Power system and control method for the same

Abstract

To provide a power system capable of actualizing efficient temperature rise of oil while suppressing an increase in manufacturing cost and weight, and provide a control method for the same.SOLUTION: A power system 10A includes an oil supply device 14 having: a supply flow path 60; a bypass flow path 66 for bypassing a branch part 72; and an on-off valve 68, and is formed so that a first pressure loss becomes smaller than a second pressure loss. The first loss includes a pressure loss which occurs when oil flows until arriving at a starter 32 from a connection portion 80, and a pressure loss which occurs when the oil is distributed in the stator flow path. The second pressure loss is a pressure loss which occurs when the oil flows until arriving at a rotor 30 from the connection portion via a branch part 72 and a second introduction flow path 74.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a power system and a method for controlling a power system. [Background technology]

[0002] In recent years, technological developments have been underway in power systems that contribute to energy efficiency in order to ensure that more people have access to affordable, reliable, sustainable and advanced energy.

[0003] Patent Document 1 describes the use of waste heat from a battery charger to heat engine oil. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2013-501189 Summary of the Invention [Problem to be solved by the invention]

[0005] There is a need for better power systems and methods of controlling power systems.

[0006] The present invention aims to solve the above-mentioned problems. [Means for solving the problem]

[0007] A first aspect of the present disclosure includes a rotating electrical machine having a stator and a rotor, an oil supply device having a supply pump that supplies oil, a stator flow path for circulating the oil to the stator, a rotor flow path for circulating the oil to the rotor, and an oil recovery device for returning the oil that has circulated through the stator flow path and the rotor flow path to the oil supply device, wherein the oil supply device includes a supply flow path having a first introduction flow path that guides the oil sent from the supply pump to the stator, and a second introduction flow path that branches off from the first introduction flow path via a branch portion and guides the oil to the rotor, and an oil recovery device that has a second introduction flow path above the branch portion in the first introduction flow path so as to bypass the branch portion. a bypass flow path connecting a first portion, which is a portion on the downstream side of the bypass flow path, to a second portion, which is a portion of the first inlet flow path downstream of the branching portion; and an on-off valve for opening and closing the bypass flow path, wherein the first pressure loss is formed to be smaller than a second pressure loss, the first pressure loss including a pressure loss that occurs when the oil flows from a connecting portion between the bypass flow path and the second portion to reach the stator and a pressure loss that occurs when the oil circulates through the stator flow path, and the second pressure loss being a pressure loss that occurs when the oil flows from the connecting portion through the branching portion and the second inlet flow path to reach the rotor.

[0008] A second aspect of the present disclosure is a control method for a power system that controls the above-mentioned power system, wherein the power system includes an engine having a shaft that rotates integrally with the rotor, and includes a coil temperature rise control step in which, when the temperature of the oil is lower than a predetermined startable temperature, a control unit controls the current supplied to a coil portion of the stator to cause the coil portion to heat up without rotating the rotor. [Effects of the Invention]

[0009] A better power system and method for controlling the power system may be provided. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 1 is a schematic diagram of a power system according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a block diagram of the control device for the power system. [Figure 3] FIG. 3 is a flowchart showing a method for controlling a power system. [Figure 4] FIG. 4 is an explanatory diagram of the oil flow in the power system. [Figure 5] FIG. 5 is an explanatory diagram of the oil flow in the power system. [Figure 6] FIG. 6 is an explanatory diagram of the oil flow in the power system. [Figure 7] Figure 7 is a timing chart of the oil temperature and rotor rotation speed. [Figure 8] FIG. 8 is an explanatory diagram of vector control of a rotating electrical machine. [Figure 9] FIG. 9 is a schematic diagram of a power system according to a second embodiment of the present invention. [Figure 10] FIG. 10 is an explanatory diagram of the oil flow in the power system. [Figure 11] FIG. 11 is an explanatory diagram of the oil flow in the power system. DETAILED DESCRIPTION OF THE INVENTION

[0011] A power system supplies oil sent from a supply pump to a rotating electric machine. When starting the power system in a low-temperature environment (e.g., an environment below freezing point), the oil has a relatively high viscosity, which can easily cause excessive oil pressure, so it is necessary to raise the oil temperature to reduce the oil viscosity. If a heating device for raising the oil temperature is provided in the power system, the manufacturing cost and weight of the power system increase. The present disclosure has been made in view of these problems, and can provide a power system and a control method for the power system that can efficiently raise the oil temperature while suppressing increases in manufacturing cost and weight.

[0012] (First embodiment) FIG. 1 is a schematic diagram of a power system 10A according to a first embodiment of the present invention. The power system 10A is mounted on, for example, an aircraft. The aircraft is, for example, an electric vertical take-off and landing aircraft (eVTOL). Note that the aircraft is not limited to an electric vertical take-off and landing aircraft. Furthermore, the power system 10A is not limited to being mounted on an aircraft, and may be mounted on a ship, a vehicle, etc. The power system 10A may also be provided on a stationary power generation device.

[0013] 1, power system 10A includes a power plant 12, an oil supply device 14, and an oil recovery device 16. Power plant 12 has a rotating electric machine 18 and a gas turbine engine (engine) 20. Rotating electric machine 18 can drive, for example, a VTOL rotor (not shown) of an electric vertical take-off and landing aircraft.

[0014] The rotating electric machine 18 has a rotating electric machine main body 22, a bearing portion 24, a partition member 26, and a casing 28. The rotating electric machine main body 22 includes a rotor 30 and a stator 32. The rotor 30 has a rotating shaft 30a and a magnet portion 30b provided on the outer periphery of the rotating shaft 30a. The rotating shaft 30a is connected to, for example, a shaft portion 20a of the gas turbine engine 20. That is, the shaft portion 20a rotates integrally with the rotor 30. The magnet portion 30b is, for example, a permanent magnet. The stator 32 is formed in an annular shape. The rotor 30 is inserted into a hole in the interior of the stator 32. The stator 32 has a coil portion 32a and a stator core 32b. The stator core 32b includes an iron core (not shown). The rotor 30 and the stator 32 are not limited to the configurations described above.

[0015] For example, when starting to drive the gas turbine engine 20, the rotating electric machine 18 functions as a motor that rotates the shaft portion 20a of the gas turbine engine 20 by supplying current to the coil portion 32a of the stator 32 to rotate the rotor 30. The rotating electric machine 18 also functions as a generator that generates electricity when the rotor 30 is rotated by the driving force of the gas turbine engine 20. In the rotating electric machine 18, the rotor 30 and the stator 32 generate heat. Specifically, in the rotating electric machine 18, the magnet portion 30b of the rotor 30 and the coil portion 32a of the stator 32 are particularly likely to become hot.

[0016] The bearing portion 24 has a first bearing 24a and a second bearing 24b. The first bearing 24a rotatably supports one end of the rotating shaft 30a. The second bearing 24b rotatably supports the other end of the rotating shaft 30a. Each of the first bearing 24a and the second bearing 24b is, for example, a rolling bearing. Each of the first bearing 24a and the second bearing 24b may also be a plain bearing.

[0017] The partition member 26 is formed in a cylindrical shape. The rotor 30 is disposed inside the partition member 26, and the stator 32 is disposed outside the partition member 26. The partition member 26 is made of, for example, a ceramic material. The partition member 26 can be fixed to a casing 28. The partition member 26 separates the space in which the rotor 30 is disposed from the space in which the stator 32 is disposed in a liquid-tight and airtight manner. The casing 28 houses the rotating electric machine main body 22 and the bearing portion 24.

[0018] The oil supply device 14 supplies liquid oil to the rotating electrical machine 18 (power unit 12). Examples of oil include gas turbine oil. The oil cools the heat-generating parts (rotor 30 and stator 32) of the rotating electrical machine 18 and lubricates the bearings 24. The oil supply device 14 has a supply pump 34 for feeding the oil. The supply pump 34 is driven, for example, by a motor (not shown). A specific configuration of the oil supply device 14 will be described later.

[0019] The rotating electrical machine 18 is provided with a rotor flow path 36, a stator flow path 38, a lubrication flow path 40, a reservoir 42, a first discharge flow path 44, a second discharge flow path 46, and a third discharge flow path 48.

[0020] Oil guided from the oil supply device 14 flows through the rotor flow passage 36, the stator flow passage 38, and the lubrication flow passage 40. The rotor flow passage 36 and the stator flow passage 38 are arranged in parallel. The rotor flow passage 36 and the stator flow passage 38 are isolated by the partition member 26. Therefore, the oil flowing through the rotor flow passage 36 and the oil flowing through the stator flow passage 38 do not mix along the way.

[0021] The rotor flow path 36 can cool the rotor 30 by circulating oil guided from the oil supply device 14 through the rotor 30. The rotor flow path 36 includes a flow path formed inside the rotor 30. In this case, the rotor 30 can be efficiently cooled by the oil circulating inside the rotor 30. The rotor flow path 36 is a flow path open to the atmosphere. Therefore, gas (air) is mixed with the oil circulating through the rotor flow path 36.

[0022] The stator flow passage 38 can cool the stator 32 by circulating oil introduced from the oil supply device 14 through the stator 32. The stator flow passage 38 is formed to surround the stator 32. In this case, the oil can come into contact with the coil portion 32a of the stator 32, so the stator 32 can be cooled efficiently. The stator flow passage 38 is a flow passage that is not open to the atmosphere. Therefore, gas (air) does not mix with the oil flowing through the stator flow passage 38.

[0023] The lubrication passage 40 includes a first lubrication passage 40a and a second lubrication passage 40b. The first lubrication passage 40a supplies the oil that has flowed through the stator passage 38 to the first bearing 24a. The oil that has flowed through the first lubrication passage 40a is sprayed onto the first bearing 24a by the pressure of the supply pump 34. Gas (air) is mixed with the oil sprayed from the first lubrication passage 40a onto the first bearing 24a. The second lubrication passage 40b supplies the oil that has flowed through the stator passage 38 to the second bearing 24b. The oil that has flowed through the second lubrication passage 40b is sprayed onto the second bearing 24b by the pressure of the supply pump 34. Gas (air) is mixed with the oil sprayed from the second lubrication passage 40b onto the second bearing 24b.

[0024] The reservoir 42 is formed, for example, at the bottom of the casing 28. The reservoir 42 is located, for example, below the first bearing 24a and the second bearing 24b (in the direction of gravity). The size, shape, position, etc. of the reservoir 42 can be set as appropriate.

[0025] The first discharge flow path 44 guides the oil that has flowed through the first bearing 24a to the storage section 42. The second discharge flow path 46 guides the oil that has flowed through the second bearing 24b to the storage section 42. The third discharge flow path 48 guides the oil that has flowed through the rotor flow path 36 to the storage section 42. Gas (air) is mixed with the oil that flows through the first discharge flow path 44, the second discharge flow path 46, and the third discharge flow path 48. In other words, a gas-liquid mixed fluid that is a mixture of liquid oil and gaseous air is stored in the storage section 42.

[0026] The oil recovery device 16 returns the oil that has flowed through the rotor flow path 36 and the stator flow path 38 to the oil supply device 14. In other words, the oil recovery device 16 separates the oil from the gas-liquid mixture fluid stored in the reservoir 42 and returns the oil to the oil supply device 14. The oil recovery device 16 has a recovery flow path 50, a recovery pump 52, a circulation flow path 54, a gas-liquid separator 56, and a tank 58. The recovery flow path 50 is connected to the reservoir 42 and the recovery pump 52.

[0027] The recovery pump 52 is driven by, for example, a motor (not shown). The recovery pump 52 recovers the gas-liquid mixture fluid stored in the storage section 42. The capacity of the recovery pump 52 is greater than the capacity of the supply pump 34. In other words, the maximum amount of oil discharged per unit time by the recovery pump 52 is greater than the maximum amount of oil discharged per unit time by the supply pump 34.

[0028] The circulation flow path 54 guides the oil recovered by the recovery pump 52 to the supply pump 34. The circulation flow path 54 is provided with a gas-liquid separator 56 and a tank 58. The gas-liquid separator 56 separates gas from the gas-liquid mixed fluid sent by the recovery pump 52. The liquid oil from which the gas has been separated by the gas-liquid separator 56 is stored in the tank 58. The oil recovery device 16 may include components other than those described above.

[0029] The oil supply device 14 includes a supply pump 34, a supply flow path 60, a first orifice 62, a second orifice 64, a bypass flow path 66, and a relief valve (on-off valve) 68. The supply flow path 60 includes a first inlet flow path 70 and a second inlet flow path 74 branching from the first inlet flow path 70 via a branch portion 72. The first inlet flow path 70 guides oil sent from the supply pump 34 to the stator 32. The first inlet flow path 70 includes a first portion 76 and a second portion 78. The first portion 76 is a portion of the first inlet flow path 70 that is upstream of the branch portion 72. The second portion 78 is a portion of the first inlet flow path 70 that is downstream of the branch portion 72. The second inlet flow path 74 guides the oil to the rotor 30. The oil that has flowed through the second inlet flow path 74 is sprayed onto the rotor 30 by the pressure of the supply pump 34.

[0030] The first orifice 62 is a throttle portion provided in the second portion 78 of the first inlet flow path 70. The second orifice 64 is a throttle portion provided in the second inlet flow path 74. The first orifice 62 and the second orifice 64 are components for distributing an appropriate flow rate of oil to each of the stator flow path 38 and the rotor flow path 36.

[0031] The bypass flow passage 66 connects the first portion 76 and the second portion 78 so as to bypass the branch portion 72. A connecting portion 80 between the bypass flow passage 66 and the second portion 78 is located between the first orifice 62 and the stator 32.

[0032] The relief valve 68 is located at a portion where the first portion 76 and the bypass flow path 66 are connected. Hereinafter, the relief valve 68 may be referred to as the "first relief valve 68." The first relief valve 68 opens and closes the bypass flow path 66. When the pressure of the oil guided to the first relief valve 68 reaches a predetermined upper pressure limit, the first relief valve 68 opens by pushing a valve element (not shown) of the first relief valve 68 with the oil. In other words, the first relief valve 68 closes the bypass flow path 66 when the pressure of the oil guided to the first relief valve 68 is lower than the upper pressure limit.

[0033] The oil supply device 14 may include components other than those described above. For example, the oil supply device 14 may include a heat exchanger (not shown) in the first portion 76 of the first inlet flow path 70, downstream of the first relief valve 68. The heat exchanger cools the oil sent from the supply pump 34.

[0034] The power system 10A further includes an outlet passage 82 and a relief valve (outlet on-off valve) 84. The outlet passage 82 connects the stator passage 38 with the oil recovery device 16 so as to bypass the lubrication passage 40 and the bearing 24. The outlet passage 82 guides the oil that has circulated through the stator 32 to the oil recovery device 16. The outlet passage 82 is connected to the recovery pump 52.

[0035] The relief valve 84 is provided in a portion of the stator flow path 38 downstream of the stator 32. The relief valve 84 is located at a portion where the stator flow path 38 and the outlet flow path 82 are connected. Hereinafter, the relief valve 84 may be referred to as the "second relief valve 84." The second relief valve 84 opens and closes the outlet flow path 82. When the pressure of the oil guided to the second relief valve 84 reaches a predetermined upper pressure limit, the second relief valve 84 opens by pushing a valve element (not shown) of the second relief valve 84 with the oil. In other words, the second relief valve 84 closes the outlet flow path 82 when the pressure of the oil guided to the second relief valve 84 is lower than the upper pressure limit.

[0036] The power system 10A is configured so that the first pressure loss is smaller than the second pressure loss. The first pressure loss includes the pressure loss that occurs when oil flows from the connecting portion 80 to the stator 32 (to just before the stator 32) and the pressure loss that occurs when the oil flows through the stator flow path 38. When the second relief valve 84 is open, the first pressure loss also includes the pressure loss that occurs when the oil passes through the second relief valve 84. When the second relief valve 84 is closed, the first pressure loss also includes the pressure loss that occurs when the oil is sprayed onto the first bearing 24a and the second bearing 24b. The second pressure loss is the pressure loss that occurs when the oil flows from the connecting portion 80 through the branch portion 72 and the second introduction flow path 74 to the rotor 30. The oil supply device 14 is configured so that the first pressure loss is smaller than the second pressure loss. In this embodiment, since the first orifice 62 and the second orifice 64 are provided, the first pressure loss can be made smaller than the second pressure loss with a simple configuration.

[0037] FIG. 2 is a block diagram of a control device 88 of the power system 10A. As shown in FIG. 2, the power system 10A further includes a sensor 86 and a control device 88. The sensor 86 detects various types of information about the power system 10A. Detection signals from the sensor 86 are sequentially transmitted to the control device 88. The sensor 86 includes, for example, a temperature sensor. In this case, the temperature sensor detects, for example, the temperature T of the oil flowing through the portion of the supply passage 60 between the supply pump 34 and the first relief valve 68. The sensor 86 may include a pressure sensor that detects the pressure of the oil (the discharge pressure of the supply pump 34), an engine speed sensor that detects the speed of the gas turbine engine 20, etc.

[0038] The control device 88 includes a calculation unit 90 and a storage unit 92. The calculation unit 90 is configured by a processor such as a CPU (Central Processing Unit) or a GPU (Graphics Processing Unit). In other words, the calculation unit 90 is configured by processing circuitry.

[0039] The calculation unit 90 has a control unit 94, an information acquisition unit 96, and a determination unit 98. The control unit 94, the information acquisition unit 96, and the determination unit 98 can be realized by the calculation unit 90 executing a program stored in the storage unit 92.

[0040] At least a part of the control unit 94, the information acquisition unit 96, and the determination unit 98 may be realized by an integrated circuit such as an ASIC (Application Specific Integrated Circuit), an FPGA (Field-Programmable Gate Array), etc. Also, at least a part of the control unit 94, the information acquisition unit 96, and the determination unit 98 may be configured by an electronic circuit including discrete devices.

[0041] The storage unit 92 is composed of a volatile memory (not shown) and a non-volatile memory (not shown). An example of the volatile memory is a random access memory (RAM). The volatile memory is used as a working memory for the processor, and temporarily stores data necessary for processing or calculation. An example of the non-volatile memory is a read-only memory (ROM) or a flash memory. The non-volatile memory is used as a storage memory, and stores programs, tables, maps, etc. At least a part of the storage unit 92 may be provided in the processor, integrated circuit, etc. described above.

[0042] The control unit 94 is responsible for overall control of the power system 10A. The control unit 94 controls the current supplied to the coil portion 32a of the stator 32. The control unit 94 controls the gas turbine engine 20. The information acquisition unit 96 acquires various information based on detection signals sent from the sensor 86 to the control device 88. Examples of the various information include the oil temperature T, the oil pressure (the discharge pressure of the supply pump 34), and the rotation speed of the gas turbine engine 20.

[0043] Next, a control method for the power system 10A will be described. Specifically, a control method for the power system 10A when starting the power system 10A in a low temperature environment (for example, an environment below the freezing point) will be described. Figure 3 is a flowchart showing the control method for the power system 10A.

[0044] 3, in step S1, the control unit 94 starts up the power system 10A. Specifically, the control unit 94 drives each of the supply pump 34 and the recovery pump 52. When the supply pump 34 is driven, oil stored in the tank 58 is sent from the supply pump 34 to the first portion 76 of the first inlet flow path 70. In a low-temperature environment, the temperature T of the oil is low (its viscosity is high), and therefore the pressure of the oil sent from the supply pump 34 becomes higher than the upper pressure limits of the first relief valve 68 and the second relief valve 84. Therefore, the oil sent from the supply pump 34 opens the first relief valve 68 and the second relief valve 84.

[0045] Fig. 4 is an explanatory diagram of the flow of oil in the power system 10A. Specifically, Fig. 4 is an explanatory diagram showing the flow of oil when the first relief valve 68 and the second relief valve 84 are in an open state. In Fig. 4, for ease of understanding, areas where a large amount of oil flows are indicated by thick lines.

[0046] As shown in FIG. 4, when the first relief valve 68 opens, much of the oil is guided to the second portion 78 (connecting portion 80) of the first inlet flow path 70 via the bypass flow path 66. Because the first pressure loss is smaller than the second pressure loss as described above, the oil guided from the bypass flow path 66 to the connecting portion 80 does not easily flow toward the branching portion 72. Therefore, much of the oil guided from the bypass flow path 66 to the connecting portion 80 flows through the second portion 78 toward the stator 32 (stator flow path 38). The oil that has circulated through the stator flow path 38 is guided to the outlet flow path 82 via the second relief valve 84. The oil guided to the outlet flow path 82 is returned to the supply pump 34 by the recovery pump 52 via the circulation flow path 54 (gas-liquid separator 56 and tank 58).

[0047] That is, most of the oil discharged from the supply pump 34 circulates through a path that returns to the supply pump 34 via the first portion 76 of the first inlet flow path 70, the first relief valve 68, the bypass flow path 66, the second portion 78 of the first inlet flow path 70, the stator flow path 38, the second relief valve 84, the outlet flow path 82, the recovery pump 52, and the circulation flow path 54. In this case, the oil is heated by the supply pump 34 when it flows through the supply pump 34, and is also heated by the recovery pump 52 when it flows through the recovery pump 52. That is, the oil is heated by the supply pump 34 and the recovery pump 52.

[0048] The second inlet flow path 74 and the lubrication flow path 40 have relatively high flow path resistance because they require oil to be sprayed. Therefore, if highly viscous oil is circulated through the second inlet flow path 74 and the lubrication flow path 40 in a low-temperature environment, the oil pressure may become excessively high, which may cause excessive force to act on the components of the power system 10A. In contrast, the second portion 78 of the first inlet flow path 70 does not require oil to be sprayed and simply guides the oil to the stator flow path 38. Therefore, even if highly viscous oil is circulated through the second portion 78, the oil pressure will not become excessively high. Therefore, damage to the components of the power system 10A due to an excessive increase in oil pressure can be suppressed. As shown in FIG. 3, after the power system 10A is started, the process proceeds to step S2.

[0049] In step S2, the determination unit 98 determines whether the oil temperature T is lower than a predetermined possible start temperature T1. The oil temperature T is acquired by the information acquisition unit 96 based on the detection signal of the sensor 86. The possible start temperature T1 is set, for example, to an oil temperature at which the oil pressure does not become excessively high even when oil is supplied to the lubrication passage 40. The possible start temperature T1 can be set as appropriate. The possible start temperature T1 is stored in the memory unit 92. If the determination unit 98 determines that the oil temperature T is lower than the possible start temperature T1 (YES in step S2), the process proceeds to step S3.

[0050] In step S3, the control unit 94 executes coil temperature increase control. In the coil temperature increase control, the control unit 94 controls the current supplied to the coil portion 32a of the stator 32 to cause the coil portion 32a to generate heat without rotating the rotor 30. This allows the temperature of the oil flowing through the stator flow path 38 to be increased efficiently. As the oil temperature T increases, the viscosity of the oil decreases, and therefore the oil pressure also decreases. After this, the process proceeds to step S4.

[0051] In step S4, the determination unit 98 determines whether the control device 88 has received a stop signal for the power system 10A. The control device 88 receives the stop signal for the power system 10A, for example, when a user operates the stop switch for the power system 10A. If the determination unit 98 determines that the control device 88 has not received the stop signal for the power system 10A (NO in step S4), the process proceeds to step S2.

[0052] In this embodiment, when the oil temperature T reaches the startable temperature T1, the coil temperature increase control ends and the second relief valve 84 closes. That is, the upper pressure limit set for the second relief valve 84 is set to a pressure corresponding to the oil pressure at the startable temperature T1. The first relief valve 68 remains open.

[0053] Fig. 5 is an explanatory diagram of the flow of oil in the power system 10A. Specifically, Fig. 5 is an explanatory diagram showing the flow of oil when the first relief valve 68 is in an open state and the second relief valve 84 is in a closed state. In Fig. 5, for ease of understanding, areas where a large amount of oil flows are indicated by thick lines.

[0054] In this case, as shown in FIG. 5, the oil that has flowed through the stator flow path 38 flows through the second relief valve 84, and then splits into the first lubrication flow path 40a and the second lubrication flow path 40b. The oil flowing through the first lubrication flow path 40a is sprayed onto the first bearing 24a by the pressure of the supply pump 34. This causes the first bearing 24a to be lubricated by the oil. The oil that has flowed through the first bearing 24a flows down into the reservoir 42 via the first discharge flow path 44 by gravity. Gas (air) is mixed into the oil flowing through the first discharge flow path 44. In other words, the oil flowing through the first discharge flow path 44 is a gas-liquid mixed fluid.

[0055] The oil flowing through the second lubrication flow path 40b is sprayed onto the second bearing 24b by the pressure of the supply pump 34. As a result, the second bearing 24b is lubricated by the oil. The oil that has flowed through the second bearing 24b flows down into the reservoir 42 via the second discharge flow path 46 by gravity. Gas (air) is mixed into the oil flowing through the second discharge flow path 46. In other words, the oil flowing through the second discharge flow path 46 is a gas-liquid mixed fluid.

[0056] The gas-liquid mixture fluid stored in the reservoir 42 is sent by the recovery pump 52 through the recovery passage 50 to the gas-liquid separator 56. The gas-liquid mixture fluid sent to the gas-liquid separator 56 is separated into oil and gas (air) by the gas-liquid separator 56. The oil from which the gas has been separated by the gas-liquid separator 56 is led to a tank 58.

[0057] In FIG. 3, if the determination unit 98 determines that the oil temperature T is equal to or higher than the startable temperature T1 (NO in step S2), the process proceeds to step S5.

[0058] In step S5, the determination unit 98 determines whether the oil temperature T is lower than the warm-up completion temperature T2. The warm-up completion temperature T2 is stored in the memory unit 92. If the determination unit 98 determines that the oil temperature T is lower than the warm-up completion temperature T2 (YES in step S5), the process proceeds to step S6.

[0059] In step S6, the control unit 94 executes warm-up operation control. In the warm-up operation control, the control unit 94 controls the current supplied to the coil portion 32a of the stator 32 to rotate the rotor 30 in order to start the gas turbine engine 20. When the rotor 30 rotates, the shaft portion 20a of the gas turbine engine 20 rotates. When the shaft portion 20a of the gas turbine engine 20 rotates, a compressor (not shown) connected to the shaft portion 20a is driven, thereby introducing air into a combustor (not shown) of the gas turbine engine 20. The control unit 94 also controls the gas turbine engine 20 to supply fuel to the combustor and burn the fuel to generate combustion gas. The combustion gas rotates the turbine portion connected to the shaft portion 20a. This starts the gas turbine engine 20. When the rotor 30 rotates in conjunction with the rotation of the turbine portion, the rotating electric machine 18 can function as a generator.

[0060] In the warm-up operation control, the control unit 94 operates the rotating electric machine 18 at low efficiency, thereby causing the coil unit 32a to generate heat. Specifically, the control unit 94 operates the rotating electric machine 18 at a predetermined target operating efficiency. The target operating efficiency is stored in the memory unit 92. The target operating efficiency is lower than the maximum efficiency of the rotating electric machine 18. The target operating efficiency is set to increase as the oil temperature T approaches the warm-up completion temperature T2. In other words, in the warm-up operation control, the higher the oil temperature T, the higher the operating efficiency of the rotating electric machine 18. After this, the process proceeds to step S4.

[0061] In this embodiment, when the oil temperature T reaches the warm-up completion temperature T2, the warm-up operation control ends and the first relief valve 68 closes. That is, the upper pressure limit set for the first relief valve 68 is set to a pressure corresponding to the oil pressure at the warm-up completion temperature T2. In other words, the upper pressure limit set for the first relief valve 68 is smaller than the upper pressure limit set for the second relief valve 84. Note that, once the warm-up operation control ends, the stator 32 and the rotor 30 need to be cooled appropriately to prevent the temperatures of the stator 32 and the rotor 30 from becoming excessively high.

[0062] Fig. 6 is an explanatory diagram of the flow of oil in the power system 10A. Specifically, Fig. 6 is an explanatory diagram showing the flow of oil when the first relief valve 68 and the second relief valve 84 are in a closed state. In Fig. 6, the locations where oil flows are indicated by thick lines for ease of understanding.

[0063] In this case, as shown in FIG. 6 , the oil sent from the supply pump 34 passes through the first relief valve 68 and then splits into the second portion 78 of the first inlet flow path 70 and the second inlet flow path 74. The oil that flows into the second portion 78 passes through the first orifice 62 and then flows through the stator flow path 38, cooling the stator 32. The oil that flows through the stator flow path 38 splits into the first lubrication flow path 40a and the second lubrication flow path 40b. The oil guided to the first lubrication flow path 40a lubricates the first bearing 24a and then flows to the reservoir 42 via the first discharge flow path 44. The oil guided to the second lubrication flow path 40b lubricates the second bearing 24b and then flows to the reservoir 42 via the second discharge flow path 46. This allows the first bearing 24a and the second bearing 24b to be lubricated while preventing the stator 32 from generating excessive heat.

[0064] The oil that flows into the second inlet passage 74 passes through the second orifice 64, and is then sprayed onto the rotor 30 and the rotor passage 36 by the pressure of the supply pump 34. The oil that flows into the rotor passage 36 cools the rotor 30, and then flows down by gravity into the reservoir 42 via the third discharge passage 48. This makes it possible to prevent the rotor 30 from generating excessive heat.

[0065] In FIG. 3, if the determination unit 98 determines that the oil temperature T is equal to or higher than the warm-up completion temperature T2 (NO in step S5), the process proceeds to step S7.

[0066] In step S7, the control unit 94 executes normal operation control. In the normal operation control, the control unit 94 controls the power plant 12 based on the required power generation amount of the rotating electrical machine 18. The control device 88 acquires the required power generation amount from, for example, a higher-level control device (not shown). After this, the process proceeds to step S4.

[0067] In step S4, if the determination unit 98 determines that the control unit 94 has received a stop signal for the power system 10A (YES in step S4), the process proceeds to step S8. In step S8, the control unit 94 stops the power system 10A. Specifically, the control unit 94 stops the driving of each of the supply pump 34 and the recovery pump 52. After this, the process shown in FIG. 3 is completed.

[0068] FIG. 7 is a timing chart of the oil temperature T and the rotation speed of the rotor 30. As shown in FIG. 7, at time t1, the control unit 94 drives the supply pump 34 and the recovery pump 52. At time t1, the oil temperature T is lower than the start-up temperature T1, so the control unit 94 executes the coil temperature increase control. At time t1, the first relief valve 68 and the second relief valve 84 are both opened (see FIG. 4). This prevents oil with a relatively high viscosity from being introduced into the rotor flow path 36 and the lubrication flow path 40. In the coil temperature increase control, the coil 32a is heated by controlling the current supplied to the coil 32a while the rotor 30 is not rotating.

[0069] Specifically, the control unit 94 performs vector control of the rotating electric machine 18. FIG. 8 is an explanatory diagram of the vector control of the rotating electric machine 18. As shown in FIG. 8, the control unit 94 controls the d-axis current and q-axis current supplied to the coil unit 32a. The d-axis current indicates a current that generates reluctance torque and a field-weakening current. The reluctance torque is a torque generated by the stator core 32b (iron core). The field-weakening current is a current that reduces the back electromotive force. The q-axis current is a current that generates magnet torque.

[0070] In the coil temperature increase control, the control unit 94 sets the current supplied to the coil 32a to point P1 on the d-axis. In this case, the q-axis component of the current is 0. Point P1 is the point where the amount of heat generated by the coil 32a is greatest when no rotational torque is generated in the rotor 30. In the coil temperature increase control, the current supplied to the coil 32a is constant. As a result, the oil is heated by the supply pump 34 and the recovery pump 52, and is also heated by the heated coil 32a. That is, as shown in FIG. 7, the oil temperature T rises. Note that in the coil temperature increase control, the rotation speed of the rotor 30 is 0.

[0071] At time t2, when the oil temperature T reaches the startable temperature T1, the control unit 94 starts the gas turbine engine 20 and executes warm-up operation control. At time t2, the first relief valve 68 remains open, while the second relief valve 84 closes (see FIG. 5). This allows the oil, whose viscosity has decreased as the temperature rises, to be guided into the lubrication flow path 40, thereby enabling the bearing 24 to be lubricated by the oil. In the warm-up operation control, the coil 32a is heated by controlling the current supplied to the coil 32a while the rotor 30 is rotating.

[0072] Specifically, as shown in FIG. 8 , the control unit 94 controls the current supplied to the coil unit 32a so that the rotating electrical machine 18 operates at a target operating efficiency (e.g., point P2). The control unit 94 also feedback-controls the current supplied to the coil unit 32a so that the target operating efficiency approaches point P3 as the oil temperature T approaches the warm-up completion temperature T2. The operating efficiency at point P2 is lower than the operating efficiency at point P3. In other words, the rotational torque generated in the rotor 30 at point P2 is equal to the rotational torque generated in the rotor 30 at point P3, but the current at point P2 is greater than the current at point P3. Therefore, the thermal energy generated in the coil unit 32a at point P2 is greater than the thermal energy generated in the coil unit 32a at point P3. This allows the coil unit 32a to be rapidly heated at an early stage of the warm-up operation control when the oil temperature T is relatively low, and the rate of temperature rise in the coil unit 32a to be gradually reduced as the oil temperature T approaches the warm-up completion temperature T2. Therefore, it is possible to prevent the temperature of the coil portion 32a from becoming excessively high after the warm-up operation control is completed. In the warm-up operation control, the control unit 94 controls the gas turbine engine 20 to maintain the rotation speed of the rotor 30 at the first rotation speed N1.

[0073] As shown in Fig. 7, when the oil temperature T reaches the warm-up completion temperature T2 at time t3, the control unit 94 controls the rotating electrical machine 18 based on the required amount of power generation of the rotating electrical machine 18. At time t3, the first relief valve 68 closes (see Fig. 6). This allows oil to be introduced from the second inlet passage 74 to the rotor passage 36, thereby cooling the rotor 30. The control unit 94 increases the amount of power generation of the rotating electrical machine 18 by, for example, controlling the gas turbine engine 20 based on the required amount of power generation to increase the rotational speed of the rotor 30 to a second rotational speed N2.

[0074] According to this embodiment, for example, when the power system 10A is operated in a low-temperature environment, the first relief valve 68 opens, allowing relatively high-viscosity oil to flow into the bypass flow path 66. Because the first pressure loss is smaller than the second pressure loss, most of the oil that flows through the bypass flow path 66 can flow into the stator flow path 38. In this case, the temperature of the oil flowing through the stator flow path 38 can be increased by generating heat in the stator 32, eliminating the need for an additional heating device such as a heater. This makes it possible to efficiently increase the temperature of the oil while minimizing increases in the manufacturing cost and weight of the power system 10A. Therefore, a better power system 10A and a control method for the power system 10A can be provided.

[0075] (Second embodiment) 9 is a schematic diagram of a power system 10B according to a second embodiment of the present invention. In this embodiment, components similar to those of the power system 10A according to the first embodiment described above are given the same reference numerals, and detailed descriptions thereof will be omitted.

[0076] 9, the power system 10B includes an oil supply device 14a instead of the above-described oil supply device 14. Furthermore, the power system 10B does not include the above-described outlet flow path 82 and second relief valve 84.

[0077] The oil supply device 14a has a supply pump 34, a supply flow path 60, a lubrication flow path 100, a first orifice 62, a second orifice 64, a third orifice 102, a bypass flow path 66, and a relief valve 68. The lubrication flow path 100 branches off from a portion upstream of the connecting portion 80 in the supply flow path 60 and guides oil to the bearing 24.

[0078] The lubrication flow path 100 includes a lubrication introduction flow path 100a, a first lubrication flow path 100b, and a second lubrication flow path 100c. The lubrication introduction flow path 100a is connected to the second introduction flow path 74. In this embodiment, the lubrication introduction flow path 100a is connected to the branch portion 72, but this configuration is not limited to this. The first lubrication flow path 100b and the second lubrication flow path 100c branch off from the lubrication introduction flow path 100a. The first lubrication flow path 100b guides oil to the first bearing 24a. The second lubrication flow path 100c guides oil to the second bearing 24b. A third orifice 102 is provided in the lubrication introduction flow path 100a.

[0079] In the power system 10B, the first pressure loss is smaller than the second pressure loss, and the first pressure loss is smaller than the third pressure loss. The first pressure loss includes the pressure loss that occurs when oil flows from the connecting portion 80 to the stator 32 (to just before the stator 32) and the pressure loss that occurs when the oil flows through the stator flow path 38. Note that in this embodiment, the second relief valve 84 described above is not provided, and therefore no pressure loss occurs related to the second relief valve 84. The second pressure loss of the power system 10B is the same as the second pressure loss of the power system 10A described above. The third pressure loss includes the pressure loss that occurs when oil flows from the connecting portion 80 through the lubrication flow path 100 to the bearing portion 24, and the pressure loss that occurs when oil is sprayed onto the first bearing 24a and the second bearing 24b. In this embodiment, since the first orifice 62 and the third orifice 102 are provided, the first pressure loss can be made smaller than the third pressure loss with a simple configuration.

[0080] The control method for power system 10B is the same as the control method for power system 10A described above. In power system 10B, the viscosity of oil is high in a low-temperature environment, so relief valve 68 is opened by oil sent from supply pump 34.

[0081] Figures 10 and 11 are explanatory diagrams of the flow of oil in the power system 10B. Specifically, Figure 10 is an explanatory diagram showing the flow of oil when the relief valve 68 is in an open state. Figure 11 is an explanatory diagram showing the flow of oil when the relief valve 68 is in a closed state. In Figures 10 and 11, for ease of understanding, areas where a large amount of oil flows are indicated by thick lines.

[0082] As shown in FIG. 10 , when the relief valve 68 opens, much of the oil is guided to the second portion 78 (connecting portion 80) of the first introduction passage 70 via the bypass passage 66. As described above, the first pressure loss is smaller than each of the second pressure loss and the third pressure loss, and therefore the oil guided from the bypass passage 66 to the connecting portion 80 does not easily flow toward the branching portion 72. Therefore, much of the oil guided from the bypass passage 66 to the connecting portion 80 flows through the second portion 78 toward the stator passage 38. The oil that has circulated through the stator passage 38 is guided to the reservoir 42. The oil stored in the reservoir 42 is returned to the supply pump 34 by the recovery pump 52 via the circulation passage 54 (gas-liquid separator 56 and tank 58).

[0083] That is, most of the oil discharged from the supply pump 34 circulates through a path that returns the oil to the supply pump 34 via the first portion 76 of the first inlet flow path 70, the relief valve 68, the bypass flow path 66, the second portion 78 of the first inlet flow path 70, the stator flow path 38, the reservoir 42, the recovery pump 52, and the circulation flow path 54. In this case, the oil is heated by the supply pump 34 when it flows through the supply pump 34, and is also heated by the recovery pump 52 when it flows through the recovery pump 52. That is, the oil is heated by the supply pump 34 and the recovery pump 52.

[0084] Furthermore, the control unit 94 executes coil temperature increase control when the oil temperature T is lower than the startable temperature T1. This allows the temperature of the oil flowing through the stator flow path 38 to be increased efficiently. As the oil temperature T increases, the oil viscosity decreases, and the oil pressure also decreases. When the oil temperature T reaches the startable temperature T1, the relief valve 68 closes.

[0085] 11 , the oil sent from the supply pump 34 passes through the relief valve 68, and then flows separately to the second portion 78 of the first inlet passage 70, the second inlet passage 74, and the lubricant inlet passage 100a. The oil that flows into the second portion 78 passes through the first orifice 62, and then flows through the stator passage 38, thereby cooling the stator 32. The oil that flows through the stator passage 38 is led to the reservoir 42.

[0086] The oil that flows into the second inlet flow path 74 passes through the second orifice 64 and is then sprayed onto the rotor 30 by the pressure of the supply pump 34. The oil that flows into the rotor flow path 36 cools the rotor 30, and then flows down by gravity into the reservoir 42 via the third discharge flow path 48. This makes it possible to prevent the rotor 30 from generating excessive heat.

[0087] The oil introduced into the lubrication introduction passage 100a passes through the third orifice 102, and then splits into the first lubrication passage 100b and the second lubrication passage 100c. The oil introduced into the first lubrication passage 100b is sprayed onto the first bearing 24a by the pressure of the supply pump 34. The oil that has flowed through the first bearing 24a flows into the reservoir 42 via the first discharge passage 44. The oil introduced into the second lubrication passage 100c is sprayed onto the second bearing 24b by the pressure of the supply pump 34. The oil that has flowed through the second bearing 24b flows into the reservoir 42 via the second discharge passage 46. This allows the first bearing 24a and the second bearing 24b to be lubricated.

[0088] Furthermore, when the oil temperature T is lower than the warm-up completion temperature T2, the control unit 94 executes warm-up operation control. As a result, the rotating electrical machine 18 operates at a low efficiency, so that the temperature T of the oil circulating through the coil portion 32a can be efficiently raised. When the oil temperature T becomes equal to or higher than the warm-up completion temperature T2, the control unit 94 executes normal operation control.

[0089] According to this embodiment, the same effects as those of the power system 10A according to the first embodiment described above are achieved.

[0090] This embodiment is not limited to the above-described configuration. The power system 10A may be provided with electromagnetic valves (on-off valves) instead of the relief valves 68 and 84. In this case, the control device 88 can control the electromagnetic valves to open and close the bypass flow path 66. The same applies to the power system 10B.

[0091] In power systems 10A and 10B, supply pump 34 and recovery pump 52 may be driven by the rotational driving force of rotor 30 of rotating electric machine 18. In power system 10A, at least one of first orifice 62 and second orifice 64 may be omitted. In power system 10B, at least one of first orifice 62, second orifice 64, and third orifice 102 may be omitted.

[0092] The following additional notes are further disclosed regarding the above embodiment.

[0093] (Appendix 1) A power system (10A, 10B) of the present disclosure includes a rotating electric machine (18) having a stator (32) and a rotor (30), an oil supply device (14, 14a) having a supply pump (34) that sends oil, a stator flow path (38) for circulating the oil to the stator, a rotor flow path (36) for circulating the oil to the rotor, and an oil recovery device (16) for returning the oil that has flowed through the stator flow path and the rotor flow path to the oil supply device, and the oil supply device includes a supply flow path (60) having a first introduction flow path (70) that guides the oil sent from the supply pump to the stator, and a second introduction flow path (74) that branches from the first introduction flow path via a branch portion (72) and guides the oil to the rotor, and a second introduction flow path (74) that bypasses the branch portion. the first pressure loss includes a pressure loss that occurs when the oil flows from a connecting portion (80) between the bypass flow path and the second portion to reach the stator, and a pressure loss that occurs when the oil flows through the stator flow path, and the second pressure loss is a pressure loss that occurs when the oil flows from the connecting portion through the branch portion and the second introduction flow path to reach the rotor.

[0094] With this configuration, for example, when the power system is operated in a low-temperature environment, the on-off valve can be opened to allow relatively high-viscosity oil to flow into the bypass flow path. Because the first pressure loss is smaller than the second pressure loss, most of the oil that flows through the bypass flow path can be directed into the stator flow path. In this case, the oil flowing through the oil flow path can be heated by generating heat from the stator, eliminating the need for an additional heating device such as a heater. This allows the oil to be heated efficiently while minimizing increases in the manufacturing cost and weight of the power system. Therefore, a better power system can be provided.

[0095] (Appendix 2) In the power system described in Supplementary Note 1, the on-off valve may be a relief valve that is pushed open by the oil when the pressure of the oil introduced to the on-off valve reaches a predetermined upper pressure limit.

[0096] According to this configuration, the oil sent from the supply pump can be circulated through the bypass flow passage in a low-temperature environment with a simple configuration.

[0097] (Appendix 3) In the power system described in Appendix 1 or 2, a first orifice (62) may be provided in the second portion of the first inlet passage, a second orifice (64) may be provided in the second inlet passage, and the connecting portion may be located between the first orifice and the stator in the second portion.

[0098] With this simple configuration, the first pressure loss can be made smaller than the second pressure loss. Also, when the on-off valve is closed, the flow rates of oil flowing through the stator flow passage and the rotor flow passage can be set by the first orifice and the second orifice.

[0099] (Appendix 4) In the power system according to any one of Supplementary Notes 1 to 3, the rotating electric machine has a bearing portion (24) that rotatably supports the rotor, and further includes a lubrication flow path (40) for spraying the oil that has flowed through the stator flow path onto the bearing portion, an outlet flow path (82) that is provided to bypass the lubrication flow path and the bearing portion and guides the oil that has flowed through the stator to the oil recovery device, and an outlet opening / closing valve (84) that opens and closes the outlet flow path, wherein when the outlet opening / closing valve is open, the first pressure loss further includes a pressure loss that occurs when the oil flows through the outlet opening / closing valve, and when the outlet opening / closing valve is closed, the first pressure loss further includes a pressure loss that occurs when the oil is sprayed onto the bearing portion.

[0100] With this configuration, the bearing portion can be lubricated by the oil that has flowed through the stator.

[0101] (Appendix 5) In the power system described in Appendix 4, the outlet on-off valve may be a relief valve that is pushed open by the oil when the pressure of the oil introduced to the outlet on-off valve reaches a predetermined upper pressure limit.

[0102] According to this configuration, in a low-temperature environment, the oil that has flowed through the stator flow passage can be guided to the outlet flow passage with a simple configuration.

[0103] (Appendix 6) In a power system according to any one of Appendices 1 to 3, the rotating electric machine has a bearing portion that rotatably supports the rotor, and the power system further has a lubrication flow path (100) that branches off from a portion upstream of the connecting portion in the supply flow path and sprays the oil onto the bearing portion, and the first pressure loss may be smaller than a third pressure loss, and the third pressure loss may include a pressure loss that occurs when the oil flows from the connecting portion through the lubrication flow path to reach the bearing portion, and a pressure loss that occurs when the oil is sprayed onto the bearing portion.

[0104] With this configuration, since the first pressure loss is smaller than the third pressure loss, most of the oil that has flowed through the bypass passage can be directed to the stator passage. Also, when the on-off valve is closed, the bearing can be lubricated by the oil that has flowed through the lubrication passage.

[0105] (Appendix 7) In the power system described in Appendix 6, a first orifice may be provided in the second portion of the first inlet passage, a second orifice may be provided in the second inlet passage, and a third orifice (102) may be provided in the lubrication passage, and the connecting portion may be located between the first orifice and the stator in the second portion.

[0106] With this simple configuration, the first pressure loss can be made smaller than the third pressure loss. Furthermore, when the on-off valve is closed, the flow rates of oil flowing through the stator flow path, the rotor flow path, and the bearing can be set by the first orifice, the second orifice, and the third orifice.

[0107] (Appendix 8) The power system according to any one of Supplementary Notes 1 to 7 may further include an engine (20) having a shaft (20a) that rotates integrally with the rotor.

[0108] With this configuration, the rotating electric machine can function as a generator by rotating the rotor with the engine, and can also function as a motor for starting the engine by rotating the shaft of the engine with the rotating electric machine.

[0109] (Appendix 9) The power system described in Appendix 8 may further include a control unit (94) that, when the oil temperature (T) is lower than a predetermined startable temperature (T1), controls a current supplied to a coil portion (32a) of the stator to perform coil portion temperature increase control to cause the coil portion to generate heat without rotating the rotor.

[0110] With this configuration, even if the oil temperature is lower than the temperature at which the engine can be started, the coil portion can be made to generate heat, so that the oil flowing through the stator flow path can be heated by the stator.

[0111] (Appendix 10) In the power system described in Supplementary Note 9, the control unit may rotate the rotor when the temperature of the oil reaches the start-up temperature.

[0112] With this configuration, when the oil temperature reaches a temperature at which the engine can be started, the rotating electrical machine rotates the engine shaft, thereby starting the engine.

[0113] (Appendix 11) In the power system described in Appendix 10, when the temperature of the oil is equal to or higher than the start-up temperature and lower than a predetermined warm-up completion temperature (T2), the control unit may execute warm-up operation control to cause the rotating electric machine to operate at low efficiency, thereby causing the coil unit to generate heat.

[0114] According to this configuration, the rotating electrical machine is operated at low efficiency during warm-up operation control, so that the temperature of the oil flowing through the stator flow passage can be raised quickly.

[0115] (Appendix 12) In the power system described in Supplementary Note 11, the control unit may increase the operating efficiency of the rotating electric machine as the temperature of the oil approaches the warm-up completion temperature.

[0116] With this configuration, it is possible to prevent the coil portion from becoming excessively hot after the oil temperature has reached the warm-up completion temperature.

[0117] (Appendix 13) The power system control method of the present disclosure is a power system control method for controlling the power system described in Appendix 8, and includes a coil portion temperature rise control step in which, when the oil temperature is lower than a predetermined startable temperature, a control unit controls the current supplied to the coil portion of the stator to cause the coil portion to generate heat without rotating the rotor.

[0118] Such a method may provide a better method of controlling the power system.

[0119] (Appendix 14) In the power system control method described in Supplementary Note 13, the control unit may start the engine when the temperature of the oil reaches the startable temperature.

[0120] (Appendix 15) The power system control method described in Appendix 13 or 14 may further include a warm-up operation control step in which, when the temperature of the oil is equal to or higher than the start-up temperature and lower than a predetermined warm-up completion temperature, the control unit operates the rotating electric machine at low efficiency to generate heat in the coil section.

[0121] (Appendix 16) In the power system control method according to Supplementary Note 15, the control unit may increase the operating efficiency of the rotating electric machine as the temperature of the oil approaches the warm-up completion temperature.

[0122] Although the present disclosure has been described in detail, the present disclosure is not limited to the individual embodiments described above. Various additions, substitutions, modifications, partial deletions, etc. are possible in these embodiments without departing from the gist of the present disclosure or the spirit of the present disclosure derived from the content of the claims and their equivalents. These embodiments can also be implemented in combination. For example, in the above-described embodiments, the order of each operation and the order of each process are shown as examples and are not limited to these. The same applies when numerical values or mathematical expressions are used in the description of the above-described embodiments. [Explanation of symbols]

[0123] 10A, 10B... Power system 14, 14a... Oil supply device 16...Oil recovery device 18...Rotating electric machine 20...Gas turbine engine (engine) 20a...Shaft 24...bearing portion 30...rotor 32... Stator 32a... Coil section 34...Supply pump 36...Rotor flow path 38... Stator passage 40... Lubrication passage 60...supply flow path 62...first orifice 64... Second orifice 66... Bypass flow path 68...Relief valve (opening / closing valve) 70...First introduction flow path 72... Branching portion 74... Second introduction flow path 76...1st part 78...2nd part 80...connecting portion 82...outlet flow path 84...Relief valve (outlet opening / closing valve) 94...Control section 100... Lubrication passage 102... Third orifice T1…Starting temperature T2…Warm-up completion temperature

Claims

1. a rotating electric machine having a stator and a rotor; an oil supply device having a supply pump for supplying oil; a stator flow path for circulating the oil through the stator; a rotor flow path for circulating the oil through the rotor; an oil recovery device for returning the oil that has flowed through the stator flow path and the rotor flow path to the oil supply device; Equipped with The oil supply device is a supply flow path including a first inlet flow path that guides the oil sent from the supply pump to the stator, and a second inlet flow path that branches off from the first inlet flow path via a branch portion and guides the oil to the rotor; a bypass flow path connecting a first portion, which is a portion of the first introduction flow path upstream of the branch portion, and a second portion, which is a portion of the first introduction flow path downstream of the branch portion, so as to bypass the branch portion; an on-off valve for opening and closing the bypass flow path; and The first pressure loss is formed to be smaller than the second pressure loss, the first pressure loss includes a pressure loss that occurs when the oil flows from a connection portion between the bypass flow path and the second portion to the stator, and a pressure loss that occurs when the oil flows through the stator flow path, The second pressure loss is a pressure loss that occurs when the oil flows from the connecting portion through the branch portion and the second inlet flow path to reach the rotor.

2. 10. The power system of claim 1, The on-off valve is a relief valve that opens when pushed by the oil when the pressure of the oil introduced to the on-off valve reaches a predetermined upper pressure limit.

3. 10. The power system of claim 1, a first orifice is provided in the second portion of the first introduction flow path, a second orifice is provided in the second introduction flow path, The coupling portion is located between the first orifice and the stator at the second location.

4. 10. The power system of claim 1, the rotating electric machine has a bearing portion that rotatably supports the rotor, a lubrication flow path for spraying the oil that has flowed through the stator flow path onto the bearing portion; an outlet flow path that is provided to bypass the lubrication flow path and the bearing portion and that guides the oil that has flowed through the stator to the oil recovery device; an outlet on-off valve that opens and closes the outlet flow path; Furthermore, when the outlet on-off valve is open, the first pressure loss further includes a pressure loss that occurs when the oil flows through the outlet on-off valve, When the outlet on-off valve is closed, the first pressure loss further includes a pressure loss that occurs when the oil is sprayed onto the bearing portion.

5. 5. The power system of claim 4, The power system, wherein the outlet on-off valve is a relief valve that opens when pushed by the oil when the pressure of the oil introduced to the outlet on-off valve reaches a predetermined upper pressure limit value.

6. 10. The power system of claim 1, the rotating electric machine has a bearing portion that rotatably supports the rotor, the power system further includes a lubrication flow path that branches off from a portion of the supply flow path upstream of the connecting portion and sprays the oil onto the bearing portion; the first pressure loss is smaller than the third pressure loss; The third pressure loss includes a pressure loss that occurs when the oil flows from the connecting portion through the lubrication flow path to reach the bearing portion, and a pressure loss that occurs when the oil is sprayed onto the bearing portion.

7. 7. The power system of claim 6, a first orifice is provided in the second portion of the first introduction flow path, a second orifice is provided in the second introduction flow path, The lubrication passage is provided with a third orifice, The coupling portion is located between the first orifice and the stator at the second location.

8. A power system according to any one of claims 1 to 7, A power system comprising an engine having a shaft that rotates integrally with the rotor.

9. 9. The power system of claim 8, A power system comprising a control unit that, when the temperature of the oil is lower than a predetermined startable temperature, controls the current supplied to the coil unit of the stator to perform coil unit temperature increase control, causing the coil unit to generate heat without rotating the rotor.

10. 10. The power system of claim 9, The control unit rotates the rotor when the temperature of the oil reaches the start-up temperature.

11. 11. The power system of claim 10, When the temperature of the oil is equal to or higher than the start-up temperature and lower than a predetermined warm-up completion temperature, the control unit executes warm-up operation control to generate heat in the coil unit by operating the rotating electric machine at low efficiency.

12. 12. The power system of claim 11, The control unit increases the operating efficiency of the rotating electric machine as the temperature of the oil approaches the warm-up completion temperature.

13. A method for controlling a power system according to claim 8, comprising: A power system control method comprising a coil temperature rise control step in which, when the temperature of the oil is lower than a predetermined startable temperature, a control unit controls the current supplied to a coil unit of the stator to cause the coil unit to generate heat without rotating the rotor.

14. 14. A method for controlling a power system according to claim 13, comprising: The control method for a power system, wherein the control unit starts the engine when the temperature of the oil reaches the startable temperature.

15. 14. A method for controlling a power system according to claim 13, comprising: A power system control method comprising a warm-up operation control step in which, when the temperature of the oil is equal to or higher than the start-up temperature and lower than a predetermined warm-up completion temperature, the control unit operates the rotating electric machine at low efficiency to generate heat in the coil section.

16. 16. A method for controlling a power system according to claim 15, comprising: The control unit increases the operating efficiency of the rotating electric machine as the temperature of the oil approaches the warm-up completion temperature.

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