Abstract:
The present invention provides a method and apparatus for providing temporary electrical power to stationary locations and moveable locations. For example, vessel marine power systems may be directed to the reduction and elimination of air pollutants produced when using a ship&#39;s generator while at dock. The power system is modular, portable, and generates electricity over a wide range of voltages and frequencies.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to switching the frequency of electrical power provided by power modules and, more particularly, to systems and methods for the reduction and elimination of air pollutants by providing electrical power by power modules. 
     Electrical generators are commonly used for temporarily generating electricity for small loads at facilities that are remote or mobile. One current disadvantage with many such generators is that they use diesel fuel, which creates a very high quantity of air pollution. A commonly used type of diesel fuel is bunker fuel, which is one of the most air polluting fuels that can be used. Additionally, such generators commonly lack catalytic converters and other pollution control devices to minimize air pollution. 
     Another disadvantage of current generators is that they are built for a specific installation or use. In other words, such electrical generators are single voltage and single frequency systems and cannot be used at multiple sites that may have different voltage and frequency requirements. 
     The limited use of generators is evident in many environments, such as the marine environment. There is a lack of uniformity in electrical equipment used internationally. Some on-board electrical equipment may function with 50 or 60 Hz alternating current (AC). The same electrical equipment may need a voltage of 110, 220, 380, 400, 480, or even 600 volts. For a ship traveling internationally, its ability to connect to an onshore generator (which can vary from country to country) will be limited to the electrical compatibility between the generator and onboard equipment (which can also vary from country to country based on the ship&#39;s origin). Thus, the ability of a port to provide electrical power to the ship&#39;s onboard equipment will be limited to the electrical compatibility between the generator and onboard equipment. 
     Providing a range of voltage generation or frequency generation has required using more than one generator and more than one transformer. However, it is unfeasible to equip a port with multiple generators and multiple transformers. Doing so would require much space, huge investment costs, and increased safety risks. 
     Another problem is that a ship may berth at different locations of the same port depending on the type and size of cargo. Installation of an extensive electrical cable network would be required to connect a stationary generator or electrical source at a berth for ships at various locations within a port. 
     One attempt to provide a solution to the above problems is disclosed in U.S. Pat. No. 6,644,247 to Campion (“Campion”). A frequency switching system for portable power modules includes a turbocharger operatively connected to a motor and has interchangeable components that allow selecting a first or second turbocharger configuration. Frequency output may be varied by interchanging turbochargers, and voltage switching is accomplished by operating a voltage switch. To switch electrical frequencies, the design described in the Campion patent requires connecting and disconnecting integral portions of the frequency switching system. For example, the design described in the Campion patent involves switching frequency by disconnecting a first driving portion of a turbocharger from an exhaust duct, disconnecting the first driving portion from a turbocharger bypass, disconnecting the first driving portion from an exhaust gas manifold, disconnecting the first driving portion from a driven portion, and making connections between a second driving portion and corresponding locations previously disconnected from the first driving portion. Thus, much mechanical work is required to change the frequency output. 
     Besides the mechanical concerns in changing frequency output, Campion lacks effective methods for reducing air pollution and/or taking advantage of pollution control incentives offered by environmental regulatory agencies. Those agencies often offer financial incentives for reducing air pollution. For example, if an electrical power plant reduces air pollution by adopting technology that reduces emissions, then the environmental regulatory agency may issue the operator of the electrical power plant with pollution credits. A pollution credit is an incentive for reduction in air pollutants that may be used by the polluter to offset excess air pollutants at another facility. A pollution credit may be bought, sold, banked, or traded. For example, if the operator of the electrical power plant has another facility that is environmentally regulated, then the operator may use the pollution credits earned from the electrical power plant to offset pollution “penalties” for the other facility. If the operator of the electrical power plant desires to not use the pollution credits, then the operator may sell the pollution credits to operators of other facilities who can, in turn, use the credits to offset their penalties. 
     As can be seen, there is a need for an improved apparatus and methods for providing electrical power to varying electrical equipment having varying frequency and voltage needs, needing minimal use of space and capital equipment, being portable, being easily switchable between electrical frequencies and electrical voltages, and providing reduced air pollution. 
     SUMMARY OF THE INVENTION 
     In one aspect of the present invention, a method for changing a frequency of electrical power provided by a power module comprises determining a first frequency of electrical power provided by the power module; engaging a first governor to maintain the first frequency of electrical power provided by the power module; determining a second frequency of electrical power provided by the power module; and engaging a second governor to maintain the second frequency of electrical power provided by the power module. 
     In an alternative aspect of the present invention, a method for changing a voltage of electrical power provided by a power module comprises adjusting voltage of the electrical power provided by the power module with a voltage regulator; and wherein the voltage is adjusted independently of frequency of the electrical power. 
     In another aspect of the present invention, a method for providing electrical power from a first location to a second location comprises operating a motor; driving an electrical generator connected to the motor; selecting a first electrical frequency; controlling the electrical generator with a first governor and a second governor; engaging the first governor to maintain the first electrical frequency of electrical power; selecting a first electrical voltage; and delivering electrical power, at the first electrical frequency and the first electrical voltage, via a cable connected between the electrical generator and a power connection box. 
     In yet another aspect of the present invention, a method for providing power from a port to a ship electrical system comprises operating a motor positioned within a container; driving an electrical generator positioned within the container and driveably connected to the motor; selecting a first electrical frequency; controlling the electrical generator with a governor; controlling the rotational speed of the electrical generator with a speed controller; selecting a first electrical voltage; selecting a second electrical frequency; and delivering power, at the second electrical frequency and the selected first electrical voltage, via a cable connected between the electrical generator and a power connection box. 
     In a further aspect of the present invention, a method for providing power from a port to a ship comprises operating a gaseous fuel motor positioned within a container; driving a constant speed, variable load electrical generator positioned within the container and driveably connected to the gaseous fuel motor; selecting a first electrical frequency; controlling an electrical frequency produced by the electrical generator with a first governor; selecting a second electrical frequency; selecting a first electrical voltage; regulating the first electrical voltage with an adjustable voltage regulator; controlling the second electrical frequency produced by the electrical generator with a second governor; delivering power, at the second electrical frequency and the first electrical voltage, via a cable connected between the electrical generator and a power connection box. 
     In a still further aspect of the present invention, an apparatus for providing temporary power from a generator to an electrical system comprises a container; a gaseous fuel motor positioned within the container; a constant speed, variable load electrical generator driveably connected to the gaseous fuel motor; a first governor to maintain a first electrical frequency of electrical power provided by the constant speed, variable load electrical generator at the first electrical frequency; a second governor to maintain a second electrical frequency of electrical power provided by the constant speed, variable load electrical generator at the second electrical frequency; and a first speed controller and a second speed controller for controlling the rotational speed of the electrical generator. 
     In yet a still further aspect of the present invention, a power module for providing switchable power comprises a container; a motor positioned within the container; a generator connected to the motor; a first governor to maintain a first frequency of electrical power provided by the generator at the first frequency; a second governor to maintain a second frequency of electrical power provided by the generator at the second frequency; and an adjustable voltage regulator to adjust a voltage of the power provided by the generator. 
     In a still further aspect of the present invention, an electrical power network comprises a ship; a dock adjacent the ship; a gaseous fuel motor at the dock; a generator connected to the gaseous fuel motor; a first governor to maintain a first electrical frequency of electrical power provided by the generator at the first electrical frequency; a second governor to maintain a second electrical frequency of electrical power provided by the generator at the second electrical frequency; a first speed controller and a second speed controller for controlling the rotational speed of the generator; an adjustable voltage regulator to adjust a voltage of the power provided by the constant speed, variable load electrical generator; a power connection box; a generator cable for delivering the electrical power to the power connection box; and a cable connected between the power connection box and a vessel electrical system. 
     These and other aspects, objects, features and advantages of the present invention, are specifically set forth in, or will become apparent from, the following detailed description of an exemplary embodiment of the invention when read in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic of an electrical power network, according to an embodiment of the present invention; 
         FIG. 2  is a block diagram of an apparatus for providing electrical power from one location to another location, according to an embodiment of the present invention; 
         FIG. 3  is a partial sectional view of a power module, according to an embodiment of the present invention; 
         FIG. 4  is a partial, perspective view of a motor and generator of the power module of  FIG. 3 ; 
         FIG. 5  is an enlarged view of the portion of the motor within section A of  FIG. 4 ; 
         FIG. 6  is a side view, along line  6 — 6  of  FIG. 5 ; 
         FIG. 7  is a plan view, in isolation, of a linkage system, according to another embodiment of the present invention; 
         FIG. 8  is a side view, along line  8 — 8  of  FIG. 7 ; and 
         FIG. 9  is a flow diagram of a method for providing electrical power to a location, according to an embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following detailed description is of the best currently contemplated modes of carrying out the invention. The description is not to be taken in a limiting sense, but is made merely for the purpose of illustrating the general principles of the invention, since the scope of the invention is best defined by the appended claims. 
     The present invention is useful for switchable power delivery with selectable frequency and voltage settings. “Switchable power” is intended to refer to electrical power that is capable of being changed in frequency and/or voltage without mechanically connecting or disconnecting portions of a generator or motor. Additionally, the invention is useful for reducing pollution by using cleaner fuels for generating electricity and emissions controls for a motor driving a generator. The invention is useful for generating electrical power during electrical outages, or for providing auxiliary power supply. One such use is for marine vessels such as ships, boats, barges, and other watercraft that require auxiliary electrical power of a particular frequency and voltage while the vessel is berthed. The invention is also useful for providing power to vehicles, such as aircraft or trucks. 
     Prior art service generators may use bunker fuel, while the present invention may use a cleaner fuel, such as natural gas, liquefied natural gas, liquefied petroleum gas, and the like for generating electricity. The air pollution that is otherwise generated from bunker fuel is effectively reduced by instead using cleaner burning fuel motor of the present invention such that the pollution reduction may be 99% for No x  and CO and 100% for PM 10  (particulate matter). 
     Internationally, electrical systems often have different standard electrical frequencies (e.g., 50 Hz and 60 Hz) and standard electrical voltages (e.g., 110, 220, 380, 400, 480, and 600 volts). To build a power plant at a first stationary or non-stationary (moveable) location to provide electrical power to a second stationary or non-stationary (moveable) location, multiple generators and transformers have been needed at great capital expense to provide different electrical frequencies and different electrical voltages. 
     In contrast, the present invention can use one generator with two governors and two speed controllers to select a desired electrical frequency and/or a desired electrical voltage. Instead of disconnecting, assembling, and re-connecting generator components as has heretofore occurred (such as disconnecting a driving portion from an exhaust system to change a turbocharger), selecting frequencies and voltages may be accomplished by merely activating a governor to open and close a fuel valve to regulate motor rotation to set frequency and adjusting a voltage regulator to set output voltage, according to the present invention. 
     In more specifically describing the present invention, and as can be appreciated from  FIG. 1 , the present invention provides an electrical power network  10  for providing electrical power from a first location  34  to a second location  44 . The electric power network  10  may comprise a power module  30 , which may be situated at the first location  34 . The first location  34  may, as an example, be a dock  60  in a port. The network  10  may further include a fuel tank  40  to supply fuel to the power module  30 . The fuel tank  40  may supply natural gas, liquefied natural gas, liquefied petroleum gas, propane, ultra low sulphur diesel (“California diesel”), and the like. The power module  30  may supply electrical power, via a generator cable  50 , to a power connection box  250 . A cable  52  of the network  10  may be connected from the power connection box  250  to supply electrical power to the second location  44  which may, for example, be a ship  20  docked at a berth. An electrical system  54  may be a type of electrical equipment known in the art for distributing electric power at the second location  44 , such as onboard the ship  20 . 
     The electrical power network  10  may also include a machine  80 , such as a crane, for raising and lowering the power module  30  and transporting the power module through a lateral distance D, and thereby move the power module  30  from one location to another. For example, the machine  80  may move the power module  30  from a truck (not shown) to the first location  34 . Besides being moveable by the machine  80 , the portable power module  30  may be moveable, such as by a forklift (not shown) and trailerable, such that the portable power module  30  may be transported, such as by a standard 18-wheel truck and trailer (not shown), from one location to another location. 
     As shown in the block diagram in  FIG. 2 , the power module  30  may comprise a motor  100 , which may be positioned within a container  90 . The motor  100  may be, for example, a gaseous fuel motor or a turbocharged after-cooled engine. The motor  100  may be driveably connected to drive a generator  110 , which may be, for example, a constant speed, variable load electrical generator. 
     A first governor  200  and a second governor  210  may control the production of electric power from the generator  110  by controlling the rotational velocity of the generator  110 . The first and second governors  200 ,  210  can be well-known governors and may be, for example, a type manufactured by the Woodward Company of Fort Collins, Colo., U.S.A. The governors  200 ,  210  may be of the electromechanical type that operate by extending a rod to contact a fuel valve (such as a butterfly valve) of the motor  100 , and thereby open and close the fuel valve. The opening and closing of the fuel valve can regulate the fuel supply to the motor  100 , and thereby regulate the rotational speed of the generator  110 . In turn, the electrical frequency produced by the generator  110  is regulated (i.e., selected). The governors  200 ,  210  may be calibrated to regulate fuel supply in relation to motor  110  speed such that increasing and decreasing fuel supply rate respectively increases and decreases the motor  110  speed. 
     One governor (for example, first governor  200 ) may be used to set the generator  110  to a first frequency (e.g., 50 Hz) and a second governor (for example, second governor  210 ) to set the generator  110  to a second frequency (e.g., 60 Hz). For example, the first governor  200  may be calibrated to supply fuel to run the motor  100  at 1000 rpm, which may correspond (depending upon the type of motor  100  and generator  110 ) to the generator  110  producing electricity at 50 Hz. Likewise, the second governor  210  may be calibrated to supply fuel to run the motor  100  at 1200 rpm, which may correspond to the generator  110  producing electricity at 60 Hz. In another example, the first governor  200  may be calibrated to set motor  100  speed to 1500 rpm to produce 50 Hz electricity and the second governor  210  may be calibrated to set motor  100  speed to 1800 rpm to produce 60 Hz electricity. 
     The generator  110  output electrical frequency may be switched by, for example, turning off the first governor  200  and turning on the second governor  210 , to change the electrical frequency from a first frequency to a second frequency (for example, from 50 Hz to 60 Hz). Likewise, generator  110  output electrical frequency may be switched by turning off the second governor  210  and turning on the first governor  200 , to change the electrical frequency from a second frequency to a first frequency (for example, from 60 Hz to 50 Hz). 
     A first speed controller  220  and, optionally, a second speed controller  230  may control the rotational speed of the generator  110 , by controlling actuation of the governors  200 ,  210 . The present invention may operate with only the first speed controller  220  or with both the first speed controller  220  and the second speed controller  230 . The first and second speed controllers  220 ,  230  may be digital electronic controllers of a type well known in the prior art. 
     The first speed controller  220  may be associated with the motor  100 , the first governor  200 , and the second governor  210  when independent controlling of the first governor  200  and the second governor  210  is not desired or when the second speed controller  230  is malfunctioning. For example, when independent controlling is not needed, the first speed controller  220  may send instructions to deactivate the first governor  200  and activate the second governor  210 . The first speed controller  220  may receive feedback from the motor  100  to send corresponding instructions to the first governor  200  and the second governor  210 . For example, if the first speed controller  220  senses a decrease in rpm of the motor  100 , the first speed controller  220  may send instructions to the first governor  200  and the second governor  210  to open a fuel valve to increase the fuel supply to the motor  100 , which would increase the motor speed. 
     Alternatively, the first speed controller  220  may be associated with the motor  100  and the first governor  200 , while the second speed controller  230  may be associated with the motor  100  and the second governor  210  when independent controlling of the first governor  200  and the second governor  210  is desired. When the first speed controller  220  and the second speed controller  230  are both used, then the first speed controller  220  may receive feedback from the motor  100  to send corresponding instructions to the first governor  200  and the second speed controller  220  may receive feedback from the motor  100  to send corresponding instructions to the second governor  210 . For example, if the first speed controller  220  senses a decrease in rpm of the motor  100 , the first speed controller  220  may send instructions to the first governor  200  to open a first fuel valve (not shown) to increase the fuel supply to the motor  100 , which would increase motor speed. Meanwhile, the second speed controller  230  may send instructions to the second governor  210  to open the first fuel valve, and second fuel valve (not shown) when two fuel valves are desired to be operated, to increase the fuel supply to the motor  100 , which would increase the motor speed. 
     An adjustable voltage regulator  240  may be used (manually or automatically) to adjust the generator  110  output electrical voltage to varying amounts, which for example may be set to a value within a group consisting of, for example, ordinarily used voltages, such as 110, 220, 380, 400, and 480 volts. Desirably, the electrical voltage may be adjusted to a value within the range from about 380 volts to about 480 volts, depending on the voltage needed for equipment to be powered. The generator  110  output electrical voltage may be at values other than the ordinarily used voltages of 110, 220, 380, 400, and 480. The generator  110  output electrical voltage may be selected to be any voltage that can be safely delivered. The adjustable voltage regulator  240  may be a rheostat type, such as an adjustable voltage regulator manufactured by the Basler Electric Corporation of Highland, Ill., U.S.A. 
     In still referring to  FIG. 2 , the generator cable  50  may connect an electric cable spool  120  to the power connection box  250 . The power connection box  250  may permit intermediate connection among various electrical cables to connect to various electrical systems, for example, permitting the generator cable  50  to be connected to the cable  52 , which may be connected to the vessel electrical system  54 . 
     With reference to  FIG. 3 , the power module  30  may comprise a container  90 . The container  90  may comprise wheels  92  for ground transport and struts  94  for supporting the container  90  when stationary. The container  90  may be a shipping container of a standard type known in the maritime and trucking industries. The electric cable spool  120  for storing lengths of generator cable  50  may be positioned within the container  90 . A louvered vent  140 , which may provide ventilation for combustion air and cooling of the interior of the container  90 , may also be positioned within the container  90 . A switch gear  130  may be used to monitor electricity produced from the generator  110  to the second location  44  (shown in  FIGS. 1 and 2 ), such as measuring and reporting amperage, voltage, and frequency. As an example, the switch gear  130  may be of a type made by General Electric Corporation of a brand known as the Zenith Paralleling Switchgear. Exhaust from the motor  100  may exit the container  90  through an exhaust pipe  96 . A catalytic converter (not shown) may be affixed to the container  90  and the exhaust pipe  96 . 
     In  FIG. 4 , the motor  100  and the generator  110  may be attached to a fan  150  for cooling the motor  100 . A first fuel introduction device such as a carburetor  202  and an optional second fuel introduction device such as a carburetor  204  may be used to meter fuel for combustion within motor  100 . The first carburetor  202  and the second carburetor  204  may be of the type well known in the art to include a butterfly valve (not shown). The first and second carburetor  202 ,  204  may be opened and closed by the first governor  200 . Likewise, the first and second carburetor  202 ,  204  may be opened and closed by the second governor  210 . 
     Although not shown, it should be understood that the present invention may comprise other arrangements among the first governor  200 , the second governor  210 , the first carburetor  202 , and the second carburetor  204 . 
     A base  160  may support the motor  100  and the generator  110 . The base  160  may comprise steel skid rails, such as I-beams. The motor  100  and the generator  110  may be bolted onto the base  160  with spring isolators for vibration isolation during operation. The base  160  may be secured to the container by bolting or welding into the interior of the container. 
       FIG. 5 , which is an enlarged view of Section A of  FIG. 4 , depicts one arrangement among the governors  200 ,  210  and the carburetors  202 ,  204 . The first governor  200  and the second governor  210  may each comprise an extension rod  206 , which may be connected to a tie rod  208 . The tie rod  208  may be connected to a valve rod  212 , which may rotate to open and close each carburetor  202 ,  204 . 
     The relative movement of the extension rod  206 , the tie rod  208 , and the valve rod  212  is represented in  FIG. 6 , which is a view, along line  6 — 6  of  FIG. 5 . Upon actuation of the first governor  200  (such as by the first speed controller  220 , not shown), the extension rod  206  may extend along direction B. Extension of the extension rod  206  may cause rotation of the tie rod  208  along direction C. The valve rod  212  may then rotate along the same direction C. The valve rod  212  may be connected to a butterfly valve (not shown) within the first carburetor  202  to open and close the butterfly valve to start or stop the flow of fuel within the motor  100 . 
     Continuing with  FIG. 6 , the first governor  200  may be used to open or close the first carburetor  202 . To open the first carburetor  202 , the extension rod  206  may extend, along direction B, for example, away from the first governor  200 . The tie rod  208  may then rotate along direction C, for example, clockwise. The valve rod  212  may then rotate, along direction C, for example, clockwise to open the first carburetor  202 . Likewise, to close the first carburetor  202 , the extension rod  206  may move, along direction B, towards the governor  200 , moving the tie rod  208 , along direction C, for example, counterclockwise. The valve rod  212  may then move counterclockwise to close the first carburetor  202 . 
     Another embodiment of the present invention is shown in  FIG. 7  as a linkage system  214 , in isolation, of one arrangement among the governors  200 ,  210  and the carburetors  202 ,  204 . The first governor  200  and the second governor  210  may each be connected to a governor arm  216 , which may be connected to a linkage tie rod  218 . The linkage tie rod  218  may be connected to a connector rod  222 . Each connector rod may be connected to a linkage rod  260 . A translation rod  224  may be connected to a vertical rod  226 . The vertical rod  226  may be connected to a carburetor rod  228 , which may rotate to open and close the carburetors  202 ,  204 . 
     The relative movement within the linkage system  214  is represented in  FIG. 8 , which is a view, along line  8 — 8  of  FIG. 7 . The governors  200 ,  210  may act in unison. Upon actuation of the first governor  200  and the second governor  210  (such as by the first speed controller  220 , not shown), the governor arm  216  may move along direction D. Movement of the governor arm  216  may cause movement of the linkage tie rod  218  along direction E. The connector rod  222  may then move along direction F to rotate the linkage rod  260  to along the same direction F. The translation rod  224  may then move along direction G to cause vertical rod  226  to move along direction H. Next, the carburetor rod  228  (moving, for example, in direction J) may be connected to a butterfly valve (not shown) within each carburetor  202 ,  204  to open and close the butterfly valve to start or stop the flow of fuel within the motor  100  (not shown). 
     It can be seen in  FIG. 9  that the present invention also provides a method  300  for providing power, for example, from a port to a ship. The method  300  may comprise a step  310  of operating a motor  100 , which may be positioned within a container  90  for ease of transportation. Thereafter, the method  300  may comprise a step  320  of driving an electrical generator  110 , which may be positioned within the container  90 . The electrical generator  110  may be driveably connected to the motor  100 . The electrical generator  110  may be positioned within the container  90 , along with the motor  100 , to facilitate portability such that a machine  80  may move the container  90  and that the container  90  may be moved by truck (or other vehicle) without separately moving the electrical generator  110  and the motor  100 . Next, the method  300  may continue with a step  330  of selecting a first electrical frequency, based on a previous setting for electrical frequency. Step  340  may comprise controlling the first electrical frequency with a first governor  200 . Next, a step  350  may comprise controlling the rotational speed of the electrical generator  110  with a first speed controller  220  to maintain the first frequency. Thereafter, a step  360  may comprise selecting a second electrical frequency based on the needed frequency for the equipment to be powered. Thereafter, the method  300  may comprise a step  370  of selecting a first electrical voltage based on the needed voltage for the equipment to be powered and a step  380  of regulating the first electrical voltage with an adjustable voltage regulator to maintain the selected first electrical voltage. A step  390  may comprise controlling the second electrical frequency produced by the electrical generator  110  with a second governor  210 . Thereafter, a step  400  may comprise delivering power, at the second electrical frequency and the first electrical voltage, via a cable  50  connecting the electrical generator  110  and a power connection box  250  from where electrical power compatible with a vessel electrical system (not shown) may be delivered to the vessel electrical system (not shown) to power the vessel&#39;s services. 
     It should be understood, of course, that the foregoing relates to exemplary embodiments of the invention and that modifications may be made without departing from the spirit and scope of the invention as set forth in the following claims.