ABB in Norway is joining forces with a utility customer to digitalize the distribution grid. Collaborating with Norway’s second largest utility Skagerak Nett, ABB will contribute to a stronger distribution grid by increasing the reliability of power supplies.
The goal of the self-healing demo is to reduce the impact of blackouts by demonstrating fully distributed fault location, isolation and supply restoration functionality (FLISR). The system will be able to identify, locate and isolate the fault faster and thereby allow the utility provider to perform the repair quicker. This will significantly lower downtime for end customers and lower the costs for the grid operators.
This next step in the digitalization of the distribution grid is a more flexible and cost-effective smart grid solution. The idea is that sensors, computer technology, communication and software enable the grid to become autonomous and take care of itself.
When lightning strikes
Imagine a fault occurring in the distribution grid near your house, due to a lightning strike in summer, or maybe a tree fall caused by storms during winter. In this case, the circuit breaker in the main substation will open and shut the entire feeder down. Not only will this occur in the section where the fault occurred, but also the healthy part of the grid. This is to prevent damage to equipment, buildings or even people.
The new system will automatically analyze the situation, locate the fault, and disconnect the load switch breakers on each side of the fault. This enables the system to close the circuit breaker in the main substation and re-energize the sections of the grid that are still useable, or even power the distribution grid from another direction.
The solution will not prevent blackouts, but will minimize the impact of them; giving back the power industrial customers need to manufacture their product or giving domestic homes the electricity they need for heating during cold winter days.
A major step toward a more autonomous network
ABB in Norway will provide four compact secondary substations (CSS), including 24 kV SafePlus switchgear, transformer and low-voltage equipment. Each of the four smart grid substations will be equipped with motor controlled switches, state of the art instruments, controllers and communication units from ABB such as RIO600 FPI input/output units and ARC600 wireless controllers. One of the CSS’s will have a circuit breaker on the outgoing cable feeder for additional protection using a REC615 relay.
The heart of the system is ABB’s (SCADA-based) COM600 grid automation controller located in the main substation that feed the distribution grid. The COM600 unit will receive close to real-time information from the ARC600 controllers located in the four CSS’s in the distribution feeders. Their task is to transform power from the grid to a lower voltage and distribute it to houses and businesses. The ARC600 controller receives input from instruments and sensors in the substation, and distribute the signals via VPN-protected and encrypted mobile communication to the COM600 in the main substation.
The concept of distributing the self-healing and FLISR-functionality will enable the utility to make defined parts of the grid more autonomous. This can be very helpful for utilities that are not ready to implement a more centralized self-healing solution.