The present invention relates to a reactor apparatus included in an electric power system and a power converter using the same.
For an iron core of a three-phase reactor apparatus, a transformer, or the like, having a large capacity, included in an electric power system, a laminated iron core is used in general which is formed by stacking a plurality of thin plates of magnetic material such as silicon steel and amorphous metal in order to reduce a loss (iron loss) during operation. Then, three sets of coils are respectively wound around three magnetic legs composed of laminated iron cores and formed on a flat surface.
In addition, for flowing magnetic flux caused by zero-phase-sequence impedance that is generated when a voltage value of each phase and/or a mutual phase-difference in a three-phase AC power supply deviate from an ideal state, a three-phase five-leg type iron core is commonly used in which two magnetic legs, having no coil wound around, for the zero phase are further added outside the three magnetic legs.
A configuration of this three-phase five-leg type transformer is disclosed in Japanese Patent Application Publication No. H05-234783A for example. In that disclosure, a technique is disclosed in which a three-phase five-leg iron core is formed by arranging four two-legged iron cores, each being a laminated iron core formed by stacking a plurality of thin steel plates, and three magnetic legs that are main legs thereof are wound with respective phase coils.
A summary of the structure of a three-phase transformer using a three-phase five-leg type iron core disclosed in Japanese Patent Application Publication No. H05-234783A is shown in
However, as the three-phase five-leg type iron core of a conventional configuration described above is configured such that three-phase coils are arranged side by side on a flat surface, the width of a transformer or a reactor apparatus becomes large, causing a housing problem. Also, because the mutual distances between three coils are different from one another, there is a problem that symmetry of electric properties of each phase is easily deviated, causing difficulty in obtaining stability of operation and low loss property.
Therefore, the present invention solves such problems and it is intended to provide a reactor apparatus having excellent housing attributes and electric properties, and a power converter using the same.
In order to solve the problems described above, a reactor apparatus of the present invention is configured as described below. That is, the reactor apparatus is characterized to include two yoke iron cores disposed opposite each other, a plurality of magnetic leg iron cores each of which has a coil wound therearound and provided with a gap adjusting means, and one or more zero-phase magnetic leg iron cores around which a coil is not wound, wherein the two yoke iron cores disposed opposite each other are connected to each other with the plurality of magnetic leg iron cores and the one or more zero-phase magnetic leg iron cores.
In addition, the power converter of the present invention is characterized to use the reactor apparatus.
According to the present invention, a reactor apparatus having excellent housing attributes and electric properties and a power converter using the same can be provided.
Hereinafter, embodiments of the present invention will be described referring to the drawings.
A first embodiment of the present embodiment will be described referring to
As shown in
The magnetic leg iron core 31 has a cylindrical shape formed by rolling thin belt-shaped magnetic material with insulation treatment. Illustration of the magnetic leg iron core 31 with plural concentric circles in
In addition, a slit (gap) 3a (
Further, it is preferable from the viewpoint of improving the electric properties of the reactor apparatus 10 that the laminating direction of the thin belt-shaped magnetic material constituting the plurality of magnetic leg iron cores 31 is almost the same as the laminating direction of the thin belt-shaped magnetic material constituting the yoke iron cores 11a, 11b.
Furthermore, the yoke iron cores 11a, 11b and the magnetic leg iron cores 31 are formed of isotropic material having soft magnetic properties such as ferrite and a compressed powder conductor.
The yoke iron cores 11a and 11b are disposed so as to be opposite each other at the upper and lower ends of the reactor apparatus 10 (
Three magnetic leg iron cores 31 are provided between the yoke iron cores 11a and 11b, to magnetically connect the two yoke iron cores 11a and 11b to each other. However, as described below, there is a case a gap (opening, space) by a gap adjusting means 5a (
As shown in
Note that the reason the three magnetic leg iron cores 31 are disposed in the positional relation described above is for the purpose of making the reactor apparatus 10 of the present embodiment function as a three-phase reactor for three-phase AC, securing electrical symmetry.
Further, in order to prevent the inductance value of the reactor apparatus 10 from changing and a loss at the reactor apparatus 10 from increasing due to magnetic saturation of the iron cores, each of the magnetic leg iron core 31 is provided, as shown in
As shown in
Note that the coil 21 is formed of a linear conductor or a plate-like conductor provided with insulation material.
Further, as a magnetic flux is generated in the longitudinal direction of the magnetic leg iron core 31 when an electric current flows through the coil 21, in order to prevent the eddy current from flowing in the circumferential direction of the magnetic leg iron core 31 by the magnetic flux and the loss at the reactor apparatus 10 from increasing, as described above, the magnetic leg iron core 31 is provided with at least one slit 3a in the longitudinal direction to prevent the eddy current from being generated.
The zero-phase magnetic leg iron core 41 has a plurality of sheets of thin belt-shaped magnetic material laminated with insulation treatment to form a rectangular parallelepiped shape. Illustration of the zero-phase magnetic leg iron core 41 as a collection of plural rectangular parallelepipeds in
The zero-phase magnetic leg iron cores 41 are, as shown in
The zero-phase magnetic leg iron cores 41 are provided as passages for flowing the magnetic flux by zero-phase impedance generated when the phases of the three-phase AC current flowing in the coils 21 wound around the three magnetic leg iron cores 31 deviate from an ideal state.
With the structure described above, the three-phase reactor apparatus 10 is configured in which each of the iron cores is formed using a component obtained by laminating plural sheets of thin belt-shaped magnetic material.
As shown in
Next, a second embodiment of the present invention will be described.
In
Further, although it is not illustrated, the three magnetic leg iron cores 32 are respectively provided with at least one or more gap adjusting means (corresponding to 5a, 5b in
Note that the laminating direction of the thin belt-shaped magnetic material of the magnetic leg iron cores 32 and the zero-phase magnetic leg iron cores 42 is preferably made the same as the laminating direction of the yoke iron cores 11a, 11b, in particular in the radial direction.
In the above configuration shown in
In addition, as those other than the shape of the magnetic leg iron cores 32 and the coils 22 in the second embodiment are almost the same as
Next, a third embodiment of the present invention will be described.
In
These three magnetic leg iron cores 33 and three zero-phase magnetic leg iron cores 43, each having a substantially sector shape may be formed, for example, by cutting an iron core in the radial direction at a suitable angle, where the iron core is formed by rolling thin belt-shaped magnetic material in a toroidal shape with insulation treatment.
In addition, although it is not illustrated, the three magnetic leg iron cores 33 are respectively provided with at least one or more gap adjusting means (corresponding to 5a, 5b in
Further, as the coil 23 is wound around the magnetic leg iron core 33 having a substantially sector shape as described above, the coil 23 becomes to have a shape reflecting the shape of the magnetic leg iron core 33 (substantially sector shape).
In the above configuration shown in
In addition, as those other than the shape of the magnetic leg iron cores 33, the coils 23, and the zero-phase magnetic leg iron cores 43 in the third embodiment are almost the same as
Next, a fourth embodiment of the present invention will be described.
In
Similarly to the magnetic leg iron core 31 shown in the first embodiment, it is preferable to provide a slit (corresponding to 3a in
In the above configuration shown in
In addition, as those other than the shape of the zero-phase magnetic leg iron cores 44 in the fourth embodiment are almost the same as
Next, a fifth embodiment of the present invention will be described.
In
Similarly to the magnetic leg iron core 31 shown in the first embodiment, it is preferable to provide a slit (corresponding to 3a in
In the above configuration shown in
In addition, as those other than the change of the number of zero-phase magnetic leg iron cores 45 in the fifth embodiment are substantially the same as
Next, a sixth embodiment of the present invention will be described.
Note that
In
By having the hollow rectangular shape of the yoke iron cores 12a, 12b shown in
Next, a seventh embodiment of the present invention will be described.
In
In the first embodiment to the fifth embodiment, exemplary yoke iron cores 11a, 11b (
By having the hollow triangle shape of the yoke iron cores 13a, 13b shown in
Next, an eighth embodiment of the present invention will be described.
The reactor apparatus (11a, 11b, 21, 31) is mounted on a base 7, covered with a fixing jig 6 from the top, and crimped and fixed by fixing means 8a, 8b.
The base 7 and the fixing jig 6 may be formed of a sheet-like member that entirely covers the reactor apparatus, or may be formed of a frame-like member that does not entirely cover the reactor apparatus.
Also, a cooling means 9 may be arranged on the concentric axis of the yoke iron cores 11a, 11b, as appropriate.
The above fixing method and arrangement of the cooling means 9 will help the embodiment to become practical.
Note that in
Next, as a ninth embodiment of the present invention, a power converter using a reactor apparatus will be described.
In
The power converter 210 includes a rectifying circuit 211 for converting AC power of the AC power supply 213 to DC power, and an inverter circuit 212 for converting the DC power to AC power having a given voltage and a given frequency. Also, between an output terminal of the rectifying circuit 211 and an input terminal of the inverter circuit 212, a capacitor 218 for smoothing and a chopper circuit 215 are connected.
The rectifying circuit 211 is configured to include a filter circuit 223 including reactors 220 for three phases and capacitors 221 for three phases, and a bridge circuit (AC/DC converter) 222 in which a plurality of switching elements 217 made of IGBT (Insulated Gate Bipolar Transistor), one of semiconductor elements, are bridge-connected.
The inverter circuit 212 is configured to include a DC/AC conversion circuit 224 in which the plurality of switching elements 217 made of IGBT are bridge-connected, and the filter circuit 223 including the reactors 220 for three phases and the capacitors 221 for three phases.
Note that the plurality of switching elements 217 made of IGBT in the bridge circuit 222 and the DC/AC conversion circuit 224 are respectively controlled with PWM (Pulse Width Modulation) control, integrally through gate terminals, to perform the respective designated functions described above.
In addition, diodes for protecting against excess voltage are added to or are parasitic in the respective switching elements 217 made of IGBT, in inverse-parallel connection.
Further, for the reactor apparatuses 220 for three phases included in the filter circuits 223 provided in the rectifying circuit 211 and the inverter circuit 212, the reactor apparatuses of any one of the first embodiment to the eighth embodiment are used.
Furthermore, the chopper circuit 215 having the two switching elements 217 made of IGBT in series connection is connected between both terminals of the capacitor 218. One end of a coil or a reactor 219 is connected to the connecting point between the two switching elements 217, and a battery 216 is connected between the other end of the reactor 219 and an emitter of one of the switching elements 217.
In the power converter 210 described above, during normal operation, AC power from the AC power supply 213 is converted to DC power by the rectifying circuit 211, then the DC power is converted back to AC power of a given voltage and a given frequency suitable to the load 214 by the inverter circuit 212, to be supplied to the load 214.
In addition, as an operation outside the normal operation (operation 1 outside the normal operation), when power supply from the AC power supply 213 is stopped, the battery 216 and the inverter circuit 212 are connected to each other by the action of the chopper circuit 215, and the load 214 is continuously supplied with power converted to AC power by the inverter circuit 212, originated from the battery 216.
Further, as an operation during maintenance or the like (operation 2 outside the normal operation), a bypass circuit 225 is connected and AC power is supplied to the load 214 from the AC power supply 213 through the bypass circuit 225 , without passing through the rectifying circuit 211 and the inverter circuit 212. Note that the features to be provided by the bypass circuit 225 depends on the specification of the power converter 210.
As described above, the rectifying circuit 211 is an AC/DC conversion circuit that converts three-phase AC power to DC power, and the inverter circuit 212 is a DC/AC conversion circuit that converts DC power to three-phase AC power of a given voltage and a given frequency.
In these convensions, both of the rectifying circuit 211 and the inverter circuit 212 operate the plurality of switching elements that are PWM-controlled. In the process of these switching operations, harmonic current components (ripple components) are generated.
The filter circuits 223 are used for removing these generated harmonic current components and matching of impedance between the AC power supply 213 and the bridge circuit 222, and between the load 214 and the bridge circuit 222.
The filter circuit 223 is configured to use the reactors 220 for three phases and the capacitors 221 for three phases.
As the reactors 220 for three phases, the reactor apparatus of any one of the first embodiment to the eighth embodiment of the present invention described above is used.
By using the reactor apparatus according to the present embodiments for three phases, a power converter that has the electric properties of excellent symmetry among three phases and high conversion efficiency, and are reduced in size and weight can be realized and provided.
The present invention is not limited to the embodiments described above. Examples will be described hereinafter.
Although the magnetic leg iron cores 31 to 35 shown in the first to fifth embodiments described above are examples having a cylindrical shape, a rectangular parallelepiped shape and a sector shape formed by laminating the thin belt-shaped magnetic material, the reactor apparatus may be configured by any combination of the magnetic leg iron cores in these shapes.
In addition, an isotropic magnetic material such as ferrite, compressed powder material or the like may be used as the material of the iron core, and iron cores using them and iron cores using the thin belt-shaped magnetic material may be combined.
Further, with respect to the yoke iron cores 11a to 13a, 11b to 13b, the examples in the hollow toroidal shape, or in the rectangular shape and the triangle shape as
Furthermore, in the first to fifth embodiments, the number of the magnetic leg iron cores 31 to 35 has been three as shown in
Still furthermore, in the first to fourth embodiments, three magnetic leg iron cores 31 to 34 are disposed on the circumference of the yoke iron cores 11a, 11b at an angle of approximately 120° relative to the concentric axis of the yoke iron cores 11a and 11b in a circular shape having a hollow space, however it is not necessarily limited to approximately 120°. As shown in
Moreover, in
The bridge circuit 222 in the power converter 210 shown in
It may be also configured with a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), a bipolar transistor (Bipolar junction transistor), or a BiCMOS (Bipolar Complementary Metal Oxide Semiconductor), which are semiconductor switching elements. Also, it may be configured by bridge-connecting diodes that are semiconductor elements.
As an application of the reactor apparatus according to the embodiment of the present invention, an example of the uninterruptible power supply has been shown in
Supplement to the present invention and present embodiments
As described above, according to the present invention and the present embodiments, a reactor apparatus which has excellent housing attributes, improves symmetry between multiphase coils, and are excellent in operational stability and low loss property compared with a reactor apparatus that uses conventional three-phase five-leg type iron cores, and a power converter using the same can be provided.
3
a Slit
5
a,
5
b Gap adjusting means
6 Fixing jig
7 Base
8
a,
8
b Fixing means
9 Cooling means
10 Reactor apparatus
11
a,
11
b,
12
a,
12
b,
13
a,
13
b Yoke iron core
21, 22, 23, 24 Coil
31, 32, 33, 34, 35 Magnetic leg iron core
41, 42, 43, 44, 45 Zero-phase magnetic leg iron core
211 Rectifying circuit
212 Inverter circuit
213 AC power supply
214 Load
215 Chopper circuit
216 Battery
217 Switching element, IGBT
218, 221 Capacitor
219, 220 Reactor
222 Bridge circuit, AC/DC converter
223 Filter circuit
224 DC/AC conversion circuit
225 Bypass circuit
330
a,
330
b,
330
c Coil
331 Two-legged iron core
331
a,
331
b,
331
c Magnetic leg section
331
d,
331
e Zero-phase magnetic leg section
This present application is a National Stage Application of PCT Application No. PCT/JP2011/061138 filed on May 16, 2011, which applications are incorporated herein by reference.
Filing Document | Filing Date | Country | Kind | 371c Date |
---|---|---|---|---|
PCT/JP2011/061138 | 5/16/2011 | WO | 00 | 2/21/2014 |