Issue link: https://read.utilityweek.co.uk/i/665572
NETWORK / 29 / APRIL 2016 development ensured it was ready for deployment. New generation fault passage indicators Fault passage indicators (FPIs) have been used for a number of years on 11KV networks as a cost-effective way to indicate the passage of fault current. However, their reliability has historically been patchy. Over the course of the past two years, following a number of strides in embedded tech- nologies and wireless communi- cations for FPIs, PNDC has been involved in five separate FPI projects in which they impose a high volume and variety of faults onto its network to test technology capability and resilience. PNDC used a complementary set of network and laboratory simulation tests to reflect realistic operating conditions for FPI technologies. This included heavy use of the PNDC high voltage fault thrower. It conducted thorough evaluation of FPI performance under these conditions. This performance data enables improved understanding of FPI reliability and how indications should be integrated into network automation and post- fault recovery schemes. A‡er testing, PNDC collated its findings to gain a wider picture of communications- related issues for FPIs. It also issued relevant findings to inform network projects under the Innovation Funding Incentive. New generation automatic voltage regulator PNCC took part in a UK testing project for a technology from the US which had been identified during a Low Carbon Innovation Fund initiative. By adding sophisticated control parameters to standard tap changers, this technology offers a smarter solution to the common network challenges of sustaining and boosting voltage on remote parts of the network. Unlike conventional on site PNDC facilities include: HV Network u Three underground feeders – total equivalent length of 6km u One overhead feeder – total equivalent length of 60km u 11kV/400V transformers from 500kVA to 25kVA LV Network u Transformers ~ 50 to 315kVA u Mock impedances ~ 0.6km u Load banks ~ 600kVA (total) Simulation u Hardware in the Loop Simulation u 3-50µs simulation time- step u Up to 96 three-phase buses u Accurate frequency response up 3kHz Hybrid generator PNDC trialled two hybrid generator technologies from two technology developers, both of which combined a diesel engine and alternator with a battery pack. The batteries were based on different chemistries (one was a 300kVA unit based on sealed gel lead-acid, the other a 30kVA unit based on Li-ion). These technologies were designed to offer fuel efficiency, lower carbon intensity and better capacity utilisation compared with conventional diesel generators, which are used by DNOs during emergencies or planned outages. Although the larger technology did not successfully complete testing, issues with the smaller scale technology were identified and resolved and it eventually proved resilient and capable of offering cost benefits to networks. PNDC carried out accelerated testing of the complete system over 24 loading cycles to prove that the system was ready for deployment by the electricity distribution network operator. Any improvements required, in terms of grid operation standards, were shared with the clients and this joint automatic voltage regulators, this technology operates using measure of current rather than voltage. They can also be configured in delta formation rather than in-line, resulting in cost benefits for networks. The successful testing of this US technology has improved understanding of its potential for use in the UK. An independent review of PNDC's project report has also identified that the findings should be used to inform training of networks' technical and operations staff. The scope of the testing extended to Cooper Power Systems' VR-32 voltage regulators under different scenarios and with different configuration of the CL-6 Series controllers. These regulators, rated at 11kV, 220kVA were connected to PNDC's test network in closed- delta configuration. A range of settings were tested under simulated scenarios to produce a comprehensive set of use case data. Soft open point project This project was intended to release capacity across the UK's existing networks and defer the need for investment in reinforcement by synchronising and balancing across three- phase connections or at points of interconnection between low-voltage feeders. The capacity released through this approach should help networks to connect more sources of renewable power or low-carbon technologies such as electric vehicles. So‡ Open Point (SOP) technology applies power electronics to balance the load across points of imbalance, achieving better utilisation of capacity. During testing at PNDC, the SOP was connected at the open point of three separate low- voltage feeders connected to different 11kV/415V substations on PNDC's private network. The SOP technology was deployed on a live network as a prototype trial in late 2015. Carried out three phase and single phase reactive power transfer capability as well as evaluation of the SOP's ability to provide network voltage support and fault and frequency variation protection. The SOPs responses to simulated network were monitored using calibrated power quality analysers at output terminals. PNDC evaluated end to end capability of the SOP, specifically; monitoring, communication and control system capability. Find out more about PNDC at Utility Week Live, 17-18 May, Bir- mingham NEC at stand B44.