AU2013101736A4

AU2013101736A4 - Hybrid Floating Wave Power Generator

Info

Publication number: AU2013101736A4
Application number: AU2013101736A
Authority: AU
Inventors: Man mei CHAN
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-12-14
Filing date: 2013-08-09
Publication date: 2015-09-10
Anticipated expiration: 2021-08-09
Also published as: CN103867378A; TWM481290U; DE212013000254U1; CA2895216A1; WO2014089983A1; AU2013359649A1

Abstract

A hybrid floating wave power generator includes at least one floating vessel, first and second wave energy harnessing mechanisms mounted on each floating vessel, and first and second power generating systems coupled with the first and second wave energy harnessing mechanisms respectively, wherein upon undulation of waves the floating vessel sways up and down to thereby actuate the first and second wave energy harnessing mechanisms which in turn drive the first and second power generating systems respectively to generate electricity. The first wave energy harnessing mechanism includes a water cistern, and the second wave energy harnessing mechanism includes two inverted pendulums. The first power generating system is a hydraulic system and the second power generating system is a gear-driven system.

Description

WO 2014/089983 PCT/CN2013/081210 HYBRID FLOATING WAVE POWER GENERATOR Field of the Technology The present application relates generally to a power generator, and particularly to a hybrid floating wave power generator. Background In general, hydro power generation refers to stored water power generation as other forms of hydro power generation e.g. tidal power generation, floating wave powered generation and surface flowing water powered generation etc. attribute an insignificant portion in the sector of hydro power generation. The development of a hydro powered generation project calls for enormous investment and massive civil work, including river interception, diversion of river course, demolition of hills and forests, reclamation and building dams for reservoir etc., all casting serious impact on environment. Energy from ocean wave is enormous, abundant and in exhaustive over the world. As such, harnessing wave energy has been the hottest subject of exploration in hydro power generation. There are thousands of wave powered generation projects in China and abroad. Yet, large scale wave powered generation projects are rarely seen in commercial operation. In addition to requiring expensive costs for research and development, wave powered generation is always constrained by site selection, environmental and financial aspects. In adverse weather, wave harnessing device is prone to damage by waves. There are records of wave harnessing device sunken into sea bed before the end of project trials rendering catastrophic result to projects. Since the device is always submerged underwater, problems arisen from operational reliability, sea water corrosion, growth of bio-organisms, wear and tear to hinges and bearings, waterproof seals, rams and structural parts etc. are great issues to maintenance imposing huge financial burdens. There is only a couple of wave powered projects in the world that can be operated in large scale power generation while all others are still in research and experimental stages. In fact, all present wave powered projects are operating in subsides from government under environmental green act policies. Summary According to the patent application, a hybrid floating wave power generator is provided. The hybrid floating wave power generator includes at least one floating vessel; first and second wave energy harnessing mechanisms mounted on each floating vessel; and first and second 1 WO 2014/089983 PCT/CN2013/081210 power generating systems coupled with the first and second wave energy harnessing mechanisms. Upon undulation of waves the floating vessel sways up and down to actuate the first and second wave energy harnessing mechanisms which in turn drive the first and second power generating systems to generate electricity. At least one floating vessel is kept in position from drifting away by anchorage to seabed via a mooring chain. The first wave energy harnessing mechanism comprises a water-filled enclosed water cistern pivotally supported in a middle section at an upper end of a vertical support fixed on a platform deck, wherein a water-filled side of the water cistern rests on the platform deck towards a sunken side of the vessel in a wave trough, and upon the impact of a wave crest, the sunken side of the vessel rises abruptly, water inside the water cistern is tossed towards an opposite side of the water cistern, and the momentum and weight of water cause the water cistern to topple over instantly to an opposite side of the vessel, whereby the water cistern moves up and down as if a seesaw when the vessel floats on undulating waves, and the momentum of the water cistern is delivered via at least one connecting rod extending downwardly from the water cistern to operate one of the first or second power generating systems to generate electricity. The second wave energy harnessing mechanism comprises at least one inverted pendulum being supported above a platform deck at an upper end of a lever arm while a lower end thereof being supported at a pivotal point in a lower portion of the vessel, wherein the lever arm leans towards a sunken side of the vessel in a wave trough, and upon the impact of a wave crest, the sunken side of vessel rises up abruptly and the inverted pendulum is thrown towards an opposite side of the vessel by momentum of the inverted pendulum, whereby the inverted pendulum toggles back and forth when the vessel floats on undulating waves, and a lateral connecting rod pivotally connecting to the lever arm, and the momentum of the toggling pendulum is delivered via the connecting rod to operate one of the first or second power generating systems to generate electricity. The first power generating system is a hydraulic power generating system comprising two vertically positioned hydraulic cylinders with two piston rams coupled to lower ends of two connecting rods extending from the two opposite sides of the water cistern respectively, whereby the momentum of the water cistern is delivered via the two connecting rods to the two piston rams to compress hydraulic oil inside the two hydraulic cylinders, and the pressurized hydraulic oil is fed by delivery pipe to a hydraulic turbine to generate electricity. The second power generating system is a gear-driven power generating system comprising a rack with its two ends being coupled to two connecting rods extending from the two opposite 2 WO 2014/089983 PCT/CN2013/081210 sides of the water cistern via two steel wires looping around two pulleys respectively, and a bi directional gear being meshed with the rack and caused to rotate freely by the bi-directional movement of the rack as the water cistern seesaws up and down, whereby the torque of the bi directional gear is transmitted to a pair of ratchet gears via a common axle, thereby driving a plurality of gears, a flywheel and in turn a generator to rotate in one direction to generate electricity. The first power generating system is a hydraulic power generating system comprising two horizontally positioned hydraulic cylinders with two piston rams coupled to the ends of two connecting rods extending from two lever arms of two inverted pendulums, whereby the momentum of the inverted pendulums is delivered via the two connecting rods to the two piston rams to compress hydraulic oil inside the two hydraulic cylinders, and the pressurized hydraulic oil is fed by delivery pipe to a hydraulic turbine to generate electricity. The second power generating system is a gear-driven power generating system comprising a rack with its two ends being coupled to two connecting rods extending from two lever arms of two inverted pendulums respectively; and a bi-directional gear being meshed with the rack and caused to rotate freely by the lateral movement of the rack as the two inverted pendulums toggle back and forth, whereby the torque of the bi-directional gear is transmitted to a pair of ratchet gears via a common axle, thereby driving a plurality of gears, a flywheel and in turn a generator to rotate in one direction to generate electricity. The floating vessel can be transformed to a simplified vessel comprising one wave energy harnessing mechanism selected from the group consisting of a water cistern or an inverted pendulum, and one power generating system selected from the group consisting of a hydraulic power generating system or a gear-driven power generating system. Brief Description of the Dr awings For further illustration on features, and advantages of the present application, reference shall be made to the following Figures in which: Figure 1 is a schematic view of a floating wave powered generating system in accordance with an embodiment of the present application; Figure 2A is a first illustrative side view of a floating wave powered generator vessel described in a preferred embodiment of the present application; Figure 2B is a second illustrative side view of a floating wave powered generator vessel with front hull rising up in the influence of a wave crest described in a preferred embodiment of the present application; 3 WO 2014/089983 PCT/CN2013/081210 Figure 2C is a front view of a floating wave powered generator vessel system described in a preferred embodiment of the present application; Figure 3A is a first illustrative view of a floating wave powered generator vessel under the influence of a wave trough with respect to the cylindrical water cistern and the first power generating system being shown in accordance with an embodiment of the present application; Figure 3B is a second illustrative view of a floating wave powered generator vessel under the influence of a wave crest with respect to a cylindrical water cistern and the first power generating system being shown in accordance with an embodiment of the present application; Figure 3C is a schematic view of a hydraulic power generator system with reference to Figures 3A and 3B; Figure 4A is a first illustrative view of another floating wave powered generator vessel under the influence of a wave trough with respect to a cylindrical water cistern in operation with a gear powered generator system in accordance with an embodiment of the present application; Figure 4B is a second illustrative view of another floating wave powered generator vessel under the influence of a wave crest with respect to a cylindrical water cistern in operation with a gear powered generator system in accordance with an embodiment of the present application; Figure 4C is a perspective view of a gear powered generator system with reference to Figures 4Aand 4B; Figure 4d is a front view of a gear powered generator system depicted in Figure 4c with the position of the freely rotating gear and other components being shown in accordance with an embodiment of the present application ; Figure 5A is a schematic view of an inverted pendulum-powered generator vessel in operation with a hydraulic powered generator with horizontally positioned hydraulic cylinders under the influence of a wave trough in accordance with an embodiment of the present application; Figure 5B is a second schematic view of an inverted pendulum-powered generator vessel in operation with a hydraulic powered generator with horizontally positioned hydraulic cylinders under the influence of a wave crest in accordance with an embodiment of the present application; Figure 5C is an illustrative view of an inverted pendulum with reference to Figures 5a and 5b; Figure 5D is a schematic view of a hydraulic powered generator system in operation with inverted pendulums depicted in Figures 5a and 5b; 4 WO 2014/089983 PCT/CN2013/081210 Figure 6A is a first illustrative view of an inverted pendulum-powered generator vessel in operation with a gear powered generator system under the influence of a wave trough in accordance with an embodiment of the present application; Figure 6B is a second illustrative view of an inverted pendulum-powered generator vessel in operation with a gear powered generator system under the influence of a wave crest in accordance with an embodiment of the present application; Figure 6C is a first perspective view of a gear powered generator system with a rack moving from position 'B' towards position 'A' with reference to Figure 6a; and Figure 6D is a second perspective view of a gear powered generator system with a rack moving from position 'A' towards position 'B' with reference to Figure 6b. Detailed Description For further understanding on the features and operation of the invention, a detailed explanation on the specific embodiments of the present application with reference to the drawings is provided below. Referring to Figure 1, it is a schematic view of a hybrid floating wave powered generator system according to an embodiment of the present application. The hybrid floating wave powered generator system may include one or more floating wave power generators 10 inter connected by chain 91 and being moored to seabed via anchor 9. Each of the floating wave power generators 10 can be free to sway up and down in response to sea waves 12, thereby actuating two onboard wave energy harnessing mechanisms 1, 8, which in turn drive two power generating systems 60, 70 to generate electricity. The electricity generated by the floating wave power generators 10 can be fed to shore via a common underwater cable. Figures 2A to 2C are illustrative views of one floating wave power generator 10 according to an embodiment of the present application. The floating wave power generator 10 may include a floating platform or vessel 11 with first and second onboard wave energy harnessing mechanisms 1, 8. The vessel 11 can be moored to seabed by anchor 9 via mooring chain 91. Figures 2a to 2c and Figures 3a to 3c are illustrative views of the first wave energy harnessing mechanism, which may include a cylindrical water cistern 1 in operation with the first power generating system 60 having vertically positioned hydraulic cylinders 65. The water cistern 1 may be cylindrical or in any other possible shape. The water-filled cylindrical water cistern 1 can be pivotally supported in the middle section at pivotal point 4 at an upper end of vertical support 41 fixed on platform deck 3. The cylindrical water cistern 1 is raised above platform deck 3 with water-filled side of the cylindrical water cistern 1 resting on platform deck 3 towards a sunken side of vessel 11. Two crank shafts or connecting rods 5a extending from 5 WO 2014/089983 PCT/CN2013/081210 two opposite sides of the cylindrical water cistern 1 can deliver the momentum of cylindrical water cistern 1 and the enclosed mass of water 2 to operate the first power generating system 60 depicted in Figures 3a to 3c. The first power generating system 60, being a hydraulic power generating system 60, may include two vertically positioned hydraulic cylinders 65 with respective piston rams 64, pistons 63 and connecting rods 5a, a hydraulic turbine 61, a hydraulic oil tank 68, hydraulic oil delivery pipe 69 and a hydraulic pressure cistern 62 which may help absorb pressure surge of hydraulic oil 67. Figures 3A and 3B illustrate the operation of the floating wave power generator 10. Under undulating waves 12, one side of vessel 11 rises upon the impact of a wave crest and sinks in a wave trough respectively. Hence, the mass of water 2 inside cylindrical water cistern 1 is tossed back and forth and the weight of water 2 causes cylindrical water cistern 1 to topple over to the other side and vice versa as if it were a seesaw. The momentum of water 2 and cylindrical water cistern 1 can be delivered to hydraulic cylinders 65 via connecting rods 5a to compress hydraulic oil 67. The pressurized hydraulic oil 67 can then be fed to hydraulic turbine 61 to generate electricity which may be delivered to shore via underwater cable. The operation of the two kinds of wave energy harnessing mechanism, namely the cylindrical water cistern 1 and the inverted pendulums 8, is digital rather than analogue such that a wave in small amplitude may not be able to trigger the operation of the wave energy harnessing mechanism. The operation will begin until pre-designed wave amplitude has been reached. The sensitivity for operation of cylindrical water cistern 1 to topple over can be adjusted by changing the height of vertical support 41. A short support 41 can increase the sensitivity, while a tall support requires for large wave amplitude to actuate the operation. Increasing the amount of water 2 stored inside cylindrical water cistern 1 can generate more momentum but the cylindrical water cistern 1 must not be fully-filled as water 2 will be difficult in flowing back and forth to the opposite sides. Water 2 stored inside cylindrical water cistern 1 may weigh over a hundred tons capable of generating enormous momentum instantly. Hence, it is encouraged that hydraulic power generating system 60 should be engaged in large scale floating wave power generator 10 to reduce wearing of metal parts, while a gear-driven wave power generating system 70 may be engaged in small scale power generation for flexibility and ease of deployment. Figures 4Ato 4D illustrate another application of wave energy harnessing mechanism. It is a cylindrical water cistern 1 in operation with a gear-driven power generating system 70. The gear-driven power generating system 70 may include a bi-directional rack 75, a freely rotating gear 76a, a pair of ratchet gears 71a, and 71b, a plurality of unidirectional gears 76, a flywheel 72 and a power generator 73. The two ends of rack 75 are connected to two connecting rods 5a by steel wires 77 which loop around pulleys 74 respectively. Gear 76a meshes with rack 75 and is caused to rotate freely by the lateral movement of rack 75. The torque of gear 76a is then 6 WO 2014/089983 PCT/CN2013/081210 delivered to the pair of ratchet gears 71a, 71b, one positioned at two opposite sides of gear 76a via a common axle, thereby driving flywheel 72, gears 76 and in turn power generator 73 to rotate in one direction to generate electricity. As described above, the vessel 11 rises up and sinks down reciprocally under undulating waves 12 causing the first wave energy harnessing mechanism 1, which is a water-filled cylindrical water cistern 1 to operate. The water 2 inside cylindrical water cistern 1 can be tossed back and forth to opposite sides. The weight of water 2 causes cylindrical water cistern 1 to topple over to opposite sides as if it were a seesaw. The momentum of water 2 and cylindrical water cistern 1 can be delivered via vertical connecting rods 5a, steel wires 77 and pulleys 74 causing rack 75 to move laterally hence driving gear 76a to rotate freely. The torque of gear 76a can be delivered via a common axle to operate the pair of ratchet gears 71a, 71b which drive flywheel 72, gears 76 and in turn generator 73 to rotate in one direction to generate electricity. Figure 5A to 5D are illustrative views of inverted pendulums 8, being the second wave energy harnessing mechanism 8 in operation with hydraulic power generating system 60 having horizontally positioned hydraulic cylinders 65. An inverted pendulum 8 may be supported and raised above platform deck 3 by one end of lever arm 81 while the other end of lever arm 81 being supported at pivotal point 82 positioned at the lower portion of vessel 11. The inverted pendulum 8 can toggle back and forth from one side to an opposite side and vice versa in response to the undulating movement of vessel 11 under the influence of waves 12. On lever arm 81, a lateral connecting rod 5b may extend and couple to piston ram 64. The momentum of the toggling pendulum 8 can be delivered via lateral connecting rod 5b to piston 63 to compress hydraulic oil 67 inside hydraulic cylinder 65 to generate high-pressure oil 67 which can then be fed to hydraulic turbine 61 by hydraulic oil delivery pipe 69 to generate electricity before discharging to hydraulic oil storage tank 68. Hydraulic pressure cistern 62 may help absorb pressure surge of hydraulic oil 67. Referring to Figure 5C, lever arm 81 leans towards the sunken side of floating wave powered generator vessel 11. Adjusting the horizontal distance between pivotal point 82 and center of gravity 83 of pendulum 8 can change the sensitivity for operation of pendulum 8 in respect to wave amplitude. A shorter distance will result in a greater sensitivity while a longer distance will require for larger wave amplitude. Adjusting vertical distance 85 between center of gravity 83 of pendulum 8 and pivotal point 82 can change the momentum output of pendulum 8. A greater distance may generate more momentum output and increasing the weight of pendulum 8 can also increase the momentum output. Figures 6A to 6D are illustrative views of inverted pendulum 8 in operation with a gear-driven power generating system 70. The gear-driven power generating system 70 may include a rack 75, a freely rotating gear 76a coupled with a pair of ratchet gears 71a, 71b via a common axle, 7 WO 2014/089983 PCT/CN2013/081210 a plurality of gears 76, a flywheel 72 and a power generator 73. The two ends of rack 75 are coupled to respective ends of the two connecting rods 5b while the other two ends of connecting rods 5b are pivotally connected to two lever arms 81 correspondingly. Gear 76a meshes with rack 75 and is driven to rotate freely by the lateral movement of connecting rods 5b caused by the back and forth movement of two lever arms 81 as the two inverted pendulums 8 being thrown to toggle back and forth under undulating waves. The momentum of the toggling inverted pendulums 8 can then be delivered to the two horizontal connecting rods 5b through lever arms 81 to drive rack 75 to move laterally and in turn cause gear 76a to rotate freely. The torque generated by gear 76a can be delivered to the pair of ratchet gears 71a, 71b via a common axle driving flywheel 72, gears 76 and in turn generator 73 to rotate in one direction to generate electricity. In a preferred embodiment of the present application, the two wave energy harnessing mechanisms 1, 8, namely cylindrical water cistern 1 and inverted pendulums 8, can be operated together to form a hybrid floating wave power generator 10. In another approach, the two wave energy harnessing mechanisms 1, 8 can be operated individually to form two discrete wave energy harnessing systems 1, 8 wherein cylindrical water cistern 1 can be put in operation with a hydraulic power generating system 60 or a gear-driven power generating system 70; while inverted pendulums 8 can also be put in operation with hydraulic power generating system 60 or a gear-driven power generating system 70 as described in Figures 3a and 4a, and Figures 5a and 6a respectively. The present application offers a hybrid floating wave power generator 10 yet it is simple in design with all mechanical devices and equipment housed onboard of vessels 11. Hence, it has a lot of advantages over the known floating wave powered generator systems in terms of low equipment cost, ease in maintenance, convenience in deployment by simply dropping an anchor 9 with mooring line 91 to seabed, minimal impact on navigation and environment, invulnerable to stormy conditions, and most of all -- reliable power output at all times. A plurality of floating wave powered generator vessels 10 inter-connected by chain as described in Figure 1 can provide enormous power supply and a matrix of a large number of floating wave powered vessels 10 can be developed into a large scale regional power generating system. A single floating powered generator vessel 10 may serve as a buoy capable of providing power to a mooring ship or a small scale power generator system for research station or alike at distant and isolated place. Depending on requirement of application, a hybrid floating wave powered generator vessel 10 can be transformed to a simplified floating wave powered generator vessel 10 in four different configurations as follows: 1. A cylindrical water cistern 1 in operation with a hydraulic generator system 60, 2. A cylindrical water cistern 1 in operation with a gear driven generator system 70. 8 WO 2014/089983 PCT/CN2013/081210 3. An inverted pendulum system 8 in operation with a hydraulic generator system 60, 4. An inverted pendulum system 8 in operation with a gear driven generator system 70. It is envisaged that a cylindrical water cistern 1 in operation with a hydraulic generator system 60 may be suitably engaged in large scale power generator system 60 whereas an inverted pendulum system 8 in operation with a geared generator system 70 may be suitably engaged in small scale power generator system for flexibility and simple construction. The above combines with the drawings and further describes the embodiments of the present application. However, the present application is not limited to the above specific embodiments. The methods in the above specific embodiments are merely illustrative, rather than limitative in nature. The skilled in the art may, without departing from the spirit of the present application and under the condition that the claims are within the scope of protection, perform many other forms under the motivations of the present application, which all belongs within the scope of protection of the present application. 9

Claims

1. A hybrid floating wave power generator comprising: (a) at least one floating vessel; (b) first and second wave energy harnessing mechanisms mounted on each floating vessel; (c) first and second power generating systems each coupled with the first or second wave energy harnessing mechanisms; (d) wherein upon undulation of waves the floating vessel sways up and down to thereby actuate the first and second wave energy harnessing mechanisms which in turn drive the first and second power generating systems to generate electricity.

2. The hybrid floating wave power generator according to claim 1, wherein the at least one floating vessel is kept in position from drifting away by an anchor secured to seabed via a mooring chain.

3. The hybrid floating wave power generator according to claim 1, wherein the first wave energy harnessing mechanism comprises a water-filled enclosed water cistern pivotally supported in a middle section at an upper end of a vertical support fixed on a platform deck, wherein a water-filled side of the water cistern rests on the platform deck towards a sunken side of the vessel in a wave trough, and upon the impact of a wave crest, the sunken side of the vessel rises abruptly, water inside the water cistern is tossed towards an opposite side of the water cistern, and the momentum and weight of water cause the water cistern to topple over instantly to an opposite side of the vessel, whereby the water cistern seesaws up and down when the vessel floats on undulating waves, and the momentum of the water cistern is delivered via at least one connecting rod extending downwardly from the water cistern to operate one of the first or second power generating systems to generate electricity.

4. The hybrid floating wave power generator according to claim 1, wherein the second wave energy harnessing mechanism comprises at least one inverted pendulum being supported above a platform deck at an upper end of a lever arm while a lower end thereof being supported at a pivotal point in a lower portion of the vessel, wherein the lever arm leans towards a sunken side of the vessel in a wave trough, and upon the impact of a wave crest, the sunken side of vessel rises up abruptly and the inverted pendulum is thrown towards an opposite side of the vessel by momentum of the inverted pendulum, whereby the inverted pendulum toggles back and forth when the vessel floats on undulating waves, and a laterally positioned connecting rod pivotally connecting to the lever arm, and the momentum of the toggling pendulum is delivered via the connecting rod to operate one of the first or second power generating systems to generate electricity. 10 WO 2014/089983 PCT/CN2013/081210

5. The hybrid floating wave power generator according to claim 3, wherein the first power generating system is a hydraulic power generating system comprising two vertically positioned hydraulic cylinders with two piston rams coupled to lower ends of two connecting rods extending from the two opposite sides of the water cistern respectively, whereby the momentum of the water cistern is delivered via the two connecting rods to the two piston rams to compress hydraulic oil inside the two hydraulic cylinders, and the pressurized hydraulic oil is fed by delivery pipe to a hydraulic turbine to generate electricity.

6. The hybrid floating wave power generator according to claim 3, wherein the second power generating system is a gear-driven power generating system comprising a rack with its two ends being coupled to two connecting rods extending from the two opposite sides of the water cistern via two steel wires looping around two pulleys respectively, and a freely rotating gear being meshed with the rack and caused to rotate by the lateral movement of the rack as the water cistern seesaws up and down, whereby the torque of the rotating gear is transmitted to a pair of ratchet gears via a common axle, thereby driving a plurality of gears, a flywheel and in turn a generator to rotate in one direction to generate electricity.

7. The hybrid floating wave power generator according to claim 4, wherein the first power generating system is a hydraulic power generating system comprising two horizontally positioned hydraulic cylinders with two piston rams coupled to the ends of two connecting rods extending from two lever arms of two inverted pendulums, whereby the momentum of the inverted pendulums is delivered via the two connecting rods to the two piston rams to compress hydraulic oil inside the two hydraulic cylinders, and the pressurized hydraulic oil is fed by delivery pipe to a hydraulic turbine to generate electricity.

8. The hybrid floating wave power generator according to claim 4, wherein the second power generating system is a gear-driven power generating system comprising a rack with its two ends being coupled to two connecting rods extending from two lever arms of two inverted pendulums respectively; and a freely rotating gear being meshed with the rack and caused to rotate by the lateral movement of the rack as the two inverted pendulums toggle back and forth, whereby the torque of the rotating gear is transmitted to a pair of ratchet gears via a common axle, thereby driving a plurality of gears, a flywheel and in turn a generator to rotate in one direction to generate electricity. 11 WO 2014/089983 PCT/CN2013/081210

9. The hybrid floating wave power generator according to claim 1, wherein the floating vessel can be transformed to a simplified vessel comprising one wave energy harnessing mechanism selected from the group consisting of a water cistern or an inverted pendulum, and one power generating system selected from the group consisting of a hydraulic power generating system or a gear-driven power generating system. 12