FPI is a device that provides a remote and local visual indication of the occurrence of a fault, even after isolation of the line. As FPI technology has evolved, this thesis presents algorithms that are not sensitive to network reconfigurations for rapid identification of the location of faults based on the states of multiple FPIs received at the utility control center. Overhead lines are vulnerable to failures because the system equipment is exposed to extreme weather conditions.
The identification of faults in the medium voltage distribution network is difficult and time-consuming, due to the complexity of the network, relatively less advanced infrastructure and access to locations. The fault trip indicator is a device that provides visual and remote indication of a fault in the electrical power system.
Organization of Thesis
Electrical distribution systems play an important role in electrical power systems in delivering power to customers. Distribution automation allows utilities to improve the reliability, efficiency and quality of power for their customers.
Outage Management System
Functions of Outage Management System
- Fault Location
- Fault Isolation and Restoration
- Outage Metrics Calculation
- Network Reconfiguration
Later, the advent of software and communication technologies led to the development of SCADA, where the status of the circuit breaker or relay status is observed and based on the status and location of the tripped breakers, the crew isolated the fault [9]. The main purpose of the OMS system is to restore power to the maximum number of customers in a very short time. This function mainly consists of two steps: fault isolation, which checks which feeders should be activated so that the maximum number of customers is not affected.
The other function is recovery, which includes reclosing circuit breakers after isolating the fault. These algorithms check the condition of the feeders whether they are working in normal operation or emergency operation or faulty operation. Utility will issue a switching sequence based on the condition the regional level substations must follow the switching sequence and reconfigure the network accordingly.
In some cases, the switch management is a default lookup table and the network is reconfigured based on that table. This function aims to calculate outage times, the number of customers affected during the outage, and the estimated restoration time. Suppose a fault has started, customers need to know which part of the network is isolated and when it will be restored, ie the estimated restoration time.
When a fault is initiated, the circuit breaker will trip first, then this algorithm checks for the case where maximum number of customers can be supplied, power from the other sources, line loadability and according to the switching sequence is updated and the switches are in such a way to reconfigure the network that meets the above criteria.
Operation of Outage Management System
The above section mentioned the main functions of the outcome management system, whereas in addition to the failure analysis is performed which has the following functions which are part of the most important functions of OMS. Changes to the connectivity model by changing device status and adding temporary network devices such as clips or jumpers. Automatic calculation of estimated restoration times for all outages based on outage type, device type, time of day, day of week and weather conditions.
Business intelligence includes the metric calculations with price details such as from the point of view of utility, business intelligence report includes the loss he has to bear if the outage occurred. From the customer's point of view, it consists of how much time and reasons for the interruption are mentioned. Finally, a summary of the operation of OMS, it takes the input from the SCADA system, takes the help of GIS, CIS, AMI and mobile workforce management modules, provides output commands such as switching queues back to SCADA system and reaches ' a report of outage to the utilities and customers.
In Chapter 3, FPI and its operation are discussed and the architecture for OMS with FPI is introduced.
Architecture Overview
Meanwhile, based on the fault location identified by the fault location algorithm, the network will be reconfigured to supply the maximum number of customers through an alternate path until the original network is restored to normal state.
Fault Passage Indication
What is Fault Passage Indicator (FPI)
FPI is capable of detecting all types of faults like phase-to-phase faults etc. as it is located at each phase of the network. The earliest types of fault circuit indicators (FCIs) were simple overcurrent devices that used a high-magnitude magnetic flux field to mechanically move or rotate a flag indicating the passage of a fault current. Fault indicators continued to grow faster as the importance of reliability of electricity supply increased.
Public service commissions and consumers have begun to put pressure on power companies to provide better quality electricity. Indices such as "System Average Interruption Duration Index (SAIDI)", "Customer Average Interruption Duration Index (CAIDI)" and other indices are mandatory measures for power companies [11]. The widespread use of fault indicators has been recognized as the most economical and convenient way to reduce downtime.
The addition of this feature to standard FCI products increases the ability of fault indicators to adapt to circuit load parameters wherever they are installed. Further developments for the integration of fault indicators in smart automated distribution systems are taking place on a trial basis at a number of companies, but are themselves difficult to justify economically. FPI helps in improving the reliability of the system as it improves the system average interruption duration index (SAIDI) and the customer average interruption duration index (CAIDI), and also helps in reducing the unsupplied energy (ENS) .
Failure indicators can be used as a preventive tool to reduce costs for utilities and their customers, and it also had an advantage to use with and without distribution automation [18, 19].
Working of Fault Passage Indicator
Necessity of FLISR
Case Study: IEEE 69 bus system
Base Case Study
Case Study after Creating Fault
For illustration purposes, a fault is created on bus number 19 in the system by changing the dynamic data of the network at time 5 and is erased at 7. The line currents of the network in which the FPIs are installed are shown in Fig. In this state, the FPIs located in the corresponding branches change its status to 1 (indicating error) and this change in the status of the fault pass indicators indicates that the system is in an error state.
After creating fault at bus number 19, the network looks like in fig. 4.3, this indicates that the fault must be downstream of the last fault indicating fault passage indicator. For the completeness of the algorithm, the fault isolation and reconfiguration algorithm could isolate branches between nodes 18-19 and 19-20, and link switch number 70 between nodes 13 and 21 can be closed.
Throughout this operating mode, the system is said to be in reconfiguration mode. In this chapter, implementation of load flow simulation platform on IEEE 69 bus radial network is presented and the importance of setting different references for each FPI is explained. In this chapter, two algorithms are presented, one (Upstream Algorithm) which considers only its upstream devices for fault identification, and the other (Upstream and Downstream) which considers all the devices neighboring the device.
Upstream Algorithm
Upstream and Downstream Algorithm
Illustrative Example
Upstream Algorithm
Upstream and Downstream Algorithm
Here, in this pair, A1 is the device and CB1 is the Upstream device and the rest are the downstream FPIs before reconfiguration. In the next step, check the status of the switch and if the status of the switch is '1', then the fault variable is equal to CB and the first element of the fault path array is set to CB. A1 is attached to the fault path since the status of A1 is ON and is not present in the fault path before this step.
Implementation of Fault Location Algorithm
The switch data contains two columns, in which the first column is the device ID and the second column is the set of neighboring devices corresponding to the device ID. The first column indicates the fault created at the load point by connecting the fictitious mass and the second column index or FPI activated for the fault. Here, a fault is generated at a location near A8 and A1 individually, and the program is executed for both conditions, and the result shows the Fault Passage Indicator (FPI) index.
Similarly with the same fault location, Upstream and Downstream algorithm is applied, then the result obtained is shown in the following table. Here in the table the first column shows the error created at the load point by connecting a dummy. This points the way to the power company crew to check for the fault and isolate.
If the FPI ID includes the geographic location, it would be easier to isolate the error. The upstream and downstream algorithm are implemented for the reconfigured algorithm and the obtained results are shown in the table. It is observed from the second row of the table, the same fault is created by between A1 and A2, but the fault and the fault path change when the circuit is reconfigured.
If the circuit is reconfigured remotely by a distribution company via a distribution management system (DMS), the FPI indication will work with the algorithm presented.
Conclusion
Further Work
Angerer, “New Developments in Faulted Circuit Indicators Help Utilities Reduce Costs and Improve Service,” inRural Electric Power Conference, 2008 IEEE. Viplav Chaitanya, Pradeep Kumar Yemula, "Rapid identification of fault location using fault passage indicators during network reconfigurations," in Indian Smart Grid Week, vol. Brown, "Impact of smart grid on distribution system design," inPower and Energy Society General Meeting-Conversion and Delivery of Electrical Energy in the 21st Century, 2008 IEEE.
Zhibin, “Study on simulation and testing of flisr,” in Electricity Distribution (CICED), 2010 China International Conference on. Wang, "A distribution automation laboratory for undergraduate and graduate education," Power Systems, IEEE Transactions on, vol. Luan, "Automatic and fast faulted line section location method for distribution systems based on fault indicators," Power Systems, IEEE Transactions on, vol.
![Fig. 2.1 shows the operation of outage management system. An outage management system consists on network model facilitating the electrical features [10]](https://thumb-ap.123doks.com/thumbv2/azpdfnet/10482211.0/14.892.211.802.415.845/operation-management-management-consists-network-facilitating-electrical-features.webp)
