Electric vehicle control method and electric vehicle control device

Abstract

According to this electric vehicle control method, when a battery is charged by means of an external charger, the external charger is connected to the battery via a boost converter configured using a rotary electric machine and an inverter, and the battery is warmed up by transporting heat of the rotary electric machine and the inverter to the battery. In this electric vehicle control method, an allowable current, which is an input current that can be allowed by the battery, is calculated, a warm-up current, which is a current consumed as losses in the rotary electric machine and the inverter, is calculated, and a charging current to be input from the external charger is determined on the basis of the allowable current and the warm-up current. Then, when the charging current is supplied to the neutral point of the rotary electric machine, the inverter is switched such that the allowable current is supplied to the battery and a d-axis current corresponding to the warm-up current recirculates in the rotary electric machine.

Description

Control method for electric vehicles, and control device for electric vehicles

[0001] The present invention relates to a control method and control device for electric vehicles.

[0002] JP2021-192577A discloses a vehicle in which the vehicle drive motor and inverter are used as boost converters when charging the on-board battery using a charger.

[0003] Batteries have a temperature range in which they operate normally. Below this temperature range, the battery's performance deteriorates. Specifically, at low temperatures, the maximum power the battery can output (so-called output power) decreases. Also, at low temperatures, the maximum current the battery can accept as input (hereinafter referred to as the allowable current) decreases.

[0004] In cold climates and other environments where ambient temperatures are low, the batteries installed in electric vehicles may enter a low temperature state that falls below their normal operating temperature range. Furthermore, in electric vehicles, it may be necessary to charge batteries whose current capacity has decreased due to these low temperatures.

[0005] Thus, in order to quickly charge a battery whose allowable current has decreased at low temperatures, it is usually necessary to warm up the battery to restore its allowable current. Batteries are warmed up, for example, by transporting heat from rotating electric machinery and inverters. For this reason, electric vehicles may actively generate heat with rotating electric machinery and inverters in order to warm up the batteries.

[0006] However, when using a rotating electric machine and inverter as a boost converter, the amount of heat generated by the rotating electric machine and inverter is limited by the battery's allowable current. That is, if the battery's allowable current is low, the current flowing through the rotating electric machine and inverter is usually determined by the battery's allowable current. Therefore, when the battery is at a low temperature and the allowable current is low, the amount of heat generated by the rotating electric machine and inverter will inevitably be small, and the battery will not warm up. Consequently, the recovery of the allowable current is slow, and the battery charging proceeds very slowly.

[0007] The present invention aims to provide a control method and control device for electric vehicles that can quickly warm up and charge a battery when the battery is charged by an external charger and a rotating electric machine and inverter are used as a boost converter.

[0008] One aspect of the present invention is a control method for an electric vehicle in which, when charging the battery with an external charger, the external charger is connected to the battery via a boost converter configured with a rotating electric machine and an inverter, and the battery is warmed up by transporting heat from the rotating electric machine and inverter to the battery. In this control method for an electric vehicle, the allowable current, which is the input current that the battery can tolerate, is calculated, the warm-up current, which is the current consumed as loss in the rotating electric machine and inverter, is calculated, and the charging current to be input from the external charger is determined based on the allowable current and the warm-up current. Then, when the charging current is supplied to the neutral point of the rotating electric machine, the inverter is switched so that the allowable current is supplied to the battery and a d-axis current corresponding to the warm-up current flows back in the rotating electric machine.

[0009] Figure 1 is a block diagram showing the schematic configuration of an electric vehicle. Figure 2 is an explanatory diagram showing the circuit configuration of the electric powertrain. Figure 3 is a block diagram showing the configuration of the controller. Figure 4 is a block diagram showing the configuration of the current vector control unit. Figure 5 is a block diagram showing the configuration of the charging control unit. Figure 6 is a block diagram showing the configuration of the allowable current calculation unit. Figure 7 is an explanatory diagram showing the allowable power table. Figure 8 is an explanatory diagram showing the current flow in a rotating electric machine and an inverter. Figure 9 is an explanatory diagram schematically showing the switching of the inverter and the current flowing through the inverter. Figure 10 is a block diagram showing the configuration of the charging current calculation unit. Figure 11 is a block diagram showing the configuration of the dq axis current command value calculation unit. Figure 12 is an explanatory diagram showing the d axis current map. Figure 13 is an explanatory diagram showing the phase current when the d axis current flows according to the d axis current map. Figure 14 is an explanatory diagram showing the phase current when the d axis current flows according to the d axis current map. Figure 15 is an explanatory diagram showing the phase current when the d axis current flows according to the d axis current map. Figure 16 is an explanatory diagram showing the relationship between the boost ratio and the drive signal. Figure 17 is an explanatory diagram showing the current flow during the first period. Figure 18 is an explanatory diagram showing the current flow during the second period. Figure 19 is an explanatory diagram showing the current flow during the third period. Figure 20 is an explanatory diagram showing the current flow during the third period. Figure 21 is a flowchart relating to the charge control (warm-up control) of this embodiment, in which the battery is warmed up at the same time as the battery is charged using an external charger. Figure 22 is a flowchart relating to the mode selection of the charge control (warm-up control).

[0010] Embodiments of the present invention will be described below with reference to the drawings.

[0011] Figure 1 is a block diagram showing the schematic configuration of an electric vehicle 100. An electric vehicle 100 is a vehicle that generates all or part of its driving force by electric power, such as an electric vehicle or a hybrid vehicle. As shown in Figure 1, the electric vehicle 100 comprises a battery 10, an electric powertrain 11, a cooling system 12, and a controller 13.

[0012] The battery 10 stores the power for driving the electric vehicle 100. The battery 10 is composed of, for example, a lithium-ion battery and is rechargeable. The battery 10 supplies power to the electric power train 11 and is charged by the power generated by the electric power train 11 when the electric power train 11 generates power. In the present embodiment, the battery 10 can be connected to an external charger 14. Therefore, when the external charger 14 is connected to the electric vehicle 100, the battery 10 is charged by the power supplied from the external charger 14.

[0013] The battery 10 has a temperature range in which it operates normally. When the battery 10 enters a low-temperature state below this temperature range, its performance deteriorates. In the present embodiment, when the temperature of the battery 10 (hereinafter referred to as the battery temperature T ｂ ), which is lower than a predetermined temperature threshold T ｔｈ determined in advance according to the specific characteristics of the battery 10, it is assumed that the battery 10 is in a low-temperature state. Specifically, in the low-temperature state where the battery temperature T ｂ is lower than the temperature threshold T ｔｈ (T ｂ < T ｔｈ ), the maximum power that the battery can input and output (hereinafter referred to as the allowable power P ａｐｒｖ ) decreases. Also, in the low-temperature state (T ｂ < T ｔｈ ), the maximum input current that the battery 10 can tolerate (hereinafter referred to as the allowable current I ａｐｒｖ ) decreases. In the low-temperature state, if a current exceeding the allowable current I ａｐｒｖ is input to the battery 10, metal deposition or the like may occur and the battery 10 may malfunction. Therefore, when charging the battery 10 in the low-temperature state, the current input to the battery 10 is limited to the allowable current I ａｐｒｖ or less.

[0014] The electric powertrain 11 is a drive unit that generates driving force for the electric vehicle 100 using electricity supplied from the battery 10. The electric powertrain 11 may include a power generation unit that generates electricity to be stored in the battery 10. In any case, the electric powertrain 11 includes at least an inverter 21 and a rotating electric machine 22. In this embodiment, the inverter 21 and the rotating electric machine 22 constitute the drive unit of the electric vehicle 100.

[0015] The inverter 21 converts the DC power supplied from the battery 10 into AC power and supplies it to the rotating electric machine 22. When the rotating electric machine 22 generates electricity, the inverter 21 converts the AC power it generates into DC power and inputs it to the battery 10. This charges the battery 10.

[0016] The rotating electric machine 22 is either an electric motor or a generator. In this embodiment, the rotating electric machine 22 is, for example, a magnet-embedded three-phase AC synchronous motor. Therefore, the rotating electric machine 22 rotates using power supplied from the battery 10 via the inverter 21, generating driving force for the electric vehicle 100. Furthermore, when the rotating electric machine 22 is driven by the electric vehicle 100, it generates power (regenerative power) through so-called regenerative control.

[0017] In addition, in the electric vehicle 100, the electric powertrain 11 constitutes part of the connection interface to the external charger 14. In this embodiment, when the battery 10 is charged by the external charger 14, the external charger 14 may be connected to the battery 10 via the electric powertrain 11. When the external charger 14 is connected to the electric vehicle 100 in this way, the inverter 21 and the rotating electric machine 22 of the electric powertrain 11 are controlled to function as a boost converter.

[0018] The cooling system 12 is, in principle, a system for cooling the battery 10, the electric powertrain 11, and other heat-generating parts of the electric vehicle 100. The cooling system 12 is composed of, for example, a coolant circulation system that circulates water or other liquids, a heat pump system that circulates a refrigerant gas while compressing and expanding it, or a combination thereof.

[0019] The cooling system 12 has multiple refrigerant circulation paths, which can be switched as needed. The cooling system 12 cools the battery 10 and the electric powertrain 11 by circulating refrigerant that has been cooled, for example, by a radiator (not shown).

[0020] Furthermore, the cooling system 12 can circulate a coolant between, for example, the battery 10 and the electric powertrain 11 via a circulation path that does not involve a radiator. In this case, heat is transported between the battery 10 and the electric powertrain 11. In particular, in this embodiment, when it is necessary to warm up the battery 10, the cooling system 12 functions as a heat transport system that transports the heat generated in the electric powertrain 11 to the battery 10. That is, when it is necessary to warm up the battery 10, the electric vehicle 100 actively generates heat in the electric powertrain 11 and transports that heat to the battery 10 using the cooling system 12, thereby raising the battery temperature T ｂ This can be increased. As mentioned above, the allowable current I of the battery 10 in low temperature conditions ａｐｒｖ It temporarily decreases, but the battery temperature T ｂ If it rises, the allowable current I ａｐｒｖ It will recover.

[0021] The controller 13 is a control device that comprehensively controls each part of the electric vehicle 100. The controller 13 is composed of, for example, one or more computers and is programmed to control each part of the electric vehicle 100 at a predetermined control cycle. For example, the controller 13 functions as a drive control device for the electric vehicle 100, such as generating driving force or braking force in the electric vehicle 100 in response to the driver's operation of the accelerator pedal, etc.

[0022] Furthermore, when the controller 13 charges the battery 10 using the external charger 14, the controller 13 inputs the current (hereinafter referred to as the charging current I) from the external charger 14 to the electric vehicle 100. ｃｈIt functions as a charging control device that controls the following: Furthermore, when using or charging the battery 10 in a low-temperature state, the controller 13 functions as a warm-up control device that warms up the battery 10 by transporting heat from the electric powertrain 11 to the battery 10.

[0023] In particular, in this embodiment, when charging the battery 10 in a low-temperature state with the external charger 14, the controller 13 warms up the battery 10 while charging. Specifically, when charging the battery 10 in a low-temperature state with the external charger 14, the controller 13 warms up the battery 10 by actively generating heat in the electric powertrain 11 and transporting that heat to the battery 10. At the same time, the controller 13 reduces the effective magnitude of the current input to the battery 10 to the allowable current I, which is reduced due to the low-temperature state. ａｐｒｖ Charge battery 10 while limiting it to or below that level.

[0024] The external charger 14 is, for example, a charging device installed at a charging station or the like. The external charger 14 is a so-called standard charger or a fast charger.

[0025] The rated input voltage of the external charger 14 (hereinafter referred to as the external input voltage V) ｒｅｆ The ( ) is predetermined for each external charger 14. In this embodiment, the external input voltage V ｒｅｆ The external input voltage V is lower than the rated voltage of battery 10. For example, the rated voltage of battery 10 is 800V, and the external input voltage V ｒｅｆ The voltage is 400V. Therefore, when charging the battery 10 using the external charger 14, the external input voltage V is increased by a boost converter configured using the inverter 21 and the rotating electric machine 22. ｒｅｆ The voltage is boosted to the rated voltage of battery 10.

[0026] The external charger 14 inputs a current to the electric vehicle 100 in response to a request from the controller 13. That is, the charging current I that the external charger 14 inputs to the electric vehicle 100. ｃｈ This is adjusted (controlled) by controller 13.

[0027] Figure 2 is an explanatory diagram showing the circuit configuration of the electric powertrain 11. As shown in Figure 2, the rotating electric machine 22 has windings (stator windings) for each of the U, V, and W phases. One end of each of these phase windings is connected. In other words, the rotating electric machine 22 has a neutral point 23.

[0028] The rotating electric machine 22 is equipped with a rotation position detector 24 that detects the rotational position of the rotor (hereinafter simply referred to as the rotor position). The rotation position detector 24 is, for example, a resolver. The controller 13 can acquire the detection result of the rotation position detector 24 as needed. In this embodiment, the controller 13 uses the rotation position detector 24 to detect the electrical angle θ of the rotor. The controller 13 also detects the current flowing through the windings of each phase (hereinafter referred to as the phase current i). ｕｖｗ The phase current i can be detected as needed using the current sensor 25. ｕｖｗ The U-phase current i ｕ , V phase current i ｖ , and W-phase current i ｗ This is a general term for the rotor. Note that the rotor is not shown in the diagram. Also, in the scene where the battery 10 is charged using the external charger 14, the rotating electric machine 22 is stopped. For this reason, when charging the battery 10 using the external charger 14, the electrical angle θ is a fixed value determined by the stopping position of the rotor.

[0029] The inverter 21 is voltage type, and the upper and lower arms of each phase leg (UVW) are composed of switching elements and freewheeling diodes. Here, the upper arm of the U phase is Q １ And the lower arm of the U phase is Q ２ The upper arm of the V phase is Q. ３ And the lower arm of the V phase is Q ４ Furthermore, the upper arm of the W phase is Q. ５ And the lower arm of the W phase is Q ６ The switching elements of each arm are driven by the drive signal D generated by the controller 13. ｕｕ ＊ ~D ｗｌ ＊ = (D ｕｕ ＊ , D ｕｌ ＊, D ｖｕ ＊ , D ｖｌ ＊ , D ｗｕ ＊ , D ｗｌ ＊ ) switches according to the drive signal D. That is, the on / off state of each switching element is controlled by the drive signal D. ｕｕ ＊ ~D ｗｌ ＊ It can be switched by Q. １ The drive signal is D ｕｕ ＊ Q ２ The drive signal is D ｕｌ ＊ That is. Q ３ The drive signal is D ｖｕ ＊ Q ４ The drive signal is D ｖｌ ＊ And Q ５ The drive signal is D ｗｕ ＊ Q ６ Drive signal D ｗｌ ＊ That is the case. Below, unless there is a particular need to distinguish, Q １ ~Q ６ Drive signal D ｕｕ ＊ ~D ｗｌ ＊ Put them together into D ＊ It is sometimes abbreviated as follows:

[0030] The inverter 21 is connected to the battery 10 via a smoothing capacitor (input capacitor) 26. A voltage sensor 27 is provided at the input terminal of the inverter 21, and the controller 13 measures the DC voltage V at this input terminal. dｃ This can be detected as appropriate.

[0031] Battery 10 has a battery temperature T ｂ , SOC (State of Charge), and the output voltage of battery 10 (hereinafter referred to as battery voltage V ｂThe controller 13 is equipped with a battery state sensor 28 that detects the state of the battery 10, such as the battery temperature T. ｂ , SOC, and battery voltage V ｂ This can be obtained as appropriate. The SOC is a parameter representing the charge state (charge rate) of the battery 10. The battery 10 is connected to the inverter 21 via the first relay 31.

[0032] In addition, the electric powertrain 11 is equipped with a second relay 32, a third relay 33, a fourth relay 34, a smoothing capacitor 35 (input capacitor), and a voltage sensor 36 at the connection terminal to the external charger 14.

[0033] The second relay 32 is provided on the connection line between one end (positive terminal) of the external charger 14 and the neutral point 23 of the rotating electric machine 22. The third relay 33 is provided on the connection line between the other end (negative terminal) of the external charger 14 and the negative terminal of the battery 10. The fourth relay 34 is provided on the connection line that directly connects one end (positive terminal) of the external charger 14 and the positive terminal of the battery 10, without going through the rotating electric machine 22 and the inverter 21.

[0034] When the battery 10 is charged by the external charger 14, the controller 13 charges the battery 10 using one of two charging methods by controlling the open / closed states of the first relay 31, the second relay 32, the third relay 33, and the fourth relay 34.

[0035] The first charging method is a charging method in which the battery 10 is charged by directly connecting the external charger 14 and the battery 10 without going through the rotating electric machine 22 and the inverter 21. The controller 13 is, for example, an external input voltage V ｒｅｆ When the voltage is equal to the battery's rated voltage, the battery 10 is charged using the first charging method (non-boost charging method). When charging the battery 10 using the first charging method, the controller 13 closes the first relay 31, the third relay 33, and the fourth relay 34 to connect them, and opens the second relay 32 to disconnect them.

[0036] The second charging method connects the external charger 14 and the battery 10 via a boost converter configured using the rotating electrical machine 22 and the inverter 21, and charges the battery 10 by boosting the external input voltage V ｒｅｆ Thereby. When the external input voltage V ｒｅｆ is lower than the rated voltage of the battery 10, the battery 10 is charged by the second charging method (boost charging method). When charging the battery 10 by the second charging method, the controller 13 closes the first relay 31, the second relay 32, and the third relay 33 to put them in a connected state, and opens the fourth relay 34 to put it in a non-connected state.

[0037] Hereinafter, unless otherwise specified, it is assumed that the external input voltage V ｒｅｆ is lower than the rated voltage of the battery 10. Therefore, when charging the battery 10 using the external charger 14, the external charger 14 and the battery 10 are connected via a boost converter configured using the rotating electrical machine 22 and the inverter 21, and the battery 10 is charged by the second charging method.

[0038] The smoothing capacitor 35 smooths the power input from the external charger 14 to the electric vehicle 100.

[0039] The voltage sensor 36 measures the actual input voltage from the external charger 14 to the electric vehicle 100 (hereinafter referred to as the actual external input voltage V ｎ ). Therefore, the controller 13 can appropriately measure the actual external input voltage V ｎ as needed. However, hereinafter, for simplicity, it is assumed that the actual external input voltage V ｎ is equal to the external input voltage V ｒｅｆ which is the rated output voltage of the external charger 14. Therefore, when the controller 13 detects the connection of the external charger 14, it acquires information on the external input voltage V ｒｅｆ from the external charger 14. Then, the controller 13 uses the external input voltage V ｒｅｆ to execute control related to charging and warm-up of the battery 10.

[0040] FIG. 3 is a block diagram showing the configuration of the controller 13. Here, the configuration of the controller 13 for charging the battery 10 by the second charging method using the external charger 14 is shown. That is, the configuration of the controller 13 shown in FIG. 3 is a configuration for causing the rotating electrical machine 22 and the inverter 21 to function as a boost converter when charging the battery 10 using the external charger 14.

[0041] As shown in FIG. 3, the controller 13 includes a coordinate conversion unit 41, a current vector control unit 42, a coordinate conversion unit 43, a PWM control unit 44, a drive signal generation unit 45, and a charging control unit 46.

[0042] The coordinate conversion unit 43 calculates the dq-axis currents i ｕｖｗ from the phase current i ｄｑ by coordinate conversion based on the electrical angle θ of the rotor. Specifically, the coordinate conversion unit 43 calculates the dq-axis currents i ｕｖｗ from the phase current i ｄｑ according to the following equation (1).

[0043]

[0044] The dq-axis currents i ｄｑ are current components in a rectangular coordinate system that rotates according to the electrical angle θ. The dq-axis currents i ｄｑ are a general term for the d-axis current i ｄ and the q-axis current i ｑ . The d-axis current i ｄ is a current component that strengthens or weakens the magnetic field of the permanent magnet of the rotor (i.e., the magnetic field of the rotating electrical machine 22), and does not contribute to the torque of the rotating electrical machine 22. The q-axis current i ｑ is a current component that contributes to the torque of the rotating electrical machine 22.

[0045] In addition, the charging of the battery 10 using the external charger 14 is generally performed with the electric vehicle 100 stopped so that the rotating electrical machine 22 does not rotate. Therefore, in this embodiment, the q-axis current i ｑ is controlled to be substantially zero.

[0046] Furthermore, when the rotating electric machine 22 and inverter 21 function as a boost converter, the stator windings and legs of each phase (UVW) are normally controlled in perfect synchronization so that they function as three parallel boost converters. Therefore, no potential difference occurs between the phases, and normally the d-axis current i ｄ It is practically always zero.

[0047] However, in this embodiment, the d-axis current i ｄ The d-axis current i may be controlled to be a significant value (non-zero value). Specifically, when it is necessary to warm up the battery 10, the d-axis current i ｄ This is a significant value. That is, when charging the battery 10 using the external charger 14, if it is necessary to warm up the battery 10, the controller 13 operates the rotating electric machine 22 and the inverter 21 as boost converters, while intentionally supplying the rotating electric machine 22 with a d-axis current i ｄ This causes the controller 13 to generate heat in the rotating electric machine 22 and the inverter 21, and by transporting that heat to the battery 10, it promotes the warming up of the battery 10.

[0048] The current vector control unit 42 controls the dq axis current command value i ｄｑ ＊ and dq axis current i ｄｑ Based on this, the dq axis voltage command value v ｄｑ ＊ Perform the calculation.

[0049] dq axis current command value i ｄｑ ＊ is the dq axis current i ｄｑ This is the command value (target value) for the dq axis current command value i. ｄｑ ＊ is the d-axis current i ｄ The command value for the d-axis current is i. ｄ ＊ and q-axis current i ｑ The command value for the q-axis current is i. ｑ ＊ This is a general term for the dq axis current command value i ｄｑ ＊ This is set by the charging control unit 46.

[0050] In this embodiment, when it is not necessary to warm up the battery 10, the d-axis current command value i ｄ ＊ It is set to zero. On the other hand, when it is necessary to warm up the battery 10, the d-axis current command value i ｄ ＊ The value is set to a significant value. Furthermore, regardless of whether or not it is necessary to warm up the battery 10 in order to prevent the rotating electric machine 22 from rotating (generating torque) while the battery 10 is being charged, the q-axis current command value i ｑ ＊ It is set to zero.

[0051] dq axis voltage command value v ｄｑ ＊ The voltage v on the dq axis is ｄｑ This is the command value (target value) for the dq axis voltage v. ｄｑ This is the voltage in the dq-axis coordinate system. dq-axis voltage v ｄｑ The d-axis voltage v ｄ and q-axis voltage v ｑ This is a general term for the dq axis voltage command value v. ｄｑ ＊ The d-axis voltage v ｄ The command value for the d-axis voltage is the command value v. ｄ ＊ The command value for the q-axis voltage vq is the q-axis voltage command value v ｑ ＊ It is a general term for [something].

[0052] The coordinate transformation unit 43 performs a coordinate transformation based on the rotor's electrical angle θ to obtain the dq axis voltage command value v ｄｑ ＊ From the phase voltage command value v ｕｖｗ ＊ The following calculation is performed. Specifically, the coordinate transformation unit 43 calculates the dq axis voltage command value v according to the following equation (2). ｄｑ ＊ From the phase voltage command value v ｕｖｗ ＊ Perform the calculation.

[0053]

[0054] Phase voltage command value v ｕｖｗ ＊ This refers to the voltage of each phase (UVW) (hereinafter referred to as phase voltage v ｕｖｗThis is the command value (target value) for the phase voltage v. ｕｖｗ The U-phase voltage v ｕ V-phase voltage v ｖ , and W-phase voltage v ｗ This is a general term for the phase voltage command value v. ｕｖｗ ＊ The U-phase voltage v ｕ The command value for the U-phase voltage is the command value v. ｕ ＊ V-phase voltage v ｖ The command value for the V-phase voltage is the command value v. ｖ ＊ , and W-phase voltage v ｗ The command value for the W-phase voltage is the command value v. ｗ ＊ It is a general term for [something].

[0055] The PWM control unit 44 controls the phase voltage command value v ｕｖｗ ＊ DC voltage V ｄｃ , and the step-up ratio r ｓｕ Based on this, the duty cycle command values ​​Duty_uvw for each phase of UVW are set. The duty cycle command value Duty_uvw is a command value that determines the duty cycle ratio in PWM (Pulse Width Modulation) control. The duty cycle command value Duty_uvw is a collective term for the U-phase duty cycle command value Duty_u, the V-phase duty cycle command value Duty_v, and the W-phase duty cycle command value Duty_w. Specifically, the PWM control unit 44 calculates the duty cycle command value Duty_uvw according to the following equation (3). Note that although equation (3) shows the calculation of the U-phase duty cycle command value Duty_u, the V-phase duty cycle command value Duty_v and the W-phase duty cycle command value Duty_w are calculated in the same way. Boost ratio r ｓｕ r is the boost ratio of the boost converter, which is composed of a rotating electric machine 22 and an inverter 21. ｓｕ This is set by the charging control unit 46.

[0056]

[0057] The drive signal generation unit 45 generates a predetermined carrier signal S Ｃ(See Figure 9) and the duty command value Duty_uvw are compared, Q １ ~Q ６ Drive signal D ＊ (that is, D ｕｕ ＊ ~D ｗｌ ＊ ) generates. In this embodiment, the carrier signal S Ｃ It is a triangular wave.

[0058] The charging control unit 46 controls the battery temperature T ｂ SOC, battery voltage V ｂ Electrical angle θ, DC voltage V ｄｃ External input voltage V ｒｅｆ , phase current i ｕｖｗ , and using the duty cycle command value Duty_uvw, the dq axis current command value i ｄｑ ＊ , step-up ratio r ｓｕ , and the charging current command value I ｃｈ ＊ The following is calculated: Charging current command value I ｃｈ ＊ This refers to the charging current I input from the external charger 14 to the electric vehicle 100. ｃｈ This is the command value (request value) for the external charger 14.

[0059] Figure 4 is a block diagram showing the configuration of the current vector control unit 42. As shown in Figure 4, the current vector control unit 42 controls the dq axis current i ｄｑ The dq axis current command value i ｄｑ ＊ The dq-axis voltage command value v is controlled by PI (Proportional Integral) control to match or asymptotically approach the specified value. ｄｑ ＊ This is determined. Specifically, the current vector control unit 42 includes deviation calculators 47d and 47q and PI controllers 48d and 48q.

[0060] The deviation calculator 47d calculates the d-axis current command value i ｄ ＊ and d-axis current i ｄ The deviation is calculated. In this embodiment, the deviation calculator 47d calculates the d-axis current command value i ｄ ＊ From the d-axis current i ｄSubtract the value i. Similarly, the deviation calculator 47q calculates the q-axis current command value i. ｑ ＊ and q-axis current i ｑ The deviation is calculated. In this embodiment, the deviation calculator 47q calculates the q-axis current command value i ｑ ＊ From the q-axis current i ｑ Subtract it.

[0061] The PI controller 48d controls the d-axis current command value i ｄ ＊ and d-axis current i ｄ The deviation becomes zero, and the d-axis current i ｄ The d-axis current command value i ｄ ＊ The d-axis voltage command value v should match this. ｄ ＊ The PI controller 48q determines the q-axis current command value i. ｑ ＊ and q-axis current i ｑ The deviation becomes zero, and the q-axis current i ｑ The q-axis current command value i ｑ ＊ The q-axis voltage command value v should match this. ｑ ＊ To decide.

[0062] Figure 5 is a block diagram showing the configuration of the charging control unit 46. As shown in Figure 5, the charging control unit 46 includes an allowable current calculation unit 51, a warm-up current calculation unit 52, a boost ratio calculation unit 53, a charging current calculation unit 54, and a dq axis current command value calculation unit 55.

[0063] The allowable current calculation unit 51 calculates the battery temperature T ｂ , SOC, and battery voltage V ｂ Based on this, the allowable current I of battery 10 ａｐｒｖ Perform the calculation.

[0064] The warm-up current calculation unit 52 calculates the phase current i ｕｖｗ Based on the duty cycle command value Duty_uvw, the warm-up current I ｄｃ－ｈ Calculate (estimate) the warm-up current I. ｄｃ－ｈ This is the current (DC current component) consumed as losses in the rotating electric machine 22 and inverter 21, which function as a boost converter. Warm-up current I ｄｃ－ｈThis causes the rotating electric machine 22 and inverter 21 to generate heat as all or part of the energy is consumed. This heat generated in the rotating electric machine 22 and inverter 21 is then transported to the battery 10. Therefore, the warm-up current I ｄｃ－ｈ This is essentially the current component that contributes to warming up the battery 10.

[0065] The step-up ratio calculation unit 53 calculates the DC voltage V ｄｃ and external input voltage V ｒｅｆに Based on this, the boost ratio r of the boost converter configured using the rotating electric machine 22 and the inverter 21 ｓｕ The boost ratio calculation unit 53 calculates the boost ratio r using the following formula (4). ｓｕ Perform the calculation.

[0066]

[0067] The charging current calculation unit 54 calculates the allowable current I ａｐｒｖ , warm-up current I ｄｃ－ｈ , and the step-up ratio r ｓｕ Based on this, the charging current command value I ｃｈ ＊ To calculate (determine) this.

[0068] The dq-axis current command value calculation unit 55 calculates the rotor electrical angle θ and the battery temperature T. ｂ , charging current command value I ｃｈ ＊ , and the step-up ratio r ｓｕ Based on this, the dq axis current command value i ｄｑ ＊ The calculation unit 55 calculates the charging current command value I from the external charger 14. Specifically, the dq-axis current command value calculation unit 55 calculates the charging current command value I from the external charger 14. ｃｈ ＊ The corresponding charging current I ｃｈ When the allowable current I is supplied to the neutral point 23 of the rotating electric machine 22, ａｐｒｖ The following is supplied to the battery 10, and the warm-up current I in the rotating electric machine 22 ｄｃ－ｈ Corresponding d-axis current i ｄ The dq-axis current command value i is used to switch the inverter 21 so that the current can be recycled. ｄｑ ＊ Perform the calculation.

[0069] Figure 6 is a block diagram showing the configuration of the allowable current calculation unit 51. As shown in Figure 6, the allowable current calculation unit 51 includes an allowable power calculation unit 56 and a conversion unit 57.

[0070] The allowable power calculation unit 56 calculates the battery temperature T ｂ Based on the SOC, the power that the battery 10 can allow to input and output (hereinafter referred to as allowable power P) ａｐｒｖ The power calculation unit 56 calculates the battery temperature T based on experiments or simulations. ｂ and SOC, and allowable power P ａｐｒｖ It has a pre-associated allowable power table 58 (see Figure 7) with [kW] and . Therefore, the allowable power calculation unit 56 refers to the allowable power table 58 to determine the specific battery temperature T when attempting to charge the battery 10. ｂ and the allowable power P corresponding to SOC ａｐｒｖ Perform the calculation.

[0071] The conversion unit 57 converts the battery voltage V ｂ Using the allowable power P ａｐｒｖ Allowable current I ａｐｒｖ It converts (converts) to the allowable power P. Specifically, the conversion unit 57 converts to the allowable power P. ａｐｒｖ Battery voltage V ｂ By dividing by, the allowable current I ａｐｒｖ The calculation is performed. That is, I ａｐｒｖ = P ａｐｒｖ / V ｂ That is the case.

[0072] Figure 7 is an explanatory diagram showing the allowable power table 58. In Figure 7, the allowable power P is shown as a guideline. ａｐｒｖ This shows the lines where the power output is 0kW, 50kW, and 100kW.

[0073] As shown in Figure 7, even with the same SOC, the battery temperature T ｂ The lower the allowable power P, the lower it becomes. ａｐｒｖ The temperature decreases. Also, the battery 10 maintains the same battery temperature T. ｂ Even so, the allowable power P decreases as SOC decreases. ａｐｒｖ The temperature decreases. In other words, simply put, the battery 10's temperature T ｂOr, the lower the SOC, the more the allowable power P ａｐｒｖ It decreases.

[0074] Area A ０ The allowable power P ａｐｒｖ The power consumption is over 100 kW, and in effect, the battery temperature is almost zero. ｂ Area A is an area where the battery 10 can be used and charged without being restricted by the above. １ The battery temperature T ｂ Due to the decrease in the above, the allowable power P ａｐｒｖ This is the region where power output is limited to approximately 50 kW to 100 kW. Region A ２ The battery temperature T ｂ Due to the decrease in the above, the allowable power P ａｐｒｖ This is a region where the power output is severely limited to approximately 0 kW to 50 kW. And then there is region A. ３ The battery temperature T ｂ Due to the decrease in these factors, the allowable power P ａｐｒｖ The current becomes 0 kW or less, which is a region where the battery 10 cannot be used or charged in practice.

[0075] In this embodiment, a temperature threshold T is used to determine whether the battery 10 is in a low-temperature state. ｔｈ For example, when SOC is 100%, the allowable power P ａｐｒｖ The temperature is set to a temperature where the power output drops below 100 kW, or a temperature below that. In other words, the temperature threshold T ｔｈ Based on experiments or simulations, the battery temperature T ｂ Allowable power P corresponding to the decrease ａｐｒｖ The temperature is set to a level where the decrease becomes unnecessarily significant.

[0076] Next, the warm-up current calculation unit 52 calculates the warm-up current I ｄｃ－ｈ This section details the method for calculating (estimating) this value.

[0077] Figure 8 is an explanatory diagram showing the current flow in the rotating electric machine 22 and the inverter 21. As shown in Figure 8, the DC current I flows between the battery 10 and the inverter 21. ｄｃ The current is assumed to be flowing out from the positive terminal of battery 10. DC current I ｄｃThe current flowing through each arm (Q1 to Q6) of the inverter 21 is, respectively, i ｕｕ i ｕｌ i ｖｕ i ｖｌ i ｗｕ i ｗｌ Therefore, the flow from the upper arm to the lower arm is considered the positive direction. Phase current i ｕｖｗ The direction in which current flows from the inverter 21 to the windings of each phase is defined as the positive direction. At this time, the zero-sequence current i flows through the rotating electric machine 22 and the inverter 21. ０ The direction in which current flows out from the rotating electric machine 22 to the external charger 14 is considered the positive direction. Therefore, the charging current i supplied from the external charger 14 is considered positive. ｃｈ and zero-sequence current i ０ is, i ０ = -I ｃｈ The relationship is as follows. Note that the zero-sequence current i ０ This is the DC current component of the current flowing through the rotating electric machine 22 and the inverter 21 that flows in the same phase (same direction) in common to each of the U, V, and W phases.

[0078] At this time, DC current I ｄｃ This is expressed by equation (5) or equation (6) below. Also, the zero-sequence current i ０ This is expressed by the following equation (7).

[0079]

[0080] Figure 9 is a schematic diagram illustrating the switching of the inverter 21 and the current flowing through the inverter 21. Figure 9 shows the U-phase, but the V-phase and W-phase are similar. Figure 9(A) shows the U-phase current i ｕ This is shown. Figure 9(B) shows the U-phase duty command value Duty_u as a solid line. The dashed line in Figure 9(B) represents the carrier signal S Ｃ Figure 9(C) shows the upper arm of the U phase (Q １ ) Drive signal D ｕｕ ＊ This is shown. Figure 9(D) shows the U-phase lower arm (Q ２ ) Drive signal D ｕｌ ＊ This is shown. Figure 9(E) shows the U-phase upper arm (Q １ The current i flowing through ) ｕｕThis is shown. And Figure 9(F) shows the U-phase lower arm (Q ２ The current i flowing through ) ｕｌ This indicates.

[0081] As shown in Figure 9(A), for simplicity, the U-phase current i is used here. ｕ is a constant value (i ｕ Assume that > ​​0). Also, as shown in Figure 9(B), period P ａ Therefore, the U-phase duty command value Duty_u is 0.75 (75%), and the period P ｂ Let's assume the U-phase duty cycle command value Duty_u is 0.25 (25%). Period P ａ , P ｂ These are the carrier signals S, respectively. Ｃ This is the duration of one cycle.

[0082] At this time, the U-phase duty cycle command value Duty_u and the carrier signal S Ｃ Through the compare match, as shown in Figures 9(C) and 9(D), the U-phase upper arm (Q １ ) Drive signal D ｕｕ ＊ and U-phase lower arm (Q ２ ) Drive signal D ｕｌ ＊ The on / off states switch complementaryly. And the U-phase current i ｕ The U-phase arm (Q １ Q ２ Of these, the current flows through the switching elements of the arms that are ON. No current flows through the switching elements of the arms that are OFF. The U-phase current i flows through the arms that are ON. ｕ The duration for which this is flowing is proportional to the duty cycle defined by the duty command value Duty_u.

[0083] Therefore, as shown by the dashed lines in Figures 9(E) and 9(F), the carrier signal S Ｃ P is the period of one cycle. ａ In this case, the upper arm of the U phase (Q １ Current i flowing through ) ｕｕ The average value (effective value) of i ｕｕ－ａｖｅ is 0.75i ｕ Therefore, the U-phase lower arm (Q ２ Current i flowing through ) ｕｌThe average value (effective value) of i ｕｌ－ａｖｅ is -0.25i ｕ Similarly, period P ｂ In this case, the upper arm of the U phase (Q １ Current i flowing through ) ｕｕ The average value (effective value) of i ｕｕ－ａｖｅ is 0.25i ｕ Therefore, the U-phase lower arm (Q ２ Current i flowing through ) ｕｌ The average value (effective value) of i ｕｌ－ａｖｅ is -0.75i ｕ That is the case.

[0084] That is, the carrier signal S Ｃ DC current I during one cycle ｄｃ is the phase current i ｕｖｗ And calculations can be performed based on the duty cycle command value Duty_uvw. Specifically, the DC current I ｄｃ The average value (effective value) of I ｄｃ－ａｖｅ This is expressed by equation (8) or equation (9) below.

[0085]

[0086] The warm-up current calculation unit 52 calculates the DC current I as described above. ｄｃ The average value I ｄｃ－ａｖｅ From this, zero-sequence current i ０ By removing the contribution of i, the dq-axis current i ｄｑ (Essentially the d-axis current i) ｄ The current component originating from ) is the warm-up current i ｄｃ－ｈ It is estimated that the warm-up current calculation unit 52 calculates the warm-up current I according to the following equation (10). ｄｃ－ｈ The following is calculated: Equation (10) is given by the phase current i ｕｖｗ Assuming they are approximately equal (i ｕ = i ｖ = i ｗ = i ０ / 3), for example, in equation (8), each phase current i ｕｖｗ From zero-sequence current i ０ Components derived from (i ０ It is derived by subtracting ( / 3).

[0087]

[0088] Figure 10 is a block diagram showing the configuration of the charging current calculation unit 54. As shown in Figure 10, the charging current calculation unit 54 consists of an adder 59 and a multiplier 60. The adder 59 calculates the allowable current I ａｐｒｖ and warm-up current I ｄｃ－ｈ The multiplication unit 60 then calculates the allowable current I ａｐｒｖ and warm-up current I ｄｃ－ｈ The sum of the step-up ratio r ｓｕ By multiplying by this, the charging current command value I ｃｈ ＊ The charging current calculation unit 54 calculates the charging current command value I according to the following formula (11). ｃｈ ＊ To calculate (determine) this.

[0089]

[0090] Figure 11 is a block diagram showing the configuration of the dq-axis current command value calculation unit 55. As shown in Figure 11, the dq-axis current command value calculation unit 55 includes a warm-up requirement determination unit 61, an additional d-axis current calculation unit 62, and a dq-axis current determination unit 63.

[0091] The warm-up requirement determination unit 61 determines the battery temperature T ｂ Based on this, it is determined whether or not the battery 10 needs to be warmed up. Specifically, as shown in Table 1 below, the warm-up necessity determination unit 61 determines whether or not the battery temperature T ｂ temperature threshold T ｔｈ By comparing this with the following, it is determined whether the battery 10 is in a low-temperature state. Battery temperature T ｂ The temperature threshold T ｔｈ If the temperature is lower than the allowable current I, and the battery 10 is in a low temperature state and cannot be charged quickly, the warm-up requirement determination unit 61 warms up the battery 10 and the allowable current I ａｐｒｖ It was determined that it was necessary to restore the engine, and the warm-up execution flag k ｈｅａｔ Set to 1 (k ｈｅａｔ =1). On the other hand, the battery temperature T ｂ The temperature threshold T ｔｈ The above is the allowable current I ａｐｒｖWhen the temperature is relatively high and the battery 10 can be charged quickly without causing malfunctions such as metal deposition, the warm-up requirement determination unit 61 determines that warming up the battery 10 is unnecessary and the warm-up execution flag k ｈｅａｔ Set to zero (k ｈｅａｔ = 0).

[0092]

[0093] The additional d-axis current calculation unit 62 calculates an additional or increased d-axis current i based on the electric angle θ of the rotor, in order to actively generate heat in the rotating electric machine 22 and inverter 21 and warm up the battery 10. ｄ (Hereafter, additional d-axis current i ｄ The command value for ') (hereinafter, the additional d-axis current command value i) ｄ ＊ The value of ' is calculated. Additional d-axis current command value i ｄ ＊ ' represents the d-axis current i ｄ This parameter determines the amount of increase.

[0094] As mentioned above, when the battery 10 is not warmed up and the rotating electric machine 22 and inverter 21 are simply used as boost converters, the switching of the arms of each phase U, V, and W is perfectly synchronized, so the q-axis current i ｑ Not only does it not flow, but in principle the d-axis current i ｄ It doesn't flow either (i ｄ = 0). Therefore, the additional d-axis current command value i has a significant value. ｄ ＊ ' represents the d-axis current command value i in a scenario where the battery 10 must be warmed up at the same time as charging the battery 10 with the external charger 14. ｄ ＊ It functions as such. Additional d-axis current command value i has a significant value. ｄ ＊ '(d-axis current command value i) ｄ ＊ This has the effect of slightly shifting the switching timing of each phase (UVW).

[0095] In this embodiment, the additional d-axis current calculation unit 62 calculates the charging current command value I ｃｈ ＊Based on this, the additional d-axis current command value i ｄ ＊ ′(additional d-axis current i ｄ The size of ′) is adjusted. Also, in this embodiment, the additional d-axis current calculation unit 62 is the boost ratio r ｓｕ Based on this, the phase current i ｕｖｗ This adjusts the relative load (heat generation) between the upper and lower arms during the phase in which the maximum value is achieved.

[0096] Specifically, the additional d-axis current calculation unit 62 includes a d-axis current map (64, 65) and a selector 66.

[0097] d-axis current map (hereinafter, i ｄ The map shows the electrical angle θ and the additional d-axis current i that should flow. ｄ This is a map that pre-defines the correspondence between '. The additional d-axis current calculation unit 62 calculates this i ｄ Refer to the map and select the additional d-axis current command value i according to the electrical angle θ. ｄ ＊ Perform the calculation '.

[0098] Note i ｄ The map shows the maximum additional d-axis current i that can be added for each electrical angle θ to warm up the battery 10 while charging it using the external charger 14. ｄ ' is defined.

[0099] The maximum additional d-axis current i that can be added. ｄ ' is the charging current I ｃｈ It changes depending on the size of i ｄ The map shows the charging current I ｃｈ (or charging current command value I ｃｈ ＊ ) Additional d-axis current i ｄ ′ is determined to change. Also, an additional d-axis current i ｄ The specific size of ′ (|i ｄ ′|) is the phase current i flowing through the rotating electric machine 22. ｕｖｗ The maximum value of is determined to be as large as possible. Specifically, the additional d-axis current i ｄ ' represents the current i flowing through the multiple switching elements of the inverter 21. ｕｕ ~i ｗｌEither of these should be set to a value that substantially corresponds to the durability of the switching element, or the phase current i flowing through the rotating electric machine 22 should be set accordingly. ｕｖｗ The value is determined such that one of them is effectively the maximum value corresponding to the durability of the stator winding.

[0100] In this embodiment, the additional d-axis current calculation unit 62 is the first i ｄ Map 64 and 2nd i ｄ Two types of i on map 65 ｄ It includes a map.

[0101] 1st i ｄ Map 64 shows the phase current i ｕｖｗ To maximize the positive phase current i, i. ｕｖｗ (i ｕ i ｖ i ｗ The current with the largest absolute value among them becomes the positive current, and an additional d-axis current i ｄ This is a d-axis current map with ' defined. In other words, the first i ｄ Map 64 shows the maximum phase current i ｕｖｗ In the phase in which the current flows, an additional d-axis current i is added such that the load on the upper arm is relatively higher, or the heat generated by the upper arm is relatively greater. ｄ ′ is defined below. In the following, the first i ｄ The additional d-axis current command value i is calculated by referring to map 64. ｄ ＊ ' represents the first additional d-axis current command value i ｄ１ ＊ ′

[0102] 2nd i ｄ Map 65 shows the phase current i ｕｖｗ The phase current i is maximized so that it is maximized on the negative side, i.e., the maximum phase current i ｕｖｗ An additional d-axis current i is added so that the current is in the negative direction. ｄ ′ represents the d-axis current map. In other words, the second i ｄ Map 65 shows the maximum phase current i ｕｖｗ In the phase in which the current flows, an additional d-axis current i is added such that the load on the lower arm is relatively higher, or the heat generated by the lower arm is relatively greater. ｄ ′ is defined below. ｄThe additional d-axis current command value i is calculated by referring to map 65. ｄ ＊ ′ is the second additional d-axis current command value i ｄ２ ＊ ′

[0103] The selector 66 has a step-up ratio r. ｓｕ Based on this, the first additional d-axis current command value i ｄ１ ＊ ′ or second additional d-axis current command value i ｄ２ ＊ ′ is the final additional d-axis current command value i ｄ ＊ Output as '.

[0104] Specifically, the step-up ratio r ｓｕ If the ratio is more than twice (r ｓｕ ≥2), the selector 66 sets the first additional d-axis current command value i ｄ１ ＊ ′ is the final additional d-axis current command value i ｄ ＊ Output as '. That is, r ｓｕ When ≥ 2, an additional d-axis current i for warming up is required. ｄ ' represents the phase current i flowing through the rotating electric machine 22. ｕｖｗ It is determined so that it is maximized on the positive side. On the other hand, when the boost ratio rsu is less than 2 times (r ｓｕ <2) The selector 66 sets the second additional d-axis current command value i ｄ２ ＊ ′ is the final additional d-axis current command value i ｄ ＊ Output as '. That is, r ｓｕ When < 2, the additional d-axis current i for warming up ｄ ' represents the phase current i flowing through the rotating electric machine 22. ｕｖｗ It is determined so that it is maximized on the negative side.

[0105] The dq axis current determination unit 63 sets the warm-up execution flag k ｈｅａｔ and additional d-axis current command value i ｄ ＊ Based on ', the final d-axis current command value i ｄ ＊The dq-axis current determination unit 63 determines the q-axis current command value i in order to prevent torque from being generated and to prevent the rotating electric machine 22 from rotating. ｑ ＊ The value is determined (set) to zero. Then, the dq-axis current determination unit 63 determines the d-axis current command value i according to the following equation (12). ｄ ＊ Perform the calculation.

[0106]

[0107] That is, k ｈｅａｔ = 1, and when warming up the battery 10, the d-axis current command value i ｄ ＊ The additional d-axis current command value i ｄ ＊ It becomes equal to ' and has a significant value. For this reason, the rotating electric machine 22 and the inverter 21 receive an additional d-axis current command value i ｄ ＊ d-axis current i corresponding to ' ｄ As a result, the amount of heat generated by the rotating electric machine 22 and the inverter 21 increases. Therefore, the warming up of the battery 10 is accelerated, and the allowable current I ａｐｒｖ This allows for a quicker recovery. As a result, even when the rotating electric machine 22 and inverter 21 are used as boost converters, the charging of the battery 10 is accelerated.

[0108] On the other hand, k ｈｅａｔ If = 0 and there is no need to warm up the battery 10, the d-axis current command value i ｄ ＊ The additional d-axis current command value i ｄ ＊ Regardless of the value of ′, it is zero. Therefore, the d-axis current i is supplied to the rotating electric machine 22 and the inverter 21. ｄ It does not flow. However, the battery temperature T is such that there is no need to warm up the battery 10 in the first place. ｂ The allowable current I is high. ａｐｒｖ Since it is in a large state, the charging of battery 10 will proceed appropriately without any particular delay.

[0109] Figure 12 shows the d-axis current map (i ｄ This is an explanatory diagram showing the map. Figure 12(A) is the first i ｄMap 64 is shown. Figure 12(B) shows the second i ｄ Map 65 is shown. In Figures 12(A) and 12(B), the solid line represents the charging current command value I ｃｈ ＊ Or charging current I ｃｈ If it is almost zero (I ｃｈ ＊ = I ｃｈ i (≒0[A]) ｄ This is a map. The dashed line represents the charging current command value I. ｃｈ ＊ Or charging current I ｃｈ If it is moderate (for example, I ｃｈ ＊ = I ｃｈ i (≒50 [A]) ｄ This is a map. The dashed line represents the charging current command value I. ｃｈ ＊ Or charging current I ｃｈ When it is relatively large (for example, I ｃｈ ＊ = I ｃｈ i (≒100 [A]) ｄ It's a map.

[0110] As shown in Figure 12(A), the first i ｄ Map 64 generates a first additional d-axis current i according to the electrical angle θ. ｄ１ The sign of ′ is reversed. Specifically, in the range of θ = 0 to 30, 90 to 150, 210 to 270, 330 to 360 [deg], the first i ｄ Map 64 shows the first additional d-axis current command value i ｄ１ ＊ Set ' to a positive value. On the other hand, in the range of θ = 30 to 90, 150 to 210, 270 to 330 [deg], the first i ｄ Map 64 shows the first additional d-axis current command value i ｄ１ ＊ Set ' to a negative value. This sets the first additional d-axis current command value i to the rotating electric machine 22 and inverter 21. ｄ１ ＊ d-axis current i corresponding to ' ｄ When this flows, the maximum phase current i ｕｖｗ This represents a positive current.

[0111] As shown in Figure 12(B), the second i ｄ Map 65 calculates the second additional d-axis current i according to the electrical angle θ. ｄ２ The sign of ′ is reversed. However, in the range of θ = 0 to 30, 90 to 150, 210 to 270, 330 to 360 [deg], the second i ｄ Map 65 shows the second additional d-axis current command value i ｄ２ ＊ Set ' to a negative value. On the other hand, in the range of θ = 30 to 90, 150 to 210, 270 to 330 [deg], the second i ｄ Map 65 shows the second additional d-axis current command value i ｄ２ ＊ Set ' to a positive value. This will set a second additional d-axis current command value i to the rotating electric machine 22 and inverter 21. ｄ２ ＊ d-axis current i corresponding to ' ｄ When this flows, the maximum phase current i ｕｖｗ This results in a negative current.

[0112] Note that the d-axis current i flows in the positive direction. ｄ In the rotating electric machine 22, a magnetic field is formed to strengthen the magnetic flux of the permanent magnets in the rotor. That is, the d-axis current i ｄ The positive direction is the direction that strengthens the magnetic field of the rotating electric machine 22. And the d-axis current i flows in the negative direction. ｄ In the rotating electric machine 22, a magnetic field is formed to weaken the magnetic flux of the permanent magnets in the rotor. That is, the d-axis current i ｄ The negative direction is the direction that weakens the magnetic field of the rotating electric machine 22, which is the weakening magnetic field direction.

[0113] Therefore, when θ = 0 to 30, 90 to 150, 210 to 270, 330 to 360 [deg], the first i ｄ Map 64 sets the first additional d-axis current command value i to increase the magnetic flux of the rotating electric machine 22. ｄ１ ＊ It can also be said that it defines '. Similarly, when θ = 30 to 90, 150 to 210, 270 to 330 [deg], the first i ｄ Map 64 weakens the magnetic flux of the rotating electric machine 22 by setting the first additional d-axis current command value i ｄ１ ＊It can be said that it defines '.

[0114] Similarly, when θ = 0 to 30, 90 to 150, 210 to 270, 330 to 360 [deg], the second i ｄ Map 65 weakens the magnetic flux of the rotating electric machine 22 by setting a second additional d-axis current command value i ｄ２ ＊ It can also be said that it defines '. Similarly, when θ = 30 to 90, 150 to 210, 270 to 330 [deg], the second i ｄ Map 65 sets the first additional d-axis current command value i to increase the magnetic flux of the rotating electric machine 22. ｄ１ ＊ It can be said that it defines '.

[0115] That is, the first i ｄ Map 64 and 2i ｄ Map 65 generates an additional d-axis current i that strengthens the magnetic flux of the rotating electric machine 22 according to the electrical angle θ. ｄ ′, or an additional d-axis current i that weakens the magnetic flux of the rotating electric machine 22. ｄ It could also be described as a map where you choose '.

[0116] As shown in Figure 12(A), the first i ｄ Map 64 shows the first additional d-axis current command value i at each electrical angle θ. ｄ１ ＊ The magnitude of ' is the charging current command value I ｃｈ ＊ Adjust based on the following. Similarly, as shown in Figure 12(B), the second i ｄ Map 65 shows the second additional d-axis current command value i at each electrical angle θ. ｄ２ ＊ The magnitude of ' corresponds to the charging current command value I ｃｈ ＊ Adjust based on this first additional d-axis current command value i ｄ１ ＊ ′ and the second additional d-axis current command value i ｄ２ ＊ The size of ′ is adjusted by the phase current i flowing through the rotating electric machine 22. ｕｖｗ This is done to make the maximum value as large as possible. First additional d-axis current command value i ｄ１ ＊ ′ and the second additional d-axis current command value iｄ２ ＊ By adjusting the magnitude of ′, an additional d-axis current i ｄ ′ is essentially the current i flowing through the multiple switching elements of the inverter 21. ｕｕ ~i ｗｌ Either of these is substantially the maximum value corresponding to the durability of the switching element, or the phase current i flowing through the rotating electric machine 22. ｕｖｗ One of these effectively represents the maximum value corresponding to the durability of the stator winding.

[0117] Figure 13 shows the d-axis current i according to the d-axis current map (64, 65). ｄ Phase current i when the current flows ｕｖｗ This is an explanatory diagram showing the first i ｄ Map 64 specifies the first additional d-axis current command value i ｄ１ ＊ d-axis current i corresponding to ' ｄ The phase current i realized by ｕｖｗ This is shown. Figure 13(B) shows the second i ｄ Map 65 specifies the second additional d-axis current command value i ｄ２ ＊ d-axis current i corresponding to ' ｄ The phase current i realized by ｕｖｗ This is shown. Note that Figure 13 shows the charging current command value I ｃｈ ＊ (Charging current I ｃｈ The phase current i when ) is almost zero ｕｖｗ This shows that Figure 13 represents the d-axis current i corresponding to the solid line in Figure 12. ｄ The phase current i realized by ｕｖｗ This is shown. Also, in Figure 13, i ｌｉｍ is the phase current i ｕｖｗ This is the maximum value and is predetermined according to the durability of the switching element or stator winding. In Figure 13, the solid line represents the U-phase current i ｕ The dashed line indicates the V-phase current i. ｖ The dashed line indicates the W-phase current i ｗ This indicates.

[0118] As shown in Figure 13(A), the first i ｄ Map 64 specifies the first additional d-axis current command value i ｄ１＊ d-axis current i corresponding to ' ｄ When flowing, the phase current i ｕｖｗ Regardless of the electrical angle θ, the maximum positive value (+i ｌｉｍ ) can be taken. On the other hand, as shown in Figure 13(B), the second i ｄ Map 65 specifies the second additional d-axis current command value i ｄ２ ＊ d-axis current i corresponding to ' ｄ When flowing, the phase current i ｕｖｗ Regardless of the electric angle θ, the maximum negative value is (-i ｌｉｍ ) can be taken.

[0119] Figure 14 also shows the d-axis current i according to the d-axis current map (64, 65). ｄ Phase current i when the current flows ｕｖｗ This is an explanatory diagram showing the first i ｄ Map 64 specifies the first additional d-axis current command value i ｄ１ ＊ d-axis current i corresponding to ' ｄ The phase current i realized by ｕｖｗ This is shown. Figure 14(B) shows the second i ｄ Map 65 specifies the second additional d-axis current command value i ｄ２ ＊ d-axis current i corresponding to ' ｄ The phase current i realized by ｕｖｗ This is shown. However, Figure 14 shows the charging current command value I ｃｈ ＊ (Charging current I ｃｈ ) When the phase current i is moderate ｕｖｗ This shows that Figure 14 represents the d-axis current i corresponding to the dashed line in Figure 12. ｄ The phase current i realized by ｕｖｗ This indicates that.

[0120] Charging current I ｃｈ If there is a phase current i ｕｖｗ The charging current I ｃｈ A negative bias is added accordingly, but as shown in Figure 14(A), the first i ｄ Map 64 specifies the first additional d-axis current command value i ｄ１ ＊ d-axis current i corresponding to ' ｄWhen flowing, the phase current i ｕｖｗ Regardless of the electrical angle θ, the maximum positive value (+i ｌｉｍ ) can be taken. Also, as shown in Figure 14(B), the second i ｄ Map 65 specifies the second additional d-axis current command value i ｄ２ ＊ d-axis current i corresponding to ' ｄ When flowing, the charging current I ｃｈ Even if a corresponding negative bias is applied, the phase current i ｕｖｗ Regardless of the electric angle θ, the maximum negative value is (-i ｌｉｍ ) can be taken.

[0121] Figure 15 also shows the d-axis current i according to the d-axis current map (64, 65). ｄ Phase current i when the current flows ｕｖｗ This is an explanatory diagram showing the first i ｄ Map 64 specifies the first additional d-axis current command value i ｄ１ ＊ d-axis current i corresponding to ' ｄ The phase current i realized by ｕｖｗ This is shown. Figure 15(B) shows the second i ｄ Map 65 specifies the second additional d-axis current command value i ｄ２ ＊ d-axis current i corresponding to ' ｄ The phase current i realized by ｕｖｗ This is shown. However, Figure 15 shows the charging current command value I ｃｈ ＊ (Charging current I ｃｈ Phase current i when ) is relatively large ｕｖｗ This shows that Figure 14 represents the d-axis current i corresponding to the dashed line in Figure 12. ｄ The phase current i realized by ｕｖｗ This indicates that.

[0122] As shown in Figure 15(A), the first i ｄ Map 64 specifies the first additional d-axis current command value i ｄ１ ＊ d-axis current i corresponding to ' ｄ When flowing, the phase current i ｕｖｗ The charging current I ｃｈ With a large negative bias added accordingly, the maximum positive value (+i) is taken as far as possible.ｌｉｍ It is maximized so as to approach ). Also, as shown in Figure 14(B), the second i ｄ Map 65 specifies the second additional d-axis current command value i ｄ２ ＊ d-axis current i corresponding to ' ｄ When flowing, the charging current I ｃｈ Even if a large negative bias is applied accordingly, the phase current i ｕｖｗ Regardless of the electric angle θ, the maximum negative value is (-i ｌｉｍ ) can be taken.

[0123] Thus, the first i ｄ Map 64 and 2i ｄ Map 65 shows the electrical angle θ and the charging current I. ｃｈ (Charging current command value I ｃｈ ＊ ) Accordingly, the phase current i ｕｖｗ The first additional d-axis current command value i is set to maximize the value i ｄ１ ＊ ′ and the second additional d-axis current command value i ｄ２ ＊ It defines '.

[0124] Figure 16 shows the step-up ratio r. ｓｕ and drive signal D ＊ = D ｕｕ ＊ ~D ｗｌ ＊ This is an explanatory diagram showing the relationship. Figure 16(A) shows the boost ratio r ｓｕ When is twice (r ｓｕ =2) Drive signal D ＊ This is shown. Figure 16(B) shows the boost ratio r ｓｕ When (r) is greater than twice ｓｕ >2) Drive signal D ＊ This is shown. And Figure 16(C) shows the boost ratio r. ｓｕ When it is less than twice (r ｓｕ <2) Drive signal D ＊ This is shown. In Figures 16(A) to (C), the horizontal axis represents time, and here the carrier signal S Ｃ Drive signal D for the duration of one cycle ＊ This indicates that.

[0125] Note that in Figure 16, the first period P１ The upper arm (Q １ Q ３ Q ５ ) is off, and the lower arm (Q ２ Q ４ Q ６ ) is ON, and the lower arm (Q ２ Q ４ Q ６ This is the period during which current flows. Second period P ２ The upper arm (Q １ Q ３ Q ５ ) is ON, and the lower arm (Q ２ Q ４ Q ６ ) is off, and the upper arm (Q １ Q ３ Q ５ This is the period during which current flows. And the third period P ３ This is the first period P １ and the second period P ２ This is the switching period, and the d-axis current i is used for warming up. ｄ It occurs when flowing.

[0126] As shown in Figure 16(A), the rotating electric machine 22 and the inverter 21 are set to a boost ratio r ｓｕ If it is to function as a 2x boost converter, then the first period P １ and the second period P ２ The lengths are approximately equal (P １ ≒P ２ ). However, in this embodiment, the d-axis current i is used for warming up. ｄ To add this, the pulse width of each phase is different. Therefore, the first period P １ and the second period P ２ During the third period P ３ This occurs. In this embodiment, the rotating electric machine 22 is in a stopped state, and no induced voltage is generated. Therefore, the third period P ３ This is the first period P １ and the second period P ２ In comparison, this is a very short period. In other words, the d-axis current i is maintained for warm-up. ｄ Even with the addition of this, the difference in pulse width between each phase is very small. Third period P ３For example, U-phase switching (D ｕｕ ＊ and D ｕｌ ＊ This is a state where only the switching of ( ) has occurred. Below, in the first period P １ and the second period P ２ The state in which the lengths are approximately equal is called the reference state.

[0127] Then, as shown in Figure 16(B), the rotating electric machine 22 and the inverter 21 are set to a boost ratio r ｓｕ When it functions as a boost converter with a voltage increase of more than 2, compared to the reference state, the first period P １ The second period P ２ The period becomes shorter. That is, the first period P １ This is the second period P ２ It will take longer in terms of time (P １ >P ２ ).

[0128] On the other hand, as shown in Figure 16(C), the rotating electric machine 22 and the inverter 21 are set to a boost ratio r ｓｕ When it functions as a boost converter with a voltage boost of less than 2, compared to the reference state, the first period P １ The second period P becomes shorter. ２ This becomes longer. In other words, the first period P １ This is the second period P ２ It becomes shorter in time than (P １ <P ２ ).

[0129] Figure 17 shows the first period P １ This is an explanatory diagram showing the flow of current in [the system]. In Figure 17, the maximum phase current i is shown according to the electrical angle θ. ｕｖｗ U-phase current i ｕ Therefore, the V-phase current i ｖ and W-phase current i ｗ The U-phase current i ｕ The example below illustrates a scene that is 1 / 2 of the total. Below, as an example, the first period P １ In this case, the U-phase current i ｕ The current is +100A, and the V-phase current i ｖ and W-phase current i ｗ Let's assume it's -50A.

[0130] As shown in Figure 17, the first period P １ So, Q ２ Q ４ Q ６ Because it is ON, an additional d-axis current i is added for warming up. ｄ The phase current i realized by ｕｖｗ Q ２ Q ４ Q ６ It recirculates through this. For this reason, in the inverter 21, the lower arm (Q) of each phase is mainly used. ２ Q ４ Q ６ ) develops a fever. That is, during the first period P １ So, the lower arm (Q ２ Q ４ Q ６ The thermal load on ) is high. In this case, the arm (switching element) that generates the most heat is Q. ２ That is the case.

[0131] Figure 18 shows the second period P ２ This is an explanatory diagram showing the flow of current in the second period P. ２ So, Q １ Q ３ Q ５ Because it is on, an additional d-axis current i is added for warming up. ｄ The phase current i realized by ｕｖｗ Q １ Q ３ Q ５ The current flows back through this. For this reason, in the inverter 21, the upper arm (Q) of each phase is mainly used. １ Q ３ Q ５ ) develops a fever. That is, period P ２ So, the upper arm (Q １ Q ３ Q ５ The thermal load on ) is high. In this case, the arm (switching element) that generates the most heat is Q. １ That is the case.

[0132] Thus, the first period P １ and the second period P ２ Therefore, the arms subjected to the heat load are switched between the upper and lower arms. For this reason, the boost ratio r ｓｕis twice and the first period P １ and the second period P ２ are substantially equal in length in the reference state (r ｓｕ = 2, P １ = P ２ ), the inverter 21 generates heat substantially uniformly as a whole. However, as described above, when the boost ratio r ｓｕ is greater than twice and the first period P １ is longer than the second period P ２ (r ｓｕ > 2, P １ > P ２ ), the heat load in the inverter 21 is biased toward the lower arm (Q ２ , Q ４ , Q ６ ). Also, when the boost ratio r ｓｕ is less than twice and the first period P １ is shorter than the second period P ２ (r ｓｕ < 2, P １ < P ２ ), the heat load in the inverter 21 is biased toward the upper arm (Q １ , Q ３ , Q ５ ).

[0133] Therefore, in this embodiment, when the boost ratio r ｓｕ is 2 or more (r ｓｕ ≥ 2), the additional d-axis current calculation unit 62 uses, as the final additional d-axis current command value i ｄ ＊ ′, the first additional d-axis current command value i ｄ defined by the first i ｄ１ ＊ ′ map 64. And when the boost ratio r ｓｕ is less than twice (r<00​​​​​​​​​​​​Map 64 and the second i ｄ are switched with Map 65. As a result, the additional d-axis current calculation unit 62 causes the arm with the largest heat generation in the third period P ３ to be different from the arm with the largest heat generation in the shorter one of the first period P １ or the second period P ２ to disperse the heat generation locations in the inverter 21. Specifically, it is as follows.

[0134] FIGS. 19 and 20 are explanatory diagrams showing the current flow in the third period P ３ . Here, similar to FIGS. 17 and 18, in the first period P １ , the U-phase current i ｕ is +100 A, the V-phase current i ｖ and the W-phase current i ｗ are -50 A, and in the second period P ２ , the U-phase current i ｕ is -100 A, the V-phase current i ｖ and the W-phase current i ｗ are +50 A. For the third period P ３ , the flow of the phase current i ｕｖｗ is shown.

[0135] FIG. 19 shows the flow of the phase current i ｕｖｗ when the additional d-axis current command value i ｕ ′ is set such that the U-phase current i ｄ ＊ ′, which is the largest phase current i ｕｖｗ , becomes a positive current. In other words, in FIG. 19, the flow of the phase current i ｄ when the first additional d-axis current command value i ｄ１ ＊ ′ set by Map 64 is used as the final additional d-axis current command value i ｄ ＊ ′ is shown. ｕｖｗ As shown in FIG. 19, when using the first additional d-axis current command value i

[0136] ′, in the third period P ｄ１ ＊ ′, for example, the U-phase current i ３ is the upper arm (Q ｕ is the upper arm (Q １) flows, V-phase current i ｖ and W-phase current i ｗ The lower arm (Q ４ Q ６ ) flows through it. At this time, the arm (switching element) that generates the most heat has the largest phase current i ｕｖｗ The U-phase current i ｕ Q １ Therefore, the first additional d-axis current command value i ｄ１ ＊ When using ′, the third period P ３ In this case, the arm (switching element) that generates the most heat is in the first period P １ It is the same as the arm (switching element) that generates the most heat.

[0137] On the other hand, Figure 20 shows the maximum phase current i. ｕｖｗ The U-phase current i ｕ The additional d-axis current command value i will result in a negative current. ｄ ＊ Phase current i when ' is set ｕｖｗ This shows the flow. In other words, in Figure 20, the second i ｄ Map 65 sets the second additional d-axis current command value i ｄ２ ＊ ′ is the final additional d-axis current command value i ｄ ＊ Phase current i when used as ' ｕｖｗ This shows the flow.

[0138] As shown in Figure 20, the second additional d-axis current command value i ｄ２ ＊ When using ′, the third period P ３ For example, the U-phase current i ｕ The lower arm (Q ２ ) flows, V-phase current i ｖ and W-phase current i ｗ The upper arm (Q ３ Q ５ ) flows through it. At this time, the arm (switching element) that generates the most heat has the largest phase current i ｕｖｗ The U-phase current i ｕ Q ２ Therefore, the second additional d-axis current command value i ｄ２＊ When using ′, the third period P ３ The arm (switching element) with the largest heat generation in is the same as the arm (switching element) with the largest heat generation in the second period P ２ is the same as the arm (switching element) with the largest heat generation in the second period P

[0139] Therefore, the boost ratio r ｓｕ is 2 or more (r ｓｕ ≧2), and since the first period P １ is longer than the second period P ２ (P １ >P ２ ), when the heat load is biased to the lower arm (Q ２ ), the additional d-axis current calculation unit 62 uses the first additional d-axis current command value i ｄ１ ＊ ′ as the final additional d-axis current command value i ｄ ＊ ′, and causes the phase current i ３ in the third period P ｕｖｗ to flow as shown in FIG. 19. As a result, compared to the case where the second additional d-axis current command value i ｄ２ ＊ ′ is used as the final additional d-axis current command value i ｄ [[ID=3q]] ＊ ′ and the phase current i ３ in the third period P ｕｖｗ flows as shown in FIG. 20, the heat load on Q ２ is reduced.

[0140] Also, when the boost ratio r ｓｕ is less than 2 times (r ｓｕ <2), and since the first period P １ is shorter than the second period P ２ (P １ <P ２ ), when the heat load is biased to the upper arm (Q １ ), the additional d-axis current calculation unit 62 uses the second additional d-axis current command value i ｄ２ ＊ ′ as the final additional d-axis current command value i ｄ ＊ ′, and causes the phase current i ３ in the third period P ｕｖｗ to flow as shown in FIG. 20. As a result, the first additional d-axis current command value i ｄ１＊ ′ is the final additional d-axis current command value i ｄ ＊ ′ is used as, 3rd period P ３ Phase current i ｕｖｗ Q １ The heat load is reduced.

[0141] Figure 21 is a flowchart of the charging control (warm-up control) of this embodiment, which also warms up the battery 10 when charging the battery 10 using the external charger 14.

[0142] As shown in Figure 21, when it is detected that the external charger 14 has been connected to the electric vehicle 100, in step S10, the charging control unit 46 acquires parameters indicating the operating status of the inverter 21, the rotating electric machine 22, and the external charger 14. Specifically, in step S10, the charging control unit 46 acquires the electrical angle θ and the phase current i ｕｖｗ DC voltage V ｄｃ , and external input voltage V ｒｅｆ (or V ｎ ) obtain.

[0143] In step S11, the charge control unit 46 acquires parameters indicating the state of the battery 10. Specifically, in step S11, the charge control unit 46 acquires the battery temperature T ｂ , SOC, and battery voltage V ｂ Obtain it.

[0144] In step S12, the boost ratio calculation unit 53 calculates the boost ratio r of the boost converter composed of the rotating electric machine 22 and the inverter 21. ｓｕ The warm-up current calculation unit 52 determines the warm-up current I ｄｃ－ｈ The allowable current I of the battery 10 is calculated (estimated). In step S14, the allowable current calculation unit 51 calculates (estimates) the allowable current I of the battery 10. ａｐｒｖ The charge current calculation unit 54 calculates the charge current command value I. ｃｈ ＊ The charging current command value I is calculated and sent to the external charger 14. ｃｈ ＊ The charging current I that matches this ｃｈ It requests input.

[0145] Subsequently, in step S16, the dq-axis current command value calculation unit 55 determines whether warming up is necessary or not, and the battery temperature T ｂ and temperature threshold T ｔｈ Compare the following. At this time, the battery temperature T ｂ The temperature threshold T ｔｈ If the battery temperature T is lower than the specified value, and the warm-up requirement determination unit 61 determines that the battery 10 needs to be warmed up, the process proceeds to step S17. ｂ The temperature threshold T ｔｈ If the warm-up requirement determination unit 61 determines that there is no need to warm up the battery 10, the process proceeds to step S18.

[0146] In step S17, the additional d-axis current calculation unit 62 and the dq-axis current determination unit 63 determine a d-axis current command value i that has a significant value corresponding to the electrical angle θ, etc. ｄ ＊ The following is calculated: Also, the q-axis current command value i ｑ ＊ It is set to zero.

[0147] In step S18, the dq-axis current determination unit 63 determines the d-axis current command value i ｄ ＊ and q-axis current command value i ｑ ＊ Set both to zero.

[0148] In step S19, the current vector control unit 42 sets the dq axis current command value i set in step 17 or step S18. ｄｑ ＊ Based on this, the dq axis voltage command value v ｄｑ ＊ The PWM control unit 44 calculates the dq-axis voltage command value v. ｄｑ ＊ The duty command value Duty_uvw is set accordingly. In step S21, the drive signal generation unit 45 generates a drive signal D corresponding to the duty command value Duty_uvw. ＊ = D ｕｕ ＊ ~D ｗｌ ＊ Then, in step S22, the drive signal generation unit 45 generates the drive signal D ＊By inputting this to the inverter 21, the Q of the inverter 21 １ ~Q ６ It is controlled.

[0149] Therefore, when charging the battery 10 using the external charger 14 and the boost converter consisting of the rotating electric machine 22 and the inverter 21, if the battery 10 needs to be warmed up, the current flowing through the rotating electric machine 22 will be limited to the allowable current I ａｐｒｖ DC current I equivalent to ｄｃ In addition, warm-up current i ｄｃ－ｈ The corresponding d-axis current i ｄ It flows. And the allowable current I ａｐｒｖ DC current I equivalent to ｄｃ This is supplied to the battery 10, and the added d-axis current i ｄ This is recirculated through the rotating electric machine 22 and inverter 21 and consumed as a loss. Therefore, compared to the case where the rotating electric machine 22 and inverter 21 are simply used as boost converters, the rotating electric machine 22 and inverter 21 have a d-axis current i ｄ The power consumption generates a lot of heat. Also, the heat from the rotating electric machine 22 and inverter 21 is transported to the battery 10 by the cooling system 12. Therefore, according to the charge control of this embodiment, the battery 10 warms up faster than when the rotating electric machine 22 and inverter 21 are simply used as boost converters, and the allowable current I ａｐｒｖ The battery also recovers quickly. As a result, the battery 10 is charged more rapidly than when the rotating electric machine 22 and inverter 21 are simply used as boost converters.

[0150] [Modified Version] The charging control of the above embodiment substantially includes the first to third modes.

[0151] In the first mode, the rotating electric machine 22 and the inverter 21 are given an allowable current I ａｐｒｖ and warm-up current I ｄｃ－ｈ Of which, the effective warm-up current I ｄｃ－ｈ This is the mode in which only the following current flows. More precisely, in the first mode, the rotating electric machine 22 and the inverter 21 receive a warm-up current I. ｄｃ－ｈ The corresponding d-axis current i ｄ This is a mode in which only the current I flows. ａｐｒｖThis is the control state when the value is close to zero.

[0152] In the second mode, the rotating electric machine 22 and the inverter 21 are given an allowable current I ａｐｒｖ and warm-up current I ｄｃ－ｈ This is a mode in which both currents flow. More precisely, the second mode is when the allowable current I ａｐｒｖ DC current I equivalent to ｄｃ and warm-up current I ｄｃ－ｈ The corresponding d-axis current i ｄ This is the mode in which the current flows. This is the control state mainly described in the above embodiment.

[0153] The third mode then provides the rotating electric machine 22 and inverter 21 with an allowable current I ａｐｒｖ and warm-up current I ｄｃ－ｈ Of these, the effectively allowable current I ａｐｒｖ This is the mode in which only the allowable current I flows. More precisely, the third mode is when the rotating electric machine 22 and inverter 21 receive the allowable current I ａｐｒｖ DC current I equivalent to ｄｃ This is a mode in which only the current flows. This is a control state in which the rotating electric machine 22 and inverter 21 are simply used as boost converters.

[0154] In the above embodiment, these modes are defined by the battery temperature T ｂ Due to the increase in the allowable current I ａｐｒｖ When it recovers, or when the battery temperature T ｂ The system automatically switches when the engine no longer needs warming up due to the increase in temperature. However, as explained below, the controller 13 can more explicitly switch the charging control mode.

[0155] Figure 22 is a flowchart relating to the mode selection for charge control (warm-up control). As shown in Figure 22, in step S31, the controller 13 selects the allowable current I ａｐｒｖ It determines whether the allowable current I ａｐｒｖ A threshold ε is set in advance for the allowable current I ａｐｒｖ When the threshold ε is less than or equal to the allowable current I ａｐｒｖ It is determined that this is effectively zero.

[0156] In step S31, the allowable current I ａｐｒｖ When it is determined that the value is substantially zero, the process proceeds to step S32, and the controller 13 performs the first mode of charge control.

[0157] When the rotating electric machine 22 and inverter 21 are used as a boost converter for the external charger 14, the allowable current I ａｐｒｖ When the allowable current I is zero and no current can be supplied to the battery 10, no current flows to the rotating electric machine 22 and the inverter 21. Therefore, the rotating electric machine 22 and the inverter 21 do not generate heat, the battery 10 does not warm up, and the battery 10 cannot be charged. In contrast, in the first mode of charge control, the allowable current I ａｐｒｖ Even if it is zero, the d-axis current i of the rotating electric machine 22 and inverter 21 ｄ This causes the battery temperature T to flow. ｂ The allowable current I gradually increases. ａｐｒｖ It recovers. Therefore, according to the charging control in the first mode, the battery 10 can be charged.

[0158] In step S31, the allowable current I ａｐｒｖ If it is determined that the current is not zero and that the battery 10 can accept a certain amount of current, the process proceeds to step S33.

[0159] In step S33, the controller 13 sets the allowable current I ａｐｒｖ A predetermined current threshold I ｔｈ Compare with the current threshold I. ｔｈ The allowable current I ａｐｒｖ DC current I equivalent to ｄｃ This is a threshold for determining whether the battery 10 warms up quickly based solely on the heat generated by the current. Current threshold I ｔｈ This is determined by fitting, for example, based on experiments or simulations.

[0160] In step S33, the allowable current I ａｐｒｖ Current threshold I ｔｈ Smaller than, allowable current I ａｐｒｖ DC current I equivalent to ｄｃIf it is determined that the heat generated by the device alone would require a considerable amount of time to warm up and charge the battery 10, the process proceeds to step S34, and the controller 13 executes the second mode of charging control. As explained in the above embodiment, the second mode of charging control allows the battery 10 to warm up and charge more quickly.

[0161] In step S33, the allowable current I ａｐｒｖ Current threshold I ｔｈ The above is true, and the allowable current I ａｐｒｖ DC current I equivalent to ｄｃ When it is determined that the warming and charging of the battery 10 can proceed without delay solely due to the heat generated by the device, the process proceeds to step S35, and the controller 13 executes the third mode of charging control. That is, the controller 13, similar to step S18 of the second mode, determines the d-axis current command value i in the dq-axis current determination unit 63. ｄ ＊ and q-axis current command value i ｑ ＊ Set both to zero. This causes the rotating electric machine 22 and the inverter 21 to simply function as boost converters for the external charger 14.

[0162] Furthermore, the charging control for the first mode, second mode, or third mode may be performed independently. In other words, the controller 13 does not need to be configured to perform all three charging modes: the first mode, the second mode, and the third mode. The controller 13 may be configured to perform only the charging control for the first mode. The controller 13 may be configured to perform only the charging control for the second mode. Alternatively, the controller 13 only needs to be configured to perform charging control for at least one of the first or second modes.

[0163] As described above, the control method for an electric vehicle according to the above embodiment and its modifications is a control method for an electric vehicle 100 in which, when charging the battery 10 with an external charger 14, the external charger 14 is connected to the battery 10 via a boost converter configured using a rotating electric machine 22 and an inverter 21, and the battery 10 is warmed up by transporting heat from the rotating electric machine 22 and the inverter 21 to the battery 10. In this control method for an electric vehicle 100, the allowable current I is the current that the battery 10 can accept as input. ａｐｒｖ The warm-up current I is calculated to be the current consumed as a loss in the rotating electric machine 22 and inverter 21. ｄｃ－ｈ The allowable current I is calculated. ａｐｒｖ and warm-up current I ｄｃ－ｈ Based on this, the charging current I input from the external charger 14 ｃｈ (=I ｃｈ ＊ Determine the charging current I ｃｈ When the allowable current I is supplied to the neutral point 23 of the rotating electric machine 22, ａｐｒｖ The following is supplied to the battery 10, and the warm-up current I in the rotating electric machine 22 ｄｃ－ｈ Corresponding d-axis current i ｄ The inverter 21 is switched so that the current flows back.

[0164] Thus, when the rotating electric machine 22 and inverter 21 are used as boost converters for the external charger 14, the allowable current I of the rotating electric machine 22 and inverter 21 is set. ａｐｒｖ The corresponding DC current I ｄｃ In addition, the d-axis current i for warming up ｄ By switching the inverter 21 so that current flows through it, the warm-up of the battery 10 is accelerated, and the allowable current I ａｐｒｖ Recovery is accelerated. Therefore, the battery 10 can be charged quickly even in low temperature conditions. In particular, when the rotating electric machine 22 and inverter 21 are used simply as a normal boost converter, the allowable current I in low temperature conditions ａｐｒｖ Battery 10 with reduced allowable current I ａｐｒｖ Due to this limitation, it is practically impossible to warm up or charge the machine. In contrast, as described above, the rotating electric machine 22 and inverter 21 function as boost converters, while the d-axis current iｄ If you allow it to flow, the allowable current I at low temperatures will be ａｐｒｖ Even with a degraded battery 10, it can be warmed up and charged quickly and with almost no interruption.

[0165] In the above embodiment and modified version of the electric vehicle control method, the charging current I ｃｈ The allowable current I ａｐｒｖ and warm-up current I ｄｃ－ｈ The sum of the boost ratios of the boost converter, r ｓｕ The calculation is performed by multiplying by .

[0166] Thus, the charging current I ｃｈ (Charging current command value I ｃｈ ＊ ) calculates the DC current I supplied to the battery 10. ｄｃ The allowable current I ａｐｒｖ The charging current I is within the range I ｃｈ This allows for particularly accurate determination. Therefore, it is possible to reliably prevent battery failure while promoting the warming and charging of the battery 10.

[0167] In the above embodiment and modified version of the electric vehicle control method, the charging current I ｃｈ Accordingly, the d-axis current i ｄ (=i ｄ Adjust the size of ′).

[0168] Additional d-axis current i for warming up ｄ The magnitude of the charging current I ｃｈ It changes depending on (see Figure 12). Therefore, as described above, the charging current I ｃｈ The d-axis current i ｄ By adjusting the size, the maximum possible d-axis current i can be obtained within the range that the inverter 21 and the rotating electric machine 22 can withstand. ｄ This allows for the flow of current. Therefore, the battery 10 can be warmed up and charged particularly quickly.

[0169] In the control method for electric vehicles according to the above embodiment and its modified form, the d-axis current i ｄ The magnitude of is the phase current i flowing through the rotating electric machine 22. ｕｖｗ It is determined so that the maximum value is maximized.

[0170] Thus, the phase current i ｕｖｗ The maximum value should be as large as possible (for example, i ｕ >i ｖ = i ｗ In this case, the U-phase current i ｕ (To make it as large as possible), add d-axis current i for warming up. ｄ By determining the size of the rotating electric machine 22 and inverter 21, the amount of heat generated is maximized. This allows the battery 10 to be warmed up and charged particularly quickly.

[0171] In the control method for electric vehicles according to the above embodiment and modified example, the d-axis current i ｄ This refers to the multiple switching elements (Q) that the inverter 21 has. １ ~Q ６ Current i flowing through ) ｕｕ ~i ｗｌ The phase current i flowing through the rotating electric machine 22 is set to the maximum value corresponding to the durability of the switching element. ｕｖｗ It is determined so that it is the maximum value corresponding to the winding's durability.

[0172] In this way, the d-axis current i is as low as possible within the range that the inverter 21 and the rotating electric machine 22 can withstand. ｄ Increasing this value allows the battery 10 to be warmed up and charged particularly quickly while preventing overheating failures of the inverter 21 and the rotating electric machine 22.

[0173] In the control method for electric vehicles according to the above embodiment and modified example, the d-axis current i ｄ Depending on the stopping position (θ) of the rotor of the rotating electric machine 22, the current flows in either the strengthening magnetic field direction, which strengthens the magnetic field of the rotating electric machine 22, or the weakening magnetic field direction, which weakens the magnetic field of the rotating electric machine 22.

[0174] Add d-axis current i for warm-up ｄ In principle, the current can flow in either the direction of the strengthening magnetic field or the direction of the weakening magnetic field. However, as described above, the d-axis current i depends on the rotor's stopping position (electrical angle θ). ｄ When the orientation (sign) is changed, the multiple switching elements (Q) of the inverter 21 change １ ~Q ６This makes it easier to distribute the heat load on the switching element (Q) due to the uneven distribution of the heat load. １ ~Q ６ This allows for the normalization of the degree of deterioration.

[0175] In the above embodiment and modified control method for electric vehicles, the boost ratio r of the boost converter ｓｕ If the ratio is more than twice (r ｓｕ ≧2), d-axis current i ｄ The phase current i flowing through the rotating electric machine 22 is ｕｖｗ The boost ratio r of the boost converter is determined to be maximized on the positive side. ｓｕ If it is less than twice (r ｓｕ <2), d-axis current i ｄ The phase current i flowing through the rotating electric machine 22 is ｕｖｗ It is determined so that it is maximized on the negative side.

[0176] Thus, the step-up ratio r ｓｕ The phase current i ｕｖｗ The d-axis current i is maximized on the positive or negative side. ｄ Once determined, the inverter 21 has multiple switching elements (Q １ ~Q ６ This makes it easier to distribute the heat load on the switching element (Q) due to the uneven distribution of the heat load. １ ~Q ６ This allows for the normalization of the degree of deterioration.

[0177] The control method for electric vehicles according to the above embodiment and modified example is the allowable current I ａｐｒｖ and warm-up current I ｄｃ－ｈ Of these, the warm-up current I ｄｃ－ｈ The first mode involves flowing current, and the allowable current I ａｐｒｖ and warm-up current I ｄｃ－ｈ The second mode allows both to flow, and the allowable current I ａｐｒｖ and warm-up current I ｄｃ－ｈ Of these, the allowable current I ａｐｒｖ It has a third mode that flows and

[0178] In this way, when performing charging control in the first to third modes, the optimal warm-up method can be selected according to the state of the battery 10. Therefore, the battery 10 can be warmed up and charged efficiently.

[0179] The control device for the electric vehicle according to the above embodiment and modified example is a control device (controller 13) for the electric vehicle 100 that, when charging the battery 10 with an external charger 14, connects the external charger 14 to the battery 10 via a boost converter configured using a rotating electric machine 22 and an inverter 21, and warms up the battery 10 by transporting heat from the rotating electric machine 22 and the inverter 21 to the battery 10. This control device (controller 13) for the electric vehicle 100 controls the allowable current I, which is the input current that the battery 10 can tolerate. ａｐｒｖ The allowable current calculation unit 51 calculates the allowable current I, which is the current consumed as loss in the rotating electric machine 22 and inverter 21. ｄｃ－ｈ A warm-up current calculation unit 52 calculates the allowable current I ａｐｒｖ and warm-up current I ｄｃ－ｈ Based on this, the charging current I input from the external charger 14 ｃｈ (≒I ｃｈ ＊ A charging current calculation unit 54 that determines the charging current I ｃｈ When the allowable current I is supplied to the neutral point 23 of the rotating electric machine 22, ａｐｒｖ The following is supplied to the battery 10, and the warm-up current I in the rotating electric machine 22 ｄｃ－ｈ Corresponding d-axis current i ｄ (≒i ｄ The dq-axis current command value i is used to switch the inverter 21 so that the ') flows back. ｄｑ ＊ It includes a dq-axis current command value calculation unit 55 that calculates the following:

[0180] Thus, when the rotating electric machine 22 and inverter 21 are used as boost converters for the external charger 14, the allowable current I of the rotating electric machine 22 and inverter 21 is set. ａｐｒｖ The corresponding DC current I ｄｃ In addition, the d-axis current i for warming up ｄ By switching the inverter 21 so that current flows through it, the warm-up of the battery 10 is accelerated, and the allowable current I ａｐｒｖ Recovery is accelerated. Therefore, even in low temperature conditions, the battery 10 can be charged quickly. In particular, while the rotating electric machine 22 and inverter 21 function as boost converters, the d-axis current iｄ By flowing this, the allowable current I at low temperatures ａｐｒｖ Even with a degraded battery 10, it can be warmed up and charged quickly and with almost no interruption.

[0181] Although embodiments and modifications of the present invention have been described above, the configurations described in the above embodiments and modifications represent only a part of the application examples of the present invention and are not intended to limit the technical scope of the present invention.

Claims

1. A control method for an electric vehicle, in which, when charging the battery with an external charger, the external charger is connected to the battery via a boost converter configured with a rotating electric machine and an inverter, and the battery is warmed up by transporting heat from the rotating electric machine and the inverter to the battery, the method comprising: calculating the allowable current, which is the maximum input current that the battery can tolerate; calculating the warm-up current, which is the current consumed as loss in the rotating electric machine and the inverter; determining the charging current to be input from the external charger based on the allowable current and the warm-up current; and switching the inverter so that when the charging current is supplied to the neutral point of the rotating electric machine, the allowable current is supplied to the battery and a d-axis current corresponding to the warm-up current flows back in the rotating electric machine.

2. A method for controlling an electric vehicle according to claim 1, wherein the charging current is calculated by multiplying the sum of the allowable current and the warm-up current by the boost ratio of the boost converter.

3. A method for controlling an electric vehicle according to claim 2, wherein the magnitude of the d-axis current is adjusted according to the charging current.

4. A method for controlling an electric vehicle according to claim 3, wherein the magnitude of the d-axis current is determined such that the maximum value of the phase current flowing through the rotating electric machine is increased.

5. A method for controlling an electric vehicle according to claim 4, wherein the d-axis current is determined such that the current flowing through a plurality of switching elements of the inverter becomes the maximum value corresponding to the durability of the switching elements, or the phase current flowing through the rotating electric machine becomes the maximum value corresponding to the durability of the winding.

6. A method for controlling an electric vehicle according to claim 1, wherein the d-axis current is flowed in a direction that strengthens the magnetic field of the rotating electric machine, or in a direction that weakens the magnetic field of the rotating electric machine, depending on the stopping position of the rotor of the rotating electric machine.

7. A method for controlling an electric vehicle according to claim 1, wherein when the boost ratio of the boost converter is 2 or more, the d-axis current is determined so as to maximize the phase current flowing through the rotating electric machine on the positive side, and when the boost ratio of the boost converter is less than 2, the d-axis current is determined so as to maximize the phase current flowing through the rotating electric machine on the negative side.

8. A control method for an electric vehicle according to claim 1, comprising: a first mode in which the warm-up current is supplied from the allowable current and the warm-up current; a second mode in which both the allowable current and the warm-up current are supplied; and a third mode in which the allowable current is supplied from the allowable current and the warm-up current.

9. A control device for an electric vehicle, which, when charging the battery with an external charger, connects the external charger to the battery via a boost converter configured with a rotating electric machine and an inverter, and warms up the battery by transporting heat from the rotating electric machine and the inverter to the battery, comprising: an allowable current calculation unit that calculates an allowable current which is the input current that the battery can tolerate; a warm-up current calculation unit that calculates a warm-up current which is the current consumed as loss in the rotating electric machine and the inverter; a charging current calculation unit that determines the charging current to be input from the external charger based on the allowable current and the warm-up current; and a dq-axis current command value calculation unit that calculates a dq-axis current command value for switching the inverter so that when the charging current is supplied to the neutral point of the rotating electric machine, the allowable current is supplied to the battery and a d-axis current corresponding to the warm-up current flows back in the rotating electric machine.

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