In response to the key engineering problems of photovoltaic grid-connected inverter cluster resonance suppression affected by impedance, in this paper, a control strategy based on disturbance observer is proposed dynamically compensate for damping coefficient controlled system and improve robustness system. First, an mathematical model 200 MW established, mechanism active influenced analyzed. S...

As the integration of Distributed Energy Resources (DERs) in modern grids is increasing, the microgrid concept has been established. In the case of converter-dominated microgrids without communication links, the droop control method is mainly adopted in the primary control level. Normally, the economic operation of the microgrid is incorporated in the secondary control level, requiring communic...

Research in learning from demonstration has focused on transferring movements from humans to robots. However, a need is arising for robots that do not just replicate the task on their own, but that also interact with humans in a safe and natural way to accomplish tasks cooperatively. Robots with variable impedance capabilities opens the door to new challenging applications, where the learning a...

This paper deals with the numerical prediction of the aeroacoustic behavior of orifices under grazing flow conditions. A hybrid computational aeroacoustics approach is adopted where the steady, incompressible, mean flow over the orifice is obtained from a RANS simulation. In a next step, the mean flow variables are used to solve the linearized Navier–Stokes equations (LNSE), using a Runge–Kutta...

in recent years, virtual communities have been significantly popular and almost all of them are targeted for business profitability. in our study, the profitability of these communities for businesses has been analyzed from a commercial perspective. the study considers virtual community as a business model which can have a great impact on consumer purchase decision process. with respect to refe...

studies show that any complications including hemorrhage, lack of blood supply, lack of oxygen supply, and death of cells in a tissue, will have a clear effect on electrical properties of that tissue. thus, by measuring impedance of a set of tissues, potential problems of the damaged tissue may be found. since electrical impedance is closely related to the measuring frequency, obviously, every ...

Compared to voltage mode circuits, current circuits have advantages such as large dynamic range, fast speed, wide frequency band, and good linearity. In recent years, the development of call flow modeling technology has been rapid become an important foundation for analog integrated circuits. this paper, a chaotic oscillation circuit based on differential transconductance amplifier (CDTA) is pr...

Abstract In the high frequency link matrix converter parallel system, impedance parameters on each line are unequal so that output power of is not equal. To solve this problem, reason why cannot be divided equally under droop control strategy analyzed, and a sharing based adaptive virtual proposed. This introduces in voltage-current dual-loop system with control, uses converter’s information fa...

Grid-forming inverters are sensitive to large grid disturbances that may engender overcurrent due their voltage source behavior. To overcome this critical issue and ensure the safety of system, current limitation techniques have be implemented. In context, variable virtual impedance (VI) appears as a suitable solution for problem. The design basically rests on static considerations, while, its ...

In this paper control systems design approach, based on siding mode methods, that allows maintain some functional relation – like bilateral or multilateral systems, establishment of virtual relation among mobile robots or control of haptic systems is presented. It is shown that all basic motion control problems trajectory tracking, force control, hybrid position/force control scheme and the imp...