Evaluating the robustness of an active network management function in an operational environment

This paper presents the integration process of a distribution network Active Network Management (ANM) function within an operational environment in the form of a Micro-Grid Laboratory. This enables emulation of a real power network and enables investigation into the effects of data uncertainty on an online and automatic ANM algorithm's control decisions. The algorithm implemented within the operational environment is a Power Flow Management (PFM) approach based around the Constraint Satisfaction Problem (CSP). This paper show the impact of increasing uncertainty, in the input data available for an ANM scheme in terms of the variation in control actions. The inclusion of a State Estimator (SE), with known tolerances is shown to improve the ANM performance

Wide-angle effects in multi-tracer power spectra with Doppler corrections

We examine the computation of wide-angle corrections to the galaxy power spectrum including redshift-space distortions and relativistic Doppler corrections, and also including multiple tracers with differing clustering, magnification and evolution biases. We show that the inclusion of the relativistic Doppler contribution, as well as radial derivative terms, are crucial for a consistent wide-angle expansion for large-scale surveys, both in the single and multi-tracer cases. We also give for the first time the wide-angle cross-power spectrum associated with the Doppler magnification-galaxy cross correlation, which has been shown to be a new way to test general relativity. In the full-sky power spectrum, the wide-angle expansion allows integrals over products of spherical Bessel functions to be computed analytically as distributional functions, which are then relatively simple to integrate over. We give for the first time a complete discussion and new derivation of the finite part of the divergent integrals of the form $\int_{0}^{\infty} \mathrm{d} r r^{n} j_{\ell}(k r) j_{\ell^{\prime}}(q r)$, which are necessary to compute the wide-angle corrections when a general window function is included. This facilitates a novel method for integrating a general analytic function against a pair of spherical Bessel functions.Comment: 41 pages and 2 figures. V3 has substantial improvements and new results. V4 is to appear in JCA

Demographic and clinical characteristics of UK military veterans attending a psychological therapies service

© 2014 The Authors. Aims and method To investigate the demographic and clinical characteristics of subgroups of UK veterans attending a dedicated psychological therapies service following the Improving Access to Psychological Therapies (IAPT) treatment model. Veterans accessing a newly established service in the north-west were categorised into three groups: early service leavers, those with a physical disability, and substance and/or alcohol misusers. Anxiety, depression and social functioning were measured pre- and post-treatment. Results Veterans vary in their demographic and clinical characteristics as well as in treatment efficacy, as measured by the post-treatment scores on probable depression and anxiety. Therapy appears to be most effective in early service leavers, whereas veterans with a physical disability or a substance or alcohol misuse problem tend not to do as well in terms of symptoms of depression or anxiety. Clinical implications This study highlights the importance of targeting different veteran subgroups for dedicated psychological therapy

Knowledge usage in new product development (NPD)

New product development (NPD) can be described as both complex and multidisciplinary, and also as an activity that often requires significant amounts of design knowledge. Typically, there will be a large body of knowledge that designers can call upon, and use, during the design process from many areas including human factors, materials, business, manufacturing technologies and so on. The provision of this knowledge to designers during the design process is vital to the successful development of the product or system being designed, and to the future competitiveness of the company involved. Given that even the most routine of design tasks is dependent upon vast amounts of expert knowledge and supporting information, there is an obvious need for some sort of support which will free designers from much of the drudgery involved in searching and locating appropriate knowledge. This paper presents the findings from an initial review of designers knowledge needs in small-to-medium sized enterprises (SMEs) who are involved in new product design and development. This review forms part of a larger ongoing study which is concerned with the development of a support framework for representing and providing design knowledge

Long-lived Five-Coordinate Platinum(IV) Intermediates : regiospecific C-C coupling

Three different phosphine derivatives of doubly cyclometallated diphenypyridine complexes of Pt(II), 1, were reacted with methyliodide to give octahedral Pt(IV) complexes, 2, as two isomers. Treatment of either isomer of complexes 2 with AgBF4, to abstract iodide, gave long-lived five-coordinate complexes 3, which could be trapped as pyridine adducts. Complexes 3 underwent a C-C coupling reaction, at a rate that depended on phosphine size, to give a methyl group attached to the original diphenylpyridine. Recylometallation was then performed and the cycle of reactions was repeated to give a diphenylpyridine doubly methylated on only one phenyl, with complete regiospecificity. NMR was used to demonstrate the geometry of all complexes in solution, with multiple Xray crystal structures confirming these assignments

Validation of algorithms to estimate distribution network characteristics using power-hardware-in-the-loop configuration

Distribution system operators (DSOs) require accurate knowledge of the status of the network in order to ensure the continuity and quality of power supply. In this context, the National Physical Laboratory (NPL) and the Power Network Demonstrations Centre (PNDC) have been working together in the development and validation of optimal sensor placement and network topology estimation algorithms. This paper presents the description of two of these algorithms as well as the topology configuration of the PNDC distribution network considered to gather measurements for the validation of the algorithms. A Power-Hardware-in-the-Loop (P-HiL) configuration has been used as the testbed, where a number of physical measurement devices are installed in the physical network and an extended number of devices are virtually installed in the simulate network. The applications of the proposed algorithms to the measurements along with results from the P-HiL tests are presented in the paper

Multi-sample differential protection scheme in DC microgrids

This paper proposes a novel solution to the issue of protection instability caused by time synchronization error in high-speed differential protection schemes for DC microgrids. DC microgrids provide a more efficient platform to integrate fast-growing renewable energy sources, energy storage systems, and electronic loads. However, the integration of distributed generators (DG) may result in variable fault current magnitude and direction during fault conditions, potentially causing mis-coordination of conventional time graded overcurrent relays. One identified solution to this issue utilizes high-speed differential protection schemes to maintain effective selectivity in DG-dominated DC microgrids. However, as DC short-circuit fault currents are highly transient, microseconds of synchronization error in the measured line currents may cause protection stability issues, whereby mal-operation of relays may occur as a result of faults external to the protected zone. This paper investigates the impact of time synchronization errors for high-speed differential protection in DC distribution systems. It then proposes a multi-sample differential (MSD) scheme that performs multiple differential comparisons over a sampling window to ensure the stability of high-speed differential protection schemes for external faults whilst maintaining sensitivity to internal faults

132 kV optical voltage sensor for wide area monitoring, protection and control applications

This paper reports on the design, construction and initial testing of a fiber-optic voltage sensor for applications in the field of wide area monitoring, protection and control of high voltage power networks. The 132-kV sensor prototype, combining a capacitive voltage divider (CVD) and an optical low voltage transducer (LVT), was evaluated through laboratory testing and its performance was assessed based on the accuracy requirements specified by the IEC standards for low-power passive voltage transformers. The preliminary results show that the device has the potential to comply with the requirements of the 0,2 class for metering devices, and the 3P and 0,5P classes for protective and multipurpose devices, respectively, as specified by IEC 61869-11. As the device is based on a fiber Bragg grating written in a standard, low-loss, single-mode telecommunication fiber, it has the potential to be deployed as part of a distributed network of sensors along the power network over a wide geographical area, enabling novel power system protection and control strategies