JP2006042529A - Inverter control device of air conditioner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To achieve further improvement of operation efficiency and further reduction of loss, undesired sound, and noise in an air conditioner. <P>SOLUTION: A SiC (silicon carbide) is applied to an inverter 9, in an inverter control device of the air conditioner provided with a PWM inverter that comprises a rectifier 6, a DC reactor 7, a DC smoothing capacitor 8, and the inverter 9 to drive a compressor 1 of the air conditioner that has a coolant circuit where the compressor 1, a condenser 2, a throttle device 3, and a evaporator 4 are connected with coolant piping. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an inverter control device for an air conditioner, and more particularly to an inverter control device for an air conditioner in which various characteristics such as operation efficiency and noise are improved.

  In recent years, it has become a common configuration to apply an inverter device also in the field of an air conditioner, and an electric motor provided in a compressor of the air conditioner is driven at a variable speed by PWM control of the inverter device. High-efficiency operation control and detailed air-conditioning capability control are realized.

  By the way, in such a conventional air conditioner equipped with an inverter device, an IGBT (Insulated Gate Bipolar Transistor) element is applied to the main circuit of the inverter device for variable speed control of the electric motor. Is common (for example, Patent Document 1).

  In the air conditioner disclosed in this document, in order to reduce noise caused by the induction motor with an inverter and realize high-efficiency operation, the compressor of the air conditioner and the induction driving this compressor are used. The motor is hermetically sealed in the chamber, and an IGBT is used as a switching element of an inverter that controls the rotation of the induction motor, and a carrier frequency for inverter control is set to a frequency of 4 kHz to 10 kHz.

JP-A-8-35711

  However, the prior art disclosed in Patent Document 1 has the following problems because the IGBT element is applied to the main circuit of the inverter device for variable speed control of the electric motor.

  That is, in the conventional air conditioner, it is necessary to limit the heat generation due to the switching loss of the IGBT element itself in relation to the operating temperature characteristics of the IGBT element, and the upper limit of the carrier frequency is about 15 KHz. Therefore, a large amount of ripple current remains at the output of the inverter device, resulting in problems such as a reduction in operating efficiency of the motor and noise.

  Further, the loss of the IGBT element is determined by the magnitude of “Vce × Ic” as in the case of a general transistor, but in the light load operation which is a steady operation state, the loss in the above “Vce × Ic” Since Vce changes at a substantially constant value, there is a problem that it is difficult to improve the operation efficiency (inverter efficiency).

  Further, a current called a recovery current flows through a flywheel diode (hereinafter referred to as “FWD diode”) connected in parallel to the IGBT during a period in which the IGBT element is off, and a harmonic current ( There is a problem that large noise is generated due to ripple current.

  The present invention has been made in view of the above, and has an inverter control that can realize an air conditioner with higher efficiency, lower loss, lower noise, and lower noise as compared with conventional air conditioners. An object is to provide an apparatus.

  In order to solve the above-described problems and achieve the object, an inverter control device of an air conditioner according to the present invention has a refrigerant circuit in which a compressor, a condenser, a throttle device, and an evaporator are connected by a refrigerant pipe. In the inverter control device for an air conditioner comprising a PWM inverter having a rectifier that drives the compressor of the air conditioner, a DC reactor, a DC smoothing capacitor, and an inverse converter, SiC (silicon A carbide element is applied.

  According to the inverter control device of the air conditioner according to the present invention, since the SiC (silicon carbide) element is applied to the inverter, the loss when the air conditioner is operated at a light load can be reduced. There is an effect that can be done.

  Embodiments of an inverter control device for an air conditioner according to the present invention will be described below in detail with reference to the drawings. In addition, this invention is not limited by this embodiment.

Embodiment 1 FIG.
FIG. 1 is a diagram illustrating a schematic configuration of an air-conditioning apparatus including an inverter control device according to Embodiment 1 of the present invention. In the upper right part of the figure, the compressor 1, the condenser 2, the throttling means (decompressor) 3, and the evaporator 4 are sequentially connected by a refrigerant pipe to constitute a refrigerant circuit of the air conditioner. On the other hand, a PWM inverter 15 which is a main circuit of the inverter control device is configured in the upper left part of the figure. That is, the PWM inverter 15 includes a power source 5, a rectifier 6 including a diode, a DC reactor 7, a DC smoothing capacitor 8, and an inverse converter 9 to which a SiC (silicon carbide) module is applied as a switching element. Moreover, each control means of the inverter control apparatus which controls the PWM inverter 15 and controls the compressor 1 of an air conditioning apparatus is comprised by the lower part of the figure. That is, each control means of the inverter control device includes a DC bus voltage detecting means 10, an output current detecting means 11, an output frequency setting means 12, a PWM calculating means 13, and an inverse converter driving means 14.

  In each of these control means, the DC bus voltage detection means 10 detects the voltage applied to the inverse converter 9, and the output current detection means 11 detects the output current output from the inverse converter 9 to the compressor 1. To detect. Based on signals from the DC bus voltage detection means 10, the output current detection means 11, and the output frequency setting means 12, the PWM calculation means 13 determines the required air conditioning capability of the air conditioner and the required drive torque when driving the compressor. A PWM calculation signal that is output is generated and output to the inverse converter driving means 14. The inverse converter drive means 14 performs PWM control on the inverse converter 9 on which the SiC module is mounted based on the PWM calculation signal output from the PWM calculation means 13.

  In the air conditioner of this embodiment, the SiC module is applied to the inverter 9 as described above. The SiC module has features such that the switching operation is faster than that of the IGBT module and can be operated even at a very high temperature (for example, 200 degrees or more). Therefore, even if the carrier frequency is increased to 15 KHz or more by the PWM calculation means 13, it can be operated without any problem. For example, the problem of heat generation caused by high-speed switching operation does not occur. Further, since the switching operation itself is high speed, the switching loss is reduced, and the distortion component of the output voltage and the output current can be reduced. In addition, since the response characteristic to the transient state becomes high speed, the generation of noise due to the recovery current of the FWD diode is also reduced. Furthermore, by setting the carrier frequency to 15 KHz or more, noise based on the carrier sound can be shifted to a high audible range. Furthermore, since the control frequency can be increased by setting the carrier frequency to 15 KHz or more, detailed operation control for the air conditioner can be easily realized.

Moreover, the air conditioning apparatus provided with the inverter control apparatus according to this embodiment has the following advantages in terms of loss. FIG. 2 is a diagram showing loss characteristics based on Ic of IGBT and SiC. Since the SiC module has a structure equivalent to that of a MOSFET, its loss characteristic is “Ron × Ic ² ” as shown in FIG. The loss characteristic of the IGBT is “Vce × Ic”. In general, when the air conditioner is operated with a light load, the operation becomes low frequency and the collector current becomes small. Therefore, in the case of low frequency operation, the “Ron × Ic ² ” curve has a lower loss than the “Vce × Ic” curve, as shown in FIG. It can be reduced on the order of squares.

  As described above, in this embodiment, since the SiC module is applied to the inverter provided in the inverter control device of the air conditioner, the carrier frequency of PWM control is set to 15 KHz or more. Thus, an air conditioner can be realized in which various characteristics relating to efficiency, loss, noise, noise and the like are improved as compared with a conventional air conditioner.

  In the above description, the case of controlling by raising the carrier frequency of PWM control to 15 KHz or more has been described in detail, but it is needless to say that in the same configuration, the carrier frequency can be lowered to 15 KHz or less. That is.

Embodiment 2. FIG.
FIG. 3A is a diagram illustrating an installation place of the inverter 9 provided in the inverter control device according to the second embodiment of the present invention. The change from Embodiment 1 shown in FIG. 1 is characterized in that an inverse converter 9 to which SiC is applied is placed in close contact with the compressor 1 or the discharge pipe connecting the compressor 1 and the condenser 2. There is. In addition, about another structure, it is the same as that of Embodiment 1, or is equivalent, The illustration of those parts is abbreviate | omitted.

  FIG. 3-2, FIG. 3-3, and FIG. 3-4 show specific examples of the arrangement of the inverse converter 9. FIG. That is, FIG. 3-2 is a diagram illustrating an example in which the upper surface of the compressor has a discharge temperature and the inverse converter 9 is attached to the portion, and FIG. 3-3 is the discharge side of the compressor. It is a figure which shows an example which set it as the structure, and attached the reverse converter 9 to the site | part, FIG. 3-4 is a figure which shows an example which set it as the attachment structure which can radiate heat to discharge piping, and attached the reverse converter 9 to the site | part It is. In addition to the arrangement examples shown in FIGS. 3-2 to 3-4, if there is a high-temperature part (for example, an oil separator) that can move heat with respect to the refrigerant, it may be installed in the part. .

  3-5 is a diagram for explaining the heat dissipation structure of the inverse converter 9. FIG. In the inverter control device according to the present invention, since the SiC module is applied to the inverter 9, it is desired to avoid exposing the charging unit and the like while the inverter 9 is very hot. For this reason, as shown in the figure, portions other than the heat radiation surface of the SiC module 9A are covered with an insulating heat insulating material 9B. By adopting such a heat dissipation structure, the exhaust heat of SiC can be used for a cooling operation or a cycle of heating operation while utilizing the characteristics of SiC that can be used even at high temperatures. Moreover, since the installation site is a high-temperature part that is equal to or higher than the ambient temperature, there is also an advantage that there is no concern about condensation.

  As described above, according to the inverter control device of the air conditioner of this embodiment, the inverse converter is brought into close contact with the high temperature part on the refrigerant circuit of the air conditioner, so that heat exchange is performed. There is an effect that the exhaust heat can be used for a cooling operation or a heating operation cycle.

Embodiment 3 FIG.
FIG. 4 is a diagram illustrating the configuration of the inverter control device according to the third embodiment of the present invention. In the inverter control device shown in the figure, in addition to the configuration of the first embodiment shown in FIG. 1, a small capacity normal choke 16 is added to the output wiring between the inverter 9 and the compressor 1. In addition, about another structure, it is the same as that of Embodiment 1, or is equivalent, The illustration of those parts is abbreviate | omitted.

  Since the output of the inverter control device is generated by intermittent on / off control of the switching element, the current flowing in the output wiring connecting the inverse converter 9 and the compressor 1 inevitably contains a high frequency component. . Therefore, when the electric motor included in the compressor is operated with high efficiency, a choke coil having a predetermined inductance component is generally inserted between the inverter 9 and the compressor 1. It is a configuration.

  On the other hand, in the present invention, the SiC module is applied to the inverter provided in the inverter control device of the air conditioner, and the carrier frequency for PWM control is set to 15 KHz or higher, so the carrier frequency of 15 KHz or lower was used. Compared to the case, the frequency component of the distortion current is shifted to a high frequency. Therefore, the suppression of the high-frequency component of the distortion current caused by the increase in the carrier frequency has a desired effect with a small-capacity choke coil as compared with an inverter control device using a conventional IGBT element. Obtainable.

  As described above, according to the inverter control device of the air conditioner of this embodiment, since an element having an inductance component is inserted into the electrical wiring connecting the inverse converter and the compressor, the carrier frequency The high frequency component of the distortion current caused by the higher frequency can be effectively suppressed with a small-capacity inductance component.

Embodiment 4 FIG.
FIG. 6 is a diagram illustrating a circuit configuration of the inverter 9 included in the inverter control device according to the fourth embodiment of the present invention. FIG. 5 is a diagram showing a circuit configuration of an inverse converter 9 that has been generally employed conventionally, and is shown for comparison with the circuit configuration of FIG. FIG. 5 is compared with FIG. 6. In FIG. 5, the upper arm (each element connected to the + side of the DC smoothing capacitor 8) side and the lower arm (the + side of the DC smoothing capacitor 8) are opposite. Each element) connected to the terminal on the side is an N-channel element 18, but in FIG. 6, the upper arm side is the P-channel element 17 and the lower arm side is the N-channel element 18. The function is realized. As shown in FIG. 6, the drive power supply is not displaced by the operation of each element of the upper and lower arms because the element on the upper arm side is a complementary connection having a reverse polarity relationship with the element on the lower arm side. It has the advantage that it can be shared. In each element of the upper and lower arms, the drain part is usually connected so as to be connected to the insulating substrate, but the source part is connected to the insulating substrate so as to dissipate heat, whereby the potential of each element with respect to the insulating substrate is set. Fluctuation is suppressed and it is effective in improving noise.

  As described above, according to the inverter control device of the air conditioner of this embodiment, the upper arm of the inverse converter is configured by the FET channel P-channel element, and the lower arm is configured by the FET channel N-channel element. Therefore, the potential fluctuation of each element with respect to the insulating substrate can be suppressed, and noise can be reduced.

Embodiment 5. FIG.
The fifth embodiment relates to the function of generating the PWM calculation signal of the PWM calculation means 13. More specifically, the influence of the operation delay of the switching element in the inverse converter 9 is localized and compressed from the inverse converter 9. The present invention relates to a function for generating a PWM calculation signal capable of suppressing errors and harmonic components of an output voltage output to the machine 1. In the first to fourth embodiments, the switching element provided in the inverter 9 has been described as being limited to the SiC module. However, this embodiment is not limited to the SiC module. It can also be applied to switching elements such as IGBTs. In addition, about another structure, it is the same as that of Embodiment 1, or is equivalent, The illustration of those parts is abbreviate | omitted.

  FIG. 7A is a diagram illustrating an output voltage waveform of the three-phase inverter by the 180 ° energization method. In the figure, U, V, and W indicate the on / off switching of the upper and lower arms, and the upper waveform is shown when the upper arm is on, and the lower waveform is shown when the lower arm is on. Is shown. The energization time of the upper arm and the energization time of the lower arm are equal and are energized every 180 °. On the other hand, each part of Vuv, Vvw, Vwu shows the voltage waveform between the output lines of the three-phase inverter corresponding to the on / off of the upper and lower arms, and the wave height is based on the voltage Vdc of the DC part.

  FIG. 7-2 is a schematic diagram showing a voltage vector and a current vector generated in a Y-type load connected to a three-phase inverter driven by a 180 ° energization method, and FIG. 7-3 is a 180 ° energization method. It is the schematic which shows the voltage vector and current vector which arise in the (DELTA) -type load connected to the three-phase inverter driven by. The 180 ° energization method is characterized in that either the upper arm or the lower arm is always turned on. As a result, the line voltage Vuv is obtained in both the Y-type load and the Δ-type load. , Vvw, Vwu, either “± Vdc” or “0” appears.

  On the other hand, FIG. 8A is a diagram illustrating an output voltage waveform of the three-phase inverter by the 120 ° energization method. The definition of the waveform of each part of U, V, and W and the waveform of each part of Vuv, Vvw, and Vwu are the same as in FIG. The 120 ° energization method is common to the 180 ° energization method in that the energization time of the upper arm and the energization time of the lower arm are the same, but there is a section in which neither the upper arm nor the lower arm element is on. This is different from the 180 ° energization method. As a result, when the waveforms of the respective parts of Vuv, Vvw, and Vwu shown in FIG. 8A are viewed, the output line voltage produces an output voltage of ± (1/2) Vdc in addition to ± Vdc. The voltage of ± (1/2) Vdc is obtained by dividing the line voltage generated between both ends of the phase in which either the upper arm or the lower arm is on, and the output phase current is 0. This occurs at the terminal portion of the phase where neither the upper arm nor the lower arm is on.

  FIG. 8-2 is a schematic diagram showing a voltage vector and a current vector generated in a Y-type load connected to a three-phase inverter driven by a 120 ° energization method, and FIG. 8-3 is a drive by a 120 ° energization method. It is the schematic which shows the voltage vector and current vector which arise in the (DELTA) type load connected to the three-phase inverter made. As shown in these figures, the current flowing inside the load varies depending on whether the three-phase load is Y-connected or Δ-connected, but the output line voltage between the terminals where the output phase current is not 0 or the output phase current There is no difference depending on whether the terminal voltage or the like of the phase is 0 or Y connection or Δ connection.

  In both the 180 ° energization method and the 120 ° energization method, these output potentials (for example, “± Vdc” and “0” in the 180 ° energization method, and “± Vdc” and “± ( 1/2) Vdc ") is generated by a combination of on / off of the upper and lower arms (so-called" powering vector ") and a combination of three upper arms or three lower arms (so-called" zero vector ") ) Can be combined to generate a wide variety of output voltages and transition to a variety of output voltages.

  FIG. 9 and FIG. 10 are diagrams for explaining the function of generating the PWM calculation signal according to the fifth embodiment. More specifically, FIG. 9 shows the selection vector (power running vector and zero vector) in the 120 ° energization method. ) And a region surrounded by the selection vector. FIG. 10 is a chart showing combinations of selection vectors (powering vector and zero vector) selected for each region shown in FIG. For comparison with the 120 ° energization method, selection vectors and combinations of selection vectors in the 180 ° energization method are shown in FIGS. 11 and 12, respectively.

  Returning to FIG. 9, Vuv, Vvw, and Vwu are coordinate axes indicating the direction of the line voltage vector, and each have a phase difference of 120 °. The numbers in parentheses attached to the inner small hexagonal vertex and the outer large hexagonal vertex indicate the operating status (on / off combination) of the upper and lower arms, and each operating status is “1”. “= Upper arm on”, “0” = lower arm on, and “1/2” = upper and lower arms off. Each of the upper and lower arms can take any one of the three states “1”, “0”, and “1/2”, and therefore 3 × 3 × 3 = 27 combinations are possible. As combinations (power running vectors) in which voltages are generated, 12 vectors from the origin to the respective vertices of the above-mentioned large and small hexagons correspond. Of these vectors, {(1, 0, 1), (0, 0, 1), (0, 1, 1), (0, 1, 0), (1, 1, 0), ( 1,0,0)} has a vector length of 1 (corresponding to the output of “± Vdc”), {(1,0,1 / 2), (1 / 2,0,1), (0,1 / 2, 1), (0, 1, 1/2), (1/2, 1, 0), (1, 1/2, 0)} has a vector length of 1 / (√3) (“ Equivalent to the output of “± (1/2) Vdc”). The remaining 15 vectors excluding these 12 vectors are zero vectors in which no output voltage is generated.

  By combining such a power running vector and a zero vector, it is possible to generate an arbitrary voltage vector in 24 regions a to x shown in FIG. More specifically, two powering vectors in the vicinity of each region (for example, (1, 0, 1/2) and (1/2, 0, 1) for region a) and an optimum zero for each region Vectors can be generated in combination with their respective generation time ratios. FIG. 10 shows combinations of selection vectors selected for each region and optimum zero vectors for each region.

  In FIG. 10, for example, two vectors (1/2, 0, 1) and (0, 1/2, 1) are selected as arbitrary voltage vectors (powering vectors) in the region b, and are optimal for the region b. As a zero vector, (1/2, 1/2, 1) is selected. The reason why this zero vector is optimal is the transition pattern of the upper and lower arms. For example, when transitioning from (1/2, 0, 1), which is one vector of the power vector of region b, to (1/2, 1/2, 1), which is the zero vector of region b, It is only necessary to turn the second switching element of the arm from on to off. In addition, when transitioning from (0, 1/2, 1), which is the other vector of the power vector of region b, to (1/2, 1/2, 1), which is the zero vector of region b, It is only necessary to turn the first switching element of the arm from on to off.

  This is greatly different from the case of the 180 ° energization method shown in FIGS. In the case of the 180 ° energization method, selectable zero vectors are a combination of (0, 0, 0) or (1, 1, 1) as shown at the origin in FIG. In the case of the 180 ° energization method, for example, when a transition is made from (1, 0, 1), which is a power vector of region A, to (1, 1, 1), which is one of zero vectors of region A, It is necessary to transition the second switching element of the arm from OFF to ON, and to transition the second switching element of the lower arm from ON to OFF. In other words, in the case of the 180 ° energization method, the two states of the upper arm and the lower arm have to be changed. Therefore, the number of times of switching increases compared to the case of the 120 ° energization method, and the operation delay of the switching element, etc. Are affected, and these effects are accumulated to increase output voltage errors and harmonic components of the output voltage.

  In the case of the 180 ° energization method, it is necessary to set an upper and lower short-circuit prevention period in order to prevent the switching elements of the upper arm and the lower arm from being turned on simultaneously, and the distortion of the output voltage is further increased. On the other hand, in the case of the 120 ° energization method, by selecting the optimum zero vector for each region, the 1/2 pattern can be effectively used when the voltage vector is switched. Since switching can be avoided, the setting of the upper and lower short-circuit prevention period is unnecessary, and distortion of the output voltage is suppressed.

  In the case of the 180 ° energization method, only the output voltage of “0” or “Vdc” can be used as the output voltage, so that the use of the zero vector cannot be suppressed. To use a lot of zero vectors means to increase the influence of the operation delay of the element and to reduce the average output of the output voltage at the same time. Therefore, it is desirable to avoid using the zero vectors as much as possible. On the other hand, in the 120 ° energization method, in particular, in the case of a small voltage output, the output voltage of “(1/2) Vdc” can be used as the output voltage, so that the use of the zero vector can be suppressed. effective. Further, since the potential fluctuation can be suppressed low by using the output voltage of “(1/2) Vdc”, an effect of further suppressing the distortion of the output voltage can be obtained.

  As described above, according to the inverter control device of the air conditioner of this embodiment, the PWM calculation signal for controlling the PWM inverter constituted by the three-phase inverter is based on the selection vector of the 120 ° energization method. Therefore, the influence of the operation delay of the switching element in the inverse converter can be localized, and the error and the harmonic component of the output voltage output to the compressor can be suppressed.

  As described above, the inverter control device of the air conditioner according to the present invention is useful for the operation control of the air conditioner, in particular, the improvement of the operation efficiency of the air conditioner, the noise level generated from the air conditioner, It is suitable for improving the noise level.

It is a block diagram which shows the structure of the inverter control apparatus of the air conditioning apparatus concerning this invention. It is a figure which shows the loss characteristic based on Ic of IGBT and SiC. It is a figure which shows the installation place of the reverse converter comprised by the inverter control apparatus concerning Embodiment 2 of this invention. It is a figure which shows an example which attached the reverse converter to the compressor upper surface as a structure site | part used as discharge temperature. It is a figure which shows an example which attached the reverse converter to the compressor side surface as a structure site | part used as discharge temperature. It is a figure which shows an example which attached the reverse converter to the discharge piping as an attachment structure site | part which can thermally radiate. It is a figure for demonstrating the heat dissipation structure of an inverse converter. It is a figure which shows the structure of the inverter control apparatus concerning Embodiment 3 of this invention. It is a figure which shows the circuit structure of the inverse converter concerning a prior art. It is a figure which shows the circuit structure of the reverse converter comprised by the inverter control apparatus concerning Embodiment 4 of this invention. It is a figure which shows the output voltage waveform of the three-phase inverter by a 180 degree energization system. It is the schematic which shows the voltage vector and current vector which arise in the Y-type load connected to the three-phase inverter driven by the 180 degree energization method. It is the schematic which shows the voltage vector and current vector which arise in the (DELTA) type load connected to the three-phase inverter driven by the 180 degrees energization system. It is a figure which shows the output voltage waveform of the three-phase inverter by a 120 degree electricity supply system. It is the schematic which shows the voltage vector and current vector which arise in the Y-type load connected to the three-phase inverter driven by the 120 degree energization method. It is the schematic which shows the voltage vector and current vector which arise in the (DELTA) type load connected to the three-phase inverter driven by the 120 degrees energization system. It is a figure which shows the area | region enclosed by the selection vector (power running vector and zero vector) in a 120 degree electricity supply system, and a selection vector. 10 is a chart showing combinations of selection vectors (powering vector and zero vector) selected for each region shown in FIG. 9. It is a figure which shows the area | region enclosed by the selection vector (power running vector and zero vector) in a 180 degrees electricity supply system, and a selection vector. 12 is a chart showing combinations of selection vectors (powering vector and zero vector) selected for each region shown in FIG. 11.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Condenser 3 Throttling means 4 Evaporator 5 Power supply 6 Rectifier 7 DC reactor 8 DC smoothing capacitor 9 Inverter 9A SiC module 9B Heat insulating material 10 DC bus voltage detection means 11 Output current detection means 12 Output frequency setting means 13 PWM arithmetic means 14 Inverter drive means 15 PWM inverter 16 Normal choke 17 P channel element 18 N channel element

Claims (7)

A compressor, a condenser, a throttle device, and a rectifier, a DC reactor, a DC smoothing capacitor, and an inverse converter for driving the compressor of an air conditioner having a refrigerant circuit in which an evaporator is connected by a refrigerant pipe. In an inverter control device for an air conditioner equipped with a PWM inverter,
An inverter control device for an air conditioner, wherein a SiC (silicon carbide) element is applied to the inverse converter.   2. The inverter control device for an air conditioner according to claim 1, wherein heat exchange is performed by bringing the inverse converter into close contact with a high temperature portion on a refrigerant circuit of the air conditioner in the previous period.   The inverter control device for an air conditioner according to claim 1, wherein the PWM inverter is operated at a carrier frequency of 15 kHz or more.   The inverter control device for an air conditioner according to claim 1, wherein an element having an inductance component is inserted into an electrical wiring connecting the inverse converter and the compressor.   The inverse converter includes FET-structured elements as an upper arm and a lower arm, wherein the upper arm is composed of a P-channel element, and the lower arm is composed of an N-channel element. The inverter control apparatus of the air conditioning apparatus of claim | item 1. A compressor, a condenser, a throttle device, and a rectifier, a DC reactor, a DC smoothing capacitor, and an inverse converter for driving the compressor of an air conditioner having a refrigerant circuit in which an evaporator is connected by a refrigerant pipe. In an inverter control device for an air conditioner equipped with a PWM inverter,
Inverse converter driving means for PWM controlling the inverse converter;
PWM calculation means for generating a PWM calculation signal to be output to the inverse converter driving means based on the applied voltage to the inverse converter, the output current from the inverse converter and the setting information of the output frequency;
With
The PWM inverter is a three-phase inverter,
The inverter control device for an air conditioner, wherein the PWM calculation signal is generated based on a selection vector of a 120 ° energization method.   The inverter control apparatus for an air conditioner according to claim 6, wherein a SiC (silicon carbide) element or an IGBT (insulated gate bipolar transistor) element is applied to the inverse converter.

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