JP5222640B2 - Refrigeration equipment - Google Patents

Description

  The present invention relates to a refrigeration apparatus such as an air conditioner or a refrigerator, and more particularly to a refrigeration apparatus that variably controls the rotation speed of a permanent magnet synchronous motor that drives a compressor of a refrigeration cycle by an inverter device.

  For example, in a refrigeration apparatus such as an air conditioner or a refrigerator, it is known to employ vector control for an inverter apparatus in order to realize a highly efficient operation. Since vector control uses motor constants (specifically, resistance, induced voltage, and inductance), it is necessary to set the motor constants in advance. However, the motor constant varies depending on variations at the time of manufacturing the motor and operating conditions, and there is a possibility that a deviation occurs between the preset set value and the actual value. Therefore, a vector control device has been proposed that identifies motor constants immediately before actual operation or during actual operation and automatically corrects the motor constant setting value (see, for example, Patent Document 1).

  The vector control device described in Patent Document 1 includes a current detector that detects a three-phase alternating current, a coordinate conversion unit that converts a detected value of the three-phase alternating current into a d-axis current detection value and a q-axis current detection value, A d-axis current command calculation unit that generates a second d-axis current command value in accordance with a deviation between the first d-axis current command value and the detected d-axis current value; a first q-axis current command value and a q-axis; A q-axis current command calculation unit that generates a second q-axis current command value based on a deviation from the detected current value; a motor constant identification unit that identifies a motor constant and corrects the motor constant set value; and a motor constant Vector control calculation unit (voltage) that calculates the d-axis voltage command value and the q-axis voltage command value based on the set value, the rotation speed command value, the second d-axis current command value, and the second q-axis current command value Command calculation unit), and convert the d-axis voltage command value and the q-axis voltage command value to a three-phase AC voltage command value. A standard conversion unit, and a power converter that is applied to the permanent magnet synchronous motor a voltage proportional to the voltage command value of three-phase AC. In the high speed range, the d-axis current is controlled to “zero” and “a predetermined value other than zero”, and the difference between the second d-axis current command value and the difference between the d-axis current detection values in these two control states. (Or the difference between the first d-axis current command values), and the ratio between the difference between the d-axis current command values and the difference between the detected d-axis current values (or the difference between the first d-axis current command values). Is multiplied by the set value of the d-axis inductance to correct the set value of the d-axis inductance. Further, in the high speed range, if the q-axis current is “predetermined value or more”, the ratio between the second q-axis current command value and the q-axis current detection value (or the first q-axis current command value) is set to the q-axis. The q-axis inductance setting value is corrected by multiplying the inductance setting value.

JP 2007-49843 A

  The motor constant identification accuracy affects the motor control performance (specifically, drive efficiency, response speed, stability, etc.). In particular, the inductance identification accuracy is related to motor maximum torque control. And driving efficiency is greatly affected. In the above control device, the d-axis current command value is controlled to “zero” and “predetermined value other than zero”, and the difference between the second d-axis current command value and the difference between the d-axis current detection values in these two control states. Based on the above, the d-axis inductance is identified. For this reason, there is room for improvement in terms of inductance identification accuracy because it is easily affected by current ripples and phase variations.

  Further, in the refrigeration apparatus, there is a state where the refrigerant circulation is not stable at the start of operation and a load fluctuation occurs and the refrigeration cycle is not stable, and the current of the compressor motor is not stable. Therefore, in order to increase the identification accuracy of the inductance, it is necessary to perform the identification while the refrigeration cycle is relatively stable.

  An object of the present invention is to provide a refrigeration apparatus that can increase the identification accuracy of inductance and improve the operation efficiency.

  (1) In order to achieve the above object, the present invention includes a refrigeration cycle including a compressor, a condenser, an expansion valve, and an evaporator, a permanent magnet synchronous motor that drives the compressor, and a vector. In the refrigeration apparatus including an inverter device that variably controls the rotation speed of the motor by control, the inverter device generates an AC power from a DC power and supplies the AC power to the motor, and an input DC of the inverter circuit Current detection means for detecting current or output AC current, current detection calculation means for calculating a d-axis current detection value and a q-axis current detection value from the current detected by the current detection means, and a first d-axis current command A d-axis current command calculation means for generating a second d-axis current command value by correcting the first d-axis current command value based on a deviation between the value and the detected d-axis current value, and a first q-axis current Command value and Q-axis current command calculation means for generating a second q-axis current command value by correcting the first q-axis current command value based on a deviation from the detected shaft current value, and a motor constant setting value including an inductance setting value A voltage command calculation means for calculating a d-axis voltage command value and a q-axis voltage command value based on the rotation speed command value, the second d-axis current command value, and the second q-axis current command value; Inverter control means for controlling the inverter circuit based on the command value and the q-axis voltage command value, and as the identification mode, the first d-axis current command value is set to a predetermined value while fixing the rotation speed command value for a predetermined time. The identification mode control means fixed to the value, the difference between the second d-axis current command value and the first d-axis current command value in the identification mode is integrated to calculate the average value, and based on this, the inductance is calculated. Calculates the correction amount for the set value, and the correction amount An inductance identification unit configured to use the added inductance setting value for calculation of the voltage command calculation unit, and the identification mode control unit sets the first q-axis current command value to zero when the motor is started. The identification mode is executed after the end of the first start mode in which the vector control operation is set to a value other than and the operation is performed for a predetermined time while being fixed at a predetermined rotation speed.

  (2) In the above (1), preferably, the identification mode control means is in a vector control operation in which the first q-axis current command value is a value other than zero when the motor is started, After the first start mode, the identification mode is executed after the end of the second start mode in which the engine is operated for a predetermined time while being fixed at the number of revolutions selected according to the outside air temperature.

  (3) In order to achieve the above object, the present invention includes a refrigeration cycle including a compressor, a condenser, an expansion valve, and an evaporator, a permanent magnet synchronous motor that drives the compressor, and a vector. In a refrigeration apparatus comprising an inverter device that variably controls the rotation speed of the motor by control, a blower for promoting heat exchange in at least one of the condenser and the evaporator, and in accordance with the start of the motor When the air blower is started, the air conditioner further includes a air blower control device that executes a first start mode in which the air blower is fixed at a predetermined rotation speed and is operated for a predetermined time. An inverter circuit that generates AC power from DC power and supplies it to the motor, and current detection means for detecting an input DC current or an output AC current of the inverter circuit Current detection calculation means for calculating a d-axis current detection value and a q-axis current detection value from the current detected by the current detection means, and a deviation between the first d-axis current command value and the d-axis current detection value. The d-axis current command calculation means for correcting the first d-axis current command value to generate the second d-axis current command value, and the deviation between the first q-axis current command value and the q-axis current detection value A q-axis current command calculating means for correcting the first q-axis current command value based on the first q-axis current command value to generate a second q-axis current command value; a motor constant setting value including an inductance setting value; a rotation speed command value; Voltage command calculation means for calculating the d-axis voltage command value and the q-axis voltage command value based on the d-axis current command value and the second q-axis current command value, and the d-axis voltage command value and the q-axis voltage command value Inverter control means for controlling the inverter circuit based on the The identification mode control means for fixing the first d-axis current command value to a predetermined set value while fixing the time and the rotational speed command value, the second d-axis current command value in the identification mode and the first The difference from the d-axis current command value is integrated to calculate the average value, and based on this, the correction amount of the inductance setting value is calculated, and the inductance setting value obtained by adding the correction amount is calculated by the voltage command calculation means. The identification mode control means during vector control operation in which the first q-axis current command value is set to a value other than zero when the motor is started, The identification mode is executed after the end of the first start mode of the blower control means.

  (4) In the above (3), preferably, when starting the blower, the blower control means fixes the blower to a rotational speed selected according to an outside air temperature after the first start mode for a predetermined time. The identification mode control means is in a vector control operation in which the first q-axis current command value is set to a value other than zero when the motor is started, and the blower is operated. After completion of the second start mode of the control means, the identification mode is executed.

  (5) In the above (3), preferably, the blower control means selects the blower according to the outside air temperature and the discharge temperature of the compressor after the first start mode when starting the blower. The identification mode control means executes a vector control operation in which the first q-axis current command value is set to a value other than zero when starting the motor. The identification mode is executed after the end of the second start mode of the blower control means.

  (6) To achieve the above object, the present invention provides a refrigeration cycle including a compressor, a condenser, an expansion valve, and an evaporator, a permanent magnet synchronous motor that drives the compressor, and a vector. In a refrigeration apparatus comprising an inverter device that variably controls the rotation speed of the motor by control, a start mode for fixing the expansion valve to an opening selected in accordance with an outside air temperature for a predetermined time in accordance with the start of the compressor The inverter device further includes an inverter circuit that generates AC power from DC power and supplies the AC power to the motor, and current that detects input DC current or output AC current of the inverter circuit Detection means; current detection calculation means for calculating a d-axis current detection value and a q-axis current detection value from the current detected by the current detection means; a first d-axis current command value and d D-axis current command calculation means for generating a second d-axis current command value by correcting the first d-axis current command value based on a deviation from the detected current value; a first q-axis current command value and q Q-axis current command calculation means for generating a second q-axis current command value by correcting the first q-axis current command value based on a deviation from the detected shaft current value, and a motor constant setting value including an inductance setting value A voltage command calculation means for calculating a d-axis voltage command value and a q-axis voltage command value based on the rotation speed command value, the second d-axis current command value, and the second q-axis current command value; Inverter control means for controlling the inverter circuit based on the command value and the q-axis voltage command value, and as the identification mode, the first d-axis current command value is set to a predetermined value while fixing the rotation speed command value for a predetermined time. The identification mode control means to be fixed to the value and the first in the identification mode The difference between the d-axis current command value and the first d-axis current command value is integrated to calculate the average value, and based on this, the inductance setting value correction amount is calculated, and the correction amount is added to the inductance setting Inductance identifying means configured to use a value for calculation of the voltage command calculating means, and the identification mode control means sets the first q-axis current command value to a non-zero value when starting the motor. The identification mode is executed after the start of the start mode of the expansion valve control means during the vector control operation.

  (7) In any one of the above (1) to (6), preferably, the identification mode control means executes the identification mode so as to repeat a predetermined number of times set in advance.

  (8) In the above (7), preferably, the identification mode control means fixes the first d-axis current command value to a predetermined set value that differs depending on the number of repetitions of the identification mode.

  According to the present invention, it is possible to increase the identification accuracy of inductance and improve the operation efficiency.

  Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.

  FIG. 1 is a schematic diagram illustrating a configuration of an air conditioner according to the present embodiment.

  In FIG. 1, an air conditioner 100 includes a refrigeration cycle in which a compressor 101, a four-way valve 102, an outdoor heat exchanger 103, an outdoor expansion valve 104, an indoor expansion valve 105, an indoor heat exchanger 106, and an accumulator 107 are sequentially connected. Have. The compressor 101, the four-way valve 102, the outdoor heat exchanger 103, the outdoor expansion valve 104, the accumulator 107, and the like are provided in the outdoor unit 108, and the indoor expansion valve 105, the indoor heat exchanger 106, and the like are provided in the indoor unit 109. Yes. The outdoor unit 108 is provided with an outdoor fan 110 for promoting heat exchange, and the outdoor fan 110 is driven by a motor 111. The indoor unit 109 is provided with an indoor blower 112 for promoting heat exchange, and the indoor blower 112 is driven by a motor 113.

  For example, when the room is cooled, the four-way valve 102 is in a communication state indicated by a solid line in the drawing (more specifically, the compressor 101 and the outdoor heat exchanger 103 are connected, and the accumulator 107 and the indoor heat exchanger 106 are connected. State). Thereby, the refrigerant | coolant compressed with the compressor 101 flows in into the outdoor heat exchanger 103, is heat-exchanged with air with the outdoor heat exchanger 103, and is condensed. After that, the pressure is reduced by the indoor expansion valve 105 and flows into the indoor heat exchanger 106, the heat is exchanged with the air by the indoor heat exchanger 106, and the vapor is evaporated, and then returns to the compressor 101 via the accumulator 107. . On the other hand, for example, when heating the room, the four-way valve 102 is in a communication state indicated by a broken line in the figure (more specifically, the compressor 101 and the indoor heat exchanger 106 are connected, and the accumulator 107 and the outdoor heat exchanger 103 are connected. State). Thereby, the refrigerant | coolant compressed with the compressor 101 flows in into the indoor heat exchanger 106, is heat-exchanged with air with the indoor heat exchanger 106, and is condensed. Thereafter, the pressure is reduced by the outdoor expansion valve 104 and flows into the outdoor heat exchanger 103, and heat is exchanged with the air by the outdoor heat exchanger 103 to evaporate and return to the compressor 101 via the accumulator 107. .

  The compressor 101 is driven by a permanent magnet synchronous motor 114, and the rotation speed (operation frequency) of the compressor motor 114 is variably controlled by an inverter device 210. Thereby, it respond | corresponds to the capability required for a refrigerating cycle. Further, the rotation speed of the outdoor blower motor 111, the opening degree of the outdoor expansion valve 104, switching of the four-way valve 102, and the like are also controlled by the inverter device 210. The number of rotations of the indoor fan motor 113, the opening degree of the indoor expansion valve 105, and the like are controlled by a control device (not shown), and the control device and the inverter device 210 cooperate with each other.

  FIG. 2 is a schematic diagram showing the configuration of the inverter device 210.

  In FIG. 2, the inverter device 210 converts the AC power from the AC power source 251 into DC power, and generates AC power from the DC power generated by the converter circuit 225 to generate the compressor motor 114. The inverter circuit 221 supplied to the inverter, the current detection circuit 233 that detects the input DC current of the inverter circuit 221 using the shunt resistor 224, the fan drive circuit 281 that drives the outdoor fan motor 111, and the outdoor expansion valve 104. The microcomputer 231, the driver circuit 232, the blower drive circuit 281, and the expansion valve drive by adjusting the high voltage generated by the expansion valve drive circuit 282, the microcomputer 231, and the converter circuit 225 to a control power supply of about 5V or 15V, for example. A power supply circuit 235 to be supplied to the circuit 282 and the like, and a converter circuit 22 And a voltage detection circuit 234 for detecting the output DC voltage.

  The converter circuit 225 is a circuit in which a plurality of rectifying elements 226 are bridge-connected, and converts AC power from the AC power supply 251 into DC power. The inverter circuit 221 is a circuit in which a plurality of switching elements 222 are connected in a three-phase bridge. In addition, a flywheel element 223 is provided along with the switching element 222 so that the switching element 222 regenerates a counter electromotive force generated at the time of switching. The driver circuit 232 controls a switching operation of the switching element 222 by amplifying a weak signal (a PWM signal described later) from the microcomputer 231. Thereby, AC power is generated by the inverter circuit 221 and its frequency is controlled.

  An electromagnetic contactor 253, a power factor improving reactor 252, and a smoothing capacitor 270 are connected to the output side of the converter circuit 225. Further, an inrush current limiting resistor 254 is provided in parallel with the electromagnetic contactor 253 so that the electromagnetic contactor 253 that is closed when the power is turned on does not weld due to an excessive inrush current flowing through the smoothing capacitor 270.

  The microcomputer 231 has a control function of the outdoor fan motor 111 and controls the rotation speed of the outdoor fan motor 111 via the fan drive circuit 281. The microcomputer 231 has a control function for the outdoor expansion valve 104 and controls the opening degree of the outdoor expansion valve 104 via the expansion valve drive circuit 282.

  Further, the microcomputer 231 has a control function (sensorless type vector control function) of the compressor motor 114, and controls the inverter circuit 221 via the driver circuit 232, thereby rotating the compressor motor 114. The number is to be controlled. Specifically, the drive current of the compressor motor 114 (in other words, the output AC current of the inverter circuit 221) is reproduced based on the input DC current of the inverter circuit 221 detected by the current detection circuit 233. This eliminates the need for a current sensor for detecting alternating current. Further, the rotational speed and phase (magnetic pole position) of the compressor motor 114 are estimated, and a speed sensor and a magnetic pole position sensor are not required. Details of such a vector control function will be described below.

  FIG. 3 is a block diagram showing a functional configuration related to the control of the compressor motor 114 of the microcomputer 231. FIG. 4 is a block diagram showing the functional configuration of the speed / phase estimation unit shown in FIG. 3, and FIG. 5 shows the functional configuration of the motor constant identification unit and vector control calculation unit shown in FIG. FIG.

3 to 5, the microcomputer 231 detects the motor from the speed / phase estimation unit 18 that estimates the rotational speed detection value ω and the phase detection value θdc of the motor 114, the direct current Ish detected by the current detection circuit 233, and the like. The current reproduction unit 19 that estimates the drive currents 114 (current detection values of three-phase AC) Iu, Iv, and Iw, and the current detection values Iu, Iv, and Iw of the three-phase AC based on the phase detection value θdc Compressor operation that outputs a three-phase / two-axis converter 20 that converts the detection value Idc and the qc-axis current detection value Iqc and a mode command (in detail, a start mode, an identification mode, or a normal mode command described later) a command unit 9, rotational speed command generating unit 10 that generates a rotational speed command value omega ^* in accordance with the mode command from the compressor operation command unit 9, and the rotation speed command value calculated by the subtraction unit 11 omega ^* speed Deviation from detected value ω becomes zero Sea urchin, a q-axis current command generation unit 12 for generating a first qc-axis current command value Iqc ^*, to generate a first dc-axis current command value Idc ^* in accordance with the mode command from the compressor operation command unit 9 a d-axis current command generation unit 13; a motor constant identification unit 14 that outputs motor constant setting values (specifically, a resistance setting value r ^* , an induced voltage setting value Ke ^* , and a virtual inductance setting value L ^* ); 1 dc-axis current command value Idc ^* , first qc-axis current command value Iqc ^* , motor constant setting value, rotation speed command value ω ^*, etc., and dc-axis voltage command value Vdc ^* and qc-axis voltage command value The vector control calculation unit 15 for calculating Vqc ^* and the dc-axis voltage command value Vdc ^* and the qc-axis voltage command value Vqc ^* based on the phase detection value θdc are converted into three-phase AC voltage command values Vu ^* , Vv ^* , Vw ^*. 2-axis / 3-phase converter 16 that converts to 3-phase and 3-phase intersection Voltage command value Vu ^* of, Vv ^*, and a PWM output unit 17 for outputting to the driver circuit 232 to generate a PWM signal (pulse width modulation signal) that is proportional respectively to the Vw ^*.

Based on the DC current Ish detected by the current detection circuit 233 and the three-phase AC voltage command values Vu ^* , Vv ^* , Vw ^* calculated by the 2-axis / 3-phase converter 16, the current reproduction unit 19 The three-phase AC current detection values Iu, Iv, and Iw are estimated. The three-phase / two-axis conversion unit 20 converts the three-phase AC current detection values Iu, Iv, and Iw into the dc-axis current detection value Idc and the qc-axis current based on the phase detection value θdc estimated by the speed / phase estimation unit 18. The detection value Iqc is converted (see Equation 1 below). As shown in FIG. 6, the dq axis is the motor rotor axis, the do-qo axis is the motor maximum torque axis, the dc-qc axis is the estimated axis of the control system, and the do-qo axis and dc-qc The axis error with respect to the axis is defined as Δθc.

The speed / phase estimation unit 18 includes an axis error calculation unit 21 that calculates an axis error Δθc, a zero generation unit 22 that gives a zero command to the axis error Δθc, a speed calculation unit 23 that estimates a rotational speed detection value ω, and a phase And a phase calculator 24 for estimating the detected value θc. The axis error calculation unit 21 includes a dc-axis voltage command value Vdc ^* , a qc-axis voltage command value Vqc ^* , a dc-axis current detection value Idc, a qc-axis current detection value Iqc, motor constant setting values r ^* , Ke ^* , L ^* , Then, the axis error Δθc is calculated based on the rotation speed command value ω ^* (see the following formula 2).

The speed calculation unit 23 estimates the rotation speed detection value ω so that the axis error Δθc calculated by the axis error calculation unit 21 becomes zero. In other words, the zero generator 22 and the rotation speed calculator 23 constitute a PLL control circuit. For example, when the axis error Δθc is positive, the speed calculation unit 23 estimates that the rotation speed detection value ω is increased because the dc-qc axis of the control system is advanced from the do-qo axis of the motor maximum torque. On the other hand, for example, when the axis error Δθc is negative, the dc-qc axis of the control system is delayed from the do-qo axis of the motor maximum torque, so that the rotational speed detection value ω is estimated to be decreased. Then, the q-axis current command generation unit 12 is configured such that the deviation between the rotation speed detection value ω estimated by the speed calculation unit 23 and the rotation speed command value ω ^* generated by the speed command generation unit 10 becomes zero. A first qc-axis current command value is generated.

  The phase calculation unit 24 integrates the rotation speed detection value ω estimated by the speed calculation unit 23 to calculate the phase θdc of the control system.

The vector control calculation unit 15 includes a q-axis current command calculation unit 31, a d-axis current command calculation unit 33, and a voltage command calculation unit 34. The q-axis current command calculation unit 31 calculates the first qc-axis current command value Iqc ^* based on the difference between the first qc-axis current command value Iqc ^* calculated by the subtraction unit 30 and the qc-axis current detection value Iqc. The second qc-axis current command value Iqc ^** is generated by correction. Similarly, the d-axis current command calculation unit 33 calculates the first dc-axis current command value based on the difference between the first dc-axis current command value Idc ^* calculated by the subtraction unit 32 and the dc-axis current detection value Idc. Idc ^* is corrected to generate a second dc-axis current command value Idc ^** .

The voltage command calculation unit 34 includes a second qc-axis current command value Iqc ^** , a second dc-axis current command value Idc ^** , motor constant setting values r ^* , Ke ^* , L ^* , and a rotational speed command value ω. Based on _* , the dc-axis voltage command value Vdc ^* and the qc-axis voltage command value Vqc ^* are calculated (see the following Equation 3). In the present embodiment, it is assumed that the d-axis inductance setting value Ld and the q-axis inductance setting value Lq are substantially equal, and this is set as a virtual inductance L (= Ld = Lq).

The 2-axis / 3-phase converter 16 converts the dc-axis voltage command value Vdc ^* and the qc-axis current detection value Vqc ^* into a 3-phase AC voltage command value based on the phase detection value θdc estimated by the speed / phase estimation unit 18. Conversion into Vu ^* , Vv ^* , Vw ^* (see Equation 4 below).

  Here, the principle of the identification method of the virtual inductance L, which is the greatest feature of this embodiment, will be described.

When the motor constant set value (r ^* , Ke ^* , L ^* ) matches the actual motor constant (r, Ke, L) in the steady state, the current detection values Idc, Iqc (or the first value) The current command values Idc ^** , Iqc ^* ) and the second current command values Idc ^** , Iqc ^**, which are inputs to the voltage command calculation unit 34, are substantially equal. However, if the motor constant set value (r ^* , Ke ^* , L ^* ) and the actual motor constant (r, Ke, L) are different, the current detection values Idc, Iqc (or the first current command value) Deviation occurs between Idc ^* , Iqc ^* ) and the second current command values Idc ^** , Iqc ^** . Details thereof will be described below.

In the steady state, the relationship between the current detection values Idc and Iqc and the voltage command values Vdc ^* and Vqc ^* is approximately expressed by the following Equation 5.

In a steady state, the rotational speed command value ω ^* and the rotational speed detection value ω are substantially equal, and the first dc-axis current command value Idc ^* and the dc-axis current detection value Idc are substantially equal. Further, assuming that the motor 114 is rotating at a medium or high speed or the error of the resistance set value r ^* is small (r ^* = r), the following Expression 6 can be derived from Expression 3 and Expression 5. it can. If this equation 6 is modified, the following equation 7 is obtained.

Further, if the predetermined set value Idc ^* _at is given as the first dc-axis current command value after the identification of the induced voltage is completed (Ke ^* = Ke), the virtual inductance set value L ^An equation for obtaining the error ΔL ^* of ^* can be derived (see Equation 8 below).

  The motor constant identification unit 14 includes an input switching unit 36, an integration unit 37, a storage unit 38, and an addition unit 39 in order to identify the virtual inductance L described above. The compressor operation command unit 9 outputs an identification mode command to the speed command generation unit 10 and the d-axis current command generation unit 13 after completion of the start mode in the vector control operation (see the later-described diagram), and an input switching unit. 36 is switched to the connected state.

The speed command generation unit 10 fixes the rotational speed command value ω ^* in accordance with the identification mode command. The d-axis current command generation unit 13 fixes the first d-axis current command value Idc ^* to a predetermined set value Idc ^* _at in accordance with the identification mode command. The predetermined set value Idc ^* _at is preferably set to be relatively small in order to avoid the influence of the inverter eddy current and the motor magnetic saturation, and the identification accuracy is ensured while taking into account the current detection resolution and calculation error of the control device. Therefore, for example, it may be set in a range of about 1/10 to 1/2 of the rated current of the motor.

The accumulating unit 37 sends the difference between the second d-axis current command value Idc ^** calculated by the subtracting unit 35 and the first d-axis current command value Idc ^* (= Idc ^* _at) via the input switching unit 36. Input and integrate the differences during the identification mode period to calculate the average value. Then, using Equation 8 above to calculate the virtual inductance setting value L ^* of the error [Delta] L ^*. In order to suppress the influence of current ripple and phase variation, it is preferable to set the time constant so that the response of the integration unit 37 is slower than the control response of the vector control calculation unit 15. When the identification mode is performed n times and errors ΔL ^* _1,..., ΔL ^* _n are obtained, the sum ΔL ^* _all (= ΔL ^* _1 +... + ΔL ^* _n) is stored in the storage unit 38. . The addition unit 39 adds the error ΔL ^* _all stored in the storage unit 38 and the virtual inductance initial setting value L ^* _0, and uses this as the virtual inductance setting value L ^* , so that the voltage command calculation unit 34 of the vector control calculation unit 15. And output to the speed / phase estimation unit 18.

  Next, operations and effects of this embodiment will be described with reference to FIG.

  The inverter device 210 drives the motor 114 by sensorless type vector control, calculates the axis error Δθc using the above Equation 2, and estimates the phase θdc. However, in order to accurately calculate the accuracy of the phase θdc, the rotational speed ω of the motor 114 (that is, the rotational speed Nc of the compressor 101) needs to be about 5 to 10% or more of the rating. Therefore, the motor 114 is started by three operation controls (positioning, synchronous operation, and vector control operation). First, in positioning, the rotor magnetic pole of the motor 114 is positioned by increasing the dc axis current while setting the qc axis current I to zero. Thereafter, in the synchronous operation, the rotational speed ω of the motor 114 is increased while the dc axis current is fixed. When the rotational speed ω of the motor 114 reaches about 5 to 10% of the rating, the control shifts to vector control operation, and the qc-axis current is increased.

  When shifting to the vector control operation, first, a start mode for preventing the liquid return of the compressor 101 is executed. That is, the compressor operation command unit 9 shown in FIG. 3 outputs a start mode command to the speed command generation unit 10 and the d-axis current command generation unit 13. In the start mode, the rotation speed Nc of the compressor 101 is increased to a predetermined rotation speed Nc1 (for example, about 30 to 50% of the rating), fixed to the predetermined rotation speed Nc1, and set for a predetermined time (for example, T2). Drive for about 1 minute).

After the start mode ends, the identification mode is executed. That is, the compressor operation command unit 9 outputs the identification mode command to the speed command generation unit 10 and the d-axis current command generation unit 13 and switches the input switching unit 36 to the connected state. In the identification mode, the rotation speed command value ω ^* is fixed for a predetermined time (for example, T1 = 2 to 5 seconds) (that is, the rotation speed Nc of the compressor 101 is fixed to the predetermined rotation speed Nc1). First d-axis current command value Id ^* is fixed to a predetermined set value Idc ^* _at. In the present embodiment, for example, the identification mode is repeated three times. Then, the motor constant identification unit 14 calculates an average value by integrating the difference between the second d-axis current command value Id ^** and the first current command value Id ^* (= Idc ^* _at) in the identification mode. , it calculates the virtual inductance setting value L ^* of the correction amount [Delta] L ^* based on this. Thereafter, the vector control operation is performed using the inductance setting value L ^* obtained by adding the correction amount ΔL ^* .

  After all the identification modes are completed (for example, after about 10 to 20 seconds have elapsed since the start mode is completed), the normal mode is entered. That is, the compressor operation command unit 9 outputs a normal mode command to the speed command generation unit 10 and the d-axis current command generation unit 13. In the normal mode, the rotational speed Nc of the compressor 101 is controlled according to the indoor suction temperature detected by the detector (not shown) and the indoor set temperature set by the setting device (not shown).

  In this embodiment, by using the above-described virtual inductance identification method, it is possible to improve the identification accuracy while suppressing the influence of current ripple and phase variation. In this embodiment, since the identification mode is executed after the start mode of the compressor is completed, identification can be performed in a state where the refrigeration cycle is relatively stable, and identification accuracy can be improved. In addition, since the identification mode is repeated a plurality of times, the identification accuracy can be increased. As a result, driving efficiency can be improved.

In the first embodiment, the case where the first dc-axis current command value Idc ^* is fixed at the same predetermined value Idc ^* _at is described as an example of the identification mode, but the present invention is not limited to this. That is, for example, as in the modification shown in FIG. 8, predetermined setting values (Idc ^* _at1, Idc ^* _at2, Idc ^* _at3) that differ depending on the number of repetitions of the identification mode (for example, the first time, the second time, and the third time). It may be fixed to. Also in such a modification, the same effect as the first embodiment can be obtained.

  In the first embodiment, as the compressor start mode, the compressor 101 is fixed to a predetermined rotation speed Nc1 set in advance and operated for a predetermined time, and the identification mode is executed after the start mode ends. However, the present invention is not limited to this. That is, for example, as in the modification shown in FIG. 9, as the first start mode, the compressor 101 is fixed at a predetermined rotation speed Nc1 (for example, about 30 to 50% of the rated value) for a predetermined time (for example, , T2 = 1 minute), and then, as the second start mode, the rotation speed Nc2 selected according to the outside air temperature detected by the detector (not shown) (for example, within a range of 30 to 50% of the rating) ) For a predetermined time (for example, T3 = 2 to 5 minutes), and the identification mode may be executed after the end of the second start mode. Also in such a modification, the same effect as the first embodiment can be obtained.

  A second embodiment of the present invention will be described. In the present embodiment, the identification mode is executed after the start mode of the blower is completed. Note that in this embodiment, the same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  FIG. 10 is a block diagram illustrating a functional configuration related to the control of the compressor motor 114 and the control of the outdoor fan motor 111 of the microcomputer 231 in the present embodiment. FIG. 11 is a time chart for explaining the operation of the air conditioner 100 in the present embodiment.

  The microcomputer 231 of the inverter device 210 has a blower operation command unit 40, and the blower operation command unit 40 outputs a drive command to the blower drive circuit 281, for example, an outdoor blower almost simultaneously with the start of the compressor motor 114. The motor 111 is started. At this time, the outdoor blower motor 111 is raised to a predetermined rotation speed Nf1 (for example, the maximum rotation speed) set in advance, fixed to the predetermined rotation speed Nf1, and a start mode for operating for a predetermined time is executed. When the start mode ends (for example, after about 10 seconds have passed since the outdoor blower motor 111 is started, the compressor motor 114 is set to be in vector control operation), the normal mode is set. Transition. In the normal mode, for example, in the case of indoor heating, the rotational speed Nf of the outdoor blower motor 111 is controlled according to the outlet temperature of the outdoor heat exchanger 103 detected by a detector (not shown). The rotational speed Nf of the outdoor fan motor 111 is controlled according to the outlet temperature of the outdoor heat exchanger 103 and the discharge temperature of the compressor 101 detected by a detector (not shown).

The compressor operation command unit 9 outputs an identification mode command to the speed command generation unit 10 and the d-axis current command generation unit 13 when the blower start command end information is input from the blower operation command unit 40. The input switching unit 36 is switched to a connected state (in this embodiment, the compressor operation command unit 9 is described as not outputting a command for the start mode of the compressor). In response to this, the speed command generation unit 10 fixes the rotation speed command value ω ^* to the current value, and the d-axis current command generation unit 13 sets the first d-axis current command value Id ^* to a predetermined set value Idc ^* _at. To fix. The motor constant identification unit 14 calculates the average value by integrating the difference between the second d-axis current command value Id ^** and the first current command value Id ^* (= Idc ^* _at) in the identification mode. to calculate the virtual inductance setting value L ^* of the correction amount [Delta] L ^* based on. Thereafter, vector control is performed using the virtual inductance setting value L ^* to which the correction amount ΔL ^* is added.

  Also in this embodiment, since the identification method of the virtual inductance is the same as that of the first embodiment, the identification accuracy can be improved while suppressing the influence of current ripple and phase variation. Moreover, in this embodiment, since identification mode is performed after completion | finish of the start mode of an air blower, identification can be performed in the state where the refrigerating cycle was comparatively stable, and identification accuracy can be improved. As a result, driving efficiency can be improved.

In the second embodiment, the case where the first dc-axis current command value Idc ^* is fixed at the same predetermined value Idc ^* _at has been described as an example of the identification mode. However, the identification mode is not limited to this. Depending on the number of repetitions, the predetermined set value may be fixed. Also in such a modification, the same effect as the second embodiment can be obtained.

  Further, in the second embodiment, as the start mode of the blower, the outdoor blower 110 is fixed to a predetermined rotation speed Nf1 set in advance and operated for a predetermined time, and the identification mode is executed after the start mode ends. Although the case has been described as an example, the present invention is not limited to this. That is, for example, as in the modification shown in FIG. 12, as the first start mode, the outdoor blower 110 is fixed at a predetermined rotation speed Nf1 (for example, the maximum rotation speed) and is operated for a predetermined time, and thereafter 2 As the start mode, the rotation speed Nf2 selected according to the outside air temperature (or the outside air temperature and the indoor suction temperature) (for example, within a range of 15 to 80% of the maximum rotation speed) is fixed for a predetermined time (for example, 3 to 5 minutes). About), the identification mode may be executed after the end of the second start mode. Also in such a modification, the same effect as the second embodiment can be obtained.

  A third embodiment of the present invention will be described. In the present embodiment, the identification mode is executed after the start mode of the expansion valve is completed. In the present embodiment, the same parts as those in the first and second embodiments are denoted by the same reference numerals, and description thereof will be omitted as appropriate.

  FIG. 13 is a block diagram showing a functional configuration related to the control of the compressor motor 114 and the control of the outdoor expansion valve 104 of the microcomputer 231 in this embodiment. FIG. 14 is a time chart for explaining the operation of the air conditioner 100 according to this embodiment.

  The microcomputer 231 of the inverter device 210 has an expansion valve operation command unit 41. The expansion valve operation command unit 41 outputs a drive command to the expansion valve drive circuit 282, for example, almost at the start of the compressor motor 114. At the same time, the outdoor expansion valve 104 is started. At this time, a start mode is executed in which the outdoor expansion valve 104 is fixed at a predetermined opening degree V (for example, about 10 to 50%) for a predetermined time. When the start mode ends (for example, after about 2 to 10 minutes from the start of the outdoor expansion valve 104, the compressor motor 114 is set to be in vector control operation). Migrate to In the normal mode, for example, the opening degree V of the outdoor expansion valve 104 is controlled according to the discharge temperature of the compressor 101.

The compressor operation command unit 9 outputs an identification mode command to the speed command generation unit 10 and the d-axis current command generation unit 13 when the expansion valve start command end information is input from the expansion valve operation command unit 41. At the same time, the input switching unit 36 is switched to the connected state (in this embodiment, the compressor operation command unit 9 is described as not outputting a command for the start mode of the compressor). In response to this, the speed command generation unit 10 fixes the rotation speed command value ω ^* to the current value, and the d-axis current command generation unit 13 sets the first d-axis current command value Id ^* to a predetermined set value Idc ^* _at. To fix. The motor constant identification unit 14 calculates the average value by integrating the difference between the second d-axis current command value Id ^** and the first current command value Id ^* (= Idc ^* _at) in the identification mode. to calculate the virtual inductance setting value L ^* of the correction amount [Delta] L ^* based on. Thereafter, vector control is performed using the virtual inductance setting value L ^* to which the correction amount ΔL ^* is added.

  Also in this embodiment, since the virtual inductance identification method is the same as in the first and second embodiments, the identification accuracy can be improved while suppressing the influence of current ripple and phase variation. . In this embodiment, since the identification mode is executed after the start mode of the expansion valve is completed, the identification can be performed in a state where the refrigeration cycle is relatively stable, and the identification accuracy can be improved. As a result, driving efficiency can be improved.

In the third embodiment, the case where the first dc-axis current command value Idc ^* is fixed at the same predetermined value Idc ^* _at is described as an example of the identification mode. However, the identification mode is not limited to this. Depending on the number of repetitions, the predetermined set value may be fixed. Also in such a modification, the same effect as the third embodiment can be obtained.

Although not specifically described above, the d-axis current command calculation unit 33 and the q-axis current command calculation unit 31 input the inductance set value L ^* identified by the motor constant identification unit 14 and input it. Based on this, the control gain may be adjusted (see Equation 9 below). In this case, the same effect as described above can be obtained.

  Further, the inverter device 210 has a blower drive circuit 281 as a blower control means and a blower control function of the microcomputer 231, and has a configuration having an expansion valve drive circuit 282 as an expansion valve control means and an expansion valve control function of the microcomputer 231. Although described as an example, the present invention is not limited to this. That is, for example, a control device serving as a blower control unit may be provided separately from the inverter device, and may cooperate with each other. Further, for example, a control device as an expansion valve control means may be provided separately from the inverter device and cooperate with each other. In these cases, the same effect as described above can be obtained.

It is the schematic showing the structure of the air conditioner in the 1st Embodiment of this invention. It is the schematic showing the structure of the inverter apparatus in the 1st Embodiment of this invention. It is a block diagram showing the functional structure regarding the motor control for the compressor of the microcomputer of the inverter apparatus in the 1st Embodiment of this invention. FIG. 4 is a block diagram illustrating a functional configuration of a speed / phase estimation unit illustrated in FIG. 3. FIG. 4 is a block diagram illustrating a functional configuration of a motor constant identification unit and a vector control calculation unit illustrated in FIG. 3. It is a figure showing a motor rotor axis | shaft, a motor maximum torque axis | shaft, and the estimation axis | shaft of a control system. It is a time chart for demonstrating operation | movement of the air conditioner in the 1st Embodiment of this invention. It is a time chart for demonstrating operation | movement of the air conditioner in the 1st modification of this invention. It is a time chart for demonstrating operation | movement of the air conditioner in the 2nd modification of this invention. It is a block diagram showing the functional structure regarding the motor control for compressors of the microcomputer of the inverter apparatus in the 2nd Embodiment of this invention, and the motor control for outdoor air blowers. It is a time chart for demonstrating operation | movement of the air conditioner in the 2nd Embodiment of this invention. It is a time chart for demonstrating operation | movement of the air conditioner in the 3rd modification of this invention. It is a block diagram showing the functional structure regarding the motor control for compressors and the outdoor expansion valve control of the microcomputer of the inverter apparatus in the 3rd Embodiment of this invention. It is a time chart for demonstrating operation | movement of the air conditioner in the 3rd Embodiment of this invention.

Explanation of symbols

9 Compressor operation command section (identification mode control means)
14 Motor constant identification unit 15 Vector control calculation unit 16 2-axis / 3-phase conversion unit (inverter control means)
17 PWM output section (inverter control means)
19 Current reproduction unit (current detection calculation means)
20 3-phase / 2-axis converter (current detection calculation means)
31 q-axis current command calculation unit (q-axis current command calculation means)
33 d-axis current command calculation unit (d-axis current command calculation means)
34 Voltage command calculation unit (voltage command calculation means)
35 Subtraction unit (inductance identification means)
36 Input switching unit (inductance identification means)
37 Integration part (Inductance identification means)
38 Storage unit (inductance identification means)
39 Adder (Inductance identification means)
40 Blower operation command section (Blower control means)
41 Expansion valve operation command section (expansion valve control means)
100 Air Conditioner 101 Compressor 103 Outdoor Heat Exchanger (Condenser, Evaporator)
104 Outdoor expansion valve 106 Indoor heat exchanger (condenser, evaporator)
110 Outdoor blower 114 Compressor motor 210 Inverter device 221 Inverter circuit 224 Shunt resistance (current detection means)
231 Microcomputer 233 Current detection circuit (current detection means)
281 Blower drive circuit (Blower control means)
282 Expansion valve drive circuit (expansion valve control means)
Idc dc-axis current detection value Idc ^* first dc-axis current command value Idc ^** second dc-axis current command value Iqc qc-axis current detection value Iqc ^* first qc-axis current command value Iqc ^** second qc Axis current command value Ish DC current Ke ^* Induced voltage setting value L ^* Virtual inductance setting value r ^* Resistance setting value Vdc ^* dc axis voltage command value Vqc ^* qc axis voltage command value ω ^* Rotational speed command value

Claims (8)

A refrigeration cycle including a compressor, a condenser, an expansion valve, and an evaporator, a permanent magnet synchronous motor that drives the compressor, and an inverter device that variably controls the rotational speed of the motor by vector control. In the refrigeration apparatus provided,
The inverter device is
An inverter circuit that generates AC power from DC power and supplies it to the motor;
Current detecting means for detecting an input DC current or an output AC current of the inverter circuit;
Current detection calculation means for calculating a d-axis current detection value and a q-axis current detection value from the current detected by the current detection means;
D-axis current command calculation means for generating a second d-axis current command value by correcting the first d-axis current command value based on a deviation between the first d-axis current command value and the detected d-axis current value; ,
Q-axis current command calculation means for correcting the first q-axis current command value based on the deviation between the first q-axis current command value and the detected q-axis current value to generate a second q-axis current command value; ,
The d-axis voltage command value and the q-axis voltage command value are calculated based on the motor constant setting value including the inductance setting value, the rotation speed command value, the second d-axis current command value, and the second q-axis current command value. Voltage command calculation means;
inverter control means for controlling the inverter circuit based on a d-axis voltage command value and a q-axis voltage command value;
Identification mode control means for fixing the first d-axis current command value to a predetermined set value while fixing the rotational speed command value for a predetermined time as the identification mode;
In the case of the identification mode, the difference between the second d-axis current command value and the first d-axis current command value is integrated to calculate the average value, and based on this, the correction amount of the inductance setting value is calculated. Inductance identification means that uses the inductance setting value obtained by adding the correction amount for the calculation of the voltage command calculation means,
When the motor is started, the identification mode control means is in a vector control operation in which the first q-axis current command value is set to a value other than zero, and is fixed at a predetermined rotation speed set in advance. A refrigeration apparatus that executes an identification mode after completion of a first start mode that operates for a predetermined time.   2. The refrigeration apparatus according to claim 1, wherein the identification mode control unit is in a vector control operation in which the first q-axis current command value is set to a value other than zero when the motor is started. A refrigeration apparatus that executes an identification mode after the end of a second start mode in which the engine is operated for a predetermined time while being fixed at a rotational speed selected according to the outside air temperature after the first start mode. A refrigeration cycle including a compressor, a condenser, an expansion valve, and an evaporator, a permanent magnet synchronous motor that drives the compressor, and an inverter device that variably controls the rotational speed of the motor by vector control. In the refrigeration apparatus provided,
A blower for promoting heat exchange in at least one of the condenser and the evaporator;
When the blower is started in accordance with the start of the motor, it further includes blower control means for executing a first start mode in which the blower is fixed at a predetermined rotation speed and is operated for a predetermined time. ,
The inverter device is
An inverter circuit that generates AC power from DC power and supplies it to the motor;
Current detecting means for detecting an input DC current or an output AC current of the inverter circuit;
Current detection calculation means for calculating a d-axis current detection value and a q-axis current detection value from the current detected by the current detection means;
D-axis current command calculation means for generating a second d-axis current command value by correcting the first d-axis current command value based on a deviation between the first d-axis current command value and the detected d-axis current value; ,
Q-axis current command calculation means for correcting the first q-axis current command value based on the deviation between the first q-axis current command value and the detected q-axis current value to generate a second q-axis current command value; ,
The d-axis voltage command value and the q-axis voltage command value are calculated based on the motor constant setting value including the inductance setting value, the rotation speed command value, the second d-axis current command value, and the second q-axis current command value. Voltage command calculation means;
inverter control means for controlling the inverter circuit based on a d-axis voltage command value and a q-axis voltage command value;
Identification mode control means for fixing the first d-axis current command value to a predetermined set value while fixing the rotational speed command value for a predetermined time as the identification mode;
In the case of the identification mode, the difference between the second d-axis current command value and the first d-axis current command value is integrated to calculate the average value, and based on this, the correction amount of the inductance setting value is calculated. Inductance identification means that uses the inductance setting value obtained by adding the correction amount for the calculation of the voltage command calculation means,
The identification mode control means is in a vector control operation in which the first q-axis current command value is set to a value other than zero at the start of the motor, and after the first start mode of the blower control means is finished. A refrigeration apparatus that executes an identification mode.   4. The refrigeration apparatus according to claim 3, wherein when the blower is started, the blower control unit is operated for a predetermined time after fixing the blower at a rotational speed selected according to an outside air temperature after the first start mode. The identification mode control means is in a vector control operation in which the first q-axis current command value is set to a value other than zero at the start of the motor, and the identification mode control means A refrigeration apparatus that executes an identification mode after the end of the second start mode.   4. The refrigeration apparatus according to claim 3, wherein when the blower is started, the blower control means fixes the blower to a rotational speed selected according to an outside air temperature and a discharge temperature of the compressor after the first start mode. The identification mode control means is in a vector control operation in which the first q-axis current command value is set to a value other than zero when starting the motor. The identification mode is executed after the end of the second start mode of the blower control means. A refrigeration cycle including a compressor, a condenser, an expansion valve, and an evaporator, a permanent magnet synchronous motor that drives the compressor, and an inverter device that variably controls the rotational speed of the motor by vector control. In the refrigeration apparatus provided,
In accordance with the start of the compressor, further comprising expansion valve control means for executing a start mode for fixing the expansion valve to an opening selected according to the outside air temperature for a predetermined time,
The inverter device is
An inverter circuit that generates AC power from DC power and supplies it to the motor;
Current detecting means for detecting an input DC current or an output AC current of the inverter circuit;
Current detection calculation means for calculating a d-axis current detection value and a q-axis current detection value from the current detected by the current detection means;
D-axis current command calculation means for generating a second d-axis current command value by correcting the first d-axis current command value based on a deviation between the first d-axis current command value and the detected d-axis current value; ,
Q-axis current command calculation means for correcting the first q-axis current command value based on the deviation between the first q-axis current command value and the detected q-axis current value to generate a second q-axis current command value; ,
The d-axis voltage command value and the q-axis voltage command value are calculated based on the motor constant setting value including the inductance setting value, the rotation speed command value, the second d-axis current command value, and the second q-axis current command value. Voltage command calculation means;
inverter control means for controlling the inverter circuit based on a d-axis voltage command value and a q-axis voltage command value;
Identification mode control means for fixing the first d-axis current command value to a predetermined set value while fixing the rotational speed command value for a predetermined time as the identification mode;
In the case of the identification mode, the difference between the second d-axis current command value and the first d-axis current command value is integrated to calculate the average value, and based on this, the correction amount of the inductance setting value is calculated. Inductance identification means that uses the inductance setting value obtained by adding the correction amount for the calculation of the voltage command calculation means,
The identification mode control means is in a vector control operation in which the first q-axis current command value is set to a value other than zero at the start of the motor, and after the start mode of the expansion valve control means ends, A refrigeration apparatus that executes an identification mode.   The refrigeration apparatus according to any one of claims 1 to 6, wherein the identification mode control means executes the identification mode so as to repeat a predetermined number of times set in advance.   8. The refrigeration apparatus according to claim 7, wherein the identification mode control means fixes the first d-axis current command value to a predetermined set value that differs depending on the number of repetitions of the identification mode.

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