Cor Warmer

Distributed Control Concepts using Multi-Agent technology and Automatic Markets: An indispensable feature of smart power grids

Multi-agent technology is state of the art ICT. It is not yet widely applied in power control systems. However, it has a large potential for bottom-up, distributed control of RES and DER in future power systems. At least two major European R&D projects (MicroGrids and CRISP) have investigated its potential. Both grid-related as well as market related applications have been studied. This paper will focus on two field tests, performed in the Netherlands, applying multi-agent control by means of the PowerMatcher concept. In the PowerMatcher concept (http://www.powermatcher.net/) software agents are used as representatives of the power producing and/or consuming installations. Via market algorithms a strategy is determined to ensure, that their operational schemes are coordinated in order to balance supply and demand according to the business case. The algorithms in the PowerMatcher use a bottom-up electronic market mechanism. Building such a system, controlling primary user processes on one hand, assuring local autonomy, and operating on the electricity market on the other hand, appears to be feasible with mainstream ICT-components. We will describe and discuss a number of results from two field tests performed with the PowerMatcher concept, and discuss further developments.

A field test using agents for coordination of residential micro-chp

In the Netherlands decentralised generation of heat and power by mu-CHP units in households is expected to penetrate the market at high speed in the coming years. Using ICT these mu-CHP units can be integrated into a smart power system or virtual power plant. Other local production and consumption of electricity such as PV, wind, heat pumps and electrical vehicles can be added to this cluster. The main goal of a smart power system is to optimize the value of decentralised power production and consumption in view of the total energy value chain. The PowerMatcher is a multi-agent based control concept (and software package) for coordination of demand and supply in electricity networks with a high share of distributed generation. The concept is demonstrated in several real life field tests. One of these field tests is a virtual power plant consisting of 10 mu-CHP units reducing the local peak demand of the common low-voltage grid segment the mu-CHP units are connected to. In this way the VPP supports the local distribution network operator (DNO) to defer reinforcements in the grid infrastructure (transformers and cables). To realize this VPP, an ICT-communication network containing a hardware and software infrastructure has been added to a test rollout of mu-CHP installations in The Netherlands. Main conclusion from the field test is that a peak reduction of 30 -50% can be achieved, depending on summer or winter season.

Monitoring and Control for Energy Efficiency in the Smart House

The high heterogeneity in smart house infrastructures as well as in the smart grid poses several challenges when it comes into developing approaches for energy efficiency. Consequently, several monitoring and control approaches are underway, and although they share the common goal of optimizing energy usage, they are fundamentally different at design and operational level. Therefore, we consider of high importance to investigate if they can be integrated and, more importantly, we provide common services to emerging enterprise applications that seek to hide the existing heterogeneity. We present here our motivation and efforts in bringing together the PowerMatcher, BEMI and the Magic system.

Local DER driven grid support by coordinated operation of devices

In the traditional operation of electricity networks the system operator has a number of ancillary services available for preservation of system balance. These services are called upon near real-time, after the planning phase. Ancillary services consist of regulating power, reserve capacity and emergency capacity, each with their own characteristics. Regulating power is deployed via load frequency control. Reserve capacity is used to release regulating power and can be called upon to maintain a balance or to counterbalance or resolve transmission restrictions. Both are traded at the Dutch energy market under an auction model with a single buyer (TenneT). Emergency capacity is rewarded on the basis of accessibility/availability within 15 minutes. In local electricity networks neither planning nor ancillary services exist. Planning is done by aggregation into large customer groups. For ancillary services one relies on the system operation as sketched above. In local electricity networks with a large share of distributed generation the costs of keeping the electricity system reliable and stable will increase further and technical problems may arise. The European SmartGrids initiative responds to these challenges in their strategic research agenda. One of the issues addressed in this agenda is the changing role of the distribution grid in which users get a more active role. One opportunity is the introduction of ancillary-type services at the distribution level, utilizing different types of producing and consuming devices in the local network, in order to make the total system more dependable. Distributed generation has a number of characteristics that are similar to characteristics of consumption. Part of it is intermittent / variable, although to a large extent predictable (PV, wind versus lighting, electronic devices). Another part is task-driven (micro-CHP versus electrical heating). Yet another part is controllable or shiftable in time. And storage can behave both ways. The main key words here are flexibility and variability. This flexibility provides a virtual storage capacity within the electricity grid that can be utilized for balancing services at the local grid. We will present how the PowerMatcher concept, developed by ECN, supports the setting up of local balancing markets in a flexible and logical way. The ICT is already available as an enabling technology. The concept has been demonstrated in several field tests.

Architectures for novel energy infrastructures: Multi-agent based coordination patterns

Due to the increased proportion of small renewable energy sources in a distributed setting (DG-RES), active control of small distributed energy producing and consuming systems will play an important role in future electricity grids [1]. These distributed energy resources have production patterns, which are either partially stochastic (e.g. wind, solar cells) or are coupled to the primary user process (e.g. co-generation of heat and electricity). Furthermore, on the demand-side, and increasingly on the electricity storage side, opportunities exist for actively serving stability applications in the grid by real-time supply/demand coordination. In the future, an information and communication layer for grid coordination could serve a portfolio of ICT-applications on timescales running from seconds to hours. To get a grip on these (r)evolutionary developments, possibly toppling the electricity grid, in this paper, architecture requirements for future high proportion DG-RES electricity grids are collected from a Power Electronics System point of view as well as from an ICT point of view using an inventory of business models in the power grid that focus on coordination of multiple small-scale DG-RES resources. Modeled from an ICT point-of-view, these give rise to architectures for applications that can successively be implemented in hardware and software as active components in the distribution grid. A number of possible grid control strategy coordination patterns (GCPs), which are defined in a generic, reusable manner, can be seen to emerge. GCPs, connected and intertwined to one another on several layers (physical, commercial) of the grid, together, can provide the framework for coordination in the overall intelligent grid. Bottom-up approaches of implementing coordination in future active grids appear to be the method of choice to use in implementing the GCPs. Software agents [2], [3] coordinating primary processes using market algorithms, as implemented in the PowerMatcher approach [3]-[4], appear to be very suited for this.

Field Trials towards Integrating Smart Houses with the Smart Grid

Treating homes, offices and commercial buildings as intelligently networked collaborations can contribute to enhancing the efficient use of energy. When smart houses are able to communicate, interact and negotiate with both customers and energy devices in the local grid, the energy consumption can be better adapted to the available energy supply, especially when the proportion of variable renewable generation is high. Several efforts focus on integrating the smart houses and the emerging smart grids. We consider that a highly heterogeneous infrastructure will be in place and no one-size-fits-all solution will prevail. Therefore, we present here our efforts focusing not only on designing a framework that will enable the gluing of various approaches via a service-enabled architecture, but also discuss on the trials of these.