JP5707352B2 - Permanent magnet motor and air conditioner - Google Patents

Description

  The present invention relates to a permanent magnet motor using a PWM control system and a drive system using the same, and more particularly to suppression of demagnetization at the time of starting a permanent magnet motor.

  In general, high performance neodymium magnets are used in permanent magnet motors for miniaturization and high efficiency. However, since rare earth elements are expensive, neodymium magnets using rare earth elements are a factor that increases the price.

  On the other hand, a permanent magnet motor using a ferrite magnet can be priced lower than a permanent magnet motor using a neodymium magnet. However, the demagnetization resistance of the ferrite magnet becomes weaker as the temperature becomes lower. For this reason, when the motor is started in a low-temperature environment, the magnet may be permanently demagnetized by the magnetic field generated by the motor current, and the original motor output may not be produced.

  As one of the methods for suppressing the demagnetization of the ferrite magnet due to the motor current at a low temperature, Patent Document 1 proposes a method of reducing the current limit value of the current flowing through the motor depending on the temperature. Patent Document 2 proposes a method of heating an electric motor using a heater or the like at a low temperature.

  On the other hand, as a method for starting by estimating the magnetic pole position without using a position sensor when the permanent magnet motor is stopped, a method using the magnetic saturation characteristics of the motor has been proposed. There are a method using a change in the terminal voltage of the non-conduction phase of the inverter being used, a method using a change in the motor current with respect to a high-frequency applied voltage pulse disclosed in Patent Document 4, and the like.

JP 2009-136054 A JP 2002-354888 A JP 2009-189176 A JP2011-050198A

  In the method of reducing the current limit value of the current flowing to the motor according to the temperature described in Patent Document 1, it is possible to start the motor without demagnetizing the ferrite magnet at a low temperature. However, depending on the driving conditions, the motor Cannot output the power required for startup.

  In the method of heating a motor using a high-frequency current from a heater or an inverter of Patent Document 2, it is possible to start the motor by heating the motor in the same manner as at room temperature even at low temperatures. Is required, which increases the number of parts and increases costs.

  Patent Document 3 and Patent Document 4 can detect the position of the magnetic pole from the stopped state of the electric motor and can stably start the motor from the stopped state. However, the method for starting the ferrite magnet at a low temperature is disclosed. Not.

  An object of the present invention is to warm a motor without providing additional components while preventing low-temperature demagnetization of a magnet that is likely to be demagnetized at low temperatures.

Based on an inverter circuit that converts DC power into AC power, a motor connected to the inverter circuit that has a permanent magnet that is susceptible to demagnetization and a plurality of windings, and an angle at which the output of the magnet torque is maximized A warm-up operation mode in which a reactive current flows in a range from minus 90 degrees to plus 90 degrees, a permanent magnet position detecting means for estimating or detecting the position of the permanent magnet, and a compressor driven by an electric motor , After the position of the permanent magnet is estimated or detected by the permanent magnet position detecting means, the warm-up operation mode is performed based on the detection result of the permanent magnet position detecting means, and the permanent magnet position detecting means is detected after the warm-up operation mode is completed. Based on the result, an effective current flows in a direction in which the electric motor generates torque .

  According to the present invention, heat is generated in the winding while preventing low temperature demagnetization. Therefore, it is possible to warm the electric motor without providing additional components while preventing the low-temperature demagnetization of the magnet that is likely to be demagnetized at low temperatures.

It is a block diagram which shows the whole block diagram of the permanent magnet motor drive device of Example 1 of this invention. It is the schematic which showed the temperature and demagnetization start current in a ferrite magnet. It is the schematic which showed the flow of the starting system in the conventional system and the system of Example 1. FIG. It is the figure which showed the example of a setting of the reactive current in the electric motor warming-up driving | operation of Example 1 of this invention. It is the schematic which showed the flow of the starting system of the system which warms up an electric motor with a harmonic current, and the system of Example 1. FIG. It is a block diagram at the time of changing the structure of Example 1 into the system which performs a current detection with a direct-current bus current detector, and performs a magnetic pole position determination with the motor current at the time of a harmonic voltage pulse application. It is a block diagram at the time of changing the structure of Example 1 into the system which performs a magnetic pole position determination with a position detector. It is the schematic which showed the flow of the starting system of the modification 1 of this invention. It is a whole block diagram of the air conditioner using the permanent magnet electric motor drive device of Example 1 of the present Example 2. In the structure of the present Example 2, it is a whole schematic diagram of the structure which circulates the refrigerant | coolant by the circulation of a refrigerant | coolant, and bypass piping to a compressor. It is the schematic which showed the indoor unit discharge temperature at the time of driving by the system of the present Example 2. It is the schematic which showed the relationship between the indoor unit discharge temperature when the rapid heating command of this Example 3 was requested | required, and an electric motor electric current. It is the schematic which showed the flow of the relationship between the compressor temperature and the motor current in the case of the timer reservation time at the time of timer reservation.

  Examples of the present invention will be described below.

A first embodiment of the present invention will be described with reference to FIGS.
In the present embodiment, the control method of the present invention is applied to the permanent magnet motor drive device 1 that drives the permanent magnet motor 3, and an example is described in which start-up having an operation mode in which a reactive current flows in the direction of magnetizing is described. To do. Here, the reactive current refers to a current that does not generate torque. For example, the reactive current and the voltage have a phase difference of 90 degrees. On the other hand, the effective current refers to a current that generates torque. For example, the effective current and the voltage are in phase.

  As shown in FIG. 1, a permanent magnet motor drive apparatus 1 is a permanent magnet using an inverter circuit 4 that converts DC power into AC power, and a magnet that is connected to the inverter circuit 4 and is easily demagnetized at a low temperature, for example, a ferrite magnet. An applied voltage command based on the phase current detection circuit 6 for detecting the motor current flowing through the magnet motor 3, the phase current information 6A detected by the phase current detection circuit 6, and the phase voltage information 7A detected by the phase voltage detection circuit 7. It is comprised by the control apparatus 5 which performs inverter control using the pulse signal 8A. The inverter circuit 4 generates an inverter main circuit 41 composed of an IGBT and a semiconductor switching element such as a diode, and a gate signal to the IGBT of the main circuit based on an applied voltage command pulse signal 8A from the inverter control unit 8. The gate driver 42 is configured to be configured.

  The control device 5 uses the phase current information 6A detected by the phase current detection circuit 6, the temperature information 10A detected by the temperature detection unit 10, and the magnetic pole position information 9A estimated by the magnetic pole position determination unit 9. The magnetic pole position is determined by using the inverter control unit 8 for calculating the applied voltage command pulse information 8A, the phase voltage information 7A detected by the phase voltage detection circuit 7, and the applied voltage command pulse signal 8A output from the inverter control unit 8. The magnetic pole position determining unit 9 is configured to determine.

  In the configuration of FIG. 1, the magnetic pole position determination unit 9 shows the configuration of the method described in Patent Document 3 described above. However, like the configuration shown in FIG. 6, the DC bus current detection unit and the harmonic voltage pulse May be applied to each phase of the three-phase motor to estimate the magnetic pole position, and the configuration of the magnetic pole position determination unit 9 may use a system that can estimate the magnetic pole position when stopped. The magnetic pole position estimation method is not specified. Further, as in the configuration shown in FIG. 7, even with the method of determining the magnetic pole position from the position information 14 </ b> A from the position detection unit 14, it is possible to perform the start-up with the operation mode in which the reactive current flows in the direction of increasing magnetism in this embodiment. Is possible.

By supplying a current to increase magnetic direction, it is possible to generate a torque. On the other hand, the demagnetizing direction refers to a range other than the magnetizing direction.

Here, FIG. 2 shows a schematic diagram of the demagnetization start current with respect to the temperature of the ferrite magnet used in the permanent magnet motor 3. As shown in FIG. 2, the ferrite magnet has a characteristic that resistance to demagnetization becomes weaker as the temperature becomes lower. When the minimum motor drive guarantee temperature is T _MIN and the demagnetization start current at which the demagnetization of the ferrite magnet starts is I _T-MIN , the maximum current I _INV-MAX that the inverter can output is I _{INV-MAX If it is} larger than _T-MIN , the ferrite magnet may be demagnetized if it is started at low temperature _TMIN depending on the driving conditions. For this reason, the temperature of the ferrite magnet of the motor is heated to T _INV-MAX, which is a temperature at which demagnetization does not occur even when the inverter outputs the maximum current I _INV-MAX , thereby demagnetizing even at a low temperature T _MIN . You can start without

  The activation method of the present invention will be described with reference to FIGS. 1 and 3. First, in order to clarify the activation method described in Patent Document 3, a conventional activation method will be described.

  In the conventional starting method, the magnetic pole position is estimated by estimating the phase of the induced voltage of the motor from the voltage applied to the motor and the motor current. Therefore, in the low-speed drive range from the stop of the motor where the induced voltage is small. Cannot perform sensorless drive. Therefore, as shown in Fig. 3 (a), sensorless driving is possible by flowing current from the inverter control unit 8 in the direction of magnetizing on the control and performing positioning operation / synchronous operation regardless of the position of the magnetic pole. The rotation speed of the electric motor is increased to an appropriate range, and startup is switched to sensorless driving. The right side of FIG. 3 (a) shows an outline of a current vector diagram in the synchronous operation section when the magnet magnetization direction is the d-axis and the current direction for outputting torque is the q-axis.

In the conventional starting method described above, since the magnetic pole position is unknown in the positioning operation / synchronous operation section, the motor current may flow in the demagnetization direction. Therefore, in order to avoid demagnetization by low-temperature T _MIN at the motor current, it is necessary to start the motor with a small current value than demagnetization starting current I _T-MIN ferrite magnet at a low temperature T _MIN. Further, since the current value is limited depending on the driving conditions, it is impossible to output the torque necessary for starting, and the motor may not be started. Also, when switching from synchronous operation to sensorless drive, the control becomes unstable and step-out easily occurs. Depending on the drive conditions, excessive current flows in the motor due to step-out at the time of switch and demagnetization may occur. There is also sex.

  On the other hand, in the starting method described in Patent Document 3, in the magnetic pole position estimation section shown in FIG. 3B, the inverter control unit 8 selects two phases to be energized among the three-phase windings of the motor, and the pulse The applied voltage command pulse signal 8A is output by the width modulation operation. The magnetic pole position determination unit 9 samples the terminal voltage of the non-energized phase of the applied voltage command pulse information 8A among the phase voltage information 7A detected by the phase voltage detection circuit 7 in synchronization with the applied voltage pulse signal of the energized phase. Thus, the magnetic pole position is determined. Further, in the sensorless drive section, the absolute value of the sampling value is compared with the reference voltage, and the energization mode is sequentially switched according to the comparison result, so that the current vector diagram of FIG. As described above, it is possible to perform sensorless driving from a stopped state without using a position sensor without flowing an invalid current that does not contribute to torque.

In the starting method described in Patent Document 3 described above, sensorless driving is performed immediately after the magnetic pole position estimation section ends. For this reason, when starting at the low temperature T _MIN shown in FIG. 2, depending on the driving conditions, the inverter may output a current _{equal to} or greater than the demagnetization start current I _T-MIN and the ferrite magnet may be demagnetized.

  Below, operation | movement of the inverter control part 8 which has a driving | operation mode which flows a reactive current in the direction of a magnetization which is a starting system of this invention is demonstrated.

  As shown in FIG. 3C, the magnetic pole position determination unit 9 estimates the magnetic pole position of the motor in the magnetic pole position estimation section. Then, the inverter control unit 8 uses the magnetic pole position information 9A to perform an operation mode in which an invalid current flows in the direction of magnet increase, and performs sensorless drive after the motor warm-up operation is completed.

  As shown in FIG. 3 (c), the electric motor warm-up that is an operation mode in which a reactive current is passed in the direction of magnet increase of the magnet between the magnetic pole position estimation section and the sensorless drive section, which is the starting method described in Patent Document 3. By providing the operation section, it becomes possible to heat the ferrite magnet of the electric motor.

In the motor warm-up period, the temperature of the ferrite magnet is heated to the temperature T _INV-MAX where demagnetization does not start even when the maximum current I _INV-MAX that can be output by the inverter flows. Even when the maximum current I _INV-MAX is output from the inverter, the ferrite magnet can be driven without demagnetization. In addition, in order to determine the magnet's magnetizing direction and flow reactive current in the magnetic pole position estimation section, the inverter maximum output current I _INV-MAX larger than the demagnetization starting current I _T-MIN at the low temperature T _{MIN is set} to the motor coil. It is possible to heat the ferrite magnet without demagnetizing even if it is applied to the magnet.

  As shown in FIG. 4A, the inverter control unit 8 switches between the temperature information 10A detected by the temperature detection unit 10 of the permanent magnet motor 3 and the temperature T1. When the temperature information 10A is lower than the temperature T1, the voltage application command pulse information 8A that causes the set reactive current to flow to the electric motor is output. On the other hand, when the temperature information 10A is equal to or higher than the temperature T1, voltage application command pulse information 8A with the reactive current set to 0 is output. In other words, when the temperature of the permanent magnet motor 3 is lower than the temperature T1, the inverter circuit 4 outputs a reactive current to the permanent magnet motor 3 in the direction of magnetizing, and when the temperature is equal to or higher than the temperature T1, the inverter circuit 4 supplies the permanent magnet motor 3. Does not output reactive current in the magnetizing direction.

  In addition, in order to suppress the fluctuation | variation of the position at the time of switching, as shown in FIG.4 (b), the system which changes a reactive current from the temperature T2 to the temperature T3 by a fixed ratio may be used. Further, in order to make switching of the reactive current even smoother, as shown in FIG. 4C, a method of changing the reactive current from the temperature T2 to the temperature T3 while changing the ratio like a curve may be used.

  In addition, the reactive current is not switched based on the temperature information 10A of the permanent magnet motor 3, but the reactive current is switched based on the time from the start of the motor warm-up operation without using the temperature detection unit 10. Also good. Furthermore, without using the temperature detection unit 10, the resistance value of the motor is estimated from the applied voltage and the motor current of the motor, and invalid based on the value obtained by converting the resistance value into the temperature from the relationship between the resistance value and the temperature acquired in advance. It is good also as a structure which switches an electric current.

  As described above, the permanent magnet motor 3 using the ferrite magnet is heated by the inverter control unit 8 having an operation mode in which an invalid current flows in the direction of increasing the magnet, so that the motor is warmed up without adding components such as a heater at a low temperature. Driving is possible. Also, by heating the ferrite magnet until the demagnetization start current is below the maximum current that can be output by the inverter, even if the inverter outputs the maximum current depending on the drive conditions after sensorless driving, the ferrite magnet is driven without demagnetization. Is possible.

Further, a high-frequency current having an amplitude smaller than the demagnetization start current I _T-MIN at the low temperature T _{MIN is} passed from the inverter circuit described in Patent Document 2 shown in FIG. 5B, in the motor warming-up operation of the present invention shown in FIG. 5B, a current larger than the demagnetization start current I _T-MIN at the low temperature T _{MIN is} supplied from the inverter circuit to the magnetization direction of the ferrite magnet. Therefore, the motor can be warmed up with a larger reactive power, and the time required for motor warm-up operation can be shortened.

  In addition, by providing a motor warm-up operation section in which a reactive current flows in the direction of magnetization of the motor during sensorless startup of the motor, the motor can be started simultaneously with the motor start command, and the motor startup time can be shortened. Can be planned. Furthermore, since the loss during driving of the motor also contributes to the temperature rise of the magnet, the temperature rise of the magnet is accelerated, the motor warm-up operation time can be shortened, and switching to the normal operation mode in which the efficiency is maximized earlier is possible. It becomes.

  In addition, by adjusting the magnitude of the reactive current based on the temperature of the motor, the elapsed time of the motor warm-up operation, the temperature converted value of the resistance value, it is not necessary to pass the reactive current more than necessary, It is possible to reduce extra loss during the motor warm-up operation.

Next, Example 2 which is a modification of Example 1 will be described with reference to FIG.
As shown in the current vector diagram of FIG. 3 (d), during sensorless driving, the magnetic pole position determination unit 9 determines the d-axis direction, which is the direction of magnet magnetization, so that the motor is driven in the direction in which torque is generated in the motor. At the same time as sensorless driving, which is an operation mode in which current flows, it is possible to perform motor warm-up operation, which is an operation mode in which reactive current flows in the direction of magnetization.

  By providing an operation mode in which an ineffective current flows in the direction of magnet increase of the magnet of the motor during startup of the motor, startup of the motor can be accelerated compared to when sensorless driving is started after the end of motor warm-up operation. In addition, the loss during sensorless driving also contributes to the temperature rise of the magnet, so the temperature rise of the magnet is accelerated, the time for supplying the reactive current in the magnetizing direction can be shortened, and the switching to the normal operation mode becomes possible earlier. .

  Next, Embodiment 3 which is a modification of Embodiment 1 will be described with reference to FIG. In this modification, the magnetic pole position estimation section and the electric motor warm-up operation section are performed before the conventional starting system. In addition, description is abbreviate | omitted about the point which is common in the permanent magnet motor drive device of Example 1. FIG.

  When the control device 5 shown in FIG. 1 is realized by an integrated circuit such as a microcomputer, it is desirable to reduce the calculation load of the microcomputer. Therefore, before the conventional starting method, the motor is heated by the magnetic pole position estimation section and the motor warm-up operation section. Further, by setting the magnetic pole position estimation method to a method of estimating the magnetic pole position from the voltage applied to the motor and the motor phase current described in Patent Document 4 shown in FIG. 6, it is possible to perform the motor warm-up operation. .

  As described above, before starting with the conventional start-up method, the motor is heated by the motor warm-up operation section in which the reactive current flows in the direction of magnetizing, thereby minimizing the control device change and the computational load on the microcomputer. It becomes possible to suppress. In addition, it is possible to heat the motor in the motor warm-up operation section without adding a special circuit or the like. In addition, when the magnetic pole position estimation is performed by the method described in Patent Document 4, since the sound of the applied harmonic pulse voltage is generated, the magnetic pole position estimation time is shortened and the activation is performed by the conventional activation method. The generation of sound can be minimized.

  The example which applied the permanent-magnet-motor drive device 1 of Example 1 to the compressor drive of the air conditioner 100 is demonstrated using FIGS. 9-12. As shown in FIG. 9, the air conditioner 100 according to the present embodiment includes an outdoor unit 101 that exchanges heat with the outside air, an indoor unit 102 that exchanges heat with the room, and a pipe 103 that connects the two. The outdoor unit 101 heats the compressor 104 that compresses the refrigerant, the compressor drive motor 105 that drives the compressor, the motor drive device 106 that controls the compressor 104, the compressor temperature detector 107, the compressed refrigerant and the outside air. It is comprised from the heat exchanger 108 to exchange. The permanent magnet motor drive device 1 of the first embodiment is applied to the motor drive device 106. The indoor unit 102 includes a heat exchanger 109 that exchanges heat with the room, and a blower 110 that blows air into the room.

  As shown in FIG. 9, when the outside air temperature is low, the compressor drive motor 105 in the outdoor unit 101 is also in a low temperature state. For this reason, when a ferrite magnet is used for the electric motor 105, demagnetization of the ferrite magnet occurs at the time of start-up, and there is a possibility that the power required for the compressor cannot be output.

  In the present embodiment, the permanent magnet motor drive device 1 of the first embodiment is applied to the air conditioner 100, and when the compressor drive motor 105 to which the ferrite magnet is applied is at a low temperature, an operation mode in which an ineffective current is passed in the direction of magnetization is performed. In this way, the compressor drive motor 105 is heated. The motor temperature is detected by replacing the motor temperature detector shown in the first embodiment with the compressor temperature detector 107. In the present embodiment, a starting method at a low temperature of the compressor drive motor of the air conditioner will be described.

FIG. 10 shows changes in the temperature of air discharged from the indoor unit (hereinafter referred to as “air blowing temperature”) with respect to the time when the air conditioner is started. 10A shows a case where the method described in Patent Document 2 shown in FIG. 5A is used, FIG. 10B shows a case where the start-up method of the first embodiment is used, and FIG. 10C shows an air conditioner. The 2nd starting method which warms a magnet using the refrigerant of this is shown. Here, the time T4, T5, T6, the time from coming start command to the air conditioner to the indoor unit discharge temperature reaches the target value T _T.

  First, the starting method of the first embodiment will be described. The starting method according to the first embodiment is a method in which a reactive current is applied in the magnet increasing direction to warm the magnet while performing sensorless driving after estimating the magnetic pole position shown in FIG. Thus, by simultaneously performing the drive of the compressor and the warm-up of the magnet, it is possible to shorten the time from the start command to the air conditioner to the hot air blow-out of the indoor unit.

  Next, the second activation method will be described. The second activation method is a method of warming the magnet using the refrigerant of the air conditioner in addition to the activation method of the first embodiment. FIG. 11 shows the air conditioner system and the refrigerant flow in the heating operation. In the second starting method, a bypass pipe 111 is added which bypasses the high-temperature refrigerant from the compressor 104 and returns it to the compressor.

  In a normal heating operation, the high-temperature refrigerant compressed by the compressor 104 dissipates heat in the heat exchanger 109 of the indoor unit, and the cooled refrigerant absorbs heat of the outside air in the heat exchanger 108 of the outdoor unit. Return to the compressor 104. On the other hand, in the second starting method, the high-temperature refrigerant discharged from the compressor through the bypass pipe 111 is returned to the compressor as it is immediately after the compressor 104 is started and until the magnet is warmed.

  By using the second start-up method, the temperature in the compressor can be raised and the magnet can be warmed rapidly. As shown in FIG. 10 (c), the discharge temperature of the indoor unit is further increased compared to the first method. The target value can be reached quickly, and the time until the hot air is blown out can be further shortened.

  By applying the present invention to an air conditioner, for example, when a magnet that is easily demagnetized at a low temperature, such as a ferrite magnet, is used as a compressor drive motor, the time until hot air blowing can be shortened, and comfort and usability are improved. An improved air conditioner can be provided.

  Next, in the air conditioner of the second embodiment, an embodiment according to the present invention when quick heating is requested from a remote controller or the like will be described.

In FIG. 12, the horizontal axis indicates time, and the vertical axis indicates the indoor unit discharge temperature ((a1) (b1)) and the compressor drive motor current ((a2) (b2)). Here, T _OUT-T represents the target indoor unit discharge temperature, T _P-UP represents the time when the rapid heating command is requested, and T 7 and T 8 indicate the time when T _OUT-T has reached T _OUT-T . 12 (a1) and 12 (a2) are conventional driving methods, and FIGS. 12 (b1) and 12 (b2) are driving methods to which the present invention is applied.

  In general air conditioner operation, as shown in FIGS. 12 (a1) and 12 (a2), when a rapid heating command is input, the rotational speed and torque of the compressor drive motor are increased to increase the discharge temperature of the indoor unit. Let However, in the conventional method, depending on the outdoor air temperature, it takes time for the indoor unit discharge temperature to reach the target value. In other words, rapid heating may be difficult.

  Therefore, as shown in FIGS. 12 (b1) and 12 (b2), when a rapid heating command is requested, a mode in which a reactive current is energized in the magnet magnetization direction is used together, and the winding of the compressor driving motor is used. The compressed refrigerant is further heated using the heat generated from. And since the heated refrigerant radiates heat indoors from the indoor heat exchanger, the heat generated by the motor winding can be used for heating. Therefore, rapid heating can be realized as compared with the methods of FIGS. 12 (a1) and 12 (a2). Moreover, since the heat generation of the motor winding does not depend on the outdoor temperature, the influence of the outdoor temperature can be suppressed.

  As described above, by applying the present invention to rapid heating of an air conditioner, comfort as a heater can be improved.

  Next, the operation at the time of timer reservation will be described with reference to FIG. 13 when the present invention is applied.

In FIG. 13 (a1) and FIG. 13 (b1), the horizontal axis represents time, and the vertical axis represents compressor temperature. In FIG. 13 (a2) and FIG. 13 (b2), the horizontal axis represents time, and the vertical axis represents the motor current for driving the compressor. Here, T _TIMER indicates the time when timer reservation is set, T _COMP-S indicates the target magnet temperature, and T9 and T10 indicate the time when the motor starts energization / startup operation according to the time set by T _TIMER. Yes. The target magnet temperature is replaced by the compressor temperature.

  Here, FIGS. 13 (a1) and 13 (a2) are obtained by applying the activation method of FIG. 3 (c) to the activation method at the time of timer reservation, and FIGS. 13 (b1) and 13 (b2) This is a method to which the activation method of FIG.

  The detailed operation has been described in FIGS. 3 (c) and 3 (d) and will be omitted. However, in the method of FIG. 3 (c), the warm-up operation is performed with the electric motor stopped, and thus the operation is applied to the air conditioner. In such a case, during normal operation, the warm-up time may take a long time and the comfort of the air conditioner may be impaired.

However, as described above, when applied at the time of start-up by timer reservation, the warm-up operation can be started before the timer reservation time T _TIMER as shown in FIGS. 13 (a1) and 13 (a2). There is no decrease in comfort over time.

  Furthermore, as shown in FIG. 13 (b1) and FIG. 13 (b2), by using the starting method of FIG. 3 (d) together, the warm-up time with the motor stopped can be shortened, It also leads to reduction of electricity usage.

  In this embodiment, two methods have been described as typical methods. However, the activation method of the second embodiment described above can be used in combination.

  As described above, by applying the present invention to the starting method at the time of timer reservation, a magnet that is easily demagnetized, such as a ferrite magnet, can be applied to an electric motor for driving a compressor without impairing the comfort and usability of the air conditioner. .

  In addition, this invention is not limited to an above-described Example, Various modifications are included. For example, the above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described. Further, a part of the configuration of one embodiment can be replaced with the configuration of another embodiment, and the configuration of another embodiment can be added to the configuration of one embodiment. Further, it is possible to add, delete, and replace other configurations for a part of the configuration of each embodiment.

  Each of the above-described configurations, functions, processing units, processing means, and the like may be realized by hardware by designing a part or all of them with, for example, an integrated circuit. Each of the above-described configurations, functions, and the like may be realized by software by interpreting and executing a program that realizes each function by the processor. Information such as programs, tables, and files that realize each function can be stored in a recording device such as a memory, a hard disk, or a solid state drive, or a recording medium such as an IC card, an SD card, or a DVD.

  Further, the control lines and information lines indicate what is considered necessary for the explanation, and not all the control lines and information lines on the product are necessarily shown. In practice, almost all the components are connected to each other.

  A permanent magnet motor driving apparatus according to the present invention includes an inverter circuit that converts DC power to AC power, a motor that is connected to the inverter circuit and has a permanent magnet that is likely to be demagnetized at low temperatures, and a plurality of windings, and a permanent magnet And warm-up operation in which a reactive current is passed in the direction of increasing the magnetization.

  The permanent magnet motor driving device of the present invention comprises a permanent magnet position detecting means for estimating or detecting the position of the permanent magnet, and performs a warm-up operation based on the detection result of the permanent magnet position detecting means. After the operation is completed, an effective current is supplied to the winding in the direction in which the electric motor generates torque based on the detection result of the permanent magnet position detection means.

  The permanent magnet motor driving device of the present invention comprises a permanent magnet position detecting means for estimating or detecting the position of the permanent magnet, and performs a warm-up operation based on the detection result of the permanent magnet position detecting means. During operation, an effective current is passed through the winding in the direction in which the motor generates torque based on the detection result of the permanent magnet position detection means.

  Further, the permanent magnet motor driving device of the present invention performs the warm-up operation based on the temperature of the motor, the time from the start of the warm-up operation, or the temperature converted value of the resistance value estimated from the applied voltage and current to the motor. finish.

Moreover, the permanent magnet of the permanent magnet motor driving device of the present invention is a ferrite magnet.
Moreover, the air conditioner of this invention is provided with the compressor driven with an electric motor, and the temperature detector which detects the temperature of a compressor, and makes temperature detected from the temperature detector into the temperature of an electric motor.

  Moreover, the air conditioner of this invention is provided with the bypass piping part which connects piping before suction | inhalation of a compressor, and piping after discharge of a compressor.

DESCRIPTION OF SYMBOLS 1 Permanent magnet motor drive device 2 DC power supply 3 Permanent magnet motor 4 Inverter circuit 41 Inverter main circuit 42 Gate driver 5 Controller 6 Phase current detection circuit 7 Phase voltage detection circuit 8 Inverter control unit 9 Magnetic pole position judgment unit 10 Temperature detection unit 11 Temperature discriminating unit 12 DC bus current detecting unit 13 Three-phase current detecting unit 14 Position detecting unit

Claims (6)

An inverter circuit for converting DC power into AC power;
A motor connected to the inverter circuit and having a permanent magnet and a plurality of windings that are susceptible to demagnetization at low temperatures;
A warm-up operation mode in which a reactive current flows in a direction in which the permanent magnet is magnetized;
A permanent magnet position detecting means for estimating or detecting the position of the permanent magnet ,
At startup, after estimating or detecting the position of the permanent magnet by the permanent magnet position detection means, the warm-up operation mode is performed based on the detection result of the permanent magnet position detection means,
A permanent magnet motor drive device that performs sensorless drive after the warm-up operation mode ends . An inverter circuit for converting DC power into AC power;
A motor connected to the inverter circuit and having a permanent magnet and a plurality of windings that are susceptible to demagnetization at low temperatures;
A warm-up operation mode in which a reactive current flows in a direction in which the permanent magnet is magnetized;
A permanent magnet position detecting means for estimating or detecting the position of the permanent magnet ,
At startup, after estimating or detecting the position of the permanent magnet by the permanent magnet position detection means, the warm-up operation mode is performed based on the detection result of the permanent magnet position detection means,
A permanent magnet motor driving device that performs sensorless driving in the warm-up operation mode . The warm-up operation mode is terminated based on the temperature of the motor, the time from the start of the warm-up operation mode , or the temperature converted value of the resistance value estimated from the applied voltage and current to the motor. The permanent magnet motor drive device according to claim 1 or 2 . The permanent magnet, the permanent magnet motor drive system according to any one of claims 1 to 3, characterized in that a ferrite magnet. A compressor driven by the electric motor;
A temperature detector for detecting the temperature of the compressor,
The air conditioner equipped with the permanent magnet motor drive device according to any one of claims 1 to 4 , wherein the warm-up operation mode is performed when a temperature of the compressor is equal to or lower than a predetermined temperature. A bypass pipe section that communicates the pipe before suction of the compressor and the pipe after discharge of the compressor ;
The refrigerant discharged from a pipe after discharge of the compressor through the bypass pipe portion is caused to flow to a pipe before suction of the compressor when the temperature of the compressor is equal to or lower than a predetermined temperature. 5. The air conditioner according to 5 .