WO2014007432A1

WO2014007432A1 - Single-phase full-bridge inverter for providing improved power quality

Info

Publication number: WO2014007432A1
Application number: PCT/KR2012/008506
Authority: WO
Inventors: 박성준; 최우석
Original assignee: 전남대학교산학협력단
Priority date: 2012-07-02
Filing date: 2012-10-18
Publication date: 2014-01-09
Also published as: KR101297320B1

Abstract

The present invention relates to a single-phase full-bridge inverter for achieving high power quality through AC output waveforms of multiple levels, such as four levels, five levels, and the like by using the same number of switches as the existing full-bridge inverter having a three-level AC output waveform as an inverter having a function of generating a single-phase AC output voltage from DC input power and providing the single-phase AC output voltage to a load.

Description

Single Phase Full Bridge Inverter Delivers Improved Power Quality

The present invention is an inverter having a function of generating a single-phase AC output voltage from a DC input power supply and supplying it to a load. The multi-level, such as four levels and five levels, is the same number of switches as a conventional full bridge inverter having a three-level AC output waveform. The present invention relates to a single-phase full bridge inverter that generates power of an AC output waveform and achieves high power quality.

In general, the inverter inputs a DC power supply (Vdc) and generates an output having a value of 0, ± Vdc, and a power conversion that controls the magnitude, frequency, and harmonic components of the AC voltage by appropriately adjusting the width of the output voltage. Say the device.

In this way, the inverter that outputs only 0, ± Vdc is called a three-level inverter, and these inverters are used in many commercial areas, and in particular, they are widely used in AC motor driving and uninterruptible power supply (UPS).

In the three-level inverter, pulse width modulation (PWM) is widely used to control the output voltage, and this switching method uses a high switching frequency to obtain a high quality output voltage. However, since the input DC power must be higher than the maximum value of the output AC, the high voltage is switched. Thus, the stress on the load side and the electromagnetic magnetic compatibility (EMC) are largely affected by dv / dt. In addition, high switching power requires a high switching frequency, which increases switching losses.

In order to complement these three-level inverters, multi-level inverters have been proposed. However, the conventional multilevel inverter has a disadvantage of using a plurality of switches. However, since the voltage rating of each switch is lower than that of using a three-level inverter, there is no big difference in the cost of the switch itself in actual production.

However, an increase in the number of switches means an increase in driving circuits for driving the switches, which increases the complexity of the circuit and increases the cost.

The disadvantages of such a multi-level inverter are summarized as follows.

-Increasing cost due to the increase in the number of switches: Increasing the cost of inverters due to the increase in the number of switch elements, diodes, driving circuits and other passive elements

-Complex circuit structure: The circuit is complicated because a large number of switching elements and additional circuits are required.

Complex implementation algorithms: complex switching drive algorithms for multiple switch control and separate algorithms for voltage unbalance control.

Therefore, there is an urgent need for an inverter capable of applying a stable structure of existing inverter elements without increasing costs and obtaining a good output with stable operation even when driving an inverter.

The present invention for solving the above problems is a structure using the proposed topology of the three-level AC output waveform of the conventional single-phase full bridge inverter with the same number of switches and switching speed, the four-level, five-level AC, etc. The main object of the present invention is to provide an inverter system that has an output waveform and improves total harmonic distortion (THD: Total Harmonic Distortion) to improve power quality.

Another object of the present invention is to prevent the increase in cost according to the configuration by making it possible to use the device configuration used in the three-level inverter, while improving the output efficiency.

In addition, another object of the present invention is to configure a five-level inverter that can obtain a more stable output by adding a predetermined element to the configuration of the basic four-level inverter, so as to obtain a more efficient AC output in addition to some configuration It is.

The present invention for achieving the above object, the power supply unit to which power is applied; A switch unit intermitting the power supplied from the power generation unit; And a load end to which power of the power generation unit is applied by the operation of the switch unit, wherein the power generation unit includes a first power generation unit, a second power generation unit, and a third power generation unit, and the first power generation unit and the second power source. A first terminal switch having one side connected between the forming parts and the other side connected to the load terminal first pole; A second terminal switch having one side connected between the second power generation unit and the third power generation unit and the other side connected to the load terminal first pole; A reverse terminal switch having one side connected to the other side of the first power generation unit and the other side connected to the load second second pole; And a positive terminal switch having one side connected to the other side of the third power generation unit and the other side connected to the load-side second pole.

Thus, in a preferred embodiment of the present invention, the first capacitor between the both ends of the first power source forming portion; Second capacitors between both ends of the second power generation unit; And a third capacitor between both ends of the third power source forming unit.

In addition, in a preferred embodiment of the present invention, the power is applied between the first pole and the second pole on both sides of the load terminal, the amount of power that the power of the second power source and the third power source is combined is applied. State, a state in which positive power is applied to the third power generation unit, a state in which negative power is applied in the first power generation unit, and a negative power in which the power of the first power generation unit is combined with the power of the second power generation unit is applied. It is characterized by forming a state in which the four-level power to the state is applied.

The present invention configured as described above has the effect of producing an output voltage and a current having a higher power quality while having the same number of switching elements and the same switching frequency as a conventional single-phase full bridge inverter.

Therefore, another effect of the present invention is to enable the application of the device configuration used in the three-level inverter to prevent the increase in cost according to the configuration, the output efficiency is good.

Further, another effect of the present invention is to configure a five-level inverter that can obtain a stable output by adding a predetermined element to the basic four-level inverter configuration, it is possible to obtain a more efficient AC output in addition to some configuration as described above. To ensure that

1 is a basic circuit diagram of a single-phase full bridge inverter according to the present invention.

2 is a basic circuit diagram of an embodiment of a single-phase full bridge inverter in which a plurality of capacitors are connected to a single power source in the embodiment power supply of FIG. 1 according to the present invention.

FIG. 3 is a circuit diagram of an exemplary embodiment in which a single-phase full bridge inverter according to the present invention is applied with a positive maximum value in a four-level embodiment.

4 is an exemplary circuit diagram of a state in which a single-phase full bridge inverter according to the present invention is applied with a positive intermediate value in a four-level embodiment.

FIG. 5 is a circuit diagram of an exemplary embodiment in which a single-phase full bridge inverter according to the present invention is applied to a load with a negative intermediate value among four level embodiments.

FIG. 6 is an exemplary circuit diagram of a state in which a single negative full bridge inverter is applied to a load as a negative lowest value among four level embodiments.

7 is a graph of the voltage waveform and the filtered waveform of the load stage detected by the four-level embodiment in the single-phase full bridge inverter according to the present invention.

FIG. 8 is a circuit diagram of an exemplary embodiment in which a single-phase full bridge inverter according to the present invention is applied with a positive maximum value in a five-level embodiment.

FIG. 9 is an exemplary circuit diagram of a state in which a single-phase full bridge inverter according to the present invention is applied to a load as a positive intermediate value among five level embodiments.

FIG. 10 is a circuit diagram of an exemplary embodiment in which a single-phase full bridge inverter according to the present invention forms a "0" voltage from both voltages by a switch connected between both terminals of a load in a five-level embodiment.

FIG. 11 is an exemplary circuit diagram of a state in which a zero voltage is formed from a negative voltage by a switch connected between both terminals of a load in a five-phase embodiment in the single-phase full bridge inverter according to the present invention.

FIG. 12 is a circuit diagram of an exemplary embodiment of a state in which a single intermediate full bridge inverter is applied to a load as a negative intermediate value among five level embodiments. FIG.

FIG. 13 is an exemplary circuit diagram of a state in which a single negative full bridge inverter according to the present invention is applied to a load as a negative lowest value among five level embodiments.

14 is a graph of the voltage waveform and the filtered waveform of the load stage detected by the five-level embodiment in the single-phase full bridge inverter according to the present invention.

15 is a control block diagram of a single-phase full bridge inverter according to the present invention.

16 is an exemplary view for explaining a schematic function of a single-phase full bridge inverter according to the present invention.

17 is an exemplary view of the operation of a typical single-phase full bridge inverter.

18 is an exemplary diagram of a state table of the inverter formed of FIG. 17.

Hereinafter, with reference to the accompanying drawings will be described in detail.

That is, the single-phase full bridge inverter 10 which provides improved power quality according to the present invention may interrupt the power supply unit to which power is applied to the load, and the power supplied from the power supply unit, as shown in FIGS. 1 to 15. A switch unit or the like is configured. Then, the power of the power generation unit is applied to the load end 11 by the operation of the switch unit.

In particular, in the single-phase full bridge inverter 10 according to the present invention, the power generation unit includes a first power generation unit VDC_A, a second power generation unit VDC_B, a third power generation unit VDC_C, and the like, which are connected in series. It is. As a result of the operation of the switch unit connected to the first power generator VDC_A, the second power generator VDC_B, the third power generator VDC_C, and the like, some powers of the power generators are combined and applied to the load. . Therefore, a plurality of levels of power are sequentially applied to the load stage. Accordingly, the full bridge inverter of the present invention operates with a switching frequency to have a stable AC output. That is, a multi-level alternating current output including the first power generator VDC_A, the second power generator VDC_B, the third power generator VDC_C, and the like can be obtained.

Accordingly, the power generator of the present invention, that is, the first power generator VDC_A, the second power generator VDC_B, the third power generator VDC_C, etc., as shown in FIG. It may be implemented by including a capacitor of, may be implemented by including a single voltage source and a plurality of capacitors as shown in FIG.

As described above, each power source forming unit refers to a voltage forming unit in a portion where a voltage is applied to the load, and thus will include a forming portion of a voltage formed by a plurality of capacitors. For example, the first power generation unit VDC_A refers to an output portion in a load side direction at both ends of the first capacitor, and the second power generation unit VDC_B refers to an output portion in a load side direction at both ends of the second capacitor. The third power generation unit VDC_C defines the output portion in the load side direction at both ends of the third capacitor.

That is, in the example of the power generation unit, in the embodiment of FIG. 1, the first power generation unit VDC_A is implemented by the first capacitor C1 connected in parallel with the first voltage source Vdc_1, and the second power generation unit ( VDC_B consists of a second capacitor C2 connected in parallel with the second voltage source Vdc_2, and furthermore, a third capacitor (VDC_C) connected in parallel with the third voltage source Vdc_2. It is made of C3). Therefore, in the power generator according to the embodiment of FIG. 1, the first power generator VDC_A is a power applied from both ends output from the first capacitor C1 connected in parallel with the first voltage source Vdc_1 to the load side. The second power generator VDC_B is a power applied from both ends output from the second capacitor C2 connected in parallel with the second voltage source Vdc_2 to the load side, and the third power generator VDC_C The third capacitor C3 connected in parallel with the three voltage sources Vdc_3 is a power source applied at both ends output to the load side.

As such, the power generation unit includes a portion in which power is applied to the load side from the individual capacitors, and in the case where a plurality of voltage sources are formed, it is generally various means such as general power, solar, wind, tidal power, charging power, and the like. It will be suitable for the embodiment of the voltage source supplied by.

Next, an example of the power generation unit may be implemented by a single voltage source and a plurality of capacitors in the embodiment of FIG. 2. In the example of FIG. 2, the first capacitor C1, the second capacitor C2, The third capacitor C3 and the like are connected in series with each other, and the three capacitors connected in series will be configured to be coupled in parallel with a single voltage source.

That is, as an example of the configuration of the power generator, the first power generator VDC_A is a power applied from both ends output from the first capacitor C1 to the load side, and the second power generator VDC_B is the second capacitor C2. Is the power applied from both ends output to the load side, and the third power generation unit (VDC_C) will be the power applied from both ends output to the load side from the third capacitor (C3). In the case of such a single power source, it will be an embodiment of a case where a configuration of a power supply or a charging power is generally provided in a single configuration.

As described above, the power generation unit implemented in the present invention includes a plurality of capacitors for implementing a multi-level together with a voltage source (Vdc, or Vdc_1, Vdc_2, Vdc_3, etc.) in a single or plural number, and applied to both ends of individual capacitors. As a power source, a plurality of power forming units are formed to be supplied to a load end.

According to the embodiment of the power generation unit implemented as described above, a plurality of independent DC power sources or capacitors connected in series may be used to configure individual voltage generation units according to the installation situation.

In general, the single-phase full bridge inverter has a function of generating a single-phase AC output voltage from a single DC input power supply and supplying it to a load as in the examples of FIGS. 16 and 17.

Looking at the operation of such a single-phase full bridge inverter, the AC output voltage waveform of the single-phase full bridge inverter is determined according to the method of controlling the bidirectional switching switch Sa and Sb. That is, in the example of FIGS. 16 and 17 as a single-phase full bridge inverter, four switches and two poles are included, and the output voltage Vo is equal to the difference between the two pole voltages Va and Vb. That is, the output voltage that can be supplied to the load according to the contact state of the switches Sa and Sb will be output as shown in FIG. As described above, the single-phase full bridge inverter as shown in FIGS. 16 to 18 generates an AC waveform from a single DC input power source, where the AC output voltage has three output levels of + Vdc, 0, and -Vdc.

Unlike the single-phase full bridge inverter having three output levels, the inverter has multiple output levels. The multi-level inverter has some advantages over the three-level inverter, and the summary is as follows.

-Increased voltage level: 3 level inverter has only 0, ± Vdc voltage level, but multi-level inverter is capable of 0 or ± Vdc, ± 2Vdc, ..., ± mVdc. High quality output voltage can be obtained.

-High voltage output with low voltage rating switch: Since the switches are connected in series, the voltage rating required for each switch is lowered.

-The dv / dt of the switch is low, so there is little occurrence of EMC.

-Various control methods through various switch control are available.

Referring to the detailed configuration of the switch unit of the single-phase full bridge inverter 10 that provides the improved power quality according to the present invention, first, the configuration of the switch unit in the four-level single-phase full bridge inverter as shown in Figs. It may be prepared as follows.

First, a first terminal switch SW1 having one side connected between the first power generator VDC_A and the second power generator VDC_B and the other side connected to the first pole 1 of the load terminal 11 is provided. do. Through this first terminal switch SW1, a single power source of the first power generator VDC_A, or a sum of powers of the second power generator VDC_B and the third power generator VDC_C is applied to the load terminal. .

Next, a second terminal switch SW2 having one side connected between the second power generation unit VDC_B and the third power generation unit VDC_C and the other side connected to the load pole 11 and the first pole 1 is connected. Prepared. Through the second terminal switch SW2, the power of the sum of the first power generator VDC_A and the second power generator VDC_B or the single power of the third power generator VDC_C is applied to the load terminal. .

In addition, a reverse terminal switch SW3 having one side connected to the other side of the first power generation unit VDC_A and the other side connected to the second pole 2 of the load terminal 11 is provided. Through the reverse terminal switch SW3, a single power source of the first power generator VDC_A or a sum of powers of the first power generator VDC_A and the second power generator VDC_B is applied to the load terminal.

Further, a positive terminal switch SW4 is connected to one side of the third power generation unit VDC_C, and the other side thereof is connected to the load pole 11 and the second pole 2. Through the positive terminal switch SW4, the power of the sum of the second power generator VDC_B and the third power generator VDC_C or the single power of the third power generator VDC_C is applied to the load terminal.

As described above, the inverter according to the present invention includes three power generation units in total, such as the first power generation unit VDC_A, the second power generation unit VDC_B, and the third power generation unit VDC_C. Four switch members are basically connected between the four power supply units.

Thus, depending on whether or not the control operation of the switch member, the voltage is applied to the load in a plurality of voltage state in which a total of three power source forming unit power supplies are combined. This results in an AC output having a stable form.

As shown in the accompanying drawings in a detailed configuration for this purpose, the first capacitor (C1) between the both ends of the first power source forming unit (VDC_A), the second capacitor (C2) between both ends of the second power source forming unit (VDC_B) ) And a third capacitor C3 and the like between both ends of the third power generation unit VDC_C. Thus, power is stably supplied by these capacitors, so that the AC generation operation is smooth. In addition, if necessary, various electronic circuit materials may be added to form a stable circuit.

The 4-level single-phase full bridge inverter according to the present invention configured as described above is to generate a single-phase AC output voltage using four switches from a DC input power source having a level of 4EA and supply it to a load as in the accompanying drawings. .

The 4-level single-phase full bridge inverter according to the present invention has a 4EA input voltage level by the 3EA DC input of the input side, wherein the AC output voltage is (VDC_B + VDC_C), (VDC_C),-(VDC_A),- It has four output levels, such as (VDC_A + VDC_B). The waveform for this is as shown in FIG.

Thus, as an embodiment implemented in the single-phase full bridge inverter 10 providing improved power quality according to the present invention, an embodiment of a four-level single-phase full bridge inverter having a total of four states of voltage will be described first.

In particular, the state in which the power is applied between the first pole (pole1) and the second pole (pole2) on both sides of the load stage 11 by the inverter according to the present invention, the power of the second power generation unit (VDC_B) The positive power of the third power generator VDC_C is applied, the positive power of the third power generator VDC_C is applied, and the negative power of the first power generator VDC_A The power is applied to a total of four levels, such as a state of being applied, a state of applying negative power in which the power of the first power generation unit VDC_A and the power of the second power generation unit VDC_B are combined.

Looking at the example that the power is applied to the load for each level as follows.

First, an inverter control unit 21 for controlling the first terminal switch SW1, the second terminal switch SW2, the reverse terminal switch SW3, and the positive terminal switch SW4 of the switch unit is provided. Each switch member is operated by the control of 21).

Thus, under the control of the inverter control unit 21, an up-pulse control signal (for example, a switch "ON" signal) is transmitted from the inverter control unit 21 to the first terminal switch SW1 and the positive terminal switch SW4. will be. Thus, the first terminal switch SW1 and the positive terminal switch SW4 are operated. As a result, as shown in FIG. 3, the power of the second power generator VDC_B and the power of the third power generator VDC_C are added to the first pole 1 and the second pole 2 of the load terminal 11. Power is applied.

For example, a case where the first power generator VDC_A is 100V, the second power generator VDC_B is 200V, and the third power generator VDC_C is set to 100V will be described as follows. Could be.

That is, as shown in FIG. 3, the first terminal switch SW1, the positive terminal switch SW4, and the like are operated by the control, so that a second power supply is provided between the first pole 1 and the second pole 2 on both sides of the load terminal 11. The power of 300V in which the power applied from the forming unit VDC_B and the third power forming unit VDC_C is combined will be applied. That is, it will be applied to both sides of the load stage with a positive maximum power supply.

Next, under the control of the inverter controller 21, the inverter controller 21 transmits a control signal of an up-pulse (for example, a switch "ON" signal) to the second terminal switch SW2 and the positive terminal switch SW4. Will be. Thus, the second terminal switch SW2 and the positive terminal switch SW4 are operated. Therefore, as shown in FIG. 4, the positive power of the third power generation unit VDC_C is applied to the first pole 1 and the second pole 2 of the load terminal 11.

For example, when the first power generator VDC_A is 100V, the second power generator VDC_B is 200V, and the third power generator VDC_C is set to 100V, as shown in FIG. The terminal switch SW2, the positive terminal switch SW4, and the like are operated so that the power applied from the third power generation unit VDC_C between the first pole 1 and the second pole 2 on both sides of the load terminal 11. A positive 100V supply will be applied. That is, it will be applied to both sides of the load stage with a positive medium value power supply.

In addition, under the control of the inverter controller 21, an up-pulse control signal (for example, a switch “ON” signal) is transmitted from the inverter controller 21 to the first terminal switch SW1 and the reverse terminal switch SW3. will be. Thus, the first terminal switch SW1 and the reverse terminal switch SW3 are operated. Therefore, as shown in FIG. 5, the negative power of the first power generator VDC_A is applied to the first pole 1 and the second pole 2 of the load terminal 11.

For example, when the first power generation unit VDC_A is 100V, the second power generation unit VDC_B is 200V, and the third power generation unit VDC_C is set to 100V, as shown in FIG. The terminal switch SW1, the reverse terminal switch SW3, and the like are operated so that the power applied from the first power generation unit VDC_A is provided between the first pole 1 and the second pole 2 on both sides of the load terminal 11. A negative 100V supply will be applied. That is, they will be applied to both sides of the load with a negative median supply.

In addition, under the control of the inverter control unit 21, the uplink control signal (for example, a switch "ON" signal) is transmitted from the inverter control unit 21 to the second terminal switch SW2 and the reverse terminal switch SW3. will be. Thus, the second terminal switch SW2 and the reverse terminal switch SW3 are operated. As a result, as shown in FIG. 6, the power of the first power generator VDC_A and the power of the second power generator VDC_B are added to the first pole 1 and the second pole 2 of the load terminal 11. Power is applied.

For example, when the first power generator VDC_A is 100V, the second power generator VDC_B is 200V, and the third power generator VDC_C is set to 100V, as shown in FIG. The terminal switch SW2 and the reverse terminal switch SW3 are operated so that the first power source forming unit VDC_A and the second power source are disposed between the first pole 1 and the second pole 2 on both sides of the load terminal 11. The negative power of 300V to which the power applied from the forming unit VDC_B is added will be applied. That is, it will be applied to both sides of the load stage with a negative maximum power supply.

In the embodiment of the four-level formation state of such a voltage, an example of the circuit formation state according to each voltage formation state is as follows.

That is, each switch will be operated by the inverter controller 21 controlling the first terminal switch SW1, the second terminal switch SW2, the reverse terminal switch SW3, and the positive terminal switch SW4 of the switch unit.

Accordingly, as shown in FIG. 3, when the first terminal switch SW1 and the positive terminal switch SW4 operate under the control of the inverter control unit 21, the first terminal switch SW1 and the load terminal 11 on one side of the load terminal 11 are operated. A current flow circuit including the second power generator VDC_B and the third power generator VDC_C together with the other terminal switch SW4 is formed. Therefore, the power of the second power generator VDC_B and the power of the third power generator VDC_C are applied to the first pole 1 and the second pole 2 of the load terminal 11. .

As shown in FIG. 4, when the second terminal switch SW2 and the positive terminal switch SW4 are operated, the second terminal switch SW2 on one side of the load terminal 11 and the positive terminal switch SW4 on the other side of the load terminal 11. ) And a circuit of the current flow including the third power generator VDC_C. Thus, the positive power of the third power generation unit VDC_C is applied to the first pole 1 and the second pole 2 of the load terminal 11.

In addition, as shown in FIG. 5, when the first terminal switch SW1 and the reverse terminal switch SW3 are operated, the first terminal switch SW1 on one side of the load terminal 11 and the reverse terminal switch SW3 on the other side of the load terminal 11. ) And a circuit of the current flow including the first power generator VDC_A. As a result, the negative power of the first power generator VDC_A is applied to the first pole 1 and the second pole 2 of the load terminal 11.

6, when the second terminal switch SW2 and the reverse terminal switch SW3 operate, the second terminal switch SW2 on one side of the load terminal 11 and the reverse terminal switch SW3 on the other side of the load terminal 11 are operated. ) And a circuit of the current flow including the first power generator VDC_A and the second power generator VDC_B. Therefore, a negative power obtained by adding the power of the first power generator VDC_A and the power of the second power generator VDC_B to the first pole 1 and the second pole 2 of the load terminal 11 is applied. .

As described above, in the operation of the four-level single-phase full bridge inverter, depending on the operation state of each switch, the state of applying the voltage applied to the load of the three power forming units can be made in various ways, in particular in FIG. Likewise it may be provided to have a stable output state of the alternating current.

As described above, the single-phase full bridge inverter providing improved power quality according to the present invention includes three power supply units and four basic switches of VDC_A, VDC_B, and VDC_C as shown in FIGS. 1 to 7. That is, in this single-phase full bridge inverter, two switches form one pole (node) centered on the VDC_B DC input, and the switches are located at the positive and negative poles of VDC_A and VDC_C. pole2) (node).

The inverter topology consists of two poles that switch independently, and the two switches of each pole perform complementary switching and the output voltage of the inverter according to these four basic switch states. Adjust

In order to check the output voltage level of the proposed inverter, look at the voltage of pole according to On / Off of each switch. When SW1 is on, the voltage of pole becomes the voltage of VDC_B + VDC_C, and when SW2 is on, the voltage of VDC_C Becomes

When SW3 is ON, the voltage of Pole2 becomes VDC_A + VDC_B + VDC_C. When SW4 is On, zero voltage appears. According to On / Off of each switch, the voltage that can be formed by the output voltage of the inverter becomes the voltage difference between the two poles. Therefore, when each VDC_A is 100V, VDC_B is 200V, and VDC_C is 100V, the output voltage of the proposed inverter is represented by 4 levels such as + 100V, + 300V, -100V, -300V as shown in FIGS. .

Next, an embodiment in which the load stage voltage is 5 levels in the single-phase full bridge inverter 10 providing improved power quality according to the present invention will be described with reference to FIGS. 8 to 14.

In the embodiment of such a five-level inverter, the basic configuration will be prepared as in the four-level embodiment described above. That is, it includes a power supply unit to which power is applied, a switch unit to control the power supplied from the power generation unit, and a load end 11 to which power is applied to the power generation unit by the operation of the switch unit.

The power generation unit is formed by connecting the first power generation unit VDC_A, the second power generation unit VDC_B, and the third power generation unit VDC_C. In addition, as a detailed configuration example of the switch unit, a first terminal is connected between the first power source forming unit (VDC_A) and the second power source forming unit (VDC_B) and the other end is connected to the load terminal 11, the first pole (pole1) A second terminal switch SW2 having one side connected between the switch SW1, the second power generation unit VDC_B, and the third power generation unit VDC_C and the other side connected to the load terminal 11 and the first pole 1. ), One end of the first power generator VDC_A and the other end of the reverse terminal switch SW3 and the third power generator VDC_C are connected to the load terminal 11 and the second pole 2. One end is connected to the other side and the other end is provided with a positive terminal switch (SW4) and the like connected to the load terminal 11, the second pole (pole2).

In addition, a first pole 1 of the load terminal 11 to which the first terminal switch SW1 and the second terminal switch SW2 are connected, and the reverse terminal switch SW3 and the forward terminal switch SW4 are connected to each other. The reverse voltage switch SW5 and the net voltage switch SW6 are connected between the load pole 11 and the second pole 2.

As a result, power is applied between the first pole 1 and the second pole 2 of the load terminal 11 at both ends of the power source of the second power source forming unit VDC_B and the third power source forming unit VDC_C. The positive power of the sum of the powers is applied, the positive power of the third power generation unit VDC_C is applied, the negative power of the first power generation unit VDC_A is applied, and the first power generation unit. The power of VDC_A and the power of the second power generator VDC_B are combined to have a negative power applied thereto.

Thus, a state of forming a "0" voltage by the backlight voltage switch SW5 and the net voltage switch SW6 is formed to achieve a state in which 5-level power is applied.

Accordingly, the first terminal switch SW1 and the second terminal switch SW2 are connected to the first pole 1 at one side of the load terminal 11, and the reverse terminal switch SW3 and the positive terminal switch SW4 are connected to the load terminal ( 11) It is connected to the second pole (pole2) on the other side, the reverse voltage switch (SW5) and the net voltage switch (SW6) connected between the first pole (pole1) and the second pole (pole2) on both ends of the load (11) ) May be made in series connection or parallel connection according to the installation situation.

As described above, the five-level single-phase full bridge inverter 10 providing improved power quality according to the present invention uses single-phase alternating current using four switches from a DC input power source having a level of 3EA, as in the accompanying drawings. It has a function of generating an output voltage and supplying it to a load.

In this proposed 5-level single-phase full bridge inverter, the output voltage level is 5 by (DC_B + VDC_C), (VDC_C), 0,-(VDC_A),-(VDC_A + VDC_B), etc. Has two output levels. And the waveform is made as shown in FIG.

As described above, with reference to the accompanying drawings, an example in which power is applied to a load stage in each level in an embodiment for five levels is as follows.

First, the inverter control unit 21 controls each switch unit including the first terminal switch SW1, the second terminal switch SW2, the reverse terminal switch SW3, the positive terminal switch SW4, and the like as in the fourth level. Is provided and the respective switch members are operated by the control of the inverter control unit 21.

Thus, under the control of the inverter control unit 21, the uplink control signal (for example, the switch "ON signal) will be transmitted from the inverter control unit 21 to the first terminal switch SW1 and the positive terminal switch SW4. Thus, the first terminal switch SW1 and the positive terminal switch SW4 are operated, so that the second power source is connected to the first pole 1 and the second pole 2 of the load terminal 11 as shown in FIG. The amount of power in which the power of the forming unit VDC_B and the power of the third power forming unit VDC_C are combined is applied.

For example, when the first power generation unit VDC_A is 100V, the second power generation unit VDC_B is 200V, and the third power generation unit VDC_C is set to 100V, as shown in FIG. The terminal switch SW1 and the positive terminal switch SW4 are operated so that the second power generation part VDC_B and the third power supply are formed between the first pole 1 and the second pole 2 on both sides of the load terminal 11. The power of the combined 300V power applied from the forming unit VDC_C may be applied. That is, it will be applied to both sides of the load stage with a positive maximum power supply.

Next, under the control of the inverter control unit 21, the uplink control signal (for example, the switch "ON signal") is transmitted from the inverter control unit 21 to the second terminal switch SW2 and the positive terminal switch SW4. Thus, the second terminal switch SW2 and the positive terminal switch SW4 are operated, and as a result, as shown in Fig. 9, the third end of the load pole 11 is connected to the first pole 1 and the second pole 2. The positive power of the power generator VDC_C is applied.

For example, when the first power generator VDC_A is 100V, the second power generator VDC_B is 200V, and the third power generator VDC_C is set to 100V, as shown in FIG. The terminal switch SW1, the positive terminal switch SW4, and the like are operated so that the power applied from the third power generation unit VDC_C between the first pole 1 and the second pole 2 on both sides of the load terminal 11. A positive 100V supply will be applied. That is, it will be applied to both sides of the load stage with a positive medium value power supply.

In particular, by the control of the inverter control unit 21, the inverter control unit 21 will be implemented to transmit the up-pulse control signal (for example, the switch "ON signal") to the net voltage switch SW6 side. ), And the first terminal switch SW1, the second terminal switch SW2, the reverse terminal switch SW3, and the positive terminal switch SW4 are cut off, so that the load terminal 11 is shown in FIG. The first pole (pole1) and the second pole (pole2) have a voltage of "0", especially when the voltage "0" is applied to both sides of the load by the operation of the switch voltage SW6. This will apply when switching to a negative value.

For example, when the first power generator VDC_A is 100V, the second power generator VDC_B is 200V, and the third power generator VDC_C is set to 100V, the net voltage under control as shown in FIG. 10. The switch SW6 is operated to achieve a "0" voltage between the first pole 1 and the second pole 2 on both sides of the load terminal 11.

Next, under the control of the inverter control unit 21, the inverter control unit 21 will transmit an up-pulse control signal (for example, a switch "ON signal") to the reverse voltage switch SW5 side. SW5 is operated, and the first terminal switch SW1, the second terminal switch SW2, the reverse terminal switch SW3, and the forward terminal switch SW4 are cut off, and as shown in FIG. 11) A voltage of "0" is formed at the first pole and the second pole 2. When the reverse voltage switch SW5 is operated to achieve a voltage of "0" at both sides of the load terminal, a negative value is obtained. Will be applied when converting from to a positive value.

For example, when the first power source forming unit VDC_A is 100V, the second power source forming unit VDC_B is 200V, and the third power source forming unit VDC_C is set to 100V, the reverse voltage is controlled by the control as shown in FIG. 11. The switch SW5 is operated to achieve a "0" voltage between the first pole 1 and the second pole 2 on both sides of the load terminal 11.

In addition, under the control of the inverter controller 21, an up-pulse control signal (for example, a switch “ON signal”) will be transmitted from the inverter controller 21 to the first terminal switch SW1 and the reverse terminal switch SW3. Thus, the first terminal switch SW1 and the reverse terminal switch SW3 are operated, so that the first power source is connected to the first pole 1 and the second pole 2 of the load terminal 11 as shown in FIG. The negative power of the forming unit VDC_A is applied.

For example, when the first power generation unit VDC_A is 100V, the second power generation unit VDC_B is 200V, and the third power generation unit VDC_C is set to 100V, as shown in FIG. The terminal switch SW1, the reverse terminal switch SW3, and the like are operated so that the power applied from the first power generation unit VDC_A is provided between the first pole 1 and the second pole 2 on both sides of the load terminal 11. A negative 100V supply will be applied. That is, it will be applied to both sides of the load stage with a negative median power supply.

In addition, under the control of the inverter control unit 21, the uplink control signal (for example, the switch "ON signal") will be transmitted from the inverter control unit 21 to the second terminal switch SW2 and the reverse terminal switch SW3. Thus, the second terminal switch SW2 and the reverse terminal switch SW3 are operated, so that the first power source is connected to the first pole 1 and the second pole of the load terminal 11 as shown in FIG. The negative power, which is the sum of the power of the forming unit VDC_A and the power of the second power forming unit VDC_B, is applied.

For example, when the first power generation unit VDC_A is 100V, the second power generation unit VDC_B is 200V, and the third power generation unit VDC_C is set to 100V, as shown in FIG. The terminal switch SW2 and the reverse terminal switch SW3 are operated so that the first power source forming unit VDC_A and the second power source are disposed between the first pole 1 and the second pole 2 on both sides of the load terminal 11. The negative power of 300V to which the power applied from the forming unit VDC_B is added will be applied. That is, it will be applied to both sides of the load stage with a negative maximum power supply.

As such, when the first power generator VDC_A is 100V, the second power generator VDC_B is 200V, and the third power generator VDC_C is set to 100V, + 300V, + 100V, 0V, and -100V. And a five-level voltage application state, such as -300V, thereby obtaining a stable AC output as shown in FIG. 14.

As described above, in the embodiment of the five-level formation state of the voltage, an example of the circuit formation state according to each voltage formation state is as follows.

That is, the switches are operated by the inverter controller 21 controlling the first terminal switch SW1, the second terminal switch SW2, the reverse terminal switch SW3, and the positive terminal switch SW4 of the switch unit.

Accordingly, as shown in FIG. 8, the second power generation unit VDC_B and the third power generation unit together with the first terminal switch SW1 on one side of the load terminal 11 and the positive terminal switch SW4 on the other side of the load terminal 11. It forms a circuit of current flow that includes (VDC_C). Therefore, the power of the second power generator VDC_B and the power of the third power generator VDC_C are applied to the first pole 1 and the second pole 2 of the load terminal 11. .

Next, as shown in FIG. 9, the current flow includes the third power supply unit VDC_C together with the second terminal switch SW2 on one side of the load terminal 11 and the positive terminal switch SW4 on the other side of the load terminal 11. Will form a circuit. Thus, the positive power of the third power generation unit VDC_C is applied to the first pole 1 and the second pole 2 of the load terminal 11.

As shown in FIG. 10, the net voltage switch SW6 connected between the first pole 1 and the second pole 2 of the load terminal 11 is operated to provide the load terminal 11 with the first pole 1. The second pole pole2 has a voltage of "0". As described above, the embodiment in which the voltage "0" is formed at the load terminal by the operation of the net voltage switch SW6 will be applied to the embodiment in which the voltage "0" is formed in the "+" voltage state.

In addition, as shown in FIG. 11, the reverse voltage switch SW5 is connected between the first pole 1 and the second pole 2 of the load terminal 11 to operate the first pole 1 of the load terminal 11. The second pole pole2 has a voltage of "0". As described above, the embodiment in which the zero voltage is formed at the load terminal by the operation of the reverse voltage switch SW5 will be applied to the embodiment in which the zero voltage is formed in the "-" voltage state.

Next, as shown in FIG. 12, the current flow includes the first power switch VDC_A together with the first terminal switch SW1 on one side of the load terminal 11 and the reverse terminal switch SW3 on the other side of the load terminal 11. Will form a circuit. Thus, the negative power of the first power generation unit VDC_A is applied to the first pole 1 and the second pole 2 of the load terminal 11.

Further, as shown in FIG. 13, the first power generator VDC_A and the second power generator together with the second terminal switch SW2 on one side of the load terminal 11 and the reverse terminal switch SW3 on the other side of the load terminal 11. It forms a circuit of current flow including (VDC_B). Thus, the negative power of the power of the first power generator VDC_A and the power of the second power generator VDC_B is applied to the first pole 1 and the second pole 2 of the load terminal 11. .

As described above, in the operation of the five-level single-phase full bridge inverter, the application state of the voltage applied to the load terminals of the three power generation units may be variously varied according to the operation state of each switch. Likewise it may be provided to have a stable output state of the alternating current.

As described above, the five-level single-phase full bridge inverter providing improved power quality according to the present invention includes three DC power supplies and four basic switches of VDC_A, VDC_B, and VDC_C as shown in FIGS. 8 to 14. That is, it includes a basic power generation unit and a switching unit, such as the four-level single-phase full bridge inverter described above, with two switches forming one pole around the VDC_B DC input, and each of VDC_A and VDC_C ( The switches are located at +) and (-) to form another pole. In addition to this, switch members are further provided for forming a voltage of " 0 ".

The inverter topology consists of two poles that switch independently, and the two switches of each node perform complementary switching and adjust the output voltage of the inverter according to these four basic switch states. In addition, when switching to the "+" voltage and "-" voltage, it is to form a "0" voltage respectively.

In order to check the output voltage level of the proposed inverter, the voltage of pole according to On / Off of each switch is examined. When SW1 is on, the voltage of pole becomes the voltage of VDC_B + VDC_C, and when SW2 is on, the voltage of VDC_C is do.

When SW3 is ON, the voltage of Pole2 becomes VDC_A + VDC_B + VDC_C. When SW4 is On, zero voltage appears. According to On / Off of each switch, the voltage that can be formed by the output voltage of the inverter becomes the voltage difference between the two poles. Therefore, when each VDC_A is 100V, VDC_B is 200V, and VDC_C is 100V, the output voltage Vac of the proposed inverter is represented by 4 levels of + 100V, + 300V, -100V, -300V.

In addition, the operation of SW5 and SW6 connected between the poles achieves a total of five levels forming a "0" voltage.

As described above, the single-phase full bridge inverter of the present invention, which forms a five-level power level, can obtain an AC output having a stable shape.

The embodiments of the present invention have been described in detail above, but since the embodiments have been described so that those skilled in the art to which the present invention pertains can easily carry out the present invention, The technical spirit of the present invention should not be interpreted limitedly.

Claims

A power supply unit to which power is applied;

A switch unit intermitting the power supplied from the power generation unit; And

A load end to which power is applied to the power generation unit by the operation of the switch unit;

The power generator includes a first power generator, a second power generator, and a third power generator,

A first terminal switch having one side connected between the first power generation unit and the second power generation unit and the other side connected to the load terminal first pole;

A second terminal switch having one side connected between the second power generation unit and the third power generation unit and the other side connected to the load terminal first pole;

A reverse terminal switch having one side connected to the other side of the first power generation unit and the other side connected to the load second second pole; And

A positive terminal switch having one side connected to the other side of the third power generation unit and the other side connected to the load-side second pole;

Single-phase full bridge inverter comprising a.
The method of claim 1,

First capacitors between both ends of the first power generation unit;

Second capacitors between both ends of the second power generation unit; And

Third capacitors between both ends of the third power source forming unit;

Single-phase full bridge inverter comprising a.
The method of claim 1,

The state where the power is applied between the first pole and the second pole on both sides of the load end,

A state in which a positive power of the sum of the power of the second power generation unit and the power of the third power generation unit is applied, a state in which a positive power of the third power generation unit is applied, a state in which a negative power of the first power generation unit is applied, The single-phase full bridge inverter of claim 1, wherein the power supply of the first power generating portion and the power supply of the second power generating portion is applied to the four-level power to the state that the negative power is applied.
The method of claim 1,

By the control of the inverter control unit for controlling the first terminal switch, the second terminal switch, the reverse terminal switch, the positive terminal switch of the switch unit,

The first terminal switch and the positive terminal switch are operated by transmitting a control signal from the inverter control unit to the first terminal switch and the positive terminal switch to form a power source and a third power source of the second power generator in the load terminals of the first and second poles. Positive power is applied to which negative power is added,

The second terminal switch and the positive terminal switch are operated by transmitting a control signal from the inverter control unit to the second terminal switch and the positive terminal switch, and the positive power of the third power generating unit is applied to the first pole and the second pole of the load terminal. ,

The first terminal switch and the reverse terminal switch are operated by transmitting a control signal from the inverter control unit to the first terminal switch and the reverse terminal switch, so that negative power is applied to the first and second poles of the load terminal. ,

The second terminal switch and the reverse terminal switch are operated by transmitting a control signal from the inverter control unit to the second terminal switch and the reverse terminal switch to form a power source and a second power source of the first power generator in the first and second poles of the load terminal. The single-phase full bridge inverter, characterized in that the negative power is applied to the negative power.
The method of claim 1,

By the control of the inverter control unit for controlling the first terminal switch, the second terminal switch, the reverse terminal switch, the positive terminal switch of the switch unit,

Together with the first terminal switch on one side of the load terminal and the positive terminal switch on the other side of the load terminal, a current flow circuit including a second power generation portion and a third power generation portion is formed, The amount of power in which the power of the second power generating unit and the power of the third power generating unit is combined is applied,

Together with the second terminal switch on one side of the load terminal and the positive terminal switch on the other side of the load terminal, a circuit of current flow including the third power generation portion is formed, so that the amount of the third power generation portion in the first and second poles of the load Power is applied,

Together with the first terminal switch on one side of the load terminal and the reverse terminal switch on the other side of the load terminal, a circuit of current flow including the first power generation portion is formed, so that the negative pole of the first power generation portion is formed on the first pole and the second pole of the load stage. Power is applied,

Together with the second terminal switch on one side of the load terminal and the reverse terminal switch on the other side of the load terminal, a current flow circuit including the first power generation portion and the second power generation portion is formed, and the first pole and the second pole of the load stage are formed. A single-phase full bridge inverter, characterized in that the negative power of the sum of the power supply of the first power supply and the second power supply is applied.
The method of claim 1,

A reverse voltage switch and a net voltage switch are connected between a first pole of a load terminal to which the first terminal switch and a second terminal switch are connected, and a second pole of a load terminal to which the reverse terminal switch and the positive terminal switch are connected. ,

The state where the power is applied between the first pole and the second pole on both sides of the load end,

A state in which a positive power of the sum of the power of the second power generation unit and the power of the third power generation unit is applied, a state in which a positive power of the third power generation unit is applied, a state in which a negative power of the first power generation unit is applied, In addition to the state in which the negative power of the sum of the power of the first power generation unit and the power of the second power generation unit is applied,

Single-phase full bridge inverter, characterized in that to form a state in which a five-level power is applied to form a state of forming a "0" voltage by the reverse voltage switch, the net voltage switch.
The method of claim 6,

Single phase full bridge inverter, characterized in that the reverse voltage switch and the net voltage switch connected between the first pole and the second pole on both sides of the load end are connected in series or in parallel.
The method of claim 6,

By the control of the inverter control unit for controlling the first terminal switch, the second terminal switch, the reverse terminal switch, the positive terminal switch, the net voltage switch, the reverse voltage switch of the switch unit,

The first terminal switch and the positive terminal switch are operated by transmitting a control signal from the inverter control unit to the first terminal switch and the positive terminal switch to form a power source and a third power source of the second power generator in the load terminals of the first and second poles. Positive power is applied to which negative power is added,

The second terminal switch and the positive terminal switch are operated by transmitting a control signal from the inverter control unit to the second terminal switch and the positive terminal switch, and the positive power of the third power generating unit is applied to the first pole and the second pole of the load terminal. ,

The first terminal switch and the reverse terminal switch are operated by transmitting a control signal from the inverter control unit to the first terminal switch and the reverse terminal switch, so that negative power is applied to the first and second poles of the load terminal. ,

The second terminal switch and the reverse terminal switch are operated by transmitting a control signal from the inverter control unit to the second terminal switch and the reverse terminal switch to form a power source and a second power source of the first power generator in the first and second poles of the load terminal. Negative power with negative power applied is applied,

The net voltage switch is operated by transmitting a control signal from the inverter control unit to the net voltage switch side, and the first terminal switch, the second terminal switch, the reverse terminal switch, and the positive terminal switch are blocked to operate. At zero voltage,

The reverse voltage switch is operated by transmitting a control signal from the inverter control unit to the reverse voltage switch side, and the first terminal switch, the second terminal switch, the reverse terminal switch, and the positive terminal switch are blocked to operate. Single-phase full bridge inverter, characterized in that to form a "0" voltage.
The method according to claim 6 or 7,

By the control of the inverter control unit for controlling the first terminal switch, the second terminal switch, the reverse terminal switch, the positive terminal switch, the net voltage switch, the reverse voltage switch of the switch unit,

Together with the first terminal switch on one side of the load terminal and the positive terminal switch on the other side of the load terminal, a current flow circuit including a second power generation portion and a third power generation portion is formed, The amount of power in which the power of the second power generating unit and the power of the third power generating unit is combined is applied,

Together with the second terminal switch on one side of the load terminal and the positive terminal switch on the other side of the load terminal, a circuit of current flow including the third power generation portion is formed, so that the amount of the third power generation portion in the first and second poles of the load Power is applied,

Together with the first terminal switch on one side of the load terminal and the reverse terminal switch on the other side of the load terminal, a circuit of current flow including the first power generation portion is formed, so that the negative pole of the first power generation portion is formed on the first pole and the second pole of the load stage. Power is applied,

Together with the second terminal switch on one side of the load terminal and the reverse terminal switch on the other side of the load terminal, a current flow circuit including the first power generation portion and the second power generation portion is formed, and the first pole and the second pole of the load stage are formed. The negative power, which is the sum of the power of the first power generation unit and the power of the second power generation unit, is applied.

The net voltage switch connected between the first pole and the second pole on both sides of the load stage is operated to achieve a voltage of "0" at the first pole and the second pole of the load stage.

A single-phase full bridge inverter, wherein a reverse voltage switch connected between first and second poles of both ends of the load stage is operated to form a "0" voltage on the first and second poles of the load stage.