We designed a distributed collision‐free formation flight control law in the framework of nonlinear model predictive control. Formation configuration is determined virtual reference point coordinate system. Obstacle avoidance guaranteed by cost penalty, and intervehicle collision penalty combined with new priority strategy.

Due to the development of science and technology, people are increasingly interested in portable flexible devices, demand is deepening.Among them, sensors play an important role signal transmission between equipment.We study a low-cost, easy-to-prepare, can-be mass-produced pressure sensor element, which made silver nanowires/polyvinyl butyral/melamine sponge (AgPMS).Due chemical stability nanowires its wrapped structure on melamine skeleton, AgPMS can maintain constant resistance 5000 times...

A collision-free formation flight controller for unmanned aerial vehicle (UAV) is designed in the framework of nonlinear model predictive control (MPC). It can consider input saturation and state constraints explicitly. Formation configuration determined based on virtual reference point method, which has no error propagation formation. The a distributed way. Based tracking error, objective function each UAV MPC framework. new type cost function, UAV's velocity orientation relative distance...

Based on a novel multilevel voltage source converter (VSC) used for electric drive, the pre-charging process of is fully analyzed, so as to find suitable control strategy. For single with redundant modules, divided into two stages, unlock charging course in particular analyzed. To ensure normal operation converter, an optimized method presented. modular system rectifier side and inverter side, strategy separately analyzed proved be effective.

This paper analyzes the characteristics of submodule (SM) voltage fundamental frequency and second-order harmonic ripples with consideration negative state full-bridge SM. The optimal operation point, which minimizes ripples, is derived. Both design principle analytical expressions for SM capacitance dimensioning are presented, comparison between energy storage requirements without states in arm reference voltages also carried out under same constraints on transmission power, modulation...

The DC voltage dynamics of droop-controlled source converter based multi-terminal HVDC system (VSC-MTDC) are more complicated due to their transient overshoot and steady-state deviation. Firstly, solve the dynamic problems VSC-MTDC with strong adjacent AC system, a practical reduced-order model is established in control timescale. Besides, droop-based outer controller considered as droop admittance lag-lead characteristic, which provides physical explanation caused by coefficients. Moreover,...

This article presents an in-depth study on the circuit dynamics and control strategy of recently proposed full-bridge five-branch modular multilevel converter (FB5B-MMC) to qualify its application potential for comprehensive power quality management cophase railway system (RPS) with detailed consideration nonideal operating conditions. In particular, coupling induced by branch inductor parameter discrepancy, effects voltages, currents, capacitor voltage stability, fluctuations brought...

Featuring high modularity, scalability and transformerless structure, cascaded H-bridge (CHB) based power quality compensator (PQC) is a promising solution for railway system (RPS). Firstly, branch rating requirements of the conventional CHB PQCs co-phase RPS are analyzed under two typical traction transformer schemes, i.e., V-v scheme Scott scheme. Then, novel PQC with special wiring connection style proposed, which achieves reduced total submodule quantity capacity compared in schemes. In...

This paper conducts a thorough analysis on the circuit dynamics of single-phase direct ac-ac modular multilevel converter (MMC) to address branch energy divergence problem in railway power conditioning application scenario. Based analysis, full degree freedom (DOF) based control scheme is proposed. By controlling all DOFs coordinated manner, extended controllability can be achieved, which enables each branch's regulated individually without deteriorating terminal currents. As result,...

This paper introduces a single-phase five-branch direct ac-ac modular multilevel converter (MMC) with the capability of equal frequency conversion for railway power conditioning applications. By analyzing branch energy balance mechanism, basic operating principle proposed MMC is clarified and control strategy also proposed. Comparisons between traditional matrix (MMMC) on voltage current ratings as well capacitor dimension requirements are presented. The effectiveness topology validated...

Series connection of low-voltage power cells has been considered as an alternative microgrid configuration to supply rated voltage point common coupling (PCC) loads. However, in the previous studies, major focus was on regulation system. Similar conventional shunt-distributed generation (DG)-unit-based islanded microgrid, PCC harmonic problem can be serious without any active control. In order provide enhanced quality this system, a flexible compensation approach is developed via...

In this article, a bypass pulse injection-based pulsewidth modulation approach is proposed for mitigating line current harmonics of grid-tied current-source converters (CSCs) operating at low switching frequency. First, the relationship between CSC output harmonic and format analyzed. Then, through online adjustment both location width, seventh component actively regulated to mitigate corresponding current. Meanwhile, action may be associated with additional amplification fifth To deal...

For medium- to high-voltage AC/AC conversion applications, direct scheme by adopting the modular multilevel converter (MMC) shows remarkable advantages on costs and efficiency compared with AC/DC/AC solution which employs a back-to-back MMC configuration. However, suffers from branch energy instability when frequencies of input output are equal. This paper presents sept-branch (SB-MMC) topology for applications. The feature this SB-MMC is its capability equal frequency three-phase...

Hybrid transmission systems associated with line commutated converters (LLC) and voltage source (VSC) have gradually become a particular solution for high direct current (HVDC) transmission. The full-bridge submodule (FBSM) based modular multilevel converter (FB-MMC) has gained significant attention its dc reversal fault ride through capabilities. However, large capacitance is essential power of FB-MMC, increasing cost size rapidly. This paper analyzes the FBSM fundamental frequency...

This article investigates the recently proposed full-bridge five-branch modular multilevel converter (FB5B-MMC) for power quality enhancement of cophase railway system (RPS) with high-level penetration nonlinear inductive traction loads. Since circuit topology FB5B-MMC is asymmetric respect to its two ports, different configurations exist when connecting into RPS. First, an optimized configuration and corresponding compensation scheme are proposed. The operation features uniform distribution...

Modular multilevel converter (MMC) has been proved a prospective topology in high voltage and power occasions. Hybrid MMC mixed with half-bridge (HB) full-bridge submodules (FBSMs), which achieves good tradeoff between devices quantity dc short circuit fault handling capability, attracts extensive attention. In this paper, the characteristics of SM capacitor ripples are analyzed detail when FBSM negative state is utilized. The optimal operation point derived minimizes fundamental frequency...

Power system restoration decision making optimization is important for its safe and rapid after blackout occurred. Generally, multi-criteria (MCDM) method employed to provide support dispatchers. Reasonable weights are conducive support. In order reduce the subjectivity of weights, this paper proposes a novel weighting method. Firstly, weighted least-square used determine subjective according attributes preference maker. Secondly, information entropy theory acquire objective weights. At...

Real-time simulation of modular multilevel converter (MMC)-based HVDC is one the most important and difficult technologies in area power electronics research. This paper presents a methodology for hardware loop (HIL) CPU/FPGA-based real-time one-terminal MMC up to 468 levels using detailed equivalent model, system based on full-scale physical control system, including actual sub module boards. The testing subject accompanying are same symmetric structure, without expensive third part HIL...

For medium- to high-voltage ac-ac conversion applications, direct modular multilevel converters (MMCs) show advantages on power density compared indirect (ac-dc-ac) MMCs. However, MMCs suffer from branch energy divergence when the operation frequencies of input and output are equal. This paper investigates three-phase single-phase MMC under equal frequency condition proposes a novel control strategy balance its branches' energies. The effectiveness is validated by simulation results.