Power converter

Abstract

Power converter for converting electrical power of a three-phase electric rotary machine (80) including a first winding set (81) and a second winding set (82), the power converter comprising: a first inverter (10) corresponding to the first winding set; a second inverter (20) corresponding to the second winding set; and a control unit (41, 42, 43) including a command calculation unit (52 to 54, 62, 63) that calculates a first voltage command value with respect to a voltage to be applied to the first winding set and a second voltage command value with respect to a voltage to be applied to the second winding set, and an excess correction unit (552) that corrects a value corresponding to a first voltage command that corresponds to the first voltage command value and a value corresponding to a second voltage command that corresponds to the second voltage command value.wherein: if one of the values ​​corresponding to a first voltage command and the other of the values ​​corresponding to a second voltage command exceeds a limit value set according to a voltage that can be output, the excess correction unit performs excess correction processing to correct the other of the values ​​corresponding to a first voltage command and the other of the values ​​corresponding to a second voltage command according to an excess amount above the limit value.

Description

[0001] The present disclosure relates to a power converter.

[0002] Previously, a motor drive device for driving a multi-winding motor including several winding sets was known. For example, in patent document 1, a fifth-order harmonic and a seventh-order harmonic are superimposed to reduce a voltage spike in order to suppress torque ripple.

[0003] Patent document 1 requires a current phase to be obtained in order to perform correction using the components of fifth-order harmonics and the components of seventh-order harmonics, which results in a relatively large computational load. Furthermore, a computational error can occur when calculating the components of fifth- and seventh-order harmonics. Thus, there is a possibility that torque ripple cannot be adequately controlled due to this computational error. Patent Document 1: JP-2014-121189-A

[0004] One objective of the present disclosure is to provide a power converter that can improve voltage utilization while minimizing current ripple.

[0005] According to one aspect of the present disclosure, a power converter for converting electrical power of a three-phase electric rotary machine comprising a first winding set and a second winding set includes: a first inverter corresponding to the first winding set; a second inverter corresponding to the second winding set; and a control unit including a command calculation unit that calculates a first voltage command value with respect to a voltage to be applied to the first winding set and a second voltage command value with respect to a voltage to be applied to the second winding set, and an excess correction unit that corrects a value corresponding to a first voltage command that corresponds to the first voltage command value and a value corresponding to a second voltage command that corresponds to the second voltage command value.If one of the values ​​corresponding to a first voltage command and the other of the values ​​corresponding to a second voltage command exceeds a limit set according to a voltage that can be output, the excess correction unit performs excess correction processing to correct the other of the values ​​corresponding to a first voltage command and the other of the values ​​corresponding to a second voltage command according to an excess amount above the limit.

[0006] If either the value corresponding to the first voltage command or the value corresponding to the second voltage command exceeds a limit set according to the output voltage, the excess correction unit performs excess correction processing to correct the other value corresponding to the first and second voltage commands by the excess amount above the limit. In this case, where the winding set and inverter are considered a single system, if a value corresponding to a voltage command in one system exceeds the limit preset according to the output voltage, the other system compensates for the excess. Thus, it is possible to improve voltage utilization while minimizing current ripple.

[0007] The foregoing and further tasks, features and advantages of the present disclosure will become more apparent in the following detailed description in conjunction with the drawings.

[0008] They show:

[0009] Fig. 1 a schematic configuration diagram representing a configuration of an electric power steering system according to a first embodiment of the present disclosure;

[0010] Fig. 2 a circuit diagram to illustrate an electrical configuration of a power converter according to the first embodiment of the present disclosure;

[0011] Fig. 3 a block diagram to explain a control unit according to the first embodiment of the present disclosure;

[0012] Fig. 4 a diagram to illustrate a voltage control processing according to the first embodiment of the present disclosure;

[0013] Fig. 5 a flowchart to explain an excess correction processing according to the first embodiment of the present disclosure;

[0014] Fig. 6 a diagram to illustrate a first zero-point voltage change value according to the first embodiment of the present disclosure;

[0015] Fig. 7 a diagram to illustrate a first upper-lower limit processing value according to the first embodiment of the present disclosure;

[0016] Fig. 8 a diagram to illustrate a first surplus amount according to the first embodiment of the present disclosure;

[0017] Fig. 9 a diagram to illustrate a first correction amount according to the first embodiment of the present disclosure

[0018] Fig. 10 a diagram to illustrate a second zero-point voltage change value according to the first embodiment of the present disclosure;

[0019] Fig. 11 a diagram to explain a second upper-lower limit processing value according to the first embodiment of the present disclosure;

[0020] Fig. 12 a diagram to illustrate a second excess amount according to the first embodiment of the present disclosure;

[0021] Fig. 13 a diagram to explain a second correction amount according to the first embodiment of the present disclosure;

[0022] Fig. 14A and Fig. 14B Diagrams to illustrate a first excess correction value according to the first embodiment of the present disclosure;

[0023] Fig. 15A and Fig. 15B Diagrams to illustrate a second excess correction value according to the first embodiment of the present disclosure;

[0024] Fig. 16 a circuit diagram to explain an electrical configuration of a power converter according to a second embodiment of the present disclosure;

[0025] Fig. 17 a flowchart to explain an excess correction processing according to the second embodiment of the present disclosure;

[0026] Fig. 18 a flowchart to explain the excess correction processing according to the second embodiment of the present disclosure;

[0027] Fig. 19 a diagram to illustrate a first zero-point voltage change value according to the second embodiment of the present disclosure;

[0028] Fig. 20 a diagram to illustrate a first upper-lower limit processing value according to the second embodiment of the present disclosure;

[0029] Fig. 21 a diagram to illustrate a first surplus amount according to the second embodiment of the present disclosure;

[0030] Fig. 22 a diagram to illustrate a first phase transformation amount according to the second embodiment of the present disclosure;

[0031] Fig. 23 a diagram to illustrate a second zero-point voltage change value according to the second embodiment of the present disclosure;

[0032] Fig. 24 a diagram to explain a second upper-lower limit processing value according to the second embodiment of the present disclosure;

[0033] Fig. 25 a diagram to explain a second excess amount according to the second embodiment of the present disclosure;

[0034] Fig. 26 a diagram to illustrate a second phase transformation amount according to the second embodiment of the present disclosure;

[0035] Fig. 27 a diagram to explain a second correction amount according to the second embodiment of the present disclosure;

[0036] Fig. 28A and Fig. 28B Diagrams to illustrate a first excess correction value according to the second embodiment of the present disclosure;

[0037] Fig. 29 a diagram to illustrate a first correction amount according to the second embodiment of the present disclosure;

[0038] Fig. 30A and Fig. 30B Diagrams to illustrate a second excess correction value according to the second embodiment of the present disclosure;

[0039] Fig. 31 a block diagram to explain a control unit according to a third embodiment of the present disclosure;

[0040] Fig. 32 a block diagram to illustrate a current correction value calculation unit according to the third embodiment of the present disclosure; and

[0041] Fig. 33 a diagram to illustrate a control unit according to a fourth embodiment of the present disclosure.

[0042] A power converter according to the present disclosure is described below based on the drawings. In several subsequent embodiments, substantially identical configurations are designated with the same reference numerals, and a repeated description of the same is omitted. FIRST VERSION

[0043] A power converter according to the first embodiment of the present disclosure is described with reference to Fig. 1 to Fig. 15 described. A power converter 1 The present embodiment relies on an electric power steering device. 5 to assist a driver's steering controls together with an engine 80 applied, which represents an electric rotary machine. Fig. Figure 1 shows an overall configuration of a steering system 90 including the electric power steering device 5 The steering system 90 includes a steering wheel 91 as a steering component or steering element, a steering column 92 , a sprocket 96 , a rack 97 , a pair of wheels 98 , the electric power steering device 5 and the like.

[0044] The steering wheel 91 is connected to the steering column 92connected. The steering column 92 is equipped with a torque sensor 94 equipped to detect a steering torque entered by the driver who is turning the steering wheel 91 operated. The pinion 96 is at the top of the steering column 92 provided for, and engages with the rack 97 one. The wheels 98 are connected to the respective ends of the rack 97 connected by a hub or the like.

[0045] If the driver turns the steering wheel 91 turns the steering column 92 , which is connected to the steering wheel 91 is connected, rotated. The pinion 96 converts the rotational movement of the steering column 92 into a linear movement of the rack 97 and the pair of wheels 98 is set at an angle corresponding to an offset amount of the rack 97 guided.

[0046] The electric power steering device 5 includes: the engine80 to deliver the support torque, steering the steering wheel 91 supported by the driver; the power converter 1 , which is used for the drive control of the motor 80 A reduction gear is used. 9 , which is a power transmission element that transmits the rotation of the motor 80 reduced and the rotation on the steering column 92 or the rack 97 transfers; and the like.

[0047] By the engine 80 powered by a battery 105 (compare Fig. 2), which is a DC power supply source, the motor is powered 80 driven to drive the reduction gear 9 to rotate normally or in reverse. The following is a battery voltage. 105 referred to as a power supply voltage Vb. As in Fig. The engine shown in 2 is the one that is depicted in 2. 8A three-phase brushless motor including a rotor and a stator, neither of which are shown. The rotor is a cylindrical element with a permanent magnet attached to its surface and has magnetic poles. Winding sets 81 , 82 are wound on the stator. The first winding set 81 has a U1 coil 811 , a V1 coil 812 and a W1 coil 813 The second winding set 82 has a U2 coil 821 , a V2 coil 822 and a W2 coil 823 The U1 coil 811 and the U2 coil 821 They are located at positions with phases that are offset by 30°. This also applies to the V-phase and the W-phase. Thus, in the first embodiment, the first winding set 81 and the second winding set is electrically conductive, with the phases offset by 30°.

[0048] The power converter 1includes a first inverter 10 , a second inverter 20 , current sensing units 17 , 27 , a rotation angle sensor 29 , power supply relay 31 , 32 , a control unit 41 and the like. The first inverter 10 has six switching elements 11 until 16 and converts a current to the first winding set 81 In the following, a switching element is also referred to as a SW element. The switching elements 11 until 13 are connected to the high-potential side and the switching elements 14 until 16 are connected to the low-potential side. A connection point of the U-phase switching elements. 11 , 14 The pair is connected to one end of the U1 coil. 811 connected. A connection point of the V-phase switching elements 12 , 15 The pair is connected to one end of the V1 coil. 812connected. A connection point of the W-phase switching elements 13 , 16 The pair is connected to one end of the W1 coil. 813 tied together.

[0049] The second inverter 20 has six switching elements 21 until 26 and converts a current to the second winding set 82 The switching elements 21 until 23 are connected to the high-potential side and the switching elements 24 until 26 are connected to the low-potential side. A connection point of the U-phase switching elements. 21 , 24 The pair is connected to one end of the U2 coil. 821 connected. A connection point of the V-phase switching elements 22 , 25 The pair is connected to one end of the V2 coil. 822 connected. A connection point of the W-phase switching elements 23 , 26 The pair is connected to one end of the W2 coil. 823 connected. Each of the switching elements 11until 16 , 21 until 26 In the present embodiment, a MOSFET (metal-oxide-semiconductor field-effect transistor) is used, but it could equally be an IGBT (insulated-gate bipolar transistor), a thyristor, or the like. In the present embodiment, the switching elements correspond to... 11 until 13 , 21 until 23 the high-potential switching element and the switching elements 14 until 16 , 24 until 26 correspond to the low-potential switching element.

[0050] The first current sensing unit 17 has current sensing elements 171 , 172 , 173 The U1 current sensing element 171 is on a connecting line between the connection point of the U-phase switching elements 11 , 14 and the U1 coil 811 provided for and detects a current in the U1 coil 811 The V1 current sensing element172 is on a connecting line between the connection point of the V-phase switching elements 12 , 15 and the V1 coil 812 provided for and detects a current in the V1 coil 812 The W1 current sensing element 173 is on a connecting line between the connection point of the W-phase switching elements 13 , 16 and the W1 coil 813 provided for and detects a current in the W1 coil 813 A measurement value of the current flowing in the U1 coil 811 The current flowing is referred to as a U1 current sensing value Iu1. This is a sensing value of the current flowing in the V1 coil. 812 The current flowing is referred to as a V1 current sensing value Iv1. This is a sensing value of the current flowing in the W1 coil. 813 The flow is referred to as a W1 current sensing value Iw1.

[0051] The second current detection unit 27 has current sensing elements 271 , 272 ,273 The U2 current sensing element 271 is on a connecting line between the connection point of the U-phase switching elements 21 , 24 and the U2 coil 821 provided for and detects a current in the U2 coil 821 The V2 current sensing element 272 is on a connecting line between the connection point of the V-phase switching elements 22 , 25 and the V2 coil 822 designed and detects a current in the V2 coil 822 The W2 current sensing element 273 is on a connecting line between the connection point of the W-phase switching elements 23 , 26 and the W2 coil 823 designed and detects a current in the W2 coil 823 A measurement value of the current flowing in the U2 coil 821 The current flowing is referred to as a U2 current sensing value Iu2. This is a sensing value of the current flowing in the V2 coil. 822The current flowing is referred to as a V2 current sensing value Iv2. This is a sensing value of the current flowing in the W2 coil. 823 The flowing current is referred to as a W2 current sensing value Iw2. The current sensing elements 171 until 173 , 271 until 273 The present embodiment uses Hall elements. The rotation angle sensor 29 detects a rotation angle of the motor 80 An electrical angle θ of the motor 80 , which is measured by the rotation angle sensor 29 When detected, the signal is sent to the control unit. 41 issued.

[0052] The first power supply relay 31 Can energy be supplied from the battery? 105 to the first inverter 10 interrupt. The second power supply relay 32 Can energy be supplied from the battery? 105 to the second inverter 20interrupt. In the present embodiment, each of the power supply relays 31 , 32 a MOSFET similar to a switching element 11 and the like, but it could be an IGBT, a mechanical relay, or the like. Furthermore, it is the case where the MOSFETs are used for the power supply relays. 31 , 32 Preferably, a reverse polarity protection relay, not shown, should be used, which is connected in series with the power supply relays. 31 , 32 is connected to reverse the direction of a parasitic diode so that when the battery 105 If it is incorrectly connected in the opposite direction, it prevents a current from flowing through the parasitic diode in the opposite direction.

[0053] The first capacitor 33 is in parallel with the battery 105 and the first inverter 10 connected. The second capacitor 34is in parallel with the battery 105 and the second inverter 20 connected. The capacitors 33 , 34 They store charges to power the inverters. 10 , 20 to support and suppress a noise component such as a peak current or surge current.

[0054] In the present embodiment, the first winding set 81 , the first inverter 10 regarding the line control for the first winding set 81 , the first power measurement unit 17 , the first power supply relay 31 and the first capacitor 33 as a first system 101 used. Furthermore, the second winding set is used. 82 , the second inverter 20 regarding line control for the second winding set 82 , the second current sensing unit 27 , the second power supply relay 32and the second capacitor 34 as a second system 102 used.

[0055] The control unit 41 controls the entire power converter 1 and includes a microcomputer or similar device that performs various calculations. Each processing step is carried out by the control unit. 41 It can be software processing, performed by executing a pre-stored program in a CPU, or it can be hardware processing, performed using a dedicated electronic circuit. The control unit 41 generates a control signal to control the on / off of each of the switching elements 11 until 16 , 21 until 26 based on the steering torque measured by the torque sensor 94 (compare Fig. 1) is obtained, of the electrical angle θ, which is obtained from the rotation angle sensor 29is obtained, and so on. The generated control signal is sent to the gates of the switching elements. 11 until 16 , 21 until 26 through a drive circuit 35 issued.

[0056] As in Fig. As shown in 3, the control unit 41 a three-phase-to-two-phase conversion unit 51 , a control device 52 , a voltage limiting unit 53 , a two-phase-to-three-phase conversion unit 54 , a modulation calculation unit 55 and the like.

[0057] The three-phase-to-two-phase conversion unit 51 has a three-phase-to-two-phase conversion unit 511 for a first system and a three-phase-to-two-phase conversion unit 512 for a second system. The three-phase-to-two-phase conversion unit 511For a first system, dq conversion is performed for the U1 current sensing value Iu1, the V1 current sensing value Iv1 and the W1 current sensing value Iw1, which are from the first current sensing unit. 17 The three-phase-to-two-phase conversion unit is obtained based on the electric angle θ and calculates a first d-axis current sensing value Id1 and a first q-axis current sensing value Iq1. 512 For a second system, dq conversion is performed for the U2 current sensing value Iu2, the V2 current sensing value Iv2 and the W2 current sensing value Iw2, which are taken from the second current sensing unit. 27 The value is obtained based on the electric angle θ and calculates a second d-axis current detection value Id2 and a second q-axis current detection value Iq2.

[0058] Based on a d-axis current command value Id* and a q-axis current command value Iq* according to a torque command value, the d-axis current sensing values ​​Id1, Id2 and the q-axis current sensing values ​​Iq1, Iq2, the control unit calculates 42 a first prelimit d-axis voltage command value Vd1*_a, a first prelimit q-axis voltage command value Vq1*_a, a second prelimit d-axis voltage command value Vd2*_a and a second prelimit q-axis voltage command value Vq2*_a by PI calculation or the like.

[0059] The voltage limiting unit 53 has a first voltage limiting unit 531 and a second voltage limiting unit 532 and limits a voltage using the amplitude of a dq-axis voltage. The first voltage limiting unit 531The second voltage limiting unit limits the first pre-limiting d-axis voltage command value Vb1*_a and the first pre-limiting q-axis voltage command value Vq1*_a and calculates a first d-axis voltage command value Vd1* and a first q-axis voltage command value Vq1*. 532 limits the second prelimit d-axis voltage command value Vd2*_a and the second prelimit q-axis voltage command value Vq2*_a and calculates a second d-axis voltage command value Vd2* and a second q-axis voltage command value Vq2*.

[0060] Voltage limiting processing in the first voltage limiting unit 531 will be discussed below with reference to Fig. 4 described. Processing in the second voltage limiting unit. 532 is similar to the processing in the first voltage limiting unit 531and thus a description thereof is omitted. A stress vector with a d-axis component that is the first prelimit d-axis stress command value Vd1*_a, and with a q-axis component that is the first prelimit q-axis stress command value Vq1*_a, is called a first prelimit stress vector A1_a. If the magnitude of the first prelimit stress vector A1_a is not greater than an amplitude limit V_lim, the first prelimit d-axis stress command value Vd1*_a is set to the first d-axis stress command value Vd1*, and the first prelimit q-axis stress command value Vq1*_a is set to the first q-axis stress command value Vq1*. Furthermore, as in Fig. As shown in Figure 4, if the magnitude of the first prelimiting stress vector A1_a is greater than the amplitude limit V_lim, the first prelimiting d-axis stress command value Vd1*_a is set to the first d-axis stress command value Vd1* and the q-axis component is limited such that the stress vector A1, after limiting, reaches the amplitude limit V_lim, and the obtained value is set to the first q-axis stress command value Vq1*.

[0061] The amplitude limit value V_lim at dq-axis coordinates is calculated by formula (1). For example, if the power supply voltage Vb is set to 12 V and a duty cycle maximum value Dmax is set to 103.5%, the amplitude limit value V_lim is approximately 8.87 V. In the case where the excess correction processing described later is not performed, the duty cycle maximum value Dmax is 100% and the amplitude limit value V_lim is approximately 8.49 V. V_lim = Vb × (√2) × Dmax / 100 (1)

[0062] The maximum duty cycle value Dmax is predetermined by an offline calculation, so that the value becomes one that can be output when the excess correction processing described later is executed. In the present embodiment, the current sensing elements 171 until 173 , 271 until 273 as the Hall elements are used, and the currents in the winding sets 81 , 82The current is directly measured, and the duty cycle is usable up to 100%. If the current is measured using a shunt resistor, as in the second embodiment described later, sampling is only possible up to a predetermined maximum duty cycle (e.g., 93%). In this case, the maximum duty cycle value Dmax is obtained by multiplying the predetermined maximum duty cycle by 103.5%, and the amplitude limit V_lim is also a different value.

[0063] The two-phase-to-three-phase conversion unit 54 has a two-phase-to-three-phase conversion unit 541 for a first system and a two-phase-to-three-phase conversion unit 542 for a second system. The two-phase-to-three-phase conversion unit 541For a first system, reverse dq conversion is performed for the first d-axis voltage command value Vd1* and the first q-axis voltage command value Vq1* based on the electric angle θ, and calculates a U1 voltage sensing value Vu1*, a V1 voltage sensing value Vv1*, and a W1 voltage sensing value Vw1*. The two-phase-to-three-phase conversion unit 542 For a second system, reverse dq conversion is performed for the second d-axis voltage command value Vd2* and the second q-axis voltage command value Vq2* on the basis of the electric angle 0, and calculates a U2 voltage command value Vu2*, a V2 voltage command value Vv2*, and a W2 voltage command value Vw2*.

[0064] Hereinafter, the U1 voltage command value Vu1*, the V1 voltage command value Vv1*, and the W1 voltage command value Vw1* will appropriately be referred to as (first) voltage command values ​​Vu1*, Vv1*, and Vw1*, respectively. The U2 voltage command value Vu2*, the V2 voltage command value Vv2* and the W2 voltage command value Vw2* are appropriately referred to as (second) voltage command values ​​Vu2*, Vv2*, Vw2*.

[0065] The modulation calculation unit 55 The duty cycle command values ​​Du1, Dv1, Dw1, Du2, Dv2, Dw2 are calculated based on the voltage command values ​​Vu1*, Vv1*, Vw1*, Vu2*, Vv2*, Vw2*. The duty cycle command values ​​Du1, Dv1, Dw1, Du2, Dv2, Dw2 are then sent to the inverters. 10 , 20 through the drive circuit 35 newly issued (in Fig. 3 not shown).

[0066] The modulation calculation unit 55 has a duty cycle conversion unit 551 and an excess correction unit 552The duty cycle conversion unit 551 The duty cycle unit performs duty cycle conversion for the first voltage command values ​​Vu1*, Vv1*, Vw1* and calculates the first duty cycle conversion values ​​Du1_c, Dv1_c, Dw1_c. Furthermore, the duty cycle conversion unit performs... 551 Duty cycle conversion for the second voltage command values ​​Vu2*, Vv2*, Vw2* and calculates second duty cycle conversion values ​​Du2_c, Dv2_c, Dw2_c. The excess correction unit 552 performs excess correction processing in which the excess voltage exceeds a limit value set by the system 101 can be output on the side of the second system 102 is compensated, and the excess above a limit of the voltage supplied by the second system 102 The output that can be displayed is shown on the side of the first system. 101 compensated. This processing improves the voltage utilization rate.

[0067] The excess correction processing of the present embodiment is described with reference to a Fig. The flowchart shown in section 5 describes the excess correction processing of the present embodiment. The excess correction unit is responsible for the excess correction process. 552 executed. At step S101, the excess correction unit determines 552 A maximum duty cycle MaxD1, which is the largest of the first duty cycle conversion values ​​Du1_c, Dv1_c, Dw1_c obtained by performing the duty cycle conversion of the first voltage instruction values ​​Vu1*, Vv1*, Vw1*. Subsequently, step S101 is omitted and written as S101. This also applies to the other steps.

[0068] In S102, the excess correction unit determines 552 A minimum duty cycle MinD1, which is the smallest of the first duty cycle conversion values ​​Du1_c, Dv1_c, Dw1_c. At S103, the excess correction unit determines 552An intermediate duty cycle (MidD1). The intermediate duty cycle, or average duty cycle (MidD1), is expressed by formula (2). In formula (2), “150” represents that if the average of each phase duty cycle is 50%, the sum of the three phase duty cycles 150 This also applies to formula (6). MidD1 = 150 – MaxD1 – MinD1 (2)

[0069] At S104, the excess correction unit calculates 552 The first zero-point voltage change values ​​Du1_ca11, Dv1_ca11, Dw1_ca11. These values ​​are calculated using formulas (3-1), (3-2), and (3-3), respectively. This calculation process modifies the zero-point voltage by equalizing the maximum and minimum duty cycles. However, even when the zero-point voltage is changed, it does not affect the motor's operation. 80not, unless a line voltage is changed. The first zero-point voltage change values ​​Du1_ca11, Dv1_ca11, Dw1_ca11 are as in Fig. 6 shown. Fig. In section 6, a value relating to the U-phase is indicated by a solid line, a value relating to the V-phase by a dashed line, and a value relating to the W-phase by a dashed line. This also applies to the other drawings described later. Du1_ca11 = Du1_c – MidD1 × 0.5 + 50 (3-1) Dv1_ca11 = Dv1_c – MidD1 × 0.5 + 50 (3-2) Dw1_ca11 = Dw1_c – MidD1 × 0.5 + 50 (3-3)

[0070] At S105, the excess correction unit limits 552The first zero-point voltage change values ​​Du1_ca11, Dv1_ca11, Dw1_ca11 are calculated such that they are within the range between a predetermined lower limit RL1 and a predetermined upper limit RH1, and the first upper-lower limit processing values ​​Du1_ca12, Dv1_ca12, Dw1_ca12 are calculated. If the first zero-point voltage change value Du1_ca11 is not less than the lower limit RL1 and not greater than the upper limit RH1, the first zero-point voltage change value Du1_ca11 is used as the upper-lower limit processing value Du1_ca12. If the first zero-point voltage change value Du1_ca11 is less than the lower limit RL1, the lower limit RL1 is set to the first upper-lower limit processing values ​​Du1_ca12.If the first zero-point voltage change value Du1_ca11 is greater than the upper limit RH1, the upper limit RH1 is set to the first upper-lower limit processing values ​​Du1_ca12. This also applies to the first upper-lower limit processing values ​​Dv1_ca12 and Dw1_ca12.

[0071] The first upper-lower limit processing values ​​Du1_ca12, Dv1_ca12, Dw1_ca12 are as in Fig. 7 shown. Fig. Figure 7 is an example where the lower limit RL1 is 0% and the upper limit RH1 is 100%. This also applies to Fig. 11, as described later. The lower limit RL1 and the upper limit RH1 can be set arbitrarily. For example, with regard to dead time, the on-time required for current detection, and the like, the lower limit RL1 can be set to 4% and the upper limit RH1 to 93%.

[0072] At S106, the excess correction unit calculates552 The first excess amounts Du1_h10, Dv1_h10, Dw1_h10. The first excess amounts Du1_h10, Dv1_h10, Dw1_h10 are amounts by which the first zero-point stress change values ​​Du1_ca11, Dv1_ca11, Dw1_ca11 exceed the lower limit RL1 or the upper limit RH1 and are expressed by formulas (4-1), (4-2) and (4-3), respectively. Furthermore, the first excess amounts Du1_h10, Dv1_h10, Dw1_h10 are as in Fig. 8 shown. Fig. Figure 8 shows a modulation ratio of approximately 0% in enlarged form. This also applies to Fig. 9, Fig. 12, Fig. 13 and the like. Du1_h10 = Du1_ca11 – Du1_ca12 (4-1) Dv1_h10 = Dv1_ca11 – Dv1_ca12 (4-2) Dw1_h10 = Dw1_ca11 – Du1_ca12 (4-3)

[0073] At S107, the excess correction unit calculates 552The first correction amounts Du1_h11, Dv1_h11, Dw1_h11 are the values ​​obtained by converting the first excess amounts Du1_h10, Dv1_h10, Dw1_h10 into the coordinate system of the second system. 102 The first correction values ​​Du1_h11, Dv1_h11, Dw1_h11 can be obtained using a rotation matrix. The first correction values ​​Du1_h10, Dv1_h10, Dw1_h10 can be obtained by performing the dq conversion of the first excess values ​​Du1_h10, Dv1_h10, Dw1_h10 in the coordinate system of the first system. 101 and performing the reverse dq conversion of the dq conversion values ​​in the coordinate system of the second system 102 The first correction amounts du1_h11, dv1_h11, dw1_h11 are expressed by formulas (5-1), (5-2) and (5-3) respectively. Du1_h11 = (Du1_h10 – Dv1_h10) / (√3) (5-1) Dv1_h11 = (Dv1_h10 – Dw1_h10) / (√3) (5-2) Dw1_h11 = (Dw1_h10 – Du1_h10) / (√3) (5-3)

[0074] The first correction amounts Du1_h11, Dv1_h11, Dw1_h11 are, as in Fig. Figure 9 shows that a position marked "u, v" means that Du1_h11 and Dv1_h11 have the same value and that lines or conduits are superimposed on them. Similarly, "u, w" means that Du1_h11 and Dw1_h11 have the same value, and "v, w" means that Dv1_h11 and Dw1_h11 have the same value. This also applies to Fig. 13.

[0075] In S108, the excess correction unit determines 552 A maximum duty cycle MaxD2, which is the largest value of the second duty cycle conversion values ​​Du2_c, Dv2_c, Dw2_c obtained by performing the duty cycle conversion of the second voltage instruction values ​​Vu2*, Vv2*, Vw2*. At S109, the excess correction unit determines 552 A minimum duty cycle MinD2, which is the smallest value of the second duty cycle conversion values ​​Du2_c, Dv2_c, Dw2_c. At S110, the excess correction unit determines 552an intermediate duty cycle MidD2. The intermediate duty cycle MidD2 is expressed by formula (6). MidD2 = 150 – MaxD2 – MinD2 (6)

[0076] The following description of the processing of S111 to S114 has been appropriately omitted, as it is essentially similar to the processing of S104 to S107. For S111, the excess correction unit calculates 552 The second zero-point voltage change values ​​Du2_ca11, Dv2_ca11, Dw2_ca11 are calculated using formulas (7-1), (7-2), and (7-3), respectively. The second zero-point voltage change values ​​Du2_ca11, Dv2_ca11, Dw2_ca11 are as described in Fig. 10 shown. Du2_ca11 = Du2_c – MidD2 × 0.5 + 50 (7-1) Dv2_ca11 = Dv2_c – MidD2 × 0.5 + 50 (7-2) Dw2_ca11 = Dw2_c – MidD2 × 0.5 + 50 (7-3)

[0077] In S112, the excess correction unit limits 552The second zero-point voltage change values ​​Du2_ca11, Dv2_ca11, Dw2_ca11 are calculated to be within the range between the predetermined lower limit RL1 and the predetermined upper limit RH1, and the second upper-lower limit processing values ​​Du2_ca12, Dv2_ca12, Dw2_ca12 are calculated. The second upper-lower limit processing values ​​Du2_ca12, Dv2_ca12, Dw2_ca12 are as in Fig. 11 shown.

[0078] At S113, the excess correction unit calculates 552 Second excess amounts Du2_h10, Dv2_h10, Dw2_h10. The second excess amounts Du2_h10, Dv2_h10, Dw2_h10 are amounts by which the second zero-point voltage change values ​​Du2_ca11, Dv2_ca11, Dw2_ca11 exceed the lower limit RL1 or the upper limit RH1, and are each expressed by formulas (8-1), (8-2), (8-3). Furthermore, the second excess amounts Du2_h10, Dv2_h10, Dw2_h10 are as in Fig. 12 shown. Du2_h10 = Du2_ca11 – Du2_ca12 (8-1) Dv2_h10 = Dv2_ca11 – Dv2_ca12 (8-2) Dw2_h10 = Dw2_ca11 – Du2_ca12 (8-3)

[0079] At S114, the excess correction unit calculates 552 The second correction amounts Du2_h11, Dv2_h11, Dw2_h11 are the values ​​obtained by converting the second excess amounts Du2_h10, Dv2_h10, Dw2_h10 into the coordinate system of the first system. 101 The second correction amounts Du2_h11, Dv2_h11, Dw2_h11 can be obtained by performing the dq conversion of the second excess amounts Du2_h10, Dv2_h10, Dw2_h10 in the coordinate system of the second system. 102 and performing the reverse dq conversion of the dq conversion values ​​in the coordinate system of the first system 101The second correction amounts Du2_h11, Dv2_h11, Dw2_h11 are expressed by formulas (9-1), (9-2) and (9-3), respectively. Furthermore, the second correction amounts Du2_h11, Dv2_h11, Dw2_h11 are calculated as in Fig. 13 shown. Du2_h11 = (Du2_h10 – Dw2_h10) / (√3) (9-1) Dv2_h11 = (Dv2_h10 – Du2_h10) / (√3) (9-2) Dw2_h11 = (Dw2_h10 – Dv2_h10) / (√3) (9-3)

[0080] The processing of S101 to S107 and the processing of S108 to S114 can be carried out in the order of the processing of S108 to S114 and the processing of S101 to S107, or can be carried out simultaneously in parallel.

[0081] In S115, the first upper / lower limit processing values ​​Du1_ca12, Dv1_ca12, Dw1_ca12 are corrected by the second correction amounts Du2_h11, Dv2_h11, Dw2_h11 to assign the first excess correction values ​​Du1_ca13, Dv1_ca13, Dw1_ca13. The first excess correction values ​​Du1_ca13, Dv1_ca13, Dw1_ca13 are expressed by formulas (10-1), (10-2) and (10-3), respectively. Du1_ca13 = Du1_ca12 + Du2_h11 (10-1) Dv1_ca13 = Dv1_ca12 + Dv2_h11 (10-2) Dw1_ca13 = Dw1_ca12 + Dw2_h11 (10-3)

[0082] In S116, the second upper / lower limit processing values ​​Du2_ca12, Dv2_ca12, Dw2_ca12 are corrected by the first correction amounts Du1_h11, Dv1_h11, Dw1_h11 to assign second excess correction values ​​Du2_ca13, Dv2_ca13, Dw2_ca13. The second excess correction values ​​Du2_ca13, Dv2_ca13, Dw2_ca13 are expressed by formulas (11-1), (11-2), and (11-3), respectively. Du2_ca13 = Du2_ca12 + Du1_h11 (11-1) Dv2_ca13 = Dv2_ca12 + Dv1_h11 (11-2) Dw2_ca13 = Dw2_ca12 + Dw1_h11 (11-3)

[0083] In the present embodiment, the excess correction values ​​Du1_ca13, Dv1_ca13, Dw1_ca13, Du2_ca13, Dv2_ca13, Dw2_ca13 are sent to the drive circuit. 35 output as the duty cycle command values ​​Du1, Dv1, Dw1, Du2, Dv2, Dw2.

[0084] Fig. 14A and Fig. 14B shows the first excess correction values ​​Du1_ca13, Dv1_ca13, Dw1_ca13 and Fig. 15A and Fig. 15B shows the second excess correction values ​​Du2_ca13, Dv2_ca13, Dw2_ca13. Fig. 14A the entirety of the first excess correction values ​​Du1_ca13, Dv1_ca13, Dw1_ca13 and Fig. Figure 14B shows a modulation ratio of approximately 0% in enlarged form. Fig. 14. Thin lines indicate the first upper-lower limit processing values ​​Du1_ca12, Dv1_ca12, Dw1_ca12, before they are corrected by the second correction amounts Du2_h11, Dv2_h11, Dw2_h11. This also applies to Fig. 15A and Fig. 15B.

[0085] In the present embodiment, the duty cycle conversion values ​​Du1_c, Dv1_c, Dw1_c, Du2_c, Dv2_c, Dw2_c at S104 and S111 are modulated to change the zero-point voltage, wherein the zero-point voltage obtained by the modulation is compared with the voltage before the change, thereby achieving an improvement in the voltage utilization rate. Furthermore, as in Fig. 14A and Fig. As shown in Figure 14B, the first excess correction values ​​Du1_ca13, Dv1_ca13, Dw1_ca13 are values ​​obtained by correcting the first upper-lower limit processing values ​​Du1_ca12, Dv1_ca12, Dw1_ca12 with the second correction amounts Du2_h11, Dv2_h11, Dw2_h11. The second correction amounts Du2_h11, Dv2_h11, Dw2_h11 are values ​​that are in the second system. 102 on the basis of the second surplus amounts Du2_h10, Dv2_h10, Dw2_h10, which are the surplus above the lower limit RL1 or the upper limit RH1.

[0086] Similar to how in Fig. 15A and Fig. As shown in Figure 15B, the second excess correction values ​​Du2_ca13, Dv2_ca13, Dw2_ca13 are values ​​obtained by correcting the second upper-lower limit processing values ​​Du2_ca12, Dv2_ca12, Dw2_ca12 by the first correction amounts Du1_h11, Dv1_h11, Dw1_h11. The first correction amounts Du1_h11, Dv1_h11, Dw1_h11 are values ​​that are in the first system 101 The voltage utilization rate is calculated based on the first excess amounts Du1_h10, Dv1_h10, and Dw1_h10, which represent the excess above the lower limit RL1 or the upper limit RH1. This makes it possible to improve the voltage utilization rate by using a cancel winding without increasing the torque ripple. Furthermore, the cancel winding of the first winding set... 81 the second winding set and the quenching winding of the second winding set 82 is the first winding set 81 .

[0087] In the present embodiment, a voltage phase is not used in the calculation of the correction amounts Du1_h11, Dv1_h11, Dw1_h11, Du2_h11, Dv2_h11, Dw2_h11, thus eliminating the need to calculate an arctangent. This reduces the computational load compared to the case where correction is performed using a value calculated using a voltage phase such as a fifth-order harmonic, a seventh-order harmonic, or the like. Furthermore, since the correction is based on the excess value above the lower or upper limit on the other system, current ripple can be minimized. Additionally, unlike the case where correction is based on the fifth-order or seventh-order harmonic, the dq conversion does not increase or decrease duty cycles in the first system. 101and the second system 102 by the same amount, thus avoiding the occurrence of an error in the processing for calculating the correction amount.

[0088] As described in detail above, the power converter 1 The power or energy of the three-phase motor in the present embodiment 80 , which is the first winding set 81 and the second winding set 82 features and the first inverter 10 , the second inverter 20 and the control unit 41 includes. The first inverter 10 is corresponding to the first winding set 81 planned. The second inverter 20 is according to the second winding set 82 provided. The control unit 41 has the control unit 52 , the voltage limiting unit 53 , the two-phase-to-three-phase conversion unit 54, the duty cycle conversion unit 551 and the excess correction unit 552 The control unit 52 , the voltage limiting unit 53 and the two-phase-to-three-phase conversion unit 54 calculate the first voltage command values ​​Vu1*, Vv1*, Vw1* with respect to a voltage applied to the first winding set 81 to be applied, and the second voltage command values ​​Vu2*, Vv2*, Vw2* with respect to a voltage applied to the second winding set 82 to be created.

[0089] The excess correction unit 552The first duty cycle conversion values ​​Du1_c, Dv1_c, Dw1_c and the second duty cycle conversion values ​​Du2_c, Dv2_c, Dw2_c, which are the values ​​corresponding to the first voltage command values ​​Vu1*, Vv1*, Vw1*, are corrected. If either value corresponding to the first voltage command or the second voltage command exceeds the lower limit RL1 or the upper limit RH1, which is set according to a voltage that can be output, the excess correction unit corrects the error. 552 the other of the value corresponding to the first voltage command and the value corresponding to the second voltage command according to the excess amounts Du1_h10, Dv1_h10, Dw1_h10, Du2_h10, Dv2_h10, Dw2_h10 above the lower limit RL1 or the upper limit RH1.

[0090] In particular, if the first zero-point voltage change values ​​Du1_ca11, Dv1_ca11, Dw1_ca11 exceed the lower limit RL1 or the upper limit RH1, which is set according to a voltage that can be output, the excess correction unit corrects 552 The second upper-lower limit processing values ​​Du2_ca12, Dv2_ca12, Dw2_ca12 are adjusted according to the first excess amounts Du1_h10, Dv1_h10, Dw1_h10. Furthermore, if the second zero-point voltage change values ​​Du2_ca11, Dv2_ca11, Dw2_ca11 exceed the lower limit RL1 or the upper limit RH1, which is set according to a voltage that can be output, the excess correction unit corrects. 552The first upper-lower limit processing values ​​Du1_ca12, Dv1_ca12, Dw1_ca12 correspond to the second excess amounts Du2_h10, Dv2_h10, Dw2_h10. In the present embodiment, if the value corresponding to the voltage command in one system exceeds the lower limit RL1 or the upper limit RH1, which is set according to a voltage that can be output, the excess is compensated in the other system. Thus, it is possible to improve the voltage improvement rate while minimizing the current ripple.

[0091] The excess correction unit 552 Executes excess correction processing for the zero-point voltage change values ​​Du1_ca11, Dv1_ca11, Dw1_ca11, Du2_ca11, Dv2_ca11, Dw2_ca11, which are obtained by changing the zero-point voltage. Changing the zero-point voltage can lead to further improvement in the voltage utilization rate.

[0092] The power converter 1It also includes the current sensing units. 17 , 27 to detect a current that encircles each phase of the first winding set 81 and the second winding set 82 Furthermore, the first voltage command values ​​Vu1*, Vv1*, Vw1* and the second voltage command values ​​Vu2*, Vv2*, Vw2* are calculated based on the current sensing values ​​Iu1, Iv1, Iw1, Iu2, Iv2, Iw2, which are determined by the current sensing units. 17 , 27 This allows for appropriate calculation of the voltage command values ​​Vu1*, Vv1*, Vw1*, Vu2*, Vv2*, Vw2* by current feedback control or current regulation.

[0093] The first voltage command values ​​Vu1*, Vv1*, Vw1* and the second voltage command values ​​Vu2*, Vv2*, Vw2* are values ​​limited by the predetermined amplitude limit value V_lim to be values ​​that can be corrected according to the excess amounts Du1_h10, Dv1_h10, Dw1_h10, Du2_h10, Dv2_h10, Dw2_h10. Thus, it is possible to perform the excess correction processing appropriately.

[0094] The engine 80 is used for the electric power steering device 5 The output torque is used to assist and support the steering of the steering wheel. 91 the driver. In the power converter 1 In the present embodiment, since the torque ripple is reduced, sound and vibration that occur in the electric power steering device are eliminated. 5 are generated, are reduced.

[0095] In the present embodiment, the control unit corresponds to 52, the voltage limiting unit 53 and the two-phase-to-three-phase conversion unit 54The command calculation unit and the lower limit RL1 and the upper limit RH2 correspond to the limit value. Furthermore, in the present embodiment, the first zero-point voltage change values ​​Du1_ca11, Dv1_ca11, Dw1_ca11 correspond to the value corresponding to a first voltage command, and the second zero-point voltage change values ​​Du2_ca11, Dv2_ca11, Dw2_ca11 correspond to the value corresponding to a second voltage command.Furthermore, it is assumed that correcting the first upper-lower limit processing values ​​Du1_ca12, Dv1_ca12, Dw1_ca12, which limit the upper and lower limits of the first zero-point voltage change values ​​Du1_ca11, Dv1_ca11, Dw1_ca11, and correcting the second upper-lower limit processing values ​​Du2_ca12, Dv2_ca12, Dw2_ca12, which limit the upper and lower limits of the second zero-point voltage change values ​​Du2_ca11, Dv2_ca11, Dw2_ca11, is included in the concept of correcting the other value corresponding to a first voltage command and the value corresponding to a second voltage command. SECOND VERSION

[0096] Fig. 16 to Fig. Figures 30 show a second embodiment of the present disclosure. As in Fig. As shown in 16, a power converter differs. 2 of the present embodiment of the power converter 1the first embodiment in that current sensing units 18 , 28 instead of the current sensing units 17 , 27 are planned. The first power measurement unit 18 has current sensing elements 181 , 182 , 183 The U1 current sensing element 181 is between the U-phase switching element 14 and the mass is provided and detects a current in the U1 coil 811 The V1 current sensing element 182 is between the V-phase switching element 15 and the mass is provided and detects a current in the V1 coil 812 The W1 current sensing element 183 is between the W-phase switching element 16 and the mass is provided and detects a current in the W1 coil 813 .

[0097] The second current detection unit 28 has current sensing elements 281 , 282 , 283The U2 current sensing element 281 is between the U-phase switching element 24 and the mass is provided and detects a current in the U2 coil 821 The V2 current sensing element 282 is between the V-phase switching element 25 and the mass is provided and detects a current in the V2 coil 822 The W2 current sensing element 283 is between the W-phase switching element 26 and the mass is provided and detects a current in the W2 coil 823 The current sensing elements 181 until 183 , 281 until 283 The present embodiments are shunt resistors.

[0098] With the between the switching elements 14 until 16 and the mass-provided current sensing elements 181 until 183 will happen when the switching elements 14 until 16 are out, a current is not allowed, in the current detection elements181 until 183 to flow, and therefore the current cannot be detected. This makes it necessary to perform the current detection in a state where all phases or two phases of the switching elements are energized. 14 until 16 are. The current sensing is performed in the state where the two phases of the switching elements are 14 until 16 If one phase is switched on, the current in the phase that is switched off can be calculated using the current sensing values ​​of the two phases that are switched on. This also applies to the current sensing in the second current sensing unit. 28 .

[0099] In the present embodiment, assuming that the power supply voltage Vb is 12 V and the duty cycle maximum value Dmax is 100.2%, the amplitude limiting value V_lim at dq-axis coordinates with respect to voltage limiting in the voltage limiting unit 53Approximately 8.5 V (compare formula (1-2)). The maximum duty cycle value Dmax is a value that is predefined offline or independently of the computer, similar to the first embodiment. In the case where the excess correction processing is not executed when the switching elements are on-periods 14 until 16 , 24 until 26 Taking into account the factors required for current sensing, the amplitude limit value V_lim is approximately 8.32 V, since the maximum value of the line voltage is 98% when the duty cycle is converted.

[0100] Furthermore, the second embodiment differs from the first embodiment in the excess correction processing, which is carried out by the excess correction unit. 552is executed. A modulation method for performing a modulation such that the duty cycle of the smallest phase has a predetermined lower limit is referred to as flatbed modulation, and a modulation method for performing a modulation such that the duty cycle of the largest phase has a predetermined upper limit is referred to as flat-peak modulation. The excess correction processing of the present embodiment is described with reference to in Fig. 17 and Fig. The 18 flowcharts are described. The processing of S201 to S203 in Fig. 17 is similar to the processing of S101 to S103 in Fig. 5.

[0101] In S204, the excess correction unit compares 552a lower all-phase on duty cycle PD1 with a lower or a lower two-phase on duty cycle PD2, wherein the duty cycle PD1 corresponds to an all-phase on period P1, which is a period in which all phases of the switching elements are switched on. 14 until 16 at the time of flatbed modulation, the duty cycle PD2 corresponds to a two-phase one-period P2, which is one period in which two phases of the switching elements are switched on. 14 until 16 are switched on. The lower all-phase-on duty cycle PD1 and the lower two-phase-on duty cycle PD2 are expressed by formulas (12-1) and (12-2) respectively. PD1 = 100 – (MaxD1 – MinD1) (12-1) PD2 = MaxD1 – MidD1 (12-2)

[0102] If the lower all-phase on duty cycle PD1 is compared to the lower two-phase on duty cycle PD2, and the lower all-phase on duty cycle PD1 is not lower than the lower two-phase on duty cycle PD2, then the all-phase on period P1 is not shorter than the two-phase on period P2. Therefore, it is assumed that the current is detected when all phases of the switching elements are energized. 14 until 16 This represents flatbed modulation. Furthermore, if the lower two-phase on-duty ratio PD2 is greater than the lower all-phase on-duty ratio PD1, then the two-phase on-period P2 is longer than the all-phase on-period P1. Thus, the current is assumed to be detected when two phases of the switching elements are switched on. 14 until 16 one of them is what flat-peak modulation represents.

[0103] If it is determined that the lower all-phase-on duty cycle PD1 is not lower than the lower two-phase-on duty cycle PD2 (S204: NO), processing continues with S208. If the lower two-phase-on duty cycle PD2 is determined to be higher than the lower all-phase-on duty cycle PD1 (S204: YES), processing continues with S205.

[0104] At S205, the excess correction unit 552 a stationary phase in the first system 101 as the maximum phase. If the lower two-phase on-duty ratio PD2 is greater than the lower all-phase on-duty ratio PD1, the zero-point voltage is changed by the flat-peak modulation.

[0105] At S206, the excess correction unit calculates the first zero-point voltage change values ​​Du1_ca21, Dv1_ca21, Dw1_ca21 at the time of the flat-peak modulation. The zero-point voltage change values ​​Du1_ca21, Dv1_ca21, Dw1_ca21 at the time of the flat-peak modulation are expressed by formulas (13-1), (13-2) and (13-3), respectively. Du1_ca21 = Du1_c – MaxD1 + RH2 (13-1) Dv1_ca21 = Dv1_c – MaxD1 + RH2 (13-2) Dw1_ca21 = Dw1_c – MaxD1 + RH2 (13-3)

[0106] In S207, the excess correction unit limits 552The first zero-point voltage change values ​​Du1_ca21, Dv1_ca21, Dw1_ca21 at the time of flat-peak modulation are calculated to be within the range between a predetermined lower limit RL2 and a predetermined upper limit RH2, and the first upper-lower limit processing values ​​Du1_ca22, Dv1_ca22, Dw1_ca22 are calculated at the time of flat-peak modulation. One detail of the upper-lower limit processing is similar to that of S105.

[0107] The lower limit RL2 and the upper limit RH2 can be arbitrarily defined. In the present embodiment, the lower limit RL2 is set to 2%, taking the dead time into account. Furthermore, the upper limit RH2 is set to 100%, as it is assumed that the current sensing is performed at the moment when the two phases of the switching elements are switched on. 14 until 16 are.

[0108] At S208, where processing continues if the lower all-phase-on duty cycle PD1 is determined to be not smaller than the lower two-phase-on duty cycle PD2 (S204: NO), the excess correction unit uses 552 the stationary phase in the first system 101 than the minimum phase. If the lower all-phase on-duty ratio PD1 is greater than the lower two-phase on-duty ratio PD2, the zero-point voltage is changed by the flatbed modulation.

[0109] At S209, the excess correction unit calculates 552The first zero-point voltage change values ​​Du1_ca21, Dv1_ca21, Dw1_ca21 at the time of flatbed modulation. The first zero-point voltage change values ​​Du1_ca21, Dv1_ca21, Dw1_ca21 at the time of flatbed modulation are expressed by formulas (14-1), (14-2) and (14-3), respectively. The first zero-point voltage change values ​​Du1_ca21, Dv1_ca21, Dw1_ca21, calculated at S206 or S209 are in Fig. 19 shown. Du1_ca21 = Du1_c – MinD1 + RL3 (14-1) Dv1_ca21 = Dv1_c – MinD1 + RL3 (14-2) Dw1_ca21 = Dw1_c – MinD1 + RL3 (14-3)

[0110] In the S210, the excess correction unit limits 552the first zero-point voltage change values ​​Du1_ca21, Dv1_ca21, Dw1_ca21 at the time of flatbed modulation to be within the range between a predetermined lower limit RL3 and a predetermined upper limit RH3, and calculates first upper-lower limit processing values ​​Du1_ca22, Dv1_ca22, Dw1_ca22 at the time of flatbed modulation.

[0111] The lower limit RL3 and the upper limit RH3 can be arbitrarily set. In the present embodiment, the lower limit RL3 is set to 0%. Furthermore, since the current sensing is performed at the time when all phases of the switching elements are 14 until 16 If one is the upper limit RH3 is set to 93% with respect to the time required to switch on all phases of the switching elements 14 until 16 and for the convergence of the clanging of currents in the current sensing elements 141 until 143and the like is required. The first upper-lower limit processing values ​​Du1_ca22, Dv1_ca22, Dw1_ca22, which are calculated at S207 or S210, are in Fig. 20 shown.

[0112] At S211, where processing continues from S207, the excess correction unit calculates 552 First excess amounts Du1_h20, Dv1_h20, Dw1_h20. The first excess amounts Du1_h20, Dv1_h20, Dw1_h20 are amounts by which the first zero-point stress change values ​​Du1_ca21, Dv1_ca21, Dw1_ca21 exceed the lower limit RL2 or the upper limit RH2 and are expressed by formulas (15-1), (15-2) and (15-3), respectively. Du1_h20 = Du1_ca21 – Du1_ca22 (15-1) Dv1_h20 = Dv1_ca21 – Dv1_ca22 (15-2) Dw1_h20 = Dw1_ca21 – Du1_ca22 (15-3)

[0113] At S212, the excess correction unit calculates 552the first phase conversion amounts Du1_h21, Dv1_h21, Dw1_h21, the values ​​are obtained by converting the first excess amounts Du1_h20, Dv1_h20, Dw1_h20 into the coordinate system of the second system 102 The first phase conversion values ​​Du1_h21, Dv1_h21, Dw1_h21 can be obtained using a rotation matrix. The first phase conversion values ​​Du1_h20, Dv1_h20, Dw1_h20 can be obtained by performing the dq conversion for the first and first excess values ​​Du1_h20, Dv1_h20, Dw1_h20, respectively, in the coordinate system of the first system. 101 and performing the reverse dq conversion of the dq conversion values ​​in the coordinate system of the second system. The first phase conversion amounts Du1_h21, Dv1_h21, Dw1_h21 are expressed by formulas (16-1), (16-2) and (16-3), respectively. Du1_h21 = (Du1_h20 – Dv1_h20) / (√3) (16-1) Dv1_h21 = (Dv1_h20 – Dw1_h20) / (√3) (16-2) Dw1_h21 = (Dw1_h20 – Du1_h20) / (√3) (16-3)

[0114] The first excess values ​​Du1_h20, Dv1_h20, Dw1_h20 are 0 at the time of flatbed modulation during calculation. Therefore, the calculation of the first excess values ​​Du1_h20, Dv1_h20, Dw1_h20 and the calculation of the first phase conversion values ​​Du1_h21, Dv1_h21, Dw1_h21 are omitted. Although the processing continues from S210 to S213 in the present embodiment, similar to the time of flat-tip modulation, the first excess values ​​Du1_h20, Dv1_h20, Dw1_h20 and the first phase conversion values ​​Du1_h21, Dv1_h21, Dw1_h21 can be calculated. The first excess values ​​Du1_h20, Dv1_h20, Dw1_h20 are calculated as in Fig. 21 is shown, and the first phase conversion amounts Du1_h21, Dv1_h21, Dw1_h21 are as in Fig. 22 is shown.

[0115] As in Fig. As shown in section 18, the processing of S213 to S215, which continues from S210 or S212, is similar to the processing of S108 to S110 in Fig. 5. In S216, the excess correction unit compares 552 a lower all-phase-on duty cycle PD3 with a lower two-phase-on duty cycle PD4, wherein the duty cycle PD3 corresponds to an all-phase-on period P1, which is a period in which all phases of the switching elements are switched on. 24 until 26 are switched on at the time of flatbed modulation, and the duty cycle PD4 corresponds to a two-phase one-period P4, which is one period in which two phases of the switching elements are switched on. 24 until 26 are switched on. The lower all-phase on duty cycle PD3 and the lower two-phase on duty cycle PD4 are expressed by formulas (17-1) and (17-2) respectively. PD3 = 100 – (MaxD2 – MinD2) (17-1) PD4 = MaxD2 – MidD2 (17-2)

[0116] Similar to S204, if the lower all-phase on-duty ratio PD3 is compared with the lower two-phase on-duty ratio PD4, and the lower all-phase on-duty ratio PD3 is not smaller than the lower two-phase on-duty ratio PD4, then the all-phase on-duty period P3 is not shorter than the two-phase on-duty period P4. Therefore, it is assumed that the current is detected when all phases of the switching elements are energized. 24 until 26 This represents flatbed modulation. Furthermore, if the lower two-phase on-rate PD4 is greater than the lower all-phase on-rate PD3, then the two-phase on-period P4 is longer than the all-phase on-period P3. Thus, the current is assumed to be detected when two phases of the switching elements are switched on. 24 until 26 one is, as the flat-peak modulation or what the flat-peak modulation represents.

[0117] If the lower all-phase-on duty cycle PD3 is determined to be no less than the lower two-phase-on duty cycle PD4 (S216: NO), processing continues with S220. If the lower two-phase-on duty cycle PD4 is determined to be greater than the lower all-phase-on duty cycle PD3 (S216: YES), processing continues with S217.

[0118] A detailed description of the processing of S217 to S224 has been appropriately omitted, as it is essentially similar to the processing of S205 to S212. In S217, the excess correction unit... 552 A stationary phase in the second system S102 is considered the maximum phase. If the lower two-phase on-duty ratio PD4 is greater than the lower all-phase on-duty ratio PD3, the zero-point voltage is modified by the flat-peak modulation.

[0119] At S218, the excess correction unit calculates 552 The second zero-point voltage change values ​​Du2_ca21, Dv2_ca21, Dw2_ca21 at the time of the flat-peak modulation. The second zero-point voltage change values ​​Du2_ca21, Dv2_ca21, Dw2_ca21 at the time of the flat-peak modulation are expressed by formulas (18-1), (18-2) and (18-3), respectively. Du2_ca21 = Du2 – MaxD2 + RH2 (18-1) Dv2_ca21 = Dv2 – MaxD2 + RH2 (18-2) Dw2_ca21 = Dw2 – MaxD2 + RH2 (18-3)

[0120] In S219, the excess correction unit limits 552 the second zero-point voltage change values ​​Du2_ca21, Dv2_ca21, Dw2_ca21 at the time of flat-peak modulation to be within the range between the lower limit RL2 and the upper limit RH2, and calculates second upper-lower limit processing values ​​Du2_ca22, Dv2_ca22, Dw2_ca22 at the time of flat-peak modulation.

[0121] In S220, where processing continues if the lower all-phase on-duty ratio PD3 is determined to be not smaller than the lower two-phase on-duty ratio PD4 (S216: NO), the excess correction unit takes 552 the stationary phase in the second system 102 as the minimum phase. If the lower all-phase on-duty ratio PD3 is not smaller than the lower two-phase on-duty ratio PD4, the zero-point voltage is changed by the flatbed modulation.

[0122] At S221, the excess correction unit calculates 552The second zero-point voltage change values ​​Du2_ca21, Dv2_ca21, Dw2_ca21 at the time of flatbed modulation. The second zero-point voltage change values ​​Du2_ca21, Dv2_ca21, Dw2_ca21 at the time of flatbed modulation are expressed by formulas (19-1), (19-2) and (19-3), respectively. The second zero-point voltage change values ​​Du2_ca21, Dv2_ca21, Dw2_ca21, which are calculated at S217 or S220, are in Fig. 23 shown. Du2_ca21 = Du2_c – MinD2 + RL3 (19-1) Dv2_ca21 = Dv2_c – MinD2 + RL3 (19-2) Dw2_ca21 = Dw2_c – MinD2 + RL3 (19-3)

[0123] In S222, the excess correction unit limits 552The second zero-point voltage change values ​​Du2_ca21, Dv2_ca21, Dw2_ca21 are calculated at the time of flatbed modulation to be within the range between the predetermined lower limit RL3 and the predetermined upper limit RH3, and the second upper-lower limit processing values ​​Du2_ca22, Dv2_ca22, Dw2_ca22 are calculated at the time of flatbed modulation. The second upper-lower limit processing values ​​Du2_ca22, Dv2_ca22, Dw2_ca22, calculated at S219 or S222, are as described in Fig. 24 shown.

[0124] At S223, where processing continues from S219, the excess correction unit calculates 552Second excess amounts Du2_h20, Dv2_h20, Dw2_h20. The second excess amounts Du2_h20, Dv2_h20, Dw2_h20 are amounts by which the second zero-point stress change values ​​Du2_ca21, Dv2_ca21, Dw2_ca21 exceed the lower limit RL2 or the upper limit RH2, and are expressed by formulas (20-1), (20-2) and (20-3), respectively. Du2_h20 = Du2_ca21 – Du2_ca22 (20-1) Dv2_h20 = Dv2_ca21 – Dv2_ca22 (20-2) Dw2_h20 = Dw2_ca21 – Du2_ca22 (20-3)

[0125] In S224, the excess correction unit is calculated 552 second phase conversion amounts Du2_h21, Dv2_h21, Dw2_h21, which are the values ​​obtained by converting the second excess amounts Du2_h20, Dv2_h20, Dw2_h20 into the coordinate system of the first system 101The second phase conversion amounts Du2_h21, Dv2_h21, Dw2_h21 can be obtained by performing the dq conversion of the second excess amounts Du2_h20, Dv2_h20, Dw2_h20 in the coordinate system of the second system. 102 and performing the reverse dq conversion of the dq conversion values ​​in the coordinate system of the first system 101 The second phase conversion amounts Du2_h21, Dv2_h21, Dw2_h21 are expressed by formulas (21-1), (21-2) and (21-3) respectively. Du2_h21 = (Du2_h20 – Dw2_h20) / (√3) (21-1) Dv2_h21 = (Dv2_h20 – Du2_h20) / (√3) (21-2) Dw2_h21 = (Dw2_h20 – Dv2_h20) / (√3) (21-3)

[0126] Similar to the first system 101The second excess amounts Du2_h20, Dv2_h20, Dw2_h20 are calculated at the time of flatbed modulation. Therefore, the calculation of the second excess amounts Du2_h20, Dv2_h20, Dw2_h20 and the calculation of the second phase conversion amounts Du2_h21, Dv2_h21, Dw2_h21 are omitted. Although the processing from S122 with S225 continues similarly to the time of flat-tip modulation in the present embodiment, the second excess amounts Du2_h20, Dv2_h20, Dw2_h20 and the second phase conversion amounts Du2_h21, Dv2_h21, Dw2_h21 can be calculated. The second excess amounts Du2_h20, Dv2_h20, Dw2_h20 are calculated as in Fig. 25 is shown and the second phase conversion amounts Du2_h21, Dv2_h21, Dw2_h21 are as in Fig. Figure 26 shows the processing of S210 to S212 and the processing of S213 to S214 can be carried out in the order of the processing of S213 to S224 and the processing of S210 to S212, or can be carried out simultaneously in parallel.

[0127] In S225, the excess correction unit modulates 552 the second phase conversion amounts Du2_h21, Dv2_h21, Dw2_h21 such that the second correction amount to correct the stationary phase is 0, and calculates second correction amounts Du2_h22, Dv2_h22, Dw2_h22.

[0128] If the stationary phase in the first system 101 The U-phase is, the second correction amounts Du2_h22, Dv2_h22, Dw2_h22 are expressed by formulas (22-1), (22-2) and (22-3), respectively. Du2_h22 = 0 (22-1) Dv2_h22 = Dv2_h21 – Du2_h21 (22-2) Dw2_h22 = Dw2_h21 – Du2_h21 (22-3)

[0129] If the stationary phase in the first system 101The V-phase is, the second correction amounts Du2_h22, Dv2_h22, Dw2_h22 are expressed by formulas (23-1) (23-2) and (23-3), respectively. Du2_h22 = Du2_h21 – Dv2_h21 (23-1) Dv2_h22 = 0 (23-2) Dw2_h22 = Dw2_h21 – Dv2_h21 (23-3)

[0130] If the stationary phase in the first system 101 In the W-phase, the second correction amounts Du2_h22, Dv2_h22, Dw2_h22 are expressed by formulas (24-1) (24-2) and (24-3), respectively. Du2_h22 = Du2_h21 – Dw2_h21 (24-1) Dv2_h22 = Dv2_h21 – Dw2_h21 (24-2) Dw2_h22 = 0 (24-3)

[0131] The second correction amounts Du2_h22, Dv2_h22, Dw2_h22 are as in Fig. 27 is shown.

[0132] In S226, the excess correction unit corrects 552The first upper / lower limit processing values ​​Du1_ca22, Dv1_ca22, Dw1_ca22 are replaced by the second correction amounts Du2_h22, Dv2_h22, Dw2_h22 to give the first correction values ​​Du1_ca23, Dv1_ca23, Dw1_ca23. The first excess correction values ​​Du1_ca23, Dv1_ca23, Dw1_ca23 are expressed by formulas (25-1), (25-2) and (25-3), respectively. Du1_ca23 = Du1_ca22 + Du2_h22 (25-1) Dv1_ca23 = Dv1_ca22 + Dv2_h22 (25-2) Dw1_ca23 = Dw1_ca22 + Dw2_h22 (25-3)

[0133] The first excess correction values ​​Du1_ca23, Dv1_ca23, Dw1_ca23 are as in Fig. 28A and Fig. 28B is shown. Fig. 28A shows the totality of the first excess correction values ​​Du1_ca23, Dv1_ca23, Dw1_ca23. Fig. Figure 28B shows a modulation ratio of approximately 0% in an enlarged form, and thin lines indicate the first upper-lower limit processing values ​​Du1_ca22, Dv1_ca22, Dw1_ca22 before they are corrected by the second correction amounts Du2_h22, Dv2_h22, Dw2_h22. This also applies to the one described later. Fig. 30.

[0134] In S227, the excess correction unit modulates 552 the phase conversion amounts Du1_h21, Dv1_h21, Dw1_h21 such that the first correction amount to correct the stationary phase is 0, and calculates the first correction amounts Du1_h22, Dv1_h22, Dw1_h22.

[0135] If the stationary phase in the second system 102 In the U-phase, the first correction amounts Du1_h22, Dv1_h22, Dw1_h22 are expressed by formulas (26-1), (26-2) and (26-3), respectively. Du1_h22 = 0 (26-1) Dv1_h22 = Dv1_h21 – Du1_h21 (26-2) Dw1_h22 = Dw1_h21 – Du1_h21 (26-3)

[0136] If the stationary phase in the second system 102 The V-phase is, the first correction amounts Du1_h22, Dv1_h22, Dw1_h22 are expressed by formulas (27-1), (27-2) and (27-3). Du1_h22 = Du1_h21 – Dv1_h21 (27-1) Dv1_h22 = 0 (27-2) Dw1_h22 = Dw1_h21 – Dv1_h21 (27-3)

[0137] If the stationary phase in the second system 102 The W-phase is, the first correction amounts Du1_h22, Dv1_h22, Dw1_h22 are expressed by formulas (28-1), (28-2) and (28-3). Du1_h22 = Du1_h21 – Dw1_h21 (28-1) Dv1_h22 = Dv1_h21 – Dw1_h21 (28-2) Dw1_h22 = 0 (28-3)

[0138] The first correction amounts Du1_h22, Dv1_h22, Dw1_h22 are in Fig. 29 shown.

[0139] In S228, the excess correction unit corrects 552The second upper / lower limit processing values ​​Du2_ca22, Dv2_ca22, Dw2_ca22 are replaced by the first correction amounts Du1_h22, Dv1_h22, Dw1_h22 to assign second excess correction values ​​Du2_ca23, Dv2_ca23, Dw2_ca23. The second excess correction values ​​Du2_ca23, Dv2_ca23, Dw2_ca23 are expressed by formulas (29-1), (29-2), and (29-3), respectively. Du2_ca23 = Du2_ca22 + Du1_h22 (29-1) Dv2_ca23 = Dv2_ca22 + Dv1_h22 (29-2) Dw2_ca23 = Dw2_ca22 + Dw1_h22 (29-3)

[0140] The second excess correction values ​​Du2_ca23, Dv2_ca23, Dw2_ca23 are as in Fig. 30A and Fig. 30B is shown.

[0141] In the present embodiment, the excess correction values ​​Du1_ca23, Dv1_ca23, Dw1_ca23, Du2_ca23, Dv2_ca23, Dw2_ca23 are sent to the drive circuit. 35 as the duty cycle command values ​​Du1, Dv1, Dw1, Du2, Dv2, Dw2.

[0142] In the present embodiment, the first inverter 10 and the second inverter 20 the high-potential switching elements 11 until 13 , 21 until 23 and the low-potential switching elements 14 until 16 , 24 until 26 , which are paired for the respective phases. The current sensing units 18 , 28 are between the low-potential switching elements 14 until 16 , 24 until 26 and connected to ground. Therefore, the shunt resistors can be suitable as current sensing elements. 181 until 183 , 281 until 283 be used.

[0143] The excess correction unit 552 compares the all-phase-on period P1, in which the low-potential switching elements 14 until 16of three phases, with the two-phase one-period P2, in which the low-potential switching elements 14 until 16 of two-phase systems, and changes the zero-point voltage such that current sensing can be performed in the longer period. Furthermore, compare the excess correction unit. 552 the all-phase-on period P3, in which the low-potential switching elements 24 until 26 of three phases, with the two-phase one-period P4, in which the low-potential switching elements 24 until 26 of two-phase systems, and modifies the zero-point voltage such that current sensing can be performed over a longer period. This makes it possible to improve the voltage utilization rate while the current sensing is performed by the current sensing units. 18 , 28, which are provided on the low-potential side. Furthermore, a similar effect to that of the first embodiment is achieved or realized. In the present embodiment, the lower limits RI2, RL3 and the upper limits RH2, RH3 correspond to the limit value. THIRD VERSION

[0144] Fig. 31 and Fig. Figures 32 show a third embodiment of the present disclosure. As in Fig. As shown in 31, the control unit differs. 42 the third embodiment differs from those of the first and second embodiments in that the control unit 42 a current correction value calculation unit 56 and a current correction unit 57 in addition to the three-phase-to-two-phase conversion unit 51 , to the control unit 52 , to the voltage limiting unit 53 , to the two-phase-to-three-phase conversion unit 54and to the modulation calculation unit 55 exhibits.

[0145] In the excess correction processing, the first system 101 Duty cycles equivalent to the first excess amounts Du1_h20, Dv1_h20, Dw1_h20 are subtracted, and duty cycles equivalent to the second correction amounts Du2_h22, Dv2_h22, Dw2_h22 according to the second excess amounts Du2_h20, Dv2_h20, Dv2_h20 are added. Furthermore, in the second system... 102Duty cycles equivalent to the second excess amounts Du2_h20, Dv2_h20, Dw2_h20 are subtracted, and duty cycles equivalent to the first correction amounts Du1_h22, Dv1_h22, Dw1_h22 according to the first excess amounts Du1_h20, Dv1_h20, Dv1_h20 are added. In the present embodiment, currents are estimated according to the duty cycles to be changed by the excess correction processing in order to correct the current sensing values ​​Iu1, Iv1, Iw1, Iu2, Iv2, Iw2.

[0146] As in Fig. The current correction value calculation unit shown in figure 32 is... 56 subtractor 561 , 564 , voltage conversion units 562 , 565 and electricity estimation units 563 , 566 . Fig. Figure 32 shows an example where the calculation of the second embodiment is performed by the excess correction unit. 552 is executed.

[0147] The first subtractor 561The first excess amount Du1_h20 is subtracted from the second U-phase correction amount Du2_h22 to calculate a first duty cycle change value ΔDu1. Similarly, the first subtractor subtracts 561 The first excess amount Dv1_h20 is subtracted from the second V-phase correction amount Dv2_h22 to calculate a first duty cycle change value ΔDv1, and the first excess amount Dw1_h20 is subtracted from the second W-phase correction amount Dw2_h22 to calculate a first duty cycle change value ΔDw1. The first duty cycle change values ​​ΔDu1, ΔDv1, ΔDw1 can be used as modified amounts by which the duty cycles of the first duty cycle conversion values ​​Du1_c, Dv1_c, Dw1_c are changed by the excess correction processing.

[0148] The first voltage conversion unit 562 multiplies each of the first duty cycle change values ​​ΔDu1, ΔDv1, ΔDw1 obtained by the first subtractor. 561The first voltage change values ​​ΔVu1, ΔVv1, ΔVw1, obtained by converting the duty cycles into voltages, are calculated using (Vb / 100). 563 estimates currents according to the first voltage change values ​​ΔVu1, ΔVv1, ΔVw1 to calculate first current correction values ​​CurrU1_h, CurrV1_h, CurrW1_h.

[0149] The second subtractor 564 The second excess amount Du2_h20 is subtracted from the first U-phase correction amount Du1_h22 to calculate a second duty cycle change value ΔDu2. Similarly, the second subtractor subtracts 564The second excess amount Dv2_h20 is subtracted from the first V-phase correction amount Dv1_h22 to calculate a second duty cycle change value ΔDv2, and the second excess amount Dw2_h20 is subtracted from the first W-phase correction amount Dw1_h22 to calculate a second duty cycle change value ΔDw2. The second duty cycle change values ​​ΔDu2, ΔDv2, ΔDw2 can be used as the modified amounts by which the duty cycles of the second duty cycle conversion values ​​Du2_c, Dv2_c, Dw2_c are changed by the excess correction processing.

[0150] The second voltage conversion unit 565 multiplies each of the second duty cycle change values ​​ΔDu2, ΔDv2, ΔDw2, which are calculated by the second subtractor. 564 The second current estimation unit is calculated using (Vb / 100) to calculate the second voltage change values ​​ΔVu2, ΔVv2, ΔVw2, which are obtained by converting the duty cycles into voltages. 566estimates current values ​​according to the second voltage change values ​​ΔVu2, ΔVv2, ΔVw2 to calculate second current correction values ​​CurrU2_h, CurrV2_h, CurrW2_h.

[0151] Furthermore, in a case where the calculation of the first embodiment is performed in the excess correction unit, it is also possible 552 To perform the calculation, the first current correction values ​​CurrU1_h, CurrV1_h, CurrW1_h are calculated based on the second correction amounts Du2_h11, Dv2_h11, Dw2_h11 and the first excess amounts Du_h10, Dv1_h10, Dw1_h10. Furthermore, the second current correction values ​​CurrU2_h, CurrV2_h, CurrW2_h can be calculated based on the first correction amounts Du1_h11, Dv1_h11, Dw1_h11 and the second excess amounts Du2_h10, Dv2_h10, Dw2_h10.

[0152] As in Fig. As shown in 31, the current correction unit corrects 57The current correction unit corrects the U1 current sensing value Iu1 by the current correction value CurrU1_h, the V1 current sensing value Iv1 by the current correction value CurrV1_h, and the W1 current sensing value Iw1 by the current correction value CurrW1_h. Furthermore, the current correction unit corrects 57 The U2 current sensing value Iu2 is corrected by the current correction value CurrU2_h, the V2 current sensing value Iv2 is corrected by the current correction value CurrV2_h, and the W2 current sensing value Iw2 is corrected by the current correction value CurrW2_h. In the present embodiment, the corresponding current correction values ​​CurrU1_h, CurrV1_h, CurrW1_h, CurrU2_h, CurrV2_h, CurrW2_h are subtracted from the current sensing values ​​Iu1, Iv1, Iw1, Iu2, Iv2, Iw2. The current correction calculation in the current correction unit 57 is not limited to subtraction, but can be any form of calculation. The three-phase-to-two-phase conversion unit 51performs the three-to-two-phase conversion using the current sensing values ​​Iu1, Iv1, Iw1, Iu2, Iv2, Iw2, which are corrected by the current correction values ​​CurrU1_h, CurrV1_h, CurrW1_h, CurrU2_h, CurrV2_h, CurrW2_h.

[0153] The control unit 42 It also has the current correction value calculation unit 56 and the current correction unit 57 The current correction value calculation unit 56 The current correction unit calculates the current correction values ​​CurrU1_h, CurrV1_h, CurrW1_h, CurrU2_h, CurrV2_h, and CurrW2_h according to currents generated by the excess correction processing. 57The current sensing values ​​Iu1, Iv1, Iw1, Iu2, Iv2, Iw2 are corrected based on the current correction values ​​CurrU1_h, CurrV1_h, CurrW1_h, CurrU2_h, CurrV2_h, CurrW2_h. This enables a more appropriate calculation of the voltage command values ​​Vu1*, Vv1*, Vw1*, Vu2*, Vv2*, Vw2*. Furthermore, similar effects to those of the preceding embodiments are achieved. FOURTH VERSION

[0154] Fig. Figure 33 shows a fourth embodiment of the present disclosure. As in Fig. As shown in 33, it has a control unit 43 in the present embodiment the three-phase-to-two-phase conversion unit 51 , a sum-difference conversion unit 61 , a control device 62 , a system conversion unit 63 , the voltage limiting unit 53 , the two-phase-to-three-phase conversion unit 54 , the modulation calculation unit 55, a surplus determination unit 65 and the like. The sum-difference conversion unit. 61 Converts the d-axis current measurement values ​​Id1, Id2 and the q-axis current measurement values ​​Iq1, Iq2 into sums and differences. Specifically, it calculates the sum-difference conversion unit. 61 a d-axis current sum Id1 + Id2, a d-axis current difference Id1 – Id2, a q-axis current sum Iq1 + Iq2, and a q-axis current difference Iq1 – Iq2. As in the third embodiment, the d-axis current sensing values ​​Id1, Id2 and the q-axis current sensing values ​​Iq1, Iq2 can be values ​​based on the current sensing values ​​Iu1, Iv1, Iw1, Iu2, Iv2, Iw2, which are corrected by the current correction values ​​CurrU1_h, CurrV1_h, CurrW1_h, CurrU2_h, CurrV2_h, CurrW2_h.

[0155] The control unit 62 includes a d-axis summing control device 621 , a d-axis differential control device 622, a q-axis summation control device 623 and a q-axis differential control device 624 The d-axis summation control unit 621 It calculates a d-axis voltage sum command value Vd+* by PI calculation or the like, based on the d-axis current sum command value Id+* and the d-axis current sum Id1 + Id2. The d-axis differential control unit 622 It calculates a d-axis voltage differential command value Vd–* by PI calculation or the like, based on the d-axis current differential command value Id–* and the d-axis current difference Id1 – Id2. The q-axis summation control unit 623 It calculates a q-axis voltage sum command value Vq+* by PI calculation or the like, based on the q-axis current sum command value Iq+* and the q-axis current sum Iq1 + Iq2. The q-axis differential control unit 624It calculates a q-axis voltage differential command value Vq–* by PI calculation or the like, based on the q-axis current differential command value Iq–* and the q-axis current difference Iq1 – Iq2. In the present embodiment, the current differential command values ​​Id–*, Iq–* are 0.

[0156] The system conversion unit 63converts the sum voltage command values ​​Vd+*, Vq+* and the difference voltage command values ​​Vd–*, Vq–* into the first prelimit d-axis voltage command value Vd1*_a, the first prelimit q-axis voltage command value Vq1*_a, the second prelimit d-axis voltage command value Vd2*_a and the second prelimit q-axis voltage command value Vq2*_a. Furthermore, the voltage control processing, excess correction processing and the like, which are performed on the basis of the first prelimit d-axis voltage command value Vd1*_a, the first prelimit q-axis voltage command value Vq1*_a, the second prelimit d-axis voltage command value Vd2*_a and the second prelimit q-axis voltage command value Vq2*_a, are similar to those of the preceding embodiments.While either the excess correction processing of the first embodiment or that of the second embodiment can be used, the description here assumes that the excess correction processing of the second embodiment is performed.

[0157] The surplus determination unit 65 Determines whether the excess correction processing is executed. If at least one of the excess amounts Du1_h20, Dv1_h20, Dw1_h20, Du2_h20, Dv2_h20, Dw2_h20 is not 0, the excess correction processing is executed. Furthermore, if all of the excess amounts Du1_h20, Dv1_h20, Dw1_h20, Du2_h20, Dv2_h20, Dw2_h20 are 0, the excess correction is not executed.

[0158] Whether excess correction processing is performed can be determined based on the phase conversion amounts Du1_h21, Dv1_h21, Dw1_h21, Du2_h21, Dv2_h21, Dw2_h21 or the correction amounts Du1_h22, Dv1_h22, Dw1_h22, Du2_h22, Dv2_h22, Dw2_h22 instead of the excess amounts Du1_h20, Dv1_h20, Dw1_h20, Du2_h20, Dv2_h20, Dw2_h20. In the case of excess correction processing of the first embodiment, the determination can be carried out in a similar manner as above.

[0159] The surplus determination unit 65 can determine that the excess correction is performed when voltages are applied to the winding sets 81 , 82 The voltages applied to the winding sets are greater than a voltage determination limit. 81 , 82Voltage command values ​​can be applied in the respective calculation processes of the voltage command values ​​Vd1*_a, Vq1*_a, Vd2*_a, Vq2*_a and the like, pre-limitation by the voltage limiting unit. 53 These could be actual voltages that are actually applied to the winding sets. 81 , 82 concerns. Furthermore, the surplus determination unit determines 65 , that the excess correction is performed when a rotational speed of the motor is reached. 80 The result is greater than a rotational speed determination limit value. The determination result is sent to the d-axis differential control unit. 622 and the q-axis differential control unit 624 If it is determined that the excess correction is to be carried out, the differential control devices reduce the output. 622 , 624The control response behavior. It should be noted that switching off the control of the differential control devices 622 , 624 This is also included in the concept of reducing response behavior.

[0160] The first voltage command values ​​Vu1*, Vv1*, Vw1* and the second voltage conversion values ​​Vu2*, Vv2*, Vw2* are determined using the summation control devices. 621 , 623 to control a sum of currents that are in the first winding set 81 and the second winding set 82 flow, and using the differential control devices 622 , 624 to control a difference between the current in the first winding set 81 flows, and current that flows in the second winding set 82 flows, calculated. When the excess correction processing is executed, the differential control devices reduce. 622 , 624the response behavior compared to when excess correction processing is not performed.

[0161] In the present embodiment, a command value is calculated by controlling the sum and difference, thereby reducing or enabling the influence of temperature changes, variations between elements, and the like. Furthermore, when excess correction processing is performed, the differential control response is suppressed or limited to avoid a weak differential control state during excess correction, thus enabling a reasonable reduction of torque ripple. Furthermore, similar effects to those of the preceding embodiments are achieved. OTHER EXECUTION FORMS(I) Value corresponding to a first voltage command, value corresponding to a second voltage command

[0162] In some embodiments, the first zero-point voltage change value corresponds to the value corresponding to a first voltage command, and the second zero-point voltage change value corresponds to the value corresponding to a second voltage command. In another embodiment, each value corresponding to a first voltage command and each value corresponding to a second voltage command is not limited to the zero-point voltage change value but can itself be a voltage command value. That is, excess correction processing can be performed using a voltage command value prior to duty cycle conversion. Furthermore, each value corresponding to a first voltage command and each value corresponding to a second voltage command can be a value other than the zero-point voltage change value, calculated based on a voltage command value, such as a duty cycle conversion value.Furthermore, the value used for excess correction processing is not limited to a value in the three-phase coordinate system, but can be a value in another coordinate system. (II) Current sensing unit

[0163] In the second embodiment, the current sensing element is provided between the low-potential switching element and ground. In a further embodiment, the current sensing element located on the low-potential side can be any element capable of detecting current, such as a Hall effect sensor instead of a shunt resistor. Furthermore, the current sensing element can be located at any point where a phase current can be detected, such as on the high-potential side of the high-potential switching element. It is also desirable to define the limit value according to the current sensing element and the location where the current sensing element is positioned.

[0164] In the preceding embodiments, each of the first and second voltage command values ​​is calculated by current feedback control or by current control based on the current sensing value, respectively. In a further embodiment, each of the first and second voltage command values ​​can be calculated by not using the current sensing value, but by performing feedforward control of, for example, an electrical angle, rotational speed, or the like. In this case, the current sensing can be omitted. (III) Excess Correction Unit

[0165] In the foregoing embodiments, the excess correction unit performs the excess correction processing for the first zero-point voltage change value and the second zero-point voltage change value, which are values ​​obtained by changing the zero-point voltage. In a further embodiment, the excess correction unit can perform the excess correction processing without changing the zero-point voltage. (IV) Voltage limiting unit

[0166] In the foregoing embodiments, if the pre-limiting voltage vector is greater than the amplitude limit value, the q-axis component is modified to limit the voltage command value, so that the voltage command value becomes the amplitude limit value. In another embodiment, the voltage command value, in order not to be greater than the amplitude limit value, can be limited by any method, such as controlling both the d-axis and x-axis components, instead of modifying the q-axis component. (V) Electric rotary machine

[0167] In the preceding embodiments, the winding sets of the electric rotary machine are arranged with phases offset by 30°. In a further embodiment, the phase difference between the winding sets is not limited to 30°, but can be any degree. Furthermore, the line phase difference is not limited to 30° and can be any degree other than 0°. The electric rotary machine is used for the electric power steering device. In a further embodiment, the electric rotary machine can be applied to an onboard device other than the electric power steering device, or it can be applied to a non-onboard device. Furthermore, the electric rotary machine is not limited to the motor, but can be a generator or a so-called motor-generator, which has combined functions of an electric motor and a generator.For the foregoing, the present disclosure is not limited to any of the embodiments and can be implemented in a variety of forms within a scope that does not depart from the spirit of the disclosure.

[0168] It should be noted that a flowchart or the processing of the flowchart in the present application comprises sections (also referred to as steps), each of which is represented, for example, as S101. Furthermore, each section can be divided into several subsections, while several sections can be combined into a single section. Each of the sections thus configured can also be referred to as a device, a module, or means.

[0169] While the present disclosure has been described with reference to its embodiments, it is evident that the disclosure is not limited to embodiments and constructions. The present disclosure is intended to cover different modifications and equivalent arrangements. Furthermore, in addition to the various combinations and configurations, further combinations and configurations, including more, fewer, or only a single element, are also within the teaching and scope of the present disclosure. QUOTES INCLUDED IN THE DESCRIPTION

[0170] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0171] JP 2014-121189 A

[0003]

Claims

[1] Power converter for converting electrical power of a three-phase electric rotary machine ( 80 ) including a first winding set ( 81 ) and a second winding set ( 82 ), where the power converter has: a first inverter ( 10 ), which corresponds to the first winding set; a second inverter ( 20 ), which corresponds to the second winding set; and a control unit ( 41 , 42 , 43 ) including a command calculation unit ( 52 until 54 , 62 , 63 ), which calculates a first voltage command value with respect to a voltage to be applied to the first winding set, and a second voltage command value with respect to a voltage to be applied to the second winding set, and an excess correction unit ( 552), which corrects a value corresponding to a first voltage command that corresponds to the first voltage command value, and corrects a value corresponding to a second voltage command that corresponds to the second voltage command value, wherein: If one of the values ​​corresponding to a first voltage command and the other of the values ​​corresponding to a second voltage command exceeds a limit value that is set according to a voltage that can be output, the excess correction unit performs excess correction processing to correct the other of the values ​​corresponding to a first voltage command and the other of the values ​​corresponding to a second voltage command according to an excess amount above the limit value. [2] Power converter according to claim 1, wherein: The excess correction unit performs excess correction processing for the value corresponding to a first voltage command and the value corresponding to a second voltage command whose zero-point voltage is changed. [3] Power converter according to claim 2, further comprising: a current sensing unit ( 17 , 18 , 27 , 28 ), which detects a current passing through each phase of the first winding set and the second winding set, wherein: The command calculation unit calculates the first voltage command value and the second voltage command value based on a current sensing value detected by the current sensing unit. [4] Power converter according to claim 3, wherein: Each of the first inverter and the second inverter has a high-potential switching element ( 11 until 13 , 21 until 23) and a low-potential switching element ( 14 until 16 , 24 until 26 ) includes providing a pair corresponding to each phase; and the current sensing unit ( 18 , 28 ) is arranged between the low-potential switching element and a ground. [5] Power converter according to claim 4, wherein: The excess correction unit compares an all-phase on-period, in which the low-potential switching element of each phase switches on, with a two-phase on-period, in which the low-potential switching element of each of the two phases switches on; and The excess correction unit changes the zero-point voltage to capture current for one of the all-phase one-period and two-phase one-period that is longer than the other of the all-phase one-period and two-phase one-period. [6] Power converter according to any one of claims 3 to 5, wherein: the control unit ( 42 ) further includes: a current correction value calculation unit ( 56 ), which calculates a current correction value according to a current generated by the excess correction processing; and a current correction unit ( 57 ), which corrects the current sensing value based on the current correction value. [7] Power converter according to any one of claims 1 to 6, wherein: the first voltage command value and the second voltage command value using a summation control device ( 621 , 623 ) and a differential control device ( 622 , 624 ) are calculated; The summation control device controls the sum of a current flowing in the first winding set and a current flowing in the second winding set; The differential control device controls a difference between the current flowing in the first winding set and the current flowing in the second winding set; and When the excess correction unit performs the excess correction processing, the differential control unit sets a lower response behavior than when the excess correction unit does not perform the excess correction processing. [8] Power converter according to any one of claims 1 to 7, wherein: The first voltage command value and the second voltage command value are limited by a predetermined amplitude limit value in order to be corrected according to the excess amount. [9] Power converter according to any one of claims 1 to 8, wherein: the electric rotary machine for an electric power steering device ( 5 ) is used; and the electric rotary machine a steering control of a steering component (91 ) assisted by a driver according to an initial torque.

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