JP2007336626A - Motor drive device, compressor drive device and motor driving method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor drive device capable of determining a starting voltage condition suitable for a driven motor to start and drive the motor, a compressor drive device provided with the motor drive device and the motor capable of starting and driving a compressor under a starting voltage condition suitable for the compressor, and a motor driving method capable of starting and driving the motor under a starting voltage condition suitable for the motor. <P>SOLUTION: A control circuit 24 previously stores an applying voltage condition corresponding to the resistance values of the wirings 11u, 11v, 11w of the motor 10, calculates the resistance values of the wirings 11u, 11v, 11w based on a current value detected by a current detection circuit 23, determines a starting voltage condition based on the resistance values and the applying voltage condition, and starts the motor 10 by controlling an inverter circuit 22. Also the current detection circuit 23 detects a current value in driving the motor 10 under the determined starting voltage condition, thereby correcting the starting voltage condition so as to accommodate the current value within predetermined limits. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a motor driving device for starting and driving a motor such as a three-phase brushless motor, a compressor driving device for driving a compressor mounted in a device such as an air conditioner or a refrigerator, and starting of the motor. The present invention also relates to a motor driving method for performing driving and the like.

  Devices such as an air conditioner or a refrigerator are equipped with a compressor for compressing air and reducing the temperature of the air. The compressor performs a compression operation by a driving force from a motor, and a three-phase brushless motor is used as the motor, for example. When driving a brushless motor, it is necessary to detect the position of the rotor of the motor and switch the energization to the windings of each phase. As a method of detecting the position of the rotor, a sensor such as a Hall element is used. There are a method for detecting the position and a sensorless method for detecting the position based on the induced voltage generated in the winding of the motor as the rotor rotates. The sensorless method does not use a Hall element, and therefore has an advantage that it is not subject to temperature limitation by the Hall element, and is widely used as a brushless motor driving method for operating a compressor such as an air conditioner or a refrigerator. .

  However, when a brushless motor is driven by a sensorless method, it is necessary to rotate the rotor from the state where the rotor of the motor is stopped at the time of startup, and no induced voltage is generated when the rotor is stopped. Cannot be detected. For this reason, at the time of startup, the motor winding is energized under a predetermined startup condition, and after the rotation of the rotor is stabilized, the driving is switched to the above-described sensorless system.

  When a brushless motor is started and driven by such a method, there is a period during which the rotor performs unstable rotation for a short time after the start, and a large current may flow through the windings of the motor during this period. There is. When a large current flows through the motor winding, the circuit board or the like on which the motor or a circuit for driving the motor is mounted may be destroyed. For this reason, the driving device for driving the motor is provided with a protection function for stopping the driving of the motor when a current exceeding a certain value flows in the winding of the motor. Therefore, if the current flowing in the motor winding at startup is too large, the motor may not be started. If the current flowing in the motor winding is too small, the rotor may be rotated at a sufficient speed. The startup conditions for energizing the motor windings at startup may be various tests or measurements, etc., because there is a risk that switching to the above-described sensorless drive that drives based on the induced voltage cannot be performed. Based on the result, it is necessary to determine a condition for reliably rotating the rotor.

  In Patent Document 1, a plurality of activation patterns corresponding to the temperature of the armature winding of the brushless motor are stored in advance, and when the brushless motor is activated, the ambient temperature of the brushless motor is detected by a temperature sensor, and the detected ambient temperature is detected. There has been proposed a brushless motor control method in which a startup pattern is selected in accordance with the temperature and a control signal is output to an inverter unit in accordance with the selected startup pattern to start the brushless motor. In this control method, regardless of the temperature change of the armature winding of the brushless motor, an abnormal stop due to overcurrent does not occur, and the brushless motor can be started appropriately.

In Patent Document 2, in an air conditioner, the temperature of an outdoor exchanger is detected by a temperature sensor during heating, and the temperature of the indoor exchanger or a heat sink provided in an inverter circuit for driving a compressor is detected by a temperature sensor during cooling. A compressor drive control method is proposed that detects a detected temperature as an internal or external temperature of the compressor, and starts the compressor while correcting the startup voltage and the startup V / F characteristic according to the temperature. . By this drive control method, the compressor can be started stably and the element burden due to overcurrent can be reduced.
JP-A-9-312996 Japanese Patent Laid-Open No. 11-62843

  However, when a compressor such as an air conditioner or a refrigerator is driven by a brushless motor, the optimum motor starting condition varies depending on the type or characteristics of the driven compressor. Therefore, for example, when the compressor is replaced when the air conditioner or the refrigerator is repaired, particularly when the compressor is replaced with a different type of compressor, the predetermined start-up condition is an appropriate condition. There is a possibility that the motor cannot be started. Even when the motor is replaced, the appropriate starting condition is unknown, so that the motor may not be started. In addition, for example, when a new compressor is incorporated into a product and is operated on a trial basis at the stage of product development, there is a possibility that the motor cannot be started because the starting condition of the new compressor is unknown. . Even when a new motor is incorporated into a product and operated on a trial basis, there is a possibility that the motor cannot be started because the starting condition of the new motor is unknown.

  Moreover, the control method of the brushless motor described in Patent Document 1 and the drive control method of the compressor described in Patent Document 2 determine appropriate starting conditions according to changes in the ambient temperature of the brushless motor or the compressor. It is a premise that optimum starting conditions at a steady temperature have been determined, and the above-described problems such as when the compressor or the motor is replaced cannot be solved.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a characteristic value such as a resistance value, inductance, or capacity of a motor winding, an amount of current flowing through the winding, or a winding. The motor applied voltage condition corresponding to the electric quantity such as the amount of voltage applied to the motor is stored in advance, the characteristic value or electric quantity of the motor is detected, and the detected characteristic value or electric quantity and the stored applied voltage condition are determined. To provide a motor drive device that can start and drive a motor by determining a start voltage condition suitable for the motor to be driven by determining the start voltage condition of the motor and starting the motor. It is in.

  Another object of the present invention is to use a resistance value of the winding calculated from the current value flowing through the winding of the motor as the characteristic value for determining the starting voltage condition. An object of the present invention is to provide a motor drive device that can start and drive a motor by simply determining a start voltage condition according to the characteristics of the motor to be operated.

  Another object of the present invention is to start and drive the motor by a PWM (Pulse Width Modulation) method by setting the determined starting voltage condition to the duty ratio of the pulse voltage applied to the motor. An object of the present invention is to provide a motor drive device that can determine the conditions for the operation.

  Another object of the present invention is to determine the start-up voltage condition when the start-up voltage condition is not determined, and not to determine the start-up voltage condition when the start-up voltage condition is determined. Since the motor is started and driven based on the startup voltage condition stored in the above, it is not necessary to determine the startup voltage condition once the startup voltage condition is determined, and startup can be performed at high speed. The object is to provide a motor drive device.

  Another object of the present invention is to re-determine the start-up voltage condition when an instruction to determine the start-up voltage condition is accepted, even if the start-up voltage condition is already stored. By providing the configuration, an object of the present invention is to provide a motor drive device that allows a user, a designer, a repairer, or the like to determine appropriate start-up voltage conditions again.

  Another object of the present invention is to store a start-up voltage condition input from the outside, and start the motor based on this start-up voltage condition, so that a user, a designer, a repairer, etc. SUMMARY OF THE INVENTION An object of the present invention is to provide a motor driving device capable of starting and driving a motor by changing the starting voltage condition on a trial basis.

  Another object of the present invention is to detect the current flowing through the motor winding after starting the motor, and correct the starting voltage condition when the amount of current is outside the predetermined range. Accordingly, it is an object of the present invention to provide a motor driving device capable of correcting the starting voltage condition so as to be optimum in accordance with a load such as a compressor driven by the motor.

  Another object of the present invention is to start the motor or compressor in accordance with the characteristics of the motor or the compressor by driving the motor by any one of the motor driving devices described above and driving the compressor by the motor. An object of the present invention is to provide a compressor drive device that can determine voltage conditions and start and drive a compressor.

  Another object of the present invention is to store in advance the applied voltage condition of the motor corresponding to the motor characteristic value or electric quantity, detect the motor characteristic value or electric quantity, and detect the detected characteristic value or By determining and starting the motor starting voltage condition based on the quantity of electricity and the stored applied voltage condition, the starting voltage condition suitable for the motor to be driven can be determined, and the motor can be started and driven. It is to provide a motor driving method.

  The motor driving device according to the present invention is activated by applying a starting voltage to the motor, and in the motor driving device that drives the motor, an applied voltage condition to the motor is associated with a characteristic value or an electric quantity of the motor. On the basis of the applied voltage condition stored in the storage means, the detection means for detecting the characteristic value or electric quantity of the motor, the characteristic value or electric quantity detected by the detection means, and the storage means And a starting means for starting the motor by applying a starting voltage to the motor based on the starting voltage condition determined by the determining means.

  In the present invention, a motor applied voltage condition corresponding to a characteristic value such as a resistance value, inductance, or capacity of a winding of a motor, or an electric quantity such as an amount of current flowing through the winding or an amount of voltage applied to the winding. Store in advance. The characteristic value or electric quantity of the motor is detected, and the starting voltage condition suitable for the motor is determined based on the detected characteristic value or electric quantity and the stored applied voltage condition. The motor is started according to the determined starting voltage condition, and the motor is driven. Since the motor performance is known from the motor characteristic value or electric quantity, and the amount of current that flows when the motor is started can be estimated, the applied voltage condition that allows the motor to start reliably without a large current flowing through the motor, By storing in advance for each characteristic value or electric quantity of the motor, the motor can be started appropriately.

  In the motor driving device according to the present invention, the detecting means applies a voltage applying means for applying a predetermined voltage, and when the voltage applying means applies a voltage, a current flowing through the winding of the motor. Current detecting means for detecting, and detecting a resistance value of the winding based on the voltage and the current.

  In the present invention, before starting the motor, a predetermined voltage is applied to the motor, and the current flowing through the winding of the motor is detected. The resistance value of the motor winding can be detected from the voltage and current at this time, and the starting voltage condition is determined based on the detected resistance value of the winding. By detecting the resistance value of the winding, the characteristics of the motor can be easily obtained.

  In the motor driving apparatus according to the present invention, the starting means applies a pulse voltage to start the motor, and the determining means determines a duty ratio of the pulse voltage. It is characterized by that.

  In the present invention, the motor is driven by the PWM method, and the starting voltage condition determined from the characteristic value or the electric quantity of the motor is the duty ratio of the pulse voltage applied to the motor. When the motor is driven by the PWM method, by adjusting the pulse width of the voltage applied to the motor, i.e., the duty ratio, the motor torque or rotational speed is controlled to determine the appropriate duty ratio. The motor can be properly started.

  The motor driving apparatus according to the present invention further includes a determination condition storage unit that stores the start-up voltage condition determined by the determination unit, and the determination unit does not store the start-up voltage condition. The start-up voltage condition is determined based on the start-up voltage condition stored in the determination condition storage section when the determination condition storage section stores the start-up voltage condition. The motor is started.

  In the present invention, the starting voltage condition determined from the characteristic value or electric quantity of the motor and the applied voltage condition is stored. When starting the motor again, if the starting voltage condition is already determined and stored, the stored starting voltage condition is read and the motor is started based on the starting voltage condition. When the starting voltage condition is not stored, the starting voltage condition is determined from the characteristic value or electric quantity of the motor and the applied voltage condition as described above. Once the start-up voltage condition is determined, the configuration of the motor or the drive target driven by the motor is rarely changed, and it is highly possible that the start-up can be performed under the same start-up voltage condition. By memorizing, start-up time can be shortened.

  Further, the motor drive device according to the present invention is characterized by comprising a receiving means for receiving an instruction to determine the starting voltage condition by the determining means when the determining condition storage means stores the starting voltage condition. To do.

  In the present invention, the determination of the motor start voltage condition is instructed by the user, designer, repairer, etc., and the motor drive device that has received the instruction is started even if the start voltage condition is already stored. Determine the voltage condition again. Thereby, for example, when the configuration of the motor or the driving target driven by the motor is changed, it is possible to determine the optimum starting voltage condition for the changed configuration.

  In addition, the motor drive device according to the present invention includes an accepting unit that accepts an external input of the starting voltage condition stored in the determination condition storing unit.

  In the present invention, the start voltage condition of the motor is directly input by a user, a designer, a repair person, or the like, and the motor driving device that receives the start condition starts the motor based on the input start voltage condition. For example, even when the configuration of the motor or the driving target driven by the motor is changed, when the optimum starting voltage condition is already known, or the designer changes the starting voltage condition to evaluate the device In some cases, the starting voltage condition can be directly input.

  Further, the motor drive device according to the present invention includes a current detection means for detecting a current flowing through the winding of the motor activated by the activation means, and an amount of current detected by the current detection means is within a predetermined range. Determining means for determining whether or not, and a correcting means for correcting the start-up voltage condition when it is determined that the determining means is out of a predetermined range.

  In the present invention, the motor is started under the determined starting voltage condition, and then the amount of current flowing through the motor winding is detected. It is checked whether or not the detected current amount is within a predetermined range, and if it is out of the predetermined range, the starting voltage condition is corrected. The detection of the current amount and the correction of the starting voltage condition are repeatedly performed until the current amount falls within a predetermined range. Even if the characteristics of the motor are the same, if the characteristics of the drive target such as the compressor driven by the motor are different, the optimal starting voltage condition is different, so the starting voltage condition is corrected according to the amount of current after starting. By doing so, it is possible to obtain a starting voltage condition suitable for the characteristics of the drive target.

  A compressor driving device according to the present invention comprises any one of the motor driving devices described above and a motor driven by the motor driving device, and the compressor is driven by the motor. Features.

  In the present invention, the motor is driven by any one of the motor driving devices described above, and the compressor is driven by the motor. With the above-described configuration, the starting voltage condition suitable for the characteristics of the motor or the compressor can be determined, and the compressor can be started.

  Further, the motor driving method according to the present invention is started by applying a starting voltage to the motor, and in the motor driving method for driving the motor, it is applied to the motor in association with a characteristic value or an electric quantity of the motor. The voltage condition is stored in advance, the characteristic value or electric quantity of the motor is detected, and the starting voltage condition of the motor is determined and determined based on the detected characteristic value or electric quantity and the stored applied voltage condition. A starting voltage is applied to the motor based on the starting voltage condition, and the motor is started.

  In the present invention, the motor applied voltage condition corresponding to the motor characteristic value or the electric quantity is stored in advance. The characteristic value or electric quantity of the motor is detected, and the starting voltage condition of the motor is determined based on the detected characteristic value or electric quantity and the stored applied voltage condition. The motor can be properly started by storing in advance a start voltage condition that can start the motor reliably without flowing a large current for each motor characteristic value or electric quantity.

  In the case of the present invention, the applied voltage condition of the motor corresponding to the motor characteristic value or electric quantity is stored in advance, the motor characteristic value or electric quantity is detected, and the detected characteristic value or electric quantity is stored as the application. By starting the motor by determining the starting voltage condition of the motor based on the voltage condition, there is no possibility of starting failure due to overcurrent flowing in the motor or insufficient current, and optimal starting The motor can be started and driven under voltage conditions. In addition, since the starting voltage condition of the motor is automatically determined, it is not necessary for the user, the designer or the repairer to set the starting voltage condition. Therefore, the reliability and convenience of the motor drive device can be improved.

  In the case of the present invention, the resistance value of the winding is configured by using the resistance value of the winding calculated from the current value flowing through the winding of the motor as the characteristic value for determining the starting voltage condition. Therefore, the characteristics of the motor can be easily obtained, and the starting voltage condition according to the characteristics of the motor can be easily determined. Therefore, an increase in cost due to mounting this function on the motor drive device can be suppressed.

  Further, in the case of the present invention, the starting voltage condition determined from the motor characteristic value or the electric quantity is set to the duty ratio of the pulse voltage applied to the motor, so that the starting voltage condition suitable for driving the motor by the PWM method is obtained. Can be determined.

  Further, according to the present invention, the starting voltage condition determined from the characteristic value or electric quantity of the motor and the applied voltage condition is stored, and when the motor is started again, the starting voltage condition is already determined and stored. In the case where the motor is driven, the stored start-up voltage condition is read out, and the motor is started based on the start-up voltage condition. Can improve convenience.

  Further, in the case of the present invention, when the instruction for determining the start-up voltage condition is received and the start-up voltage condition is determined again, the user is changed when the configuration of the motor or the drive target driven by the motor is changed. Since the starter voltage condition optimum for the configuration after the change can be determined by giving an instruction from the designer or the repairer, the convenience of the motor drive device can be improved.

  In addition, in the case of the present invention, the startup voltage condition input from the outside is stored, and the motor is started based on the startup voltage condition, thereby changing the configuration of the motor or the driving target driven by the motor. Even when the optimum starting voltage condition is already known, or when the designer changes the starting voltage condition and evaluates the device, the user, the designer, or the repair person starts. Since the voltage condition can be directly input, the convenience of the motor driving device can be enhanced.

  Further, according to the present invention, the motor is started under the determined starting voltage condition, and then the amount of current flowing through the motor winding is detected, and when the current amount is outside the predetermined range, the starting voltage condition is set. By adopting the correction configuration, the startup voltage condition can be corrected according to the characteristics of the drive target such as a compressor driven by the motor, so that the motor can be started more reliably. Reliability can be increased.

  In the case of the present invention, the starting voltage condition suitable for the characteristics of the motor or the compressor is determined by driving the motor by any one of the motor driving devices described above and driving the compressor by the motor. Since the compressor can be started and driven, the reliability of the compressor driving device can be improved.

  Further, according to the present invention, the applied voltage condition of the motor corresponding to the motor characteristic value or electric quantity is stored in advance, the motor characteristic value or electric quantity is detected, and the detected characteristic value or electric quantity is stored. By determining and starting the motor based on the applied voltage conditions, it is possible to start and drive the motor under the optimal starting voltage conditions. Therefore, the start-up and driving reliability of the motor can be improved.

  Hereinafter, the present invention will be specifically described with reference to the drawings showing embodiments thereof. FIG. 1 is a block diagram showing a configuration of a compressor driving device according to the present invention. In the figure, reference numeral 1 denotes a compressor drive device that mounts a motor 10 and a motor drive circuit 20 that rotationally drives the motor 10 and drives the compressor 5 by the rotation of the motor 10. The compressor drive device 1 is mounted on, for example, an outdoor unit of an air conditioner, and the air conditioner cools the air by driving the compressor 5 by the compressor drive device 1, and the cooled air Is circulated from the outdoor unit to the indoor unit and discharged into the room to adjust the temperature.

  The compressor 5 is a machine that compresses the gas to a certain pressure while sucking and discharging the gas. The compressor 10 reciprocates the piston or the cylinder by the rotation of the motor 10, or the rotor or the impeller rotates. The air is compressed. In addition to the compressor 5, the air conditioner is equipped with a condenser, an expansion valve, an evaporator, and the like, which constitute a refrigeration cycle to cool the air.

  The motor 10 is a brushless motor having three phases of a U phase, a V phase, and a W phase, and includes, for example, a rotor provided with a permanent magnet and a stator provided with three windings 11u, 11v, and 11w. I have. One end of the rotor of the motor 10 is connected to the compressor 5 so that the compressor 5 is powered by the rotation of the motor 10. The three windings 11u, 11v, and 11w have a star connection circuit configuration in which one end of each of the windings is connected in common, and the other end of each winding is connected to three input terminals of the motor 10, and a motor driving circuit. A voltage is applied from 20 to the input terminal so that the motor 10 is driven to rotate.

  The motor drive circuit 20 includes a converter circuit 21, an inverter circuit 22, a current detection circuit 23, and a control circuit 24. The converter circuit 21 converts an AC voltage supplied from the commercial AC power supply 50 into a DC voltage, and internally includes a rectifier circuit, a smoothing circuit, a power factor correction circuit, and the like (not shown). The rectifier circuit has a circuit configuration in which, for example, four diodes are bridge-connected, and converts an AC voltage from the commercial AC power supply 50 into a undulating DC voltage called a pulsating current. The output of the rectifier circuit is smoothed by a smoothing circuit composed of a smoothing capacitor or the like and output as a DC voltage to the inverter circuit 22. The DC voltage converted by such a rectifier circuit and the smoothing circuit has a current waveform. Since this becomes a pulse and the power factor is poor, this is improved by a power factor correction circuit.

  FIG. 2 is a circuit diagram illustrating a configuration example of the inverter circuit 22. The inverter circuit 22 includes six transistors Q1 to Q6 and six backflow prevention diodes D1 to D6. A DC voltage is applied to the terminals 21a and 21b from the converter circuit 21, and a terminal 24a. A control signal from the control circuit 24 is given to .about.24f. The high potential side of the output voltage of the converter circuit 21 is supplied to the terminal 21a, and the low potential side is supplied to the terminal 21b.

  The transistors Q1 and Q2 are connected in series between the terminals 21a and 21b, and the potential between the transistors Q1 and Q2 is applied to the winding 11w of the motor 10. A diode D1 is connected in parallel to the transistor Q1, and a diode D2 is connected in parallel to the transistor Q2. Similarly, the transistors Q3 and Q4 are connected in series between the terminals 21a and 21b, and the potential between the transistors Q3 and Q4 is applied to the winding 11v of the motor 10. A diode D3 is connected in parallel to the transistor Q3, and a diode D4 is connected in parallel to the transistor Q4. Transistors Q5 and Q6 are connected in series between terminals 21a and 21b so that the potential between transistors Q5 and Q6 is applied to winding 11u of motor 10. A diode D5 is connected in parallel to the transistor Q5, and a diode D6 is connected in parallel to the transistor Q6. The transistors Q1 to Q6 are controlled to be turned on / off in accordance with the voltages applied from the terminals 24a to 24f.

  With the configuration shown in the figure, the inverter circuit 22 controls the voltage applied to the terminals 24a to 24f, thereby applying a voltage in any direction to any two windings of the three windings 11u, 11v, and 11w of the motor 10. It can be applied. For example, when the transistors Q1 and Q4 are turned on, the paths of the terminal 21a, the winding 11w, the winding 11v, and the terminal 21b are conducted, and a voltage is applied to the windings 11w and 11v.

  In FIG. 2, the simplest configuration of the inverter circuit 22 is illustrated. In addition to the illustrated configuration, for example, a booster circuit that boosts the voltage supplied from the converter circuit 21 is provided, and the winding of the motor 10 It is good also as a structure which can change the voltage value of the voltage applied to 11u, 11v, and 11w. In this case, the motor 10 can be driven by a PAM (Pulse Amplitude Modulation) method.

  Terminals 24 a to 24 f of the inverter circuit 22 are connected to the control circuit 24. The control circuit 24 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), an A / D conversion circuit, and the like (not shown). The inverter circuit 22 is controlled by reading and processing by the CPU. The control circuit 24 is configured to output six pulse signals to the inverter circuit 22 in order to control the inverter circuit 22, and the six pulse signals are input to the terminals 24a to 24f of the inverter circuit 22, and the six pulses are output. The on / off of the transistors Q1 to Q6 of the inverter circuit 22 is controlled by the signal. That is, the control circuit 24 controls the inverter circuit 22 by the PWM method.

  The control circuit 24 detects the induced voltage generated in the windings 11u, 11v, and 11w of the motor 10, such as the output timing and pulse width (duty ratio) of the six pulse signals to be supplied to the inverter circuit 22. It is determined on the basis of information such as the voltage value of the induced voltage given from (not shown) and the current value given from the current detection circuit 23 for detecting the current flowing through the windings 11u, 11v, 11w. By detecting the induced voltage, the rotational position of the rotor of the motor 10 can be detected, and the voltage is applied to the appropriate two windings of the motor 10 in an appropriate direction according to the rotational position of the rotor. The inverter circuit 22 is controlled.

  The current detection circuit 23 is provided in a path for supplying a DC voltage from the converter circuit 21 to the inverter circuit 22 and is provided in one of the two supply paths. The current detection circuit 23 has a shunt resistor arranged in the supply path from the converter circuit 21 to the inverter circuit 22. The current detection circuit 23 detects the voltage applied to both ends of the shunt resistor, thereby detecting the two windings of the motor 10. The current value of the flowing current is detected. However, the resistance value of the shunt resistor is sufficiently smaller than the resistance values of the windings 11u, 11v, and 11w of the motor 10. The current value detected by the current detection circuit 23 is given to the control circuit 24. The control circuit 24 compares the current value given from the current detection circuit 23 with a predetermined threshold value, and a large current exceeding the threshold value flows. In this case, the rotation of the motor 10 is stopped.

  When the control circuit 24 controls the inverter circuit 22 to rotationally drive the motor 10, if the motor 10 is rotating stably, it is generated in the windings 11u, 11v, 11w of the motor 10 as described above. The induced voltage is detected, and the inverter circuit 22 can be controlled based on the detection result. However, when the motor 10 is not rotating, no induced voltage is generated in the windings 11u, 11v, and 11w, and the control circuit 24 cannot control the inverter circuit 22. Also when the rotation of the motor 10 is unstable, the inverter circuit 22 cannot be controlled because the detected induced voltage is unstable. This is a problem that occurs when the rotation of the motor 10 is started, that is, when the motor 10 is started.

  Therefore, the control circuit 24 stores the output timing, duty ratio, and the like of the six pulse signals given to the inverter circuit 22 at the time of start-up as start-up voltage conditions in the RAM, and reads out the stored start-up voltage conditions when the motor 10 is started up. Thus, the inverter circuit 22 is controlled. Further, when the starting voltage condition is not stored in the RAM, the control circuit 24 measures the resistance values of the windings 11u, 11v, and 11w of the motor 10 and determines the optimum starting voltage condition based on the measurement result. It has a function to do. The resistance values of the windings 11u, 11v, and 11w of the motor 10 can be calculated from the current value detected by the current detection circuit 23 when a predetermined voltage is applied to the motor 10. The RAM provided in the control circuit 24 is preferably a nonvolatile RAM such as a flash memory or an EEPROM.

  FIG. 3 is a flowchart showing the procedure of the startup process of the motor 10 performed by the control circuit 24 of the motor drive circuit 20 according to the present invention. In this flowchart, a configuration is shown in which the duty ratio of the pulse signal given to the inverter circuit 22 by the control circuit 24 as the starting voltage condition is determined. For example, when the operation start button of the air conditioner is operated by the user and driving of the compressor 5 is started, first, the control circuit 24 checks whether the activation voltage condition is already stored in the RAM (step S1). ). When the starting voltage condition is not stored (S1: NO), the inverter circuit 22 is controlled to apply a predetermined voltage to the motor 10 (step S2), and the current value of the current flowing through the motor 10 at this time is detected. Detection is performed by the circuit 23 (step S3).

The resistance values of the windings 11u, 11v, and 11w of the motor 10 are R, the resistance value of the shunt resistance of the current detection circuit 23 is r, and the voltage value of the voltage applied to the motor 10 in step S2 is V. When the current value of the current detected by the current detection circuit 23 is I, the following equation (1) is established according to Ohm's law.
V = (2 × R + r) × I (1)
The resistance value R can be calculated by the following equation (2).
R = (1/2) × (V / I−r) (2)
Therefore, based on the detected current value and the applied voltage value, the resistance values of the windings 11u, 11v, and 11w of the motor 10 are calculated by the above equation (2) (step S4).

  In the ROM provided in the control circuit 24, the duty ratio of the pulse signal given to the inverter circuit 22 as an applied voltage condition in association with the resistance values of the windings 11u, 11v, 11w of the motor 10 is displayed in the applied voltage condition table. I remember it. FIG. 4 is a table showing a configuration example of the applied voltage condition table stored in the control circuit 24 of the motor drive circuit 20 according to the present invention. In the applied voltage condition table, the duty ratio of the pulse signal is associated with seven cases from 0.3 [Ω] to 0.9 [Ω] for each resistance value 0.1 [Ω] of the winding. I remember it. The control circuit 24 calculates the resistance value by the equation (2) in step S4, then reads the applied voltage condition table stored in the ROM (step S5), and based on the calculated resistance value, the duty ratio of the pulse signal That is, the starting voltage condition is determined (step S6).

  The control circuit 24 controls the inverter circuit 22 based on the starting voltage condition determined in step S6 to start the motor 10. However, the control circuit 24 starts under a starting voltage condition suitable for the motor 10 and the compressor 5. In order to make it possible, the start-up voltage condition determined in step S6 is corrected (step S7). FIG. 5 is a flowchart showing the procedure of the startup voltage condition correction process performed by the control circuit of the motor drive circuit 20 according to the present invention, which is the process performed in step S7 of FIG.

  First, the control circuit 24 controls the inverter circuit 22 under the starting voltage condition determined in step S6, and applies a voltage to the motor 10 (step S31). At this time, the current value I of the current flowing through the motor 10 is detected by the current detection circuit 23 (step S32), and it is checked whether or not the detected current value I is smaller than a predetermined upper limit value Imax. (Step S33). When the current value I of the current is equal to or higher than the upper limit value Imax (S33: NO), the duty ratio as the starting voltage condition is decreased by 0.2 [%] (step S34), and the process returns to step S31. If the current value I of the detected current is smaller than the upper limit value Imax (S33: YES), it is further checked whether or not the current value I of the current is larger than the lower limit value Imin (step S35). When the current value I of the current is equal to or lower than the lower limit value Imin (S35: NO), the duty ratio as the starting voltage condition is increased by 0.2 [%] (step S36), and the process returns to step S31.

  As described above, the control circuit 24 performs the correction of the duty ratio in step S34 or S36, the application of the voltage to the motor 10 and the detection of the current value I of the current in the current detection circuit 23, the current value I of the current. Is repeated until the value falls within the range between the upper limit value Imax and the lower limit value Imin. When the current value I of the current detected in step S35 is greater than the lower limit value Imin, that is, when the current value I of the current falls within the range between the upper limit value Imax and the lower limit value Imin (S35: YES), the starting voltage condition correction The process ends, and the process returns to the process of the flowchart shown in FIG. The upper limit value Imax and the lower limit value Imin are determined in advance when the motor drive circuit 20 is designed, and are stored in the ROM in the control circuit 24.

  After correcting the start-up voltage condition, the control circuit 24 stores the corrected start-up voltage condition in the internal RAM (step S8). Thereby, the motor 10 can be started by reading the starting voltage condition memorize | stored in RAM at the next starting. If the starting voltage condition is stored in the RAM in step S1 (S1: YES), the starting voltage condition is read from the RAM (step S9), and the inverter circuit 22 is controlled based on the read starting voltage condition. A voltage is applied to the motor 10 (step S10).

  After storing the starting voltage condition in step S8 or applying a voltage to the motor 10 in step S10, the motor 10 waits for the motor 10 to rotate stably, and then the windings 11u, 11v, and 11w of the motor 10 are turned on. Driving based on the generated induced voltage is started (step S11), and the starting process of the motor 10 is ended.

  When the operation of the air conditioner is started, the motor driving circuit 20 determines the starting voltage condition when the starting voltage condition is not stored in the RAM of the control circuit 24, as shown in the flowchart of FIG. Once the starting voltage condition is determined, the motor 10 is driven according to the determined starting voltage condition. However, when a user, a designer, a repairer, or the like replaces the motor 10 or the compressor 5, the starting voltage condition is set so that the optimum starting voltage condition is satisfied for the replaced motor 10 or the compressor 5. So that it can be redetermined. In addition, when the optimum starting voltage condition is already known, or when the air conditioner is operated by changing the starting voltage condition on a trial basis, the user, the designer or the repairer etc. You can enter and set conditions. These operate the motor drive circuit 20, the compressor drive device 1 or the operation button or operation switch (not shown) of the air conditioner to give an instruction to redetermine the start-up voltage condition, or start-up voltage condition You can do this by typing

  FIG. 6 is a flowchart showing the procedure of the redetermination of the starting voltage condition and the input receiving process performed by the control circuit 24 of the motor drive circuit 20 according to the present invention. First, the control circuit 24 checks whether or not an input of a start-up voltage condition has been received by operating an operation button or an operation switch (step S51). When the input of the starting voltage condition is not received (S51: NO), it is further checked whether an instruction for re-determining the starting voltage condition is received (step S52). If an instruction to redetermine the start-up voltage condition has not been received (S52: NO), the process returns to step S51 and waits until an input of the start-up voltage condition is accepted or an instruction to redetermine the start-up voltage condition is accepted. .

  When an instruction to redetermine the starting voltage condition is received in step S52 (S52: YES), the inverter circuit 22 is controlled to apply a predetermined voltage to the motor 10 (step S53). Is detected by the current detection circuit 23 (step S54). Next, based on the detected current value and the applied voltage value, the resistance values of the windings 11u, 11v, and 11w of the motor 10 are calculated by the above equation (2) (step S55), and the application shown in FIG. The voltage condition table is read (step S56), and the duty ratio, that is, the starting voltage condition is determined based on the calculated resistance value (step S57). Further, the control circuit 24 performs the startup voltage condition correction process shown in FIG. 5 to correct the startup voltage condition (step S58), and stores the corrected startup voltage condition in the RAM provided therein (step S59).

  When the input of the starting voltage condition is received in step S51 (S51: YES), the control circuit 24 stores the received starting voltage condition in the RAM provided therein (step S60), and the motor according to the received starting voltage condition. A voltage is applied to 10 (step S61). After storing the starting voltage condition in step S59 or applying a voltage to the motor 10 in step S61, the motor 10 waits for the motor 10 to rotate stably, and the windings 11u, 11v, and 11w of the motor 10 are turned on. Driving based on the generated induced voltage is started (step S62), and the process is terminated.

  In the compressor driving device 1 having the above configuration, when the starting voltage condition is not determined at the time of turning on the power, the resistance values of the windings 11u, 11v, and 11w of the motor 10 are obtained and stored in advance. By determining the starting voltage condition from the condition table and correcting the starting voltage condition shown in FIG. 5, the motor 10 can be started under a starting voltage condition suitable for the motor 10 and the compressor 5. Further, by storing the determined startup voltage condition in the RAM of the control circuit 24, it is only necessary to read the startup voltage condition from the RAM at the next startup, so that the startup time of the motor 10 can be shortened. it can. In addition, even after once determining the starting voltage condition, if an instruction to perform redetermination is accepted, the user, the designer, the repairer, or the like can perform the determination of the starting voltage condition again. When the compressor 5 or the motor 10 is replaced, it is possible to determine the starting voltage condition suitable for the compressor 5 or the motor 10 after the replacement. Further, when a startup voltage condition suitable for the motor 10 and the compressor 5 is known in advance by a configuration in which a user, a designer, a repairer, or the like can directly input the startup voltage condition, the startup voltage condition Thus, the motor 10 can be driven, and the motor 10 can be driven on a trial basis by inputting various start-up voltage conditions.

  In the present embodiment, the motor 10 is a three-phase brushless motor. However, the present invention is not limited to this, and the same configuration can be applied to other types of motors. Further, the duty ratio is stored in the applied voltage condition table as the applied voltage condition. However, the present invention is not limited to this. For example, when the inverter circuit 22 can drive the motor 10 by the PAM method, the application is performed. Other values such as a voltage value of a voltage to be applied may be stored as a voltage condition. Moreover, although it was set as the structure which calculates the resistance value of the windings 11u, 11v, and 11w of the motor 10, it is not restricted to this, For example, the current value and duty ratio are matched and memorize | stored in the applied voltage condition table, The duty ratio may be determined directly from the current value of the current detected by the current detection circuit 23, and the voltage value and the duty ratio are stored in the applied voltage condition table in association with each other. It is good also as a structure which determines a duty ratio directly from the voltage value of the voltage which concerns on an inside shunt resistance.

It is a block diagram which shows the structure of the compressor drive device which concerns on this invention. It is a circuit diagram which shows one structural example of an inverter circuit. It is a flowchart which shows the procedure of the starting process of the motor which the control circuit of the motor drive circuit which concerns on this invention performs. It is a chart which shows the example of 1 composition of the applied voltage condition table which the control circuit of the motor drive circuit concerning the present invention memorizes. It is a flowchart which shows the procedure of the starting voltage condition correction process which the control circuit of the motor drive circuit which concerns on this invention performs. It is a flowchart which shows the procedure of the redetermination of the starting voltage condition and the input reception process which the control circuit of the motor drive circuit which concerns on this invention performs.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor drive device 10 Motor 11u, 11v, 11w Winding 20 Motor drive circuit (motor drive device)
21 Converter circuit 22 Inverter circuit (starting means, voltage applying means)
23 Current detection circuit (detection means, current detection means)
24 Control circuit (storage means, determination means, activation means, determination condition storage means, reception means, determination means, correction means)

Claims (9)

In a motor driving device that starts by applying a starting voltage to a motor and drives the motor,
A storage means for storing a voltage condition applied to the motor in association with a characteristic value or an electric quantity of the motor;
Detecting means for detecting a characteristic value or an electric quantity of the motor;
Determining means for determining a starting voltage condition of the motor based on a characteristic value or an electric quantity detected by the detecting means and an applied voltage condition stored by the storage means;
A motor drive device comprising: start means for applying a start voltage to the motor based on the start voltage condition determined by the determining means to start the motor. The detection means includes
Voltage application means for applying a predetermined voltage;
Current detecting means for detecting a current flowing through the winding of the motor when the voltage applying means applies a voltage; and
The motor driving apparatus according to claim 1, wherein a resistance value of the winding is detected based on the voltage and the current. The starting means is configured to start the motor by applying a pulse voltage;
The motor driving apparatus according to claim 1, wherein the determining unit determines a duty ratio of the pulse voltage. A determination condition storage means for storing the starting voltage condition determined by the determination means;
The determination unit is configured to determine a start voltage condition when the determination condition storage unit does not store a start voltage condition,
The starter is configured to start the motor based on the start-up voltage condition stored in the determination-condition storage when the determination-condition storage stores a start-up voltage condition. The motor drive device as described in any one of Claim 3.   5. The motor drive device according to claim 4, further comprising a receiving unit that receives an instruction to determine a starting voltage condition by the determining unit when the determining condition storing unit stores a starting voltage condition.   6. The motor driving apparatus according to claim 4, further comprising a receiving unit that receives an external input of the starting voltage condition stored in the determination condition storing unit. Current detection means for detecting a current flowing through the winding of the motor activated by the activation means;
Determination means for determining whether or not the amount of current detected by the current detection means is within a predetermined range;
The motor drive device according to any one of claims 1 to 6, further comprising: a correction unit that corrects the start-up voltage condition when the determination unit determines that it is outside the predetermined range. A motor drive device according to any one of claims 1 to 7,
A motor driven by the motor driving device,
A compressor driving device characterized in that the compressor is driven by the motor. In a motor driving method of starting by applying a starting voltage to a motor and driving the motor,
In association with the characteristic value or electric quantity of the motor, preliminarily store the applied voltage condition to the motor,
Detect the characteristic value or quantity of electricity of the motor,
Based on the detected characteristic value or quantity of electricity and the stored applied voltage condition, determine the starting voltage condition of the motor,
A motor driving method characterized by starting a motor by applying a starting voltage to the motor based on the determined starting voltage condition.

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