SYSTEM AND METHOD TO INCREASE THE OVERALL SYSTEM EFFICIENCY OF
INTERNAL COMBUSTION BASED ELECTRIC GENERATORS
[0001] This application claims priority from U.S. Provisional Application 61/379,606 for a
"SYSTEM AND METHOD TO INCREASE THE OVERALL SYSTEM EFFICIENCY OF
INTERNAL COMBUSTION BASED ELECTRIC GENERATORS," by T. Russell, filed Sept. 2,
2010, which is hereby incorporated by reference in its entirety and from U.S. Non-Provisional
Utility Application 13/223,262 for a "SYSTEM AND METHOD TO INCREASE THE OVERALL
SYSTEM EFFICIENCY OF INTERNAL COMBUSTION BASED ELECTRIC GENERATORS," by
T. Russell et al., filed August 3 1, 201 1, which is also hereby incorporated by reference in its
entirety.
TECHNICAL FIELD
[0002] The disclosed systems and methods are directed to remote power systems and
more particularly to systems that enable the optimization of use of generators and the like that
are employed in non-grid power systems. The disclosed systems and methods control the
operation of non-grid power systems to optimize the efficiency of system components including
generator sets (Gensets), batteries, etc. Accordingly, the disclosed system optimizes generator
operation through the use of energy storage and electronic controls.
BACKGROUND ART
[0003] It is well-known that remote power systems often use generators powered by
diesel engines and similar devices. Such systems may be provided by companies such as
SAIC, NEC Corp., Lockheed-Martin Corp. and Mechron Power Systems.
DISCLOSURE OF THE INVENTION
[0004] Although aspects of the following disclosure are directed to military applications,
it will be appreciated that the disclosed systems and methods find further use in various remote
and non-grid power applications (military, oil, remote cell and communication sites, off grid,
emergency/disaster power, developing nations, and other generator-based industries), where
the systems are not connected to or intertied with a utility grid. Moreover, fuel consumption and
cost, along with personnel safety, are issues of concern for the military in remote in-theater
locations. Through generator optimization, the disclosed systems and methods can reduce fuel
consumption by 25%-30%. Moreover, the proposed system eliminates the need for full size
back-up gensets and works in conjunction with main or primary generators. The disclosed
system provides the energy storage necessary to allow a main genset to run at optimal
efficiency and then be turned off for periods of time. During this time, the batteries in the system
(referred to as the Genset Eliminator™) will provide power to base operations and allow for
silent operation.
LUUU5J by optimizing t e use profile o† existing generators witn tne Uenset biiminator tne
users can reduce fuel consumption during operations; decrease exposure of personnel to
enemy attacks and lower causalities while delivering fuel, as well as reduce generator
maintenance. Estimates have shown that generators running at optimal load require 50% less
maintenance than those operating at 20% efficiency.
[0006] Tactical operation features and benefits of the Genset Eliminator include: lower
thermal and acoustic footprint; four operational modes, including a silent mode, with electrical
power fully operational; off-the-shelf electronics and batteries for serviceability; and ease of use
for operational personnel. Furthermore, the Genset Eliminator can be paired or combined with
other power sources including renewable energy sources such as wind turbines and solar
panels. By adding energy storage to renewable sources, energy can be stored and then used
when needed.
[0007] At remote in-theater military bases, electrical power is supplied from gensets that
are operating 24 hours / day. At the present time, most generators are sized and operated to
handle the peak load that may occur only at certain times throughout the day. The actual time
during which this peak is needed is very limited; and gensets typically run at loads far below
their rated capacities. Running generators with a low load forces the engine to operate at a
level which compromises its efficiency and reduces its service-life. With the high number of
attacks aimed at personnel delivering fuel and the dramatic rise in the price of oil, the case for
using the Genset Eliminator is driven by a potential for reductions in casualties and fuel usage.
[0008] Accordingly, disclosed in embodiments herein are methods and systems for the
reliable and efficient delivery of remote power, including: a power source (e.g., Genset); an
energy storage system (e.g., battery bank); and a control system that monitors power
consumption and history, as well as the characteristics of the energy storage system, and
controls the use of the power source and/or energy storage system so as to maximize the
efficiency of the power source when it is operational.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] FIG. 1 is a general block diagram of the layout of a system in accordance with the
disclosed embodiments;
FIG. 2 is a chart illustrating the efficiency of a generator relative to its rated load
capacity;
FIG. 3 is a general flow diagram illustrating operations carried out by the
disclosed embodiments in various scenarios;
FIG. 4 is an illustration of a conventional genset deployed with a system as
disclosed herein;
FIG. 5A is one illustrative embodiment of a trailer-mounted system as disclosed
herein;
FIG. 5B is an assembly view of a skid-mounted, trailerable embodiment for the
system disclosed herein;
FIGS. 5C - 5F illustrate additional alternative embodiments for system disclosed
herein;
FIG. 5G illustrates a housing for a system as disclosed herein;
FIGS. 6 and 7 are charts providing operational information relative to an
exemplary embodiment;
FIG. 8 is a detailed block diagram depicting a system in accordance with the
disclosed embodiments;
FIGS. 9A-B are a detailed top and side views of an alternative embodiment of the
system;
FIG. 10 is an exemplary wiring diagram for connecting a system in accordance
with the disclosed embodiments; and
FIG. 11 is an exemplary wiring diagram for a system in accordance with the
disclosed embodiments.
[0010] The various embodiments described herein are not intended to limit the
disclosure to those embodiments described. On the contrary, the intent is to cover all
alternatives, modifications and equivalents as may be included within the spirit and scope of the
disclosure.
BEST MODE FOR CARRYING OUT THE INVENTION
[0011] As more particularly set forth below and depicted in the following FIGS. 1 - 9, the
disclosed system 100 and methods will allow a Generator and Engine combination (Genset 110)
to operate at or near its peak efficiency point under normal conditions. When the Genset is not
operated at the peak efficiency, the system will shut down the Genset and operate from
batteries. Typically, but not always, the Genset achieves the maximum efficiency at or near the
system's capacity. FIG. 1 presents the basic system diagram.
[0012] Referring to FIG. 1, in the block diagram for the system 100, the genset 110 is a
generic electrical generator rotated by a prime mover such as a diesel engine or similar means.
The genset is operated at or near the maximum efficiency that can be achieved by assuring that
the load attached to the genset, both as active electrical load and/or battery charging load, is at
or near the capacity of the generator. The control system 120, for example a digital
microprocessor based system, supervises and controls the operation of the power system to
maintain the maximum realizable efficiency, health of the battery bank and the overall safe and
convenient operation of the system. Advanced programming techniques allow a user to
optimize the system both for efficiency, convenience and/or life of the batteries and Genset. It
should be noted that energy use patterns of the user can be learned / stored by the control
system (e.g., in a memory accessible by the control system microprocessor) and managed for
the operation. Battery charger 130 charges the battery bank when directed to by the control
system. DC - to - AC inverter 140 converts the stored direct-current (DC) energy of the battery
anK 5 to alternating-current A ) power as required ine uenset biiminator can also deliver
the raw DC power from the battery banks for DC loads without going through the inverters.
[0013] When the Genset is not operating, a chemical battery bank 150 will supply the
necessary energy to operate a DC-AC power inverter and thus maintain AC power. The battery
bank (e.g., Lead Acid, Li-Ion or other chemistry) will be charged during the time that the Genset
is operating. If the battery charge level becomes depleted, the Genset will be brought on to
supply the energy to charge the batteries and operate the load.
[0014] Efficiency Improvement (Diesel Generation Embodiment)
[0015] The following disclosure is largely specific to a Diesel Engine as a source of
power for the Genset as will be explained. Similar approaches used with other engines or prime
movers will result in an efficiency improvement that may be greater or less than the example.
[0016] There are several factors that will impact the efficiency improvement of the
system. These factors include; engine efficiency at the operation point of the engine, efficiency
of the battery charger, efficiency of the DC to AC inverter and round trip efficiency of the energy
storage medium. Other factors enter into the efficiency of the system but with a much lesser
impact.
[0017] The first factor that can be controlled is how closely the system can operate at or
near the Genset's optimal efficiency. In those cases where the Genset is forced to operate
without it's output being at or near the maximum efficiency point of the engine, due to the load
and the amount of energy demanded by the chargers being the wrong value (e.g., mismatched),
the overall system efficiency will suffer. In the case of a Diesel Genset as the main source of
electrical energy, the efficiency is best if the Genset is operated at or near the system's rated
capacity. FIG. 2 presents an average of several commercially available Diesel Gensets. The
efficiency of the Genset is compared to the percentage of the load on the generator.
[0018] As shown in FIG. 2, if the Genset is operating below 100% of the rated capacity
the efficiency of the system suffers. Other factors impact the operational patterns of the Genset
as well. The value where the set point of the Genset operates regardless of the state of charge
on the battery bank is variable with both the prime mover and the battery chemistry dominating
the decision. In the case of Lead-Acid Batteries with a Diesel Genset the optimum state of
charge to begin recharge appears to be on the order of 60% with the exact values having other
dependencies that would vary that solution from application to application. The particular setpoints
(e.g., state of charge to begin recharge) for a bank of batteries will depend not only on the
battery type or chemistry, but other factors such as battery age, temperature, etc.
[0019] Ideally the battery charger would put sufficient demand on the Genset to operate
at or near optimal. To accomplish this, the battery bank must be sized to allow charging rates
sufficient that will bring the load on the generator to the point where they can operate efficiently
and not recharge the cells in the battery at an excessive rate. This can typically be
accomplished by sizing a lead acid battery bank to allow charging requiring in excess of 4-8
hours to fully charge a fully depleted bank. Another possible embodiment is where the
generator is sized at a level slightly less than a peak power requirement for the load, and then a
combination of generator and battery power is supplied to the AC Buss, where the current
exceeds the capacity of the generator or the batteries individually and is achieved by a
combination of both. In this manner a smaller generator may be employed, particularly one that
is more efficient or is more likely to operate at its highest efficiency when on.
[0020] Depicted in FIG. 3 is a logical flow diagram for an embodiment of the disclosed
system. As will be described in more detail below, the system operates by first determining if
the state-of-charge (SOC) is greater than the maximum charge level of the battery bank. If so,
charging the batteries by the battery charger (and connected generator) is inhibited. Assuming
the battery bank can accept additional charge, the system next determines whether the load
(current power requirement) is greater than the minimum load, or if the state-of-charge is less
than the minimum charge. If either test is true (Yes), then the Genset is enabled and the "Run
Genset" operation is initiated. If the state-of-charge is not less than the minimum charge, then
the inverter is used to provide power to the load from the battery bank.
[0021] Turning to the "Run Genset" operation, once initiated, if the state-of-charge for
the battery bank is greater than the maximum charge, the charging of the batteries is inhibited
and the load is powered from the Genset. Otherwise, the batteries are charged and the Genset
further provides power to the load. It will be appreciated that in this state of operation, the
amount of power used to charge the battery bank can be controlled to further optimize the
efficiency of the Genset, thereby powering the loads and charging the batteries at the most
efficient output of the Genset. Also contemplated is the use of time-of-day limits as well as other
programmable controls by which to more specifically control the operation of the system. For
example, the system could include programmable time-of-day ranges to specify either times
when the genset is not to be used, or is okay to be used. These time ranges could be employed
so that the system initiates an earlier charge operation in order to assure that the batteries are
fully charged at the beginning of a non-Genset operation period (e.g., during late-evening or
early morning hours).
[0022] Having described the general operation of the systems and methods employed, a
specific embodiment is now discussed. Current practice in many remote power systems is that
gensets in the field are paired with a back-up genset to assure a reliable power supply. Since
10kW gensets are a common size, this example will use that size in the following description.
The advantages of a Genset Eliminator are valid for any size generator up to and above 30kW.
Above that, the number and size of the batteries needed might prevent a direct replacement of
larger generators, unless multiple Genset Eliminators are linked together to create a larger
storage capacity. However, this approach really has no limit as to the power levels. Using the
Genset Eliminator as part of a distributed network of smaller generators or in an array
themselves may also permit efficient and economical energy storage and distribution.
LUU.-3J I he main genset supplies all o† tne energy to run daily operations and raciiity
equipment. The additional genset is available when the primary genset is off-line due to
refueling, repairs or maintenance. An installation may have more than one genset, depending
on its energy requirements.
[0024] As noted above, an improved system with a better operating efficiency, lower fuel
consumption and more operating modes, including a silent mode, is referred to as the Genset
Eliminator. The system was designed for ease of use in operation and service by utilizing
common off-the-shelf batteries and components, some of which are already in use by the U.S.
military. As shown in the example of FIG. 4 , the back-up genset in a conventional dual-genset
configuration has been replaced with the Genset Eliminator. Referring to FIG. 4, there is shown
a conventional genset 200 and a Genset Eliminator system 100. The Genset Eliminator
includes batteries, a small emergency generator 160 and associated equipment, which may be
mounted on an appropriate trailer (e.g., military trailer M105A2), skid/pallet or other means of
transport.
[0025] FIG. 5A is one illustrative embodiment of a trailer-mounted Genset Eliminator
system 100. In the illustrated embodiment, the system 100 is integrated with a trailer 218.
System 100 includes a cabinet 220 for storage of batteries and associated controls and
electronics (e.g., 120, 130, 140, not shown), and a 3kW generator 160. Also included is a shelf
and lockable box 230 for storage of related tools, interconnection cables, etc.
[0026] FIG. 5B is an assembly view of a skid-mounted system 100 that is suitable for
installation on or transport by trailer 218. The trailerable embodiment of FIG. 5B also illustrates
a housing or cabinet 220 that includes a compartment 224 for storing a plurality of batteries in
battery bank 150 inside of the compartment in racks or similar structures to retain the batteries
while being transported. The cabinet includes a cover 228 for the Genset Eliminator as well. As
will be appreciated from the illustration in FIG. 5B, the housing of system 100 is attached to a
skid type frame 240, such that the system is structurally supported by the frame and is capable
of being deployed by trailer 218 and the skid removed therefrom or remaining on the trailer.
[0027] Also considering FIGS. 5C - 5F, illustrated therein are the following alternative
configurations: illustrate additional alternative embodiments for the system:
FIG. 5C illustrates a 25 kW skid-based system including a backup generator 160;
FIG. 5D illustrates a 25 kW skid-based system with no backup generator;
FIG. 5E illustrates a 20 - 60 kW skid-based system with no backup generator;
and
FIG. 5F illustrates a 20 - 60 kW skid-based system with no backup generator and
no trailer.
[0028] Turning next to FIG. 5G illustrated therein is a housing 220 for the Genset
Eliminator. The housing, as described above includes a compartment 224 for storage of the
batteries, as well as a cover (not shown). The rear face of the housing includes not only an
access opening in order to inspect tne batteries, but also includes various connections and
controls. Included on the rear face are various bus contacts 330, 340, 120 VAC plugs 320 and a
control interface 310, 350 as more specifically described and illustrated in FIG. 11.
[0029] The Genset Eliminator uses an approach that will significantly reduce the fuel
consumption by exchanging the second genset for a system that will enable main or primary
gensets to be operated at 85-95% of the rated load capacity for any time they are in use. By
charging the batteries while at the same time supplying the base operations with power, the
generators operate at higher efficiency. Once the batteries are charged, the system switches
between battery power (when the energy requirements are lower) and the generator (when the
load is high enough to allow for efficient operation) as was generally depicted in the flow
diagram of FIG. 3. While running on batteries, the primary genset is off, allowing for silent
operation. This switch between power sources will be seamless to the user. The result is lower
fuel consumption and less noise. The Genset Eliminator also allows for maintenance of the main
generator without a loss of power during such maintenance.
[0030] While the Genset Eliminator could be heavier than the typical 10kW genset
(approx. 300-1000 lbs.) it is still within the allowable weight of a light tactical trailer. Efficiency
improvements achieved by the gensets will result in immediate and substantial savings in
money and tactical effectiveness but more importantly, in lives.
[0031] The Genset Eliminator can be configured with lead acid batteries, or alternative
battery chemistries such as Li-Ion, cobalt oxide and iron phosphate. More specifically, Lithium
Ion batteries are advantageous due to their higher operating temperature range and lighter
weight. Lithium Ion batteries provide a tremendous weight advantage when compared to lead
acid batteries (8 -10 times lighter than lead acid batteries needed for equivalent power storage)
making Li-Ion much more portable. In addition Lithium Ion batteries can operate in
temperatures up to 140°F (60°C) which far exceeds the temperature range of lead acid
chemistry batteries, while not requiring air conditioning or cooling. Li-Ion batteries will charge
more efficiently than lead acid batteries, thereby increasing the overall efficiency of the system.
Future versions of the Genset Eliminator will incorporate renewable energy sources, in
combination with gensets, such as wind and solar.
[0032] The following descriptions list the functional and operating differences between of
current genset configurations and the Genset Eliminator working in conjunction with a main
generator:
Main Genset (Currently) - without Genset Eliminator
Runs continuously to supply power for base at energy demand rate.
Running at typically low (20%) output is not optimized for generator efficiency
Large thermal and acoustic footprint
With Backup Genset
Sits idle for most of the time.
Used only as a bacK up to main genset wnen it needs fueling or servicing.
Main Genset: With Genset Eliminator
Utilized during times of heavy demand
Genset is always run at optimal efficiency load level of 85-95%
Excess energy generated is used to charge batteries
When batteries are charged, the genset is switched off and batteries supply
energy to base.
With Genset Eliminator:
Optimizes main generator so it runs at highest efficiency.
Batteries provide power at other times
Can be operated in Silent Mode
Small Emergency Back-up genset may be included
[0033] The Genset Eliminator, for example, consists of an array of batteries, charger and
all necessary equipment to enable the system to run efficiently and safely and can even tie to
the local power grid if available, in a transportable configuration. It is backed up by an
emergency generator. More specifically, the equipment in a single Genset Eliminator includes
the following:
• Inverter(s)
• Power supply/battery charger
• Armasafe+ Hawker Batteries, for example
• Cabinet
• Genset (3kW size for example)
• Trailer
• Control System
• Miscellaneous Electrical Hardware, cables, connectors
[0034] The Genset Eliminator offers numerous benefits, including: lower cost ; reduction
in fuel consumption of 25-30% over the standard diesel; genset operated independently;
reduced engine maintenance due to more optimal loading; Improved response to short term
surge requirements; reduced operating hours on gensets in use; off-the-shelf electronics and
batteries; tactical operations benefits; four operational modes, with electrical power fully
available, including silent; significantly fewer power interruptions; reduced thermal and acoustic
footprint; and is scalable as required.
[0035] The business justification for the Genset Eliminator can be broken into three main
components (reduced exposure of personnel to lEDs and the hazards of fuel transport are not
addressed):
uei savings - Annual expected fuel savings tor tne U.S. Military savings per generator
are calculated first. The percent savings for U.S. Military is then extrapolated from that
data.
Total Cost of Ownership - Cost benefit on a per generator basis of the Genset
Eliminator™.
Pay Back Evaluation - A simplified payback analysis which evaluates how many months
of operation are needed to have the fuel savings equal the initial cost. .
[0036] The Genset Eliminator™ achieves fuel savings by operating existing gensets in a
more efficient output range. As shown in the FIG. 2, for example, a generator operates more
efficiently when operating at or near its maximum output capacity. Because gensets are sized
to accommodate the largest expected load, gensets often operate with a load that is far less
than the rated load capacity during significant portions of a 24 hour period. During the time
when the load is less than the peak, the overall efficiency of the system (energy in the fuel to
electrical energy) can be as low as 25%. When the system is operated more optimally, the
efficiency can approach 33%. The Genset Eliminator achieves the most savings when the
genset is operated at or near the rated capacity. And, as suggested above, the ability to
periodically couple the output of the genset and batter/inverter may allow for smaller-sized
gensets to be deployed in the first place.
[0037] Referring also to FIG. 6 (Operation Summary), illustrated is an example of
possible operational power demand shown as a function of the time of day. This assumes that
during the night, the power consumption is reduced significantly from the typical daytime use.
During the daytime hours, the power consumption peaks twice per day, normally associated with
early morning and late afternoon activities. This obviously varies greatly from location to
location but the overall impact will be similar.
[0038] Several system parameters are key in the optimization of the genset. The
parameters for this example have been optimized to achieve the best fuel savings and to
minimize the need for the genset to run during sleeping hours (e.g., 10 PM to 5 AM). As noted
previously, other operational requirements can be incorporated when identified. Key parameters
included in this example are number of batteries, battery capacity, allowable depth of discharge
of batteries, charge rate, and size of generator (in kW).
[0039] Referring also to FIG. 7, representing Genset and Genset Eliminator parameters
over a 24-hour period, various operating parameters of the Genset Eliminator are presented
during use. It is important to note that the genset is either on or off. This assures maximum
cost avoidance. The level of discharge on the battery bank is also controlled to increase or
maximize the life of the battery. Additionally the charging rate on the battery is controlled to
minimize battery deterioration during fast charging.
LUU4UJ Using this input data, a simulation o† the Uenset biiminator in operation snows
that the daily cost savings are potentially significant. In the example, savings per generator are
shown to be:
• Operating Genset without Genset Eliminator™ : 8.9 gallons
• Operating Genset with Genset Eliminator™ : 6.6 gallons
• Percent Reduction in fuel: 26%
[0041] Total Cost of Ownership
[0042] Through the use of the Genset Eliminator a return on investment time of
approximately 30 months would be realized. Maintenance costs with the Genset Eliminator are
estimated to be half since generators will be running at a higher percentage of rated load
capacity. [UNITED STATES MILITARY ACADEMY (West Point, New York) CENTER FOR
ARMY ANALYSIS (Fort Belvoir, Virginia) Army Tactical Hybrid Power system Analysis and
Design (May 2004) ] The example takes into account that the batteries on the Genset
Eliminator would be replaced periodically. Additionally the standard practice of always having a
standby genset on site would no longer be necessary, therefore eliminating that cost as well.
[0043] In one system configuration, the Genset Eliminator includes as many off-the-shelf
components as possible for ease of repair and replacement. For example, lead acid or other
types of batteries, and the associated equipment allowing the operation and grid connection, are
the backbone of the system. Similar to FIG. 1, FIG. 8 is a basic block diagram showing the
configuration of one embodiment of the Genset Eliminator.
[0044] Referring also to FIGS. 8 and 9, the control system 120 will monitor power
consumption, time of day and other parameters to determine the optimal time(s) to charge the
battery bank. Additionally, it will allow the user to input the various operational requirements that
need to be considered in the logic of the system. This will optimize the timing and duration of
the genset's operation. With 28.8 - 40 kW-hrs of storage capacity, the battery bank could
require several hours of charging at a time. This would allow sufficient time for the engine to
operate efficiently. FIG. 8 also illustrates the backup or standby generator 160 in accordance
with one of the Genset Eliminator embodiments.
[0045] The optimum time(s) to operate the Genset Eliminator or main genset is based
on the following parameters:
• Operate the system on batteries when extended operations with low consumptions
are expected. This is typically at night.
• Operate the genset when the load expectation is high. This will reduce the need for
high power draw from the batteries and thus extend the life of the batteries.
• Charge the batteries also when there is high load expectation. This will decrease the
charge rate and extend the life of the batteries.
• Allow the genset to be shut down for service and maintenance while operating from
the battery bank.
• Offer the user the advantage of silent operation reducing the acoustic and thermal
signature.
[0046] It should be noted that these scenarios do not conflict. Therefore, the goals of
reduced energy consumption, quiet night-time operation and extending the life of the battery
bank can be achieved simultaneously.
[0047] The Genset Eliminator will have at least four operational modes:
[0048] MODE 1: True Hybrid Mode: This will be the default mode for the Genset
Eliminator.
[0049] State 1a: Battery Charging State. In this state, the generator is operating. The
output is used to charge the battery bank and to supply power to the user. When the battery
receives a predetermined optimum charge level, the generator is shutdown and the system
changes to State 1b. The battery is charged at the highest rate possible that is safe for the
battery and delivers the power demanded by the user. The optimum goal is to operate the
generator at 85-95% of the rated capacity. This will maximize the efficiency of generator.
[0050] State 1b: Battery Output State. In this state the generator is not operating.
Power is being delivered to the end user from the batteries. The batteries are only drained to a
level that will maximize the life of the batteries. When the stored energy on the battery bank is
drained to this level, the generator is started and the system will be returned to State 1a. In this
state the output will be converted to AC via a high efficiency/high power quality inverter.
[0051] MODE 2 : Forced Silent Mode. In this mode, the generator will be prevented from
coming on. The output of the batteries can be drawn down until fully discharged. Draining the
batteries completely is not optimal for battery longevity. In this mode the power delivery system
will present the minimal detection footprint. This mode may also be used to maintain or repair
the main genset. The batteries will take longer to fully recharge.
[0052] MODE 3 : Bypass Mode. In this mode the system is forced to operate with the
battery banks and the associated electronics eliminated from the system. This mode would be
the same as not having the battery bank connected. This mode is invoked by a manual bypass
switch on the Control/Charger/lnverter unit.
[0053] MODE 4 : Recovery Mode. In this mode the batteries are charged carefully after
long operation in the Forced Silent Mode (Mode 2) discharge. This will automatically occur
when required.
[0054] The Genset Eliminator is designed to be a self-sufficient unit with all the
components necessary for operation and maintenance. Referring to FIGS. 9A-B, a Genset
Eliminator conceptual layout is shown. The system's housing will be separated into
compartments, as will now be described in more detail relative to the illustrated embodiment:
LUU55J A compartment stores tne main battery bank. I o ensure maximum efficiency
and protection, the cabinet will be insulated and water resistant. Ventilation will be designed into
the system to minimize heat build-up. The battery bank will be mounted on a shock and
vibration structure to ensure that the batteries will not be compromised when transported over
rough terrain.
[0056] Compartments 2 and 3 contain a shock isolated rack system(s) for the electronics
in the system. In this rack will be input rectifiers/battery charger, DC to AC power inverter and
the overall control system.
[0057] The batteries may require replacement. To simplify the field replacement of a
battery or a group of batteries, the compartment will have access to the battery banks from both
sides of the Genset Eliminator™. All necessary tools and special equipment for replacement
will be provided with a maintenance kit.
[0058] The system's dimensions (approximate) are expected to be 42 inches high with a
foot print of 60 inches by 48 inches and will be limited to a weight of less than 3000 pounds.
These dimensions have been chosen to allow transport via a standard military trailer). During
the design of the system, the maximum number of batteries will be implemented while not
exceeding this weight.
[0059] Specific effort will be devoted to simple convenient operation to make the Genset
Eliminator as similar to existing equipment operation to facilitate training and field acceptance.
[0060] As described and contemplated herein the Genset Eliminator™ can be bypassed
for full generator use (pass through). A Genset Eliminator, working in conjunction with the main
generator, will have the following specifications:
LUUbij As will be appreciated, alternatives to tne disclosed examples may include:
a. Various Battery Chemistries such as Pb-Acid, Li-Ion or any other that may yet to
be discovered.
b. Incorporation of alternative energy sources such as fuel cells, solar or wind
power.
c . Concept can range from small to very large power capacity. Savings is
independent of size.
[0062] Possible uses include any place that a system is operated from power that is not
derived from the power grid or it is impractical to derive power from the grid.
[0063] Referring next to FIG. 10, depicted therein is an exemplary wiring diagram for
connecting system 100 to a genset 110 in accordance with the disclosed embodiments. This
wiring arrangement contains AC to DC rectifiers, a DC to AC inverter, and a transfer switch,
which physically allow for energy to be routed from either generator (or alternative input power
source such as solar) to the load, and/or to the battery for charging. The system utilizes a DC
Buss methodology for battery charge / discharge and solar/alternative energy inputs.
Additionally an AC Buss is utilized for energy transfer in the system, both in and out of the
system. The control system (CONTROLS) determines when and how much energy is directed
to each element, serving to most efficiently utilize energy being generated and consumed. The
control system, which includes a processor operating under programmatic control, has the
capability to divert energy to the battery when charging is needed and also shut off the
generator when the battery is charged and the generator output is not needed. The functions of
the controller may be manually overridden, or forced, to achieve a particular function.
Monitoring and display of the voltage and current through the system is available to a user.
[0064] FIG. 11 illustrates an exemplary wiring diagram for a system in accordance with a
disclosed embodiment. In this embodiment the DC Buss is contained within the battery
enclosure. The illustrated wiring arrangement utilizes a central battery that houses the transfer
switch and bi-directional inverters/ rectifiers (to achieve 3 phase capability) to which AC energy
is provided and drawn. In one embodiment, certain control functionality may be provided by the
OutBack Model Mate 3 controller 310, available from OutBack Power Technologies, Inc., as
more particularly described in the MATE3 System Display and Controller Owner's Manual (Rev.
B © July 201 1 by OutBack Power Technologies), which is hereby incorporated by reference in
its entirety. The control system including the MATE3 310 plus a programmable controller 350
provides overall control of the system allowing the user to choose the amount of energy being
directed to and from all elements within the system. Separate cables are connected from the
controller(s) to the two generators, and signals on those cables are used to control (e.g., start
and stop) the two generators as needed by the system to meet load requirements. A pair of
separate single phase 120VAC Outlets 320 are shown as output choices of the system. The
genset input connections are depicted at , wnereas tne system output is provided at
connectors 340.
[0065] Controller 350 is a programmable master controller, including a microcontroller or
microprocessor, as well as a user interface. The controller operates under programmatic
control, receiving inputs from the various subcomponents of system 100, and providing output
signals to control the components as well as the switching and interfacing to the load, gensets,
etc. An exemplary master controller is a Texas Instruments Stellaris Arm Cortex M3 processor.
In addition to providing the control of contacts and emergency stop functionality, the master
controller also operates as the master or supervisory controller of the system.
[0066] The master controller provides the following functions, several of which may be
pre-programmed or which may be adjusted or modified via a user interface and/or computer
connection:
Programmable limits on battery charging rate and max./min. voltages allowed;
Directing power to and or from various inputs and outputs;
Determining and sending signals to start and stop the generators;
Determining the amount of energy that can be used for charging based on the external
demand;
Monitoring temperature of batteries and other system components, and shut down the
system according to temperature limits;
Monitoring the battery performance characteristics so as to provide an alarm(s) and/or
shut down portions of the battery or the entire battery if predetermined limits are exceeded;
Controlling and monitoring the output voltage and frequency as well as other critical
factors;
Providing data storage and output for monitoring capability;
Providing an interface for access for bypass, lock out, and programming;
Recording of various criteria, such as run time, temperature(s), etc.; and
Emergency stop.
[0067] As described above, the control system, including the master controller,
determines when and how much energy is directed to each element, serving to efficiently utilize
energy being generated and consumed. The control system has the capability to divert energy
to the battery when charging is needed and to also shut off the generator when the battery
system is fully charged. As in the prior embodiment, the functions of the controller may be
manually overridden, or forced, to achieve a particular function. Monitoring and display of the
voltage and current through the system is available to the user, either via a display associated
with the Mate 3 controller or via an optional display or even a remote computer interface.
[0068] It will be appreciated that several of the above-disclosed embodiments and other
features and functions, or alternatives thereof, may be desirably combined into many other
different systems or applications. Also, various presently unforeseen or unanticipated
alternatives, moditications, variations or improvements therein may be subsequently made by
those skilled in the art which are also intended to be encompassed by the following claims.

CLAIMS :
1. A system for delivery of remote power to a load, including:
a fuel-driven power source connected to said load;
a rechargeable energy storage system, arranged to receive energy from said power
source and supply energy to said load; and
a control system that monitors power consumption by the load and history, as well as the
characteristics of said energy storage system, and controls the use of the power source and
energy storage system to maximize the efficiency of the fuel-driven power source when
operational.
2. The system according to claim 1, wherein the energy storage system includes Li-ion
batteries.
3. The system according to claim 2, wherein the Li-ion batteries may be depleted to at
least 50% depth of discharge.
4. The system of claim 1 wherein the power source is a genset.
5. The system according to claim 4, further including a standby generator having an
output capacity smaller than the capacity of the genset, yet suitable for recharging the energy
storage system.
6. The system according to claim 1 wherein the control system is programmable and
includes set-points which further control the operation of the power source and energy storage
system.
7. The system according to claim 6, wherein said controller is capable of controlling the
operation of the system in accordance with a plurality of modes.
8. The system of claim 7, wherein the operational mode of the system, as controlled by
the control system, is selected from the group consisting of:
a true hybrid mode where the power source is operated in response to a state-of-charge
of the energy storage system;
a forced silent mode where the power source is disabled;
a bypass mode where the energy storage system is disabled; and
a recovery mode where the energy storage system is recharged.
9. The system according to claim 1, wherein said energy storage system and said
control system are affixed to a skid frame.
10. The system according to claim 9, wherein said skid frame may be affixed to a trailer.
11. A method for the reliable and efficient delivery of remote power to a load, including:
operating a fuel-driven power source to provide power to the load;
providing a rechargeable energy storage system, that is capable of receiving power from
the power source and providing power to the load; and
using a control system, monitoring power consumption by tne load and tne history o†
such consumption, as well as the characteristics of the energy storage system, and controlling
the use of the power source and energy storage system to operate the power source at its
highest output efficiency.
12. The method according to claim 11, wherein the energy storage system includes Liion
batteries.
13. The method according to claim 12, wherein the Li-ion batteries are depleted to at
least 50% dept of discharge.
14. The method of claim 11 wherein the power source is provided by a genset.
15. The method according to claim 14, wherein the power source further includes
providing a standby generator having an output capacity smaller than the capacity of the genset,
yet suitable for recharging the energy storage system.
16. The method according to claim 11 further including programming set-points which
control the operation of the power source and energy storage system.
17. The method according to claim 16, wherein said controller controls the operation of
the system in accordance with one of a plurality of modes.
18. The method of claim 17, wherein the mode of the system is selected from the group
consisting of:
a true hybrid mode where the power source is operated in response to a state-of-charge
of the energy storage system;
a forced silent mode where the power source is disabled;
a bypass mode where the energy storage system is disabled; and
a recovery mode where the energy storage system is recharged.