JP4893157B2 - Power converter - Google Patents

Description

  The present invention relates to noise reduction in a power converter, and more particularly, to suppression of noise source current flowing through a ground line of a cooling fin.

  In the conventional power converter, a filter capacitor for charging power, an inverter, a detachable unit in which the inverter is housed, a first core group installed on the input side in the unit, and an output side in the unit It is composed of a second core group that is installed, supplies overhead power, and outputs power to the load. By arranging the first and second core groups in the immediate vicinity of the semiconductor element which is a noise generation source, it is possible to prevent a phenomenon in which a leakage current flows through a floating capacitance existing between the wiring and the device box frame ( For example, see Patent Document 1).

  Also, when installing a heat receiving plate to dissipate the semiconductor element, attach the heat receiving plate to the housing through a sufficiently thick insulator and electrically connect it to the grounding point through a conductive wire through a resistor. The resonance current flowing through the closed loop path can be suppressed. The resistor connected to the ground line gives a damping effect to the current flowing through the ground line (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2004-187368 (page 5, FIG. 1) JP 2002-136153 A (pages 3 to 4, FIG. 1)

  In the conventional power converter, when installing fins, which are heat receiving plates, to dissipate semiconductor elements, via the stray capacitance between the inverter and the fin, the inverter → fin → ground line → filter capacitor → inverter path As a result, a resonance path is formed by stray inductance in the stray capacitance and the ground line, and a resonance current flows through the ground line in accordance with the switching operation of the semiconductor element constituting the inverter. This resonance current becomes a radiation noise source, which has a problem of inducing interference and affecting the radio wave band. In order to suppress resonance, it is possible to prevent the resonance current from becoming a radiation noise source by connecting a resistance to the ground line and giving a damping effect to the resonance current. However, a separate resistance is provided for the ground line. There is a need. In addition, since the resistor has a generally constant impedance from low frequency to high frequency, selecting a high impedance resistor to suppress the relatively high frequency current that is the source of radiation noise increases the impedance to the low frequency band you want to ground. Therefore, there is a problem that sufficient grounding cannot be obtained.

  The present invention has been made to solve the above-described problems, and provides a sufficient damping effect for the resonance operation without providing a separate resistance or the like for the resonance path via the grounding line, and is low. A power converter capable of obtaining a grounding action with sufficiently low impedance in the frequency domain is obtained.

A power converter according to a first aspect of the present invention receives power from a DC power supply system, drives an load, cooling means for cooling the inverter, high-voltage wiring connecting the DC power supply system and the inverter, and grounds the inverter. A core having a through-hole through which the ground wiring passes and a ground wire for grounding the cooling means are characterized in that the ground wire is wound around the core and then connected to the ground wiring between the core and the inverter. To do.

A power conversion device according to a second aspect of the present invention is a power converter that receives power from a direct-current power supply system and drives a load, a cooling means that cools the inverter, and a second hole that has a through-hole through which load wiring connects the inverter and the load. And a ground wire for grounding the cooling means, and the ground wire is wound around the second core and then connected to a ground wire in the vicinity of the inverter .

A power conversion device according to a third aspect of the invention receives an electric power from a DC power supply system, drives an load, cooling means for cooling the inverter, high-voltage wiring connecting the DC power supply system and the inverter, and grounds the inverter. A core having a through hole through which the ground wiring passes, a ground wire for grounding the cooling means, and a ground wire core having a through hole around which the ground wire is wound , the ground wire between the core and the inverter It is connected to the ground wiring .

  A power converter according to a fourth aspect of the present invention is a converter that receives power from an AC power supply system and generates a DC voltage, an inverter that receives the DC voltage and drives a load, and a first cooling means that cools the inverter; A second cooling means for cooling the converter, a third core having a through-hole through which the low-voltage side wiring connecting the AC power supply system and the converter, a first grounding line for grounding the first cooling means, A second grounding wire for grounding the second cooling means, wherein the first grounding wire and the second grounding wire are each wound around a third core and then grounded. It is.

  A power converter according to a fifth aspect of the invention is a converter that receives power from an AC power supply system and generates a DC voltage, an inverter that receives the DC voltage and drives a load, and a first cooling means that cools the inverter; Second cooling means for cooling the converter, a fourth core having a through hole through which load wiring connecting the inverter and the load is passed, a first grounding line for grounding the first cooling means, and a second cooling And a second grounding wire for grounding the means, wherein the first grounding wire and the second grounding wire are wound around the fourth core and then grounded.

  A power conversion device according to a sixth aspect of the invention includes a converter that receives power from an AC power supply system and generates a DC voltage, an inverter that receives the DC voltage and drives a load, and a first cooling means that cools the inverter; A second cooling means for cooling the converter, a third core having a through-hole through which the low-voltage side wiring connecting the AC power supply system and the converter, a first grounding line for grounding the first cooling means, A second grounding wire for grounding the second cooling means; a first grounding wire core having a through hole around which the first grounding wire is wound; and a through hole around which the second grounding wire is wound. And a second grounding wire core.

A power conversion device according to a seventh aspect of the invention receives an electric power from a DC power supply system, drives an load, cooling means for cooling the inverter, high-voltage wiring connecting the DC power supply system and the inverter, and grounds the inverter. A core having a through-hole through which the ground wiring is passed and a ground wire for grounding the cooling means, and a ground loop, the cooling means, the inverter, and the ground wiring constitute a wiring loop that passes through the core through-hole. It is a feature.

  According to the first to sixth inventions, since the ground wire for grounding the cooling means for cooling the inverter is wound around the core having the through hole, the cooling means is increased by increasing the high-frequency impedance of the ground wire. It is possible to suppress the noise source current that occurs with resonance through the grounding wire.

  Further, according to the seventh aspect, since the wiring loop constituted by the ground wire, the cooling means, the inverter, and the ground wire passes through the core having the through hole, the noise source current can be suppressed.

Embodiment 1 FIG.
FIG. 1 is a configuration diagram of a power conversion apparatus showing Embodiment 1 for carrying out the present invention. In FIG. 1, a power converter 101 receives power from a DC power supply system via a pantograph 1 and a reactor 2 that collect DC system voltage, converts the DC voltage into AC voltage, and drives a motor 6 that is a load. It is comprised by the inverter 4, the capacitor | condenser 3, and the fin 5 which is a cooling means which cools the semiconductor element which comprises the inverter 4. FIG. In addition, two wires are provided: a high-voltage wire 21 that connects the reactor 2 connected to the DC power supply system and the inverter 4, and a ground wire 22 that grounds the inverter 4 to the ground 7. Furthermore, load wirings 23a, 23b, and 23c for connecting the inverter 4 and the motor 6 that is a load are provided.

  The power conversion device 101 includes a core 8 having a through-hole through which the high-voltage wiring 21 and the ground wiring 22 pass, and a ground wire 9 that grounds the fin 5 serving as a cooling means. The ground wire 9 is wound around the core 8. After being turned, it is grounded to earth 7. By installing the core 8, it is possible to reduce the common mode current that leaks to the power system side generated by the inverter 4. If the number of windings for winding the core 8 is at least one or more, there is an effect of noise reduction. As the number of turns increases, the noise reduction effect also improves, but there is a possibility that stray capacitance occurs between the wound windings. In addition, the core 8 may be selected according to the specifications of the power conversion device 101. However, in this embodiment, for example, a ring-shaped ferrite core having an outer diameter of about 120 mm, an inner diameter of about 100 mm, and a thickness of about 30 mm is also used.

  When the ground line 9 is directly grounded without going through the core 8, the path of the inverter 4 → fin 5 → ground line 9 → capacitor 3 → inverter 4 through the stray capacitance between the inverter 4 and the fin 5. Thus, a resonance path is formed by stray capacitance and stray inductance in the ground line 9 and the like. However, when the ground wire 9 is wound around the core 8 as in the present embodiment, the resonance frequency of the resonance path is lowered by the impedance of the core 8. Further, if the material of the core 8 is such that the main component of impedance at the resonance frequency of the core 8 is resistance, a damping effect can be obtained with respect to the resonance path.

  Thus, by grounding the core 8 around the core 8 and grounding, the existing core 8 can be used to lower the resonance frequency or obtain resonance damping without providing a new resistor. it can. For this reason, the resonance frequency by the path of the inverter 4 → fin 5 → ground line 9 → capacitor 3 → inverter 4 can be shifted to a desired low resonance frequency, or a damping effect can be given to the resonance itself. Can be brought into a state where there is no practical problem. In this way, it is possible to take measures against the radiation noise source without increasing the component cost.

  Also, since the ground wire 9 can be configured with a relatively thin wire harness or the like since there is no power transfer, it can be easily wound around the core 8, and the impedance can be increased by simply increasing the number of turns wound around the core 8. Can be increased to the required amount. In the present embodiment, a wire harness having a diameter of about 10 mm is used. Furthermore, since the core 8 is made of, for example, ferrite or amorphous, the impedance is low in the low frequency band near the direct current, and the impedance does not increase remarkably even if the number of turns wound around the core 8 is increased. Thus, a low impedance is obtained in a low frequency band while obtaining a high impedance, and a sufficient grounding effect can be obtained in the vicinity of the direct current. Specifically, the effect of noise reduction is remarkable in a frequency band of about 100 kHz to several MHz. The ground wire 9 may be directly grounded to the ground 7 after being wound around the core 8.

  As described above, since the ground wire 9 that grounds the fin 5 that cools the inverter 4 is wound around the core 8 having the through-hole, the ground wire 9 of the fin 5 is increased by increasing the high-frequency impedance of the ground wire 9. It is possible to suppress the noise source current that occurs with resonance via the.

Embodiment 2. FIG.
FIG. 2 is a configuration diagram of a power conversion device showing Embodiment 2 for carrying out the present invention. In FIG. 2, the second core 10 is installed between the inverter 4 and the load 6 and is different from the first embodiment in that no core is installed on the DC power supply system side of the inverter 4. 2, the same reference numerals as those in FIG. 1 denote the same or corresponding parts, and this is common throughout the entire specification. Moreover, the aspect of the component which appears in the whole specification is an illustration to the last, and is not limited to these description.

  In FIG. 2, the power conversion device 102 includes a second core 10 having a through hole through which load wirings 23 a, 23 b, and 23 c that connect the inverter 4 and the motor 6 that is a load are collectively passed. In addition, a ground wire 11 for grounding the fin 5 as a cooling means is provided, and the ground wire 11 is wound around the second core 10 and then grounded to the ground 7. The second core 10 suppresses a common mode current generated by the inverter 4 via the motor 6.

  When the ground line 11 is directly grounded without passing through the second core 10, the inverter 4 → fin 5 → ground line 11 → capacitor 3 → inverter via the stray capacitance between the inverter 4 and the fin 5. The resonance path is formed by the stray capacitance and the stray inductance in the ground line 11 and the like by the four paths. However, when the ground wire 11 is wound around the second core 10 as in the present embodiment, the resonance frequency of the resonance path is lowered by the impedance of the second core 10. Further, if the material of the second core 10 is such that the main component of impedance at the resonance frequency of the second core 10 is resistance, a damping effect can be obtained with respect to the resonance path.

  In this way, the ground wire 11 wraps around the second core 10 and grounds it, so that the existing second core 10 can be used to lower the resonance frequency or provide resonance without using a new resistor. Since damping can be obtained, the resonance frequency by the path of inverter 4 → fin 5 → ground line 11 → capacitor 3 → inverter 4 can be shifted to a desired low resonance frequency, or the resonance itself can be given a damping effect. A radiation noise source can be made into a state which does not become a problem practically. In this way, it is possible to take measures against the radiation noise source without increasing the component cost.

  In addition, since the ground wire 11 can be configured with a relatively thin wire harness because there is no power transfer, it can be easily wound around the second core 10 and the number of turns that can be easily wound around the second core 10. By increasing the impedance, the impedance can be increased to the required amount. Furthermore, since the second core 10 is made of, for example, ferrite or amorphous, the impedance is low in the low frequency band near the direct current, and the impedance increases remarkably even if the number of turns wound around the second core 10 is increased. Without obtaining a high impedance in the resonance frequency band, the impedance becomes low in the low frequency band, and a sufficient grounding effect can be obtained in the vicinity of the direct current.

  As described above, since the ground wire 11 that grounds the fin 5 that cools the inverter 4 is wound around the second core 10 having the through-hole, by increasing the high-frequency impedance of the ground wire 11, It is possible to suppress a noise source current that occurs with resonance through the ground wire 11.

Embodiment 3 FIG.
FIG. 3 is a configuration diagram of a power conversion device showing Embodiment 3 for carrying out the present invention.
In FIG. 3, the second embodiment is different from the first embodiment in that a second core 10 is installed between the inverter 4 and the motor 6 that is a load. In FIG. 3, the power conversion device 103 collects load wirings 23 a, 23 b, and 23 c that connect the inverter 4 and the motor 6 that is a load, in addition to the core 8 having a through hole through which the high-voltage wiring 21 and the ground wiring 22 pass. A second core 10 having a through-hole through which it passes. Further, a ground wire 12 for grounding the fin 5 as a cooling means is provided. The ground wire 12 is wound around the second core 10 and then wound around the core 8 and grounded to the ground 7. . The ground wire 12 may be wound around the core 8 and further wound around the second core 10 before being grounded to the ground 7.

  When the ground line 12 is directly grounded without going through the core 8 and the second core 10, the inverter 4 → fin 5 → ground line 12 → capacitor via the stray capacitance between the inverter 4 and the fin 5. 3 → The path of the inverter 4 forms a resonance path by stray capacitance and stray inductance in the ground line 12 and the like. However, when the ground wire 12 is wound around the core 8 and the second core 10 as in the present embodiment, the resonance frequency of the resonance path is lowered by the impedance of the core 8 and the second core 10. Further, if the material of the core 8 and the second core 10 is such that the main component of the impedance at the resonance frequency of the core 8 and the second core 10 is a resistance, a damping effect is exerted on the resonance path. can get.

  As described above, the ground wire 12 is wound around the core 8 and the second core 10 and grounded, so that the resonance frequency can be obtained using the existing core 8 and the second core 10 without newly providing a resistor. Can be lowered or resonance damping can be obtained. For this reason, the resonance frequency by the path of the inverter 4 → fin 5 → ground line 12 → capacitor 3 → inverter 4 can be shifted to a desired low resonance frequency, or a damping effect can be given to the resonance itself. Can be brought into a state where there is no practical problem. In this way, it is possible to take measures against the radiation noise source without increasing the component cost.

  Further, since the ground wire 12 can be configured with a relatively thin wire harness since there is no power transfer, it can be easily wound around the core 8 and the second core 10, respectively. By increasing the number of turns wound around each of the cores 10, the impedance can be increased to a necessary amount. Furthermore, since the core 8 and the second core 10 are made of, for example, ferrite or amorphous, the impedance is low in a low frequency band near the direct current, and the number of turns wound around each of the core 8 and the second core 10 is reduced. Even if the impedance is increased, the impedance does not increase remarkably. While obtaining a high impedance in the resonance frequency band, the impedance becomes low in the low frequency band, and a sufficient grounding effect can be obtained in the vicinity of the direct current. In addition, since the impedances of the existing core 8 and the second core 10 are simultaneously used, a further attenuation effect can be obtained with respect to the resonance current flowing through the ground line 12 of the fin 5. Also, since the ground wire 12 of the fin 5 is the only ground wire, and the ground wire 12 is wound around the core 8 and the second core 10, the effect of noise reduction by the two cores can be achieved simultaneously without increasing the number of ground wires. can get.

  As described above, since the ground wire 12 that grounds the fin 5 that cools the inverter 4 is wound around the core 8 and the second core 10 that have the through holes, by increasing the high-frequency impedance of the ground wire 12, It is possible to further suppress the noise source current that occurs with resonance through the ground line 12 of the fin 5.

Embodiment 4 FIG.
FIG. 4 is a configuration diagram of a power conversion device showing Embodiment 4 for carrying out the present invention.
In FIG. 4, the ground wire 61 is not wound around the core 8 but differs from the first embodiment in that the ground wire 61 is wound around a ground wire core 60 different from the core 8. In FIG. 4, the power conversion device 104 includes a ground wire core 60 having a through hole around which the ground wire 61 is wound, in addition to the core 8 having a through hole through which the high-voltage wiring 21 and the ground wiring 22 pass. Yes. The ground line 61 may be connected to the ground wiring side of the inverter 4 or may be directly connected to the ground 7.

  When the grounding wire 61 is directly grounded without going through the grounding wire core 60, the inverter 4 → fin 5 → grounding wire 61 → capacitor 3 → inverter via the stray capacitance between the inverter 4 and the fin 5. The resonance path is formed by the stray capacitance and the stray inductance in the ground line 61 and the like by the four paths. However, when the ground wire 61 is wound around the ground wire core 60 as in the present embodiment, the resonance frequency of the resonance path is lowered by the impedance of the ground wire core 60. If the material of the ground wire core 60 is such that the main component of the impedance at the resonance frequency of the ground wire core 60 is a resistance, a damping effect can be obtained with respect to the resonance path.

  Thus, the grounding wire 61 is wound around the grounding wire core 60 and grounded, so that the resonance frequency can be lowered, or resonance damping can be obtained. For this reason, the resonance frequency by the path of inverter 4 → fin 5 → ground line 61 → capacitor 3 → inverter 4 can be shifted to a desired low resonance frequency, or a damping effect can be given to the resonance itself. It can be in a state that does not cause any problems.

  Also, since the ground wire 61 can be configured with a relatively thin wire harness since there is no power transfer, it is easy to wind around the ground wire core 60, and the number of turns of the ground wire core 60 can be easily increased. The impedance can be increased to the required amount. In addition, since the ground wire core 60 is made of, for example, ferrite or amorphous material, the impedance becomes low in a low frequency band near the direct current, and the impedance does not increase remarkably even if the number of turns of the ground wire core 60 is increased. While obtaining a high impedance in the resonance frequency band, the impedance becomes low in the low frequency band, and a sufficient grounding effect can be obtained in the vicinity of the direct current as compared with grounding via a conventional resistor.

  As described above, since the ground wire 61 for grounding the fin 5 for cooling the inverter 4 is wound around the ground wire core 60 having a through hole, the ground wire core 60 needs to be separately installed. By increasing the high-frequency impedance of the line 61, it is possible to suppress the noise source current that occurs with resonance through the ground line 61 of the fin 5.

Embodiment 5 FIG.
FIG. 5 is a configuration diagram of a power conversion device showing Embodiment 5 for carrying out the present invention. In FIG. 5, a power converter 105 receives power from an AC power supply system through a pantograph 30 and a transformer 31 that collect AC system voltage and generates a DC voltage, and converts the DC voltage into AC voltage. Then, an inverter 34 that drives a motor 35 that is a load, a capacitor 33, a fin 37 that is a first cooling means for cooling a semiconductor element that constitutes the inverter 34, and a semiconductor element that constitutes the converter 32 are cooled. 2 and fins 36 serving as cooling means. Further, two wires of low voltage side wires 51 and 52 for connecting the transformer 31 connected to the AC power supply system and the converter 32 are provided. Furthermore, load wirings 53a, 53b and 53c for connecting the inverter 34 and the motor 35 which is a load are provided. One end of the transformer 31 is grounded to the ground 39.

  The power conversion device 105 includes a third core 38 having a through hole through which the two low-voltage side wires 51 and 52 are passed, a first grounding wire 41 that grounds the fin 37 that is the first cooling means, The first grounding wire 41 is wound around the third core 38 and then grounded to the ground 45, and the second grounding wire 40 is grounded. The ground wire 40 is wound around the third core 38 and then grounded to the ground 45. By installing the third core 38, it is possible to reduce the common mode current that leaks to the power system side generated by the inverter 34. If the number of turns of the first ground wire 41 and the second ground wire 40 that winds the third core 38 is at least one or more times, there is an effect of reducing noise. The greater the number of turns, the better the noise reduction effect, but there may be stray capacitance between the windings that are wound.

  When the first ground line 41 and the second ground line 40 are directly grounded without passing through the third core 38, the converter 32 → fins are connected via the stray capacitance between the converter 32 and the fins 36. 36 → second ground line 40 → ground 45 → ground 39 → transformer 31 → converter 32 and the stray capacitance between the inverter 34 and the fin 37, and the inverter 34 → fin 37 → first ground The path of the line 41 → the ground 45 → the ground 39 → the transformer 31 → the converter 32 → the capacitor 33 forms a resonance path due to the stray capacitance and the stray inductance in the ground line or the like. However, when the first ground line 41 and the second ground line 40 are wound around the third core 38 as in the present embodiment, the two resonance paths are caused by the impedance of the third core 38. The resonance frequency of Further, if the material of the third core 38 is such that the main component of impedance at the resonance frequency of the third core 38 is resistance, a damping effect can be obtained with respect to the resonance path.

  As described above, the first ground line 41 and the second ground line 40 are wound around the third core 38 and grounded, so that the existing third core 38 is used without newly providing a resistor. Thus, the resonance frequency can be lowered or resonance damping can be obtained. Therefore, the path of converter 32 → fin 36 → second ground line 40 → earth 45 → earth 39 → transformer 31 → converter 32 and inverter 34 → Fin 37 → first ground line 41 → earth 45 → earth 39 → transformer 31 → converter 32 → shifting the resonance frequency to the desired low resonance frequency or giving a damping effect to the resonance itself Therefore, the radiation noise source can be put into a state that does not cause a problem in practice. In this way, it is possible to take measures against the radiation noise source without increasing the component cost.

  In addition, since the first grounding wire 41 and the second grounding wire 40 can be configured with a relatively thin wire harness because there is no power transfer, the first grounding wire 41 and the second grounding wire 40 can be easily wound around the third core 38. By increasing the number of turns wound around the third core 38, the impedance can be increased to a necessary amount. Furthermore, since the third core 38 is made of, for example, ferrite or amorphous, the impedance is low in the low frequency band near the direct current, and the impedance increases remarkably even if the number of turns wound around the third core 38 is increased. Without obtaining a high impedance in the resonance frequency band, the impedance becomes low in the low frequency band, and a sufficient grounding effect can be obtained in the vicinity of the direct current.

  As described above, since the ground wires 40 and 41 for grounding the fins 36 and 37 for cooling the converter 32 and the inverter 34 are wound around the third core 38 having a through hole, the high-frequency impedance of the ground wires 40 and 41 is increased. By increasing the noise source current, it is possible to suppress the noise source current that occurs with resonance through the ground lines 40 and 41 of the fins 36 and 37.

Embodiment 6 FIG.
FIG. 6 is a configuration diagram of a power conversion device showing Embodiment 6 for carrying out the present invention. In FIG. 6, the fourth core 42 is installed between the inverter 34 and the load 35, and is different from the fifth embodiment in that the third core is not installed on the transformer 31 side of the converter 32. The power conversion device 106 includes a fourth core 42 having a through hole through which load wirings 53a, 53b, and 53c that connect the inverter 34 and the motor 35 that is a load are collectively passed. In addition, a first grounding wire 44 for grounding the fins 37 serving as the first cooling means and a second grounding wire 43 for grounding the fins 36 serving as the second cooling means are provided. The wire 44 is wound around the fourth core 42 and then grounded to the ground 46, and the second ground wire 43 is wound around the fourth core 42 and then grounded to the ground 46. By installing the fourth core 42, it is possible to reduce the common mode current leaking to the power system side generated by the inverter 34.

  When the first ground line 44 and the second ground line 43 are directly grounded without going through the fourth core 42, the converter 32 → fins are connected via the stray capacitance between the converter 32 and the fins 36. 36 → second ground line 43 → ground 46 → ground 39 → transformer 31 → converter 32 and stray capacitance between inverter 34 and fin 37, inverter 34 → fin 37 → first ground The path of the line 44 → the ground 46 → the ground 39 → the transformer 31 → the converter 32 → the capacitor 33 forms a resonance path due to the stray capacitance and the stray inductance in the ground line and the like. However, as in the present embodiment, by passing the fourth core 42 through the first ground line 44 and the second ground line 43, the resonance frequencies of the two resonance paths are caused by the impedance of the fourth core 42. Go down. In addition, if the material of the fourth core 42 is such that the main component of impedance at the resonance frequency of the fourth core 42 is resistance, a damping effect can be obtained with respect to the resonance path.

  As described above, the first ground wire 44 and the second ground wire 43 are wound around the fourth core 42 and grounded, so that the existing fourth core 42 is used without newly providing a resistor. Thus, the resonance frequency can be lowered or resonance damping can be obtained. Therefore, the converter 32 → the fin 36 → the second ground line 43 → the ground 46 → the ground 39 → the transformer 31 → the path of the converter 32 and the inverter 34 → Fin 37 → first ground wire 44 → earth 46 → earth 39 → transformer 31 → converter 32 → shifting the resonance frequency to the desired low resonance frequency or giving a damping effect to the resonance itself Therefore, the radiation noise source can be put into a state that does not cause a problem in practice. In this way, it is possible to take measures against the radiation noise source without increasing the component cost.

  In addition, since the first grounding wire 44 and the second grounding wire 43 can be configured by a relatively thin wire harness because there is no power transfer, it is easy to wind around the fourth core 42 and easily. By increasing the number of turns wound around the fourth core 42, the impedance can be increased to a necessary amount. Further, since the fourth core 42 is made of, for example, ferrite or amorphous, the impedance is low in the low frequency band near the direct current, and the impedance increases remarkably even if the number of turns wound around the fourth core 42 is increased. Therefore, a high impedance is obtained in the resonance frequency band while a low impedance is obtained in the low frequency band, and a sufficient grounding effect can be obtained in the vicinity of the direct current.

  As described above, since the ground wires 43 and 44 that ground the fins 36 and 37 that cool the converter 32 and the inverter 34 are wound around the fourth core 42 having the through holes, the high-frequency impedance of the ground wires 43 and 44 is increased. Is increased, noise source current generated with resonance through the ground lines 43 and 44 of the fins 36 and 37 can be suppressed.

Embodiment 7 FIG.
FIG. 7 is a configuration diagram of a power conversion device showing Embodiment 7 for carrying out the present invention. 7 is different from the fifth embodiment in that a fourth core 42 is installed between the inverter 34 and the motor 35 as a load. In FIG. 7, in addition to the third core 38 having a through hole through which the two low-voltage side wires 51 and 52 are passed, the power conversion device 107 includes load wires 53a and 52b for connecting the inverter 34 and the motor 35 as a load. A fourth core 42 having a through-hole through which 53b and 53c pass together is provided. In addition, a first grounding wire 48 for grounding the fins 37 serving as the first cooling means is provided, and the first grounding wire 48 is wound around the fourth core 42 and then the third core. It is wound around 38 and grounded to earth 49. Further, a second ground wire 47 for grounding the fin 36 as the second cooling means is provided, and the second ground wire 47 is wound around the fourth core 42 and then the third core. It is wound around 38 and grounded to earth 49. The order of winding around the third core 38 and the fourth core 42 may be reversed.

  Even in such a configuration, by increasing the high-frequency impedance of the ground lines 47 and 48, it is possible to further suppress the noise source current generated with resonance through the ground lines 47 and 48 of the fins 36 and 37. .

Embodiment 8 FIG.
FIG. 8 is a configuration diagram of a power conversion device showing Embodiment 8 for carrying out the present invention.
In FIG. 8, the first ground wire 73 is not wound around the third core 38, but is wound around the first ground wire core 71 different from the third core 38, and the second ground wire 74. Is different from the fifth embodiment in that it is not wound around the third core 38 but is wound around the second grounding wire core 72 different from the third core 38. In FIG. 8, the power conversion device 108 includes a third core 38 having a through hole through which the two low-voltage side wires 51 and 52 are passed, and a first through hole in which the first ground line 73 is wound. A first grounding wire core 71 and a second grounding wire core 72 having a through hole around which the second grounding wire 74 is wound are separately provided.

  When the first ground line 73 is directly grounded without the first ground line core 71 and the second ground line 74 is not directly grounded without the second ground line core 72, the converter 32 and the fin 36, the path of the converter 32 → fin 36 → second ground line 74 → earth 45 → earth 39 → transformer 31 → converter 32 and the stray capacitance between the inverter 34 and the fin 37 Thus, the path of the inverter 34 → fin 37 → first ground line 73 → earth 45 → earth 39 → transformer 31 → converter 32 → capacitor 33 forms a resonance path due to stray capacitance and stray inductance in the ground line and the like. The However, as in the present embodiment, the first ground line 73 is connected to the first ground line core 71 and the second ground line 74 is connected to the second ground line core 72 to The resonance frequency of the resonance path is lowered. Alternatively, the material of the first grounding wire core 71 and the second grounding wire core 72 is the main component of impedance at the resonance frequency of the first grounding wire core 71 and the second grounding wire core 72. If this is the case, a damping effect can be obtained for the resonance path.

  Thus, the first grounding wire 73 is wound around the first grounding wire core 71 and grounded, and the second grounding wire 74 is wound around the second grounding wire core 72 and grounded. Since the frequency can be lowered or the damping of resonance can be obtained, the path of converter 32 → fin 36 → second ground line 74 → earth 45 → earth 39 → transformer 31 → converter 32 and inverter 34 → fin 37 Since the resonance frequency by the path of the first ground line 73 → the earth 45 → the earth 39 → the transformer 31 → the converter 32 → the capacitor 33 can be shifted to a desired low resonance frequency, or a damping effect can be given to the resonance itself. A radiation noise source can be made into a state which does not become a problem practically.

  In addition, since the first ground line 73 and the second ground line 74 can be configured by a relatively thin wire harness since there is no power transfer, the first ground line core 71 and the second ground line core 72 are configured. The number of turns of the first grounding wire core 71 and the second grounding wire core 72 can be easily increased to increase the impedance to a necessary amount. Further, since the first grounding wire core 71 and the second grounding wire core 72 are made of, for example, ferrite or amorphous material, the impedance becomes low in a low frequency band near the direct current, and the first grounding wire core 71. And even if the number of turns of the second grounding wire core 72 is increased, the impedance does not increase remarkably, and the impedance becomes low in the low frequency band while obtaining high impedance in the resonance frequency band, compared with the grounding through the conventional resistor. A sufficient grounding effect can be obtained in the vicinity of the direct current.

  As described above, the first ground wire 73 that grounds the fin 37 that cools the inverter 34 is wound around the first ground wire core 71 having the through hole, and the fin 36 that cools the converter 32 is grounded. Since the two ground wires 74 are wound around the second ground wire core 72 having a through hole, the first and second ground wire cores 71 and 72 need to be separately installed. By increasing the high-frequency impedance of the second ground lines 73 and 74, it is possible to suppress the noise source current that occurs with resonance through the first and second ground lines 73 and 74 of the fins 36 and 37. .

Embodiment 9 FIG.
FIG. 9 is a configuration diagram of a power conversion device showing Embodiment 9 for carrying out the present invention. 9 is different from the first embodiment in that the ground wire 91 is not wound around the core 8. The power converter 109 receives power from the DC power supply system via the pantograph 1 and the reactor 2 that collect DC system voltage, converts the DC voltage into AC voltage, and drives the motor 6 that is a load; The capacitor 3 is constituted by fins 5 that are cooling means for cooling the semiconductor elements constituting the inverter 4. In addition, two wires are provided: a high-voltage wire 21 that connects the reactor 2 connected to the DC power supply system and the inverter 4, and a ground wire 22 that grounds the inverter 4 to the ground 7. Furthermore, a core 8 having a through hole through which the high-voltage wiring 21 and the ground wiring 22 are passed, and a ground wire 91 for grounding the fin 5 serving as a cooling means are provided. In the present embodiment, the ground wire 91 is not wound around the core 8. However, a wiring loop is configured by the ground wire 91, the fins 5 serving as cooling means, the inverter 4, and the ground wiring 22.

  Since this wiring loop passes through the through hole of the core 8 by the ground wiring 22, it is possible to obtain an impedance equivalent to one winding. That is, even if the ground wire 91 is not directly wound around the core 8 but directly grounded to the ground 7, an impedance equivalent to one winding can be obtained. Even in this case, by inserting the core 8 in the path of the inverter 4 → the fin 5 → the ground line 91 → the capacitor 3 → the inverter 4, the resonance frequency corresponding to one turn is shifted to a desired low resonance frequency. Or a damping effect can be given to the resonance itself. Even when the converter is arranged, an equivalent effect can be obtained by configuring the wiring loop as shown in the present embodiment.

  As described above, since the wiring loop constituted by the ground wire 91, the fin 5, the inverter 4, and the ground wire 22 passes through the through hole of the core 8, the resonance occurs through the ground wire 91 of the fin 5. Noise source current can be suppressed.

  In the first to fourth embodiments, even if the ground wiring 22 that is grounded to the ground 7 is directly grounded to the ground 7 without penetrating the core 8, a noise source is generated with resonance through the ground wire of the fin 5. Current can be suppressed.

  In the fifth to eighth embodiments, fins 37 as first cooling means for cooling the semiconductor elements of inverter 34 and fins 36 as second cooling means for cooling the semiconductor elements of converter 32 are used. However, even when these fins 36 and 37 are shared, at least one of the third core 38 and the fourth core 42 is connected to the ground line composed of at least one. The same effect can be obtained by winding either one of them.

It is a block diagram of the power converter device which shows Embodiment 1 of this invention. It is a block diagram of the power converter device which shows Embodiment 2 of this invention. It is a block diagram of the power converter device which shows Embodiment 3 of this invention. It is a block diagram of the power converter device which shows Embodiment 4 of this invention. It is a block diagram of the power converter device which shows Embodiment 5 of this invention. It is a block diagram of the power converter device which shows Embodiment 6 of this invention. It is a block diagram of the power converter device which shows Embodiment 7 of this invention. It is a block diagram of the power converter device which shows Embodiment 8 of this invention. It is a block diagram of the power converter device which shows Embodiment 9 of this invention.

Explanation of symbols

  1,30 pantograph, 2 reactor, 3,33 capacitor, 4,34 inverter, 5,36,37 fin, 6,35 motor, 7,39,45,46,49 earth, 8 core, 10 second core, 38 3rd core, 42 4th core, 9, 11, 12, 61, 91 Ground wire, 21 High voltage wiring, 22 Ground wiring, 23a-23c, 53a-53c Load wiring, 31 Transformer, 32 Converter, 40 , 43, 47, 74 Second ground line, 41, 44, 48, 73 First ground line, 51, 52 Low voltage side wiring, 60 Ground line core, 71 First ground line core, 72 Second Core for ground wire, 101-109 power converter.

Claims (9)

An inverter that receives power from a DC power supply system and drives a load;
Cooling means for cooling the inverter;
A core having a through-hole through which a high-voltage wiring connecting the DC power supply system and the inverter, and a ground wiring for grounding the inverter;
A ground wire for grounding the cooling means,
The power converter according to claim 1, wherein the ground wire is wound around the core and then connected to the ground wire between the core and the inverter . A second core having a through-hole through which load wiring connecting the inverter and the load is passed;
The power converter according to claim 1, wherein the ground wire is grounded after being wound around the second core. An inverter that receives power from a DC power supply system and drives a load;
Cooling means for cooling the inverter;
A second core having a through hole through which a load wiring connecting the inverter and the load is passed;
A ground wire for grounding the cooling means,
The power converter according to claim 1, wherein the ground wire is wound around the second core and then connected to the ground wire in the vicinity of the inverter . An inverter that receives power from a DC power supply system and drives a load;
Cooling means for cooling the inverter;
A core having a through-hole through which a high-voltage wiring connecting the DC power supply system and the inverter, and a ground wiring for grounding the inverter;
A ground wire for grounding the cooling means;
A grounding wire core having a through hole around which the grounding wire is wound ,
The power converter according to claim 1 , wherein the ground line is connected to the ground line between the core and the inverter . A converter that receives power from an AC power supply system and generates a DC voltage;
An inverter that receives the DC voltage and drives a load;
First cooling means for cooling the inverter;
A second cooling means for cooling the converter;
A third core having a through-hole through which the low-voltage side wiring connecting the AC power supply system and the converter;
A first ground line for grounding the first cooling means;
A second ground line for grounding the second cooling means,
The power converter according to claim 1, wherein the first ground line and the second ground line are wound around the third core and then grounded. A fourth core having a through-hole through which load wiring connecting the inverter and the load is passed;
The power converter according to claim 5, wherein the first ground line and the second ground line are grounded after being wound around the fourth core, respectively. A converter that receives power from an AC power supply system and generates a DC voltage;
An inverter that receives the DC voltage and drives a load;
First cooling means for cooling the inverter;
A second cooling means for cooling the converter;
A fourth core having a through hole through which a load wiring connecting the inverter and the load is passed;
A first ground line for grounding the first cooling means and a second ground line for grounding the second cooling means;
The power converter according to claim 1, wherein the first ground line and the second ground line are each wound after being wound around the fourth core. A converter that receives power from an AC power supply system and generates a DC voltage;
An inverter that receives the DC voltage and drives a load;
First cooling means for cooling the inverter;
A second cooling means for cooling the converter;
A third core having a through-hole through which the low-voltage side wiring connecting the AC power supply system and the converter;
A first ground line for grounding the first cooling means;
A second ground line for grounding the second cooling means;
A first grounding wire core having a through hole around which the first grounding wire is wound;
A power conversion device comprising: a second grounding wire core having a through hole around which the second grounding wire is wound. An inverter that receives power from a DC power supply system and drives a load;
Cooling means for cooling the inverter;
A core having a through-hole through which a high-voltage wiring connecting the DC power supply system and the inverter, and a ground wiring for grounding the inverter;
A ground wire for grounding the cooling means,
The power converter according to claim 1 , wherein a wiring loop that passes through the through hole of the core is configured by the ground line, the cooling unit, the inverter, and the ground wiring.

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