JP6398681B2 - Current estimation device - Google Patents

Description

  The present invention relates to a power conversion circuit and a current estimation device applied to a system including a rotating electrical machine that performs power transmission with a DC power supply by energization operation to the power conversion circuit.

  Conventionally, as can be seen in Patent Document 1 below, a control device that calculates d and q axis currents in a dq coordinate system based on a voltage equation of a rotating electrical machine is known. Specifically, in this control device, the d and q axis currents are calculated based on the d axis inductance.

Japanese Patent No. 5396906

  Incidentally, there is a technique for estimating a current flowing between a DC power supply and a power conversion circuit in a system including a power conversion circuit and a rotating electrical machine that transmits electric power to the DC power supply by energizing the power conversion circuit. In this technique, the d and q axis currents are calculated based on a predetermined d axis inductance, and the current flowing between the DC power supply and the power conversion circuit is estimated based on the calculated d and q axis currents. To do.

  Here, the d-axis inductance changes due to the influence of abrupt magnetic saturation that occurs when the d-axis current is greater than zero. In this case, there is a concern that an actual d-axis inductance greatly deviates from a predetermined d-axis inductance, and an estimation error of a current flowing between the DC power supply and the power conversion circuit becomes large. It is also conceivable to accurately grasp the characteristics of the d-axis inductance when the above-described sudden magnetic saturation occurs. However, it is difficult to accurately grasp this characteristic.

  An object of the present invention is to provide a current estimation device that can suitably suppress an estimation error of a current flowing between a DC power source and a power conversion circuit.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

  The present invention is applied to a system including a power conversion circuit (13) and a rotating electrical machine (12) that performs power transmission with a DC power source (14) by energizing the power conversion circuit, and the rotating electrical machine is predetermined. Current estimation means for estimating a current flowing between the DC power supply and the power conversion circuit based on the d-axis inductance, and a d-axis current in the dq coordinate system of the rotating electrical machine has a predetermined value greater than zero. And a phase operation means for manipulating a voltage phase, which is a phase of the voltage vector, to cause the q-axis component of the voltage vector of the power conversion circuit to follow the induced voltage component of the rotating electrical machine. To do.

  In a state where the q-axis component of the voltage vector matches the induced voltage component, the d-axis current is zero. In view of this point, in the above invention, the q-axis component of the voltage vector is made to follow the induced voltage component of the rotating electrical machine by operating the voltage phase on condition that the d-axis current becomes a predetermined value larger than 0. For this reason, it can be avoided that the actual d-axis inductance greatly deviates from a predetermined d-axis inductance used for current estimation. Thereby, the estimation error of the current by the current estimation means can be suitably suppressed.

1 is an overall configuration diagram of a motorcycle. The whole block diagram of the control system of a starter generator. The time chart which shows the output signal of a magnetic pole position detection sensor. The block diagram which shows the process of an applied voltage calculation part. The block diagram which shows the process of an electric current estimation part. The figure which shows an example of the increase aspect of the electric current estimation error in an idling state. A dq coordinate system indicating that the d-axis current becomes 0 by causing the q-axis voltage to follow the induced voltage. The flowchart which shows the procedure of an induced voltage tracking control process. The time chart which shows the rotation fluctuation in 1 combustion cycle. The figure which shows the guard process aspect of a voltage phase.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment in which a current estimation device according to the present invention is applied to a motorcycle (motorcycle) equipped with an engine as an in-vehicle main machine will be described with reference to the drawings.

  As shown in FIG. 1, a motorcycle 10 includes an engine 11, a starting generator 12 as a rotating electric machine, an inverter 13 as a power conversion circuit, a battery 14 as a DC power source, a transmission 15, a clutch 16, and driving wheels. 17 and a control device 20. The engine 11 is an in-vehicle main unit of the motorcycle 10, and is a single-cylinder four-stroke engine in the present embodiment. The combustion control of the engine 11 may be performed by another control device (not shown) different from the control device 20, or may be performed by the control device 20.

  An input side (specifically, for example, an engine-side pulley) of the transmission 15 is connected to a first end of an output shaft of the engine 11 (hereinafter referred to as a crankshaft 11a). In the present embodiment, an automatic transmission (specifically, a continuously variable transmission) is used as the transmission 15. Drive wheels 17 are connected to the output side of the transmission 15 (specifically, for example, a drive wheel pulley) via a clutch 16 and a secondary reduction mechanism (not shown).

  The clutch 16 is in a state capable of transmitting power between the output side of the transmission 15 and the drive wheel 17 (hereinafter referred to as a clutch meet state), and the power between the output side of the transmission 15 and the drive wheel 17 is cut off. It is possible to switch to one of the following states (hereinafter referred to as the clutch disengaged state). In the present embodiment, an automatic centrifugal clutch is used as the clutch 16. The automatic centrifugal clutch according to the present embodiment includes a clutch shoe connected to the output side of the transmission 15, a clutch spring, and a clutch outer connected to the drive wheel 17 side. In this configuration, when the engine 11 is rotating at a low speed, the clutch shoe is contracted by the elastic force of the clutch spring, and the clutch shoe and the clutch outer are brought into a non-contact state. As a result, the clutch is disengaged. On the other hand, when the rotational speed of the engine 11 increases and the centrifugal force acting on the clutch shoe increases, the clutch shoe expands by overcoming the elastic force of the clutch spring, and the clutch shoe comes into contact with the clutch outer. As a result, the clutch meet state is established. In particular, in the present embodiment, the clutch 16 is configured so that the clutch meet state is established when the rotational speed of the crankshaft 11a becomes equal to or higher than a predetermined rotational speed (> 0). In the present embodiment, the predetermined rotational speed is set to a rotational speed higher than the idle rotational speed of the engine 11.

  A rotating shaft of a rotor constituting the starter / generator 12 is directly connected to the second end of the crankshaft 11a. For this reason, the rotor of the starting generator 12 rotates integrally with the crankshaft 11a. The starter generator 12 can operate as an electric motor (starter for starting the engine) and a generator, and is attached to the engine block. In this embodiment, the starter generator 12 is a three-phase AC permanent magnet type synchronous machine, and includes the rotor provided with a permanent magnet and a stator around which each phase winding is wound.

  Then, the control system of the starting generator 12 is demonstrated using FIG. The starter / generator 12 is electrically connected to the battery 14 via the inverter 13. The inverter 13 includes a series connection body of upper arm switches Sup, Svp, Swp and lower arm switches Sun, Svn, Swn. A first end of a U-phase winding (not shown) of the starter / generator 12 is connected to a connection point between the U-phase upper and lower arm switches Sup and Sun, and a connection point between the V-phase upper and lower arm switches Svp and Svn. A first end of a V-phase winding (not shown) is connected to a connection point between the W-phase upper and lower arm switches Swp and Swn. The second ends of the U, V, and W phase windings are short-circuited. That is, in this embodiment, the starter generator 12 is Y-connected. The positive terminal of the battery 14 is connected to the high potential side terminal of each upper arm switch Sup, Svp, Swp, and the negative terminal of the battery 14 is connected to the low potential side terminal of each lower arm switch Sun, Svn, Swn. Is connected.

  Incidentally, as each of the switches Sup to Swn, for example, a voltage-controlled semiconductor switching element such as a MOS-FET or IGBT can be used. Each freewheel diode Dup-Dwn is connected in antiparallel to each switch Sup-Swn. Each freewheel diode Dup to Dwn may be a body diode or an external diode when each switch is a MOS-FET, for example.

  The control system includes a voltage sensor 18 and a magnetic pole position detection sensor 19. In the present embodiment, the voltage sensor 18 detects the voltage between the terminals of the battery 14. Further, the magnetic pole position detection sensor 19 (for example, a hall sensor, more specifically, a hall IC) is provided corresponding to each phase, and outputs an output signal as shown in FIG. 3 according to the rotation of the rotor. To do. Thereby, the rotation angle (electrical angle θ) of the starting generator 12 can be grasped at an electrical angle interval of 60 °. In FIG. 3, output signals corresponding to the U, V, and W phases are shown as SigU, SigV, and SigW.

  Returning to the description of FIG. 2, the output signals of the voltage sensor 18 and the magnetic pole position detection sensor 19 are input to the control device 20. The control device 20 is configured mainly with a microcomputer. In the present embodiment, the control device 20 controls the inter-terminal voltage of the battery 14 (hereinafter referred to as the battery voltage VDC) detected by the voltage sensor 18 to the target voltage Vtgt when the starter generator 12 is operated as a generator. Therefore, the inverter 13 is operated. Specifically, the control device 20 calculates U, V, and W phase applied voltages Vu, Vv, and Vw for driving the starter generator 12 by a known three-phase 180 ° energization method based on the detection values of the various sensors. To do. The control device 20 turns on / off the switches Sup to Swn based on the calculated applied voltage. As a result, the upper arm switch and the lower arm switch are alternately turned on at every electrical angle of 180 ° for each phase, and the switching of the upper arm switch to the off state is performed at an electrical angle of 120 for each phase. Switching is performed so as to shift by °.

  Here, the control system according to the present embodiment does not include a current sensor that detects the DC current IDC flowing in the electrical path connecting the battery 14 and the inverter 13. For this reason, in this embodiment, the control apparatus 20 performs the electric current estimation process which estimates the direct current IDC. Hereinafter, after the control of the starter generator 12 is described, the current estimation process will be described.

  The control device 20 includes a speed calculation unit 21, an applied voltage calculation unit 22, a current estimation unit 23 (corresponding to “current estimation unit”), and an SOC calculation unit 24 (corresponding to “charge rate calculation unit”). The speed calculation unit 21 calculates the rotational speed ω (electrical angular speed) of the starter generator 12 based on the output signal of the magnetic pole position detection sensor 19 (specifically, for example, the interval of the logical inversion timing of the output signal).

  The applied voltage calculation unit 22 calculates each phase applied voltage Vu, Vv, Vw that is a command value of the applied voltage for each phase winding. Hereinafter, the applied voltage calculation unit 22 will be described with reference to FIG. In the applied voltage calculation unit 22, the voltage deviation calculation unit 22 a (corresponding to “voltage deviation calculation unit”) calculates the voltage deviation ΔV by subtracting the battery voltage VDC from the target voltage Vtgt of the battery 14. Phase calculation unit 22b (corresponding to “phase calculation means”) calculates voltage phase δ, which is the phase of output voltage vector Vn of inverter 13, based on voltage deviation ΔV. In the present embodiment, the voltage phase δ is calculated as an operation amount for performing feedback control of the voltage deviation ΔV to 0. Specifically, for example, the voltage phase δ may be calculated by proportional control or proportional integral control using the voltage deviation ΔV as an input. Here, in the present embodiment, the voltage phase δ when the voltage vector Vn rotates clockwise with the positive q axis in the dq coordinate system as a reference is defined as a positive value. In particular, in the present embodiment, rotating the voltage vector Vn clockwise is referred to as retarding the voltage phase δ, and rotating the voltage vector Vn counterclockwise is referred to as advancing the voltage phase δ. I will do it. The voltage amplitude that is the amplitude of the voltage vector Vn is assumed to be “Vamp”.

  The phase calculation unit 22b calculates the voltage phase δ within a range from 0 ° to a specified phase when the starter generator 12 is operated as a generator. The prescribed phase is set to a value larger than 0 ° and smaller than 90 °. In the present embodiment, the prescribed phase is set to 30 ° due to restrictions on the mounting position of the magnetic pole position detection sensor 19 on the stator teeth. However, the prescribed phase is not limited to 30 °, and may be set to other values as long as the value is larger than 0 ° and smaller than 90 °.

  The voltage phase δ calculated by the phase calculation unit 22b is input to the tracking control unit 22c. The follow-up control unit 22c performs a predetermined process on the input voltage phase δ and outputs it. The follow-up control unit 22c will be described in detail later.

  The voltage phase δ output from the tracking control unit 22c is input to the rectangular wave signal generation unit 22d. The rectangular wave signal generation unit 22d is configured to apply each phase applied voltage Vu, Vv, Vw as a rectangular wave signal based on the input voltage phase δ, the battery voltage VDC, and the output signal of the magnetic pole position detection sensor 19 (not shown). Is calculated. Specifically, first, the voltage amplitude Vamp is calculated by multiplying the battery voltage VDC by the voltage utilization rate. Here, the voltage utilization rate is the ratio of the command value of the voltage amplitude Vamp to the battery voltage VDC. In the present embodiment, the voltage utilization rate is set to the upper limit “0.78”. Then, based on the calculated voltage amplitude Vamp and voltage phase δ, each phase applied voltage Vu, Vv, Vw for 180 ° energization is calculated. The rectangular wave signal generation unit 22 d outputs the calculated phase applied voltages Vu, Vv, Vw to the inverter 13.

  Further, the rectangular wave signal generation unit 22d generates a d-axis voltage Vd that is a d-axis component of the voltage vector Vn and a q-axis voltage that is a q-axis component of the voltage vector Vn based on the voltage phase δ and the voltage amplitude Vamp. Vq is calculated.

  Returning to the description of FIG. 2, the current estimating unit 23 calculates the rotational speed ω calculated by the speed calculating unit 21, the battery voltage VDC, and the d and q axis voltages Vd and Vq calculated by the rectangular wave signal generating unit 22d. Is used to estimate the direct current IDC. Hereinafter, the current estimation process performed by the current estimation unit 23 will be described with reference to FIG. In the current estimation unit 23, the dq axis current estimation unit 23a receives the rotation speed ω and estimates the d and q axis currents id and iq based on the following equation (eq1).

上式（ｅｑ１）において、「Ｒａ」は電機子巻線抵抗を示し、「Ｌｄ」，「Ｌｑ」はｄ，ｑ軸インダクタンスを示し、「Ψａ」は誘起電圧定数を示す。上式（ｅｑ１）は、永久磁石同期機の電圧方程式を表す下式（ｅｑ２）に対して、過渡現象を無視するとの条件を課し、ｄ，ｑ軸電流ｉｄ，ｉｑについて変形することで導くことができる。なお、下式（ｅｑ２）において、「ｐ」は微分演算子を示す。

In the above equation (eq1), “Ra” represents an armature winding resistance, “Ld” and “Lq” represent d and q axis inductances, and “Ψa” represents an induced voltage constant. The above equation (eq1) imposes a condition that the transient phenomenon is ignored with respect to the following equation (eq2) representing the voltage equation of the permanent magnet synchronous machine, and is derived by modifying the d and q axis currents id and iq. be able to. In the following equation (eq2), “p” represents a differential operator.

上式（ｅｑ１）において、ｄ，ｑ軸インダクタンスＬｄ，Ｌｑ、巻線抵抗Ｒａ及び誘起電圧定数Ψａは、制御対象とする回転電機の仕様や実験データ等で予め定められた固定値であり、記憶手段としての機器定数記憶部２３ｂ（例えば、不揮発性メモリ）に記憶されている。なお、巻線抵抗Ｒａ及び誘起電圧定数Ψａが温度依存性を有することから、巻線抵抗Ｒａ及び誘起電圧定数Ψａを温度と関係付けたテーブルやマップを予め作成しておき、テーブルやマップを用いて巻線抵抗Ｒａ及び誘起電圧定数Ψａを設定してもよい。

In the above equation (eq1), d, q-axis inductances Ld, Lq, winding resistance Ra, and induced voltage constant Ψa are fixed values determined in advance by the specifications of the rotating electrical machine to be controlled, experimental data, etc. It is memorize | stored in the apparatus constant memory | storage part 23b (for example, non-volatile memory) as a means. Since the winding resistance Ra and the induced voltage constant Ψa are temperature dependent, a table or map relating the winding resistance Ra and the induced voltage constant Ψa to the temperature is created in advance, and the table or map is used. The winding resistance Ra and the induced voltage constant Ψa may be set.

  The direct current estimation unit 23c uses the battery voltage VDC, the d and q axis currents id and iq estimated by the dq axis current estimation unit 23a, and the d and q axis voltages Vd and Vq calculated by the rectangular wave signal generation unit 22d. As an input, the DC current IDC is estimated based on the following equation (eq3).

先の図２の説明に戻り、ＳＯＣ算出部２４は、直流電流推定部２３ｃによって推定された直流電流ＩＤＣの積算値に基づいて、バッテリ１４の充電率ＳＯＣを算出する。算出された充電率ＳＯＣは、例えば車両の各種処理に用いられる。

Returning to the description of FIG. 2, the SOC calculation unit 24 calculates the charging rate SOC of the battery 14 based on the integrated value of the DC current IDC estimated by the DC current estimation unit 23c. The calculated charging rate SOC is used for various processes of the vehicle, for example.

  By the way, when the d-axis current has a positive value, the estimation error ΔIerr of the DC current IDC increases as shown in FIG. Here, FIG. 6 shows changes in the estimated value of the DC current IDC, the measured value of the DC current, the d-axis current id, and the engine speed N. FIG. 6 shows that after time t1, the operating state of the engine 11 shifts to the idle operating state, the d-axis current shifts from a negative value to a positive value, and the estimation error ΔIerr increases. The estimated error ΔIerr increases when the d-axis current is a positive value because the actual d-axis inductance is reduced due to the influence of abrupt magnetic saturation, and the actual d-axis inductance is stored in the device constant storage unit 23b. This is because it greatly deviates from the d-axis inductance Ld. In particular, when the engine rotational speed (the rotational speed of the crankshaft 11a) is in the vicinity of the idle rotational speed, when the voltage phase δ reaches the specified phase, the rotational speed ω of the starter generator 12 is low and the starter generator 12 is induced. Since the voltage is small, the d-axis current becomes a positive value and the estimation error ΔIerr is likely to increase.

  Therefore, in the present embodiment, when the d-axis current becomes a positive value under the situation where the current estimation process is performed, the tracking control unit 22c performs a process for setting the d-axis current to 0. Hereinafter, the reason why the d-axis current can be reduced to 0 with reference to FIG.

  In FIG. 7, the voltage vector when the voltage phase δ becomes the specified phase (30 °) is indicated by “Vn0”, and the voltage vector when the q-axis voltage Vq matches the induced voltage “ω × Ψa” is indicated by “Vn1”. The voltage vector when the voltage phase δ is larger than the voltage vector Vn1 is indicated by “Vn2”. Further, each current vector corresponding to each voltage vector Vn0, Vn1, Vn2 is indicated by “In0, In1, In2”.

  As shown in the figure, the d and q-axis armature reactions occur depending on the positional relationship between the induced voltage vector and the voltage vector. Specifically, when the q-axis component of the voltage vector Vn0 is larger than the induced voltage, the current vector is a current vector In0 in which a positive d-axis current flows due to the d-axis armature reaction. Here, when the q-axis component of the voltage vector Vn1 matches the induced voltage, the d-axis armature reaction disappears, so the current vector becomes a current vector In1 such that the d-axis current becomes zero. In the voltage vector Vn2 whose voltage phase is larger than the voltage vector Vn1, the sign of the d-axis current is inverted, and the current vector becomes a current vector In2 in which a negative d-axis current flows. Thus, the phase of the current vector changes according to the deviation between the q-axis component of the voltage vector and the induced voltage. Using this fact, the d-axis current is set to 0 under the situation where the current estimation process is performed.

  FIG. 8 illustrates processing performed by the tracking control unit 22c. This process is repeatedly executed at a predetermined processing cycle, for example.

  In this series of processes, first, in step S10, it is determined whether or not a clutch meet state is present. If it is determined in step S10 that the clutch meet state is not established (the clutch is disengaged), the process proceeds to step S11 where the calculation rotational speed ωc is set to one combustion cycle (720 ° C. A) of the engine 11 as shown in FIG. ) Is the minimum value ωmin of the rotational speed ω. This process is provided in view of the fact that an estimation error of the direct current IDC is likely to occur in the clutch disengaged state. That is, in the clutch meet state, the rotational shaft of the starter generator 12 is connected to the drive wheels 17, so that the rotational inertia increases and the rotational fluctuation of the starter generator 12 is suppressed. On the other hand, in the clutch disengaged state, the rotating shaft of the starter generator 12 is not connected to the drive wheels 17, so that the rotational inertia is reduced, and the rotation fluctuation of the starter generator 12 accompanying the combustion control of the engine 11 is reduced. growing. For this reason, when the induced voltage “ωc × Ψa” is calculated in step S13, which will be described later, using the rotational speed ω for each time, the calculated induced voltage may be larger than the actual induced voltage. In this case, even if the q-axis voltage Vq follows the calculated induced voltage, the d-axis current cannot be reduced to 0 or less.

  Therefore, in this embodiment, when the clutch is disengaged, the minimum value ωmin of the rotational speed in one combustion cycle of the engine 11 is used for calculation of the induced voltage.

  On the other hand, if it is determined in step S10 that the clutch meet state is reached, the process proceeds to step S12, and the calculation rotational speed ωc is set to the latest rotational speed ωi grasped from the output signal of the magnetic pole position detection sensor 19.

  After completing the processes in steps S11 and S12, the process proceeds to step S13. In step S13, the voltage amplitude Vamp, the calculation rotational speed ωc, the voltage phase δ calculated by the phase calculation unit 22b, and the induced voltage constant ψa stored in the device constant storage unit 23b are input, and the following equation (eq4) Based on the above, an induced voltage deviation INDEX is calculated.

上式（ｅｑ４）において、電圧振幅Ｖａｍｐは、バッテリ電圧ＶＤＣに電圧利用率の上限値「０．７８」を乗算することで算出すればよい。そして、誘起電圧偏差ＩＮＤＥＸが０よりも大きいか否かを判断する。この処理は、ｄ軸電流が０よりも大きいか否かを判断するための処理である。

In the above equation (eq4), the voltage amplitude Vamp may be calculated by multiplying the battery voltage VDC by the upper limit value “0.78” of the voltage utilization rate. Then, it is determined whether the induced voltage deviation INDEX is larger than zero. This process is a process for determining whether or not the d-axis current is larger than zero.

  If an affirmative determination is made in step S13, it is determined that the d-axis current is greater than 0, and the process proceeds to step S14. In step S14, the voltage phase δ is set as an operation amount for feedback-controlling the induced voltage deviation INDEX to 0 on condition that the voltage phase δ is not more than the specified phase while expanding the specified phase from 30 ° to 90 °. calculate. Here, the larger the induced voltage deviation INDEX, the larger the voltage phase δ is calculated. That is, in order to control the q-axis voltage Vq to the induced voltage, the voltage phase δ calculated by the phase calculation unit 22b is corrected. Note that the specified phase after the upper limit expansion is 90 ° because if the voltage phase δ is excessively retarded, the q-axis current decreases and the power generation amount decreases or the d-axis current increases. This is to avoid an increase in loss. Incidentally, in the present embodiment, the processing of this step includes “induced voltage calculation means” and “phase change means”.

  If a negative determination is made in step S13, or if the process of step S14 is completed, the process proceeds to step S15. In step S15, when the voltage phase δ exceeds the guard value α, a guard process for limiting the voltage phase δ with the guard value α is performed. In the present embodiment, as shown in FIG. 10, the guard value α is set to be smaller as the q-axis voltage is larger than the voltage phase when the induced voltage matches the induced voltage and the calculation rotational speed ωc is higher. The guard value α is set to a value of 90 ° or less. This process is a process for avoiding an increase in the q-axis current due to an excessive retardation of the voltage phase δ and an excessive increase in the generated power of the starting generator 12. FIG. 10 shows an example in which the voltage vector is changed from Vn1 to Vn2 by the process of step S14, but the voltage vector is changed to Vn3 by the guard process. In the present embodiment, the processing of this step includes “guard value calculation means”.

  Incidentally, if a negative determination is made in step S13, it is determined that the d-axis current is 0 or less.

  According to the embodiment described in detail above, the following effects can be obtained.

  (1) When the induced voltage deviation INDEX is larger than 0, the q-axis voltage Vq is made to follow the induced voltage “ωc × Ψa”. For this reason, it can be avoided that the actual d-axis inductance greatly deviates from the predetermined d-axis inductance Ld used for current estimation. Thereby, the estimation error of DC current IDC can be suppressed suitably. Therefore, it is possible to avoid a decrease in the calculation accuracy of the charging rate SOC of the battery 14.

  (2) When the induced voltage deviation INDEX is larger than 0, the voltage phase δ calculated by the phase calculating unit 22b is changed while the specified phase is expanded to 90 ° so that the q-axis voltage Vq follows the induced voltage. did. If a restriction is imposed to make the voltage phase equal to or less than the specified phase, the q-axis voltage Vq may not be allowed to follow the induced voltage by operating the voltage phase δ when the d-axis current is greater than 0. . For this reason, in the situation where the d-axis current is larger than 0, the specified phase is expanded to 90 degrees. Thereby, it can avoid that a follow-up is prevented. Here, if the specified phase is expanded beyond 90 °, there is a concern that the power generation efficiency of the starter generator 12 may decrease due to a decrease in power generation due to a decrease in q-axis current and an increase in loss due to an increase in d-axis current. is there. Therefore, a decrease in power generation efficiency can be suppressed by setting the upper limit to 90 °.

  (3) In the clutch disengaged state, the minimum value ωmin of the rotational speed in one combustion cycle of the engine 11 was used for calculating the induced voltage. In the present embodiment, since the clutch is disengaged when the engine 11 is idling, the clutch disengaged state is a state where the induced voltage is low and the fluctuation of the rotational speed is large. Even under this circumstance, the q-axis voltage Vq can be accurately set to the induced voltage or less, and the d-axis current can be set to 0 or less. Thereby, the estimation error of the direct current IDC can be accurately suppressed even before the clutch meet.

  (4) The voltage phase δ is limited by the guard value α. For this reason, it is possible to prevent an excessive retardation of the voltage phase δ and, in turn, avoid an excessive increase in generated power.

(Other embodiments)
The above embodiment may be modified as follows.

  In the above embodiment, the follow-up control unit 22c calculates the induced voltage deviation INDEX and determines that the d-axis current is larger than 0 when the calculated induced voltage deviation INDEX is larger than 0. However, the present invention is not limited to this. . For example, the follow-up control unit 22c may determine whether the d-axis current id estimated by the dq-axis current estimation unit 23a is larger than 0, or the induced voltage deviation INDEX or the d-axis current id is 0. It may be determined whether the value is larger than the value exceeding.

  The starter / generator 12 is not limited to a permanent magnet type synchronous machine, and may be a field winding type synchronous machine having a field winding on a rotor, for example. The starter generator 12 is not limited to the Y-connected one, and may be a Δ-connected one, for example.

  The clutch 16 is not limited to an automatic centrifugal clutch, and may be an intermittent clutch configured to be switchable between a clutch meet state and a clutch disengaged state by a user's clutch lever operation, for example.

  The driving method of the starter generator 12 is not limited to the three-phase 180 ° energization method, and may be another energization method such as a three-phase 120 ° energization method.

  The voltage usage rate used in the rectangular wave signal generation unit 22d of FIG. 4 is not limited to the upper limit value, and may be a value less than the upper limit value.

  In step S14 of FIG. 8, the voltage phase δ may be changed so that the induced voltage deviation INDEX is feedback-controlled to a specified value that is not zero. That is, the voltage phase δ may be changed so that the d-axis current is a specified current less than a specified value.

  If the negative determination is made in step S13 of FIG. 8, the voltage phase δ calculated by the phase calculation unit 22b may be input to the rectangular wave signal generation unit 22d as it is.

  In each of the above embodiments, the rotational speed used for calculating the induced voltage may be calculated as follows. Specifically, for each combustion cycle (720 ° CA) of the engine 11, the rotation speed when the rotation angle position of the crankshaft 11a becomes a preset rotation angle position (hereinafter referred to as a rotation speed at a predetermined angle position) is calculated. To do. Then, based on the calculated rotational speed at the predetermined angular position and the minimum value of the rotational speed of one combustion cycle determined in advance by experiments or the like, the minimum rotational speed value ωmin used for calculating the induced voltage is calculated. Also good. Specifically, for example, the difference or deviation value between the rotational speed at the predetermined angular position and the minimum value of the rotational speed determined in advance through experiments or the like is calculated, and the rotational speed at the predetermined angular position is calculated based on the calculated difference or deviation value. The minimum value ωmin may be calculated by correction.

  In each of the above embodiments, the minimum value ωmin of the rotational speed in one combustion cycle of the engine 11 is used for calculation of the induced voltage. However, the present invention is not limited to this, for example, the rotational speed ω immediately before or after the minimum value ωmin. Alternatively, a rotational speed ω slightly higher than the minimum value ωmin may be used.

  -The power conversion circuit is not limited to a three-phase inverter. In short, any other power conversion circuit may be used as long as it is a power conversion circuit that can convert the AC voltage output from the starter generator 12 into a DC voltage and apply it to the battery 14.

  The application target of the present invention is not limited to a motorcycle, but may be other vehicles such as an automobile.

  DESCRIPTION OF SYMBOLS 12 ... Starter generator, 13 ... Inverter, 14 ... Battery, 20 ... Control apparatus.

Claims (6)

Applied to a system including a power conversion circuit (13) and a rotating electrical machine (12) that performs power transmission with a DC power source (14) by energization operation to the power conversion circuit;
Current estimation means for estimating a current flowing between the DC power source and the power conversion circuit based on a predetermined d-axis inductance of the rotating electrical machine;
The q-axis component of the voltage vector of the power conversion circuit follows the induced voltage component of the rotating electrical machine on condition that the d-axis current in the dq coordinate system of the rotating electrical machine becomes a predetermined value larger than 0. A current estimation apparatus comprising: phase operation means for operating a voltage phase which is a phase of a voltage vector. defining the voltage phase as a positive value when the voltage vector rotates clockwise with respect to the positive q-axis in the dq coordinate system;
The phase operation means includes
A phase calculating means for calculating the voltage phase for controlling the rotating electrical machine on condition that the voltage phase is set to be equal to or less than a specified phase that is greater than 0 ° and smaller than 90 °;
On the condition that the d-axis current becomes the predetermined value, the phase calculation unit calculates the q-axis component of the voltage vector while expanding the prescribed phase to 90 ° in order to follow the induced voltage component. The current estimation apparatus according to claim 1, further comprising phase changing means for changing the voltage phase. A guard value that is larger than the prescribed phase and set to 90 ° or less, and is set larger when the rotational speed of the rotating electrical machine is lower than when the rotational speed of the rotating electrical machine is high is calculated. A guard value calculating means;
The current estimation apparatus according to claim 2, wherein the phase changing unit changes the voltage phase with the guard value as an upper limit. The system can transmit power between an engine (11) as an in-vehicle main machine, drive wheels (17) connected to the engine output shaft (11a), and the engine output shaft and the drive wheels. And a clutch (16) configured to be switchable to any one of a state where the power between the output shaft of the engine and the driving wheel is cut off, and mounted on a vehicle (10),
The rotating shaft of the rotating electrical machine is directly connected to the output shaft of the engine,
The phase operating means is a rotational speed of the rotary shaft, provided that the clutch is in the disengaged state, and a rotational speed in the vicinity of a minimum value of the rotational speed in one combustion cycle of the engine. 4. The method according to claim 1, further comprising: an induced voltage calculation unit configured to calculate the induced voltage component based on the voltage phase, and operating the voltage phase so that the calculated induced voltage component follows the q-axis component of the voltage vector. The current estimation device according to claim 1.   The current estimation apparatus according to claim 4, wherein the vehicle is a motorcycle. The phase operation means includes
Voltage deviation calculating means for calculating a deviation between the voltage of the DC power supply and the target voltage;
Phase calculating means for calculating the voltage phase as an operation amount for performing feedback control of the voltage deviation to 0 on condition that the voltage phase is set to be equal to or smaller than a specified phase which is greater than 0 ° and smaller than 90 °; Including
The current estimation apparatus according to claim 1, further comprising a charge rate calculation unit that calculates a charge rate of the DC power source based on the current estimated by the current estimation unit.

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