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    Power-to-Hydrogen and Hydrogen-to-X : system Analysis of the techno-economic, legal, and regulatory conditions
    (IEA Hydrogen Technology Programme, 2020-09) Lucchese, P.; Mansilla, C.; Tilli, O.; Prost, J.; Samsatli, S.; Leaver, Jonathan; Dickinson, R.; Grand-Clement, L.; Funez, C.; Unitec Institute of Technology; Clean Energy Associates (CEA); IEA Hydrogen TCP
    P2X pathway definitions has the aim to clarify terminologies that are often used but with different meanings or intentions which leads to misunderstanding and ambiguity. The Task Force Definitions have addressed this issue in the first chapter of this document, clarifying the terminologies adopted for the rest of the document. Once the hydrogen pathways from the production step to the application side are defined, the current hydrogen status is inspected. As numerous its energy applications are, hydrogen is mainly used today as a chemical component in industries like ammonia production and refineries. The energy related hydrogen pathways are currently mainly seen through demonstration projects. The Power to X demos around the world is reviewed and analysed within the framework of ST2. The results show that the investigated pathways are diversified with a recent trend towards hydrogen industrial applications attracting interest
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    Protection and automation of distribution network with Inverter based Energy Systems (IES) rated up to 10 kVA
    (Published by Power Systems Group, Department of Electrical & Computer Engineering, Faculty of Engineering University of Auckland, 2016) Mishra, A.; Farzinfar, M.; Bahadornejad, Momen; Murphy, K.; Faarooqui, N. U.; Nair, N.K.C.; Unitec Institute of Technology
    With increasing penetration of Inverter based Energy System (IES), it is necessary to investigate the impact of IES presence on existing distribution network, particularly protection. To carry out comprehensive protection assessment due to IES penetration, the distribution network is subdivided into three zones- home zone, LV zone, MV zone. The impact of IES on the MV zone and its recommended guidelines is elaborated in the accompanying report 1 for Critical Step (CS) 2.3.4. The main aim of this report 2 for CS 2.3.4 is to highlight the impact of the integration of IES rated up to 10 kVA in Low Voltage (LV) distribution network and recommend guidelines for safety and protection. A comprehensive literature review is undertaken to understand the behavior of the Distributed Energy Resource (DER), and the potential impacts on existing protection schemes employed. The DERs are divided into two broad categories during analysis - rotating machine based DER and inverter based DER. Based on the literature review, simulation and testing carried out it is concluded the fault current contribution of inverter based DER does not typically exceed 1.2 p.u. while for rotating machines it is typically known to be between 5-10 times their rated current. Various penetration levels of IES and with different configurations of low voltage distribution network are simulated in DIgSILENT software to analyze the impact of IES on the existing protection scheme. The accurate modelling of the inverter is achieved by real time laboratory testing of various models of grid connected inverters. It is found that high penetration levels of IES on LV feeders do not cause any protection issues in the home zone and the existing safety and protection schemes as detailed in AS/NZS 3000 is adequate. The impact of Arc Fault Resistance (AFR) and the penetration level of IES on the operation time of the existing protection device (fuse) for the feeder have been assessed through simulations for the LV grid zone. The 6 typical Orion representative networks have been used to demonstrate the potential protection impact. The feeders are categorized based on the impedance characteristics and fault levels following as per the IEC 60725 suggested methods. Feeders with high probability of potential protection miscoordination could be identified through this process. Several faults of varying AFR are conducted, including symmetrical and unsymmetrical faults, combined with varying percentage of ICP with connected, to identify issues with operation of LV fuse. Single phase connections with maximum of 5 kVA rated IES and three phase connections with maximum of 10 kVA rated IES case studies have been simulated. It is found that for an extreme case of high impedance faults, at the end of feeders having over-head line, could pose issues for regular operation of fuses, and in some cases cause sympathetic tripping of fuse in the adjacent feeder. The analysis carried out shows that there will be no impact on existing LV feeder protection for three phase faults, as the fault contribution from grid stays significantly larger than fault contribution from the IES cluster. However, for single line to ground faults, the existing protection scheme will have to be re-evaluated for fuse insensitivity and miscoordination issues for LV feeders, when the IES penetration exceeds around 50% of transformer rating. The procedure to carry out impact of IES on the existing protection scheme for LV distribution network is demonstrated for residential network 1 of the typical Orion feeder with realistic fuse rating and similar studies can be undertaken to evaluate the existing protection scheme for other different LV feeder configurations with IES penetration. A simple solution suggested in this report to address the issue of miscoordination is indexing of fuse with increasing penetration to compensate for reduced load demand. Other potential solution like implementation of GREEN Grid interconnection box is proposed and discussed in detail in Report 1 ‘Protection and Automation of Distribution Network with Inverter Based Energy Systems (IES) Rated greater than 10 kVA’. The existing standards and practices for protection and installation of DG in New Zealand’s 29 distribution utilities are reviewed in this report. The special protection and installation guidelines for inverter based energy system that is followed by international utilities with high penetration of IES have also been reviewed in this report. Based on actual inverter testing, simulation studies and the current standards, safety and protection guidelines are proposed for New Zealand to ensure safe and reliable integration of IES in the low voltage network which is the key industry relevant outcome of this report. Protection settings for the IES and the grid are recommended. The requirements and recommended settings of power limiting devices to be used by utilities in case of limited export of power due to network constraints are defined. These safety and protection requirements are incorporated in section 2.3 of ‘Guideline for the Connection of Small-Scale Inverter Based Distributed Generation’ released by Electricity Engineers’ Association for industry consultation. The simulation and modelling used for protection has been better informed through the several detailed tests conducted on different models of inverter. These tests included LVRT properties, VAR control modes (grid support functionalities), and anti-islanding tests. The testing experience from this report would be continued further for ongoing critical steps on extended reserves (Automatic Under-Frequency Load Shedding), which is part of forthcoming Work Packages associated with CS 2.3.6. The representative LV modelling work presented in this report will be used to realize Work Package items related to voltage control methods as part of CS 2.3.7.
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    Vector’s residential photovoltaic trials : a report on experience
    (University of Auckland, 2016-01-14) Bahadornejad, Momen; Murphy, K.; Nair, N.K.C.; Williams, G.; Bishop, J.; Unitec Institute of Technology
    In 2013, Vector initiated the SunGenie program; a residential solar Photovoltaic (PV)/battery storage system, to assess the uptake with customers and the effect on the grid with a solar integrated battery solution. This was the first of its kind in New Zealand and after extensive studies and design work Vector started the rollout of their SunGenie solar storage package to a total 289 homes (2015 figure) on their network. The idea behind the program was to investigate new methods of dealing with fluctuating grid demand and to assess the development and implementation of a utility-led battery storage solution. As part of the GREEN Grid project, critical step 2.3.5, the University of Auckland’s Power Systems Group (PSG) was responsible to closely follow the initiation, design, data collection, testing & monitoring phases of Vector’s PV trials and to record the experiences and lessons learnt that will provide to be useful for all New Zealand utilities. The experiences recorded from PSG’s involvement in Vectors SunGenie trials have been included in this document. The initiation of the solar photovoltaic trials, combining research with industry, developed a strong working relationship between PSG and Vector. PSG initially provided Vector with the background knowledge of PV and battery technologies and the grid impacts of runaway take-up of residential PV. With this knowledge of PV/ Battery systems, published as a white paper, Vector developed their SunGenie business plan for the trials. PSG participated further in the PV trials in the testing of the inverters and their protection and automation settings. An inverter test bench was developed at the University of Auckland and after a series of tests performed on three shortlisted inverters, a choice was made on the inverter that proved best to use and PSG recommended the required inverter settings. The key findings from the trials, detailed in this document, are aimed at not only the utilities but also to inform the general public and potential customers with the knowledge taken from the initiation, design, testing and operation stages of Vector’s solar PV/battery trials. Future work includes the monitoring and data acquisition of the SunGenie’s performance. This monitoring will provide Vector with the possible grid impacts if any, of the PV systems in the future. Vector have also agreed to continue working with PSG in the next critical step of the GREEN Grid project in which new methods of coordinated voltage control will be tested alongside a new “residential clustered PV/storage” project owned by Vector. This work has already commenced and PSGs involvement in these trials will continue until the 30th September 2017. Report revision 1.0 (14th January 2016)
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    ICT practices in New Zealand distribution utilities : discussion paper on smart meters, communication technologies & ripple control
    (University of Auckland, 2014-10) Joish, J.H.S.; Bahadornejad, Momen; Nair, N.K.C.; Unitec Institute of Technology
    New Zealand (NZ) electricity distribution sector is experiencing changes in terms of deployment of new technologies and processes to interact with consumers and also manage the network better. This report addresses the practices followed by 29 NZ distribution companies for their Smart / advanced metering implementation, communication technologies used and the existing ripple control infrastructure. This discussion document also identifies the relevant NZ Smart metering regulations together with concurrent International practices and implementation. This discussion document will help form the basis of a coordinated approach by NZ distribution companies for utilizing their existing Information and Communication Technologies (ICT) plans and implementation in future. During the GREEN Grid 2014 annual conference in November 2014, we will solicit opinions from participating utilities for their viewpoint on the current state of affairs of ICT as identified in this discussion paper. This will thus help GREEN Grid to publish a practical NZ ICT Distribution Network Operator (DNO) roadmap for monitoring, protection and control of the network and offer services that are better informed by industry stakeholder engagement and extract maximum benefit to all consumers. NOTICE: This work supported financially by the New Zealand Ministry of Business, Innovation and Employment (MBIE) GREEN Grid project funding. The GREEN Grid project is a joint project led by the University of Canterbury with the University of Auckland’s Power System Group and the University of Otago’s Centre for Sustainability, Food, and Agriculture, and with a number of electricity industry partners. The project, officially titled “Renewable Energy and the Smart Grid” will contribute to a future New Zealand with greater renewable generation and improved energy security through new ways to integrate renewable generation into the electricity network. The project aims to provide government and industry with methods for managing and balancing supply and demand variability and delivering a functional and safe distribution network in which intermittent renewable generation is a growing part of the energy supply. New Zealand currently generates about 75 percent of its electricity from renewable generation, making it a world-wide leader in this area.
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    New project management models : productivity Improvement for Infrastructure
    (Sustainable Built Environment National Research Centre (SBEnrc), 2014-12) Kenley, Russell; Harfield, T.; Unitec Institute of Technology
    This research examined new approaches to the construction and maintenance of infrastructure to identify models for improving productivity. Existing solutions were identified across two categories: vertical and horizontal infrastructure. New models are proposed for three phases: Design, Construction and Asset Management.