JP6774249B2 - Thermoelectric generation system - Google Patents

Description

The present invention relates to a thermoelectric power generation system.

Conventionally, the Rankine cycle that uses heat to generate mechanical energy is known. For example, the Rankine cycle applied to a vehicle uses the waste heat of the engine generated in the vehicle to generate mechanical energy. Specifically, the Rankine cycle includes a flow path in which a heated working medium circulates, a Rankine cycle pump provided in the flow path for circulating the working medium, and an expansion of the working medium provided in the flow path. Includes an inflator that produces rotational energy. Further, by connecting a generator to the expander, it is possible to generate electricity using the rotational energy generated by the expander. In this way, the thermoelectric power generation system including the Rankine cycle and the generator realizes thermoelectric power generation, which is power generation using heat. In the field of such a thermoelectric power generation system, a technique of connecting a generator to both a Rankine cycle pump and an expander has been proposed in order to reduce the size of the device.

For example, Patent Document 1 describes a heat exchanger that heats a working fluid by waste heat of a vehicle in order to provide a compact and cost-reduced vehicle waste heat recovery system without lowering the waste heat recovery efficiency. A Rankine cycle having an expander that expands the working fluid heated by the heat exchanger, a capacitor that cools the working fluid expanded by the expander, and a pump that circulates the working fluid cooled by the condenser. In a vehicle exhaust heat recovery system including a pump and a load machine connected to the expander, the load machine drives the pump as a motor and uses the power of the expander as a generator to generate power. The technology to be used is disclosed.

JP-A-2006-242174

In this way, by connecting the generator to both the Rankine cycle pump and the expander, the device can be miniaturized as compared with the case where the Rankine cycle pump is driven by a dedicated electric motor. .. However, in the field of thermoelectric power generation systems, it is considered desirable to miniaturize the equipment more effectively.

When the generator is connected to both the Rankine cycle pump and the inflator, the rotation shafts of the Rankine cycle pump and the inflator may be configured to rotate integrally. In such a case, it is difficult to adjust the difference in the rotational speeds of the Rankine cycle pump and the expander. Therefore, the flow rate of the working medium discharged from each of the Rankine cycle pump and the expander to the downstream side (hereinafter referred to as the discharge flow rate). Also referred to as), it can be difficult to adjust the difference.

When the difference between the discharge flow rates of the Rankine cycle pump and the inflator is fixed, the volume of the working medium of the gas phase supplied to the inflator (hereinafter, also referred to as steam volume flow rate) becomes substantially constant. In such a case, according to the ideal gas law, the temperature (hereinafter, also referred to as steam temperature) and pressure (hereinafter, also referred to as vapor pressure) of the working medium of the gas phase supplied to the expander are determined. Has a correlation. Therefore, as the steam temperature rises, the vapor pressure may become excessively high, which may damage the expander. On the other hand, as the steam temperature decreases, the vapor pressure can become excessively low, so that the amount of power generation can decrease as the rotational energy generated by the expander decreases. Therefore, it becomes necessary to adjust the difference in the discharge flow rates of the Rankine cycle pump and the expander according to the steam temperature.

Here, when the generator is connected to both the Rankine cycle pump and the inflator, the Rankine cycle pump and the inflator are provided with a mechanism for adjusting the discharge amount per rotation of the Rankine cycle pump and the inflator. It is conceivable that the difference in discharge flow rate can be adjusted. However, since such a mechanism has a relatively large number of parts, it may be difficult to miniaturize the device more effectively.

Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a new and improved thermoelectric power generation system capable of more effectively miniaturizing an apparatus. To do.

In order to solve the above problems, according to a certain viewpoint of the present invention, a flow path through which the heated working medium circulates, a Rankin cycle pump provided in the flow path for circulating the working medium, and a flow path provided in the flow path. A Rankin cycle including an expander that expands the working medium to generate rotational energy, and a driving force that can generate power using the rotational energy generated by the expander and that drives the Rankin cycle pump. A motor generator unit capable of outputting and a control device are provided, and the motor generator unit is connected to the rotation shaft of the Rankin cycle pump and is arranged in the circumferential direction so that a plurality of permanent magnets have alternately different polarities. A plurality of soft magnetic materials were arranged in the circumferential direction so as to face each other on the outer peripheral side of the first rotor with a gap in between the first rotor and the rotating shaft of the expander. a second rotor, wherein disposed opposite via a gap on the outer peripheral side of the second rotor, seen including a stator having a plurality of armatures are arranged in the circumferential direction, and the control device, By controlling the frequencies of the AC currents flowing through the plurality of armatures of the stator, the rotational speed of the rotating magnetic field generated by the stator is controlled, and by controlling the rotational speed of the rotating magnetic field, the first The first rotor and the second rotor control the rotational speeds of the first rotor and the second rotor, and according to the steam temperature, which is the temperature of the working medium of the gas phase supplied to the expander. A thermal power generation system is provided that controls the rotational speed ratio, which is the ratio of the rotational speeds of .

When the steam temperature is higher than the boiling point of the working medium at a predetermined pressure, the control device may increase the rotation speed ratio as the steam temperature increases.

When the steam temperature is equal to or lower than the boiling point of the working medium at the predetermined pressure, the control device may increase the rotation speed ratio as the steam temperature decreases.

In order to solve the above problems, according to another aspect of the present invention, the flow path through which the heated working medium circulates, the Rankin cycle pump provided in the flow path and circulating the working medium, and the flow path. A Rankin cycle including an expander provided to expand the working medium to generate rotational energy, and a driving force capable of generating power using the rotational energy generated by the expander and for driving the Rankin cycle pump. It is a thermal power generation system including a motor generator unit capable of outputting the above, and a control device. The motor generator unit is connected to the rotation shaft of the Rankin cycle pump, and a plurality of permanent magnets have alternately different polarities. The first rotor arranged in the circumferential direction and the first rotor are provided so as to face each other on the outer peripheral side of the first rotor via a gap, and are connected to the rotation shaft of the expander to form a plurality of soft magnetic materials. Includes a second rotor disposed in the circumferential direction and a stator provided on the outer peripheral side of the second rotor so as to face each other with a gap in between and a plurality of armors arranged in the circumferential direction. The control device controls the rotation speed of the rotating magnetic field generated by the stator by controlling the frequencies of the alternating currents flowing through the plurality of armatures of the stator, and controls the rotation speed of the rotating magnetic field. By controlling the rotational speeds of the first rotor and the second rotor, when the thermal power generation system is started, the rotational speed of the first rotor is adjusted by the operating medium of the Rankin cycle. the greater the degree of heating, Ru is increased to a high rotational speed, thermal power generation system is provided.

As described above, according to the present invention, the device can be miniaturized more effectively.

It is a schematic diagram which shows an example of the schematic structure of the charging system of the vehicle which concerns on embodiment of this invention. It is explanatory drawing which shows an example of the structure of the motor generator part and the surroundings which concerns on this embodiment. It is sectional drawing which shows an example of the structure of the motor generator part which concerns on the same embodiment. It is explanatory drawing which shows an example of the vapor pressure curve of a working medium. It is explanatory drawing for demonstrating an example of the relationship between a steam temperature and a target vapor pressure. It is explanatory drawing which shows an example of the map which shows the relationship between a steam temperature and a target rotation speed ratio. It is a flowchart which shows an example of the flow of the process performed by the control device which concerns on this embodiment. It is a collinear diagram which shows an example of the behavior of a motor generator part at the time of starting a thermoelectric generation system. It is a collinear diagram which shows an example of the behavior of a motor generator part after a thermoelectric generation system is started. It is a collinear diagram which shows an example of a motor generator part at the time of stopping a thermoelectric generation system.

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the present specification and the drawings, components having substantially the same functional configuration are designated by the same reference numerals, so that duplicate description will be omitted.

<1. Charging system configuration>
First, with reference to FIG. 1, a schematic configuration of a vehicle charging system 10 according to an embodiment of the present invention will be described. FIG. 1 is a schematic view showing an example of a schematic configuration of the charging system 10 according to the present embodiment. As shown in FIG. 1, the charging system 10 mainly includes an engine 11, a driving force transmission system 51, a driving wheel 21, a high-voltage battery 31, a traveling motor generator 41, and a motor generator unit 300. , Rankine cycle 70, and control device 100. Further, the charging system 10 includes at least the Rankine cycle 70 and the motor generator unit 300 to form the thermoelectric power generation system 90.

The engine 11 starts or stops according to the running state of the vehicle. For example, the engine 11 starts or stops according to a required torque while the vehicle is running. The driving force generated by the operation of the engine 11 is transmitted to the driving wheels 21 via the driving force transmission system 51. The cylinder block and cylinder head of the engine 11 are provided with a cooling water flow path 13 through which cooling water circulates in order to cool the engine 11. The waste heat of the engine 11 is recovered by the cooling water circulating in the cooling water flow path 13. The cooling water flow path 13 is connected to the heat exchanger 74 of the Rankine cycle 70 outside the engine 11, and exchanges heat with the operating medium of the Rankine cycle 70 in the heat exchanger 74.

The high voltage battery 31 is a high voltage (for example, 200V) power supply source. Specifically, the high-voltage battery 31 supplies electric power to the motor generator unit 300 and the traveling motor generator 41 that outputs the driving force of the vehicle, and also to the low-voltage battery that supplies electric power to various devices in the vehicle. Supply power. The high-voltage battery 31 stores the electric power generated by the motor generator unit 300 and the electric power generated by the traveling motor generator 41, respectively.

The traveling motor generator 41 has a function as a driving motor that generates a driving force for the vehicle. Further, the traveling motor generator 41 has a function as a braking power generation generator that generates electricity by using the kinetic energy of the vehicle when the vehicle is decelerated and stores the generated electric power in the high voltage battery 31. The traveling motor generator 41 includes, for example, a three-phase AC motor and an inverter device, and is electrically connected to the high-voltage battery 31 via the inverter device. The inverter device also has a function as a converter device.

When the traveling motor generator 41 functions as a drive motor, the DC power supplied from the high-voltage battery 31 is converted into AC power by the inverter device and supplied to the motor. As a result, the driving force is generated by the motor. The driving force generated by the traveling motor generator 41 is transmitted to the driving wheels 21 via the driving force transmission system 51. The control device 100 controls the generation of the driving force by the traveling motor generator 41 by controlling the inverter device.

When the traveling motor generator 41 functions as a braking power generator when the vehicle is decelerating, the control device 100 controls the inverter device, so that the motor generates electricity using the rotational energy of the drive wheels 21 to generate electricity. The generated AC power is converted into DC power by the inverter device and stored in the high voltage battery 31. As a result, resistance is given to the rotation of the drive wheels 21, and braking force is generated. The control device 100 controls the power generation by the traveling motor generator 41 by controlling the inverter device. Specifically, the control device 100 controls the output voltage of the traveling motor generator 41 via the inverter device.

The Rankine cycle 70 uses the waste heat of the vehicle engine 11 to generate mechanical energy. As shown in FIG. 1, the Rankine cycle 70 includes a working medium flow path 71, a Rankine cycle pump 73, a heat exchanger 74, an expander 75, a condenser 77, and a tank 79.

The working medium flow path 71 is a flow path through which the heated working medium circulates. As the working medium, for example, water, chlorofluorocarbons, or alcohol can be applied.

The Rankine cycle pump 73 is a pump that sucks up the working medium stored in the tank 79 and circulates the working medium in the working medium flow path 71. The Rankine cycle pump 73 is connected to the motor generator unit 300. Specifically, the rotating shaft 73a of the Rankine cycle pump 73 is connected to the first rotor of the motor generator unit 300, which will be described later. Further, the Rankine cycle pump 73 is driven by the motor generator unit 300. Specifically, a driving force is generated by the motor generator unit 300 based on an operation instruction from the control device 100, and the driving force is output to the rotation shaft 73a of the Rankine cycle pump 73, so that the Rankine cycle pump 73 The drive is configured to be controlled.

The working medium flow path 71 and the cooling water flow path 13 are connected to the heat exchanger 74. In the heat exchanger 74, heat exchange is performed between the working medium and the cooling water. As a result, the working medium is heated and vaporized by the cooling water having the waste heat of the engine 11.

The expander 75 expands the working medium vaporized by the heat exchanger 74 to generate rotational energy. Specifically, in the expander 75, the working medium is sucked into the expansion chamber, the working medium expands in the expansion chamber, and the impeller receives the flow of the working medium, so that the rotating shaft 75a connected to the impeller 75a The energy of the rotational movement of is generated. The inflator 75 is connected to the motor generator unit 300. Specifically, the rotating shaft 75a of the expander 75 is connected to the second rotor of the motor generator unit 300, which will be described later. Further, the rotational energy generated by the expander 75 is transmitted from the rotary shaft 75a to the motor generator unit 300.

The condenser 77 condenses the working medium of the gas phase that has passed through the expander 75. Specifically, the condenser 77 cools the working medium by releasing the heat of the working medium to the outside of the working medium flow path 71. As a result, the working medium of the gas phase is condensed. The working medium condensed by the condenser 77 is stored in the tank 79. The working medium stored in the tank 79 is sucked up again by the Rankine cycle pump 73. In this way, the working medium circulates in the Rankine cycle 70 by sequentially flowing through the Rankine cycle pump 73, the heat exchanger 74, the expander 75, the condenser 77, and the tank 79.

The motor generator unit 300 can generate electricity by using the rotational energy generated by the expander 75. Further, the motor generator unit 300 can output a driving force for driving the Rankine cycle pump 73. The motor generator unit 300 includes, for example, an inverter device, and is electrically connected to the high voltage battery 31 via the inverter device. The inverter device also has a function as a converter device.

When the motor generator unit 300 functions as a thermal power generator that generates electric power using the rotational energy generated by the expander 75, the inverter device is controlled by the control device 100 to generate electric power and generate electric power. AC power (specifically, three-phase AC power) is converted into DC power by the inverter device and stored in the high-voltage battery 31. The control device 100 controls the power generation by the motor generator unit 300 by controlling the inverter device. Specifically, the control device 100 controls the output voltage of the motor generator unit 300 via the inverter device.

When the motor generator unit 300 functions as a drive motor that outputs a driving force for driving the Rankin cycle pump 73, the DC power supplied from the high-voltage battery 31 is AC power (specifically, three) by the inverter device. It is converted into (phase AC power) and supplied to the motor generator unit 300. As a result, the driving force is generated by the motor generator unit 300. The driving force generated by the motor generator unit 300 is output to the rotating shaft 73a of the Rankine cycle pump 73. Thereby, the Rankine cycle pump 73 is driven. In the present embodiment, the driving force generated by the motor generator unit 300 can also be output to the rotating shaft 75a of the expander 75. Thereby, the rotation speed of the inflator 75 can be controlled. The control device 100 controls the generation of the driving force by the motor generator unit 300 by controlling the inverter device.

The motor generator unit 300 according to the present embodiment includes a first rotor connected to the rotating shaft 73a of the Rankin cycle pump 73, a second rotor connected to the rotating shaft 75a of the expander 75, a stator, and the like. including. The motor generator unit 300 is configured to generate a rotating magnetic field when an alternating current flows through the stator. Further, in the motor generator unit 300, the rotation speeds of the first rotor, the second rotor, and the rotating magnetic field have a predetermined relationship. As a result, it is possible to adjust the difference in the discharge flow rates of the Rankine cycle pump 73 and the expander 75, so that the device can be miniaturized more effectively. The details of the motor generator unit 300 will be described later.

Further, in the motor generator unit 300, the above-mentioned inverter device is specifically electrically connected to the stator. Therefore, the stator is electrically connected to the high voltage battery 31 via the inverter device. In the motor generator unit 300, the control device 100 may control the frequency of the alternating current flowing through the stator to control the rotational speed of the rotating magnetic field generated by the stator. As a result, as will be described later, the rotation speeds of the first rotor and the second rotor in the motor generator unit 300 are controlled.

As described above, in the present embodiment, the thermoelectric power generation system 90 capable of performing thermoelectric power generation, which is power generation using heat, includes at least the Rankine cycle 70 and the motor generator unit 300.

Further, the charging system 10 may be provided with a pump rotation speed sensor 201, an inflator rotation speed sensor 203, a steam temperature sensor 205, and a water temperature sensor 207.

The pump rotation speed sensor 201 detects the rotation speed of the Rankine cycle pump 73 and outputs the detection result. The pump rotation speed sensor 201 is provided, for example, in the vicinity of the rotation shaft 73a of the Rankine cycle pump 73.

The inflator rotation speed sensor 203 detects the rotation speed of the inflator 75 and outputs the detection result. The inflator rotation speed sensor 203 is provided, for example, in the vicinity of the rotation shaft 75a of the inflator 75.

The steam temperature sensor 205 detects the steam temperature, which is the temperature of the working medium supplied to the expander 75, and outputs the detection result. The steam temperature sensor 205 is provided, for example, on the upstream side of the expander 75 of the working medium flow path 71 of the Rankine cycle 70.

The water temperature sensor 207 detects the temperature of the cooling water of the engine 11 and outputs the detection result. The water temperature sensor 207 is provided, for example, in the vicinity of the engine 11.

The control device 100 includes a CPU (Central Processing Unit) which is an arithmetic processing unit, a ROM (Read Only Memory) which is a storage element for storing programs and arithmetic parameters used by the CPU, a program used in executing the CPU, and a program thereof. It is composed of a RAM (Random Access Memory) or the like, which is a storage element that temporarily stores parameters and the like that change as appropriate during execution.

The control device 100 controls the operation of each device constituting the charging system 10. For example, the control device 100 issues an operation command to each actuator to be controlled by using an electric signal. Specifically, the control device 100 controls the power generation and drive of the motor generator unit 300 and the power generation and drive of the traveling motor generator 41. More specifically, the control device 100 controls the rotation speed of the rotating magnetic field generated by the stator by controlling the frequency of the alternating current flowing through the stator of the motor generator unit 300. Further, the control device 100 receives the information output from each sensor. The control device 100 may communicate with each sensor by using CAN (Control Area Network) communication. The function of the control device 100 according to the present embodiment may be divided by a plurality of control devices, and in that case, the plurality of control devices may be connected to each other via a communication bus such as CAN. .. The details of the control device 100 will be described later.

<2. Motor generator>
Subsequently, the motor generator unit 300 according to the present embodiment will be described with reference to FIGS. 2 and 3. Specifically, after explaining the configuration of the motor generator unit 300, the relationship between the rotation speeds of the first rotor, the second rotor, and the rotating magnetic field in the motor generator unit 300 will be described.

(Constitution)
First, the configuration of the motor generator unit 300 according to the present embodiment will be described with reference to FIGS. 2 and 3. FIG. 2 is an explanatory diagram showing an example of the configuration of the motor generator unit 300 and its surroundings according to the present embodiment. FIG. 3 is a cross-sectional view showing an example of the configuration of the motor generator unit 300 according to the present embodiment. Specifically, FIG. 3 is a cross-sectional view of the AA cross section shown in FIG. 2 orthogonal to the central axis of the motor generator unit 300.

As shown in FIGS. 2 and 3, the motor generator unit 300 has a first rotor 310, a second rotor 320 provided on the outer peripheral side of the first rotor 310 facing each other via a gap, and a second rotor 320. Includes a stator 330, which is provided on the outer peripheral side of the two rotor 320 so as to face each other via a gap. Further, the first rotor 310 is connected to the rotation shaft 73a of the Rankine cycle pump 73. Thereby, the rotating shaft 73a of the Rankine cycle pump 73 can be made rotatable in synchronization with the first rotor 310. Further, the second rotor 320 is connected to the rotating shaft 75a of the expander 75. Thereby, the rotating shaft 75a of the expander 75 can be made rotatable in synchronization with the second rotor 320. The second rotor 320 has a substantially cylindrical shape, for example, as will be described later. The second rotor 320 may be connected to the rotating shaft 75a of the expander 75 via a connecting portion 340 provided on the one end side so as to close the opening on the one end side. The connection portion 340 has, for example, a disk shape coaxial with the central axis of the second rotor 320. The connecting portion 340 may be formed integrally with the second rotor 320, or may be formed as a separate body.

Specifically, the first rotor and the second rotor of the motor generator unit 300 are rotatable around the central axis of the stator 330. Further, the central axis of the stator 330, the rotating shaft 73a of the Rankine cycle pump 73, and the rotating shaft 75a of the inflator 75 may be located coaxially. Further, the first rotor 310 and the second rotor 320 may be composed of a part of the same members as the rotary shaft 73a of the Rankin cycle pump 73 and the rotary shaft 75a of the expander 75, respectively, and the Rankin cycle pump It may be composed of a member different from each of the rotating shaft 73a of 73 and the rotating shaft 75a of the expander 75.

In the following, power is directly transmitted between the first rotor 310 and the rotation shaft 73a of the Rankin cycle pump 73, and the rotation speeds of the rotation shaft 73a of the first rotor 310 and the Rankin cycle pump 73 match. An example of this will be mainly described. Further, in the case where power is directly transmitted between the second rotor 320 and the rotating shaft 75a of the expander 75, and the rotation speeds of the second rotor 320 and the rotating shaft 75a of the expander 75 match. , Mainly explained. Further, in the following, the rotation speeds of the rotation shaft 73a of the Rankin cycle pump 73 and the rotation shaft 75a of the expander 75 are also simply referred to as the rotation speeds of the Rankin cycle pump 73 and the expander 75, respectively.

The first rotor 310 or the second rotor 320 may be connected to the rotary shaft 73a of the Rankin cycle pump 73 or the rotary shaft 75a of the expander 75, respectively, via a speed reducer such as a gear. In that case, the rotation speed of the rotation shaft 73a of the first rotor 310 and the Rankin cycle pump 73, or the rotation speed of the rotation shaft 75a of the second rotor 320 and the expander 75 differs from each other according to the reduction ratio of the speed reducer. obtain.

A plurality of permanent magnets 313 are arranged in the first rotor 310 in the circumferential direction so as to have different polarities alternately. The first rotor 310 has, for example, a substantially cylindrical shape, and includes a cylindrical member 311 having a substantially cylindrical shape and a plurality of permanent magnets 313 as shown in FIGS. 2 and 3.

Specifically, the central axis of the cylindrical member 311 is located coaxially with the central axis of the stator 330. Further, the cylindrical member 311 may be made of various metals, for example. As shown in FIG. 3, for example, the plurality of permanent magnets 313 are provided on the outer peripheral side of the cylindrical member 311 at equal intervals along the circumferential direction of the cylindrical member 311. Each of the permanent magnets 313 has an north pole or an south pole polarity on the outer peripheral side. Specifically, in the first rotor 310, permanent magnets 313 having an N-pole polarity on the outer peripheral side and permanent magnets 313 having an S-pole polarity on the outer peripheral side are alternately arranged in the circumferential direction. Further, each of the permanent magnets 313 extends in the axial direction of the cylindrical member 311. The axial length of the permanent magnet 313 may be substantially the same as the axial length of the stator 330, for example, as shown in FIG.

In the present embodiment, as shown in FIG. 3, since the first rotor 310 is provided with 16 permanent magnets 313, the number of pole pairs n1 of the plurality of permanent magnets 313 is 8, but the plurality of permanent magnets The value of the pole logarithm n1 of 313 is not particularly limited. The pole logarithm n1 means the number of pairs of N pole and S pole in the first rotor 310.

A plurality of soft magnetic materials 323 are arranged in the circumferential direction on the second rotor 320. The second rotor 320 has, for example, a substantially cylindrical shape, and includes a cylindrical member 321 having a substantially cylindrical shape and a plurality of soft magnetic materials 323 as shown in FIGS. 2 and 3.

Specifically, the central axis of the cylindrical member 321 is located coaxially with the central axis of the stator 330. Further, the cylindrical member 321 may be made of, for example, stainless steel which is a non-magnetic material. As shown in FIG. 3, for example, the plurality of soft magnetic materials 323 are provided at equal intervals along the circumferential direction of the cylindrical member 321 between the outer peripheral surface and the inner peripheral surface of the cylindrical member 321. Further, each of the soft magnetic materials 323 extends in the axial direction of the cylindrical member 321. The axial length of the soft magnetic material 323 may be substantially the same as the axial length of the stator 330, for example, as shown in FIG.

In the present embodiment, as shown in FIG. 3, the number n2 of the soft magnetic material 323 is 16, but the number n2 of the soft magnetic material 323 is not particularly limited.

A plurality of armatures are arranged on the stator 330 in the circumferential direction. The stator 330 has, for example, a substantially cylindrical shape, and as shown in FIGS. 2 and 3, the stator 330 includes an iron core 331 having a substantially cylindrical shape, and a plurality of coils 333.

The iron core 331 is formed by, for example, laminating a plurality of steel plates. A plurality of slots 331a are provided in the inner peripheral portion of the iron core 331. Specifically, as shown in FIG. 3, a plurality of slots 331a are provided at equal intervals along the circumferential direction of the iron core 331 on the inner peripheral portion of the iron core 331. Further, each of the slots 331a extends in the axial direction of the iron core 331. A coil 333 is wound around each of such slots 331a. Specifically, a plurality of pairs of U-phase, V-phase, and W-phase coils 333 are provided along the circumferential direction of the iron core 331. A portion of the iron core 331 around which each of the coils 333 is wound and each of the coils 333 correspond to each of the armatures in the stator 330.

In the present embodiment, the number of pole pairs n3 of the plurality of armatures formed by the iron core 331 and the plurality of coils 333 is 8. The number of pole pairs n3 of the plurality of armatures of the stator 330 is not particularly limited. The pole logarithm n3 means the number of pairs of N pole and S pole in the stator 330.

As described above, the stator 330 is electrically connected to the high voltage battery 31 via the inverter device. Specifically, the inverter device is electrically connected to the coil 333 of the stator 330. Therefore, when the motor generator unit 300 functions as a thermoelectric generator or a drive motor, an alternating current flows through the plurality of coils 333. Specifically, in such a case, the three-phase alternating current is configured to flow through the plurality of coils 333. Since a plurality of armatures are arranged in the circumferential direction of the stator 330, a rotating magnetic field that rotates around the central axis of the stator 330 is generated by flowing a three-phase alternating current through the plurality of coils 333.

(Relationship between the rotation speeds of the first rotor, the second rotor, and the rotating magnetic field)
Subsequently, the relationship between the rotation speeds of the first rotor 310, the second rotor 320, and the rotating magnetic field in the motor generator unit 300 according to the present embodiment will be described.

As described above, in the motor generator unit 300 according to the present embodiment, the first rotor 310 and the first rotor 310 are arranged in the circumferential direction so that the plurality of permanent magnets 313 have alternately different polarities. The second rotor 320, which is provided to face the outer peripheral side of the second rotor 320 via a gap and has a plurality of soft magnetic materials 323 arranged in the circumferential direction, and the second rotor 320 facing the outer peripheral side of the second rotor 320 via a gap. Includes a stator 330, which is provided with a plurality of armatures arranged in the circumferential direction.

In recent years, a device called a magnetic flux modulation type motor having a configuration similar to that of the motor generator unit 300 has been known. Specifically, in a general magnetic flux modulation type motor, a first rotor in which a plurality of permanent magnets are alternately arranged in different polarities and a gap on the outer peripheral side of the first rotor are provided. A second rotor is provided so as to face each other and a plurality of soft magnetic materials are arranged in the circumferential direction, and a second rotor is provided so as to face each other on the outer peripheral side of the second rotor via a gap, and a plurality of armatures are arranged in the circumferential direction. It is provided with a provided stator. The first rotor 310, the second rotor 320, and the stator 330 in the present embodiment correspond to the first rotor, the second rotor, and the stator in the magnetic flux modulation type motor, respectively.

In such a magnetic flux modulation type motor, an alternating current flows through a plurality of armatures of the stator to generate a rotating magnetic field that rotates around the central axis of the stator. Here, it is known that the relationship between the rotation speeds of the first rotor, the second rotor, and the rotating magnetic field in the magnetic flux modulation type motor corresponds to the relationship between the rotation speeds of the sun gear, the carrier, and the ring gear in the planetary gear mechanism. Has been done. Hereinafter, in order to facilitate understanding of the relationship between the rotation speeds of the first rotor, the second rotor, and the rotating magnetic field in the motor generator unit 300 according to the present embodiment, the first in a general magnetic flux modulation type motor. The relationship between the rotation speeds of the 1-rotor, the 2nd rotor, and the rotating magnetic field will be described.

When an alternating current is flowing through a plurality of armatures of the stator, the plurality of armatures generate a magnetomotive force F as a force for generating a magnetic flux in the space between the stator and the first rotor. The electromotive force F at time t in a direction inclined by an angle θ in the circumferential direction from a predetermined reference axis in the radial direction of the magnetic flux modulation type motor (hereinafter, also referred to as θ direction) is the number of pole pairs of a plurality of armors of the stator. Is n30 and the rotational speed of the rotating magnetic field is ω30, it is expressed by the following equation (1). K1 in the equation (1) is a coefficient set according to various design specifications of the magnetic flux modulation type motor.

Further, since a plurality of soft magnetic materials are arranged in the circumferential direction in the second rotor, the permeance P as a value indicating the magnitude of the magnetic flux generated in the space between the stator and the first rotor with respect to the magnetomotive force F. The spatial distribution of is fluctuating according to the attitude of the second rotor. The permeance P at time t in the θ direction is expressed by the following equation (2), where n20 is the number of soft magnetic materials and ω20 is the rotation speed of the second rotor. Note that K2 and K3 in the equation (2) are coefficients set according to various design specifications of the magnetic flux modulation type motor.

Based on the equations (1) and (2), the distribution of the magnetic flux φ generated in the space between the stator and the first rotor can be calculated. Specifically, the magnetic flux φ at time t in the θ direction is obtained by multiplying the magnetomotive force F represented by the equation (1) by the permeance P represented by the equation (2). It is represented by 3).

Here, the following equation (4) is derived by rearranging the right side of equation (3) using the addition theorem of trigonometric functions.

Hereinafter, the first, second, and third terms on the right side of the equation (4) will be referred to as the first component, the second component, and the third component of the magnetic flux φ, respectively. According to the second and third terms on the right side of the equation (4), the spatial frequency of the second component and the spatial frequency of the third component of the magnetic flux φ are (n20-n30) and (n20 + n30), respectively. Further, according to the second and third terms on the right side of the equation (4), the rotational speed ω102 of the second component and the rotational speed ω103 of the third component of the magnetic flux φ are the following equations (5) and (3), respectively. It is represented by 6).

Therefore, by setting the number of pole pairs n10 of the permanent magnets of the first rotor to (n20-n30), the first rotor is rotated at the rotation speed ω102 of the second component of the magnetic flux φ represented by the equation (5). Can be done. Further, by setting the number of pole pairs n10 of the permanent magnets of the first rotor to (n20 + n30), the first rotor can be rotated at the rotation speed ω103 of the second component of the magnetic flux φ represented by the equation (6). ..

Here, in the magnetic flux modulation motor, for example, the number of pole pairs n10 of the permanent magnets of the first rotor is set to (n20-n30). In that case, the rotation speed ω10 of the first rotor coincides with the rotation speed ω102 of the second component of the magnetic flux φ represented by the equation (5). Therefore, by substituting ω10 for ω102 in the equation (5) and rearranging it, the following equation (7) showing the relationship between the rotation speeds of the first rotor, the second rotor, and the rotating magnetic field is derived.

As described above, the number of pole pairs n10 of the permanent magnets of the first rotor is a value obtained by subtracting the number of pole pairs n30 of the plurality of armatures of the stator from the number n20 of the soft magnets of the second rotor. In other words, the number n20 of the soft magnetic material is a value obtained by adding the number n30 of the pole pairs of the plurality of armatures to the number n10 of the pole pairs of the permanent magnet. Therefore, based on such a relationship, the following equation (8) is derived by substituting (n10 + n30) for the number n20 of the soft magnets in the equation (7).

Here, when the number of teeth of the sun gear and the ring gear are M10 and M30, respectively, the relationship between the rotation speed U10 of the sun gear, the rotation speed U20 of the carrier, and the rotation speed U30 of the ring gear in the planetary gear mechanism is as follows. It is known to be represented by 9).

According to equations (8) and (9), the relationship between the rotational speeds of the first rotor, the second rotor, and the rotating magnetic field in the magnetic flux modulation type motor is the rotational speed of the sun gear, carrier, and ring gear in the planetary gear mechanism. It was shown to correspond to the relationship.

By the way, as described above, the first rotor 310, the second rotor 320, and the stator 330 in the motor generator unit 300 according to the present embodiment are the first rotor and the second rotor in the magnetic flux modulation type motor described above. Corresponds to rotors and stators. Further, in the motor generator unit 300 according to the present embodiment, for example, the number n1 of the pole pairs n1 of the plurality of permanent magnets 313 in the first rotor 310 is 8, and the number n2 of the soft magnetic material 323 in the second rotor 320 is 16. The number of pole pairs n3 of the plurality of armatures in the stator 330 is 8. As described above, in the present embodiment, the number n2 of the soft magnetic material 323 of the second rotor 320 is the pole pair number n1 of the permanent magnet 313 of the first rotor 310 and the pole pair number of the permanent magnet 313 of the first rotor 310. It is a value obtained by adding n1.

Therefore, according to the equation (8), the relationship between the rotation speed ω1 of the first rotor 310, the rotation speed ω2 of the second rotor 320, and the rotation speed ω1 of the rotating magnetic field in the motor generator unit 300 according to the present embodiment. Is expressed by the following equation (10).

Therefore, the relationship between the rotation speeds of the first rotor 310, the second rotor 320, and the rotating magnetic field in the motor generator unit 300 according to the present embodiment is the relationship between the rotation speeds of the sun gear, the carrier, and the ring gear in the planetary gear mechanism. Corresponds to sex. Specifically, the rotation speeds of the sun gear, the carrier, and the ring gear of the planetary gear mechanism are aligned on a straight line on the collinear diagram. Therefore, by adjusting the rotation speed ω3 of the rotating magnetic field, the rotation speed ω1 of the first rotor 310 and the rotation speed ω2 of the second rotor 320 can be relatively adjusted. For example, by increasing the rotation speed ω3 of the rotating magnetic field, the rotation speed ω2 of the second rotor 320 can be increased with respect to the rotation speed ω1 of the first rotor 310.

Further, according to the present embodiment, the rotation shaft 73a of the Rankine cycle pump 73 can be rotated in synchronization with the first rotor 310. Further, the rotating shaft 75a of the expander 75 can be rotated in synchronization with the second rotor 320. Thereby, by adjusting the rotation speed ω3 of the rotating magnetic field, the rotation speeds of the Rankine cycle pump 73 and the expander 75 can be relatively adjusted. Therefore, the difference in rotational speed between the Rankine cycle pump 73 and the inflator 75 can be adjusted. Therefore, the difference in the discharge flow rates of the Rankine cycle pump 73 and the expander 75 can be adjusted without providing a mechanism having a relatively large number of parts. Therefore, the device can be miniaturized more effectively.

<3. Control device>
Subsequently, the functions of the control device 100 according to the present embodiment will be described with reference to FIGS. 4 to 6.

The control device 100 controls the rotation speed ω3 of the rotating magnetic field generated by the stator 330 by controlling the frequencies of the alternating currents flowing through the plurality of armatures of the stator 330. Specifically, the control device 100 can control the frequency of the alternating current flowing through the plurality of armatures of the stator 330 by outputting an operation instruction to the inverter device connected to the coil 333 of the stator 330. Further, the control device 100 controls the rotation speed ω1 of the first rotor 310 and the rotation speed ω2 of the second rotor 320 by controlling the rotation speed ω3 of the rotating magnetic field. Thereby, the rotation speed ω1 of the first rotor 310 and the rotation speed ω2 of the second rotor 320 can be relatively adjusted. Therefore, since the rotation speeds of the Rankine cycle pump 73 and the inflator 75 can be relatively adjusted, it is possible to adjust the difference in the discharge flow rates of the Rankine cycle pump 73 and the inflator 75.

In the control device 100, for example, the ratio of the rotation speed ω1 of the first rotor 310 to the rotation speed ω2 of the second rotor 320 according to the steam temperature which is the temperature of the operating medium of the gas phase supplied to the expander 75. The rotation speed ratio is controlled. Thereby, the difference in the discharge flow rates of the Rankine cycle pump 73 and the expander 75 can be appropriately adjusted according to the steam temperature. Hereinafter, the rotation speed ratio will be described as meaning a value obtained by dividing the rotation speed ω2 of the second rotor 320 by the rotation speed ω1 of the first rotor 310. In other words, the rotation speed ratio is the ratio of the rotation speed ω2 of the second rotor 320 to the rotation speed ω1 of the first rotor 310. Therefore, the rotation speed ratio corresponds to the ratio of the rotation speed of the expander 75 to the rotation speed of the Rankine cycle pump 73. Therefore, the rotation speed ratio corresponds to the ratio of the discharge amount of the expander 75 to the discharge amount of the Rankine cycle pump 73.

Specifically, in the control device 100, the vapor pressure, which is the pressure of the working medium of the gas phase supplied to the expander 75, approaches the target vapor pressure as the target value of the vapor pressure set according to the steam temperature. As such, the rotation speed ratio is controlled. The target vapor pressure is preferentially set to the upper limit value P10 of the vapor pressure set in advance based on, for example, various design specifications of the vehicle. Specifically, the upper limit value P10 can be set from the viewpoint of ensuring a larger amount of power generation based on the mechanical strength of the members constituting the Rankine cycle 70 or the physical properties of the working medium. Hereinafter, the relationship between the steam temperature and the target vapor pressure will be described with reference to FIGS. 4 and 5.

FIG. 4 is an explanatory diagram showing an example of the vapor pressure curve C10 of the working medium. In FIG. 4, a vapor pressure curve C10 showing the boiling point for each pressure when the temperature of the working medium is taken on the horizontal axis and the pressure of the working medium is taken on the vertical axis is shown. The vapor pressure curve C10 shown in FIG. 4 corresponds to a part of the phase diagram of the working medium, and in FIG. 4, the melting curve showing the freezing point for each pressure and the sublimation curve showing the sublimation pressure for each temperature are shown. , Omitted.

As shown in FIG. 4, the boiling point corresponding to the upper limit value P10 of the vapor pressure is the temperature Tmb10 corresponding to the point D1 on the vapor pressure curve C10. In the region on the higher temperature side than the vapor pressure curve C10, the working medium becomes the gas phase, and in the region on the lower temperature side than the vapor pressure curve C10, the working medium becomes the liquid phase. Therefore, when the pressure of the working medium is the upper limit value P10 and the temperature of the working medium is higher than the temperature Tmb10, the working medium becomes a gas phase. Therefore, when the steam temperature is higher than the temperature Tmb10, the target vapor pressure is set to the upper limit value P10 as shown in FIG.

On the other hand, when the pressure of the working medium is the upper limit value P10 and the temperature of the working medium is lower than the temperature Tmb10, the working medium becomes a liquid phase. Here, the working medium becomes a gas phase at each temperature in a region below the saturated vapor pressure, which is the pressure corresponding to the point on the vapor pressure curve C10 shown in FIG. Therefore, when the steam temperature is lower than the temperature Tmb10, the target vapor pressure is set to, for example, the saturated vapor pressure for each vapor temperature. As shown in FIG. 4, the saturated vapor pressure decreases as the temperature of the working medium decreases. Therefore, when the steam temperature is the temperature Tmb10 or less, the target vapor pressure is specifically set to a smaller value as the steam temperature is lower, as shown in FIG. As described above, when the steam temperature is the temperature Tmb10 or less, the amount of power generation can be increased by preferentially setting a value close to the upper limit value P10 as the target vapor pressure for each steam temperature.

Specifically, the control device 100 controls the rotation speed ratio according to the steam temperature so that the vapor pressure becomes the target vapor pressure shown in FIG. The control device 100 controls the rotation speed ratio using, for example, the map M10 shown in FIG. Map M10 shows the relationship between the steam temperature and the target rotation speed ratio. The target rotation speed ratio is a target value of the rotation speed ratio set according to the steam temperature. The control device 100 uses the map M10 to control the rotation speed ratio based on the steam temperature so as to approach the target rotation speed ratio. The control device 100 controls the rotation speed ratio so that the rotation speed ratio obtained based on the detection results output from the pump rotation speed sensor 201 and the inflator rotation speed sensor 203 approaches the target rotation speed ratio, for example. May be good. The storage element of the control device 100 may store in advance information indicating the relationship between the command value of the frequency of the alternating current flowing through the plurality of armatures of the stator 330 and the steam temperature, and the control device 100 may store the information. May control the rotation speed ratio using the information. Further, the steam temperature is obtained based on the detection result output from the steam temperature sensor 205.

As shown in FIG. 5, when the steam temperature is higher than the temperature Tmb10, the target vapor pressure is the upper limit value P10 regardless of the steam temperature. According to the ideal gas law, the vapor pressure correlates with a value obtained by dividing the vapor temperature by the vapor volume flow rate, which is the volume of the working medium of the gas phase supplied to the expander 75. Therefore, when the steam temperature is higher than the temperature Tmb10, the upper limit value P10 is set regardless of the steam temperature by setting the target rotation speed ratio so that the steam volume flow rate increases as the steam temperature rises. Can be maintained at. As described above, the rotation speed ratio corresponds to the ratio of the discharge amount of the expander 75 to the discharge amount of the Rankine cycle pump 73. Therefore, in the map M10, as shown in FIG. 6, when the steam temperature is higher than the temperature Tmb10, the target rotation speed ratio is set to a larger value as the steam temperature is higher.

As described above, when the steam temperature is higher than the boiling point Tmb10 of the working medium at the upper limit value P10 which is a predetermined pressure, the rotation speed ratio may be increased as the steam temperature becomes higher. Thereby, when the steam temperature is higher than the temperature Tmb10, the vapor pressure can be maintained at the upper limit value P10 regardless of the steam temperature. Therefore, it is possible to prevent the vapor pressure from becoming excessively high due to the increase in the steam temperature. Therefore, it is possible to prevent the inflator 75 from being damaged. In addition, it is possible to prevent the vapor pressure from becoming excessively low due to the decrease in the steam temperature. Therefore, it is possible to prevent the amount of power generation from decreasing as the rotational energy generated by the expander 75 decreases.

Further, as shown in FIG. 5, when the steam temperature is the temperature Tmb10 or less, the target vapor pressure is set to a smaller value as the steam temperature is lower. According to the ideal gas law, the larger the vapor volume flow rate, the lower the vapor pressure. Therefore, when the steam temperature is Tmb10 or less, the steam pressure is reduced as the steam temperature is lower by setting the target rotation speed ratio so that the steam volume flow rate increases as the steam temperature becomes lower. Can be a value. As described above, the rotation speed ratio corresponds to the ratio of the discharge amount of the expander 75 to the discharge amount of the Rankine cycle pump 73. Therefore, in the map M10, as shown in FIG. 6, when the steam temperature is the temperature Tmb10 or less, the target rotation speed ratio is set to a larger value as the steam temperature is lower.

As described above, when the steam temperature is equal to or lower than the boiling point temperature Tmb10 of the working medium at the upper limit value P10, the control device 100 may increase the rotation speed ratio as the steam temperature decreases. Thereby, when the steam temperature is the temperature Tmb10 or less, the vapor pressure can be matched with the saturated vapor pressure for each steam temperature. Therefore, for each steam temperature, the steam temperature can be set to a relatively high value, so that the amount of power generation can be increased.

Further, when the thermoelectric generation system 90 is started, the control device 100 raises the rotation speed ω1 of the first rotor 310 to a higher rotation speed as the operating medium of the Rankine cycle 70 is heated. May be good. The greater the degree to which the working medium is heated, the greater the amount of heat that can be recovered by the Rankine cycle 70. Further, the rotation shaft 73a of the Rankine cycle pump 73 can rotate in synchronization with the first rotor 310. Therefore, the rotation speed of the Rankine cycle pump 73 can be controlled according to the amount of heat that can be recovered by the Rankine cycle 70, so that the power generation efficiency can be improved.

Specifically, when it is determined that the thermoelectric generation system 90 is started, the control device 100 increases the rotation speed ω1 to a target rotation speed as a target value. The target rotation speed can be calculated, for example, based on the temperature of the cooling water of the engine 11 detected by the water temperature sensor 207. Specifically, the control device 100 determines that the higher the temperature of the cooling water, the greater the degree to which the operating medium of the Rankine cycle 70 is heated, and calculates a large value as the target rotation speed. The temperature of the cooling water of the engine 11 is obtained based on the detection result output from the water temperature sensor 207. Specifically, the control device 100 controls the rotation speed ω3 of the rotating magnetic field so that the rotation speed ω1 rises to the target rotation speed when it is determined to start the thermoelectric generation system 90.

The determination as to whether or not to start the thermoelectric generation system 90 may be performed by the control device 100, or may be performed by another control device different from the control device 100. For example, it may be determined whether or not to start the thermoelectric power generation system 90 based on the remaining capacity SOC (State Of Charge) of the high-voltage battery 31, the driving state of the engine 11, or the temperature of the cooling water.

Further, the control device 100 may stop the rotation of the rotating magnetic field when the thermoelectric generation system 90 is stopped. Specifically, when the thermoelectric generation system 90 is stopped, the control device 100 stops the rotation of the rotating magnetic field by bringing the frequency of the alternating current flowing through the plurality of armatures of the stator 330 close to zero.

The control device 100 may stop the rotation of the rotating magnetic field when it is determined to stop the thermoelectric generation system 90. The determination as to whether or not to stop the thermoelectric generation system 90 may be performed by the control device 100, or may be performed by another control device different from the control device 100. For example, it is determined whether or not to stop the thermoelectric power generation system 90 based on the on / off state of the ignition switch, the presence or absence of a failure in the thermoelectric power generation system 90, the amount of power generated by the thermoelectric power generation system 90, or the remaining capacity SOC of the high voltage battery 31. Can be done. Specifically, the control device 100 may determine that the thermoelectric generation system 90 is stopped when it receives information indicating that the ignition switch has been turned off. Further, the control device 100 may determine that the thermoelectric power generation system 90 is stopped when the remaining capacity SOC of the high voltage battery 31 is relatively high. Further, the control device 100 may determine that the thermoelectric power generation system 90 is stopped when a failure occurs in the thermoelectric power generation system 90.

<4. Operation>
Subsequently, the flow of processing performed by the control device 100 according to the present embodiment will be described.

(Control flow)
First, the control flow by the control device 100 according to the present embodiment will be described with reference to the flowchart shown in FIG. FIG. 7 is a flowchart showing an example of the flow of processing performed by the control device 100 according to the present embodiment. The process shown in FIG. 7 may be performed when it is determined to start the thermoelectric generation system 90.

As shown in FIG. 4, first, the control device 100 raises the rotation speed ω1 of the first rotor 310 to the target rotation speed (step S501). Next, the control device 100 raises the rotation speed ratio to the target rotation speed ratio (step S503). Next, the control device 100 maintains the rotation speed ratio at the target rotation speed ratio (step S505). Then, the control device 100 determines whether or not to stop the thermoelectric generation system 90 (step S507). If it is not determined to stop the thermoelectric generation system 90 (step S507 / NO), the determination process of step S507 is repeated. On the other hand, when it is determined to stop the thermoelectric power generation system 90 (step S507 / YES), the control device 100 stops the rotation of the rotating magnetic field (step S509), and the process shown in FIG. 7 ends.

(Behavior of the motor generator)
Subsequently, with reference to FIGS. 8 to 10, the behavior of the motor generator unit 300 when the control device 100 according to the present embodiment controls the motor generator unit 300 will be described. 8 to 10 are collinear diagrams showing an example of the behavior of the motor generator unit 300 in each driving state of the thermoelectric generation system 90. In each collinear diagram, the rotation speeds of the first rotor 310, the second rotor 320, and the rotating magnetic field of the motor generator 300 in each driving state of the thermal power generation system 90 are shown.

Here, the rotation speeds of the sun gear, the carrier, and the ring gear of the planetary gear mechanism are in a linear relationship on the collinear diagram. Further, as described above, the relationship between the rotation speeds of the first rotor 310, the second rotor 320, and the rotating magnetic field in the motor generator 300 is the relationship between the rotation speeds of the sun gear, the carrier, and the ring gear in the planetary gear mechanism. Corresponds to sex. Therefore, on the co-line diagram shown in FIGS. 8 to 10, the rotation speeds of the first rotor 310, the second rotor 320, and the rotating magnetic field are in a linear relationship. In the common diagram, the distance between the vertical axes indicating the rotational speeds of the first rotor 310, the second rotor 320, and the rotating magnetic field is fixed to the pole pair number n1 of the permanent magnet 313 of the first rotor 310. It is determined according to the ratio of the plurality of armors in the child 330 to the number of pole pairs n3.

FIG. 8 is a collinear diagram showing an example of the behavior of the motor generator unit 300 when the thermoelectric power generation system 90 is started. In FIG. 8, each rotational speed before the thermoelectric generation system 90 is started is indicated by a chain double-dashed line. As shown in FIG. 8, before the thermoelectric generation system 90 is started, the rotation speeds of the first rotor 310, the second rotor 320, and the rotating magnetic field are 0.

Since the expander 75 is not rotating when the thermoelectric generation system 90 is started, no rotational energy is generated in the expander 75. The control device 100 causes the motor generator unit 300 to function as a driving motor, and outputs a driving force to the rotating shaft 73a of the Rankine cycle pump 73. When starting the thermoelectric generation system 90, the control device 100 rotates the rotating magnetic field in the direction opposite to the rotation direction of the first rotor 310, as shown in FIG. The rotation direction of the first rotor 310 is the case where the Rankine cycle 70 corresponding to the case where the operating medium is sucked up from the tank 79 by the Rankine cycle pump 73 and circulates in the operating medium flow path 71 is operating normally. Is the direction that coincides with the rotation direction of the Rankine cycle pump 73. The rotation direction of the second rotor 320 coincides with the rotation direction of the first rotor 310.

In this way, the control device 100 controls the frequency of the AC current flowing through the plurality of armatures of the stator 330 so that the rotating magnetic field rotates in the direction opposite to the rotation direction of the first rotor 310. As shown in FIG. 8, the rotation speed ω1 of the first rotor 310 increases. Further, the rotation speed ω1 of the first rotor 310 increases to the target rotation speed by controlling the rotation speed ω3 of the rotating magnetic field by the control device 100.

Although each rotation speed is schematically shown in FIG. 8 for ease of understanding, strictly speaking, the rotation speed of the expander 75 increases after the Rankine cycle pump 73 is driven. The rotation speed ω2 of the second rotor 320 begins to increase as the rotation speed ω2 begins to increase.

FIG. 9 is a collinear diagram showing an example of the behavior of the motor generator unit 300 after the thermoelectric generation system 90 is started. Specifically, FIG. 9 is a collinear diagram showing an example of the behavior of the motor generator unit 300 after the rotation speed ω1 of the first rotor has risen to the target rotation speed. In FIG. 9, each rotation speed when the rotation speed ω1 of the first rotor rises to the target rotation speed is indicated by a two-dot chain line.

After the rotation speed ω1 of the first rotor rises to the target rotation speed, the rotation speed of the inflator 75 is relatively low, so that the amount of rotational energy generated in the inflator 75 is relatively small. The control device 100 causes the motor generator unit 300 to function as a driving motor, and outputs a driving force to the rotating shaft 75a of the expander 75. After the rotation speed ω1 of the first rotor has risen to the target rotation speed, the control device 100 rotates the rotating magnetic field in a direction consistent with the rotation direction of the first rotor 310, as shown in FIG. Increase the rotation speed ω3.

As described above, the rotation speed ω3 of the rotating magnetic field is increased by the control device 100 in the direction corresponding to the rotation direction of the first rotor 310, so that the rotation speed of the first rotor 310 is as shown in FIG. The rotation speed ω2 of the second rotor 320 increases with respect to ω1. As a result, the rotation speed ratio, which is the ratio of the rotation speed ω2 of the second rotor 320 to the rotation speed ω1 of the first rotor 310, can be increased. As described above, the control device 100 controls the rotation speed ratio so as to approach the target rotation speed ratio. Here, the steam temperature can fluctuate after the rotation speed ratio reaches the target rotation speed ratio. Specifically, the control device 100 uses the map M10 shown in FIG. 6 to control the rotation speed ratio based on the steam temperature so as to approach the target rotation speed ratio.

Thereby, according to the present embodiment, the difference in the discharge flow rates of the Rankine cycle pump 73 and the expander 75 can be appropriately adjusted according to the steam temperature. Therefore, it is possible to prevent the vapor pressure from becoming excessively high due to the increase in the steam temperature, and thus it is possible to prevent the inflator 75 from being damaged. Further, since it is possible to prevent the vapor pressure from becoming excessively low due to the decrease in the steam temperature, it is possible to prevent the amount of power generation from decreasing as the rotational energy generated by the expander 75 decreases. be able to.

The rotation speed ratio rises until the target rotation speed ratio is reached, and then fluctuates so as to follow the target rotation speed ratio. Here, after the rotation speed ratio reaches the target rotation speed ratio, the rotation speed of the inflator 75 is relatively high, so that the amount of rotational energy generated in the inflator 75 is relatively large. Therefore, the control device 100 basically causes the motor generator unit 300 to function as a thermoelectric generator to generate electric power.

FIG. 10 is a collinear diagram showing an example of the behavior of the motor generator unit when the thermoelectric power generation system is stopped. Specifically, FIG. 10 is a collinear diagram showing an example of the behavior of the motor generator unit after it is determined to stop the thermoelectric power generation system 90. In FIG. 9, each rotation speed when the rotation speed ratio is maintained at the target rotation speed ratio is indicated by a chain double-dashed line.

After it is determined that the thermoelectric generation system 90 is stopped, the control device 100 brings the frequency of the alternating current flowing through the plurality of armatures of the stator 330 close to zero. As the frequency of the alternating current flowing through the plurality of armatures of the stator 330 decreases, the rotation speed ω3 of the rotating magnetic field decreases. Therefore, as shown in FIG. 10, as the rotation speed ω3 of the rotating magnetic field decreases, the rotation speed ω1 of the first rotor 310 and the rotation speed ω2 of the second rotor 320 decrease. As a result, the rotation of the first rotor 310, the second rotor 320, and the rotating magnetic field is stopped, so that the thermoelectric generation system 90 is stopped.

<5. Conclusion>
As described above, according to the present embodiment, the motor generator unit 300 includes the first rotor 310 and the second rotor 320 provided on the outer peripheral side of the first rotor 310 so as to face each other with a gap. , A stator 330 provided on the outer peripheral side of the second rotor 320 facing each other via a gap. A plurality of permanent magnets 313 are arranged in the first rotor 310 in the circumferential direction so as to have different polarities alternately. A plurality of soft magnetic materials 323 are arranged in the circumferential direction on the second rotor 320. A plurality of armatures are arranged on the stator 330 in the circumferential direction. Therefore, the relationship between the rotation speeds of the first rotor 310, the second rotor 320, and the rotating magnetic field in the motor generator unit 300 corresponds to the relationship between the rotation speeds of the sun gear, the carrier, and the ring gear in the planetary gear mechanism.

Further, the first rotor 310 is connected to the rotation shaft 73a of the Rankine cycle pump 73. Thereby, the rotating shaft 73a of the Rankine cycle pump 73 can be made rotatable in synchronization with the first rotor 310. Further, the second rotor 320 is connected to the rotating shaft 75a of the expander 75. Thereby, the rotating shaft 75a of the expander 75 can be made rotatable in synchronization with the second rotor 320. Therefore, by adjusting the rotation speed ω3 of the rotating magnetic field, the rotation speeds of the Rankine cycle pump 73 and the expander 75 can be relatively adjusted. Thereby, the difference in the rotational speeds of the Rankine cycle pump 73 and the inflator 75 can be adjusted. Therefore, the difference in the discharge flow rates of the Rankine cycle pump 73 and the expander 75 can be adjusted without providing a mechanism having a relatively large number of parts. Therefore, the device can be miniaturized more effectively.

In the above, an example in which the thermoelectric power generation system according to the present invention is applied to a hybrid vehicle has been described, but the technical scope of the present invention is not limited to such an example. For example, the thermoelectric power generation system according to the present invention can be applied to a vehicle that travels by a driving force output from an engine 11 and does not have a high voltage battery 31 as a power source. In that case, the electric power generated by the motor generator unit 300 using the mechanical energy generated by the Rankin cycle 70 may be stored in a low-voltage battery that supplies electric power to various devices in the vehicle.

Further, in the above description, an example in which the driving force generated by the operation of the engine 11 is transmitted to the driving wheels 21 via the driving force transmission system 51 has been described, but the technical scope according to the present invention is the same. Not limited. For example, the driving force generated by the operation of the engine 11 may be transmitted to a generator (not shown) connected to the engine 11 and used for power generation by the generator. The electric power generated by the generator may be configured to be stored in the high voltage battery 31.

Further, in the above description, an example in which the Rankine cycle 70 generates mechanical energy by exchanging heat with the cooling water for recovering the waste heat of the engine 11 of the vehicle has been described, but the technical aspects of the present invention have been described. The scope is not limited to such examples. For example, the Rankine cycle 70 may generate mechanical energy by exchanging heat with the exhaust gas having waste heat of the engine 11 of the vehicle. In such a case, the working medium flow path 71 and the exhaust gas piping may be connected to the heat exchanger 74.

Further, although the example in which the battery is a high voltage battery 31 has been described above, the technical scope of the present invention is not limited to such an example. For example, the battery is a low voltage that supplies electric power to various devices in the vehicle. It may be a battery. In such a case, the motor generator unit 300 and the traveling motor generator 41 are electrically connected to the low-voltage battery, respectively, and the electric power generated by the motor generator unit 300 and the electric power generated by the traveling motor generator 41 in the braking power generation. Can each be configured to be stored in a low voltage battery.

Further, although the example in which the thermoelectric power generation system 90 including the Rankine cycle 70 and the motor generator unit 300 is applied to a vehicle has been described above, the technical scope of the present invention is not limited to such an example. For example, the thermoelectric power generation system according to the present invention can be applied to other mobile objects such as ships and facilities such as factories.

In addition, the processes described using the flowchart in the present specification do not necessarily have to be executed in the order shown in the flowchart. Some processing steps may be performed in parallel. Further, additional processing steps may be adopted, and some processing steps may be omitted.

Although the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited to these examples. It is clear that a person having ordinary knowledge in the field of technology to which the present invention belongs can come up with various modifications or applications within the scope of the technical ideas described in the claims. , These are also naturally understood to belong to the technical scope of the present invention.

10 Charging system 11 Engine 13 Cooling water flow path 21 Drive wheel 31 High voltage battery 41 Driving motor generator 51 Driving force transmission system 70 Rankin cycle 71 Operating medium flow path 73 Rankin cycle pump 73a Rotor shaft 74 Heat exchanger 75 Expander 75a Rotation Axis 77 Condenser 79 Tank 90 Thermal power generation system 100 Control device 201 Pump rotation speed sensor 203 Inflator rotation speed sensor 205 Steam temperature sensor 207 Water temperature sensor 300 Motor generator unit 310 1st rotor 311 Column member 313 Permanent magnet 320 2nd rotation Child 321 Cylindrical member 323 Soft magnetic material 330 Stator 331 Iron core 331a Slot 333 Coil

Claims (4)

Includes a flow path through which the working medium to be heated circulates, a Rankine cycle pump provided in the flow path that circulates the working medium, and an expander provided in the flow path that expands the working medium to generate rotational energy. Rankine cycle and
A motor generator unit capable of generating electricity using the rotational energy generated by the expander and outputting a driving force for driving the Rankine cycle pump.
Control device and
With
The motor generator unit
A first rotor connected to the rotating shaft of the Rankine cycle pump and arranged in the circumferential direction so that a plurality of permanent magnets have alternately different polarities.
A second rotor, which is provided on the outer peripheral side of the first rotor so as to face each other via a gap, is connected to the rotation shaft of the expander, and has a plurality of soft magnetic materials arranged in the circumferential direction.
A stator provided on the outer peripheral side of the second rotor facing each other via a gap, and a plurality of armatures arranged in the circumferential direction.
Only including,
The control device is
By controlling the frequency of the alternating current flowing through the plurality of armatures of the stator, the rotational speed of the rotating magnetic field generated by the stator is controlled.
By controlling the rotation speed of the rotating magnetic field, the rotation speeds of the first rotor and the second rotor can be controlled.
The rotation speed ratio, which is the ratio of the rotation speeds of the first rotor and the second rotor, is controlled according to the steam temperature, which is the temperature of the working medium of the gas phase supplied to the expander.
Thermoelectric generation system. The control device, when the steam temperature is higher than the boiling point of the working medium at a given pressure, as the steam temperature is increased, thereby increasing the rotational speed ratio, the thermal power generation system according to claim 1. The thermoelectric power generation system according to claim 2 , wherein the control device increases the rotation speed ratio as the steam temperature decreases when the steam temperature is equal to or lower than the boiling point of the working medium at the predetermined pressure. Includes a flow path through which the working medium to be heated circulates, a Rankine cycle pump provided in the flow path to circulate the working medium, and an expander provided in the flow path to expand the working medium to generate rotational energy. Rankine cycle and
A motor generator unit capable of generating electricity using the rotational energy generated by the expander and outputting a driving force for driving the Rankine cycle pump.
Control device and
It is a thermoelectric power generation system equipped with
The motor generator unit
A first rotor connected to the rotating shaft of the Rankine cycle pump and arranged in the circumferential direction so that a plurality of permanent magnets have alternately different polarities.
A second rotor, which is provided on the outer peripheral side of the first rotor so as to face each other via a gap, is connected to the rotation shaft of the expander, and has a plurality of soft magnetic materials arranged in the circumferential direction.
A stator provided on the outer peripheral side of the second rotor facing each other via a gap, and a plurality of armatures arranged in the circumferential direction.
Including
The control device is
By controlling the frequency of the alternating current flowing through the plurality of armatures of the stator, the rotational speed of the rotating magnetic field generated by the stator is controlled.
By controlling the rotation speed of the rotating magnetic field, the rotation speeds of the first rotor and the second rotor can be controlled.
When the thermoelectric generation system is started, the rotation speed of the first rotor is increased to a higher rotation speed as the working medium of the Rankine cycle is heated to a greater extent.
Thermoelectric generation system.

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