Power conversion device

Abstract

To provide a power conversion device capable of suppressing damages of internal components such as an input circuit even in an abnormal state such as a ground fault.SOLUTION: In a power conversion device 1 which inputs AC voltage 2 and outputs DC voltage by voltage doublers 101, 102, a rush current suppression part 105 is arranged in series on a side of a neutral line of the AC voltage 2. The rush current suppression part 105 is constituted of a current limiting resistor 51 and a relay 52, and limits charging current to capacitors 21, 22 in supply of the AC voltage 2.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a power conversion device that inputs a single-phase AC voltage and outputs a DC voltage by double-voltage rectification.

Background Art

[0002] A power conversion device for motor drive generally includes a rectifier section that converts an AC voltage into a DC voltage, a capacitor that smoothes the DC voltage, and an inverter section that inversely converts the DC voltage. The rectifier section mainly uses two types of circuit methods depending on the voltage value of the AC voltage. When the AC voltage exceeds 200 volts, a full-wave rectifier circuit is used. When the AC voltage is about 100 volts to 120 volts, a double-voltage rectifier circuit is used. In the double-voltage rectifier circuit, a DC voltage approximately twice the peak value of the AC voltage can be obtained. Therefore, in either the case of a 100-volt system or a 200-volt system of the AC voltage, the inverter section can be configured with the same components as those of a 200-volt system to form a power conversion device.

[0003] Patent Document 1 discloses a power conversion device that performs double-voltage rectification on single-phase AC and outputs AC power through a two-phase inverter circuit.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] FIG. 14 of Patent Document 1 shows a circuit composed of an input terminal for inputting an AC voltage, a noise filter circuit including a fuse, an inductance element, and a capacitor, an inrush current suppression circuit including a resistor, a switch element, and a delay circuit for suppressing the charging current at power-on, and a double-voltage rectifier circuit including two diodes and two capacitors.

[0006] Here, in the figure, one of the AC input lines is represented as L and the other as N. In a single-phase AC voltage, L and N generally represent the voltage line side and the neutral line (grounded) side in a single-phase three-wire commercial power supply. The voltage line side (Live side) is L and the neutral line side (Neutral side) is N respectively.

[0007] In the figure, when the high-voltage side of the DC voltage or the low-voltage side of the DC voltage on the right side of the figure is grounded due to connection errors, dust adhesion, etc., the ground current flows into the inrush current suppression circuit. This is because the inrush current suppression circuit is connected in series to the voltage line side of the AC input line on the left side of the figure.

[0008] In the figure, the inrush current suppression circuit is configured such that the switch element turns on after a delay time determined by the delay circuit. Therefore, when the AC input line is turned on with the DC voltage grounded, the ground current flows through the resistor R5, which is a component of the inrush current suppression circuit. As a result, there is a possibility that the resistor R5 may be damaged, such as burned out, before the ground current is limited by the resistor R5 and the protective fuse blows.

[0009] One of the purposes of providing the fuse is to suppress damage to the components of the internal circuit in the event of an abnormal state such as a ground fault. However, in the circuit of the figure, there was a possibility that the above purpose could not be achieved by the fuse.

[0010] Therefore, an object of the present invention is to provide a power conversion device that outputs a DC voltage by double voltage rectification and can suppress damage to the components of the internal circuit such as the input circuit even in an abnormal state such as a ground fault.

Means for Solving the Problem

[0011] As an example of the means for solving the above problem, in a power conversion device that inputs an AC voltage and outputs a DC voltage by double voltage rectification, the inrush current suppression unit is arranged on the neutral line side of the AC current.

Effect of the Invention

[0012] In the power conversion device according to the present invention, in a power conversion device that outputs a DC voltage by voltage rectification, when an abnormal state such as a ground fault occurs in the DC voltage, it is possible to prevent damage to the components of the internal circuit by the fuse blowing.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2A

Figure 2B

Figure 3A

Figure 3B

Figure 4A

Figure 4B

Figure 5A

Figure 5B

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

Embodiment

[0015] FIG. 1 is a circuit configuration diagram of the power conversion device 1 in this embodiment. It includes a rectifier section 101 that inputs an AC voltage 2 and outputs a DC voltage, a capacitor 102 that smooths the DC voltage, a regenerative braking section 103 connected in parallel with the capacitor 102, an inverter section 104 that converts the DC voltage into AC power, an inrush current suppression section 105, and a main circuit terminal block 108. Also, as an example of external equipment connected to the power conversion device 1, a braking resistor 33, a regenerative braking unit 106, and a fuse unit 107 are described.

[0016] The connection of the rectifier section 101 and the capacitor 102 shown in FIG. 1 is generally called a voltage doubler rectifier circuit. In the positive half-cycle of the AC voltage 2 (the state where the voltage of L1 is higher than that of N), the diode 11 and the capacitor 21 conduct. In the negative half-cycle of the AC voltage 2 (the state where the voltage of L1 is lower than that of N), the diode 12 and the capacitor 22 conduct. Since the capacitors 21 and 22 each half-wave rectify the AC voltage 2, for example, when the effective value of the AC voltage is 100 volts, the voltages of the capacitors 21 and 22 are each about 141 volts, which is the peak voltage of the AC voltage, and the DC voltage is about 282 volts, which is the sum of the voltages of the capacitors 21 and 22.

[0017] The regenerative braking section 103 is composed of a diode 31 and a switching element 32. Also, a braking resistor 33 is connected between the connection point of the diode 31 and the switching element 32 and the high voltage side of the DC voltage. In the figure, RB in 103 is connected to RB on the left side of the figure. The regenerative braking section 103 drives the switching element 32 when the DC voltage becomes higher than a predetermined value, consumes energy with the braking resistor 33, and suppresses the rise of the DC voltage.

[0018] The inverter section 104 is composed of switching elements 41 to 46 and outputs AC power to the motor 3. U, V, and W on the right side in the figure are respectively connected to U, V, and W on the left side in the figure. In FIG. 1, the circuit symbol of an IGBT is applied as a representative example for the switching element, but other power semiconductors such as MOSFETs can also be applied.

[0019] The inrush current suppression unit 105 is composed of a current-limiting resistor 51 and a relay 52, and is arranged for the purpose of limiting the charging current to the capacitors 21 and 22 when the AC voltage 2 is applied. When the potential difference between the high-voltage side and the low-voltage side of the DC voltage is lower than a predetermined value, such as immediately after the application of the AC voltage 2, the relay 52 is in the off state and the capacitors 21 and 22 are charged through the current-limiting resistor 51. When the capacitors 21 and 22 are charged and become higher than a predetermined value, the relay 52 transitions to the on state. Note that in FIG. 1, a relay is applied as a representative, but another element such as a triac may be applied. Also, in FIG. 1, a current-limiting resistor is applied, but an element having a resistance component such as a thermistor may be used.

[0020] The regenerative braking unit 106 is installed outside the power conversion device 1 in parallel with the DC voltage for the purpose of further increasing the braking torque of the inverter with respect to the regenerative braking unit 103. The fuse unit 107 is arranged for the purpose of preventing secondary disasters to devices other than the power conversion device 1 that share the AC voltage 2 and preventing damage to components inside the power conversion device 1 when an unexpected situation such as a ground fault occurs in the circuit inside the power conversion device 1. Therefore, when an unexpected situation such as a ground fault due to a wiring error occurs, it is a desired operation that the fuses in the fuse unit 107 blow without the components inside the power conversion device 1 being damaged. Note that in FIG. 1, the fuse unit 107 has fuses 71 and 72, and fuses are arranged on both input lines, but it may be connected to only one side of the voltage line. Also, a device having a function of cutting off when a current of a certain amount or more flows, such as a breaker instead of a fuse, may be used.

[0021] The main circuit terminal block 108 is a terminal block for connecting the inside of the power conversion device 1 and the peripheral equipment outside the power conversion device 1. As described above, since the power conversion device 1 can be connected to various external equipments such as the braking resistor 33, the regenerative braking unit 106, and the motor 3, connection terminals are provided. Here, the description names of the high-power parts etc. connected to the main circuit terminal block 108 used in the present invention hereinafter will be described.

[0022] The alternating voltage 2 is a single-phase alternating voltage with one side as the voltage line and the other side as the neutral line from a single-phase three-wire system, and the voltage line side is denoted as L1 and the neutral line side is denoted as N. Also, the high voltage side of the DC voltage is denoted as +, the low voltage side is denoted as -, the terminal to which the braking resistor 33 is connected is denoted as RB, and the three-phase AC output to the motor 3 is denoted as U, V, and W, respectively.

[0023] Next, with reference to FIG. 2, in the power conversion device 1 described in this embodiment, the operation when the high voltage side (+) of the DC voltage is grounded due to an operator's wiring error, dust adhesion, etc. will be described.

[0024] FIGS. 2A and 2B show the operation when the power is turned on in a state where the high voltage side (+) of the DC voltage is grounded and has the same potential as the neutral line of the alternating voltage 2 with respect to the circuit configuration diagram of FIG. 1, and the main components related to circuit protection are extracted from the circuit configuration diagram of FIG. 1. FIGS. 2A and 2B focus on the operation between the alternating voltage 2 and the DC voltage, and the description of the regenerative braking unit 103, the inverter unit 104, etc. in FIG. 1 is omitted. Also, FIGS. 2A and 2B are drawings for explaining the operation immediately after the power is turned on, and the relay 52 in FIG. 1 is assumed to be in an off state at all times, so the description is omitted.

[0025] Note that FIG. 2A shows the positive half cycle of the alternating voltage 2 (the state where the voltage of L1 is higher than that of N), and FIG. 2B shows the negative half cycle of the alternating voltage 2 (the state where the voltage of L1 is lower than that of N). The broken line represents the current path, and the dotted line connecting the high voltage side (+) and the neutral line (N) of the DC voltage represents the grounding path.

[0026] As shown in FIG. 2A, in the positive half cycle of the alternating voltage 2, when the alternating voltage 2 is applied in a state where the high voltage side (+) of the DC voltage is grounded, a grounding current flows through the route of alternating voltage 2 - fuse 71 - diode 11. Since this current is a current in which the voltage of the alternating voltage 2 is short-circuited through the system impedance, etc., a large current sufficient to blow the fuse 71 flows. By making the diode 11 on the short-circuit path an element that can withstand the current that blows the fuse 71, the operation of blowing the external fuse without damaging the components inside the power conversion device 1 targeted in the present invention is realized.

[0027] As shown in FIG. 2B, when the AC voltage 2 is applied in the negative half-cycle of the AC voltage 2 with the high voltage side (+) of the DC voltage grounded, current flows through the route of AC voltage 2 - fuse 72 - current limiting resistor 51 - capacitor 22 - diode 12 - fuse 71. The illustrated current is the initial charging operation of capacitor 22 and flows regardless of whether there is a ground fault, so it is a normal operation. To capacitor 21, the voltage of the current limiting resistor 51 is applied in the reverse direction with respect to the polarity of capacitor 21. There is no problem when a non-polar capacitor such as a film capacitor is applied to capacitor 21, but when a polar capacitor such as an electrolytic capacitor is applied, a voltage is instantaneously applied in the reverse direction. However, the period during which the voltage is applied is only the period of the time constant determined by the resistance value of the current limiting resistor 51 at the time of initial charging and the capacitance of capacitor 22, and it is a short period. Also, as the charging of capacitor 22 progresses, the current transiently decreases, so the voltage value also decays. Therefore, even when a polar capacitor is applied to capacitor 21, the specifications can be set so as to have the characteristics to withstand during the negative half-cycle period of the AC voltage 2. Therefore, the specifications may be set so as to prevent damage to the components inside the power conversion device 1 during the negative half-cycle period of the AC voltage 2.

[0028] After the period shown in FIG. 2B, the AC voltage 2 becomes the operation of the positive half-cycle shown in FIG. 2A. Therefore, the power conversion device 1 shown in FIG. 1 can realize the operation in which the external fuse blows without the components inside the power conversion device 1 being damaged even when the high voltage side (+) of the DC voltage is grounded.

[0029] In other words, arranging the current-limiting resistor 51 in series on the neutral line side of the AC voltage is an example of a feature of the present invention. On the other hand, Patent Document 1 only discloses an example in which the inrush current suppression circuit 70 is arranged on the voltage line side of the AC voltage in FIG. 14. Since the installation side of the current-limiting resistor is exactly the opposite in Patent Document 1 and the present invention, based on this fundamental difference, the present invention can achieve unique effects that cannot be achieved in Patent Document 1. That is, in a power conversion device that outputs a DC voltage by double voltage rectification, when an abnormal state such as a ground fault occurs in the DC voltage, it is possible to prevent damage to the components of the internal circuit by fusing the fuse.

[0030] In the above description of this embodiment, an example of a current-limiting resistor has been described. Similarly, examples in which an inrush current suppression circuit or an element that can contribute to the suppression of the inrush current is arranged in series on the neutral line side of the AC voltage are all included in the disclosure scope of this specification.

[0031] Next, with reference to FIG. 3, the operation of the power conversion device 1 when the low voltage side (-) of the DC voltage is grounded due to an operator's wiring error or dust adhesion will be described.

[0032] FIGS. 3A and 3B show the operation when the power is turned on in a state where the low voltage side (-) of the DC voltage is grounded and has the same potential as the neutral line of the AC voltage 2 with respect to the circuit configuration diagram of FIG. 1. Similar to FIG. 2, it is a drawing obtained by extracting the main components related to circuit protection from the circuit configuration diagram of FIG. 1. Also, FIG. 3A is the positive half cycle of the AC voltage 2 similar to FIG. 2A, and FIG. 3B is the negative half cycle of the AC voltage 2 similar to FIG. 2B. The broken line represents the current path, and the dashed line connecting the low voltage side (-) of the DC voltage and the neutral line (N) represents the ground fault path.

[0033] As shown in Fig. 3A, when the AC voltage 2 is applied in the positive half-cycle with the low-voltage side (-) of the DC voltage grounded, current flows through the route of AC voltage 2 - fuse 71 - diode 11 - capacitor 21 - current-limiting resistor 51 - fuse 72. The current shown in the figure is the initial charging operation of capacitor 21, and it flows regardless of whether there is a ground fault, so it is a normal operation. Also, unlike Fig. 2B, since the voltage of the current-limiting resistor 51 is applied to capacitor 22 in the same direction as the polarity of capacitor 21, no damage to the components inside the power conversion device 1 occurs during the positive half-cycle period of the AC voltage 2.

[0034] As shown in Fig. 3B, when the AC voltage 2 is applied in the negative half-cycle with the low-voltage side (-) of the DC voltage grounded, a ground fault current flows through the route of AC voltage 2 - diode 12 - fuse 71. Since this current is the current that the voltage of the AC voltage 2 is short-circuited through the system impedance, etc., a large current sufficient to blow the fuse 71 flows. By making the diode 12 on the short-circuit path an element that can withstand the current that blows the fuse 71, the operation of blowing the external fuse without damaging the components inside the power conversion device 1 as intended in the present invention is realized.

[0035] After the period shown in Fig. 3A, the AC voltage 2 enters the operation of the negative half-cycle shown in Fig. 3B. Therefore, even when the low-voltage side (-) of the DC voltage is grounded in the power conversion device 1 shown in Fig. 1, the operation of blowing the external fuse without damaging the components inside the power conversion device 1 is satisfied.

[0036] As described above with reference to Figs. 2 and 3, in the present invention, it is possible to prevent damage to the components of the internal circuit by blowing the fuse even when a ground fault occurs on either the high-voltage side or the low-voltage side of the DC voltage.

[0037] Next, a comparative example of the present invention will be described with reference to Figs. 4A and 4B. Figs. 4A and 4B are obtained by extracting the main components related to circuit protection from Fig. 14 of Patent Document 1 and expressing their concepts, similar to Figs. 2A and 3A of the present case.

[0038] Further, FIG. 4A shows the positive half cycle of the AC voltage 2, and FIG. 4B shows the negative half cycle of the AC voltage 2. The broken line represents the current path, and the dashed line connecting the high voltage side (+) of the DC voltage and the neutral line (N) represents the path of the ground fault.

[0039] As shown in FIG. 4A, in the positive half cycle of the AC voltage 2, when the AC voltage 2 is applied with the high voltage side (+) of the DC voltage grounded, a ground fault current flows through the route of AC voltage 2 - fuse 71 - current limiting resistor 51 - diode 11. This current is the current that the voltage of the AC voltage 2 is short - circuited through the system impedance and the resistance value of the current limiting resistor 51. Different from FIG. 2A, since the current limiting resistor 51 exists in the path of the ground fault current, the ground fault current is limited by the resistance value of the current limiting resistor 51.

[0040] As shown in FIG. 4B, in the negative half cycle of the AC voltage 2, when the AC voltage 2 is applied with the high voltage side (+) of the DC voltage grounded, a current flows through the route of AC voltage 2 - fuse 72 - current limiting resistor 51 - capacitor 22 - diode 12 - fuse 71. The illustrated current is the initial charging operation of the capacitor 22, and since it flows regardless of the presence or absence of a ground fault, it is a normal operation.

[0041] Here, consider the state shown in FIG. 4B where the capacitor 22 is not charged at all, the voltage of the capacitor 22 is approximately 0 volts, and the AC voltage of the AC voltage 2 instantaneously reaches the peak. In this case, since the voltage of the capacitor 22 is approximately 0 volts, a current that the voltage of the AC voltage 2 is instantaneously short - circuited through the system impedance and the resistance value of the current limiting resistor 51 flows as an inrush current. That is, a current of approximately the same magnitude as the current shown in FIG. 4A can flow instantaneously. Therefore, if the fuse 71 is designed with a specification to blow in the abnormal situation of FIG. 4A, there is a possibility that the fuse 71 will blow even in the initial charging operation which is originally a normal operation.

[0042] Also, although not shown, in the input circuit described in Patent Document 1, when the low voltage side (-) of the DC voltage is grounded and the power is turned on with the same potential as the neutral line of the AC voltage 2, the operation is also in a state where the operation and polarity shown in FIG. 4 are reversed, and has the same problem.

[0043] Therefore, for the sake of repetition, since the installation side of the current-limiting resistor is exactly the opposite in Patent Document 1 and the present invention, based on such fundamental differences, the present invention can achieve specific effects that cannot be achieved in Patent Document 1.

[0044] As described above, the novelty and inventiveness of the present invention over the disclosure of FIG. 14 of Patent Document 1 are already clear. Here, even when the timing of the ground fault is different from the descriptions in FIGS. 2 and 3, the effectiveness of the present invention will be supplementarily explained below.

[0045] FIGS. 5A and 5B are diagrams for explaining the operation when a power supply is turned on with a normal connection that is not in a ground fault state, the relay 52 transitions to the on state, and then the high voltage side (+) of the DC voltage or the low voltage side (-) of the DC voltage experiences a ground fault.

[0046] When a ground fault occurs during the positive half-cycle of the AC voltage 2 shown in FIG. 5A, since the ground fault current does not flow through the relay 52, regardless of the presence or absence of the relay 52, the operation is the same as that of FIG. 2A described above and the fuse 71 blows. Also, when a ground fault occurs during the negative half-cycle of the AC voltage 2 shown in FIG. 5B, in addition to the normal voltage doubling rectification operation shown by the dashed line in FIG. 5B, a short-circuit current of the capacitor 21 flows through the route of capacitor 21 - fuse 72 - relay 52 (the path of the double-dashed line in FIG. 5B).

[0047] Here, when the fuse 72 is designed to blow due to the short-circuit current of the capacitor 21, by designing the relay 52 to withstand the short-circuit current of the capacitor 21, an operation can be realized in which the external fuse blows without the components inside the power conversion device 1 being damaged. Also, when the fuse 72 is designed not to blow due to the short-circuit current of the capacitor 21, due to the short circuit of the capacitor 21, the potential difference between the high-voltage side (+) of the DC voltage and the low-voltage side (-) of the DC voltage becomes approximately half compared to the normal voltage-doubling rectification operation. Therefore, the relay 52 transitions to the OFF state, and after the operation shown in FIG. 2B described above, it transitions to the operation shown in FIG. 2A described above. As a result, as described above, an operation can be realized in which the external fuse blows without the components inside the power conversion device 1 being damaged.

[0048] As described above, in the present invention, in the power conversion device 1 that inputs a single-phase AC voltage generated between the voltage line side (L1) and the neutral line side (N), performs voltage-doubling rectification via the fuse unit 107 and the inrush current suppression unit 105, and outputs a DC voltage, a configuration in which one of the inrush current suppression units 105 is connected to the neutral line side (N) and the other is connected to the connection point of the capacitors 21 and 22 is shown. Thereby, a unique effect that cannot be achieved in FIG. 14 of Patent Document 1 can be achieved. That is, in a power conversion device that outputs a DC voltage by voltage-doubling rectification, it is possible to prevent the components of the internal circuit from being damaged by the blowing of the fuse in the event of an abnormal state such as a ground fault of the DC voltage.

[0049] The present invention described in detail above can be expressed in one sentence as a power conversion device that inputs an AC voltage and outputs a DC voltage by voltage-doubling rectification, characterized in that the inrush current suppression unit is arranged on the neutral line side of the AC current. Also, in a power unit characterized by having a motor by this power conversion device, the possibility of failure can be reduced, and a more stable operating rate can be realized. Furthermore, by configuring a production facility using at least a part of the above power unit, a highly reliable production facility can be constructed that reduces the possibility of failure and enables more stable production.

Example

[0050] Next, this embodiment will be described with reference to FIG. 6. In the power conversion device 1 described in this embodiment, diodes 13 and 14 are further added in parallel to the diodes 11 and 12, which are the components of the rectifying unit 101 in FIG. 1, to form the rectifying unit 101.

[0051] Similar to FIG. 2A, FIG. 6 shows the operation when the power supply is turned on in a state where the high-voltage side (+) of the DC voltage is grounded and becomes the same potential as the neutral line of the AC voltage 2. Similar to FIG. 2, the main components related to circuit protection are extracted. Similar to FIG. 2A of the first embodiment, when the AC voltage 2 is applied in a state where the high-voltage side (+) of the DC voltage is grounded, a ground fault current flows through the route of the AC voltage 2 - fuse 71 - rectifying unit 101. Here, during the period from when the power supply is turned on until the fuse 71 blows, since the ground fault current flows through the diodes of the rectifying unit 101, it is desirable that the diodes of the rectifying unit 101 have an instantaneous current withstand capacity such as a surge forward current that can withstand the blowing of the fuse 71. Therefore, as shown in FIG. 6, by increasing the number of parallel diodes in the rectifying unit 101, the instantaneous current can be shared by the number of parallel connections, and damage to the rectifying unit 101 can be more suppressed compared to the case where the diodes are not connected in parallel.

[0052] Of course, making three or more in parallel is also within the scope of the disclosure of this specification.

Embodiment

[0053] Next, this embodiment will be described with reference to FIG. 7. FIG. 7 is an explanatory diagram of a terminal block nameplate 109 that clarifies the terminal arrangement that can be used in the power conversion device 1.

[0054] As described above, peripheral equipment such as a fuse unit 107, a braking resistor 33, a regenerative braking unit 106, and a motor 3 are connected to the power conversion device 1 as an example. As shown in FIG. 7, a terminal block nameplate 109 that indicates signal names connected to the main circuit terminal block, such as the voltage line side (L1) and the ground line (N), is added to suppress the occurrence of wiring errors, which is one of the causes of ground faults. Thereby, it is possible to reduce the risk of occurrence of abnormal states such as a direct current voltage grounding due to human error, and to suppress damage to components of the internal circuit due to fuse blowing. Of course, the risk of ground fault extends to various factors such as not only human error but also external high voltages such as dust and lightning. Therefore, the necessity and effectiveness of the present invention are important regardless of the presence or absence of the nameplate.

Explanation of Signs

[0055] 1: Power conversion device 2: Alternating current voltage 3: Motor 11, 12, 13, 14, 31: Diodes 21, 22, 102: Capacitors 32, 41, 42, 43, 44, 45, 46: Switching elements 33: Braking resistor 51: Current limiting resistor 52: Relay 71, 72: Fuses 101: Rectifying section 103: Regenerative braking section 104: Inverter section 105: Inrush current suppression section 106: Regenerative braking unit 107: Fuse unit 108: Main circuit terminal block 109: Terminal block nameplate

Claims

1. A power conversion device that inputs an AC voltage and outputs a DC voltage by double voltage rectification, wherein an inrush current suppression unit is arranged on the neutral line side of the AC current.

2. A power device having a motor driven by the power conversion device according to Claim 1.

3. A production facility having the power device according to Claim 2.

4. In a power conversion device that inputs an AC voltage and outputs a DC voltage, a first input terminal to which the voltage line side of the AC voltage is connected, a second input terminal to which the neutral line side is connected, a rectifying unit connected to the first input terminal, which doubles the AC voltage and outputs a DC voltage, a first capacitor arranged on the high voltage side of the DC voltage and a second capacitor arranged on the low voltage side of the DC voltage, an inrush current suppression unit for suppressing the inrush current to the capacitor, wherein the inrush current suppression unit is a power conversion device connected to the second input terminal.

5. In the power conversion device according to Claim 4, the first capacitor and the second capacitor are connected in series between the high voltage side and the low voltage side of the DC voltage, wherein the inrush current suppression unit is a power conversion device with one connected to the second input terminal and the other connected to the connection point of the first capacitor and the second capacitor.

6. In the power conversion device according to Claim 4, the rectifying unit is composed of a first diode with its cathode connected to the high voltage side of the DC voltage and its anode connected to the first input terminal, and a second diode with its cathode connected to the first input terminal and its anode connected to the low voltage side of the DC voltage.

7. In the power conversion device according to Claim 4, during the half cycle in which the voltage on the voltage line side of the AC voltage is higher than that on the neutral line side, the first capacitor is charged, and during the half cycle in which the voltage on the voltage line side of the AC voltage is lower than that on the neutral line side, the second capacitor is charged.

8. In the power conversion device according to Claim 4, an overcurrent protection device is connected in series between the first input terminal and the commercial power supply.

9. In the power conversion device according to Claim 6, a third diode and a fourth diode are respectively connected in parallel to the first diode and the second diode.

10. In the power conversion device according to Claim 4, A main circuit terminal block connectable to the first input terminal, the second input terminal, the high voltage side of the DC voltage, or the low voltage side of the DC voltage, A power conversion device including a nameplate indicating the signal names of the main circuit terminal block.

11. In the power conversion device according to claim 4, An inverter section that converts the DC voltage into an AC voltage, and a power conversion device including a terminal that outputs the AC voltage.

12. In the power conversion device according to claim 11, A regenerative braking section connected in parallel to the capacitor, and a power conversion device including a terminal of the regenerative braking section.

13. In the power conversion device according to claim 4, The inrush current suppression section includes a parallel combination of a current-limiting resistor and a relay, and a power conversion device.

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