JP5784553B2 - Power converter - Google Patents

Description

  The present invention relates to a power converter that transmits power from one of a first DC voltage source and a second DC voltage source to the other.

  For example, in the following Patent Document 1, in a vehicle including a main unit battery that stores electric energy supplied to a rotating machine as an in-vehicle main unit and an auxiliary battery that stores electric energy supplied to the in-vehicle auxiliary unit, A device including a step-down converter for stepping down a voltage and applying it to an auxiliary battery is described. According to this, the electric energy of the main battery can be charged to the auxiliary battery by operating the step-down converter.

Japanese Examined Patent Publication No. 7-57041

  By the way, in the above case, it is necessary to provide a step-down converter for transmitting electric power from the main battery to the auxiliary battery, resulting in an increase in the number of parts. Furthermore, when power is transmitted from the auxiliary battery to the main battery, it is necessary to provide a boost converter.

  The present invention has been made in the process of solving the above-described problems, and an object thereof is to provide a new power conversion device that transmits power from one of the first DC voltage source and the second DC voltage source to the other. There is to do.

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

  According to the first aspect of the present invention, there is provided a rotating machine (10) including two sets of a plurality of stator windings connected to each other, and a first DC voltage source ( 20) a first DC / AC converter circuit (INV1) having a switching element (S ¥ # 1) connected to each of the positive electrode and the negative electrode, and a second of the two sets of the stator windings. The DC voltage source (22) is applied to a system including a second DC / AC converter circuit (INV2) including a switching element (S ¥ # 2) connected to each of a positive electrode and a negative electrode of the DC voltage source (22). Either between the negative side DC bus and the negative side DC bus of the second DC / AC converter circuit, or between the positive side DC bus of the first DC / AC converter circuit and the positive side DC bus of the second DC / AC converter circuit Are each other An open / close means (24) connected to open and close between the first set and the second set; and in a situation where driving of the rotating machine is stopped, the open / close means is closed and the first set Operating means (30) for operating the first DC / AC converter circuit and the second DC / AC converter circuit to control transmission of electrical energy from one DC voltage source and the second DC voltage source to the other; And the operating means energizes part of the first set of stator windings and part of the second set of stator windings to transfer energy stored in either one of the stator windings. The phase difference in electrical angle between a part of the first set of stator windings and a part of the second set of stator windings is stored in a line and the energy is charged to one of the other. Part of the first set of stator windings and the second Wherein the smaller than the phase difference of other than the part of the stator winding.

  In the above invention, a rotating machine having a first set of stator windings and a second set of stator windings is used, and the electric power from one of the first DC voltage source and the second DC voltage source to the other is used. Transmission control can be performed. In addition, at this time, by using only a part of each stator winding, the inductance of the inductor used for power transmission can be increased as compared with the case of using all of the stator windings. For this reason, a ripple current can be reduced. Furthermore, it becomes easy to fix the rotor by reducing the phase difference between the first set and the second set to be energized.

  In addition, about the expansion of the concept regarding the following typical embodiment concerning this invention, it describes in the column of "other embodiment" after typical embodiment.

1 is a system configuration diagram according to a first embodiment. FIG. The flowchart which shows the procedure of the transmission control of the electric power concerning the embodiment. The figure which shows the said transmission control aspect. The circuit diagram which shows the said transmission control aspect. The circuit diagram which shows the said transmission control aspect. The figure which shows the effect of the said embodiment. The time chart which shows the switching control concerning 2nd Embodiment. The time chart which shows the switching control concerning the modification of the said embodiment. The time chart which shows the switching control concerning the modification of the said embodiment.

<First Embodiment>
Hereinafter, a first embodiment in which a power conversion device according to the present invention is applied to a mild hybrid vehicle will be described with reference to the drawings.

  The motor generator 10 shown in FIG. 1 has a rotor mechanically connected to drive wheels and a crankshaft of an internal combustion engine. The motor generator 10 plays a role as an initial rotation applying means for applying an initial rotation to the internal combustion engine, a role as a torque assist means at the time of starting and acceleration of the vehicle, and a role as a power generating means at the time of regeneration. .

  The motor generator 10 includes a field winding 12, a first set of stator windings wu 1, wv 1, ww 1 and a second set of stator windings wu 2, wv 2, ww 2. The first set of stator windings wu1, wv1, and ww1 are connected to each other at a neutral point, and the second set of stator windings wu2, wv2, and ww2 are also connected to each other at a neutral point. The first set of stator windings wu1, wv1, and ww1 are out of phase with each other by “120 °” in terms of electrical angle, and the second set of stator windings wu2, wv2, and ww2 are also “ 120 ° "phase is shifted. In this embodiment, the phase difference between each of the first set of stator windings wu1, wv1, and ww1 and each of the second set of stator windings wu2, wv2, and ww2 is 30 °.

  The first set of stator windings wu1, wv1, and ww1 are connected to a first DC voltage source (first battery 20) via a first DC / AC conversion circuit (first inverter INV1). The first inverter INV1 includes three sets of series connection bodies of a switching element S ¥ p1 (¥ = u, v, w) and a switching element S ¥ n1. These series-connected bodies are connected in parallel to the first battery 20, and the connection point between the switching element S ¥ p1 and the switching element S ¥ n1 is connected to the stator winding w ¥ 1.

  The second set of stator windings wu2, wv2, and ww2 are connected to a second DC voltage source (second battery 22) via a second DC / AC conversion circuit (second inverter INV2). The second inverter INV2 includes three sets of series connection bodies of the switching element S ¥ p2 (¥ = u, v, w) and the switching element S ¥ n2. These series-connected bodies are connected in parallel to the second battery 22, and the connection point between the switching element S ¥ p2 and the switching element S ¥ n2 is connected to the stator winding w ¥ 2.

  In the present embodiment, MOS field effect transistors are assumed as the switching elements S ¥ # 1, S ¥ # 2 (¥ = u, v, w: # = p, n). In the figure, diodes D ¥ # 1 and D ¥ # 2 connected in reverse parallel to the switching elements S ¥ # 1 and S ¥ # 2 are body diodes.

  The first battery 20 is higher in open circuit voltage at the same charging rate than the second battery 22. In particular, in the present embodiment, it is assumed that the terminal voltage of the first battery 20 is about four times the terminal voltage of the second battery 22. Specifically, for example, the terminal voltage of the first battery 20 is assumed to be about “48V”, and the terminal voltage of the second battery 22 is assumed to be about “12V”. This is because the second battery 22 is assumed to be a normal auxiliary battery.

  In accordance with the setting of the terminal voltage, in this embodiment, the number of turns N1 of the first set of stator windings wu1, wv1, and ww1 is larger than the number of turns N2 of the second set of stator windings wu2, wv2, and ww2. doing. In particular, in the present embodiment, it is assumed that the number of turns N1 is four times the number of turns N2.

  The neutral point of the first set of stator windings and the neutral point of the second set of stator windings are connected to each other via a relay 24. The relay 24 is an electronically operated opening / closing means for opening / closing an electrical path connecting the pair of neutral points.

  The field winding 12 can be supplied with power from the first battery 20 via the regulator 14. The regulator 14 includes a brush and is means for energizing the field winding 12 through the brush. Further, the negative-side DC buses Ln1 and Ln2 of the first inverter INV1 and the second inverter INV2 are connected to each other.

  The control device 30 is a control device that controls the motor generator 10 and uses the torque of the motor generator 10 as a control amount. That is, the control device 30 receives the detection value of the rotation angle sensor 32 that detects the rotation angle (electrical angle θ) of the rotor of the motor generator 10 as an input, and switches the switching element S ¥ # 1 (¥ = u, v, w; # = p, n), and the operation signal g ¥ # 2 of the switching element S ¥ # 2 of the second inverter INV2 is generated and output, so that the first inverter INV1 or The second inverter INV2 is operated.

  Specifically, for example, in order to apply initial rotation to the internal combustion engine, the motor generator 10 is controlled by powering the first set of stator windings wu1, wv1, and ww1, or torque assist processing during acceleration is performed. The motor generator 10 is subjected to power running control by energizing the first set of stator windings wu1, wv1, ww1. At this time, when the charging rate of the second battery 22 is large, the second set of stator windings wu2, wv2, and ww2 may be energized. Furthermore, during regenerative control, load torque is generated, and the current flowing through the first set of stator windings wu1, wv1, and ww1 is collected in the first battery 20. At this time, depending on the charging rate of the second battery 22, a process of collecting the current flowing in the second set of stator windings wu2, wv2, and ww2 in the second battery 22 may be performed.

  In addition, the control device 30 is also a control device in which the first battery 20 and the second battery 22 are controlled, and the charging rate is a control amount. This is because the relay 24 is in a closed state, via a part of the first set of stator windings w ¥ 1 (¥ = u, v, w) and a part of the second set of stator windings w ¥ 2. The process of transmitting power from one of the first battery 20 and the second battery 22 to the other is performed. Incidentally, the relay 24 is in an open state, for example, during powering control of the motor generator 10.

  FIG. 2 shows the procedure of this process. This process is repeatedly executed by the control device 30 at a predetermined cycle, for example.

  In this series of processes, first, in step S10, it is determined whether or not the vehicle is stopped. This process is for determining whether or not a permission condition for controlling transmission of power from one of the first battery 20 and the second battery 22 to the other is satisfied. When an affirmative determination is made in step S10, it is determined in step S12 whether there is a charge request for the first battery 20 or the second battery 22. In other words, it is determined whether or not there is a request for the transmission control. If an affirmative determination is made in step S12, the operation signal m1 of the relay 24 is set as a closing operation command in step S14.

  In the subsequent step S16, the electrical angle θ is detected. In step S18, the first set of stator windings w ¥ 1 (¥ = u, v, w) and the second set of stator windings w ¥ 2 are determined to be energized. In this embodiment, the number of energization targets (here, “2”) in the first set of stator windings w ¥ 1 is the number of energization targets in the second set of stator windings w ¥ 2. It is larger than the number (here, “1”). This is because the winding resistance of the first set of stator windings w ¥ 1 is greater than the winding resistance of the second set of stator windings w ¥ 2. Here, the winding resistance of the first set of stator windings w ¥ 1 increases because the number of turns N1 is larger than the number of turns N2, but the first set of stator windings w ¥ 1 and second windings. This is a result of making the accommodation space the same for the pair of stator windings w ¥ 2.

  Furthermore, in this embodiment, the phase difference between the energization target of the first set of stator windings w ¥ 1 and the energization target of the second set of stator windings w ¥ 2 is minimized, and these energizations The energization target is selected so that the phase difference between the target and the d-axis is minimized. That is, for example, as shown in FIG. 3A, the magnetic flux direction of the field (d-axis direction) is between the first set of V phases (V1) and the second set of U phases (U2). The first set of U phase (U1) and V phase (V1) and the second set of U phase (U2) are energized. That is, the phase difference between the first set of U phases (U1) and the second set of U phases (U2), and the phase difference between the first set of V phases (V1) and the second set of U phases (U2). Is smaller than the case where the second set of stator windings to be energized is the V-phase stator winding vv2 or the W-phase stator winding ww2.

  Here, reducing the phase difference between the first set of energization targets and the second set of energization targets is a setting for fixing the rotor satisfactorily. That is, since directivity can be imparted to the composite vector in the energization direction, the rotor can be fixed at an angle at which the direction of the composite vector in the energization direction matches the d-axis direction. On the other hand, for example, when the phase difference is large, it is difficult to provide directivity in the energization direction, and it is difficult to fix the rotor.

  The reason why the phase difference between the energization target and the d-axis is minimized is to minimize the amount of displacement of the rotor. This is because the angle at which the direction of the combined vector in the energization direction coincides with the d-axis direction is the angle at which the rotor is fixed.

  By the way, by setting the first set of energization targets and the second set of energization targets as part of the first set and the second set, respectively, the inductance of the energized inductor can be increased, and as a result, the ripple current Can also be reduced.

  In step S20 shown in FIG. 2, the on-time ratio (Duty) for one cycle of the on / off operation of the switching element S ¥ p1 on the first inverter INV1 side is set, and the first inverter INV1 and the second inverter The inverter INV2 is operated. At this time, the energization process of the field winding 12 is also performed.

  FIG. 3B shows a switching control mode in the case where the rotor stop position is that shown in FIG. As illustrated, in this case, the switching element Sup1 and the switching element Sun1 of the first inverter INV1 are complementarily driven, and the switching element Svp1 and the switching element Svn1 are complementarily driven. Further, the switching element Sup2 of the second inverter INV2 is always turned on.

  As a result, when power transmission control is performed from the first battery 20 to the second battery 22, as shown in FIG. 4 (a), during the period in which the switching elements Sup1 and Svp1 are turned on, Current flows through the second battery 22 via the windings wu1, wv1 and the stator winding wu2, and the energy stored in the stator windings wu1, wv1 and the stator winding wu2 gradually increases. On the other hand, when the switching elements Sup1, Svp1 are turned off and the switching elements Sun1, Svn1 are turned on, as shown in FIG. 4B, the stator windings wu1, wv1, the stator windings A current flows through a loop path including wu2, the second battery 22, and the switching elements Sun1 and Svn1, and energy stored in the stator windings wu1 and wv1 and the stator winding wu2 is gradually reduced.

  On the other hand, when power transmission control is performed from the second battery 22 to the first battery 20, as shown in FIG. 5A, the second battery 22 and the stator windings are turned on during the period when the switching elements Sun 1 and Svn 1 are turned on. A current flows through a loop path including the line wu2, the stator windings wu1 and wv1, and the switching elements Sun1 and Svn1, and the energy stored in the stator windings wu1 and wv1 and the stator winding wu2 gradually increases. On the other hand, when the switching elements Sun1, Svn1 are turned off and the switching elements Sup1, Svp1 are turned on, as shown in FIG. 5 (b), the stator winding wu2, A current flows through the first battery 20 via the stator windings wu1 and wv1, and the energy stored in the stator windings wu1 and wv1 and the stator winding wu2 gradually decreases.

  Here, regarding the converter constituted by the first inverter INV1 and the second inverter INV2, the voltage on the second battery 22 side is set as the output voltage Vout, the voltage on the first battery 20 side is set as the input voltage Vin, and the switching element Sup1, When the time ratio D of the time when Svp1 is turned on is used, the following expression (c1) is established.

(Vin−Vout) · D = Vout (1−D) (c1)
When the above formula (c1) is modified, the following formula (c2) is obtained.

Vout = D · Vin (c2)
For this reason, when the relationship of “Vb <D · Va” is established between the terminal voltage Va of the first battery 20 and the terminal voltage Vb of the second battery 22, as shown in FIG. Electric power is transmitted from one battery 20 to the second battery 22. On the other hand, when the relationship of “Vb> D · Va” is established, power is transmitted from the second battery 22 to the first battery 20 as shown in FIG.

  In a succeeding step S22, it is determined whether or not the charging is completed. This may be determined, for example, as to whether or not the charging rate on the charging side is equal to or greater than a threshold value. When the charging is completed, in step S24, the switching operation is stopped and the operation signal m1 is switched to the opening operation command, whereby the neutral point of the first set of stator windings v ¥ 1 and the second set of stators are switched. A path connecting the neutral point of the winding v ¥ 2 is opened.

  When the process of step S24 is completed or when a negative determination is made in steps S10 and S12, this series of processes is temporarily terminated.

  FIG. 6 shows the effect of this embodiment in comparison with the comparative example. Here, in the comparative example, only one set of stator windings is provided, and a separate battery is connected to each of the neutral point and the input terminal of the inverter. It is an example which transmits electric power between the battery connected and the battery connected to the input terminal of the inverter.

  As shown in the figure, in this embodiment, the inductance of the inductor used for power transmission control is larger than that in the comparative example. This is realized by limiting the energization target to a part of the stator windings v ¥ 1, v ¥ 2. As a result, the ripple current is reduced, and consequently the switching noise is reduced.

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

  (1) A part of the first set of stator windings v ¥ 1 and a part of the second set of stator windings v ¥ 2 are energized, and either from the first battery 20 or the second battery 22 On the other hand, power transmission was controlled. Thereby, it is not necessary to provide a dedicated converter in order to control transmission of power from one of the first battery 20 and the second battery 22 to the other.

  (2) The phase difference between part of the first set of stator windings v ¥ 1 to be energized and part of the second set of stator windings v ¥ 2 to be energized is The phase difference between a part of the first set of stator windings v ¥ 1 and the second set of stator windings v ¥ 2 other than the energization target is made smaller. Thereby, directivity can be given to the energization direction, and it becomes easy to fix the rotor by transmission control.

  (3) On the second battery 22 side where the terminal voltage is low, the switching element S ¥ p2 of the upper arm is fixed to the ON state, and the upper and lower arms are driven complementarily on the first battery 20 side. Thereby, the operation of a known step-up / step-down chopper circuit can be simulated.

  (4) The stator windings v ¥ 1, v ¥ 2 to be energized are selected so that the phase difference from the d axis is the smallest. As a result, the amount of displacement of the rotor can be reduced during transmission control.

(5) On the first battery 20 side with a high terminal voltage, the number of stator windings v ¥ 1 to be energized is larger than that on the second battery 22 side with a low terminal voltage. As a result, the combined resistance of the stator winding v ¥ 1 to be energized can be suitably reduced in a situation where the stator winding v ¥ 1 has a larger resistance than the stator winding v ¥ 2.
Second Embodiment
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In this embodiment, the number of stator windings v ¥ 1, v ¥ 2 to be energized during transmission control is one in each of the first set and the second set.

  FIG. 7 illustrates a switching control mode for transmission control according to the present embodiment. In the figure, the U-phase upper arm switching element Sup1 and the lower arm switching element Sun1 of the first inverter INV1 are complementarily driven, and the U-phase upper arm switching element Sup2 and the lower arm of the second inverter INV2. An example of complementary driving of the switching element Sun2 is shown. Here, one cycle of ON / OFF of the switching element Sup1 of the first inverter INV1 and one cycle of ON / OFF of the switching element Sup2 of the second inverter INV2 are set to be equal to each other.

  In the figure, the left side shows a case where the on-time time ratio D1 with respect to one cycle of the first inverter INV1 is larger than the on-time time ratio D2 with respect to one cycle of the second inverter INV2. Illustrate. In this case, the ratio of the time when the voltage applied to the stator windings vu1, vu2 is “Va−Vb” is the time ratio D2, the ratio of the time when the voltage is “Va” is “D1-D2”, and “0”. The ratio of the time becomes “1-D1”. Here, in the converter constituted by the first inverter INV1 and the second inverter INV2, when the second battery 22 side is the output voltage Vout and the first battery 20 side is the input voltage Vin, the following expression (c3) is established. To do.

Vout = (2D2-D1) · Vin / D2 (c3)
Therefore, in the case of “Vb <(2D2-D1) · Va / D2”, power is transmitted from the first battery 20 to the second battery 22, and in the case of “Vb> (2D2-D1) · Va / D2”, Power is transmitted from the second battery 22 to the first battery 20.

  On the other hand, on the right side of the figure, the on-time time ratio D2 with respect to one on / off cycle of the second inverter INV2 is larger than the on-time time ratio D1 with respect to one cycle of the first inverter INV1. The case is illustrated. In this case, the ratio of the time when the voltage applied to the stator windings vu1, vu2 is “Va−Vb” is the time ratio D1, the ratio of the time when the voltage is “Vb” is “D2-D1”, and “0”. The ratio of time to become “1-D2”. Here, in the converter constituted by the first inverter INV1 and the second inverter INV2, when the second battery 22 side is the output voltage Vout and the first battery 20 side is the input voltage Vin, the following equation (c4) is established. To do.

Vout = D1 · Vin / D2 (c4)
Therefore, when “Vb <D1 · Va / D2”, electric power is transmitted from the first battery 20 to the second battery 22, and when “Vb> D1 · Va / D2”, the second battery 22 transmits the first battery. Power is transmitted to 20.

Thus, in this embodiment, the time ratio D1 of the on time with respect to one cycle of on / off of the first inverter INV1 and the time ratio D2 of the on time with respect to one cycle of on / off of the second inverter INV2 are two. One parameter determines the relationship between the input voltage and the output voltage. Therefore, the degree of freedom of voltage control is improved.
<Other embodiments>
Each of the above embodiments may be modified as follows.

"About duty ratio control for transmission control"
The switching element S ¥ p1 of the upper arm of the first inverter INV1 and the switching element S ¥ n1 of the lower arm are complementarily driven, and the switching element S ¥ p2 of the upper arm of the second inverter INV2 and the switching of the lower arm Complementary driving of the element S ¥ n2 is not limited to that exemplified in the second embodiment (FIG. 7). For example, as illustrated in FIG. 8, the phases of the first inverter INV1 and the second inverter INV2 may be shifted. Even in this case, if one switching cycle is the same in the first inverter INV1 and the second inverter INV2, the output voltage is determined by the ratio of each state in this cycle. That is, in the example shown in FIG. 8, the time ratio D1 of the period when the voltage applied to the stator winding is “Va−Vb”, the time ratio D2 of the period of “Va”, and the period of “Vb”. The output voltage is determined by the time ratio D3 and the time ratio D4 of the period of “0”.

  The time ratio control after grasping the magnitude relationship between the terminal voltage of the first DC voltage source and the terminal voltage of the second DC voltage source is not limited to that exemplified in the first embodiment (FIG. 3). . For example, it may be illustrated in FIG. FIG. 9 shows periodically the switching element Sup1 of the upper arm of the first inverter INV1 corresponding to the one with the higher terminal voltage and the switching element Sun2 of the lower arm of the second inverter INV2 corresponding to the one with the lower terminal voltage. An example of on / off operation is shown. Here, in the converter constituted by the first inverter INV1 and the second inverter INV2, when the first battery 20 side is the input voltage Vin, the time ratio D1 of the time when the switching element Sup1 of the upper arm is turned on and the lower side The relationship of “Vout = D1 · Vin / (1−D2)” is established by the time ratio D2 of the time when the switching element Sun2 of the arm is turned on. This relationship is established regardless of the switching phase as long as “D2 ≦ D1”.

  However, the ON / OFF cycle of the first inverter INV1 and the ON / OFF cycle of the second inverter INV2 are not necessarily the same. For example, when one cycle is N (> 1) times the other cycle, the relationship between the input voltage and the output voltage depending on the time ratio of the state defined for each applied voltage of the stator winding in one cycle Therefore, it is possible to perform power transmission control based on this.

“About stator windings that are energized for transmission control”
It is not restricted to what was illustrated in said each embodiment. For example, in the case where there are five first sets of stator windings connected to each other at neutral points, three of them may be energized. Further, for example, in each of the first group and the second group, there are five stator windings, the number of energization targets in the first group is 3, and the number of energization targets in the second group is 1, 2, or Three may be used.

  In the above embodiment, the accommodation spaces of the first set of stator windings wu1, wv1, and ww1 and the second set of stator windings wu2, wv2, and ww2 are equal to each other. However, the present invention is not limited to this. For example, the accommodation space on the side where the number of turns is large (the first set of stator windings wu1, wv1, ww1) may be relatively large. In this case, the resistance of the stator winding can be the same in the first set and the second set. In this case, in the first embodiment, the motivation for increasing the number of stator windings to be energized with the larger number of turns disappears.

“About the phase difference in the electrical angle of the stator windings that are energized during transmission control”
For example, there are five stator windings in both the first set and the second set, the number of energization targets in the first set is 3, and the number of energization targets in the second set is 3. However, the definition of the phase difference can be applied by extending the concept described in the above embodiment. That is, in this case, for each of the second set of stator windings to be energized, an average value thereof is calculated for the phase difference from each of the first set of stator windings to be energized, and these average values are calculated. The average of the second set of stator windings to be energized may be smaller than when the first set of stator windings to be energized is changed.

"First DC voltage source and second DC voltage source"
The magnitude | size of a terminal voltage is not restricted to what was illustrated in the said embodiment, and is not restricted to the structure which uses one as an auxiliary battery.

  The open-circuit voltages at the same charging rate are not limited to different from each other, and may be the same except for individual differences.

"About rotating machines"
The field winding is not limited to being excited by the power of the first battery 20, but may be excited by the power of the second battery 22.

  Means for exciting the field winding is not limited to one having a path connecting the DC voltage source and the field winding. For example, the magnetic flux generated by the current flowing in the stator winding may be one in which an exciting current flows due to a change in interlinkage magnetic flux interlinking the field winding (winding field type synchronous machine).

  For example, a permanent magnet may be provided.

  Note that the number of stator windings having neutral points connected to each other is not limited to “3”, as described in the section “About stator windings to be energized for transmission control”.

“About the first DC / AC converter circuit and the second DC / AC converter circuit”
The switching element is not limited to one using a MOS field effect transistor. For example, an insulated gate bipolar transistor (IGBT) may be provided. In this case, a diode is connected in antiparallel to the IGBT. Even with such a configuration, if an IGBT and a diode are provided on the same semiconductor substrate, it can be applied to the first embodiment (FIG. 3). That is, in this case, it is known that the on-resistance of the diode increases when the IGBT is turned on. Therefore, instead of turning on the switching element Sup2 of the second inverter INV2 in the example illustrated in FIG. 3, the switching elements Svp2 and Swp2 may be turned on. As a result, the on-resistances of the diodes Dvp2 and Dwp2 are larger than the on-resistance of the diode Dup2, so that the diode Dup2 can be selectively energized.

“Connection between the first DC / AC converter circuit and the second DC / AC converter circuit”
In the said embodiment (FIG. 1), although negative electrode side DC bus-line Ln1, Ln2 was connected, you may connect not only this but positive-side DC bus line Lp1, Lp2. In this case, for example, the previous example of FIG. 3 in the first embodiment may be changed so that the switching element Sun2 of the second inverter INV2 is always turned on.

“About stator winding arrangement”
The setting is not limited to the case where the phase difference between the first set of stator windings and the second set of stator windings adjacent thereto is “30 °”.

"Connection of stator winding"
It is not limited to those connected to each other at neutral points. For example, a delta connection may be used. In this case, although it is not easy to change the energization direction according to the magnetic flux direction of the field, setting is made to reduce the phase difference between the energization targets of the stator winding w ¥ 1 and the stator winding w ¥ 2. It is possible to achieve the effects described above.

  DESCRIPTION OF SYMBOLS 10 ... Motor generator, 20 ... 1st battery, 22 ... 2nd battery, 30 ... Control apparatus (one Embodiment of an operation means).

Claims (6)

A rotating machine (10) comprising two sets of a plurality of stator windings connected to each other;
A first DC / AC converter circuit including a switching element (S ¥ # 1) that connects each of the first set of stator windings of the two sets to the positive electrode and the negative electrode of the first DC voltage source (20). INV1)
A second DC / AC conversion circuit including a switching element (S ¥ # 2) that connects each of the second set of stator windings of the two sets to the positive electrode and the negative electrode of the second DC voltage source (22). INV2), and
Between the negative-side DC bus of the first DC-AC converter and the negative-side DC bus of the second DC-AC converter, the positive-side DC bus of the first DC-AC converter, and the positive of the second DC-AC converter Either of the side DC bus is connected to each other,
Opening and closing means (24) for opening and closing between the first set and the second set;
In a situation where driving of the rotating machine is stopped, the opening / closing means is closed, and the first DC voltage source and the second DC voltage source are controlled to transmit electric energy from one of the first DC voltage source and the second DC voltage source to the other. Operating means (30) for operating one DC / AC converter circuit and the second DC / AC converter circuit,
The operation means energizes a part of the first set of stator windings and a part of the second set of stator windings to transfer the energy stored in either one of the stator windings to the one part of the stator windings. Storing and charging the energy to one of the other,
The phase difference in the electrical angle between a part of the first set of stator windings and a part of the second set of stator windings is determined by a part of the first set of stator windings and the second set of stators. A power conversion device characterized in that the phase difference is smaller than a part of the winding other than the part.   The operation means includes an operation target for the transmission control among the switching elements constituting the first DC / AC conversion circuit, and an operation for the transmission control among the switching elements constituting the second DC / AC conversion circuit. 2. The power conversion device according to claim 1, wherein one cycle of on / off of one of the targets is set to an integer multiple of one cycle of the other on / off.   In the one of the one cycle, the operation means determines a voltage value applied to the stator winding as a terminal voltage of the first DC voltage source, a terminal voltage of the second DC voltage source, and the first DC voltage. 3. The power converter according to claim 2, wherein at least three of a differential pressure between a terminal voltage of a voltage source and a terminal voltage of the second DC voltage source and zero are used. The first DC voltage source has a larger open end voltage at the same charging rate than the second DC voltage source,
The switching element of the second DC / AC converter circuit is a MOS field effect transistor,
The switching means includes a switching element on a positive side of the first DC voltage source and a negative electrode for a switching element that constitutes the first DC / AC conversion circuit and is connected to a part of the stator windings of the first set. The second DC voltage among the switching elements that constitute the second DC / AC conversion circuit and are connected to a part of the stator windings of the second set. The power conversion device according to claim 1, wherein the switching element on the positive electrode side of the source is turned on. The first set of stator windings are connected at a neutral point;
The second set of stator windings are connected at a neutral point,
The opening / closing means opens and closes between the neutral point of the first set and the neutral point of the second set,
Under a situation where the driving of the rotating machine is stopped, an acquisition means for acquiring information on the rotation angle of the rotor of the rotating machine,
The operation means includes selection means for selecting, as the stator winding to be energized, the one having the smallest phase difference from the field direction of the rotating machine based on the information on the rotation angle. The power converter device of any one of Claims 1-4. The first DC voltage source has a larger open end voltage at the same charging rate than the second DC voltage source,
6. The power conversion according to claim 1, wherein the number of the first set of stator windings to be energized is greater than the number of the second set of stator windings. apparatus.

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