JP2007225188A - Refrigeration cycle device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a refrigerating cycle device capable of driving an expansion machine with high reliability including stopping by controlling rotational frequency of a rotating machine by estimating a magnetic pole position of a rotor of the rotating machine mounted in the expansion machine. <P>SOLUTION: The refrigeration cycle device equipped with the expansion machine 2 includes: an induced voltage estimating portion 24 for estimating induced voltage generated in each phase of a stator winding of the rotating machine 2b mounted in the expansion machine 2; a rotor position/speed detecting portion 25 for estimating magnetic pole position and speed of the rotor of the rotating machine 2b on the basis of the induced voltage estimated by the induced voltage estimating portion 24; and a rotating machine control device 18 including a power convertor 19 capable of being operated as a normal convertor and a reverse convertor. The expansion machine 2 is constrained by making a direct current electricity flow to the rotating machine 2b by the rotating machine control device 18 from immediately after the compressor 1 stops until a predetermined time has passed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a refrigeration cycle apparatus including an expander.

  In recent years, in an apparatus for driving an electric motor such as a compressor in an air conditioner, there is an increasing need to reduce power consumption from the viewpoint of protecting the global environment. As one of the technologies for reducing the power consumption, there is a refrigeration cycle apparatus that recovers power from an expander driven by expansion energy of refrigerant and uses the recovered power as auxiliary power for driving the compressor. Yes (see, for example, Patent Document 1).

  FIG. 3 is a system configuration diagram of the refrigeration cycle apparatus described in Patent Document 1. In FIG. 3, this refrigeration cycle apparatus includes a compressor 1 for compressing refrigerant, a condenser 3 for condensing refrigerant, an evaporator 4 for evaporating refrigerant, and expansion energy of the refrigerant provided between the condenser 3 and the evaporator 4. The expansion turbine 2a is driven by the expansion turbine 2a, and the expansion turbine 2a is directly connected to the generator 2d via the power shaft 2c. AC power from the AC power supply 11 is converted into DC power by the first converter 31, and this DC power is converted into AC power by the inverter 16 and the compressor 1 is driven.

  On the other hand, the expansion turbine 2a driven by the expansion energy of the refrigerant drives the generator 2d via the power shaft 2c, and AC power obtained from the generator 2d is input to the second converter 32. The second converter 32 converts AC power obtained from the generator 2 d into DC power, and this DC power is used as auxiliary power for driving the compressor 1.

  However, in this configuration, since there is no means for controlling the rotation speed of the expansion turbine 2a (that is, the generator 2d via the power shaft 2c), the expansion turbine 2a (that is, the rotation speed that is optimal in the refrigeration cycle) (that is, There was a problem that it was impossible to operate the generator 2d) via the power shaft 2c.

  Therefore, a means for controlling the number of revolutions of the generator 2d is required. However, in recent years, a highly efficient synchronous generator in which a permanent magnet is arranged on a rotor is used as a generator from the viewpoint of protecting the global environment. In order to control the rotational speed of the synchronous generator, a variable speed converter (hereinafter referred to as a PWM converter) that performs PWM control based on rotor position information is required. In particular, when applied to the generator in the expander of the refrigeration cycle apparatus described in Patent Document 1, it is difficult to attach a position sensor for detecting the magnetic pole position of the rotor, so the stator winding of the synchronous generator A method has been devised for estimating the magnetic pole position of the rotor by estimating the induced voltage generated in (see, for example, Non-Patent Document 1).

FIG. 4 is a configuration diagram of the wind power generation system described in Non-Patent Document 1. In FIG. 4, an embedded magnet synchronous generator 42 (symbol in the drawing is IPMSG) is driven by a windmill 41 connected through a gear. Here, in the position / velocity estimation unit 44, the embedded magnet synchronous power generation is internally provided from the γ-δ axis current obtained by coordinate conversion of the detected currents iu and iv from the current detectors 20a and 20b at the estimated position θ and the voltage command value. The rotor position and speed of the embedded magnet synchronous generator 42 are estimated by estimating the induced voltage of the embedded magnet synchronous generator 42 using the model of the machine 42. The torque command Tg * is derived by the maximum power tracking control unit 45 from the estimated speed ω of the embedded magnet synchronous generator 42, and the loss of the embedded magnet synchronous generator 42 is minimized by the maximum efficiency control unit 46 from the torque command Tg *. Such current commands id * and iq * are derived. The current flowing through the embedded magnet synchronous generator 42 is current feedback controlled by the voltage command generator 47 and is driven by the PWM converter 43.
JP 61-29647 A "Proceedings of the IEEJ National Conference", 2002, 4th volume, P209-210

  However, when the system configuration described in Non-Patent Document 1 is applied to the refrigeration cycle apparatus described in Patent Document 1, the rotation of the expansion turbine (that is, the generator via the power shaft) is rotated at an optimal rotation speed in the refrigeration cycle. The number of the energy can be controlled, but the expansion energy does not disappear immediately when the compressor in operation is stopped, and while the expansion energy exists, the expansion turbine (ie, via the power shaft) The generator will continue to be driven. Here, when the PWM converter is continuously operated, the electric energy is extracted while the rotation speed of the generator is controlled. However, when the compressor that consumes the electric energy is stopped, the extracted electric energy is accumulated. There has been a problem that the device is destroyed when the accumulated electric energy exceeds the allowable value of the device such as the PWM converter.

  Further, when the operation of the PWM converter is stopped together with the stop of the compressor, the expansion turbine enters a free-run state, and the rotation speed continues to increase while the expansion energy exists. When the value is exceeded, there is a problem that the expansion turbine is destroyed.

  The present invention solves the above-mentioned conventional problems, and controls the rotational speed of the rotating machine by estimating the magnetic pole position of the rotor of the rotating machine provided in the expander, and has reliability including stopping. It aims at providing the refrigerating-cycle apparatus for implement | achieving the drive of a high expander.

  In order to solve the conventional problems, a refrigeration cycle apparatus of the present invention includes a compressor that compresses a refrigerant, a condenser that condenses the refrigerant, an evaporator that evaporates the refrigerant, the condenser, and the evaporator. Rotation of a rotating machine including an expander provided between and driven by the expansion energy of the refrigerant, and a power converter operable as a forward converter and a reverse converter, and directly connected to the expander via a power shaft A rotating machine control means for controlling the number, and the rotating machine control means restrains the expander by causing a direct current to flow through the rotating machine until a predetermined time elapses after the compressor is stopped. It is characterized by this.

  As a result, when the compressor is stopped, the rotation speed of the expander continues to increase due to the expansion energy present in the refrigeration cycle, and the electric energy obtained by the regenerative operation by the rotating machine control means continues to accumulate. An element such as a power converter can be prevented from being destroyed, and a safe stop of the expander can be realized.

  The refrigeration cycle apparatus of the present invention controls the rotational speed of the rotating machine by estimating the magnetic pole position of the rotor of the rotating machine provided in the expander, and drives the expander with high reliability including stopping. Can be realized.

A first invention is provided by a compressor that compresses a refrigerant, a condenser that condenses the refrigerant, an evaporator that evaporates the refrigerant, and an expansion energy of the refrigerant that is provided between the condenser and the evaporator. An expander, and a power converter capable of operating as a forward converter and a reverse converter, and a rotating machine control means for controlling the rotational speed of a rotating machine directly connected to the expander via a power shaft, When the compressor is stopped by allowing the rotating machine control means to restrain the expander by causing a direct current to flow through the rotating machine until a predetermined time elapses immediately after the compressor is stopped, The rotation speed of the expander continues to increase due to the expansion energy present in the cycle, and electrical energy obtained by regenerative operation by the rotating machine control means continues to accumulate, destroying elements such as power converters. It can be prevented, it is possible to realize a stop of safe expander.

  According to a second aspect of the invention, in particular, in the first aspect of the invention, by gradually increasing the magnitude of the direct current flowing through the rotating machine with respect to the elapsed time, the change in the direct current flowing through the rotating machine is moderated. By doing so, the physical stress given to the mechanism of the expander when restraining the expander can be reduced.

  According to a third aspect of the present invention, in particular, in the first aspect of the invention, the magnitude of the direct current flowing through the rotating machine is increased with respect to the elapsed time so that the change in the direct current flowing through the rotating machine is continuously smoothed. By doing so, the physical stress given to the mechanism of the expander when restraining the expander can be further reduced.

  According to a fourth aspect of the invention, in particular, in any one of the first to third aspects, an upper limit value set in advance so that the magnitude of the direct current flowing through the rotating machine is smaller than the demagnetizing current of the rotating machine. The demagnetization of the rotating machine can be surely prevented when the expander is restrained.

  According to a fifth aspect of the invention, in particular, in any one of the first to fourth aspects of the invention, the rotating machine control means is applied to the rotating machine, current detecting means for detecting a current flowing in a stator winding of the rotating machine, and the rotating machine. An induced voltage estimating means for estimating an induced voltage generated in the rotating machine from a value of an applied voltage to be detected and a current value detected by the current detecting means, and an induced voltage value estimated by the induced voltage estimating means By providing the rotor position speed detecting means for estimating the rotor magnetic pole position of the rotating machine, it is not necessary to attach a position sensor for detecting the magnetic pole position of the rotor such as an encoder or a resolver, thereby reducing cost and reliability. Can be improved.

  In a sixth aspect of the invention, in particular, in any one of the first to fifth aspects of the invention, while the compressor is in operation, the rotary machine is regeneratively operated by the rotary machine control means to drive power from the expander. By using the recovered power as auxiliary power for driving the compressor, the power of the compressor can be significantly reduced, and energy saving can be achieved.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments.

(Embodiment 1)
FIG. 1 shows a system configuration of a refrigeration cycle apparatus according to a first embodiment of the present invention. This refrigeration cycle is provided between the compressor 1 that compresses the refrigerant, the condenser 3 that condenses the refrigerant, the evaporator 4 that evaporates the refrigerant, and the condenser 3 and the evaporator 4. It is comprised from the expansion turbine 2a of the expander 2 driven, and the expansion turbine 2a is directly connected with the rotary machine 2b via the power shaft 2c.

  Further, AC power from the AC power supply 11 is converted into DC power by the rectifier circuit 12, and after the voltage is smoothed by the smoothing capacitor 13, the DC power is converted into an inverter 16 that converts DC power into AC power, and an operation commander. The compressor is converted into alternating current power by a compressor control unit 15 including an inverter control unit 17 that generates a drive signal for driving the inverter 16 based on the rotation speed command value of the compressor 1 from the unit 14. 1 is driven.

  On the other hand, the expansion turbine 2a driven by the expansion energy of the refrigerant drives the rotating machine 2b via the power shaft 2c to generate AC power. The generated AC power is converted into DC power by the regenerative operation by the rotating machine control device 18 based on the rotational speed command value of the rotating machine 2b from the operation command unit 14, and this DC power is supplied to the compressor 1. In order to be used as auxiliary power for driving, wiring is provided at both ends of the electrolytic capacitor 13.

  Here, in order to satisfy the rotational speed as instructed in the rotating machine control device 18, the target rotational speed (the rotational speed command value of the rotating machine 2b) and the current speed ω (estimated by the rotor magnetic pole position speed detecting means 24). The current error of the estimated speed), the phase current detection values (iu, iv, iw) of the rotating machine 2b detected by the current detectors 20a, 20b and the current detector 21, and the rotor magnetic pole position speed detection. A sine wave drive unit 22 for calculating an applied voltage command value (vu *, vv *, vw *) of the rotating machine 2b from the magnetic pole position θ estimated by the means 24, a current detection value and a voltage command value (vu *, vv). *, Vw *) based on the induced voltage estimator 23 for estimating the induced voltage generated in each phase of the stator winding of the rotating machine 2b, and the induced voltage estimated by the induced voltage estimator 23. Magnetic pole of rotor in machine 2b A rotor position / speed detector 24 that estimates position and speed, a PWM signal generator 25 that converts voltage command values (vu *, vv *, vw *) into drive signals for driving the power converter 19; It is comprised from the power converter 19 which can operate | move as a converter and an inverter.

  Here, when the rotational speed of the rotating machine 2b is controlled by the rotating machine control device 18, since the power running operation or the regenerative operation is performed according to the magnitude of the expansion energy, the rotor of the rotating machine 2b is operated in either operation mode. It must be possible to estimate the magnetic pole position. Hereinafter, after describing the specific operation of the rotating machine control device 18 in the case of the power running operation of the rotating machine 2b, only the difference from the case of the power running operation will be described in the case of the regenerative operation.

  First, in the sine wave drive unit 22, a speed control gain (KPW: proportional to speed control) is set so that the speed error between the rotational speed command value ω * of the rotating machine 2b given from the operation command unit 14 and the estimated speed ω becomes zero. Using the gain, KIW (speed control integral gain), the current command value I * is calculated by the PI control represented by the equation (1).

  Next, the dq-axis current command value (id *, iq *) is obtained by the calculation of the equations (2) and (3) using the calculated current command value I * and the current command phase βT.

  In addition, the phase current command values (iu *, iv *, iw *) of the stator winding are the dq axis current command values (id *, iq *) and the current magnetic pole position θ (rotor magnetic pole position speed estimation means 24). Is obtained by performing two-phase to three-phase conversion by the calculations of Expressions (4) to (6) using the current value of the estimated position estimated by (1). Since the two-phase to three-phase conversion is publicly known, the description thereof is omitted.

  Therefore, the current error between the phase current command value (iu *, iv *, iw *) and the phase current detection value (iu, iv, iw) obtained from the current detectors 20a, 20b and the current detection unit 21 becomes zero. As described above, the voltage command value (vu *, Vk *, KIKn, n = 1, 2, 3 (for three phases)) is controlled by the PI control expressed by the equations (7) to (9). vv *, vw *) is calculated.

  The phase current detection values (iu, iv, iw) are subjected to three-phase to two-phase conversion to obtain dq-axis current detection values (id, iq), and dq-axis current command values (id *, iq *) and dq-axis After obtaining the dq axis voltage command value (vd *, vq *) by PI control so that the current error from the current detection value (id, iq) becomes zero, the dq axis voltage command value (vd *, vq *) The phase voltage command values (vu *, vv *, vw *) may be obtained by performing two-phase to three-phase conversion. Here, since the three-phase to two-phase conversion is also known in the same manner as the two-phase to three-phase conversion, the description thereof is omitted.

  Specifically, the dq-axis current command value (id, iq) is obtained by the calculations of Expressions (10) and (11).

  The dq-axis voltage command values (vd *, vq *) are current control gains (KPD: d-axis current proportional gain, KID: d-axis current integral gain, KPQ: q-axis current proportional gain, KIQ: q-axis current integral gain. ) Is used to calculate the equations (12) and (13).

  Therefore, the phase voltage command values (vu *, vv *, vw *) are calculated by the equations (14) to (16) by performing two-phase to three-phase conversion on the dq-axis voltage command values (vd *, vq *). Is required.

  Next, a method for estimating the induced voltage of the rotating machine 2b according to the first embodiment of the present invention will be described. The induced voltage values (eu, ev, ew) induced in the windings of the respective phases use the phase current detection values (iu, iv, iw) and the phase voltage command values (vu *, vv *, vw *). Is obtained by the calculations of equations (17) to (19).

  Here, R is the resistance per phase of the winding of the rotating machine 2b, and L is its inductance. Further, d (iu) / dt, d (iv) / dt, d (iw) / dt are time derivatives of iu, iv, and iw, respectively, and the following equations are obtained by expanding the equations (17) to (19). obtain.

  Here, R is resistance per winding phase, la is leakage inductance per winding phase, La is an average value of effective inductance per winding phase, and Las is an amplitude of effective inductance per winding phase. It is. D (iu) / dt, d (iv) / dt, and d (iw) / dt are obtained by first-order Euler approximation. Note that the u-phase current iu is obtained by changing the sign of the sum of the v-phase current iv and the w-phase current iw. Furthermore, when Expressions (20) to (22) are simplified, Expressions (23) to (25) shown below are obtained. Here, assuming that the phase current detection values (iu, iv, iw) are sine waves, the phase current detection values (iu, iv, iw) are created from the current command amplitude I * and the current command phase βT. Simplified. In the present embodiment, the induced voltage estimation unit 23 obtains an induced voltage estimated value (eu, ev, ew) from Expressions (23) to (25).

  Next, the rotor position speed estimation unit 24 estimates the magnetic pole position and speed of the rotor in the rotating machine 2b using the induced voltage estimated values (eu, ev, ew). The rotor position / speed estimation unit 24 corrects the estimated position θ recognized by the rotating machine control device 18 by using the error of the induced voltage, thereby obtaining the estimated position θ by converging it to a true value. Also, an estimated speed ω is generated therefrom. Therefore, an induced voltage reference value (eum, evm, ewm) of each phase is obtained by the following equation. However, the induced voltage amplitude value em is obtained by matching the amplitude values of eu, ev, and ew.

  A deviation ε between the induced voltage reference value esm (s = u, v, w (s represents a phase)) thus obtained and the induced voltage estimated value es is obtained. If the deviation ε becomes 0, the estimated value is estimated. Since the position θ becomes a true value, the estimated position θ is obtained by performing PI calculation using the deviation ε so that the deviation ε is converged to zero. Further, the estimated speed ω is obtained by calculating the fluctuation value of the estimated position θ.

  Finally, the PWM signal generation unit 13 converts the drive signal into a drive signal for driving the power converter 19 based on the phase voltage command values (vu *, vv *, vw *) derived by the sine wave drive unit 22. The The power converter 19 is operated by this drive signal.

  Note that by changing the phase of the voltage command values (vu *, vv *, vw *) applied to the rotating machine 2b, it is possible to switch from powering operation to regenerative operation. By using (−βT) instead of the current command phase βT, the magnetic pole position and speed in the rotating machine 2b can be estimated even during regenerative operation. However, when the compressor 1 is driven by the compressor control device 15 and the expansion turbine 2a starts to be driven by the expansion energy, the estimated speed ω increases, so the current command value I * decreases and its sign Since the switching from the power running operation to the regenerative operation is performed at the time of reverse rotation, it is necessary to change the sign of the current command phase βT according to the timing.

  With the above configuration, the rotating machine control device 18 generates the estimated position θ using the deviation ε between the induced voltage estimated value derived from the model based on the phase voltage equation and the induced voltage reference value, and generates a sinusoidal phase current. The position sensorless sine wave drive that enables power running operation and regenerative operation by flowing a flow, and it is not necessary to install a position sensor that detects the magnetic pole position of the rotor, such as an encoder or resolver. Improvements can be made.

  Further, in the rotating machine control device 18 of the refrigeration cycle apparatus in the embodiment of the present invention, as shown in FIG. 2A, a constant direct current is supplied to the rotating machine 2b until a predetermined time elapses immediately after the compressor 1 stops. The expander 2 (expansion turbine 2a) is restrained by continuing to flow the current Is. For example, the phase current command values (iu *, iv *, iw *) of the stator windings are set to iu * = Is, iv * = Iw * = − Is / 2 is set, and voltage command values (vu *, vv *, vw *) necessary for flowing a direct current are derived using the equations (7) to (9). As a result, when the compressor 1 is stopped, the rotational speed of the expander 2 (expansion turbine 2a) continues to increase due to the expansion energy present in the refrigeration cycle, or is obtained by regenerative operation by the rotary machine control device 18. It is possible to prevent the elements such as the power converter 19 from being destroyed due to the stored electric energy.

  Further, in the rotating machine control device 18 of the refrigeration cycle apparatus in the embodiment of the present invention, as shown in FIG. 2B, the direct current is increased stepwise with respect to the time elapsed immediately after the compressor 1 is stopped. It is preferable to do this. As a result, the physical stress applied to the mechanism of the expander 2 (expansion turbine 2a) when the expander 2 (expansion turbine 2a) is constrained is reduced by moderately changing the direct current flowing through the rotating machine 2b. can do.

  In FIG. 2B, the DC current value Is0 (elapsed time T1 or less) → Is1 (elapsed time T2 or less) → Is2 (greater than the elapsed time T2) has three stages, but the number of stages may be further increased. Needless to say.

Further, in the rotating machine control device 18 of the refrigeration cycle apparatus according to the embodiment of the present invention, as shown in FIG. 2C, the direct current is increased in proportion to the time elapsed immediately after the compressor 1 is stopped. It is preferable to do this. As a result, the physical current given to the mechanism of the expander 2 (expansion turbine 2a) when the expander 2 (expansion turbine 2a) is restrained by continuously smoothing the change in the direct current flowing through the rotating machine 2b. The stress can be further reduced than in the case of FIG.

  As shown in FIGS. 2 (a), 2 (b) and 2 (c), the magnitude of the direct current flowing through the rotating machine 2b is previously set to be smaller than the demagnetizing current of the rotating machine 2b. With the set upper limit value, demagnetization of the rotating machine 2b can be surely prevented when the expander 2 (expansion turbine 2a) is restrained.

  Further, after the compressor 1 is started by the compressor control device 15, the rotator 2 b is regeneratively operated by the rotator control device 18 to recover power from the expander 2, and the recovered power is used as the compressor 1. By using it as auxiliary power for driving the compressor 1, the power of the compressor 1 can be greatly reduced, and energy saving can be achieved.

  In FIG. 1, the two current detectors 20a and 20b for detecting the current of the rotating machine 2b are provided and used for estimating the magnetic pole position and speed of the rotor. Needless to say, a means for detecting the current of the rotating machine 2b from the current flowing in the wiring between the device 19 and the smoothing capacitor 13 may be used.

  In FIG. 1, the rotational speed control is performed so that the rotational speed of the rotating machine 2 b follows the rotational speed command value of the rotating machine 2 b given from the operation command unit 14. Needless to say, the torque may be controlled.

  As described above, the refrigeration cycle apparatus according to the present invention controls the rotational speed of the rotating machine by estimating the magnetic pole position of the rotor of the rotating machine provided in the expander, and has reliability including stopping. Since the drive of a high expander is realizable, it can apply also to products, such as a heat pump type water heater of a carbon dioxide refrigerant.

The system block diagram of the refrigerating-cycle apparatus in embodiment of this invention (A) Operation explanatory diagram of the rotating machine control device of the refrigeration cycle apparatus in the embodiment of the present invention (b) Operation explanatory diagram of the rotating machine control device of the refrigeration cycle apparatus in the embodiment of the present invention (c) Explanatory drawing of operation | movement of the rotary machine control apparatus of the refrigerating-cycle apparatus in embodiment System configuration diagram of conventional refrigeration cycle equipment System configuration diagram of conventional wind power generation system

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Expander 2a Expansion turbine 2b Rotating machine 2c Power shaft 2d Generator 3 Condenser 4 Evaporator 11 AC power supply 12 Rectifier circuit 13 Smoothing capacitor 14 Operation command part 15 Compressor control device 16 Inverter 17 Inverter control part 18 Rotation Machine control device 19 Power converter 20 a, 20 b Current detector 21 Current detection unit 22 Sine wave drive unit 23 Induced voltage estimation unit 24 Rotor position speed detection unit 25 PWM signal generation unit 26 Abnormality determination unit 31 First converter 32 First 2 converters 41 windmills 42 interior magnet synchronous generator (IPMSG)
43 PWM converter 44 Position / speed estimation unit 45 Maximum power tracking control unit 46 Maximum efficiency control unit 47 Voltage command generation unit

Claims (6)

A compressor that compresses the refrigerant; a condenser that condenses the refrigerant; an evaporator that evaporates the refrigerant; an expander that is provided between the condenser and the evaporator and is driven by the expansion energy of the refrigerant; A power converter capable of operating as a converter and a reverse converter, and comprising a rotating machine control means for controlling the number of rotations of the rotating machine directly connected to the expander via a power shaft, and the compressor is stopped A refrigeration cycle apparatus that restrains the expander by causing a direct current to flow through the rotating machine by the rotating machine control means until a predetermined time elapses immediately thereafter. The refrigeration cycle apparatus according to claim 1, wherein a magnitude of a direct current flowing through the rotating machine is increased stepwise with respect to an elapsed time. The refrigeration cycle apparatus according to claim 1, wherein a magnitude of a direct current flowing through the rotating machine is increased with respect to an elapsed time. The magnitude | size of the direct current which flows into the said rotary machine is provided with the preset upper limit so that it may become smaller than the demagnetizing current of the said rotary machine, The any one of Claims 1-3 characterized by the above-mentioned. Refrigeration cycle equipment. The rotating machine control means includes a current detecting means for detecting a current flowing in a stator winding of the rotating machine, an applied voltage value applied to the rotating machine, and a current value detected by the current detecting means. Induced voltage estimating means for estimating the induced voltage generated in the rotating machine, and rotor position speed detecting means for estimating the rotor magnetic pole position of the rotating machine based on the induced voltage value estimated by the induced voltage estimating means. The refrigeration cycle apparatus according to any one of claims 1 to 4, wherein the refrigeration cycle apparatus is provided. While the compressor is operating, auxiliary power for driving the compressor by recovering power from the expander by regenerating the rotating machine by the rotating machine control means. The refrigeration cycle apparatus according to claim 1, wherein the refrigeration cycle apparatus is used as a refrigeration cycle apparatus.

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