Local Communication in Populations of Thermostatically Controlled Loads

2020 ◽  
Vol 1 (3) ◽  
Author(s):  
Jason Kuwada ◽  
Ryan Schwartz ◽  
John F. Gardner
Keyword(s):  
Stability Analysis ◽  
Demand Response ◽  
Aggregate Behavior ◽  
Thermostatically Controlled Loads ◽  
Simulation Results ◽  
Negative Impacts ◽  
Proposed Modification ◽  
Linearized Model ◽  
Insight Into ◽  
Aggregate System

Abstract Thermostatically controlled loads (TCLs) have shown great potential for demand response (DR) in electric grid operations. However, it has been commonly seen that DR events using TCLs may cause load synchronization and unwanted oscillatory effects, especially in homogeneous populations. In an attempt to mitigate the negative impacts of DR events, a decentralized method is proposed that modifies each thermostat behavior based on the activity of a small number of nearby TCLs. This feedback introduces the possibility of instability in the aggregate behavior. A stability analysis is performed on a linearized model of the aggregate system and the results of that analysis compared to simulation results. The proposed modification of thermostat behavior results in fourfold reduction in the post-DR peak while suppressing ensuing oscillations at the expense of a modest increase in compressor cycling. The linearized model also provides insight into the aggregate behavior of the population.

Stability Analysis of Demand Response Systems Utilizing Locally Communicating Thermostatically Controlled Loads

2019 ◽  
Author(s):  
Jason Kuwada ◽  
John F. Gardner
Keyword(s):  
Stability Analysis ◽  
Demand Response ◽  
Aggregate Behavior ◽  
Communication Topology ◽  
Response Systems ◽  
Thermostatically Controlled Loads ◽  
Negative Impacts ◽  
Insight Into ◽  
Varying Population ◽  
Aggregate System

Abstract Thermostatically Controlled Loads (TCLs) have shown great potential for Demand Response (DR) events. However, it has been commonly seen that DR events using TCLs may cause load synchronization and unwanted oscillatory effects, especially in homogeneous populations. In an attempt to mitigate the negative impacts of DR events, a decentralized method is proposed that modifies each thermostat behavior based on the activity of nearby TCLs. This feedback introduces the possibility of instability in the aggregate behavior. A stability analysis is performed on a model of the aggregate system and the results of that analysis compared to simulation results. Several populations were considered, varying population size, communication topology, thermostat deadband and heterogeneity of the population. While the linearized analysis failed to accurately predict instabilities in the aggregate system, it did provide insight into global behavior.

scholarly journals Structure Formation in Anisotropic Disks

2006 ◽  
Vol 2 (S235) ◽  
pp. 143-143
Author(s):  
Eduard Vorobyov ◽  
Christian Theis
Keyword(s):  
Stability Analysis ◽  
Linear Stability ◽  
Linear Stability Analysis ◽  
Disk Galaxies ◽  
Structural Elements ◽  
Small Perturbations ◽  
Gravitational Instabilities ◽  
Hydrodynamical Simulations ◽  
Axisymmetric Structures ◽  
Insight Into

The majority of normal disk galaxies are characterized by non-axisymmetric structures like spirals or bars. These structural elements have been widely discussed in the literature as a result of gravitational instabilities which are connected to growing density waves or global instabilities of disks. A first insight into the properties of galactic discs was provided by linear stability analysis. However, a disadvantage of linear stability analysis remained its restriction to small perturbations, both in amplitude and wavelength. Thus, numerical simulations, especially hydrodynamical and stellar-hydrodynamical simulations became a primary tool for the analysis of galactic evolution.

Tip-Over Stability Analysis for a Wheeled Mobile Manipulator

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Shuai Guo ◽  
Tao Song ◽  
Fengfeng (Jeff) Xi ◽  
Richard Phillip Mohamed
Keyword(s):  
Stability Analysis ◽  
Path Planning ◽  
Static Load ◽  
System Stability ◽  
Mobile Manipulator ◽  
Inertial Forces ◽  
Horizontal Position ◽  
Reaction Forces ◽  
Simulation Results

A method is presented for tip-over stability analysis of a wheeled mobile manipulator. A wheeled mobile manipulator may tip over resulting from its operation. In this study, first a Newton–Euler formulation is applied to formulate the manipulator’s reaction forces and moments exerted onto the mobile platform. Tip-over criterion is derived to judge the system stability. Three load and motion analyses are carried on. The first static load deals with links and payload to show the effect of the horizontal position of the system’s center of gravity (CG). The second and third are the inertial forces resulting from joint speeds and accelerations, respectively. Case study is path planning with tip-over criterion result which can make the system stable along the path. The simulation results demonstrate the effectiveness of the proposed method.

Performance Analysis and Improvement Approach of HEV Extended Expansion Gasoline Engine

2011 ◽  
Vol 317-319 ◽  
pp. 1999-2006
Author(s):  
Yu Wan ◽  
Ai Min Du ◽  
Da Shao ◽  
Guo Qiang Li
Keyword(s):  
Mathematical Model ◽  
Performance Analysis ◽  
Fuel Consumption ◽  
Economic Performance ◽  
Gasoline Engine ◽  
Engine Performance ◽  
Valve Train ◽  
Gasoline Engines ◽  
Simulation Results ◽  
Negative Impacts

According to the boost mathematical model verified by experiments, the valve train of traditional gasoline engine is optimized and improved to achieve extended expansion cycle. The simulation results of extended expansion gasoline engine shows that the extended expansion gasoline engine has a better economic performance, compared to traditional gasoline engines. The average brake special fuel consumption (BSFC) can reduce 22.78 g / kW•h by LIVC, but the negative impacts of extended expansion gasoline engine restrict the potential of extended expansion gasoline engine. This paper analyzes the extended expansion gasoline engine performance under the influence of LIVC, discusses the way to further improve extended expansion gasoline engine performance.

Landscape Fragmentation Around Us – Integrating the Issue into Educational Processes at Primary and Secondary Schools

2020 ◽  
Author(s):  
Ivo Dostál ◽  
Petr Anděl ◽  
Marek Havlíček ◽  
František Petrovič
Keyword(s):  
Landscape Fragmentation ◽  
The Czech Republic ◽  
Educational Processes ◽  
Wildlife Migration ◽  
Negative Impacts ◽  
Proposed Modification ◽  
The Given ◽  
History Classes ◽  
Impacts Of Human Activity

The steadily increasing landscape fragmentation and the reduction of permeability for wildlife are among the most negative impacts of human activity on the environment. In terms of education, theseproblems appear to be rather demanding, withthe difficulty corresponding tosecondary school standards. Considering the multiple interdisciplinary connections, the entire process cannot be sufficiently understood without a relevant amount of preliminary knowledge. Such a corpus of information is acquired especially through biology/ecology, geographyand history classes, but links to other subjects can be found too. The paper presents didactic methods facilitating the actual presentation of the theme to pupils/students; in this context, the authors discuss the possibilities of integrating the given problems into applicable schoolsubjects andoutline the risks arising from the proposed modification and/ or expansion of the teaching procedures. Also the links to data and supporting methodological materials are included that will allow the teacher to obtain enough information on the topicsto comprehend all the aspects and complexities of the innovated classes. In the corresponding sections, the papercharacterizes individual topics to be combined with selected teaching methods, especially as regards worksheets, project-oriented education, anda case study relating to afield trip targeting one of the areas of high importance for wildlife migration in the Czech Republic.

Anti-neutrophil cytoplasmic antibodies-associated vasculitis: a guide and case study

2020 ◽  
Vol 29 (22) ◽  
pp. 1333-1340
Author(s):  
Helena Boyer ◽  
Gerri Mortimore
Keyword(s):  
Hearing Loss ◽  
Information Value ◽  
Ocular Involvement ◽  
Treatment Regimens ◽  
Related Information ◽  
Increased Risk ◽  
Red Flag ◽  
Negative Impacts ◽  
Insight Into

Vasculitis is a relatively rare and poorly understood condition causing inflammation of the blood vessels, which in turn can affect a patient's respiratory and renal systems. In some cases, ocular involvement can cause loss of sight and hearing loss may also be a red flag for vasculitis, which, if not treated early, can cause complete hearing loss. Anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) is a group comprising granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA) and eosinophilic granulomatosis (EGP). AAV is fatal if untreated and as increased risk escalates with age, coupled with a decline in renal function, these are the principal predictors of poor outcome. Vital roles for nursing vasculitis patients lie in managing inflammation and pain, as these distressing symptoms are prevalent in the disease. Because of the multiple complications that can occur with vasculitis, treatment-related information is a high priority for these patients. As nurses are well placed to deliver information, value lies in their role in reducing the negative impacts on treatment regimens and compliance that accompany patients' poor insight into their condition.

Stability Analysis of a Class of Nonlinear Controllers

2003 ◽  
Author(s):  
T. Ravichandran ◽  
G. R. Heppler ◽  
D. W. L. Wang
Keyword(s):  
Stability Analysis ◽  
Exponential Stability ◽  
Tracking Control ◽  
Global Exponential Stability ◽  
Feedback Controller ◽  
Nonlinear Gain ◽  
Nonlinear Controllers ◽  
Simulation Results ◽  
Pd Feedback Controller ◽  
The Stability

The stability analysis of a class of nonlinear PD-plus-feedforward controllers is presented for the tracking control of rigid robot manipulators. The controller structure is composed of a nonlinear gain PD feedback controller and a manipulator dynamics feedforward term. The class of representations used for the nonlinear gain PD feedback controller is extended and global exponential stability is proved. Simulation results are included to illustrate the performance of this class of nonlinear controllers.

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