SMART GRID, SMART CITY TECHNICAL CASE STUDIES DISTRIBUTION MONITORING AND CONTROL (DM&C) QUICK FACTS What is DM&C? DM&C refers to technologies used to remotely monitor asset utilisation, loading, faults and power quality on the distribution network and to provide realtime information to the network operator. What was trialled? Over 4,000 DM&C devices measuring current, voltage and power factor at distribution substations have been installed as of end of 2013. Trial period Ongoing program started in 2008. What were the outcomes? The installed devices enable real-time monitoring of the low-voltage network, for example peak demand, utilisation, faults and power quality, avoiding manual collection of data and minimising fault patrols. IN BRIEF The distribution monitoring and control (DM&C) program involves technologies that have the potential to deliver operational efficiencies and improve asset utilisation through continuous remote monitoring of distribution substations and the lowvoltage (LV) network. From 2008 to the end of 2013, more than 4,000 monitoring devices measuring current, voltage and power factor were installed as part of the standalone program, which was further evaluated for Smart Grid, Smart City. Traditionally, only a small number of high-value assets at the zone substation level have been monitored, as the relative costs of the monitoring equipment and associated communications did not make it economically feasible on the HV or LV networks. Continuous remote monitoring of LV distribution assets could provide valuable information on asset utilisation, faults and network state, which can be used to optimise transformer and LV line loading, improve the planning and design processes and improve network reliability by narrowing down the location of faults. The DM&C solution deployed collects continuous measurements of voltage, current, real and reactive power across all three phases in the distribution substation. The deployment of the DM&C devices has provided the network operator with the ability to obtain real-time measurement data from any substation fitted with the equipment. A visualisation tool developed for the program allows the network operator to access and analyse any collected data, giving greater insight into the network state. This case study also reports on the indicative business case for deploying DM&C in Australia on a per feeder basis. Page 1 of 6 SMART GRID, SMART CITY TECHNICAL CASE STUDIES DISTRIBUTION MONITORING AND CONTROL (DM&C) Kiosk Kiosk The AU$100 million Smart Grid, Smart City Program ran between 2009 and 2013, testing arguably one of the widest ranging technology assessments of smart grid products in the world. Incoming Feeder Maximum Demand Indicator: Measures SCADA only 1Ø currentMeasures to +/-20%. Manually read only 1Ø current; Monthly data download every 6 months SCADA Measures only 1Ø current; Monthly data download Maximum Demand Indicator Measures only 1Ø current to +/- 20% at Transformer, manually read every 6 months Maximum Demand Indicator Measures only 1Ø current to DISTRIBUTION SUBSTATION +/- 20% at Transformer, manually read every 6 months Figure 1: Legacy Equipment and Measurements PolyLogger: Connected to each of the LV feeders every four years to measure voltage and current PolyLogger / MaxiAmp Measures 3Ø current and voltage on each distributor; manually read every 4 years PolyLogger / MaxiAmp Measures 3Ø current and voltage on each distributor; manually read every 4 years CURRENT INDUSTRY APPROACH AND ITS LIMITATIONS The monitoring of distribution network assets is generally limited to only a small number of high-value assets at the zone substation level. Data from assets on the LV distribution network is commonly collected through routine inspections by field staff. Maximum demand indicators (MDI) are installed in most distribution substations. They record the maximum demand supplied by each substation since the last read and reset of the device. Typically the MDIs are manually read twice a year to gather information regarding the peak summer and winter demands for each substation. The MDI readings form the basis for forecasting future demand and drive the maintenance, upgrade and planning processes for distribution substations. The readings inform network operators of what the maximum demand was during the period since the last read, but provide no information regarding when the maximum demand event occurred and its duration. Load surveys are collected for a period of one week every four years to identify overloads and phase imbalances on distribution transformers. These measurements are assumed to be representative, but provide only a very limited view of the operating conditions. With limited real-time information available, the network design and planning process is based on conservative assumptions regarding asset utilisation and capacity. This can lead to higher capital investment costs and customer bills. The management of network state is also affected by the limited availability of realtime data, with network state in many cases still managed using pin boards, where the control room operators manually move pins to update their view of the network state. Page 2 of 6 Customer calls in combination with feeder patrols working their way along the feeder are used to determine fault locations. If no fault is located through this approach, a process of elimination is used to identify the faulty section by sectionalising and re-energising different parts of the feeder through manual switching. The main limitation with the current approach is that it subjects assets to faults and can take considerable time for field staff to patrol the feeder once on site. Remotely measures 3Ø current and θ (bidirectional and no Remotely measures 3Ø saturation) current and θ (bi- Kiosk directional and no saturation) Kiosk SMART GRID, SMART CITY TECHNICAL CASE STUDIES DISTRIBUTION MONITORING AND CONTROL (DM&C) Remotely measures 3Ø current and θ (biOtherand no directional saturation) Kiosk Optical Sensor: Measures 3Ø current and phase angle (bidirectional and no saturation) Kiosk Other Remotely measures 3Ø current and θ (bidirectional and no saturation) Incoming Feeder Other Remotely measures 3Ø voltage to +/- 1% (i.e. LV Voltage Sensor: Measures 3Ø voltage to +/-1% Remotely measures 3Ø voltage to +/- 1% (i.e. LV Bus) Smart Device DM&C Module: Collects data and communicates Smart either viaDevice 3G or WiMAX Smart Device Various communications options including 3G and WiMAX Various communications options including 3G and WiMAX Various communications options including 3G and WiMAX Smart Remotely measures 3ØBus) Device voltage to +/- 1% (i.e. LV Bus) Various communications options including 3G and WiMAX Remotely measures 3Ø voltage to +/- 1% (i.e. LV Bus) Other Remotely measures 4 x 3Ø current to +/- 5% (i.e. each distributor) Remotely measures 4 x 3Ø current to +/- 5% (i.e. each distributor) Current Transformers: DISTRIBUTION SUBSTATION Remotely measures 4 x 3Ø current to +/- 5% (i.e. each distributor) 3Ø4current RemotelyMeasures measures x 3Ø to +/-5% on each LV feeder current to +/- 5% (i.e. each distributor) Figure 2: DM&C Equipment and Measurements BEST PRACTICE APPROACH AND POTENTIAL BENEFITS Continuous remote monitoring of the LV network can greatly improve a network provider’s insight into network state, fault locations and asset utilisation. In practice, the approach involves installing monitoring devices at several points on the network, for example on distribution substations, capable of providing measurements such as voltage, current and power factor. More advanced solutions can also measure environmental factors such as air temperature, wind speed and humidity to provide a more accurate view of asset condition. Fault indicators installed on HV feeders can provide the network operator with information regarding fault locations. The data from the monitoring devices is transmitted to the control room to enable real-time information sharing and stored for planning and design purposes. This provides real-time information on asset utilisation, loading, power quality and phase imbalances and delivers operational efficiencies by automating data collection normally collected by field crews. The collected data may be used to improve the network performance and provide data for the grid operators to optimise the network planning and design process. When a fault occurs information from line fault indicators can be used to narrow down the search area for the field crew, enabling power to be restored to customers more quickly. Page 3 of 6 SMART GRID, SMART CITY TECHNICAL CASE STUDIES DISTRIBUTION MONITORING AND CONTROL (DM&C) You might also be interested in: Con Edison of New York – Smart Grid Project Figure 3: DM&C Device Installed in Kiosk Substation Figure 4: Sensors Installed on LV Board THE TRIAL From 2008 to the end of 2013, more than 4,000 monitoring devices measuring current, voltage and power factor were installed as part of the standalone DM&C project, which was further evaluated for Smart Grid, Smart City. Its key objectives were to: • Deliver a visualisation capability to search, filter and view measurement data • Improve accuracy and timing of LV network measurement data • Enable continuous monitoring of distribution substation performance and utilisation Sites were selected based on a number of criteria, including fault frequencies and durations, high utilisation and the number of customers served. The rationale behind this was to identify distribution substations where enabling remote monitoring would be likely to deliver the greatest benefits. Most distribution networks fundamentally have three design types for distribution substations: kiosk, chamber and pole transformers. A number of different enclosure designs to house the DM&C equipment were required, along with enclosure modifications to ensure that devices installed outdoors could cope with adverse weather conditions. Four enclosure designs were ultimately developed as part of the program to fit almost 60% of kiosk substations. The equipment was installed by two separate teams; one for the physical installation of the equipment; and the other for calibrating and commissioning the equipment. Where possible, installations coincided with other outages to reduce the impact on customers. The DM&C solution deployed for the program provides online real-time data and collects continuous measurements of voltage, current, real and reactive power across all three phases in the substation. In addition, it provides extra analogue and digital inputs/outputs. This makes it possible to monitor or control additional equipment in the distribution substations. Examples are sensors measuring temperature, humidity, fire, water level and battery status. Page 4 of 6 SMART GRID, SMART CITY TECHNICAL CASE STUDIES DISTRIBUTION MONITORING AND CONTROL (DM&C) The visualisation tool provides a user interface for viewing alarms and events, historical analysis Figure 5: Substation Load Measurements Aggregated for Each Phase functions, TRIAL OUTCOMES LESSONS LEARNT graphical The deployment of the DM&C devices The unique layout of substations in information has provided the distributor with the most cases required new installation of electrical ability to obtain real-time measurement designs for each substation type. The networks, data regarding utilisation, power development of modular solutions quality and phase imbalances from any that could be adjusted to the different detailed substation fitted with the equipment. designs was crucial to the success of the device status, project. Remote readings provide an and network understanding of how long the The complex and sensitive nature of status. substation had to maintain supply at DM&C equipment requires a stringent or near the maximum, giving far better insight into the asset’s life expectancy. Remote readings down to each phase of each distributor makes it possible to accurately estimate temperatures that the equipment would have experienced, which could be fed into the maintenance schedules to help predict when the asset should be upgraded, maintained or replaced. This enables a much more proactive regime, ultimately enabling improvements in network reliability. A key outcome of the DM&C program was the development of a fit-forpurpose web-based visualisation tool giving access to the DM&C measurement data. Figure 5 shows substation load measurements aggregated for each phase, with each phase represented by a different colour. Phases are sized based on their proportionate load, with larger circles representing imbalanced phases. A cluster of substations with phase imbalances increase line losses and asset wear-and-tear. Page 5 of 6 quality assurance testing process to ensure that the equipment works as expected prior to it being installed in the field. Appropriately skilled staff need to provide ongoing testing of the equipment. As part of the DM&C program, a smart grid testing facility was built for this specific purpose, where all devices were tested prior to installation. The need for two separate teams in some cases to install the equipment resulted in two site visits to complete the installation. Ensuring that the entire installation work is done in one site visit would reduce cost and make the deployment more efficient. The incorporation of DM&C equipment into new substations as part of the factory assembly process would significantly reduce costs. SMART GRID, SMART CITY TECHNICAL CASE STUDIES REFERENCES Ausgrid, Substation and Feeder Monitoring, Technical Compendium, 2014 J Haumann, GA1184 Distribution Monitoring & Control Trial Report, SGSC Supporting Document, 2014 Net Benefit (NPV 2014 AU$ Real '000) DISTRIBUTION MONITORING AND CONTROL (DM&C) $400 $15 $356 $350 $18 $160 $300 $250 $194 $200 $150 $100 $50 $0 $0.4 Search Costs VCR Figure 6: Cost Benefit Analysis Load Surveys Benefits PQ Surveys DM&C Opex Costs DM&C Capex Net Benefit BUSINESS CASE NEXT STEPS Figure 6 shows the indicative costbenefit analysis of deploying DM&C per feeder in Australia. It suggests a benefitto-cost ratio of approximately 2:1. The Consortium undertaking the independent analysis and reporting for Smart Grid, Smart City assessed the findings from the trial and has identified the following key next steps and actions for Australia: The main benefit on a system level is related to the Value of Customer Reliability (VCR). This benefit is realised from the monitoring devices enabling faster location of faults, which results in quicker restoration times. Benefits related to eliminating the need for manual data collection are limited. The main cost element is the capital cost for devices and installations, with a small portion related to operating costs associated with communications infrastructure and fault management. Figure 6 shows that without the benefit from VCR, the investment would not be cost-effective. An important step to verify the VCR benefit is to confirm that the current VCR accurately reflects the value that customers place on reliability. The work by the Australian Energy Regulator to develop a methodology to determine the national VCR is a key step in this process. Many DM&C benefits can also be provided by alternative smart grid technologies including Fault Detection, Isolation and Restoration. The technology deployed first can undermine the business case for the other. Page 6 of 6 $0.3 • Further investigation into current network reliability incentives need to be considered to unlock full customer benefits • As the retrofit cost of existing assets is significant, monitoring capabilities should be integrated into assets at vendor-level to reduce implementation costs. • Develop data management and visualisation tools at an early stage to optimise benefits. • Consider the trade-offs and overlap when evaluating FDIR and DM&C business cases.