JP2010041744A - Uninterruptible power supply device, and method of manufacturing the same - Google Patents

Abstract

An uninterruptible power supply that can use common hardware for three-phase three-wire AC and three-phase four-wire AC, and a method for manufacturing the same.
A four-circuit rectifiers 11 to 14 connected to a three-phase AC input terminal, four-circuit inverters 21 to 24, a converter 31 connected to a fifth input terminal i5 and a fifth output terminal. , 32, and for three-phase three-wire AC, one of the three phases with different phases is connected to the input terminals i1 and i2, and the other one of the three-phase inputs is connected to the input terminals i3 and i4. The remaining one of the inputs is connected to the input terminal i5, the output terminals o1 and o2 are output terminals for one phase of the three-phase output, and the output terminals o3 and o4 are output terminals for the other one phase of the three-phase output. The output terminal becomes the output terminal for the remaining one phase of the three-phase output, and for three-phase four-wire AC, three-phase inputs with different phases are connected to the input terminal, and the neutral phase n input Is connected to the input terminal, the output terminal is a three-phase output terminal, and the output terminal is The output terminal of the sexual phase n.
[Selection] Figure 1

Description

  The present invention relates to an uninterruptible power supply and a method for manufacturing the same.

  An uninterruptible power supply (also referred to as “UPS”) is widely used as a backup power supply for securing power even when a commercial power supply fails. Below, the uninterruptible power supply for three-phase alternating current of the structure which is not insulated between alternating current input and alternating current output is demonstrated. Three-phase AC includes three-wire AC that is distributed using three wires or cables, that is, three-phase three-wire AC, and four-wire AC that is distributed using four wires or cables, that is, three-wire AC. There is a phase four-line AC. In Japan, the three-phase three-wire 200V class is common, but overseas, the four-wire 400V class is common. Corresponding to such a difference in power distribution system, a different circuit configuration is required for the uninterruptible power supply.

FIG. 6 is a diagram showing a circuit configuration of a conventional uninterruptible power supply apparatus corresponding to three-phase three-wire AC. This circuit configuration is shown as a conventional example in Patent Document 1, for example. The uninterruptible power supply shown in FIG. 6 includes rectifiers 11, 12, and 13 that convert alternating current into direct current, a battery BT that stores direct current, and inverters 21, 22, and 23 that convert direct current into alternating current, and an alternating current power source. Is normal, the alternating current is converted into direct current by the rectifiers 11, 12, and 13 and input to the inverters 21, 22, and 23, and the battery BT is charged. When the AC power supply is interrupted, the direct current stored in the battery BT is converted into an inverter. 21, 22, and 23, and AC power is supplied to the load. A DC capacitor _CD is connected to the DC link between the rectifiers 11, 12, 13 and the inverters 21, 22, 23. Three-phase R, S, and T alternating current distributed in a three-wire system is input to the rectifiers 11, 12, and 13 via the LC circuit. The inverters 21, 22, and 23 output three-phase U, V, and W alternating current through the LC circuit.

  As the rectifiers 11, 12, 13 and the inverters 21, 22, 23, bridge circuits composed of high-speed switching elements such as IGBTs (Insulated Gate Bipolar Transistors) and diodes connected in antiparallel thereto are used. The high-speed switching element is controlled by PWM (pulse width modulation). In FIG. 6, the configuration for this control is omitted. As the rectifiers 11, 12, 13 and inverters 21, 22, 23, simpler or cheaper configurations can be adopted, but the input power factor can be increased, and the input current does not include harmonic components. Therefore, the bridge circuit as described above is used.

FIG. 7 is a diagram showing a circuit configuration of a conventional uninterruptible power supply device corresponding to three-phase four-wire AC. This circuit configuration is the same as that shown in Patent Document 2, for example. In addition, about the part which has the same circuit structure as the uninterruptible power supply device shown in FIG. 6, the difference of a rated current is disregarded and it shows with the same code | symbol as FIG. The uninterruptible power supply device shown in FIG. 7 is similar to the uninterruptible power supply device shown in FIG. 6. Rectifiers 11, 12, and 13 that convert alternating current into direct current, a battery BT that stores direct current, and an inverter that converts direct current into alternating current 21, 22, and 23, and when the AC power source is healthy, the alternating current is converted into direct current by the rectifiers 11, 12, and 13 and input to the inverters 21, 22, and 23, and the battery BT is charged. At the time of a power failure, the direct current stored in the battery BT is input to the inverters 21, 22, and 23 to supply alternating current power to the load. A DC capacitor _CD is connected to the DC link between the rectifiers 11, 12, 13 and the inverters 21, 22, 23. Three-phase R, S, and T having different phases among the four-wire inputs are input to the rectifiers 11, 12, and 13 via the LC circuit, respectively. The remaining one of the four-wire inputs is a neutral phase n, and the capacitors of the LC circuit connected to the inputs of the rectifiers 11, 12, 13 are three-phase R, S, T as shown in the circuit configuration of FIG. It is connected between each phase and the neutral phase n, not between the inputs. The inverters 21, 22, and 23 output three-phase U, V, and W alternating current through the LC circuit. The capacitor of the LC circuit connected to the outputs of the inverters 21, 22, 23 is also connected between each phase and the neutral phase n, not between the three phases U, V, W, similarly to the input side. The In addition, when the input voltage and the output voltage are not balanced, a potential difference is generated between the neutral phase n on the input side and the neutral phase n on the output side. The converter 31 is provided in the direct current link between 12 and 13 and the inverters 21, 22, and 23, and is connected to the neutral phase n through reactance.
Japanese Patent No. 3122613 Japanese Patent No. 3115143

  The uninterruptible power supply for three-phase three-wire AC and the uninterruptible power supply for three-phase four-wire AC also have parts similar to the circuit configuration. However, because the circuit current rating differs between the 200V class and the 400V class, the three-phase three-wire 200V class uninterruptible power supply for Japan and the three-phase four-wire 400V class uninterruptible power supply for overseas use components and circuit configurations. Are also manufactured differently.

  An object of the present invention is to solve such problems and to provide an uninterruptible power supply that can use common hardware for three-phase three-wire AC and three-phase four-wire AC and a method for manufacturing the same. And

  According to a first aspect of the present invention, a rectifier that converts alternating current to direct current, a battery that stores direct current, and an inverter that converts direct current to alternating current, and when the alternating current power supply is healthy, the alternating current is converted into direct current by the rectifier. Three-phase AC in an uninterruptible power supply that converts and inputs to the inverter and charges the battery, and when the AC power supply fails, inputs the DC stored in the battery to the inverter and supplies AC power to the load. And five input terminals and five output terminals, and as a rectifier, it has four circuits connected to the first to fourth input terminals among the five input terminals, and as an inverter, Among the five output terminals, there are four circuits connected to the first to fourth output terminals, the fifth input terminal of the five input terminals and the fifth output terminal of the five output terminals. And connected between them A converter that eliminates the difference, and for three-phase three-wire AC, one of the three-phase inputs having different phases is connected to two of the first to fourth input terminals. The other one of the inputs is connected to the remaining two input terminals of the first to fourth input terminals, and the other one of the three-phase inputs is connected to the fifth input terminal of the five input terminals. The two output terminals of the first to fourth output terminals are output terminals for one phase out of the three-phase outputs, and the remaining two output terminals of the first to fourth output terminals are the three-phase output terminals. Of these, the other one-phase output terminal is used, the fifth output terminal is the remaining one-phase output terminal among the three-phase outputs, and the three-phase four-wire AC has three-phase inputs with different phases. Connected to three of the first to fourth input terminals, the neutral phase input is connected to the fifth input terminal, There is provided an uninterruptible power supply characterized in that three of the first to fourth output terminals are three-phase output terminals and the fifth output terminal is a neutral-phase output terminal. .

  The converter can be constituted by two parallel circuits having a current rating equivalent to each of the four circuits connected to the first to fourth output terminals. Further, a bidirectional chopper for stepping down and stepping up the direct current voltage can be provided between the direct current link connecting the rectifier and the inverter and the battery.

  According to the second aspect of the present invention, five input terminals and five output terminals are provided for three-phase alternating current, and correspond to the first to fourth input terminals among the five input terminals. Four rectifier mounting portions for mounting a rectifier that converts alternating current to direct current are provided, and an inverter that converts direct current to alternating current is attached corresponding to the first to fourth output terminals among the five output terminals. The fifth input terminal of the five input terminals is set as a neutral phase input on the circuit board provided with four inverter mounting portions, and corresponds to three of the first to fourth input terminals. A rectifier is attached to the rectifier mounting portion, the fifth output terminal of the five output terminals is set to a neutral phase, and an inverter is attached to the inverter mounting portion corresponding to three of the first to fourth output terminals. A method for manufacturing the uninterruptible power supply is provided.

  According to the present invention, common hardware can be used for three-phase three-wire AC and three-phase four-wire AC. More specifically, for example, when the current rating for three-phase three-wire AC is almost twice that for three-phase four-wire AC, such as the three-wire 200V class and the four-wire 400V class, the 400V class A circuit component is selected with a current rating of 200V, and a rectifier and an inverter can be used in parallel for a 200V class three-phase three-wire AC.

[First Embodiment]
FIG. 1 is a diagram showing a circuit configuration of an uninterruptible power supply according to a first embodiment of the present invention. Here, the configuration corresponding to the three-phase AC of both the three-wire system 200V class and the four-wire system 400V class will be described as an example. Note that circuits denoted by the same reference numerals as used in the description of the conventional example are the same circuits as the conventional ones, and the description thereof is omitted or simplified.

This uninterruptible power supply device has five input terminals i1 to i5 and five output terminals o1 to o5 for three-phase AC, a rectifier for converting AC to DC, 11 to 14, and DC It has a battery BT for storing and inverters 21 to 24 for converting direct current to alternating current. When the alternating current power supply is healthy, the alternating current is converted to direct current by the rectifiers 11 to 14 and input to the inverters 21 to 24 and the battery BT is When the AC power supply is charged and the AC power is interrupted, the DC stored in the battery BT is input to the inverters 21 to 24 to supply AC power to the load. The four circuit rectifiers 11 to 14 are connected to the first to fourth input terminals i1 to i4 among the five input terminals i1 to i5 through the LC circuit, respectively. The inverters 21 to 24 are respectively connected to the first to fourth output terminals o1 to o4 among the five output terminals o1 to o5 via the LC circuit. The uninterruptible power supply apparatus includes converters 31 and 32 that are connected to the fifth input terminal i5 and the fifth output terminal o5 via LC circuits, respectively, and eliminate the potential difference therebetween. A DC capacitor _CD is connected to a DC link between the rectifiers 11 to 14, the inverters 21 to 24, and the converters 31 and 32.

[Usage form in three-phase three-wire AC]
FIG. 2 is a diagram showing a usage pattern of the uninterruptible power supply circuit shown in FIG. 1 for three-phase three-wire AC. When used for three-phase three-wire AC, the R phase of the three-phase R, T, and S inputs having different phases is the two input terminals i1 of the first to fourth input terminals i1 to i4. And i2, the T-phase input is connected to the remaining two input terminals i3 and i4, and the S-phase input is connected to the fifth input terminal i5. Further, the two output terminals o1 and o2 of the first to fourth output terminals o1 to o4 become the output terminals for the U phase among the three-phase outputs U, W, and V, and the remaining two output terminals o3 and o4 is a W-phase output terminal, and the fifth output terminal o5 is a V-phase output terminal.

  That is, after the three-phase three-wire AC input, the first phase R is input from the two input terminals i1 and i2 to the rectifiers 11 and 12 via the LC circuits, respectively. The second phase S is input to the input terminal i5. The third phase T is input from the two input terminals i3 and i4 to the rectifiers 13 and 14 via the LC circuit, respectively. Each of the rectifiers 11 to 14 converts the input alternating current into direct current, supplies power to the inverters 21 to 24, and charges the battery BT. The inverters 21 and 22 operate in parallel, convert direct current into alternating current, and output the first phase U to the output terminals o1 and o2 via the LC circuit. The inverters 23 and 24 also operate in parallel, convert direct current into alternating current, and output the third phase W to the output terminals o3 and o4 via the LC circuit. The converters 31 and 32 balance the input voltage and the output voltage, and eliminate the potential difference generated between the second phase S on the input side and the second phase V on the output side. That is, when there is an S-phase input, the power supply to the battery BT and the output of the second phase V are adjusted. When the S-phase input stops, the operation as an inverter is performed.

[Usage form in three-phase four-wire AC]
FIG. 3 is a diagram showing a usage pattern of the uninterruptible power supply circuit shown in FIG. 1 for three-phase four-wire AC. When used for three-phase four-wire AC, three-phase R, S, and T inputs having different phases are connected to three input terminals i1 to i3 among the first to fourth input terminals i1 to i4. Connected, the input of the neutral phase n is connected to the fifth input terminal i5, and the three output terminals o1 to o3 of the first to fourth output terminals o1 to o5 are three-phase U, V, W The fifth output terminal o5 is the neutral phase n output terminal.

  That is, after the three-phase four-wire AC input, the first phase R is input from the input terminal i1 to the rectifier 11 via the LC circuit. The second phase S is input from the input terminal i2 to the rectifier 12 via the LC circuit. The third phase T is input to the rectifier 13 from the input terminal i3 via the LC circuit. The circuit from the input terminal i4 to the rectifier 14 is not used in the case of this three-phase four-wire AC. Each of the rectifiers 11 to 13 converts the input alternating current into direct current, supplies power to the inverters 21 to 23 and charges the battery BT. Each of the inverters 21 to 23 converts direct current to alternating current, and outputs the first phase U to the output terminal o1, the second phase V to the output terminal o2, and the third phase W to the output terminal o3 via the LC circuit. . The converters 31 and 32 balance the input voltage and the output voltage, and eliminate the potential difference generated between the neutral phase n on the input side and the neutral phase n on the output side.

  The input terminal i4, the rectifier 14, the inverter 24, the output terminal o4, and the LC circuit associated therewith are not necessary when this uninterruptible power supply circuit is used in a three-phase four-wire AC. Therefore, when manufacturing an uninterruptible power supply circuit used only for three-phase four-wire AC, the same components as the uninterruptible power supply circuit shown in FIG. Implementation can be omitted. That is, five input terminals (corresponding to input terminals i1 to io5 shown in FIG. 3) and five output terminals (corresponding to output terminals o1 to o5 shown in FIG. 3) are provided for three-phase alternating current. And four rectifier attachments for attaching rectifiers that convert alternating current into direct current corresponding to first to fourth input terminals (corresponding to input terminals i1 to i4 shown in FIG. 3) among the five input terminals 4 for attaching inverters for converting direct current to alternating current corresponding to first to fourth output terminals (corresponding to output terminals o1 to o4 shown in FIG. 3) among the five output terminals. The circuit board provided with the inverter mounting portion, that is, the circuit board common to the three-phase three-wire AC is used. The fifth input terminal (corresponding to the input terminal i5 shown in FIG. 3) of the five input terminals is set as a neutral phase input, and three of the first to fourth input terminals (the input shown in FIG. 3). A rectifier (corresponding to the rectifiers 11 to 13 shown in FIG. 3) is attached to the rectifier mounting portion corresponding to the terminals i1 to i3), and the fifth output terminal (the output terminal o5 shown in FIG. 3) among the five output terminals. Corresponding to three of the first to fourth output terminals (corresponding to the output terminals o1 to o3 shown in FIG. 3) with inverters (inverters 21 shown in FIG. 3). 22 and 23).

[Comparison of current ratings]
Table 1 shows a comparison between the current rating required for a four-wire 400V class uninterruptible power supply and the current rating required for a three-wire 200V class uninterruptible power supply. Here, the conventional example shown in FIGS. 6 and 7 will be described first, and then the current rating in the uninterruptible power supply shown in FIGS. 1 to 3 will be described.

  Assuming that the input / output voltage is 400 V and the input / output current is 15 A, the average current flowing through the IGBTs of the rectifiers 11 to 13 and the inverters 21 to 23 in the conventional example shown in FIG. 7 is 6.5 A. Further, the average current flowing through the IGBT of the converter 31, that is, the n-phase current becomes maximum when a single-phase rectifying load having the same rating is connected between the output phase and the neutral phase of U, V, and W, respectively. The route of the current flowing through each of the IGBTs of the inverters 21 to 23 is three times that of 11.5 A. On the other hand, if the input voltage is 200 V and the power consumption is the same, the input / output current is 30 A, and the average current flowing through the IGBTs of the rectifiers 11 to 13 and the inverters 21 to 23 in the conventional example shown in FIG. . That is, the current rating of the circuit excluding the converter 31 is twice that of the 400V class in the 200V class.

  Therefore, in the circuit configuration shown in FIGS. 1 to 3, circuit components are selected with a current rating of 400V class, and those are used in parallel in the 200V class. That is, the rectifiers 11 to 14 and the inverters 21 to 24 are configured with a current rating corresponding to the 400V class, and by using these two in parallel, the 200V class can be supported. Regarding the converters 31 and 32, the current is three times the root of the current flowing through the IGBTs of the inverters 21 to 23 in the case of three-phase four-wire, and the same as the first phase U and the third phase W of AC output in the case of three-phase three-wire A large current flows. The converters 31 and 32 are not so different in current between the three-phase four-wire and the three-phase three-wire, and a converter having a rating corresponding to both the 200 V class and the 400 V class can be used. However, parts with different ratings will be mixed. In order to avoid this, it is preferable that a circuit is configured in parallel with each of the inverters 21 to 24 and a circuit element having the same current rating as that of the inverters 21 to 24 is used.

[Second Embodiment]
4 and 5 are diagrams showing a circuit configuration of the uninterruptible power supply according to the second embodiment of the present invention and a usage pattern thereof. FIG. 4 is a usage pattern for three-phase three-wire AC, and FIG. The usage form for three-phase four-wire AC is shown. In addition, the part of the code | symbol same as the code | symbol used in 1st Embodiment shows the part same as the thing of 1st Embodiment, The description is abbreviate | omitted or simplified.

  This uninterruptible power supply apparatus includes a bidirectional chopper 41 for stepping down and boosting a DC voltage between a DC link connecting the rectifiers 11 to 14 and the inverters 21 to 24 and the battery BT. Different from form. By using such a bidirectional chopper 41, a battery BT having an arbitrary voltage lower than the voltage of the DC link can be used. As the bi-directional chopper 41, one having a rating corresponding to both the 200 V class and the 400 V class can be used alone, but a circuit having a parallel configuration and the same current rating as the rectifiers 11 to 14 and the inverters 21 to 24 is used. A configuration is preferable.

  As mentioned above, although embodiment of this invention was described, this invention can be variously changed unless the summary is changed. For example, the corresponding three-phase alternating current is not limited to the 200V class and the 400V class, and what if the current rating for the three-phase three-wire alternating current is almost twice that for the three-phase four-wire alternating current Any voltage may be used. The configurations of the LC circuit between the input terminals i1 to i5 and the rectifiers 11 to 14, the inverters 21 to 24, or the LC circuits between the converters 31 and 32 and the output terminals o1 to o5 are appropriately selected as necessary. Or it can be changed. As the rectifiers 11 to 14, the inverters 21 to 24, and the converters 31 and 32, it is preferable to use a bridge circuit using an IGBT. ) Can also be used, and it is also possible to change to other inexpensive configurations. Further, different circuit configurations may be used for the rectifiers 11 to 14, the inverters 21 to 24, and the converters 31 and 32.

It is a figure which shows the circuit structure of the uninterruptible power supply which concerns on the 1st Embodiment of this invention. It is a figure which shows the usage type as an object for three-phase three-wire alternating current of the uninterruptible power supply circuit shown in FIG. It is a figure which shows the usage type as an object for three-phase four-wire alternating current of the uninterruptible power supply circuit shown in FIG. It is a figure which shows the circuit configuration of the uninterruptible power supply which concerns on the 2nd Embodiment of this invention, and the usage type as an object for three-phase three-wire alternating current. It is a figure which shows the usage type as an object for three-phase four-wire alternating current of the uninterruptible power supply device shown in FIG. It is a figure which shows the circuit structure of the uninterruptible power supply of the prior art example corresponding to a three-phase three-wire alternating current. It is a figure which shows the circuit structure of the uninterruptible power supply of the prior art example corresponding to a four-phase three-wire alternating current.

Explanation of symbols

11-14 Rectifier 21-24 Inverter 31, 32 Converter BT Battery C _DC DC capacitor i0-i5 Input terminal o0-o5 Output terminal

Claims (4)

It has a rectifier that converts alternating current to direct current, a battery that stores direct current, and an inverter that converts direct current to alternating current. When the AC power is healthy, the alternating current is converted into direct current by the rectifier and input to the inverter. In the uninterruptible power supply that charges the battery and the AC power supply is in the event of a power failure, the DC power stored in the battery is input to the inverter and the AC power is supplied to the load.
It has 5 input terminals and 5 output terminals for three-phase AC,
The rectifier has four circuits connected to the first to fourth input terminals among the five input terminals,
The inverter has four circuits connected to the first to fourth output terminals among the five output terminals,
A converter connected to the fifth input terminal of the five input terminals and the fifth output terminal of the five output terminals to eliminate a potential difference therebetween;
For three-phase three-wire AC, one of the three-phase inputs with different phases is connected to two of the first to fourth input terminals, and the other of the three-phase inputs is The remaining two input terminals of the first to fourth input terminals are connected to the remaining one of the three-phase inputs to the fifth input terminal of the five input terminals, respectively. The two output terminals of the first to fourth output terminals are output terminals for one phase of the three-phase outputs, and the remaining two output terminals of the first to fourth output terminals are of the three-phase outputs. The other output terminal for one phase, the fifth output terminal is the output terminal for the remaining one phase of the three-phase output,
For three-phase four-wire AC, three-phase inputs having different phases are connected to three input terminals among the first to fourth input terminals, and a neutral phase input is the fifth input terminal. Connected to an input terminal, three of the first to fourth output terminals are three-phase output terminals, and the fifth output terminal is a neutral-phase output terminal. Uninterruptible power supply.   2. The uninterruptible power supply according to claim 1, wherein the converter includes two parallel circuits having a current rating equivalent to each of the four circuits connected to the first to fourth output terminals. An uninterruptible power supply.   The uninterruptible power supply according to claim 1 or 2, further comprising: a bidirectional chopper for stepping down and stepping up a DC voltage between a DC link connecting the rectifier and the inverter and the battery. Power failure power supply.   A rectifier provided with five input terminals and five output terminals for the three-phase AC, and converting AC to DC corresponding to the first to fourth input terminals among the five input terminals. Four rectifier mounting portions for mounting are provided, and four inverter mounting portions for mounting an inverter that converts direct current to alternating current corresponding to the first to fourth output terminals among the five output terminals. The fifth input terminal of the five input terminals is set as a neutral phase input on a circuit board provided with a rectifier at a rectifier mounting portion corresponding to three of the first to fourth input terminals. An uninterruptible power supply characterized in that the fifth output terminal of the five output terminals is a neutral phase, and an inverter is attached to an inverter attachment portion corresponding to three of the first to fourth output terminals. A method for manufacturing a power supply device.

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