Electrical equipment and control method for electrical equipment

Abstract

To provide an electrical device and a control method for the electrical device that can suppress a decrease in efficiency during power conversion during charging.SOLUTION: An electrical device 10 includes a power storage device 11, a rotating electric machine including an α-phase first coil 23 (α1) and an α-phase second coil 24 (α2), and a power control unit 10a that controls the exchange of power between the power storage device 11 and the rotating electric machine. The power control unit 10a includes a first full-bridge circuit 12a connected to both ends of the α-phase first coil 23 (α1) and a second full-bridge circuit 12b connected to both ends of the α-phase second coil 24 (α2). When transmitting power between the first full-bridge circuit 12a and the second full-bridge circuit 12b via the α-phase first coil 23 (α1) and the α-phase second coil 24 (α2), the power control unit 10a controls the phase difference between the first full-bridge circuit 12a and the second full-bridge circuit 12b within a range including 90° to 180°.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electric device and a method for controlling the electric device. [Background technology]

[0002] In recent years, research and development has been conducted into charging mobility vehicles equipped with secondary batteries that contribute to energy efficiency, in order to ensure that more people have access to affordable, reliable, sustainable and advanced energy. Conventionally, a DAB (Dual Active Bridge) DC-DC converter having a bridge circuit with switching elements on each of the primary and secondary sides of a transformer has been known as an insulated bidirectional converter used for power conversion in charging, for example (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-152687 Summary of the Invention [Problem to be solved by the invention]

[0004] In technology related to charging and supplying power to mobility vehicles equipped with secondary batteries, when a DAB DC-DC converter is formed by combining a stator winding of a motor with a bridge circuit using switching elements, suppressing a decrease in efficiency is an issue. For example, when the phase difference between the primary bridge circuit and the secondary bridge circuit is controlled within a range of 0 to 90° as conventional control for a DAB DC-DC converter such as the above-mentioned conventional technology, there is a risk that the efficiency during power conversion will decrease due to increased iron loss caused by using the stator winding of the motor.

[0005] In order to solve the above-mentioned problems, the present invention aims to suppress a decrease in efficiency during power conversion during charging, thereby contributing to improved energy efficiency. [Means for solving the problem]

[0006] In order to solve the above problems and achieve the above object, the present invention employs the following aspects. (1): An electric device (e.g., electric device 10 in the embodiment) according to one aspect of the present invention includes a power storage device (e.g., power storage device 11 in the embodiment), a rotating electric machine (e.g., rotating electric machine 16(M) in the embodiment) including a first coil (e.g., α-phase first coil 23 (α1) in the embodiment) and a second coil (e.g., α-phase second coil 24 (α2) in the embodiment), and a power control unit (e.g., power control unit 10a in the embodiment) connected to the power storage device and the rotating electric machine and controlling the exchange of power between the power storage device and the rotating electric machine. The power control unit includes a first full bridge circuit (for example, the first full bridge circuit 12a in the embodiment) connected to both ends of the first coil, and a second full bridge circuit (for example, the second full bridge circuit 12b in the embodiment) connected to both ends of the second coil, and when power is transmitted between the first full bridge circuit and the second full bridge circuit via the first coil and the second coil, the power control unit controls a phase difference between the first full bridge circuit and the second full bridge circuit within a range including 90° to 180°.

[0007] (2): In the electrical device described in (1) above, the first coil and the second coil may be open-ended, and the rotating electric machine may include a stator core (e.g., stator core 42 in the embodiment) in which a slot (e.g., slot 43 in the embodiment) shared by the magnetically coupled first coil and second coil is formed.

[0008] (3): In the electric device described in (2) above, the rotating electric machine includes at least one coil (for example, a β-phase first coil 33 (β1) and a β-phase second coil 34 (β2) in the embodiment) connected to an external power supply, and the power control unit includes a first circuit breaker (for example, a first circuit breaker 25 in the embodiment) connected between the positive poles of the first full bridge circuit and the second full bridge circuit, a second circuit breaker (for example, a second circuit breaker 26 in the embodiment) connected between the negative poles of the first full bridge circuit and the second full bridge circuit, and a second circuit breaker (for example, a second circuit breaker 27 in the embodiment) connected to both ends of the at least one coil. and at least one third full bridge circuit (for example, third full bridge circuit 13a and fourth full bridge circuit 13b in the embodiments) connected between one end of the at least one coil and the at least one third full bridge circuit, and at least one third circuit breaker (for example, third circuit breaker 35 and fourth circuit breaker 36 in the embodiments) connected between one end of the at least one coil and the at least one third full bridge circuit, and may include a power supply connection member (for example, AC power supply connection portion 15 in the embodiments) connected to both ends of the third circuit breaker to connect the power control unit and the at least one coil to the external power supply.

[0009] (4): A method for controlling an electric device according to one aspect of the present invention includes a power storage device (e.g., the power storage device 11 in the embodiment), a rotating electric machine (e.g., the rotating electric machine 16(M) in the embodiment) including a first coil (e.g., the α-phase first coil 23(α1) in the embodiment) and a second coil (e.g., the α-phase second coil 24(α2) in the embodiment), a first full-bridge circuit (e.g., the first full-bridge circuit 12a in the embodiment) connected to both ends of the first coil, and a second full-bridge circuit (e.g., the second full-bridge circuit 12b in the embodiment) connected to both ends of the second coil. a power control unit (for example, power control unit 10a in the embodiment) connected to the power storage device and the rotating electric machine to control the exchange of power between the power storage device and the rotating electric machine, the method comprising the step of controlling a phase difference between the first full bridge circuit and the second full bridge circuit within a range including 90° to 180° when power is transmitted between the first full bridge circuit and the second full bridge circuit via the first coil and the second coil. [Effects of the Invention]

[0010] According to the above (1), when performing insulated power conversion using the first coil and the second coil of a rotating electric machine, even if the ratio of iron loss to total loss increases due to the material forming the rotating electric machine, iron loss can be reduced by non-standard control. That is, by controlling the phase difference between the first full-bridge circuit and the second full-bridge circuit within a relatively large range including 90° to 180°, the sum of the currents flowing through the first coil and the second coil can be reduced, and the magnetic flux offset between the primary side and the secondary side can be increased, thereby reducing iron loss and effectively suppressing a decrease in efficiency.

[0011] In the case of (2) above, even if the material forming the stator core of the rotating electrical machine prioritizes high magnetic flux density and has magnetic properties that increase loss in the high frequency range, the reduction in iron loss can effectively suppress a decrease in efficiency. The magnetically coupled first coil and second coil can improve power conversion efficiency.

[0012] In the case of (3) above, when the rotating electric machine is driven by the power storage device, it can function as an inverter of a quadruple full-bridge circuit. When the power storage device is being charged with DC from an external power supply, the combination of each coil of the rotating electric machine and each full-bridge circuit of the power control unit can function as a non-insulated DC-DC converter. When the power storage device is being charged with AC from an external power supply, the combination of the first coil and second coil of the rotating electric machine and the first full-bridge circuit and second full-bridge circuit can function as an insulated bidirectional DC-DC converter. For example, in the case of voltage boost operation during AC charging, rapid charging can be performed for a voltage of the power storage device that is higher than the charging voltage from the external power supply.

[0013] According to the above (4), when performing insulated power conversion using the first coil and the second coil of a rotating electric machine, even if the ratio of iron loss to total loss increases due to the material forming the rotating electric machine, iron loss can be reduced by non-standard control. That is, by controlling the phase difference between the first full-bridge circuit and the second full-bridge circuit within a relatively large range including 90° to 180°, the sum of the currents flowing through the first coil and the second coil can be reduced, and the magnetic flux offset between the primary side and the secondary side can be increased, thereby reducing iron loss and effectively suppressing a decrease in efficiency. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a diagram showing a configuration of an electrical device according to an embodiment of the present invention. [Figure 2] 2 is a diagram illustrating the configuration of each full-bridge circuit and a rotating electric machine in the electric device according to the embodiment of the present invention. FIG. [Figure 3] FIG. 10 is a diagram showing an example of time changes in current of each α-phase coil in the embodiment of the present invention and the comparative example. [Figure 4] 5A and 5B are diagrams showing examples of changes in output voltage and losses (iron loss and copper loss) according to the phase between the first full-bridge circuit and the second full-bridge circuit in the embodiment of the present invention and the comparative example. [Figure 5] FIG. 10 is a configuration diagram of a rotating electric machine as an electric device according to a modified example of the embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an electric device according to an embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a diagram showing the configuration of an electric device 10 according to an embodiment. Fig. 2 is a diagram showing the configuration of each of full-bridge circuits 12a, 12b, 13a, 13b and a rotating electric machine 16 in the electric device 10 according to the embodiment. The electrical device 10 of the embodiment is mounted on, for example, an electric vehicle, an electric moving body, an electric machine, a power supply device, etc. Examples of the electric vehicle include an electric car equipped with a rotating electric machine as a power source, a saddle-ride vehicle, a kick scooter, a hybrid vehicle combining a rotating electric machine with an internal combustion engine, and a fuel cell vehicle combining a power storage device with a fuel cell. Examples of the electric moving body include a robot, an aircraft, and a surface or underwater moving body. Examples of the electric machine include construction machinery equipped with a rotating electric machine as a power source. Examples of the power supply device include a stationary or mobile power supply device that discharges and charges a power storage device.

[0016] (Electrical Equipment) 1 and 2, an electrical device 10 of the embodiment includes, for example, a power storage device 11, a first power conversion unit 12 and a second power conversion unit 13, a DC power supply connection unit 14 and an AC power supply connection unit 15, a rotating electrical machine 16(M), a gate drive unit 17, and an electronic control unit 18. Note that, for example, the first power conversion unit 12 and the second power conversion unit 13, the DC power supply connection unit 14 and the AC power supply connection unit 15, the gate drive unit 17, and the electronic control unit 18 configure a power control unit 10a.

[0017] The power storage device 11 is connected to a first power conversion unit 12 and a second power conversion unit 13, which will be described later. The power storage device 11 includes, for example, a plurality of battery cells connected in series or in parallel. Each battery cell is, for example, a secondary battery such as a lead-acid battery, a lithium-ion battery, a nickel-metal hydride battery, or an all-solid-state battery, a capacitor such as an electric double-layer capacitor, or a composite battery that combines a secondary battery and a capacitor. Each battery cell is repeatedly charged and discharged. The power storage device 11 exchanges power with the rotating electric machine 16 via the power control unit 10a. The power storage device 11 is charged by an external power source (an external DC power source and an external AC power source).

[0018] The first power conversion unit 12 includes a first full-bridge circuit 12a and a second full-bridge circuit 12b. Each of the first full-bridge circuit 12a and the second full-bridge circuit 12b includes a so-called H-bridge circuit formed by a plurality of switching elements bridge-connected in two phases. Each switching element is a transistor such as a MOSFET (Metal Oxide Semiconductor Field Effect Transistor) made of silicon carbide (SiC) or an IGBT (Insulated Gate Bipolar Transistor). Each switching element is, for example, an N-channel MOSFET. The switching elements are, for example, pairs of transistors that form the high-side arm and low-side arm element units 21a and 21b of each phase. The pairs of transistors in each element unit 21a and 21b are, for example, connected in parallel. Each full-bridge circuit 12a, 12b may include a rectifying element such as a free wheel diode connected in parallel in the forward direction from the emitter to the collector between the collector and emitter of each transistor.

[0019] The first power conversion unit 12 includes, for example, a first switch 22 connected between midpoints Q2 and Q3 of the first and second full-bridge circuits 12a and 12b. The midpoint Q2 of the first full-bridge circuit 12a is, for example, a connection point between the high-side arm element unit 21a (a2H) and the low-side arm element unit 21b (a2L), which are connected in series in the second phase of the first and second phases of the two phases of the first full-bridge circuit 12a. For example, the midpoint Q2 is a connection point between the source of the high-side arm element unit 21a (a2H) and the drain of the low-side arm element unit 21b (a2L). The midpoint Q3 of the second full-bridge circuit 12b is, for example, a connection point between the high-side arm element unit 21a (a3H) and the low-side arm element unit 21b (a3L), which are connected in series in the first phase of the first and second phases of the two phases of the second full-bridge circuit 12b. For example, the midpoint Q3 is the connection point between the source of the element portion 21a (a3H) of the high-side arm and the drain of the element portion 21b (a3L) of the low-side arm.

[0020] The first switch 22 is, for example, a bidirectional switch formed by two switching elements. Each switching element is a transistor such as a MOSFET or an IGBT, for example, an N-channel MOSFET. The first switch 22 includes, for example, two transistors connected in anti-series. The two transistors are connected in series in opposite directions, for example, by connecting their sources to each other. The first switch 22 switches between conducting and blocking the current between the midpoints Q2 and Q3 by turning on (conducting) and off (blocking) the two transistors. Each transistor may include a rectifying element such as a free wheel diode connected in parallel in the forward direction from the emitter to the collector between the collector and the emitter.

[0021] The first power conversion unit 12 is connected to an α-phase first coil 23 (α1) and an α-phase second coil 24 (α2) of a rotating electric machine 16 (described later). The α-phase first coil 23 is connected between midpoints Q1 and Q2 of a first full-bridge circuit 12a. The α-phase second coil 24 (α2) is connected between midpoints Q3 and Q4 of a second full-bridge circuit 12b. The midpoint Q1 of the first full-bridge circuit 12a is, for example, a connection point between a high-side arm element unit 21a (a1H) and a low-side arm element unit 21b (a1L) that are connected in series in the first phase of the first full-bridge circuit 12a. For example, the midpoint Q1 is a connection point between a source of the high-side arm element unit 21a (a1H) and a drain of the low-side arm element unit 21b (a1L). The midpoint Q4 of the second full-bridge circuit 12b is, for example, a connection point between the high-side arm element unit 21a (a4H) and the low-side arm element unit 21b (a4L), which are connected in series in the second phase of the second full-bridge circuit 12b. For example, the midpoint Q4 is a connection point between the source of the high-side arm element unit 21a (a4H) and the drain of the low-side arm element unit 21b (a4L).

[0022] The first power conversion unit 12 includes a first circuit breaker 25 connected between the positive electrodes of the first full bridge circuit 12a and the second full bridge circuit 12b, and a second circuit breaker 26 connected between the negative electrodes of the first full bridge circuit 12a and the second full bridge circuit 12b. Each of the first and second switchgears 25 and 26 is, for example, a contactor, and switches on (conducting) and off (disconnecting) the connection between the first full-bridge circuit 12a and the second full-bridge circuit 12b.

[0023] The first power conversion unit 12 includes, for example, a capacitor 27 connected between the positive and negative poles. The capacitor 27 smoothes voltage fluctuations that occur due to the switching operation of each switching element of the first power conversion unit 12 between on (conduction) and off (cutoff). The first power conversion unit 12 includes, for example, a first current sensor 28a arranged between the α-phase first coil 23 (α1) and the midpoint Q2, a second current sensor 28b arranged between the α-phase second coil 24 (α2) and the midpoint Q4, and a third current sensor 28c arranged between the storage device 11 and the first power conversion unit 12. For example, the first current sensor 28a detects the current flowing through the α-phase first coil 23 (α1), and the second current sensor 28b detects the current flowing through the α-phase second coil 24 (α2). The third current sensor 28c detects the current flowing between the first power conversion unit 12 and the power storage device 11.

[0024] The second power conversion unit 13 includes a third full-bridge circuit 13a and a fourth full-bridge circuit 13b. Each of the third full-bridge circuit 13a and the fourth full-bridge circuit 13b includes a so-called H-bridge circuit formed by, for example, a plurality of switching elements bridge-connected in two phases. Each switching element is, for example, a MOSFET such as SiC or a transistor such as IGBT. Each switching element is, for example, an N-channel MOSFET. The switching elements are, for example, pairs of transistors that form the high-side arm and low-side arm element units 31a, 31b of each phase. The pairs of transistors in each element unit 31a, 31b are, for example, connected in parallel. Each of the full-bridge circuits 13a and 13b may include a rectifying element such as a free wheel diode connected in parallel in the forward direction from the emitter to the collector between the collector and emitter of each transistor.

[0025] The second power conversion unit 13 includes, for example, a second switch 32 connected between midpoints R2 and R3 of the third and fourth full-bridge circuits 13a and 13b. The midpoint R2 of the third full-bridge circuit 13a is, for example, a connection point between the high-side arm element unit 31a (b2H) and the low-side arm element unit 31b (b2L), which are connected in series in the second phase of the first and second phases of the two phases of the third full-bridge circuit 13a. For example, the midpoint R2 is a connection point between the source of the high-side arm element unit 31a (b2H) and the drain of the low-side arm element unit 31b (b2L). The midpoint R3 of the fourth full-bridge circuit 13b is, for example, a connection point between the high-side arm element unit 31a (b3H) and the low-side arm element unit 31b (b3L), which are connected in series in the first phase of the first and second phases of the two phases of the fourth full-bridge circuit 13b. For example, the midpoint R3 is the connection point between the source of the element portion 31a (b3H) of the high-side arm and the drain of the element portion 31b (b3L) of the low-side arm.

[0026] The second switch 32 is, for example, a bidirectional switch formed by two switching elements. Each switching element is a transistor such as a MOSFET or an IGBT, for example, an N-channel MOSFET. The second switch 32 includes, for example, two transistors connected in anti-series. The two transistors are connected in series in opposite directions, for example, by connecting their sources to each other. The second switch 32 switches between conducting and blocking the current between the midpoints R2 and R3 by turning on (conducting) and off (blocking) the two transistors. Each transistor may include a rectifying element such as a free wheel diode connected in parallel in the forward direction from the emitter to the collector between the collector and the emitter.

[0027] The second power conversion unit 13 is connected to a β-phase first coil 33 (β1) and a β-phase second coil 34 (β2) of a rotating electric machine 16 (described later). The β-phase first coil 33 is connected between midpoints R1 and R2 of a third full-bridge circuit 13a. The β-phase second coil 34 (β2) is connected between midpoints R3 and R4 of a fourth full-bridge circuit 13b. The midpoint R1 of the third full-bridge circuit 13a is, for example, a connection point between a high-side arm element unit 31a (b1H) and a low-side arm element unit 31b (b1L) that are connected in series in the first phase of the third full-bridge circuit 13a. For example, the midpoint R1 is a connection point between the source of the high-side arm element unit 31a (b1H) and the drain of the low-side arm element unit 31b (b1L). The midpoint R4 of the fourth full-bridge circuit 13b is, for example, a connection point between the high-side arm element unit 31a (b4H) and the low-side arm element unit 31b (b4L), which are connected in series in the second phase of the fourth full-bridge circuit 13b. For example, the midpoint R4 is a connection point between the source of the high-side arm element unit 31a (b4H) and the drain of the low-side arm element unit 31b (b4L).

[0028] The second power conversion unit 13 includes a third circuit breaker 35 connected between one end of the β-phase first coil 33 (β1) and the third full-bridge circuit 13a, and a fourth circuit breaker 36 connected between one end of the β-phase second coil 34 (β2) and the fourth full-bridge circuit 13b. Each of the third and fourth switchgears 35 and 36 is, for example, a contactor. The third switchgear 35 is connected, for example, between one end of the β-phase first coil 33 (β1) and a midpoint R1 of the first phase of the third full-bridge circuit 13a, and switches the connection between the β-phase first coil 33 (β1) and the midpoint R1 on (conduction) and off (disconnection). The fourth switchgear 36 is connected, for example, between one end of the β-phase second coil 34 (β2) and a midpoint R4 of the fourth phase of the fourth full-bridge circuit 13b, and switches the connection between the β-phase second coil 34 (β2) and the midpoint R4 on (conduction) and off (disconnection).

[0029] The second power conversion unit 13 includes, for example, a capacitor 37 connected between the positive and negative electrodes. The capacitor 37 smoothes voltage fluctuations that occur due to the switching operation of each switching element of the second power conversion unit 13 between on (conduction) and off (cutoff). The second power conversion unit 13 includes, for example, a fourth current sensor 38a arranged between the β-phase first coil 33 (β1) and the midpoint R2, and a fifth current sensor 38b arranged between the β-phase second coil 34 (β2) and the midpoint R4. For example, the fourth current sensor 38a detects the current flowing through the β-phase first coil 33 (β1), and the fifth current sensor 38b detects the current flowing through the β-phase second coil 34 (β2).

[0030] The DC power supply connection unit 14 and the AC power supply connection unit 15 include, for example, connectors for DC power and AC power of predetermined standards. The DC power supply connection unit 14 and the AC power supply connection unit 15 are connected to an external DC power supply (external DC power supply) and an AC power supply (external AC power supply) based on, for example, a commercial power supply connected to a power grid. The DC power supply connection unit 14 is connected, for example, to the negative electrode of the second power conversion unit 13 and to the midpoint of each of the first switch 22 and the second switch 32 (that is, between the two transistors connected in anti-series). The AC power supply connection unit 15 is connected, for example, to each of the first midpoint R1 and the fourth midpoint R4 of the second power conversion unit 13, and to each of the connection points between the β-phase first coil 33 (β1) and the third circuit breaker 35 and the connection point between the β-phase second coil 34 (β2) and the fourth circuit breaker 36.

[0031] The rotating electric machine 16 (M) is, for example, a two-phase AC brushless DC motor. The rotating electric machine 16 includes, for example, an α-phase first coil 23 (α1), an α-phase second coil 24 (α2), a β-phase first coil 33 (β1), a β-phase second coil 34 (β2), a rotor 41, and a stator core 42. The rotor 41 is equipped with a permanent magnet for a field magnet. The stator core 42 is formed of an electromagnetic steel sheet such as silicon steel. The stator core 42 is fitted with coils α1, α2, β1, and β2 that generate a rotating magnetic field that rotates the rotor 41.

[0032] The α-phase first coil 23 (α1) and the α-phase second coil 24 (α2), and the β-phase first coil 33 (β1) and the β-phase second coil 34 (β2) are so-called open-end coils, and the ends of each coil α1, α2, β1, β2 are not connected to each other (i.e., each coil α1, α2, β1, β2 is disconnected from each other) and are drawn out to the outside of the rotating electric machine 16.

[0033] The α-phase first coil 23 (α1) and the α-phase second coil 24 (α2) are, for example, arranged so that the spatial phase difference between them is zero, and are wound in the same direction around different teeth of the stator core 42 when viewed from the axial direction along the central axis of the rotating electric machine 16 (M). The α-phase first coil 23 (α1) and the α-phase second coil 24 (α2) are, for example, arranged so as to share a part of a slot 43 formed in the stator core 42, and are magnetically coupled to each other with the same polarity. The β-phase first coil 33 (β1) and the β-phase second coil 34 (β2) have, for example, zero spatial phase difference therebetween and are wound in the same direction around different teeth of the stator core 42 when viewed from the axial direction along the central axis of the rotating electric machine 16 (M). The β-phase first coil 33 (β1) and the β-phase second coil 34 (β2) are, for example, arranged so as to share a part of a slot 43 formed in the stator core 42, and are magnetically coupled to each other with the same polarity.

[0034] The α-phase first coil 23 (α1) and α-phase second coil 24 (α2) and the β-phase first coil 33 (β1) and β-phase second coil 34 (β2) are arranged so as not to magnetically interfere with each other by making the spatial phase difference between them 90°. For example, the coils α1, α2, β1, and β2 are attached to the stator core 42 by concentrated winding or distributed winding, and the number of turns of the coils α1, α2, β1, and β2 is the same.

[0035] The rotating electric machine 16(M) generates rotational power by performing power running operation using electric power supplied from the first electric power conversion unit 12 and the second electric power conversion unit 13. When the rotating electric machine 16(M) is connected to the wheels of a vehicle, for example, it generates driving force for traveling using electric power supplied from the first electric power conversion unit 12 and the second electric power conversion unit 13. The rotating electric machine 16(M) may generate power by performing regenerative operation using rotational power input from the wheels of the vehicle. When the rotating electric machine 16(M) is connected to the internal combustion engine of the vehicle, for example, it may generate power using the power of the internal combustion engine.

[0036] The gate drive unit 17 switches on (conducting) and off (disconnecting) each of the switching elements of the first power conversion unit 12 and the second power conversion unit 13 and each of the disconnectors 25, 26, 35, 36, and 39 based on a control signal received from the electronic control unit 18. For example, the gate drive unit 17 switches on (conducting) and off (disconnecting) each of the switching elements of the full bridge circuits 12a, 12b, 13a, and 13b by outputting a gate signal generated by amplifying and level-shifting a control signal.

[0037] The electronic control unit 18 comprehensively controls the operations of the power control unit 10a and the rotating electric machine 16(M). For example, the electronic control unit 18 is a software function unit that functions when a processor such as a CPU (Central Processing Unit) executes a predetermined program. The software function unit is an ECU (Electronic Control Unit) that includes a processor such as a CPU, a ROM (Read Only Memory) that stores programs, a RAM (Random Access Memory) that temporarily stores data, and electronic circuits such as a timer. At least a part of the electronic control unit 18 may be an integrated circuit such as an LSI (Large Scale Integration).

[0038] The electronic control unit 18 generates control signals that indicate the timing to turn on (conducting) and off (disconnecting) each of the switching elements of the first power conversion unit 12 and the second power conversion unit 13 and each of the disconnectors 25, 26, 35, 36, 39. The electronic control unit 18 inputs the generated control signals to the gate drive unit 17.

[0039] FIG. 3 is a diagram showing a partial configuration of the electrical device 10 according to the embodiment. 1, 2, and 3, the electrical device 10 includes, for example, a sensor 51 that detects the phase (rotation angle) θ of the rotor 41 of the rotating electrical machine 16 (M), and a restriction mechanism 52 that restricts power transmission in a power transmission mechanism connected to the rotor 41. The restriction mechanism 52 is, for example, an electric parking brake and parking lock mechanism in a vehicle.

[0040] (Control operation of electrical equipment) When the rotating electric machine 16 (M) is in power running or regenerative operation, the electronic control unit 18 sets the first circuit breaker 25 and the second circuit breaker 26 to an on (conducting) state. By switching the first switch 22 and the second switch 32 between on (conducting) and off (disconnecting), the electronic control unit 18 switches between a series connection of the α-phase coils α1, α2 and a series connection of the β-phase coils β1, β2, and a parallel connection of the α-phase coils α1, α2 and a parallel connection of the β-phase coils β1, β2. The electronic control unit 18 performs, for example, current feedback control using a current detection value of the rotating electric machine 16(M) and a current target value corresponding to a torque command value of the rotating electric machine 16(M), and generates a control signal that instructs the driving of each switching element of the first power conversion unit 12 and the second power conversion unit 13.

[0041] During DC charging, that is, when the power storage device 11 is charged by an external DC power supply connected to the DC power supply connection unit 14, the electronic control unit 18 sets the first circuit breaker 25 and the second circuit breaker 26 to an on (conductive) state. For example, with respect to an external DC power supply having a lower voltage than the power storage device 11, the electronic control unit 18 causes each of the combination of the α-phase coils α1, α2 and the first power conversion unit 12 and the combination of the β-phase coils β1, β2 and the second power conversion unit 13 to function as a non-insulated DC-DC converter that performs a boost operation using so-called chopper control.

[0042] During AC charging, i.e., when charging the power storage device 11 using an external AC power source connected to the AC power source connection portion 15, the electronic control unit 18 sets the first circuit breaker 25 and the second circuit breaker 26 to an off (disconnected) state for insulation. The electronic control unit 18, for example, sets the α-phase first coil 23 (α1) and the α-phase second coil 24 (α2), which are magnetically coupled to each other with the same polarity, as a coil of a DC conversion phase (α-phase) used for conversion between DC powers. The electronic control unit 18, for example, causes the combination of the α-phase coils α1, α2 and the first power conversion unit 12 to function as a DAB (Dual Active Bridge) DC-DC converter, which is an insulated bidirectional (step-up and step-down) converter.

[0043] The electronic control unit 18, for example, configures the β-phase first coil 33 (β1) and the β-phase second coil 34 (β2), which are magnetically coupled to each other with the same polarity, as the coil of the AC power supply input phase (β-phase) connected to the external AC power supply. The electronic control unit 18, for example, causes the combination of the β-phase coils β1 and β2 and the second power conversion unit 13 to function as a so-called full-bridgeless (or bridgeless and totem-pole) power factor correction (PFC) circuit that converts AC power to DC power. The so-called bridgeless PFC is a PFC that does not include a bridge rectifier made up of multiple bridge-connected diodes, while the so-called totem-pole PFC is a PFC that includes a pair of switching elements of the same conductivity type connected in series in the same direction (totem-pole connection). The electronic control unit 18, for example, controls the switching of each switching element in each full bridge circuit 13a, 13b of the second power conversion unit 13, thereby rectifying and boosting the AC power received from the external AC power source to DC power and improving the power factor of the input voltage Vac and the input current Iac.

[0044] For example, when transmitting power between the first full bridge circuit 12a and the second full bridge circuit 12b via the α-phase first coil 23 (α1) and the α-phase second coil 24 (α2), the electronic control unit 18 controls the phase difference between the first full bridge circuit 12a and the second full bridge circuit 12b within a range including 90° to 180° in addition to the range from 0° to 90°. Fig. 3 is a diagram showing an example of time changes in current of each of the α-phase coils α1 and α2 in the embodiment and the comparative example. Fig. 4 is a diagram showing an example of changes in output voltage and loss (iron loss and copper loss) according to the phase between the first full-bridge circuit 12a and the second full-bridge circuit 12b in the embodiment and the comparative example.

[0045] In the embodiment and comparative example shown in FIG. 3 , the conditions, such as the primary-side voltage, secondary-side voltage, switching frequency, and output, are the same for the combination of the full-bridge circuits 12a, 12b of the first power conversion unit 12 and the α-phase coils α1, α2 of the rotating electric machine 16(M). The embodiment corresponds to a case where the phase difference between the full-bridge circuits 12a, 12b is controlled within a range including 90° to 180° (e.g., 136°, etc.), while the comparative example corresponds to a case where the phase difference between the full-bridge circuits 12a, 12b is controlled within a range from 0° to 90° (e.g., 44°, etc.). In the embodiment, the currents in the α-phase coils α1, α2 are larger than in the comparative example, but the larger phase difference reduces the sum of the currents in the α-phase coils α1, α2. In the embodiment, the sum of the currents in the α-phase coils α1, α2 is smaller than in the comparative example, and the magnetic flux offset between the primary and secondary sides is increased, thereby reducing iron loss.

[0046] The embodiment and comparative example shown in FIG. 4 have the same output power, for example. The embodiment is a DAB DC-DC converter that combines the full-bridge circuits 12a, 12b of the first power conversion unit 12 with the α-phase coils α1, α2 of the rotating electric machine 16(M). The comparative example is a DAB DC-DC converter having a core made of a different material than that of the embodiment. The stator core 42 of the rotating electric machine 16(M) of the embodiment is formed of an electromagnetic steel sheet such as silicon steel. The core of the comparative example is a powder magnetic core formed of soft magnetic iron powder, for example. In the comparative example, copper loss is greater than iron loss, and copper loss increases when the phase difference is in the range of 90° to 180°. In the embodiment, iron loss is greater than copper loss when the phase difference is in the range of 0° to 90°, and total loss is reduced as iron loss decreases when the phase difference is in the range of 90° to 180°.

[0047] As described above, according to the electric device 10 and the control method for the electric device 10 of the embodiment, when performing insulated power conversion using the α-phase coils 23 (α1), 24 (α2) of the rotating electric machine 16 (M), iron loss can be reduced by non-standard control even if, for example, the ratio of iron loss to total loss increases due to the material forming the rotating electric machine 16 (M). By controlling the phase difference between the first full-bridge circuit 12a and the second full-bridge circuit 12b within a relatively large range including 90° to 180°, the sum of the currents flowing through the α-phase coils 23 (α1), 24 (α2) can be reduced, and the magnetic flux offset between the primary side and the secondary side can be increased, thereby reducing iron loss and effectively suppressing a decrease in efficiency.

[0048] Even if the material forming the stator core 42 of the rotating electrical machine 16(M) is, for example, an electromagnetic steel sheet, which prioritizes high magnetic flux density and has magnetic properties that increase loss in the high frequency range, a decrease in efficiency can be effectively suppressed by reducing iron loss. The magnetically coupled α-phase coils 23(α1), 24(α2) can improve power conversion efficiency.

[0049] When the rotating electric machine 16(M) is driven by the power storage device 11, the power control unit 10a can function as an inverter of a quadruple full-bridge circuit. When the power storage device 11 is being charged with DC from an external power source, the combination of each coil of the rotating electric machine 16(M) and each full-bridge circuit can function as a non-insulated DC-DC converter. When the power storage device 11 is being charged with AC from an external power source, the combination of each α-phase coil 23(α1), 24(α2) of the rotating electric machine 16(M) and the first and second full-bridge circuits 12a and 12b can function as an insulated bidirectional DC-DC converter. For example, in the case of a voltage boost operation during AC charging, the power storage device 11 can be quickly charged at a voltage higher than the charging voltage from the external power source.

[0050] (Variation) Modifications of the embodiment will be described below. Note that the same parts as those in the above-described embodiment will be denoted by the same reference numerals, and descriptions thereof will be omitted or simplified. In the above-described embodiment, the α-phase first coil 23 (α1) and the α-phase second coil 24 (α2), and the β-phase first coil 33 (β1) and the β-phase second coil 34 (β2) are each wound around different teeth of the stator core 42, but this is not limited to this. FIG. 5 is a configuration diagram of a rotating electric machine 16A of the electric device 10 according to a modification of the embodiment. As shown in FIG. 5, the α-phase first coil 23 (α1) and the α-phase second coil 24 (α2), and the β-phase first coil 33 (β1) and the β-phase second coil 34 (β2) may each be wound around the same teeth of the stator core 42.

[0051] In the above-described embodiment, the β-phase first coil 33 (β1) and the β-phase second coil 34 (β2) are magnetically coupled to each other with the same polarity, but this is not limiting, and the β-phase first coil 33 (β1) and the β-phase second coil 34 (β2) may be magnetically coupled to each other with opposite polarities. In this case, for example, a disconnector may be provided connected between one end of the β-phase first coil 33 (β1) and a midpoint R2 of the second phase of the third full-bridge circuit 13a, or a disconnector may be provided between one end of the β-phase second coil 34 (β2) and a midpoint R3 of the third phase of the fourth full-bridge circuit 13b.

[0052] In the above-described embodiment, current flows from the external AC power supply to the β-phase first coil 33 (β1) and the β-phase second coil 34 (β2) during AC charging, but this is not limited to this. For example, at least one of a circuit breaker that switches on (conduction) and off (disconnection) of the connection between the AC power supply connection unit 15 and the β-phase first coil 33 (β1) and a circuit breaker that switches on (conduction) and off (disconnection) of the connection between the AC power supply connection unit 15 and the β-phase second coil 34 (β2) may be provided. In this case, the current may be set to flow only through the β-phase first coil 33 (β1) or the β-phase second coil 34 (β2).

[0053] In the above-described embodiment, the DC power supply connection unit 14 is connected in a parallel pattern to the negative electrode of the second power conversion unit 13 and the midpoint of each of the first switch 22 and the second switch 32 (i.e., between the two transistors connected in anti-series), but this is not limiting. For example, the DC power supply connection unit 14 may be connected in a series pattern to the negative electrode of the second power conversion unit 13 and the midpoint Q4 of the first power conversion unit 12 and the midpoint R4 of the second power conversion unit 13. For example, the DC power supply connection unit 14 may be connected in another parallel pattern to the negative electrode of the second power conversion unit 13 and the midpoints Q2 and Q4 of the first power conversion unit 12 and the midpoints R2 and R4 of the second power conversion unit 13.

[0054] The embodiments of the present invention are presented as examples and are not intended to limit the scope of the invention. These embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are intended to be included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as defined in the claims. [Explanation of symbols]

[0055] 10...electrical equipment, 10a...power control unit, 11...power storage device, 12...first power conversion section, 12a...first full bridge circuit, 12b...second full bridge circuit, 13...second power conversion section, 13a...third full bridge circuit, 13b...fourth full bridge circuit (third full bridge circuit), 14...DC power supply connection section, 15...AC power supply connection section (power supply connection member), 16...rotating electric machine (M), 17...gate drive unit, 18 ...Electronic control unit, 22...First switch, 23...α-phase first coil (α1) (first coil), 24...α-phase second coil (α2) (second coil), 25...First circuit breaker, 26...Second circuit breaker, 32...Second switch, 33...β-phase first coil (β1) (coil), 34...β-phase second coil (β2) (coil), 35...Third circuit breaker, 36...Fourth circuit breaker (third circuit breaker), 41...Rotor, 42...Stator core, 43...Slot.

Claims

1. a power storage device; a rotating electric machine including a first coil, a second coil, and at least one coil connected to an external power supply; a power control unit connected to the power storage device and the rotating electric machine, and controlling the exchange of power between the power storage device and the rotating electric machine; Equipped with The power control unit a first full-bridge circuit connected to both ends of the first coil; a second full bridge circuit connected to both ends of the second coil; Equipped with When power is transmitted between the first full bridge circuit and the second full bridge circuit via the first coil and the second coil, a phase difference between the first full bridge circuit and the second full bridge circuit is controlled within a range including 90° to 180°. Electrical equipment.

2. the first coil and the second coil are open-ended, The rotating electric machine includes a stator core having a slot formed therein, the slot being shared by the first coil and the second coil that are magnetically coupled to each other. The electrical device according to claim 1 .

3. The power control unit a first breaker connected between the positive electrodes of the first full-bridge circuit and the second full-bridge circuit; a second breaker connected between the negative electrodes of the first full-bridge circuit and the second full-bridge circuit; at least one third full bridge circuit connected across the at least one coil; at least one third breaker connected between one end of the at least one coil and the at least one third full bridge circuit; Equipped with a power supply connection member that is connected to both ends of the third breaker to connect the power control unit and the at least one coil to the external power supply; The electrical device according to claim 2.

4. a power storage device; a rotating electric machine including a first coil, a second coil, and at least one coil connected to an external power supply; a power control unit including a first full-bridge circuit connected to both ends of the first coil and a second full-bridge circuit connected to both ends of the second coil, and connected to the power storage device and the rotating electric machine to control the exchange of power between the power storage device and the rotating electric machine; A control method for an electrical device comprising: a step of controlling a phase difference between the first full bridge circuit and the second full bridge circuit within a range including 90° to 180° when power is transmitted between the first full bridge circuit and the second full bridge circuit via the first coil and the second coil.

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