WO2009119123A1

WO2009119123A1 - Refrigeration equipment

Info

Publication number: WO2009119123A1
Application number: PCT/JP2009/050055
Authority: WO
Inventors: 佳明栗田; 達夫安藤; 邦明高塚; 孝大石; 励笠原; 健木下; 健太郎三浦
Original assignee: 日立アプライアンス株式会社
Priority date: 2008-03-28
Filing date: 2009-01-07
Publication date: 2009-10-01
Also published as: TW200940917A; JP2009236445A; CN101946136B; JP4194645B1; CN101946136A; TWI355477B

Abstract

An air conditioner comprises a permanent magnet synchronous motor for driving a compressor in a refrigeration cycle, and an inverter performing variable control of the number of revolutions of the motor by vector control, wherein a microcomputer of the inverter fixes a first d-axis current command value Id* to a predetermined set value while fixing a speed command value ω*, for a predetermined time, as identification mode during vector control operation. An average value is operated by integrating the difference of a second d-axis current command value Id** and the first d-axis current command value Id* in case of the identification mode, a correction amount ΔL* of an inductance set value L* is operated based on the average value, and then vector control operation is performed using an inductance set value L* to which the correction amount ΔL* is added.

Description

Refrigeration equipment

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 device in order to realize high-efficiency 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. In view of this, a vector control apparatus has been proposed in which motor constants are identified immediately before or during actual operation and the motor constant setting value is automatically corrected (see, for example, JP 2007-49843 A).

JP 2007-49843 A

A vector control device described in Japanese Patent Application Laid-Open No. 2007-49843 includes a current detector that detects a three-phase alternating current, and coordinates that convert the detected value of the three-phase alternating current into a d-axis current detection value and a q-axis current detection value. A conversion unit; 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; and a first q-axis current command A q-axis current command calculation unit that generates a second q-axis current command value based on the deviation between the value and the q-axis current detection value, and a motor constant identification unit that identifies the motor constant and corrects the motor constant set value And a vector control for calculating a d-axis voltage command value and a q-axis voltage command value based on the set value of the motor constant, the rotational speed command value, the second d-axis current command value, and the second q-axis current command value Three-phase AC between the calculation unit (voltage command calculation unit), d-axis voltage command value, and q-axis voltage command value Includes a coordinate converter for converting the voltage command values, 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.

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.

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

To achieve the above object, the present invention provides a refrigeration apparatus comprising a compressor of a refrigeration cycle, 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. The inverter device includes an inverter circuit that generates AC power from DC power and supplies the AC power to the motor, a current detection unit that detects an input DC current or an output AC current of the inverter circuit, and a d detected from the current detected by the current detection unit. A current detection calculation unit for calculating an axis current detection value and a q-axis current detection value, and correcting the first d-axis current command value based on a deviation between the first d-axis current command value and the d-axis current detection value. A first d-axis current command value is generated based on a deviation between the first q-axis current command value and the detected q-axis current value. The second q-axis current finger A q-axis current command calculation unit that generates a value, a d-axis based on a motor constant setting value including an inductance setting value, a rotation speed command value, a second d-axis current command value, and a second q-axis current command value A voltage command calculation unit that calculates a voltage command value and a q-axis voltage command value; an inverter control unit that controls an inverter circuit based on the d-axis voltage command value and the q-axis voltage command value; and a first q-axis current command value An identification mode control unit for fixing the first d-axis current command value to a predetermined set value while fixing the rotation speed command value for a predetermined time as an identification mode during vector control operation in which , 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 an average value, and based on this, the correction amount of the inductance setting value is calculated, Inductance setting value with the correction amount added And a inductance identification unit as adapted to use in the calculation of the voltage command calculation unit.

According to the present invention, it is possible to increase the identification accuracy of inductance and improve the operation efficiency.
Other objects, features and advantages of the present invention will become apparent from the following description of embodiments of the present invention with reference to the accompanying drawings.

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

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

In FIG. 1, an air conditioner 110 has a refrigeration cycle in which a compressor 101, an indoor heat exchanger 102, an indoor expansion valve 104, an outdoor heat exchanger 105, and an accumulator 107 are sequentially connected. For example, when the room is cooled, the refrigerant compressed by the compressor 101 is condensed and liquefied by the outdoor heat exchanger 105, and then reduced by the indoor expansion valve 104 and evaporated by the indoor heat exchanger 102. It returns to the compressor 101. The indoor heat exchanger 102 and the indoor expansion valve 104 are provided in the indoor unit 109, and the indoor unit 109 is provided with an indoor blower 103 for promoting heat exchange. The compressor 101, the outdoor heat exchanger 105, the accumulator 107, and the like are provided in the outdoor unit 108, and the outdoor unit 108 is provided with an outdoor blower 106 for promoting heat exchange.

The compressor 101 is driven by a permanent magnet synchronous motor 111, and the rotation speed (operation frequency) of the motor 111 is variably controlled by an inverter device 210. Thereby, it respond | corresponds to the capability required for a refrigerating cycle. Further, the opening degree of the indoor expansion valve 104 or the outdoor expansion valve (not shown), the rotation speed of the indoor blower 103 and the outdoor blower 106, a four-way valve (not shown) for switching between the cooling / heating operation modes, and the like are controlled. Yes.

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 and supplies the AC power to the motor 111. The inverter 221, the microcomputer 231 that controls the inverter circuit 221 via the driver circuit 232, the high voltage generated by the converter circuit 225 is adjusted to a control power supply of about 5 V or 15 V, for example, the microcomputer 231, the driver circuit 232, etc. , A voltage detection circuit 234 that detects the output DC voltage of the converter circuit 225, a current detection circuit 233 that detects the input DC current of the inverter circuit 221 using the shunt resistor 224, and an outside temperature thermistor 261. Outside temperature to detect the outside temperature using A detection circuit 262, a discharge temperature detection circuit 264 that detects the discharge temperature of the compressor 101 using the discharge temperature thermistor 263, and a discharge pressure detection circuit 266 that detects the discharge pressure of the compressor 101 using the discharge pressure sensor 265. It has.

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.

Between the converter circuit 225 and the inverter circuit 221, an electromagnetic contactor 253 for operating or stopping the motor 111, a power factor improving reactor 252, and a smoothing capacitor 270 are connected. 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 sensorless type vector control function. That is, the drive current of the motor 111 (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, and the AC current is A current sensor for detection is not required. Further, the rotational speed and phase (magnetic pole position) of the motor 111 are estimated, and a speed sensor and a magnetic pole position sensor are not required. Details of such vector control will be described below.

FIG. 3 is a block diagram showing a functional configuration 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 uses the speed / phase estimation unit 18 for estimating the rotation speed detection value ω and the phase detection value θdc of the motor 111, the DC current Ish detected by the current detection circuit 233, and the like. A current reproduction unit 19 that estimates 111 drive currents (current detection values of three-phase alternating current) Iu, Iv, and Iw, and current detection values Iu, Iv, and Iw of three-phase alternating current based on the phase detection value θdc. Rotation speed command value calculated by the three-phase / 2-axis conversion unit 20 that converts the detection value Idc and the qc-axis current detection value Iqc, the speed command generation unit 10 that generates the rotation speed command value ω ^* , and the subtraction unit 11 The q-axis current command generation unit 12 that generates the first qc-axis current command value Iqc ^* and the first dc-axis current command value Idc ^* so that the deviation between ω ^* and the rotational speed detection value ω becomes zero ^. D-axis current command generation to generate Generator 13, motor constant setting unit 14 for outputting motor constant setting values (specifically, resistance setting value r ^* , induced voltage setting value Ke ^* , and virtual inductance setting value L ^* ), and a first dc axis Calculate dc-axis voltage command value Vdc ^* and qc-axis voltage command value Vqc ^* based on current command value Idc ^* , first qc-axis current command value Iqc ^* , motor constant setting value, rotation speed command value ω ^*, etc. The vector control calculation unit 15 that performs the dc-axis voltage command value Vdc ^* and the qc-axis voltage command value Vqc ^* dc-axis voltage command value based on the phase detection value θdc and three-phase AC voltage command values Vu ^* , Vv ^* , Vw biaxial / three-phase converting unit 16 that converts to ^*, the voltage command value of three-phase AC ^Vu ^*, Vv *, Vw ^* to generate and output to the driver circuit 232, respectively proportional to the PWM signal (pulse width modulation signal) Do And a WM output unit 17.

The current reproduction unit 19 is 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 conversion unit 16. 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 axis An 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 rotational 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 maximum motor torque. On the other hand, when the shaft error Δθc is negative, for example, 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 d-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 rotational speed detection value ω estimated by the speed calculation unit 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 ^* ) and the actual motor constant (r, Ke, L) coincide with each other 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 the inputs of the voltage command calculation unit 34, are substantially equal. However, if the motor constant set value (r ^* , Ke ^* , L ^* ) is different from the actual motor constant (r, Ke, L), the current detection values Idc, Iqc (or the first current command value) Idc ^{^*,} Iqc ^*) and the second current command value ^Idc **, deviation occurs between the ^{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 the 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 111 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.

Furthermore, after the identification of the induced voltage is completed (Ke ^* = Ke), if a predetermined set value Idc ^* _at is given as the first dc-axis current command value, 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 identification mode control unit 35, 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 identification mode control unit 35 receives, for example, the rotational speed detection value ω estimated by the speed / phase estimation unit 18 during the vector control mode operation of the motor 111, and the rotational speed detection value ω is set to a predetermined value. It is determined whether or not ω1 has been reached. For example, when the rotational speed detection value ω reaches the predetermined value ω1 (in other words, when the rotational speed detection value ω rises or falls to the predetermined value ω1), the identification mode is set as the identification mode for a predetermined time, the speed command generator 10 and the d-axis current command. The generation unit 13 is instructed in the identification mode, and the input switching unit 36 is switched to the connected state. In the present embodiment, the identification mode is executed by repeating a predetermined number of times (for example, three times) set in advance.

The speed command generation unit 10 fixes the rotational speed command value ω ^* to the current value 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 the 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 40 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. Then, 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, the operation of this embodiment will be described with reference to FIG.

The inverter device 120 drives the permanent magnet synchronous motor 111 by sensorless vector control, calculates the axis error Δθc using the above formula 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 111 (that is, the rotational speed N of the compressor 101) needs to be about 5 to 10 or more. Therefore, the motor 111 is started in three operation control modes (positioning mode, synchronous operation mode, and vector control operation mode). First, in the positioning mode, the rotor magnetic pole of the motor 111 is positioned by increasing the dc axis current while setting the qc axis current to zero. Thereafter, in the synchronous operation mode, the rotational speed ω of the motor 111 (that is, the rotational speed N of the compressor 101) is increased while the dc-axis current is fixed. When the rotational speed of the motor 111 (that is, the rotational speed N of the compressor 101) reaches about the rated value of about 5 to 10, the mode shifts to the vector control operation mode, and the qc-axis current is increased.

Then, after shifting to the vector control operation mode, when the rotational speed ω of the motor reaches the predetermined value ω1 (that is, when the rotation speed N of the compressor 101 reaches the predetermined value N1), the identification mode is set for a predetermined time, The first d-axis current command value Id ^* is fixed to a predetermined set value Idc ^* _at while fixing the speed command value ω ^* . Then, the difference between the second d-axis current command value Id ^** and the first current command value Id ^* (= Idc ^* _at) in the identification mode is integrated to calculate an average value, and based on this A correction amount ΔL ^* of the virtual inductance setting value L ^* is calculated, and then the vector control operation is performed using the inductance setting value L ^* obtained by adding the correction amount ΔL ^* .

In this embodiment, the identification accuracy of the virtual inductance L can be increased while suppressing the influence of current ripple and phase variation. Moreover, the identification accuracy of the virtual inductance L can be improved by executing the identification mode in accordance with the operating conditions such as the rotation speed of the compressor 101 and repeatedly performing the preset number of times. Therefore, the driving efficiency can be improved.

In the above-described embodiment, the identification mode control unit 35 receives the rotational speed detection value ω estimated by the speed / phase estimation unit 18 and the rotational speed detection value ω reaches a predetermined value ω1. Although the case where the identification mode is executed has been described as an example, the present invention is not limited to this. That is, for example, the direct current Ish detected by the current detection circuit 233 may be input, and the identification mode may be executed when the direct current Ish reaches a predetermined value Ish1 (see FIG. 7 described above). Alternatively, for example, the discharge pressure Pd of the compressor 101 detected by the discharge pressure detection circuit 266 may be input, and the identification mode may be executed when the discharge pressure Pd reaches a predetermined value Pd1 (see FIG. 8). For example, the discharge temperature Td detected by the discharge temperature detection circuit 264 may be input, and the identification mode may be executed when the discharge temperature Td reaches a predetermined value Td1 (see FIG. 9). Further, for example, the outside air temperature Ta detected by the outside air temperature detection circuit 262 may be input, and the identification mode may be executed when the outside air temperature Ta reaches a predetermined Ta1 (see FIG. 10). In these cases, the same effect as described above can be obtained.

In the above-described 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 present invention is not limited to this. That is, for example, it may be fixed to 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) (see FIG. 11). ). Further, for example, when the outside air temperature Ta detected by the outside air temperature detection circuit 262 is equal to or higher than a predetermined reference value Ta2, the first dc-axis current command value Idc ^* is fixed to a predetermined set value Idc ^* _at4, When the outside air temperature Ta detected by the outside air temperature detection circuit 262 is less than a predetermined reference value Ta2, it may be fixed to Idc ^* _at5 (where Idc ^* _at4 ≠ Idc ^* _at5) (see FIG. 12). In these cases, the same effect as described above can be obtained.

Although not specifically described in the above embodiment, 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. 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.

While the above description has been made with reference to exemplary embodiments, it will be apparent to those skilled in the art that the invention is not limited thereto and that various changes and modifications can be made within the spirit of the invention and the scope of the appended claims.

It is the schematic showing the structure of the air conditioning apparatus which is one Embodiment of this invention. It is the schematic showing the structure of the inverter apparatus in one Embodiment of this invention. It is a block diagram showing the functional structure of the microcomputer of the inverter apparatus in one 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 estimated axis of a control system. It is a time chart for demonstrating operation | movement of the air conditioning apparatus in one Embodiment of this invention. It is a time chart for demonstrating operation | movement of the air conditioning apparatus in the 1st modification of this invention. It is a time chart for demonstrating operation | movement of the air conditioning apparatus in the 2nd modification of this invention. It is a time chart for demonstrating operation | movement of the air conditioning apparatus in the 3rd modification of this invention. It is a time chart for demonstrating operation | movement of the air conditioning apparatus in the 4th modification of this invention. It is a time chart for demonstrating operation | movement of the air conditioning apparatus in the 5th modification of this invention.

Claims

In a refrigeration apparatus comprising a compressor of a refrigeration cycle, 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,
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;
During the vector control operation in which the first q-axis current command value is set to a value other than zero, the first d-axis current command value is set to a predetermined set value while fixing the rotation speed command value for a predetermined time as the identification mode. Identification mode control means fixed to
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. A refrigeration apparatus comprising: an inductance identification unit configured to use an inductance setting value obtained by adding a correction amount for calculation of the voltage command calculation unit.
2. The refrigeration apparatus according to claim 1, further comprising a rotation speed acquisition means for acquiring the rotation speed of the motor, wherein the identification mode control means is preset with the rotation speed of the motor acquired by the rotation speed acquisition means. A refrigeration apparatus that executes an identification mode when a predetermined value is reached.
2. The refrigeration apparatus according to claim 1, wherein the identification mode control means executes the identification mode when the current detected by the current detection means reaches a predetermined value set in advance.
2. The refrigeration apparatus according to claim 1, further comprising discharge pressure detection means for detecting a discharge pressure of the compressor, wherein the identification mode control means is configured such that the discharge pressure of the compressor detected by the discharge pressure detection means is previously detected. A refrigeration apparatus that executes an identification mode when a set predetermined value is reached.
2. The refrigeration apparatus according to claim 1, further comprising discharge temperature detection means for detecting a discharge temperature of the compressor, wherein the identification mode control means is configured such that the discharge temperature of the compressor detected by the discharge temperature detection means is in advance. A refrigeration apparatus that executes an identification mode when a set predetermined value is reached.
2. The refrigeration apparatus according to claim 1, further comprising an outside air temperature detecting means for detecting an outside air temperature, wherein the identification mode control means has the outside air temperature detected by the outside air temperature detecting means reaching a predetermined value. In this case, the refrigeration apparatus that executes the identification mode.
2. The refrigeration apparatus according to claim 1, 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 according to the number of repetitions of the identification mode.
2. The refrigeration apparatus according to claim 1, further comprising an outside air temperature detecting means for detecting an outside air temperature, wherein the identification mode control means converts the first d-axis current command value into an outside air temperature detected by the outside air temperature detecting means. A refrigeration apparatus that fixes to different predetermined set values depending on.