JP7196525B2 - Permanent magnet synchronous motor drive system - Google Patents

Description

The present invention relates to a drive system for driving a permanent magnet synchronous motor using an inverter. It relates to a fail-safe technology that short-circuits windings to perform a retraction operation to the safe side.

FIG. 11 is a main circuit configuration diagram of a drive system for a permanent magnet synchronous motor.
In FIG. 11, 10 is a DC power supply, 20 is a three-phase voltage type inverter composed of semiconductor switching elements _Qu , _Qv , _Qw , _Qx , _Qy , _Qz such as IGBTs and MOSFETs, PMSM is a permanent magnet synchronous is the motor. In the following, the permanent magnet synchronous motor PMSM is also simply referred to as a synchronous motor, and only the stator windings are illustrated.

In the drive system described above, if the rotor of the synchronous motor is forcibly driven by an external factor, the regenerative voltage generated by the operation of the generator may become excessive, destroying the switching elements and causing danger to the human body. There is
For this reason, various inventions have heretofore been provided in which an abnormality such as a DC voltage of an inverter is detected and a fail-safe operation is performed.

For example, FIG. 12 shows an inverter fail-safe device described in Patent Document 1. In FIG. In FIG. 12, reference numeral 30 denotes a drive switching circuit that generates drive signals (gate signals) for switching elements Q _u and Q _x that constitute one phase leg of the inverter 20 . This drive switching circuit 30 includes a three-phase PWM drive circuit 32, a three-phase short-circuit drive circuit 33 connected to an overvoltage detection circuit 31, and switching elements Q _u and Q _x according to the output signals of the drive circuits 32 and 33. and an AND circuit 34 and an OR circuit 35 for generating a drive signal of .
The overvoltage detection circuit 31 and the drive circuits 32 and 33 are also used to generate drive signals for switching elements of other phases.

In the conventional technology described above, the switching elements Q _u and Q _x are driven through the AND circuit 34 and the OR circuit 35 by the PWM signal from the three-phase PWM drive circuit 32 in normal operation.
Further, when the DC voltage of the inverter 20 exceeds the voltage set by the overvoltage detection circuit 31, the output signal of the three-phase short-circuit drive circuit 33 is input to the switching element _Qx via the OR circuit 35, and the switching element _Qx is It is short-circuited together with the switching elements Q _y and Q _z of the phase. As a result, the rotation speed of the synchronous motor can be decreased, and the DC voltage of the inverter 20 can be decreased to a normal value.

Further, FIG. 13 shows an inverter fail-safe device described in Patent Document 2. As shown in FIG. 13, 36 is a control device, 37 is a DC voltage detection means, 38 is an inverter drive circuit having a fail-safe function, 38a is a short-circuiting means for turning on the switching element of the inverter 20, and 38b is for intermittently turning on the switching element. 38c is an intermittent short circuit means for turning off the switching element.

In this prior art, as shown in FIG. 14, the short-circuiting operation by the short-circuiting means 38a (steps S51 and S52) is performed according to the magnitude relationship between the DC voltage detected by the DC voltage detecting means 37, the short-circuit threshold value, and the smaller open threshold value. ), the opening operation by the opening means 38c (steps S53 and S54), or the intermittent short-circuiting operation by the intermittent short-circuiting means 38b. As a result, the lower arm of all phases of the inverter 20 is short-circuited (line-to-line short circuit), the upper and lower arms of all phases are opened (line-to-line open), or intermittently short-circuited, thereby performing a fail-safe operation when the DC voltage rises. .
In addition, in Patent Document 2, it is possible to perform a short-circuit operation, an open operation, etc., based on the result of comparison with a predetermined threshold for the AC voltage of the inverter and the rotational speed of the motor.

The prior art described in Patent Documents 1 and 2 mentioned above mainly relates to fail-safe technology when the DC voltage of the inverter becomes overvoltage.
On the other hand, Patent Documents 3 to 5 disclose conventional techniques for detecting a short-circuit failure or the like of a switching element that constitutes an inverter, specifying a short-circuited phase (leg) or upper and lower arms, and performing a retraction operation.

For example, in Patent Document 3, when a phase current of a certain value or more flows even though an abnormality of an inverter is detected and all upper and lower arms are turned off, a difference current based on a signal obtained by smoothing each phase current and a one-phase current Identify the number of short-circuited phases, short-circuited phases and upper and lower arms by comparing each current level of short-circuit, two-phase short-circuit (two-phase same arm short-circuit), and three-phase short-circuit (three-phase same arm short-circuit). is disclosed in which the evacuation operation is performed by another inverter after short-circuiting.
Note that FIG. 15(a) shows the current waveform of each phase when one phase (U phase) is shorted, FIG. 15(b) shows the waveform when two phases (U phase and V phase) are shorted, and FIG. 15(c) shows the current waveform when three phases are shorted. is.

Further, in Patent Document 4, a one-phase, two-phase, or three-phase short-circuit is determined based on the presence or absence of a phase where the three-phase alternating current generated by the back electromotive force of a synchronous motor crosses zero and the number of phases, and one-phase or three-phase short circuit is determined. A technique is disclosed for performing safe operation by short-circuiting an upper arm or a lower arm according to the direction of the current of the short-circuited phase when two phases are short-circuited.
Furthermore, in Patent Document 5, three-phase short-circuit control is performed when one-phase short-circuit fault occurs, and in that state, it is detected that one-phase open-circuit fault (short-circuit of the other two phases) has occurred, and safe operation is performed. A technique for doing so is disclosed.

Japanese Patent No. 5813167 (paragraphs [0011] to [0019], FIGS. 1, 2, etc.) Japanese Patent No. 5398815 (paragraphs [0008] to [0013], FIGS. 1, 5, etc.) Japanese Patent No. 5003589 (paragraphs [0024] to [0033], FIGS. 3, 4, etc.) JP 2016-123141 A (paragraphs [0040] to [0043], FIG. 8, etc.) Japanese Patent No. 5277817 (paragraphs [0101] to [0120], FIG. 7, etc.)

The prior arts described in Patent Documents 1 and 2 do not deal with short-circuit fixation or open-fixation of switching elements, and the synchronous motor may not be driven when these failures occur.
Further, in the conventional techniques described in Patent Documents 1 to 5, when the switching elements of the upper arm or the lower arm of all phases of the inverter are turned ON to perform the fail-safe operation, the switching elements of the opposite arm are short-circuited or fixed. If open fixation or the like occurs, there is a risk of causing a secondary failure due to, for example, short-circuiting of the upper and lower arms.

Therefore, the problem to be solved by the present invention is to focus on the balance state of each phase output current of the inverter, detect the short-circuit sticking or open sticking of the switching element, avoid the short-circuit of the upper and lower arms, and rotate the stator winding of the synchronous motor. To provide a drive system for a permanent magnet synchronous motor which is short-circuited to perform fail-safe operation.

In order to solve the above problems, the invention according to claim 1 includes a three-phase inverter for driving a three-phase permanent magnet synchronous motor, and a control device for generating drive signals for semiconductor switching elements that constitute the inverter. In a permanent magnet synchronous motor drive system comprising:
The control device is
a first function for detecting an abnormality in the inverter;
a second function for detecting each phase output current of the inverter;
In order to short-circuit the stator windings of the permanent magnet synchronous motor when an abnormality is detected by the first function, the upper and lower arms of the inverter are controlled according to the balance state of each phase output current detected by the second function. a third function of generating the drive signal so as to turn on the semiconductor switching elements of the upper arm or the lower arm of all phases while avoiding a short circuit;
with
A drive circuit that generates the drive signal has the first function,
The third function further turns off all the semiconductor switching elements of the inverter when an abnormality is detected by the drive circuit, and switches between the upper arm or the lower arm of the inverter according to the balance state of each phase output current. When it is determined whether or not the semiconductor switching elements of the arms are stuck to a short circuit, and when it is determined that the semiconductor switching elements of the upper arm or the lower arm of the inverter are not stuck to a short circuit, the upper arm or the lower arm of all the legs of the inverter is determined. The semiconductor switching element is turned on to short-circuit the stator windings, and it is determined whether the upper arm or the lower arm has open sticking according to the balance state of each phase output current, or it is determined that there is no sticking failure. characterized by

The invention according to claim 2 is the permanent magnet synchronous motor drive system according to claim 1,
The third function further turns on the semiconductor switching elements of the upper arm or the lower arm of the inverter for legs other than the abnormal leg when it is determined that the semiconductor switching elements of the upper arm or the lower arm of the inverter are stuck. and the stator winding is short-circuited, and whether the upper arm or the lower arm has the short-circuit fixation is determined according to the balance state of the output currents of the respective phases .

According to a third aspect of the present invention, there is provided a drive for a permanent magnet synchronous motor having a three-phase inverter for driving a three-phase permanent magnet synchronous motor, and a control device for generating drive signals for semiconductor switching elements forming the inverter. In the system
The control device is
a first function for detecting an abnormality in the inverter;
a second function for detecting each phase output current of the inverter;
In order to short-circuit the stator windings of the permanent magnet synchronous motor when an abnormality is detected by the first function, the upper and lower arms of the inverter are controlled according to the balance state of each phase output current detected by the second function. a third function of generating the drive signal so as to turn on the semiconductor switching elements of the upper arm or the lower arm of all phases while avoiding a short circuit;
with
The first function is provided by a portion other than the drive circuit that generates the drive signal,
The third function further determines whether or not the semiconductor switching elements of the upper arm or the lower arm of the inverter are open-fixed according to the balance state of the output currents of the respective phases when an abnormality is detected by the first function. It is characterized by judging that there is no sticking failure .

According to a fourth aspect of the present invention, there is provided a drive for a permanent magnet synchronous motor having a three-phase inverter for driving a three-phase permanent magnet synchronous motor, and a control device for generating drive signals for semiconductor switching elements constituting the inverter. In the system
The control device is
a first function for detecting an abnormality in the inverter;
a second function for detecting each phase output current of the inverter;
In order to short-circuit the stator windings of the permanent magnet synchronous motor when an abnormality is detected by the first function, the upper and lower arms of the inverter are controlled according to the balance state of each phase output current detected by the second function. a third function of generating the drive signal so as to turn on the semiconductor switching elements of the upper arm or the lower arm of all phases while avoiding a short circuit;
with
A drive circuit that generates the drive signal has the first function,
The third function further turns off all the semiconductor switching elements of the inverter when an abnormality is detected by the drive circuit, and switches between the upper arm or the lower arm of the inverter according to the balance state of each phase output current. Judge the presence or absence of short-circuit fixation of the semiconductor switching element of the arm,
Further, the third function is, when it is determined that the semiconductor switching element of the upper arm or the lower arm of the inverter has a short-circuit fixation , the semiconductor switching element of the upper arm or the lower arm of the leg other than the abnormal leg of the inverter. The side element is turned ON to short-circuit the stator winding, and it is determined whether the short- circuit is stuck in the upper arm or the lower arm according to the balance state of the output current of each phase, and it is determined that the short-circuit is stuck. The time is characterized in that the element on the other side is turned on instead of the element on the one side .

According to the first aspect of the invention, when the windings of the synchronous motor are finally short-circuited when an abnormality occurs in the inverter, the fail-safe operation can be reliably performed while avoiding secondary failures such as short-circuiting of the upper and lower arms. It is possible to identify the leg (phase) in which the failure has occurred and determine whether or not the switching element is short-circuited.
Further , according to the invention of claim 1 or 2 , it is possible to specify the arm in which short-circuit sticking or open sticking has occurred, or to determine the presence or absence of sticking failure.
Furthermore, according to the third aspect of the invention, when an abnormality is detected in a portion other than the drive circuit, it is possible to identify the arm in which the open fixation has occurred, or to determine whether or not there is a fixation failure.
Further, according to the fourth aspect of the invention, when it is determined that the semiconductor switching element of the upper arm or the lower arm of the inverter is stuck to a short circuit, the semiconductor switching device of the upper arm or the lower arm of the leg other than the abnormal leg of the inverter is detected. When the element on one side of the element is turned ON and the stator winding is successfully short-circuited, it can be determined that the semiconductor switching element on the upper arm or the lower arm of the abnormal leg is short-circuited and fixed.

1 is a main circuit configuration diagram of a drive system according to an embodiment of the present invention; FIG. FIG. 2 is a functional block diagram of a control device for the inverter in FIG. 1; 4 is a flow chart showing a control sequence when an abnormality is detected in the embodiment of the present invention; FIG. 4 is an explanatory diagram of each phase current when all gates are cut off; FIG. 4 is an explanatory diagram of each phase current during a normal winding short circuit; FIG. 5 is an explanatory diagram of each phase current when a switching element of an upper arm is short-circuited and stuck; FIG. 5 is an explanatory diagram of each phase current when a switching element of a lower arm is short-circuited and stuck; FIG. 4 is an explanatory diagram of each phase current when the switching element of the upper arm is stuck open; FIG. 4 is an explanatory diagram of each phase current when the switching element of the lower arm is stuck open; 4 is a flow chart showing a control sequence when another abnormality is detected in the embodiment of the present invention; 1 is a main circuit configuration diagram of a drive system for a permanent magnet synchronous motor; FIG. 1 is a configuration diagram of a conventional technology described in Patent Document 1; FIG. 1 is a configuration diagram of a conventional technology described in Patent Document 2; FIG. 4 is a flow chart showing a fail-safe operation described in Patent Document 2; FIG. 4 is a waveform diagram showing phase currents at one-phase, two-phase, and three-phase short-circuits;

An embodiment of the present invention will be described below with reference to the drawings.
FIG. 1 is a main circuit configuration diagram of a drive system according to this embodiment. In FIG. 1, 10 is a DC power supply, 20 is a three-phase voltage inverter composed of semiconductor switching elements _Qu , _Qv , _Qw , _Qx , _Qy , _Qz such as IGBTs, and PMSM is a permanent magnet synchronous motor. be. MOSFETs, power transistors, or the like may be used as the switching elements _Qu , _Qv , _Qw , _Qx , _Qy , and _Qz .
Current detectors 40u, 40v, and 40w are provided in the output lines of the respective phases (U, V, and W phases) of the inverter 20, and the current detection values of the respective phases are obtained by the control calculation unit in the control device shown in FIG. 52 is entered.

FIG. 2 is a functional block diagram of a control device for inverter 20. As shown in FIG. This control device includes a gate drive circuit 51 that generates gate signals for switching elements Q _i (i=u to z), and a control operation section 52 that is mainly composed of software.
The control calculation unit 52 has a phase current detection function 52a to which detection signals from the current detectors 40u, 40v, and _40w are input, and an abnormality detection function that detects inverter abnormalities including short-circuit failures and open-circuit failures of the switching elements Qi. 52b, a control sequence processing function 52c that executes a control sequence to be described later based on the phase current detection function 52a and the abnormality detection function 52b, and a PWM signal for the switching element _Qi for PWM-controlling the inverter 20 during normal operation. A PWM output function 52d for switching, a port output function _52e for forcibly turning on the switching element Qi when an abnormality occurs, and a switching function 52f for switching between these output functions 52d and 52e.
Further, the gate drive circuit 51 generates a gate signal for turning ON/OFF the switching element Qi according to the output of the switching function _52f .

Next, the operation of this embodiment will be described.
The control sequence processing function 52c executes the control sequence of FIG. 3 when an abnormality such as a short-circuit failure or an open-circuit failure of a switching element occurs, and finally short-circuits the stator winding of the synchronous motor PMSM to perform a fail-safe operation. conduct.

Here, as the abnormality detection function of the gate drive circuit 51, a DESAT function for detecting a momentary short circuit between the upper and lower arms to cut off the gate and an overcurrent detection function for the sense current are known. However, although these anomaly detection functions can identify the leg where the anomaly has occurred, it is not possible to identify the top and bottom of the arm. is also impossible to discriminate.
Therefore, in the present embodiment, the control sequence processing function 52c focuses on the balance of the three-phase current at the time of occurrence of an abnormality, and the winding short-circuit is performed while identifying the upper and lower sides of the inverter leg or arm where the abnormality occurs.

The control sequence when an abnormality occurs will be described below with reference to the flow chart of FIG. 3 and FIGS. 4 to 10. FIG.
FIG. 3 shows a circuit for performing fail-safe operation by controlling switching elements so as to short-circuit the stator windings of the synchronous motor PMSM when an abnormality in the inverter 20 is detected by the DESAT function or the like of the gate drive circuit 51. control sequence.

First, when an abnormality is detected during the operation of the synchronous motor PMSM by the inverter 20, gate signals to all the switching elements Q _i (i=u to z) are cut off (step S1), and then each phase of the inverter 20 is turned off. A current balance is determined (step S2).
When the switching elements _Qi are normal, the switching elements Qi that are turned off by blocking all gates can conduct current only through the _freewheeling diodes. A regenerative current flows in the directions shown in FIGS. At this time, the phases of the phase currents _Iu , _Iv , and _Iw are out of phase with each other by 120[°] as shown in FIG. 4(d), and the balance is maintained (step S2 OK).

In this case, since all the switching elements are normally turned off according to the all-gate cutoff command, it can be determined that the short circuit is not fixed.
Therefore, the winding short-circuit is attempted by turning on the switching elements of one arm, for example, the upper arm of all phases via the port output function 52e, the switching function 52f and the gate drive circuit 51 of FIG. 2 (step S3).

Next, the balance of each phase current of inverter 20 is determined again (step S4). If the switching elements of the upper arm are not stuck open, the switching elements of the upper arm of all phases are turned ON in step S3, so the phase currents _Iu , _Iv , and _Iw should be balanced. .
That is, when the phase currents _Iu , _Iv , and _Iw are in balance (step S4 OK), at least the upper arm switching element is not stuck in a short circuit or open, and the ON state of the upper arm switching element Winding short circuit is working normally. FIG. 5(a) shows the current paths when the _windings are normally short- _circuited by turning _ON the switching element of the upper arm, and FIG. It is a waveform diagram.

Next, if it is not necessary to confirm whether or not there is a sticking failure in the switching element of the lower arm (step S5 Yes), it is determined that the winding short-circuit has been successfully completed by turning on the switching element of the upper arm, and the process ends (step S31). .

Also, if the phase currents _Iu , _Iv , and _Iw are unbalanced in step S2 (step S2 NG), it can be determined that the switching element of the upper arm or the lower arm is short-circuited.
Here, FIGS. 6A, 6B, and 6C show the current corresponding to the polarity of the induced voltage in the stator winding when, for example, the switching element _Qu of the U-phase upper arm is short-circuited and stuck. showing the route. Since all the gates are cut off by the step S1, the current due to the induced voltage flows only through the free wheel diode of the inverter 20 as shown in FIGS. 6(a) and 6(b). However, if, for example, a switching element in a certain leg is short-circuited and fixed, a current with the opposite polarity to the sum of the currents flowing through the other two phases will flow through this switching element. A sticking leg can be identified.
For example, when a short-circuit sticking occurs in the switching element _Qu , a current path exists via the switching element _Qu as shown in FIG. A current I _u =−(I _v +I _w ) is observed.

Therefore, it is determined that the abnormal leg due to the short-circuit sticking is the U phase, and for the other two phases (V phase, W phase), for example, by turning ON the upper arm switching elements of all phases, the upper arm switching elements are turned ON. , and attempt to short-circuit the windings (step S6).
As a result, if the phase currents _Iu , _Iv , and _Iw are in balance (step S7 OK), the winding short-circuit due to the turning on of the switching element of the upper arm is successful, and the upper arm of the U phase, which is the abnormal leg. It is determined that the switching element of the arm is short-circuited and stuck, and the process is terminated (step S32).

Further, if the phase currents _Iu , _Iv , and _Iw are unbalanced in step S7 of FIG. 3 (step S7 NG), the switching element _Qx in the lower arm of the U phase, which is the abnormal leg, is short-circuited and fixed. There is a possibility that
Here, FIGS. 7(a) and 7(b) show a case where all gates are cut off (step S1) when the switching element _Qx is short-circuited and each phase current is unbalanced (step S2 NG). 7(c) and (d), turning on the upper arm switching elements of the V and W phases other than the U phase to try to short-circuit the windings (step S6), each phase current is This is the current path in the case of imbalance (step S7 NG).
FIG. 7(e) shows the case where the switching element of the lower arm is turned on to try to short-circuit the windings of the V and W phases other than the U phase, which is the abnormal leg (steps S8 and S33). It is a current path, and it is determined that the U-phase lower arm switching element _Qx is short-circuited and fixed, and the process ends.

If the phase currents I _u , I _v , and I _w are unbalanced in step S4 of FIG. 3 (step S4 NG), the upper arm switching elements of all phases are stuck open and fixed. It may not be possible to turn on the element to short the windings. Therefore, the switching elements of the lower arm of all phases are turned on to short-circuit the windings, and it is determined that the switching elements are stuck open in the upper arm, and the process is terminated (steps S9 and S34).

FIG. 8(a) shows, for example, when the switching element _Qu of the upper arm is fixed open and all the gates are cut off (step S1) and each phase current is balanced (step S2 OK). The current paths in FIGS. 8(b) and 8(c) are those in which the upper arm switching elements of all phases are turned on to attempt winding short-circuiting (step S3), and when each phase current is unbalanced (step S4 NG ) is the current path. FIG. 8(d) shows the case where it is determined that the switching element of the lower arm is turned on after that, the winding short-circuit is successful, and the switching element _Qu of the upper arm is stuck open (steps S9 and S34). is the current path of

Furthermore, in step S5, if it is necessary to check whether or not there is a sticking failure in the lower arm switching elements (step S5 No), the lower arm switching elements of all phases are turned on to attempt winding short-circuiting (step S10). ), and then the balance of each phase current is judged again (step S11).
Then, if the phase currents are balanced (step S11 OK), it is determined that the winding short-circuit has succeeded and there is no sticking failure in the switching element of the lower arm (step S35). If the phase currents are unbalanced (step S11 NG), the upper arm switching element is turned ON again to complete the winding short circuit, and it is determined that the lower arm switching element is stuck open. is terminated (steps S12, S36).

FIG. 9(a) shows, for example, when the switching element _Qx in the lower arm of the U phase is fixed open, all the gates are cut off (step S1) and each phase current is balanced (step S2 OK ), FIG. 9(b) is the current path when the upper arm switching element is turned ON to attempt winding short-circuiting (step S3), and each phase current is balanced (step S4 OK). is.
9(c) and (d), when it is necessary to check whether there is a sticking failure in the switching element of the lower arm (step S5 No), the switching element of the lower arm is turned on to try winding short circuit. As a result, each phase current becomes unbalanced (steps S10, S11 NG), and then the upper arm switching elements of all phases are turned ON again, and the winding short circuit is successful (steps S12, S36). be.

In addition, in this type of motor drive system, in addition to the abnormality detected by the gate drive circuit 51, various abnormalities such as overcurrent in each phase current of the inverter and overvoltage in the DC input voltage may occur. For these abnormalities as well, it is effective to perform a fail-safe operation by short-circuiting the windings of the synchronous motor PMSM in order to suppress the generation of unnecessary excitation voltage and regenerative torque.
In view of the above points, when an abnormality detected by a function other than the abnormality detection function of the gate drive circuit 51 (here, referred to as other abnormality) occurs, the windings are finally short-circuited according to the control sequence of FIG. is desirable.

In FIG. 10, when other abnormalities are detected, it is assumed that the short-circuit fixation detected by the gate drive circuit 51 has not occurred. (step S21), and then the balance of each phase current is determined (step S22).
The subsequent steps (S23-S27 and S41-S44) are the same as the steps (S5, S9-S12 and S31, S35, S36, S34) in FIG.

It should be noted that even if the other abnormalities described above occur, the possibility of the switching element being stuck open remains. It is determined that the upper arm or the lower arm is stuck open (steps S44, S43).
In this case, it is not possible to identify the leg (phase) where open sticking occurs, but since it is clear that the current waveform has remarkable characteristics, the waveform characteristics are further analyzed to identify the sticking leg. is also possible.

10: DC power supply 20: Inverters 40u, 40v, 40w: Current detector 51: Gate drive circuit 52: Control calculation unit 52a: Phase current detection function 52b: Abnormality detection function 52c: Control sequence processing function 52d: PWM output function 52e: Port output function 52f: Switching functions _Qu , _Qv , _Qw , _Qx , _Qy , _Qz , Qi _: Semiconductor switching elements PMSM: Permanent magnet synchronous motor

Claims (4)

In a permanent magnet synchronous motor drive system comprising a three-phase inverter for driving a three-phase permanent magnet synchronous motor and a control device for generating drive signals for semiconductor switching elements constituting the inverter,
The control device is
a first function for detecting an abnormality in the inverter;
a second function for detecting each phase output current of the inverter;
In order to short-circuit the stator windings of the permanent magnet synchronous motor when an abnormality is detected by the first function, the upper and lower arms of the inverter are controlled according to the balance state of each phase output current detected by the second function. a third function of generating the drive signal so as to turn on the semiconductor switching elements of the upper arm or the lower arm of all phases while avoiding a short circuit;
with
A drive circuit that generates the drive signal has the first function,
The third function further turns off all the semiconductor switching elements of the inverter when an abnormality is detected by the drive circuit, and switches between the upper arm or the lower arm of the inverter according to the balance state of each phase output current. When it is determined whether or not the semiconductor switching elements of the arms are stuck to a short circuit, and when it is determined that the semiconductor switching elements of the upper arm or the lower arm of the inverter are not stuck to a short circuit, the upper arm or the lower arm of all the legs of the inverter is determined. The semiconductor switching element is turned on to short-circuit the stator windings, and it is determined whether the upper arm or the lower arm has open sticking according to the balance state of each phase output current, or it is determined that there is no sticking failure. A driving system for a permanent magnet synchronous motor characterized by: In the permanent magnet synchronous motor drive system according to claim 1,
The third function further turns on the semiconductor switching elements of the upper arm or the lower arm of the inverter for legs other than the abnormal leg when it is determined that the semiconductor switching elements of the upper arm or the lower arm of the inverter are stuck. 1. A drive system for a permanent magnet synchronous motor, characterized in that the stator windings are short-circuited by allowing the stator windings to rotate, and it is determined in which of the upper arm or the lower arm there is the short-circuit fixation according to the balance state of the output currents of the respective phases . In a permanent magnet synchronous motor drive system comprising a three-phase inverter for driving a three-phase permanent magnet synchronous motor and a control device for generating drive signals for semiconductor switching elements constituting the inverter ,
The control device is
a first function for detecting an abnormality in the inverter;
a second function for detecting each phase output current of the inverter;
In order to short-circuit the stator windings of the permanent magnet synchronous motor when an abnormality is detected by the first function, the upper and lower arms of the inverter are controlled according to the balance state of each phase output current detected by the second function. a third function of generating the drive signal so as to turn on the semiconductor switching elements of the upper arm or the lower arm of all phases while avoiding a short circuit;
with
The first function is provided by a portion other than the drive circuit that generates the drive signal,
The third function further determines whether or not the semiconductor switching elements of the upper arm or the lower arm of the inverter are open-fixed according to the balance state of the output currents of the respective phases when an abnormality is detected by the first function. A drive system for a permanent magnet synchronous motor, characterized in that it judges that there is no sticking failure . In a permanent magnet synchronous motor drive system comprising a three-phase inverter for driving a three-phase permanent magnet synchronous motor and a control device for generating drive signals for semiconductor switching elements constituting the inverter ,
The control device is
a first function for detecting an abnormality in the inverter;
a second function for detecting each phase output current of the inverter;
In order to short-circuit the stator windings of the permanent magnet synchronous motor when an abnormality is detected by the first function, the upper and lower arms of the inverter are controlled according to the balance state of each phase output current detected by the second function. a third function of generating the drive signal so as to turn on the semiconductor switching elements of the upper arm or the lower arm of all phases while avoiding a short circuit;
with
A drive circuit that generates the drive signal has the first function,
The third function further turns off all the semiconductor switching elements of the inverter when an abnormality is detected by the drive circuit, and switches between the upper arm or the lower arm of the inverter according to the balance state of each phase output current. Judge the presence or absence of short-circuit fixation of the semiconductor switching element of the arm,
Further, the third function is, when it is determined that the semiconductor switching element of the upper arm or the lower arm of the inverter has a short-circuit fixation , the semiconductor switching element of the upper arm or the lower arm of the leg other than the abnormal leg of the inverter. The side element is turned ON to short-circuit the stator winding, and it is determined whether the short- circuit is stuck in the upper arm or the lower arm according to the balance state of the output current of each phase, and it is determined that the short-circuit is stuck. A driving system for a permanent magnet synchronous motor, characterized in that, when time, an element on the other side is turned ON instead of the element on the one side .

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