JP2014072920A - Motor system, motor controller, motor control program, and motor control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for generating a torque close to the original maximum output torque of an AC motor, while preventing occurrence of a situation where the AC motor is uncontrollable, when driving the AC motor by 1 pulse control.SOLUTION: A controller (6) of a motor system (1) includes torque limit means (13) for generating a limited torque command in response to a torque command given externally, phase command generation means (14-16) for generating a phase command by performing current control in response to the limited torque command, phase limit means (17) for generating a limited phase command by limiting the phase command so as not to exceed a specific phase limit value, and 1 pulse control output means (18) for generating a control signal that controls an inverter (3) in response to the limited phase command. The torque limit means (13) generates a limited torque command so as the limited torque command not to increase when the phase command exceeds the phase limit value.

Description

  The present invention relates to a motor system, a motor control device, a motor control program, and a motor control method, and more particularly to a technique for driving an AC motor by one-pulse control.

  One pulse control (rectangular wave voltage phase driving) is known as one of driving methods for driving an AC motor (for example, a synchronous motor). One-pulse control is a driving method that generates a driving voltage for each phase so that a rectangular wave having a single pulse having a half-cycle pulse width per cycle is obtained. One-pulse control is disclosed in, for example, Japanese Patent Application Laid-Open No. 2000-358393. Patent Document 1 discloses that the torque command value is lowered when the voltage command value exceeds the maximum voltage value that can be generated by the inverter.

ここで、Ｒａは電機子巻線抵抗値であり、φａは電機子巻線の鎖交磁束であり、ωは角速度であり、Ｌｄは、ｄ軸インダクタンスであり、Ｌｑはｑ軸インダクタンスであり、Ｉｄはｄ軸電流であり、Ｉｑはｑ軸電流である。 In the one-pulse control, current control, that is, torque control is performed by controlling the voltage phase δ. FIG. 1 shows a voltage vector diagram in one-pulse control. This voltage vector diagram is based on the following voltage equation that holds for steady state AC motors:

Here, Ra is an armature winding resistance value, φa is an interlinkage magnetic flux of the armature winding, ω is an angular velocity, Ld is a d-axis inductance, Lq is a q-axis inductance, Id is a d-axis current, and Iq is a q-axis current.

  In the one-pulse control, the voltage phase δ is determined so that the q-axis current Iq becomes a value corresponding to the requested torque (that is, torque command). When the torque command is increased, the voltage phase δ is increased, thereby increasing the q-axis current so as to realize the torque required for the torque command. At this time, the voltage phase δ is determined such that the magnitude of the voltage vector is maintained at the voltage amplitude | Va | (ie, the voltage vector is maintained on a voltage limit circle of radius | Va |). The

  On the other hand, the voltage phase δ needs to be limited to a specific limit value or less. That is, since the voltage vector is bound to the voltage limit circle, the voltage phase δ is essentially limited to 90 °. Current control becomes impossible for a torque command that requires torque that cannot be realized even when the voltage phase δ is 90 °. In addition, if the voltage phase δ is in the range near 90 °, the controllability deteriorates. Against this background, the voltage phase δ is limited to a specific limit value (for example, 80 °) that is slightly smaller than 90 °. In this case, the torque command is also generated so that the voltage phase δ is smaller than the limit value.

  One problem is that if the motor characteristics change, for example, the motor operating temperature, bus voltage (DC voltage supplied to the inverter), or rotor position detection error changes, the voltage phase δ is fixed to a specific limit value. That can happen. When the motor characteristic variation occurs, even if it is intended to generate the torque command so that the voltage phase δ is smaller than the specific limit value, a situation where the torque required for the torque command cannot actually be generated may occur. In this case, the voltage phase δ is fixed to the specific limit value. This means that the AC motor becomes uncontrollable, which is not preferable.

  In order to prevent a situation in which the voltage phase is fixed to a specific limit value due to motor characteristic fluctuations, it is conceivable to set the torque command to be small with a margin. However, with this method, it is not possible to draw out torque performance that should originally be realized in an AC motor.

  Patent Document 2 (Japanese Patent Application Laid-Open No. 2010-17020) discloses the relationship between the phase of the rectangular wave voltage and the torque output from the AC motor in order to more reliably output the torque that can be originally obtained from the AC motor. Is stored in the storage device of the motor control device as a map (that is, a model of an AC motor), the limit phase is determined using the map, and the rectangular wave voltage is within the phase range defined by the limit phase. A technique for setting a target voltage phase is disclosed. However, in the technique of Patent Document 2, if there is an error in the map, that is, the AC motor model, the motor performance cannot be maximized.

JP 2000-358393 A JP 2010-17020 A

  Accordingly, the object of the present invention is inherently obtained in an AC motor while preventing the occurrence of a situation in which the AC motor becomes uncontrollable when the voltage phase is fixed to a specific value when the AC motor is driven by one-pulse control. The object is to provide a technique for generating a torque as close as possible to the expected torque.

  In one aspect of the present invention, a motor system includes an AC motor, an inverter that drives the AC motor, and a control device that controls the inverter by one-pulse control. The control device generates a phase command by performing a current control of a current supplied to the inverter in response to the torque limit means for generating a torque command after the limit according to a torque command given from the outside, and in response to the torque command after the limit A phase command generating means for controlling, a phase limiting means for generating a post-restricted phase command by limiting the phase command so as not to exceed a specific phase limit value, and a control signal for controlling the inverter in response to the post-restricted phase command. 1-pulse control output means for generating. The torque limiting means generates the post-limit torque command so that the post-limit torque command does not increase when the phase command exceeds the phase limit value.

  Here, it is preferable that the torque limiting means decreases the post-limit torque command while the phase command exceeds the phase limit value. In one embodiment, the rate of decrease per unit time during which the post-limit torque command decreases while the phase command exceeds the phase limit value is constant.

  Further, it is preferable that the torque limiting means generates the post-limit torque command so that the post-limit torque command follows the torque command when the phase command does not exceed the phase limit value.

  In another aspect of the present invention, a control device that controls an inverter that drives an AC motor by one-pulse control includes a torque limiting unit that generates a limited torque command from a torque command given from the outside, and a response to the limited torque command Phase control generating means for generating a phase command by controlling the current supplied to the inverter, and a phase limit for generating a post-limit phase command by limiting the phase command so as not to exceed a specific phase limit value And a one-pulse control output means for generating a control signal for controlling the inverter in response to the post-limit phase command. The torque limiting means generates the post-limit torque command so that the post-limit torque command does not increase when the phase command exceeds the phase limit value.

  In still another aspect of the present invention, a motor control program controls a computing device that controls an inverter that drives an AC motor by one-pulse control, and the following means: Torque restriction that generates a restricted torque command from a torque command given from outside Means, a phase command generating means for generating a phase command by controlling the current supplied to the inverter in response to the post-limit torque command, and after limiting the phase command so as not to exceed a specific phase limit value It functions as a phase limiting means for generating a phase command and a one-pulse control output means for generating a control signal for controlling the inverter in response to the post-limit phase command. Here, the torque limiting unit is a unit that generates the post-limit torque command so that the post-limit torque command does not increase when the phase command exceeds the phase limit value.

  According to still another aspect of the present invention, a motor control method for controlling an inverter that drives an AC motor by one-pulse control generates a post-restricted torque command from an externally applied torque command, and responds to the post-restricted torque command. A step of generating a phase command by performing current control of the current supplied to the inverter, a step of generating a limited phase command by limiting the phase command so as not to exceed a specific phase limit value, and after the limitation Generating a control signal for controlling the inverter in response to the phase command. The post-limit torque command is generated so that the post-limit torque command does not increase when the phase command exceeds the phase limit value.

  According to the present invention, when an AC motor is driven by one-pulse control, the phase command is fixed at a specific value, and the AC motor cannot be controlled. Torque as close as possible can be generated.

It is a voltage vector figure in 1 pulse control. It is a block diagram which shows the structure of the motor system of one Embodiment of this invention. It is a functional block diagram of the inverter controller in this embodiment. It is a timing chart which shows operation of a motor system in this embodiment.

  FIG. 2 is a block diagram showing the configuration of the motor system 1 according to the embodiment of the present invention. The motor system 1 includes a motor 2, an inverter 3, a resolver 4, an R / D (resolver-digital) converter 5, and an inverter controller 6.

  The motor 2 is connected to the inverter 3 by a u-phase power line 7u, a v-phase power line 7v, and a w-phase power line 7w. The motor 2 is an AC motor (for example, a permanent magnet motor or a synchronous motor) that operates by being supplied with three-phase power from the inverter 3 via the u-phase power supply line 7u, the v-phase power supply line 7v, and the w-phase power supply line 7w. . The u-phase power supply line 7u, the v-phase power supply line 7v, and the w-phase power supply line 7w are provided with current sensors 8u, 8v, and 8w for measuring the u-phase current Iu, the v-phase current Iv, and the w-phase current Iw, respectively. It is done. Note that it is not always necessary to detect all of the u-phase current Iu, the v-phase current Iv, and the w-phase current Iw. Two of these three currents may be measured and the remaining one may be computed.

  The resolver 4 and the R / D converter 5 are a group of devices used for detecting the rotor position (that is, the rotor angle) θ of the motor 2. The resolver 4 outputs two signals depending on sin θ and cos θ according to the rotor position θ. The R / D converter 5 calculates the rotor position θ from these two signals and outputs digital data indicating the rotor position θ.

The inverter controller 6 is a control device that controls the inverter 3 so that the motor 2 generates a torque corresponding to a torque command T ^* given from the outside. The inverter controller 6 turns on / off the power transistor of the inverter 3 in response to the detected u-phase current Iu, v-phase current Iv, w-phase current Iw and rotor position θ in addition to the torque command T ^* given from the outside. A control signal S _CTRL to be controlled is generated. The control signal S _CTRL typically includes gate drive signals that drive the gates of the power transistors of the positive and negative arms of the u-phase, v-phase, and w-phase, respectively.

  The motor system 1 having such a configuration is used, for example, in a drive system that drives drive wheels of an electric vehicle or a hybrid car. In this case, the driving force generated by the motor 2 is transmitted to the driving wheels.

  FIG. 3 is a functional block diagram showing calculation in the inverter controller 6. The inverter controller 6 of this embodiment is configured to perform one-pulse control (rectangular wave voltage phase control). Specifically, in the inverter controller 6, the following calculation: speed calculation 11, three-phase to two-phase conversion 12, torque limit calculation 13, current command calculation 14, current PI control 15, dq-Vaδ conversion 16, δ limit calculation 17 And 1 pulse control output calculation 18 is performed. These calculations may be realized by software (program) installed in the inverter controller 6. In this case, an arithmetic device such as a CPU (central processing unit) may be used as the inverter controller 6. In addition, the above calculation may be implemented as hardware, or may be implemented as a combination of hardware and software.

  In the speed calculation 11, the rotor speed ω is calculated from the rotor position θ calculated by the R / D converter 5.

  In the three-phase to two-phase conversion 12, the three-phase to two-phase conversion is performed on the u-phase current Iu, the v-phase current Iv, and the w-phase current Iw using the rotor position θ calculated by the R / D converter 5. D-axis current Id and q-axis current Iq are calculated.

In the torque limit calculation 13, a calculation is performed to limit the torque command T ^* given from the outside according to the δ limit flag flag_δ _LIM and generate the limited torque command T _LIM ^* . The post-limit torque command T _LIM ^* is a torque command that is actually used in the one-pulse control in the inverter controller 6. Further, as will be described later, the δ limit flag flag_δ _LIM is obtained by current control in response to the post-limit torque command T _LIM ^* (in this embodiment, the current command calculation 14, the current PI control 15 and the dq-Vaδ conversion 16). This is a flag generated according to whether or not the generated phase command δ ^* exceeds a specific phase upper limit value δ _MAX . The δ limit flag flag_δ _LIM is asserted when the phase command δ ^* exceeds a specific phase upper limit value δ _MAX . On the other hand, when the phase command δ ^* is smaller than the phase upper limit value δ _MAX , the δ limit flag flag_δ _LIM is negated. In the state where the δ limit flag flag_δ _LIM is negated, in the torque limit calculation 13, the post-limit torque command T _LIM ^* is generated so as to follow the torque command T ^* . In this case, an increase in the post-limit torque command T _LIM ^* is permitted. On the other hand, when the δ limit flag flag_δ _LIM is asserted, the post-limit torque command T _LIM ^* is limited so as not to increase further. That is, an increase in the post-limit torque command T _LIM ^* is prohibited.

More specifically, in the present embodiment, when the δ limit flag flag_δ _LIM is asserted, the forcible decrease of the post-limit torque command T _LIM ^* is started, thereby increasing the post-limit torque command T _LIM ^* . Is limited. Here, “forced decrease of the post-restricted torque command T _LIM ^* ” means that the post-restricted torque command T _LIM ^* is reduced regardless of the torque command T ^* given from the outside. In the present embodiment, the rate of decrease dT _LIM ^* / dt per unit time of the post-restricted torque command T _LIM ^* when the post-restricted torque command T _LIM ^* is forcibly reduced is constant at a predetermined value D _DCR. .

Further, in the present embodiment, even after the limited torque command T _LIM ^* is generated so as to follow the torque command T ^* (the δ limit flag flag_δ _LIM is negated), the limited torque command T _LIM ^{When *} is increasing, the rate of increase of the post-limit torque command T _LIM ^* with respect to the unit time is limited to be equal to or less than the predetermined value D _MAX . Even when the post-restricted torque command T _LIM ^* is increased, the post-restricted torque command T _LIM ^* is satisfied if the change rate (increase rate) per unit time of the post-restricted torque command T _LIM ^* is less than or equal to a predetermined value D _MAX T _LIM ^* is generated to match the torque command T ^* . The role of the torque limit calculation 13 will be described in detail later.

In the current command calculation 14, a d-axis current command Id ^* and a q-axis current command Iq ^* are calculated based on the post-restricted torque command T _LIM ^* and the rotor speed ω.

In the current PI control 15, PI control is performed in response to the difference between the d-axis current Id and the d-axis current command Id ^{* and} the difference between the q-axis current Iq and the q-axis current command Iq ^*. A voltage command Vd ^* and a q-axis voltage command Vq ^* are calculated. Further, in the dq-Vaδ conversion 16, the d-axis voltage command Vd ^* and the q-axis voltage command Vq ^* are converted into a voltage amplitude command Va ^* and a phase command δ ^* . The three-phase to two-phase conversion 12, the current PI control 15, and the dq-Vaδ conversion 16 described above control the u-phase current Iu, the v-phase current Iv, and the w-phase current Iw, that is, the phase command δ ^* by current control ^. Constitutes a series of operations to generate.

In the δ limit calculation 17, a calculation is performed to limit the phase command δ ^* to be equal to or lower than the phase upper limit value δ _MAX to generate a post-limit phase command δ _LIM ^* . The post-limit phase command δ _LIM ^* is a phase command that is actually used for one-pulse control. Specifically, when the phase command δ ^* is smaller than the phase upper limit value δ _MAX , the post-limit phase command δ _LIM ^* is generated so as to coincide with the phase command δ ^* . On the other hand, the phase instruction [delta] ^* cases exceeds the phase upper limit [delta] _MAX, limits after phase command [delta] _LIM ^* is set to phase upper limit value [delta] _MAX. By such calculation, the post-limit phase command δ _LIM ^* that is a phase command actually used for one-pulse control is limited to the phase upper limit value δ _MAX or less.

In addition, in the δ limit calculation 17, a δ limit flag flag_δ _LIM is generated. When the phase command δ ^* is smaller than the phase upper limit value δ _MAX , the δ limit flag flag_δ _LIM is negated. On the other hand, when the phase command δ ^* exceeds the phase upper limit value δ _MAX , the δ limit flag flag_δ _LIM is asserted. The role of the δ limit calculation 17 will be described in detail later.

In the 1-pulse control output calculation 18, calculation is performed to generate a control signal S _CTRL that controls on / off of the power transistor of the inverter 3 from the post-limit phase command δ _LIM ^* .

  In FIG. 3, the operation of the inverter controller 6 is illustrated as a functional block, but it should be noted that the inverter controller 6 can be realized by software, hardware, and a combination thereof that perform equivalent operations. .

  Subsequently, the operation of the motor system 1 of the present embodiment and the phase control performed in the one-pulse control of the present embodiment will be described.

In the motor system 1 of the present embodiment, actual phase command used in the one-pulse control (i.e., post-restriction phase command [delta] _{LIM ^*)} is generated such that the following phase upper limit [delta] _MAX. Such a calculation is realized by the δ limit calculation 17. Specifically, (specifically, the current command calculation 14, the current PI control 15 and dq-Vaδ converting 16) current control when the phase instruction [delta] ^* generated by less than the phase upper limit value [delta] _MAX, [delta] limited operation 17 , The post-limit phase command δ _LIM ^* is generated so as to coincide with the phase command δ ^* . On the other hand, when the phase command δ ^* exceeds the phase upper limit value δ _MAX , the post-limit phase command δ _LIM ^* is set to the phase upper limit value δ _MAX in the δ limit calculation 17.

In addition, when the phase command δ ^* generated by the current control exceeds the phase upper limit value δ _MAX , the torque command actually used for one-pulse control, that is, the post-limit torque command T _LIM ^* is limited. Such a calculation is realized by the torque limit calculation 13. In torque limit operation 13, the phase instruction [delta] ^* is smaller than the phase upper limit [delta] _MAX is limited after the torque command T _LIM ^* is generated so as to follow the torque command T ^*. On the other hand, the post-limit torque command T _LIM ^* is prohibited from increasing as long as the phase command δ ^* generated by the current control exceeds the phase upper limit value δ _MAX . In the present embodiment, the post-limit torque command T _LIM ^* is forcibly decreased. Here, “forcibly decreased” means that the post-limit torque command T _LIM ^* is decreased regardless of the torque command T ^* given from the outside.

With such an operation, the motor system 1 according to the present embodiment prevents the voltage phase from being fixed to a specific value for a long time in one-pulse control. As described above, it is important to prevent the voltage phase from being fixed to a specific value for a long time from the viewpoint of preventing the motor 2 from being in an uncontrollable state. In addition, since the torque command actually used for 1-pulse control (post-limit torque command T _LIM ^* ) is maintained in a range in which the phase command δ ^* is close to the phase upper limit value δ _MAX , Torque characteristics (particularly, maximum torque) that can be realized from the characteristics can be realized. Hereinafter, the one-pulse control of this embodiment will be described with a specific example.

FIG. 4 is a timing chart showing an example of the operation of the motor system 1 of the present embodiment. In the operation of FIG. 4, the torque command T ^* given from the outside increases from time t ₀ to time t ₄ and decreases from time t ₄ to time t ₈ . Hereinafter, operations from time t ₀ to time t ₈ , particularly changes in the phase command δ ^* , the post-restricted phase command δ _LIM ^* , the δ limit flag flag_δ _LIM , and the post-restricted torque command T _LIM ^* will be described in detail. In actual use, it will be obvious to those skilled in the art that the change in the torque command T ^* is not limited to that shown in FIG.

The torque command T ^* is increasing in the period when the time t is t ₀ <t <t ₁ . ^* The torque command ^{T *} Response to limit after the torque command to increase ^T, the phase instruction [delta] ^*, and limited after the phase command [delta] _LIM ^* also increases. However, during the period of t ₀ <t <t ₁ , the phase command δ ^* is smaller than the phase upper limit value δ _MAX , and therefore the post-limit phase command δ _LIM ^* coincides with the phase command δ ^* , and the post-limit torque command T ^{* Corresponds} to the torque command T ^* .

The torque command T ^* continues to increase even during the period of t ₁ <t <t ₂ . However, since the phase command δ ^* reaches the phase upper limit value δ _MAX at time t ₁ , the post-limit phase command δ _LIM ^* is limited to the phase upper limit value δ _MAX during the period of t ₁ <t <t _2. . In addition, in response to the phase command δ ^* exceeding the phase upper limit value δ _MAX , the δ limit flag flag_δ _LIM is asserted at time t ₁ . In response to the assertion of the δ limit flag flag_δ _LIM , forcibly decreasing the post-limit torque command T _LIM ^* is started at time t ₁ . As described above, “forced reduction of the post-restricted torque command T _LIM ^* ” means that the post-restricted torque command T _LIM ^* is reduced regardless of the torque command T ^* given from the outside. In the present embodiment, the rate of decrease dT _LIM ^* / dt per unit time of the post-restricted torque command T _LIM ^* when the post-restricted torque command T _LIM ^* is forcibly reduced is constant at a predetermined value D _DCR. . The phase command δ ^* once exceeds the phase upper limit value δ _MAX , but starts to decrease after taking a certain maximum value by decreasing the post-limit torque command T _LIM ^* .

In time _{t 2, the} phase instruction [delta] ^* generated by a current control becomes smaller than the phase upper limit [delta] _MAX, [delta] limiting flag Flag_deruta _LIM is negated. In response to the negation of the δ limit flag flag_δ _LIM , the forced decrease of the post-limit torque command T _LIM ^* is stopped.

After the forced reduction of the post-limit torque command T _LIM ^* is stopped, the post-limit torque command T _LIM ^* is generated so as to follow the torque command T ^* in the period t ₂ <t <t _3. . The torque command ^{T *} is at time _{t 2, the} so limited after the torque command _{T LIM} ^* greater than limitation after the torque command _{T LIM} ^* is increased. However, the rate of increase dT _LIM ^* / dt per unit time of the post-limit torque command T _LIM ^* is limited to a predetermined value D _MAX or less. The phase command δ ^* once takes a minimum value due to the increase in the post-limit torque command T _LIM ^* , and then starts increasing again.

Thereafter, until the torque command T ^* is decreased to the phase instruction [delta] ^* generated by a current controlled to a value as smaller than the phase upper limit [delta] _MAX, the same operation is repeated. That is, the phase command δ ^* is increased in accordance with the increase in the post-limit torque command T _LIM ^* , and the phase command δ ^* reaches the phase upper limit value δ _MAX at time t ₃ , so the period of t ₃ <t <t ₅ In, the post-limit phase command δ _LIM ^* is limited to the phase upper limit value δ _MAX . In addition, in response to the phase command δ ^* exceeding the phase upper limit value δ _MAX , the δ limit flag flag_δ _LIM is asserted at time t ₃ . In response to the assertion of the δ limit flag flag_δ _LIM , forcibly decreasing the post-limit torque command T _LIM ^* is started at time t ₃ . The decrease rate dT _LIM ^* / dt per unit time of the post-limit torque command T _LIM ^* is constant at a predetermined value D _DCR . The phase command δ ^* once exceeds the phase upper limit value δ _MAX , but starts to decrease after taking a certain maximum value by decreasing the post-limit torque command T _LIM ^* .

When the phase command δ ^* becomes smaller than the phase upper limit value δ _{MAX at} time t ₅ , the δ limit flag flag_δ _LIM is negated. In response to the negation of the δ limit flag flag_δ _LIM , the forced decrease of the post-limit torque command T _LIM ^* is stopped.

After the decrease of the post-limit torque command T _LIM ^* is stopped, the post-limit torque command T _LIM ^* is generated so as to follow the torque command T ^* during the period of t ₅ <t <t ₆ . The torque command ^{T *} is at time _{t 5,} so limit after the torque command _{T LIM} ^* greater than limitation after the torque command _{T LIM} ^* is increased. However, the rate of increase dT _LIM ^* / dt per unit time of the post-limit torque command T _LIM ^* is limited to a predetermined value D _MAX or less. The phase command δ ^* once takes a minimum value due to the increase in the post-limit torque command T _LIM ^* , and then starts increasing again.

Since the phase command δ ^* reaches the phase upper limit value δ _MAX at time t ₆ , the post-limit phase command δ _LIM ^* is limited to the phase upper limit value δ _MAX during the period of t ₆ <t <t ₇ . In addition, in response to the phase command [delta] ^* exceeds the phase upper limit [delta] _MAX, [delta] limiting flag Flag_deruta _LIM at time _{t 6} is asserted. In response to the assertion of δ limiting flag flag_δ _LIM, at time _{t 6,} forced reduction in the post-restriction torque command _{T LIM} ^* is started. The decrease rate dT _LIM ^* / dt per unit time of the post-limit torque command T _LIM ^* is constant. The phase command δ ^* once exceeds the phase upper limit value δ _MAX , but starts to decrease after taking a certain maximum value by decreasing the post-limit torque command T _LIM ^* .

When the phase command δ ^* becomes smaller than the phase upper limit value δ _{MAX at} time t ₇ , the δ limit flag flag_δ _LIM is negated. In response to the negation of the δ limit flag flag_δ _LIM , the forced decrease of the post-limit torque command T _LIM ^* is stopped, and the post-limit torque command T _LIM ^* starts to be generated so as to follow the torque command T ^* . In the operation of FIG. 4, at time _{t 7} is restricted after the torque command _{T LIM} ^* matches the torque command ^{T *,} further, after the time _{t 7,} the torque command ^{T *} is decreased, subsequently, the post-restriction The torque command T _LIM ^* is decreased in accordance with the torque command T ^* .

According to the operation described above, it is possible to prevent the phase command from being fixed to a specific value for a long time in one-pulse control, and to prevent the motor 2 from falling into an uncontrollable state. In addition, according to such an operation, the torque command actually used in the one-pulse control (that is, the post-limit torque command T ^* ) is such that the phase command δ ^* is close to the phase upper limit value δ _MAX. Since the range is maintained, the highest performance (particularly, the maximum torque) that can be realized from the characteristics of the motor 2 can be extracted.

In the above embodiment, the post-limit torque command T _LIM ^* is forcibly decreased in response to the assertion of the δ limit flag flag_δ _LIM , so that the increase of the post-limit torque command T _LIM ^* is prohibited. In this way, the prohibition and permission control of the post-limit torque command T _LIM ^* may be performed. For example, the phase instruction [delta] ^* that are generated by the current control to generate the phase upper limit [delta] _MAX near the phase command [delta] ^* were fed back to the torque command T ^* by limiting after the torque command when in a specific range of T _LIM ^* May be. That is, when the phase command δ ^* is δ ^* > δ _MAX −α (α is a predetermined value),
T _LIM ^* = T ^* −Kδ ^*
As to generate a limit after the torque command _{T LIM} ^*, the phase instruction [delta] ^* may generate a phase upper limit [delta] _MAX limit after the torque command so as not to exceed _{T LIM} ^*.

In the present embodiment, the inverter controller has a plurality of drive systems including one-pulse control (for example, PWM (pulse
(width modulation) control) may be switched and used. In this case, the operation of the present embodiment described above is executed when one-pulse control is selected.

  Although the embodiment of the present invention has been specifically described above, it should be noted that the present invention is not limited to the above-described embodiment and can be implemented with various modifications obvious to those skilled in the art.

1: Motor system 2: Motor 3: Inverter 4: Resolver 5: R / D converter 6: Inverter controller 7u: u-phase power line 7v: v-phase power line 7w: w-phase power lines 8u, 8v, 8w: current sensor 11: Speed calculation 12: Three-phase to two-phase conversion 13: Torque limit calculation 14: Current command calculation 15: Current PI control 16: dq-Vaδ conversion 17: δ limit calculation 18: 1 pulse control output calculation Iu: u-phase current Iv: v-phase current Iw: w-phase current T ^* : torque command:
Id: d-axis current Iq: q-axis current T _LIM ^* : post-limit torque command Id ^* : d-axis current command Iq ^* : q-axis current command Vd ^* : d-axis voltage command Vq ^* : q-axis voltage command δ ^* : phase Command δ _LIM ^* : Phase command after limit S _CTRL : Control signal flag_δ _LIM : δ limit flag δ _MAX : Phase upper limit value θ: Rotor position ω: Rotor speed

Claims (10)

An AC motor,
An inverter for driving the AC motor;
A control device for controlling the inverter by one-pulse control,
The control device includes:
Torque limiting means for generating a post-limit torque command according to a torque command given from outside;
Phase command generating means for generating a phase command by performing current control of current supplied to the inverter in response to the post-limit torque command;
Phase limiting means for limiting the phase command so as not to exceed a specific phase limit value and generating a post-limit phase command;
One-pulse control output means for generating a control signal for controlling the inverter in response to the post-limit phase command,
The torque limiting means generates the post-limit torque command so that the post-limit torque command does not increase when the phase command exceeds the phase limit value. The motor system according to claim 1,
The torque limiting means reduces the post-limit torque command while the phase command exceeds the phase limit value. The motor system according to claim 2,
A reduction rate per unit time during which the post-limit torque command decreases while the phase command exceeds the phase limit value. The motor system according to any one of claims 1 to 3,
The torque limiting unit generates the post-limit torque command so that the post-limit torque command follows the torque command when the phase command does not exceed the phase limit value. A control device for controlling an inverter that drives an AC motor by one-pulse control,
Torque limiting means for generating a post-limit torque command from a torque command given from outside;
Phase command generating means for generating a phase command by controlling the current supplied to the inverter in response to the post-limit torque command;
Phase limiting means for limiting the phase command so as not to exceed a specific phase limit value and generating a post-limit phase command;
One-pulse control output means for generating a control signal for controlling the inverter in response to the post-limit phase command,
The torque control means generates the post-limit torque command so that the post-limit torque command does not increase when the phase command exceeds the phase limit value. The motor control device according to claim 5,
The torque limiting means reduces the post-limit torque command while the phase command exceeds the phase limit value. An arithmetic unit that controls an inverter that drives an AC motor by one-pulse control,
Torque limiting means for generating a post-limit torque command from a torque command given from outside;
Phase command generating means for generating a phase command by controlling the current supplied to the inverter in response to the post-limit torque command;
Phase limiting means for limiting the phase command so as not to exceed a specific phase limit value and generating a post-limit phase command;
A program for functioning as one-pulse control output means for generating a control signal for controlling the inverter in response to the post-limit phase command,
A motor control program for generating the post-limit torque command so that the post-limit torque command does not increase when the phase command exceeds the phase limit value. The motor control program according to claim 7,
The torque control means reduces the post-limit torque command while the phase command exceeds the phase limit value. A motor control method for controlling an inverter that drives an AC motor by one-pulse control,
Generating a post-limit torque command from a torque command given from outside;
Generating a phase command by performing current control of a current supplied to the inverter in response to the post-limit torque command;
Generating a post-limit phase command by limiting the phase command so as not to exceed a specific phase limit value;
Generating a control signal for controlling the inverter in response to the post-limit phase command,
The post-limit torque command is generated so that the post-limit torque command does not increase when the phase command exceeds the phase limit value. The motor control method according to claim 9,
The post-limit torque command is decreased while the phase command exceeds the phase limit value.

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