JP2010035396A - Battery current suppression method and battery current suppression controller - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a battery current suppression method which enables a battery current to be suppressed within a range of a set value of the battery by detecting the input and output currents of the battery and the battery current, which is the output current, and by correcting a torque command if the current exceeds the set value and which is consequently capable of preventing the early deterioration of the battery, and to provide a battery current suppression controller. <P>SOLUTION: A motor drive system includes a current sensor S3, which detects an output current and an input current of the battery B, and an input/output excessive amount detector 120, which determines whether or not the output current and the input current are within the range of the upper limit value of the output current and that of the input current. The motor drive system further includes a battery output current suppression controller 150 and a battery input current suppression controller 170, which correct the torque command so as to hold the battery current within the ranges if the output current and the input current are out of the ranges of the upper limit value of the output current and that of the input current respectively. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a battery current suppression method and a battery current suppression control device that can suppress an input current and an output current of a battery.

  A general motor drive system that uses a battery as the power source of the motor and charges the regenerative current of the motor to the battery will be described with reference to FIG. FIG. 3 is a functional block circuit diagram of an ECU or a control unit that controls the motor M based on the torque command T *.

  In the motor drive system, the current map 20 includes a d-axis current command (hereinafter referred to as a d-axis command Id *) and a q-axis current command (hereinafter referred to as a q-axis command) based on a torque command T * given from the outside. Iq *) is obtained using the three-dimensional maps for the d-axis command Id * and the q-axis command Iq *, respectively. The three-dimensional map is a three-dimensional map of the torque command T *, the rotational speed ω of the motor M, and the battery voltage Vdc. The rotational speed ω of the motor is calculated by the rotational speed calculator 33 based on the rotational angle θ of the motor M detected by the rotational angle sensor 34. Next, deviations between the d-axis command Id * and the q-axis command Iq * and the actual d-axis current Id and q-axis current Iq of the motor M are obtained, respectively.

  The actual d-axis current Id and q-axis current Iq of the motor M are obtained as follows. The current value (motor current) of the two phases (field winding) of the motor M is detected by the current sensors S1 and S2, and is input to the three-phase / two-phase coordinate conversion unit 22, and the three-phase / two-phase coordinate conversion unit 22 calculates the current value for the remaining one phase, and uses the rotation angle θ of the motor M detected by the rotation angle sensor 34 to coordinate-convert the three-phase phase current of the motor M, thereby d An axial current Id and a q-axis current Iq are obtained. The current sensors S1 and S2 correspond to motor current detection means for detecting the motor current of the motor M.

  The PI control units 24 and 26 perform PI (proportional integration) control from the deviation between the d-axis command Id * and the q-axis command Iq * and the actual d-axis current Id and q-axis current Iq, and the d-axis voltage command Vd *. Q-axis voltage command Vq * is calculated.

The two-phase / three-phase coordinate converter 28 converts the rotation angle θ of the motor M and the d-axis voltage command Vd * and the q-axis voltage command Vq * into three-phase voltage command values Vu *, Vv *, and Vw *.
The PWM conversion unit 30 converts the PWM signal into a PWM signal based on the three-phase voltage command values Vu *, Vv *, and Vw *, and outputs the PWM signal to the inverter 32. The inverter 32 drives the motor M (AC motor) based on the PWM signal using the battery B as a current source. Such a motor driver system is known from Patent Document 1, for example.
JP 2002-58106 A

  In the motor drive system using the battery B as a power source as described above, the inverter 32 controls the motor M to achieve the torque command. At this time, the battery B is used as a current source, and its output current is used without limit. For this reason, when the electric current exceeding a battery specification is output, there exists a possibility of leading to the early deterioration of the battery B. FIG. Further, when the battery B inputs the regenerative current of the motor M, the battery B may be deteriorated at an early stage as described above when receiving a current exceeding the battery specification. Further, if the regenerative current is received while the battery B is fully charged, the battery B may be overcharged and the battery B may be deteriorated.

Patent Document 1 discloses that a battery voltage is detected during regeneration, and the value of the torque command is decreased when the battery voltage is equal to or higher than a predetermined low voltage.
However, this technique corrects the torque command in relation to the battery voltage. In other words, when the motor rotates at a high speed regardless of the battery voltage, a regenerative current that is a large current is input as the input current of the battery, and as a result, an input current exceeding the battery specification is input. This cannot be prevented, and in this case, there is a problem that the battery deteriorates early.

  According to the present invention, when the battery current that is the input / output current and the output current of the battery is detected and exceeds the set value range, the torque command is corrected to be suppressed within the set value range of the battery. As a result, it is an object of the present invention to provide a battery current suppression method that can prevent early deterioration of the battery.

  Another object of the present invention is to detect a battery current which is an input / output current and an output current of a battery and, when exceeding a set value range, correct a torque command to thereby set a battery set value range. It is an object of the present invention to provide a battery current suppression control device that can be suppressed inward, and as a result, can prevent early deterioration of the battery.

  In order to solve the above-described problems, claim 1 supplies a battery current output from a battery based on a d-axis command and a q-axis command obtained based on a torque command to the motor via an inverter, and A battery current suppression method in a battery power supply apparatus that inputs a regenerative current from a motor through the inverter and accepts the regenerative current as a battery current input to the battery, the battery current detecting method, A determination step for determining whether or not the battery current is within a set value range; and if the battery current is outside the set value range, the torque command is set so that the battery current is within the set value range. The present invention is summarized as a battery current suppressing method including a step of correcting the above.

  According to the first aspect of the present invention, when it is determined whether or not the detected battery current is within the set value range, if the battery current is outside the set value range, the battery current is within the set value range. The torque command is corrected as follows.

  A second aspect of the present invention is the method according to the first aspect, wherein the battery current is an output current output from the battery during power running, and the determination step is performed when the output current is within a range of a first upper limit value as a set value. The correction step is a step of correcting the torque command so that the output current is within the first upper limit value when the output current is outside the range of the first upper limit value. It is characterized by being.

  In the invention of claim 2, it is determined whether or not the detected output current is within the range of the first upper limit value. When the output current is outside the range of the first upper limit value, the torque command is corrected so that the output current falls within the first upper limit value.

  A third aspect of the present invention is the method according to the first aspect, wherein the battery current is an input current input to the battery at the time of regeneration, and the determination step is performed such that the input current is within a range of a second upper limit value as a set value. The correction step is a step of correcting the torque command so that the input current falls within the second upper limit value when the input current is outside the range of the second upper limit value. It is characterized by being.

  In the invention of claim 3, it is determined whether or not the detected input current is within the range of the second upper limit value. Then, when the input current is outside the range of the second upper limit value, the torque command is corrected so that the input current falls within the second upper limit value.

  According to a fourth aspect of the present invention, a battery current output from a battery based on a d-axis command and a q-axis command obtained based on a torque command is supplied to a motor via an inverter, and a regenerative current from the motor is supplied to the inverter. A battery current suppression control device in a battery power supply device that receives the regenerative current as a battery current input to the battery, the battery current detection means for detecting the battery current, and the battery current is Determining means for determining whether or not the battery current is within a set value range; and if the battery current is outside the set value range, the torque command is corrected so that the battery current is within the set value range. A gist of a battery current suppression control device comprising a correction means.

  In the invention of claim 4, the battery current detecting means detects the battery current, and the determining means determines whether or not the battery current is within a set value range. Then, when the battery current is out of the set value range, the correction means corrects the torque command so that the battery current is within the set value range.

  A fifth aspect of the present invention is the method according to the fourth aspect, wherein the battery current is an output current output from the battery during power running, and the determination means determines whether the output current is within a range of a first upper limit value as a set value. And the correction means corrects the torque command so that the output current falls within the first upper limit value when the output current is outside the range of the first upper limit value. .

  In the invention of claim 5, the determining means determines whether or not the output current is within a range of a first upper limit value as a set value, and the correcting means is that the output current is outside the range of the first upper limit value. At this time, the torque command is corrected so that the output current falls within the first upper limit value.

  A sixth aspect of the present invention is the method according to the fourth aspect, wherein the battery current is an input current input to the battery at the time of regeneration, and the determination means determines whether the input current is within a range of a second upper limit value as a set value. The correction means corrects and increases the value of the d-axis command so that the input current falls within the second upper limit value when the input current is outside the range of the second upper limit value. It is characterized by making it.

  In the invention of claim 6, the determining means determines whether or not the input current is within a range of a second upper limit value as a set value, and the correcting means is that the output current is outside the range of the second upper limit value. At this time, the value of the d-axis command is corrected and increased so that the output current falls within the second upper limit value.

  The invention of claim 7 is the motor current detection means for detecting the motor current of the motor, the torque calculation means for calculating the torque based on the motor current, and the torque calculated by the torque calculation means. A q-axis command correcting means for correcting the q-axis command based on a deviation from the torque command, and when the motor is regenerated by correcting the q-axis command by the q-axis command correcting means. It is characterized by suppressing torque fluctuation.

  In the seventh aspect of the invention, the motor current detecting means detects the motor current of the motor, and the torque calculating means calculates the torque based on the motor current. The q-axis command correction unit corrects the q-axis command based on the deviation between the torque calculated by the torque calculation unit and the torque command. As a result, the q-axis command correction means corrects the q-axis command to suppress torque fluctuations during motor regeneration.

  The invention of claim 8 comprises the motor temperature detection means for detecting the motor temperature of the motor according to claim 7, wherein the torque calculation means calculates torque based on the motor temperature and the motor current. Features.

  According to the first to seventh aspects of the present invention, when the battery current which is the input / output current and the output current of the battery is detected and exceeds the set value range, the torque command is corrected to correct the battery current. It can be suppressed within the set value range, and as a result, early deterioration of the battery can be prevented. In addition, the driver design between the inverter and the motor can be performed regardless of the characteristics of the battery.

According to the seventh aspect of the present invention, torque fluctuations during motor regeneration can be suppressed by correcting the q-axis command by the q-axis command correcting means.
According to the eighth aspect of the present invention, since the motor torque is calculated based on the motor current in consideration of the motor temperature, the motor torque can be calculated with high accuracy. As a result, the q-axis command can be accurately corrected by the deviation between the accurately calculated torque and the torque command, the torque control accuracy can be improved, and torque fluctuations during motor regeneration can be suppressed.

(First embodiment)
Below, the battery current suppression method and the battery current suppression control device of the present invention are used as a battery power supply device for a motor (for example, an AC motor such as a synchronous motor or an induction motor) capable of power running and regeneration. A first embodiment embodied in the motor drive system will be described with reference to FIGS. 1 and 2. FIG. 1 is a functional block diagram of an ECU (electronic control unit) 100 that controls motor control of the motor drive system of the present embodiment.

  The ECU 100 includes a current map 110, an input / output excess detector 120, correction value generation units 130 and 140, a battery output current suppression controller 150, a torque feedback controller 160, a battery input current suppression controller 170, a PI control unit 180, A torque deviation generation unit 190, a torque calculator 200, and a three-phase / two-phase coordinate conversion unit 270 are included.

  The input / output excess detector 120 outputs an output current as a battery current output from the battery B to the inverter 280 and an input current as a battery current input from the motor M via the inverter 280 when the motor M is in a regenerative state. Is connected to a current sensor S3. The input / output excess detector 120 determines the output current when the current value detected by the current sensor S3 (hereinafter referred to as the detected current Idc) is a positive value, and as the input current when the current value is negative. judge. The current sensor S3 corresponds to battery current detection means, and the input / output excess detector 120 corresponds to determination means.

  Further, the input / output excess detector 120 is configured such that the detection current Idc (output current or input current) is the output current upper limit value (OutLim) as the first upper limit value, or the input current upper limit value (InLim) as the second upper limit value. It is determined whether or not it is within the range, and an outover value or an inover value is output to the correction value generation units 130 and 140, respectively, according to the determination result. The output current upper limit value (OutLim) and the input current upper limit value (InLim) correspond to set values. Note that OutLim> −InLim.

  The output current upper limit value (OutLim) is set so that the output current exceeding the specification of the battery B does not occur because the output current exceeding the specification of the battery B leads to the early deterioration of the battery B. Value.

  Also, the input current upper limit value (InLim) is likely to be overcharged when the input current (regenerative current) exceeds the specification of battery B during regeneration, leading to early deterioration of battery B. The value is set so as not to generate an input current exceeding the specification of the battery B. The output current upper limit value (OutLim) and the input current upper limit value (InLim) are stored in advance in a readable manner in storage means such as a memory (not shown). The output current upper limit value (OutLim) and the input current upper limit value (InLim) may be applied from the outside together with the torque command T *.

  Specifically, the input / output excess detector 120 sets the outover value (OutOver) if the detected current Idc determined as the output current is within the output current upper limit (OutLim), that is, OutLim−Idc ≧ 0. 0 and the inover value (InOver) are set to 0 and output.

  Further, the input / output excess detector 120 sets the outover value to | OutLim when the detected current Idc determined as the output current exceeds the output current upper limit value (OutLim), that is, OutLim−Idc <0. The output is set to −Idc | and the inover value (InOver) is set to 0.

  Further, the input / output excess detector 120 detects an in-over if the detected current Idc determined as the input current is within the input current upper limit (InLim) as the second upper limit, that is, if −InLim−Idc ≦ 0. A value (InOver) is set to 0 and an outover value (OutOver) is set to 0 for output.

  Further, the input / output excess detector 120 detects an inover if the detected current Idc determined as the input current exceeds the input current upper limit (InLim), that is, if -InLim-Idc> 0. A value (InOver) is set to | -InLim-Idc | and an outover value (OutOver) is set to 0 for output.

  In FIG. 2, the vertical axis represents actual Idc, and the horizontal axis represents Idc based on the torque command. In the graph of FIG. 2, the “solid line part” from 0 on the vertical axis and the “dotted line part” above the output current upper limit (OutLim) indicate the output current. In the graph of FIG. 2, the “solid line portion” of less than 0 on the vertical axis and the “dotted line portion” of −InLim or higher indicate the input current.

  Thus, the input / output excess detector 120 determines whether the output current and the input current are within the output current upper limit value (OutLim) and the input current upper limit value (InLim), respectively. This corresponds to a determination step of determining whether or not the value is within the set value range.

  When the outover value is 0, the correction value generation unit 130 generates a torque command correction value Th of 0 and outputs it to the battery output current suppression controller 150. Further, when the outover value is | OutLim−Idc |, the correction value generation unit 130 generates a torque command correction value Th (≠ 0) by PI control, and outputs the torque command correction value Th to the battery output. Output to the current suppression controller 150. The torque command correction value Th (≠ 0) generated when the outover value is | OutLim−Idc | is feedback-controlled so that the detected current Idc detected as the output current is the output current upper limit value (OutLim). It is a value to make it within.

  The battery output current suppression controller 150 outputs a value (T * −Th) obtained by subtracting the torque command correction value Th from the torque command T * input from the outside to the current map 110. Further, the battery output current suppression controller 150 outputs a value (T * −Th) obtained by subtracting the torque command correction value Th from the torque command T * to the torque deviation generation unit 190. The voltage sensor 175 detects the battery voltage Vdc of the battery B and outputs it to the current map 110. The rotation speed calculation unit 310 calculates the rotation speed ω (that is, the rotation speed) per unit time of the motor M using the rotation angle θ of the motor M detected by the rotation angle sensor 290, and Enter the rotation speed ω.

  The current map 110 obtains a d-axis command Id * and a q-axis command Iq * based on a three-dimensional map. Specifically, the current map 110 includes a three-dimensional map for obtaining the d-axis command Id * and a three-dimensional map for obtaining the q-axis command Iq *. These maps are three-dimensional maps each consisting of (T * −Th), the rotational speed ω, and the battery voltage Vdc. The current map 110 obtains the d-axis command Id * and the q-axis command Iq * based on the input (T * −Th), the rotational speed ω, and the battery voltage Vdc based on the respective maps.

  The battery output current suppression controller 150 correcting the torque command T * with the torque command correction value Th corresponds to a step of correcting the torque command so that the battery current falls within the set value range. The battery output current suppression controller 150 corresponds to a correction unit.

  The correction value generation unit 140 generates a d-axis command correction value Idh of 0 and outputs it to the battery input current suppression controller 170 when the inover value is 0. When the inover value is | -InLim-Idc |, the correction value generation unit 140 generates a d-axis command correction value Idh by PI control, and uses the d-axis command correction value Idh as the battery input current. It outputs to the suppression controller 170. The d-axis command correction value Idh generated when the inover value is | -InLim-Idc | is feedback controlled so that the detected current Idc detected as the input current is within the input current upper limit (InLim). Is the value to be

  The battery input current suppression controller 170 adds the d-axis command correction value Idh to the d-axis command Id * output from the current map 110. As a result, Id * + Idh is output from the battery input current suppression controller 170, and when the motor M is in the regenerative state, the input current (detected current Idc) of the battery B is within the input current upper limit (InLim). Become.

  The correction of the d-axis command Id * by the d-axis command correction value Idh by the battery input current suppression controller 170 corresponds to a step of correcting the torque command so that the battery current is within the set value range. The battery input current suppression controller 170 corresponds to a correction unit.

  The three-phase / two-phase coordinate conversion unit 270 calculates the current of the remaining one phase by inputting the two-phase current of the motor M detected by the current sensors S1 and S2, and detects it by the rotation angle sensor 290. Using the rotation angle θ of the motor M, the phase current of the three-phase motor M is coordinate-transformed to obtain the d-axis current Id and the q-axis current Iq. The torque calculator 200 calculates the actual torque T of the motor M from the d-axis current Id and the q-axis current Iq by the following equation.

T = K _M · Iq + K _R · Id (1)
In the formula (1), _{K M} is the magnet torque constant, is _{K R} is reluctance torque constant. The torque calculator 200 corresponds to torque calculation means. Torque deviation generator 190 calculates a deviation (ie, torque control error) between (T * −Th) input from battery output current suppression controller 150 and actual torque T, and outputs it to PI controller 180.

The PI control unit 180 inputs the torque control error, performs PI (proportional integration) control, and calculates an operation amount Iqh of the q-axis current corresponding to the torque control error.
The torque feedback controller 160 increases or decreases the operation amount of the q-axis current from the PI control unit 180 with respect to the q-axis command Iq * from the current map 110. The torque feedback controller 160 corresponds to q-axis command correction means.

ECU 100 also includes a q-axis current deviation generator 210, a d-axis current deviation generator 220, PI controllers 230 and 240, a two-phase / three-phase coordinate converter 250, and a PWM converter 260.
The q-axis current deviation generation unit 210 calculates a deviation between the Iq * + Iqh input from the torque feedback controller 160 and the q-axis current Iq input from the three-phase / two-phase coordinate conversion unit 270 (that is, a q-axis current control error). Calculate and output to the PI control unit 230. On the other hand, the d-axis current deviation generation unit 220 is a deviation between the Id * + Idh input from the battery input current suppression controller 170 and the d-axis current Id input from the three-phase / two-phase coordinate conversion unit 270 (that is, the d-axis current Control error) is calculated and output to the PI control unit 240.

  The PI control units 230 and 240 perform PI (proportional integration) control from the input q-axis control error and d-axis current control error, respectively, and calculate the q-axis voltage command Vq * and the d-axis voltage command Vd *. The two-phase / three-phase coordinate conversion unit 250 converts the d-axis voltage command Vd * and the q-axis voltage command Vq * into three-phase voltage command values Vu *, Vv *, and Vw *.

  The PWM converter 260 converts the PWM signal into a PWM signal based on the three-phase voltage command values Vu *, Vv *, and Vw *, and outputs the PWM signal to the inverter 280. Inverter 280 uses battery B as a current source to drive motor M (AC motor) based on the PWM signal.

(Function)
The operation of the motor drive system configured as described above will be described.
In the case of power running, the inverter 280 drives the motor M based on the PWM signal using the battery B as a current source. At this time, the output current output from the battery B to the motor M is detected by the current sensor S3.

  During the power running, if the detected current Idc exceeds the output current upper limit (OutLim) (that is, OutLim−Idc <0), the output current from the battery B (detected current Idc) becomes excessive. In such a case, the input / output excess detector 120 sets the outover value to | OutLim−Idc | and outputs it to the correction value generation unit 130.

  As a result, the correction value generation unit 130 generates a torque command correction value Th (≠ 0) by PI control based on the outover value (| OutLim−Idc |), and the torque command correction value Th (≠ 0). Is output to the battery output current suppression controller 150. As a result, the torque command T * input from the outside is corrected by the battery output current suppression controller 150 with the torque command correction value Th. The torque command correction value Th (≠ 0) is a value that causes the detected current Idc detected as the output current to be within the output current upper limit value (OutLim) by performing feedback control. As a result, feedback control is performed, and the output current is suppressed within the output current upper limit value (OutLim), that is, limited to the torque that can be output with the battery current within the output current upper limit value (OutLim).

  In the case of regeneration, that is, when the motor M is in a regeneration state, an input current input from the motor M via the inverter 280 is detected by the current sensor S3. Thus, detecting the battery current (output current, input current) by the current sensor S3 corresponds to a step of detecting the battery current.

  During the regeneration, if the detected current Idc exceeds the input current upper limit (InLim) (that is, -InLim-Idc> 0), the input current to the battery B (detected current Idc) becomes excessive. It is a case. In such a case, the input / output excess detector 120 sets the inover value (InOver) to | −InLim−Idc | and outputs it to the correction value generation unit 140. The case where the input current becomes excessive is a case where the motor M is generating electricity at a high speed.

  Then, the correction value generation unit 140 generates the d-axis command correction value Idh by PI control based on the inover value of | -InLim-Idc |, and uses the d-axis command correction value Idh to control the battery input current. The battery input current suppression controller 170 adds the d-axis command correction value Idh to the d-axis command Id * output from the current map 110.

  The d-axis command correction value Idh generated when the inover value is | -InLim-Idc | is feedback controlled so that the detected current Idc detected as the input current is the input current upper limit value (InLim). It is a value to make it within.

As a result, by causing the d-axis current to flow beyond the d-axis command Id *, the motor M consumes current so as to suppress the input current within the input current upper limit value (InLim).
At this time, if the torque fluctuates, the torque control is performed while suppressing the q-axis current.

  That is, the torque deviation generator 190 calculates a deviation (torque control error) between (T * −Th) output from the battery output current suppression controller 150 and the actual torque T output from the torque calculator 200. The PI controller 180 calculates the q-axis current manipulated variable Iqh according to the torque control error. In the case of regeneration, the outover value output from the input / output excess detector 120 is 0, and therefore the torque command correction value Th output from the correction value generation unit 130 is 0. (T * −Th) is a torque command T *.

  For this reason, at the time of regeneration, the operation amount Iqh of the q-axis current corresponding to the torque control error between the torque command T * and the actual torque T is calculated. The torque feedback controller 160 increases or decreases the operation amount of the q-axis current from the PI control unit 180 with respect to the q-axis command Iq *.

As a result, torque fluctuations are suppressed by the torque control as described above.
The present embodiment has the following effects.
(1) In the battery current suppression method of the present embodiment, the output current and the input current (battery current) are detected, and it is determined whether or not the battery current is within the range of the output current upper limit value and the input current upper limit value (set value). When the battery current is outside the range of the output current upper limit value and the input current upper limit value, the torque command is corrected so that the battery current is within the set value range.

  As a result, by suppressing the output current and input current within the ranges of the output current upper limit value and the input current upper limit value, it is possible to prevent the battery B from premature deterioration, and the inverter 280 and the motor M regardless of the characteristics of the battery B. The driver design between.

  (2) The battery current suppression method of this embodiment determines whether the output current (battery current) is within the range of the output current upper limit value (OutLim) during powering, and the output current is the output current upper limit value. When outside the range of (OutLim), correct the torque command so that the output current is within the output current upper limit (OutLim). As a result, at the time of power running, by suppressing the output current within the range of the output current upper limit value, the early deterioration of the battery B can be prevented, and the driver design between the inverter 280 and the motor M is possible regardless of the characteristics of the battery B. Can do.

  (3) The battery current suppression method of the present embodiment determines whether the input current (battery current) is within the input current upper limit (InLim) during regeneration, and the input current is the input current upper limit. When outside the range of (InLim), the torque command is corrected so that the input current falls within the input current upper limit (OutLim). As a result, at the time of regeneration, by suppressing the input current within the range of the input current upper limit value, early deterioration of the battery B can be prevented, and the driver design between the inverter 280 and the motor M is possible regardless of the characteristics of the battery B. Can do.

  (4) The motor drive system of the present embodiment includes a current sensor S3 (battery current detection means) that detects an output current and an input current (battery current), an output current and an input current that are an output current upper limit value, and an input current upper limit value. An input / output excess detector 120 (determination means) for determining whether or not the value (set value) is within the range is provided. The motor drive system also includes a battery output current suppression controller 150 that corrects the torque command so that the battery current is within the set value range when the output current and the input current are outside the set value range. A battery input current suppression controller 170 (correction means) is provided.

  As a result, by suppressing the output current and the input current within the range of the output current upper limit value and the input current upper limit value, it is possible to prevent the battery B from premature deterioration, and the inverter 280 and the motor M regardless of the characteristics of the battery B. The driver design between.

  (5) In the present embodiment, the input / output excess detector 120 (determination means) determines whether or not the output current is within the range of the output current upper limit value (OutLim) during powering, and the battery output current suppression controller 150 (correction means) corrects the torque command so that the output current falls within the output current upper limit value (OutLim) when the output current is outside the range of the output current upper limit value (OutLim).

  As a result, the motor drive system of the present embodiment can prevent early deterioration of the battery B by suppressing the output current within the range of the output current upper limit value during power running, regardless of the characteristics of the battery B. Driver design between the inverter 280 and the motor M can be performed.

  (6) In the present embodiment, during regeneration, the input / output excess detector 120 determines whether or not the input current is within the range of the input current upper limit value (OutLim) as the set value, and the battery input current suppression controller 170 (correction means) corrects and increases the value of the d-axis command so that the input current falls within the input current upper limit value (OutLim) when the input current is outside the range of the input current upper limit value (OutLim).

  As a result, at the time of regeneration, by suppressing the input current within the range of the input current upper limit value, early deterioration of the battery B can be prevented, and the driver design between the inverter 280 and the motor M is possible regardless of the characteristics of the battery B. Can do.

  (7) The motor drive system of this embodiment includes current sensors S1 and S2 (motor current detection means) that detect the motor current of the motor M, and a torque calculator 200 (torque calculation) that calculates torque based on the motor current. Means). The motor drive system also includes a torque feedback controller 160 (q-axis command correcting means) that corrects the q-axis command Iq * based on the deviation between the actual torque T calculated by the torque calculator 200 and the torque command T *. Is provided. And the motor drive system of this embodiment suppresses the torque fluctuation at the time of regeneration of the motor M by correcting the q-axis command Iq * of the torque feedback controller 160. As a result, torque fluctuations during motor regeneration can be suppressed by correcting the q-axis command by the q-axis command correcting means.

(Second Embodiment)
Next, the battery current suppression control device of the second embodiment will be described with reference to FIGS. In addition, about the same structure as 1st Embodiment or an equivalent structure, the same code | symbol is attached | subjected, the detailed description is abbreviate | omitted, and it demonstrates focusing on a different structure.

  In the second embodiment, in addition to the configuration of the first embodiment, a motor temperature sensor 300 serving as a motor temperature detecting means for detecting the temperature of the motor M (hereinafter referred to as the motor temperature Mthrm) is further provided in the motor M. This is different from the first embodiment. The motor temperature sensor 300 can be a thermistor, for example, but is not limited to the thermistor.

  The rotation speed calculation unit 310 calculates the rotation speed ω (that is, the rotation speed) per unit time of the motor M using the rotation angle θ of the motor M detected by the rotation angle sensor 290, and Enter the rotation speed ω.

  Also in the current map 110 of the second embodiment, similarly to the first embodiment, the d-axis command Id * and the q-axis command Iq * are obtained based on the three-dimensional map. Specifically, the current map 110 includes a three-dimensional map for obtaining the d-axis command Id * and a three-dimensional map for obtaining the q-axis command Iq *. These maps are three-dimensional maps each consisting of (T * −Th), the rotational speed ω, and the battery voltage Vdc. The current map 110 obtains the d-axis command Id * and the q-axis command Iq * based on the input (T * −Th), the rotational speed ω, and the battery voltage Vdc based on the respective maps.

The torque calculator 200 calculates the actual torque T of the motor M from the motor temperature M _thrm detected by the motor temperature sensor 300, the d-axis current Id input from the three-phase / 2-phase coordinate converter 270, and the q-axis current Iq. To do.

Specifically, first, a torque calculator 200, calculated using Equation (2), d-axis current Id, q-axis current Iq, the reference temperature (constant) S _THRM, the magnet torque constant _{K M} based on To do. Incidentally, the magnet torque constant K _M is the motor constant calculated from equation (2), varies with the q-axis current Iq and the motor temperature M _THRM. In Equation (2), a, b, c, and d are calculation coefficients.

K _M = a × Iq ² + b × Iq + c + d × (S _thrm −M _thrm )
(2)
Next, the torque calculator 200 calculates the actual torque T using equation (3).

T = (K _M −K _R × Id) × Iq (3)
Here, K _R is a reluctance torque constant.
Equation (3) is derived from the theoretical torque equation (4) of the motor.

T = p {φ− (Ld−Lq) Id} Iq (4)
Here, p is the number of pole pairs of the motor M, φ is the number of flux linkages, Ld is a d-axis inductance, and Lq is a q-axis inductance, which are constants. Also, the calculated coefficient a, b, c, d, a reference temperature S _THRM and reluctance constant K _R is to be based on experimental, or simulation results.

The operation of the battery current suppression control device configured as described above will be described with reference to FIGS. 5 and 6.
In the battery current suppression control device, the torque calculator 200 performs a torque calculation based on the q-axis current Iq and the d-axis current Id. At this time, the torque is calculated based on the equation (3) that _takes into account the motor temperature M _thrm. Even when these values are changed, the actual torque T can be calculated with high accuracy. The actual torque T calculated in this way is calculated by the torque deviation generator 190 to calculate a deviation from (T * −Th), and the current value Iq * is fed back and corrected by the torque feedback controller 160. Torque control accuracy can be improved.

FIG. 5 is a graph showing torque calculation accuracy and torque control accuracy in the present embodiment.
FIG. 5 shows that when the torque command T * is 70 Nm and the motor temperature M _thrm changes, “measured torque before correction”, “calculated torque before correction”, “measured torque after correction”, and “after corrected torque” The numerical value of “calculated torque” is plotted. In the figure, the motor temperature [° C.] is on the horizontal axis and the torque [Nm] is on the vertical axis.

  Here, the measured torque is an actual torque as a result of measuring the torque of the motor M. The “measurement torque before correction” is a measurement result of actual torque in the case of the first embodiment. “After-correction measured torque” is a measurement result of actual torque in the case of the second embodiment.

  The “calculated torque before correction” is a torque calculated by the equation (1) of the first embodiment. The “calculated torque after correction” is the torque calculated by the expression (3) of the second embodiment.

  As shown in FIG. 5, the “measured torque before correction” was larger than the torque command T * (70 Nm), and it was confirmed that the measured torque was reduced as the motor temperature increased.

  On the other hand, the “measured torque after correction” was very close to the torque command T * (70 Nm), and even if the motor temperature rose, the value as the torque command T * (70 Nm) was obtained. Was confirmed.

  The “calculated torque before correction” is larger than the torque command T * (70 Nm), and it has been confirmed that the deviation from the “measured torque before correction” increases as the motor temperature rises. On the other hand, it was confirmed that the “calculated torque after correction” was a value close to the torque command T * (70 Nm) and was calculated accurately regardless of the motor temperature value.

FIG. 6 shows the measurement result of the phase current (that is, the motor current) with respect to the motor temperature Mthrm in the battery current suppression control device of the present embodiment. The horizontal axis represents time [minutes], the left vertical axis represents phase current [Arms], and the right vertical axis represents motor temperature [° C.]. As the motor temperature M _thrm rises with time, it can be seen that control for increasing the phase current is also performed by correcting the q-axis current Iq.

In the current map 110 according to the first embodiment, the motor constant (that is, the magnet torque constant K _M ) changes due to changes in the motor temperature and the motor current, but this does not correspond to this change. For this reason, in the first embodiment, torque according to the torque command cannot be output with high accuracy, but in the second embodiment, torque can be output with high accuracy.

In this manner, in the second embodiment, the torque of the motor M is calculated based on the motor current taking the motor temperature M _thrm into consideration, and therefore the torque of the motor M can be calculated with high accuracy. As a result, the q-axis command can be accurately corrected by the deviation between the accurately calculated torque and the torque command, the torque control accuracy can be improved, and torque fluctuations during motor regeneration can be suppressed.

In addition, this invention is not limited to the said embodiment, You may change the structure of the said embodiment as follows.
In the above-described embodiment, each of the three phases of the motor M is detected by a current sensor, and the motor current of each phase is input to the three-phase / two-phase coordinate conversion unit 270. The d-axis current Id and the q-axis current Iq may be obtained using the rotation angle θ of the motor M.

  In the above embodiment, the current sensor S3 detects the input current and output current as battery current. However, the input current and output current as battery current are detected, that is, calculated. Also good. In this case, it is possible to calculate from the voltage of each phase output to the inverter 280, the duty ratio, and the current value of each phase of the motor M.

  In the above embodiment, the torque feedback controller 160, the PI controller 180, the torque deviation generator 190, and the torque calculator 200 are provided. However, these may be omitted and the torque feedback control may be omitted.

  In the configuration of the embodiment, a PID control unit may be provided instead of the PI control units 180, 230, and 240 that perform PI control, and PID (proportional, integral, and differential) control may be performed.

The functional block circuit diagram of ECU which controls the motor of the motor drive system of 1st Embodiment. Explanatory drawing which shows the relationship between Idc, an output current upper limit, and an input current upper limit. The functional block circuit diagram of ECU which controls the motor of the conventional motor drive system. The functional block circuit diagram of ECU which controls the motor of the motor drive system of 2nd Embodiment. The graph which shows the measurement result of the torque accuracy and torque control accuracy of 2nd Embodiment. The graph which shows transition of the phase current with respect to the motor temperature of 2nd Embodiment.

Explanation of symbols

100 ... ECU, 110 ... current map, 120 ... input / output excess detector,
130 ... correction value generation unit, 140 ... correction value generation unit,
150 ... battery output current suppression controller (correction means),
160 ... torque feedback controller (q-axis command correcting means),
170 ... battery input current suppression controller (correction means), 180 ... PI controller,
190 ... torque deviation generator, 200 ... torque calculator (torque calculator),
210 ... q-axis current deviation generator, 220 ... d-axis current deviation generator,
230 ... PI control unit, 240 ... PI control unit,
250 ... 2-phase / 3-phase coordinate converter, 260 ... PWM converter,
270 ... 3-phase / 2-phase coordinate conversion unit 270, 280 ... inverter,
290 ... rotation angle sensor,
300 ... motor temperature sensor (motor temperature detecting means),
B ... Battery, M ... Motor,
S1, S2 ... current sensors (motor current detection means),
S3: Current sensor (battery current detection means).

Claims (8)

A battery current output from the battery based on the d-axis command and the q-axis command obtained based on the torque command is supplied to the motor via the inverter, and a regenerative current from the motor is input via the inverter; A battery current suppression method in a battery power supply device that accepts a regenerative current as a battery current input to the battery,
Detecting the battery current;
A determination step of determining whether or not the battery current is within a range of a set value;
A battery current suppression method comprising: a correction step of correcting the torque command so that the battery current falls within the set value range when the battery current is outside the set value range. The battery current is an output current output from the battery during power running,
The determination step is a step of determining whether or not the output current is within a range of a first upper limit value as a set value;
The correction step is a step of correcting the torque command so that the output current falls within the first upper limit value when the output current is outside the range of the first upper limit value. The battery current suppressing method according to claim 1. The battery current is an input current input to the battery during regeneration,
The determination step is a step of determining whether or not the input current is within a range of a second upper limit value as a set value;
The correction step is a step of correcting the torque command so that the input current falls within the second upper limit value when the input current is outside the range of the second upper limit value. The battery current suppressing method according to claim 1. A battery current output from the battery based on the d-axis command and the q-axis command obtained based on the torque command is supplied to the motor via the inverter, and a regenerative current from the motor is input via the inverter; A battery current suppression control device in a battery power supply device that accepts a regenerative current as a battery current input to the battery,
Battery current detection means for detecting the battery current;
Determining means for determining whether or not the battery current is within a set value range;
When the battery current is outside the set value range, the battery current suppression control device includes a correction unit that corrects the torque command so that the battery current is within the set value range. The battery current is an output current output from the battery during power running,
The determination means determines whether the output current is within a range of a first upper limit value as a set value;
The said correction | amendment means correct | amends the said torque instruction so that an output current may be settled in the said 1st upper limit value when the said output current is outside the range of the said 1st upper limit value. Battery current suppression control device. The battery current is an input current input to the battery during regeneration,
The determination means determines whether or not the input current is within a range of a second upper limit value as a set value,
The correction means corrects and increases the value of the d-axis command so that the input current falls within the second upper limit value when the input current is outside the range of the second upper limit value. The battery current suppression control device according to claim 4. Motor current detection means for detecting the motor current of the motor;
Torque calculating means for calculating torque based on the motor current;
Q-axis command correction means for correcting the q-axis command based on a deviation between the torque calculated by the torque calculation means and the torque command;
The battery current suppression control device according to claim 6, wherein torque fluctuations during regeneration of the motor are suppressed by correcting the q-axis command by the q-axis command correcting unit. Motor temperature detecting means for detecting the motor temperature of the motor;
The battery current suppression control device according to claim 7, wherein the torque calculation unit calculates a torque based on the motor temperature and the motor current.

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