FIELD OF INVENTION: ...
This invention relates to the power backup system. More particularly, the present
invention provides an integrating power backup system which effectively uses the
energy of a generator.
PRIOR ART:
In many applications of electrical generator systems, steady state load demand is
typically low relative to generator power capacity. In contrast, generator selection is
often driven by peak power requirements that can be transitory in nature. Such
generators may be considered "oversized" during the majority of time they are used.
As a result, in certain situations power generation systems include an electrical energy
storage device to supplement generator power during peak usage, which facilitates a
reduction in generator size. In some systems, the generator is selected with sufficient
capacity to charge the storage device at the same time it supplies power to electrical
loads below a given level.
In certain applications, a power backup system also includes a generator set and
electrical storage device in the form of one or more electrochemical cells or batteries.
Unfortunately, the ability to desirably integrate and collectively manage generator and
electrical storage device operation can be challenging. Thus, there is an ongoing
demand for further contributions in this area of technology.
Reference may be made to the following:
US Patent No. 7,880,331 (2008157593) relates to a management of an electric power
generation and storage system. DC electric power from a DC bus is inverted to
provide AC electricity to one or more electrical loads, and AC power from a variable
speed generator is rectified to provide a first variable amount of electric power to the
DC bus. This technique also includes determining power applied to the electrical
loads, and dynamically controlling the amount of power supplied from the generator
and an electrical energy storage device in response to the power applied to the loads.
This system does not show any intelligence to utilize the generator only when
required depending on the load and battery status
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Publication No. JP8308290 discloses an ef!ective use of the energy of an engine
generator, and the energy of DC power supply about the inverter device which links
an engine generator and DC power supply. This system does not show any
intelligence to utilize the generator only when required depending on the load and
battery status
Publication No. JP2003284397 relates to an inverter-controlled generator which is
favorable in ease of use, enables reduction in change in characteristics and the
production of noise, allows a power generation system capable of supplying sufficient
power to a load even in low engine speed ranges to be constituted by simple structure,
and improves fuel efficiency. This patent does not show any intelligence to utilize the
generator only when required depending on the load and battery status
US Publication No. 2009204838 relates to a backup power system and method may
include a transfer switch, connections to primary and secondary power sources, a
stored energy component, and an interconnected controller with a processor and
memory. The transfer switch may provide power to an external load from a selected
one of the primary power source, the secondary power source, or the stored energy
component.
US Patent No.6,184,593 relates to electronic circuit, such as a UPS, interfaces a main
ac power source and at least one secondary power source to a load. The secondary
power source(s) may include one or more auxiliary generators, a flywheel motor
generator or micro turbine with high speed motor generator, and/or any of a variety of
dc storage devices. This patent deals with the management of an electric power
generation and storage system.
US Patent No. 7,862,938 relates to a fuel cell and heat engine hybrid system using a
high-temperature fuel cell having an anode compartment adapted to receive fuel from
a fuel supply path and to output anode exhaust gas and a cathode compartment
adapted to receive oxidant gas and to output cathode exhaust gas. This patent deals
with the fuel cell and heat engine hybrid system
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US Patent No. 6,835,481 relates to the fuel cell system having partial and/or total
redundancy of at least one operational comP"onent, such as a redundancy of fuel cell
stacks and/or fuel processors. This patent deals with the management of an electric
power generation and storage system
US Patent No. 7,939,968 relates to methods and apparatus for providing
uninterruptible power. The uninterruptible power supply includes a first input to
receive input power from an input power source, an output to provide output power, a
bypass input to receive bypass power from a bypass power source, wherein the bypass
input is selectively coupled to the output to provide output power from the bypass
power source, an input power circuit coupled to the first input and having a DC output
that provides DC power having a first DC voltage level, a back-up power source
coupled to the input power circuit to provide DC power at the DC output in a back-up
mode of operation, and an inverter circuit having an output coupled to the DC output
of the input power circuit and having an output coupled to the output of the
uninterruptible power supply to provide the output power derived from at least one of
the input power source and the back-up power source. This patent deals with the
management of an electric power generation and storage system
US Patent No. 6,737,762 relates to a local power generation system generates a
substantially DC voltage at an inverter input, which is modulated to generate a
resulting output AC power signal to a load. The inverter input voltage may be
obtained from an engine generator, providing an AC power signal that is rectified, or
from a fuel cell generator providing a DC voltage that is converted to the desired
voltage value at the inverter input. This system does not show any intelligence to
utilize the generator only when required depending on the load and battery status.
US Patent No. 6,624,533 relates to power controller for controlling an engine-driven
generator includes a high voltage DC bus interconnecting various power modules. In
electrical communication with the DC bus are a bi-directional DC-DC converter
constructed to transfer electrical power from the DC bus to a battery to charge the
battery and from the battery to the DC bus. This system does not show any
intelligence to utilize the generator only when required depending on the load and
battery status
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Publication No. JP9056086 relates to method for controlling uninterruptible power
unit. An uninterruptible power unit 30 is pro;ided with a frequency monitor circuit 31
which monitors the frequency of a commercial power supply 1 and, when the
frequency deviates from the rated frequency of the commercial power supply by ±4%,
makes a diesel power generator to operate surely by continuing the operation of the
unit 30 by stopping charging operations and the operations of an active filter. When
the frequency is restored to the rated frequency, the unit 30 restarts the charging
operations and the operations of the active filter. This system does not show any
intelligence to utilize the generator only when required depending on the load and
battery status
Publication No. W02008063575 relates to electric power system includes an engine,
a generator driven by the engine, an electrical energy storage device, power control
circuitry coupling the generator and storage device together, and a processor coupled
to the circuitry. This system does not show any intelligence to utilize the generator
only when required depending on the load and battery status
US Publication No. 20110049980 relates to system and method for adaptive control
of power among a plurality of loads based on a categorization of the loads as either
delayable or non-delayable, wherein the non-delayable loads are preferably supplied
power over the delayable loads. In one aspect, the system may be used to allocate
limited power from a backup power source. This system does not show any
intelligence to utilize the generator only when required depending on the load and
battery status
US Patent No. 7,053,497 relates to load monitoring apparatus for monitoring the load
applied to a portable generator. The apparatus includes a sensor, and a humanly
perceptible indicator that indicates at least one discontinuous load power frequency.
The system does not show any intelligence to utilize the generator only when required
depending on the load and battery status
7,157,885 relates to a method for controlling an inverter controlled generator set
which comprises a DC power source section having as a power source a generator
driven by an engine and an inverter which converts an output of said DC power
source section into an AC output, the method comprising a step of controlling a
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rotational speed of the engine so that the 1-C output suitable for driving a load is
output from the inverter; wherein, after the engine is started, the rotational speed of
the engine is controlled by a constant speed control mode for maintaining the
rotational speed of the engine at a set rotational speed, and the rotational speed of the
engine is increased to the set rotational speed; and wherein an operation of the
inverter is started after the rotational speed of the engine reaches the set rotational
speed. This system does not show any intelligence to utilize the generator only when
required depending on the load and battery status
7,786,616 relates to a local power generation system generates DC voltage at an
inverter input, modulated to generate an AC power signal to a load. The inverter input
voltage may be obtained from an engine generator, providing a rectified AC power
signal. An energy storage device helps maintain DC voltage at the inverter input when
load power draw increases or during engine startup or acceleration, for example, until
the engine accommodates increased power demand. This system does not show any
intelligence to utilize the generator only when required depending on the load and
battery status
7,962,772 relate to a backup power system and method may include a transfer switch,
connections to primary and secondary power sources, a stored energy component, and
an interconnected controller with a processor and memory. The transfer switch may
provide power to an external load from a selected one of the primary power source,
the secondary power source, or the stored energy component.
7,256,507 relates to an inverter controlled generator set including: a power supply unit
that uses a generator driven by an engine as a power supply to output a DC voltage;
an inverter device that converts the output voltage of the power supply unit into an
AC voltage; and a rotational speed control unit that controls a rotational speed of the
engine so as to be kept at a target rotational speed suitable for a load applied to the
inverter device, wherein the rotational speed control unit is comprised so that a
settling time when the rotational speed of the engine is caused to converge to the
target rotational speed in a state where the load is above a set value is longer than a
settling time when the rotational speed is caused to converge to the target rotational
speed in a state where the load is below the set value, in order to minimize an
operation sound of the engine when the load is intermittently driven. This system does
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not show any intelligence to utilize the generator only when required depending on
the load and battery status
20050200205 relates to a method and system for providing constant critical AC
electrical load with primary, secondary, and in some cases a tertiary source of power
with higher reliability and lower operating and capital costs and lower emissions than
the traditional utility supply, uninterruptible power supply (UPS), and battery primary
power source, and diesel generator back-up systems that are predominately used
today. Specifically, the disclosed system utilizes on-site power generation to provide
primary power and includes full utility and UPSIDC storage back-up systems.
JP2003l11428 relates to the inverter control means which performs constant voltage
and constant frequency control in such a manner that the output voltage and output
frequency become constant, when a detected current value is at most a first previously
determined reference value, and controls the output current in such a manner that
output power of the inverter becomes constant, when the detected current value
exceeds the first reference value. This system does not show any intelligence to utilize
the generator only when required depending on the load and battery status
JP2lll235 relates to a commercial power supply is power-rectified, DCs are
generated and a battery for backup is floated, and load is supplied with the ACs of
VVVF generated by power-inverting the DCs. A bypass circuit including switches is
formed to the power rectifier and inverter and a spare AC generator is connected to
the switch. This system does not show any intelligence to utilize the generator only
when required depending on the load and battery status
7,692,409 relates to a generator controller which displays genset fault messages, a
genset elapsed time hour meter, service countdown reminder, monitors battery voltage
changes over multiple periods of time to establish and display the "battery level," uses
the "battery level" to automatically start and stop the genset and accepts multiple run
requests from AC loads such as HVAC systems, and incorporates safety or other start
inhibit features.
Reference may be made to an article entitled "Generator Interactive Sine Wave
Inverter" by Power Solutions Australia. The article talks about an interactive inverter
system which provides mains quality power efficiently and automatically. It uses
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batteries to store energy for periods when power demand is low and automatically
starts a diesel generator. set when demand is high or when the batteries require
recharging. This mode of operation ensures that diesel fuel is efficiently converted to
electricity by only running the generator at medium to heavy loads and only for a
small proportion of the day. Power is drawn from the batteries and converted to a
mains quality sine wave by a microprocessor-controlled inverter. The generator is
automatically started and stopped by the inverter. While the generator is operating it
supplies power to the load and the inverter recharges the batteries. However if heavy
loads occur both the inverter and the generator can supply the load giving a peak
capacity equal to the sum of the inverter and generator ratings. This allows smaller
generators to be used compared with inverter charger systems.
This system does not include the DO fuel measurement and warning system because
of this the DO can run out of fuel and ultimately stop. I our system all the parameters
such as output voltage, current DO fuel level and RPM etc. are measured and in case
of a low fuel level warning is generated in terms of both audio and visual alarm. The
emergency load can still be run on the inverter backup when the DO runs out of fuel.
Reference may be made to an article entitled "Xantrex auto generator start for RS
inverter by Xantrex Technology Inc, Alternative Energy Store Inc". The article talks
about the automatic generator start (AOS) is a Xanbus Enabled device that can
automatically activate a generator to provide an MS or RS Inverter/ Charger with
power to recharge depleted batteries or assist with heavy loads. Compatible with
popular generators, the AOS adds intelligence to power management and eliminates
time spent monitoring batteries and inverter loads.
Reference may be made to an article entitled "Automatic Generator Start by Outback
Power". The article talks about the combination of generator and inverter is common
in remote or off-grid sites. Since OutBack inverters can recharge batteries with a
generator, the inverter can automatically start the generator.
Reference may be made to an article entitled "Optimum sizing of battery-integrated
diesel generator for remote electrification through design-space approach" by P.
Arun, Rangan Banerjee, Santanu Bandyopadhyay, Energy; Volume 33, Issue 7, Pages
1155-1168, July 2008. The article talks about the methodology for the optimum
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sizing of integrated system involving diesel generator and battery bank for an isolated
electrical power generation. The proposed methodology is based on the design-space
approach involving a time series simulation of the entire system. Based on the
proposed approach, for a given load demand, characteristics of the diesel generator
and battery bank, a sizing curve is identified on the diesel generator rating vs. storage
capacity diagram.
Reference may be made to an article entitled "Lower environmental impact generator
technology" by Fischer Panda, 2011. The article talks about the onset of smart
inverter-charger enable a DC generator to be offered as a sensible solution for any
power generation system. The Victron Multi-Plus inverter/ charger enable all AC
consumers on board to be run from the batteries. They operate automatically as a
charger when shore or AC generator power is available and as an inverter when mains
power is not available.
Reference may be made to an article entitled "Genverter- the new hybrid diesel
generator/ inverter combination" by Whisper Power. The article talks about
Genverter, the perfect synthesis of a modern diesel engine with the alternator
incorporated into the flywheel. A bi-directional switch mode sine wave inverter
operating as a three step battery charger when land power is connected or generator is
running, an automatic power management system controlling generator/ inverter/ land
power and an optional battery pack which can be mounted below the generator.
Thus the conventional systems talks about the generator system in combination with
the charge storage system and sensing unit. None of the above said system talks about
using the energy ofthe generator and increasing the fuel efficiency.
Therefore, there exists a need to provide an integrated system which effectively uses
the energy of a generator.
Thus in view of the above prior art, the present invention provides a power backup
system integrated with a sensing unit and generator to use the energy of the generator
effectively. The present invention provides a system and method of increasing the fuel
efficiency of the generator.
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OBJECTS OF THE INVENTION
Primary object of the present invention is to provide a power backup system which
effectively uses the energy of a generator.
Another object of the present invention is to provide a power backup system used
with the generator to increase the fuel efficiency.
Another objective of the present invention is to fuel gauging ofthe generator and state
of charge of the battery bank connected and then optimizing there use.
Yet another object of the present invention is to provide a method of bifurcation of
unutilized load and utilization of rest of the load in the charging of batteries of power
backup systemcorresponding excess power for charging the battery bank.
Yet another object of the present invention is to provide an integrated backup system
which can calculate the peak load and distribute the power accordingly
Another object of the present invention is to provide a renewable energy based power
backup system which automatically switches the generator ON as per the requirement.
Yet another object of the present invention is to provide a cost effective and reliable
power solution.
At the outset of the description, which follows, it is to be understood that the
ensuing description only illustrates a particular form of this invention. However,
such a particular form is only an exemplary embodiment without intending to
imply any limitation on the scope of this invention. Accordingly, the description
is to be understood as an exemplary embodiment and teaching of the invention
and not intended to be taken restrictively.
BREIF DESCRIPTION OF THE INVENTION:
The invention is described in detail and therefore, should not be construed to
limit the scope of the invention.
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Accordingly the present invention provides an integrated power backup system which
comprises a generator, a sensing unit and an inverter with storage device for utilizing
the maximum efficiency of the generator. The generator and inverter are used in
combination to increase the fuel efficiency. The invention offers cost effective and
reliable power solution. The present invention is a hybrid power driving system.
Accordingly the generator and the inverter are in synchronization. The power backup
system is an intelligent power backup system which automatically starts the generator
as per the requirement. The generator will only get start when the load requirement is
higher than the capacity which can be supplied through the inverter.
Reference may be made to the figure 2 and figure 3 of the article entitled "Part load
Analysis of the Diesel generator" that represents the relation between cost verses
capacity load of diesel generator. It shows that at lower load the cost of per unit
generated is substantially higher and causes high losses. As the percentage load is
increased the cost per unit reduces which gives more savings.
The load profile of any typical system has both peak load and light load times Figure
2 shows a typical profile of a system. The generator usually gives maximum
efficiency. So by dynamically controlling the battery charging the effective load on
the generator can be increased so that the generator works in its peak fuel efficiency
band.
Figure 3 shows that how the charging current to the battery is controlled so that the
generator can be maintained close to its peak efficiency and at the same time battery
is charged with excess power..
The present invention incorporates an intelligent control to keep the generator at is
optimal operation point to increase its fuel efficiency
In an embodiment, the system monitors generator and their fuel status and give
advance indication and alarms to the user in case of critical condition of low fuel etc.
The system automatically chooses the mains supply, DO and some other sources such
as solar power to keep the battery charged and optimize the fuel consumption of
generator for the emergency conditions
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The intelligent control measures the status of the different power sources such as
mains, DG fuel status and battery charge status based on the requirement of output
load the sources are used.
The storage device is charged using such as but not limited to the mains/ solari
renewable etc. A sensing unit is provided with the backup system for generators
which can sense the full load capacity of a generator. Then accordingly, the rest of the
load can be split to charge the storage device of the power backup system. This can
either be done manually or controlled through the backup system.
The above may be considered as an exemplary embodiment.
It is to be understood that the above-described embodiments are illustrative of only a
few of the many possible specific embodiments, which can represent applications of
the principles of the invention. However, numerous and varied other arrangements
can be readily devised in accordance with these principles by those skilled in the art
without departing from the spirit and scope of the invention.