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“Traditional Fault Passage Indicators (FPIs) are devices used in distribution grid to detect fault intervals. These devices are typically attached to overhead lines to measure if a fault has occurred in the downstream direction of the device. This is done by measuring if a short-circuit current has flown through the sensor. FPIs are generally classified into two types: non-communicable and communicable devices. Non-communicable FPIs do not support external communication and will only provide an on-site alarm by blinking a red light. Communicable FPIs can provide in addition to the red-light alarm an message to a SCADA system. However, the message sent is typically limited to notifying the SCADA system that a fault has occurred between FPI devices as an fault interval. Therefore, FPIs don’t provide accurate information on the fault’s location or type.

In contrast, the Safegrid’s Intelligent Grid System (IGS) is based on a current and high-frequency transient measurements. The fault locations are calculated up to 100 meters (330ft) accuracy with coordinate information. This is a major advantage to the simple fault interval information that FPIs are able to provide. The locations are calculated by using the transient signals created by the faults, added with GPS synchonization on the sensor to triangulate the excact fault’s location. Additionally, the transient based fault locating is earthing agnostic: the earthing method, such as compensated or isolated earthing, is irrelevant to the transient technology. The system also works in all grid types, such as 3-phase/3-wire or 4-wire with neutral grids.

Knowing the exact locations provided by Safegrid, operational personnel are able to quickly fix the faults. This results in reduced costs and outage times. Moreover, the system’s modern data science tools enable preventive maintenance features, such as identifying cable insulation failures by detecting partial discharges. This information can help network operators move from time-based maintenance plans to condition-based maintenance plans.”

Protection relays are built to protect network assets and humans from electrical hazards. However, protection relays are not sufficient themselves to identify fault locations precisely. Moreover, protection relays are limited in identifying different fault locations or types. Safegrid’ works in parallel with protection relays by supporting the existing automation by precisely locating fault locations and fault types occuring in the grid.

Yes. The transient based fault detection can detect even high impedance earth faults and intermittent earth faults.

The Safegrd Grayhawk and Grayfox sensors do not need any configuration during the installation. This is a major benefit compared to traditional communicable FPIs that need I/O mapping to SCADA and other labor needing parametrization work. Simply install the sensors and start using the system.

Safegrid system works in 3-phase/3-wire power systems as well as in 3-phase/4-wire power systems. Safegrid sensors can be used with any kind of power system grounding method. The voltage level can be between 10.. 240 kV. Moreover, the network impedance is not used by the system in any way to calculate faults.

The placement planning and sensors quantity is based on the grid topology. As a rule of thumb, a sensor is needed after every 5 – 10 km (3 – 6 miles) of grid length.

The Safegrid IGS-solution uses the GridGuardian cloud platform to analyze and vizualize grid events. GridGuardian provides a secure communication between the sensors and the cloud server. In the user-interface, visual real-time monitoring in both browser and mobile interfaces are provided. GridGuardian supports SMS and email alerts in addition to the report functions.

The sensors use cellular communication to provide measurement data to the cloud. All devices are shipped with internal M2M multicarrier sim-cards working anywhere in the world. Safegrid provides the data package and it’s costs are covered by Safegrid in the SaaS fee.

“The Safegrid IGS system is a standalone grid monitoring system that doesn’t require any integration to SCADA or DMS systems to operate.

However, even as IGS system is designed to function as an independent grid monitoring solution, utilities typically have the need to integrate with their existing systems. These systems are typically DMS, OMS, ADMS and resource management systems. For the integration, Safegrid’s provides REST API interface for a modern, flexible, and secure way to integrate the GridGuardian service into existing distribution or outage management system. With the REST API, the calculated fault locations and fault classifications can be transferred to an external system for further inspection and benefits.

For example, you can visualize the fault locations in an existing monitor, export the fault locations to be part of DMS/OMS fault management process, or manage organizational tasks for field patrol works. One of the more advanced examples is an integration to FLIR system for automatic fault isolation.”

In a standard project, customer first delivers the network topology and other related data to Safegrid. Safegrid then delivers the agreed amount of sensors to the customer and creates GridGuardian instance for the customer. The typical project schedule is from 1-3 months, with most time needed for the physical sensor installations by the customer.

Grayfox sensors are installed in cable feeders with rogowski coils. Grayhawk sensors are installed in overhead lines just below the conductors as a wireless sensors. Both sensor types can be installed on a live-line by a single installer, greatly reducing labor costs and networks breaks needed to implement the IGS-system.

The GridGuard cloud server is hosted by Microsoft Azure in Europe

All Safegrid products are CE and FCC compliant

The sensors do not need any maintenance

0.5 W on average per sensor