Power generation system

Abstract

To provide a power generating system capable of supplying low-cost and highly efficient power to a device of different battery voltage specifications.SOLUTION: A power generating system 1 has a plurality of power generating modules 100 equipped with an engine 200 which burns fuel to generate power, a renewable energy-derived fuel supply device 900 which burns renewable energy-derived fuel in the engine 200 to generate power, a power generator 300 which generates AC power from the power of the engine 200, an AC / DC converter 400 which converts AC power to DC power and a module power output unit 401 which outputs the DC power. Adjacent module power output units 401 are connected to each other via a plurality of parallel adjustment switches 31 which can be opened / closed. The parallel adjustment switches 31 are connected in series and has a DC power output unit 700 connected with at least one of the module power output units 401 via one of a plurality of series adjustment switches 30.SELECTED DRAWING: Figure 1A

Description

[Technical Field]

[0001] The present invention relates to a power generation system and a power generation control method. [Background technology]

[0002] In recent years, as electric vehicles (EVs) have become more popular, their short driving range has become an issue. While efforts have been made to solve this problem by increasing battery capacity, this has created a new issue: the long charging times required.

[0003] For this reason, it is expected that rapid charging, which increases the battery voltage and enables charging power to be supplied in a shorter time, will become widespread.

[0004] On the other hand, from the perspective of a stable supply of electricity, with the spread of renewable energy (hereafter referred to as "RE"), there is a desire to increase adjustable power sources that can follow fluctuations in electricity demand. As the amount of renewable energy introduced continues to increase, it will become difficult to follow demand fluctuations simply by adjusting the load factor of the current base power source, so it has been proposed to aim for a stable supply of electricity, including rapid charging for EVs, by introducing battery energy storage systems (BESS) and power generation devices using internal combustion engines.

[0005] In the technology described in Patent Document 1, power generated by a plurality of DC power supply devices is combined at a DC power supply bus, and the combined power is distributed to EVs.

[0006] Furthermore, in the technology described in Patent Document 2, when the power synthesized at the DC power supply bus is distributed to the EV, it is supplied at a voltage that matches the battery voltage of the EV by passing it through a DC / DC converter.

[0007] It is also possible to supply power from the DC power bus to the power grid via a DC / AC converter. In the technology described in Patent Document 3, the DC / AC converters installed between the DC power bus and the power grid are consolidated into one unit. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Patent No. 6441520 [Patent Document 2] Patent No. 6570779 [Patent Document 3] Japanese Patent Publication No. 2020-68544 Summary of the Invention [Problem to be solved by the invention]

[0009] Currently, EV battery voltages are mainly around 400V, but with the further spread of rapid charging in mind, this is expected to increase to 800V or higher. However, since the average lifespan of a car is around 10 years, in the future there will be a mixture of multiple battery voltage specifications, such as 400V and 800V.

[0010] Therefore, the method of combining power generated by a DC power supply device at a DC power supply bus, as in the technique described in Patent Document 1, has a problem in that it is not possible to supply power to EVs with different voltage specifications.

[0011] Furthermore, as in the technologies described in Patent Documents 2 and 3, if a DC / DC converter is placed between the DC power bus and the EV, it becomes possible to supply power to EVs with different voltage specifications. However, this method requires a DC / DC converter for each EV, which increases equipment costs and hinders widespread adoption.

[0012] Furthermore, when the battery voltage specifications or the amount of power supplied to the battery change, the efficiency of the power generation device using the internal combustion engine also changes, but there is a limit to how much efficiency reduction can be avoided by simply adjusting the operating point of the internal combustion engine.

[0013] Since power generation efficiency has a significant impact on CO2 emissions, the challenge is how to maintain and improve power generation efficiency when the voltage specifications and amount of power supplied vary greatly depending on the EV being fast-charged.

[0014] However, none of Patent Documents 1 to 3 mentions the above problem.

[0015] As such, with conventional technology, it has been difficult to provide low-cost, highly efficient rapid charging for EVs with different battery voltage specifications. An object of the present invention is to provide a power generation system and a power generation control method that can supply electric power at low cost and with high efficiency to devices with different battery voltage specifications. [Means for solving the problem]

[0016] In order to achieve the above object, the present invention is configured as follows.

[0017] A power generation system having a plurality of power generation modules, each including an engine that burns fuel to generate power, a renewable energy-derived fuel supply device that causes the engine to burn fuel derived from renewable energy to generate power, a generator that generates AC power from the power of the engine, an AC / DC converter that converts the AC power to DC power, and a module power output unit that outputs the DC power, wherein adjacent module power output units are connected to each other via a plurality of parallel adjustment switches that can open and close a connection, and the parallel adjustment switches are connected to each other so as to form a continuous series connection, and at least one of the module power output units is connected via one of the plurality of series adjustment switches. a regulation circuit unit configured with the parallel regulation switch and the series regulation switch; and a control unit that detects a required power demand for the DC power output unit and controls the power generation module and the regulation circuit unit based on the required power. Equipped with.

[0018] Further, in the power generation control method, a power generation control method for a power generation system including a plurality of power generation modules, each including an engine that generates power by burning fuel, a renewable energy-derived fuel supply device that causes the engine to burn fuel derived from renewable energy to generate power, a generator that generates AC power from the power of the engine, an AC / DC converter that converts the AC power to DC power, and a module power output unit that outputs the DC power, wherein adjacent module power output units are connected to each other via a plurality of parallel adjustment switches that can open and close a connection, and the parallel adjustment switches are connected to each other to form a continuous series connection, a DC power output unit that connects at least one of the module power output units via one of a plurality of series adjustment switches, and a regulation circuit unit constituted by the parallel adjustment switch and the series adjustment switch, the method comprising: detecting a required power required for the DC power output unit, and controlling the power generation module and the regulation circuit unit based on the required power . [Effects of the Invention]

[0019] According to the present invention, it is possible to provide a power generation system and a power generation control method that are capable of supplying electric power at low cost and with high efficiency to devices with different battery voltage specifications.

[0020] Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments. [Brief explanation of the drawings]

[0021] [Figure 1A] 1 is an explanatory diagram of a power generation system for rapid charging and a power generation state according to a first embodiment of the present invention. [Figure 1B] 1 is an explanatory diagram of a power generation system for rapid charging and a power generation state according to a first embodiment of the present invention. [Figure 2] 1 is an explanatory diagram of a power generation system for rapid charging and a power generation state according to a first embodiment of the present invention. [Figure 3] 1 is an explanatory diagram of a power generation system for rapid charging and a power generation state according to a first embodiment of the present invention. [Figure 4A] FIG. 2 is an explanatory diagram of an operating point of the engine in the first embodiment of the present invention. [Figure 4B] FIG. 2 is an explanatory diagram of an operating point of the generator in the first embodiment of the present invention. [Figure 4C] FIG. 2 is an explanatory diagram of an operating point of the generator in the first embodiment of the present invention. [Figure 5A] FIG. 6 is an explanatory diagram of a power generation system for rapid charging and a power generation state according to a second embodiment of the present invention. [Figure 5B] FIG. 6 is an explanatory diagram of a power generation system for rapid charging and a power generation state according to a second embodiment of the present invention. [Figure 6] FIG. 10 is an explanatory diagram of a control device and a control method for a rapid charging power generation system according to a third embodiment of the present invention. [Figure 7] 10 is a flowchart of a control method for a power generation system for rapid charging according to a third embodiment of the present invention. [Figure 8A] FIG. 10 is an explanatory diagram of a power generation system for rapid charging and a power generation state according to a fourth embodiment of the present invention. [Figure 8B] FIG. 10 is an explanatory diagram of a power generation system for rapid charging and a power generation state according to a fourth embodiment of the present invention. [Figure 9] FIG. 10 is an explanatory diagram of a power generation system for rapid charging and a power generation state according to a fifth embodiment of the present invention. [Figure 10A] FIG. 2 is an explanatory diagram showing the relationship between power demand and generated power. [Figure 10B] FIG. 2 is an explanatory diagram showing the relationship between power demand and generated power. [Figure 10C] FIG. 2 is an explanatory diagram showing the relationship between power demand and generated power. [Figure 11A] 1 is an explanatory diagram of a power generation system for rapid charging different from the present invention and a power generation state. [Figure 11B] 1 is an explanatory diagram of a power generation system for rapid charging different from the present invention and a power generation state. [Figure 11C] 1 is an explanatory diagram of a power generation system for rapid charging according to an example different from the present invention, and a power generation state thereof; [Figure 12A] FIG. 4 is an explanatory diagram of an operating point of a generator engine in an example different from the present invention. [Figure 12B] FIG. 10 is an explanatory diagram of an operating point of a generator in an example different from the present invention. [Figure 12C] FIG. 10 is an explanatory diagram of an operating point of a generator in an example different from the present invention. [Figure 13A] 10 is an explanatory diagram of another example of a power generation system for rapid charging different from the present invention and a power generation state. FIG. [Figure 13B] 10 is an explanatory diagram of another example of a power generation system for rapid charging different from the present invention and a power generation state. FIG. [Figure 13C] 10 is an explanatory diagram of another example of a power generation system for rapid charging different from the present invention and a power generation state. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0022] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, the same components are designated by the same symbols. Since their names and functions are the same, duplicated explanations will be avoided. While the following description focuses on a power generation system for rapid charging, the effects of the present invention are not limited to this, and can be applied to power generation systems and power generation control methods in general that supply power to power consumption devices with different voltage specifications. [Example]

[0023] Example 1 A first embodiment of the present invention will be described below. 1A to 4C are explanatory diagrams of a first embodiment of the present invention.

[0024] Prior to describing the first embodiment of the present invention, the relationship between power demand and generated power, problems with examples different from the present invention, and operating points of the engine (internal combustion engine) and the generator will be described.

[0025] Figures 10A to 10C are explanatory diagrams showing the relationship between power demand and generated power. Figures 11A to 11C are explanatory diagrams of a rapid charging power generation system and power generation state that are an example different from the present invention. Figures 12A to 12C are explanatory diagrams of operating points of a power generation engine and a generator in an example different from the present invention. Figures 13A to 13C are explanatory diagrams of another example rapid charging power generation system and power generation state that are different from the present invention.

[0026] As a background to the present invention, the relationship between power demand and generated power will be explained using Figures 10A to 10C. The reason why the relationship between power demand and generated power will be explained is that although the current balance between power supply and demand is relatively stable, it is highly likely that a stable supply of power will not be able to be maintained in the future, and the present invention aims to solve this problem.

[0027] As shown by the thick solid line in Figure 10A, power demand changes from moment to moment, and the power generation shown by the bar graph is adjusted to follow this power demand. However, the power generated by renewable energy sources such as wind and solar (the shaded area of ​​the bar graph) fluctuates depending on weather conditions. For this reason, fluctuations in power demand and fluctuations in the output of renewable energy sources are followed by adjusting the power generation of the base power source.

[0028] Base power sources are mainly composed of thermal power plants, nuclear power plants, and hydroelectric power plants, and the power generation is often adjusted by changing the load factor of hydroelectric power plants and some thermal power plants.

[0029] In the example shown in FIG. 10A, the renewable energy power source ratio is approximately 20% on an hourly average, which is relatively close to the current power source mix in Japan.

[0030] In contrast, when the renewable energy power source ratio reaches around 50%, fluctuations in the output of renewable energy power sources become more pronounced than fluctuations in power demand, as shown in Figure 10B. In this situation, it becomes difficult to keep up with fluctuations in power demand simply by changing the load factor of the base power source, and rising power generation costs due to a decline in the availability rate of the base power source and a decline in power generation efficiency also become serious issues.

[0031] In addition, as shown in Figure 10C, as rapid charging of EVs becomes widespread, the demand for electricity required for rapid charging will be large and irregular within a short period of time.

[0032] Existing base power sources cannot cope with such sudden fluctuations in electricity demand. This is because existing base power sources are made up of large-scale power plants that are connected to the grid and cannot cope with short-term fluctuations in demand. While the aforementioned hydroelectric power plants and some thermal power plants can adjust their power generation by changing the load factor, this is limited to small amounts of power generation.

[0033] It will also be difficult to secure the necessary electricity by building new hydroelectric or thermal power plants. This is because suitable sites for hydroelectric power generation are scarce, and thermal power generation produces large amounts of CO2, which would defeat the purpose of introducing renewable energy toward carbon neutrality. Furthermore, since both new hydroelectric and thermal power plants will be operated at low load rates for power adjustment purposes, it will be extremely difficult to recover the construction costs.

[0034] From the above, as shown in Figure 10C, if renewable energy sources and rapid charging become widespread at the same time, the gap between supply and demand for electricity will widen significantly, which will likely lead to destabilization of the power grid, frequent power outages, and an inability to maintain economic activity.

[0035] One solution proposed is to provide a stable supply of electricity, including rapid charging for EVs, by introducing battery energy storage systems (BESS). However, BESS has issues such as high installation costs and the large amount of CO2 emissions during manufacturing.

[0036] Furthermore, because rapid charging of a BESS would result in a sudden increase in power demand, which would defeat the purpose, it is necessary to charge the BESS over a relatively long period of time.For this reason, in order to meet the rapid charging demand for EVs that is concentrated during the day, for example, the BESS must be equipped with a battery capacity several times the amount of power required by the EV battery, and a corresponding installation area must be secured.

[0037] Therefore, this will lead to further increases in costs and CO2 emissions during manufacturing, and it is unlikely that this will become widespread.

[0038] As another solution, the introduction of a power generation device using an internal combustion engine has been proposed, but the conventional technology has many problems, which will be explained using Figures 11A to 13C.

[0039] First, a power generation system for rapid charging different from the present invention is shown in Figures 11A and 11B, and its power generation state is shown in Figure 11C. Figures 11A and 11B show the operating state of the power generation system at different times 0 and T1, respectively, which correspond to times 0 and T1 in Figure 11C.

[0040] 11A, the power generation system 10 is composed of power generation modules 100a and 100b. Each of the power generation modules 100a and 100b includes an engine 200, a generator 300 that generates AC power from the power of the engine 200, an AC / DC converter 400 that converts the AC power to DC power, and a module power output unit 401 that outputs the DC power.

[0041] The module power output unit 401 is connected to the DC power output unit 700 and supplies charging power to the EV battery. At time 0, EV batteries B1a and B1b with voltage specifications of 800V and 400V are respectively connected to the power generation modules 100a and 100b. At time T1, the charging of the 400V EV battery B1b is completed, and the 800V EV battery B2b is newly connected to the DC power output unit 700b.

[0042] FIG. 11C shows the generated power of the power generation modules 100a and 100b and the outputs of the DC power output units 700a and 700b at this time. Looking at the period from time 0 to T0, the power generation module 100a generates power with an output voltage of 800V and a magnitude of P2. This is directly output as power with a voltage of 800V and a magnitude of P2 by the DC power output unit 700a and supplied to the battery B1a. The power generation module 100b generates power with an output voltage of 400V and a magnitude of P1 (<P2). This is directly output as power with a voltage of 400V and a magnitude of P1 by the DC power output unit 700b and supplied to the battery B1b.

[0043] Generally, the magnitude of the power that can be supplied to the battery depends on the battery temperature. Therefore, when the battery temperature is low immediately after the start of charging (time 0 to T0), a large amount of power can be directly supplied to the battery. However, when the charging progresses to time T0 to T1, the battery temperature becomes high. Therefore, it is necessary to reduce the power supplied to the battery to suppress the temperature rise.

[0044] That is, the power generation module 100a gradually reduces the generated power from P2 to P1 while maintaining the output voltage of 800V, and the power generation module 100b gradually reduces the generated power from P1 to zero while maintaining the output voltage of 400V, and supplies them to the batteries B1a and B1b respectively. At time T1, the battery B1b is fully charged.

[0045] Next, looking at times T1 to T2, power generation module 100a gradually reduces the generated power from P1 to zero while maintaining an output voltage of 800V, and continues to supply power to battery B1a. At time T2, battery B1a is fully charged. If the battery capacities of batteries B1a (voltage specification 800V) and B1b (voltage specification 400V) were the same, the charging time for battery B1a would be shorter, but here we assume that the battery capacity of B1a is about three times that of B1b. If the voltage specifications of batteries B1a and B1b were the same, the charging time would be proportional to the battery capacity, but as shown in Figure 11C, because the voltage specification of battery B1a is 800V, its charging time is reduced to about 1.5 times that of battery B1b.

[0046] In this way, even if the battery capacity increases, it is possible to avoid a significant increase in the battery charging time by increasing the voltage.

[0047] Meanwhile, from time T1 to time T2, an 800V EV battery B2b is newly connected to DC power output unit 700b of power generation module 100b. As a result, power generation module 100b generates power with an output voltage of 800V and magnitude P2. This power is output as is by DC power output unit 700b and supplied to battery B2b.

[0048] After time T2, the power generating module 100a stops operating. The power generating module 100b gradually reduces the generated power from P2 to 0 while maintaining the output voltage of 800V, and continues to supply power to the battery B2b.

[0049] The operating points of the engine and generator at this time are shown in Figures 12A to 12C. The generator modules 100a and 100b have the same specifications and both have the characteristics shown in Figures 12A to 12C.

[0050] In general, engines are designed to maximize efficiency at their most frequent operating points. In Figure 12A, operating points where engine efficiency is maximized include operating point X22 with rotation speed N2 and output power P2, and operating point X11 with rotation speed N1 and output power P1. In contrast, the operating point where generator efficiency is maximized varies depending on the output voltage. For example, in the case of an output voltage of 800V, efficiency is maximized at operating point X22 with rotation speed N2 and output power P2, as shown in Figure 12B, whereas in the case of an output voltage of 400V, efficiency is maximized at operating point X11 with rotation speed N1 and output power P1, as shown in Figure 12C.

[0051] Therefore, when supplying power to a battery with a voltage specification of 800V, the operating point at which the efficiency of the system combining the engine and generator (hereinafter abbreviated as system efficiency) is maximized is the operating point X22 of output P2, based on the results shown in Figures 12A and 12B.

[0052] Furthermore, as charging progresses and the generated power decreases from P2 to P1 to P0, the corresponding operating point becomes X22 to X11 to X10. While the operating point transitions from X22 to X11, the engine operates at a highly efficient operating point and the generator also operates at a relatively highly efficient operating point, so high system efficiency can be maintained.

[0053] On the other hand, while the operating point transitions from X11 to X10, both the engine and the generator are operated in a low efficiency state, and the system efficiency also drops significantly.

[0054] On the other hand, when power is supplied to a battery with a voltage specification of 400V, the operating point at which the system efficiency is maximized is the operating point X11 of the output P1, based on the results shown in FIGS. 12A and 12C.

[0055] Furthermore, as charging progresses and the generated power decreases from P1 to P0, the corresponding operating point changes from X11 to X10. While the operating point changes from X11 to X10, both the engine and generator are operated at low efficiency, resulting in a significant drop in system efficiency.

[0056] Although either operating point X11 or X21 can be selected for output P1, it can be determined that operating point X11, which provides superior system efficiency, should be selected. 12A to 12C show that the engine and generator have the same rotation speed, but the same can be said if a transmission is interposed between the engine and generator and the generator is rotated at a predetermined gear ratio relative to the engine rotation speed.

[0057] 12A to 12C, the following can be said regarding the power generation efficiency at each time in FIG. 11C.

[0058] Between times 0 and T0, power generating module 100a and power generating module 100b are operated at operating points X22 and X11, respectively, where efficiency is maximized. Between times T0 and T1, the operating point of power generating module 100a shifts from X22 to X11, maintaining high-efficiency operation, but the operating point of power generating module 100b shifts from X11 to X10, causing it to operate at a low efficiency. After time T1, the operating point of power generating module 100a shifts from X11 to X10, causing it to operate at a low efficiency.

[0059] On the other hand, the power generation module 100b is operated at the operating point X22 where the efficiency is maximum, and from time T2 to T3, the operating point shifts from X22 to X11, maintaining high-efficiency operation, but from time T3 onwards, the operating point shifts from X11 to X10, operating at a low efficiency.

[0060] Here, when the total amount of power generated by the power generating modules 100a and 100b between times 0 and T4 shown in FIG. 11C is taken as 100%, the amount of power generated in low-efficiency operation accounts for 15%.

[0061] As described above, the advantages and disadvantages of the configurations of the different examples of the present invention shown in FIGS. 11A to 11C can be summarized as follows from the viewpoints of the degree of freedom in the generated voltage, the degree of freedom in adjusting the load factor, and the power generation efficiency. 1) There is a high degree of freedom in the power generation voltage. This is because the operating point can be changed for each power generation module. This has the advantage of being able to flexibly accommodate EV batteries with different voltage specifications.

[0062] 2) The degree of freedom in adjusting the load factor is low. This is because power cannot be shared between power generation modules. As a result, as shown in Fig. 11C for the power generation module 100a between times T1 and T2, the power generation module 100a frequently operates at a low load, which makes it difficult to shorten the charging time.

[0063] 3) Power generation efficiency is low. This is related to 2) above, but the closer the battery is to full charge, the lower the load and efficiency of the operating points of the power generation modules 100a and 100b become. This poses a problem in that it is not possible to reduce CO2 emissions.

[0064] As a solution to the above problems 2) and 3), the technology shown in Figures 13A to 13C is disclosed in Patent Document 2. Figures 13A and 13B show the operating state of a power generation system for rapid charging at different times 0 and T1, respectively, and Figure 13C shows the power generation state.

[0065] 13A, the outputs of AC / DC converters 400a and 400b of power generation modules 100a and 100b are both connected to a power combining and distribution device 2. Furthermore, two outputs from the power combining and distribution device 2 are connected to DC power output units 700a and 700b via DC / DC converters 500a and 500b, respectively.

[0066] With this configuration, the power of the multiple power generation modules 100a, 100b can be aggregated by the power combining and distribution device 2 and then freely distributed to multiple EV batteries.

[0067] As a result, as shown in Figures 11A and 11B, compared to a configuration in which an EV battery is connected to each power generation module 100a and 100b, the amount of power supply to each EV battery can be adjusted over a wider range, thereby reducing charging time.

[0068] However, when the generated power is aggregated by the power combining and distribution device 2, a constraint arises in that the output voltages of the plurality of power generating modules 100a and 100b must be made the same.

[0069] FIG. 13C shows the power generated by the power generation modules 100a and 100b and the outputs of the DC power output units 700a and 700b.

[0070] With regard to the power generation efficiency at each time in FIG. 13C, the following can be said with reference to FIGS. 12A to 12C.

[0071] Between times 0 and T0, both power generation modules 100a and 100b generate power with an output voltage of 800 V. In order to aggregate the generated power in the power combining and distribution device 2, it is necessary to make the output voltages of the two power generation modules 100a and 100b equal in this way.

[0072] At this time, power generating module 100a, which outputs power of magnitude P2, is operated at operating point X22, where the system efficiency is maximized. Power generating module 100b, which outputs power of magnitude P1, is also operated at operating point X11, where the system efficiency is high. A portion of the power combined by power combining and distribution device 2 is output from DC power output unit 700a via DC / DC converter 500a as power of magnitude P2 at a voltage of 800V, and supplied to battery B1a. The remaining power is output from DC power output unit 700b via DC / DC converter 500b as power of magnitude P1 at a voltage of 400V, and supplied to battery B1b.

[0073] Since the total output of the power generation modules 100a and 100b needs to be P1+P2, it is also possible for each of them to output power of (P1+P2) / 2. In this case, both of the power generation modules 100a and 100b are operated at an operating point intermediate between the operating points X22 and X11 shown in Figures 12A to 12C.

[0074] As charging progresses from time T0 to time T1, both power generation modules 100a and 100b gradually reduce their power generation while maintaining an output voltage of 800V. Power generation module 100a shifts from operating point X22 to X11 and maintains high-efficiency operation, but power generation module 100b shifts from operating point X11 to X10, operating at a lower efficiency. At time T1, battery B1b is fully charged.

[0075] Next, from time T1 to time T2, power generation module 100a increases its power generation power to P2 while maintaining an output voltage of 800V, and then gradually reduces it to P1. That is, the operating point shifts from X22 to X11 while maintaining high system efficiency. Meanwhile, power generation module 100b outputs power of magnitude P2 at an output voltage of 800V and is operated at operating point X22, where its efficiency is maximized. Most of the power aggregated by power combining and distribution device 2 is output from DC power output unit 700b via DC / DC converter 500b as power of voltage 800V and magnitude P3 (>P2) and supplied to battery B2b. The remaining power is supplied from DC power output unit 700a via DC / DC converter 500a to battery B1a at a voltage of 800V.

[0076] 13A and 13B, it is possible to supply a single EV battery with power exceeding the maximum power generation power P2 of a single power generation module. As a result, battery B2b is fully charged at time T3, significantly shortening the charging time. Furthermore, when the total power generation amount of power generation modules 100a and 100b between times 0 and T3 shown in FIG. 13C is taken as 100%, the power generation amount resulting in low-efficiency operation is about 10%, which improves power generation efficiency compared to the configurations shown in FIGS. 11A and 11B.

[0077] As described above, the advantages and disadvantages of the technical configurations different from the present invention shown in FIGS. 13A to 13C can be summarized as follows from the viewpoints of the degree of freedom in power generation voltage, the degree of freedom in load factor adjustment, and power generation efficiency.

[0078] 1) High degree of freedom in generated voltage. This is because it is possible to freely distribute power to multiple EV batteries via a power combining and distribution device. This has the advantage of being able to flexibly accommodate EV batteries with different voltage specifications.

[0079] 2) High degree of freedom in load factor adjustment. This is because the power from multiple power generation modules can be aggregated using a power combining and distribution device. As a result, as shown in Figure 13C between times T1 and T2, multiple power generation modules can be operated at high load, and power exceeding the maximum power generation output of a single power generation module can be supplied to a single EV battery, thereby shortening charging time.

[0080] 3) Power generation efficiency is improved compared to the configurations shown in Figures 11A and 11B. This is related to 2) above, but it is because multiple power generation modules can be operated at high load and high efficiency operating points. However, low-efficiency operating states still exist.

[0081] Therefore, the configurations shown in FIGS. 13A and 13B are improved over the configurations shown in FIGS. 11A and 11B in terms of the above 2) and 3).

[0082] However, since one DC / DC converter 500a or 500b is necessarily required for each DC power output unit 700a, 700b, there is a significant problem in terms of equipment costs.

[0083] Furthermore, since the DC / DC converters 500a, 500b are responsible for aggregating and outputting the power generated by the multiple power generation modules 100a, 100b, a single unit must have the power capacity of multiple AC / DC converters 400a, 400b, which inevitably results in larger equipment and higher costs.

[0084] Furthermore, in order to suppress heat generation from the battery, the DC / DC converters 500a and 500b operate for a long period of time with the supplied power significantly reduced compared to their maximum power capacity, and the maximum power capacity is only required for a short period of time. This results in extremely low operational efficiency as a facility, making cost recovery extremely difficult and creating a bottleneck for widespread use.

[0085] Patent Document 1 discloses a configuration in which generated power is collected in a power combining and distribution device and then distributed directly to a DC power output unit without going through a DC / DC converter. However, with this configuration, the output voltage of the DC power output unit is limited to the single voltage specification collected in the power combining and distribution device, which poses a problem of significantly reducing the flexibility of the generated voltage mentioned in 1) above.

[0086] The configurations shown in Figures 11A, 11B, 13A, and 13B described above have been disclosed previously, but it has not been disclosed how the system efficiency in EV rapid charging applications differs among the configurations shown in Figures 11A, 11B, 13A, and 13B.

[0087] 11A, 11B, 13A, and 13B, there are always inefficient operating states, but no literature has been found that points out this as a problem.Furthermore, there is no literature that points out problems with the configurations shown in Figures 11A, 11B, 13A, and 13B in terms of the degree of freedom in power generation voltage, the degree of freedom in load factor adjustment, and power generation efficiency.

[0088] The present invention provides a power generation system, a control device, and a control method that can solve the above-mentioned problems associated with the technologies shown in Figures 11A, 11B, 13A, and 13B. That is, it provides a system that is low cost and has excellent flexibility in power generation voltage, flexibility in load factor adjustment, and power generation efficiency.

[0089] The principle will be explained below.

[0090] 1A, 1B, 2, and 3 are explanatory diagrams of a power generation system 1 for rapid charging and a power generation state in the first embodiment of the present invention. Figures 4A, 4B, and 4C are explanatory diagrams of operating points of the engine and the generator in the first embodiment of the present invention.

[0091] 1A and 1B show the operating state of the power generation system for rapid charging at different times 0 and T1, respectively, and FIGS. 2 and 3 show the power generation state.

[0092] 1A, the power generation system 1 is composed of multiple power generation modules 100a, 100b, 100c, and 100d. Each of the power generation modules 100a, 100b, 100c, and 100d includes an engine 200 (200a, 200b, 200c, and 200d) that burns fuel to generate power, a renewable energy-derived fuel supply device 900 (only one is shown, but each of the power generation modules 100a, 100b, 100c, and 100d may be provided with a renewable energy-derived fuel supply device 900) that causes the engine 200 (200a, 200b, 200c, and 200d) to burn fuel derived from renewable energy to generate power, a generator 300 that generates AC power from the power of the engine 200, an AC / DC converter 400 (400a, 400b, 400c, and 400d) that converts the AC power to DC power, and a module power output unit 401 that outputs the DC power.

[0093] Adjacent module power output sections 401 are connected to one another via parallel adjustment switches 31a, 31b, and 31c that can open and close the connection, and the parallel adjustment switches 31a, 31b, and 31c are connected to one another so as to form a continuous series connection.

[0094] Furthermore, at least one of the module power output units 401 provided in each of the multiple power generation modules 100 (100a, 100b, 100c, 100d) is connected to a DC power output unit 700 (700a, 700b) via a series adjustment switch 30 (30a, 30c).

[0095] In addition, at least two parallel adjustment switches 31 (31a, 31b) are provided between adjacent DC power output units 700 (700a, 700c). The parallel adjustment switches 31a, 31b and the series adjustment switches 30 (30a, 30c) are provided in the adjustment circuit unit 3 and may have any configuration as long as they are switches that can be opened and closed freely.

[0096] However, since current flows when supplying power to the battery, a switch with low conduction loss is preferable. Specifically, a low-loss semiconductor switch or a mechanical contact with low contact resistance is desirable. From the perspective of achieving lower costs, a mechanical contact is preferable.

[0097] 1A, the series regulating switches 30a and 30c are connected to the DC power output units 700a and 700c, respectively, while the series regulating switches 30b and 30d are electrically open. Furthermore, two parallel regulating switches 31a and 31b are provided between adjacent DC power output units 700a and 700c. With this configuration, when both DC power output units 700a and 700c are used simultaneously, the output ratio of 700a:700c can be freely changed between 2:2 and 1:3.

[0098] The renewable energy-derived fuel supply device 900 shown in FIG. 1A is provided in the power generation system 1 according to the embodiment of the present invention, but is not shown in the other drawings.

[0099] Here, there are two major differences between the configuration of the first embodiment of the present invention shown in FIGS. 1A and 1B and the example shown in FIGS. 13A and 13B.

[0100] The first point is that small-capacity power generation modules 100 (100a, 100b, 100c, 100d) are used so that the number of power generation modules 100 (four in Example 1 shown in Figures 1A and 1B) is greater than the number of DC power output units (two in the example shown in Figures 13A and 13B).

[0101] The second point is that the power generated by each power generation module 100 (100a, 100b, 100c, 100d) is aggregated and distributed by the adjustment circuit 3, and is freely distributed to multiple EV batteries without using a DC / DC converter.

[0102] As a result, the power generation voltage can be freely set for each power generation module 100 (100a, 100b, 100c, 100d), and the amount of power supplied to each EV battery can be adjusted over a wider range, making it possible to provide low-cost, highly efficient rapid charging for EVs with different battery voltage specifications.

[0103] At time 0 in Figure 1A, the outputs of AC / DC converters 400a, 400b of power generation modules 100a, 100b are combined by parallel adjustment switch 31a and then connected to DC power output unit 700a by series adjustment switch 30a. Similarly, the outputs of AC / DC converters 400c, 400d of power generation modules 100c, 100d are combined by parallel adjustment switch 31c and then connected to DC power output unit 700c by series adjustment switch 30c. At this time, parallel adjustment switch 31b between power generation modules 100b and 100c is open. An EV battery B1a with a voltage specification of 800V is connected to DC power output unit 700a, and an EV battery B1c with a voltage specification of 400V is connected to DC power output unit 700c.

[0104] At time T1 shown in FIG. 1B, charging of the 400V EV battery B1c connected to the DC power output unit 700c is completed, and an 800V EV battery B2c is newly connected. At this time, the output of the AC / DC converter 400a of the power generation module 100a is connected to the DC power output unit 700a by the series adjustment switch 30a. Meanwhile, the outputs of the AC / DC converters 400b, 400c, and 400d of the power generation modules 100b, 100c, and 100d are combined by the parallel adjustment switches 31b and 31c, and then connected to the DC power output unit 700c by the series adjustment switch 30c. The parallel adjustment switch 31a between the power generation modules 100a and 100b is open. EV batteries B1a and B2c, each with a voltage specification of 800V, are connected to the DC power output units 700a and 700c, respectively.

[0105] 2 shows the power generated by the power generation modules 100a, 100b, 100c, and 100d and the outputs of the DC power output units 700a and 700c in the connection state shown in FIG. 1A and FIG. 1B. The power generation outputs P1' and P2' of the power generation modules 100 (100a, 100b, 100c, and 100d) are half the power generation outputs P1 and P2 of the engines shown in FIG. 13A to FIG. 13C.

[0106] 4A to 4C show the operating points of the engine and generator at this time. The generator modules 100a, 100b, 100c, and 100d have the same specifications and all have the characteristics shown in FIGS. 4A to 4C. In FIGS. 4A to 4C, the same can be said for the example shown in FIGS. 12A to 12C, except that the outputs P0', P1', and P2' are half the generated power P0, P1, and P2 shown in FIGS. 12A to 12C, respectively.

[0107] Regarding the power generation efficiency at each time in FIG. 2, the following can be said with reference to FIGS. 4A to 4C.

[0108] Between times 0 and T0, power generation modules 100a and 100b each generate power with an output voltage of 800V and magnitude P2' (=P2×0.5). This power is combined by adjustment circuit unit 3 and output as power with a voltage of 800V and magnitude P2 by DC power output unit 700a, which is supplied to battery B1a. Power generation modules 100c and 100d each generate power with an output voltage of 400V and magnitude P1' (=P1×0.5). This power is combined by adjustment circuit unit 3 and output as power with a voltage of 400V and magnitude P1 by DC power output unit 700c, which is supplied to battery B1c. At this time, power generation modules 100a and 100b, which output power with a voltage of 800V and magnitude P2', operate at operating point X22', thereby maximizing system efficiency. The power generation modules 100c and 100d, which output power of 400V and magnitude P1', are also operated at the operating point X11', and the system efficiency is maximized.

[0109] As charging progresses and the time passes from T0 to T1, the battery temperature rises, making it necessary to reduce the power supplied to the battery to suppress the temperature rise. However, the power generation system 1 in the first embodiment of the present invention has the advantage that, because it uses small-capacity power generation modules 100 (100a, 100b, 100c, 100d), the multiple engines 200 (200a, 200b, 200c, 200d) can continue to operate efficiently at high loads. Specifically, the power generation module 100a can maintain high-efficiency operation at an operating point X22' with an output P2'. The power generation module 100b gradually reduces its power generation from P2' to P1' to 0, i.e., the operating point transitions from X22' to X11' to X10', but the efficiency is low only around time T1. At this time, the output of the DC power output unit 700a is supplied to the battery B1a while being gradually reduced from P2 to P1.

[0110] Similarly, the power generation module 100c maintains high-efficiency operation at an operating point X11' with an output P1' for a while, and then gradually reduces from P1' to 0. That is, the operating point shifts from X11' to X10', but the efficiency remains low only around time T1. The power generation module 100d gradually reduces the power generation output from P1' to 0 at time T0. That is, as the operating point shifts from X11' to X10', the efficiency remains low, but for a short period of time. At this time, the output of the DC power output unit 700c is supplied to the battery B1c while gradually reducing from P1 to 0. Then, at time T1, the battery B1c becomes fully charged.

[0111] Next, looking at times T1 to T2, power generation module 100a gradually reduces the power generation from P2' (= P2 × 0.5 = P1) → P1' → 0 while maintaining the output voltage of 800V. In other words, the operating point transitions from X22' → X11' → X10', but the efficiency only becomes low around time T2. At this time, the output of DC power output unit 700a is supplied to battery B1a while gradually reducing from P1 to 0. At time T2, battery B1a becomes fully charged.

[0112] On the other hand, power generation modules 100b, 100c, and 100d can each maintain high-efficiency operation at operating point X22' with an output voltage of 800 V and magnitude P2'. These are combined by adjustment circuit unit 3, and output as power with a voltage of 800 V and magnitude P3 (=P2' × 3) by DC power output unit 700c, and supplied to battery B2c.

[0113] After time T2, power generation module 100a stops operating. While maintaining an output voltage of 800V, power generation modules 100b, 100c, and 100d gradually reduce their power generation from P2' to P1' to 0 in turn. That is, the operating point shifts from X22' to X11' to X10', but the low efficiency only lasts for a short time. At this time, the output of DC power output unit 700c is gradually reduced from P3 to 0 and supplied to battery B2c.

[0114] In this way, by using the configuration shown in Figures 1A and 1B, it becomes possible to freely adjust the amount of power supply to EVs with different battery voltage specifications without using DC / DC converter 500 (500a, 500b) shown in Figures 13A and 13B.

[0115] As a result, battery B2c is fully charged at time T3, significantly shortening the charging time. Furthermore, when the total amount of power generated by power generation modules 100a, 100b, 100c, and 100d between times 0 and T3 shown in Figure 2 is taken as 100%, the amount of power generated in low-efficiency operation is only about 5%, significantly improving power generation efficiency compared to the configurations shown in Figures 11A, 11B, 13A, and 13B.

[0116] As described above, the configuration of the power generation system 1 according to the first embodiment of the present invention shown in FIGS. 1A and 1B can be summarized as follows from the viewpoints of the degree of freedom in the generated voltage, the degree of freedom in adjusting the load factor, and the power generation efficiency.

[0117] 1) High degree of freedom in the generated voltage. This is because it can be freely distributed to multiple EV batteries via the adjustment circuit unit 3. This has the advantage of being able to flexibly accommodate EV batteries with different voltage specifications.

[0118] 2) There is a high degree of freedom in adjusting the load factor. This is because the power of multiple power generation modules 100 can be aggregated in the adjustment circuit unit 3. As a result, as shown in time T1 to T2 in Figure 2, multiple power generation modules can be operated at high load, and power exceeding the maximum power generation power of a single power generation module can be supplied to a single EV battery, thereby significantly shortening charging time.

[0119] 3) The power generation efficiency of the power generation system 1 of Example 1 is significantly improved compared to the examples shown in Figures 11A and 11B and the examples shown in Figures 13A and 13B. This is related to 2) above, but it is because the multiple power generation modules 100 (100a, 100b, 100c, 100d) can be operated at a high load and a highly efficient operating point.

[0120] Regarding 3), further efficiency improvement can be achieved by operating as shown in Fig. 3. That is, at an operating point where the efficiency of the power generation modules 100 (100a, 100b, 100c, 100d) decreases, the operation of the power generation modules 100 (100a, 100b, 100c, 100d) where the efficiency decreases is stopped. However, by continuing to operate another power generation module to replace the power that should have been generated by the power generation module whose operation has been stopped, it is possible to supply the power necessary to fully charge the battery.

[0121] 3, between times 0 and T2, power generation module 100b stops after time T0 while its output is decreasing from P2' to P1'. Power generation module 100a continues operating at operating point X22' until after time T1, and then stops while its output is decreasing from P2' to P1'. The other power generation modules 100c and 100d also stop operating in the same way before they reach low-efficiency operation.

[0122] This allows the amount of power supplied from the DC power output unit 700a to the battery B1a to be maintained at the same level as the generated power shown in Figure 2, while avoiding operating points at which the power generation modules 100 (100a, 100b, 100c, 100d) become inefficient, and allowing them to always operate at highly efficient operating points.

[0123] The above has described the principle by which a power generation system can be provided that is low cost and has excellent flexibility in power generation voltage, flexibility in load factor adjustment, and power generation efficiency according to the first embodiment of the present invention.

[0124] In the prior art, there was no idea of ​​connecting multiple small engines in parallel, but rather the idea was to aggregate and distribute the output of existing large-scale power generation facilities on a DC bus. When using such large-scale power generation facilities, it is difficult to immediately respond to the charging power required for the DC power output unit 700, as shown at times 0 and T1 in Figure 2.

[0125] Furthermore, even if only a portion of the system is replaced with a small engine generator, it is difficult to maintain high-efficiency operation of the entire power generation system because the power supply fluctuates significantly during rapid charging.

[0126] In addition to the above issues, it will be necessary to support EVs with different battery voltage specifications in reality, which means that if existing large-scale power generation facilities are used, new DC / DC converters will be required, which will inevitably increase costs.

[0127] The first embodiment of the present invention is novel in that the outputs of a plurality of small engine power generation modules 100 (100a, 100b, 100c, 100d) arranged side by side are not aggregated by a DC bus, but are appropriately combined only by parallel adjustment switches 31a, 31b, and 31c, and that the combined power is appropriately output only by series adjustment switches 30a and 30c without going through a DC / DC converter.

[0128] This allows the power generation modules 100 (100a, 100b, 100c, 100d) to freely output voltages that match various battery specifications, respond immediately to requested power, and always maintain a highly efficient operating state.

[0129] Furthermore, the engines that make up the small power generation modules 100 (100a, 100b, 100c, 100d) use existing inexpensive internal combustion engines for automobiles, the generators use inexpensive motors (electric motors) that are mass-produced for EVs, and the AC / DC converters 400a, 400b, 400c, 400d use inexpensive inverters that are mass-produced for EVs, thereby significantly reducing the equipment costs of the power generation modules 100 (100a, 100b, 100c, 100d). The engines may also be used secondhand engines from internal combustion engine automobiles, in which case the equipment costs can be further reduced.

[0130] To realize such a configuration, the number Np of parallel adjustment switches 31a, 31b, 31c included in the adjustment circuit unit 3 and the number Ns of DC power output units 700 (700a, 700b) should be set to Np>Ns.

[0131] As described above, according to the first embodiment of the present invention, it is possible to provide a power generation system and a power generation control method that can supply electric power at low cost and with high efficiency to devices with different battery voltage specifications.

[0132] Example 2 Next, a second embodiment of the present invention will be described with reference to Fig. 5A and Fig. 5B. Fig. 5A and Fig. 5B are explanatory diagrams of a rapid charge power generation system 1 and a power generation state in the second embodiment of the present invention. Fig. 5A and Fig. 5B show the operating state of the rapid charge power generation system 1 at different times 0 and T1, respectively.

[0133] 5A and 5B differ from FIGS. 1A and 1B showing the first embodiment in that DC power output units 700a and 700d are connected to the series adjustment switches 30a and 30d, respectively, provided in the adjustment circuit unit 3, while three parallel adjustment switches 31a, 31b, and 31c are arranged between adjacent DC power output units 700a and 700d. The series adjustment switches 30b and 30c are electrically open. The adjustment circuit unit 3 is configured by standardizing a pair of series adjustment switches 30 and parallel adjustment switches 31 as the minimum unit and combining multiple pairs. This further reduces the cost of the adjustment circuit unit 3. In addition, intentionally providing the series adjustment switches 30b and 30c in the open state allows for flexible addition of DC power output units 700 according to demand patterns.

[0134] With this configuration, when both DC power output units 700a, 700d are used simultaneously, the output ratio of power output unit 700a:power output unit 700d can be freely changed between 1:3 and 3:1.

[0135] Therefore, compared to the configuration of the power generation system 1 of Example 1 shown in FIGS. 1A and 1B, the amount of power supply to multiple EV batteries can be adjusted over a wider range, which increases the number of cases where charging time can be shortened.

[0136] In the power generation system 1 shown in Figures 5A and 5B, three parallel adjustment switches 31 (31a, 31b, 31c) are arranged between adjacent DC power output units 700a and 700d, but the number of parallel adjustment switches 31 may be a number x (≧3) greater than or equal to 3.

[0137] In this case, the output ratio between the adjacent DC power output sections 700a and 700x can be freely changed between 1:x and x:1. In addition, although the number Ns of DC power output units 700 is set to 2 in FIGS. 5A and 5B, even when Ns is 3 or more, the output ratio can be changed over a wide range by configuring adjacent DC power output units 700 in a similar manner.

[0138] The other configurations are the same as those in the first embodiment.

[0139] In the second embodiment of the present invention, the same effects as those of the first embodiment can be obtained, and in addition, the amount of power supply to multiple EV batteries can be adjusted over a wider range, thereby shortening the charging time.

[0140] Example 3 A third embodiment of the present invention will be described with reference to FIGS.

[0141] 6 and 7 are explanatory diagrams of a control device and a power generation control method for a rapid charging power generation system 1 according to a third embodiment of the present invention.

[0142] As shown in FIG. 6, the power generation system 1 includes an adjustment circuit unit 3 having parallel adjustment switches 31a, 31b, and 31c and series adjustment switches 30a, 30b, 30c, and 30d, and also includes a control unit (ECU) 4 that controls the power generation modules 100 (100a, 100b, 100c, and 100d) and the adjustment circuit unit 3 based on the required power Pr detected by the DC power output unit 700 (700a and 700b).

[0143] The power generation module 100 (100a, 100b, 100c, 100d) is composed of a renewable energy-derived fuel supply device 900, an engine 200 (200a, 200b, 200c, 200d) equipped with an engine controller (not shown), a generator 300, an AC / DC converter 400 (400a, 400b, 400c, 400d), and a module power output unit 401.

[0144] As shown in Figure 7, the control unit 4 detects the required power Pr required by the DC power output unit 700 (700a, 700b) in step S1, and determines whether to open or close the parallel adjustment switches 31a, 31b, 31c and the series adjustment switches 30a, 30d in step S2 based on the required power Pr, and also determines whether to operate the power generation modules 100a, 100b, 100c, 100d in steps S3 (S3a, S3b, ...) and onwards.

[0145] In step S4 (S4Y, S4N), a stop command (step S4N) or an operation command (step S4Y (rotation speed command, torque command, proportion of renewable energy-derived fuel, etc.)) is given to engine 200 (200a, 200b, 200c, 200d, particularly the engine controller (not shown) and renewable energy-derived fuel supply device 900), and in step S5, a drive command (current command, voltage command) is given to AC / DC converter 400 (400a, 400b, 400c, 400d).

[0146] In step S4, the control unit 4 can determine the proportion of the renewable energy-derived fuel to be burned in the engines 200a, 200b, 200c, and 200d by the renewable energy-derived fuel supply device 900, according to the required electric power Pr.

[0147] The decisions and commands of the control unit 4 in each step from step S2 to step S5 may be generated based on a pre-calculated efficiency map of the power generation modules 100a, 100b, 100c, and 100d, or may be generated based on an efficiency map obtained by measuring and calculating state quantities during actual operation by some means.Furthermore, the control unit 4 may be configured to determine whether to open or close the parallel adjustment switches 31a, 31b, and 31c and the series adjustment switches 30a and 30d, and to determine whether to operate the power generation modules and the operating points, using data that has been mathematically and statistically processed by machine learning or the like based on state quantities during operation of some or all of the power generation modules 100a, 100b, 100c, and 100d.

[0148] By such control, it becomes possible to avoid operating points at which the power generation modules 100a, 100b, 100c, and 100d become inefficient, and to always operate at operating points at which they are highly efficient.

[0149] The other configurations are the same as those in the first embodiment.

[0150] According to the third embodiment of the present invention, the same effects as those of the first embodiment can be obtained. In addition, the control unit 4 is configured to control the power generation modules 100 (100a, 100b, 100c, 100d) and the adjustment circuit unit 3 based on the required power Pr detected by the DC power output unit 700 (700a, 700b). Therefore, it is possible to avoid operating points that result in low efficiency and operate at operating points that are highly efficient.

[0151] Example 4 A fourth embodiment of the present invention will be described with reference to FIGS. 8A and 8B.

[0152] 8A and 8B are explanatory diagrams of a rapid charging power generation system 1 and a power generation state according to a fourth embodiment of the present invention.

[0153] 8A, the power generation system 1 includes seven power generation modules 100 (100a, 100b, 100c, 100d, 100e, 100f, and 100g), an adjustment circuit unit 3 that aggregates their outputs, three DC power output units 700a, 700d, and 700g, and displays 5 (5a, 5b, and 5c) installed near each DC power output unit 700 (700a, 700b, and 700c). As described above, if the adjustment circuit unit 3 is standardized, the system can be configured at low cost even when the number of power output units 700 is increased in this way.

[0154] Three parallel adjustment switches 31a, 31b, and 31c are arranged between adjacent DC power output units 700a and 700d, and three parallel adjustment switches 31d, 31e, and 31f are arranged between adjacent DC power output units 700d and 700g. Assuming that the allowable power and allowable voltage of all three DC power output units 700 (700a, 700d, and 700g) are identical, the output ratios of DC power output unit 700a:DC power output unit 700d and DC power output unit 700d:DC power output unit 700g can be freely changed between 1:3 and 3:1. On the other hand, if the allowable power and allowable voltage of only DC power output unit 700d are increased by approximately double, the output ratio of DC power output unit 700a:DC power output unit 700d:DC power output unit 700g can be increased to 1:5:1.

[0155] The display 5 (5a, 5b, 5c) displays the battery voltage specifications to be output by each DC power output unit 700 (700a, 700d, 700g). To show that multiple battery voltage specifications are supported, for example, 800 / 400V may be displayed, or a specific voltage may be displayed. When a specific voltage is displayed, the open / closed states of the parallel adjustment switches 31a, 31b, 31c, 31d, 31e, 31f and the series adjustment switches 30a, 30b, 30c, 30d, 30e, 30f of the adjustment circuit unit 3 can be determined in advance according to that voltage. This enables charging power to be generated quickly when an EV battery is connected, thereby shortening the charging time.

[0156] Furthermore, when a preset voltage is displayed on the display 5 (5a, 5b, 5c), the voltage to be displayed may be determined based on data mathematically and statistically processed by machine learning using past operating history, etc. The display 5 (5a, 5b, 5c) may also display information other than voltage specifications. For example, the display 5 may display allowable power, allowable current, charging power cost (¥ / kWh), or, if an EV battery is connected, remaining charging time, current power supply, amount of power supply, charging power cost, etc.

[0157] In Figure 8A, DC power output units 700a and 700d are set to 800V, and 700g is set to 400V. At this time, parallel adjustment switches 31c and 31f are open, while the others remain connected. If accurate demand predictions can be made based on machine learning data, operating in this manner can reduce the time required for the switch switching operation of adjustment circuit unit 3, thereby shortening charging time.

[0158] 8B, by displaying or hiding the indicator 5b of the DC power output unit 700d with an "x", it is possible to open the series adjustment switch 30d and put the DC power output unit 700d in an unconnected state. As a result, six parallel adjustment switches 31a, 31b, 31c, 31d, 31e, and 31f are arranged between the adjacent DC power output units 700a and 700g, and the output ratio of the DC power output unit 700a:DC power output unit 700g can be freely changed between 1:6 and 6:1.

[0159] 8B, parallel adjustment switch 31a is in an open state, so only power from power generation module 100a is supplied to DC power output unit 700a, and parallel adjustment switches 31b, 31c, 31d, 31e, and 31f are in a connected state, so the combined power of six power generation modules 100b to 100g is supplied to DC power output unit 700g. For example, by operating in this manner at night when there are fewer EV rapid charging users, the charging time can be significantly reduced, even for rapid charging of electric trucks with large battery capacities.

[0160] Furthermore, in the fourth embodiment, a control unit 4 similar to that in the third embodiment shown in FIG. 4 may be arranged, and at least one of the voltage, current, or required power output by the DC power output units 700a, 700d, and 700g may be displayed on the display 5.

[0161] Furthermore, in the fourth embodiment, a control unit 4 similar to that in the third embodiment shown in FIG. 4 is arranged, and when any of the DC power output units 700a, 700d, and 700g does not output the required power, the control unit 4 displays on the display 5 the voltage that the DC power output unit 700a, 700d, and 700g that is not outputting the required power can output.

[0162] In this case, the control unit 4 can be configured to determine the voltage value to be displayed by the indicator 5 based on the past operation history and data obtained from machine learning or the like.

[0163] The other configurations are the same as those in the first embodiment.

[0164] According to the fourth embodiment, it is possible to obtain the same effect as in the first embodiment, and in addition, since the DC power output units 700a, 700b, and 700c are configured to have the displays 5a, 5b, and 5c, the user can quickly select the DC power output unit 700a, 700b, and 700c that is suitable for the battery voltage specifications of the user's EV vehicle, etc.

[0165] Example 5 A fifth embodiment of the present invention will be described with reference to FIG.

[0166] FIG. 9 is an explanatory diagram of a power generation system 1 for rapid charging and a power generation state according to a fifth embodiment of the present invention.

[0167] The embodiment shown in FIG. 9 differs from the fourth embodiment shown in FIGS. 8A and 8B in that a DC / AC converter 600 that converts DC power into AC power for the grid is connected to one of the module power output units 401 via the grid connection adjustment switch 32, thereby enabling power supply to the grid.

[0168] In particular, as shown in FIG. 9, by connecting the system connection adjustment switch 32 to the end 33 of a series connection of parallel adjustment switches 31a, 31b, 31c, 31d, 31e, and 31f (the end of the series of parallel adjustment switches), it is possible to supply greater power to the system.

[0169] By displaying an "X" or not displaying the indicators 5b and 5c of the DC power output units 700d and 700g, it is possible to open the series adjustment switches 30d and 30g and put the DC power output units 700d and 700g into an unconnected state.

[0170] In this case, when the parallel adjustment switch 31c is opened, the three power generation modules 100a to 100c supply power for rapid charging from the DC power output unit 700a, while the four power generation modules 100d to 100g supply power to the grid via the DC / AC converters 400d to 400g. For example, by operating in this manner at night when there are few users of EV rapid charging, it is possible to play a role in providing stable power to the local area.

[0171] In the technology described in Patent Document 1, a DC / AC converter is provided for each power supply and demand facility, but in the present invention, only one DC / AC converter 600 is required, which allows for a smaller installation area and reduced facility costs.

[0172] Furthermore, the technology described in Patent Document 3 discloses a technology in which DC power collected in a power combining and distribution device is supplied to a grid via a DC / AC converter, but an EV battery is also connected to the power combining and distribution device via a DC / DC converter.

[0173] In this case, the output of the DC / DC converter fluctuates from moment to moment depending on the state of charge of the EV battery, and these fluctuations may also affect the output of the DC / AC converter, causing instability in the power supply to the grid.

[0174] In contrast to this, in the fifth embodiment of the present invention, the power supplied to the EV battery and the power supplied to the grid can be operated independently of each other, so that the power supplied to the grid does not become unstable.

[0175] The other configurations are the same as those in the first embodiment.

[0176] According to the fifth embodiment, it is possible to obtain the same effects as those of the first embodiment, and in addition, since the configuration is such that power can be supplied to other systems via the DC / AC converter 600, it is also possible to play a role as a stable power source for the region.

[0177] The power generation control method of the present invention is configured as follows.

[0178] Fuel derived from renewable energy is burned in multiple engines 200 to generate power, multiple generators 300 are operated using the power of the multiple engines 200 to generate multiple AC powers, the multiple AC powers are converted into multiple DC powers by multiple AC / DC converters 400, and at least one or more of the multiple DC powers are combined and output. [Explanation of symbols]

[0179] 1... power generation system, 3... adjustment circuit section, 4... control section (ECU), 5a, 5b, 5c... display, 30a, 30b, 30c, 30d, 30e, 30f... series adjustment switch, 31a, 31b, 31c, 31d, 31e, 31f... parallel adjustment switch, 32... grid connection adjustment switch, 33... series end of parallel adjustment switch, 100a, 100b, 100c, 100d, 100e, 100f, 100g ···Power generation module, 200a, 200b, 200c, 200d, 200e, 200f, 200g···Engine, 300···Generator, 400a, 400b, 400c, 400e, 400f, 400g···AC / DC converter, 401···Module power output unit, 600···DC / AC converter, 700a, 700c, 700d, 700g···DC power output unit, 900···Renewable energy-derived fuel supply device

Claims

1. A power generation system having a plurality of power generation modules, each including: an engine that burns fuel to generate power; a renewable energy-derived fuel supply device that causes the engine to burn fuel derived from renewable energy to generate power; a generator that generates AC power from the power of the engine; an AC / DC converter that converts the AC power to DC power; and a module power output unit that outputs the DC power, the module power output units adjacent to each other are connected to each other via a plurality of parallel adjustment switches that can open and close the connection, and the parallel adjustment switches are connected to each other so as to form a continuous series connection, and a DC power output unit that connects at least one of the module power output units via one of the plurality of series adjustment switches; an adjustment circuit unit configured with the parallel adjustment switch and the series adjustment switch; a control unit that detects a required power that is required for the DC power output unit and controls the power generation module and the adjustment circuit unit based on the required power; A power generation system comprising:

2. The power generation system according to claim 1, The control unit detects the required power required by the DC power output unit, and determines whether to open or close the parallel adjustment switch and the series adjustment switch according to the required power, and also determines whether to operate the power generation module and its operating point.

3. The power generation system according to claim 2, The control unit determines whether to open or close the parallel adjustment switch and the series adjustment switch based on the state quantities of the power generation module during operation and data obtained from machine learning, etc., and determines whether the power generation module needs to be operated and its operating point.

4. The power generation system according to claim 2 or 3, The power generation system is characterized in that the control unit determines a ratio of the renewable energy-derived fuel to be burned in the engine by the renewable energy-derived fuel supply device according to the required power.

5. The power generation system according to any one of claims 2 to 4, A display is provided near the DC power output unit, A power generation device characterized in that, when the DC power output unit detects the required power, the control unit displays at least one of the voltage, current, or the required power output by the DC power output unit on the display.

6. The power generation system according to claim 5, A power generation system, characterized in that, when the DC power output unit does not output the required power, the control unit displays on the display a voltage that the DC power output unit can output.

7. 7. The power generation system according to claim 6, A power generation system characterized in that the control unit determines the voltage value to be displayed by the display device based on past operating history and data obtained from machine learning, etc.

8. The power generation system according to any one of claims 1 to 7, A power generation system, wherein the number Np of the parallel adjustment switches included in the adjustment circuit unit and the number Ns of the DC power output units satisfy the relationship Np>Ns.

9. 9. The power generation system according to claim 1, The power generation system is characterized in that the adjustment circuit unit is connected to a plurality of the DC power output units, and at least two of the parallel adjustment switches are provided between adjacent DC power output units.

10. 10. The power generation system according to claim 1, a power generation system further comprising a grid connection adjustment switch and a DC / AC converter, wherein one of the plurality of module power output units converts DC power to AC power for the grid via the grid connection adjustment switch.

11. The power generation system according to claim 10, A power generation system, wherein the grid connection adjustment switch is connected to an end of a series connection of the plurality of parallel adjustment switches.

12. 12. The power generation system according to claim 1, The power generation system is characterized in that the engine is an internal combustion engine of an automobile.

13. 13. The power generation system according to any one of claims 1 to 12, The power generation system is characterized in that the generator is a motor for an EV.

14. 14. The power generation system according to claim 1, The power generation system is characterized in that the AC / DC converter is an inverter for an EV.

15. 15. The power generation system according to any one of claims 1 to 14, The power generation system is characterized in that the adjustment circuit section is configured to include at least two or more sets of switch modules, each of which is made up of a set of the parallel adjustment switch and the series adjustment switch.

16. A power generation system comprising a plurality of power generation modules each including an engine that burns fuel to generate power, a renewable energy-derived fuel supply device that burns fuel derived from renewable energy in the engine to generate power, a generator that generates AC power from the power of the engine, an AC / DC converter that converts the AC power to DC power, and a module power output unit that outputs the DC power; the module power output units adjacent to each other are connected to each other via a plurality of parallel adjustment switches that can open and close the connection, and the parallel adjustment switches are connected to each other so as to form a continuous series connection, and a DC power output unit that connects at least one of the module power output units via one of the plurality of series adjustment switches; a power generation control method for a power generation system including an adjustment circuit unit configured by the parallel adjustment switch and the series adjustment switch, Detecting a required power for the DC power output; A power generation control method, comprising controlling the power generation module and the adjustment circuit unit based on the required power.

Images