JP2009038849A - Rotary container drive and its control method, washing machine, dryer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent a three-phase motor from rotating in a noncontrolling state with power stored in a smoothing capacitor owing to malfunction caused by various faults after AV voltage supply to a DC power supply is interrupted. <P>SOLUTION: When a microcomputer 4 detects interruption of AC voltage supply to a DC power supply circuit 2 and rotation stop due to stoppage of power supply to a three-phase motor 9, voltage output is continued in fixed pattern from an inverter circuit 5 depending on the electrical angle at the stop position of the three-phase motor 9 and an exciting current is supplied to the three-phase motor 9. When the input voltage of the inverter circuit 5 is insufficient for the lower limit level, or when an upper limit time elapsed, power supply to the three-phase motor 9 is stopped. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  In the present invention, a DC voltage generated from the voltage of an AC power supply is smoothed by a smoothing capacitor and supplied to an inverter circuit, and a rotary container containing an object to be stirred is rotated by a three-phase motor fed from the inverter circuit. The present invention relates to a rotating container driving device, a control method thereof, and a washing machine and a dryer provided with the rotating container driving device.

  A washing machine / dryer, or a washing / drying machine that combines these functions, supplies the output voltage (AC voltage) of a commercial power supply (AC power supply) to a DC power supply that performs AC / DC conversion, and the DC power supply outputs it. The DC voltage is smoothed by a smoothing capacitor and supplied to the inverter circuit. The inverter circuit switches the output voltage and supplies it to the three-phase motor. A rotating container driving device for rotating the container) by the three-phase motor. In addition, in a washing machine or dryer of a type in which a rotating drum is directly driven by a three-phase motor (a type in which the direction of the rotation axis of the three-phase motor coincides with the direction of the rotation center line of the rotating drum), A large-capacity smoothing capacitor is provided between the circuit and the circuit.

  On the other hand, recent washing machines and the like are equipped with an energization switch for switching the AC voltage input line to / from the DC power supply by a relay switch or the like, and when a power-off operation is performed on a predetermined operation unit or a process such as washing is performed. In some cases, when the operation is completed, the power switch switches to a standby state in which the supply of AC voltage to the DC power supply is interrupted. As a result, power consumption (standby power) in the standby state is reduced.

By the way, even if the supply of the AC voltage to the DC power supply is interrupted while the power supply from the inverter circuit to the three-phase motor is stopped, the state in which charges are accumulated in the smoothing capacitor continues for a long period of time. For this reason, if a malfunction occurs due to abnormalities in the sensor or control circuit after the three-phase motor is stopped, the three-phase motor rotates in an uncontrolled state due to the electric power stored in the smoothing capacitor, and the rotating drum rotates in conjunction therewith. There is a risk of spinning. In a washing machine or dryer, while the rotating drum is stopped, the user can access the rotating drum by putting clothes in and out, so it is very dangerous if the rotating drum starts to rotate during the access.
On the other hand, conventional washing machines, etc. have a discharge resistor, and when the supply of AC voltage to the DC power supply is interrupted, the process of discharging the charge stored in the smoothing capacitor through the discharge resistor is executed. There is something to do. As a result, it is possible to prevent the three-phase motor from rotating in an uncontrolled state by the electric power stored in the smoothing capacitor after the supply of the AC voltage to the DC power supply is shut off.
In Patent Document 1 and Patent Document 2, when the supply of AC voltage to the DC power supply is interrupted, the rotational position (electrical angle) of the three-phase motor is detected at any time, and the detected rotational position (electrical angle) is detected. Accordingly, there is shown a device that discharges charges accumulated in a smoothing capacitor by controlling a voltage output pattern of an inverter circuit so that an exciting current is supplied to a three-phase motor.
JP-A-7-223430 JP 2002-369570 A

However, when the electric charge stored in the smoothing capacitor is discharged through the discharging resistor, there is a problem that the installation space and cost of the components are increased as much as the discharging resistor is provided.
Also, as shown in Patent Documents 1 and 2, when the rotational position (electrical angle) of the three-phase motor is detected at any time and the voltage output pattern of the inverter circuit is controlled according to the detected rotational position (electrical angle), If the rotational position (electrical angle) of the three-phase motor is erroneously detected due to a sensor abnormality or the like, there is a problem that the three-phase motor may continue to rotate until the discharge of the smoothing capacitor is completed.
Accordingly, the present invention has been made in view of the above circumstances, and its object is to smooth the output voltage of a DC power supply by a smoothing capacitor and supply it to an inverter circuit, and to supply power from the inverter circuit. In a rotating container drive device that rotates a rotating container that contains an object to be stirred by a motor, the AC voltage supply to the DC power supply was cut off and then accumulated in a smoothing capacitor due to malfunctions due to various abnormalities. An object of the present invention is to provide a rotating container driving device capable of preventing a three-phase motor from rotating in an uncontrolled state by electric power, a control method thereof, and a washing machine and a dryer provided with the rotating container driving device.

In order to achieve the above object, a rotating container driving device according to the present invention supplies an AC voltage from an AC power source to a DC power source, smoothes the DC voltage output from the DC power source by a smoothing capacitor, and supplies it to an inverter circuit. The inverter circuit switches the output voltage and supplies it to the three-phase motor, thereby rotating the rotating container containing the object to be stirred by the three-phase motor. The following (1-1) to ( 1-5) The constituent elements shown in 1-5) are provided.
(1-1) AC interruption detection means for detecting occurrence of an AC interruption state in which supply of an AC voltage to the DC power supply is interrupted.
(1-2) Inverter power supply stop control means for stopping power supply to the three-phase motor by the inverter circuit.
(1-3) Electrical angle detection means for detecting an electrical angle of the three-phase motor.
(1-4) A motor that detects the electrical angle of the stop and stop position of the three-phase motor based on the detection angle of the electrical angle detection means after the power supply to the three-phase motor is stopped by the inverter power supply stop control means. Stop detection means.
(1-5) When the occurrence of the AC interruption state is detected by the AC interruption detection means and the stop of the three-phase motor is detected by the motor stop detection means, the detection is detected by the motor stop detection means. Inverter constant power supply control means for continuously supplying a constant pattern of voltage from the inverter circuit and supplying an excitation current to the three-phase motor according to the electrical angle at the stop position of the three-phase motor.
As a method for detecting the occurrence of the AC cutoff state, for example, when an energization switch for switching the interruption (interruption / connection) of the AC voltage input line to the DC power supply is provided, A method for detecting the occurrence of the AC interruption state when the AC voltage input line is interrupted, or a case in which a sensor circuit for detecting that the voltage level is less than a predetermined level is provided in the AC voltage input line. A method of detecting the occurrence of the AC interruption state from the detection result of the sensor circuit is conceivable.

  The rotary container driving device according to the present invention is configured such that after confirming the interruption of the supply of AC voltage to the DC power supply and the stop of the three-phase motor due to the stop of the power supply to the three-phase motor, The voltage output pattern is held in a constant pattern that supplies the excitation current. As a result, in the three-phase motor, a force that keeps its rotational position substantially at the stop position is generated by the action of the excitation current, and the electric charge accumulated in the smoothing capacitor is forcibly discharged through the three-phase motor. For this reason, after the rotating container is stopped (after the three-phase motor is stopped), the three-phase motor is prevented from rotating in an uncontrolled state due to power accumulated in the smoothing capacitor due to malfunction caused by various abnormalities. it can. In particular, since the voltage output pattern of the inverter circuit is kept constant, the detection angle of the electrical angle detection means is erroneously detected even if an abnormality occurs that erroneously detects an angle that deviates from the actual electrical angle. The voltage output pattern of the inverter circuit does not change according to the electrical angle, and the risk of rotating the three-phase motor until the smoothing capacitor is discharged can be prevented. Moreover, such a safe forced discharge function can be realized without increasing installation space and cost by adding new parts such as a discharge resistor.

By the way, if the interruption of the supply of AC voltage to the DC power supply is erroneously detected due to some abnormality, the supply of excitation current to the three-phase motor is continued for a long time, the three-phase motor becomes abnormally hot, or power is wasted. Is consumed.
Therefore, when the constant power supply control means of the inverter exceeds the predetermined upper limit time from the inverter circuit when the voltage output duration of the constant pattern from the inverter circuit to the three-phase motor exceeds a predetermined upper limit time. It is conceivable to stop the power supply to
This avoids the high temperature rise and wasteful power consumption of the three-phase motor due to malfunction.
Further, the state in which the smoothing capacitor is further discharged and the input voltage of the inverter circuit is less than the predetermined level (operation lower limit voltage) is a safe state where the inverter circuit can no longer drive the three-phase motor to rotate.
On the other hand, the output voltage of the DC power source is lower than the input voltage of the inverter circuit in the inverter circuit, the control means (microcomputer etc.) such as the constant inverter power supply control means, and various power consumption components such as various sensors. In general, these components are also supplied to the auxiliary power supply (voltage drop circuit) that supplies the voltage. Normally, these components are charged even if the voltage of the smoothing capacitor is less than the operating level of the inverter circuit. In many cases, the remaining smoothing capacitor can operate as a power supply source.
Therefore, it is conceivable that the rotary container driving device according to the present invention further comprises a voltage shortage detecting means for detecting a voltage shortage state in which the input voltage of the inverter circuit is less than a predetermined level. In this case, when the constant voltage supply control means detects that the voltage shortage state is detected by the voltage shortage detection means while the voltage output of the constant pattern from the inverter circuit to the three-phase motor is continued, The power supply from the inverter circuit to the three-phase motor is stopped.
As a result, after the inverter circuit is in a safe state where the three-phase motor cannot be driven to rotate, the control means (such as a microcomputer) performs final termination processing using the smoothing capacitor with the charge remaining as the power supply source. it can.

The electrical angle of the three-phase motor detected by the electrical angle detector and the electrical angle of the stop position of the three-phase motor detected by the motor stop detector depend on the magnetic pole position of the three-phase motor. It can be any of a plurality of electric angle ranges to be divided. In this case, the voltage output of the constant pattern supplies the exciting current to the three-phase motor at the central angle of the electrical angle range of the stop position of the three-phase motor detected by the motor stop detecting means. It is conceivable that the voltage output does not supply torque current.
In a three-phase motor drive device, the electrical angle of the three-phase motor is divided into a plurality of electrical angle ranges (for example, 0 to 60 degrees, 60 to 120 degrees, 120 to 180 degrees,. ) Is a function normally provided for controlling the inverter circuit. Thus, when the electrical angle detection resolution is low, only the excitation current is supplied to the three-phase motor at the detected central angle of the electrical angle range (no torque current is supplied). Voltage output pattern (constant pattern) If the voltage is supplied at, the maximum difference that can occur between the electrical angle corresponding to the excitation current (the electrical angle at which the torque current becomes zero) and the actual electrical angle of the three-phase motor is minimized, and this is caused by the voltage supply. The maximum angle of rotation of the resulting three-phase motor can be minimized.
Moreover, this invention can also be grasped | ascertained as a washing machine or dryer provided with the drum container which accommodates to-be-washed | cleaned material or to-be-dried material, and the rotating container drive device which concerns on this invention which rotationally drives the drum container.

Moreover, this invention can also be grasped | ascertained as a control method of a rotating container drive device.
That is, the control method of the rotary container driving device according to the present invention supplies an AC voltage from an AC power source to a DC power source, smoothes a DC voltage output from the DC power source by a smoothing capacitor, and supplies the smoothed voltage to an inverter circuit. The inverter circuit switches the output voltage and supplies it to the three-phase motor, thereby controlling a rotating container driving device for rotating the rotating container containing the object to be stirred by the three-phase motor. -1) to (2-4) is a control method for executing each procedure.
(2-1) An AC interruption detection procedure for detecting occurrence of an AC interruption state in which supply of an AC voltage to the DC power supply is interrupted by a predetermined detection means.
(2-2) An inverter power supply stop control procedure for stopping power supply to the three-phase motor by the inverter circuit by a predetermined control means.
(2-3) After stopping the power supply to the three-phase motor by the inverter power supply stop control procedure, based on the detection angle of the electric angle detection for detecting the electric angle of the three-phase motor by a predetermined detection means, Motor stop detection procedure to detect the electrical angle at the stop and stop position of the three-phase motor.
(2-4) When the occurrence of the AC interruption state is detected by the AC interruption detection procedure and the stop of the three-phase motor is detected by the motor stop detection procedure, the motor is detected by a predetermined control means. A constant inverter power supply control procedure in which a constant pattern of voltage output is continued from the inverter circuit and an excitation current is supplied to the three-phase motor in accordance with the electrical angle at the stop position of the three-phase motor detected by the stop detection procedure.
The order of execution is not limited between the AC interruption detection procedure, the inverter power supply stop control procedure, and the motor stop detection procedure. That is, after executing the AC interruption detection procedure, the inverter power supply stop control procedure and the motor stop detection procedure are executed, and after the inverter power supply stop control procedure and the motor stop detection procedure are executed, the AC power supply stop control procedure and the motor stop detection procedure are executed. It is conceivable to execute a blockage detection procedure or to execute them in parallel.
Also according to the control method of the rotary container driving device according to the present invention, the same effect as the above-described rotary container driving device according to the present invention can be obtained.

  In the present invention, when it is confirmed that the supply of AC voltage to the DC power supply has been interrupted and the three-phase motor has been stopped due to the power supply to the three-phase motor being stopped, The rotation position is held almost at the stop position and the electric charge accumulated in the smoothing capacitor is forcibly discharged through the three-phase motor. For this reason, it is possible to prevent the rotating container (three-phase motor) from rotating in an uncontrolled state due to the power accumulated in the smoothing capacitor due to malfunctions caused by various abnormalities after the rotating container (three-phase motor) is stopped. . In particular, even when an abnormality occurs in which the detection angle of the electrical angle detecting means is misdetected with respect to the actual electrical angle, the voltage output pattern of the inverter circuit changes according to the erroneously detected electrical angle. Therefore, the risk of rotating the three-phase motor until the discharge of the smoothing capacitor can be prevented. Moreover, such a safe forced discharge function can be realized without increasing installation space and cost by adding new parts such as a discharge resistor.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings so that the present invention can be understood. The following embodiment is an example embodying the present invention, and does not limit the technical scope of the present invention.
Here, FIG. 1 is a block diagram showing a schematic configuration of the rotating container driving device X according to the embodiment of the present invention, FIG. 2 is a flowchart showing a procedure of smoothing capacitor discharge processing by the rotating container driving device X, and FIG. FIG. 4 is a diagram illustrating a first example of an output voltage pattern from the inverter circuit to the three-phase motor in the discharge process, and FIG. 4 is a diagram illustrating a second example of an output voltage pattern from the inverter circuit to the three-phase motor in the smoothing capacitor discharge process. 5 is a cross-sectional view of the washing / drying machine Z on which the rotary container driving device X is mounted.

First, a schematic configuration of the washing / drying machine Z on which the rotary container driving device X according to the embodiment of the present invention is mounted will be described with reference to a cross-sectional view shown in FIG.
As shown in FIG. 5, the washing / drying machine Z includes a three-phase motor 9, a drum container 20, a water tank 21, a front door 22, and the like.
In the washing / drying machine Z, the drum container 20 accommodates an object to be washed (clothing or the like) when executing the washing process, and a rotating container that accommodates an object to be dried (clothing or the like) when executing the drying process. It is. The drum container 20 is arranged so that its rotation center line is slightly upward.
The three-phase motor 9 is a motor that directly rotates the drum container 20 (drives the direction of the rotation axis of the three-phase motor 9 to coincide with the direction of the rotation center line of the drum container 20). The rotary container driving device X includes the three-phase motor 9 and circuits and sensors for driving the motor.
The water tank 21 is formed around the drum container 20 and stores washing water when the washing process is executed, and is discharged from a large number of openings provided in the drum container 20 when the drying process is executed. Receiving moisture from the material to be dried and discharging it out of the tank.
The front door 22 is a door (lid) that opens and closes a loading / unloading port for an object (stirred object) with respect to the drum container 20.

Next, the configuration of the rotary container driving device X will be described with reference to the block diagram shown in FIG.
As shown in FIG. 1, the rotating container drive device X includes an energization switch 1, a DC power supply circuit 2, a smoothing capacitor 3, a motor drive circuit 8, a three-phase motor 9, an operation unit 10, a power-off detection circuit 11, and a magnetic pole detection unit. 12 etc.
The motor drive circuit 8 includes a microcomputer 4 (hereinafter referred to as a microcomputer), an inverter circuit 5, an auxiliary power supply 6, a voltage low detection circuit 7, and the like.
The operation unit 10 is an operation input unit having operation keys such as a power key and a washing course selection key, and a signal indicating the operation content is transmitted to the energizing switch 1 and the microcomputer 4.
The energizing switch 1 includes a relay switch and the like, and is a circuit that switches between alternating input and output of an AC voltage from the input terminal of the AC power supply G (commercial power supply) to the DC power supply circuit 2.
More specifically, the energization switch 1 responds to a power OFF operation (such as a power key pressing operation) on the operation unit 10 in a state where an AC voltage from the AC power supply G is supplied to the DC power supply circuit 2. In response to the power OFF command from the microcomputer 4, the AC voltage supply to the DC power supply circuit 2 is switched off. Further, the energizing switch 1 supplies an AC voltage to the DC power supply circuit 2 in response to a power ON operation (such as pressing a power key) to the operation unit 10 while the AC voltage to the DC power supply circuit 2 is cut off. Switch to the state to do.

The DC power supply circuit 2 is a circuit that converts an AC voltage supplied from the AC power supply G through the energization switch 1 into a DC voltage. The output voltage Vm (DC voltage) of the DC power supply circuit 2 is smoothed by the smoothing capacitor 3 and supplied to the inverter circuit 5.
Further, the output voltage Vm of the DC power supply circuit 2 is supplied to other components with low power consumption such as the auxiliary power supply 6 and the low voltage detection circuit 7 and various sensors (not shown) in addition to the inverter circuit 5.
The auxiliary power supply 6 is a circuit that converts the output voltage Vm of the DC power supply circuit 2 (input voltage Vm of the inverter circuit 5) into a DC voltage Vs lower than the output voltage Vm, and the output voltage Vs is supplied to the microcomputer 4.
The voltage low detection circuit 7 is in a state where the input voltage Vm of the inverter circuit 5 is less than the lower limit level (predetermined level) necessary for normal operation of the inverter circuit 5 (hereinafter, referred to as a voltage shortage state), for example, by a comparator or the like. (An example of the voltage shortage detection means). The detection signal is transmitted to the microcomputer 4.
Here, the auxiliary power supply 6 and the components (such as the microcomputer 4) that receive power supply from the auxiliary power supply 6 accumulate charges in the smoothing capacitor 3, and then the discharge proceeds and the voltage low detection circuit 7 causes the voltage shortage state. Even after this is detected, normal operation is possible for a while using the smoothing capacitor 3 in which the electric charge remains as a power supply source.
The inverter circuit 5 is supplied with the DC voltage Vm from the DC power supply circuit 2, switches the output voltage and supplies it to the three-phase motor 9 to rotate the three-phase motor 9. The three-phase motor 9 that rotates in this way rotates the drum container 20 (an example of a rotating container that contains the object to be stirred) by direct drive.
As is well known, the inverter circuit 5 includes an upper-phase switching element (upper-phase element) and a lower-phase side composed of transistors and the like for each of the three phases U, V and W of the three-phase motor 9. A switching element (lower phase element) is provided, and the voltage output pattern is switched by switching between ON / OFF thereof.

The magnetic pole detector 12 is a sensor that detects the rotor position (that is, the magnetic pole position) of the three-phase motor 9. The magnetic pole detection unit 12 includes three hall sensors that detect the moment of switching between the north pole and the south pole of the permanent magnet in the three-phase motor 9, and the hall sensors are arranged at every 120 electrical degrees. The combination of the detection signals (ON / OFF) of these three hall sensors represents the rotor position (magnetic pole position) of the three-phase motor 9. Here, the number of pole pairs of the three-phase motor 9 in the present embodiment is 10, and the magnetic pole detector 12 detects the rotation of the three-phase motor 9 at every mechanical angle of 6 degrees. A detection signal from the magnetic pole detection unit 12 is transmitted to the microcomputer 4.
The power-off detection circuit 11 is provided on the primary side (AC power supply G side) of the energizing switch 1 in the AC voltage input line, and whether or not the AC voltage from the AC power supply G is input to the rotary container driving device X. Is a circuit for detecting The detection signal is transmitted to the microcomputer 4. That is, the power-off detection circuit 11 is connected to the outlet of the AC power source G and the AC voltage is applied to the energizing switch 1, the power cord is disconnected from the outlet, the AC power source G is interrupted, etc. This is a circuit for detecting that the AC voltage is not applied to the energizing switch 1 due to the above.

The microcomputer 4 is a processor that executes an angle calculation process for detecting an electrical angle (electrical angle range) of the three-phase motor 9 and a control process for the inverter circuit 5 by executing a program stored in advance in a ROM (not shown). (Computer).
Hereinafter, the microcomputer 4 that executes the inverter control process by executing a predetermined program module is referred to as a control calculation unit 4a, and the microcomputer 4 that executes an angle calculation process by executing a predetermined program module. Is referred to as an angle calculation unit 4b.
Based on the detection signal from the magnetic pole detector 12, the angle calculator 4b has six electrical angle ranges (30 ° ± 30 range, 90 °) in which the electrical angle of the three-phase motor 9 is divided according to the magnetic pole position. Processing to detect whether the degree is within ± 30 °, 150 ° ± 30 °, 210 ° ± 30 °, 270 ° ± 30 °, or 330 ° ± 30 ° ). That is, the magnetic pole detection unit 12 and the angle calculation unit 4 b are an example of an electrical angle detection unit that detects the electrical angle of the three-phase motor 9, and the detected angle is classified according to the magnetic pole position of the three-phase motor 9. One of six (plural) electrical angle ranges (θi ± Δθ, where subscript i is a number selected from an integer of 1 to 6).

As described above, the rotary container driving device X supplies the AC voltage from the AC power supply G to the DC power supply circuit 2, smoothes the DC voltage output from the DC power supply circuit 2 by the smoothing capacitor 3, and the inverter circuit. 5, and the inverter circuit 5 switches the output voltage and supplies it to the three-phase motor 9, so that the drum container 20 containing the object to be stirred such as clothing is rotationally driven by the three-phase motor 9. .
In the rotary container driving device X, the control calculation unit 4a controls the output pattern of the output voltage from the inverter circuit 5 to each phase (U phase, V phase, W phase) of the three-phase motor 9.
Further, when the washing process and the drying process are completed, the control calculation unit 4a outputs a power OFF command to the energizing switch 1 so that the rotary container driving device X is connected to the DC power supply circuit 2. The operating state in which the AC voltage is supplied is shifted to a standby state in which the supply of the AC voltage to the DC power supply circuit 2 is interrupted. As a result, power consumption (standby power) in the standby state is reduced.

Next, the procedure of the smoothing capacitor discharge process by the control calculation unit 4a will be described with reference to the flowchart shown in FIG.
The smoothing capacitor discharge process shown in FIG. 2 is a process that is started when the washing process or the drying process is completed. S1, S2,... Represent processing procedure identification codes.
When the washing process or the drying process ends, the control calculation unit 4a executes a predetermined operation end process (S1). Here, the operation end process executed by the control calculation unit 4a includes a process of stopping the power supply to the three-phase motor 9 by the inverter circuit 5 (the inverter power supply stop control means, an example of the procedure). For example, the control calculation unit 4a turns off all upper phase elements and lower phase elements of each phase of UVW included in the inverter circuit 5, or turns off all upper phase elements of each phase of UVW. The power supply to the three-phase motor 9 is stopped by turning on all the lower-phase elements.
In addition, the operation end process includes, for example, a process of recording information necessary for the next activation in a predetermined nonvolatile memory (not shown) among information temporarily stored in the nonvolatile memory included in the microcomputer 4. .
When the control calculation unit 4a determines that the operation end processing is completed (S2), it outputs an AC voltage from the AC power source G to the DC power circuit 2 by outputting a power OFF command to the energizing switch 1. Shut off (S3). Thereafter, the microcomputer 4 (including the control calculation unit 4a and the angle calculation unit 4b) and the inverter circuit 5 operate by being supplied with electric power from the smoothing capacitor 3 in which charges are accumulated.
In step S, the control operation unit 4a has cut off the AC voltage input line to the DC power supply circuit 2 by the energizing switch 1 and thus the supply of the AC voltage to the DC power supply circuit 2 is cut off ( Hereinafter, it is detected (determined) that the AC interruption state has occurred (the AC interruption detection means, an example of the same procedure).

Next, after the power supply to the three-phase motor 9 is stopped (S3), the control calculation unit 4a is based on the electrical angle range θi ± 30 [degrees] of the three-phase motor 9 calculated as needed by the angle calculation unit 4b. Then, it is detected that the three-phase motor 9 is stopped (S4), and an electrical angle range corresponding to the stop position of the three-phase motor 9 (hereinafter referred to as a stop electrical angle range θst ± 30 [degrees]) is detected (S5). , The motor stop detection means, an example of the procedure).
More specifically, the control calculation unit 4a performs the rotation of the three-phase motor 9 when the electrical angle range θi ± 30 [degrees] calculated as needed by the angle calculation unit 4b does not change within a predetermined time. It is determined that the motor has stopped (S4), and the electrical angle range θi ± Δθ calculated by the angle calculator 4b at the time of determination is detected as the stop electrical angle range θst ± 30 [degrees] (S5).
As described above, the electrical angle (θi ± 30 [degrees]) of the three-phase motor 9 calculated (detected) by the angle calculator 4b is also the stop position of the three-phase motor 9 detected by the control calculator 4a. The electrical angle (θst ± 30 [degrees]) is also one of the 6 electrical angle ranges divided according to the magnetic pole position of the three-phase motor 9.

And the control calculating part 4a is detected by step S4, when generation | occurrence | production of the said AC interruption | blocking state is detected as mentioned above (S3), and the stop of rotation of the three-phase motor 9 is detected (S4). The voltage output pattern of the inverter circuit 5 is determined in accordance with the stop electrical angle range θst ± Δθ (the electrical angle range of the stop position of the three-phase motor 9), and according to the determination result, a constant pattern of voltage output ( An excitation current is supplied from the inverter circuit 5 to the three-phase motor 9 by continuing to output a DC voltage with a fixed voltage level ratio for each phase (S6, the inverter constant power supply control means, an example of the procedure) ).
As described above, the rotary container driving device X is configured to shut off the supply of AC voltage to the DC power supply circuit 2 (S3) and stop the three-phase motor (S4) by stopping the power supply to the three-phase motor 9 (S1). Is confirmed, the voltage output pattern of the inverter circuit 5 for the three-phase motor 9 is held in a certain pattern for supplying the excitation current (S6).
As a result, in the three-phase motor 9, a force is generated to hold the rotational position almost at the stop position by the action of the excitation current, and the electric charge accumulated in the smoothing capacitor 3 is forcibly discharged through the three-phase motor 9. Consumed as heat). For this reason, after the drum container 20 is stopped (after the three-phase motor 9 is stopped), the three-phase motor 9 is rotated in an uncontrolled state by the electric power stored in the smoothing capacitor 3 due to malfunctions due to various abnormalities. Can be prevented. In particular, since the voltage output pattern of the inverter circuit 5 is kept constant, even if an abnormality that misdetects an angle deviated from the actual electrical angle occurs due to a failure of the magnetic pole detection unit 12 or the like, it is erroneously detected. Therefore, the voltage output pattern of the inverter circuit 5 does not change according to the electrical angle, and the risk of rotating the three-phase motor 9 until the smoothing capacitor 3 is discharged can be prevented. Moreover, such a safe forced discharge function can be realized without increasing the installation space and cost by adding new parts such as a discharge resistor.

3 and 4 are data tables representing a first example and a second example of the correspondence relationship between the stop electrical angle range θst ± Δθ and the voltage output pattern of the inverter circuit 5. In the data tables shown in FIGS. 3 and 4, the numerical value representing the ratio [%] is the ratio of the output voltage to each phase with respect to the input voltage in the inverter circuit 5 (hereinafter referred to as the output voltage level value).
The voltage output patterns (voltage output of a constant pattern in step S6) to the U, V, and W phases shown in FIGS. 3 and 4 are the center of the stop electrical angle range θst ± Δθ with respect to the three-phase motor 9. This is a voltage output pattern in which excitation current is supplied at angle θst but torque current is not supplied (torque source flow becomes zero).
For example, in the first example of FIG. 3, when the stop electrical angle range is 30 ± 30 [degrees], only the excitation current is applied to the three-phase motor 9 when the electrical angle is 30 [degrees]. A voltage output pattern (40 [%] for the U phase, 20 [%] for the V phase, 0 [%] for the W phase) to be supplied (no torque current is supplied)). Similarly, in the first example of FIG. 3, when the stop electrical angle range is 210 ± 30 [degrees], only the excitation current is applied to the three-phase motor 9 when the electrical angle is 210 [degrees]. Output voltage pattern (0 [%] for U phase, 20 [%] for V phase, 40 [%] for W phase).
The second example shown in FIG. 4 is an example in which the output voltage level value of the output voltage of the inverter circuit 5 is set higher than that in the first example shown in FIG. That is, when the excitation current is supplied to the three-phase motor 9 by the voltage output in the pattern shown in FIG. 4, the smoothing capacitor is supplied rather than the excitation current is supplied to the three-phase motor 9 by the voltage output in the pattern shown in FIG. The electric charge accumulated in 3 can be discharged earlier.
In both the examples of FIG. 3 and FIG. 4, the output voltage level difference between phases (U phase−V phase, V phase−W phase, W phase−U phase) is set so as to satisfy the relationship of 0. ing. By adjusting the output voltage level value for each phase in advance while satisfying this relationship, the time required to complete the discharge of the charge accumulated in the smoothing capacitor 3 can be adjusted.
In step S6, the control calculation unit 4a determines the inverter circuit 5 for the three-phase motor 9 according to the correspondence between the stop electrical angle range θst ± Δθ and the voltage output pattern of the inverter circuit 5 shown as a data table in FIG. Determine the voltage output pattern. For example, the control calculation unit 4a reads the information in the data table from a nonvolatile memory that stores the information in advance, and based on the read information and the stop electrical angle range θst ± Δθ detected in step S5, The voltage output pattern of the inverter circuit 5 for the motor 9 is determined.

By the way, in the three-phase motor 9, when there is a difference between the electrical angle θst corresponding to the excitation current and the actual electrical angle of the three-phase motor 9, the excitation current is reduced and a magnetic field is generated in the three-phase motor 9 (that is, , Torque current is supplied), and a torque for rotating the three-phase motor 9 is generated by the difference. When the detection resolution of the electrical angle in the three-phase motor 9 is low (here, 60 [degrees]) as in the present embodiment, the rotation angle due to the generation of torque current can be relatively large. On the other hand, as in the present embodiment, if the voltage output (S6) in a constant pattern for supplying only the excitation current at the detected central angle θst of the stop electrical angle range is performed on the three-phase motor 9, The maximum difference that can occur between the electrical angle θst corresponding to the excitation current (the electrical angle at which the torque current becomes zero) and the actual electrical angle of the three-phase motor 9 is minimized, and the three-phase motor 9 that can be generated by voltage supply The maximum angle of rotation can be minimized (in this embodiment, 30 [degrees]).
If there is a difference between the electrical angle θst corresponding to the excitation current and the actual electrical angle of the three-phase motor 9, the higher the duty ratio of the output voltage to each phase for supplying the excitation current, A higher torque is generated in the motor 9, which may lead to an unfavorable situation in terms of safety. Therefore, the output voltage level value of each phase for supplying the excitation current takes into consideration the balance between the discharge time of the charge accumulated in the smoothing capacitor 3 and the torque (safety) that can be generated in the three-phase motor 9. Is set.

Further, the control calculation unit 4a continues to output a predetermined pattern of voltage from the inverter circuit 5 to the three-phase motor 9 (S6), and then determines whether or not a predetermined discharge termination condition is satisfied (S7), It is determined at any time whether or not the set discharge upper limit time has passed (S8). Here, the discharge end condition is that the low voltage detection circuit 7 detects the voltage shortage state.
When the voltage low detection circuit 7 detects the voltage shortage state while the voltage output of the constant pattern from the inverter circuit 5 to the three-phase motor 9 is continued (YES in S7), The power supply from the inverter circuit 5 to the three-phase motor 9 is stopped (S9, an example of the inverter constant power supply control means).
As a result, after the inverter circuit 5 enters a safe state where the three-phase motor 9 cannot be driven to rotate (the above-mentioned voltage shortage state), the microcomputer 4 or the like is finally used with the smoothing capacitor with the charge remaining as the power supply source. End processing (step S10 to be described later) can be executed.

In addition, the control calculation unit 4a also determines that the duration of the voltage output from the inverter circuit 5 to the three-phase motor 9 exceeds the discharge upper limit time (YES in S8). The power supply to the three-phase motor 9 is stopped (S9, an example of the constant inverter power supply control means). Note that the discharge upper limit time is longer than the calculated time which is considered to be required until the voltage shortage state is reached due to the relationship with the power consumption of the inverter circuit 5 according to the voltage output pattern in step S6. Is set. For example, when the calculation time is 1 second, the discharge upper limit time is set to 3 seconds or the like. Of course, it is possible to set a shorter or longer time.
Thereby, even if the interruption of the supply of the AC voltage to the DC power supply circuit 2 is erroneously detected due to some abnormality, the supply of the excitation current to the three-phase motor 9 is continued for a long period of time, and the three-phase motor 9 becomes abnormally high temperature. Or inconvenience of wasted power consumption.
Finally, the control calculation unit 4a (microcomputer 4) executes a final termination process using the smoothing capacitor 6 with a slight charge remaining as a power supply source (S10), and terminates the smoothing capacitor discharge process. This termination process (S10) is, for example, a process of recording information on occurrence history of abnormality such as the fact that the discharge upper limit time has passed in a state where the discharge termination condition is not satisfied in a predetermined nonvolatile memory (not shown), For example, the front door 22 is unlocked.
Thus, the safety is further improved by releasing the lock of the front door 22 after the discharge of the smoothing capacitor 3 is completed.

In the embodiment described above, the control arithmetic unit 4a performs the power supply stop process (S1) from the inverter circuit 5 to the three-phase motor 9 and then shuts off the AC voltage input line by the energizing switch 1. An example is shown in which the occurrence of an AC interruption state is detected (S3), and then the stop detection process (S4, S5) of the three-phase motor 9 is executed.
On the other hand, the control calculation unit 4a also generates the AC interruption state even when the power interruption detection circuit 11 provided in the AC voltage input line detects that the AC voltage level is less than the predetermined level. Detect. As a result, the control calculation unit 4a detects the sudden occurrence of the AC cutoff state caused by the power cord being unplugged from the outlet or a power failure of the AC power supply G.
When the control calculation unit 4a detects the occurrence of the sudden AC interruption state by the detection signal from the power interruption detection circuit 11, the control calculation unit 4a excludes the process of step S3 from the smoothing capacitor discharge process shown in FIG. The processes (S1, S2, S4 to S10) are executed. In this case, after detecting the AC cutoff state, the control calculation unit 4a executes a power supply stop process (S1) from the inverter circuit 5 to the three-phase motor 9 and a stop detection process (S4, S5) of the three-phase motor 9. It will be.
When the control calculation unit 4a executes the smoothing capacitor discharge process described above, even if the sudden AC cut-off state occurs, the rotating container (three-phase motor) is eliminated by the electric power stored in the smoothing capacitor. It is possible to prevent rotation in a controlled state.
The rotating container driving device X is mounted on a washing machine, a dryer, and a washing / drying machine having both functions, and the drum container 20 is driven to rotate. It is also conceivable to use it as a driving device for other rotating containers.

  The present invention can be used in a rotating container driving device that rotationally drives a container.

The block diagram showing the schematic structure of the rotating container drive device X which concerns on embodiment of this invention. The flowchart showing the procedure of the smoothing capacitor discharge process by the rotary container drive device X. The figure showing the 1st example of the output voltage pattern from the inverter circuit to a three-phase motor in smooth capacitor discharge processing. The figure showing the 2nd example of the output voltage pattern from the inverter circuit to a three-phase motor in smooth capacitor discharge processing. Sectional drawing of the washing-drying machine Z in which the rotation container drive device X is mounted.

Explanation of symbols

X: Rotating container driving device Z: Washer / dryer 1: Energizing switch 2: DC power supply circuit 3: Smoothing capacitor 4: Microcomputer 4a: Control calculation unit 4b: Angle calculation unit 5: Inverter circuit 6: Auxiliary power supply 7: Low voltage Detection circuit 8: Motor drive circuit 9: Three-phase motor 10: Operation unit 11: Power-off detection circuit 12: Magnetic pole detection unit 20: Drum container 21: Water tank 22: Front door

Claims (7)

Supply the AC voltage from the AC power source to the DC power source, smooth the DC voltage output by the DC power source with a smoothing capacitor, and supply it to the inverter circuit. The inverter circuit switches the output voltage and supplies it to the three-phase motor. Thus, a rotating container driving device for rotating a rotating container containing an object to be stirred by the three-phase motor,
AC interruption detection means for detecting the occurrence of an AC interruption state in which the supply of AC voltage to the DC power supply is interrupted;
Inverter power supply stop control means for stopping power supply to the three-phase motor by the inverter circuit;
Electrical angle detection means for detecting the electrical angle of the three-phase motor;
Motor stop detection means for detecting the electrical angle of the stop and stop position of the three-phase motor based on the detection angle of the electrical angle detection means after the power supply to the three-phase motor is stopped by the inverter power supply stop control means;
The three-phase motor detected by the motor stop detection means when the occurrence of the AC cutoff state is detected by the AC cutoff detection means and the stop of the three-phase motor is detected by the motor stop detection means. Constant inverter power supply control means for continuously supplying a constant pattern of voltage output from the inverter circuit and supplying an excitation current to the three-phase motor according to the electrical angle of the stop position of
A rotating container driving device comprising:   The inverter constant power supply control means, when the duration of the voltage output of the constant pattern from the inverter circuit to the three-phase motor exceeds a predetermined upper limit time, the inverter circuit to the three-phase motor The rotating container driving device according to claim 1, wherein power supply is stopped. A voltage shortage detecting means for detecting a voltage shortage state in which the input voltage of the inverter circuit is less than a predetermined level;
The inverter constant power supply control means, when the voltage shortage detection means detects the voltage shortage state while continuing the voltage output of the constant pattern from the inverter circuit to the three-phase motor, from the inverter circuit The rotating container driving device according to claim 1, wherein power supply to the three-phase motor is stopped. The electrical angle of the three-phase motor detected by the electrical angle detection means and the electrical angle of the stop position of the three-phase motor detected by the motor stop detection means are classified according to the magnetic pole position of the three-phase motor. One of a plurality of electrical angle ranges,
The voltage output of the constant pattern supplies the excitation current to the three-phase motor at the central angle of the electrical angle range of the stop position of the three-phase motor detected by the motor stop detection means and does not supply the torque current. It is a voltage output, The rotary container drive device in any one of Claims 1-3.   A washing machine comprising: a drum container that houses a laundry; and the rotating container driving device according to any one of claims 1 to 4 that rotationally drives the drum container.   A drying machine comprising: a drum container that accommodates an object to be dried; and the rotating container driving device according to any one of claims 1 to 4 that rotationally drives the drum container. Supply the AC voltage from the AC power source to the DC power source, smooth the DC voltage output by the DC power source with a smoothing capacitor, and supply it to the inverter circuit. The inverter circuit switches the output voltage and supplies it to the three-phase motor. Thus, there is provided a control method for a rotating container driving device for rotating a rotating container containing an object to be stirred by the three-phase motor,
AC interruption detection procedure for detecting occurrence of an AC interruption state in which supply of an AC voltage to the DC power supply is interrupted by a predetermined detection means;
An inverter power supply stop control procedure for stopping power supply to the three-phase motor by the inverter circuit by a predetermined control means;
An electrical angle detection procedure for detecting an electrical angle of the three-phase motor by a predetermined electrical angle detection means;
After the power supply to the three-phase motor is stopped by the inverter power supply stop control procedure, the three-phase motor is stopped based on the detection angle of the electrical angle of the three-phase motor by the electrical angle detection procedure by a predetermined detection means. And a motor stop detection procedure for detecting the electrical angle of the stop position,
When the occurrence of the AC interruption state is detected by the AC interruption detection procedure, and when the stop of the three-phase motor is detected by the motor stop detection procedure, it is detected by the motor stop detection procedure by a predetermined control means. An inverter constant power supply control procedure for continuously supplying a constant pattern of voltage output from the inverter circuit and supplying an excitation current to the three-phase motor according to the electrical angle at the stop position of the three-phase motor.
The control method of the rotary container drive device characterized by performing.

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