Power conversion device and apparatus using refrigeration cycle

Abstract

A power conversion device (1) comprises: a power factor improvement circuit (100) that includes at least one reactor and operates at a carrier frequency; and a noise filter part (400) that is electrically connected between the power factor improvement circuit (100) and an alternating-current power supply (600). The power conversion device (1) has at least two resonant frequencies.

Description

Power conversion equipment and refrigeration cycle application equipment

[0001] The present disclosure relates to a power conversion device that converts AC power into DC power and a refrigeration cycle device.

[0002] Conventionally, power conversion devices used in air conditioners and the like are provided with smoothing capacitors in addition to converter circuits, inverter circuits, etc., and reactors for purposes such as reducing harmonic currents. Capacitors and reactors are large components compared to other components, and in order to reduce the size of the power conversion device, the size of the capacitors and reactors must be reduced. Reducing the size of the capacitors and reactors means reducing the capacitance of the capacitors and reactors, which requires additional noise countermeasures in the power conversion device.

[0003] To address this problem, Patent Document 1 discloses a technology that eliminates the need for noise countermeasures while compacting the layout of a power conversion device. In the power conversion device described in Patent Document 1, the resonant frequency of the resonant circuit formed by the capacitor and reactor is set so that the capacitor and reactor pass ripple current components contained in the DC current output from the converter circuit and attenuate current components having the same frequency as the carrier frequency of the inverter circuit.

[0004] Patent No. 6828516

[0005] Power conversion devices used in air conditioners and the like are often provided with a noise filter section. The noise filter section is composed of a common mode choke coil, an X capacitor, which is a capacitor connected between the lines of a power supply line, and the like. Therefore, when a power conversion device provided with a noise filter section is connected to a power supply, there is a problem in that the power supply current in the power conversion device may oscillate due to the influence of the power supply inductance, the noise filter section, the reactor, and the like.

[0006] The present disclosure has been made in view of the above, and has an object to provide a power conversion device that is equipped with a noise filter unit and is capable of preventing oscillation of a power supply current.

[0007] In order to solve the above-mentioned problems and achieve the object, the power conversion device according to the present disclosure includes a power factor correction circuit that includes at least one reactor and operates at a carrier frequency, and a noise filter unit that is electrically connected between the power factor correction circuit and an AC power supply, and has at least two resonant frequencies.

[0008] The power conversion device according to the present disclosure has an advantage that it is possible to prevent oscillation of the power supply current while including a noise filter unit.

[0009] FIG. 1 is a diagram showing an example of the configuration of a power conversion device according to embodiment 1; FIG. 2 is a diagram showing an example of the configuration of a noise filter unit provided in the power conversion device according to embodiment 1; FIG. 3 is a diagram showing an example of the frequency characteristics of the power supply current flowing from the converter output voltage source to the combined power supply inductance in the equivalent circuit shown in FIG. 3; FIG. 4 is a diagram showing, as a comparative example, an example of the analyzed waveform of the power supply current when the noise filter unit is not taken into account in the power conversion device and the first resonance frequency is close to the current control response of the power factor correction circuit; FIG. 5 is a diagram showing, as a comparative example, an example of the analyzed waveform of the power supply current when the noise filter unit is not taken into account in the power conversion device and the second resonance frequency is close to the carrier frequency of the power factor correction circuit; FIG. 1 shows a configuration example when the power factor improvement circuit of the power conversion device according to embodiment 1 is a three-phase three-wire converter. FIG. 1 shows a configuration example when the power factor improvement circuit of the power conversion device according to embodiment 1 is a three-phase four-wire converter. FIG. 1 shows a configuration example when the power factor improvement circuit of the power conversion device according to embodiment 1 is a single-phase converter. FIG. 2 shows a configuration example when the power factor improvement circuit of the power conversion device according to embodiment 1 is a single-phase converter. FIG. 3 shows a configuration example when the power factor improvement circuit of the power conversion device according to embodiment 1 is a three-phase three-wire converter.

[0010] Hereinafter, a power conversion device and a refrigeration cycle application device according to an embodiment of the present disclosure will be described in detail with reference to the drawings.

[0011] First Embodiment Fig. 1 is a diagram showing an example of the configuration of a power conversion device 1 according to a first embodiment. The power conversion device 1 includes a power factor correction circuit 100 and a noise filter unit 400. The power conversion device 1 is connected to an AC power supply 600. The power factor correction circuit 100 includes a switching element, a diode, a reactor, and the like. The power factor correction circuit 100 includes at least one reactor and is configured to generate a carrier frequency f ｃｒｒ In the following description, the carrier frequency f ｃｒｒ This is the carrier frequency f ｃｒｒ The noise filter unit 400 is electrically connected between the power factor correction circuit 100 and the AC power supply 600 .

[0012] 2 is a diagram showing an example of the configuration of the noise filter unit 400 included in the power conversion device 1 according to embodiment 1. The noise filter unit 400 includes a common mode choke coil 401 and X capacitors 402 and 403 that are capacitors connected between the lines of the power supply lines.

[0013] 3 is a diagram showing an example of an equivalent circuit when the power conversion device 1 according to the first embodiment is connected to an AC power supply 600. The equivalent circuit of the power conversion device 1 is composed of a reactor 200, a converter output voltage source 300, a combined power supply inductance 700, and a noise filter unit 400. The converter output voltage source 300 means that the converter output voltage contains an AC component due to the switching of the power factor correction circuit 100. The current flowing through the reactor 200 is referred to as a reactor current i Ｌ The current flowing through the combined power supply inductance 700 is the power supply current i ｓ In the noise filter section 400, the self-inductance of the common mode choke coil 401 is cancelled out, so a leakage inductance component appears in the equivalent circuit. In the noise filter section 400, the leakage inductance component appearing in the equivalent circuit is defined as inductance 404 in the normal mode of the common mode choke coil. Hereinafter, inductance 404 in the normal mode of the common mode choke coil will be referred to as inductance 404 of the normal component of the common mode choke coil.

[0014] FIG. 4 shows the power supply current i flowing from the converter output voltage source 300 to the combined power supply inductance 700 in the equivalent circuit shown in FIG. ｓ 4 is a diagram showing an example of the frequency characteristics of the power conversion device 1. In FIG. 4, the horizontal axis indicates frequency and the vertical axis indicates gain. The equivalent circuit shown in FIG. 3 includes the reactor 200, the X capacitors 402 and 403, and the combined power supply inductance 700, and therefore two resonance points appear as shown in FIG. 4. In other words, the power conversion device 1 has two resonance frequencies. The lower of the resonance points, i.e., the resonance frequency, is referred to as the first resonance frequency f ｒ１ The higher resonance point, i.e., the resonance frequency, is called the second resonance frequency f ｒ２ It is called.

[0015] Here, if the reactor 200 is designed without taking the noise filter unit 400 into consideration, the power conversion device 1 will have a power supply current i ｓ may oscillate.

[0016] FIG. 5 shows a comparative example in which the noise filter unit 400 is not taken into consideration in the power conversion device 1 and the first resonance frequency f ｒ１ and the current control response of the power factor correction circuit 100 are close to each other. ｓ 5 is a diagram showing an example of an analysis waveform of the power supply current i ｓ is shown in the upper left, and the power supply current i ｓ is shown in the lower left. In the upper left and lower left graphs shown in Fig. 5, the horizontal axis represents time and the vertical axis represents current. As shown in Fig. 5, the first resonant frequency f ｒ１ and the current control response of the power factor correction circuit 100 are close to each other, so the power supply current i ｓ will oscillate.

[0017] FIG. 6 shows a comparative example in which the noise filter unit 400 is not taken into consideration in the power conversion device 1 and the second resonant frequency f ｒ２ and the carrier frequency f of the power factor correction circuit 100 ｃｒｒ When the power supply current i is close to ｓ6 is a diagram showing an example of an analysis waveform of the power supply current i ｓ is shown in the upper left, and the power supply current i ｓ is shown in the lower left. In the upper left and lower left graphs shown in Fig. 6, the horizontal axis represents time and the vertical axis represents current. As shown in Fig. 6, the second resonant frequency f ｒ２ and the carrier frequency f of the power factor correction circuit 100 ｃｒｒ Since the values ​​are close, the power supply current i ｓ will oscillate.

[0018] Therefore, in the following, in the power conversion device 1, the power supply current i ｓ In order to prevent this oscillation, the setting ranges of reactor 200, inductance 404 of the normal component of the common mode choke coil, and X capacitors 402 and 403 will be described taking noise filter section 400 into consideration.

[0019] FIG. 7 shows the resonant frequency generated in the power conversion device 1 according to the first embodiment and the carrier frequency f of the power factor correction circuit 100. ｃｒｒ 7, the horizontal axis represents frequency. In the power conversion device 1, the power supply current i ｓ In order to prevent oscillation, the magnitude relationship of the frequencies shown in FIG. 7 is established.

[0020] (Point 1) Specifically, the first resonant frequency f ｒ１ is the carrier frequency f ｃｒｒ This limits the range of the capacitance of the reactor 200 and the capacitance of the X capacitors 402 and 403 of the noise filter unit 400. The power conversion device 1 has a first resonant frequency f ｒ１ Therefore, the power supply current i ｓ Here, when the combined power supply inductance 700 is taken into consideration, the relationship of the following equation (1) is established.

[0021]

[0022] (Point 2) The second resonance frequency f ｒ２ As shown in equation (2), the carrier frequency f ｃｒｒ This limits the range of the capacitance of the inductance 404 of the normal component of the common mode choke coil and the capacitance of the X capacitors 402 and 403. ｒ２ Therefore, the power supply current i ｓ This can prevent oscillation.

[0023]

[0024] In addition, in formula (1) and formula (2), L １ is the capacity of the reactor 200, and L ２ is the capacitance of the inductance 404 of the normal component of the common mode choke coil, and L ３ｍａｘ is the capacitance L of the combined power supply inductance 700 ３ The capacity is the maximum value in L ３ｍｉｎ is the capacitance L of the combined power supply inductance 700 ３ The capacitance is the minimum value in ａ is the capacitance of the X capacitors 402 and 403, and k １１ and k １２ is a specified real coefficient greater than 0 and less than 1. ｒ１－１ is the first resonant frequency f when the maximum value of the combined power supply inductance 700 is taken into consideration. ｒ１ and f ｒ１－２ is the first resonant frequency f when the minimum value of the combined power supply inductance 700 is taken into consideration. ｒ１ is.

[0025] As shown in Fig. 3, the equivalent circuit of the power conversion device 1 includes a combined power supply inductance 700. The output from the converter output voltage source 300 in the equivalent circuit shown in Fig. 3 is expressed as v о The current flowing through the combined power supply inductance 700 is the power supply current iｓ Then, the power supply current i of the composite power supply inductance 700 ｓ The transfer function is expressed by equation (3).

[0026]

[0027] In formula (3), L ３ is the capacitance of the combined power supply inductance 700. The frequency at which the denominator of equation (3) becomes zero is the resonant frequency. Approximate, the first resonant frequency f ｒ１ can be expressed as equation (4), and the second resonant frequency f ｒ２ can be expressed as in equation (5).

[0028]

[0029]

[0030] Therefore, if the power conversion device 1 can be expressed by an equivalent circuit as shown in FIG. 3, the resonant frequency can be calculated from the equations (4) and (5). ３ The larger the first resonance frequency f ｒ１ will be lower.

[0031] Hereinafter, specific explanations will be given for the cases where the power factor correction circuit 100 of the power conversion device 1 is a single-phase converter, a three-phase three-wire converter, and a three-phase four-wire converter.

[0032] First, a case where the power conversion device 1 is a single-phase converter will be described. Fig. 8 is a first diagram showing a configuration example when the power factor correction circuit 100 of the power conversion device 1 according to the first embodiment is a single-phase converter. The power factor correction circuit 100 of the power conversion device 1 shown in Fig. 8 includes a diode bridge, a reactor, a switching element, a diode, and a capacitor. When the power factor correction circuit 100 of the power conversion device 1 shown in Fig. 8 is a single-phase converter, and the power factor correction circuit 100 is applied to the equivalent circuit of Fig. 3, L １ is the capacity of reactor 200, and L ２ When the common mode choke coil 401 is one stage, it is the capacitance of the inductance 404 of the normal component of the common mode choke coil for 2×1 phase, and L ３is the capacitance of the combined power supply inductance 700 for 2×1 phase.

[0033] (Point 3) When the power factor correction circuit 100 is a single-phase converter, the capacity L of the reactor 200 １ and the capacitance C of the X capacitors 402 and 403 ａ The product of these is the carrier frequency f ｃｒｒ That is, the range is limited based on the capacity L of the reactor 200. １ and the capacitance C of the X capacitors 402 and 403 ａ The range of the resonant frequency and carrier frequency f ｃｒｒ By making the relational expression, when the power conversion device 1 is connected to the AC power supply 600, the reactor capacity for the combined power supply inductance 700, that is, the capacity L ３ Even when the first resonant frequency f ｒ１ Therefore, the power supply current i of the composite power supply inductance 700 can be ｓ The relational expression at this time is expressed by equation (6).

[0034]

[0035] In this way, when the power factor correction circuit 100 is a single-phase converter, the capacity L of the reactor 200 is １ and the capacitance C of the X capacitors 402 and 403 ａ The product of these is the carrier frequency f ｃｒｒ The range is limited by equation (6) based on the above.

[0036] Point 3 is the capacity L of reactor 200. １ The first resonance frequency f ｒ１ is the carrier frequency f ｃｒｒ In other words, by moving the power conversion device 1 away from the band of current control, the power supply current i ｓ Equation (6) can prevent the oscillation of k １１ = 0.1, L ３Even when the power conversion device 1 is actually connected to the AC power supply 600, the power supply current i ｓ Although the configuration of the noise filter unit 400 has been described in the case of the π-type filter shown in FIG. 2 and the like, any configuration other than the π-type filter may be used as long as a resonant circuit is formed by a reactor and an X capacitor.

[0037] (Point 4) When the power factor correction circuit 100 is a single-phase converter, the capacity L of the reactor 200 １ and the capacitance C of the X capacitors 402 and 403 ａ The product of these is the carrier frequency f ｃｒｒ That is, the range is limited based on the capacity L of the reactor 200. １ and the capacitance C of the X capacitors 402 and 403 ａ The range of the resonant frequency and the carrier frequency f ｃｒｒ By making the relational expression, when the power conversion device 1 is connected to the AC power supply 600, the reactor capacity for the combined power supply inductance 700, that is, the capacity L ３ Even when the first resonant frequency f ｒ１ Therefore, the power supply current i of the composite power supply inductance 700 can be ｓ The relational expression at this time is expressed by equation (7).

[0038]

[0039] In this way, when the power factor correction circuit 100 is a single-phase converter, the capacity L of the reactor 200 is １ and the capacitance C of the X capacitors 402 and 403 ａ The product of these is the carrier frequency f ｃｒｒ The range is limited by equation (7) based on the above.

[0040] Point 4 is the capacity L of reactor 200. １ The first resonance frequency f ｒ１ is the carrier frequency f ｃｒｒIn other words, by moving the power conversion device 1 away from the band of current control, the power supply current i ｓ Equation (7) can prevent the oscillation of k １２ = 0.9982, L ３ Even when the power conversion device 1 is actually connected to the AC power supply 600, the power supply current i ｓ Although the configuration of the noise filter unit 400 has been described in the case of the π-type filter shown in FIG. 2 and the like, any configuration other than the π-type filter may be used as long as a resonant circuit is formed by a reactor and an X capacitor.

[0041] (Point 5) When the power factor correction circuit 100 is a single-phase converter, the capacitance L of the inductance 404 of the normal component of the common mode choke coil of the noise filter unit 400 ２ and the capacitance C of the X capacitors 402 and 403 ａ The second resonant frequency f ｒ２ is the carrier frequency f ｃｒｒ That is, the capacitance L of the inductance 404 of the normal component of the common mode choke coil of the noise filter section 400 is set to a higher value. ２ and the capacitance C of the X capacitors 402 and 403 ａ The power conversion device 1 has a second resonant frequency f ｒ２ Therefore, the power supply current i of the composite power supply inductance 700 can be ｓ The relational expression at this time is expressed by equation (8).

[0042]

[0043] In this way, when the power factor correction circuit 100 is a single-phase converter, the capacitance L of the inductance 404 of the normal component of the common mode choke coil ２ and the capacitance C of the X capacitors 402 and 403 ａ The product of these is the carrier frequency f ｃｒｒ The range is limited by equation (8) based on the above.

[0044] Point 5 is the capacitance L of the inductance 404 of the normal component of the common mode choke coil of the noise filter section 400. ２ and the capacitance C of the X capacitors 402 and 403 ａ The second resonant frequency f ｒ２ is the carrier frequency f ｃｒｒ By increasing the power supply inductance 700, the power conversion device 1 can reduce the power supply current i ｓ Equation (8) can prevent the carrier frequency f ｃｒｒ <Second resonance frequency f ｒ２ In this way, the power conversion device 1 has a capacitance L of the inductance 404 of the normal component of the common mode choke coil of the noise filter unit 400 that satisfies the formula (8). ２ and the capacitance C of the X capacitors 402 and 403 ａ By setting the above, even when the power conversion device 1 is actually connected to the AC power supply 600, the power supply current i ｓ Although the configuration of the noise filter unit 400 has been described in the case of the π-type filter shown in FIG. 2 and the like, any configuration other than the π-type filter may be used as long as a resonant circuit is formed by a reactor and an X capacitor.

[0045] Although the power factor correction circuit 100 provided in the power conversion device 1 has been described as a single-phase converter as shown in Fig. 8, the present invention is not limited to this as long as it can be transformed into an equivalent circuit as shown in Fig. 3. The power factor correction circuit 100 may be an interleaved converter. Furthermore, although the configuration of the noise filter unit 400 has been described as including one stage of common mode choke coil 401, the configuration may include two or more stages of common mode choke coil 401.

[0046] Next, a case where the power conversion device 1 is a three-phase three-wire converter will be described. Fig. 9 is a first diagram showing a configuration example when the power factor correction circuit 100 of the power conversion device 1 according to the first embodiment is a three-phase three-wire converter. The power factor correction circuit 100 of the power conversion device 1 shown in Fig. 9 includes three reactors, a converter circuit having a plurality of switching elements, and a capacitor. When the power factor correction circuit 100 of the power conversion device 1 shown in Fig. 9 is a three-phase three-wire converter, and the power factor correction circuit 100 is applied to the equivalent circuit of Fig. 3, L １ is the capacity of reactor 200, and L ２ When the common mode choke coil 401 is two-stage, it is the capacitance of the inductance 404 of the normal component of the common mode choke coil for 2×1 phase, and L ３ is the capacitance of the combined power supply inductance 700 for one phase. When the power conversion device 1 is a three-phase three-wire converter, the concept is the same as when the power conversion device 1 is a single-phase converter.

[0047] (Point 6) When the power factor correction circuit 100 is a three-phase three-wire converter, the capacity L of the reactor 200 １ and the capacitance C of the X capacitors 402 and 403 ａ The product of these is the carrier frequency f ｃｒｒ That is, the range is limited based on the capacity L of the reactor 200. １ and the capacitance C of the X capacitors 402 and 403 ａ The range of the resonant frequency and carrier frequency f ｃｒｒ By making the relational expression, when the power conversion device 1 is connected to the AC power supply 600, the reactor capacity for the combined power supply inductance 700, that is, the capacity L ３ Even when the first resonant frequency f ｒ１ Therefore, the power supply current i of the composite power supply inductance 700 can be ｓ The relational expression at this time is expressed by equation (9).

[0048]

[0049] In this way, when the power factor correction circuit 100 is a three-phase three-wire converter, the capacity L of the reactor 200 is １ and the capacitance C of the X capacitors 402 and 403 ａ The product of these is the carrier frequency f ｃｒｒ The range is limited by equation (9) based on the above.

[0050] Point 6 is the capacity L of reactor 200. １ The first resonance frequency f ｒ１ is the carrier frequency f ｃｒｒ In other words, by moving the power conversion device 1 away from the band of current control, the power supply current i ｓ Equation (9) can prevent the oscillation of k １１ = 0.1643, L ３ Even when the power conversion device 1 is actually connected to the AC power supply 600, the power supply current i ｓ Although the configuration of the noise filter unit 400 has been described in the case of the π-type filter shown in FIG. 2 and the like, any configuration other than the π-type filter may be used as long as a resonant circuit is formed by a reactor and an X capacitor.

[0051] (Point 7) When the power factor correction circuit 100 is a three-phase three-wire converter, the capacity L of the reactor 200 １ and the capacitance C of the X capacitors 402 and 403 ａ The product of these is the carrier frequency f ｃｒｒ That is, the range is limited based on the capacity L of the reactor 200. １ and the capacitance C of the X capacitors 402 and 403 ａ The range of the resonant frequency and the carrier frequency f ｃｒｒ By making the relational expression, when the power conversion device 1 is connected to the AC power supply 600, the reactor capacity for the combined power supply inductance 700, that is, the capacity L ３ Even when the first resonant frequency f ｒ１Therefore, the power supply current i of the composite power supply inductance 700 can be ｓ The relational expression at this time is expressed by equation (10).

[0052]

[0053] In this way, when the power factor correction circuit 100 is a three-phase three-wire converter, the capacity L of the reactor 200 is １ and the capacitance C of the X capacitors 402 and 403 ａ The product of these is the carrier frequency f ｃｒｒ The range is limited by equation (10) based on the above.

[0054] Point 7 is the capacity L of reactor 200. １ The first resonance frequency f ｒ１ is the carrier frequency f ｃｒｒ In other words, by moving the power conversion device 1 away from the band of current control, the power supply current i ｓ Equation (10) can prevent the oscillation of k １２ = 0.9991, L ３ Even when the power conversion device 1 is actually connected to the AC power supply 600, the power supply current i ｓ Although the configuration of the noise filter unit 400 has been described in the case of the π-type filter shown in FIG. 2 and the like, any configuration other than the π-type filter may be used as long as a resonant circuit is formed by a reactor and an X capacitor.

[0055] (Point 8) When the power factor correction circuit 100 is a three-phase three-wire converter, the capacitance L of the inductance 404 of the normal component of the common mode choke coil of the noise filter unit 400 ２ and the capacitance C of the X capacitors 402 and 403 ａ The second resonant frequency f ｒ２ is the carrier frequency f ｃｒｒ That is, the capacitance L of the inductance 404 of the normal component of the common mode choke coil of the noise filter section 400 is set to a higher value. ２and the capacitance C of the X capacitors 402 and 403 ａ The power conversion device 1 has a second resonant frequency f ｒ２ Therefore, the power supply current i of the composite power supply inductance 700 can be ｓ The relational expression at this time is expressed by equation (11). Note that equation (11) is the same as equation (8) above.

[0056]

[0057] In this way, when the power factor correction circuit 100 is a three-phase three-wire converter, the capacitance L of the inductance 404 of the normal component of the common mode choke coil ２ and the capacitance C of the X capacitors 402 and 403 ａ The product of these is the carrier frequency f ｃｒｒ The range is limited by equation (11) based on the above.

[0058] Point 8 is the capacitance L of the inductance 404 of the normal component of the common mode choke coil of the noise filter section 400. ２ and the capacitance C of the X capacitors 402 and 403 ａ The second resonant frequency f ｒ２ is the carrier frequency f ｃｒｒ By increasing the power supply inductance 700, the power conversion device 1 can reduce the power supply current i ｓ Equation (11) can prevent the carrier frequency f ｃｒｒ <Second resonance frequency f ｒ２ In this way, the power conversion device 1 has a capacitance L of the inductance 404 of the normal component of the common mode choke coil of the noise filter unit 400 that satisfies the formula (11). ２ and the capacitance C of the X capacitors 402 and 403 ａ By setting the above, even when the power conversion device 1 is actually connected to the AC power supply 600, the power supply current i ｓAlthough the configuration of the noise filter unit 400 has been described in the case of the π-type filter shown in FIG. 2 and the like, any configuration other than the π-type filter may be used as long as a resonant circuit is formed by a reactor and an X capacitor.

[0059] Although the configuration of the noise filter section 400 has been described in the case where the common mode choke coil 401 is one stage, the common mode choke coil 401 may be configured to have two or more stages.

[0060] Next, a case where the power conversion device 1 is a three-phase four-wire converter will be described. Fig. 10 is a first diagram showing a configuration example when the power factor correction circuit 100 of the power conversion device 1 according to the first embodiment is a three-phase four-wire converter. The power factor correction circuit 100 of the power conversion device 1 shown in Fig. 10 includes three reactors, a converter circuit having a plurality of switching elements, and a capacitor. When the power factor correction circuit 100 of the power conversion device 1 shown in Fig. 10 is a three-phase four-wire converter, and the power factor correction circuit 100 is applied to the equivalent circuit of Fig. 3, L １ is the capacity of reactor 200, and L ２ When the common mode choke coil 401 is two-stage, L is the capacitance of the inductance 404 of the normal component of the common mode choke coil for 4 × 1 phase. ３ is the capacitance of the combined power supply inductance 700 for two phases. When the power conversion device 1 is a three-phase four-wire converter, the concept is the same as when the power conversion device 1 is a single-phase converter.

[0061] (Point 9) When the power factor correction circuit 100 is a three-phase four-wire converter, the capacity L of the reactor 200 １ and the capacitance C of the X capacitors 402 and 403 ａ The product of these is the carrier frequency f ｃｒｒ That is, the range is limited based on the capacity L of the reactor 200. １ and the capacitance C of the X capacitors 402 and 403 ａ The range of the resonant frequency and carrier frequency f ｃｒｒBy making the relational expression, when the power conversion device 1 is connected to the AC power supply 600, the reactor capacity for the combined power supply inductance 700, that is, the capacity L ３ Even when the first resonant frequency f ｒ１ Therefore, the power supply current i of the composite power supply inductance 700 can be ｓ The relational expression at this time is expressed by equation (12).

[0062]

[0063] In this way, when the power factor correction circuit 100 is a three-phase four-wire converter, the capacity L of the reactor 200 is １ and the capacitance C of the X capacitors 402 and 403 ａ The product of these is the carrier frequency f ｃｒｒ The range is limited by equation (12) based on

[0064] Point 9 is the capacity L of the reactor 200. １ The first resonance frequency f ｒ１ is the carrier frequency f ｃｒｒ In other words, by moving the power conversion device 1 away from the band of current control, the power supply current i ｓ Equation (12) can prevent the oscillation of k １１ =0.08872,L ３ Even when the power conversion device 1 is actually connected to the AC power supply 600, the power supply current i ｓ Although the configuration of the noise filter unit 400 has been described in the case of the π-type filter shown in FIG. 2 and the like, any configuration other than the π-type filter may be used as long as a resonant circuit is formed by a reactor and an X capacitor.

[0065] (Point 10) When the power factor correction circuit 100 is a three-phase four-wire converter, the capacity L of the reactor 200 １ and the capacitance C of the X capacitors 402 and 403 ａ The product of these is the carrier frequency f ｃｒｒThat is, the range is limited based on the capacity L of the reactor 200. １ and the capacitance C of the X capacitors 402 and 403 ａ The range of the resonant frequency and the carrier frequency f ｃｒｒ By making the relational expression, when the power conversion device 1 is connected to the AC power supply 600, the reactor capacity for the combined power supply inductance 700, that is, the capacity L ３ Even when the first resonant frequency f ｒ１ Therefore, the power supply current i of the composite power supply inductance 700 can be ｓ The relational expression at this time is expressed by equation (13).

[0066]

[0067] In this way, when the power factor correction circuit 100 is a three-phase four-wire converter, the capacity L of the reactor 200 is １ and the capacitance C of the X capacitors 402 and 403 ａ The product of these is the carrier frequency f ｃｒｒ The range is limited by equation (13) based on the above.

[0068] Point 10 is the capacity L of reactor 200. １ The first resonance frequency f ｒ１ is the carrier frequency f ｃｒｒ In other words, by moving the power conversion device 1 away from the band of current control, the power supply current i ｓ Equation (13) can prevent the oscillation of k １２ = 0.9872, L ３ Even when the power conversion device 1 is actually connected to the AC power supply 600, the power supply current i ｓ Although the configuration of the noise filter unit 400 has been described in the case of the π-type filter shown in FIG. 2 and the like, any configuration other than the π-type filter may be used as long as a resonant circuit is formed by a reactor and an X capacitor.

[0069] (Point 11) When the power factor correction circuit 100 is a three-phase four-wire converter, the capacitance L of the inductance 404 of the normal component of the common mode choke coil of the noise filter unit 400 ２ and the capacitance C of the X capacitors 402 and 403 ａ The second resonant frequency f ｒ２ is the carrier frequency f ｃｒｒ That is, the capacitance L of the inductance 404 of the normal component of the common mode choke coil of the noise filter section 400 is set to a higher value. ２ and the capacitance C of the X capacitors 402 and 403 ａ The power conversion device 1 has a second resonant frequency f ｒ２ Therefore, the power supply current i of the composite power supply inductance 700 can be ｓ The relational expression at this time is expressed by equation (14). Note that equation (14) is the same as equations (8) and (11) described above.

[0070]

[0071] In this way, when the power factor correction circuit 100 is a three-phase four-wire converter, the capacitance L of the inductance 404 of the normal component of the common mode choke coil ２ and the capacitance C of the X capacitors 402 and 403 ａ The product of these is the carrier frequency f ｃｒｒ The range is limited by equation (14) based on

[0072] Point 11 is the capacitance L of the inductance 404 of the normal component of the common mode choke coil of the noise filter section 400. ２ and the capacitance C of the X capacitors 402 and 403 ａ The second resonant frequency f ｒ２ is the carrier frequency f ｃｒｒ By increasing the power supply inductance 700, the power conversion device 1 can reduce the power supply current i ｓ Equation (14) can prevent the oscillation of the carrier frequency f ｃｒｒ <Second resonance frequency f ｒ２In this way, the power conversion device 1 has a capacitance L of the inductance 404 of the normal component of the common mode choke coil of the noise filter unit 400 that satisfies the formula (14). ２ and the capacitance C of the X capacitors 402 and 403 ａ By setting the above, even when the power conversion device 1 is actually connected to the AC power supply 600, the power supply current i ｓ Although the configuration of the noise filter unit 400 has been described in the case of the π-type filter shown in FIG. 2 and the like, any configuration other than the π-type filter may be used as long as a resonant circuit is formed by a reactor and an X capacitor.

[0073] Although the configuration of the noise filter section 400 has been described in the case where the common mode choke coil 401 is one stage, the common mode choke coil 401 may be configured to have two or more stages.

[0074] The specific configuration of the power conversion device 1 is not limited to the examples shown in FIGS. 8 to 10 . FIG. 11 is a second diagram showing a configuration example when the power factor correction circuit 100 of the power conversion device 1 according to embodiment 1 is a single-phase converter. The power factor correction circuit 100 of the power conversion device 1 shown in FIG. 11 includes a diode bridge, a reactor, switching elements, a diode, and a capacitor. The power conversion device 1 shown in FIG. 11 differs from the power conversion device 1 shown in FIG. 8 in the position of the reactor. FIG. 12 is a third diagram showing a configuration example when the power factor correction circuit 100 of the power conversion device 1 according to embodiment 1 is a single-phase converter. The power factor correction circuit 100 of the power conversion device 1 shown in FIG. 12 includes a reactor, a converter circuit having a plurality of switching elements, and a capacitor. In this way, the power conversion device 1 may be configured to include a converter circuit.

[0075] 13 is a second diagram showing a configuration example when the power factor correction circuit 100 of the power conversion device 1 according to the first embodiment is a three-phase three-wire converter. The power factor correction circuit 100 of the power conversion device 1 shown in FIG. 13 includes three reactors, a diode bridge, switching elements, a diode, and a capacitor. In this way, the power conversion device 1 may be configured to include a diode bridge.

[0076] 14 is a second diagram showing a configuration example when the power factor correction circuit 100 of the power conversion device 1 according to the first embodiment is a three-phase four-wire converter. The power factor correction circuit 100 of the power conversion device 1 shown in FIG. 14 includes three reactors, a diode bridge, switching elements, a diode, and a capacitor. In this way, the power conversion device 1 may be configured to include a diode bridge.

[0077] As described above, according to this embodiment, the power conversion device 1 includes the power factor correction circuit 100 and the noise filter unit 400. In the power conversion device 1, the first resonant frequency f ｒ１ is the carrier frequency f of the power factor correction circuit 100 ｃｒｒ The product of the capacity of the reactor and the capacity of the X capacitor included in the power factor correction circuit 100 is set lower than the carrier frequency f ｃｒｒ In the power conversion device 1, the range is limited based on the second resonance frequency f ｒ２ is the carrier frequency f of the power factor correction circuit 100 ｃｒｒ The product of the capacitance of the inductance 404 of the normal component of the common mode choke coil included in the power factor correction circuit 100 and the capacitance of the X capacitor is set higher than the carrier frequency f ｃｒｒ As a result, the power conversion device 1, which includes the noise filter unit 400, can reduce the power supply current i ｓ It is possible to prevent oscillation.

[0078] Second Embodiment In the first embodiment, the case where the power conversion device 1 has two resonant frequencies has been described. In the second embodiment, the case where the power conversion device 1 has three resonant frequencies will be described.

[0079] Fig. 15 is a first diagram showing an example of an equivalent circuit when the power conversion device 1 according to the second embodiment is connected to an AC power supply 600. The equivalent circuit of the power conversion device 1 shown in Fig. 15 is different from the equivalent circuit of the power conversion device 1 of the first embodiment shown in Fig. 3 in the configuration of the noise filter section 400. The noise filter section 400 of the equivalent circuit of the power conversion device 1 shown in Fig. 15 has an X capacitor 405 and a normal component inductance 406 of the common mode choke coil added to the noise filter section 400 of the equivalent circuit of the power conversion device 1 shown in Fig. 3. In this case, the power conversion device 1 has three resonant frequencies.

[0080] Fig. 16 is a second diagram showing an example of an equivalent circuit when the power conversion device 1 according to the second embodiment is connected to an AC power supply 600. The equivalent circuit of the power conversion device 1 shown in Fig. 16 is different from the equivalent circuit of the power conversion device 1 of the first embodiment shown in Fig. 3 in the configuration of the noise filter section 400. The noise filter section 400 of the equivalent circuit of the power conversion device 1 shown in Fig. 16 has X capacitors 405 and 407 and normal component inductances 406 and 408 of the common mode choke coil added to the noise filter section 400 of the equivalent circuit of the power conversion device 1 shown in Fig. 3. In this case, the power conversion device 1 has four resonant frequencies.

[0081] In this way, the power conversion device 1 has at least two resonant frequencies. Even when the power conversion device 1 has three or more resonant frequencies, the two resonant frequencies on the low frequency side are set to the carrier frequency f ｃｒｒ and the first resonant frequency f ｒ１ and the carrier frequency f ｃｒｒ and the second resonant frequency f ｒ２ By making the relationship between the power conversion device 1 and the AC power supply 600 satisfy the above, the power supply current i ｓThis can prevent oscillation.

[0082] Although the noise filter unit 400 has been described as having a π-type filter configuration, this is not limiting. The noise filter unit 400 does not necessarily have to have a π-type filter configuration, as long as a resonant circuit is formed by the inductance of the normal component of the common mode choke coil and the X capacitor, and the configuration can be converted into the equivalent circuit of the power conversion device 1 as shown in FIG. 3, 15, or 16. Furthermore, by connecting one or more π-type filters or two or more T-type filters as the configuration of the noise filter unit 400, the equivalent circuit of the power conversion device 1 becomes as shown in FIG. 3, 15, or 16, and the power conversion device 1 has two or more resonant frequencies. Furthermore, although the noise filter unit 400 has been described as having one or two common mode choke coils, the number of common mode choke coil stages may be any number, since it is considered as a combined inductance. Furthermore, L ２ Although the capacitance of the inductance 404 of the normal component of the common mode choke coil has been described, it can be similarly considered as the inductance component of the noise filter section 400. In the power conversion device 1, the noise filter section 400 includes a common mode choke coil 401 of one or more stages.

[0083] Third Embodiment Fig. 17 is a diagram showing a configuration example of a refrigeration cycle-applied device 900 according to a third embodiment. The refrigeration cycle-applied device 900 according to the third embodiment includes the power conversion device 1 described in the first embodiment and the like. The refrigeration cycle-applied device 900 according to the third embodiment can be applied to products equipped with a refrigeration cycle, such as air conditioners, refrigerators, freezers, and heat pump water heaters. In Fig. 17, components having the same functions as those in the first embodiment are denoted by the same reference numerals as those in the first embodiment. The power conversion device 1 shown in Fig. 17 includes an inverter (not shown) for driving a motor 916.

[0084] The refrigeration cycle applied device 900 includes a compressor 914 , a four-way valve 902 , an indoor heat exchanger 906 , an expansion valve 908 , and an outdoor heat exchanger 910 attached via refrigerant piping 912 .

[0085] Inside the compressor 914, a compression mechanism 904 that compresses the refrigerant and a motor 916 that operates the compression mechanism 904 are provided.

[0086] The refrigeration cycle device 900 can perform heating or cooling operation by switching the four-way valve 902. The compression mechanism 904 is driven by a motor 916 that is variably controlled in speed.

[0087] During heating operation, as shown by the solid arrow, the refrigerant is pressurized by the compression mechanism 904 and sent out, passes through the four-way valve 902, the indoor heat exchanger 906, the expansion valve 908, the outdoor heat exchanger 910 and the four-way valve 902 and returns to the compression mechanism 904.

[0088] During cooling operation, as shown by the dashed arrow, the refrigerant is pressurized by the compression mechanism 904 and sent out, and returns to the compression mechanism 904 through the four-way valve 902, the outdoor heat exchanger 910, the expansion valve 908, the indoor heat exchanger 906 and the four-way valve 902.

[0089] During heating operation, the indoor heat exchanger 906 acts as a condenser to release heat, and the outdoor heat exchanger 910 acts as an evaporator to absorb heat. During cooling operation, the outdoor heat exchanger 910 acts as a condenser to release heat, and the indoor heat exchanger 906 acts as an evaporator to absorb heat. The expansion valve 908 reduces the pressure of the refrigerant to expand it.

[0090] The configurations shown in the above embodiments are merely examples, and may be combined with other known technologies, or different embodiments may be combined with each other. It is also possible to omit or modify parts of the configurations as long as they do not deviate from the gist of the invention.

[0091] 1 Power conversion device, 100 Power factor correction circuit, 200 Reactor, 300 Converter output voltage source, 400 Noise filter section, 401 Common mode choke coil, 402, 403, 405, 407 X capacitor, 404, 406, 408 Inductance of normal component of common mode choke coil, 600 AC power source, 700 Combined power source inductance, 900 Refrigeration cycle applied equipment, 902 Four-way valve, 904 Compression mechanism, 906 Indoor heat exchanger, 908 Expansion valve, 910 Outdoor heat exchanger, 912 Refrigerant piping, 914 Compressor, 916 Motor.

Claims

1. a power factor correction circuit including at least one reactor and operating at a carrier frequency; a noise filter unit electrically connected between the power factor correction circuit and an AC power supply, the noise filter unit including an X capacitor, which is a capacitor connected between lines of a power supply line, and a common mode choke coil; Equipped with The inverter has at least two resonant frequencies, and a first resonant frequency generated by the reactor and the noise filter unit is set lower than the carrier frequency. Power conversion device.

2. The product of the capacity of the reactor and the capacity of the X capacitor is limited in range based on the carrier frequency. The power conversion device according to claim 1 .

3. When the power factor correction circuit is a single-phase converter, the capacity L of the reactor １ and the capacitance C of the X capacitor ａ The product of these is the frequency f of the carrier frequency ｃｒｒ Based on this, the range is limited by the following formula (1): The power conversion device according to claim 2 . [Equation 1]

4. When the power factor correction circuit is a single-phase converter, the capacity L of the reactor １ and the capacitance C of the X capacitor ａ The product of these is the frequency f of the carrier frequency ｃｒｒ Based on this, the range is limited by the following formula (2): The power conversion device according to claim 2 . [Equation 2]

5. When the power factor correction circuit is a three-phase three-wire converter, the capacity L of the reactor １ and the capacitance C of the X capacitor ａ The product of these is the frequency f of the carrier frequency ｃｒｒ Based on this, the range is limited by the following formula (3): The power conversion device according to claim 2 . [Equation 3]

6. When the power factor correction circuit is a three-phase three-wire converter, the capacity L of the reactor １ and the capacitance C of the X capacitor ａ The product of these is the frequency f of the carrier frequency ｃｒｒ Based on this, the range is limited by the following formula (4): The power conversion device according to claim 2 . [Equation 4]

7. When the power factor correction circuit is a three-phase four-wire converter, the capacity L of the reactor １ and the capacitance C of the X capacitor ａ The product of these is the frequency f of the carrier frequency ｃｒｒ Based on this, the range is limited by the following formula (5): The power conversion device according to claim 2 . [Equation 5]

8. When the power factor correction circuit is a three-phase four-wire converter, the capacity L of the reactor １ and the capacitance C of the X capacitor ａ The product of these is the frequency f of the carrier frequency ｃｒｒ Based on this, the range is limited by the following formula (6): The power conversion device according to claim 2 . [Equation 6]

9. A power factor correction circuit including at least one reactor and operating at a carrier frequency; a noise filter unit electrically connected between the power factor correction circuit and an AC power supply, the noise filter unit including an X capacitor, which is a capacitor connected between lines of a power supply line, and a common mode choke coil; Equipped with The noise filter has at least two resonance frequencies, and a second resonance frequency generated by the noise filter is set higher than the carrier frequency. Power conversion device.

10. The range of the product of the capacitance of the inductance of the normal component of the common mode choke coil and the capacitance of the X capacitor is limited based on the carrier frequency. The power conversion device according to claim 9.

11. When the power factor correction circuit is a single-phase converter, a three-phase three-wire converter, or a three-phase four-wire converter, the capacitance L of the inductance of the normal component of the common mode choke coil is ２ and the capacitance C of the X capacitor ａ The product of these is the frequency f of the carrier frequency ｃｒｒ Based on this, the range is limited by the following formula (7): The power conversion device according to claim 10. [Equation 7]

12. the noise filter unit includes one or more stages of the common mode choke coil; The power conversion device according to claim 1 .

13. the noise filter unit is a π-type filter; The power conversion device according to claim 1 .

14. A refrigeration cycle device comprising the power conversion device according to any one of claims 1 to 13.

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