Transcript Existing DC Power Grid Systems and

Protection and Switching in
Low Voltage Smart DC Grids
Robert Pinnock
TRW Conekt
Stratford Road
Solihull
B90 4GW
UK
Tel: +44 (0)121 627 3548
Email: [email protected]
Web: www.conekt.co.uk
Conekt - Who Are We?
Consultancy in Engineering, Knowledge and Technology
• Conekt is the technology and
engineering consultancy business of
TRW Automotive
• The origins of Conekt date back to
the mid 1950s as the former Lucas
Research Centre
• Conekt provides specialist
engineering consultancy and testing
/ validation services to customers in
aerospace, automotive, defence and
other markets
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Contents of Report (and This Presentation)
This work considers the feasibility of developing smart DC power grid
technology for domestic and small commercial premises, focussing on
Issues relating to circuit switching and protection:
1. Executive Summary
2. Introduction
3. Safety Issues
4. Switching Devices
5. Protection Measures
6. Arcing, erosion and Corrosion
7. Technology Cross-over Opportunities from Existing DC Power Grid Systems
8. DC Voltage Level Issues
9. Gallium Nitride (GaN) Technology – State of the Art (see separate presentation)
10. DC Power Grid Design Issues
11. Conclusions and Recommendations
12. Appendices
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Aims of the Report
The primary aims of the report may be summarized as follows:
-To survey the current state of the art in switching and circuit protection technology for
Smart DC grid applications, with particular emphasis on issues which must be
addressed before the commercial deployment of such systems in domestic or small
commercial premises becomes viable
-To assess the capability of new developments in GaN semiconductor devices to meet
the switching and circuit protection needs of Smart DC grids (separate presentation
by GaN Systems Ltd following this one)
-To review the means by which switching and circuit protection are implemented in DC
power systems for other markets, particularly automotive and aerospace, and to
consider opportunities for technology cross-over from and into the Smart DC grid
market.
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Introduction – The DC Power Grid Concept
The main perceived advantages of a smart DC power grid for domestic and
small commercial premises include:
- Improved efficiency and ease-of-use (through reduction in unnecessary AC-DC power conversion
processes and (hence) power adapters, cabling, etc.)
- Improved ability to utilize power derived from renewable resources (solar, wind, etc.) which are
often DC or “pseudo-DC” in nature
Set against these perceived advantages is the basic question:
- Are these advantages sufficient to persuade suppliers and consumers to embrace DC grid
technology (given the fact that, whatever its shortcomings, the current AC power distribution
system to domestic and small commercial premises works pretty well, and everyone is used to it)?
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Introduction – The DC Power Grid Concept (cont.)
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Safety Issues
The main safety issues arising from the use of Smart DC grids in domestic or small
commercial premises are:
- electric shock and burn hazards
- arcing and arc flash hazards
- fire hazards arising from over-current conditions
The existing AC power distribution network includes switching and protection devices
and systems designed to help prevent accidents and the associated impact on people
and equipment from arising.
Similar switching and protection measures will also need to be implemented in a Smart
DC power distribution system, but the inherent differences between AC and DC power
delivery mean that these systems will not be exactly the same
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Safety Issues – Electric Shock and Burn Hazards
In terms of electric shock and burn hazards, the safety issues associated with a LV DC
power grid are similar to those encountered with a typical AC power grid, and similar
measures are required to help prevent, or minimize the effect of, hazardous events
Electric shock in humans (and animals) is a complex issue, influenced by many factors:
- voltage level
- current level
- source frequency (AC causes more ventricular fibrillation than DC)
- length of time the person is exposed to a live electrical source
Burns associated with electric shocks may be:
- surface burns (at points where electrical current enters and exits the body)
- internal tissue burns (where current flows through the body – currents > 1.5 A can cause
potentially fatal internal tissue burns
DC voltages  60 V and AC voltages  42.4 V peak are generally deemed to be “safe” for direct
human contact
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Safety Issues – Arcing and Arc Flash Hazards
Devices which may cause arcing include switches, circuit breakers, relay contacts, fuses and
various fault conditions (poor cable terminations, damaged wires, worn insulation, etc.)
The issue is of greater concern in DC power networks than in AC systems because the “zerocrossings” (as the current reverses direction) in an AC power network tend to extinguish any arcs,
whilst a DC system tends to maintain an arc across an air gap. Switching inductive loads in DC
systems is particularly problematic as the electrical current cannot immediately drop to zero and a
transient arc tends to occur across the separating switch contacts. Techniques such as the use of
snubber circuits can be used to help prevent arcing.
The primary hazards are:
- Burns (from touching surfaces made hot through arcing)
- Fires
- Electric Shock (from damaged components or devices)
- Arc Flash:
An arc flash is an electrical arc having sufficient energy
to cause an electrical short circuit through the air to ground
or another conductor. Arc flash temperatures can reach
in excess of 22,000 °C in less than 1 ms.
Arc flash can occur at voltages as low as 50 V
Picture from www.arcadvisor.com
Used with permission
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Safety Issues – Hazards from Over-current
Conditions
An over-current is a current that exceeds the ampere rating of the conductors (cable) and / or
equipment (motors, instruments, electrical devices, etc.) on an electrical circuit. Over-currents
include overloads and short circuits
Overload current: an over-current that is confined to normal current paths (typically occurs when too many
loads are present on a power network so that the rated current limit is exceeded)
Short circuit:
an over-current flowing outside normal current paths (typically occurs when electrical
insulation of a conductor is damaged). Short circuit currents may reach thousands of
Amps and require very rapid interruption
Fuses and circuit-breakers provide protection against over-current faults in both AC and DC
power distribution systems. However, this is a particular challenge in DC networks, due to
the difficulty of rapidly switching very high DC short circuit currents (primarily because of
lack of “zero-crossings” of the electrical current)
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Switching Devices
Mechanical Switches:
- familiar as the means by which individual electrical loads are switched in a domestic AC ring main
- such switches will still be an important feature of a domestic or small commercial DC grid, but will need to
be capable of operating appropriately and safely, particularly as regards the management of switching arcs
- commercially-available switches for electrical power circuits are generally only rated for use on AC circuits:
where a DC rating is given, the DC current rating is considerably less than the AC rating
Electromechanical Switches (Relays):
- electromagnetic devices that convert a magnetic flux, generated by the application of a low voltage
electrical control signal (either AC or DC) across the relay terminals, into a pulling mechanical force which
operates the electrical contacts within the relay
- contact resistance (primarily due to arcing causing damage to the relay contacts) is worse in DC power
systems due to their greater susceptibility to arcing (leads to reduced relay life – but careful choice of
silver-based alloy materials for the contact tips can help)
- reed relay switches are used for rapidly switching relatively low currents at low voltages – but, smaller
contact size leads to greater propensity for arcing damage in DC power systems
- device ratings for AC and DC use are different: for example, an electromechanical relay rated at 10 A at
250 V AC may typically be rated at 10 A at only 30 V DC or just 0.15 A at 250 V DC
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Switching Devices (cont.)
Circuit Breakers:
- automatically-operated electrical switches designed
to protect an electrical circuit from damage arising
from overload conditions or short circuit faults
Residual Current Devices (RCDs):
- automatically-operated electrical switches designed
to switch when an earth leakage current causes an
imbalance in the electrical current in the live and
neutral arms of a power circuit
Both of these are specifically circuit protection devices (discussed further in “Protection Measures” section)
Solid State Devices (Switches, Relays, Circuit Breakers, etc.) :
- based on a variety of power semiconductor switching technologies
(e.g. power diodes, bipolar power transistors, power MOSFETs,
insulated gate bipolar transistors (IGBTs), silicon-controlled
rectifiers (SCRs), gate turn-off thyristors (GTOs), integrated gate
commutated thyristors (IGCTs), etc.)
- provide high-speed switching without the problems arising from
contact erosion due to arcing (however, may still require snubber
circuits for protection when switching inductive loads)
- older devices based on Si: newer devices based on wide band-gap
semiconductors such as SiC and GaN): these provide enhance
performance (switching at GHz rates, high temperature (> 200 °C)
operation, etc. – described further in following presentation by GaN
Systems Ltd)
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Protection Measures
As with AC power grids, a well-designed protection system will be necessary to ensure safe and
reliable operation of a Smart DC grid. The protection system will comprise protective components
(fuses, circuit breakers, etc.) together with suitable grounding arrangements.
However, for the Smart DC power grid, the protection system design will be influenced by many
factors, including such fundamentals as the DC voltage level used (and whether there is more than one
DC voltage present, or a combination of DC and AC) and whether the DC power grid is connected to
the AC power distribution system (interconnected operation) or isolated from it (islanded operation)
Reliable implementation of DC power grids will require a number of requirements to be met in terms of
system protection. Depending on the particular implementation, these may include:
- no single point of failure
- redundantly-fed electrical zones or buses that can be rapidly separated from the bulk power system
- ability rapidly to re-configure the system (e.g. “island” the system from the AC power system)
- ability to locate and isolate faults without the need for inter-component communications
- ability to recover from a fault to a reliable configuration and mode of operation
- load prioritization into sensitive versus non-sensitive
- minimization of the effect of a faulted load on other loads
- redundant feeds to sensitive loads
- ability quickly to shed non-sensitive loads
- load and power flow management from a centralized control
- transient operational capability in degraded modes, such as loss of cooling and loss of power flow control
- condition-based maintenance
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Protection Measures (cont.)
Whilst many protection devices intended for operation in AC power delivery systems will also
operate in DC systems, there are certain factors which need to be considered carefully when
designing protection measures for Smart DC grids because they may influence the device
ratings which need to be applied in the two situations
Devices available for protection against short-circuit currents and over-currents arising from
overload conditions are fuses and various forms of circuit breaker. In addition, residual current
devices (RCDs) can provide protection from possible electric shocks arising from earth leakage
conditions
Fuses:
- characterized by parameters such as response time, current and voltage rating, interrupt capability, AC or DC
(or both) operation, etc.
- In DC power grid applications, a fuse does not benefit from the current-reversal effect inherent in AC power
systems: hence, the fuse must be capable of acting rapidly enough itself to extinguish any arcs. Fuses
designed specifically for DC power grid applications are therefore typically more complex (and costly)
- If AC fuses are used in DC systems, care must be taken to ensure that the voltage and current ratings are
appropriate for DC application, since these will not in most cases be the same as for the AC application
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Protection Measures (cont.)
Circuit Breakers:
- circuit breakers are generally rated both by the normal current that they are expected to carry, and the
maximum short circuit current that they can safely interrupt
- many commercially-available circuit breakers are optimized on the assumption that the circuit-breaking
process will be aided by the natural zero-current condition of the AC system: hence, such devices are at best
sub-optimally applied to DC systems
- circuit breakers designed specifically for use in DC power grid systems exist – again these tend to be more
complex and costly than their AC counterparts
- solid-state circuit breakers potentially have considerable advantages for application in DC power grids, in
terms both of providing much more rapid switching of fault currents, and in improving the flexibility of the
protection system:
Current Control
Inductance
Solid-state
Switch
Current
Sensor
Filter
Capacitor
To other
DC Loads
To DC Load
In this example of a solid-state circuit
breaker, the solid-state switch is the main
device for current-limiting and fault current
interruption. The inductor limits the rate of
rise of the fault current, and the freewheeling diode limits di/dt on the inductor
when the solid-state switch is turned off
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Protection Measures (cont.)
Grounding and Ground Fault Detection Using RCDs:
- grounding is a complex issue and there are many different approaches to designing grounding in an electrical
power distribution system: depending on factors such as the actual voltages involved and the general system
lay-out, DC power grids may be ungrounded, high-resistance grounded, or low-resistance grounded. In
addition, the ground in such systems could be connected either to one of the poles or to the mid-rail point of
the DC supply
- in general, grounding arrangements used for AC power distribution grids can be translated into equivalent
arrangements for DC power grids: these arrangements include:
- TN grounding (consumer appliance grounded through power distribution system’s ground connection)
- TT grounding (consumer appliance having ground connection independent of the ground connection of the
power distribution system)
- IT grounding (the power distribution system itself has no ground connection)
- for various reasons (e.g. the problem of corrosion of grounding cables in DC power systems), IT grounding is
often advocated for DC power distribution systems
- RCD devices will be necessary in Smart DC grids as they are for AC systems: however, the operating
principle of RCDs used for AC systems is unsuitable for use in DC systems. Hence, new RCD technology will
need to be developed for use in DC power grids: such devices do not seem to be available at present
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Arcing, Erosion and Corrosion
Any DC power distribution system will need to deal with the problems of arcing (and sparking),
erosion and corrosion in system components such as switches, relays, plugs, cables, etc.
Arcing (and Sparking) and Erosion
The arc phenomenon is an electrical breakdown of a gas (e.g. air) which produces an on-going plasma
discharge, allowing current to continue flowing across broken electrical contacts
- in a typical Smart DC grid installation, arcing may occur, for example, when power to a load is removed, either by
means of a mechanical switch or electromechanical relay, or when a power plug is removed
- arcing may also occur in fault conditions (e.g. worn sheathing allowing arcing between exposed conductors
- arcing issues are exacerbated in DC power grids because DC systems do not have the self-extinguishing tendency
associated with AC power systems (due to the current “zero-crossing”)
- arcing issues can be mitigated in DC systems through the use of snubber circuits, “free-wheeling” diodes, or solidstate switching devices
Spark phenomena may occur in situations where there exists a strong electric field able to create an ionized
conductive channel through the air. This effect may occur, for example, during plugging in of loads to the DC
power grid, particularly in the case of capacitive loads
Arcing and sparking events are hazardous primarily
because they can lead to burn and fire hazards, Also,
they can be indicative of wiring faults which could
represent an electric shock hazard. They also can
lead to excessive wear and shortened life of switches
and plugs due to erosion of the electrical contacts
Picture from Wikipedia Commons
Author: ArcsuppressionT
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Arcing, Erosion and Corrosion (cont.)
Corrosion
Corrosion (both electrolytic corrosion and galvanic corrosion) is a typical problem of DC power systems in the
open air. Corrosion can also be a problem inside domestic dwellings, for example in humid areas, or where
moisture is allowed to penetrate through the insulation layers of electrical cabling
- the problem of corrosion is considerably larger in DC systems than in AC systems: in particular, grounding
electrodes are much more susceptible to corrosion in DC systems because of the continuous presence of a
reduction (or “redox”) potential between the active and return conductor (thereby continually fulfilling one of
the conditions needed for corrosion to occur)
- the other condition - the presence of an electrolyte - is also fulfilled whenever moisture is allowed to come
into contact with the conductors
- corrosion is also potentially a serious issue at the electronic board and component level (e.g. a study
with a major public service transport organisation in the 1990s showed that corrosion of electronic
components and boards was one of the biggest causes of maintenance issues)
Prevention of corrosion is best achieved by ensuring good separation of the electrolyte and
the conductors or contacts by insulation. For a DC power grid system for a domestic or small
commercial building, this may require the installation of electrical cabling with improved
insulation properties.
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Existing DC Power Grid Systems and Technology
Cross-over Opportunities
Automotive
The traditional electrical system in vehicles (12 V / 14 V in cars, 24 V / 28 V in trucks and larger
commercial vehicles) is a good example of a DC power grid. For reasons of improving fuel economy,
reducing emissions, and providing greater levels of vehicle occupant comfort and safety, many
functions which previously were done mechanically are now done through electrical and electronic
means, through motors, sensors, ECUs , and associated solid-state electronic components
Fuses
Rectifier
ECU 1
Control
Signals
Electrical
Loads
Ignition
Switch
A
Alternator
M
Starter
Motor
Battery
ECU 2
ECU n
Control
Signals
Electrical
Loads
Control
Signals
Electrical
Loads
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Existing DC Power Grid Systems and Technology
Cross-over Opportunities (cont.)
Automotive
- Switches: mechanical switches in automotive systems are increasingly being replaced by semiconductor
power switches which enable more efficient use of vehicle power, and better control of vehicle electrical loads
- Fuses: whilst traditional “blade-type” automotive fuses are still used, newer types of “re-settable” fuse (e.g.
polymeric positive temperature coefficient (PTC) fuses and semiconductor fuses) are being increasingly used
- Hybrid and Electric Vehicles: these use batteries operating at much higher voltage levels (hundreds of
volts) than “traditional” vehicles, and require specific features to manage issues associated with high power
DC grids (e.g. special measures to avoid arcing erosion in relays switching large DC currents)
- All sectors of the automotive market are driving the development of power semiconductor components such
as IGBTs for high-speed, high-power switching. New wide band-gap semiconductor materials such as SiC
and GaN offer even greater performance enhancements
The development and use of power semiconductors in automotive applications has been
derived from their development and use in the power distribution industry. Continued
investment amongst automotive suppliers in developing these new semiconductor components
depends on the availability of suitable markets for them: however, if the automotive market
(particularly the HEV / EV market) does grow as predicted, then the associated development of
these new power semiconductor switches may well feed back into other markets such as the
power distribution sector
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Existing DC Power Grid Systems and Technology
Cross-over Opportunities (cont.)
Automotive 42 Volts: Parallels with Domestic Smart DC Grids
In the 1990s, and into the new millennium, there was considerable concern amongst automotive vehicle
manufacturers and system suppliers that higher future vehicle electrical loads would render the 12 / 14 V
vehicle electrical system inadequate. For this reason, the 42 V standard for vehicle electrical systems was
proposed. The potential benefits included:
- lower load currents
- better fuel economy
- increased system flexibility
- opportunities for new vehicle systems
The potential transition from the 12 V / 14 V vehicle electrical system to a dual 14 V / 42 V system also meant
that a number of technical issues had to be tackled by the automotive supply chain in order to allow the
implementation of reliable switching and protection functions. These issues included:
- increased switch / connector arcing potential
- steering column safety (specific safety concerns over having 42 V in the steering column)
- reverse battery and jump starting concerns
- 42 V / 14 V short circuits
- shock hazard and other safety issues (e.g. load partitioning of critical systems)
But…
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Existing DC Power Grid Systems and Technology
Cross-over Opportunities (cont.)
… in the end, 42 V in vehicles didn’t happen, despite appearing to be an “obvious” solution to a
pressing need at the time. Some of the reasons for the failure of 42 V are:
- improved alternator designs meant that the 14 V system was, in fact, able to cope with the higher electrical
demands of new vehicle systems
- because not all electrical loads in vehicles are actually better operated at 42 V (and also because there would
in any case need to be a transition period towards a 42 V standard), the need for a dual 14 V / 42 V electrical
system was realized. Such a dual system had disadvantages in terms both of complexity (e.g. need for
careful power management, more complex circuit protection requirements, etc.) and cost
In the automotive world, where cost is critical, the need for 42 V turned out to be insufficiently pressing
to force its introduction, despite potential advantages. This point is worth bearing in mind when
considering the potential introduction of Smart DC grids in domestic and small commercial premises.
The potential advantages of such a shift may be clear, but unless the need really is sufficiently
pressing, the status quo may be difficult to overcome.
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Existing DC Power Grid Systems and Technology
Cross-over Opportunities (cont.)
Other Existing DC Power Grids:
Aerospace:
The trend in the aircraft industry is
towards “more electric” operation. to
optimize aircraft performance, decrease
operation and maintenance costs, and
reduce emissions of air pollutant gases.
To achieve the goals of MEA, a number
of different power generation and
electrical system topologies are under
investigation by the aircraft industry,
including means for providing adequate
system protection critical for an aircraft
system.
Picture from Wikipedia Commons: Author: All_Nippon_Airways_Boeing_787-8_Dreamliner_JA801A_OKJ.jpg: Spaceaero2)
There is a trend for using only high voltage DC systems for power distribution and management in MEA. The
potential advantages of using a high voltage DC distribution system are seen as enabling weight, size and
power loss reduction, whilst increasing the levels of transmitted power. Another area where the development
of semiconductor power electronics and switches is impacting on aircraft electrical power distribution system
design is that of protective solid-state circuit breakers
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Existing DC Power Grid Systems and Technology
Cross-over Opportunities (cont.)
Other Existing DC Power Grids:
Rail:
Modern DC railway power supplies chiefly operate at traction voltages of 600 - 750 V DC via third-rail
collection or 1.5 kV or 3kV from overhead lines
Ships:
The primary power distribution system installed in ships is AC; however, DC distribution systems are used for
combat systems, auxiliary systems, and emergency systems in submarines. Small DC networks, supplied by
rectifiers or AC / DC motor-generator sets, supply outlets for battery charging. Some submarines have high
voltage DC generators that supply static frequency converters for producing 450 V, three-phase, 60 Hz power
for the ship’s user equipment, and DC power for main battery charging. Circuits are protected using both fuses
and various types of circuit breaker
Photovoltaic Power Systems:
The shift towards “green” sources of renewable power has seen the corresponding development of supply
chains for providing the system components required for both large-scale and small-scale implementation of
these power systems. This is particularly so with photovoltaics (PV) for small- and medium-scale applications.
Several companies are now supplying all the components (including DC-rated switches and fuses) required for
both off-grid and grid-connected PV systems
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Existing DC Power Grid Systems and Technology
Cross-over Opportunities (cont.)
Other Existing DC Power Grids:
Telecommunication and Data Systems:
Traditional analogue telephone systems operate from a -48 V DC supply situated in the telephone exchange.
Due to this legacy requirement, -48 V is still a common standard for current telecommunication data centres
which have to handle data as well as voice systems.
Related to the issue of DC power supply in telecommunication data centres are Power Over Ethernet (PoE)
and Powered USB technologies. PoE (operating at up to 57 V DC) and Powered USB (operating at up to 24 V
DC) are systems designed to transport electrical power, along with data, to telephones, wireless LAN access
points, cameras, remote switches, computers, peripherals, and other electronic devices.
E-merge Alliance:
The E-merge Alliance is open industry association championing the adoption of safe (24 V) DC power
distribution in commercial buildings through the development of a family of E-Merge Alliance standards. The
work of the E-Merge Alliance is based on the concept of DC micro-grids operating alongside traditional AC
networks throughout commercial buildings. This hybrid AC and DC platform is being designed as an open
architecture, with the focus on reducing or eliminating inefficient AC to DC conversions between power sources
and digital devices by converting and distributing power in DC form.
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Voltage Levels
An issue which has particular relevance to switching and protection strategies in DC power
grids is that of the actual DC voltage level (or levels) used in the power distribution system.
Also related to this is the question of whether or not there is a co-existent AC power grid.
Some of the issues to take into account are:
Voltage Drop and Power Loss in Cables:
Voltage drops in cables can be quite considerable.. For example, a current of 20 A and a cable length of 40 m will give
a voltage drop of approximately 3 V for cable cross-section of 10 mm and V to 12 V for cable cross-section of 2.5 mm.
These are absolute voltage drop values: hence, with respect to a very low DC voltage level (say 24 V), they represent
a considerable percentage of the total available voltage
Variable DC Ratings of Appliances and the Need for DC-DC Conversion:
Suitable DC-DC converters are likely still to be required to enable different domestic appliances to operate from a DC
power grid, whatever its nominal voltage level. Whilst “intelligent” and efficient DC-DC converters can be envisaged,
making use of fast-acting semiconductor switching technologies and communication techniques to enable “automatic”
selection of the required voltage for a particular appliance, a DC power grid does not in itself eliminate the need for
voltage conversion.
Safety Issues – Rail to Rail Short Circuits:
The possibility of electrical short circuits occurring between different sub-grids of a multi-level DC power grid, or
between a DC power grid and an AC power grid which are co-existent in a particular property, means that suitable
protection against the occurrence of such circumstances will be required, adding significant complication to the
protection system for the power grid.
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Conclusions
- Lessons learned from other DC power distribution users such a automotive and aerospace can be applied to
Smart DC grids
- In terms of switching and circuit protection, the main problems arising from the deployment of DC (rather than
AC) power grids are:
- How to deal safely with arcs which occur at switch contacts or other points where a DC circuit is broken
- How to deal with over current protection, especially the provision of resettable devices rather than fuses
- How to deal with detection of earth faults and other stray leakage paths
- How to deal with corrosion of cables, circuits and other system components
- How to optimize the DC power grid architecture to provide an appropriate level of safety
- Recent developments in silicon power semiconductor technology, and emerging SiC and GaN technologies
are making available new, fast, solid-state switching devices which could be employed to produce high
efficiency, very low-cost converters, switches and circuit protection devices
- The UK has a strong capability in device, packaging and circuit design which could shorten design cycles and
drive both performance and cost. The SIGs, KTN’s, NMI, TSB, EPSRC, UKTI and BIS are already having a
strong influence and should further encourage (and fund) the necessary co-operations to build a coherent
supply chain
- There is clearly a dichotomy between, on the one hand, the question “Who is going to invest in creating new
electrical appliances compatible with the DC grid concept if the infrastructure does not exist?” and on the
other hand, the question “Who is going to create the infrastructure if there is no demand?” Strong, clearly
understood, tangible benefits to be gained from the adoption of the new DC power grid technology will be
needed in order for both questions to be answered.
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Recommendations
- Innovation is urgently needed to develop new circuit switching and protection devices and systems for Smart
DC grids. These will need to be both functional and cost effective. UK SMEs and universities have much
potential to address this with the appropriate support, e.g. from TSB or EPSRC
- More work is required to identify in detail the requirements and specifications for Smart DC grids (at both
system and component level) along with the most promising market sectors. Focusing on the best
commercial opportunities will be essential if the emerging Smart DC sector is to reach critical mass and take
advantage of devices and techniques already in use in other markets such as automotive. This will be best
achieved through the Smart DC SIG as it can engage with all the key stakeholders
- Development of standards will be essential if the Smart DC market is to gain confidence and grow
- Emerging semiconductor technologies such as GaN offer an opportunity for the UK to develop a world leading
supply chain which could bring long-term benefits to UK plc as Smart DC systems are deployed worldwide.
Further rapid investment is essential to maintain and grow the UK’s position in the face of strong international
competition
- The Smart DC SIG is ideally placed to bring together the appropriate technology developers, energy utilities
and end users. Further investment in the Smart DC SIG is strongly recommended as a very cost-effective
way to promote UK capability in this emerging technology area.
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This copyrighted document is the property of TRW Limited. No license is granted by TRW to anyone to use, reproduce or exploit any content. Any authorized copies made by any method must also include this legend. Copyright TRW Limited 2012.
Email: [email protected]
Web: www.conekt.co.uk