Charge / discharge control method and charge / discharge control system

Abstract

The present invention relates to: a rotary electric machine that rotates by the interaction between magnetic flux generated by a permanent magnet and coil magnetic flux which is composite magnetic flux of magnetic flux generated by coils of a plurality of phases, to thereby cause an electric vehicle to travel; a battery that supplies power to and receives power from the rotary electric machine; an inverter that controls, on the basis of a voltage command value, supplying and receiving of power between the battery and the rotary electric machine; and a charge / discharge control method that is for executing charging / discharging of the battery in a mode of energizing the rotary electric machine by outputting, to the inverter, a charging / discharging voltage command value at which torque is not generated in one direction in the rotary electric machine while the electric vehicle is stopped, as the voltage command value. If torque ripple occurs in the rotary electric machine during execution of the charging / discharging: a d-axis current command value for generating a magnetic flux component in a direction opposite to the magnetic flux direction of the permanent magnet is set on the basis of the magnitude of the torque ripple; a correction voltage command value is calculated on the basis of the d-axis current command value; and a value obtained by adding the correction voltage command value to the charging / discharging voltage command value is outputted to the inverter as the voltage command value.

Description

Charge / discharge control method and charge / discharge control system

[0001] This invention relates to a charge / discharge control method and a charge / discharge control system.

[0002] US11171504B2 discloses a charging device that uses the inverter and three-phase AC motor of a motor drive system as boost converters when charging the battery of an electric vehicle with an external power source. More specifically, this charging device controls the switching operation of the inverter so that the q-axis current of the motor is set to zero or a d-axis current flows that cancels out the magnetic flux of the magnets.

[0003] US11171504B2 is a technology that controls the inverter without generating torque to supply current to the motor (stator winding), but it results in large variations in the u-phase current, v-phase current, and w-phase current, leading to increased copper loss.

[0004] Therefore, the present invention aims to provide a charge / discharge control method and a charge / discharge system that reduce copper loss in a rotating electric machine when charging and discharging a battery in a manner in which current is supplied to the rotating electric machine when the electric vehicle is stopped.

[0005] According to one aspect of the present invention, a charging and discharging control method for a battery is provided, comprising: a rotating electric machine that drives an electric vehicle by rotating due to the action of a permanent magnet magnetic flux generated by a permanent magnet and a coil magnetic flux which is a composite magnetic flux of magnetic fluxes generated by a plurality of phase coils; a battery that exchanges power with the rotating electric machine; an inverter that controls the exchange of power between the battery and the rotating electric machine based on a voltage command value; and a charging and discharging control method that energizes the rotating electric machine by outputting a charging and discharging voltage command value to the inverter as a voltage command value when the electric vehicle is stopped, such that no unidirectional torque is generated in the rotating electric machine. In this charging and discharging control method, when a torque ripple occurs in the rotating electric machine during charging and discharging, a d-axis current command value that generates a magnetic flux component in the opposite direction to the magnetic flux direction of the permanent magnet is set based on the magnitude of the torque ripple, a correction voltage command value is calculated based on the d-axis current command value, and the value obtained by adding the correction voltage command value to the charging and discharging voltage command value is output to the inverter as a voltage command value.

[0006] Figure 1 is a block diagram showing the schematic configuration of a rotating electric machine system. Figure 2 is an equivalent circuit for the U-phase of a rotating electric machine when a boost converter is configured. Figure 3 is a diagram showing the relationship between charge / discharge output, rotation angle, and torque ripple. Figure 4 is a diagram showing the relationship between torque ripple and d-axis current. Figure 5 is an explanatory diagram showing the coil magnetic flux generated in a rotating electric machine during charge / discharge control. Figure 6 is a diagram showing the waveforms of the u-phase current, v-phase current, w-phase current, d-axis current, q-axis current, and torque ripple when a corrected d-axis current command is not applied. Figure 7 is a diagram showing the waveforms of the u-phase current, v-phase current, w-phase current, d-axis current, q-axis current, and torque ripple when a corrected d-axis current command is applied. Figure 8 is a diagram showing the torque ripple waveform when an electric vehicle is stopped on an inclined surface and a corrected d-axis current command is not applied. Figure 9 is a diagram showing the torque ripple waveform when an electric vehicle is stopped on an inclined surface and a corrected d-axis current command is applied.

[0007] Embodiments of the present invention will be described below with reference to the drawings.

[0008] [Basic Configuration] Figure 1 is a block diagram showing the schematic configuration of the rotating electric machine system 100. The rotating electric machine system 100 is a vehicle drive system or power generation system installed in electric vehicles such as hybrid vehicles and electric vehicles. Therefore, as shown in Figure 1, the rotating electric machine system 100 comprises a battery 7, an inverter 6, a rotating electric machine 9, and a controller 1. Of these, the inverter 6 and the rotating electric machine 9 are, for example, substantially integrated and constitute a so-called electric powertrain. External equipment 27 may also be connected to the rotating electric machine system 100.

[0009] Battery 7 is a rechargeable DC power source. Battery 7 supplies power to drive the rotating electric machine 9. That is, when driving the rotating electric machine 9, Battery 7 supplies a DC voltage (V) to the inverter 6. ＤＣ ) is input. On the other hand, when the rotating electric machine 9 generates electricity, the battery 7 is charged by that electricity.

[0010] If the external equipment 27 is a rapid charger or the like, the battery 7 is charged by the power supplied by the external equipment 27 via the electric powertrain. At this time, the input voltage (V) from the external equipment 27 ＩＮ (Figure 2) is boosted by the electric powertrain as needed. This provides an output voltage (V) suitable for charging. ＯＵＴ The battery 7 is charged by (Figure 2). In this embodiment, the voltage of the battery 7 (V ＤＣ The input voltage (V) is, for example, 800V. The rapid charger connected as external equipment 27 is a DC power source, and its voltage (input voltage (V) ＩＮ The voltage is, for example, 400V or 800V. Therefore, when a 400V fast charger is connected, the output voltage (V ＯＵＴ The voltage is boosted to 800V.

[0011] If the external equipment 27 is a device that consumes power, the battery 7 can be discharged and power supplied to the external equipment 27 via the electric powertrain. At this time, the input voltage to the external equipment 27 is stepped down by the electric powertrain as needed.

[0012] The inverter 6 converts the DC power output by the battery 7 into AC power and supplies it to the rotating electric machine 9. This drives the rotating electric machine 9. Conversely, when the rotating electric machine 9 generates power, the inverter 6 converts the AC power generated by the rotating electric machine 9 into DC power and supplies it to the battery 7.

[0013] When external equipment 27 is connected to the rotating electric machine system 100, the inverter 6 can configure a boost converter or a buck converter together with the rotating electric machine 9. Specifically, all or part of the switching elements and freewheeling diodes that make up the inverter 6 are used as elements of a boost converter or a buck converter. When the external equipment 27 is a rapid charger or the like, the inverter 6 can configure a boost converter together with the rotating electric machine 9, and the input voltage (V ＩＮ The output voltage (V) obtained by boosting the voltage of ) ＯＵＴ) is applied to the battery 7. Further, when the external facility 27 is a device or the like that consumes electric power, the inverter 6 constitutes a step-down converter together with the rotating electric machine 9. Accordingly, the external facility 27 is supplied with electric power from the battery 7 at a required voltage.

[0014] The rotating electric machine 9 is an electric motor or a generator. When the rotating electric machine 9 is an electric motor, the rotating electric machine system 100 is a drive system for an electric vehicle or the like equipped therewith. When the rotating electric machine 9 is a generator, the rotating electric machine system 100 is a power generation system for a hybrid vehicle or the like equipped therewith. In the present embodiment, it is assumed that the rotating electric machine 9 is an electric motor for driving a vehicle.

[0015] The rotating electric machine 9 is an embedded permanent-magnet AC synchronous machine and has a plurality of phases. Accordingly, the rotating electric machine 9 includes a rotor in which a permanent magnet 92 (see FIG. 5) is embedded, and a stator having a plurality of independent coils. The rotating electric machine 9 rotates due to the interaction between a magnetic flux generated by the permanent magnet 92 (hereinafter referred to as permanent magnet magnetic flux) and a combined magnetic flux of magnetic fluxes generated by the plurality of phases of coils (hereinafter referred to as coil magnetic flux). Further, the plurality of phases of coils are connected by so-called star connection (Y-connection) and have a neutral point. In the present embodiment, the rotating electric machine 9 is an embedded permanent-magnet three-phase AC synchronous motor. Accordingly, the rotating electric machine 9 includes a rotor having the permanent magnet 92, and a stator having uvw three-phase stator coils connected by Y-connection.

[0016] When the external facility 27 is connected to the rotating electric machine system 100, the rotating electric machine 9 constitutes a boost converter or a step-down converter together with the inverter 6. Specifically, the coil of each phase is used as an inductor of the boost converter or the step-down converter. At this time, one terminal of the external facility 27 is connected to the neutral point of the rotating electric machine 9.

[0017] Note that a current flowing through the coil of each of the uvw phases (hereinafter, three-phase current (I ｕｖｗ ), neutral point voltage (V ｎ ), rotation angle (θ) of the rotor (permanent magnet 92) ｒ ) can all be detected at any timing. In the present embodiment, the three-phase current (I ｕｖｗThe neutral point voltage (V) is detected by the current sensor 20a. ｎ ), detected by a voltage sensor (not shown). Rotation angle (θ ｒ The rotation angle (θ) is detected by the rotation sensor 13 (resolver). ｒ The angle is measured counterclockwise in the uvw coordinate system, with the position of the u-phase coil (U) as the reference angle (0°).

[0018] Controller 1 is a control device that comprehensively controls the operation of each part of the rotating electric machine system 100. Controller 1 is composed of, for example, one or more computers and is programmed to cause each part to perform predetermined operations. In this embodiment, Controller 1 is a charge / discharge control device for controlling the charging or discharging of the battery 7 by configuring a DC / DC converter with the inverter 6 and the rotating electric machine 9. The charge / discharge control program for operating the inverter 6 and the rotating electric machine 9 as a DC / DC converter may be provided in a form stored on a storage medium.

[0019] Specifically, the controller 1 controls the overall operation of the rotating electric machine system 100 by inputting a PWM (pulse width modulation) signal to the inverter 6. For example, the controller 1 generates a PWM signal (referred to as a rotation control PWM signal) to control the rotation of the rotating electric machine 9, and controls the rotational speed and torque of the rotating electric machine 9 by inputting this signal to the inverter 6. The controller 1 generates the rotation control PWM signal based, for example, the amount of accelerator operation.

[0020] Furthermore, in this embodiment, even when external equipment 27 is connected to the rotating electric machine system 100, the controller 1 inputs a PWM signal (hereinafter referred to as the converter PWM signal) to the inverter 6 to operate the electric powertrain as a DC / DC converter. As a result, the inverter 6 and the rotating electric machine 9 function as a boost converter or a buck converter. The controller 1 outputs a three-phase current (I ｕｖｗ ), neutral point voltage (V ｎ ), and rotation angle (θ ｒ Based on this, a PWM signal for the converter is generated.

[0021] External equipment 27 is equipment or devices installed separately from the vehicle on which the rotating electric system 100 is mounted. External equipment 27 supplies power to the rotating electric system 100, or is supplied with power from the rotating electric system 100. External equipment 27 that supplies power to the rotating electric system 100 is, for example, a fast charger installed at a charging station or other chargers. External equipment 27 that is supplied with power from the rotating electric system 100 is, for example, outdoor equipment. Hereinafter, external equipment 27 will be assumed to be a fast charger. Therefore, when external equipment 27 is connected to the rotating electric system 100, it charges the battery 7.

[0022] In addition to using the electric powertrain as a DC / DC converter, the controller 1 can also discharge the battery 7 by supplying d-axis current to the u-phase, v-phase, and w-phase, and perform warm-up control of the battery 7 through self-heating during discharge. In this case, the rotating electric machine system 100 performs warm-up control while isolated from the external equipment 27.

[0023] As shown in Figure 1, the external equipment 27 is connected to the electric powertrain via the first relay switch 24, the second relay switch 25, and the third relay switch 26.

[0024] The first relay switch 24 is connected to the high-voltage side of the battery 7 (the DC voltage side of the inverter 6).

[0025] The second relay switch 25 is connected to the low-voltage side of the battery 7 (the DC voltage side of the inverter 6).

[0026] The third relay switch 26 is connected to the neutral point (n) of the rotating electric machine 9 (the connection point of the u-phase coil, v-phase coil, and w-phase coil).

[0027] The low-voltage side of the battery 7 (the DC voltage of the inverter 6) and the neutral point (n) of the rotating electric machine 9 are connected via a neutral point capacitor 8.

[0028] The output voltage of the battery 7 is applied between the first relay switch 24 and the second relay switch 25.

[0029] The neutral point voltage (Vn) of the rotating electric machine 9 (the voltage across the neutral point capacitor 8) is applied between the third relay switch 26 and the second relay switch 25.

[0030] As shown in Figure 1, the external equipment 27 is connected to the electric powertrain (inverter 6, rotating electric machine 9), battery 7, and neutral point capacitor 8 via the first relay switch 24, second relay switch 25, and third relay switch 26.

[0031] The first relay switch 24, the second relay switch 25, and the third relay switch 26 are controlled to be on or off by the controller 1.

[0032] External equipment 27 sets the maximum voltage (V) of the rapid charging voltage. ＱＣｍａｘ The information is sent to controller 1.

[0033] When the controller 1 is charging the battery 7, the maximum voltage (V) ＱＣｍａｘ ) is the voltage of battery 7 (V ＤＣ When the voltage is 800V, the first relay switch 24 and the second relay switch 25 are set to the ON state (conductive state), and the third relay switch 26 is set to the OFF state (non-conductive state). This allows the DC voltage of the external equipment 27 to be supplied directly to the battery 7, thereby rapidly charging the battery 7.

[0034] When the controller 1 is charging the battery 7, the maximum voltage (V) ＱＣｍａｘ ) is the voltage of battery 7 (V ＤＣ When the voltage is lower than a predetermined value (=400 [V]), the first relay switch 24 is set to the off state (non-conductive state), and the second relay switch 25 and the third relay switch 26 are set to the on state (conductive state). As a result, the DC voltage of the external equipment 27 is supplied to the neutral point (n) of the rotating electric machine 9. Furthermore, the controller 1 sends a neutral point current command (I) to the external equipment 27, as described later. ｎ ＊ ) outputs a neutral point current command (I ｎ ＊ The neutral point current (I ｎThe controller 1 then uses the electric powertrain as a boost converter to boost the DC voltage of the external equipment 27 and charges the battery 7 by supplying the boosted voltage to the battery 7.

[0035] Figure 2 shows the equivalent circuit for the u-phase of the rotating electric machine 9 when a boost converter is configured. As shown in Figure 2, the boost converter (u-phase) composed of the inverter 6 and the rotating electric machine 9 includes a first series circuit in which an upper arm (a parallel circuit of an upper switching element 61uu and an upper feedback diode 62uu) and a lower arm (a parallel circuit of a lower switching element 61ul and a lower feedback diode 62ul) are connected in series, a second series circuit in which an inductor 91u (u-phase coil) and a neutral point capacitor 8 are connected in series, and a smoothing capacitor 63 connected in parallel to the first series circuit. Furthermore, the end of the second series circuit on the inductor 91u side is connected to the midpoint of the connection between the upper and lower arms of the first series circuit and is connected to the end on the lower arm side of the second series circuit. The voltage applied to the neutral point capacitor 8 is the input voltage (V) applied from the external equipment 27. ＩＮ ) and the voltage applied to the smoothing capacitor 63 becomes the output voltage (V) applied to the battery 7. ＯＵＴ )

[0036] In the boost converter shown in Figure 2, the upper switching element 61uu is kept in the off state, and the lower switching element 61ul is controlled to be on / off (a PWM signal is input). The coil of the rotating electric machine 9 (here, the u-phase coil) functions as the inductor 91u of the boost converter. Here, the configuration of the boost converter is shown for the u-phase, but the v-phase and w-phase are configured similarly. The boost converters for each phase (u, v, w) are connected in parallel to the battery 7. Note that by configuring the boost converter shown in Figure 2 so that the lower switching element 61ul is kept in the off state and the upper switching element 61u is controlled to be on / off (a PWM signal is input), it becomes a buck converter that reduces the voltage of the battery 7 and supplies it to the external equipment 27.

[0037] Therefore, it is possible to select and use any of the boost converters for each phase (u, v, w). In this embodiment, when the inverter 6 and the rotating electric machine 9 are used as boost converters, all phase boost converters are used simultaneously.

[0038] Furthermore, since the boost converters for each phase are in parallel, the timing for turning the switching elements on and off can be determined substantially independently in each phase boost converter. However, when current flows through the coils of each phase, torque is normally generated in the rotating electric machine 9. For this reason, when using the inverter 6 and the rotating electric machine 9 as a boost converter, it is necessary to suppress the torque generated in the rotating electric machine 9 to the extent that it does not substantially rotate. The extent to which the rotating electric machine 9 does not substantially rotate means, for example, not to the extent that it does not violate the electric parking brake (so-called park lock). In other words, when a boost converter is configured using the inverter 6 and the rotating electric machine 9 and the battery 7 is charged, at least the state in which the rotating electric machine 9 does not rotate is maintained.

[0039] Returning to Figure 1, the controller 1 controls the maximum voltage (V ＱＣｍａｘ Information from external equipment 27 such as ) and the voltage of battery 7 (V ＤＣ Based on the neutral point voltage command (V ｎ ＊ ) and neutral point current command (I ｎ ＊ ) generates a neutral point voltage command (V ｎ ＊ ) is output to the differencer 2, and the neutral point current command (I ｎ ＊ ) is output to external equipment 27.

[0040] Here, the neutral point voltage command (V ｎ ＊ ), for example, it is preset by a higher-level controller (not shown) based on the specific characteristics of the external equipment 27 connected to the rotating electric machine system 100. Also, the neutral point voltage command (V ｎ ＊ ) may be pre-set by user settings. In any case, in this embodiment, the neutral point voltage command (V ｎ ＊The neutral point voltage (V) is predetermined. Controller 1 controls the neutral point voltage (V) using PI (Proportional-Integral) control, PID (Proportional-Integral-Differential) control, etc. ｎ ) is the neutral point voltage command (V ｎ ＊ The neutral point current command (I ｎ ＊ ) will be decided.

[0041] The differencer 2 receives the neutral point voltage command (V ｎ ＊ ) From, the neutral point voltage (V ｎ The difference obtained by subtracting ) is output to the voltage controller 3.

[0042] The voltage controller 3 controls the output from the differencer 2 and the voltage of the battery 7 (V ＤＣ Based on this, the basic duty cycle command (D) for generating the PWM signal. ｎ ＊ This generates a value and outputs it to adder 4.

[0043] Adder 4 is controlled by the basic duty cycle command (D ｎ ＊ ) and the corrected duty cycle command (ΔD) described below ｕｖｗ ＊ ) and add them together to determine the final duty cycle (D ｕｖｗ ＊ This generates a signal and outputs it to the PWM signal generator 5.

[0044] The PWM signal generator 5 outputs the final duty cycle command (D ｕｖｗ ＊ ) and the voltage of battery 7 (V ＤＣ Based on this, a PWM signal is generated that determines the timing for switching each switching element of the inverter 6 according to a predetermined PWM method such as spatial vector PWM control. Here, the PWM signal generated by the PWM signal generator 5 is either a boost PWM signal or a buck PWM signal. The PWM signal generator 5 can generate PWM signals independently for each switching element of the UVW phase.

[0045] In this embodiment, the PWM signal generator 5 particularly generates the first PWM signal (hereinafter referred to as PWM１ (and the second PWM signal (hereinafter referred to as PWM) ２ It generates two types of PWM signals. １ This determines the timing for switching at least one of the switching elements in each of the UVW phases. ２ This determines the timing for switching the switching elements of other phases.

[0046] The PWM signal generator 5, based on the selection signal input from the switching phase selection unit 19 (described later), selects at least one of the U-phase switching elements, V-phase switching elements, and W-phase switching elements to generate a PWM signal. １ Switching control is performed using this method, and the remaining two are PWM ２ Switching control is performed by this method.

[0047] The angle detector 14 detects the rotation angle (θ) of the rotor when the electric vehicle (rotating electric machine 9) is stopped, i.e., when the external equipment 27 is connected, via the rotation sensor 13. ｒ ) detects.

[0048] The rotation angle selector 15 detects the rotation angle (θ) when the external equipment 27 is connected. ｒ Based on this, the target rotation angle (θ ｒ ＊ Select (set) the target rotation angle (θ). ｒ ＊ When using the external equipment 27 (i.e., when the external equipment 27 charges the battery 7, or when the battery 7 supplies power to the external equipment 27), the rotation angle (θ) that the rotating electric machine 9 should maintain is... ｒ This parameter represents the target value of ).

[0049] The rotation angle (θ) detected when the external equipment 27 is connected to the rotating electric machine system 100 ｒ ) (Initial value θ below) ｒ－ｉｎｉ (This refers to the rotation angle (θ) when the electric vehicle is stopped. ｒ Therefore, it is essentially random and can take any angle from 0° to 360°. Also, when using the external equipment 27, the energy loss that occurs in the inverter 6 and the rotating electric machine 9 is the rotation angle (θ). ｒ), it varies depending on the case, and if the rotation angle (θ ｒ ) changes while the external device 27 is in use, the property and magnitude of energy loss occurring in the inverter 6 and the rotating electrical machine 9 also change. And the ideal rotation angle (θ ｒ ) with small energy loss in the inverter 6 and the rotating electrical machine 9 is predetermined depending on the configuration and the like of the inverter 6 and the rotating electrical machine 9. Therefore, in the present embodiment, the ideal rotation angle (θ ｒ ) is the target rotation angle (θ ｒ ＊ ) which is preset. As a result, as will be described later, the rotation angle (θ ｒ ) is the ideal rotation angle (θ ｒ ) that is the target rotation angle (θ ｒ ＊ ) is controlled to match or follow.

[0050] Specifically, when the external device 27 is used, in a case where the switching element of the inverter 6 is controlled such that coil magnetic flux (Φ) is generated in the so-called q-axis direction, the target rotation angle (θ ｒ ＊ ) is θ ｒ（ｑ） ＊ ≡ any one of {30°, 90°, 150°, 210°, 270°, 330°} is selected. In the present embodiment, the target rotation angle setter 32 selects, from among the respective values of θ ｒ（ｑ） ＊ the value closest to the initial value θ ｒ－ｉｎｉ and sets this value as the target rotation angle (θ ｒ ＊ ). Accordingly, energy loss is minimized and this state is maintained.

[0051] The torque generator 16 obtains the value by subtracting the rotation angle (θ ＊ ) from the target rotation angle (θr ｒ ), which is the deviation (Δθ ｒ ) based on which the torque command (T ＊ ) is calculated. The rotation angle controller 33 uses PI control, PID control or the like to make the deviation (Δθ ｒ ) become zero, that is, make the rotation angle (θ ｒ ) become the target rotation angle (θｒ ＊ Torque command (T ＊ Set the torque command (T ＊ ) is the rotation angle (θ) when using the external equipment 27. ｒ This is the target value for the torque (T) that the rotating electric machine 9 should generate in order to adjust the ).

[0052] The current generator 17 receives the torque command (T ＊ ) Correction q-axis current command (I ｑａ ＊ ) generates a corrected q-axis current command (I ｑａ ＊ ) When using external equipment 27, the rotating electric machine 9 receives a torque command (T ＊ The current generator 17 is set to generate a torque (T) corresponding to the current. The current generator 17, for example, refers to a torque table to generate a corrected q-axis current command (I ｑａ ＊ The torque table is predetermined based on experiments or simulations. Here, the torque table is set for a state where the rotational speed (electrical angular velocity) of the rotating electric machine 9 is substantially zero, and the torque command (T ＊ ) and corrected q-axis current command (I ｑａ ＊ ) are pre-assigned.

[0053] The torque detection means 10 is, for example, a torque sensor (not shown) attached to an electric parking brake (not shown). The torque sensor detects the rotational vibration component received from the rotating electric machine 9 (a drive force transmission system that transmits the driving force of the rotating electric machine 9 to the drive wheels) as a torque ripple (ΔT). Alternatively, the torque detection means 10 may monitor the acceleration detected by an acceleration sensor (not shown) mounted on the electric vehicle, or the phase current detected by a current sensor 20a, and detect the changes in these as a torque ripple (ΔT).

[0054] Torque ripple (ΔT) is, for example, a corrected q-axis current command (I) output by the current generator 17. ｑａ ＊This is generated in the rotating electric machine 9. In addition, the warm-up control of the battery 7 may cause a vibration component in the rotational direction in the rotating electric machine 9, which is detected as torque ripple (ΔT).

[0055] As mentioned above, the rotation angle (θ) ｒ When this changes, the nature and magnitude of the energy loss occurring in the inverter 6 and the rotating electric machine 9 also change, and therefore the torque ripple (ΔT) also changes.

[0056] Therefore, as shown in Figure 3, the torque detection means 10 is the charge / discharge output of the battery 7 (neutral point current command (I ｎ ＊ )) and rotation angle (θ ｒ It has a map showing the relationship between the power output (I) and the torque ripple (ΔT). This map (and other maps) can be set experimentally. The torque detection means 10 has a map showing the relationship between the power output (I) and the neutral point current command (ΔT) of the battery 7. ｎ ＊ )), and rotation angle (θ ｒ Alternatively, you can input the values ​​into the map and calculate the torque ripple (ΔT).

[0057] The torque ripple controller 11 issues a corrected d-axis current command (I) based on the input torque ripple (ΔT). ｄａ ＊ The result is calculated and output to the adder 12.

[0058] The torque ripple controller 11 controls the torque ripple (ΔT) and a correction d-axis current command (I) to reduce the torque ripple (ΔT) (peak value) to a predetermined value (for example, a value lower than the maximum torque (Tmax) that the electric parking brake allows). ｄａ ＊ It has a map (Figure 4) that has a relationship with ). The map shown in Figure 4 can be set in advance by experiment or simulation. Therefore, the torque ripple controller 11 inputs the input torque ripple (ΔT) into the map (Figure 4) to correct the d-axis current command (I ｄａ ＊The following is calculated: Note that multiple maps are prepared to correspond to the angle of the inclined surface, charge / discharge output, etc., and a map corresponding to the angle of the inclined surface, charge / discharge output, etc. during charging and discharging may be selected from among the multiple maps.

[0059] When an electric vehicle is stopped on an inclined surface that tilts in the front-to-rear direction of the vehicle, the vehicle's own weight applies a downward force to the electric parking brake. At this time, the torque detection means 10 detects the torque ripple (ΔT) and the tilt torque (T) caused by the inclined surface. ｐ The torque (ΔT + Tp) obtained by adding the t(T) is detected and output to the torque ripple controller 11. ｐ ) may be estimated by the sensor value of a tilt sensor (not shown) attached to the electric vehicle.

[0060] As described above, the torque ripple controller 11 has the maximum torque (Tmax) that the electric parking brake allows as a known value. Therefore, the torque ripple controller 11 takes the torque (ΔT+Tp-Tmax) obtained by subtracting the maximum torque (Tmax) (absolute value) from the torque (ΔT+Tp) (absolute value) detected by the torque detection means 10 and a correction d-axis current command (I) to reduce the torque (ΔT+Tp) (peak value) to a predetermined value (for example, a value lower than the maximum torque (Tmax) that the electric parking brake allows). ｄａ ＊ It has a map (Figure 4) that has a relationship with ).Therefore, the torque ripple controller 11 converts the torque (ΔT + Tp) detected by the torque detection means 10 into torque (ΔT + Tp - Tmax), inputs this into the map (Figure 4) and corrects the d-axis current command (I ｄａ ＊ Calculate the result.

[0061] When external equipment 27 is connected, the controller 1 issues a basic dq axis current command (I ｄｑ ＊ This generates a value and outputs it to the adder 12.

[0062] Basic dq-axis current command (I ｄｑ０ ＊ ) is the d-axis current (i) that flows through the rotating electric machine 9 when using the external equipment 27. ｄ) and q-axis current (i ｑ This is the target value for the basic d-axis current command (I ｄ０ ＊ ) and basic q-axis current command (i ｑ０ ＊ ) consists of the following. In this embodiment, the basic d-axis current command (I ｄ０ ＊ ) and basic q-axis current command (I ｑ０ ＊ ) are all zero. That is, when using external equipment 27, in principle, I ｄｑ０ ＊ = (I ｄ０ ＊ , I ｑ０ ＊ ) = (0,0) is set in advance. This allows the three-phase current (I ｕｖｗ ) (Three-phase current command (I ｕｖｗ ＊ The time average of )) is equalized. As a result, when the external equipment 27 is used, the rotating electric machine 9 does not generate torque and, as a result, does not rotate.

[0063] The adder 12 receives the basic dq axis current command (I) from the controller 1. ｄｑ０ ＊ ) and the corrected d-axis current command (I ｄａ ＊ The sum of the two values ​​is calculated by adding them together, and the sum of the two values ​​is output to the adder 18.

[0064] The adder 18 takes the summation value input from the adder 12 and the corrected q-axis current command (I) input from the current generator 17. ｑａ ＊ ) and add them together to give the dq axis current command (I ｄｑ ＊ ) is calculated, and the dq axis current command (I ｄｑ ＊ ) is output to the subtractor 21.

[0065] The first coordinate converter 20 receives the u-phase current detection value (I) detected by the current sensor 20a. ｕ ), v-phase current detection value (I ｖ ), w-phase current detection value (I ｗ ) is the detected value of the dq axis current (I ｄｑIt is converted to ) and output to subtractor 21.

[0066] The subtractor 21 receives the dq axis current command (I) input from the adder 18. ｄｑ ＊ ) The dq axis current detection value (I ｄｑ Subtracting ) results in a subtracted value (I ｄｑ ＊ -I ｄｑ The subtraction value is calculated and output to the second coordinate converter 22.

[0067] The second coordinate converter 22 receives the subtraction value (I) input from the subtractor 21. ｄｑ ＊ -I ｄｑ ) is converted to a fixed coordinate system (uvw phase) based on the electrical angle (rotation angle (θr)) of the rotating electric machine 9 (I ｕｖｗ ＊ -I ｕｖｗ Convert to the converted value (I ｕｖｗ ＊ -I ｕｖｗ The current is output to the current controller 23.

[0068] The current controller 23 receives the converted value (I) from the second coordinate converter 22. ｕｖｗ ＊ -I ｕｖｗ ) and the voltage of battery 7 (V ＤＣ Based on ), the converted value (I ｕｖｗ ＊ -I ｕｖｗ (I ＵＶＷ I ＵＶＷ ＊ Correction duty cycle command (ΔD) to follow the ｕｖｗ ＊ ) is calculated using PID control, etc., and the corrected duty cycle command (ΔD ｕｖｗ ＊ The corrected duty cycle (ΔD) is output to adder 4. ｕｖｗ ＊ ) When using external equipment 27, the corrected d-axis current command (I ｄａ ＊ ) and corrected q-axis current command (I ｑa ＊ ) in accordance with the basic duty directive (D ｎ ＊This is a correction drive signal used to correct the (basic drive signal) and modulate the drive pattern of the switching elements of the inverter 6.

[0069] The switching phase selection unit 19 has a rotation angle (θ ｒ The following is input: The switching phase selection unit 19 selects, for example, the u-phase magnetic flux (φ Ｕ ), v-phase magnetic flux (φ Ｖ ), w-phase magnetic flux (φ Ｗ ) of which the rotation angle (θ ｒ A single-phase PWM signal that generates the magnetic flux with the smallest intersection angle with ) ２ Set to PWM, and one of the remaining two phases of the PWM signal １ Set the other to PWM ２ A setting signal for setting is output to the PWM signal generator 5. As a result, the controller 1 outputs this PWM １ and PWM ２ By controlling the operation of the switching elements of each phase accordingly, the coil magnetic flux generated in the rotating electric machine 9 is generated along the q-axis direction, thereby controlling the three-phase current (I ｕｖｗ Adjust the phase of ).

[0070] [Coil Magnetic Flux and Torque Ripple Generated in Rotating Electric Machine 9] Figure 5 is an explanatory diagram showing the coil magnetic flux generated in the rotating electric machine 9 during charge and discharge control. When the inverter 6 and the rotating electric machine 9 are used as a DC / DC converter, the direction in which the permanent magnet 92 embedded in the rotor is facing differs depending on the timing at which the rotation of the rotating electric machine 9 is stopped. However, for simplicity, here we assume that the permanent magnet 92 has its N pole facing the u-phase coil (U). In this case, the controller 1 controls the current flowing through the w-phase coil (W) (W-phase current (I ｗ )) PWM １ The current flowing through the u-phase coil (U) and v-phase coil (V) is controlled by the current (U-phase current (I ｕ ) and V-phase current (I ｖ )) PWM ２ It is controlled by the controller 1. And the controller 1 is PWM １ and PWM ２The phase difference is set to half the period of the carrier wave. As a result, coil magnetic flux (Φ) directed in the positive direction of the q-axis, as shown in Figure 5(A), and coil magnetic flux (Φ) directed in the negative direction of the q-axis, as shown in Figure 5(B), are generated alternately. The coil magnetic flux (Φ) is the magnetic flux φ generated by the coils of each phase uvw. Ｕ ､φ Ｖ ､φ Ｗ This is the combined magnetic flux.

[0071] Thus, when the coil magnetic flux (Φ) is generated along the q-axis direction, the q-axis current (I ｑ ) flows, but the d-axis current (I ｄ ) is practically zero (or if it occurs, it is extremely small). dq axis current (I ｄｑ In a situation where both of these conditions are met, the q-axis current (I ｑ This usually determines the magnitude of the torque generated by the rotating electric machine 9.

[0072] Generally, the torque (T) generated in the rotating electric machine 9 ｅ ) is the d-axis current (I ｄ ), q-axis current (I ｑ ), magnetic flux (λ ｆ ), d-axis inductance (L ｄ ), q-axis inductance (L ｑ Using the number of poles (P), it can be calculated as follows.

[0073] Therefore, if the q-axis current (Iq) is not zero, as described above, the coil magnetic flux (Φ) directed in the positive direction of the q-axis and the coil magnetic flux (Φ) directed in the negative direction of the q-axis are generated alternately, which can cause a torque ripple (ΔT) that oscillates in the direction of rotation of the rotor.

[0074] In Patent Document 1, I ｄ = λ ｆ / (L ｑ -L ｄ Set to (1) and λ ｆ + (L ｄ ―L ｑ ) I ｄ By setting the term to zero, the torque (T ｅ The average torque is set to zero. However, as mentioned above, the d-axis current (I ｄIf the setting is increased, the variation in the u-phase current, v-phase current, and w-phase current becomes large, and the losses (copper losses) in the rotating electric machine 9 become very large.

[0075] On the other hand, in this embodiment, as shown in Figure 5, the magnetic flux (field weakening) is in the opposite direction to the direction of the magnetic flux of the permanent magnet 92 (Φ(I) ｄａ ＊ A corrected d-axis current command (I) generates ｄａ ＊ ) is applied. Corrected d-axis current command (I ｄａ ＊ ) is (L ｑ -L ｄ If ) is a positive value, it will be set to a negative value, (L ｑ -L ｄ If ) is a negative value, it is set to a positive value, and λ in equation (1) ｆ + (L ｄ ―L ｑ ) I ｄ This acts in a direction that decreases the value of the term. As a result, the torque (T) in equation (1) ｅ ), that is, torque ripple (ΔT) can be reduced.

[0076] Furthermore, in Figure 5, for the sake of explanation, the permanent magnet 92 is drawn as elongated in the d-axis direction, but in reality, the permanent magnet 92 is usually a thin plate with a thickness in the d-axis direction. Therefore, when a coil magnetic flux (Φ) is generated along the d-axis direction, eddy currents are likely to be generated in the permanent magnet 92 accordingly. Then, the temperature of the rotating electric machine 9 (especially the rotor) rises due to the loss caused by the eddy currents (hereinafter referred to as eddy current loss). However, when a coil magnetic flux (Φ) is generated along the q-axis direction, eddy currents are less likely to be generated due to the actual shape of the permanent magnet 92. Therefore, by generating a coil magnetic flux (Φ) along the q-axis direction, eddy current loss and the temperature rise of the rotating electric machine 9 due to eddy current loss are suppressed. In other words, according to the charge / discharge control described above, when a DC / DC converter is configured using the inverter 6 and the rotating electric machine 9, the phases flowing to each phase are adjusted so that a coil magnetic flux (Φ) along the q-axis direction is generated, thereby suppressing eddy current loss and the temperature rise of the rotating electric machine 9 due to eddy current loss.

[0077] [Corrected d-axis current command and torque ripple] Figure 6 shows the waveforms of the u-phase current, v-phase current, w-phase current, d-axis current, q-axis current, and torque ripple when the corrected d-axis current command is not applied. Figure 7 shows the waveforms of the u-phase current, v-phase current, w-phase current, d-axis current, q-axis current, and torque ripple when the corrected d-axis current command is applied.

[0078] In Figure 6, the torque detection means 10 and torque ripple controller 11 shown in Figure 1 are absent, and the basic dq axis current command (I) output from the controller 1 is absent. ｄｑ０ ＊ ) and the corrected q-axis current command (I) output from the current generator 17. ｑａ ＊ Based on the sum of ) and the corrected duty cycle command (ΔD ｕｖｗ ＊ ) is generating.

[0079] U phase current (I ｕ ) and v-phase current (I ｖ ) is PWM ２ The w-phase current (I ｗ ) is PWM １ It is generated by the q-axis current (I ｑ ) is a corrected q-axis current command (I ｑａ ＊ ) causes vibration and generates torque ripple (ΔT), and the peak value of this ripple exceeds, for example, the maximum torque (Tmax) that the electric parking brake can handle. d-axis current (I ｄ ) is the corrected d-axis current command (I ｄａ ＊ It is zero because it does not include ).

[0080] On the other hand, Figure 7 has the torque detection means 10 and torque ripple controller 11 shown in Figure 1, and the basic dq axis current command (I) output from the controller 1. ｄｑ０ ＊ ) and the corrected d-axis current command (I) output from the torque ripple controller 11. ｄａ ＊ ) and the corrected q-axis current command (I ｑａ ＊ Based on the sum of ) and the corrected duty cycle command (ΔD ｕｖｗ ＊) is generating.

[0081] Therefore, the d-axis current (I ｄ ) is the corrected d-axis current command (I ｄａ ＊ ) is included and is a value far from zero (a constant value). As a result, a magnetic flux (field weakening) is generated in the opposite direction to the magnetic flux of the rotor's permanent magnet 92, so the torque (T) in equation (1) ｅ ) decreases. Furthermore, the map shown in Figure 4 (ΔT and I ｄａ ＊ (Map showing the relationship) Corrected d-axis current command (I ｄａ ＊ This setting allows the torque ripple (ΔT) to be kept below the maximum torque (Tmax).

[0082] Figure 8 shows the torque ripple waveform when an electric vehicle is stopped on an inclined surface and no corrected d-axis current command is applied. Figure 9 shows the torque ripple waveform when an electric vehicle is stopped on an inclined surface and a corrected d-axis current command is applied.

[0083] Figure 8 shows the tilt torque (T) caused by the force of the electric vehicle moving downwards on the inclined surface when the electric vehicle stops on an inclined surface, relative to the electric parking brake. ｐ A torque (TΔ) is applied, and a torque ripple (ΔT) is added to it. Therefore, for example, the minimum value (absolute value) of the torque ripple (TΔ) is the same as or less than the maximum torque (Tmax) (absolute value), but the maximum value (absolute value) of the torque ripple (TΔ) exceeds the maximum torque (Tmax) (absolute value).

[0084] In Figure 9, the map shown in Figure 4 ((ΔT + Tp - Tmax) and I ｄａ ＊ (Map showing the relationship) Corrected d-axis current command (I ｄａ ＊ This setting allows the maximum value of the torque ripple (ΔT) to be less than or equal to the maximum torque (Tmax).

[0085] Note that the corrected d-axis current command (I ｄａ ＊By setting this, the characteristic curves of rotation angle and torque ripple shown in Figure 3 change to be approximately similar in shape, with the value in the vertical axis direction decreasing.

[0086] [Comparison of copper loss between comparative example and this embodiment] The inventors of this application compared and examined the copper loss between the comparative example and this embodiment. The rotating electric machine 9 in question has a rotation angle (θ) when stopped. ｒ ) is 10 [deg], the winding resistance is 10 [mΩ], and the d-axis inductance (L ｄ ) to 200 [μH], q-axis inductance (L ｑ ) to 300 [μH], permanent magnet magnetic flux (λ ｆ The d-axis current (I ｄ Before control of I ｄ = 0[A], I ｑ = 0[A], I ｕ = 50 [A], I ｖ = 50 [A], I ｗ The setting was set to 50 [A]. The copper loss at this time was 75 [W].

[0087] In the comparative example (Patent Document 1), the d-axis current (I ｄ ) λ ｆ / (L ｑ The -Ld) was set to 1250 [A] and Iq = 0 [A]. The copper loss at this time was 15700 [W]. Therefore, in the comparative example, the torque (T ｅ ), that is, it is theoretically possible to reduce the torque ripple (ΔT) to zero, but the copper loss will be extremely large.

[0088] On the other hand, in this embodiment, if there is a requirement to reduce the torque ripple (ΔT) by 20%, ｄ = 1250 × 0.2 = 250 [A] can be set, and the copper loss at this time (winding resistance × (d-axis current)) ２ (Proportional to) is 0.2 × 0.2 × 100 [%] = 4 [%] when compared to the comparative example, which shows that it can be reduced by 96 [%] compared to the comparative example.

[0089] [Effects of this embodiment] The charge / discharge control method of this embodiment includes a rotating electric machine 9 that drives an electric vehicle by rotating due to the action of the permanent magnet magnetic flux generated by a permanent magnet 92 and the coil magnetic flux which is the combined magnetic flux of the magnetic fluxes generated by multiple phase coils, a battery 7 that exchanges power with the rotating electric machine 9, and an inverter 6 that controls the exchange of power between the battery 7 and the rotating electric machine 9 based on a voltage command value, wherein when the electric vehicle is stopped, the charging / discharging voltage command value (basic duty cycle command (D)) is such that no unidirectional torque is generated in the rotating electric machine 9. ｎ ＊ A charge / discharge control method for performing charge and discharge of a battery 7, wherein the battery 7 is energized by outputting a voltage command value (Φ(I)) towards the inverter 6, and when a torque ripple (ΔT) occurs in the rotating electric machine 9 during charge / discharge, the magnetic flux component (Φ(I)) in the opposite direction to the magnetic flux direction of the permanent magnet 92 is used. ｄａ ＊ )) generates a d-axis current command value (corrected d-axis current command (I ｄａ ＊ The d-axis current command value (corrected d-axis current command (I)) is set based on the magnitude of the torque ripple (ΔT), and the d-axis current command value (corrected d-axis current command (I)) is set. ｄａ ＊ )) based on the correction voltage command value (correction duty cycle command (ΔD ｕｖｗ ＊ )) calculate the correction voltage command value (correction duty cycle command (ΔD ｕｖｗ ＊ )) Charge / discharge voltage command value (basic duty cycle command (D ｎ ＊ The value obtained by adding it to the final duty command (D ｕｖｗ ＊ The value is output to the inverter 6 as a voltage command value.

[0090] By the above method, the d-axis current (I ｄ ) is the d-axis current command value (corrected d-axis current command (I ｄａ ＊ The switching elements of the inverter 6 are controlled to follow the d-axis current command value (corrected d-axis current command (I ｄａ ＊ )) is torque ripple (ΔT) (or torque ripple (ΔT) + gradient torque (T ｐIts size is controlled based on ), and the torque ripple (ΔT) can be reduced by the required amount by weakening the field on the permanent magnet 92. Corrected d-axis current command (I ｄａ ＊ ) is torque (T ｅ It is not necessary to set this value to a large enough value to be zero. Therefore, it is possible to suppress both torque ripple during charge and discharge control and suppress copper loss.

[0091] In this embodiment, when the rotating electric machine 9 and inverter 6 are used as converters for transferring power between the battery 7 and the external equipment 27, the rotation angle (θ) of the rotating electric machine 9 ｒ ) detects the rotation angle (θ ｒ Based on the above, a first coil group (e.g., w-phase coils) consisting of one or more coils from the multi-phase coils that forms a magnetic field in a direction perpendicular to the magnetic flux direction of the permanent magnet 92 is determined, and a second coil group (e.g., u-phase coils, v-phase coils) consisting of a different combination of coils from the first coil group is determined, and a first switching element (a switching element connected to the w-phase coils) that controls the exchange of power between the battery 7 and the first coil group and a second switching element (a switching element connected to the u-phase coils, a switching element connected to the v-phase coils) that controls the exchange of power between the battery 7 and the second coil group is determined, and the timing for switching the first switching element (PWM) is determined. １ ) and the timing of switching the second switching element (PWM ２ ) and make them different from each other.

[0092] By using the method described above, the direction of the generated magnetic flux can be limited to the q-axis while canceling out current ripple, by aligning the magnetic flux generated during charging and discharging with the q-axis direction and separating the current phases of the two groups of coils. This makes it possible to achieve both reduced losses and reduced current ripple during charging and discharging.

[0093] In this embodiment, torque ripple is detected by the sensor value of an acceleration sensor attached to the electric vehicle.

[0094] Using the above method, the torque ripple (ΔT) generated by the rotating electric machine 9 is measured as acceleration by an acceleration sensor, and the measured value is used as the d-axis current command value (corrected d-axis current command (I ｄａ ＊ This allows for feedback to be provided to the following: Therefore, torque ripple (ΔT) can be suppressed with high precision.

[0095] In this embodiment, the torque ripple (ΔT) is defined as the rotation angle (θ) of the rotating electric machine 9. ｒ It is estimated based on the following.

[0096] By the above method, the rotation angle (θ) ｒ A map is pre-configured that shows the relationship between the rotation angle (θ) and the torque ripple (ΔT), and the rotation angle (θ) is pre-configured. ｒ By inputting this into the map, the torque ripple (ΔT) can be estimated. Therefore, it becomes unnecessary to add sensors to measure the torque ripple (ΔT).

[0097] Torque ripple (ΔT) is used to control the output of the charge / discharge (neutral point current command (I ｎ ＊ It is estimated by the size of ( ).

[0098] By the above method, for example, the rotation angle (θ) ｒ When the change in torque ripple (ΔT) due to the change in ) is small, the charge / discharge output (neutral point current command (I) ｎ ＊ A map is pre-configured that shows the relationship between the magnitude of the charge / discharge output and the torque ripple (ΔT). By inputting the charge / discharge output into this map, the torque ripple (ΔT) can be estimated. Therefore, it becomes unnecessary to add a sensor to measure the torque ripple (ΔT).

[0099] In this embodiment, the torque ripple (ΔT) is estimated based on the sensor value of a torque sensor (not shown) that measures the torque applied to the parking brake (electric parking brake) of an electric vehicle.

[0100] Using the above method, the maximum torque (Tmax) applied to the parking brake (electric parking brake) is measured by a torque sensor, and the torque measurement value is corrected to the d-axis current command value (corrected d-axis current command (I)) to prevent the torque applied to the parking brake from exceeding the maximum torque (Tmax).ｄａ ＊ This allows for feedback to be provided. Therefore, damage to the parking brake (electric parking brake) due to torque ripple (ΔT) generated by charging and discharging can be prevented.

[0101] In this embodiment, when an electric vehicle is parked on a road surface that is inclined in the longitudinal direction of the vehicle, the inclination torque (T) applied to the parking brake (electric parking brake) due to the inclination is ｐ The sum of the torque (ΔT + T) and torque ripple (ΔT) ｐ When the combined torque (ΔT + T) exceeds the maximum torque (Tmax) that the parking brake (electric parking brake) can tolerate, the combined torque (ΔT + T) ｐ The difference (ΔT + T) obtained by subtracting the maximum torque (Tmax) from ) ｐ - Based on Tmax, the d-axis current command value (corrected d-axis current command (I ｄａ ＊ Set )).

[0102] The above method enables high-precision suppression of torque ripple (ΔT).

[0103] In this embodiment, the gradient torque (T ｐ This is estimated based on the sensor values ​​of a tilt sensor (not shown) attached to the electric vehicle.

[0104] By the above method, the tilt torque (T) applied due to the inclination is calculated. ｐ The tilt torque (T) is estimated using the sensor value of a tilt sensor (not shown), and the tilt torque (T) is estimated using this sensor value. ｐ The sum of the values ​​of the torque ripple detection means and the d-axis current value (corrected d-axis current command (I)) is adjusted according to the amount by which the sum exceeds the maximum torque (Tmax) of the parking brake (electric parking brake). ｄａ ＊ This commands the following: ))). Therefore, damage to the parking brake (electric parking brake) due to torque ripple (ΔT) generated by charging and discharging can be prevented without the addition of a torque sensor.

[0105] The charge / discharge control system of this embodiment includes a rotating electric machine 9 that drives an electric vehicle by rotating due to the action of the permanent magnet flux generated by the permanent magnet 92 and the coil flux, which is the combined magnetic flux of the magnetic fluxes generated by the multiple phase coils; a battery 7 that exchanges power with the rotating electric machine 9; an inverter 6 that controls the exchange of power between the battery 7 and the rotating electric machine 9 based on a voltage command value; and a charge / discharge voltage command value (basic duty cycle command (D)) that prevents unidirectional torque from being generated in the rotating electric machine 9 when the electric vehicle is stopped. ｎ ＊ A charge / discharge control system including a control unit (controller 1) that performs charging and discharging of a battery 7 in a manner that energizes a rotating electric machine 9 by outputting a magnetic flux component (Φ(I)) as a voltage command value toward an inverter 6, wherein when a torque ripple (ΔT) occurs in the rotating electric machine 9 during the execution of charging and discharging, the control unit (controller 1) controls the magnetic flux component (Φ(I)) in the opposite direction to the magnetic flux direction of the permanent magnet 92. ｄａ ＊ )) generates a d-axis voltage command value (corrected d-axis current command (I ｄａ ＊ The d-axis current command value (corrected d-axis current command (I)) is set based on the magnitude of the torque ripple (ΔT), and the d-axis current command value (corrected d-axis current command (I)) is set. ｄａ ＊ )) based on the correction voltage command value (correction duty cycle command (ΔD ｕｖｗ ＊ )) calculate the correction voltage command value (correction duty cycle command (ΔD ｕｖｗ ＊ )) Charge / discharge voltage command value (basic duty cycle command (D ｎ ＊ The value obtained by adding it to the final duty command (D ｕｖｗ ＊ The value is output to the inverter 6 as a voltage command value.

[0106] With the above configuration, the d-axis current (I ｄ ) is the d-axis current command value (corrected d-axis current command (I ｄａ ＊ The switching elements of the inverter 6 are controlled to follow the d-axis current command value (corrected d-axis current command (I ｄａ ＊ )) is torque ripple (ΔT) (or torque ripple (ΔT) + gradient torque (Tｐ Its size is controlled based on ), and the torque ripple (ΔT) can be reduced by the required amount by weakening the field on the permanent magnet 92. Corrected d-axis current command (I ｄａ ＊ ) is torque (T ｅ It is not necessary to set this value to a large enough value to be zero. Therefore, it is possible to suppress both torque ripple during charge and discharge control and suppress copper loss.

[0107] Although embodiments of the present invention have been described above, the configurations described in the above embodiments 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 charge / discharge control method for performing charging and discharging of a battery, wherein a rotating electric machine drives an electric vehicle by rotating due to the action of a permanent magnet magnetic flux generated by a permanent magnet and a coil magnetic flux which is a composite magnetic flux of magnetic fluxes generated by multiple phase coils; a battery that exchanges power with the rotating electric machine; an inverter that controls the exchange of power between the battery and the rotating electric machine based on a voltage command value; and a charge / discharge voltage command value that does not generate unidirectional torque in the rotating electric machine when the electric vehicle is stopped, thereby energizing the rotating electric machine by outputting the voltage command value to the inverter, wherein when a torque ripple occurs in the rotating electric machine during the execution of the charge / discharge, a d-axis current command value that generates a magnetic flux component in the opposite direction to the magnetic flux direction of the permanent magnet is set based on the magnitude of the torque ripple; a correction voltage command value is calculated based on the d-axis current command value; and the correction voltage command value is added to the charge / discharge voltage command value and the resulting value is output to the inverter as the voltage command value.

2. A charge / discharge control method according to claim 1, in which the rotating electric machine and the inverter are used as converters for transferring power between the battery and external equipment, wherein the rotation angle of the rotating electric machine is detected, and based on the rotation angle, a first coil group consisting of one or more of the coils that form a magnetic field in a direction perpendicular to the magnetic flux direction of the permanent magnet and a second coil group consisting of a different combination of the coils from the first coil group are determined from the multiphase coils, a first switching element that controls the transfer of power between the battery and the first coil group and a second switching element that controls the transfer of power between the battery and the second coil group are determined from the switching elements constituting the inverter, and the timing for switching the first switching element and the timing for switching the second switching element are made different from each other.

3. The charge / discharge control method according to claim 1, wherein the torque ripple is detected by the sensor value of an acceleration sensor attached to the electric vehicle.

4. The charge / discharge control method according to claim 1, wherein the torque ripple is estimated based on the rotation angle of the rotating electric machine.

5. The charge-discharge control method according to claim 1, wherein the torque ripple is estimated by the charge-discharge output.

6. The charge / discharge control method according to claim 1, wherein the torque ripple is estimated based on the sensor value of a torque sensor that measures the torque applied to the parking brake of the electric vehicle.

7. The charge / discharge control method according to claim 6, in which the electric vehicle is parked on a road surface that is inclined in the longitudinal direction of the vehicle, and the sum of the inclination torque applied to the parking brake due to the inclination and the torque ripple exceeds the maximum torque that the parking brake can tolerate, and the d-axis current command value is set based on the difference obtained by subtracting the maximum torque from the sum of the torques.

8. The charge / discharge control method according to claim 7, wherein the tilt torque is estimated based on the sensor value of a tilt sensor attached to the electric vehicle.

9. A charge / discharge control system comprising: a rotating electric machine that drives an electric vehicle by rotating due to the action of a permanent magnet magnetic flux generated by a permanent magnet and a coil magnetic flux which is a composite magnetic flux of magnetic fluxes generated by a plurality of phase coils; a battery that exchanges power with the rotating electric machine; an inverter that controls the exchange of power between the battery and the rotating electric machine based on a voltage command value; and a control unit that performs charging and discharging of the battery in a manner that energizes the rotating electric machine by outputting a charge / discharge voltage command value to the inverter as the voltage command value when the electric vehicle is stopped, wherein the control unit sets a d-axis current command value that generates a magnetic flux component in the opposite direction to the magnetic flux direction of the permanent magnet when a torque ripple occurs in the rotating electric machine during the execution of charging and discharging, based on the magnitude of the torque ripple, calculates a correction voltage command value based on the d-axis current command value, and outputs the value obtained by adding the correction voltage command value to the charge / discharge voltage command value as the voltage command value to the inverter.

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