loss of traditional predictive control.


2010 ◽  
Vol 44-47 ◽  
pp. 3970-3975
Author(s):  
Ke Wang ◽  
Bin Chen ◽  
Wen Han Chen ◽  
Hua Xu ◽  
Jia Xin Yuan

At first, this paper compared the present some advantages and disadvantages of reactive power compensation devices, and analysis the disadvantages of these devices in practical application deficiencies, then put forward a new kind of reactive power compensation principle. With the development of power electronic devices, this paper put forward a new type of reactive power compensation which based on RB-IGBT of SVC mode, synthesize the advantages of domestic reactive power compensation devices at present, and the prospect of application is very good.


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