JP2010252534A - Motor drive control system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor drive control system that reduces overall size of the system by eliminating an installation space of a current sensor between an inverter and a three-phase AC motor. <P>SOLUTION: The motor drive control system includes: a three-phase AC motor 2 having a neutral point 7 where all winding end parts of n-phase (U-phase, V-phase, and W-phase) coils are gathered; an inverter 3 for supplying AC power to each phase of the three-phase AC motor 2; and current sensors 5a, 5b for detecting each phase-current flowing from the inverter 3 to the U-phase and the W-phase of the three-phase AC motor. The current sensor 5a is arranged at the winding end part of the U-phase coil short of the neutral point 7, while the current sensor 5b is arranged at the winding end part of the W-phase coil short of the neutral point 7. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a motor drive control system that controls driving of a multiphase AC motor.

  Conventionally, three-phase AC power converted by an on / off operation of a switching element of an inverter is supplied to a three-phase AC motor to drive the three-phase AC motor, and further, the three-phase AC motor is driven to the three-phase AC motor. There is known a motor drive control system that performs feedback control based on phase currents flowing through coils of each phase (U phase, V phase, W phase) (for example, Patent Document 1).

JP 2008-125186 A

  By the way, the motor control device of Patent Document 1 has three current sensors that detect phase currents flowing in coils of each phase (U phase, V phase, W phase) of a three-phase AC motor, and each current sensor Is arranged between the inverter and the three-phase AC motor. As described above, since each current sensor is arranged between the inverter and the three-phase AC motor, an installation space is required for arranging each current sensor between the inverter and the three-phase AC motor, thereby reducing the size of the entire apparatus. It was difficult to plan.

  Accordingly, an object of the present invention is to provide a motor drive control system that can reduce the size of the entire system by eliminating the installation space for a current sensor between an inverter and a three-phase AC motor.

  In order to achieve the above object, a motor drive control system according to the present invention includes a multi-phase AC motor having a neutral point in which all coil winding end sides of n-phase (where n is 3 or more) are integrated, A power converter for supplying AC power to each phase of the phase AC motor, and current detection means for detecting a phase current flowing from the power converter to at least the (n-1) phase of the multiphase AC motor. ing. And each said current detection means is each arrange | positioned at the coil winding end part of the (n-1) phase at least before the said neutral point, It is characterized by the above-mentioned.

  According to the motor drive control system of the present invention, each phase current detection means is disposed at least at the end of the coil winding of the (n-1) phase before the neutral point, so that the power converter and the multiphase alternating current are arranged. An installation space for disposing each current detection means between the motors is not necessary, and the entire apparatus can be reduced in size.

Schematic which shows the electric circuit structure of the motor drive control system which concerns on Embodiment 1 of this invention. The schematic diagram which shows the arrangement structure of the three-phase alternating current motor and inverter of the motor drive control system which concern on Embodiment 2 of this invention. Schematic which shows the side surface of the three-phase alternating current motor which provided the neutral point and the current sensor in the end surface. The schematic diagram about the arrangement configuration of the neutral point and current sensor in Embodiment 3 of the present invention. The schematic diagram about the arrangement configuration of the neutral point and current sensor in Embodiment 4 of the present invention.

Hereinafter, the present invention will be described based on the illustrated embodiments.
<Embodiment 1>
FIG. 1 is a schematic diagram showing an electric circuit configuration of a motor drive control system according to Embodiment 1 of the present invention.

  As shown in FIG. 1, a motor drive control system 1 according to this embodiment includes a three-phase AC motor 2, an inverter 3 as a power converter that rotationally drives the three-phase AC motor 2 by PWM control, and an inverter 3. Detected by the connected DC power supply 4, two current sensors 5 a and 5 b for detecting phase currents flowing in the U phase and V phase of each phase of the three-phase AC motor 2, and at least current sensors 5 a and 5 b, respectively. And a control unit 6 that controls the inverter 3 so as to feedback-control the rotational drive of the three-phase AC motor 2 based on the phase current value.

  In the present embodiment, the three-phase AC motor 2 has 15 teeth in a stator (stator) (not shown), and each tooth (U phase, V phase, W phase) has coils Uc, Vc and Wc are wound respectively. That is, in this three-phase AC motor 2, five coils Uc, Vc, Wc are arranged in parallel for each phase (U phase, V phase, W phase), and each phase (U phase, V phase, W phase). The end of winding of each coil Uc, Vc, Wc of the phase) is coupled at a neutral point (connection point of U phase, V phase, W phase) 7.

  The inverter 3 has one switching leg in one coil by using each switching element 8a, 8b of the upper and lower arms connected in series as one switching leg and having five switching legs per phase. Diodes 9a and 9b are connected in parallel to the switching elements 8a and 8b, respectively.

  That is, in the inverter 3, the U-phase coils Uc of the three-phase AC motor 2 are electrically connected to the five switching legs 11 of the U-phase arm 10, and the five switching legs 13 of the V-phase arm 12 are connected to the five switching legs 13. The V-phase coils Vc of the three-phase AC motor 2 are electrically connected, and the W-phase coils Wc of the three-phase AC motor 2 are electrically connected to the five switching legs 15 of the W-phase arm 14. Yes. As each switching element 8a, 8b, for example, a MOS-FET can be used.

  A DC power supply 4 is connected to the U-phase arm 10, the V-phase arm 12, and the W-phase arm 14. Further, smoothing capacitors 16 for smoothing the DC power supplied to the switching elements 8a and 8b are parallel to the switching legs 11, 13, and 15 of the U-phase arm 10, the V-phase arm 12, and the W-phase arm 14, respectively. Are connected to each.

  The current sensor 5a is disposed at the coil winding end portion where the U-phase coils Uc of the three-phase AC motor 2 before the neutral point 7 are bundled, and the total current flowing in the U-phase of the three-phase AC motor 2 ( U-phase current) is detected. The current sensor 5b is disposed at the coil winding end portion where the W-phase coils Wc of the three-phase AC motor 2 before the neutral point 7 are bundled, and the total current flowing in the W-phase of the three-phase AC motor 2 is A current (W-phase current) is detected.

In the three-phase AC motor 2, the sum of the currents flowing through the respective phases (U phase, V phase, W phase) is 0 (zero). Therefore, the control unit 6 calculates the total current (V-phase current) flowing in the remaining V-phase when Iu is the current flowing in the U-phase (U-phase current) and Iw is the current flowing in the W-phase (W-phase current). Iw can be calculated from the following equation (1).
Iv = 0− (Iu + Iw) (1)

  Next, the operation of the motor drive control system 1 according to the present embodiment configured as described above will be described.

  When this motor drive control system 1 is applied to drive control of a travel drive motor installed in a drive system such as an electric vehicle (including a fuel cell vehicle) or a hybrid vehicle, for example, A torque command value corresponding to the required driving force of the three-phase AC motor 2 that is a traveling drive motor is calculated based on accelerator opening information (accelerator pedal depression amount) and vehicle speed information input from the sensor.

  Then, a PWM signal having a duty ratio corresponding to the calculated torque command value is output to the switching elements 8a and 8b of the U-phase arm 10, V-phase arm 12 and W-phase arm 14 of the inverter 3, and the switching elements 8a and 8b. ON / OFF control. By the on / off control of the switching elements 8a and 8b, the DC power supplied from the DC power source 4 which is a battery (high-voltage secondary battery such as a lithium ion battery) is converted into three-phase AC power, and the three-phase AC motor 2 Three-phase AC power is supplied to each of the phases (U phase, V phase, W phase). The three-phase AC motor 2 is rotationally driven at a rotational speed based on the torque command value by three-phase AC power supplied to each phase (U phase, V phase, W phase).

  At this time, the current sensor 5a detects the total current flowing in the U phase of the three-phase AC motor 2, and the current sensor 5b detects the total current flowing in the W phase of the three-phase AC motor 2. And the control part 6 respond | corresponds to each current value which flows into the U phase and W phase which were each detected by the current sensors 5a and 5b, the current value which flows into the V phase calculated by said Formula (1), and the said torque command value. Feedback control is performed so that the target current values of the respective phases coincide with each other, and the three-phase AC motor 2 is rotationally driven with a required driving force according to the traveling state with high accuracy.

  Thus, according to the motor drive control system 1 of the present embodiment, the coil winding end portion where the U-phase coils Uc 7 before the neutral point are bundled, and the W-phase coils Wc 7 before the neutral point. With the configuration in which the current sensors 5a and 5b are arranged at the coil winding end portions bundled together, there is no need to provide a space for arranging the current sensor between the inverter 3 and the three-phase AC motor 2 as in the conventional case. And the three-phase AC motor 2 can be integrally connected, and the entire system can be reduced in size.

  Further, even in the case of a motor having a three-phase 15 teeth configuration in which five coils are wound per phase like the three-phase AC motor 2, the three-phase is formed only by the current sensors 5 a and 5 b disposed before the neutral point 7. The current of each phase of the AC motor 2 can be detected, and the number of current sensors can be greatly reduced, so that the cost can be reduced.

<Embodiment 2>
FIG. 2 is a schematic diagram showing an arrangement configuration of a three-phase AC motor and an inverter of the motor drive control system according to the second embodiment of the present invention. In addition, the same code | symbol is attached | subjected to the member which has the same function as Embodiment 1 shown in FIG. 1, and the overlapping description is abbreviate | omitted.

  Also in the present embodiment, as in the first embodiment, the coil winding end portion where the U-phase coils Uc before the neutral point 7 are bundled and the coil where the W-phase coils Wc before the neutral point 7 are bundled Current sensors 5a and 5b are arranged at the winding end portions, respectively. Thereby, as shown in FIG. 2, in the motor drive control system according to the present embodiment, the inverter 3 is integrally connected to the axial end surface on one side (left side in FIG. 2) of the three-phase AC motor 2, and the other side. The neutral point 7 of each coil of each phase is arranged on the axial end face on the side (right side in FIG. 2). The electric circuit configuration of the motor drive control system of this embodiment is the same as that of the first embodiment shown in FIG.

  2 and 3, the neutral point 7 is formed between the coil end 17 of each phase coil disposed on the other axial end surface of the three-phase AC motor 2 and the end surface of the stator 18. It is arrange | positioned in the space (space between a back yoke part and teeth). The current sensors 5a and 5b for detecting U-phase and W-phase currents are respectively provided with U-phase and V-phase coils (not shown) immediately before the neutral point 7 disposed on the end surfaces of the coil end 17 and the stator 18. Are arranged near the end of the coil winding. In this way, the neutral point 7 of the three-phase AC motor 2 is provided on the end surface opposite to the extraction end surface side of each coil connected to each switching leg of the inverter 3.

  A rotation angle sensor 20 such as a resolver or encoder for detecting the rotation angle of the rotor 19 is disposed on the end surface on the side where the neutral point 7 of the rotor 19 with which a motor shaft (not shown) is fitted. Has been.

  As described above, in this embodiment, the space of the back yoke portion formed by the coil end thickness of the coil of each phase is used on both end surfaces in the axial direction of the three-phase AC motor 2. The inverter 3 is integrally connected to the axial end surface on one side, and the neutral point 7 of each coil of each phase is arranged on the axial end surface on the other side, thereby eliminating the useless space and reducing the size of the entire system. Can be achieved.

  Further, by arranging the current sensors 5a and 5b on the end surface opposite to the inverter 3, the current sensors 5a and 5b can be free from the influence of switching noise generated in the inverter 3. Therefore, the current sensors 5a and 5b only need a noise countermeasure for preventing the influence of noise generated by the rotational drive of the three-phase AC motor 2, and therefore the noise countermeasure can be simplified.

  Further, the neutral point 7, the current sensors 5 a and 5 b, and the rotation angle sensor 20 are arranged on the other end face of the three-phase AC motor 2 (end face opposite to the end face where the inverter 3 is arranged), thereby providing a three-phase. Since the space on the other end face side of the AC motor 2 can be effectively used to eliminate the useless space, it is possible to reduce the size of the entire system.

<Embodiment 3>
In this embodiment, as shown in FIG. 4, each phase (U phase, V phase, W phase) is a circle on the other end surface of the three-phase AC motor (the end surface opposite to the end surface on which the inverter is arranged). An annular U-phase bus bar 21, V-phase bus bar 22, and W-phase bus bar 23 are provided, connecting take-out portions of coils wound at equal intervals in a three-phase AC motor, and forming a bus bar for each phase. ing. Other configurations are the same as those of the first and second embodiments.

  In addition, the V-phase bus bar 22 of the bus bars 21, 22, 23 of each phase also serves as a neutral point. The V-phase bus bar 22 also serving as the neutral point and the other bus bars (U-phase bus bar 21 and W-phase bus bar 23) are connected by connection lines 24 and 25, respectively. The current sensors 5a and 5b are arranged. Current sensor 5 a detects a U-phase current flowing in U-phase bus bar 21 of three-phase AC motor 2, and current sensor 5 b detects a W-phase current flowing in W-phase bus bar 23.

  Thus, in this embodiment, each phase (U phase, V phase, W phase) is provided with the annular U-phase bus bar 21, V-phase bus bar 22, and W-phase bus bar 23, respectively. Compared with the case where the coil is formed only by the coil without providing the above, the cross-sectional area of the bus bar for each phase can be reduced, and the neutral point can be formed in a space-saving manner.

  In addition, the V-phase bus bar 22 of the bus bars 21, 22, and 23 of each phase also serves as a neutral point, thereby saving space rather than forming a new neutral point after combining each phase. Can do. Furthermore, by connecting the V-phase bus bar 22 also serving as the neutral point and the other bus bars (U-phase bus bar 21 and W-phase bus bar 23) with connection lines 24 and 25, respectively, one connection line is reduced. This can save space. Thereby, in this embodiment, since space can be saved, the entire system can be reduced in size.

<Embodiment 4>
In contrast to the configuration of the third embodiment, in this embodiment, as shown in FIG. 5, a notch 26 is formed in a bus bar (U-phase bus bar 21, W-phase bus bar 23) other than the V-phase bus bar 22 that also serves as a neutral point. , 27 and connecting lines 24, 25 between the V-phase bus bar 22 that also serves as a neutral point and the other bus bars (U-phase bus bar 21, W-phase bus bar 23) through the notches 26, 27, respectively. The current sensors 5a and 5b are arranged in the notches 26 and 27, respectively, connected to each other. Current sensor 5 a detects a U-phase current flowing in U-phase bus bar 21 of three-phase AC motor 2, and current sensor 5 b detects a W-phase current flowing in W-phase bus bar 23.

  As described above, in the present embodiment, the current sensors 5a and 5b are disposed in the cutout portions 26 and 27 provided in the U-phase bus bar 21 and the W-phase bus bar 23, respectively, so that the current sensors 5a and 5b are more space-saving. Therefore, the entire system can be downsized.

1 Motor drive control system 2 3-phase AC motor (multi-phase AC motor)
3 Inverter (Power converter)
4 DC power supply 5a, 5b Current sensor (current detection means)
6 Control unit 7 Neutral point 8a, 8b Switching element 10 U-phase arm 12 V-phase arm 14 W-phase arm 18 Stator 19 Rotor 20 Rotation angle sensor 21 U-phase bus bar 22 V-phase bus bar 23 W-phase bus bar 24, 25 Connection line 26 , 27 Notch

Claims (5)

  a multi-phase AC motor having a neutral point in which all coil winding end sides of n-phase (where n is 3 or more) are aggregated, and a power converter for supplying AC power to each phase of the multi-phase AC motor; Current detecting means for detecting a phase current flowing from the power converter to at least the (n-1) phase of the multiphase AC motor, and each current detecting means at least before the neutral point ( n-1) A motor drive control system, wherein the motor drive control system is arranged at the end of coil winding of the phase.   2. The power converter is disposed on one axial end face of the multiphase AC motor, and the neutral point is disposed on the other axial end face of the multiphase AC motor. The motor drive control system described in 1.   The rotation angle sensor which detects the rotation angle of the rotor of the said polyphase AC motor is arrange | positioned at the axial direction end surface at the side which has arrange | positioned the said neutral point of the said polyphase AC motor. Motor drive control system.   The coil winding end portion of each phase is collected as a bus bar for each phase, so that one of the bus bars also serves as the neutral point, the bus bar also serves as the neutral point, and each of the other The motor drive control system according to claim 1, wherein the current detection means is provided on each connection line connected to the bus bar.   A notch portion is provided in each of the other bus bars other than the bus bar that also serves as the neutral point, and each connection line provided with the current detection means is disposed in the notch portion. Item 5. The motor drive control system according to Item 4.

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