JP5531112B2 - Air conditioner, hot water supply system - Google Patents

Description

  The present invention relates to an air conditioner and a hot water supply system.

  Conventionally, the compressor is started by energizing an electric heater attached to the container containing the compressor or by causing a current to flow through the compressor motor with a low voltage that does not allow the compressor motor to rotate. There is known an air conditioner in which a refrigerant is heated before (see Patent Document 1).

Japanese Patent Laid-Open No. 11-94371

  In the air conditioner described in Patent Document 1, a large electric heater must be installed to heat the refrigerant.

The air conditioner according to the first aspect of the present invention performs at least a heating operation for heating a room, and includes an indoor heat exchanger installed indoors and an outdoor heat exchange installed outdoor. A compressor that compresses the refrigerant circulated between the indoor heat exchanger and the outdoor heat exchanger, a motor that drives the compressor, and a switching element that conducts or interrupts DC power. And an inverter circuit that generates AC power for supplying the motor from the DC power using the switching element, and a control that outputs a drive signal for controlling the operation of the switching element to the inverter circuit based on the rotation speed command. Circuit. In this air conditioner, the control circuit can select any one of a plurality of operation modes including at least a quick heating operation mode for rapid heating and a normal operation mode during the heating operation. Further, in the quick warming operation mode, the control circuit obtains the phase position of the AC power through which the switching element is conducted, outputs a drive signal based on the obtained phase position, and reduces the difference between the predetermined set temperature and room temperature. The phase position of the alternating current power at which the switching element is conducted is changed so that higher order harmonic components are removed from the alternating current power .
According to a second aspect of the present invention, in the air conditioner of the first aspect, when you start the heating operation, after the control circuit selects the Hayadan operation mode was selected Hayadan operation mode, setting When the difference between the temperature and the room temperature falls within a predetermined range, the control circuit preferably selects the normal operation mode.
According to a third aspect of the present invention, in the air conditioner of the first or second aspect, in the normal operation mode, the control circuit may be outputted a drive signal based on the PWM control.
According to the fourth aspect of the present invention, in the air conditioner of any one of the first to third aspects, the current value of the reactive current flowing through the motor in the quick warming operation mode is set to the reactive current flowing through the motor in the normal operation mode. it is preferably greater than the current value Kusuru.
According to the fifth aspect of the present invention, the air conditioner according to any one of the first to fourth aspects further includes a four-way valve that switches a circulation direction of the refrigerant. In this air conditioner, the plurality of operation modes further include a defrosting operation mode for defrosting the outdoor heat exchanger. When the defrosting operation mode is selected by the control circuit, the four-way valve switches the circulation direction of the refrigerant in a direction opposite to the quick warming operation mode and the normal operation mode. In the defrosting operation mode, the control circuit obtains the phase position of AC power through which the switching element is conducted, and outputs a drive signal based on the obtained phase position . You may do this.
According to a sixth aspect of the present invention, in the air conditioner of the fifth aspect, the current value of the reactive current flowing through the motor in the defrosting operation mode, much larger than the current value of the reactive current flowing through the motor in the normal operating mode It is preferable to do.
A hot water supply system according to a seventh aspect of the present invention is connected to a water pipe, a first heat exchanger that warms the water flowing in the water pipe, a hot water storage tank that stores water warmed by the first heat exchanger, A second heat exchanger that absorbs heat from the outside air to warm water by the first heat exchanger, a compressor that compresses a refrigerant circulated between the first heat exchanger and the second heat exchanger, A motor for driving the compressor, a switching element for conducting or blocking DC power, an inverter circuit for generating AC power for supplying the DC power to the motor using the switching element, and a rotational speed command And a control circuit for outputting a drive signal for controlling the operation of the switching element to the inverter circuit. In this hot water supply system, the control circuit can select any one of a plurality of operation modes including at least a rapid hot water supply operation mode for warming water and a normal operation mode . Further, in the rapid hot water supply operation mode, the control circuit obtains the phase position of the alternating current power at which the switching element is conducted, outputs a drive signal based on the obtained phase position, and the alternating current power increases as the temperature of the water or the outside air temperature increases. The phase position of the alternating current power through which the switching element is conducted is changed so that a higher order harmonic component is removed in FIG .
According to the eighth aspect of the present invention, in the hot water supply system according to the seventh aspect, the control circuit is configured to switch between the rapid hot water supply operation mode and the normal operation mode based on at least one of water temperature, outside air temperature, and time. It is preferable to select at least one of them.
According to a ninth aspect of the present invention, the hot water system of the seventh or eighth aspect, if you select the normal operation mode, the control circuit may be outputted a drive signal based on the PWM control.
According to the tenth aspect of the present invention, in the hot water supply system according to any one of the seventh to ninth aspects, the control circuit can output a drive signal so that a predetermined reactive current flows through the motor in the rapid hot water supply operation mode. it can.
According to an eleventh aspect of the present invention, in the hot water supply system according to the tenth aspect, the control circuit includes a second threshold value where the temperature of water is lower than the predetermined first threshold value and the outside air temperature is predetermined. If the water temperature is less than the predetermined third threshold and the time is within the predetermined time zone, the drive signal is sent so that the reactive current flows through the motor in the rapid hot water supply operation mode. It is preferable to output .

  According to the present invention, an electric heater or the like can be significantly reduced in size. Alternatively, there is no need to add an electric heater and parts related to the electric heater.

It is a figure which shows the structure of an air conditioner. It is a figure which shows the structure of a motor control apparatus. It is a figure which shows the structure of a control circuit. It is a principle explanatory view of harmonic deletion. It is a flowchart which shows the basic principle of a harmonic deletion. It is a figure which shows the production | generation process and characteristic of a line voltage pattern. It is a figure which shows the structure of a 1st pulse modulator. It is a figure which shows the structure of a pulse generator. It is a flowchart of a table search type pulse generation procedure. It is a flowchart of a real-time arithmetic pulse generation procedure. It is a flowchart of a pulse pattern calculation. It is a figure which shows the generation method of the pulse by a phase counter. It is a figure which shows the change with respect to the modulation degree of a line voltage waveform. It is a figure which shows the conversion table | surface of a line voltage and a phase terminal voltage. It is a figure which shows the example of conversion from a line voltage pulse to a phase terminal voltage pulse. It is a figure which shows the change of an electricity supply system, a motor rotation speed, and room temperature. It is a figure which shows the difference in the motor current waveform by the electricity supply method. It is a figure which shows the change of the room temperature and heat generation amount in the case of performing a defrost operation. It is a figure which shows operation | movement of the refrigerating cycle at the time of heating operation, air_conditionaing | cooling operation, and defrost operation. It is a figure which shows the relationship between the motor rotation speed at the time of a defrost operation, and d-axis current. It is a figure which shows the relationship between external temperature, a motor rotation speed, and an electricity supply method. It is a figure which shows switching of a control mode. It is a figure which shows a mode that PWM control mode and PHM control mode were switched. It is a figure which shows the external appearance of the control circuit comprised by HIC. It is a figure which shows the external appearance which modularized and combined the control circuit and the inverter circuit. It is a figure which shows the structure of a heat pump type hot-water supply system. It is a figure which shows the change of an electricity supply system, motor rotation speed, and water temperature. It is a figure which shows the relationship between external temperature, water temperature, and an electricity supply method. It is a figure which shows the relationship between time, water temperature, and the electricity supply method. It is a figure which shows the structure of a 2nd pulse modulator. It is a figure which shows the detail of an inverter circuit.

-First embodiment-
An air conditioner according to an embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a diagram illustrating a configuration of an air conditioner 300 according to an embodiment. The air conditioner 300 includes an indoor unit housing 301, a heat exchanger 302, a fan 303, an input circuit 304, an outdoor unit housing 305, a heat exchanger 306, a fan 307, a compressor 308, a compressor motor 309, and a four-way valve. 310, a motor control device 311 and a pipe 312 are provided.

  The heat exchanger 302, the fan 303 and the input circuit 304 are accommodated in the indoor unit housing 301. These are installed as indoor units in a room such as a building. On the other hand, the heat exchanger 306, the fan 307, the compressor 308, the compressor motor 309, the four-way valve 310, and the motor control device 311 are housed in the outdoor unit housing 305. These are installed as outdoor units outside a building or the like.

  A pipe 312 is provided between the heat exchanger 302 of the indoor unit and the heat exchanger 306 of the outdoor unit. The pipe 312 is connected to the compressor 308 via the four-way valve 310. The piping 312 is filled with a refrigerant. The compressor 308 is driven by a compressor motor 309 and compresses the refrigerant. The operation of the compressor motor 309 is controlled by a motor control device 311.

  The refrigerant compressed by the compressor 308 becomes a high temperature and high pressure state, passes through the pipe 312, and is sent to the heat exchanger 302 of the indoor unit during heating. In the indoor unit, heat accumulated in the refrigerant is dissipated in the heat exchanger 302, and warm air is blown into the room by the fan 303. The refrigerant that has become liquid due to heat dissipation is sent to the heat exchanger 306 of the outdoor unit. The heat exchanger 306 absorbs the heat of vaporization from the outside air and then returns to the compressor 308 as a gas. In this way, the refrigerant is circulated between the heat exchanger 302 and the heat exchanger 306, whereby the air conditioner 300 performs the heating operation.

  On the other hand, at the time of cooling, the refrigerant is circulated in the opposite direction to that at the time of heating. That is, the refrigerant compressed by the compressor 308 is sent to the heat exchanger 306 of the outdoor unit. In the outdoor unit, the heat accumulated in the refrigerant is radiated in the heat exchanger 306. The refrigerant that has become liquid due to heat dissipation is sent to the heat exchanger 302 of the indoor unit. The heat exchanger 302 absorbs the heat of vaporization from the indoor air and then returns to the compressor 308 as a gas. In this manner, the refrigerant is circulated between the heat exchanger 302 and the heat exchanger 306, whereby the air conditioner 300 performs a cooling operation.

  The switching of the refrigerant circulation direction during heating and cooling as described above is performed by the four-way valve 310. That is, at the time of heating, the refrigerant compressed in the compressor 308 is discharged to the heat exchanger 302 of the indoor unit, and then returns to the compressor 308 through the heat exchanger 306 of the outdoor unit. The state of can be switched. On the other hand, at the time of cooling, the refrigerant compressed in the compressor 308 is discharged to the heat exchanger 306 of the outdoor unit, and then returns to the compressor 308 through the heat exchanger 302 of the indoor unit. The state of 310 is switched.

  When a user operates a remote controller or the like to input an operation command to the input circuit 304 of the indoor unit, the input circuit 304 performs heating operation and cooling operation based on the operation command and information such as room temperature. While selecting either, the rotational speed of the compressor motor 309 is calculated. Then, the four-way valve 310 is switched according to the selected operating state, and a speed command corresponding to the calculated rotational speed is transmitted to the motor control device 311. The motor control device 311 controls the operation of the compressor motor 309 based on the speed command received from the input circuit 304, and causes the air conditioner 300 to perform a heating operation or a cooling operation.

  FIG. 2 is a diagram illustrating a configuration of the motor control device 311. The motor control device 311 includes a DC power source 1, an inverter circuit 2, a current detector 4, a voltage detector 5, and a control circuit 6, and is connected to a compressor motor 309.

  The DC power source 1 is configured by a known converter device using a rectifier circuit or the like, and generates predetermined DC power from a commercial AC power source and supplies it to the inverter circuit 2. The voltage of the DC power generated by the DC power source 1 is detected by the voltage detector 5 and output to the control circuit 6.

  The inverter circuit 2 has a switching element for conducting or interrupting the DC power output from the DC power source 1. The inverter circuit 2 generates AC power from the DC power using the switching element, and supplies the AC power to the compressor motor 309. Supply. For example, when the compressor motor 309 is a three-phase AC motor, the inverter circuit 2 has one or more switching elements for each phase. The operation of each switching element is controlled by a drive signal from the control circuit 6.

  The details of the inverter circuit 2 are shown in FIG. Here, a three-phase inverter will be described as an example. The inverter circuit 2 includes a switching element 151 and a diode 152 that operate as an upper arm, and a switching element 161 and a diode 162 that operate as a lower arm. Series circuit 150 in which the upper arm and the lower arm are connected in series constitutes each phase (U phase, V phase, W phase) of inverter circuit 2. Based on the drive signal output from the control circuit 6, the switching elements 151 and 161 are driven to supply power to the compressor motor 309 from an intermediate connection point between the upper arm and the lower arm.

  The current value of the AC power supplied from the inverter circuit 2 to the compressor motor 309 is detected for each phase by the current detector 4, and a signal indicating the detection result is output from the current detector 4 to the control circuit 6. The When the compressor motor 309 is a three-phase AC motor, only the current value of the two phases is detected by the current detector 4, and the current value of the other one phase is estimated based on these detection results. Good.

  Based on the speed command from the input circuit 304 and the current value of the AC power detected by the current detector 4, the control circuit 6 inverts drive signals for controlling the operation of each switching element of the inverter circuit 2. Output to circuit 2. In response to the drive signal, each switching element of the inverter circuit 2 is repeatedly turned on or off, whereby the DC power from the DC power source 1 is converted into AC power and supplied to the compressor motor 309. The compressor motor 309 drives the compressor 308 using this AC power, whereby the refrigerant is compressed in the compressor 308, and the heating operation or the cooling operation according to the operation command is performed.

  FIG. 3 is a diagram illustrating a configuration of the control circuit 6. The control circuit 6 includes a d-axis current command generator 61, a speed controller 62, a voltage command calculator 63, a first pulse modulator 64 and a second pulse modulator 65, a speed / phase estimator 66, a three-phase / 2-phase. A converter 67 and a switch 68 are included. In FIG. 3, the compressor motor 309 is a three-phase AC motor, and phase current detection signals lu, lv, and lw detected for each of the U phase, V phase, and W phase are supplied from the current detector 4 to the control circuit. 6 shows an example of input to 6.

The phase current detection signals lu, lv, and lw input to the control circuit 6 are converted into a d-axis current signal Idc and a q-axis current signal Iqc by a three-phase / two-phase converter 67, and the voltage command calculator 63 and the speed / Each is output to the phase estimator 66.

  When a speed command (rotational speed command) f1 * is input from the input circuit 304 to the control circuit 6, a deviation between the speed command f1 * and the rotational speed f1 output from the speed / phase estimator 66 is calculated. The result is output to the speed controller 62. The speed controller 62 generates a q-axis current command signal Iqc * based on the deviation between the speed command f1 * and the rotational speed f1, and outputs the q-axis current command signal Iqc * to the voltage command calculator 63. On the other hand, the d-axis current command generator 61 generates a predetermined d-axis current command signal Idc * and outputs it to the voltage command calculator 63. Note that the value of the d-axis current command signal Idc * generated by the d-axis current command generator 61 is 0 in a normal state.

  The voltage command calculator 63 is based on the d-axis current command signal Idc * from the d-axis current command generator 61 and the q-axis current command signal Iqc * from the speed controller 62. And q-axis voltage command signal Vqc *. At this time, the voltage command calculator 63 causes the d-axis voltage command signal Vdc * and the q-axis so that the actual current flowing through the compressor motor 309 follows the d-axis current command signal Idc * and the q-axis current command signal Iqc *. Obtain the voltage command signal Vqc *. The calculated d-axis voltage command signal Vdc * and q-axis voltage command signal Vqc * are output from the voltage command calculator 63 to the first pulse modulator 64, the second pulse modulator 65, and the speed / phase estimator 66. .

  The speed / phase estimator 66 includes a d-axis current signal Idc and a q-axis current signal Iqc from the three-phase / two-phase converter 67, and a d-axis voltage command signal Vdc * and a q-axis voltage command from the voltage command calculator 63. Based on the signal Vqc *, the rotational speed and voltage phase of the compressor motor 309 are estimated. Based on these estimation results, the rotational speed f1 is output to the preceding stage of the speed controller 62 and the first pulse modulator 64, and the phase signal θdc is output to the first pulse modulator 64, the second pulse modulator 65, and Output to the three-phase / two-phase converter 67.

  The pulse modulator 64 is based on the d-axis voltage command signal Vdc * and q-axis voltage command signal Vqc * from the voltage command calculator 63, and the rotational speed f1 and phase signal θdc from the speed / phase estimator 66. A pulse signal corresponding to the timing at which each switching element of the inverter circuit 2 is turned on or off is generated and output to the switch 68. At this time, the first pulse modulator 64 performs the switching operation of each switching element based on the phase of the AC waveform so that AC power in which the harmonic component of the rectangular AC current is reduced to some extent is output from the inverter circuit 2. A pulse signal for control is generated. In the following description, the pulse signal output from the first pulse modulator 64 is referred to as a PHM pulse signal. A control method performed using the PHM pulse signal is referred to as PHM control.

  On the other hand, the second pulse modulator 65 is based on the d-axis voltage command signal Vdc * and q-axis voltage command signal Vqc * from the voltage command calculator 63 and the phase signal θdc from the speed / phase estimator 66. A pulse signal corresponding to the timing at which each switching element of the inverter circuit 2 is turned on or off is generated by a known PWM (Pulse Width Modulation) method, and is output to the switch 68. In the following description, the pulse signal output from the second pulse modulator 65 is referred to as a PWM pulse signal.

Details of the second pulse modulator 65 will be described with reference to FIG. The second pulse modulator 65 includes a two-phase / three-phase converter 651, a comparator 652, and a carrier wave generator 653. The d-axis voltage command signal and the q-axis voltage command signal output from the voltage command calculator are input to the two-phase / three-phase converter 651, and the AC waveform three-phase voltage command signals V _U *, V _V *, V Convert to _W *. The three-phase voltage command signals V _U *, V _V *, and V _W * are output to the comparison circuit 652. The comparison circuit 652 compares the three-phase voltage command signals V _U *, V _V *, and V _W * with the triangular carrier wave output from the carrier wave generator 653, and outputs a PWM pulse signal that drives the switching element. .

  The switch 68 selects either the PHM pulse signal output from the first pulse modulator 64 for PHM control or the PWM pulse signal output from the second pulse modulator 65 for PWM control. Note that which pulse signal the switch 68 selects will be described in detail later. The PHM pulse signal or PWM pulse signal selected by the switch 68 is output to the inverter circuit 2 as a drive signal.

  As described above, a PHM pulse signal or a PWM pulse signal is output as a drive signal from the control circuit 6 to the inverter circuit 2. In response to the drive signal, each switching element of the inverter circuit 2 is turned on or off to convert the DC power from the DC power source 1 into AC power.

  Next, a method for generating a PHM pulse signal by the first pulse modulator 64 for PHM control will be described. 4 (a), 4 (b), and 4 (c) are diagrams for explaining the basic principle of deleting a harmonic component by a PHM pulse signal.

  The control method having the smallest number of switching times per unit phase when converting DC power to AC power is rectangular wave control. In this rectangular wave control state, as shown in FIG. 4A, switching is performed once in a half cycle, that is, twice in one cycle. In such a rectangular wave control, the number of times of switching is significantly smaller than in the PWM method, so that the loss due to switching is greatly reduced. However, on the other hand, the AC power waveform contains many harmonic components such as fifth order, seventh order, and eleventh order, and these harmonic components cause distortion. Therefore, in order to reduce distortion due to harmonics, it is desirable to increase the number of switching times of the switching element as compared with the state of the rectangular wave control shown in FIG. The harmonic components to be removed at this time vary depending on the purpose of use of the AC power to be converted, but it is not necessary to remove all the harmonic components. Therefore, the number of times of switching is reduced as compared with the PWM method. For example, in AC power supplied to a three-phase rotating electrical machine, harmonic components that are multiples of 3 cancel each other out, so that it does not become a big problem even if it is not removed.

  The removal of the above harmonic components will be described below by taking a method of removing the fifth harmonic component as an example. As shown in FIGS. 4A and 4B, the fifth-order harmonic component is a vibration waveform having a peak value of five times in a period of an electrical angle π that is a half cycle of the AC power waveform. The rectangular wave shown in FIG. 4A includes a number of harmonic components obtained by Fourier expansion in addition to the sine wave, and one of the harmonic components is the fifth harmonic component. This fifth-order harmonic component is superimposed for each unit phase, for example, every half cycle, as shown in FIG. Of course, when the superimposed waveform is Fourier-expanded, it becomes the above-mentioned fifth harmonic.

  When erasing the fifth harmonic component included in the rectangular wave, it is desirable to erase all the harmonics to be deleted from the viewpoint of reducing the number of switching times as much as possible. Therefore, as shown in FIG. 4 (b), the first pulse modulator 64 is configured so as to obtain an AC power waveform obtained by deleting a superimposed waveform having the same area as the fifth harmonic component included in the rectangular wave at a specific position. To generate a PHM pulse signal. Note that in the AC power waveform of FIG. 4B, the superposed waveform combined into one every half cycle is deleted. By doing in this way, the frequency | count of switching when deleting a 5th-order harmonic component from a rectangular wave can be decreased.

  FIG. 4C is a waveform of a PHM pulse signal for generating the AC power waveform shown in FIG. When such a PHM pulse signal is generated by the first pulse modulator 64 and the switching element of the inverter circuit 2 is operated according to the PHM pulse signal, the AC power having a waveform as shown in FIG. 2 is output. As a result, AC power from which the fifth-order harmonic component has been deleted is supplied from the inverter circuit 2 to the compressor motor 309.

  Other harmonic components can be deleted by the same method. FIG. 5 is a flowchart showing the basic principle of deleting each harmonic component. Here, Fourier series expansion is performed with the line voltage waveform as f (ωt), and each of f (ωt) = − f (ωt + π) and f (ωt) = f (π−ωt) due to the symmetry of the pulse waveform. This shows that the PHM pulse signal can be generated by considering the conditions. That is, the pulse pattern of the PHM pulse signal can be obtained by solving an equation in which a harmonic order component to be deleted by Fourier series expansion of f (ωt) is zero.

  FIG. 6 is a diagram showing, as an example, a generation process and characteristics of a pulse waveform pattern in the U-phase and V-phase line voltages for eliminating the third, fifth, and seventh harmonics. However, the line voltage is the potential difference between the terminals of each phase. If the phase voltage of the U phase is Vu and the phase voltage of the V phase is Vv, the line voltage Vuv of the U phase and the V phase is Vuv = Vu−Vv. Represented. Since the V-line and W-phase line voltages and the W-phase and U-phase line voltages are the same, generation of line-voltage patterns between the U-phase and the V-phase will be described below as a representative example.

  The horizontal axis of FIG. 6 represents the phase based on the fundamental wave of the U-phase and V-phase line voltage. Hereinafter, this is referred to as a UV inter-line voltage reference phase θuvl. This UV line voltage reference phase θuvl corresponds to the electrical angle shown on the horizontal axis of FIGS. 4 (a) and 4 (c). Note that the pulse waveform pattern in the section of π ≦ θuvl ≦ 2π is a symmetrical shape obtained by vertically inverting the pulse waveform pattern in the section of 0 ≦ θuvl ≦ π shown in the figure, and therefore is omitted in FIG.

  As shown in FIG. 6, the fundamental wave of the voltage pulse is a sine wave voltage with θuvl as a reference. The pulses to be generated are respectively arranged at positions as illustrated in the figure with respect to θuvl according to the procedure shown in the figure centering on π / 2 of the fundamental wave. Here, since θuvl corresponds to the electrical angle as described above, the pulse arrangement position in FIG. 6 can be represented by the electrical angle. Therefore, hereinafter, the arrangement position of this pulse is defined as a specific electrical angle position. As a result, pulse trains S1 to S4 and S1 'to S2' are formed. This pulse train has a spectral distribution that does not include the third, fifth, and seventh harmonics of the fundamental wave. In other words, this pulse train is a waveform obtained by removing the third, fifth, and seventh harmonics from the rectangular wave in the interval of 0 ≦ θuvl ≦ 2π. The order of the harmonics to be deleted can be other than the third, fifth, and seventh orders.

  The configuration of the first pulse modulator 64 for PHM control is shown in FIG. The first pulse modulator 64 includes a voltage phase difference calculator 641, a modulation degree calculator 642, and a pulse generator 644. The d-axis voltage command signal Vdc * and the q-axis voltage command signal Vqc * output from the voltage command calculator 63 are input to the voltage phase difference calculator 641 and the modulation factor calculator 642 in the first pulse modulator 64.

The voltage phase difference calculator 641 calculates the phase difference between the voltage phase represented by the d-axis voltage command signal Vdc * and the voltage phase represented by the q-axis voltage command signal Vqc *. When this voltage phase difference is δ, the voltage phase difference δ is expressed by Expression (1).
δ = arctan (-Vdc * / Vdc *) (1)

The voltage phase difference δ calculated by the voltage phase difference calculator 641 is added to the phase signal θdc from the speed / phase estimator 66 and then output to the pulse generator 644 as the voltage phase signal θv. The voltage phase signal θv is expressed by Expression (2) when the rotor phase angle represented by the phase signal θdc is θre.
θv = δ + θre (2)

The modulation factor calculator 642 calculates the modulation factor by normalizing the magnitudes of the vectors represented by the d-axis voltage command signal Vdc * and the q-axis voltage command signal Vqc * with the voltage of the DC power supply 1, and determines the modulation factor. A corresponding modulation degree signal a is output to the pulse generator 644. In this embodiment, the modulation factor signal a is determined based on the voltage of the DC power source 1, and the modulation factor a tends to decrease as the voltage increases. Further, as the amplitude value of the command value increases, the degree of modulation a tends to increase. More specifically, when the voltage of the DC power supply 1 is Vdc, it is expressed by Expression (3). In equation (3), Vd represents the amplitude value of the d-axis voltage command signal Vdc *, and Vq represents the amplitude value of the q-axis voltage command signal Vqc *.
a = (√ (Vd ^ 2 + Vq ^ 2)) / Vdc (3)

  The pulse generator 644 includes a voltage phase signal θv obtained by adding the phase signal θdc to the voltage phase difference δ output from the voltage phase difference calculator 641, the modulation degree signal a from the modulation degree calculator 642, and Based on the rotation speed f1 from the speed / phase estimator 66, pulse signals based on PHM control corresponding to the U phase, the V phase, and the W phase are generated. Then, the generated pulse signal is output to the switch 68.

  The pulse generator 644 is realized by a phase searcher 645 and a timer counter comparator 646, for example, as shown in FIG. Based on the voltage phase signal θv, the modulation degree signal a, and the rotational speed f1, the phase searcher 645 determines the phase from which the switching pulse is to be output from the U-phase, V-phase, Each phase of the W phase is searched, and information on the search result is output to the timer counter comparator 646. The timer counter comparator 646 generates a PHM pulse signal as a switching command for each of the U phase, the V phase, and the W phase based on the search result output from the phase search unit 645. The PHM pulse signal for each phase generated by the timer counter comparator 646 is output to the switch 68 as described above.

  FIG. 9 is a flowchart illustrating in detail the procedure of pulse generation by the phase searcher 645 and the timer counter comparator 646 of FIG. The phase searcher 645 captures the modulation degree signal a as an input signal in step 801 and captures the voltage phase signal θv as an input signal in step 802. In the subsequent step 803, the phase searcher 645 calculates the voltage phase range corresponding to the next control period in consideration of the control delay time and the rotational speed f1, based on the input current voltage phase signal θv. . Thereafter, in step 804, the phase searcher 645 performs a ROM search. In this ROM search, switching on and off phases are searched from a table stored in advance in a ROM (not shown) within the voltage phase range calculated in step 803 based on the input modulation degree signal a. .

  The phase searcher 645 outputs the information on the switching ON / OFF phase obtained by the ROM search in step 804 to the timer counter comparator 646 in step 805. The timer counter comparator 646 converts this phase information into time information in step 806, and generates a PHM pulse signal using a compare match function with the timer counter. The process of converting the phase information into time information uses the rotational speed f1. Alternatively, the PHM pulse may be generated by using the comparison match function with the phase counter in step 806 based on the information on the switching ON / OFF phase obtained by the ROM search in step 804.

  The timer counter comparator 646 outputs the PHM pulse signal generated at step 806 to the switch 68 at the next step 807. The processes in steps 801 to 807 described above are performed in the phase searcher 645 and the timer counter comparator 646, whereby a PHM pulse signal is generated in the pulse generator 644.

  Alternatively, instead of the flowchart of FIG. 9, pulse generation may be performed by executing the processing shown in the flowchart of FIG. 10 in the pulse generator 644. In this process, as shown in the flowchart of FIG. 9, a switching phase is generated for each control cycle of the voltage command calculator 63 without using a table search method for searching a switching phase using a table stored in advance. It is.

  The pulse generator 644 receives the modulation degree signal a in step 801 and the voltage phase signal θv in step 802. In the following step 820, the pulse generator 644 calculates the voltage on / off phase of switching based on the input modulation degree signal a and the voltage phase signal θv in consideration of the control delay time and the rotation speed f1. A pulse pattern calculation for determining each control period of the device 63 is performed. Then, the phase information obtained based on the rotation speed f1 is converted into time information, and a PHM pulse signal is generated using a compare match function with a timer counter or a phase counter. The generated PHM pulse signal is output to the switch 68 at step 807.

  Details of the pulse pattern calculation in step 820 are shown in the flowchart of FIG. In step 821, the pulse generator 644 designates the harmonic order to be deleted based on the rotational speed f1. In accordance with the harmonic order thus designated, the pulse generator 644 performs processing such as matrix calculation in the subsequent step 822, and outputs the pulse reference angle in step 823.

  The matrix operation in step 822 is performed according to the determinants expressed by the following equations (4) to (7).

  Here, as an example, the case of eliminating the third, fifth, and seventh order components is taken up.

  When the third, fifth, and seventh harmonic components are specified in step 821 as the harmonic orders to be deleted, the pulse generator 644 performs matrix calculation in the next step 822.

  Here, a row vector like Formula (4) is created with respect to the 3rd, 5th, and 7th erasure orders.

・・・（４）

... (4)

  Each element in the right parenthesis of Equation (4) is k1 / 3, k2 / 5, and k3 / 7. Any odd number can be selected for k1, k2, and k3. However, k1 = 3, 9, 15, k2 = 5, 15, 25, k3 = 7, 21, 35, etc. must not be selected. Under this condition, the third, fifth and seventh order components are completely eliminated.

  In more general terms, the value of each element of Equation (4) is determined by setting the harmonic order from which the denominator value is deleted and the numerator value being an arbitrary odd number excluding an odd multiple of the denominator. be able to. Here, in the example of Expression (4), the number of elements in the row vector is three because there are three types of erasure orders (third order, fifth order, and seventh order). Similarly, a row vector having N elements can be set for N types of erasure orders, and the value of each element can be determined.

  In Equation (4), by setting the numerator and denominator values of each element other than those described above, the spectrum can be shaped instead of deleting the harmonic component. Therefore, the numerator and denominator values of each element may be arbitrarily selected for the main purpose of spectrum shaping rather than elimination of harmonic components. In that case, the numerator and denominator values do not necessarily have to be integers, but the numerator value should not be an odd multiple of the denominator. Further, the values of the numerator and denominator need not be constants, and may be values that change according to time.

  As described above, when there are three elements whose values are determined by the combination of the denominator and the numerator, a vector of three columns can be set as shown in Equation (4). Similarly, a vector of N elements whose value is determined by a combination of a denominator and a numerator, that is, a vector of N columns can be set. Hereinafter, this N-column vector is referred to as a harmonic-based phase vector.

  When the harmonic compliant phase vector is a three-column vector as shown in equation (4), the harmonic compliant phase vector is transposed and the calculation of equation (5) is performed. As a result, pulse reference angles from S1 to S4 are obtained.

  The pulse reference angles S1 to S4 are parameters representing the center position of the voltage pulse, and are compared with a triangular wave carrier described later. As described above, when the pulse reference angle is four (S1 to S4), generally, the number of pulses per one cycle of the line voltage is 16.

・・・（５）

... (5)

  Further, when the harmonic compliant phase vector is four columns as in the equation (6) instead of the equation (4), the matrix calculation equation (7) is applied.

・・・（６）

... (6)

・・・（７）

... (7)

  As a result, pulse reference angles from S1 to S8 are obtained. At this time, the number of pulses per cycle of the line voltage is 32.

  The relationship between the number of harmonic components to be deleted and the number of pulses is generally as follows. That is, when there are two harmonic components to be deleted, the number of pulses per cycle of the line voltage is 8 pulses, and when there are 3 harmonic components to be deleted, the number of pulses per cycle of the line voltage Is 16 pulses, and when there are 4 harmonic components to be deleted, the number of pulses per cycle of the line voltage is 32 pulses, and when there are 5 harmonic components to be deleted, one cycle of the line voltage The number of hits is 64 pulses. Similarly, as the number of harmonic components to be deleted increases by one, the number of pulses per cycle of the line voltage doubles.

  However, in the case of a pulse arrangement in which a positive pulse and a negative pulse are overlapped by a line voltage, the number of pulses may be different from the above.

  When the pulse reference angle is obtained by the matrix operation described above, the pulse generator 644 outputs the pulse reference angle in step 823. In the next step 824, the output pulse reference angle is compared with a triangular wave, thereby obtaining pulse waveforms of three types of line voltages, UV line voltage, VW line voltage, and WU line voltage, respectively. The pulse waveforms of these line voltages are the same pulse waveform having a phase difference of 2π / 3. Therefore, only the UV line voltage will be described below as a representative of each line voltage.

  Here, the relationship between the reference phase θuvl of the voltage between UV rays, the voltage phase signal θv, and the magnetic pole position θe is represented by the equation (8).

  θuvl = θv + π / 6 = θre + δ + π / 6 [rad] (8)

  The waveform of the UV line voltage expressed by the equation (8) is line symmetric about the position of θuvl = π / 2, 3π / 2 and point-symmetrical about the position of θuvl = 0, π. Become. Therefore, the waveform of one cycle of UV voltage pulse (θuvl is from 0 to 2π) is symmetrical or up / down every π / 2 based on the pulse waveform between θuvl from 0 to π / 2. It can be expressed by arranging them symmetrically.

  One method for realizing this is to compare the center phase of the UV line voltage pulse in the range of 0 ≦ θuvl ≦ π / 2 with a 4-channel phase counter, and based on the comparison result, one period, that is, 0 ≦ θuvl. This is an algorithm for generating a UV line voltage pulse in a range of ≦ 2π. The conceptual diagram is shown in FIG.

  FIG. 12 shows an example in which there are four line voltage pulses in the range of 0 ≦ θuvl ≦ π / 2. In FIG. 12, pulse reference angles S1 to S4 represent the center phases of the four pulses.

  carr1 (θuvl), carr2 (θuvl), carr3 (θuvl), and carr4 (θuvl) represent each of the 4-channel phase counters. Each of these phase counters is a triangular wave having a period of 2π rad with respect to the reference phase θuvl. Further, carr1 (θuvl) and carr2 (θuvl) have a deviation of dθ in the amplitude direction, and the relationship between carr3 (θuvl) and carr4 (θuvl) is the same.

  dθ represents the width of the line voltage pulse. The amplitude of the fundamental wave changes linearly with respect to this pulse width dθ.

  The line voltage pulse is a pulse reference angle S1 that represents the center phase of each pulse in the range of 0 ≦ θuvl ≦ π / 2 and each phase counter carr1 (θuvl), carr2 (θuvl), carr3 (θuvl), carr4 (θuvl) Formed at each intersection with ~ S4. Thereby, a symmetrical pulse signal is generated every 90 degrees.

  More specifically, a pulse with a width dθ having a positive amplitude is generated at a point where carr1 (θuvl), carr2 (θuvl) and S1 to S4 coincide with each other. On the other hand, at the point where carr3 (θuvl), carr4 (θuvl) and S1 to S4 coincide with each other, a pulse having a negative amplitude and a width dθ is generated.

  FIG. 13 shows an example in which the waveform of the line voltage generated using the method described above is drawn for each modulation degree. In FIG. 13, k1 = 1, k2 = 1, and k3 = 3 are selected as the values of k1, k2, and k3 in Equation (4), respectively, and the line spacing when the modulation degree is changed from 0 to 1.0. An example of a voltage pulse waveform is shown. FIG. 13 shows that the pulse width increases almost in proportion to the increase in modulation degree. The effective value of the voltage can be increased by increasing the pulse width in this way. However, for pulses near θuvl = 0, π, 2π, the pulse width does not change even when the modulation degree changes at a modulation degree of 0.4 or more. Such a phenomenon is caused by overlapping of a pulse having a positive amplitude and a pulse having a negative amplitude.

  When the pulse waveforms of the three types of line voltages, UV line voltage, VW line voltage, and WU line voltage, are respectively obtained by the method described above, the pulse generator 644 determines each line voltage in step 825. Output at. In the next step 826, each output line voltage is converted into a gate pulse of each phase.

  FIG. 14 shows a conversion table for converting each line voltage into a gate pulse of each phase, that is, a phase terminal voltage pulse in step 826. In FIG. 14, the leftmost mode in the table is a number assigned to existing switching states. In modes 1 to 6, the relationship from the line voltage to the phase terminal voltage is determined in a one-to-one relationship. Each mode is an active period in which energy is transferred between the DC side and the three-phase AC side. The line voltage in FIG. 14 is obtained by normalizing and organizing patterns that can be taken as potential differences between different phases with the voltage Vdc of the DC power supply 1. For example, in mode 1, Vuv → 1, Vvw → 0, and Vu → −1 are indicated, but this is normalized when Vu−Vv = Vdc, Vv−Vw = 0, and Vw−Vu = −Vdc. It shows. At this time, the phase terminal voltage (proportional to the gate voltage) is Vu → 1 (U-phase upper arm on, lower arm off), Vv → 0 (V-phase upper arm off, lower arm on), Vw In the case of 0 (the upper arm of the W phase is turned off and the lower arm is turned on), that is, the case where Vu = Vdc, Vv = 0, and Vw = 0 is normalized. Modes 2 to 6 are based on the same concept.

  FIG. 15 shows a state in which the line voltage pulse waveform illustrated in FIG. 13 is converted into a phase terminal voltage pulse according to the conversion table of FIG. In FIG. 15, the upper stage shows a UV line voltage pulse as a representative example of the line voltage, and the U phase terminal voltage Vu, V phase terminal voltage Vv, and W phase terminal voltage Vw are shown below.

  The upper part of FIG. 15 shows the number of the mode (the active period in which energy is transferred between the DC side and the three-phase AC side) and the period in which the three-phase is short-circuited. During the three-phase short-circuit period, either the three-phase upper arm is turned on or the three-phase lower arm is turned on, either switch depending on the switching loss or conduction loss situation. Select a mode.

  For example, when the UV line voltage Vuv is 1, the U-phase terminal voltage Vu is 1 and the V-phase terminal voltage Vv is 0 (modes 1 and 6). When the UV line voltage Vuv is 0, the U-phase terminal voltage Vu and the V-phase terminal voltage Vv are the same value, that is, Vu is 1 and Vv is 1 (mode 2, 3-phase short circuit), or Vu is 0 and Vv is 0 (mode 5, 3-phase short circuit). When the UV line voltage Vuv is −1, the U-phase terminal voltage Vu is 0 and the V-phase terminal voltage Vv is 1 (modes 3 and 4). Based on such a relationship, each pulse of the phase voltage, that is, the phase terminal voltage (gate voltage pulse) is generated.

  In the first pulse modulator 64 for PHM control, a PHM pulse signal is generated and output to the switch 68 by the method as described above.

  Next, selection of a pulse signal by the switch 68 will be described. As described above, the switch 68 selects either the PHM pulse signal output from the first pulse modulator 64 for PHM control or the PWM pulse signal output from the second pulse modulator 65 for PWM control. And output to the inverter circuit 2 as a drive signal. The selection of the pulse signal is performed as follows based on the rotation speed (rotation speed) of the compressor motor 309.

  FIG. 16 shows an example of changes in the rotation speed and room temperature of the compressor motor 309 when the air conditioner 300 starts the heating operation. In the upper diagram of FIG. 16, the horizontal axis represents the passage of time, and the vertical axis represents the motor speed and the room temperature. In this figure, a change example of the motor rotation speed by PWM control is shown as the motor rotation speed A, and a change example of the motor rotation speed when the PWM control and the PHM control are used together as the motor rotation speed B is shown by a broken line. A solid line indicates an example of a change in room temperature by PWM control as room temperature A, and an example of a change in room temperature when PWM control and PHM control are used together as room temperature B.

  In the case of PWM control, when the air conditioner 300 starts the heating operation at time t0, the motor rotation speed A increases until it reaches the maximum rotation speed. After that, when the refrigeration cycle of the air conditioner 300 is sufficiently warmed up, hot air is blown out from the indoor unit at time t1. Thereby, the room temperature A gradually increases.

  When the difference between the preset set temperature and room temperature A becomes less than a predetermined threshold value T1 at time t2, the number of motor lines A starts to decrease according to the speed command from the input circuit 304, and the room temperature accordingly A rises gradually. Thereafter, when the difference between the set temperature and the room temperature A becomes less than a predetermined threshold value T2 (T1> T2) at time t3, the slope at which the number of motor lines A decreases changes. When the room temperature A coincides with the set temperature at time t4, the number of motor lines A becomes constant, and the compressor motor 309 is driven in a low rotation state.

  In the case of PWM control as described above, as indicated by reference numeral 161 in FIG. 16, energization by PWM control is always performed from the inverter circuit 2 to the compressor motor 309 during heating operation. At this time, in the control circuit 6, the switching unit 68 always selects the PWM pulse signal output from the second pulse modulator 65 for PWM control and outputs it to the inverter circuit 2.

  On the other hand, when PWM control and PHM control are used in combination, when the air conditioner 300 starts the heating operation at time t0, the motor rotation speed B increases until it reaches the maximum rotation speed. The maximum rotational speed at this time is higher than that of the motor rotational speed A described above. Thereafter, when the refrigeration cycle of the air conditioner 300 is sufficiently warmed up, warm air starts to be blown out from the indoor unit at time t1 'earlier than time t1. Thereby, the room temperature B gradually increases.

  Thereafter, the same operation as in the PWM control is performed. That is, when the difference between the set temperature and the room temperature B becomes less than the threshold value T1 at time t2 ′, the number of motor lines B starts to decrease in response to the speed command from the input circuit 304, and the room temperature B The rise will be moderate. Thereafter, when the difference between the set temperature and the room temperature B becomes less than the threshold value T2 at time t3 ', the slope at which the number of motor lines B decreases is changed. When the room temperature B coincides with the set temperature at time t4 ', the number of motor lines B becomes constant, and the compressor motor 309 is driven in a low rotation state.

  In FIG. 16, each time t1, t2, t3 and t4 in the case of PWM control is compared with each time t1 ′, t2 ′, t3 ′ and t4 ′ in the case where PWM control and PHM control are used together. It can be seen that both are faster when PWM control and PHM control are used in combination. That is, by using both PWM control and PHM control, heating can be performed more rapidly than when only conventional PWM control is used.

  When the PWM control and the PHM control as described above are used in combination, as indicated by reference numeral 162 in FIG. 16, the period from the start of the heating operation until the motor rotation speed B reaches a predetermined rotation speed is PWM. Energization by the control is performed from the inverter circuit 2 to the compressor motor 309. This is because it is difficult to apply PHM control when the motor speed is low and the energization rate is small. At this time, in the control circuit 6, the switch 68 selects the PWM pulse signal output from the second pulse modulator 65 for PWM control and outputs it to the inverter circuit 2.

  Thereafter, in a period from time t2 ′ when the number of motor lines B reaches the maximum number of revolutions and starts to decrease from that (period D1) and a period from time t2 ′ to time t3 ′ (period D2), Energization is performed by PHM control using different PHM pulse patterns. At this time, in the control circuit 6, the switch 68 selects the PHM pulse signal output from the first pulse modulator 64 for PHM control, and outputs it to the inverter circuit 2. In the following description, the PHM pulse pattern used in the PHM control in the period D1 is referred to as PHM1, and the PHM pulse pattern used in the PHM control in the period D2 is referred to as PHM2.

  After time t3 ', energization by PWM control is performed. At this time, in the control circuit 6, the switch 68 selects the PWM pulse signal output from the second pulse modulator 65 for PWM control and outputs it to the inverter circuit 2.

  As described above, between the start of the heating operation and the time t3 ', the heating operation is performed using both PWM control and PHM control. Hereinafter, such an operation mode is referred to as a quick warm operation mode. On the other hand, after time t3 ', the heating operation is performed using only the PWM control as in the conventional case. Hereinafter, such an operation mode is referred to as a normal operation mode. The control circuit 6 selects these operation modes according to the situation, and outputs a drive signal corresponding to the selected operation mode to the inverter circuit 2.

  FIGS. 17A and 17B are diagrams showing differences in current waveforms depending on the energization method. FIG. 17A shows an example of the waveform of the U-phase alternating current by the PWM control method, and FIG. 17B shows an example of the waveform of the U-phase alternating current by the PHM control method. In FIGS. 17A and 17B, the vertical axis indicates the magnitude of current, and the horizontal axis indicates time.

  17 (a) and 17 (b), the waveform of the U-phase alternating current by the PHM control method, that is, the waveform of the alternating current flowing through the compressor motor 309 in the fast warming operation mode, is the U-phase alternating current by the PWM control method. It can be seen that the waveform is a distorted waveform containing more harmonic components than the waveform of the AC current flowing through the compressor motor 309 in the normal operation mode. In other words, the AC power supplied from the inverter circuit 2 to the compressor motor 309 in the rapid warm-up operation mode has more harmonics than the AC power supplied from the inverter circuit 2 to the compressor motor 309 in the normal operation mode. Contains ingredients. This is because iron loss (such as eddy current loss) generated in the compressor motor 309 increases when the PHM control method is used, and the compressor motor 309 itself generates heat compared to the PWM control method. It is shown that. This heat is absorbed by the refrigerant flowing in the compressor 308 and used as heat energy in the air conditioner 300. In other words, when the PHM control method is used, the heat generated by the compressor motor 309 can also be used as the heat during the heating operation, so that the start-up during the heating operation is faster and shorter than when the PWM control method is used. The room temperature can be raised over time.

  However, the more the harmonics are included in the alternating current flowing through the compressor motor 309, the more torque pulsation occurs in the compressor motor 309. Therefore, it is desirable to adjust the harmonic content in accordance with the operating state of the compressor 308 (motor rotation speed, etc.). In the above-described rapid warm-up operation mode, this is realized by using different PHM1 and PHM2 pulse patterns. Thus, since the PHM control can delete any harmonic order, it can be easily applied to the present driving method. In other words, the driving method of the present invention can be achieved by using PHM control.

  Next, the PHM control in the quick warming operation mode will be described. The pulse pattern PHM1 used in the PHM control in the period D1 in the fast warming operation mode has a waveform with a smaller number of pulses and closer to a rectangular wave than the pulse pattern PHM2 used in the PHM control in the period D2. Or it may be a rectangular wave. As a result, the maximum rotational speed can be made higher than in the case of PWM control as described above. On the other hand, in the pulse pattern PHM2 used in the PHM control in the period D2, more harmonic components are deleted from the AC power supplied to the compressor motor 309 by increasing the number of pulses. Thereby, the iron loss which generate | occur | produces in the motor 309 for compressors is reduced, and it is set as the highly efficient driving | running state.

  In the above description, the order of harmonic components to be deleted from the AC power supplied to the compressor motor 309 is switched using two types of pulse patterns PHM1 and PHM2, but three or more types of pulse patterns are used. May be used. In that case, as the difference between the set temperature and the room temperature becomes smaller and the motor rotational speed becomes lower accordingly, the higher order harmonic components are removed from the AC power supplied to the compressor motor 309. It is preferable to change the PHM control pulse pattern, that is, the phase position of AC power through which each switching element of the inverter circuit 2 is conducted.

  In FIG. 3, the first pulse modulator 64 generates the above-described PHM pulse signal, and the second pulse modulator 65 generates the above-described PWM pulse signal. The first pulse modulator 64 and the second pulse modulator 65 according to the present embodiment are not limited thereto, and the harmonics of the three-phase alternating current in the quick warm-up operation mode shown in FIG. It is controlled to generate more than the harmonics of the alternating current.

  For example, when the second pulse modulator 65 generates the above-described PWM pulse signal, the first pulse modulator 64 uses a trapezoidal overmodulation control method, a control method for reducing the PWM carrier frequency, It is conceivable to switch the energization method such as current energization.

  Also, between the first pulse modulator 64 and the second pulse modulator 65, PWM control method, PHM control method, trapezoidal overmodulation control method, control method for reducing PWM carrier frequency, energization such as 120 degree energization It is only necessary to combine the switching methods so that the rapid heating operation mode generates more harmonics than the normal operation mode.

  FIG. 18 shows an example of changes in the room temperature and the amount of generated heat when the air conditioner 300 performs the defrosting operation. In FIG. 18, the horizontal axis represents the passage of time, and the vertical axis represents the room temperature and the amount of generated heat. In this figure, an example of a change in room temperature is indicated by a solid line, and a change in the amount of generated heat is indicated by a broken line.

  When the air conditioner 300 is operated for heating when the outside air temperature is low such as in winter, moisture in the air adheres to the heat exchanger 302 of the outdoor unit and becomes frost. As the frost adheres, the heat exchange performance of the heat exchanger 302 decreases. As a result, as shown in FIG. 18, the amount of generated heat gradually decreases from time t0 to time t1, and accordingly, the room temperature once increased gradually decreases. Therefore, when the heat exchange performance of the heat exchanger 302 decreases to some extent, the air conditioner 300 starts the defrosting operation at time t1.

  When the defrosting operation is started, the air conditioner 300 switches the refrigerant circulation direction to the opposite direction to that of the previous one, that is, the same direction as the cooling operation, by the four-way valve 310. Thereby, the heat exchanger 302 of the outdoor unit is warmed to melt the attached frost.

  19 (a) and 19 (b) are diagrams showing the operation of the refrigeration cycle in the heating operation, the cooling operation, and the defrosting operation. As shown in FIG. 19A, during the heating operation, the refrigerant compressed by the compressor 308 is sent to the heat exchanger 302 of the indoor unit through the four-way valve 310, and then the heat exchanger 306 of the outdoor unit. It returns to the compressor 308 through the four-way valve 310. On the other hand, as shown in FIG. 19B, during the cooling operation and the defrosting operation, after the refrigerant compressed by the compressor 308 is sent to the heat exchanger 306 of the outdoor unit via the four-way valve 310, the indoor unit The heat exchanger 302 and the four-way valve 310 return to the compressor 308. In addition, as shown in FIG. 19B, a bypass valve is provided in front of the heat exchanger 302 of the indoor unit, and the refrigerant returns to the compressor 308 through the bypass valve during the defrosting operation. The cold refrigerant after being radiated by the heat exchanger 306 may be prevented from passing through the heat exchanger 302 of the indoor unit.

  After the start of the defrosting operation at time t1, when a predetermined defrosting period elapses as shown in FIG. 18, the air conditioner 300 stops the defrosting operation and restarts the heating operation at time t2. At this time, the air conditioner 300 restores the refrigerant circulation direction switched by the four-way valve 310, and blows warm air from the indoor unit. Thereafter, the switching between the defrosting operation and the heating operation is repeated in the same manner.

  In addition, the length of the defrosting period from the time t1 to t2 may be preset, and may be judged from the frost adhesion state etc. In this defrosting period, the amount of generated heat becomes 0 as shown in FIG. 18, and the room temperature decreases. When the heating operation is resumed at time t2 after the defrost period has elapsed, the amount of generated heat increases, and the room temperature also increases accordingly.

  FIG. 20 shows an example of changes in the rotational speed of the compressor motor 309 and the d-axis current during the defrosting period and the heating period. In the following description, the operation mode in the defrost period is referred to as a defrost operation mode. In the upper diagram of FIG. 20, the horizontal axis represents the passage of time, and the vertical axis represents the motor rotation speed and the d-axis current. In this figure, a change example of the motor rotation speed is indicated by a broken line, and a change example of the d-axis current is indicated by a solid line.

  When the air conditioner 300 starts the defrosting operation mode at time t1, the motor rotation speed starts to increase and reaches the maximum rotation speed at time t2. Thereafter, when a predetermined defrosting period elapses, the defrosting operation mode is stopped at time t3. During this defrosting operation mode, the d-axis current which is a reactive current flows in the field weakening direction with respect to the minus side, that is, the compressor motor 309 according to the motor rotation speed. As a result, in the defrosting operation mode, in addition to the iron loss described above, the copper loss generated in the compressor motor 309 is further increased. In this way, the amount of heat generated by the compressor motor 309 itself is further increased, the amount of heat absorbed by the refrigerant flowing in the compressor 308 is increased, and the amount of heat released in the heat exchanger 306 of the outdoor unit is increased. ing. As a result, the defrosting ability can be improved. Furthermore, since the d-axis current is allowed to flow to the negative side, the compressor motor 309 can be rotated at a higher speed by the field weakening.

  In the defrosting operation mode, as shown in the lower diagram of FIG. 20, during the period from the time t1 until the motor rotation speed reaches a predetermined rotation speed, energization by PWM control is performed from the inverter circuit 2 to the compressor motor 309. Is called. This is because, as described above, it is difficult to apply PHM control when the motor rotation speed is low and the energization rate is small. At this time, in the control circuit 6, the switch 68 selects the PWM pulse signal output from the second pulse modulator 65 for PWM control and outputs it to the inverter circuit 2.

  Thereafter, the motor rotation speed reaches the maximum rotation speed at time t2, and is maintained until time t3 when the defrosting period ends. In this period, energization by PHM control is performed. The PHM pulse signal used here is the aforementioned pulse pattern PHM1 and has a waveform with a small number of pulses and a square wave. As a result, iron loss is generated in the compressor motor 309 so that the compressor motor 309 generates heat. The pulse waveform used here is not limited to the pulse pattern PHM1, and may be another pulse waveform or a rectangular wave. At this time, in the control circuit 6, the switch 68 selects the PHM pulse signal output from the first pulse modulator 64 for PHM control, and outputs it to the inverter circuit 2.

  When the defrosting period ends at time t3, the motor rotation speed and d-axis current are set to 0 until time t4, the compressor motor 309 is stopped, and then the heating period starts. In this heating period, as described above, the quick warming operation mode and the normal operation mode are switched on the way. That is, during the period from time t4 to time t5, the quick warm-up operation mode is selected, and PWM control, PHM control using the pulse pattern PHM1, and PHM control using the pulse pattern PHM2 are switched at predetermined timings. In addition, the normal operation mode is selected and PHM control is performed between time t5 and time t6 when the defrosting operation is started next.

  As shown in FIG. 20, during the quick warming operation mode, the d-axis current is supplied to the compressor motor 309 in the same way as in the defrosting operation mode so that the copper loss generated in the compressor motor 309 is increased. It may be. As a result, as described above, the amount of heat generated by the compressor motor 309 itself is further increased, the amount of heat absorbed by the refrigerant flowing in the compressor 308 is increased, and the amount of heat released in the heat exchanger 302 of the indoor unit is increased. Try to increase. As a result, the heating capacity can be further improved.

  In the above description, the air conditioner 300 is operated in the defrosting operation mode by the PHM control in the defrosting period, and the air conditioner 300 is switched between the quick warming operation mode by the PHM control and the normal operation mode by the PWM control in the heating period. Although the example of operating is described, only one of them may be performed. That is, while the air conditioner 300 is operated in the defrosting operation mode by PHM control during the defrosting period, the air conditioner 300 may be operated using conventional PWM control during the heating period. Alternatively, the air conditioner 300 may be operated in the defrosting operation mode by the PHM control in the defrosting period, while the air conditioner 300 may be operated using the conventional PWM control in the heating period.

  FIG. 21 is a diagram illustrating an example of the relationship between the outside air temperature, the motor rotation speed, and the control method when switching the control method of the air conditioner 300 according to the outside air temperature and the motor rotation speed. As shown in FIG. 21, for example, PWM control is performed when the motor rotation speed is less than 4000 rpm, and PHM control is performed when the motor rotation speed is 4000 rpm or more. At this time, for example, when the outside air temperature is less than 20 ° C. and heating operation is performed, the PHM control using the pulse pattern PHM1 is performed at a low temperature below the predetermined temperature to increase the harmonic component of the AC power, and otherwise PHM control using the pulse pattern PHM2 is performed to reduce the harmonic component of the AC power. In addition, when performing cooling operation or dry operation, it is not necessary to positively generate heat for the compressor motor 309, so that a pulse pattern in which harmonic components contained in AC power are smaller than those of the PHM1 and PHM2 described above. PHM control using (referred to as PHM3) is performed. Note that the switching of the control method as shown in FIG. 21 is merely an example, and the switching condition when the control method of the air conditioner 300 is switched according to the outside air temperature and the motor rotation speed is not limited to this. .

  Next, control mode switching will be described with reference to FIG. As described above, the control circuit 6 selects the PWM pulse signal or the PHM pulse signal by the switch 68 in accordance with the rotation speed of the compressor motor 309, thereby enabling the PWM control method (PWM control mode). A PHM control method (PHM control mode) is switched and used. FIG. 22 shows how control modes are switched in the control circuit 6. The rotation speed for switching the control mode can be arbitrarily changed. As the rotation speed of the compressor motor 309 increases, the control shifts to PWM control.

  Since it is desirable to reduce the distortion of the AC power supplied to the compressor motor 309 when the air conditioner 300 starts up, the switching operation of the switching element of the inverter circuit 2 is controlled by the PWM control method. The PHM control has a problem in controllability when the compressor motor 309 is in a stopped state or an ultra-low speed state, and the distortion of the AC power waveform tends to increase. Therefore, such a drawback can be compensated by combining with control by the PWM control method.

  In a low-speed operation state of the compressor motor 309, since there is a limit to the AC current that can be supplied, control is performed while suppressing the maximum generated torque. As the rotational speed of the compressor motor 309 increases, the internal induced voltage increases, and the amount of current supplied tends to decrease. For this reason, the output torque of the compressor motor 309 tends to decrease as the rotational speed increases. PHM control is effective in high-speed operation.

  The rotational speed of the compressor motor 309 for switching between control by the PWM system and PHM control is not particularly limited. For example, a state of 700 rpm or less is controlled by the PWM system, and PHM control is performed at a rotational speed higher than 700 rpm. It is possible. The range from 1500 rpm to 5000 rpm is an operation region that is very suitable for the control of the PHM method. In this region, the effect of reducing the switching loss of the switching element is greater in the control of the PHM method than in the control by the PWM method. This operation area is an operation area often used in the air conditioner 300. That is, the PHM control is very effective in the driving range closely related to daily life.

  FIG. 23 shows a state when the control circuit 6 switches the PWM control mode and the PHM control mode according to the motor rotation speed by the switch 68. Here, the line voltage pulse waveform when the control mode is switched from the PWM control mode to the PHM control mode by switching the selection destination of the switch 68 from the PWM pulse signal to the PHM pulse signal when θuvl = π. An example is shown.

  FIG. 24 shows an example of the appearance when the control circuit 6 is configured by an HIC (Hybrid Integrated Circuit). Here, an example of an HIC in which an arithmetic microcomputer and a drive circuit are integrated is illustrated. FIG. 25 shows an example of an external appearance when the control circuit 6 and the inverter circuit 2 are modularized and combined. The structure and appearance of the control circuit 6 and the inverter circuit 2 are not limited to the structure and appearance, and any structure and appearance may be used.

  When the inverter circuit 2 of the motor control device 311 in the outdoor unit housing 305 is controlled by the PWM control method, the switching element is controlled based on the carrier wave shown in FIG. In this case, if the resonance frequency of the outdoor unit casing 305, the compressor 308, or the heat exchanger 306 substantially matches the frequency of the carrier wave, very large noise may be generated. Therefore, when the PHM control method is used, noise from the outdoor unit can be suppressed by controlling so that the carrier wave of the carrier wave generator shown in FIG. 30 is not output.

  According to the air conditioner 300 of the first embodiment described above, in addition to the various functions and effects described above, the following functions and effects can be achieved.

(1) During the heating operation, the control circuit 6 uses the switch 68 to select one of the quick heating operation mode and the normal operation mode for rapid heating, and drives according to the selected operation mode. The signal is output to the inverter circuit 2. Further, the AC power supplied to the compressor motor 309 in the quick warming operation mode includes more harmonic components than the AC power supplied to the compressor motor 309 in the normal operation mode. Since it did in this way, more iron loss can be generated in the motor 309 for compressors in the quick warming operation mode, and the motor 309 for compressors can be made to generate heat. Therefore, the refrigerant can be heated even during the operation of the compressor 308 without adding a special device such as an electric heater. As a result, the room temperature can be quickly raised.

(2) As shown in FIG. 16, the control circuit 6 selects the quick warming operation mode when the air conditioner 300 starts the heating operation, and then the difference between the predetermined set temperature and the room temperature is within a predetermined range. Select normal operation mode when it is within. Since it did in this way, a quick heating operation mode and a normal operation mode can be switched at an appropriate timing.

(3) When the quick warm-up operation mode is selected, the control circuit 6 performs PHM control to obtain the phase position of the AC power at which the switching element of the inverter circuit 2 is conducted, and based on the obtained phase position, the drive signal Is output. On the other hand, when the normal operation mode is selected, the control circuit 6 outputs a drive signal based on the PWM control. Since it did in this way, the optimal drive signal can be output from the control circuit 6 in each of the quick warming operation mode and the normal operation mode.

(4) Even when the quick warming operation mode is selected, when the rotational speed of the compressor motor 309 is less than a predetermined value as shown in FIG. 16, the control circuit 6 is based on PWM control. Output a drive signal. Since it did in this way, in the state where application of PHM control is difficult because the motor rotation speed is low and the energization rate is small, the compressor motor 309 can be reliably controlled using PWM control.

(5) When the quick warm-up operation mode is selected, the control circuit 6 switches the pulse pattern from PHM1 to PHM2 based on the difference between the predetermined set temperature and room temperature, whereby the switching element of the inverter circuit 2 becomes conductive. The phase position of the AC power is changed, and the order of the harmonic component removed in the AC power supplied to the compressor motor 309 is switched. Specifically, the switching element of the inverter circuit 2 becomes conductive so that higher order harmonic components are removed from the AC power supplied to the compressor motor 309 as the difference between the set temperature and room temperature becomes smaller. Change the phase position of AC power. In this way, since the harmonic content in the AC power is adjusted according to the difference between the set temperature and room temperature, the optimum AC power is supplied according to the operating state of the compressor motor 309. Can do.

(6) As shown in FIG. 20, the reactive current flowing through the compressor motor 309 in the quick warming operation mode, that is, the current value of the d-axis current is larger than that flowing through the compressor motor 309 in the normal operation mode. Since it did in this way, the copper loss which the motor 309 for compressors generate | occur | produces in a quick warming operation mode can be increased, and the emitted-heat amount of the motor 309 for compressors can be increased further. As a result, the heating capacity of the air conditioner 300 can be further improved.

(7) The reactive current in the fast warming operation mode is made to flow in the field weakening direction with respect to the compressor motor 309. As a result, the compressor motor 309 can be rotated at a higher speed.

(8) The control circuit 6 selects the defrosting operation mode for performing defrosting of the heat exchanger 306 of the outdoor unit by the switch 68. When the defrosting operation mode is selected by the control circuit 6, the four-way valve 310 switches the refrigerant circulation direction to a direction opposite to the quick warming operation mode and the normal operation mode. Further, the AC power supplied to the compressor motor 309 in the defrosting operation mode includes more harmonic components than the AC power supplied to the compressor motor 309 in the normal operation mode. Since it did in this way, even in the defrosting operation mode, a lot of iron loss can be generated by the compressor motor 309, and the compressor motor 309 can generate heat. Therefore, the refrigerant can be heated even during the operation of the compressor 308 without adding a special device such as an electric heater. As a result, defrosting can be performed quickly, the defrosting period can be shortened, and a decrease in room temperature can be suppressed.

(9) When the defrosting operation mode is selected, the control circuit 6 obtains the phase position of AC power through which the switching element of the inverter circuit 2 is conducted by performing PHM control, and outputs a drive signal based on the obtained phase position. Output. On the other hand, when the normal operation mode is selected, the control circuit 6 outputs a drive signal based on the PWM control. Since it did in this way, the optimal drive signal can be output from the control circuit 6 in each of the defrosting operation mode and the normal operation mode.

(10) Even when the defrosting operation mode is selected, when the rotational speed of the compressor motor 309 is less than a predetermined value as shown in FIG. 20, the control circuit 6 is based on PWM control. Outputs a drive signal. Since it did in this way, in the state where application of PHM control is difficult because the motor rotation speed is low and the energization rate is small, the compressor motor 309 can be reliably controlled using PWM control.

(11) As shown in FIG. 20, the reactive current that flows to the compressor motor 309 in the defrosting operation mode, that is, the current value of the d-axis current is larger than that that flows to the compressor motor 309 in the normal operation mode. Since it did in this way, the copper loss which the motor 309 for compressors generate | occur | produces in a defrost operation mode can be increased, and the emitted-heat amount of the motor 309 for compressors can be increased further. As a result, the defrosting capability of the air conditioner 300 can be further improved.

(12) The reactive current in the defrosting operation mode is made to flow in the field weakening direction with respect to the compressor motor 309. As a result, the compressor motor 309 can be rotated at a higher speed.

-Second Embodiment-
Next, a hot water supply system as a second embodiment of the present invention will be described. FIG. 26 is a diagram showing a configuration of a heat pump hot water supply system 400 according to an embodiment of the present invention. The hot water supply system 400 includes an outdoor unit 401, a hot water storage tank 402, a heat exchanger 403, a fan 404, a motor controller 405, a compressor motor 406, a compressor 407, a refrigerant pipe 408, a water pipe 409, a heat exchanger 410, and an input. A circuit 411 is provided.

  The compressor 407 is driven by the compressor motor 406 and compresses the refrigerant. The operation of the compressor motor 406 is controlled by a motor control device 405.

  The refrigerant compressed by the compressor 407 becomes a high temperature and high pressure state, and is sent to the heat exchanger 410 through the refrigerant pipe 408. The heat exchanger 410 is provided with a water pipe 409 for passing water acquired from a water supply port in the vicinity of the refrigerant pipe 408. The heat accumulated in the refrigerant is dissipated in the heat exchanger 410, whereby heat exchange is performed between the refrigerant and water, and the water in the water pipe 409 is warmed. The water thus heated is stored in the hot water storage tank 402, and is supplied from the hot water outlet to each facility (bath, faucet, floor heating panel, etc.) in the building where the hot water supply system 400 is installed. . On the other hand, the refrigerant that has become liquid due to heat dissipation is sent to the heat exchanger 403, which absorbs the heat of vaporization from the outside air in the heat exchanger 403 and then returns to the compressor 407 as a gas. In this way, the coolant is circulated between the heat exchanger 403 and the heat exchanger 410, so that water is warmed in the hot water supply system 400.

  The input circuit 411 calculates the rotational speed of the compressor motor 309 based on information such as the outside air temperature, the water temperature in the hot water storage tank 402, the current time, and the like when a predetermined operating condition is satisfied. Then, a speed command corresponding to the calculated rotation speed is transmitted to the motor control device 405. The motor control device 405 has the same configuration as the motor control device 311 shown in FIG. 2 described in the first embodiment, and controls the operation of the compressor motor 406 in the same manner. Therefore, the motor controller 405 will be described below with reference to FIGS. In the following description, in order to match FIG. 26, the reference numeral of the motor control device in FIG. 2 is read from 311 to 405, and the reference numeral of the compressor motor is changed from 309 to 406.

  The motor control device 405 generates a PHM pulse signal and a PWM pulse signal by the first pulse modulator 64 and the second pulse modulator 65, respectively. The switch 68 selects one of the pulse signals based on the rotation speed (rotation speed) of the compressor motor 406 and outputs the pulse signal to the inverter circuit 2 as a drive signal. The inverter circuit 2 operates an internal switching element in accordance with the drive signal, thereby supplying AC power to the compressor motor 406 and driving the compressor motor 406.

  FIG. 27 shows an example of changes in the rotational speed and water temperature of the compressor motor 406 in the hot water supply system 400. In the upper diagram of FIG. 27, the horizontal axis represents the passage of time, and the vertical axis represents the motor rotation speed and the water temperature, respectively. In this figure, a change example of the motor rotation speed by PWM control is shown as the motor rotation speed A, and a change example of the motor rotation speed when the PWM control and the PHM control are used together as the motor rotation speed B is shown by a broken line. Further, as a water temperature A, an example of a change in water temperature by PWM control, and as a water temperature B, an example of a change in water temperature when PWM control and PHM control are used together is shown by a solid line.

  In the case of PWM control, when hot water supply system 400 starts operation at time t0, motor speed A increases until the maximum speed is reached. Thereafter, the water temperature A gradually increases after a while.

  When the difference between the preset set water temperature and the water temperature A becomes less than the predetermined threshold value T1 at time t2, the motor circuit number A starts to decrease in response to the speed command from the input circuit 411, and the water temperature accordingly A rises gradually. Thereafter, when the difference between the set temperature and the water temperature A becomes less than a predetermined threshold value T2 (T1> T2) at time t3, the slope at which the number of motor lines A decreases is changed. When the water temperature A matches the set temperature at time t4, the number of motor lines A becomes constant, and the compressor motor 406 is driven in a low rotation state.

  In the case of the PWM control as described above, as indicated by reference numeral 271 in FIG. 27, the energization by the PWM control is always performed on the compressor motor 406. At this time, in the control circuit 6, the switching unit 68 always selects the PWM pulse signal output from the second pulse modulator 65 for PWM control and outputs it to the inverter circuit 2.

  On the other hand, when PWM control and PHM control are used together, when hot water supply system 400 starts operation at time t0, motor rotation speed B increases until the maximum rotation speed is reached. The maximum rotational speed at this time is higher than that of the motor rotational speed A described above. Thereafter, the water temperature B gradually increases after a while.

  Thereafter, the same operation as in the PWM control is performed. That is, when the difference between the set water temperature and the water temperature B becomes less than the threshold value T1 at time t2 ′, the number of motor lines B starts to decrease according to the speed command from the input circuit 411, and the water temperature B changes accordingly. The rise will be moderate. Thereafter, when the difference between the set water temperature and the water temperature B becomes less than the threshold value T2 at time t3 ', the slope at which the number of motor lines B decreases is changed. When the water temperature B coincides with the set water temperature at time t4 ', the number of motor lines B becomes constant, and the compressor motor 406 is driven in a low rotation state.

  When PWM control and PHM control as described above are used in combination, as indicated by reference numeral 272 in FIG. 27, the period from the start of operation until the motor rotation speed B reaches a predetermined rotation speed is PWM control. Is supplied from the inverter circuit 2 to the compressor motor 406. This is because it is difficult to apply PHM control when the motor speed is low and the energization rate is small. At this time, in the control circuit 6, the switch 68 selects the PWM pulse signal output from the second pulse modulator 65 for PWM control and outputs it to the inverter circuit 2.

  Thereafter, in the period from time t2 ′ until the motor line number B reaches the maximum number of rotations and starts to decrease from that, energization by the pulse pattern PHM1 is performed, and in the subsequent period from time t2 ′ to time t3 ′, Energization is performed by the aforementioned pulse pattern PHM2. At this time, in the control circuit 6, the switch 68 selects the PHM pulse signal output from the first pulse modulator 64 for PHM control, and outputs it to the inverter circuit 2.

  After time t3 ', energization by PWM control is performed. At this time, in the control circuit 6, the switch 68 selects the PWM pulse signal output from the second pulse modulator 65 for PWM control and outputs it to the inverter circuit 2.

  As described above, the PWM control and the PHM control are used together between the start of operation and the time t3 '. Hereinafter, such an operation mode is referred to as a rapid hot water supply operation mode. On the other hand, after the time t3 ', the operation is performed using only the PWM control as in the conventional case. Hereinafter, such an operation mode is referred to as a normal operation mode. The control circuit 6 selects these operation modes according to the situation, and outputs a drive signal corresponding to the selected operation mode to the inverter circuit 2.

  As described for the air conditioner 300 according to the first embodiment, the AC power supplied from the inverter circuit 2 to the compressor motor 406 in the rapid hot water supply operation mode is the inverter circuit 2 in the normal operation mode. Contains more harmonic components than AC power supplied to the compressor motor 406. That is, by using the PHM control method, iron loss is generated in the compressor motor 406, and the heat generated thereby can be used to increase the water temperature in a shorter time than when the PWM control method is used. .

  Further, when the compressor motor 406 is driven at the maximum rotation speed B, the maximum rotation speed B can be made higher than the maximum rotation speed A by the PWM control by performing the PHM control by the pulse pattern PHM1. Furthermore, when the motor rotation speed is lower than the maximum rotation speed B, PHM control by the pulse pattern PHM2 is performed, so that iron loss generated in the compressor motor 406 can be reduced and a highly efficient operation state can be achieved. .

  In the hot water supply system 400 according to the second embodiment, three or more types of pulse patterns may be used as in the air conditioner 300 according to the first embodiment. In such a case, the difference between the set water temperature and the water temperature is reduced, and the higher the motor rotation speed is, the higher the higher-order harmonic components are removed from the AC power supplied to the compressor motor 406. It is preferable to change the PHM control pulse pattern, that is, the phase position of AC power through which each switching element of the inverter circuit 2 is conducted.

  FIG. 28 is a diagram illustrating an example of the relationship between the outside air temperature and water temperature and the control method when switching the control method of the hot water supply system 400 according to the outside air temperature and the water temperature. As shown in FIG. 28, for example, when the outside air temperature is relatively high (about 30 ° C.) or when the water temperature is relatively high (about 80 ° C.), PWM control is performed. On the other hand, when the outside air temperature or the water temperature is lower than this, the PHM control is performed. At this time, the pulse patterns PHM3, PHM2, and PHM1 are selected in this order so that the higher the outside air temperature or the water temperature is, the higher order harmonic components are included in the AC power supplied to the compressor motor 406.

  Further, when the outside air temperature is very low (about −10 ° C.) and the water temperature is very low (about 30 ° C.), the d-axis current is supplied to the compressor motor 406 as described above, and the compressor motor 406 is supplied. The copper loss generated in is increased. As a result, the amount of heat generated by the compressor motor 406 is further increased, the amount of heat absorbed by the refrigerant flowing in the compressor 407 is increased, and the amount of heat released from the heat exchanger 410 is increased. As a result, the hot water supply capability can be further improved.

  FIG. 29 is a diagram showing an example of the relationship between the time and water temperature and the control method when switching the control method of hot water supply system 400 according to the time and water temperature. As shown in FIG. 29, for example, when the outside air temperature is relatively high in the daytime or evening time zone, or when the water temperature is relatively high (about 60 ° C.), PWM control is performed. On the other hand, PHM control is performed when the water temperature is lower than this at night or early morning when the outside air temperature is relatively low. At this time, the pulse patterns PHM2 and PHM1 are selected in this order so that the higher the water temperature is, the higher order harmonic components are included in the AC power supplied to the compressor motor 406. Further, when the water temperature is very low (about 30 ° C.) in the midnight time zone (approximately from 22:00 to 5 o'clock), a d-axis current is supplied to the compressor motor 406, and the copper loss generated in the compressor motor 406 is detected. To increase the heat generation amount. Note that since the outside air temperature for each time zone varies greatly depending on the season, it is preferable to change the conditions in FIG. 29 for each season.

  Note that the switching of the control method as shown in FIG. 28 and FIG. 29 is merely an example, and the switching condition when switching the control method of the hot water supply system 400 according to the outside air temperature and the water temperature, or the time and the water temperature is limited to this. Is not to be done.

  According to the hot water supply system 400 of the second embodiment described above, in addition to the various functions and effects described above, the following functions and effects can be achieved.

(1) The control circuit 6 uses the switch 68 to select one of a rapid hot water supply operation mode and a normal operation mode for rapidly warming the water, and inverters a drive signal corresponding to the selected operation mode. Output to circuit 2. Further, the AC power supplied to the compressor motor 406 in the rapid hot water supply operation mode includes more harmonic components than the AC power supplied to the compressor motor 406 in the normal operation mode. Since it did in this way, more iron loss can be generated in the motor 406 for compressors in the rapid hot-water supply operation mode, and the motor 406 for compressors can be heated. Therefore, the refrigerant can be heated even during the operation of the compressor 407 without adding a special device such as an electric heater. As a result, the water temperature can be quickly raised. Furthermore, since the capacity of the hot water storage tank 402 can be reduced by this, the installation area, the installation cost and the product cost can be reduced, and the user can always use fresh hot water.

(2) As shown in FIGS. 28 and 29, the control circuit 6 selects one of the rapid hot water supply operation mode and the normal operation mode based on at least one of the water temperature, the outside air temperature, and the time. Since it did in this way, rapid hot-water supply operation mode and normal operation mode can be switched at an appropriate timing.

(3) When the rapid hot water supply operation mode is selected, the control circuit 6 obtains the phase position of AC power through which the switching element of the inverter circuit 2 is conducted by performing PHM control, and the drive signal is based on the obtained phase position. Is output. On the other hand, when the normal operation mode is selected, the control circuit 6 outputs a drive signal based on the PWM control. Since it did in this way, the optimal drive signal can be output from the control circuit 6 in each of the rapid hot water supply operation mode and the normal operation mode.

(4) Even when the rapid hot water supply operation mode is selected, when the rotation speed of the compressor motor 406 is less than a predetermined value as shown in FIG. 27, the control circuit 6 is based on PWM control. Output a drive signal. Since it did in this way, in the state where application of PHM control is difficult because the motor rotation speed is low and the energization rate is small, the compressor motor 406 can be reliably controlled using PWM control.

(5) When the rapid hot water supply operation mode is selected, the control circuit 6 switches the pulse pattern between PHM1, PHM2, and PHM3 based on at least one of the water temperature, the outside air temperature, and the time, thereby The phase position of the alternating current power through which the two switching elements are conducted is changed, and the order of the harmonic component removed in the alternating current power supplied to the compressor motor 406 is switched. Specifically, the switching element of the inverter circuit 2 becomes conductive so that higher-order harmonic components are removed from the AC power supplied to the compressor motor 406 as the temperature of water or the outside air temperature increases. Change the phase position of AC power. Since the harmonic content in the AC power is adjusted in this way, the optimal AC power can be supplied according to the operating state of the compressor motor 406.

(6) The control circuit 6 outputs a drive signal so that a predetermined reactive current, that is, a d-axis current flows to the compressor motor 406 in the rapid hot water supply operation mode. Specifically, when the water temperature is less than about 30 ° C. and the outside air temperature is less than about −10 ° C. as shown in FIG. 28, or the water temperature is about 30 ° C. as shown in FIG. The reactive current flows through the compressor motor 406 in the rapid hot water supply operation mode when the time is less than about 22:00 to 5:00. Since it did in this way, the copper loss which the compressor motor 406 generate | occur | produces in a rapid hot-water supply operation mode can be increased, and the emitted-heat amount of the compressor motor 406 can be increased further. As a result, the hot water supply capacity of the hot water supply system 400 can be further improved.

(7) The reactive current in the rapid hot water supply operation mode is made to flow in the field weakening direction with respect to the compressor motor 406. As a result, the compressor motor 406 can be rotated at a higher speed.

  The object of the present invention described above is to significantly reduce the size of an electric heater or the like, or to eliminate the need to use an electric heater. However, the present invention can achieve the following object in addition to this point.

  As shown in FIG. 1, the outdoor unit housing 305 includes an outdoor heat exchanger 306 installed outdoors, a compressor 308 that compresses refrigerant, and a compressor motor 309 that drives the compressor 308. And a motor control device 311 that receives DC power and converts it into AC power supplied to the compressor motor 309.

  When the motor control device 311 uses a PWM control method for controlling conduction or cutoff of the switching element using a carrier wave having a constant frequency, the switching cycle of the switching element is also constant. Therefore, if the state where the switching frequency of the motor control device 311 matches the resonance frequency of the compressor or the outdoor unit housing continues for a long time, vibration due to resonance occurs and noise is generated from the outdoor unit.

  Therefore, in the present embodiment, a control method that does not use a carrier with a constant frequency in either or both of the first pulse modulator 64 and the second pulse modulator 65 using the rotational speed command f1 * of FIG. 3 as an input command. Adopted. As a control method, for example, a phase position signal corresponding to a predetermined phase position in the phase of AC power output from the motor control device 311 to the compressor motor 309 is calculated, and the switching element is turned on or off based on the phase position signal. Is to control. More specifically, there are a rectangular wave control method and the above-described PHM control method.

  Thereby, the switching cycle of the switching element becomes variable according to the frequency of the AC power output to the compressor motor 309, and the resonance of the compressor due to the switching cycle and the resonance of the outdoor unit due to the switching cycle can be suppressed. . As a result, the noise of the air conditioner can be suppressed.

  Further, as in the above-described PHM control method, the predetermined phase position that suppresses the harmonic component superimposed on the AC power is calculated, and the switching or switching of the switching element is controlled based on the phase position signal. The distortion of AC power can be suppressed while reducing the number of times the element is turned on or off, and the deterioration of the controllability of the motor can be suppressed while reducing the switching loss. With the above configuration, it is possible to improve efficiency while suppressing noise. As a result, it is possible to improve efficiency while suppressing noise.

  Further, when using a control method capable of controlling the order of the harmonic component to be suppressed as in the above-described PHM control method, the order of the harmonic component to be suppressed is determined according to the rotational speed of the compressor motor 309. . Specifically, when the rotational speed of the compressor motor 309 is in the second rotational speed region that is smaller than the first rotational speed region, the motor control device 311 has a higher order than the first rotational speed region. A predetermined phase position that suppresses the higher harmonic component is calculated, and conduction or blocking of the switching element is controlled based on the phase position signal. Thereby, the distortion of the alternating current power output to the compressor motor 309 can be suppressed, and the noise of the compressor motor 309 due to the distortion of the alternating current power can be suppressed.

  In addition, by using the above-described control method that does not use a carrier wave having a constant frequency, it is possible to prevent the pipe 312 shown in FIG. 1 from being damaged due to resonance.

  Also in the heat pump hot water supply system shown in FIG. 26, the outdoor unit 401 has a housing, and the housing drives the heat exchanger 403, the compressor 407 that compresses the refrigerant, and the compressor 407. A compressor motor 406 and a motor control device 405 that receives DC power and converts it into AC power supplied to the compressor motor 406 are housed. Therefore, when the motor control device 311 uses a carrier wave having a constant frequency, the above-described noise may be generated. Therefore, by using the above-described control method that does not use a carrier wave with a constant frequency, noise due to resonance between the carrier wave and the equipment in the outdoor unit 401 can be suppressed.

  The above description is merely an example, and the present invention is not limited to the configuration of the above embodiment.

Claims (11)

An air conditioner that performs at least a heating operation for heating a room,
An indoor heat exchanger installed indoors;
An outdoor heat exchanger installed outdoors;
A compressor for compressing a refrigerant circulated between the indoor heat exchanger and the outdoor heat exchanger;
A motor for driving the compressor;
An inverter circuit having a switching element for conducting or cutting off DC power, and generating AC power for supplying the DC power from the DC power to the motor using the switching element;
A control circuit that outputs a drive signal for controlling the operation of the switching element to the inverter circuit based on a rotation speed command;
In the heating operation, the control circuit can select any one of a plurality of operation modes including at least a quick heating operation mode and a normal operation mode for rapid heating,
In the rapid warming operation mode, the control circuit obtains a phase position of the AC power through which the switching element is conducted, outputs the drive signal based on the obtained phase position, and outputs a predetermined set temperature and room temperature. An air conditioner that changes the phase position of the AC power through which the switching element conducts so that a harmonic component of a higher order is removed from the AC power as the difference becomes smaller. In the air conditioner according to claim 1,
When the heating operation is started, the control circuit selects the quick heating operation mode,
The air conditioner in which the control circuit selects the normal operation mode when the difference between the set temperature and the room temperature is within a predetermined range after the quick warm operation mode is selected. In the air conditioner according to claim 1 or 2,
In the normal operation mode, the control circuit is an air conditioner that outputs the drive signal based on PWM control. In the air conditioner according to any one of claims 1 to 3 ,
An air conditioner that makes a current value of a reactive current flowing through the motor in the quick warming operation mode larger than a current value of a reactive current flowing through the motor in the normal operation mode. In the air conditioner according to any one of claims 1 to 4 ,
A four-way valve for switching the direction of circulation of the refrigerant,
The plurality of operation modes further include a defrosting operation mode for defrosting the outdoor heat exchanger,
When the defrosting operation mode is selected by the control circuit, the four-way valve switches the circulation direction of the refrigerant to a direction opposite to the quick warming operation mode and the normal operation mode,
In the defrosting operation mode, the control circuit obtains a phase position of the AC power at which the switching element is conducted, and outputs the drive signal based on the obtained phase position. The air conditioner according to claim 5 ,
An air conditioner that makes a current value of a reactive current flowing through the motor in the defrosting operation mode larger than a current value of a reactive current flowing through the motor in the normal operation mode. A first heat exchanger connected to a water pipe and warming water flowing in the water pipe;
A hot water storage tank for storing water heated by the first heat exchanger;
A second heat exchanger that absorbs heat from the outside air to warm the water by the first heat exchanger;
A compressor for compressing a refrigerant circulated between the first heat exchanger and the second heat exchanger;
A motor for driving the compressor;
An inverter circuit having a switching element for conducting or cutting off DC power, and generating AC power for supplying the DC power from the DC power to the motor using the switching element;
A control circuit that outputs a drive signal for controlling the operation of the switching element to the inverter circuit based on a rotation speed command;
The control circuit is capable of selecting one of a plurality of operation modes including at least a rapid hot water supply operation mode and a normal operation mode for warming the water,
In the rapid hot water supply operation mode, the control circuit obtains a phase position of the AC power through which the switching element is conducted, outputs the drive signal based on the obtained phase position, and the temperature of the water or the outside air temperature is The hot water supply system which changes the phase position of the said alternating current power which the said switching element conduct | electrically_connects so that the higher order harmonic component in the said alternating current power may be removed, so that it becomes high. The hot water supply system according to claim 7 ,
The hot water supply system, wherein the control circuit selects at least one of the rapid hot water supply operation mode and the normal operation mode based on at least one of the temperature of the water, the outside air temperature, and time. The hot water supply system according to claim 7 or 8 ,
When the normal operation mode is selected, the control circuit outputs the drive signal based on PWM control. The hot water supply system according to any one of claims 7 to 9 ,
The hot water supply system, wherein the control circuit outputs the drive signal so that a predetermined reactive current flows through the motor in the rapid hot water supply operation mode. The hot water supply system according to claim 10 ,
Wherein the control circuit, the temperature of the water is the outer air temperature is less than a predetermined first threshold value is less than a predetermined second threshold value, or the temperature of the water is not the third predetermined A hot water supply system that outputs the drive signal so that the reactive current flows through the motor in the rapid hot water supply operation mode when the time is less than the threshold and the time is within a predetermined time zone.

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