Kubota GL Series Refit by RFL Alternators & Macfarlane Generators

The objective of the case study is to highlight the advantages of RFL Alternators against the Sawafuji alternators – factory fitted in Kubota GL series generators (http://www.kubota.com.au/products/power-equipment/generators/gl-series/).

The tests conducted has been shared with users to understand the benefits of the Refit kit currently provided by RFL alternators in partnership with Macfarlane Generators, Melbourne (https://www.macfarlanegenerators.com.au/products/c510/rfl-alternators).

Know a bit more about us and our partners

RFL Alternators Pty Ltd

Based in Sydney Australia, RFL Alternators Pty Ltd is a world class manufacturer of high quality permanent magnet alternators for the power generation industry. With over 25 years of investment into research and development, RFL prides itself in continuing to develop new and efficient cutting-edge technologies and products which are at industry’s forefront, and manufactures alternators to the highest of quality standards.

Macfarlane Generators

Macfarlane Generators was established in Victoria, 1949. They have since expanded into Queensland and New South Wales, opening doors in 1982. Today, they have more than 60 staff members specialising in supply, installation, parts, and servicing, of power generator sets for industrial, commercial, domestic, and recreational applications.

Macfarlane Generators have provided permanent and temporary power to an impressive range of clients including Truck trailers, Airports, Hospitals, Small towns, Phillip Island Grand Prix, The Sydney Harbour Tunnel. The company pioneered the development of acoustically silenced generators for film and television applications over 30 years ago, providing power for films and shows such as The ANZAC’s, Crocodile Dundee, and Neighbours.



 The Kubota GL Series power generators is one of the most popular and best performing small range power generators sold and used in Australia. All the below factors make the Lowboy suitable for a number of applications from industrial to home and recreational use.

Low Noise Levels: The use of the larger capacity radiator on the GL-6000/9000 generators, with oversize muffler plus a lower fan speed ensures minimum operating noise levels. A matched air cleaner hose further reduces suction noise to make sure these generators are the quietest available.

Easy Maintenance: Control panels are centrally located and easy to use, providing full operating information at a glance. Single sided maintenance reduces the operator’s workload and makes checking the oil, fuel, cooling water and battery levels a simple operation. Transportability is enhanced with special forklift openings on the base of the unit as well as one-point lifting eye.

Safety Measures: The GL-6000/9000 generators provide covers for the engine cooling fan and generator for safer operation. An automatic shutdown is activated if water temperature is too high or oil pressure drops below a safe operating level and a Starter Safety System prevents engaging again after initial start.

Improved Reliability: The Kubota super mini vertical diesel engines are water cooled and have increased performance for dependable horsepower and when direct coupled to the generator, provide continuous power output levels with minimum power loss.


Sawafuji Alternators and market demand for simplicity

The factory fitted Kubota lowboy GL Series generators use Sawafuji Elec Co manufactured


alternator which are very well built, reliable and have been proven in Japan since a long time.

However, the alternators do require very high level of electronics and are extremely complicated in their design. Information on the alternators and other products from the company are limited due to the complex engineering and electronics on the product.

The alternators and particularly the AVRs have reported some failures under extreme weather conditions of the Australian continent. Time and again there has been a market need to refit the alternators in case of failures with a much more reliable product. The main reasons for such an opportunity are

  1. High labor costs at times make replacement of the Sawafuji alternators a much more viable option than repair
  2. Sporadic availability of spares and electric components asks for products with minimal electronics and ease of maintenance
  3. Rewinding of the sawafuji alternator in case of failures is very expensive
  4. There is lack of reliability in the alternators after rewinding


RFL Alternators and the answers provided

The RF series Radial Flux Generators are a single stator, single rotor permanent magnet design. The combination of novel winding techniques with innovative rotor and stator design gives the RF series significant advantage over current commercially available technologies.

The RF series generators are designed specifically to be compact, lightweight whilst remaining highly efficient. All materials used in construction are conventional, so as to minimise manufacturing cost whilst still providing the specified performance.

The RFL RF2-12.5 Bi-Gen is a technologically advanced PM brushless alternator, offering highest energy efficiencies while maintaining minimal physical size. It sets a new industry standard. Its PM design Brush-Less Internal Magnetic Voltage Regulation (No AVR or electronics) means that possible points of failure are kept to a minimum by eliminating traditional brushes and AVRs.

We found significant advantages when refitting the Kubota Lowboy GL 6000 with RFL alternators. The units registered 10% more power, 10-15% fuel savings and much better THD Levels


The Kubota Lowboy Re-fit Kit

Product Overview: The RFL Kubota refit kit is an ideal alternative for the Kubota GL6000 and GL9000 gensets.

The kit comes complete with:

  • RFL PMG alternator.
  • Mounting foot (1)
  • Adaptor housing (2)
  • Taper drive shaft (3)

Model Options and Specifications:

  1. RF2 – 7.5 KGL6: 7kVA / 7kW single phase 50Hz 3000rpm alternator suitable for Kubota GL6000 Lowboy Generator
  2. RF2 – 12.5 KGL9: 10kVA / 10kW single phase 50Hz 3000rpm alternator suitable for Kubota GL9000 Lowboy Generator

KEY BENEFITS – Magnetic Flux Technology operates without electronics, uses less fuel while providing more power.

  • Compact and light
  • More power
  • Longer life
  • Easy to fit
  • 15% saving in fuel
  • Low service costs

Please find the complete test procedure, test reports and summary here – Kubota Lowboy GL6000 Test Report

Click here for details on the Refit Kit – RFL Kubota Kit

For many more such interesting case studies and blogs please contact us directly or visit us at https://rflalternators.com


Focus Industry – Refrigerated Transport

Based in Sydney Australia, RFL Alternators Pty Ltd is a world class manufacturer of high quality permanent magnet alternators for the power generation industry. With over 25 years of investment into research and development, RFL prides itself in continuing to develop new and efficient cutting-edge technologies and products which are at industry’s forefront, and manufactures alternators to the highest of quality standards. Today, we are excited to share our experience and contribution in one of the most critical and fastest growing industries in the world i.e. Cold Chain Logistics

Cold chain systems are crucial to the growth of global trade in perishable products and to the worldwide availability of food and health supplies. Each year, billions of tons of fresh food products and millions of dollars’ worth of exports are lost due to poor cold


chain systems in developing markets.

  • The World Economic Forum lists food crises as fourth on its top global risks of highest concern for the next 10 years.
  • Globally, billions of dollars are spent on improving agricultural processes to create higher food yields, but the fact that nearly half of all food never makes it to a consumer’s plate is largely ignored.
  • Additionally, over $260 billion of annual bio-pharma sales are dependent on cold chain logistics to ensure the efficacy of their products.

RFL Alternators in Transcool BV solutions

Key Facts and growth indicators in the cold chain logistics sector as a whole

  • Cold chain services that support perishable food distribution globally are estimated to be valued at nearly $250 billion.
  • Experts also estimate that cold chain logistics spending in support of bio-pharma industry is more than $10 billion and is expected to grow to $13 billion by 2019.
  • Asia alone contributes to $1.2 billion in growth.
  • The compound annual growth rate (CAGR) of cold chain markets is anticipated to reach nearly 16 percent into 2019.


Infrastructure and Road Transport Network

The infrastructure within a country is a key aspect in a company’s selection of export markets. Transportation infrastructure must be capable of supporting the reliable distribution of a product within the country or region without excessive delays. The International Association of Refrigerated Warehouses has noted a strong correlation of cold storage capacity to a country’s transportation score in the World Economic Forum’s Transport Index.

Transportation costs are often the most challenging obstacles to suppliers in developing countries. In countries with

well-developed cold chains, most retail and franchise service providers outsource their supply chain operations to third party logistics providers (3PLs) and to other cold chain service providers that meet their requirements based on their products and business strategies.


Improving technologies in cold transportation has created a shift in transport modes

  • Flowers are increasingly being transported to the U.S. via ocean going vessels, rather than the traditional, more expensive air transportation option.
  • In fact, global shipments of all perishable products by ocean carriers has increased rapidly over the last 35 years.
  • Reasons for the shift include greater availability of refrigerated containers, improved facilities at ports and better technology options for monitoring shipments in route.
  • Air transportation is still a heavily relied on mode of cold transportation for many high value items, such as biologic and bio-engineered drugs which can cost as much as $100,000 or more.
  • The amount of biotechnology products that require cold chain has risen drastically around the world. Nearly half of the top 50 global drug products in 2013 required cold chain services.
  • Cargo challenges in air transportation have led to some pharmaceuticals shifting to sea modes in recent years.


Reefer Trucks or Refrigerated road transport trailers

Modern refrigerated trucks, known as reefers, are designed to be very versatile and can be configured in minutes to carry a wide variety of cold products. Many trucks can carry products of varying refrigerated temperatures by adjusting internal compartments to meet specific product temperature needs. Often modern trucks are fitted with GPS monitoring systems that can provide data on location and can help operators maintain the temperature in individual compartments. Individual trucks can cost between $30,000 to well over $150,000.

Refers require industrial designers and engineers to develop efficient refrigeration units for transportation vehicles and networks. The industry has developed few key systems/solutions with specific advantages and disadvantages

  • Primary engine – Air conditioner / Refrigerated system draws the power from the prime mover itself. The system is simple and cost effective, however may have limitations
  • Auxiliary Powerpack – Use of a secondary engine to drive the refrigerated unit
  • Clip-on refrigerated units – Units that can be fixed to the containers instead of being a part of the trailer.
  • Chassis mounted APU (Generator) – A generator is mounted under the chassis in a very small footprint which can run independently and is particularly efficient in fuel consumption

RFL Permanent Magnets in Transcool’s Generator Solutions

Transcool is a dynamic company that produces these custom-made generator sets (APUs) for the transportation sector. The goal of Transcool is to produce sustainable machines with a high energy efficiency level.

After building various prototypes, Transcool succeeded in producing a generator set able to power two refrigeration sets at the same time with a fuel consumption of only 2.2 litres of diesel per operating hour. This is achieved by tuning the unit in such a way that there is sufficient power at low engine speeds (1,500 rpm). All the generator components units were carefully placed during the development to improve serviceability.

Transcool have engineered our permanent magnet alternators into their generator sets. In so doing have managed to design a very robust, compact and fuel-efficient product for the refrigerated transport industry

Innovation with regards to the packaging – Transcool have achieved rapid uptake in a short time reflective of the market place acceptance of the product. More power from drive engine and less fuel consumption.

The design of highly efficient permanent magnet generator set that exceeds industry standards, is smaller and lighter that equivalent models. We also looked at common problems of existing designs and found the durability of the RFL permanent magnet alternator to be a key point of improvement.

Our RF4-20 and RF4-30 permanent magnet alternators are smaller and lighter while being around two thirds of the length of competitor alternators. The durability of the RFL permanent magnet alternators has seen zero failures, (ie no electronics). The increased efficiency has enabled the complete genset packaging to be smaller and lighter as less fuel storage capacity is required.

Transcool have designed and built an innovative and industry leading generator set and RFL Alternators are proud to partner with Transcool in trying to change the industry landscape. If you want to know more about such case studies and how we can help solve your problem at hand, please feel free to write to us as well.


For more information on our permanent magnet alternator range, please visit our website or contact us.

DC Generators in Telecom Industry

RFL Alternators Pty Ltd., has 25 years of research in the power generation industry backing its core strengths of innovation and energy conversion to produce world class patented products which are at the cutting edge of Technology today.

Telecom sector and DC Generators

The Focus of this blog is on the changing dynamics of doing business in Telecom Infrastructure.


Early age of Mobile Telephony

Let us roll back about 25-30 years. With the advent of Mobile Telephony across the world, the need for radio communication and mobile air waves grew dramatically.

This led to the demand of a huge world-wide network of Telecom Towers from cities through to  the most remote areas. There were a number of challenges to start with some of which  still remain very relevant in today’s scenario;

  1. Availability and accessibility of land,
  2. Capability and capacity to construct the required infrastructure,
  3. Environmental factors aligned with operating the equipment from big cities to remote locations with exposure to extreme temperatures, humidity, altitude etc. and
  4. Power requirements the prime subject of this blog

Power Requirements

More often than not power to such remote locations always was a challenge and 100% of power supplied was through diesel Power Generators.

Since, the towers had to operate without a minute’s downtime in the harshest of conditions, the power generators had to be robust, powerful and at the same time extremely fuel efficient.

The first 2 requirements being the driving ones and the need for heavy AC power for Air conditioning units to shield the control units from the effects of nature, telecom companies preferred heavy power generators costing huge capital expenditure and consuming gallons of fuel, at the same time keeping a backup stock of prime power at their disposal to be used in rotation.

The whole operation was uneconomical but necessary and was never put it into question because of the lucrative revenues and bottom line growths made by Telcos around the world.

The advent of internet bubble in the 2000s

Mobile telephony in the new millennium is no longer associated with high voice calling rates and huge profits. The millennials in fact use the technology for far more complex applications and in much effective and economic communication which have depleted the bottom lines of the Telecom giants across the world severely.

The good news however is technology for infrastructure is also growing at a similar pace.

  1. Construction equipment and technology has ensured highly efficient, fast paced creation of infrastructure
  2. Modern control systems and radio communication does no longer require huge amounts of AC power and are becoming more and more resilient to environmental change, and
  3. And the footprint of cell tower infrastructure has dramatically reduced.

What has not changed rapidly with respect to the second point is the perception of Telecom Providers, Infrastructure Providers and even government regulators. In an age where fuel is becoming increasingly scarce, they still rely on highly inefficient


power generators consuming huge amounts of fuel.

DC Generators vs AC Generators in Telecom Grids

Technological advances enable telecom control units / towers to operate at higher temperatures thus eliminating the air conditioning load at site, creating significant energy savings and opening the market for DC generators.

Solid state electronics need DC power, not AC power

RFL Alternators today are trying hard to overcome this perception of 100 years of conventional systems and AC power legacy. Our cutting edge permanent magnet technology provides the following advantages;

  1. No maintenance and high reliability – limited electronics, simple efficient design only rectifications diode used
  2. Long life – With less failing, wear and tear parts our alternators promise long life
  3. Very compact – Reduced footprint ensures overall size of generator to be reduced
  4. Increased Efficiency – Use of cutting edge patented technology increases efficiency by 10 -15%% and reduces fuel consumption by up to 20%
  5. Light weight – Reduces costs of reinforcements, enclosures and increases serviceability
  6. Low DC voltage ripple



Presently 4.7 billion unique mobile subscribers and 5.7 billion projected by 2020. Telecommunications companies worldwide will invest over $1.4 trillion in the construction of new cell towers and equipment upgrades by 2020. Reducing energy cost presents a major opportunity to increase profit in an ever-shrinking unit subscriber fee base.

Mobiles are replacing land lines as primary means of communications. Now the same level of reliability is being demanded of mobile network as to wired telephone networks in yesteryears.

There is increased focus and awareness among nations for reducing carbon footprints, use of conventional fuel and energy sources to limit the dangers of Global warming.


Key Facts

  1. More than 90% of the current telecom towers use inefficient AC power.
  2. By 2030, it is predicted that 90% of the global population will have a smart phone.
  3. Australia – The large geography and remote towns and populations make it ideal for use of DC powered Generators.
  4. India – It is estimated that the telecom towers in India consume more fuel than all trucks running in the country.
  5. Africa – Large parts of the continent still suffer power outages for 12-18 hours. This makes even the most urban of sites needing highly fuel-efficient systems for tower operations.
  6. USA – With the role out of 5G networks, there will be need for better and efficient systems.

RFL Alternators Pty Ltd., and our partners are constantly trying to change perceptions and challenge traditional thought process in the Energy Generation space. We are right in the middle of innovative projects in sectors like Telecom, Marine, Transport, Renewable Energy and Military.


You can find about all of our DC PMAs in our new DC Range Products Page on the website. For more such interesting facts and to know more about all the interesting work that we are doing at RFL Alternators, please get in touch with us.

Rapid Growth Of Renewable Energy

Renewable energy production and use has grown at an overwhelming rate – the acceptance and uptake of this technology has been greater than anticipated with countries continuing to set target dates for converting to 100% renewable energy [1].

At least 30 countries generate more than 20% of their energy from renewables, and 120 countries have policy targets for longer-term shares of renewable energies. The European Sustainable Energy Vision outlines the transition of the energy supply and demand for the 27 EU countries to 100% renewable energy by 2050 [2] which was then revised to 2040 [3].

By the end of 2015, 23.7% of energy came from renewable sources: 16.6% from hydro power; 3.7% from wind; 2% from biomass; 1.2% from Photo Voltaic (PV) and 0.4% from geothermal, concentrated power and ocean [4].

Figures 1 and 2 show that solar PV has the highest growth rate, however recently large scale CSP has been gaining a lot of attention, and per kw, wind power has the fastest growth [4].

renewables figure 1

Figure 1: Average Annual Growth Rates of Renewable Energy Capacity and Biofuels Production, End-2010 to End 2015 [4]

A number of challenges arise with the use of renewable energies. Firstly, energy is not ‘on demand’ and therefore may not always be available when required. This issue is more pertinent in terms of a source like solar, which is only available during sunlight hours. The practiced solution to this problem is simply to have a combination of different power generation sources, such as those listed in Figure 2.

An important fact to note is that with the exception of solar PV (which creates DC through the photovoltaic effect), renewable sources create power through the use of a generator which is driven by a prime mover. The prime mover can be wind, steam from


concentrating solar thermal, hydro, geothermal, ocean from currents/waves, or biomass.

renewables figure 2

Figure 2: Renewable energy indicators [4]

A second challenge with renewable energy is the land size required to sustain the planet’s energy needs. For a move to 100% renewable energy every step must be taken to design the  smallest footprint. To do this energy systems must be designed to be as efficient as possible. The generator is no doubt a key factor in these systems and should be designed and retrofitted to meet the prime mover’s needs.

Accepted facts about the most efficient generators are:

1.They use permanent magnets which leads to

  • High efficiency
  • Reduced copper losses associated with energising the rotor winding
  • Less heat generation
  • High torque density
  • Unity power factor
  • Very quiet operation

2. They use Interior Permanent Magnets (IPM) allows for flux focussing, meaning

  • High flux density
  • High power density
  • Low flux leakage
  • Robust structure
  • Easy heat dissipation

3. Removing electronics to obtain

  • Increased efficiency
  • Simpler design
  • High reliability

These are all concepts well-known to Radial Flux Laboratories (RFL), however, not satisfied with this, RFL is pushing the envelope by modelling and developing new configurations tailored to improving the efficiency of generators to integrate seamlessly with the renewable energy source.

Future posts will describe RFL’s sophisticated approach and design on developing generators that integrate with wind turbines, and the development of DC generators which have many advantages including combating harmonics produced by non-linear loads.

[1] Renewable Energy World. (2013). 100 Percent Renewable Vision Building [Online]. Available FTP: http://www.renewableenergyworld.com/articles/2013/04/100-percent-renewable-vision-building.html?amp%253bbuffer_share=fdc06

[2] International Network for Sustainable Energy. (2004). EU-25 Sustainable Energy Vision 2050 [Online]. Available FTP: http://www.inforse.org/europe/VisionEU25.htm

[3] International Network for Sustainable Energy. (2004). EU-27 Sustainable Energy Vision 2040 [Online]. Available FTP: http://www.inforse.org/europe/VisionEU27.htm

[4] Global Status Repot (2016). REN21 Renewable Energy Policy Network for the 21 Century [Online]. Available FTP: http://www.ren21.net/wp-content/uploads/2016/06/GSR_2016_Full_Report.pdf

Credit: Ezra Bowen

RFL’s Unique Design is Proving Extremely Valuable

By the end of 2015, 23.7% of energy was delivered from renewable sources with 3.7% of the total worldwide electricity supplied by wind energy, which is growing at a rapid rate of 17% per annum.

Since 2011, the cost of wind generating infrastructure has fallen by 10%, making wind energy 14% cheaper than new coal and 18% cheaper than new gas.

There are a variety of electrical generators on the market for use in micro-wind turbine applications. These include induction and synchronous machines.

High-end machines use permanent magnet generators – they’re excellent because they eliminate the copper losses associated with rotor windings, making them far more


efficient than induction and wound rotor machines. As such, these generators have gained interest in replacing conventional machines with Permanent Magnet Synchronous Generators (PMSG).

Until recently, wind energy converters have been designed for speeds from 750RPM up to 1800RPM, whereas wind turbines usually operate from 20RPM to 250RPM [3]. Consequently, a gearbox has been the link between the wind turbine and the generator. Gearboxes require maintenance, decrease efficiency, are noisy and are generally the first component to fail in the system.

By increasing the number of poles in the generator, the electrical frequency increases and the gearbox can be eliminated. PMSG are able to have a smaller pole pitch and therefore more poles as only the leakage flux between the two magnets sets the limitation.

Radial Flux Laboratories (RFL) has experience in modelling and developing machines utilising concentrated fractional windings which does not require an integer slot winding and hence allows for a higher pole count.

There are advantages with both an inner and outer rotor configuration which is generally designed around the application. An inner rotor (meaning the stator is on the outside) is the most typical design and is generally chosen as the majority of losses are contributed to by the copper losses within the stator. As a result, designing with the stator on the outside gives better cooling properties for a higher efficiency. Furthermore, having the stator on the outside allows for larger slots, and consequently a more efficient or higher rated machine.

A unique outer rotor design does bring a number of advantages though. For example, the larger rotor diameter allows for a higher number of poles, and the magnets stay cooler so the likelihood of demagnetisation is reduced. Additionally, the hub allows for the blades to be directly fixed to the rotor which results in a cheaper, simpler, and more integrated design.

Dual stator machines are now being considered for various motor and generator applications. The dual stator is incorporated in synchronous generators to increase the power capability.

Recently dual stators have been found to be useful as a part of uninterruptable power supplies, standalone power supplies, and generators of both ac and dc electric power [4]. Another advantage is the reliability of having a dual winding generator.

However, dual winding machines have also traditionally had the challenge of required heat dissipation associated with the inner winding. Recognising this, RFL has developed a unique design which transfers heat from both the inner and outer stator to the casing and cooling fins.

RFL has also optimised the mechanical structure, efficiency and thermal properties. This design shows promise in wind turbine applications, where the generator is required to be sealed for increased reliability and service timeframes.

As wind energy continues to grow it is paramount that wind turbines/generators are optimised for maximum efficiency and reliability. RFL has developed the most efficient and reliable generators on the market with the smallest footprint that can be tailored to meet the wind turbines design.


[1] Renewable Energy World. (2013). 100 Percent Renewable Vision Building [Online]. Available FTP: http://www.renewableenergyworld.com/articles/2013/04/100-percent-renewable-vision-building.html?amp%253bbuffer_share=fdc06

[2] C.Techies, “Renewables now cheaper than fossil fuels in Australia,” Environmental and Energy Study Institute, pp.1, Jan. 2013.

[3] M.Widyan, “Design, optimization, construction and test of rare-earth permanent magnet electrical machines with new topology for wind energy applications” in Phd Thesis. Berlin: Technical University of Berlin, 2006, pp. 16-76

[4] A.Dwivedi and R.K.Srivastava, “Analyses of Dual Stator PM Brushless DC Motor” in IOSR Journal of Electrical and Electronics Engineering (IOSRJEEE), Volume 1, Issue 2, pp 51-57


Credit: Ezra Bowen

RFL teams up with Eniquest

Eniquest Case Study – “Compact, rugged and highly efficient generator sets”

Eniquest is an Australian leading manufacturing company that specialise in remote area power and independent energy solutions.  They provide quality, cost effective, reliable power production equipment for a variety of industries and applications.

The company is innovative and keen to adopt new efficient and environmentally responsible technologies and techniques for power production. Their systems use highly efficient technology providing a DC base with an AC inverter, and use technology that is widely recognised as the most efficient and safe way to produce and store electricity.  Eniquest have developed products that integrate with renewable energy devices to keep fuel usage to a minimum.

Eniquest has been providing reliable power distribution, providing DC Generators, AC Generators and Auxiliary Power Units to the Australian Military for over 10 years.  The relationship built with the Australian Military demonstrates Eniquest’s recognition of the need for reliable, compact and light weight power generation products. They have gained a reputation for providing power solutions that can perform efficiently and reliably in the harshest conditions.

Eniquest uses innovative power production technology to meet the ever growing industry challenges of today. Like Eniquest, RFL Alternators understand the evolving requirements of industry today and in the future and work to provide machinery that is more fuel efficient, more reliable and more innovative than currently available



RFL Alternators is a world class manufacturer of high quality permanent magnet RF2 AC2 pole series alternators which feature the powerful Magnetic Flux technology embedded in the permanent magnetic design.  The alternator is lighter in weight, has a 40% smaller footprint and is 92% more efficient than traditional wound rotor machinery.


The challenge

To further service the evolving needs and challenges faced by the Australian Military, Eniquest needed to source a highly efficient, robust and compact alternator to use in the manufacture of generator sets for military applications.


The solution

The highly efficient and compact design of the RFL alternator allowed the total generator set package Eniquest would provide to be much be smaller both in terms of size and weight.

The novel design and lack of any electronic components met the Military’s criteria for durability and the RFL Alternator is inherently compliant with MIL-STD-461 or electronic magnetic compatibility.

These qualities allowed Eniquest to service the Australian Military with technologically advanced 8kW and 16kW generator sets that meet their criteria for lower cost, low fuel consumption and superior reliability both today and in the future.

In collaboration Eniquest and RFL Alternators make a well matched team – utilising RFL’s lighter more efficient and rugged technology Eniquest would be able to provide the Australian Military with a superior, highly efficient and tough generator set to meet it’s ever growing needs.Eniquest workshop

PMSG technology supports the Army’s complex power requirements

The array of electrically powered systems used in the military has expanded beyond anticipation over the past decade and is continuing to grow at an unprecedented rate.

Unfortunately, deployed power systems have not been upgraded to meet power requirements.  The Army has an extremely rapid, mobile, spontaneous and agile deployment, making its power solution requirements some of the most complex.

The Army currently relies on power generation from a series of wound rotor diesel generators ranging from single-phase 1.3kVA generators up to three-phase 60kVA generator sets.

The current scenario for an Army deployment is to work the ‘power planning’ around each mission, this dictates the power generation and distribution to be deployed. When the mission capability increases, larger generators are needed to handle increased loads. As the mission decreases, smaller generators are required to replace the larger ones in order to keep the generator load balanced.  This causes logistical problems and breaks the scalability and modularity requirements associated with an Army deployment.

A well-known constraint on three-phase generators is load balancing techniques. The Army has been known to deploy with load banks in order to keep three-phase generators balanced and maintain a reasonable load.  This is cumbersome to a mobile deployment force.

Permanent Magnets Synchronous Generators (PMSG) like those developed by RFL Alternators have significant advantages over the conventional wound rotor generators. Firstly, load balancing. Although load balancing is recommended for PMSG technology and should be practised, it does not bear the importance that it does on traditional wound rotor generators, and certainly does not need to be as closely balanced.

Perhaps the most significant advantage with the PMSGs is they can be paralleled. This


eliminates the need for significant power planning. A “one size fits all” generator can be deployed, take for example an 8kVA generator that could run the minimal load, as the mission capability grows a second generator is paralleled, and so forth and so on. The reverse action happens as the mission capability is reduced. Generator paralleling brings with it a number of advantages including:

  • Reliability
  • Scalability
  • Ease of maintenance
  • Reduction of light loading on the prime mover
  • Reduction is cost of per Kw

Due to power demands in vehicle mounted configurations, recently the Army has been fitting vehicles with an Auxiliary Power Unit (APU). This APU has been a DC PMSG, which was chosen for two main reasons. Firstly, it eliminates the need for the vehicle to comply with strict high voltage standards and secondly, nearly all electrical equipment runs off DC voltage, so the need for rectification and voltage step-down is eliminated thus saving efficiency.  To meet these demands RFL Alternators have recently developed highly efficient DC PMSGs, which have an optional 24VDC and 48VDC output.

RFL generators are designed with an embedded permanent magnet synchronous generator using neodymium magnets. This clever design leads to highly efficient robust generators. They are smaller in size and lighter in weight than traditional wound generators and don’t have the need for complex electronic components – this dramatically increases reliability.

Our next post will reflect upon RFL Alternators have teaming up with an Australian company specialising in remote area power and independent energy to provide rugged and reliable generator sets to the Australian Army.

Electric Vehicle technology and the role of Permanent Magnets

European legislation to phase out vehicles equipped with the internal combustion engine has led to a shift in the market – making way for Electric Vehicle technology to be embraced.

Permanent Magnet BLDC drives have been identified as the most promising technology to provide the attributes required for modern Electric and Hybrid Electric Vehicles.

Awareness of environmental problems is growing dramatically throughout the world. This is leading to a tremendous interest in developing non-polluting Electric Vehicles (EV) and Hybrid Electric Vehicles (HEV).

Vehicles equipped with the traditional Internal Combustion Engines have been in existence for over a hundred years. Although ICE vehicles have been improved by modern automotive electronics technology, they only offer around 20% efficiency [1]. Electric vehicles are one of the most promising technologies that can lead to significant improvements in vehicle performance, energy utilisation efficiency, and emission reductions.

Multiple countries have already acted on enforcing a ban on combustion engines, initially led by Norway for 2025. Other European countries include Sweden, France, Germany, Belgium, Switzerland and the Netherlands whom are considering a phase-out by 2030. This is not only in order to cut CO2 emissions but also to reduce the European Union’s (EU) dependence on Russia. Outside of the EU, phase-out of ICEs also seems likely in Japan which is home to the world’s top-selling electric car, the Nissan Leaf [2].

Electric Vehicles and Hybrid Electric Vehicles have been identified to be the most viable solution to address the problems associated with the internal combustion engine. Electric drivers are the core technology for Electric Vehicles (EVs) and Hybrid Electric Vehicles (HEVs). These vehicles need to meet a number of requirements to be competitive in the automotive field, including: interior comfort, extended range, efficiency, low cost, reliability, and low maintenance [3]. These requirements lead to developing smaller efficient and higher-output motors. The basic characteristics of an electric drive for Electronic Vehicles are [4]:

  • high torque density and power density;
  • very wide speed range, covering low-speed crawling and high-speed cruising;
  • high efficiency over wide torque and speed ranges;
  • wide constant-power operating capability;
  • high torque capability for electric launch and hill climbing;
  • high intermittent overload capability for overtaking;
  • high reliability and robustness for vehicular environment;
  • low acoustic noise;
  • reasonable cost


The technologies of all component hardware are technically and markedly available on the market. At present, almost all of the major automotive manufacturers are developing either HEVs or fully EVs.

There is a large variety of electric motors that come in a number of topologies, the key being to balance high efficiency, reliability, and Size Weight and Power (Swap). Presently the three most common topologies used in EVs are Brushed DC, Brushless DC (BLDC), and AC induction.

With the advent of high-energy permanent-magnet (PM) materials, PM motors are becoming increasingly attractive. Being continually fuelled by new machine topologies and control strategies, PM BLDC drives have been identified to be the most promising to provide the characteristics needed for modern EVs and HEVs.

PM motor drives have the magnetic field excited by high-energy PMs. This means the overall weight and volume can be significantly reduced for given output torque, resulting in higher torque density, very quiet operation and almost never requiring any maintenance. Because of the absence of the rotor winding and associated rotor copper losses, their efficiency is inherently higher than that of induction motors and do not have the added concern of removing heat generated in the rotor by copper losses. Induction motors need a low pole number (two or four) which requires large copper end windings and considerable


stator back iron. This results in a larger and heavier machine [3].

In recent years, attention has been drawn to Interior Permanent Magnet (IPM) synchronous motors. This is due to their simple structure, robust configuration, high power density, easy heat dissipation, and suitability for high speed operations. The IPM motor takes advantage of flux focusing, which is performed by angling the magnets to gain a higher flux density in the air-gap than that of the PM flux density. The IPM topology has the highest power density and highest efficiency among all types of motors. Through flux focusing flux leakage is minimised up to as much as 20%. Furthermore, IPMs have a more robust rotor than that compared to other PM motors without the need of additional retainment and lower cost rectangular magnets [4] [5].

Regenerative braking can be considered a requirement in EVs it can increase the vehicle range by up to 15% [6]. Regenerative braking is easier with a PM motor because the magnets do not need to be energised. This results in less rotor heat generated with PM motors compared with induction motors which require a well-suited cooling system [7]. This gives PM motors a higher efficiency for the amount of kinetic energy that can be recovered. Without the rotor winding PM motors also produce a unity power factor. It is however noted that attention must be given to demagnetisation of higher continuous temperatures in PM motors, when designed with NdFeB magnets [7].

Legislation throughout Europe has begun to force EV into the market, and it is expected that most of the world will follow suit. This is leading to a large production of EVs. Currently IPM motors have the highest efficiency, smallest size, lowest weight and are the most efficient in recovering the vehicle’s energy in the form of regenerative braking. Due to high efficiency and smaller lighter motors, the vehicle will have an extended range on the same size battery bank.

Electric Vehicles will also play a major role in the dynamics of how we generate, store and use energy in the future.

Electric Vehicles provide an added benefit to existing energy grids – Off Peak Recharging. An EV can be recharged during the night, when the energy demand on the grid is low. This is similar to the off-peak tariff used to heat residential hot water systems.

As we move towards a more distributed generation model in the future, the additional storage capacity of an Electric Vehicle has significant potential.  Peak demand as mentioned above can be capped, and we will have the ability to consume energy at off-peak times, thus removing the expensive energy peaks currently experienced.

[1] C. R. Ferguson and A T Kirkpatrick, Internal Combustion Engines: Applied Thoermosciences, Third Ed, Colorado University. John Wiley & Sons Ltd, 2016, pp. 2.

[2] Pedestrianobservations. (2016). Several European Countries to Follow Norway’s Lead, Ban Fuel-Powered Cars [Online]. Available FTP: https://pedestrianobservations.wordpress.com/2016/04/01/several-european-countries-to-follow-norways-lead-ban-fuel-powered-cars/

[3] M. Ehsani and Y. Gao, “Hybrid Electric Vehicles: Architecture and Motor Drivers” in Proceedings of the IEEE, Vol. 95, 2007, pp. 719-728

[4] K. T Chau and C.C Chan, “Overview of Permanent-Magnet Brushless Drives for Electric and Hybrid Electric Vehicles” in IEEE transaction on industrial electronics, Vol. 55, 2008, pp. 2246-2257

[5] J.R.Hendershot, “MotorSolve analysis of the 2010 Toyota Prius Traction Motor” 2015

[6] J.Cody and O.Gol, “Regenerative braking inn an electric vehicle” in Zeszty Rplemowe – Maszyny Elektryczne, Vol. 81, 2009, pp. 113-118

[7] R.Rapter and M.Prathaler, “Regeneration of Power in Hyrbid Vehicles” VTC 2002, pp. 2063-2068