Fuses Used in Smart Home and Smart Grid Applications

With IoT connected smart homes and smart grids proliferating and electrical systems becoming ever-more complex and interconnected within that environment, power quality and safety issues become increasingly hard to manage. From energy storage systems in the home through to the nationwide grid itself, reliable protection devices are needed to avert disaster. In this space, the fuse still has a role to play. Simple, fast and above all, reliable, fuses have a job to do.
This ensemble of articles covers all that concerns the role of the fuse in smart home/smart grid applications: technical requirements, and how the technology fits into the Hudson River Power Electronics nexus including SiC based systems. Fuses in smart electrical system
The humble fuse is largely voiceless guardian; intended to protect circuits against danger, the fuse can protect a circuit by simply interrupting it on overcurrent/short circuit, and in smart systems where sensors, controllers, inverters, communications modules, and hosts of other components can become electronically connected via other electronics, accurate protective measures are vital.
While electrical home and smart grid systems are themselves largely made up of electronic devices, and it can thus be said they are ‘connected’ or ‘inter-connected’ representing a far more sophisticated electrical environment – new issues arise; and those with distributed advantages can also be distributed in vulnerability. If inter-connection is the lot of electronic connectedness, then it also highlights tricky challenge of protection for fast switching nature (between AC/DC) and rapidly appearing faults and conditions.
Fuses in smart home applications
The smart home naturally contains smart meters, energy management systems, solar inverters; battery storage units, smart (EV) chargers, and intelligent appliances. These systems run on AC and DC power and require high precision.Typical applications for fuses in the smart home include:
Residential solar PV systems: DC fuses for the overcurrent and short circuit protection of photovoltaic strings as well as inverters and battery connections
Home energy storage systems: Fast-acting fuses to protect lithium battery packs and battery management systems from thermal runaway and equipment damage.
EV charging equipment: Fuses protecting AC and DC charging equipment for both power-modules and user safety
Smart appliances and control units: Miniature fuses for the protection of sensitive electronics from out-of-spec faults
In common with other applications, fuses used in smart home environments must provide stable operation, a small package and compatibility with “modern” devices such as Silicon Carbide MOSFETS and diodes.
Fuses in Smart Grid Applications
Smart grids incorporate green energy sources, energy storage, intelligent substations and advanced monitoring. They are generally more efficient than classic grid systems, but also expose devices within them to a far broader variety of fault conditions.
Fuses are applied extensively to:
Distribution networks: protection of transformers, feeds and branch circuits from overloads and short circuits
Renewable energy integration: wind and solar power systems use DC and high-speed fuses to protect inverters and other power conversion equipment.
Energy storage systems (ESS): grid-scale battery systems use fuses with high voltage and high-breaking-capacity protection.
Power electronics cabinets: protection of SiC based inverters,Smart Grid – Higher Voltages, Higher Fault Currents, More Complex Environment.
The smart grid smart fuse now has to not only work at higher voltages and breaking capacities, as the components involved tend to be subjected to more extreme working conditions. Greater rapidity of action – switching times getting shorter with fast-responsive high-voltage SiC modules, which typically now work at switch rates in excess of 10 kHz, and so on are now evident of the use of new fuses within the smart home/grid; DC interruption capability; High voltage and high breaking capacity; Thermal stability; Coordination with circuit breakers/contactors; proper replacement and fuse selection resulting in a reduction in shut downs of the system by virtue of selective protection..
What would seem to prevail of late in regard to the use of new fuses – as in previous – is borne out by the subsequent explosion of productive use of silicon carbide. SiC has certain advantages, not least of which is having a high breakdown voltage, small power loss during switching/in ‘off’ state, and operational/and threshold temperature. Of late growth in power outputs of such devices, such as MOSFET power inverters in EVs, and of photovoltaic systems (and smart grid type equipment) leads to the quotidian use of ‘silicon’ in volume.
With this comes even greater – and greater calls upon fuse function which in many respects requires altering traditional selection of fuse – just to save from blowing – a notorious ache with a higher density switch architecture.