Integrated generator field flash

The present invention provides an engine coupled to a generator, the generator being in communication with an automatic voltage regulator. The automatic voltage regulator has an integrated field flash circuit. Further, a controller may be in communication with the field flash circuit and the controller may control an output of the field flash circuit.

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Description
CROSS REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional Patent Application No. 61/248,849 filed on Oct. 5, 2009, and the same is herein incorporated by reference in its entirety.

GOVERNMENT RIGHTS

The present invention was made with U.S. Government assistance under Department of Defense contract Number W15P7T-04-D-A003. The U.S. Government has certain rights in the invention.

BACKGROUND

The present application is directed to unique systems, apparatus, and methods involving an electric power generator driven by an internal combustion engine.

A generator set (genset) typically includes an electric power generator together with an internal combustion engine structured to mechanically drive the generator to produce electricity. Genset implementation varies greatly, including both mobile and stationary applications, primary and standby/backup power, controlled and uncontrolled environments, and the like. In many applications it is desired that the genset operate outdoors, being able to tolerate environmental extremes of temperature, humidity, precipitation, and the like. Over time, AC generators may lose magnetism after long periods of storage and may not produce residual AC. To flash the generator, a generator operator or maintenance crew would connect an external relay to the field signals of an AC generator while rotating the machine. This process potentially results in unsafe voltages as well as insufficient flashing current. Accordingly, there remains an ongoing need for further contributions in this area of technology.

SUMMARY

One embodiment of the present application includes a unique generator set (genset) configuration. Other embodiments include unique genset systems, apparatus, and methods. Further embodiments, inventions, forms, objects, features, advantages, aspects, and benefits of the present application are otherwise set forth or become apparent from the description and drawings included herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:

FIG. 1 is a partially schematic view of a genset with a flashing system.

FIG. 2 is a schematic view of a flashing arrangement.

FIG. 3 is a flow chart for a field flashing procedure.

FIG. 4 provides perspective views of the right and left side of the genset configuration showing its housing with the doors closed.

FIGS. 5 and 6 are perspective views of the right and left side, respectively, of the genset in FIG. 4 with doors open.

FIGS. 7 and 8 are perspective views of the right and left sides, respectively, of selected system components of the genset.

FIGS. 9 and 10 are perspective views of the right and left sides, respectively, of selected electrical and AC generator system components of the genset.

FIG. 11 is a schematic control diagram for the genset.

DETAILED DESCRIPTION

For purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

One nonlimiting embodiment of the present application includes genset equipment capable of providing a 30 kiloWatt (kW) VAC output. In operation, the genset is suitable for deployment in the battlefield to provide a soldier with the continuous power generation necessary for today's fielded electronic devices and various electrical equipment demands. It is developed to be fixed (skid mounted) or mobile (trailer mounted) allowing flexibility of movement. The housing assembly serves as the protective shell for the generator set. The housing has been designed with openings for maintenance and additional acoustical protection to further silence the generator set while operating. The generator has been ruggedized for unusual/harsh weather and to shield from debris.

FIG. 1 is a schematic view of a genset system with automatic field flashing. In one embodiment, the system includes an engine 100 that provides mechanical energy to drive an Alternating Current (AC) electrical generator 102 to produce electrical power. An automatic voltage regulator (AVR) 106, is in operative communication with the generator 102. A field flash circuit 104 is integrated into the AVR 106 and is also in communication with the generator 102. A controller 200, is in communication with the AVR 106, the field flash circuit 104, and may also be in communication with the generator 102 and the engine 100. The controller 200 may include the AVR 106 and the field flash circuit 104 as shown, the controller 200 may be incorporated in the field flash circuit 104, the controller 200 may be a separate controller (e.g. an ECU as is commonly used in genset applications), or the system may be configured in any way such that controller 200 is capable of providing a communications link between the AVR 106 and the field flash circuit 104 as well as controlling the flashing of the generator 102 by the field flash circuit 104. In certain embodiments, the controller 200 forms a portion of a processing subsystem including one or more computing devices having memory, processing, and communication hardware. The controller 200 may be a single device or a distributed device, and the functions of the controller may be performed by hardware or software.

FIG. 2 is a schematic view of a flashing apparatus. As is shown from FIG. 2, the field flash circuit 104 is electrically isolated. The field flash circuit 104 may include a DC-DC converter 204 in electrical communication with an electrical energy source 208. The electrical energy source 208 may be a genset battery, an external power supply, an internal power supply, such as from an alternator on engine 100, or any other source of electrical energy known to one of skill in the art at the time of invention. The DC-DC converter 204 is electrically isolated by a diode 202. In other embodiments, the DC-DC converter 204 and/or the field flash circuit 104 may be electrically isolated through the use of a switch, a field effect transistor, a diode (e.g. diode 202), or any other method of electrical isolation known to one of ordinary skill in the art at the time of invention. The field flash circuit 104 may include software logic 210 which can include various commands, modes, and operations which can control various outputs in response to various inputs or can control outputs independent of any inputs received. A pulse-width modulation (PWM) table 206 may be contained within software logic 210. The PWM table 206 may contain a plurality of PWM values which correspond to voltage values, enabling the voltage of the DC-DC converter 204 and/or the generator 102 to be controlled through the use of PWM as is commonly known in the art. The field flash circuit 104 may be integrated into the AVR 106 as is shown in FIG. 2. The field flash circuit 104 can also be integrated into the AVR 106 through other hardware configurations, software configurations, a combination of hardware and software, or any other form of integration known to one of ordinary skill in the art at the time of invention.

FIG. 3 is a flow chart for one embodiment of a field flashing procedure. An operation 300 includes starting an engine which is connected to a generator. After the engine has been started, a module 302 determines if the generator is producing residual AC voltage. If the generator is producing residual AC voltage, the generator does not need to be flashed. However, if the generator is not producing residual AC voltage, a module 304 will then determine if the engine speed has reached a starter disconnect speed. In one embodiment, if the engine speed has reached a starter disconnect speed, an operation 308 will apply a flashing current to a generator. In another embodiment, if the engine speed has reached a starter disconnect speed, an operation 306 will place the AVR into an open loop mode. Once the AVR has been placed into an open loop mode, an operation 308 will then apply a flashing current to the generator. The module 310 determines if a target output voltage has been reached by the generator. If the target output voltage has not been reached by the generator, operation 308 will again apply a flashing current to the generator. Once the target output voltage has been reached by the generator, an operation 312 reverts the AVR to closed loop operation.

In a further embodiment, an engine which is mechanically connected to a generator is started. A determination is made of when the engine speed reaches a starter disconnect speed. The starter disconnect speed may vary based on the specific engine and starter configuration utilized. When the engine has reached the starter disconnect speed, a flash current may be applied to the generator. A determination may be made of whether the generator is producing a residual AC voltage. If the generator is not producing a residual AC voltage, a flash current may then be applied to the generator. However, the generator may be flashed regardless of determining if the generator is producing a residual AC voltage, based on the demands of the end user. Furthermore, when the engine disconnect speed exceeds the starter disconnect speed, the AVR may enter an open-loop mode. In other embodiments, the AVR may remain in a closed loop mode throughout the flashing process; however, remaining in a closed loop mode may be less desirable based on production costs. Once the AVR has entered an open loop mode, a flash current may be applied to the generator until a target voltage output is read by the controller. After the target voltage is read by the controller, the AVR may be reverted to a closed-loop mode of operation.

In a further embodiment, when applying the flash current to the generator, over-current and over-voltage conditions are prevented through the use of PWM values (e.g. each PWM value corresponds to a voltage value as is commonly known in the art). Applying a flash current to the generator may also include sending a signal to flash the generator from the controller to a DC-DC converter, the DC-DC converter then sending a flash current to the generator.

In yet a further embodiment of the present invention, an engine is configured to provide mechanical power to a generator. The engine may be one of a gas turbine engine, a gasoline engine, a diesel engine, or any other engine capable of supplying sufficient mechanical power to drive a generator as is known by one of ordinary skill. An electrically isolated DC-DC converter is interfaced with an AVR, whereby the DC-DC converter is capable of providing a flash current to the generator upon command from a controller. Software logic may be incorporated into the controller. The software logic may contain a plurality of PWM values, each value corresponding to one of a plurality of voltage values. The software logic may also contain other commands, modes, operations, and the like. The DC-DC converter may be electrically isolated through the use of a diode, a switch, a field effect transistor, or any other device capable of providing electrical isolation known to one of ordinary skill. In an exemplary embodiment, the DC-DC converter can receive power from a genset battery as this is a convenient source of power for the DC-DC converter in the present genset configuration.

Further embodiments for automatically flashing an AC generator without operator intervention will follow. These embodiments eliminate the need for separate field flash circuitry as well as the need for an external relay because the field flash circuitry is incorporated into the AVR. In one embodiment, an integrated DC-DC converter, a diode, and software logic are configured to automatically flash an AC generator each time the engine hits starter disconnect speed on a genset startup. An isolated DC-DC converter is electrically isolated, allowing the flashing circuit to operate in cases of self-excited (e.g. shunt) gensets as well as separately excited (e.g. PMG or Quad) gensets. When the engine speed has passed a starter disconnect speed, the software logic enables the AVR into a boot mode, or open-loop mode. In the boot mode, the software logic reads the 3-phase average voltage of the generator output and automatically enables the DC-DC converter as well as driving an AVR transistor to a pre-determined level through PWM. The software logic can limit the DC-DC converter current into the generator field by controlling the open loop PWM during the boot mode. This process protects the DC-DC circuit from over-current and also prevents the output voltage from an over-voltage condition. While in open loop mode, the software logic may contain a pre-determined PWM vs. Voltage table that safely applies field flash current until a satisfactory output voltage is read by a controller. After the 3-phase average voltage of the generator reaches a pre-determined level (e.g. the field flash setpoint), the software logic can disable the DC-DC converter and the AVR reverts to a closed-loop mode of operation.

FIG. 4 further provides perspective views of a skid-mounted configuration of one possible form of a genset after assembly with its doors closed, and highlights various features of the same. This genset configuration is a well-enclosed, self-contained, skid-mounted mobile unit. This form of the genset includes several assemblies, including: an engine assembly, an internal fuel assembly, an external fuel assembly, an AC generator assembly, an operator control panel assembly (also known as the Digital Control System (DCS)), and an output box assembly. An optional winterization kit is available for installation in cold weather climates. This genset accommodates a continuing proliferation of electronics (computers, Personal Data Assistants (PDA), etc.), life support systems, remote field applications, military battlefield applications, global communications systems, and the like for which a continuous, uninterrupted flow of electricity is desired.

FIGS. 5 and 6 are further perspective views of the right side and left side, respectively, of the genset with doors open. The genset includes an aluminum housing with several individual body panels to enclose the engine, generator and other internal components. This housing provides protection from the environment and provides acoustical protection, but also provides for ready entry access to generator set assemblies. The housing is compartmentalized with appropriate passages/apertures interconnecting the various compartments to provide for air cooling flow over selected generator set components, such as a radiator to cool the engine, the power generator, the fueling block, various electronics, and the engine itself. The housing configuration further protects against the invasion of wind-driven rain, snow, and sand to the interior compartments containing genset equipment that may be sensitive to the same. The design and placement of a louver and a rain cap provide further protection. Self-supporting hinged doors provide interior access for scheduled service and preventive maintenance. Individual body panels are removable to allow additional access for replacement and service of major components.

All housing body panels are connected using corrosion-resistant captive nuts. All seals for the panels are mechanically fastened to the housing panels. The top panel is shown in FIG. 5, item 2. The top panel shields components from the elements. The rear panel is shown in FIG. 5, item 10. Located at the rear of the generator set, the rear panel contains the DCS access door (FIG. 5, Item 1), DCS rear access door (FIG. 5, Item 9), convenience receptacle (FIG. 5, item 7), entrance for load cables (FIG. 5, item 8), and fuel fill (FIG. 5, item 12). The right-side panel is shown in FIG. 5, item 5. Located on the right side of the generator set, the right-side panel contains the right-side access door (FIG. 5, item 3) and output box door (FIG. 5, item 6). An accessory box is shown in FIG. 5, item 4. This accessory box has been installed on the rear of the right-side access door (FIG. 5, item 3) to provide space for auxiliary equipment, such as the TM, paralleling cable, and auxiliary fuel line.

Next referring to FIG. 6, the front panel is depicted as item 1. The front panel is located on the front of the generator set and contains a NATO-compliant slave receptacle. FIG. 6, item 2 depicts the left-side panel. The left-side panel is located on the left side of the generator set and contains the left-side access door (FIG. 6, item 4). FIG. 6, item 3 depicts an accessory box, which has been installed on the rear of the left-side access door (FIG. 6, item 4) to provide space for auxiliary equipment storage, such as the TM, paralleling cable, and auxiliary fuel line.

FIG. 5, item 11 depicts a digital control system (DCS) for the genset that is a microprocessor-based control, allowing the operator and maintainer to start/stop the generator set, operate the contactor, adjust voltage and frequency, clear/reset generator faults, and perform other functions as desired and/or further described hereinafter. The DCS uses a menu-driven display format to control generator set operations. The DCS is structured to provide limited remote operation capabilities through interface with an IBM-compatible PC. The operational status of the generator set can be monitored, battleshort conditions can be set and released, and emergency stops can be executed from up to 250 feet (76.2 meters (m)) distant. Furthermore, the genset includes self-diagnostics at start up. This prognostics function monitors the protective system and will provide a warning of impending activation of protective devices. All operational data is captured every 15 minutes during operation. Faults and warnings are automatically captured upon operation of protective devices and stored in a Fault Log. Additionally, all maintenance prompts and actions are automatically captured and stored in a Maintenance Log.

The DCS is powered by a 24-VDC subsystem of the genset. Once genset mode, voltage, and frequency are determined by the DCS programming, the control automatically adjusts the display to show corresponding value limits, menus, and operational parameters. This embodiment of the genset provides limited remote operation capabilities through interface with an International Business Machine (IBM)-compatible PC. The operational status of the generator set can be monitored, and an emergency stop can be executed from up to a 250-foot (ft) (76.2-meter (m)) distance. The DCS includes a display that is a colored liquid crystal display (LCD) with a 6.5-inch (in) (165.1-millimeter (mm)) diagonal viewing area. It provides a combination of switches and LCD soft keys to allow the operator and maintainer to control the generator set. A high-level DCS control diagram is provided in FIG. 11.

In one form, the genset engine is a Cummins QSB 4.5 Tier III engine. The vertical, water-cooled, four-cycle direct injection (DI) diesel engine utilizes a four-cylinder, turbocharged process that includes a cylinder head and valve cover, crankcase assembly, pistons, main bearing case, and lubrication system. This particular engine has a built-in close crankcase ventilation (CCV) system. The engine produces mechanical energy and interconnects with the AC generator via a rotating shaft. It is mounted to the skid toward the front panel of the generator set.

A cooling system for the genset includes three cooling fans (FIG. 8, items 6) allow the generator set to operate in all required operational environments. The 16-inch, variable-speed 24-VDC cooling fans provide for a better radiator location and air flow paths for improved cooling efficiency. Intake air for the cooling system is drawn by the cooling fans through a grille on the left-side body panel. This air passes through the cooling fins of the radiator, charge air cooler, and fuel cooler, transferring heat from the cooling system to the air flow. The warm air is then expelled into the atmosphere through a grille in the top panel. The cooling system also reduces wear on the battery-charging alternator belt and water pump. Cold weather operation is also improved by regulating cabinet temperature at or near ideal operating temperatures of 195 degrees Fahrenheit (° F.) (90.5 degrees Celsius (° C.)). The coolant circulation system includes: the radiator, a charge air cooler, a fuel cooler, a thermostat, a water pump, a winterization kit, and coolant overflow reservoir. It is responsible for keeping the engine below an undesirably high temperature. FIG. 7, item 1 designates a coolant overflow bottle. Mounted to the rear panel at the fuel fill opening, the coolant overflow bottle is visible for inspection of coolant level. Access for coolant filling is provided through the top panel. The radiator (FIG. 7, item 3) acts as a heat exchanger for the engine coolant. A radiator fill port is accessible on the top body panel. The captive radiator cap prevents loss of coolant. The charge air cooler (FIG. 7, item 2) dissipates the heat from the compressed air exiting the turbocharger into the air flow. The cooling of the intake air improves the efficiency of the engine. The fuel cooler (FIG. 8, item 5) is located behind the charge air cooler. The fuel cooler is not visible unless the top panel is removed. Cooling of the fuel prior to injection into the engine can improve efficiency of the engine. A thermostat (FIG. 8, item 1) is located inside the housing where the upper radiator connects to the top of the engine. It monitors coolant temperature and adjusts the cooling system accordingly. The water pump (FIG. 8, item 8) circulates the coolant through the block and the radiator.

To facilitate proper operation under extreme cold conditions, a winterization kit (FIG. 7, item 6) is located on the inside of the right-side panel. The fuel-fired coolant heater heats coolant in extreme cold conditions, such as between −25° F. and −50° F. (−32° C. and −46° C.) by utilizing the fuel from the generator set. The winterization kit automatically activates, depending on the temperature, and features automatic heat regulation. It is controlled by the DCS, which provides the [READY TO CRANK] indicator when the heater has completed its cycle. The air cleaner assembly (FIG. 7, item 4), mounted on a bracket attached to the front and top panels, filters contaminates from the air intake. The air cleaner assembly contains an integrated, centrifugal precleaner that removes most dust particles prior to entering the air cleaner element and extends filter life and reduces maintenance costs and downtime. The engine exhaust system includes an exhaust manifold located on the right side of the engine. As exhaust leaves the compression chamber, it is routed through the exhaust manifold into a single pipe, and then through the turbocharger. The turbocharger uses exhaust gases to turn a turbine which compresses the intake air. The compressed intake air is directed to the cylinders through the intake manifold and improves the efficiency and power production of the engine. The exhaust gases exit the turbocharger and pass through the muffler (FIG. 7, item 5). The bulkhead-mounted muffler (FIG. 7, item 5) silences the exhaust pulses from the engine and expels exhaust gases through the top body panel grille.

The genset fuel system is next described. It includes fuel fill (FIG. 8, item 3) and tank (FIG. 8, item 4). A fuel compatible with the particular engine type is used. The fuel fill is located on the rear body panel and allows refueling during operation. The fuel tank is mounted directly to the skid assembly behind the front access door. The tank drain extends down into the skid area below the rear panel. The main fuel pump transmits lower pressure fuel from the fuel tank and sends it through an in-line fuel filter to the fuel filter/water separator (FIG. 8, item 7). The fuel filter/water separator element is spin-on and removes debris and water particles from fuel before it enters the engine. A water drain cock is on the bottom of the filter. The external fuel tank connection and an auxiliary connection and return (FIG. 8, item 2) are located in the fuel filler shroud. The auxiliary fuel pump transfers fuel from the auxiliary fuel tank to the genset.

The genset 24-VDC electrical system uses two 12-V batteries (FIG. 10, item 3) connected in series, that are of standard commercial size and located side-by-side on the left side of the genset. They are accessed through the left-side door. In one implementation, the batteries are capable of starting the generator set under all conditions between −50° F. (−46° C.) and 135° F. (57° C.) ambient temperatures. The genset may include a standard belt-driven alternator to charge the batteries. The starter (FIG. 10, item 2) is located on the left side of the engine above the oil pan. A NATO-compliant slave receptacle (FIG. 10, item 1) is provided should the unit require jump-starting from another 24 VDC source. In the event the engine needs to be manually turned, a three-position DEAD CRANK SWITCH is included. If the temperature is between 20° F. and −25° F. (−6° C. and −32° C.), an intake air heater(s) are used to aid in starting. For temperatures between −25° F. and −50° F. (−32° C. and −46° C.) the optional winterization kit is used as an engine starting aid.

The AC generator (FIG. 9, item 1) converts the rotating mechanical energy from the engine into electrical energy. The electrical energy is then distributed from the output box assembly through cables that enter the output box assembly. In certain implementations, the AC generator is a Cummins Power Generation CPG UC224D (Mode I, Model 1070 (50/60 Hz)) or a Marathon 30 kW (Mode II, Model 1071 (400 Hz)). The AC generator has a synchronous, brushless design with a permanent magnet and was developed specifically to meet performance requirements. The AC generator receives mechanical energy from the engine and converts it to electrical energy. The electricity produced by the AC generator is transmitted to the output terminal board.

The AC generator and voltage control system are of a drip-proof, guarded machine type and are synchronous and brushless, as specified in National Electrical Manufacturers Association (NEMA) Standard No. MG, part 33; the bearings are sealed and permanently lubricated; the AC electric power generation system leads are identified with permanent marker; and/or such leads are brought out of the frame through non-abrasive bushings and holders in the output terminal board to isolate each lead and hold it securely in place.

In certain embodiments, when operating in three-phase at rated load and frequency, the AC generator can be configured to withstand, without damage, two consecutive short circuits at the load terminals of 10 sec or less in duration within a 5-min interval at less than 300% of rated output current. The output box is located on the right-side panel and distributes electricity produced by the AC generator through the output terminal board. The output box contains the output terminal board, individual load terminals, and unit relays. All relays are socket-mounted and secured with a cover. The relay will not move unless the cover is removed.

The embodiment of FIGS. 4-11 is directed to a genset with a 30 kW rating under the Advanced Medium Module Power Sources (AMMPS) program of the U.S. Department of Defense. Under this program various implementations provide nominal AC output frequencies selectable between 50 and 60 Hertz (Hz), while others provide a nominal AC output frequency of 400 Hz; and may be configured to provide nominal output voltages selectable between 120 and 240 VAC nominal, while others include 416 VAC nominal. Nonetheless, still other embodiments may be configured to provide different output voltage(s), frequencies, and maximum peak, sustained, or rated output power levels, in addition to or in lieu of those explicitly described. For instance, such other embodiments can have power ratings of 5 kW, 10 kW, 15 kW, and 60 kW—to name just a few examples. Furthermore, while the genset of FIGS. 4-11 includes features to accommodate certain military battlefield conditions, extreme cold starting, and the like, in other embodiments some or all of such features may be absent and/or any of such features may be directed/desired for nonmilitary applications including those with other environmental considerations, or the like. Indeed, only one of the various described genset features or aspects may be included in other embodiments, and/or only one of many of the inventive features described herein may be the subject of a given invention written description or claim.

While the invention has been described in connection with what is presently considered to be the most practical and preferred embodiment, it is to be understood that the invention is not to be limited to the disclosed embodiment(s), but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims, which scope is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures as permitted under the law. Furthermore it should be understood that while the use of the word preferable, preferably, or preferred in the description above indicates that feature so described may be more desirable, it nonetheless may not be necessary and any embodiment lacking the same may be contemplated as within the scope of the invention, that scope being defined by the claims that follow. In reading the claims it is intended that when words such as “a,” “an,” “at least one” and “at least a portion” are used, there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. Further, when the language “at least a portion” and/or “a portion” is used the item may include a portion and/or the entire item unless specifically stated to the contrary.

Claims

1. A system, comprising:

an engine operably coupled to a generator;
an automatic voltage regulator operably coupled to the generator, the automatic voltage regulator having an integrated field flash circuit; and
a controller in communication with the field flash circuit, the controller controlling an output of the field flash circuit.

2. The system of claim 1, wherein the field flash circuit is electrically isolated.

3. The system of claim 2, wherein a diode between the field flash circuit and the generator electrically isolates the field flash circuit.

4. The system of claim 1, wherein the field flash circuit further comprises a DC-DC converter operably coupled to an electrical energy source, the DC-DC converter being in communication with the controller, the controller controlling an output of the DC-DC converter.

5. The system of claim 4, wherein the DC-DC converter is electrically isolated.

6. The system of claim 1, wherein the controller is further structured to determine when the engine has reached a starter disconnect speed; and

in response to determining when the engine has reached a starter disconnect speed, flashing the generator.

7. The system of claim 6, wherein the controller is further structured to apply field flash current until a target output voltage is achieved by the generator, the controller using a plurality of pulse-width modulation (PWM) values, each value corresponding to one of a plurality of voltage values.

8. The system of claim 1, wherein the automatic voltage regulator has an open-loop mode operable during generator flashing.

9. The system of claim 1, wherein the automatic voltage regulator has a closed-loop mode operable when a generator voltage output has reached a target output voltage.

10. An apparatus, comprising:

an engine operably coupled to a generator;
an automatic voltage regulator in communication with the generator and in communication with a controller; and
means for flashing the generator.

11. The apparatus of claim 10, further comprising a means for controlling the open loop pulse-width modulation during a boot mode.

12. The apparatus of claim 10, further comprising a means for reverting the automatic voltage regulator to a closed-loop mode of operation when the voltage of the generator reaches a target voltage output.

13. A method, comprising:

providing a generator operably connected to an engine;
starting the engine;
determining when the engine speed reaches a starter disconnect speed; and
in response to determining when the engine reaches a starter disconnect speed, applying a flash current to the generator.

14. The method of claim 13, further comprising determining that the generator is not producing residual AC voltage; and

in response to determining that the generator is not producing residual AC voltage, determining to apply a flash current to the generator.

15. The method of claim 13, further comprising determining when the engine disconnect speed exceeds the starter disconnect speed;

in response to determining when the engine disconnect speed exceeds the starter disconnect speed, enabling an automatic voltage regulator to enter an open loop mode;
in response to entering an open loop mode, applying a flash current to the generator until a target voltage output is read by the controller; and
in response to obtaining a target voltage output, reverting the automatic voltage regulator to a closed loop mode.

16. The method of claim 15, wherein applying the flash current to the generator until a target voltage output is obtained further comprises preventing at least one of over-current and over-voltage through the use of a plurality of PWM values, each value corresponding to one of a plurality of voltage values.

17. The method of claim 15, wherein applying a flash current to the generator further comprises:

sending a flash signal from the controller to a DC-DC converter; and
in response to the DC-DC converter receiving the flash signal, sending a flash current from the DC-DC converter to the generator.

18. A method, comprising:

providing a generator operably coupled to an engine, at least one of the generator and the engine being in communication with a controller;
interfacing an electrically isolated DC-DC converter with an automatic voltage regulator, the DC-DC converter providing a flash current to the generator upon command from the controller.

19. The method of claim 18, further comprising integrating software logic into the controller, the software logic containing a plurality of PWM values, each value corresponding to one of a plurality of voltage values.

20. The method of claim 18, further comprising providing at least one of a diode, a switch, or a field effect transistor between the DC-DC converter and the generator, electrically isolating the DC-DC converter.

21. The method of claim 18, the DC-DC converter receiving power from a genset battery.

Patent History
Publication number: 20110089911
Type: Application
Filed: Oct 5, 2010
Publication Date: Apr 21, 2011
Inventors: Jean-Marie Loisel (Coon Rapids, MN), Alyssa Marlenee (St. Louis Park, MN), Arthur J. Punyko (St. Paul, MN), John R. Salchow (Minneapolis, MN)
Application Number: 12/924,775
Classifications
Current U.S. Class: Battery Source (322/88)
International Classification: H02P 9/08 (20060101);