Today as we move through the world of industry how important it is to protect electrical systems. From high voltage power lines to low voltage circuits we must protect electrical systems from fault and failure. A properly designed electrical protection system will not only help keep equipment from being damaged, but also save personnel, reduce down time, and increase the life of electrical components.
This article gives the reader a process whereby they can design an electrical protection system that is safe and dependable, with silicon carbide (SiC) components to help.
What is an Electrical Protection System?
Electrical protection systems are designed to identify and react to electrical faults overload, short circuit and ground fault condition. The general object of an electrical protection system is to disconnect the faulty part of the electrical circuit, as rapidly as practicable so as to prevent further damage to the equipment, and lessen the possibility of causing a fire or electric shock to any person. The most common components of an electrical protection system include:
Fuses and circuit breakers: These are the devices we rely on to stop the flow of electrical energy when a fault occurs. Fuses work by melting the electrical circuitry when a certain level of current is exceeded and circuit breakers trip the electrical circuit to the open condition. Both are mandatory in…Ground Fault Protection: This protects against unintentional electrical current passing through the ground, possibly causing serious hazards such as…Surge Protection: Surge protectors are used to protect the electrical circuitry from being affected by a voltage surge caused by lightning, a power surge being sent down the circuit, or some switching of an adjacent circuit.Isolation Devices: devices such as disconnects that permit a physical wall to be established between a circuit and its power source for the purpose of safe work or repair.
The role of SiC in electrical protection
While the use of fuses, circuit breakers, etc. provides important protection to the system, it is possible to take the protection of these systems a stage further by using new materials such as silicon carbide (SiC). SiC devices have very good electrical properties, good thermal properties, good capacity for blocking, both high voltages and high temperatures. Thus there are a number of ways the modus operandi of an electrical protection system can be improved upon in the use of SiC:
Higher Voltage: SiC based semiconductors such as SiC MOSFETS and diodes can block much higher voltages than traditional silicon power components. This makes it well suited to power inverters and motor drives that work at this sort of voltage.
Better Thermal Properties: SiC has better thermal properties than silicon so heat can be dissipated better. This is significant because if electrical protection devices overheat they may no longer offer reliable protection under load. This results in less efficiency and greater running costs;
Smaller & More Compact Devices: SiC power devices can also be significantly smaller than actual rated silicon equivalents due to the much higher power density of SiC.SiC will allow for ever more compact protection devices where they are required in applications where space is especially critical
All those conditions that can be deemed extreme, reliable in harsh environments; radiation, and extreme temperatures, and high power surges.
How to construct a safe electrical protection system
The optimal construction of a safe electrical protection system requires careful fore-thought and laying out and appropriate selection of components. Here’s how to do so in easy steps:
Determine the electrical load and system requirements
This means knowing how much is it and what is required by your electrical system. So what are the voltage and current levels, and will you be using?Industrial machinery, power inverters and electrical vehicles (EV) will all have different protection requirements.
Choose the right protection devices
For example:For overcurrent, fuses or circuit breakers with an appropriate rating for your system will do, and ground fault, what have you?GFCIs, RCDs, and so. For surge, ensure you have rated them for the expected voltage surges.
Now you know the principle of operation behind how electrical protection can be achieved; Unit 420 has various functions that operate discreetly. Get to know your components, few of them can be relied on to do an effective job.
Integrate the following components into your protection system to take advantage of the single hardest substance known, silicon carbide (SiC) to give the:
SiC MOSFETs. For ideal circuit breaker replacements. Up to 10kV @ 1kA available. Reliable and can be operated and not suffer damage where silicon devices will.
SiC Diodes. The right SiC device can be an ideal bridge circuit rectifier. Voltage options of up to 6.5kV! Feed them with 3kV. Applications driving high and low voltage switches and isolation.
SiC based Power Modules. Take several of these, fuse them into one high density unit so that you can fit it in the same cabinet. faulting are remaining probable. If you haven’t lost a 148 Amp SiC then you have just been lucky. Critical components, use as wisely as you might:!
Design for Thermal Management. An isle have we missed!Heat sinks, blowers are used. Rectification that is SiC and then typically little heat is developed.
Implement Monitoring and Diagnostic Tools; Imp at the core and wiring; Sensors for temperature and more. Projects a good image of your company the first time it makes an alarm.
Testing & Calibration. Dangerous to the hazardous resettable circuit-breaker.
Regular Maintenance. Perhaps complex. Modules can be checked and need not as often as silicon types.
Safeguarding electrical equipment effectively represents insurance against failure and a hefty bill. And personnel too!