John Hastings

A smart grid information system for demand side participation: Remote control of domestic appliances to balance demand

Due to the intermittent nature of renewable generation it is desirable to consider the potential of controlling the demand-side load to smooth overall system demand. The architecture and control methodologies of such a system on a large scale would require careful consideration. Some of these considerations are discussed in this paper; such as communications infrastructure, systems architecture, control methodologies and security. A domestic fridge is used in this paper as an example of a controllable appliance. A layered approach to smart-grid is introduced and it can be observed how each smart-grid component from physical cables, to the end-devices (or smart-applications) can be mapped to these set layers. It is clear how security plays an integral part in each component of the smart-grid so this is also an integral part of each layer. The controllable fridge is described in detail and as one potential smart-grid application which maps to the layered approach. A demonstration system is presented which involves a Raspberry Pi (a low-power, low-cost device representing the appliance controller).

Synchronous islanding control in the presence of hydro-electric generation

This paper introduces a novel load sharing algorithm to enable island synchronization. The system model used for development is based on an actual system for which historical measurement and fault data is available and is used to refine and test the algorithms performance and validity. The electrical system modelled is selected due to its high-level of hydroelectric generation and its history of islanding events. The process of developing the load sharing algorithm includes a number of steps. Firstly, the development of a simulation model to represent the case study accurately - this is validated by way of matching system behavior based on data from historical island events. Next, a generic island simulation is used to develop the load sharing algorithm. The algorithm is then tested against the validated simulation model representing the case study area selected. Finally, a laboratory setup is described which is used as validation method for the novel load sharing algorithm.

Towards an improved phasor measurement unit data communications framework

This paper discusses a proposed new communications framework for phasor measurement units (PMU) optimized for use on wide area networks. Traditional PMU telecoms have been optimized for use in environments where bandwidth is restricted. The new method takes the reliability of the telecommunications medium into account and provides guaranteed delivery of data whilst optimizing for realtime delivery of the most current data. Other important aspects, such as security, are also considered.

Tracking smart grid hackers

The next-generation smart grid will rely highly on telecommunications infrastructure for data transfer between various systems. Anywhere we have data transfer in a system is a potential security threat. When we consider the possibility of smart grid data being at the heart of our critical systems infrastructure it is imperative that we do all we can to ensure the confidentiality, availability and integrity of the data. A discussion on security itself is outside the scope of this paper, but if we assume the network to be as secure as possible we must consider what we can do to detect when that security fails, or when the attacks comes from the inside of the network. One way to do this is to setup a hacker-trap, or honeypot. A honeypot is a device or service on a network which appears legitimate, but is in-fact a trap setup to catch breech attempts. This paper identifies the different types of honeypot and describes where each may be used. The authors have setup a test honeypot system which has been live for some time. The test system has been setup to emulate a device on a utility network. The system has had many hits, which are described in detail by the authors. Finally, the authors discuss how larger-scale systems in utilities may benefit from honeypot placement.

An open source analogue to digital converter for power system measurements with time synchronisation

This paper describes an open source analogue to digital converter designed to meet the requirements of power system waveform measurement. In particular, attention is given to ensuring that waveforms are synchronously sampled to maintain the relationship between the various observed quantities, and the system is synchronized to the UTC time base by means of a GPS receiver, making a wide area comparison of data and synchrophasor estimation possible. This ADC can be used as a front end in Phasor Measurement Unit (PMU) devices, amongst other applications. An advantage of this method is that the sampling clock is disciplined to the UTC time base to ensure an integer number of samples are taken per second at the desired sampling rate. The certainty of the timing of the sample data makes a wide area comparison of the data possible, providing an enabling technology for Waveform Measurement Units (WMU). An open design philosophy is used throughout, with the intention of providing visibility throughout the operation of the device, so that the end user can study its operation and evaluate and modify it within their application.

A heuristic, self-adjusting flow control mechanism for sensor data in real-time applications

In this paper the authors present an application-layer reporting-rate regulation, or flow control, mechanism that enables reliable sensor data transport over nondeterministic communication networks in latency-critical applications such as protection. This enables the real-time characteristics of a system to be preserved during unfavorable telecommunication network conditions. The proposed is a novel mechanism to adjust the sensor data reporting-rate automatically at the application-layer to ensure data delivery as close to real-time as possible in latency-critical applications; thus mitigating the effect of buffering due to network-level flow control, particularly in the event of primary link failures. A case-study application of island detection by synchrophasor is presented along with a test-bed to prove the proposed mechanism. This uses a Wide Area Network simulator, configured with real bandwidth and latency data collected from a télécoms survey of the case-study area.