KR20160108918A

KR20160108918A - inverter

Info

Publication number: KR20160108918A
Application number: KR1020150032351A
Authority: KR
Inventors: 강동엽
Original assignee: 강동엽
Priority date: 2015-03-09
Filing date: 2015-03-09
Publication date: 2016-09-21

Abstract

The present invention relates to an inverter. An output stage of a photovoltaic module is connected to sources of two field-effect transistors in parallel, a square wave is alternately supplied from a driver to gates of the field-effect transistors at a period of 60 Hz to turn on the field-effect transistors, alternating current power transformed by a square wave is applied to both ends of a primary side to which an intermediate tap of a transformer is grounded in drains of the field-effect transistors alternately turned on at the period of 60 Hz, and the transformed alternating current power output from the drains of the field-effect transistors is applied to each of the primary sides of the transformer, thereby obtaining alternating current power with desired magnitude on the secondary side of the transformer.

Description

Inverter {inverter}

More particularly, the present invention relates to an inverter of a generator for an electric automobile as well as a wind power, a water power, and a solar power generator. More specifically, The present invention relates to an inverter which obtains a desired AC power with a high efficiency by a simple structure by allowing an AC power source by a solar module to be applied to a primary side of a transformer.

In recent years, it has been well known that researches on renewable energy such as solar energy and wind power, which are representative green-friendly green energy, are actively under way due to recent problems of depletion of natural resources and environmental and stability of nuclear power generation and nuclear power generation to be.

New and renewable energy such as photovoltaic power generation is attracting considerable attention from the point of view of infinite and clean energy. It is widely used in the fields of commercial large-scale power generation complexes, automobiles (railroad cars), residential power generation and street lamps as well as gridlines and unmanned lighthouses, And special equipment.

For example, solar photovoltaic power generation systems generally consist of solar cell modules, accumulators, and inverter parts, although they differ in terms of system usage, type of load, and location conditions.

In case of using the method of transferring the solar energy directly to the power source side without a storage device such as a storage battery, a link type inverter is applied for this purpose. Even if a storage battery is used, The inverter circuit, which is an interface circuit for connecting with the AC system, is an important part.

In addition, in addition to solar power generation, the configuration of the inverter is necessary for the power generation by the wind power or the tidal power, and for the power supply of the converted power from the battery storing the generated power.

The current circular inverter of the interface circuit has an advantage that the output voltage of the inverter is lower than the grid voltage when the grid is connected, and there is no inrush current to the load short circuit and the inverter short circuit.

When using the current circular inverter, the controller using the processor is generally used in the photovoltaic power generation system. In order to reduce the ripple of the inductance and the output current, the switching frequency should be controlled at a high switching frequency. However, And the sampling frequency depending on the performance of the processor.

Thus, Patent Application No. 10-2003-0016570 (Current Source Inverter by Parallel Switching) of Mar. 17, 2003 has been proposed,

The present invention relates to a current source inverter by parallel switching for achieving a low distortion factor and a high efficiency by configuring converters in a parallel type with a cooperative inverter,

As soon as one of the converters is turned on / off, the converter is driven by a parallel type Buck-Boost converter that switches on / off the other converter so that the switching frequency of the inverter is reduced and the current of the converter is greatly reduced And the resulting output voltage ripple is greatly reduced, so that the efficiency characteristics are improved.

In addition, full-bridge inverters implement a single-phase or three-phase bridge circuit to supply power to the grid, two switches for single-phase supply per bridge branch, Respectively.

Also, the switches in the bridge circuit can be connected symmetrically or asymmetrically.

To isolate this configuration from the DC side, DE 10 2004 030 912 B3 suggested that a fifth switch be connected between the anode of the DC power source and the two bridge branches.

This fifth switch is connected to the two lower switches of the bridge branch as well as to the high frequency, respectively, but each of the upper switches of the bridge branch is closed during each half wave of the grid voltage so as to clock the switches asymmetrically Respectively.

In the full bridge circuit introduced in WO2008015298A1, a divided intermediate circuit is provided at the input end so that the switches are connected in series to each DC line between the intermediate circuit and the bridge. These switches alternately clock at high frequencies alternately with each of the two lower switches of the bridge branch, but each of the upper switches of the bridge branch is closed during each half wave of the distribution network voltage.

Two series diodes connected upstream of the bridge branch further configured the freewheel path and the center tap was connected to the center tap of the intermediate circuit.

The three-stage circuit configuration is also known. In such a circuit configuration, the bridge branch is composed of four switches, of which two center switches are bridged by two series-connected diodes during the freewheel time, thereby reducing the voltage load on the operating switches.

Also, a patent application No. 10-2009-0052647 (inverter) of Jun. 15, 2009 has been proposed,

This is an inverter for supplying electric power of a DC power source to an AC voltage distribution network N:

An asymmetric switching bridge circuit having only four switches;

Two of the four switches switch at the same frequency as the distribution network and form a part of the first device assembly and the remaining two switches switch to a frequency higher than the frequency of the distribution network, Forming a part of a spatially separated second device assembly;

The second switch has a higher switching gradient and a higher temperature stability than the first slow switch,

A first cooling element is connected to the first element assembly and a second cooling element different from the first cooling element is connected to the second element assembly,

And the second cooling element is larger than the first cooling element.

However, according to the conventional inverter as described above, an electrolytic capacitor must be provided, and the lifetime of the capacitor is significantly shortened in comparison with the lifetime of the general semiconductor, and the life of the entire inverter is shortened according to the characteristics of the surrounding environment. .

Thus, Japanese Laid-Open Patent Application No. 10-2014-0044428 filed on April 15, 2014 (Power Inverter without a condenser)

This is because DC power from a generator such as solar light, wind force, tidal force, or the like is applied to the primary side of the first transformer connected to the external AC power source and the secondary side,

Two switching elements are provided on both sides of the intermediate tap on the primary side of the first transformer,

The two gate driving ICs are connected to both sides of the intermediate tap of the secondary side of the second transformer connected to the external AC power source and the primary side,

A switching IC is provided in a wire to which AC power supplied from the secondary side of the first transformer is supplied, and an AC power source having the same frequency as that of the AC power source is alternately turned on by the two gate driving ICs, The power factor is improved by fast switching while having the same firing angle, and the condenser tank group including the electrolytic capacitor can be omitted in a simple structure, so that the life of the inverter is remarkably extended.

However, the above-described conventional power inverters omitting the condenser have a disadvantage in that the DC power from the solar module is directly converted into AC power and the efficiency is reduced during passing through a large number of parts.

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a solar module in which two switching means are connected to one solar module, And to provide an inverter for a generator for an electric vehicle as well as a wind power, a water power, and a solar power generator, which are designed to obtain a desired AC power with a high efficiency by a simple configuration by being applied to the primary side of the transformer.

According to an aspect of the present invention, there is provided an inverter including:

The output terminals of the solar modules are connected in parallel to the sources of the two field effect transistors, which are the switching means,

The square wave is alternately supplied to the gates of the two field effect transistors, which are the switching means, at a cycle of 60 Hz from the driver,

In the drains of the two field effect transistors, which are the switching means alternately turned on at a cycle of 60 Hz, the converted AC power is applied to both ends of the grounded intermediate tap of the transformer,

The converted AC power outputted from the drains of the two field effect transistors, which are a plurality of switching means, is applied to each of the plurality of primary sides of the transformers arranged in series, thereby obtaining AC power of a desired magnitude with high efficiency from the secondary side of the transformer .

With the inverter according to the present invention, the output terminals of the solar modules are connected in parallel to the sources of the two field effect transistors, which are the switching means, and are alternately turned on by the square wave alternately supplied at the cycle of 60 Hz supplied from the driver And the converted AC power is generated in the drains of the two field effect transistors to be turned on.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic view showing an overall configuration of the present invention. Fig.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

The inverter according to the present invention is intended for use in wind power, hydro power, solar power generation as well as electric power generator for electric vehicles,

A photovoltaic module (1) (1n) for performing power generation by converting light energy into electric energy by sunlight,

Switching means 2 (2n) for converting DC power into AC power in a state in which they are connected in parallel to the output terminals of the solar modules 1 (1) - (1n) and alternately turned on,

A driver 3 for selectively turning on the switching means 2 (2) - (2n) while alternately supplying a square wave having a period of 60 Hz,

The alternating current power converted and outputted from the switching means 2n to 2n which are alternately turned on at a cycle of 60 Hz is applied to the primary tapes T11 to Tn T1n so that a desired AC power source is obtained at the secondary side T2.

That is, two field effect transistors F11, F12, ..., Fn1, Fn2, which are switching means 2, ... 2n, are connected to the output terminals of the solar modules 1, Connected in parallel to the source S,

The square wave is alternately supplied to the gate G of the two field effect transistors F11, F12 ... Fn1, Fn2 which are the switching means 2 in the period of 60 Hz from the driver 3, and,

(D) of the two field effect transistors F11, F12, ..., Fn1, Fn2, which are the switching means 2 (2n) alternately turned on at a cycle of 60 Hz, (Tn) of the transformer 4 are applied to both ends of the grounded primary sides T11 to Tn,

The AC power converted by the square wave output from the drains of the two field effect transistors F11, F12, ..., Fn2, which are the plurality of switching means 2 (2n), is arranged in series Are applied to the intermediate taps t1 to tn of the primary sides T11 to Tn of the plurality of transformers 4 respectively so that the secondary side T2 of the transformer 4 has a desired size So that AC power is obtained with high efficiency.

In the inverter of the present invention constructed as described above,

The source of the two field effect transistors F11, F12, ..., Fn1, Fn2, which are the switching means 2, ..., 2n, are connected to the output terminals of the solar modules 1, S in parallel.

A square wave is alternately supplied from the driver 3 to the gate G of the two field effect transistors F11, F12 ... Fn1, Fn2 which are the switching means 2 (2n) To be turned on.

(D) of the two field effect transistors F11, F12, ..., Fn1, Fn2, which are the switching means 2 (2n) 1) ... 1n are connected to the primary tapes T11 to Tnn to which the intermediate tap t1 to tn of the transformer 4 are grounded, ), Respectively,

The AC power converted by the square wave outputted from the drains of the two field effect transistors F11, F12 ... Fn1, Fn2 which are the plurality of switching means 2 (2n) (T11) to (T1n) of the arranged transformers 4, respectively, so as to obtain AC power of a desired magnitude at the secondary side T2 of the transformer 4 with high efficiency.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but many variations and modifications may be made without departing from the scope of the invention. It will be understood by those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims.

1 ... 1n: photovoltaic module 2 ... 2n: switching means
3: Driver 4: Trance

Claims

A solar module 1 for performing power generation for converting sunlight into electric energy,
Switching means (2) for converting a DC power source into an AC power source in a state in which the output terminals of the solar module (1) are connected in parallel and are alternately turned on,
A driver (3) for selectively turning on the switching means (2) while alternately supplying rectangular waves having a period of 60 Hz,
The alternating-current power supplied from the switching means 2 alternately turned on at a cycle of 60 Hz is applied to both ends of the primary T11 grounded with the intermediate tap t1, while the AC power is obtained from the secondary T2 (4).

A plurality of photovoltaic modules 1 (1n) for performing power generation by converting light energy into electric energy by sunlight,
A plurality of switching means 2 (2n) for converting DC power into AC power in a state in which they are connected in parallel to the output terminals of the plurality of solar modules 1 (1) and,
(3) for selectively turning on the plurality of switching means (2), (2n) while alternately supplying a square wave having a period of 60 Hz,
(2n), which are alternately turned on at intervals of 60 Hz, are connected to a plurality of primary sides T11 (t1), ..., tn And a transformer (4) configured to obtain a desired alternating current power at the secondary side (T2) while being applied to both ends of the transformer (T1n), respectively.

The method according to any one of claims 1 to 3,
The switching means 2n switch the two field effect transistors F11, F12 ... Fn1, Fn2 by a square wave of 60 Hz supplied from the driver 3 And the inverter is turned on.

The method according to any one of claims 1 to 3,
Two field effect transistors F11, F12, ..., Fn1, Fn2, which are a plurality of switching means 2 (2n) coupled to a plurality of solar modules 1 (1n) T2n of the transformer 4 by applying alternating current power converted by a square wave outputted from the drain of the transformer 4 to the primary side T11 to T1n of the transformer 4 arranged in series, And the AC power of the desired size is obtained with high efficiency.