JP2011234594A - Polyphase motor driving method, polyphase motor driving system and heat pump device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving method of a polyphase motor using simple control logic, capable of suppressing the generation of a start defect even when phase interruption abnormality occurs for a motor requiring the detection of a rotor position and the determination of an output phase corresponding to the rotor position at the start, a polyphase motor driving system, and a heat pump device to which they are applied.SOLUTION: When the phase interruption abnormality occurs in an inverter circuit 13, a phase interruption abnormality detection part 61 detects the phase interruption abnormality, and a detection result is outputted from the phase interruption abnormality detection part 61 to a rotor position adjustment part 63. Then, the rotor position adjustment part 63 adjusts a rotor 31 to a position at which the torque of a brushless DC motor 30 can be generated by the output of the inverter circuit 13. In order to start from the positioned rotor position, a driving signal preparation part 16 prepares the driving signals of the inverter circuit 13, and the brushless DC motor 30 is driven.

Description

  The present invention relates to a multi-phase motor driving method, a multi-phase motor driving system, and a heat pump device, and more particularly to a multi-phase motor driving method at the time of phase loss abnormality, a multi-phase motor driving system and a heat pump device that can cope with phase loss abnormality.

  In heat pump devices, demands for brushless DC motors (hereinafter referred to as brushless DC motors) that have long life and low electrical noise and mechanical noise are increasing, for example, in fan motors. As a drive circuit for driving such a multiphase motor such as a brushless DC motor, an inverter circuit with high energy efficiency is generally used.

  By the way, for any phase of the drive output voltages for driving the multiphase motor, there may be a phase loss abnormality in which a voltage necessary for rotating the motor is not output from the inverter circuit. When the fan motor is driven with the output voltage at the time of phase loss, the applied voltage of each phase becomes unbalanced, and unbalance of the current of each phase occurs. For this reason, depending on the rotor position at the time of starting the motor, it may be impossible to start the fan because torque cannot be generated in relation to the phase that is out of phase. Even if the engine can be started, a torque in the direction opposite to the direction that should be output may be generated. Due to the above matters, problems such as an increase in current, an increase in noise and vibration, an unstable operation, and a defective start occur.

  Conventionally, in the case where there is a concern that the above-described problems occur and adversely affect the system side, as shown in Patent Document 1 (Japanese Patent Laid-Open No. 59-92799), motor drive As in the case of other abnormalities, in general, when a phase failure occurs, when the abnormality is detected, the operation of the drive circuit is stopped immediately and the multiphase motor is stopped.

  However, there are cases where it is desired to continue the operation even in the open phase state due to circumstances on the system side, and driving the motor under limited conditions is performed, for example, Patent Document 2 (Japanese Patent Laid-Open No. 2005-94873). A method for driving an electric motor in an open phase state has been proposed.

  However, the above-described method is effective for a motor in which the frequency and voltage of the output are controlled regardless of the rotor position, such as V / F control of an induction motor. Such detection of the rotor position and determination of the output phase according to the rotor position are difficult to apply as they are to a motor that is necessary at the time of starting. Further, the method proposed in Patent Document 2 is not suitable for driving in a system having only an inexpensive microcomputer or the like because vector calculation is required when performing waveform output.

  An object of the present invention is to prevent a start failure even when a phase failure occurs for a motor such as a brushless DC motor that detects a rotor position and determines an output phase according to the rotor position at the time of start. An object of the present invention is to provide a multi-phase motor driving method using a simple control logic, a multi-phase motor driving system, and a heat pump device to which they can be applied.

  The multiphase motor drive method according to the first aspect of the present invention includes a detection step, a rotor position adjustment step, and a drive step. In the detection step, a phase failure abnormality of the inverter circuit that outputs a multiphase motor drive output that matches the rotor position to the multiphase motor is detected. In the rotor position adjusting step, the rotor position is adjusted to a position where torque can be generated by the multiphase motor drive output before the multiphase motor is started at the time of the phase loss abnormality in which the phase loss abnormality is detected in the detection step. In the drive process, after the rotor position adjustment process at the time of phase loss abnormality, if the phase loss abnormality is not detected, the same multiphase motor drive output as the normal multiphase motor drive output for driving the multiphase motor is invertered The polyphase motor is driven by causing the circuit to output.

  According to the method according to the first aspect, since the mode of the phase failure that has occurred is detected by the detection step, the rotor position where torque can be generated in the phase failure that has occurred is easily identified. The Therefore, from the detection result of the detection step, in the rotor position adjustment step, the rotor can be adjusted to a position where torque can be generated with simple control logic. In the driving process, since the rotor is adjusted to a position where torque can be generated in the rotor position adjusting process, torque can be applied to the rotor at the time of starting.

  In the multiphase motor driving method according to the second aspect of the present invention, in the method according to the first aspect, the rotor position adjusting step includes a step of adjusting the rotor position by direct current excitation.

  According to the method according to the second aspect, the rotor position can be adjusted by the coil of the multiphase motor by direct current excitation, so that the adjustment for generating the power necessary for the rotor position adjustment by another power generation mechanism becomes unnecessary. The rotor position adjustment can be simplified.

  The multi-phase motor driving method according to the third aspect of the present invention is the method according to the second aspect, wherein the rotor position adjustment step is performed with respect to the rotational direction among the DC excitation phases that can be performed by an arm that is not in phase. A DC excitation phase in which the rotor position is adjusted in a section immediately after a section where there is no voltage output of the multiphase motor drive output due to an abnormality is used.

  According to the method according to the third aspect, when DC excitation is performed so that the rotor position is adjusted immediately after a section where there is no voltage output due to a phase failure in the rotational direction, torque is generated by the multiphase motor drive output. Since the section in which can be applied becomes longer, the reliability of starting the motor is improved.

  In the multiphase motor driving method according to the fourth aspect of the present invention, in the method according to any one of the first aspect to the third aspect, the detection step may be that the phase loss abnormality occurs only in one arm of one phase. If it is detected, or if it is detected that a phase loss abnormality is occurring only in one arm of one phase and the other arm of the other one phase different from one arm, an instruction to proceed to the rotor position adjustment process is issued. An instruction output step for outputting, and in other cases outputting an instruction to stop the driving of the multiphase motor.

  According to the method according to the fourth aspect, when it is detected that a phase failure abnormality is occurring only in one arm of one phase, or the phase failure abnormality is different from one arm and one arm of one phase. In other cases where it is not detected that it occurs only in the other arm of the phase, it is difficult to drive with the normal multiphase motor drive output according to the section where torque is generated. Occurrence of a problem can be prevented by stopping the driving of.

  A multiphase motor drive system according to a fifth aspect of the present invention includes an inverter circuit, detection means, rotor position adjustment means, and drive signal creation means. The inverter circuit outputs a multiphase motor drive output to the multiphase motor. The detecting means detects a phase failure in the inverter circuit. The rotor position adjusting means adjusts the rotor position to a position where torque can be generated by the multiphase motor drive output output from the inverter circuit when the phase loss is abnormal. The drive signal generating means drives the multiphase motor by causing the inverter circuit to output the same multiphase motor drive output as the normal multiphase motor drive output for driving the multiphase motor when no phase loss abnormality is detected.

  In the system according to the fifth aspect, since the detection means detects the state of the phase failure that has occurred, the rotor position where torque can be generated in the phase failure that has occurred is easily identified. The Therefore, from the detection result of the detecting means, the rotor position adjusting means can adjust the rotor to a position where torque can be generated with simple control logic. In the drive signal generating means, since the rotor is adjusted to a position where the torque can be generated by the rotor position adjusting means, it is possible to always apply torque to the rotor at the time of starting. it can. In addition, the drive signal generating means can use the conventional configuration as it is to generate a drive signal for outputting a normal multiphase motor drive output, and can be manufactured at low cost.

  The multiphase motor drive system according to the sixth aspect further includes display means capable of displaying that the detection means has detected a phase failure abnormality in the system according to the fifth aspect.

  According to the system according to the sixth aspect, it is possible to prevent the display unit from being used in an abnormal state by notifying the phase loss abnormality by the display means.

  The multi-phase motor drive system according to a seventh aspect further includes an instruction receiving unit capable of receiving an operation execution instruction for instructing driving of the multi-phase motor when the phase loss is abnormal in the system according to the sixth aspect.

  According to the system according to the seventh aspect, the instruction accepting unit can instruct externally whether or not to stop the multi-phase motor when the phase loss is abnormal, and the range of selection of the usage method when the phase loss is abnormal is widened.

  A heat pump device according to an eighth aspect includes a multiphase fan motor, an inverter circuit, detection means, rotor position adjustment means, and drive signal creation means. The multi-phase fan motor rotates the fan. The inverter circuit outputs a fan motor drive output to the fan motor. The detecting means detects a phase failure in the inverter circuit. The rotor position adjusting means adjusts the rotor position to a position where torque can be generated by the fan motor drive output output from the inverter circuit when the phase loss is abnormal. The drive signal generating means causes the inverter circuit to output the same fan motor drive output as the normal fan motor drive output for driving the fan motor when no phase loss abnormality is detected.

  According to the apparatus of the eighth aspect, since the detection means detects the mode of the phase failure that has occurred, the rotor of the fan motor that can generate the torque of the fan motor in the event of the phase failure that has occurred The position is easily identified. Therefore, from the detection result of the detection means, the rotor position adjustment means can adjust the rotor of the fan motor to a position where torque can be generated with simple control logic. In the drive signal generating means, since the rotor is adjusted to a position where the torque can be generated by the rotor position adjusting means, torque can be applied to the rotor of the fan motor at the time of starting. Occurrence can be suppressed. In addition, the drive signal generating means can use the conventional configuration as it is to generate a drive signal for outputting a normal multiphase motor drive output, and can be manufactured at low cost.

  In the multiphase motor driving method according to the first aspect of the present invention, a simple control logic is used for a motor that requires detection of the rotor position and determination of the output phase according to the rotor position at the time of start-up. Even if it occurs, it is possible to suppress the occurrence of starting failure.

  In the multiphase motor driving method according to the second aspect of the present invention, the rotor position adjustment can be simplified, and the driving at the time of the phase failure is simplified.

  In the multiphase motor driving method according to the third aspect of the present invention, the reliability of the motor start at the time of the phase loss abnormality is improved, and the motor is easy to use even at the time of the phase loss abnormality.

  In the multi-phase motor driving method according to the fourth aspect of the present invention, troubles are prevented by stopping the driving of the multi-phase motor, so that the trouble of confirming the trouble occurrence can be saved.

  In the multiphase motor drive system according to the fifth aspect of the present invention, a simple control logic is used for a motor that requires detection of the rotor position and determination of the output phase according to the rotor position at the time of start-up. Even if it occurs, it is possible to suppress the occurrence of starting failure.

  In the multiphase motor drive system according to the sixth aspect of the present invention, it is possible to prevent the system from continuing to be used in an abnormal state and to prevent the failure from deteriorating.

  In the multiphase motor drive system according to the seventh aspect of the present invention, the range of selection of the usage method at the time of the phase failure is widened, and it is easy to take an appropriate response to the phase failure.

  In the heat pump device according to the eighth aspect of the present invention, when a phase loss abnormality occurs using a simple control logic for a motor that requires detection of the rotor position and determination of the output phase according to the rotor position at the time of starting. However, it is possible to suppress the occurrence of starting failure.

The figure which shows the outline of a structure of the air conditioning apparatus which concerns on one Embodiment of this invention. The block diagram for demonstrating the fan motor drive system which concerns on one Embodiment of this invention. The flowchart which shows the outline | summary of operation | movement of the drive control part of a fan motor drive system. The timing chart for demonstrating the signal and voltage for operating a brushless DC motor at the time of a phase loss of a U-phase upper arm. The timing chart for demonstrating fixation of the rotor position before a start at the time of the phase loss abnormality of a U-phase upper arm. The timing chart for demonstrating the signal and voltage for operating a brushless DC motor at the time of a phase loss of a U-phase upper arm and a V-phase lower arm. The timing chart for demonstrating fixation of the rotor position before a start at the time of the phase loss abnormality of a U-phase upper arm and a V-phase lower arm. The block diagram for demonstrating the phase loss abnormality detection part of a fan motor drive system. The figure for demonstrating operation | movement of the phase loss abnormality detection part of FIG. The block diagram for demonstrating the conventional fan motor drive system. The timing chart for demonstrating the signal and voltage for operating a brushless DC motor at the normal time in two-phase electricity supply. (A) The vector diagram for demonstrating the output voltage in the normal time of the inverter circuit of 2 phase electricity supply. (B) The vector diagram for demonstrating the output voltage at the time of the phase loss of the inverter circuit of 2 phase electricity supply.

  Hereinafter, an air conditioner will be described as an example of a heat pump device according to an embodiment of the present invention.

(1) Outline of Air Conditioner FIG. 1 is a diagram showing an outline of a configuration of an air conditioner according to an embodiment of the present invention. The air conditioner 10 of FIG. 1 includes an outdoor unit 101 and an indoor unit 102. The outdoor unit 101 is provided with a compressor 103, a four-way switching valve 104, an outdoor heat exchanger 105, an electric valve 106, an accumulator 107, an outdoor fan 108, and the like. The indoor unit 102 includes an indoor heat exchanger 109. In addition, an indoor fan 110 and the like are provided. Here, one of the outdoor unit 101 and the indoor unit 102 corresponds to a heat source unit, and the heat source unit exchanges heat with other units to use heat.

  In the air conditioner 10, the outdoor unit 101 and the indoor unit 102 are connected by a pipe 111, whereby a refrigerant circuit in which refrigerant circulates is configured. A four-way switching valve 104 is provided on the discharge side of the compressor 103. The four-way switching valve 104 has a connection indicated by a solid line during cooling, and a connection indicated by a broken line during heating, thereby switching the flow direction of the refrigerant during cooling and during heating. The refrigerant discharged from the compressor 103 enters from one inlet of the four-way switching valve 104, and is returned to the compressor 103 through the accumulator 107 from one outlet of the four-way switching valve 104. During cooling, the port connected to the outdoor heat exchanger 105 serves as the other outlet of the four-way switching valve 104, and the refrigerant discharged from the compressor 103 is supplied to the outdoor heat exchanger 105 from the other outlet, The port connected to the exchanger 109 becomes the other inlet. Further, during heating, the mouth of the four-way switching valve 104 connected to the indoor heat exchanger 109 serves as the other outlet, and the refrigerant is supplied to the indoor heat exchanger 109 from the other outlet, and the outdoor heat exchanger 105 is supplied with the refrigerant. The connected mouth becomes the other entrance. Therefore, the refrigerant returning to the accumulator 107 is supplied by the four-way switching valve 104 from the indoor heat exchanger 109 during cooling and from the outdoor heat exchanger 105 during heating.

  In the outdoor heat exchanger 105, the inlet / outlet not connected to the four-way switching valve 104 is connected to the motor-operated valve 106. The motor valve 106 is connected to the indoor heat exchanger 109 at the inlet / outlet which is not connected to the outdoor heat exchanger 105. Then, the refrigerant circulates between the compressor 103 and the accumulator 107, the outdoor heat exchanger 105, the electric valve 106, and the indoor heat exchanger 109.

  The refrigerant circulation will be described in more detail as follows. During heating, the refrigerant that has taken in outdoor heat by the outdoor heat exchanger 105 of the outdoor unit 101 flows to the indoor heat exchanger 109 of the indoor unit 102, and the refrigerant heats indoor air by the indoor heat exchanger 109 of the indoor unit 102. discharge. Then, the refrigerant cooled by releasing heat returns from the indoor heat exchanger 109 to the outdoor heat exchanger 105. Conversely, during cooling, the refrigerant cooled by releasing heat to the outdoor heat exchanger 105 of the outdoor unit 101 flows into the indoor heat exchanger 109 of the indoor unit 102, and the refrigerant takes in heat by the indoor heat exchanger 109. Heat away from room air. The refrigerant whose temperature has risen due to the heat removed from the indoor heat exchanger 109 returns to the outdoor heat exchanger 105 again.

  In the outdoor heat exchanger 105 and the indoor heat exchanger 109, the outdoor fan 108 and the indoor fan 110 generate the outdoor air and the air flow of the indoor air that exchange heat with the refrigerant. If a phase loss abnormality occurs in the drive devices of the fan motors 108a and 110a connected to the indoor fan 110, the rotation speed of the fan motors 108a and 110a decreases, noise is generated, and the fan motors 108a and 110a It causes a malfunction that stops. If the rotational speed of the fan motors 108a and 110a is reduced or stopped, the air flow is reduced and the efficiency of heat exchange between the refrigerant and the indoor air or the outdoor air is deteriorated. 10 has taken measures to stop the operation of the air conditioner 10 by informing the outside of the abnormality.

  Also in the air conditioner 10 of this embodiment, when the outdoor fan 108 and the indoor fan 110 are stopped due to a phase failure in the fan motor drive system that drives the fan motors 108a and 110a, the efficiency of heat exchange is extremely reduced. The original function of the air conditioner 10 is no longer performed. In such a case, the air conditioner 10 should be stopped because the power consumption in the air conditioner 10 also increases or the refrigerant pressure becomes too high. But stop driving. Then, the air conditioner 10 notifies the user of the phase failure abnormality.

  However, in this air conditioner 10, even if the rotational speed of the fan motors 108a and 110a is reduced due to the phase loss abnormality and the heat exchange performance is deteriorated, the air in the outdoor heat exchanger 105 and the indoor heat exchanger 109 is reduced. Since the refrigerant and the refrigerant are separated from each other, it is unlikely that only the phase failure is a major factor that causes trouble in the refrigerant circuits of the outdoor unit 101 and the indoor unit 102. That is, when the rotational speed of the outdoor fan 108 or the indoor fan 110 is reduced, the air conditioning function can be exhibited although the performance of the air conditioning apparatus 10 is reduced. At this time, noise / vibration generated from the fan motors 108a and 110a, the fans 108 and 110, or the housing of the product may increase, but if the degree of increase is at a level that does not interfere with practical use, the operation is continued. There is no problem.

  Therefore, if the outdoor fan 108 or the indoor fan 110 can be rotated even if a phase failure abnormality occurs in the fan motor drive system of the fan motors 108a and 110a, the phase failure abnormality remains until the repair is completed. The air conditioner 10 is operated. Accordingly, it is possible to reduce the period during which the air-conditioning apparatus 10 stops and causes discomfort to the user during the phase failure. As described above, since the control for the outdoor fan 108 and the indoor fan 110 differs depending on the state of the phase failure, the function of specifying the state of the phase failure and controlling the fan motors 108a and 110a at the time of the phase failure is an air conditioner. 10 fan motor drive systems.

(2) Abnormal phase failure in fan motor drive system (2-1) Overview of conventional fan motor drive system Prior to describing the fan motor drive system according to this embodiment, the open phase abnormality in the conventional fan motor drive system is described. explain. FIG. 10 shows a circuit diagram of a main part of a conventional brushless DC motor and its drive system. A fan 80 shown in FIG. 10 represents the outdoor fan 108 and the indoor fan 110 described in FIG. The fan motor that generates power for rotating the fan 80 is a brushless DC motor 30. The brushless DC motor 30 is driven by a fan motor drive system 200. In the following description, the brushless DC motor 30 may be simply referred to as the motor 30 in some cases.

  The fan motor drive system 200 includes an inverter circuit 13, a gate drive circuit 15, a rectifier circuit 21, and a drive signal creation unit 16 and a rotation speed control unit that constitute a motor control unit 22 formed on one driver integrated circuit 20. 17 and a rotation speed calculation unit 18. The inverter circuit 13 supplies output voltages Vu, Vv, Vw to the motor 30. The rectifier circuit 21 supplies a DC voltage to the inverter circuit 13. The gate drive circuit 15 turns on and off the switching elements of the inverter circuit 13 in order to generate output voltages Vu, Vv, and Vw based on the output. The drive signal generator 16 generates six gate signals Gu, Gv, Gw, Gx, Gy, and Gz for controlling the output of the gate drive circuit 15 and outputs them to the gate drive circuit 15. The rotation speed control unit 17 controls the rotation speed of the motor 30 by a duty command D * output to the drive signal creation unit 16. The rotation speed calculation unit 18 calculates the current rotation speed vm of the motor 30 by calculation and outputs it to the rotation speed control unit 17.

  The brushless DC motor 30 driven by the fan motor drive system 200 includes a rotor 31, a stator 32, and hall sensors 33a, 33b, and 33c. The stator 32 has a star connection in which one end of the armature coils Lu, Lv, Lw is commonly connected at a neutral point n. The rotor 31 includes a permanent magnet and rotates relative to the stator 32 around the rotation axis together with the permanent magnet. The hall sensors 33a, 33b, and 33c detect the position of the rotor 31 with respect to the stator 32 based on the magnetic flux of the permanent magnet.

  The inverter circuit 13 includes upper arm switching elements 3u1, 3v1, 3w1 and lower arm switching elements 3u2, 3v2, 3w2 connected to the other ends of the armature coils Lu, Lv, Lw. When the upper arm switching elements 3u1, 3v1, 3w1 are turned on, the inverter circuit 13 connects the other ends of the armature coils Lu, Lv, Lw to the rectifier circuit 21 via the switching elements 3u1, 3v1, 3w1, respectively. Connect to the high voltage side. Further, when the lower arm switching elements 3u2, 3v2, 3w2 are turned on, the inverter circuit 13 rectifies the other end of the armature coils Lu, Lv, Lw via the respective switching elements 3u2, 3v2, 3w2. 21 is connected to the low voltage side.

  In order to rotate the brushless DC motor 30, it is necessary to change the voltage applied to the stator 32 according to the relative positional relationship between the rotor 31 and the stator 32. Therefore, it is necessary to detect the position of the rotor 31 with respect to the stator 32. In the brushless DC motor 30, the position of the rotor 31 is detected by the hall sensors 33a, 33b, and 33c. Then, hall sensor signals Hu, Hv, Hw are output from the hall sensors 33a, 33b, 33c to the fan motor drive system 12 as rotor position detection signals.

  Upon receiving the Hall sensor signals Hu, Hv, Hw, the motor control unit 22 of the fan motor drive system 200 switches the upper arm switching elements 3u1, 3v1, 3w1 and the lower arm according to the position of the rotor 31. By switching on / off of the elements 3u2, 3v2, 3w2 by the output of the gate drive circuit 15, the DC voltage supplied from the rectifier circuit 21 is converted, and the output voltage for the three phases U phase, V phase and W phase is output. Vu, Vv, and Vw are generated. For this purpose, the drive signal creation unit 16 of the motor control unit 22 outputs the timing for switching the six switching elements 3u1, 3v1, 3w1, 3u2, 3v2, and 3w2 to the gate drive circuit 15 that drives these elements. It is given by six gate signals Gu, Gv, Gw, Gx, Gy, Gz.

  Using these gate signals Gu, Gv, Gw, Gx, Gy, and Gz, the drive signal generator 16 uses the hall sensor signals Hu, Hv, Hw that specify the position of the rotor 31 and the duty command D * for controlling the rotational speed. Create based on. The motor control unit 22 includes a rotation speed control unit 17 and a rotation speed calculation unit 18. The rotation speed control unit 17 sends the duty command D * to the rotation speed calculation unit 18 from the Hall sensor signals Hu, Hv, and Hw. Is generated based on the current rotation speed vm calculated by the above and the rotation speed instruction signal v * input from the outside, and is supplied to the drive signal creation section 16. Note that an AC power supply 90 is connected to the rectifier circuit 21.

(2-2) Operation of Fan Motor Drive System FIG. 11 is a timing chart for explaining the relationship between the rotor and the output voltage of the inverter circuit in a normal state in the case of two-phase energization (120-degree energization method). In FIG. 11, the horizontal axis shows the rotor position in electrical angle. FIG. 11A is a diagram showing voltage waveforms of the induced voltages Vun, Vvn, and Vwn of the stator with the neutral point n as a reference. FIG. 11B is a diagram illustrating output waveforms of the hall sensor signals Hu, Hv, and Hw for detecting the rotor position. FIG. 11C is a diagram showing the relationship between the Hall sensor signals Hu, Hv, Hw and the position signal mode set based on the state of each signal. FIG. 11D is a diagram illustrating waveforms of the gate signals Gu, Gv, Gw, Gx, Gy, and Gz of the inverter circuit 13. FIG. 11E is a diagram showing output waveforms of the output voltages Vu, Vv, Vw of the inverter circuit 13. In the motor 30, the description will be made assuming that the forward rotation direction is counterclockwise (CCW), and the electrical angle indicating the rotor position is increased in the forward rotation direction.

  In this embodiment, a method of chopping (PWM control) the switching element of the lower arm is shown as an example, and the gate signals Gx to Gz of the lower arm are high in frequency (for example, several kHz) in the section of the position signal mode to be energized. Chopping at about 20 kHz). In the figure, the gate signal of the lower arm shown in the figure shows the chopping state at a low frequency for simplicity, but the actual output waveform is chopped at a high frequency. In these figures, the output voltage waveform is simple and does not show the state of chopping, but the actual output waveform is a waveform chopped by the PWM method.

  At the time of forward rotation, the polarities of the Hall sensor signals Hu, Hv, Hw are opposite to the induced voltages Vun, Vvn, Vwn of the stator 32. As can be seen by comparing FIG. 11A and FIG. 11B, the phase of the Hall sensor signals Hu, Hv, Hw advances by 30 degrees with respect to the induced voltages Vun, Vvn, Vwn. Further, the phases of the output voltages Vu, Vv, Vw are in phase with the induced voltage. Since the relationship between the phase of the output voltage and the induced voltage can be adjusted at the mounting position of the Hall sensor, and can also be adjusted by phase control of the output voltage, in the description of the embodiment of the present invention, There is no need to be particular about the phase.

(2-3) Operation of Conventional Fan Motor Drive System at Phase Loss FIG. 4 illustrates the relationship between the rotor and the output voltage of the inverter circuit when phase loss occurs in the U-phase upper arm during two-phase energization. It is a timing chart for doing. Examples of a phase failure occurring in the U-phase upper arm include a case where the switching element 3u1 itself fails or a case where the switching element 3u1 malfunctions because the appropriate gate signal is not output and is always off. It is done. For example, there is an open failure in which the switching element 3u1 keeps an off state even though the gate signal Gu for turning on the switching element 3u1 of the U-phase upper arm is output.

  When the gate signal Gu of FIG. 11 (d) is not output to the switching element 3u1, the gate signal is in a state as shown in FIG. 4 (d), which is shown in FIG. 4 (e). As described above, the switching element 3u1 is turned off in the section In1 in which the electrical angle is 30 degrees to 150 degrees, and no voltage is output.

  FIG. 12A is a diagram showing the output of the inverter circuit 13 in a normal state in the case of two-phase energization for convenience, and FIG. 12B is a diagram in the case of two-phase energization. It is the figure which showed the output of the inverter circuit 13 of a U-phase upper arm phase loss state with the space voltage vector. Also in the case of two-phase energization, as can be seen by comparing FIG. 12 (a) and FIG. 12 (b), the applied voltage of each phase becomes unbalanced and an unbalance of the current of each phase occurs.

(3) Configuration of Fan Motor Drive System According to this Embodiment FIG. 2 is a block diagram for explaining a fan motor drive system for driving the fan motor. The fan motor drive system 12 includes an inverter circuit 13, a driver integrated circuit 20 including a gate drive circuit, a rectifier circuit 21, and a motor control unit 22.

  The fan motor drive system 12 shown in FIG. 2 differs from the fan motor drive system 200 shown in FIG. 10 in that the phase loss abnormality detection unit 61, the rotor position detection unit 62, the rotor position adjustment unit 63, and the switching unit 64 are instructed. It is the presence or absence of the structure of the reception part 65 and the display part 66, and another structure is the same. Therefore, the description of the inverter circuit 13 and the gate drive circuit 15 and the description of the rectifier circuit 21 and the motor control unit 22 already described in FIG. 10 are omitted, and the phase loss abnormality detection unit 61, the rotor position detection unit 62, and the rotor position adjustment are omitted. The unit 63, the switching unit 64, the instruction receiving unit 65, and the display unit 66 will be described.

(3-1) Configuration for Driving in the Case of Phase Loss Abnormality The phase loss abnormality detection unit 61 detects the presence / absence of the phase loss abnormality and the phase loss location of the inverter circuit 13. The detection of the phase loss abnormality in the phase loss abnormality detection unit 61 may be performed at the start of operation of the air conditioner 10, during operation, or after operation stop, and may be performed before, during, or after rotation of the fan 80. It may be broken. However, since the rotor position of the fan 80 is adjusted when the phase loss is abnormal, it is effective to perform it before the fan 80 rotates. For example, the phase loss abnormality detection unit 61 detects whether the inverter circuit 13 can generate appropriate output voltages Vu, Vv, Vw with respect to the gate signals Gu, Gv, Gw, Gx, Gy, Gz. However, the detection includes not only direct but also indirect cases. For example, it may be detected from failure detection of individual switching elements 3u1, 3v1, 3w1, 3u2, 3v2, 3w2, measurement of the output impedance of the inverter circuit 13, and the like. What is necessary is just to be able to identify the state of the phase loss abnormality of which arm of the phase is missing. Further, it is not necessary to specify all the phase loss abnormalities, and it is sufficient that at least the state of phase loss abnormalities to be driven at the time of phase loss can be specified. An example of the phase loss abnormality detection unit 61 will be described later.

  The rotor position detector 62 detects the position of the rotor 31 based on the hall sensor signals Hu, Hv, Hw. Although it has been described that the drive signal generator 16 also detects the position of the rotor 31 based on the Hall sensor signals Hu, Hv, Hw, the rotor position detector 62 also determines the rotor position by the same method as the drive signal generator 16. To detect. Here, the rotor position detector 62 is provided separately from the drive signal generator 16 because the motor controller 22 is often formed on one integrated circuit. This corresponds to the case where it is difficult to obtain only the position detection result. If the detection result of the rotor position can be obtained from the drive signal creation unit 16, the rotor position detection unit 62 may be omitted using the detection result.

  When a predetermined phase loss abnormality is detected by the phase loss abnormality detection unit 61, the rotor position adjustment unit 63 determines the position of the rotor 31 before starting the motor 30 according to the type and situation of the detected phase loss abnormality. Adjust. Here, the type of phase failure is, for example, one of the upper arm or the lower arm is abnormal, a pair of upper and lower arms in the same phase is abnormal, and one upper arm and lower arm of different phases are abnormal. , Refers to an aspect that is classified without distinguishing phases (U phase, V phase, W phase) in which an open phase occurs. Here, the phase failure abnormality state refers to a specific state such as in which phase the phase loss abnormality occurs, the arm remains closed, or the arm remains open.

  In order to adjust the rotor position, it is necessary to have information on the rotor position that can generate torque even when a phase loss abnormality occurs for the type and situation of the phase loss abnormality. For this reason, the rotor position where torque can be generated is determined in advance from experiments and theories regarding the type and situation of the phase failure. In order to prevent start-up failure as much as possible even if a phase loss abnormality has occurred, it is preferable to match with a position where the electrical angle is as small as possible at the rotor position where torque can be continuously generated. This is because the application of torque to the rotor 31 can be continued for a long time in the direction in which the electrical angle increases during rotation. The rotor position adjustment unit 63 stores information necessary for adjusting the rotor position in an internal or external memory.

  The rotor position adjustment unit 63 can determine which position the rotor 31 is based on the detection result of the rotor position detection unit 62. That is, when a signal indicating that the rotor 31 has been moved to a desired position is input from the rotor position detection unit 62, the rotor position adjustment unit 63 ends the adjustment of the rotor position.

  The rotor position adjustment unit 63 switches connection of a switching unit 64 described later so that the output of the rotor position adjustment unit 63 is given to the gate drive circuit 15 until the adjustment of the rotor position is completed. Then, after adjusting the rotor position, the rotor position adjusting unit 63 connects the switching unit 64 so that the gate signals Gu, Gv, Gw, Gx, Gy, Gz of the drive signal generating unit 16 are given to the gate drive circuit 15. Switch.

  The switching unit 64 includes gate signals Gu, Gv, Gw, Gx, Gy, and Gz that are output from the drive signal generation unit 16 to the gate drive circuit 15, and a gate signal that is output from the rotor position adjustment unit 63 to the gate drive circuit 15. Can be switched so that one of the two is supplied to the gate drive circuit 15. The gate signal output from the rotor position adjustment unit 63 to the gate drive circuit 15 includes six different signals in the same manner as the gate signal from the drive signal creation unit 16.

  The instruction receiving unit 65 receives a signal Co1 for instructing whether or not to drive the brushless DC motor 30 when a phase loss abnormality occurs, from the outside, and to the rotor position adjusting unit 63, the motor 30 A command Od1 relating to driving is output. The signal Od1 output from the instruction receiving unit 65 may include not only a signal that indicates whether or not driving is possible with respect to occurrence of a phase loss abnormality but also a signal that indicates whether driving is possible for each state of phase loss abnormality. . In the rotor position adjusting unit 63, when the command Od1 of the instruction receiving unit 65 is an instruction not to drive the motor 30 when the phase loss is abnormal, the output of the gate drive circuit 15 is fixed to, for example, one in which all arms do not operate. Such a gate signal is output.

  The display unit 66 receives information on the presence / absence of the phase failure and / or the type of the phase failure from the rotor position adjustment unit 63 and displays the information on the outside.

  Next, the operation of the fan motor drive system 12 will be described along the flow shown in FIG. When it is time to detect the phase loss abnormality (step S1), the process proceeds to step S2, and the phase loss abnormality detection unit 61 detects the phase loss abnormality. The timing for detecting the phase loss abnormality is set to a time appropriate for the operation of the air conditioner 10, for example, detecting a phase failure when the fan 80 starts operation.

  When a phase loss abnormality has occurred, a signal indicating the detection of the phase failure and the state of the detected phase failure is output from the phase failure abnormality detection unit 61 to the rotor position adjustment unit 63. The rotor position adjustment unit 63 determines that a phase loss abnormality has been detected (step S3).

  When the rotor position adjusting unit 63 determines that the phase loss abnormality is detected in step S3, the rotor position adjustment unit 63 continues the determinations of step S4 and step S5 from the output of the phase loss abnormality detection unit 61. In step S4, the rotor position adjusting unit 63 determines whether or not the state of the phase failure is motor driveable. For example, in the case of a three-phase brushless DC motor 30, if two or more one-sided arms of different phases are missing, the rotor position adjusting unit 63 determines that the rotor cannot be driven because it cannot be rotated. It can be rotated as long as there is no phase loss in one arm, but if the upper and lower arms in the same phase are in phase, the rotor cannot be fixed. In addition, when there is no open phase in the upper and lower arms of the same phase, it is determined that the rotor position adjusting unit 63 can be driven.

  After determining that the phase loss abnormality that can be driven in step S4, in step S5, the rotor position adjustment unit 63 determines whether or not to drive the brushless DC motor 30 during phase loss based on the command Od1 from the instruction receiving unit 65. To decide.

  When step S5 is completed and it is determined that the phase loss abnormality is drivable and there is no instruction to stop driving when the phase loss occurs, the rotor position adjustment unit 63 displays an abnormality on the display unit 66. Is output. Thereby, the display unit 66 displays, for example, the state of the phase loss abnormality together with the information on the content of continuing the operation of the fan 80 although the phase loss abnormality has occurred.

  Next, the rotor position adjusting unit 63 outputs a gate signal necessary for fixing the rotor position to the gate drive circuit 15 in order to adjust the position of the rotor 31 before starting in step S7. Therefore, the rotor position adjustment unit 63 causes the switching unit 64 to switch so that the output of the rotor position adjustment unit 63 is connected to the gate drive circuit 15. Specific selection of the fan motor drive output at the time of phase failure in the rotor position adjustment unit 63 will be described later.

  In step S <b> 8, in order to drive the motor 30, the rotor position adjustment unit 63 causes the switching unit 64 to switch so that the gate signal from the drive signal creation unit 16 is output to the gate drive circuit 15. The gate signals Gu, Gv, Gw, Gx, Gy, and Gz created by the drive signal creation unit 16 are output to the gate drive circuit 15, and the motor 30 is driven by the output from the inverter circuit 13.

  If it is determined in the first step S1 that the phase loss abnormality detection timing is not reached, the state of the drive signal is continued (step S9). That is, when the motor 30 is driven by outputting based on a certain drive signal, the output is continued as it is, and when the drive is stopped, it is stopped as it is. If no phase loss abnormality is detected in step S3, the process proceeds to step S10, where normal fan motor drive output is performed. Here, the normal fan motor drive output refers to a drive output performed from the motor stop state until the desired rotation operation is continued, and does not include the fixing of the rotor position before starting as described above. The same applies to the following description.

  Further, if it is determined in step S4 that the phase loss abnormality state cannot be driven, and if there is a command to stop driving at the time of phase loss in step S5, the process proceeds to step S11, where the rotor position adjustment unit The switching is instructed from 63 to the switching unit 64 so that the gate signal of the rotor position adjusting unit 63 is given to the gate drive circuit 15. Then, the rotor position adjusting unit 63 outputs gate signals Gu, Gv, Gw, Gx, Gy, Gz that turn off the switching elements 3u1, 3v1, 3w1, 3u2, 3v2, 3w2, for example. This is because an abnormal voltage is not output from the inverter circuit 13 to the motor 30 because the operation of the switching elements 3u1, 3v1, 3w1, 3u2, 3v2, and 3w2 becomes unstable due to the phase failure. Next, the process proceeds to step S <b> 12, and a signal for abnormal display is output from the rotor position adjustment unit 63 to the display unit 66. Thereby, the display unit 66 displays the state of the phase loss abnormality along with the occurrence of the phase loss abnormality.

  In order to simplify the explanation, the explanation is made such that each step is sequentially performed. However, for example, Step S3 and Step S4 and Step S5, Step S6 and Step S7, Step S10 and Step S11, etc. are performed simultaneously. May be performed, and the order may be reversed. In step S1, the case where the timing for detecting the phase failure is provided separately from the driving of the brushless DC motor 30 has been described. However, depending on the detection method, the phase failure can be detected while rotating the motor 30. In some cases, the phase loss abnormality may be detected in parallel with the driving of the motor 30. Moreover, you may perform the abnormality display of step S6, S12 immediately after step S4.

(3-2) Specific example of motor driving at the time of phase loss In the following description, the phase loss abnormality is an abnormality that does not turn on when the switching element of the inverter circuit should be turned on. In addition, when the three-phase brushless DC motor 30 shown in FIG. 2 is configured to be driven by the inverter circuit 13, the motor 30 cannot be driven when two or more phases on one side of different phases are missing. Therefore, in order to select the fan motor drive output at the time of phase loss in the rotor position adjustment unit 63, it is necessary to distinguish between the case where the phase loss of the upper arm is one phase or less and the phase loss of the lower arm is also one phase or less. It is. Therefore, if there is no distinction between the U phase, V phase, and W phase, a phase failure occurs only in the upper arm or lower arm of one phase or under the other one phase of the upper arm or lower arm of one phase. There are two patterns when a phase failure occurs in the arm or upper arm. In these two patterns, even if there is a difference between the U phase, the V phase, and the W phase, the method for dealing with the missing phase abnormality is the same, so in the following description, the U phase, the U phase, and the V phase are missing phases. An example of the case will be described with respect to the correspondence to the two patterns.

(3-2-1) When only the U-phase upper arm is phase-opened FIG. 4 shows a brushless DC when two-phase energization is performed on the three-phase brushless DC motor when the U-phase upper arm is open. It is a timing chart for demonstrating the signal and voltage for operating a motor. In FIG. 4, the horizontal axis represents the rotor position in electrical angle. FIG. 4A shows induced voltages Vun, Vvn, and Vwn that are induced in the armature coils Lu, Lv, and Lw of the stator 32 in the normal state. FIG. 4B shows Hall sensor signals Hu, Hv, Hw output from the hall sensors 33a, 33b, 33c. FIG. 4C shows the hall sensor signals Hu, Hv, Hw and the position signal mode. FIG. 4D shows gate signals Gu, Gv, Gw, Gx, Gy, and Gz output from the drive signal generating unit 16 to drive the motor 30 when the U-phase upper arm is in phase loss. . FIG. 4E shows the output waveform of the voltage output from the inverter circuit 13 corresponding to the output of the drive signal generator 16 shown in FIG.

  Since an open phase has occurred in the U-phase upper arm, the output of the U-phase of the inverter circuit 13 does not become a normal value in the interval In1 of 30 to 150 degrees in electrical angle. In this example, this corresponds to the output of the gate signal Gu for turning off the switching element 3u1 in the interval In1 of 30 degrees to 150 degrees in electrical angle (see FIG. 4D). Thereby, in the section In1 from 30 degrees to 150 degrees, as shown in FIG. 4E, the output voltages of the U phase, V phase, and W phase of the inverter circuit 13 become zero.

  When the brushless DC motor 30 is rotating and the state shown in FIG. 4 is reached, the fan 80 is attached to the motor 30, and therefore the section of the electrical angle of 30 degrees to 150 degrees due to the inertial movement of the fan 80. Since the motor 30 continues to rotate even if there is no torque at In1, the motor 30 can continue to drive the fan 80 even if a phase failure occurs in the U-phase upper arm.

  Next, starting of the brushless DC motor 30 when a phase failure has occurred in the U-phase upper arm will be described. FIG. 5 is a timing chart for explaining the fixing of the rotor position before starting. FIG. 5A shows induced voltages induced in the armature coils Lu, Lv, and Lw at the normal time. FIG. 5B shows Hall sensor signals Hu, Hv, and Hw that are output from the Hall sensors 33a, 33b, and 33c. FIG. 4C shows the relationship between the Hall sensor signals Hu, Hv, Hw, the position signal mode, the DC excitation phase, and the rotor fixed position. In FIG. 5C, for example, “U +” represents that the U-phase upper arm is turned on, and “U−” represents that the U-phase lower arm is turned on.

  As already described, when the U-phase upper arm is open, torque cannot be generated in the section In1 having an electrical angle of 30 to 150 degrees. Further, the inverter circuit 13 cannot output the DC excitation phase for fixing the rotor 31 at the position Po1 of the electrical angle from 105 degrees to 255 degrees due to the phase loss of the U-phase upper arm. Therefore, the position where the rotor 31 can be fixed and the torque can be applied at the time of starting is limited to the position Po2 from 255 degrees to 15 degrees in electrical angle. Among these, the position Po3 where the torque can be given for a long time after fixing is preferable. When fixed at the position Po3, torque is applied at a position Po4 from 285 degrees to 30 degrees.

  By turning on the V-phase lower arm and the W-phase upper arm, the rotor 31 can be fixed at the position Po3. The V-phase lower arm and the W-phase upper arm are turned on when the position signal mode is “2” as shown in FIG. Therefore, the rotor position adjustment unit 63 outputs a gate signal corresponding to the position signal mode “2” to the gate drive circuit 15 before starting when the phase loss occurs in the U-phase upper arm. The rotor position detection unit 62 performs DC excitation until the Hall sensor signal Hu is “1” and Hv is “0”, that is, until the position signal mode is 3 or 4. When the rotor position detection unit 62 detects that the Hall sensor signal Hu is “1” and Hv is “0”, the rotor position adjustment unit 63 switches the connection in the switching unit 64 to drive. The gate signal of the signal generator 16 can be output to the gate drive circuit 15. Thereafter, the drive signal generator 16 outputs a normal motor drive output from the inverter circuit 13 according to the position signal mode, and the motor 30 is driven.

  For example, when the rotor 31 is stopped when the position signal mode of the Hall sensor signal is “1”, the V-phase upper arm and the W-phase lower arm are turned on, and then the U-phase lower arm and the V-phase upper arm are turned on. It is also possible to turn on the U-phase lower arm and W-phase upper arm and gradually turn them closer to 270 degrees before turning on the V-phase lower arm and the W-phase upper arm. In addition, since current flows gradually by performing chopping even during direct current excitation, damage to the switching element can be reduced.

(3-2-2) When the U-phase upper arm and the V-phase lower arm are phase-opened FIG. 6 shows two phases for the brushless DC motor when the U-phase upper arm and the V-phase lower arm are missing. It is a timing chart for demonstrating the signal and voltage for operating a brushless DC motor when it supplies with electricity. 6 (a), 6 (b) and 6 (c) are the same as those shown in FIGS. 4 (a), 4 (b) and 4 (c). Therefore, explanation is omitted. FIG. 6D shows gate signals Gu, Gv, Gw, Gx, Gy, Gz output from the drive signal generator 16 for driving the motor 30 when the U-phase upper arm and the V-phase lower arm are missing. It is shown. FIG. 6E shows an output waveform of the voltage output from the inverter circuit 13 in accordance with the output of the drive signal generator 16 shown in FIG.

  Since the phase loss occurs in the U-phase upper arm and the V-phase lower arm, the output of the U-phase and V-phase of the inverter circuit 13 does not become normal values in the interval In2 from 30 degrees to 210 degrees. In this example, this corresponds to the output of gate signals Gu and Gy that turn off the switching elements 3u1 and 3v2 in the interval In2 from 30 degrees to 210 degrees (see FIG. 6D). As a result, in the interval In2 from 30 degrees to 210 degrees, the output voltages of the U phase, V phase, and W phase of the inverter circuit 13 are all zero as shown in FIG.

  Next, starting of the brushless DC motor 30 when a phase failure has occurred in the U-phase upper arm and the V-phase lower arm will be described. FIG. 7 is a timing chart for explaining fixing of the rotor position before starting. FIG. 7A shows induced voltages induced in the armature coils Lu, Lv, and Lw at the normal time. FIG. 7B shows Hall sensor signals Hu, Hv, Hw output from the hall sensors 33a, 33b, 33c. FIG. 7C shows the relationship between the Hall sensor signals Hu, Hv, Hw, the position signal mode, the DC excitation phase, and the rotor fixed position.

  As already described, when the U-phase upper arm and the V-phase lower arm are open, torque cannot be generated in the section In2 having an electrical angle of 30 degrees to 210 degrees. Further, the inverter circuit 13 cannot output the DC excitation phase for fixing the rotor 31 at the position Po5 from the electrical angle of 105 degrees to 315 degrees due to the open phase of the U-phase upper arm and the V-phase lower arm. Therefore, the position where the rotor 31 can be fixed and the torque can be applied at the start is limited to the position Po6 of 315 degrees to 15 degrees in electrical angle. Among these, the position Po7 where the torque can be applied for a long time after fixing is preferable. When fixed at position Po7, torque is applied at position Po8 from 355 degrees to 30 degrees.

  In order to fix the rotor 31 to the position Po7, it is necessary to turn on the U-phase lower arm and the W-phase upper arm as shown in FIG. The U-phase lower arm and the W-phase upper arm are turned on when the position signal mode is “3” as shown in FIG. Therefore, the rotor position adjustment unit 63 outputs a gate signal corresponding to the position signal mode “3” to the gate drive circuit 15 before starting when the phase loss occurs in the U-phase upper arm. Then, the rotor position detector 62 performs DC excitation until the Hall sensor signal Hw becomes “1” and Hv becomes “0”. If the rotor position detection unit 62 detects that the Hall sensor signal Hw is “1” and Hv is “0”, the rotor position adjustment unit 63 switches the connection in the switching unit 64 to drive. The gate signal of the signal generator 16 can be output to the gate drive circuit 15. Thereafter, the drive signal generator 16 outputs a normal motor drive output from the inverter circuit 13 according to the position signal mode, and the motor 30 is driven.

  For example, when the rotor 31 is stopped when the position signal mode of the Hall sensor signal is “1” or “2”, the V-phase upper arm and the W-phase lower arm are turned on, followed by the U-phase lower arm and the V-phase. The upper phase arm may be turned on and gradually approached to 330 degrees, and then the lower V-phase arm and upper W-phase arm may be turned on.

(3-2-3) Detection of phase loss abnormality An example of the configuration of the phase loss abnormality detection unit 61 will be described with reference to FIG. The fan motor drive system 2 shown in FIG. 8 is provided with bootstrap capacitors 41, 42, and 43 for the gate drive circuit 15 on the upper arm side. The gate drive circuit 15 includes drivers 51, 52, and 53 that drive the upper arm switching elements 3u1, 3v1, and 3w1, and drivers 54, 55, and 56 that drive the lower arm switching elements 3u2, 3v2, and 3w2. Yes. The bootstrap capacitors 41, 42, and 43 supply drivers 51, 52, and 53 with voltages that drive the switching elements 3u1, 3v1, and 3w1.

  The bootstrap capacitors 41, 42, and 43 are supplied with voltage from the power source VD through resistors 47, 48, and 49 and diodes 44, 45, and 46. One end of each of the bootstrap capacitors 41, 42, and 43 is connected to the U-phase, V-phase, and W-phase output ends of the inverter circuit 13, and the other ends are connected to the anodes of the diodes 44, 45, and 46 and the drivers 51 and 52, respectively. , 53.

  In FIG. 8, the phase loss abnormality detection unit 61 includes a resistor 61a that grounds the switching elements 3u2, 3v2, and 3w2 of the lower arm and a voltage detection unit 61b that detects the voltage of the resistor 61a. The detection of the phase loss abnormality performed using the phase loss abnormality detection unit 61 is performed when the switching elements 3u1, 3v1, 3w1, 3u2, 3v2, and 3w2 are turned on when the brushless DC motor 30 is driven to detect the current in the resistor 61a. -It is necessary to make the ON period of the switching element longer than the interval of repeating OFF. Therefore, the detection of the phase loss abnormality is performed at a timing before the fan 80 is operated.

  FIG. 9 shows the relationship between the detected fault location and current detection in the phase failure abnormality detection unit 61. In FIG. 9, “X” and “◯” in the column indicating the failure location indicate the presence / absence of a phase failure, and “◯” and “X” in the column indicating the current detection indicate the presence / absence of the current flowing through the resistor 61a. In the column representing the switching mode, “O” and “X” indicate ON / OFF of the switching element.

  All six switching modes are performed in detecting a single phase failure. In the phase loss abnormality detection step, if current is detected in all six switching modes, it can be determined that no phase loss abnormality has occurred. Also, for example, if the current is not detected only when the switching elements 3u1, 3v1, 3w1, 3u2, 3v2, 3w2 are turned off, off, on, on, on, off, the phase loss abnormality occurs only in the W-phase upper arm. It can be seen that has occurred. Furthermore, although not shown in FIG. 9, if no current is detected in all six switching modes, a phase failure abnormality has occurred in three or more arms. In this case, since the phase loss has occurred in two or more phases of one arm, the brushless DC motor 30 cannot be driven. Take action to stop 30.

(4) Features The air conditioner 10 (heat pump device) drives the fan motors 108a and 110a with outputs from the inverter circuit 13 shown in FIG. FIG. 2 illustrates a brushless DC motor 30 representing these fan motors 108a and 110a. When a phase loss abnormality occurs in the inverter circuit 13, the phase loss abnormality detection unit 61 (detection means) detects the phase loss abnormality in the detection step (step S2) of FIG. This detection is performed before the motor 30 is started, and the detection result is output from the phase loss abnormality detection unit 61 to the rotor position adjustment unit 63 (rotor position adjustment means). The fan motor drive system 12 (multi-phase motor drive system) in FIG. 2 includes the inverter circuit 13, the phase loss abnormality detection unit 61, the rotor position adjustment unit 63, and the drive signal generation unit 16.

  In the rotor position adjustment step (step S7) after the detection step, the rotor position adjustment unit 63 is positioned at a position where the torque of the brushless DC motor 30 (multi-phase motor) can be generated by the output of the inverter circuit 13 at the time of phase loss. Adjust. When the U-phase upper arm is open, for example, the rotor 31 is set to the position Po3 in FIG. 5 before starting. When the U-phase upper arm and the V-phase lower arm are out of phase, for example, the rotor 31 is set to the position Po7 in FIG. 7 before starting.

  Such a position Po3 is a position signal mode “2” to “5” excluding the position signal modes “0” and “1” where no torque is generated, and the rotor is rotated among the positions Po2 where DC excitation is possible. In this case, V− and W + which are DC excitation phases appearing immediately (immediately) after the position signal modes “0” and “1” where no torque is generated are used. Thereby, torque can be applied over a long section of the subsequent position Po4, and the starting reliability is improved. At this time, since direct current excitation is used for alignment, it is not necessary to provide a separate mechanism for generating power for alignment, so that the configuration and procedure for alignment are simplified. Even when the position is set to Po7, the start can be surely performed, and the configuration and procedure for positioning are simplified by using DC excitation.

  After the rotor position adjusting process, in the driving process (step S8), the driving signal generating unit 16 (driving signal generating means) generates a driving signal of the inverter circuit 13 so as to start from the rotor position after alignment, and the brushless The DC motor 30 is driven.

  As described above, the fact that the brushless DC motor 30 is driven at the time of phase loss is transmitted from the rotor position adjusting unit 63 to the display unit 66 (display unit). Thereby, the display unit 66 can display that the phase loss abnormality detection unit 61 has detected the phase loss abnormality. By displaying the phase failure abnormality on the display unit 66, it is possible to prevent the air conditioner 10 from being used continuously without knowing that the phase failure abnormality has occurred.

  The rotor position adjusting unit 63 described above receives the operation execution instruction for instructing to drive the motor 30 when the instruction receiving unit 65 (instruction receiving unit) is in the phase loss abnormality, and the motor 30 in the case of the phase loss abnormality. To start and drive. For this reason, when it is not desired to drive the motor 30 when the phase loss is abnormal for various reasons, the instruction receiving unit 65 is instructed not to drive the motor 30 when the phase loss is abnormal, or to drive the motor 30. Do not give instructions. When the instruction receiving unit 65 instructs the rotor position adjusting unit 63 not to drive the motor 30, the rotor position adjusting unit 63 switches the drive signal generating unit 16, the gate drive circuit 15, So that the motor 30 is not driven. In addition, you may comprise so that selection of such a drive can be selected according to the kind and condition of a phase loss abnormality. Since it is possible to select whether to drive or not drive the motor 30 at the time of phase loss abnormality as necessary, the range of selection at the time of phase loss abnormality widens.

(5) Modification (5-1)
In the above-described embodiment, the rotor position adjustment unit 62 confirms that the rotor position is adjusted to a position corresponding to the phase failure when the rotor position adjustment unit 63 adjusts the rotor position. A mode for ending the adjustment 63 is shown. However, when the time for performing DC excitation is determined by experiment or simulation, the rotor position detection unit 62 may be omitted and DC excitation may be performed for a predetermined time.

(5-2)
In the above-described embodiment, a configuration in which the switching unit 64 switches the outputs of the rotor position adjustment unit 63 and the drive signal creation unit 16 and supplies either one to the gate drive circuit 15 is shown as an example. With such a configuration, the fan motor drive system 12 can be configured to easily cope with a phase loss abnormality even when the motor control unit 22 is configured by an integrated circuit or the like. However, the configuration capable of adjusting the rotor position is not limited to this, and it is sufficient if the rotor position can be adjusted in accordance with the type and situation of the phase failure.

(5-3)
In the above embodiment, an example of the phase loss abnormality detection unit 61 is illustrated in FIG. 8, but the configuration of the phase loss abnormality detection unit 61 is not limited to the mode illustrated in FIG. 8, and other configurations can be used. .

(5-4)
The fan motor drive system 12 according to the above embodiment is brushless in all cases where a phase failure occurs only in one arm of one phase and a phase failure occurs in the upper arm of one phase and the lower arm of the other phase. Although the DC motor 30 has been driven, for example, only when one phase of one arm has a phase loss or only when two different upper and lower arms have a phase loss. You may comprise so that it may drive. The state in which the phase failure is abnormal in the state is designed by appropriately selecting in specific scenes such as the degree of system performance degradation and the magnitude of noise and vibration. In general, it can be said that an operation with a lower phase can be performed closer to normal operation.

(5-5)
In the above embodiment, the case where the display unit 66 is built in the fan motor drive system 12 has been described. However, the display unit 66 is not necessarily provided integrally with the fan motor drive system 12, and the display unit 66 is not provided. Information provided for display may be transmitted from the fan motor drive system 12 provided outside the fan motor drive system 12. For example, a liquid crystal screen of an accessory device such as a remote controller of the indoor unit 102 may be used. Or when there exists a remote management apparatus which manages the air conditioning apparatus 10 remotely as the display part 66, the screen of a remote management apparatus can also be used.

(5-6)
In the above-described embodiment, the phase loss abnormality detection unit 61, the rotor position detection unit 62, and the rotor position adjustment unit 63 are shown as separate blocks. The function of selecting a signal and the function of creating a drive signal and controlling the inverter circuit 13 may be realized by a single circuit.

(5-7)
In the above embodiment, the fan motor drive system 12 uses the fan motor drive system 12 of the brushless DC motor that drives the outdoor fan 108 and the indoor fan 110 of the air conditioner 10 shown in FIG. However, the present invention can also be applied to other heat pump devices. For example, the fan motor drive system 12 can be used to drive a fan motor used in a heat source unit of a water heater. Further, the present invention can also be applied to driving a brushless DC motor used in a heat source unit as a driving system for a motor other than a fan motor such as a pump.

(5-8)
In the above-described embodiment, an example in which the inverter circuit and the gate drive circuit are formed on one driver integrated circuit 20 has been described. However, the inverter circuit and the gate drive circuit are not necessarily formed on one driver integrated circuit.

(5-9)
In the above embodiment, an example in which the rotor position adjustment is performed only at the time of phase loss has been described, but this does not prevent the rotor from being fixed at an arbitrary position when no phase loss abnormality has occurred.

(5-10)
In motors with a small number of rotor position detection sensors (hall sensors), the rotor position is generally fixed before starting, but even in such a case, the rotor fixing position is set before starting. The same effect can be obtained by adjusting the position where torque can be generated.

DESCRIPTION OF SYMBOLS 10 Air conditioning apparatus 12 Fan motor drive system 13 Inverter circuit 15 Gate drive circuit 16 Drive signal preparation part 21 Rectifier circuit 22 Motor control part 30 Brushless DC motor 61 Missing phase abnormality detection part 62 Drive signal selection part 11 Instruction reception part 12 Display part 101 outdoor unit 102 indoor unit 108 outdoor fan 110 indoor fan

JP 59-92799 A JP 2005-94873 A

Claims (8)

A detection step (S2) for detecting a phase failure in an inverter circuit that outputs a multiphase motor drive output that matches the rotor position to the multiphase motor;
A rotor position adjusting step (S7) for adjusting the rotor position to a position where torque can be generated by the multiphase motor drive output before starting the multiphase motor at the time of the phase loss abnormality where the phase loss abnormality is detected in the detection step. )When,
After the rotor position adjustment process at the time of the phase loss abnormality, when the phase loss abnormality is not detected, the inverter outputs the same multiphase motor drive output as the normal multiphase motor drive output for driving the multiphase motor. And a driving step (S8) for driving the multi-phase motor by causing the circuit to output.   The multi-phase motor driving method according to claim 1, wherein the rotor position adjusting step includes a step of adjusting the rotor position by direct current excitation.   In the rotor position adjustment step, the rotor position is located in a section immediately after a section in which no voltage output of the multi-phase motor drive output is present due to the missing phase abnormality in the rotation direction, among DC excitation phases that can be performed by an arm that is not missing. The multi-phase motor drive method according to claim 2, wherein the adjusted DC excitation phase is used.   In the detection step, when it is detected that the phase loss abnormality occurs only in one arm of one phase, or the phase loss abnormality of one phase of one phase and the other one phase different from the one arm. An instruction output step of outputting an instruction to shift to the rotor position adjustment step when it is detected that the other arm only occurs, and outputting an instruction to stop the driving of the multi-phase motor in other cases; The multiphase motor drive method according to any one of claims 1 to 3, further comprising: An inverter circuit (13) for outputting a multiphase motor drive output to the multiphase motor;
Detecting means (61) for detecting a phase failure in the inverter circuit;
Rotor position adjusting means (63) for adjusting the rotor position to a position where torque can be generated by the multi-phase motor drive output output from the inverter circuit at the time of phase loss abnormality;
Drive signal generating means for driving the multi-phase motor by causing the inverter circuit to output the same multi-phase motor drive output as the normal multi-phase motor drive output for driving the multi-phase motor when no phase loss abnormality is detected (16) A multiphase motor drive system comprising:   The multiphase motor drive system according to claim 5, further comprising display means (65) capable of displaying that the detection means has detected an abnormal phase failure.   The multiphase motor drive system according to claim 6, further comprising instruction receiving means (64) capable of receiving an operation execution instruction for instructing driving of the multiphase motor when the phase loss is abnormal. A multi-phase fan motor (30, 108a, 110a) for rotating the fan;
An inverter circuit (13) for outputting a fan motor drive output to the fan motor;
Detecting means (61) for detecting a phase failure in the inverter circuit;
Rotor position adjusting means (63) for adjusting the rotor position to a position where torque can be generated by the fan motor drive output output from the inverter circuit when the phase loss is abnormal;
A heat pump device comprising drive signal generating means (64) for causing the inverter circuit to output the same fan motor drive output as a normal fan motor drive output for driving the fan motor when no phase loss abnormality is detected.

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