Gather-and-broadcast frequency control in power systems

We propose a novel frequency control approach in between centralized and distributed architectures, that is a continuous-time feedback control version of the dual decomposition optimization method. Specifically, a convex combination of the frequency measurements is centrally aggregated, followed by an integral control and a broadcast signal, which is then optimally allocated at local generation units. We show that our gather-and-broadcast control architecture comprises many previously proposed strategies as special cases. We prove local asymptotic stability of the closed-loop equilibria of the considered power system model, which is a nonlinear differential-algebraic system that includes traditional generators, frequency-responsive devices, as well as passive loads, where the sources are already equipped with primary droop control. Our feedback control is designed such that the closed-loop equilibria of the power system solve the optimal economic dispatch problem

Fiscal federalism : dimensions of tax reform in developing countries

The authors propose four economic principles for use in deciding taxing responsibilities for various levels of government. These are: 1) efficiency of the internal common market - for efficiency in internal common market, taxes on mobile factors and tradable goods should either be assigned to the national government or coordinated among subnational governments; 2) national equity - progressive redistributive taxes ought to be assigned to the level of government having responsibility for redistribution, usually the national government. Subnational governments could levy supplementary flat rates on the federal tax base; 3) administrative costs - to minimize collection, administration, and compliance costs, a tax should be assigned to the level likely to be best informed about its base. This suggests assigning real property taxation to local governments and corporate income taxation to the national government; and 4) fiscal need - to ensure accountability, revenue means should be matched as closely as possible to revenue needs. Thus tax instruments intended to further specific policy objectives should be assigned to the level of government having the responsibility for such a service. Thus progressive redistributive taxes, stabilization instruments, and resource rent taxes would be suitable for assignment to national government; while tolls on intermunicipal roads are suitably assigned to state governments. Some resource taxes, such as royalties and fees and severance taxes on production and/or output, are designed to cover costs of local service provision and could be assigned to subnational governments. In addition, subnational governments could also impose taxes to discourage local environmental degradation. In countries with a federal level VAT, it may be too cumbersome to have subnational sales taxes. In such circumstances, the fiscal need criterion would suggest allowing subnational governments access to taxes which are traditionally regarded as suitable for national administration, such as personal income taxes. The authors also stress the importance of tax harmonization and coordination in preserving internal common market, reducing collection and compliance costs and helping to achieve national equity objectives and suggest methods of achieving such coordination vertically (between the federal and subnational governments) and horizontally (among subnational governments).Municipal Financial Management,Public Sector Economics&Finance,National Governance,Banks&Banking Reform,Environmental Economics&Policies

A Stochastic Resource-Sharing Network for Electric Vehicle Charging

We consider a distribution grid used to charge electric vehicles such that voltage drops stay bounded. We model this as a class of resource-sharing networks, known as bandwidth-sharing networks in the communication network literature. We focus on resource-sharing networks that are driven by a class of greedy control rules that can be implemented in a decentralized fashion. For a large number of such control rules, we can characterize the performance of the system by a fluid approximation. This leads to a set of dynamic equations that take into account the stochastic behavior of EVs. We show that the invariant point of these equations is unique and can be computed by solving a specific ACOPF problem, which admits an exact convex relaxation. We illustrate our findings with a case study using the SCE 47-bus network and several special cases that allow for explicit computations.Comment: 13 pages, 8 figure

Mean-Field-Type Games in Engineering

A mean-field-type game is a game in which the instantaneous payoffs and/or the state dynamics functions involve not only the state and the action profile but also the joint distributions of state-action pairs. This article presents some engineering applications of mean-field-type games including road traffic networks, multi-level building evacuation, millimeter wave wireless communications, distributed power networks, virus spread over networks, virtual machine resource management in cloud networks, synchronization of oscillators, energy-efficient buildings, online meeting and mobile crowdsensing.Comment: 84 pages, 24 figures, 183 references. to appear in AIMS 201

Consensus-based approach to peer-to-peer electricity markets with product differentiation

With the sustained deployment of distributed generation capacities and the more proactive role of consumers, power systems and their operation are drifting away from a conventional top-down hierarchical structure. Electricity market structures, however, have not yet embraced that evolution. Respecting the high-dimensional, distributed and dynamic nature of modern power systems would translate to designing peer-to-peer markets or, at least, to using such an underlying decentralized structure to enable a bottom-up approach to future electricity markets. A peer-to-peer market structure based on a Multi-Bilateral Economic Dispatch (MBED) formulation is introduced, allowing for multi-bilateral trading with product differentiation, for instance based on consumer preferences. A Relaxed Consensus+Innovation (RCI) approach is described to solve the MBED in fully decentralized manner. A set of realistic case studies and their analysis allow us showing that such peer-to-peer market structures can effectively yield market outcomes that are different from centralized market structures and optimal in terms of respecting consumers preferences while maximizing social welfare. Additionally, the RCI solving approach allows for a fully decentralized market clearing which converges with a negligible optimality gap, with a limited amount of information being shared.Comment: Accepted for publication in IEEE Transactions on Power System

Federalism, Subsidiarity, and the Role of Local Governments in an Age of Global Multilevel Governance

This article argues that current legal and political systems are incapable of dealing with human conflicts on multiple spheres (federal, state, local) simultaneously. The two dominant political theories that are supposed to solve this problem - federalism and subsidiarity, are inadequate. This article then argues that federalism and subsidiarity must be understood as distinct from one another, and subsidiarity is a better fit for the task of articulating multi-level governance, even if only as a tool for loosening the grip of federalism over our political and legal theory