JP2009106013A - Electrolytic capacitor circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To satisfy the requirement that, in an electrolytic capacitor circuit having an electrolytic capacitor in a DC circuit such as an inverter device and a DC power supply device, a circuit component should be effectively utilized (the number of the circuit components should be reduced as much as possible), and electric charges accumulated in the electrolytic capacitor should be discharged at the stop of the device or the release of a power supply. <P>SOLUTION: The electric charges accumulated in the electrolytic capacitor 8 are discharged by a charging/discharging load 6B by effectively utilizing the circuit component (the charging/discharging load 6B, in particular), and by constituting a closed circuit R including the electrolytic capacitor 8 and the charging/discharging load 6B. Due to the discharge of the electric charges accumulated in the electrolytic capacitor 8 by the charging/discharging load 6B, there is no necessity for preparing a discharging load, and then cost reduction becomes possible. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a circuit having an electrolytic capacitor in a DC circuit section such as an inverter device or a DC power supply device.

  In an electrolytic capacitor circuit having an electrolytic capacitor in a DC circuit section such as an inverter device or a DC power supply device, a precharge load is provided to prevent an overcurrent from flowing to the electrolytic capacitor when the power is turned on. In addition, a battery equipped with a discharge load is applied in order to quickly discharge the charge accumulated in the electrolytic capacitor when the apparatus is stopped or when the power supply is opened (for example, Patent Document 1).

  FIG. 7 is a schematic explanatory diagram showing an example of the above-described conventional electrolytic capacitor circuit. For example, in order to enable regeneration to the power supply side or to suppress harmonics, the forward conversion unit includes a self-extinguishing element. It is. In FIG. 7, the code | symbol 1 shows the circuit breaker inserted between the three-phase alternating current power supply and the forward conversion part 2, and is in the state normally turned on, and the supply power of three-phase alternating current power is required It shuts off according to. The forward conversion unit 2 connected to the three-phase AC power source via the circuit breaker 1 has a rectifying element 3 (for example, a diode) and a self-extinguishing capability connected in antiparallel to the rectifying element 3. And a switching element (for example, IGBT or the like; hereinafter referred to as a self-extinguishing element) 4. In the circuit unit in which the AC power is converted from DC power by the rectifying element 3 of the forward conversion unit 2, the positive electrode side (upper side in the figure) is the P arm and the negative electrode side (lower side in the figure) is the N arm. A set of forward conversion units provided in the P arm is referred to as a P arm forward conversion unit group 2P, and a set of forward conversion units provided in the N arm is referred to as an N arm forward conversion unit group 2N.

  Reference numeral 7A is constituted by a parallel connection of a precharge switch 5A and a precharge load 6A, and at least one spare connected to the DC output side of the P arm forward converter group 2P or the N arm forward converter group 2N. A charging circuit is shown, and both ends of the preliminary charging load 6A are short-circuited when the preliminary charging switch 5A is turned on (that is, no current flows through the preliminary charging load 6A).

  Reference numeral 8 denotes an electrolytic capacitor for smoothing a pulsating current waveform included in the DC output voltage of the forward conversion unit 2. In this electrolytic capacitor 8, charging is started when the power is turned on (before the preliminary charging switch 5 </ b> A is turned on), and an inrush current (a steep and enormous inrush current that flows instantaneously) generated at that time is It is suppressed by the charging load 6A. The electric charge accumulated in the electrolytic capacitor 8 is discharged by the discharge load 9 connected in series with the discharge switch 10 when the apparatus is stopped or when the power supply is opened.

  Reference numeral 11 denotes a control circuit for controlling the self-extinguishing element 4, the reverse conversion unit (not shown), etc. of the forward conversion unit 2, and the control circuit 11 is an arbitrary two-phase of the three-phase AC power supply line. Power is supplied from the line.

  Due to the configuration in which the self-extinguishing element 4 is connected in antiparallel with the rectifying element 3 as in the forward converting part 2, the voltage generated in the electric motor (not shown) is rectified by the reverse converting part (not shown). After being converted into direct current through the element 3 and smoothed by the electrolytic capacitor 8, it is converted back to three-phase alternating current by the self-extinguishing element 4 provided in the P arm forward conversion unit group 2P and the N arm forward conversion unit group 2N. And regenerated on the AC power supply side.

  Here, the state of each switch, each forward conversion unit, etc. in each operation in the electrolytic capacitor circuit shown in FIG. 7 and the operation of the electrolytic capacitor circuit will be described based on Table 1.

  As shown in Table 1, during precharge, the circuit breaker 1 is turned on, the precharge switch 5A is opened, the discharge switch 10 is opened, and the self-extinguishing element 4 provided in the P arm forward conversion unit group 2P ( ) And the N-arm forward conversion unit group 2N (the self-extinguishing element 4 provided in) is turned off. As a result, the current converted from alternating current to direct current by the rectifying element 3 of the forward converter 2 is suppressed by the precharge load 6 </ b> A and accumulated in the electrolytic capacitor 8. During normal operation, the circuit breaker 1 is turned on, the precharge switch 5A is turned on, the discharge switch 10 is opened, the P-arm forward conversion unit group 2P (the self-extinguishing element 4 provided) and the N-arm forward conversion unit The group 2N (the self-extinguishing element 4 provided in) is turned on / off. As a result, the AC power is converted from DC power by the rectifying element 3 of the forward conversion unit 2, and the pulsating waveform included in the DC output voltage is smoothed via the electrolytic capacitor 8, for example, an inverse conversion unit (not shown). Etc. At the time of discharging (when the apparatus is stopped and when the power supply is opened), the circuit breaker 1 is opened, the precharge switch 5A is opened, the discharge switch 10 is turned on, and the self-extinguishing element provided in the P arm forward conversion unit group 2P 4) and the N-arm forward conversion unit group 2N (the self-extinguishing element 4 provided in the same) are turned off. As a result, a short circuit is formed between the P arm and the N arm of the DC circuit unit, thereby forming a closed circuit R including the electrolytic capacitor 8 and the discharge load 9, and the electric charge accumulated in the electrolytic capacitor 8 is discharged into the discharge. Released by the load 9.

  Next, another example of a conventional electrolytic capacitor circuit (an electrolytic capacitor circuit in which a precharging circuit is arranged on the three-phase AC power side (input side of the P arm forward conversion unit group 2P and the N arm forward conversion unit group 2N)) is schematically illustrated. This will be described with reference to the drawings. About the same thing as FIG. 7, detailed description is abbreviate | omitted using the same code | symbol. In FIG. 8, the code | symbol 12 shows the main switch connected to the three-phase alternating current power supply via the circuit breaker 1, and is connected to the alternating current input side of P arm forward conversion part group 2P and N arm forward conversion part group 2N. The A precharge circuit 7B configured by connecting a precharge load 6A and a precharge switch 5B in series is connected in parallel with the main switch 12.

  Here, the operation of each operation switch, each forward conversion unit, etc. in the electrolytic capacitor circuit shown in FIG. 8 and the operation of the electrolytic capacitor circuit will be described with reference to Table 2.

As shown in Table 2, at the time of preliminary charging, the circuit breaker 1 is turned on, the main switch 12 is opened, the preliminary charging switch 5B is turned on, the discharge switch 10 is opened, and the P-arm forward conversion unit group 2P is prepared. The self-extinguishing element 4) and the N-arm forward conversion unit group 2N (the self-extinguishing element 4 provided) are turned off. As a result, the current converted from alternating current to direct current by the rectifying element 3 of the forward converter 2 is suppressed by the precharge load 6 </ b> A and accumulated in the electrolytic capacitor 8. During normal operation, the circuit breaker 1 is turned on, the main switch 12 is turned on, the precharge switch 5B is opened, the discharge switch 10 is opened, and the self-extinguishing element 4 provided in the P-arm forward conversion unit group 2P ( ) And the N-arm forward conversion unit group 2N (the self-extinguishing element 4 provided) is turned on / off. As a result, the AC power is converted from DC power by the rectifying element 3 of the forward conversion unit 2, and the pulsating waveform included in the DC output voltage is smoothed via the electrolytic capacitor 8, for example, an inverse conversion unit (not shown). Etc. At the time of discharging (when the apparatus is stopped and when the power is opened), the circuit breaker 1 is opened, the main switch 12 is opened, the precharge switch 5B is opened, the discharge switch 10 is turned on, and the P-arm forward conversion unit group 2P The self-extinguishing element 4) and the N-arm forward conversion unit group 2N (provided with the self-extinguishing element 4) are turned off. As a result, a short circuit is formed between the P arm and the N arm of the DC circuit unit, thereby forming a closed circuit R including the electrolytic capacitor 8 and the discharge load 9, and the electric charge accumulated in the electrolytic capacitor 8 is discharged into the discharge. Released by the load 9.
Japanese Patent Laid-Open No. 2002-78353 (page 4-5, FIG. 1) Japanese Patent Laid-Open No. 7-7807 (page 2-3, FIG. 1)

  Conventionally, as described above, the electrolytic capacitor circuit is provided with a discharge load, and when the apparatus is stopped or the power supply is opened, the discharge switch is turned on after the power supply is shut off, and the electric charge accumulated in the electrolytic capacitor is quickly transferred by the discharge load. I was able to discharge.

  However, the preliminary charging load 6A and the discharging load 9 are used only for charging and discharging the electrolytic capacitor, and are not used during normal operation, and they do not function simultaneously. That is, circuit components (two types of resistors) have not been effectively used.

  As described above, in electrolytic capacitor circuits that have electrolytic capacitors in DC circuit parts such as inverter devices and DC power supply devices, circuit components are used more effectively (the number of circuit components is reduced as much as possible), and the device is stopped. It is required that the electric charge accumulated in the electrolytic capacitor can be discharged at times or when the power supply is opened.

  The present invention has been devised in view of the above-described conventional problems, and in an electrolytic capacitor circuit having an electrolytic capacitor in a DC circuit section such as an inverter device or a DC power supply device, even when the discharge load is not provided, the device is stopped. Alternatively, the electric charge accumulated in the electrolytic capacitor can be discharged when the power supply is opened.

  Specifically, the invention according to claim 1 is formed by connecting an electrolytic capacitor for accumulating DC power from a DC power source, a charge / discharge load and a charge / discharge switching switch in parallel, and the DC power source and the electrolytic capacitor An electrolytic capacitor circuit having a charge / discharge switching circuit interposed between the DC power supply and the charge / discharge switching circuit. A discharge switch that short-circuits between the arm and the N arm, and a closed circuit including the electrolytic capacitor and the charge / discharge load is configured by turning on the discharge switch when the apparatus is stopped or when the power supply is opened. The charge accumulated in the battery is discharged by the charge / discharge load.

  The invention according to claim 2 is provided with a plurality of forward converters on the P-arm side formed by connecting rectifying elements and self-extinguishing elements in antiparallel, and each forward converter is connected to an AC power source. A plurality of conversion units, and a plurality of the forward conversion units on the N-arm side, each of the forward conversion units connected to the AC power supply, an N-arm forward conversion unit group, the P-arm forward conversion unit group, and the N-arm order An electrolytic capacitor connected to the DC output side of the conversion unit group, a charge / discharge load and a charge / discharge switching switch are connected in parallel, and the P arm forward conversion unit group or the N arm forward conversion unit group and the electrolytic capacitor An electrolytic capacitor circuit comprising a charge / discharge switching circuit that is short-circuited at both ends of the charge / discharge load at the time of turning on, when the apparatus is stopped or when the power is opened. Group and N-arm forward transformation A closed circuit including the electrolytic capacitor and the charge / discharge load is configured by on-controlling at least one in-phase forward conversion unit of the group, and the charge accumulated in the electrolytic capacitor is generated by the charge / discharge load. It is characterized by being released.

  According to a third aspect of the present invention, in the first aspect of the present invention, between the P arm forward conversion unit group, the N arm forward conversion unit group, and the charge / discharge switching circuit, between the P arm and the N arm when being turned on. A closed circuit including the electrolytic capacitor and the charging / discharging load is configured by turning on the discharge switch when the apparatus is stopped or when the power supply is opened, and the electric charge accumulated in the electrolytic capacitor is provided. Is discharged by the charge / discharge load.

  According to a fourth aspect of the present invention, there are provided a plurality of forward converters on the P-arm side, each of which includes a rectifier element and a self-extinguishing element connected in reverse parallel, and each forward converter is connected to an AC power source. A conversion unit group, and a plurality of the forward conversion units provided in the N arm, each of the forward conversion units connected to the AC power source, an N arm forward conversion unit group, the P arm forward conversion unit group, and the N arm order Charging / discharging switching composed of an electrolytic capacitor connected to the DC output side of the conversion unit group and a charge / discharge load, and interposed between the P arm forward conversion unit group and the N arm forward conversion unit group and the AC power supply An electrolytic capacitor circuit comprising: a discharge switch having one end connected to the input side of the charge / discharge circuit in the charge / discharge switching circuit and the other end short-circuited by three phases; Turn on the discharge switch when opening, P In order to prevent a short circuit between the N-arm and the N-arm, each of the P-arm forward conversion unit group and the N-arm forward conversion unit group includes an electrolytic capacitor and a charge / discharge load by turning on the forward conversion unit one by one. A closed circuit is configured, and the charge accumulated in the electrolytic capacitor is discharged by the charge / discharge load.

  According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the P arm forward conversion unit is configured so that the discharge switch is turned on when the apparatus is stopped or the power source is opened to prevent a short circuit between the P arm and the N arm. A closed circuit including an electrolytic capacitor and a charge / discharge load is configured by controlling on / off of the group and the N-arm forward conversion unit group, and the charge accumulated in the electrolytic capacitor is discharged by the charge / discharge load. Features.

  The invention according to claim 6 is provided with a plurality of forward converters on the P-arm side formed by connecting rectifying elements and self-extinguishing elements in anti-parallel, and each forward converter is connected to an AC power source. A conversion unit group, and a plurality of the forward conversion units provided in the N arm, each of the forward conversion units connected to the AC power source, an N arm forward conversion unit group, the P arm forward conversion unit group, and the N arm order Charging / discharging switching composed of an electrolytic capacitor connected to the DC output side of the conversion unit group and a charge / discharge load, and interposed between the P arm forward conversion unit group and the N arm forward conversion unit group and the AC power supply And a discharge switch having one end connected to the input side of the charge / discharge circuit in the charge / discharge switching circuit and the other end connected to the P arm, when the apparatus is stopped or Turn on the discharge switch when power is released , By turning on at least one forward converter in the N-arm forward converter group, a closed circuit including an electrolytic capacitor and a charge / discharge load is configured, and the charge accumulated in the electrolytic capacitor is caused by the charge / discharge load. It is characterized by being released.

  The invention according to claim 7 is provided with a plurality of forward converters on the P-arm side formed by connecting rectifier elements and self-extinguishing elements in anti-parallel, and each forward converter is connected to an AC power source. A conversion unit group, and a plurality of the forward conversion units provided in the N arm, each of the forward conversion units connected to the AC power source, an N arm forward conversion unit group, the P arm forward conversion unit group, and the N arm order Charging / discharging switching composed of an electrolytic capacitor connected to the DC output side of the conversion unit group and a charge / discharge load, and interposed between the P arm forward conversion unit group and the N arm forward conversion unit group and the AC power supply And a discharge switch having one end connected to the input side of the charge / discharge circuit in the charge / discharge switching circuit and the other end connected to the N arm, when the apparatus is stopped or Turn on the discharge switch when power is released , By turning on at least one forward converter in the P-arm forward converter group, a closed circuit including an electrolytic capacitor and a charge / discharge load is configured, and the electric charge accumulated in the electrolytic capacitor is caused by the charge / discharge load. It is characterized by being released.

  According to the configuration of the first or third aspect of the invention, a closed circuit including the precharge load and the electrolytic capacitor is configured by turning on the discharge switch without installing the discharge load.

  According to the configuration of the second or third aspect of the invention, the self-phase forward converter provided in the in-phase forward converter of the P-arm forward converter group and the N-arm forward converter group without installing a discharge load. By turning on at least one arc extinguishing element), a closed circuit including a precharging load and an electrolytic capacitor is formed.

  According to the configuration of the fourth aspect of the present invention, the P arm forward conversion unit group and the N arm are arranged so that the discharge switch is turned on and the P arm and the N arm are not short-circuited without installing a discharge load. A closed circuit including an electrolytic capacitor and a charge / discharge load is configured by turning on at least one forward converter (the self-extinguishing element provided therein) in each forward converter group.

  According to the configuration of the fifth aspect of the present invention, the P-arm forward conversion unit group is provided so that the discharge switch is turned on and the P-arm and the N-arm are not short-circuited without installing a discharge load. The closed circuit including the electrolytic capacitor and the charging / discharging load is configured by controlling on / off of the self-extinguishing element) and the N-arm forward conversion unit group (the self-extinguishing element provided in).

  According to the configuration of the sixth aspect of the present invention, even if no discharge load is installed, the discharge switch is turned on, and the self-extinguishing unit included in at least one of the N-arm forward converters (of the N-arm forward converter group). By turning on the arc element), a closed circuit including an electrolytic capacitor and a charge / discharge load is configured.

  According to the configuration of the seventh aspect of the present invention, even if no discharge load is installed, the discharge switch is turned on, and the self-extinguishing unit provided in at least one of the P-arm forward converters (in the P-arm forward converter group). By turning on the arc element), a closed circuit including an electrolytic capacitor and a charge / discharge load is configured.

  As described above, according to the first to seventh aspects of the present invention, the circuit component (especially charge / discharge load) is effectively used (the number of circuit components is reduced as much as possible), and the electrolytic capacitor is stopped when the apparatus is stopped or the power supply is opened. The electric charge stored in can be discharged by the charge / discharge load. As a result, it is not necessary to provide a discharge resistor, and the cost can be reduced.

  Hereinafter, an electrolytic capacitor circuit according to an embodiment of the present invention will be described in detail based on Examples 1 to 6 and the like.

  In the present embodiment, the electrolytic capacitor circuit having an electrolytic capacitor in the DC circuit portion of the inverter device or the DC power supply device constitutes a closed circuit including the electrolytic capacitor and the charge / discharge load when the device is stopped or when the power supply is opened. The electrolytic capacitor circuit is characterized in that the electric charge accumulated in the electrolytic capacitor is discharged by the charge / discharge load. Since the charge accumulated in the electrolytic capacitor is discharged by the charge / discharge load, it is not necessary to provide the discharge load.

[Example 1]
FIG. 1 is a circuit diagram of an electrolytic capacitor circuit showing a first embodiment of the present invention. The same components as those in FIG. Example 1 is an electrolytic capacitor circuit using a single-phase DC power source. Reference numeral 1 denotes a circuit breaker connected to the single-phase DC power source. A charging / discharging switching circuit 7C configured by connecting the charging / discharging switching switch 5C and the charging / discharging load 6B in parallel is connected to the input side of the electrolytic capacitor 8, and the charging / discharging switching switch 5C is turned on when the charging / discharging switching switch 5C is turned on. Both ends of the discharge load 6B are short-circuited (that is, no current flows through the charge / discharge load 6B). The electrolytic capacitor 8 is connected in parallel to the output side of the charge / discharge switching circuit 7C. Reference numeral 10 denotes a discharge switch inserted in parallel between the circuit breaker 1 and the precharge circuit 7A, and the P arm and the N arm are short-circuited when turned on. Reference numeral 11 denotes a control circuit to which power is supplied from a DC power source.

  Next, the state of each switch and the operation of the electrolytic capacitor circuit in each operation in Example 1 will be described based on Table 3.

  As shown in Table 3, at the time of preliminary charging, the circuit breaker 1 is turned on, the charge / discharge switching switch 5C is opened, and the discharge switch 10 is opened. As a result, the current suppressed by the charge / discharge load 6B is accumulated in the electrolytic capacitor 8. During normal operation, the circuit breaker 1 is turned on, the charge / discharge switching switch 5C is turned on, and the discharge switch 10 is opened. As a result, direct-current power is output to, for example, an inverse conversion unit (not shown) via the electrolytic capacitor 8. At the time of discharging (when the apparatus is stopped and the power supply is opened), the circuit breaker 1 is opened, the charge / discharge switching switch 5C is opened, and the discharge switch 10 is turned on. As a result, the P arm and the N arm are short-circuited to form a closed circuit R including the electrolytic capacitor 8 and the charge / discharge load 6B, and the charge accumulated in the electrolytic capacitor 8 is released by the charge / discharge load 6B. The

  As described above, according to the configuration of the first embodiment, the charge accumulated in the electrolytic capacitor can be discharged by the charge / discharge load 6B without installing a discharge load. In other words, by effectively using the charge / discharge load 6B, the number of circuit components can be reduced, for example, compared with the electrolytic capacitor circuit of FIGS. 7 and 8, and the cost can be reduced.

[Example 2]
FIG. 2 shows a circuit configuration diagram of an electrolytic capacitor circuit showing a second embodiment of the present invention, and the same components as those in FIG. In FIG. 2, the circuit breaker 1 is connected to a three-phase AC power source, and the forward converter 2 is connected to the three-phase AC power source via the circuit breaker 1. The forward conversion unit 2 includes a rectifying element 3 and a self-extinguishing element 4 connected in antiparallel to the rectifying element 3. In the circuit unit in which AC power is converted from DC power by the rectifying element 3 of the forward conversion unit 2, the positive electrode side (upper side in the figure) is the P arm and the negative electrode side (lower side in the figure) is the N arm. A set of forward conversion units 2 provided in the P arm is referred to as a P arm forward conversion unit group 2P, and a set of forward conversion units provided in the N arm is referred to as an N arm forward conversion unit group 2N.

  The charge / discharge switching circuit 7C configured by connecting the charge / discharge switching switch 5C and the charge / discharge load 6B in parallel is provided at least on the DC output side of the P arm forward conversion unit group 2P or the N arm forward conversion unit group 2N. When the charge / discharge switching switch 5C is turned on, both ends of the charge / discharge load 6B are short-circuited (that is, no current flows through the charge / discharge load 6B).

  The electrolytic capacitor 8 is connected to the output side of the forward conversion unit 2 through the charge / discharge switching circuit 7C, and the pulsating waveform included in the DC output voltages of the P arm forward conversion unit group 2P and the N arm forward conversion unit group 2N. Is smoothed. Reference numeral 11 denotes a control circuit that outputs a gate signal for controlling the self-extinguishing element 4 such as the forward conversion unit 2 and the reverse conversion unit (not shown). The control circuit 11 is a three-phase AC power supply line. Power is supplied from any two-phase line.

  Next, the state of each switch, each forward conversion unit and the like in each operation in the electrolytic capacitor circuit of Example 2 and the operation of the electrolytic capacitor circuit will be described based on Table 4.

  As shown in Table 4, at the time of preliminary charging, the circuit breaker 1 is turned on, the charge / discharge switching switch 5C is opened, the P-arm forward conversion unit group 2P (the self-extinguishing element 4 provided) and the N-arm forward conversion The subgroup 2N (the self-extinguishing element 4 provided in) is turned off. As a result, the power rectified by the rectifying element 3 of the forward conversion unit 2 is suppressed by the charge / discharge load 6B and accumulated in the electrolytic capacitor 8. During normal operation, the circuit breaker 1 is turned on, the charge / discharge switching switch 5C is turned on, and the P-arm forward conversion unit group 2P (the self-extinguishing element 4 provided in) and the N-arm forward conversion unit group 2N (provided). The self-extinguishing element 4) is turned on / off. As a result, the AC power is converted from DC power by the rectifying element 3 of the forward conversion unit 2, and the pulsating waveform included in the DC output voltage is smoothed via the electrolytic capacitor 8, for example, an inverse conversion unit (not shown). Etc. At the time of discharging (when the apparatus is stopped and the power supply is opened), the circuit breaker 1 is opened, the charge / discharge switching switch 5C is opened, the P-arm forward conversion unit group 2P (the self-extinguishing element 4 provided) and the N-arm order At least one of the in-phase forward conversion units 2 (the self-extinguishing element 4 provided) in the conversion unit group 2N (the self-extinguishing element 4 provided) is turned on. As a result, the self-extinguishing element 4 becomes conductive when turned on, so that the P arm and the N arm of the DC circuit section are short-circuited, and a closed circuit R including the electrolytic capacitor 8 and the charge / discharge load 6B is configured. The charge accumulated in the electrolytic capacitor 8 is released by the charge / discharge load 6B.

  As described above, according to the configuration of the second embodiment, the charge accumulated in the electrolytic capacitor can be discharged by the charge / discharge load without installing a discharge load and a discharge switch. That is, in the configuration as in the second embodiment, the same operational effects as those in the first embodiment are obtained.

[Example 3]
FIG. 3 shows an electrolytic capacitor circuit configuration diagram according to the third embodiment of the present invention, and the same components as those in FIGS. 2 and 7 are denoted by the same reference numerals and detailed description thereof is omitted. The difference between the third embodiment and the second embodiment is that, in the third embodiment, a discharge switch is provided between the P arm forward conversion section group 2P and the N arm forward conversion section group 2N and the charge / discharge switching circuit 7C. This is the point that the P arm and the N arm can be short-circuited by inserting in parallel and turning on the discharge switch.

  Here, the state of each switch, each forward conversion unit, etc. in each operation in the electrolytic capacitor circuit of Example 3 and the operation of the electrolytic capacitor circuit will be described based on Table 5.

  As shown in Table 5, at the time of preliminary charging, the circuit breaker 1 is turned on, the charge / discharge switching switch 5C is opened, the discharge switch 10 is opened, and the self-extinguishing element provided in the P arm forward conversion unit group 2P 4) and the N-arm forward conversion unit group 2N (the self-extinguishing element 4 provided in the same) are turned off. As a result, the DC power rectified by the rectifying element 3 of the forward conversion unit 2 is suppressed by the charge / discharge load 6B and accumulated in the electrolytic capacitor 8. During normal operation, the circuit breaker 1 is turned on, the charge / discharge switching switch 5C is turned on, the discharge switch 10 is opened, the P-arm forward conversion unit group 2P (the self-extinguishing element 4 provided) and the N-arm forward conversion. The subgroup 2N (the self-extinguishing element 4 provided) is turned on / off. As a result, the AC power is converted from DC power by the rectifying element 3 of the forward conversion unit 2, and the pulsating waveform included in the DC output voltage is smoothed via the electrolytic capacitor 8, for example, an inverse conversion unit (not shown). Etc. At the time of discharging (when the apparatus is stopped or when the power supply is opened), the circuit breaker 1 is opened, the charge / discharge switching switch 5C is opened, the discharge switch 10 is turned on, and the self-extinguishing unit provided in the P arm forward conversion unit group 2P The element 4) and the N-arm forward conversion unit group 2N (the self-extinguishing element 4 provided in the element 4) are turned off. As a result, a short circuit is formed between the P arm and the N arm of the DC circuit unit, so that a closed circuit R including the electrolytic capacitor 8 and the charge / discharge load 6B is formed, and the electric charge accumulated in the electrolytic capacitor 8 is reduced. It is discharged by the charge / discharge load 6.

  As described above, according to the configuration of the third embodiment, the charge accumulated in the electrolytic capacitor 8 can be discharged by the charge / discharge load 6B without installing a discharge load. That is, in the configuration as in the third embodiment, the same function and effect as those of the first embodiment or the second embodiment described above are achieved.

[Example 4]
FIG. 4 is a circuit diagram of an electrolytic capacitor circuit showing a fourth embodiment of the present invention. The same components as those in FIGS. In FIG. 4, the code | symbol 12 shows the main switch, and is inserted between the circuit breaker 1, P arm forward conversion part group 2P, and N arm forward conversion part group 2N. A charge / discharge switching circuit 7D configured by connecting the charge / discharge switching switch 5D and the charge / discharge load 6B in series is connected in parallel to the main switch 12. The discharge switch 10 provided in the AC circuit unit has one end connected between the charge / discharge switching switch 5D and the charge / discharge load 6B and the other end short-circuited by three phases.

  Next, the state of each switch, each forward conversion unit and the like in each operation in the electrolytic capacitor circuit of Example 4 and the operation of the electrolytic capacitor circuit will be described based on Table 5.

  As shown in Table 7, at the time of preliminary charging, the circuit breaker 1 is turned on, the main switch 12 is opened, the charge / discharge switching switch 5D is turned on, the discharge switch 10 is opened, and the P arm forward conversion unit group 2P The self-extinguishing element 4) and the N-arm forward conversion unit group 2N (provided with the self-extinguishing element 4) are turned off. As a result, the power suppressed by the charge / discharge load 6 </ b> B is converted from AC power to DC power by the rectifying element 3 of the forward conversion unit 2 and accumulated in the electrolytic capacitor 8. During normal operation, the circuit breaker 1 is turned on, the main switch 12 is turned on, the charge / discharge switching switch 5D is opened, the discharge switch 10 is opened, and the self-extinguishing element provided in the P-arm forward conversion unit group 2P 4) and the self-extinguishing element 4 provided in the N-arm forward conversion unit group 2N (on / off control). As a result, the AC power is converted into DC power by the rectifying element 3 of the forward conversion unit 2, and the pulsating waveform included in the DC output voltage is smoothed via the smoothing capacitor 8, for example, an inverse conversion unit (not shown). Etc. At the time of discharging (when the apparatus is stopped and the power supply is opened), the circuit breaker 1 is opened, the main switch 12 is opened, the charge / discharge switching switch 5D is opened, the discharge switch 10 is turned on, and the P arm forward conversion unit group 2P ( Switching control (P-arm forward conversion unit group 2P and N-arm forward conversion unit group) for discharging self-extinguishing element 4) and N-arm forward conversion unit group 2N Since the charge / discharge load 6B cannot be discharged if short-circuited with 2N, switching is performed so that the P-arm forward conversion unit group 2P and the N-arm forward conversion unit group 2N that are in phase are not simultaneously turned on. Control). As a result, since the self-extinguishing element 4 becomes conductive when turned on, a closed circuit R including the electrolytic capacitor 8 and the charging / discharging load 6B is formed, and the charge accumulated in the electrolytic capacitor 8 is transferred to the charging / discharging load. Released by 6B.

  As described above, according to the configuration of the fifth embodiment, the charge accumulated in the electrolytic capacitor 8 can be discharged by the charge / discharge load 6B without installing a discharge load. That is, in the configuration as in the fourth embodiment, the same operational effects as those in the first to third embodiments are obtained.

[Example 5]
FIG. 5 is a circuit configuration diagram of an electrolytic capacitor circuit showing a fifth embodiment of the present embodiment, and the same components as those in FIGS. 4 and 7 are denoted by the same reference numerals and detailed description thereof is omitted. The difference between the fifth embodiment and the fourth embodiment is that in the discharge switch 10 having one end connected between the charge / discharge switching switch 5D and the charge / discharge load 6B, in the fourth embodiment, the other end is a three-phase short circuit. However, in the fifth embodiment, the other end side is short-circuited for three phases and connected to the P arm.

  As shown in Table 7, at the time of preliminary charging, the circuit breaker 1 is turned on, the main switch 12 is opened, the charge / discharge switching switch 5D is turned on, the discharge switch 10 is opened, and the P arm forward conversion unit group 2P The self-extinguishing element 4) and the N-arm forward conversion unit group 2N (provided with the self-extinguishing element 4) are turned off. As a result, the power suppressed by the charge / discharge load 6 </ b> B is converted from AC power to DC power by the rectifying element 3 of the forward conversion unit 2 and accumulated in the electrolytic capacitor 8. During normal operation, the circuit breaker 1 is turned on, the main switch 12 is turned on, the charge / discharge switching switch 5 is opened, the discharge switch 10 is opened, and the self-extinguishing element provided in the P arm forward conversion unit group 2P ( 4) and the N-arm forward conversion unit group 2N (the self-extinguishing element 4 provided in) is turned on / off. As a result, the AC power is converted from DC power by the rectifying element 3 of the forward conversion unit 2, and the pulsating waveform included in the DC output voltage is smoothed via the electrolytic capacitor 8, for example, an inverse conversion unit (not shown). Etc. At the time of discharging (when the apparatus is stopped and the power supply is opened), the circuit breaker 1 is opened, the main switch 12 is opened, the charge / discharge switching switch 5 is opened, the discharge switch 10 is turned on, and the P-arm forward conversion unit group 2P ( Is turned off, and at least one of the N-arm forward conversion unit groups 2N is turned on (the self-extinguishing element 4). As a result, since the self-extinguishing element 4 becomes conductive when turned on, a closed circuit R including the electrolytic capacitor 8 and the charge / discharge load 6B is formed, and the charge accumulated in the electrolytic capacitor 8 is charged / discharged. Released by the load 6b.

  As described above, according to the configuration of the fifth embodiment, the charge accumulated in the electrolytic capacitor can be discharged by the charge / discharge load 6B without installing a discharge load. That is, in the configuration as in the fifth embodiment, the same operational effects as those in the first to fourth embodiments described above are obtained.

[Example 6]
FIG. 6 is a circuit diagram of an electrolytic capacitor circuit showing a sixth embodiment of the present invention. The same components as those in FIGS. 5 and 8 are denoted by the same reference numerals, and detailed description thereof is omitted. The difference between the sixth embodiment and the fifth embodiment is that in the discharge switch 10 in which one end side is connected between the charge / discharge switching switch 5D and the charge / discharge load 6B, in the fifth embodiment, the other end side is a three-phase. Although short-circuited and connected to the P-arm of the DC circuit unit, in the sixth embodiment, the other end is short-circuited three-phase and connected to the N-arm of the DC circuit unit.

  Next, the state of each switch, each forward conversion unit, etc. and the operation of the electrolytic capacitor circuit in each operation in Example 4 will be described based on Table 6.

  As shown in Table 8, at the time of preliminary charging, the circuit breaker 1 is turned on, the main switch 12 is opened, the charge / discharge switching switch 5D is turned on, the discharge switch 10 is opened, and the P arm forward conversion unit group 2P The provided self-extinguishing element 4) and the N-arm forward conversion unit group 2N are turned off (the self-extinguishing element 4 provided). As a result, the power suppressed by the charge / discharge load 6 </ b> B is converted from AC power to DC power by the rectifying element 3 of the forward conversion unit 2 and accumulated in the electrolytic capacitor 8. During normal operation, the circuit breaker 1 is turned on, the main switch 12 is turned on, the charge / discharge switching switch 5D is opened, the discharge switch 10 is opened, and the self-extinguishing element provided in the P-arm forward conversion unit group 2P 4) and the N-arm forward conversion unit group 2N (the self-extinguishing element 4 provided in) is turned on / off. As a result, the AC power is converted from DC power by the rectifying element 3 of the forward conversion unit 2, and the pulsating waveform included in the DC output voltage is smoothed via the electrolytic capacitor 8, for example, an inverse conversion unit (not shown). Etc. At the time of discharging (when the device is stopped and when the power is opened), the circuit breaker 1 is opened, the main switch 12 is opened, the charge / discharge switching switch 5D is opened, the discharge switch 10 is turned on, and the P arm forward conversion unit group 2P Among them, at least one forward conversion unit 2 (the self-extinguishing element 4 provided) is turned on, and the N-arm forward conversion unit group 2N (the self-extinguishing element 4 provided) is turned off. As a result, since the self-extinguishing element 4 can conduct when turned on, a closed circuit R including the electrolytic capacitor 8 and the charging / discharging load 6B is formed, and the charge accumulated in the electrolytic capacitor 8 is charged / discharged. Released by the load 6B.

  As described above, according to the configuration of the sixth embodiment, the charge accumulated in the electrolytic capacitor can be discharged by the charge / discharge load 6B without installing a discharge load. That is, in the configuration as in the sixth embodiment, the same operational effects as those in the first to fifth embodiments described above can be obtained.

  Although the present invention has been described in detail with respect to the specific examples described above, it is obvious that various modifications and corrections belong to the scope of the claims within the scope of the technical idea of the present invention.

  For example, in the electrolytic capacitor circuits according to Embodiments 2 to 6 of the present invention, a three-phase AC power supply circuit has been described. However, a single-phase or multiphase AC power supply circuit can also be applied. In the electrolytic capacitor circuits of Examples 4 to 6, the circuit breaker 1 or the charge / discharge switching switch 5D can be applied even if either one is omitted. 6B can be applied by installing at least two phases. Further, in the fourth embodiment, during the discharge, all the three-phase forward converters 2 are set to the switching control for discharge. However, the self-extinguishing element provided in the forward converters 2 (one each for the P arm and the N arm). 4), the charge accumulated in the electrolytic capacitor 8 is discharged by the charge / discharge load 6B (however, the forward conversion unit 2 that turns on so as not to be short-circuited between the P arm and the N arm) It is necessary to select the self-extinguishing element 4) provided in the above.

The circuit block diagram of the electrolytic capacitor circuit in Example 1 of this invention. The circuit block diagram of the electrolytic capacitor circuit in Example 2 of this invention. The circuit block diagram of the electrolytic capacitor circuit in Example 3 of this invention. The circuit block diagram of the electrolytic capacitor circuit in Example 4 of this invention. The circuit block diagram of the electrolytic capacitor circuit in Example 5 of this invention. The circuit block diagram of the electrolytic capacitor circuit in Example 6 of this invention. The circuit block diagram which shows an example of the conventional electrolytic capacitor circuit. The circuit block diagram which shows the other example of the conventional electrolytic capacitor circuit.

Explanation of symbols

DESCRIPTION OF SYMBOLS 2 ... Forward conversion part 2P ... P arm forward conversion part group 2N ... N arm forward conversion part group 3 ... Rectifier element 4 ... Self-extinguishing element 5A, 5B ... Precharge switch 5C, 5D ... Charge-discharge switching switch 6A ... Pre-charging load 6B ... Charging / discharging load 7A, 7B ... Pre-charging circuit 7C, 7D ... Charging / discharging switching circuit 8 ... Electrolytic capacitor 9 ... Discharging load 10 ... Discharge switch R ... Closed circuit

Claims (7)

An electrolytic capacitor that stores DC power from a DC power supply;
A charge / discharge switching circuit comprising a charge / discharge load and a charge / discharge switching switch connected in parallel, inserted between the DC power supply and the electrolytic capacitor, and short-circuiting both ends of the charge / discharge load when turned on; Electrolytic capacitor circuit,
Between the DC power supply and the charge / discharge switching circuit, a discharge switch that short-circuits between the P arm and the N arm when being turned on,
A closed circuit including the electrolytic capacitor and the charge / discharge load is configured by turning on the discharge switch when the apparatus is stopped or the power is opened, and the charge accumulated in the electrolytic capacitor is released by the charge / discharge load. An electrolytic capacitor circuit characterized by that. A P-arm forward conversion unit group including a plurality of forward conversion units formed by connecting rectifying elements and self-extinguishing elements in reverse parallel on the P-arm side, and each of the forward conversion units connected to an AC power source;
A plurality of the forward conversion units on the N arm side, each of the forward conversion units connected to the AC power supply, an N arm forward conversion unit group;
An electrolytic capacitor connected to the DC output side of the P arm forward converter group and the N arm forward converter group;
A charge / discharge load and a charge / discharge switching switch are connected in parallel, and at least one is inserted between the P-arm forward converter group or the N-arm forward converter group and the electrolytic capacitor, A charge / discharge switching circuit in which both ends of the load are short-circuited, and an electrolytic capacitor circuit comprising:
By turning on at least one in-phase forward conversion unit among the P-arm forward conversion unit group and the N-arm forward conversion unit group when the apparatus is stopped or when the power is released, the electrolytic capacitor and the charge / discharge load are included. An electrolytic capacitor circuit, wherein a closed circuit is configured, and the electric charge accumulated in the electrolytic capacitor is discharged by the charge / discharge load. A discharge switch that short-circuits between the P arm and the N arm when being turned on between the P arm forward conversion unit group, the N arm forward conversion unit group, and the charge / discharge switching circuit,
A closed circuit including the electrolytic capacitor and the charge / discharge load is configured by turning on the discharge switch when the apparatus is stopped or the power is opened, and the charge accumulated in the electrolytic capacitor is released by the charge / discharge load. The electrolytic capacitor circuit according to claim 2. A P-arm forward conversion unit group including a plurality of forward conversion units formed by connecting rectifying elements and self-extinguishing elements in reverse parallel on the P-arm side, and each of the forward conversion units connected to an AC power source;
A plurality of the forward conversion units on the N-arm side, each of the forward conversion units connected to the AC power supply, an N-arm forward conversion unit group;
An electrolytic capacitor connected to the DC output side of the P arm forward converter group and the N arm forward converter group;
A charge / discharge switching circuit configured by a charge / discharge load and interposed between the P arm forward conversion unit group and the N arm forward conversion unit group and an AC power source,
One end is connected to the input side of the charge / discharge circuit in the charge / discharge switching circuit, and the other end is provided with a discharge switch having a three-phase short circuit,
Turn on the forward converter in the P-arm forward converter group and the N-arm forward converter group one by one so that the discharge switch is turned on when the device is stopped or the power is turned off, so that the P arm and the N arm are not short-circuited. A closed circuit including an electrolytic capacitor and a charge / discharge load is configured by controlling, and the electric charge accumulated in the electrolytic capacitor is discharged by the charge / discharge load.   By turning on and off the P arm forward conversion unit group and the N arm forward conversion unit group so as to prevent short circuit between the P arm and the N arm by turning on the discharge switch when the apparatus is stopped or when the power is opened, 5. The electrolytic capacitor circuit according to claim 4, wherein a closed circuit including an electrolytic capacitor and a charge / discharge load is configured, and the electric charge accumulated in the electrolytic capacitor is discharged by the charge / discharge load. A P-arm forward conversion unit group including a plurality of forward conversion units formed by connecting rectifying elements and self-extinguishing elements in reverse parallel on the P-arm side, and each of the forward conversion units connected to an AC power source;
A plurality of the forward conversion units on the N-arm side, each of the forward conversion units connected to the AC power supply, an N-arm forward conversion unit group;
An electrolytic capacitor connected to the DC output side of the P arm forward converter group and the N arm forward converter group;
A charge / discharge switching circuit configured by a charge / discharge load and interposed between the P arm forward conversion unit group and the N arm forward conversion unit group and an AC power source,
A discharge switch having one end connected to the input side of the charge / discharge circuit in the charge / discharge switching circuit and the other end connected to the P arm;
A closed circuit including an electrolytic capacitor and a charge / discharge load is configured by turning on the discharge switch when the apparatus is stopped or when the power is opened, and turning on at least one forward converter in the N-arm forward converter group. The electrolytic capacitor circuit, wherein the electric charge accumulated in the electrolytic capacitor is discharged by the charge / discharge load. A P-arm forward conversion unit group including a plurality of forward conversion units formed by connecting rectifying elements and self-extinguishing elements in reverse parallel on the P-arm side, and each of the forward conversion units connected to an AC power source;
A plurality of the forward conversion units on the N-arm side, each of the forward conversion units connected to the AC power supply, an N-arm forward conversion unit group;
An electrolytic capacitor connected to the DC output side of the P arm forward converter group and the N arm forward converter group;
A charge / discharge switching circuit configured by a charge / discharge load and interposed between the P arm forward conversion unit group and the N arm forward conversion unit group and an AC power source,
A discharge switch having one end connected to the input side of the charge / discharge circuit in the charge / discharge switching circuit and the other end connected to the N arm;
A closed circuit including an electrolytic capacitor and a charge / discharge load is configured by turning on the discharge switch when the apparatus is stopped or when the power is opened, and turning on at least one forward converter in the P arm forward converter group, The electrolytic capacitor circuit, wherein the electric charge accumulated in the electrolytic capacitor is discharged by the charge / discharge load.

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