scholarly journals Research on the Structure and Control Strategy of a Novel Power Electronic Transformer for AC/DC Hybrid Distribution Network

2019 ◽  
Vol 9 (4) ◽  
pp. 727 ◽  
Author(s):  
Jingguo Rong ◽  
Xin Ai ◽  
Yunning Li ◽  
Dapeng Ren
Keyword(s):  
Control Strategy ◽  
Control Method ◽  
Distribution Network ◽  
Distribution Networks ◽  
Frequency Regulation ◽  
Power Electronic ◽  
Output Stage ◽  
Hybrid Distribution ◽  
And Control ◽  
Virtual Synchronous Machine

Power electronic transformers (PETs), as the core devices of the energy internet, are the key to achieve both effective consumption for renewable energy and the safe and coordinated operation for AC/DC hybrid system. In order to overcome the shortcomings of the existing PETs, a novel PET with an improved structure that applicable for multi-voltage level AC/DC hybrid distribution network is proposed. The topology of the proposed PET is analyzed, and the corresponding control methods are suggested for different parts. The input stage utilizes the modular multilevel converter structure and applies the virtual synchronous machine control strategy to enhance the inertia and damping of the system. The power of the output stage is adjusted flexibly and that enables the PET to provide certain power support to the upper grid and participate in its primary frequency regulation. A combined connection of input-series output-series and input-series output-parallel is applied for the dual-active-bridge modules of the isolation stage to enable network interconnection and electrical isolation of AC/DC grids with significantly different voltage levels. A power coordinated control method is then proposed to meet the power demand of the distribution networks connected to the output stage and ensure stable operations of PET simultaneously. The reliability and efficiency of the proposed PET topology and control strategy for AC/DC hybrid distribution network are finally verified via PSCAD/EMTDC simulation.

scholarly journals A Secondary Reconfigurable Inverter and Its Control Strategy

2020 ◽  
Vol 10 (20) ◽  
pp. 7021
Author(s):  
Yan Li ◽  
Peng Xiang ◽  
Yandong Chen
Keyword(s):  
Control Strategy ◽  
Control Method ◽  
Fault Tolerant ◽  
Frequency Control ◽  
Semiconductor Devices ◽  
Constant Frequency ◽  
Power Semiconductor ◽  
Power Semiconductor Devices ◽  
Simulation And Experiment ◽  
And Control

This article proposes a topology of the secondary reconfigurable inverter and the corresponding fault-tolerant control strategy. When the secondary reconfigurable inverter is operating normally, its topology structure is the TPSS circuit. When the power semiconductor devices in the inverter are faulty, the inverter circuit needs to be reconfigured. After removing the faulty power semiconductor devices, the remaining power semiconductor devices and the DC side powers are reconstructed as the TPFS structure to keep the system running normally. This article also proposes a switch-pulse-resetting algorithm. This paper adopts the control strategy connecting the constant-voltage, constant-frequency control method with the switch pulse resetting algorithm. It need not change the control algorithm when the proposed reconfigurable inverter is transformed from the normal running state into the faulty running state. The inverter dependability is greatly improved. Finally, the feasibility and effectiveness of the proposed second reconfigurable inverter topology and control strategy are verified by simulation and experiment.

scholarly journals A Novel Left-Turn Signal Control Method for Improving Intersection Capacity in a Connected Vehicle Environment

Electronics ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 1058 ◽  
Author(s):  
Chuanxiang Ren ◽  
Jinbo Wang ◽  
Lingqiao Qin ◽  
Shen Li ◽  
Yang Cheng
Keyword(s):  
Traffic Safety ◽  
Control Strategy ◽  
Control Method ◽  
Control Model ◽  
Signal Control ◽  
Signal Phase ◽  
Phase Duration ◽  
Left Turn ◽  
Intersection Signal Control ◽  
And Control

Setting up an exclusive left-turn lane and corresponding signal phase for intersection traffic safety and efficiency will decrease the capacity of the intersection when there are less or no left-turn movements. This is especially true during rush hours because of the ineffective use of left-turn lane space and signal phase duration. With the advantages of vehicle-to-infrastructure (V2I) communication, a novel intersection signal control model is proposed which sets up variable lane direction arrow marking and turns the left-turn lane into a controllable shared lane for left-turn and through movements. The new intersection signal control model and its control strategy are presented and simulated using field data. After comparison with two other intersection control models and control strategies, the new model is validated to improve the intersection capacity in rush hours. Besides, variable lane lines and the corresponding control method are designed and combined with the left-turn waiting area to overcome the shortcomings of the proposed intersection signal control model and control strategy.

Experimental Study on Hydrodynamic Characteristics of Hydrofoil of the Birds Embedded in Marine Seismic Streamers

2010 ◽  
Author(s):  
Xiaoqing Zhang ◽  
Weijing Zhang ◽  
Jun Chen
Keyword(s):  
Control Strategy ◽  
Control Method ◽  
Reference Value ◽  
Attack Angle ◽  
Hydrodynamic Characteristics ◽  
Oil Exploitation ◽  
Exact Position ◽  
Marine Seismic ◽  
And Control ◽  
Important Significance

A “bird” is a device usually being used to control the depth and position of marine seismic streamers. Exact position of the streamers can effectively promote the precision, reduce the measured times and save the costs for marine seismic exploitation. So the “birds” have important significance to marine oil exploitation. A Hydrodynamic characters test concerning a new embedded bird has been introduced in this paper. And some useful hydrodynamic character-data of the hydrofoil are obtained, such as lift-attack angle diagram, resistance-attack angle diagram, torque-attack angle diagram. These data and diagrams are more helpful for studying on the embedded bird, including the control method and control strategy etc. Above all, the results of the test have significant reference value for the control of birds and marine seismic streamers.

Speed Ratio Control Study on CVT with Electrical Control and Motor as Actuator (EM-CVT)

2013 ◽  
Vol 787 ◽  
pp. 886-890
Author(s):  
Lan Chun Zhang ◽  
You Jun Ma ◽  
Shao Yi Bel
Keyword(s):  
Control Strategy ◽  
Control Method ◽  
Speed Ratio ◽  
Electronic Control ◽  
Functional Requirements ◽  
Change Characteristics ◽  
Ratio Change ◽  
Working Principle ◽  
And Control ◽  
Control Study

In this paper,a novel CVT with electronic control and a motor as actuator (EM-CVT) is presented, whose speed ratio can be adjusted by driving the two movable discs of the primary and secondary pulley at the same time. Firstly, the EM-CVT transmission dynamics mode was established based on the analysis of EM-CVT working principle and ratio change characteristics. Secondly, the speed ratio control strategy and control method for EM-CVT was designed according to the EM-CVT features and functional requirements of the control system; Finally, the simulation was carried out to verify the validity of the control strategy and meth

Study on Current Detecting and Control Method for STATCOM across Transformer

2011 ◽  
Vol 130-134 ◽  
pp. 1933-1937
Author(s):  
Cun Ping Wang ◽  
Xiang Gen Yin ◽  
Jian Liu ◽  
Qing Xiong
Keyword(s):  
Reactive Power ◽  
Control Method ◽  
Electronic Device ◽  
Control Strategies ◽  
Power Electronic ◽  
Output Current ◽  
Load Current ◽  
Decoupling Method ◽  
Reactive Current ◽  
And Control

Static var compensator (STATCOM) is a widely used power electronic device for dynamic reactive power compensation, and its current detecting and control method generally adopts d-q decoupling method based on the synchronous rotating coordinate transformation. However, in the traditional method, the load reactive current component is directly used as the command of STATCOM output current, so it is required that the installation position of STATCOM must be consistent with load current detecting point. But in practice, STATCOM installation point and load current detecting point may be located at two different sides of the transformer. For this situation, this paper proposed an improved reactive current detecting and control method based on the principle of power balance, achieving the current detecting and control strategies when the two points are located at different sides of transformer. Finally, the simulation of system with STATCOM accessed from the third winding of transformer verifies the correctness and feasibility of the proposed method.

Overview of Impacts of Distribution Generations and Micro Grids on Active Distribution Network Operation

2014 ◽  
Vol 700 ◽  
pp. 103-110
Author(s):  
Lei Yu ◽  
Tian Yang Zhao ◽  
Xu Wu ◽  
Jian Hua Zhang
Keyword(s):  
Distribution System ◽  
Dynamic Models ◽  
Control Method ◽  
Distribution Network ◽  
Distribution Networks ◽  
Negative Effects ◽  
Active Distribution Network ◽  
System Operator ◽  
Network Operation ◽  
High Level

With recent development of technology and management in power market and equipment, more and more distributed generation (DG) is embedded in the distribution network. However the approach of connecting DG in most cases is based on a so-called ‘fit and forget’ policy and the capacity of DG is limited rigidly by distribution system operator to avoid the negative effects of high level penetration. New management technologies have been proposed to handle the integration of DGs in the distribution networks. In this review, the micro grid (MG) was treated as the local control method to coordinate DGs within a small area of distribution network. And the active distribution network (AND) was treated as the global control mechanism to actively manage DGs, MGs and other equipment. The operation framework of ADN was firstly introduced. Then based on the static and dynamic models of DGs and MGs, impacts of DGs and MGs on the ADN are surveyed from power quality, stability to the operation. Finally, the conclusion and suggestion is given in this paper.

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