JP5443107B2 - Defect detection method and apparatus for multiple BLDC three-phase DC motors using a single inverter - Google Patents

Description

  The present invention relates to the presence or absence of a defective motor and a defective motor in a BLDC (Blush Less Direct Current) three-phase DC motor including a plurality of PMSMs (Permanent Magnet Synchronous Motors) operated by a single inverter. And a device for detecting the same.

  The present applicant has applied for a control device and a control method for monitoring the synchronization state of a plurality of PMSMs in an efficient manner using a single inverter during operation of a plurality of PMSMs (a type of BLDC three-phase DC motor). -335382.

  The proposal is a control device for a plurality of PMSMs, a converter unit that rectifies a common AC power source into a DC power source, a smoothing circuit unit that smoothes a DC power source output from the converter unit, and an output from the smoothing circuit unit An inverter unit that converts a DC power source to a three-phase AC power source, a current sensor that detects a combination of output currents of different phases selected in the three-phase AC power source supplied and output from the inverter unit to a plurality of PMSMs, and A control unit for controlling a plurality of PMSMs according to a detection result of a current sensor, wherein the plurality of PMSMs are grouped in units of two or three units, and the current sensor Is connected to each one-phase or two-phase output line in the output line connected to each PMSM in the group, and the current sensor is connected. Each output line is characterized in that a different phase from each other.

Japanese Patent Application No. 2008-335382

  The above invention is an invention in which the synchronization state of a plurality of PMSMs can be monitored by detecting a zero-phase current of a three-phase alternating current supplied to each PMSM from an inverter unit. Since there is a faulty motor among a plurality of motors and there is a faulty motor, there is a problem that it cannot be detected and identified, resulting in poor operation Sometimes, multiple motors must be stopped in groups, and normal motors cannot operate efficiently while stopping or repairing or replacing only defective motors while operating normally. was there.

The present invention, when driving a plurality of BLDC three-phase DC motor in a single inverter, one less current sensor or current transformer than the number of the motor (Current Transformer) on the primary side of the motor in each The one-phase cable of each of the current transformers is passed in series, and the two-phase cables different from the one-phase cables of all the remaining motors are separately passed to the primary side of each of the current transformers . In order to solve this problem, the presence or absence of a defective motor and the defective motor are identified by the difference in the current value output of +, − or 0 of each phase of the current transformer in the combination (sector) of the output changeover switch. It was.

  In addition, each BLDC three-phase DC motor is provided with a relay switch for stopping the operation of the defective motor so that only the defective motor can be stopped while operating a normal motor.

The present invention identifies and detects a failure of a plurality of BLDC three-phase DC motors operated by a single inverter by a simple method of combining a current transformer and an output changeover switch (sector). The effect of being able to do is produced.

  By providing each BLDC three-phase DC motor with a relay switch, it is possible to stop only a defective motor while operating a normal motor.

Wiring diagram showing an example with two BLDC three-phase DC motors of the present invention Wiring diagram showing an example with three BLDC three-phase DC motors Wiring diagram showing an example with 4 units Wiring diagram showing an example in which a relay switch is provided for each motor

In the present invention, when a plurality of BLDC three-phase DC motors are operated by a single inverter, one single-phase of each of the motors is arranged on the primary side of the current transformer, which is one less than the number of motors . with passing the cable in series, respective to each of the primary side of the current transformer, through the remainder of all of said one phase and two different phase increments of the cable of the motor to each other, the combination of the output switch of the inverter (sector ) And the difference in current value output of +, −, or 0 for each phase of the current transformer , the presence or absence of a defective motor and the defective motor are specified. In addition, by providing a relay switch that cooperates with the detection of defects, only the defective motor can be stopped.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.
The wiring diagram of FIG. 1 shows an example in which two BLDC three-phase DC motors are operated by a single inverter. One between the inverter 1 and the two motors M1, M2 is one less than the number of motors. of the current transformer CT1 provided, the U-phase cable M1U motor M1 that the master motor to the primary side of the current transformer CT1, through a V-phase cable M2V and W phase cable M2W motor M2 wiring, motor M1 other U-phase cable M2U of V phase cable M1V and W-phase cable M1W and the motor M2 without passing through the current transformer CT1 is a path, which is the U, V, W-phase cable and pass through the current transformer CT1 The U-phase cable is connected to the switches SW1 and SW4 of the inverter 1, the V-phase cable is connected to the switches SW2 and SW5, and the W-phase cable is connected to the switches SW3 and SW6. It is connected to the changeover switch. The switches SW1, SW2, and SW3 and the switches SW2, SW4, and SW6 are connected to the inverter 1 in a single connection.

  In this way, when the two BLDC three-phase DC motors M1 and M2 are operated by the single inverter 1, the output switching sector, that is, the combination of the output selector switches is shown in Table 1 below. It becomes any pattern of ~ 6.

In the pattern in which sector 1 is selected and switches SW1 and SW5 are turned on, if both motors M1 and M2 are normal, current transformer CT1 includes a U-phase forward current and a V-phase reverse current. Therefore, they cancel each other, and the output current of the current transformer CT1 becomes zero depending on the AC condition.

However, if the motor M1 is defective, only the V-phase reverse current flows through the current transformer CT1, as shown in the lower part of Table 1 (CT Signal when Motor 1 is defective). When the motor M2 is defective, only the U-phase positive current flows through the current transformer CT1 (CT Signal when Motor 2 is defective).

Similarly, if the motor M1 is defective in the pattern in which the sector 2 is selected and the switches SW1 and SW6 are turned ON, only the W-phase reverse current flows through the current transformer CT1, and the motor M2 is defective. Only the U-phase positive current flows through the current transformer CT1.

Therefore, when either sector 1 or sector 2 is selected, the presence or absence of a defective motor and the identification of the defective motor can be identified by determining whether the current value of the current transformer CT1 is +, −, or 0.

When the sector 4 pattern is selected and the motor M1 is defective, only the V-phase forward current flows, and when the motor M2 is defective, the U-phase reverse current flows, or the sector 5 pattern. When the motor M1 is defective, only the W-phase forward current flows, and when the motor M2 is defective, only the U-phase reverse current flows. The presence or absence of a defective motor among the motors M1 and M2 can be identified in the same manner also from the current output value of the current transformer CT1.

The wiring diagram of FIG. 2 shows an example in which three BLDC three-phase DC motors M1 to M3 are operated by a single inverter 1, and two current transformers, one less than the number of motors, between the inverter and the motor . CT1, CT2 and provided, through series wire a U-phase cable M1U the BLDC three-phase DC motor M1 for the master motor to the primary side of the two current transformers CT1, CT2, leaving V-phase cable M1V and W phase Kepuru M1W is not through the current transformer, a V-phase cable M2V and W phase cable M2W motor M2 through the current transformer CT1, U-phase cable M2U is not through the current transformer, also the V-phase cable of the motor M3 M3V and the W-phase cable M3W are caused to pass through the current transformer CT2 and the U-phase cable M3U is not passed through the current transformer .
As described above, the configuration in which the U, V, and W phase cables passed through or not passed through the current transformers CT1 and CT2 are connected together and connected to the output changeover switch is the same as the previous example.

  The sector pattern of the switch selection in this case is the same as the previous example, but the current value that appears when any of the motors M1, M2, M3 is defective is as shown in Table 3.

As described above, even when using three BLDC three-phase DC motors operated by a single inverter and two current transformers, one less than the number of motors, it is immediately determined whether or not there is a defective motor. It can be done. Thus, even when there are three BLDC three-phase DC motors, the presence or absence of a defective motor is determined by selecting the sector and determining whether the signal value of the current output from each of the current transformers CT1 and CT2 is +,-or 0. Then, the defective motor can be specified.

FIG. 4 is a wiring diagram showing an example in which four BLDC three-phase DC motors and three current transformers are used, and the presence or absence of a defective motor can be identified in the same manner. That is, when N BLDC three-phase DC motors are operated by a single inverter, by using _N-1 current transformers CT _{1 to} CT _N-1 , presence or absence of a defective motor and its defective motor Can be specified.

  FIG. 4 shows an example in which the relay switches R1 and R2 are provided on the motors M1 and M2 in the example in which the two BLDC three-phase DC motors M1 and M2 described above are operated. When it was specified, the relay switch was linked to stop only the defective motor. Since only the defective motor is stopped, maintenance work such as repair or replacement can be performed efficiently. Even if the number of BLDC three-phase DC motors to be operated increases, a relay switch can be provided in the same manner.

  The above description shows typical embodiments of the present invention, and the present invention is not limited to these embodiments. The technical field to which the present invention belongs is within the technical scope of the claims. It should be understood that the scope of the present invention can be easily changed by those skilled in the art.

  INDUSTRIAL APPLICABILITY The present invention can be widely used as a method and apparatus that can easily perform the presence / absence and identification of defective motors of a plurality of BLDC three-phase DC motors operated by a single inverter.

1 is a single inverter M1 to M4 are BLDC three-phase DC motors M1 to 4U are U phase cables for each motor M1 to 4V are V phase cables for each motor M1 to 4W are W phase cables for each motor CT1 to CT3 are variable The flutes R1 and R2 are relay switches

Claims (3)

When operating multiple BLDC three-phase DC motors with a single inverter, one single-phase cable in the motor is connected in series to the primary side of the current transformer that is one less than the number of motors. In addition, the cables on the primary side of each of the current transformers are separately passed through two cables , each of which is different from the one phase of all of the remaining motors, to change the output changeover switch combination (sector) of the inverter. The presence or absence of a defective motor and the defective motor are specified by the difference in the current value output of +,-, or 0 of each phase of the fluidizer, and a plurality of BLDC three-phase DC motors by a single inverter Defect detection method. A current transformer that is one less than the number of motors is provided between a plurality of BLDC three-phase DC motors and a single inverter that operates the motors , and each of the primary sides of the current transformers includes a current transformer . One single-phase cable is passed in series, and two cables of two phases different from the one phase of all the remaining motors are separately passed to the primary side of each current transformer and passed to the current transformer. A failure detection device for a plurality of BLDC three-phase DC motors using a single inverter, wherein a phase that does not pass through the connected phase is connected to an output changeover switch provided in the inverter for each in-phase.   The apparatus according to claim 2, wherein each BLDC three-phase DC motor is provided with a relay switch for stopping the operation of the defective motor.

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