WO2020003807A1

WO2020003807A1 - Motor control device

Info

Publication number: WO2020003807A1
Application number: PCT/JP2019/019851
Authority: WO
Inventors: 勝洋星野
Original assignee: 日立オートモティブシステムズ株式会社
Priority date: 2018-06-27
Filing date: 2019-05-20
Publication date: 2020-01-02
Also published as: JP7069313B2; CN112292810B; JPWO2020003807A1; DE112019002548T5; CN112292810A

Abstract

In a multiphase motor, no matter which phase there is phase interruption for, the phase of the current is adjusted appropriately. A controller 203 controls the driving of a motor 100. The motor 100 has a plurality of armature windings 121a, 121b, 121c corresponding respectively to a U phase, V phase, and a W phase, and each armature winding is connected independently from each other. When there is phase interruption to any phase of the U phase, the V phase, and the W phase, with any of the normal phases excluding the phase for which there was phase interruption as a reference phase, the controller 203 adjusts the phase of the current flowing in the normal phase other than the reference phase so as to not extend to the phase for which phase interruption occurred.

Description

Motor control device

<< The present invention relates to a motor control device.

下記 As a background art in this technical field, the following Patent Document 1 is known. Patent Document 1 discloses a motor drive device that controls the driving of a multiphase motor in which armature windings of each phase are provided independently of each other, and converts DC power supplied via a DC bus into a multiphase motor. An inverter circuit that converts the power into AC power and outputs the AC power to each of the armature windings of the respective phases; and a controller for controlling the inverter circuit. A motor that adjusts a phase difference between currents flowing through the normal-phase armature windings so that when the phase is lost, the alternating-current powers of the other normal phases except for the phase that has lost the phase are canceled out with each other. A drive device is disclosed.

Patent No. 6194113

When the motor driving device described in Patent Document 1 is applied to a three-phase motor, there is no particular problem when the U phase or the W phase is lost, but when the V phase is lost, the phase of the current is adjusted. This causes a problem that the rotation direction of the motor becomes the opposite direction. As described above, the technique of Patent Literature 1 has a problem that the phase of the current cannot be appropriately adjusted depending on the phase that has been lost.

A motor control device according to the present invention has a plurality of windings corresponding to each of a plurality of phases, and controls the driving of a motor in which each winding is independently connected to each other. When any of the phases is lost, the phase of the current flowing through the normal phase other than the reference phase is defined as one of the normal phases excluding the missing phase, as the reference phase. Adjust so that there is no straddling.

According to the present invention, the phase of the current can be appropriately adjusted even if any phase is lost in the multi-phase motor.

FIG. 1 is a diagram illustrating a configuration of a motor drive system including a motor control device according to an embodiment of the present invention. Diagram showing an example of the structure of the motor Diagram showing an example of the current waveform of each phase in the motor at normal time Diagram showing magnetomotive force vector in motor at normal time Diagram showing waveform example of induced voltage, current and power of each phase in motor at normal time The figure which shows the example of a waveform of the induced voltage of each phase, a current, and electric power in the motor when the phase adjustment of the current is performed when the W phase is lost. The figure which shows an example of the current waveform of each phase before and after the phase adjustment in the motor when the W phase is lost. The figure which shows the magnetomotive force vector after the phase adjustment in the motor at the time of W phase loss The figure which shows an example of the current waveform of each phase before and after the phase adjustment in the motor when the U phase is lost. The figure which shows the magnetomotive force vector after the phase adjustment in the motor at the time of U phase being lost. The figure which shows an example of the current waveform of each phase before the phase adjustment in the motor when the V phase is lost, and after the phase adjustment by the conventional method. The figure which shows the magnetomotive force vector after the phase adjustment by the conventional method in the motor when a V phase is lost. The figure which shows an example of the current waveform of each phase before the phase adjustment in the motor when the V phase is lost, and after the phase adjustment by the method of this invention. The figure which shows the magnetomotive force vector by the method of this invention in the motor when a V phase is lost. FIG. 3 is a diagram illustrating a phase adjustment method according to the method of the present invention. Diagram for explaining vector control of motor after phase adjustment at the time of phase loss

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a configuration of a motor drive system including a motor control device according to one embodiment of the present invention. The motor drive system 200 shown in FIG. 1 is connected to a motor 100 used in a hybrid vehicle (HEV), an electric vehicle (EV), or the like, and controls driving of the motor 100. The motor drive system 200 has a DC power supply 201, a smoothing capacitor 202, a controller 203, and an inverter circuit 210.

The motor 100 is an independent winding type six-wire three-phase AC motor having three-

phase armature windings

121a, 121b, and 121c respectively corresponding to the U-phase, the V-phase, and the W-phase. These armature windings 121a to 121c are connected to the motor drive system 200 independently of each other. The motor drive system 200 can drive the motor 100 by independently controlling the current flowing through the armature windings 121a to 121c corresponding to the U phase, the V phase, and the W phase, respectively. In the following description, the armature winding 121a corresponding to the U-phase is referred to as “U-phase coil 121a”, the armature winding 121b corresponding to the V-phase is referred to as “V-phase coil 121b”, and the armature corresponding to the W-phase. The winding 121c may be referred to as a “W-phase coil 121c”.

磁 A magnetic pole position detector 113 for detecting the magnetic pole position θ of the motor 100 is attached to the output shaft 115 of the motor 100. The magnetic pole position detector 113 is configured using, for example, a resolver or the like. The detection result of the magnetic pole position θ by the magnetic pole position detector 113 is output to the controller 203.

DC power supply 201 supplies DC power to inverter circuit 210 via DC

buses

201a and 201b. As the DC power supply 201, for example, a secondary battery such as a lithium ion battery can be used.

(4) The smoothing capacitor 202 is for suppressing a change in the DC voltage caused by the operation of the inverter circuit 210, and is connected between the DC bus 201a and the DC bus 201b in parallel with the inverter circuit 210.

The controller 203 outputs drive signals Gu, Gv, and Gw to the

bridge circuits

210a, 210b, and 210c of each phase of the inverter circuit 210, respectively. The controller 203 can control the inverter circuit 210 by operating the

bridge circuits

210a, 210b, and 210c according to the drive signals Gu, Gv, and Gw, respectively. Note that the controller 203 corresponds to a motor control device according to an embodiment of the present invention.

The inverter circuit 210 has full-bridge

type bridge circuits

210a, 210b, and 210c corresponding to the U phase, the V phase, and the W phase, respectively. Each of the

bridge circuits

210a, 210b, 210c has four IGBTs 211 functioning as switching elements of the upper and lower arms, and four diodes 212 provided in parallel with the IGBTs 211. In the

bridge circuits

210a, 210b, and 210c, each IGBT 211 performs a switching operation according to the drive signals Gu, Gv, and Gw from the controller 203. As a result, the DC power supplied from the DC power supply 201 is converted into three-phase AC power, and the armature windings of each phase of the motor 100 from the

bridge circuits

210a, 210b, and 210c via the AC power cables 130 of each phase. It is output to 121a, 121b and 121c, respectively.

A current sensor 140 for detecting each current flowing through the

armature windings

121a, 121b, 121c of the motor 100 is provided on the AC power cable 130 of each phase. The current values i _u , i _v , and i _w of each phase detected by the current sensor 140 are output to the controller 203. The controller 203 performs a predetermined current control calculation based on the current values i _u , _iv , i _{w of} each phase input from the current sensor 140 and the magnetic pole position θ input from the magnetic pole position detector 113. Then, drive signals Gu, Gv, and Gw of each phase are output based on the calculation result.

FIG. 2 is a diagram showing an example of the structure of the motor 100. As shown in FIG. 2, for example, motor 100 includes stator 120 in which armature windings 121a to 121c are electrically attached to each other so as to have a phase difference of 120 ° and output shaft 115, and a plurality of permanent magnets. This is an embedded magnet type motor including a magnet 112 and a rotor 111 embedded therein. An air gap 101 is provided between the stator 120 and the rotor 111.

FIG. 3 is a diagram illustrating an example of a current waveform of each phase in the motor 100 in a normal state. In FIG. 3, when the motor 100 having the internal structure shown in FIG. 2 is connected to the motor drive system 200 as shown in FIG. 1, the AC power supplied from the motor drive system 200 causes the armature windings 121a to 121c of the motor 100 to rotate. An example is shown of current values i _u , _iv and i _w of each phase flowing through 121c. When the three-phase alternating current shown in the figure is applied, the rotor 111 of FIG. 2 rotates counterclockwise.

FIG. 4 is a diagram illustrating a magnetomotive force vector in the motor 100 in a normal state. FIG. 4 shows magnetomotive force vectors in the motor 100 corresponding to the respective electrical angles A to E shown in FIG. 4, magnetomotive force vector _{F u} represents the magnetomotive force created by the U-phase current _{i u} flowing through the U-phase coil 121a, the magnetomotive force vector _{F v} is raised to _the V-phase current _{i v,} flowing through the V-phase coil 121b is made represents magnetic, magnetomotive force vector _{F w} is, W-phase current _{i w} flowing through the W-phase coil 121c represents a magnetomotive force to make. These magnetomotive force vectors are alternating magnetic fields whose magnitude and positive / negative change with time of the current. Also, synthetic magnetomotive force vector F _uvw is a three-phase magnetomotive force vector F _u, F _v, represents the magnetomotive force which is the sum of F _w, which is a rotating magnetic field rotating remain constant magnitude with time change Become.

When the three-phase AC current shown in FIG. 3 is applied to the motor 100 having the internal structure shown in FIG. 2, the resultant magnetomotive force vector F _uvw rotates counterclockwise as shown in FIG. The rotor 111 rotates in synchronization with the magnetic field represented by the _resultant magnetomotive force vector _Fuvw . In FIG. 4 shows the A magnetomotive force vector _F u at each electrical angle of ~ _E, _F _v, F _w and synthetic magnetomotive force vector _{F uvw} shown in FIG. 3, each of the remaining F ~ M magnetomotive force vector _F u of an electrical _angle, F v, are omitted _{F w} and synthetic magnetomotive force vector _{F uvw.} At each of the electrical angles F to M, like the electrical angles A to E, these magnetomotive forces continue to rotate counterclockwise.

電圧 The voltage equation of the motor 100 using the permanent magnet as shown in FIG. 2 is represented by the following equation (1).

In the above formula (1), v _u , v _v , v _w and i _u , _iv , i _w represent the voltage and current of the U phase, V phase, W phase, respectively, and R is one phase. , And P represents a differential operator. In the equation (1), the induced voltages e _u , e _v , e _w of each phase, the self inductances L _u , L _v , L _w of each phase, and the mutual inductances M _uv , M _vw , M _wu between the phases are as follows. , And are represented by the following equations (2), (3), and (4), respectively.

In Expression (2), ω _e represents the electric angular rotation speed of the motor 100, and ψ _m represents the flux linkage of the windings of the permanent magnet 112. Further, in the equation (3), _{l a} denotes the leakage inductance of one phase of the formula (3), in _{_{(4), L a, L}} as the mean value and amplitude components of the effective inductance of one phase Each is represented.

In the case of interior permanent magnet type motor shown in FIG. 2, the formula (3), and _{L the as} ≠ 0 in (4).

The shaft torque T output from the motor 100 to the output shaft 115 is represented by the following equation (5). In the equation (5), P _OUT represents mechanical energy (shaft output) output from the motor 100 to the output shaft 115, and ω _m represents a rotation angular velocity (shaft rotation speed) of the output shaft 115. That shaft torque T is a value obtained by dividing the axial output P _OUT in the axial rotational speed omega _m. Therefore, if the shaft rotation speed ω _m and the motor shaft output P _OUT are constant values, the shaft torque T also becomes constant. In Equation (5), the number of pole pairs of the motor 100 is set to 1 and ω _e = ω _m for simplicity of calculation. However, in actuality, if the number of pole pairs of the motor 100 is P _p , The relationship ω _m = ω _e / P _p holds.

The axis output P _OUT of the motor 100 in the above equation (5) is represented by the following equation (6).

Note that the shaft output P _OUT represented by the equation (6) is equal to a value obtained by subtracting each loss such as copper loss and iron loss from the input power P _IN of the motor 100. The input power P _IN of the motor 100 is obtained by adding the products of the instantaneous voltages v _u , v _v , v _{w of} each phase and the instantaneous currents i _u , _iv , i _w as shown in the following equation (7). Value.

The relatively small embedded magnet type motor of the surface magnet type motor or salient pole ratio, as shown in equation (6), of the input power P _IN, each phase of the induced voltage e _{_u,} e _v, e _w and instantaneous current _i _u, i v, power determined by the product of _{i w} _P _u, _P _v, is _{P w} is converted mainly into shaft output _{P OUT.}

As it can be seen from equation (5), if the shaft output P _OUT is a constant value when the motor 100 is rotating at a constant axial rotation speed omega _m, shaft torque T is constant. As can be seen from equation (6), in order to make the shaft power _{P OUT} of the motor 100 constant, as mentioned above, each phase of the induced voltage _e u of the input power _{P _IN,} _e _v, e _w the instantaneous current _{_i} _u, _i _v, _i _w power _P u determined by a product _of, P v, it is necessary that the sum of _{P w} is constant.

FIG. 5 is a diagram illustrating an example of waveforms of the induced voltage, current, and power of each phase in the motor 100 in a normal state. As described above, the phase difference of the induced voltage of each phase generated U-phase coil 121a, V-phase coil 121b, the W-phase coil 121c, respectively _{_e} _u, _e _v, _e _w are both 120 °. Normally, as shown in FIG. 5, the controller 203 sets the currents i _u , _iv and i _w of the respective phases flowing through the U-phase coil 121a, the V-phase coil 121b and the W-phase coil 121c to a phase difference of 120 ° from each other. The operation timing of the IGBT 211 in each of the

bridge circuits

210a, 210b, 210c is determined so that As a result, the electric powers P _u , P _v , and P _w of each phase obtained by the product of the induced voltage and the current pulsate at a frequency twice the induced voltage and the current, as shown in FIG. Is 60 °. On the other hand, three-phase power _P _u, P v, the input power _{P IN} to the sum of _{P w} is constant as shown in FIG. Therefore, it can be seen that if the induced voltage and current are sinusoidal, torque pulsation does not occur in principle.

In the above description, it is assumed that the induced voltage waveform and the current waveform are ideal sine waves, but actually, the induced voltage waveform and the current waveform contain some harmonics, and It does not become a simple sine wave. However, even in this case, the controller 203 can operate the motor 100 without any problem by treating the induced voltage waveform or the current waveform as a sine wave and controlling the motor 100.

As described above, even in the independent winding type motor 100 that can independently control the currents flowing through the U-phase coil 121a, the V-phase coil 121b, and the W-phase coil 121c, the state in which the three-phase currents are balanced. This makes it possible to rotate the motor 100 while generating a constant torque. This principle is also valid for independent winding type multi-phase motors other than three-phase motors. That is, assuming that the number of phases of the motor is n, the current of each phase is balanced by shifting the phase of the current of each phase by 360 / n °, and the motor can be rotated with a constant torque.

At normal times, the motor drive system 200 can control the torque of the motor 100 to drive the motor 100 by rotating all the phases of the motor 100. However, for example, an abnormality occurs in the operation of the IGBT 211 in one of the

bridge circuits

210a, 210b, and 210c, or an abnormality such as a disconnection occurs in the AC power cable 130 or the wiring in the motor 100 in any phase. If any of the phases is lost and the power cannot be supplied, the torque of the motor 100 cannot be appropriately controlled by the same control method as in the normal state. That is, when any phase is lost in the AC power output from the inverter circuit 210 to the U-phase coil 121a, the V-phase coil 121b, and the W-phase coil 121c of the motor 100, respectively, If current control is performed by shifting the phases of the currents i _u , _iv and i _w by 120 °, a large torque pulsation occurs in the motor 100. Therefore, in the conventional motor drive system, when any phase is lost in the AC power output to the motor, it is necessary to stop the rotation of the motor.

On the other hand, in the motor drive system 200 according to the present invention, when any phase is lost in the AC power output to the motor 100, the controller 203 controls each of the other normal phases excluding the missing phase. The phase difference of the current flowing through the normal-phase armature winding is adjusted so that the AC powers cancel each other. Thereby, the pulsation of the output torque in the motor 100 is reduced, and the rotation of the motor 100 can be continued.

FIG. 6 is a diagram illustrating waveform examples of the induced voltage, current, and power of each phase in the motor 100 when the current phase is adjusted when the W phase is lost. If the W-phase is open phase, the controller 203 in the motor drive system 200 as shown in FIG. 6, by shifting the phase of the current i _v of the V-phase from the normal to 60 ° advances direction (left direction in the drawing) , And the phase difference between the current and the U-phase current _iu is adjusted to 60 °. Specifically, the current control operation by the control unit 203 performs, to adjust the phase of the V-phase current i _v, to be output, in accordance with the the adjusted phase, the bridge circuit 210b of the V-phase from the controller 203 In response, it outputs drive signal Gv. Thus, as shown in FIG. 6, as the valley portions of the U-phase power P peak portions _u and the V-phase power P _v, and U-phase power P _u valleys and V-phase peak portions of the power P _v of overlap, respectively So that they cancel each other out. As a result, even when the open-phase of the W-phase can be a constant three-phase power P _u, P _v, the input power P _IN to the sum of P _w as shown in FIG. Therefore, rotation of motor 100 can be continued while suppressing torque pulsation.

FIG. 7 is a diagram illustrating an example of the current waveform of each phase before and after the phase adjustment in the motor 100 when the W phase is lost. In FIG. 7, (a) shows the waveform of the previous phase adjustment U-phase current i _u and the V-phase current i _v, as described in FIG. 5, they are as a phase difference of 120 °. (B), (c) both shows a waveform after the phase adjustment U-phase current i _u and the V-phase current i _v, as described in FIG. 6, these are as a phase difference of 60 ° I have. Note that FIG. 7B shows a case where the phase of the V-phase current _iv is shifted by 60 ° from the normal time (leftward in the drawing), as described with reference to FIG. Meanwhile, unlike that described in FIG. 6, FIG. 7 (c), the shows a case where shifting the phase of the U-phase current i _u from normal to 60 ° delayed direction (right direction in the drawing).

FIG. 8 is a diagram showing the magnetomotive force vector after the phase adjustment in the motor 100 when the W phase is lost. FIG. 8 shows magnetomotive force vectors in the motor 100 corresponding to the electrical angles A to E shown in FIG. 7B. 8, the magnetomotive force vector _{F u} represents the magnetomotive force created by the U-phase current _{i u} flowing through the U-phase coil 121a, the magnetomotive force vector _{F v} is raised to _the V-phase current _{i v,} flowing through the V-phase coil 121b is made Represents magnetic force. These magnetomotive force vectors are alternating magnetic fields whose magnitude and positive / negative change with time of the current. Also, synthetic magnetomotive force vector F _uv is the magnetomotive force vector F _u, represents the magnetomotive force which is the sum of F _v, which is a rotating magnetic field rotating remain constant magnitude with time change. Since the W-phase 8 is open-phase, W-phase current i _w magnetomotive force vector F _w by is not present.

In FIG. 8, the combined magnetomotive force vector _Fuv rotates counterclockwise, and the rotor 111 rotates in synchronization with the magnetic field represented by the combined magnetomotive force vector _Fuv . That is, the rotation direction of the rotor 111 after the phase adjustment when the W phase is lost coincides with the normal rotation direction of the rotor 111 described with reference to FIG. Therefore, when the W phase is lost, the phase of the U-phase current _iu or the V-phase current _iv is adjusted as described above, so that the rotor 111 can be rotated in the normal rotation direction while suppressing torque pulsation. I understand.

As described above, the controller 203 when the W phase has open phase is, FIG. 7 (b), the by any method (c), the phase difference between the U-phase current _{i u} and _the V-phase current _{i v,} 60 ° to adjust. Thus, while maintaining the rotation state of the motor 100, it is possible to suppress the torque pulsation three-phase power P _u, P _v, the input power P _IN to the sum of P _w is constant.

FIG. 9 is a diagram illustrating an example of the current waveform of each phase before and after the phase adjustment in the motor 100 when the U phase is lost. In FIG. 9, (a) shows the waveform of the previous phase adjustment the V-phase current i _v, and W-phase current i _w, as described in FIG. 5, they are as a phase difference of 120 °. (B), it has a phase difference of (c) are both shows the waveform of the V-phase current i _v, and W-phase current i _w after phase adjustment, these 60 °. Note that FIG. 9B shows a case where the phase of the W-phase current i _w is shifted by 60 ° from the normal time (to the left in the drawing). On the other hand, shows a case where shifted in a direction from the normal delayed 60 ° (right direction in the drawing) to the phase shown in FIG. 9 (c) the V-phase current i _v.

FIG. 10 is a diagram showing the magnetomotive force vector after the phase adjustment in the motor 100 when the U phase is lost. FIG. 10 shows the magnetomotive force vector in the motor 100 corresponding to each of the electrical angles A to E shown in FIG. 9B. 10, the magnetomotive force vector _{F v} is V-phase current _{i v} that flows in V phase coil 121b represents the magnetomotive force created by the magnetomotive force vector _{F w} is caused to W-phase current _{i w} flowing through the W-phase coil 121c is made Represents magnetic force. These magnetomotive force vectors are alternating magnetic fields whose magnitude and positive / negative change with time of the current. Also, synthetic magnetomotive force vector F _vw is the magnetomotive force vector F _v, represents the magnetomotive force which is the sum of F _w, which is a rotating magnetic field rotating remain constant magnitude with time change. Since the U-phase in Figure 10 is open-phase, U-phase current i magnetomotive force vector F _u by _u does not exist.

In FIG. 10, the combined magnetomotive force vector _Fvw rotates counterclockwise, and the rotor 111 rotates in synchronization with the magnetic field represented by the combined magnetomotive force vector _Fvw . That is, the rotation direction of the rotor 111 after the phase adjustment when the U phase is lost is the same as the rotation direction of the rotor 111 in the normal state described with reference to FIG. I do. Therefore, when the U-phase is open phase, by adjusting the phase of the V-phase current i _v, and W-phase current i _w, as described above, while suppressing the torque ripple, can be rotating the rotor 111 in the forward direction I understand.

As described above, the controller 203 when the U-phase is open phase is, FIG. 9 (b), the by any method (c), the phase difference between _the V-phase current _{i v,} and W-phase current _{i w} is 60 ° to adjust. Thus, while maintaining the rotation state of the motor 100, three-phase power P _u, P _v, the input power P _IN to the sum of P _w is constant, it is possible to suppress the torque pulsation.

FIG. 11 is a diagram illustrating an example of the current waveform of each phase in the motor 100 before the phase adjustment and after the phase adjustment by the conventional method when the V phase is lost. In FIG. 11, (a) shows the waveforms of the U-phase current i _u and the W-phase current i _w before the phase adjustment, and these have a phase difference of 120 °. (B) and (c) show the waveforms of the U-phase current i _u and the W-phase current i _w after the phase adjustment by the conventional method, and these have a phase difference of 60 °. Incidentally, the W-phase current _{i w} close to the U-phase current _{i u} and shifted in the advance direction the phase shown in FIG. 11 (b) in the W-phase current _{i w} from normal (left direction in the drawing), the U-phase current _{i u} On the other hand, the case where the phase of the W-phase current i _w is delayed by 60 ° is shown. On the other hand, close the U-phase current _{i u} and W-phase current _{i w} are shifted in the direction behind the phase shown in FIG. 11 (c) the U-phase current _{i u} from normal (right direction in the drawing), the U-phase current _{i u} On the other hand, the case where the phase of the W-phase current i _w is delayed by 60 ° is shown.

FIG. 12 is a diagram showing the magnetomotive force vector of the motor 100 after the phase adjustment by the conventional method when the V phase is lost. FIG. 12 shows magnetomotive force vectors in the motor 100 corresponding to the respective electric angles A to E shown in FIG. 11B. 12, the magnetomotive force vector _{F u} represents the magnetomotive force created by the U-phase current _{i u} flowing through the U-phase coil 121a, the magnetomotive force vector _{F w} is caused to W-phase current _{i w} flowing through the W-phase coil 121c is made Represents magnetic force. These magnetomotive force vectors are alternating magnetic fields whose magnitude and positive / negative change with time of the current. Also, synthetic magnetomotive force vector F _uw is the magnetomotive force vector F _u, represents the magnetomotive force which is the sum of F _w, which is a rotating magnetic field rotating remain constant magnitude with time change. Since the V-phase in Figure 12 is open-phase, V-phase current i _v magnetomotive force vector F _v by are not present.

In FIG. 12, the resultant magnetomotive force vector F _uw rotates clockwise, and the rotor 111 rotates in synchronization with the magnetic field represented by the resultant magnetomotive force vector F _uw . That is, in the conventional method, the rotation direction of the rotor 111 after the phase adjustment when the V phase is lost is different from the rotation direction when the U phase and the W phase are lost, as described with reference to FIG. The direction of rotation of the rotor 111 is opposite. Therefore, when the V phase is lost, if the phase adjustment of the U-phase current i _u or the W-phase current i _w is performed by the conventional method as described above, the rotor 111 rotates in the reverse direction with respect to the normal rotation direction. Will be done.

Therefore, in the present invention, when the V phase is lost, the phase of the rotor 111 is adjusted by a method different from the conventional method, thereby preventing the reverse rotation of the rotor 111. The specific method will be described below.

FIG. 13 is a diagram showing an example of the current waveform of each phase before the phase adjustment and after the phase adjustment by the method of the present invention in the motor 100 when the V phase is lost. In FIG. 13, (a) shows the waveforms of the U-phase current i _u and the W-phase current i _w before the phase adjustment, and these have a phase difference of 120 ° as in FIG. (B) and (c) show the waveforms of the U-phase current i _u and the W-phase current i _w after the phase adjustment by the method of the present invention, and these have a phase difference of 60 °. In FIG. 13B, contrary to the case of FIG. 11B, the phase of the W-phase current i _w is shifted in the delay direction (rightward direction in the figure) from the normal time, and the W-phase current i _w is shifted to the U-phase. close to the current i _u, the phase of the U-phase current i _u indicates a case where as delayed 60 ° with respect to W-phase current i _w. On the other hand, contrary to the case of FIG. 13 (c) in FIG. 11 (c), W phase the U-phase current i _u and shifted in the advance direction the phase of the U-phase current i _u from normal (left direction in the drawing) The case where the current is approached to the current i _w and the phase of the U-phase current i _u is delayed by 60 ° with respect to the W-phase current i _w is shown. That is, in FIGS. 13B and 13C, the phase order of the U-phase current i _u and the W-phase current i _w is switched as compared with the cases of FIGS. 11B and 11C, respectively.

FIG. 14 is a diagram showing the magnetomotive force vector of the motor 100 after phase adjustment by the method of the present invention when the V phase is lost. FIG. 14 shows magnetomotive force vectors in the motor 100 corresponding to the electrical angles A to E shown in FIG. 13B. 14, the magnetomotive force vector _{F u} represents the magnetomotive force created by the U-phase current _{i u} flowing through the U-phase coil 121a, the magnetomotive force vector _{F w} is caused to W-phase current _{i w} flowing through the W-phase coil 121c is made Represents magnetic force. These magnetomotive force vectors are alternating magnetic fields whose magnitude and positive / negative change with time of the current. Also, synthetic magnetomotive force vector F _uw is the magnetomotive force vector F _u, represents the magnetomotive force which is the sum of F _w, which is a rotating magnetic field rotating remain constant magnitude with time change. Since the V-phase in Figure 14 is open-phase, V-phase current i _v magnetomotive force vector F _v by are not present.

In FIG. 14, the combined magnetomotive force vector F _uw rotates counterclockwise, and the rotor 111 rotates in synchronization with the magnetic field represented by the combined magnetomotive force vector F _uw . That is, according to the method of the present invention, the rotation direction of the rotor 111 after the phase adjustment when the V phase is lost is the same as that in the case where the U phase and the W phase are lost. The rotation direction can be matched. Therefore, when the V-phase is lost, the phase of the U-phase current i _u or the W-phase current i _w is adjusted by the method of the present invention as described above, so that the torque pulsation is suppressed and the rotor 111 is moved. It turns out that it can rotate in the forward direction.

As described above, when the V phase is lost, the controller 203 sets the phase difference between the U-phase current i _u and the W-phase current i _w to 60 by one of the methods shown in FIGS. ° to adjust. Thus, while maintaining the rotation state of the motor 100, it is possible to suppress the torque pulsation three-phase power P _u, P _v, the input power P _IN to the sum of P _w is constant.

Next, the phase adjustment method according to the method of the present invention will be described with reference to FIG. FIG. 15 is a diagram illustrating a phase adjustment method according to the method of the present invention.

FIG. 15A shows the phase relationship among the currents i _u , _iv and i _w of each phase when the three phases in the motor 100 are sound without any phase loss. When the three phases are sound, as shown in FIG. 15A, the currents i _u , _iv and i _w of each phase have a phase difference of 120 °.

FIG. 15 (b) represents the phase relationship between the V-phase current i _v, and W-phase current i _w of the phase-adjustment in the case of open-phase is the U phase of the three-phase in the motor 100. In this case, the controller 203 shifts the phase of the W-phase current i _w by 60 ° from the normal time as described with reference to FIG. 9B, for example. That is, when the U phase is lost, the controller 203 sets the V phase which is one of the normal phases excluding the missing U phase among the three phases as the reference phase, as shown in FIG. The phase of the W-phase current i _w flowing through the remaining W-phases is shifted in the leading direction (clockwise direction) by a shift amount of 60 °. At this time, the phase of the W-phase current i _w is adjusted without straddling the U-phase which is out of phase. Thus, even when the U phase is lost, the rotation of the motor 100 can be maintained in the normal rotation direction while suppressing the torque pulsation.

In FIG. 15B, the phase adjustment method described with reference to FIG. 9B, that is, the case where the phase of the W-phase current i _w is shifted by 60 ° in the leading direction (clockwise) with the V phase as the reference phase. However, the phase adjustment method described with reference to FIG. 9C may be used. Specifically, when the U phase is lost, the controller 203 sets the W phase, which is the other of the normal phases excluding the missing U phase among the three phases, as the reference phase, and sets the remaining V phases to the remaining V phases. the phase of the V-phase current i _v, flowing, may be shifted by a shift amount of 60 ° to the delay direction (counterclockwise direction). Phase of this time the V-phase current i _v, is adjusted without cross the open phase and U-phase.

FIG. 15 (c) represents the phase relationship between the U-phase current i _u and the V-phase current i _v, after the phase adjustment in the case of open-phase is the W phase of the three-phase in the motor 100. In this case the controller 203, for example as described in the previous FIG. 7 (b), the shifting in the direction of the phase advances 60 ° from normal the V-phase current i _v. That is, when the W phase is lost, the controller 203 sets the U phase which is one of the normal phases excluding the missing W phase among the three phases as the reference phase, as shown in FIG. as the phase of the V-phase current i _v, flowing to the rest of the V-phase, thereby advances the shift amount of shift of 60 ° in the direction (clockwise direction). Phase of this time the V-phase current i _v, is adjusted without cross the open phase was W-phase. Accordingly, even when the W phase is lost, the rotation of the motor 100 can be maintained in the normal rotation direction while suppressing the torque pulsation.

In FIG. 15C, the phase adjustment method described with reference to FIG. 7B, that is, the case where the phase of the V-phase current _iv is shifted by 60 ° in the advancing direction (clockwise) with the U-phase as the reference phase. However, the phase adjustment method described with reference to FIG. 7C may be used. Specifically, when the W phase is lost, the controller 203 sets the V phase, which is the other of the normal phases excluding the missing W phase among the three phases, as the reference phase, and sets the remaining U phases to the remaining U phases. The phase of the flowing U-phase current _iu may be shifted in the delay direction (counterclockwise) by a shift amount of 60 °. Phase of this time the U-phase current i _u is adjusted without cross the open phase was W-phase.

FIG. 15D shows the phase relationship between the U-phase current i _u and the W-phase current i _w after the phase adjustment when the V phase is lost in the three phases in the motor 100. In this case, the controller 203 shifts the phase of the W-phase current i _{w in} a direction delayed by 60 ° from the normal time, for example, as described with reference to FIG. That is, when the V phase is lost, the controller 203 sets the U phase which is one of the normal phases excluding the missing V phase among the three phases as the reference phase, as shown in FIG. The phase of the W-phase current i _w flowing through the remaining W-phase is shifted by 60 ° in a delay direction (counterclockwise direction) opposite to the U-phase open phase shown in FIG. Shift. Phase of this time the W-phase current i _w is adjusted without cross the V-phase that is open-phase. Thus, even if the V phase is lost, the rotation of the motor 100 can be maintained in the normal rotation direction while suppressing torque pulsation.

Here, a case is considered in which the phase of the W-phase current i _w is shifted in the leading direction (clockwise direction), which is the same direction as in the U-phase open phase shown in FIG. In this case, as shown in FIG. 15 (e), the phase of the W-phase current i _w is adjusted with a shift amount of 180 ° over the missing V phase. As a result, as described with reference to FIG. 12, the resultant magnetomotive force vector F _uw that rotates clockwise in the rotor 111 is generated, so that the rotation direction of the motor 100 is reversed with respect to the normal state.

In FIG. 15D, the phase adjustment method described with reference to FIG. 13B, that is, the phase of the W-phase current i _w is shifted by 60 ° in the delay direction (counterclockwise) with the U phase as the reference phase. Although the case is shown, the phase adjustment method described with reference to FIG. Specifically, when the V phase is lost, the controller 203 sets the W phase, which is the other of the normal phases excluding the missing V phase among the three phases, as a reference phase, and sets the remaining U phases to the remaining U phases. the phase of the flow the U-phase current i _u, the time W Aiketsu phase may be shifted by a shift amount of 60 ° in the direction opposite to the leading direction (clockwise direction). Phase of this time the U-phase current i _u is adjusted without cross the V-phase that is open-phase.

FIG. 16 is a diagram illustrating the vector control of the motor 100 after the phase adjustment at the time of the phase loss. When any one of the U phase, the V phase, and the W phase is lost in the motor 100, the controller 203 determines which one of the currents i _u , _iv , and i _w of each phase flows through the normal phase excluding the missing phase. After performing the above-described phase adjustment, the phase difference between the combined magnetomotive force vectors F _uv , F _vw , and F _uw of the normal phase and the magnetic pole position of the rotor 111 always becomes a certain value. Then, the amplitude and phase of the current flowing in the normal phase are controlled. Thereby, the motor 100 can be driven by changing the rotational position of the rotor 111 from, for example, FIG. 16A to FIG. 16B and continuing the same control. Note that the phase difference between the resultant magnetomotive force vector and the magnetic pole position at this time can be changed according to, for example, the operating state (torque, rotation speed) of the motor 100. The magnetic pole position can be detected by the magnetic pole position detector 113.

The reduction of torque pulsation by the current phase adjustment at the time of phase loss as described above can be applied to a multi-phase motor of an independent winding type other than three phases. That is, assuming that the number of phases of the motor to be controlled is n and the number of missing phases is m, the motor control device according to the present invention provides each normal Are adjusted so that the phase difference Dp (°) of the above satisfies the following equation (8). At this time, with any one of the normal phases as a reference phase, the phases of the currents flowing through the normal phases other than the reference phase are adjusted so as not to cross over the missing phase. Thus, it is possible to maintain the normal phase of the combined magnetomotive force vector in the same direction as in the normal state, and cancel out the normal phase AC powers. As a result, the pulsation of the output torque of the motor can be suppressed, and the rotation of the motor can be continued.
Dp = 360/2 (nm) (8)
Here, n and m are positive integers, and n ≧ m + 2

In order to satisfy the above expression (8), the phase difference Di (°) of each current flowing through the normal-phase armature winding may be adjusted so as to satisfy the following expression (9). Thus, when an open phase occurs in any of the phases, the AC powers in the normal phase are offset with each other, and pulsation of the output torque of the motor can be suppressed.
Di = 360 / (nm) -360 / n (9)

The above equation (8), (9) in the n = 3, When m = 1, Dp = 90 ° , Di = 60 ° becomes, as shown in FIG. 6 U-phase power _{P u} and the V-phase power _{P v} relationship, and each can be seen to coincide with the relationship of the U-phase current i _u and the V-phase current i _v.

According to the embodiment of the present invention described above, the following operation and effect can be obtained.

(1) The controller 203, which is a motor control device, controls driving of the motor 100. The motor 100 has a plurality of

armature windings

121a, 121b, 121c corresponding to each of a plurality of phases, and the armature windings are connected independently of each other. When any one of the plurality of phases is lost, the controller 203 sets the phase of the current flowing through the normal phase other than the reference phase as one of the normal phases excluding the missing phase as a reference phase. , So that there is no straddling over the missing phase. With this configuration, the phase of the current can be appropriately adjusted even if any phase is lost in the multiphase motor.

(2) The plurality of phases of the motor 100 correspond to the U phase, the V phase, and the W phase, respectively. When the U-phase is out of phase, the controller 203 sets one of the non-out-of-phase V-phase or W-phase as a reference phase and the remaining W-phase or V-phase as described with reference to FIGS. current flowing through the phase i _w, the phase of the i _v, shifting by a predetermined shift amount (60 °) in a predetermined shifting direction (leading direction or the delay direction). When the W phase is lost, as described with reference to FIG. 7 and FIG. 15C, one of the U phase and the V phase that is not lost is used as a reference phase and flows into the remaining V phase or U phase. The phases of the currents _iv and _iu are shifted by the shift amount (60 °) in the shift direction (leading direction or lagging direction). On the other hand, when the V phase is lost, as described with reference to FIG. 13 and FIG. 15D, one of the U phase and the W phase that is not missing is used as a reference phase and flows into the remaining W phase or U phase. The phases of the currents i _w and i _u are shifted by the shift amount (60 °) in the direction opposite to the shift direction (the delay direction or the advance direction). Thus, in a three-phase motor, which is a typical multi-phase motor, the phase of the current can be appropriately adjusted even if any of the U, V, and W phases is lost.

(3) The shift amount when the controller 203 adjusts the phases of the currents i _u , _iv and i _{w at} the time of phase loss is 60 ° in phase angle. With this configuration, it is possible to suppress the pulsation of the output torque by canceling the AC powers of the normal phase with each other without straddling the missing phase.

(4) The magnetic pole position detector 113 for detecting the magnetic pole position of the rotor 111 of the motor 100 is attached to the motor 100. The controller 203 drives the motor 100 by controlling the amplitude and phase of the current flowing in the normal phase based on the magnetic pole position detected by the magnetic pole position detector 113. With this configuration, the driving of the motor 100 can be appropriately continued even during the phase loss.

The embodiments and various modifications described above are merely examples, and the present invention is not limited to these contents as long as the features of the present invention are not impaired. Although various embodiments and modifications have been described above, the present invention is not limited to these contents. Other embodiments that can be considered within the scope of the technical idea of the present invention are also included in the scope of the present invention.

100: motor 111: rotor 113: magnetic pole position detector 120: stator 121a: armature winding (U-phase coil)
121b: armature winding (V-phase coil)
121c: armature winding (W-phase coil)
130: AC power cable 140: Current sensor 200: Motor drive system 201:

DC power supply

201a, 201b: DC bus 202: Smoothing capacitor 203: Controller 210:

Inverter circuit

210a, 210b, 210c: Bridge circuit 211: IGBT
212: diode

Claims

A motor control device that has a plurality of windings corresponding to each of a plurality of phases and controls the driving of a motor in which each winding is connected independently of each other,
When any one of the plurality of phases is lost, the phase of the current flowing in the normal phase other than the reference phase, using any of the normal phases excluding the missing phase as a reference phase, A motor control device for adjusting so as not to straddle the missing phase.
The motor control device according to claim 1,
The plurality of phases respectively correspond to a U phase, a V phase, and a W phase,
When the U-phase is out of phase, the phase of the current flowing through the remaining W-phase or the V-phase is set in a predetermined shift direction, with one of the V-phase or the W-phase that is not out of phase as the reference phase. Shift by a predetermined shift amount,
When the W phase is out of phase, one of the U phase or the V phase that is not out of phase is used as the reference phase, and the phase of the current flowing through the remaining V phase or the U phase is shifted in the shift direction. Shift by the shift amount,
When the V-phase is out of phase, one of the U-phase or the W-phase that is not out of phase is used as the reference phase, and the phase of the current flowing in the remaining W-phase or U-phase is defined as the shift direction. A motor control device for shifting in the reverse direction by the shift amount.
The motor control device according to claim 2,
The motor control device, wherein the shift amount is 60 ° in phase angle.
The motor control device according to any one of claims 1 to 3,
A magnetic pole position detector that detects a magnetic pole position of a rotor of the motor is attached to the motor,
A motor control device that drives the motor by controlling an amplitude and a phase of a current flowing in the normal phase based on the magnetic pole position detected by the magnetic pole position detector.