JP2011160568A - System interconnection generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system interconnection generator for effectively suppressing vibration which a reactor constituting a current smoothing circuit generates and occurrence of noise due to vibration. <P>SOLUTION: The system interconnection generator boosts DC power generated by a solar battery in a boosting circuit, converts the DC power into AC power in an inverter circuit and connects the AC power to an AC power supply system via the current smoothing circuit. The generator includes the reactor 31 constituting the current smoothing circuit, an interconnection device case 2 incorporating the reactor and a fixing tool 4 for fixing the reactor to the interconnection device case. The fixing tool includes a fitting wall 5A to which the reactor is fitted, a flange 5B obtained by bending an end of the fitting wall to an interconnection device case-side and bending it to an external side, bolts 7 which attachably/detachably fix the flange to the interconnection device case via a vibration absorption material 8 and a cover 6 covering the reactor fitted to the fitting wall. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a grid-connected power generation apparatus that connects power generated by power generation means to an AC power supply system.

  In recent years, solar cells, wind power generators, fuel cells, GHP, and other power generation means have been installed in homes and offices in order to contribute to solving global environmental problems. The power generation means includes a grid interconnection device (referred to as a power conditioner) configured to use the power generated by the power generation means on its own and to regenerate the surplus power to the AC power supply system. The development of grid-connected power generators has become active.

  In such a grid-connected power generation device, for example, after boosting DC power generated by a solar cell with a booster circuit, the boosted DC power is converted into AC power substantially the same as AC power of an AC power supply system by an inverter circuit. This is converted and connected to an AC power supply system via a current smoothing circuit (see, for example, Patent Document 1).

JP 2003-9398 A

  Here, the current smoothing circuit that constitutes the grid-connected power generation apparatus is normally configured by a reactor and a capacitor, and the reactor generates vibration when energized. And the vibration of this reactor was transmitted to the case which incorporates the said reactor, and there existed a problem which the said case vibrates and emits noise.

  The present invention has been made in order to solve the conventional technical problem, and the grid-connected power generation effectively suppresses the vibration generated by the reactor constituting the current smoothing circuit and the noise generated thereby. The object is to provide an apparatus.

  In order to solve the above-described problems, the grid-connected power generation device of the present invention boosts DC power generated by the power generation means with a booster circuit, converts it to AC power with an inverter circuit, and converts the AC power into the AC power supply via a current smoothing circuit. A reactor that is connected to the system and includes a reactor that constitutes a current smoothing circuit, an interconnection device case that incorporates the reactor, and a fixture for fixing the reactor to the interconnection device case. , A mounting wall to which the reactor is mounted, a flange formed by bending the end of the mounting wall to the interconnecting device case side, and then bending outward, and connecting the flange via a vibration absorber It has the volt | bolt fixed to an apparatus case so that attachment or detachment is possible, and the cover which coat | covers the reactor attached to the attachment wall.

  The grid-connected power generation device according to the invention of claim 2 is characterized in that, in the above, the cover covers the reactor at intervals.

  In the grid-connected power generation device of the invention of claim 3, in each of the above-mentioned inventions, the flange is a first bent wall continuous with the mounting wall, and a second bent continuously outward from the first bent wall. And a notch is formed at the edge of the second bent wall, and the vibration absorbing material is engaged with the notch, and the bolt penetrates the vibration absorbing material in the notch to connect to the interconnection device case. It is fixed.

  The grid-connected power generation device of the invention of claim 4 is characterized in that, in the above, the cover is attached to the first bent wall.

  According to the present invention, in the grid-connected power generation apparatus that boosts the DC power generated by the power generation means with the booster circuit, converts the DC power into AC power with the inverter circuit, and connects to the AC power supply system via the current smoothing circuit. The reactor comprises a smoothing circuit, an interconnecting device case incorporating the reactor, and a fixing device for fixing the reactor to the connecting device case. The fixing device includes an attachment wall to which the reactor is attached, A flange formed by bending the end portion of the mounting wall to the interconnection device case side and then bending outward, and a bolt for detachably fixing the flange to the interconnection device case via a vibration absorber And a cover for covering the reactor attached to the mounting wall, the reactor is separated from the wall surface of the interconnection device case, and the interconnection device is interposed in the form of a vibration absorber. It will be fixed in the case.

  As a result, the vibration generated from the reactor is transmitted to the interconnection device case, and the interconnection device case itself vibrates and adversely affects other electrical components, and the generation of noise can be effectively suppressed. Become. Further, since the reactor is covered with the cover, noise generated from the reactor itself can be suppressed.

  Further, according to the invention of claim 2, in addition to the above, the cover covers the reactor with a gap, so that the sound generated from the reactor can be more effectively reduced by the so-called muffler effect. It will be possible.

  According to the invention of claim 3, in each of the above inventions, the flange is provided with a first bent wall continuous with the mounting wall, and a second bent continuously outward from the first bent wall. And a notch is formed at the edge of the second bent wall, and the damping material is engaged with the notch, and the bolt penetrates the damping material in the notch and is fixed to the interconnection device case. Therefore, the vibration absorbing material can be easily engaged with the flange of the fixture, and can be fixed to the interconnection device case with the bolts, thereby improving the assembly workability.

  Further, according to the invention of claim 4, since the cover is attached to the first bent wall in addition to the above, the cover is attached to the second bent wall of the flange, for example, The cover does not interfere with the fixing between the flange and the interconnection device case, and the assembly workability is further improved.

It is a figure which shows the internal structure of the grid connection apparatus which comprises the grid connection power generator of one Embodiment to which this invention is applied. FIG. 2 is a partially longitudinal enlarged view of a reactor portion of the grid interconnection device of FIG. 1. It is an electric circuit diagram of the system interconnection power generator of one embodiment to which the present invention is applied. It is an expanded plane sectional view of the reactor part of the grid connection apparatus of FIG.

  Hereinafter, embodiments of the present invention will be described in detail.

  First, as shown in the electric circuit diagram of FIG. 3, the grid-connected power generation device 1 of this embodiment is configured to include a solar cell 11 and a grid-connection device 12 as power generation means. The interconnection device 12 is connected (linked) to the single-phase three wires of the AC power supply system 13. The grid-connected power generation device 1 is configured such that the DC power generated by the solar battery 11 (power generation means) is converted into AC power by the grid connection device 12 and can be supplied (regenerated) to the AC power supply system 13. Yes.

  The solar cell 11 is configured to have a large number of solar cells, and each of these solar cells receives sunlight to generate DC power (power generation).

  On the other hand, the grid interconnection device 12 includes a booster circuit 14, an inverter circuit 15, a current smoothing circuit 16, and a control device 17 that includes a microcomputer. An inverter output current detection sensor 21, a solar cell current detection sensor 41, and a DC ground fault detection sensor 42 are connected to the control device 17.

  The step-up circuit 14 inputs unstable DC power generated by the solar battery 11 through a noise filter 44 and boosts the voltage to a voltage larger than the system voltage of the AC power supply system 13. , A choke coil 23, a switch circuit 24, a diode 25, and a capacitor 26. A lightning protection arrester 46 is provided on the input side of the noise filter 44, and a power generation means side power relay 47 is provided between the solar cell 11 and the booster circuit 14.

  The smoothing capacitor 22 smoothes the DC power input to the switch circuit 24. The switch circuit 24 includes a switching element 27 and a diode 28. As the switching element 27, a power transistor, a power MOSFET, an IGBT, or the like is used. By the ON / OFF operation (gate drive) of the switching element 27, a boosted voltage is generated in the choke coil 23. Further, the capacitor 26 stores high voltage power generated by the choke coil 23. The diode 25 prevents the reverse flow of the high voltage power stored in the capacitor 26.

  By adjusting the time (ON duty) during which the switching element 27 is turned on, the boosted power boosted by the booster circuit 14 is controlled. That is, when the system voltage of the AC power supply system 13 is, for example, AC 200 V, the peak value (peak value) becomes plus or minus 280 V, so that AC power is regenerated from the system interconnection device 12 to the AC power supply system 13. Therefore, the boosted voltage by the booster circuit 14 needs to be set to an absolute value (280 V) or more of the peak value. Actually, the boosted voltage by the booster circuit 14 is set to a value 20V to 30V higher than 280V in consideration of the ON resistance of the switching element 29 of the inverter circuit 15 described later and the resistance of the reactor 31 of the current smoothing circuit 16. The

  The inverter circuit 15 is configured such that a plurality of switching elements 29 are bridge-connected, and diodes 30 (flywheel diodes) are provided corresponding to the switching elements 29, and the DC power boosted by the booster circuit 14. Is converted into AC power having a sine waveform with a phase and frequency substantially coincident with the AC power of the AC power supply system 13.

  That is, the inverter circuit 15 turns the switching element 29 on and off (gate drive), thereby converting the DC power input from the booster circuit 14 into AC power by pulse width modulation. Further, the switching element 29 is turned on so that the waveform of the AC power (AC current, AC voltage) output from the inverter circuit 15 matches the AC voltage waveform of the system voltage in the AC power supply system 13 (ON Duty) is adjusted. As a result, the phase and frequency of the AC power output from the inverter circuit 15 substantially match those of the system power of the AC power supply system 13.

  The current smoothing circuit 16 includes two reactors 31 and 31 and a capacitor 32, and smoothes the AC power converted by the inverter circuit 15. The AC power smoothed by the current smoothing circuit 16 can be regenerated to the AC power supply system 13 via the noise filter 48, the system-side power relay 49, the breaker 51, and the system connection terminal 53.

  Incidentally, 52 is an arrester for lightning protection provided on the output side of the noise filter 48, and 54 is a ground terminal. Reference numeral 56 denotes a stand-alone operation outlet, which is connected to the output side of the noise filter 48 via a stand-alone power relay 57 and a breaker 58.

  The control device 17 adjusts the ON duty of the switching element 27 in the booster circuit 14 based on the regenerative power regenerated from the grid interconnection device 12 to the AC power supply system 13, the system voltage, and the boost voltage. Control the boost voltage.

  Further, the control device 17 adjusts the ON duty of the switching element 29 in the inverter circuit 15 based on the waveform (sine wave) of the system voltage and the waveform of the output current detected by the inverter output current detection sensor 21. Control. By controlling the booster circuit 14 and the inverter circuit 15 by the control device 17, AC power substantially matching the AC power of the AC power supply system 13 can be regenerated from the grid interconnection device 12 to the AC power supply system 13. .

  Such a control device 17 is wired on the circuit board 61 together with most of the electrical components other than the solar cell 13, the reactors 31 and 31, and the terminals 53, 54 and 56 in FIG. 3. And this circuit board 61 is attached in the interconnection apparatus case 2 shown in FIG. Further, the terminals 53, 54, and 56 described above are attached in the interconnecting device case 2 on one side (front side) of the circuit board 61, and the above-described terminals in the interconnecting device case 2 on the other side (back side). The reactors 31 and 31 constituting the current smoothing circuit 16 are attached side by side.

  Next, the mounting structure of the reactors 31 and 31 will be described in detail with reference to FIGS. 1, 2, and 4. FIG. 1 shows a state in which the wall on the front side of the drawing is removed in order to show the internal configuration of the interconnection device case 2 of the grid interconnection device 12 of the embodiment.

  As shown in FIG. 1, the interconnection device case 2 of the embodiment has a box shape having a height dimension larger than a width dimension and a depth dimension, and an operation panel 3 is provided on the front surface. And the circuit board 61 is arrange | positioned in the approximate center part of the front-back direction, and is attached to wall 2A of the back side of drawing. The terminals 53, 54, and 56 are attached to the wall 2 </ b> A on the front side of the circuit board 61, and the reactors 31 and 31 are attached to the wall 2 </ b> A on the rear side of the circuit board 61. An exhaust port 72 (FIG. 2) is formed in the interconnection device case 2 at a position corresponding to the upper side of the reactors 31, 31.

  FIG. 2 shows an enlarged view in which the reactors 31 and 31 at the rear part of the interconnecting device case 2 in FIG. 1 are partially longitudinally cut, and FIG. 4 shows an enlarged plan sectional view of one reactor 31 part. In addition, since the attachment structure of both the reactors 31 and 31 is the same, it demonstrates only by one. Reactors 31 and 31 are fixed to wall 2 </ b> A of interconnection device case 2 by fixture 4. As shown in FIG. 4, the fixture 4 of the embodiment includes a bent mounting base 5, a box-like cover 6 having an opening on one side, four bolts 7, and four vibration absorbing materials 8. ... and four screws 9 ...

  The mounting base 5 has a rectangular flat mounting wall 5A to which the reactor 31 is mounted, and both ends (front and rear edges) of the mounting wall 5A on the side of the wall 2A of the interconnection device case 2 to which the mounting base 5 is to be mounted. The flanges 5B and 5B are formed by bending at substantially right angles to each other and then bending outward at approximately right angles. Each flange 5B includes a first bent wall 62 that is continuous with the mounting wall 5A, and a second bent wall 63 that is continuous from the first bent wall 62 and faces outward. Two notches 64 and 64 are formed at the edges of the bent walls 63 and 63, respectively. In addition, two screw holes 65, 65 are formed in the first bent walls 62, 62, respectively.

  The cover 6 is formed with four screw holes 66 at the opening edge. The vibration-absorbing material 8 is made of an elastic material such as rubber, and has a cylindrical shape as a whole with a through hole 67 formed in the shaft core. Is formed. The bolt 7 is a seated bolt having a height substantially matching the axial dimension of the vibration absorber 8.

  With the above configuration, the engaging portions 68 of the vibration absorbing material 8 are respectively addressed to the notches 64 formed at the edges of the second bent wall 63 of the flanges 5B and 5B, and the edges of the notches 64 are engaged with the engaging portions. The vibration absorbing material 8 is attached to each of the notches 64 by engaging with each other. Reactor 31 is attached to the surface opposite to the direction in which flange 5B of attachment wall 5A of attachment base 5 is bent. Further, the cover 6 is directed to the reactor 31 and covered. At this time, the opening edge of the cover 6 is fitted to the outside of the first bent wall 62 of the flange 5 </ b> B, and each screw hole 66 matches each screw hole 65. The cover 6 is detachably attached to the first bent wall 62 by screwing screws 9 into the screw holes 66 and 65 from the outside. In this state, the cover 6 covers the reactor 31 with a gap G1.

  In the assembled state, the through holes 67 of the vibration absorbers 8 are aligned with the four screw holes 71 that are preliminarily formed in the wall 2A and are connected to the wall 2A of the interconnection device case 2. Then, the bolt 7 is inserted into the through hole 67 of each vibration absorbing material 8 and screwed into the screw hole 71. At this time, the bolt 7 passes through the vibration absorbing material 8 in the notch 64 of the second bent wall 63, whereby the flange 5 </ b> B is detachably fixed to the wall 2 </ b> A of the interconnection device case 2 via the vibration absorbing material 8. The reactor 31 is separated from the surface of the wall 2A of the interconnection device case 2 with a gap G2 corresponding to the dimension of the first bent wall 62.

  Here, each of the reactors 31 and 31 constituting the current smoothing circuit 16 generates vibration and heat when energized. Although heat is released from the exhaust port 72, vibration is absorbed by the vibration absorbing material 8.

  That is, by fixing the reactors 31 and 31 to the interconnection device case 2 using the fixture 4 as in the embodiment, the reactors 31 and 31 are fixed through the vibration absorbing material 8 and separated from the wall 2A. Therefore, the vibration generated from the reactors 31 and 31 and transmitted to the interconnection device case 2 can be effectively suppressed. As a result, it is possible to effectively suppress the inconvenience that the interconnection device case 2 itself vibrates and adversely affects other electrical components, and the generation of noise.

  Moreover, since the reactor 31 is coat | covered with the cover 6, the noise which generate | occur | produces from the reactor 31 itself can also be suppressed now. In this case, in the embodiment, since the cover 6 covers the reactor 31 with the gap G1, the sound generated from the reactor 31 can be more effectively reduced by the so-called muffler effect.

  Further, the flange 5B of the mounting base 5 is composed of a first bent wall 62 that is continuous with the mounting wall 5A, and a second bent wall 63 that is continuous from the first bent wall 62 and faces outward. Since the notch 64 is formed at the edge of the second bent wall 63 so that the vibration absorbing material 8 is engaged with the notch 64, the vibration absorbing material 8 can be easily engaged with the flange 5B of the fixture 4. Can be combined. Since the bolt 7 penetrates the vibration absorbing material 8 in the notch 64 and is fixed to the wall 2A of the interconnection device case 2, the dimensions required for mounting can be accommodated in the flange 5B, and the assembly is generally performed. Workability is improved.

  Here, when the cover 6 is attached to the second bent wall 63 of the flange 5B with the screw 9, the screw 9 hits the wall 2A when fixing the second bent wall 63 to the wall 2A. Although there is a risk, if the cover 6 is attached to the first bent wall 62 of the flange 5B as in the embodiment, the cover 6 will not interfere with the fixing between the flange 5B and the interconnection device case 2, The assembly workability is further improved.

  Note that the shape of the interconnection device case 2 shown in the above embodiment, the circuit configuration of the grid interconnection device 14, the arrangement of the reactors 31, 31 and the like are not limited thereto, and are within the scope of the present invention. Needless to say, it can be changed. Further, the power generation means is not limited to the solar cell 11 of the embodiment, and the present invention is effective when applied to a wind power generator, a fuel cell, a GHP, and the like.

DESCRIPTION OF SYMBOLS 1 System interconnection power generation device 2 Interconnection device case 4 Fixing device 5 Mounting base 5A Mounting wall 5B Flange 6 Cover 7 Bolt 8 Damping material 9 Screw 11 Solar cell 12 System interconnection device 13 AC power supply system 14 Booster circuit 15 Inverter circuit 16 Current smoothing circuit 31 Reactor 62 First bent wall 63 Second bent wall 64 Notch G1, G2 interval

Claims (4)

In the grid-connected power generation device that boosts the DC power generated by the power generation means by the booster circuit, converts it to AC power by the inverter circuit, and connects it to the AC power supply system via the current smoothing circuit.
A reactor that constitutes the current smoothing circuit, an interconnecting device case incorporating the reactor, and a fixture for fixing the reactor to the interconnecting device case,
The fixing device includes a mounting wall to which the reactor is mounted, a flange formed by bending an end of the mounting wall to the interconnecting device case side, and then bending outward, and the flange absorbs vibration. A grid-connected power generation device comprising: a bolt that is detachably fixed to the interconnection device case via a material; and a cover that covers the reactor attached to the attachment wall.   The grid-connected power generation device according to claim 1, wherein the cover covers the reactor with an interval.   The flange includes a first bent wall that is continuous with the mounting wall, and a second bent wall that is continuously outward from the first bent wall. A notch is formed in an edge, the vibration absorbing material is engaged with the notch, and the bolt penetrates the vibration absorbing material in the notch and is fixed to the interconnection device case. The grid connection electric power generating apparatus of Claim 1 or Claim 2.   The grid-connected power generation device according to claim 3, wherein the cover is attached to the first bent wall.

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