KR20200117171A - Reactorless Unbalance Compensation Apparatus for Renewable Energy Electricity Generation - Google Patents

Abstract

The present invention relates to a reactorless unbalance compensation device for new renewable energy generation. According to the present invention, the reactorless unbalance compensation device for new renewable energy generation comprises: a load current detection unit (111); a load current conversion unit (115); a current value setting and communication unit (116) configured to set a reference current value based on an output of the load current conversion unit (115); a current control unit (114) configured to control a current based on an output of the current value setting and communication unit (116); and a vector control unit (112). According to the present invention, a quality of power can be improved.

Description

Reactorless Unbalance Compensation Apparatus for Renewable Energy Electricity Generation}

The present invention relates to a reactorless unbalance compensation device for generating renewable energy. In the power generation of new and renewable energy, an unbalance occurs in the power system due to non-linear, sudden fluctuations and large-capacity unbalanced loads, and a phenomenon in which harmonics increase. The present invention relates to an apparatus for innovatively compensating for an imbalance in a power system caused by such nonlinear, sudden fluctuations, and large unbalanced loads.

The following patented invention was disclosed for the existing unbalance compensation device.

Republic of Korea Patent Publication No. 10-1212830, published on December 14, 2012 (hereinafter referred to as [Patent Document 1]) discloses a method of compensating for an unbalance of a three-phase converter. The unbalance compensation method disclosed in [Patent Document 1] is characterized by an unbalance compensation method including a symmetric component calculation process, an unbalance compensation process, and a center vector calculation process for calculating a symmetric voltage of a three-phase balance system.

Republic of Korea Patent Publication No. 10-1172748, Announcement date 2012. 08. 14. (hereinafter referred to as [Patent Document 2]) discloses a three-phase unbalanced voltage output control device and method of an AC power supply. The above [Patent Document 2] is characterized by a three-phase unbalanced voltage output control device and method capable of generating a desired three-phase unbalanced output simply and accurately by giving a learning function to a PI (proportional-integral) controller.

Republic of Korea Patent Publication No. 10-1606882, Announcement date 2016. 03. 28. (hereinafter referred to as [Patent Document 3]) discloses a method for compensating voltage imbalance between modules of a reactive power compensation device and a reactive power compensation device. The [Patent Document 3] relates to a reactive power compensating device that outputs a compensation current for compensating reactive power generated in a three-phase load. According to an input output voltage reference value, the number of module inverters connected in series in each phase is It features a modular multi-level converter (MMC) for generating an output voltage by adjusting and a voltage unbalance compensation method for generating a compensation voltage by detecting an unbalance of each module voltage applied to the module inverters. .

However, in the existing [Patent Literature 1] to [Patent Literature 3], there is a problem that a reactor is necessarily required for an unbalance compensation device, and that a manufacturing cost is increased and a manufacturing space is required in a certain manner for the arrangement of the reactor.

[Patent Document 1] Republic of Korea Patent Publication No. 10-1212830, Announcement date 2012. 12. 14. [Patent Document 2] Korean Patent Publication No. 10-1172748, Announcement Date 2012. 08. 14. [Patent Document 3] Korean Patent Publication No. 10-1606882, Announcement Date 2016. 03. 28.

In the present invention, a reactorless imbalance compensation device in which a reactor does not exist in an imbalance compensation device for renewable energy generation is proposed. To this end, the unbalanced load current is decomposed into a positive sequence component current and a negative sequence component current in real time, and the reverse phase current is controlled to be supplied by a PWM converter. It is characterized by technical features to be supplied. In the present invention, through (1) a method of real-time detection of the positive and negative phase currents from the unbalanced three-phase current, (2) a technology for controlling the PWM converter to offset the negative-phase current of the load, and a controller design method. It is intended to provide an unbalance compensation device with (Rector) removed.

In the present invention, the following three methods of problem solving means are used for a reactorless imbalance compensation apparatus in which a reactor does not exist in an imbalance compensation apparatus for renewable energy generation. (1) A leakage transformer 110 is used that combines the general transformer 105 and the reactor 106, and (2) a method of detecting the normal and reverse current from the unbalanced three-phase current in real time, and (3) the load The solution to the problem is to apply an unbalance compensation device to the technology of controlling the PWM converter and the controller design method to cancel the reverse-phase current.

The effects of the reactorless unbalance compensation device for generating renewable energy proposed in the present invention are as follows. First, since the leakage transformer 110 that combines the general transformer 105 and the reactor 106 is used, a reactorless unbalance compensation device without the reactor 106 is provided.Second, since the reactor 106 is not provided, the transformer type Compared to this, the price is cheaper and the space of the unbalance compensation device is reduced. Third, the power quality is improved, and the power efficiency is increased because the unbalanced power is solved. Fourth, the normal current from the unbalanced three-phase current It has a characteristic effect with improved control characteristics because it detects and controls the and reverse phase current in real time. In addition, by using a leakage transformer and sharing the DC side, it can be implemented by connecting a plurality of different capacity PWM converters without circulating current.

1 is a voltage/current waveform and a harmonic analysis waveform in an unbalanced (nonlinear) load
2 is a compensated voltage/current waveform and a harmonic analysis waveform
3 is a conceptual diagram of unbalanced (nonlinear) load current compensation
Figure 4 is a conventional unbalance (nonlinear) compensation device for renewable energy generation
5 is an unbalanced (nonlinear) compensation device for generating a proposed renewable energy (first embodiment)
6 is a proposed unbalance (nonlinear) compensation device for generating renewable energy (second embodiment)
7 is a proposed unbalance (nonlinear) compensation device for generating renewable energy (third embodiment)
8 is a control unit for compensating the unbalanced (nonlinear) load current for the proposed renewable energy generation
9 is a diagram of a 3-phase-2 phase transform coordinate axis and voltage vector
Fig. 10 shows a coordinate axis rotating at a synchronous speed in the forward/reverse direction with the upward rotation of the power source
(a) Normal current vector
(b) Reverse phase current vector
Fig. 11 is a normal/reverse current detector using an observer
12 is a normal/reverse current detector using a forward average filter
13 is a normal/reverse current detector using a backward average filter
14 is an equivalent circuit per phase of a voltage converter
15 is a block diagram of a controller for controlling a normal current and a reverse current
16 is a manufactured unbalance (nonlinear) compensation device
Figure 17 is a manufactured leakage transformer

The present invention will be described in detail with reference to the accompanying drawings as follows.

1 shows a voltage/current waveform and a harmonic analysis waveform in an unbalanced (nonlinear) load. In the above unbalanced (nonlinear) load, the input current is discontinuous and a pulsed current flows close to the inrush current, so the 3rd, 5th, 7th, 9th, 11th, 13th, 15th order The harmonic of the back increases the component. Therefore, since the waveform of the current changes sharply, harmonics are generated, and the total harmonic distortion (THD) can be expressed as the ratio of the RMS values of all other high frequencies to the RMS values of the fundamental wave as shown in equation (1).

식(1)

Equation (1)

here

I _H : RMS value of total harmonic

I ₁ : RMS value of fundamental wave

I: RMS value of input current

Also, the power factor (PF) is defined as in Equation (2) based on the total harmonic distortion factor (THD).

식(2)

Equation (2)

Therefore, the main reason for the deterioration of the power factor is an increase in harmonics included in the input current waveform.

2 shows a compensated voltage/current waveform and a harmonic analysis waveform.

Looking at the compensated voltage/current waveform and harmonic analysis waveform, the current is improved to a sine wave, and the 3rd, 5th, 7th, 9th, 11th, 13th, 15th order, etc. Since the harmonic component is removed, the power factor is improved.

3 shows a conceptual diagram of unbalanced (nonlinear) load current compensation.

In the unbalanced (nonlinear) load current compensation conceptual diagram, the compensation current ic is combined with the nonlinear load current i _L to improve the compensated current is improved to a sinusoidal wave (Sin wave).

4 shows an unbalanced (nonlinear) compensation device for generating new and renewable energy in the past.

The conventional unbalanced (nonlinear) compensation device for generating new and renewable energy supplies three-phase power from the three-phase power supply unit 90 to the unbalanced load 103. Above all, in order to compensate for the unbalanced power of the unbalanced load 103, a direct current (DC) power generated from the solar cell 100 is supplied and the compensation current (ic) is supplied through the unbalanced (nonlinear) load compensating device 104. ) Is compensated through the reactor 106 and the general transformer 105. In the conventional unbalanced (nonlinear) compensation device for generating renewable energy, the unbalanced (nonlinear) load is compensated through the passive filter capacitor 107-1 and the passive filter reactor 107-2 of the passive filter 107. The device 104 plays a role of compensating for unbalanced power that has not been properly compensated.

Therefore, in the existing unbalanced (nonlinear) compensation device for generating renewable energy, the passive filter 107 of the passive filter capacitor 107-1 and the passive filter reactor 107-2 exist, and the reactor 106 and There is a characteristic of supplying the compensation current (ic) through the general transformer 105. Therefore, since the passive filter 107 is large and the reactor 106 is absolutely necessary, the size of the unbalance (nonlinear) compensating device is large, and the cost is increased.

5 shows a proposed unbalance (nonlinear) compensation device (first embodiment) for generating renewable energy.

In the present invention, the unbalanced (nonlinear) compensating device for generating renewable energy proposed above supplies three-phase power from the three-phase power supply unit 90 to the unbalanced load 103. Above all, in order to compensate for the unbalanced power of the unbalanced load 103, a direct current (DC) power generated from the solar cell 100 is supplied and the compensation current (ic) is supplied through the unbalanced (nonlinear) load compensating device 104. The biggest technical feature is that) is compensated through the leakage transformer 110. In the proposed unbalanced (nonlinear) compensation device for renewable energy generation, the biggest feature is to use the leaky transformer 110 in which the reactor 106 and the general transformer 105 are combined, thereby reducing the manufacturing cost and The space of the entire system can be very innovatively reduced. In addition, the reactor 106 and the general transformer are applied by applying an unbalance compensation device to a method for real-time detection of the normal and negative currents from the unbalanced three-phase current and the controller that controls the PWM converter to cancel the negative-phase current of the load. (105) could be combined. In addition, harmonics can be reduced by reducing the unbalanced power of the improved unbalanced load 103 without the need for the passive filter capacitor 107-1 and the passive filter reactor 107-2 through the improved control method. And there is an improved advantage that can improve the power factor.

6 shows a proposed unbalance (nonlinear) compensation device (second embodiment) for generating renewable energy.

In the present invention, the unbalanced (nonlinear) compensating device for generating renewable energy proposed above supplies three-phase power from the three-phase power supply unit 90 to the unbalanced load 103. Above all, in order to compensate for the unbalanced power of the unbalanced load 103, a plurality of unbalanced (nonlinear) loads by receiving direct current (DC) power generated from a plurality of solar cell cells (100-1,100-2,100-3, etc.) The biggest technical feature is that the compensation current ic is compensated through the plurality of leakage transformers 110-1, 110-2, 110-3, etc. through the compensation devices 104-1, 104-2, 104-3, etc. In the proposed unbalanced (nonlinear) compensation device for generating renewable energy, the biggest feature is to use a plurality of leakage transformers (110-1, 110-2, 110-3, etc.) in which the reactor 106 and the general transformer 105 are combined. And, through this, manufacturing cost can be reduced and the space of the entire system can be very innovatively reduced. In addition, the reactor 106 and the general transformer are applied by applying an unbalance compensation device to a method for real-time detection of the normal and negative currents from the unbalanced three-phase current and the controller that controls the PWM converter to cancel the negative-phase current of the load. (105) could be combined. In addition, harmonics can be reduced by reducing the unbalanced power of the improved unbalanced load 103 without the need for the passive filter capacitor 107-1 and the passive filter reactor 107-2 through the improved control method. And there is an improved advantage that can improve the power factor. In addition, a plurality of solar cells (Cell) (100-1,100-2,100-3, etc.), a plurality of unbalanced (nonlinear) load compensation devices (104-1, 104-2, 104-3, etc.), a plurality of leakage transformers (110-1, 110-2,110) -3, etc.) can be used in parallel operation in the unbalanced (nonlinear) compensating device, and through this, it is technical to easily compensate the unbalanced power even in a large-capacity (high power) unbalanced load 103 of several to tens of MW class or more. It is characterized.

7 shows a proposed unbalance (nonlinear) compensation device (third embodiment) for generating renewable energy.

In the present invention, the unbalanced (nonlinear) compensating device for generating renewable energy proposed above supplies three-phase power from the three-phase power supply unit 90 to the unbalanced load 103. Above all, in order to compensate for the unbalanced power of the unbalanced load 103, a plurality of unbalanced (nonlinear) load compensating devices 104-1,104- receiving direct current (DC) power generated from a single solar cell 100 2,104-3, etc.) through the compensation current (ic) is compensated through a plurality of leakage transformers (110-1, 110-2, 110-3, etc.) is the biggest technical feature. In the proposed unbalanced (nonlinear) compensation device for generating renewable energy, the biggest feature is to use a plurality of leakage transformers (110-1, 110-2, 110-3, etc.) in which the reactor 106 and the general transformer 105 are combined. And, through this, manufacturing cost can be reduced and the space of the entire system can be very innovatively reduced. In addition, the reactor 106 and the general transformer are applied by applying an unbalance compensation device to a method for real-time detection of the normal and negative currents from the unbalanced three-phase current and the controller that controls the PWM converter to cancel the negative-phase current of the load. (105) could be combined. In addition, harmonics can be reduced by reducing the unbalanced power of the improved unbalanced load 103 without the need for the passive filter capacitor 107-1 and the passive filter reactor 107-2 through the improved control method. And there is an improved advantage that can improve the power factor.

In the case of using a single solar cell 100 in this way, since the harmonic of the system is reduced and the circulating current is reduced, a further improved effect can be exhibited compared to that of FIG. 6 (second embodiment). have. Above all, when a plurality of solar cell (Cell) (100-1,100-2,100-3, etc.) is used as shown in FIG. 6 (second embodiment), substantially the plurality of solar cell (Cell) (100-1,100) is used. -2,100-3, etc.) are uneven in voltage and power, respectively, and there is a problem that harmonics of the system are generated due to this.

Therefore, since the method shown in FIG. 7 (third embodiment) uses a single solar cell 100, the output voltage generated from the single solar cell 100 is constant. Due to this, since the voltage output from the plurality of unbalanced (nonlinear) load compensation devices 104-1, 104-2, 104-3, etc. is also constant, the harmonic of the system is compared with that of FIG. 6 (the second embodiment). There is an advantage that is further reduced. In addition, in the transformerless type, a circulating current may occur in a single solar cell configuration, but in FIG. 7 (third embodiment), the output voltage generated from the single solar cell 100 is constant. Because it is (one fixed), there is a more improved feature that does not generate circulating current.

Accordingly, in FIG. 7 (third embodiment), a single solar cell 100, a plurality of unbalanced (nonlinear) load compensating devices 104-1, 104-2, 104-3, etc., and a plurality of leakage transformers 110-1,110 -2,110-3, etc.) can be used in parallel operation in the unbalanced (nonlinear) compensating device, and through this, the unbalanced power is easily compensated for even in the large-capacity (high power) unbalanced load 103 of several to tens of MW class or higher. , The harmonic of the system is minimized, and there is a more improved effect that circulating current does not occur in a plurality of unbalanced (nonlinear) load compensation devices 104-1, 104-2, 104-3, etc.

8 shows a controller for compensating for an unbalanced (nonlinear) load current for generating a proposed renewable energy. The control unit that compensates for the proposed unbalanced (nonlinear) load current for generating renewable energy supplies power to the unbalanced load 103 from the three-phase power supply unit 90, and a controller that substantially compensates for the unbalanced current to be. A three-phase unbalanced load current is detected by the load current detection unit 111 that detects the current supplied to the unbalanced load 103, and the load current conversion unit 115 converts the detected three-phase load current into a two-phase current. do. In addition, by receiving the output of the load current conversion unit 115, the current value setting unit and the communication unit 116 finally set the corrected current value, let the control computer 117 communicate, and if necessary, the manager directly Current value can be set directly. The compensation voltage detection unit 113-1 and the compensation current detection unit 113-2 detect the compensated voltage and current, and outputs of the compensation voltage detection unit 113-1 and the compensation current detection unit 113-2 It is supplied to the current control unit 114 through the current conversion unit 113. The current control unit 114 is based on the converted voltage and current values of the compensation voltage detection unit 113-1 and the compensation current detection unit 113-2, and the current setting values of the current value setting unit and the communication unit 116. The biggest technical feature is that the vector control unit 112 converts solar power generated from the solar cell 100, and compensates for the unbalanced power of the unbalanced load 103 through the leakage transformer 110. To do.

8 is a control unit that compensates for the proposed unbalanced (nonlinear) load current for renewable energy generation, measures the three-phase current of the unbalanced load 103 in real time, decomposes it into a normal and a reversed phase, and the compensator This is a method of compensating for the unbalance by supplying the reverse phase current of the unbalanced load, and controls the vector control unit 112 through the current control unit 114 to the normal and reverse currents detected by the load current conversion unit 115 It is the biggest technical feature.

Through this, the reactor 106 and the general transformer 105 are combined with the leakage transformer 110 to easily compensate for the unbalanced power even in the unbalanced load 103 of a large capacity (high power) of several to tens of MW class or more. To do.

FIG. 9 shows a three-phase to two-phase transformed coordinate axis and a voltage vector diagram, and FIG. 10 is a reference to a coordinate axis rotating at a synchronous speed in the forward/reverse direction with respect to the coordinate axis of the power supply in FIG. 10(a), and FIG. 10(b) ) Shows the reverse phase current vector diagram.

축을

상과 일치시킨다. 전압벡터는 도 9와 같이 정지좌표계에서 2축성분인

로 표시되고, 각속도

[rad/s]로 상회전의 방향으로 회전하게 된다. Above all, if it is assumed that the three-phase power supply is balanced, the static coordinate system

Axis

Match the prize. The voltage vector is a two-axis component in the stationary coordinate system as shown in FIG.

And angular velocity

It rotates in the direction of upward rotation at [rad/s].

와

에서와 같이, 서로 반대방향으로 회전하는

좌표계에 정상분 전류를,

좌표계에 역상분 전류를 표시할 수 있다. 따라서 회전하는 두 좌표계에 대하여, 도 9에서 전압벡터가

축에 일치 된

의 순간에, 도 10과 같이

축과

축이

축에 일치하는 좌표계로 설정할 수 있다. 이로 인하여 전류벡터는 3상의 선전류(

)가 입력되고, 식(4)에 의하여 정지좌표계의 2축 성분(

)으로 변환되며, 부하전류

는, 정상분 전류

와 역상분 전류는

를 포함하게 할 수 있다.For the unbalanced load current, there are two vectors of the normal current and the reverse current.

Wow

As in, rotating in opposite directions

Normal current in the coordinate system,

Inverse phase current can be displayed on the coordinate system. Therefore, for the two rotating coordinate systems, the voltage vector in FIG. 9 is

Matched to the axis

At the moment, as shown in Fig. 10

Axis

Axis

It can be set to a coordinate system that matches the axis. Due to this, the current vector is a three-phase line current (

) Is entered, and the biaxial component of the stationary coordinate system (

) And load current

Is the normal current

And the reverse phase current is

Can be included.

식(3)

Equation (3)

식(4)

Equation (4)

와 같이

로 나타냈으며, 좌표축

축과 함께 상회전방향의 동기속도로 회전한다. 역상분 전류는 도 10의

와 같이 좌표축

축과 함께 상회전 반대방향의 동기속도로 회전하는

이다. 정지좌표계(

축)와 각각의

좌표계,

좌표계는, 도 10으로부터 식(5)와 식(6)의 관계를 갖고 상호 변환시킬 수 있다.The normal current is shown in FIG. 10

together with

And the coordinate axis

It rotates with the shaft at a synchronous speed in the upward rotation direction. The reverse phase current is

Coordinate axis as

Rotating at a synchronous speed opposite to the upward rotation

to be. Stationary coordinate system (

Axis) and each

Coordinate System,

From Fig. 10, the coordinate system can be transformed to each other with the relationship between equations (5) and (6).

식(5)

Equation (5)

식(6)

Equation (6)

좌표계로 변환하게 된다.Therefore, the 3-phase-2 phase transformed coordinate axis and voltage vector diagram of FIG. 9 are a-axis (a-axis) and b-axis (b-axis) of a, b, and c phases electrically rotating at an angular velocity of ω at 120 degree intervals. Axis), c-axis (c-axis),

It is converted into a coordinate system.

좌표계에서

회전좌표계 및

회전좌표계로 이동시키는 것을 나타낸다. 이는 전원의 상회전과 정/역 방향 동기속도로 회전하는 좌표축에 대하여 도 10(a) 정상분 전류벡터, 도 10(b) 역상분 전류벡터를 나타낸다.In Figure 10

In the coordinate system

Rotating coordinate system and

It represents moving to the rotational coordinate system. This shows the normal current vector and Fig. 10 (b) the reverse current vector for the coordinate axis rotating at the synchronous speed in the forward/reverse direction of the power supply.

In the present invention, a three-phase current of the unbalanced load 103 is measured in real time, and is decomposed into Fig. 10(a) a normal current vector and Fig. 10(b) an inverse current vector.

Fig. 11 shows a normal/reverse current detector using an observer.

변환부)(121)를 통하여 3상의 a,b,c상의 전압을 2상의

좌표계로 변환하게 된다. 보다 구체적으로 부하전류 검출부(111)를 통하여 측정된 부하전류

를 정지좌표계(

좌표계)의 전류벡터

로 변환하는 3상/2상 변환기를 나타낸다. 관측기(120)의 구성은 관측기 이득행렬(L)(122), 적분기(123), 상태행렬(A)(124) 및 출력행렬(C)(125)로 구성되어 있다. 상기 관측기(120)의 출력인 상태벡터는 정지좌표계의 전류벡터

이며, 상기 관측기(120)의 출력인 상태벡터로부터 제1 정상분 전류 변환부(

-

변환부)(126) 및 제1 역상분 전류 변환부(

-

변환부)(127)에 의해서 각각

과

좌표계로 변환되어 상기 제1 정상분 전류 변환부(

-

변환부)(126)는 정상분 전류

를 출력하며, 상기 제1 역상분 전류 변환부(

-

변환부)(127)는 역상분 전류

를 출력하는 것을 기술적 특징으로 한다.In the normal/reverse current detector using the observer of FIG. 11, the first 3-phase-2 phase conversion unit (abc-

The voltage of the three phases a, b, and c through the converter) 121

It is converted into a coordinate system. More specifically, the load current measured through the load current detection unit 111

The stationary coordinate system (

Current vector of coordinate system)

It represents a 3-phase/2-phase converter that converts to. The configuration of the observer 120 includes an observer gain matrix (L) 122, an integrator 123, a state matrix (A) 124, and an output matrix (C) 125. The state vector that is the output of the observer 120 is the current vector of the stationary coordinate system

And, from a state vector that is an output of the observer 120, a first normal current conversion unit (

-

Conversion unit) 126 and a first reverse-phase current conversion unit (

-

Conversion unit) each by 127

and

It is converted into a coordinate system and the first normal current conversion unit (

-

Conversion unit) 126 is a normal current

And the first reversed-phase current converter (

-

Conversion unit) 127 is a reverse phase current

It is characterized by a technical feature to output.

은 상태추정오차의 수렴속도를 고려하여 설계하는 것을 특징으로 한다. 본 발명에서는 극(Pole)지정 방식을 이용하여

을 계산하는데 추정오차가 전원주파수(60Hz)의 1/4 주기 이내에 수렴하도록 기준다항식을 설계하는 방법을 가장 큰 기술적 특징으로 한다. Above all, the gain matrix of the observer 120 in the normal/reverse current detector using the observer of FIG. 11

Is characterized in that it is designed in consideration of the convergence speed of the state estimation error. In the present invention, using a pole designation method

The biggest technical feature is the method of designing the reference polynomial so that the estimation error converges within 1/4 cycle of the power frequency (60Hz).

을 계산하는데 추정오차가 전원주파수(60Hz)의 1/4 주기 이내에 수렴하기 때문에 빠른 응답특성이 가능하며, 더불어 상기 리액터(106)와 일반변압기(105)를 결합한 누설변압기(110)를 사용하여 보상전류(ic)를 공급할 수 있는 특징이 있으며, 이를 통하여 리액터(106)가 제거되었기 때문에 제조비용이 저감되며, 불평형 보상장치의 제작 공간이 줄어들며, 리액터리스 불평형 보상장치를 형성할 수 있는 매우 향상된 효과가 있다.Therefore, by using the pole designation method in the present invention

In the calculation of, since the estimated error converges within 1/4 cycle of the power frequency (60Hz), fast response characteristics are possible, and in addition, a leakage transformer 110 that combines the reactor 106 and the general transformer 105 is used to compensate. There is a characteristic capable of supplying current (ic), and since the reactor 106 is removed through this, the manufacturing cost is reduced, the manufacturing space of the imbalance compensation device is reduced, and a very improved effect that can form a reactorless imbalance compensation device There is.

와 역상분 전류

로 표현되고, 이 변수를 상태벡터

로 정의한다. 식(5)과 식(6)의 양변을 미분하여 정리하면 식(7)의 상태방정식을 얻을 수 있다. As shown in Equation (4) above, the current vector is

And reverse phase current

And this variable is a state vector

Is defined as If both sides of equations (5) and (6) are differentiated and arranged, the state equation of equation (7) can be obtained.

식(7)

Equation (7)

Consider the following equation (8) as the observer 120 for the above equation (7) model. The "^" sign in a variable can indicate an estimated value.

식(8)

Equation (8)

는 전원의 각주파수이며, 관측기 이득행렬

은 다음과 같이 나타낼 수 있다.here

Is the angular frequency of the power source, and the observer gain matrix

Can be expressed as

식(9)

Equation (9)

및 역상분

를 얻을 수 있으며, 이제 본 발명에서는 관측기의 상태추정 수렴속도를 고려하여 이득행렬

을 설계하는 방법을 제시한다. 상기 식(8)의 관측기의 추정오차의 수렴성은 행렬

의 고유치의 위치에 관계된다. 이러한 관측기를 설계하는 것은 관측기 오차의 폐루프 특성다항식

이 원하는 수렴특성을 갖는 4차 목표특성다항식

과 같아지도록 (즉,

이도록)

을 구하는 것과 등가적이다. 이제 문제는 원하는 수렴속도를 갖는

를 선정하는 것과 그러한

을 구하는 것이다. The normal portion of the stationary coordinate system from the state output of the observer

And reverse phase

Can be obtained, and now in the present invention, the gain matrix in consideration of the convergence speed of the observer

How to design it. The convergence of the estimation error of the observer in Equation (8) is a matrix

Is related to the location of the eigenvalues. Designing such an observer is a closed-loop characteristic polynomial of the observer error.

The fourth-order target characteristic polynomial with the desired convergence characteristic

To be equal to (i.e.

So)

It is equivalent to finding. Now the problem is to have the desired convergence speed

To select and such

Is to seek.

As an example of the designed system of the present invention, the target polynomial can be obtained using the following equations (10) and (11).

식(10)

Equation (10)

식(11)

Equation (11)

는 관측기의 추정오차가

로 수렴하는 시간이다. 예를 들어,

의 1/4 주기를 수렴시간으로 원한다면

[sec]이다.

가 선택되면 관측기 이득행렬을 계산해야 하는데 행렬

의 미지수가 8개이고 파라미터는 4개이기 때문에 단순한 선형방정식으로는 구할 수 없다. 그렇지만 이런 목적으로 개발된 Matlab의 극지정 공식 "place"를 이용하여 식(12)에 의하여 구할 수 있다.

을

의 근 벡터라 하면 다음 코드로 해를 얻는다.here,

Is the estimated error of the observer

It is time to converge. E.g,

If you want 1/4 cycle of the convergence time

It is [sec].

When is selected, the observer gain matrix needs to be calculated.

Since there are 8 unknowns and 4 parameters, it cannot be obtained with a simple linear equation. However, it can be obtained by equation (12) using Matlab's polar designation formula "place" developed for this purpose.

of

If we say the root vector of, we get the solution with the following code.

place

식(12)

place

Equation (12)

FIG. 12 shows a normal/reverse current detector using a forward average filter, and FIG. 13 shows a normal/reverse current detector using a backward average filter.

좌표계에 나타낸 불평형 전류를

좌표계로 변환하면, 정상분 전류와, 전원 주파수의 2배로 진동하는 역상분이 포함되어 나타난다. 반대방향으로 회전하는

좌표계로 변환하면, 역상분 전류와, 전원 주파수의 2배로 진동하는 정상분이 포함되어 나타난다.12 and 13 are methods of detecting normal and reverse currents using an average filter and an inverse transformation based on coordinate transformation.

The unbalanced current expressed in the coordinate system

When converted to a coordinate system, the normal current and the reverse phase vibrating at twice the power frequency are included. Rotating in the opposite direction

When converted to a coordinate system, the reverse phase current and the normal component vibrating at twice the power frequency are included.

는 식(13)과 같이 정상분 전류

와 역상분 전류

를 포함하고 있다. 식(13)의 정지좌표계로 표시한 전류를,

좌표계로 변환하면 식(14)와 같고,

좌표계로 변환하면 식(15)와 같이 된다. 이들을 도 12와 함께 고찰하면, 정상분 전류가 출력 될

축에 진동하는 역상 전류성분이 나타나고, 식(15)와 같이 역상분 전류가 출력 될

축에 진동하는 정상 전류성분이 나타나고 있다. The unbalanced current

Is the steady-state current as shown in equation (13)

And reverse phase current

It includes. Current expressed in the stationary coordinate system of equation (13),

Converting to the coordinate system is the same as Equation (14),

When converted to a coordinate system, it becomes as in Equation (15). Considering these together with Fig. 12, the normal current will be output.

The reverse phase current component vibrating on the axis appears, and the reverse phase current will be output as shown in Equation (15).

There is a steady current component vibrating on the shaft.

축의 평균값

를,

축의 평균값

를 취한다. 이 평균값을 가진 각각의 좌표계에서 정지좌표계로 변환한,

와

는, 평균값으로 추정한 정지좌표계의 정상성분과 역상성분의 전류가 된다. 정상성분과 역상성분의 전류가 추정이 되면,

,

이므로 식(16)에 의하여, 정상분 전류

와 역상분 전류

으로 분리한다. 이것을 상기 도 12와 상기 도 13에 보인 것처럼

축과

축으로 된, 회전하는 두 좌표계로 변환하여, 각각

와

를 출력할 수 있다.In order to eliminate the component that vibrates at twice the power frequency, which is the second term on the right side of Equations (14) and (15),

Average value of axis

To,

Average value of axis

Take Converted from each coordinate system with this average value to a stationary coordinate system,

Wow

Is the current of the stationary component and the reverse phase component estimated by the average value. When the currents of the normal and reverse phase components are estimated,

,

So, according to equation (16), the normal current

And reverse phase current

Separate with As shown in Fig. 12 and Fig. 13 above

Axis

Transformed into two axial, rotating coordinate systems, each

Wow

Can be printed.

와

의 평균값은

축과

축으로 된, 회전하는 두 좌표계에서 각각 계산을 할 수 있다. 이 평균값을 구하는 방법은 도 12와 도 13에 보인 두 가지 방법을 제시한다. 도 12의 방법은 정지좌표계의

에서,

좌표계 및

좌표계의 두 좌표계로 좌표변환을 한 다음, 필터를 사용하여 평균값을 구한다. 도 13의 방법은

와

를 필터의 입력으로 사용하기 때문에 좌표변환을 하지 않는다. remind

Wow

Is the average value of

Axis

You can perform calculations on each of the two axial, rotating coordinate systems. Two methods shown in Figs. 12 and 13 are presented as a method of obtaining this average value. The method of Fig. 12 is

in,

Coordinate system and

After converting the coordinates into two coordinate systems of the coordinate system, calculate the average value using a filter. The method of Figure 13

Wow

Since is used as the input of the filter, coordinate transformation is not performed.

식(13)

Equation (13)

식(14)

Equation (14)

식(15)

Equation (15)

식(16)

Equation (16)

좌표계와

좌표계에서, 상기 2배의 전원주파수로 진동하는 반대성분을 제거하기 위해, 필터를 이용 평균값 정상성분

과 역상성분

을 추정하여,

좌표계의 불평형 부하전류

에서 이들을 빼면 정상분 전류

와 역상분 전류

로 분리할 수 있다. 이것을 각각

좌표계와

좌표계로 변환하여

및

를 검출하는 것을 기술적 특징으로 한다.Therefore, the normal/reverse current detector using the forward average filter of FIG. 12 rotates at synchronous speeds in both forward and reverse directions.

Coordinate system and

In the coordinate system, a filter is used to remove the opposite component vibrating at the power frequency twice the average value.

And reverse phase components

By estimating,

Unbalanced load current of coordinate system

Subtract these from the normal current

And reverse phase current

Can be separated by Each of these

Coordinate system and

By converting it to the coordinate system

And

It is characterized in that it detects.

변환부)(131)를 통하여 3상의 a,b,c상의 전압을 2상의

좌표계로 변환하게 된다. 보다 구체적으로 부하전류 검출부(111)를 통하여 측정된 부하전류

를 정지좌표계(

좌표계)의 전류벡터

로 변환하는 3상/2상 변환기를 나타낸다.Therefore, the second 3-phase-2 phase conversion unit (abc-

The voltage of the three phases a, b, c through the converter) 131

It is converted into a coordinate system. More specifically, the load current measured through the load current detection unit 111

The stationary coordinate system (

Current vector of coordinate system)

It represents a 3-phase/2-phase converter that converts to.

좌표계로 변환된 전류벡터

는 전방향 평균필터부(130)를 통하여

좌표계와

좌표계로 변환하게 된다. 상기 전방향 평균필터부(130)는 제2 역상분 전류 변환부(

-

변환부)(132) - 제1 전방향 평균필터(134)를 통하여 평균값 정상성분

을 출력하며, 동시에 제2 정상분 전류 변환부(

-

변환부) - 제2 전방향 평균필터(135)를 통하여 평균값 역상성분

을 추정하게 된다.Above two

Current vector converted to coordinate system

Is through the omnidirectional average filter unit 130

Coordinate system and

It is converted into a coordinate system. The omnidirectional average filter unit 130 includes a second reverse phase current conversion unit (

-

Conversion unit) 132-Average value normal component through the first omnidirectional average filter 134

Output, and at the same time, the second normal current converter (

-

Transformation unit)-Inverse phase component of the average value through the second omnidirectional average filter 135

Is estimated.

은 제1 감산부의 제1 감산기(138-1) - 제3 정상분 전류 변환부(

-

변환부)(139)를 통하여 최종적으로

좌표계로 변환된

를 출력한다. 또한 상기 평균값 역상성분

은 제1 감산부의 제2 감산기(138-2) - 제3 역상분 전류 변환부(

-

변환부)(140)를 통하여 최종적으로

좌표계로 변환된

을 출력한다.Normal component of the average value

Is the first subtractor (138-1) of the first subtraction unit-the third normal current conversion unit (

-

Conversion unit) finally through 139

Converted to coordinate system

Prints. In addition, the average value of the reverse phase component

Is the second subtractor 138-2 of the first subtracting unit-the third inverse current conversion unit (

-

Finally through the conversion unit) 140

Converted to coordinate system

Prints.

를

좌표계와

좌표계로 변환하고, 두 좌표계에서 필터를 사용하여 평균값을 구하여 정지좌표계의

와

를 추정하며, 최종적으로

좌표계로 변환된

및

좌표계로 변환된

을 추종하는 것을 기술적 특징으로 한다.Therefore, the normal/reverse current detector using the forward average filter of FIG. 12 is the load current of the input stationary coordinate system.

To

Coordinate system and

Convert it to a coordinate system, and calculate the average value using a filter in the two coordinate systems.

Wow

Is estimated, and finally

Converted to coordinate system

And

Converted to coordinate system

It is characterized by a technical feature to follow.

In addition, there is a characteristic that the compensation current ic can be supplied by using a leakage transformer 110 that combines the reactor 106 and the general transformer 105 through this. Therefore, since the reactor 106 is removed, manufacturing cost is reduced, the manufacturing space of the imbalance compensation device is reduced, and there is a very improved effect of forming a reactorless imbalance compensation device.

변환부)(151)를 통하여 3상의 a,b,c상의 전압을 2상의

좌표계로 변환하게 된다. 보다 구체적으로 부하전류 검출부(111)를 통하여 측정된 부하전류

를 정지좌표계(

좌표계)의 전류벡터

로 변환하는 3상/2상 변환기를 나타낸다.13 is an 11th 3-phase-2 phase converter (abc-) in the normal/reverse current detector using a backward average filter.

The voltage of the three phases a, b, and c through the conversion unit) 151

It is converted into a coordinate system. More specifically, the load current measured through the load current detection unit 111

The stationary coordinate system (

Current vector of coordinate system)

It represents a 3-phase/2-phase converter that converts to.

좌표계로 변환된 전류벡터

는 제22 정상분 전류 변환부(

-

변환부)(155) - 제2 역방향 평균필터(158) - 제11 정상분 전류 변환부(

-

변환부)(154) - 제22 역상분 전류 변환부(

-

변환부)(156)를 통하여

좌표계로 변환된

을 추종한다.Above two

Current vector converted to coordinate system

Is the 22nd normal current conversion unit (

-

Conversion unit) 155-second reverse average filter 158-eleventh normal current conversion unit (

-

Conversion unit) 154-22nd reverse phase current conversion unit (

-

Conversion unit) through 156

Converted to coordinate system

Follow.

-

변환부)(156) - 제1 역방향 평균필터(157) - 제11 역상분 전류 변환부(

-

변환부)(153) - 제22 정상분 전류 변환부(

-

변환부)(155)를 통하여

좌표계로 변환된

를 추종하게 된다.In addition, the 22nd reverse-phase current conversion unit (

-

Conversion unit) 156-first reverse average filter 157-11th reverse phase current conversion unit (

-

Conversion unit) 153-22nd normal current conversion unit (

-

Conversion unit) through 155

Converted to coordinate system

Will follow.

In FIG. 12, a forward average filter is used, and in FIG. 13, a method of detecting normal and reverse currents using a backward average filter is the biggest technical feature.

와

를 구하고 이를 바탕으로 최종적으로

좌표계로 변환된

및

좌표계로 변환된

을 추종하는 것을 기술적 특징으로 한다.In the normal/reverse current detector using the reverse average filter of FIG. 13, an average value is obtained from the normal and reverse current, and the estimated value of the stationary coordinate system

Wow

And finally based on this

Converted to coordinate system

And

Converted to coordinate system

It is characterized by a technical feature to follow.

In addition, there is a characteristic that the compensation current ic can be supplied by using a leakage transformer 110 that combines the reactor 106 and the general transformer 105 through this. Therefore, since the reactor 106 is removed, manufacturing cost is reduced, the manufacturing space of the imbalance compensation device is reduced, and there is a very improved effect of forming a reactorless imbalance compensation device.

14 shows an equivalent circuit per phase of a voltage converter. The equivalent circuit per phase of the voltage-type converter is described in that the reactance voltage (V _L ) is ultimately disposed between the power supply voltage (V) 161 and the output voltage (e) 163 of the unbalanced (nonlinear) load compensator. It is characterized.

15 shows a block diagram of a controller that controls the normal current and the reverse current.

The detailed description of the current control unit 114 detects the detected compensation voltage [Vc(abc)] and the detected compensation current [ic(abc)] from the voltage and current conversion unit 113, and the detected compensation voltage [ Vc(abc)] and the detected compensation current [ic(abc)] are technically characterized in that a compensation current ic is generated through the vector control unit 112 through the current control unit 114.

전류 변환부(

-

변환부)(174) 및 제22

전류 변환부(

-

변환부)(175)를 토하여 계산부(177)의 가산기(177-1)에서 상기 제11

전류 변환부(

-

변환부)(174) 및 제22

전류 변환부(

-

변환부)(175)의 결과값이 더해진다.The detected compensation current [ic(abc)] is subtractors 170-1,171-1 of the normal and reversed phase current compensation units through a current decomposer 176, and the first and second PI control units 172,173 Through, each 11th

Current converter (

-

Conversion unit) (174) and 22

Current converter (

-

Converting unit) 175 is vomited, and the eleventh in the adder 177-1 of the calculation unit 177

Current converter (

-

Conversion unit) (174) and 22

Current converter (

-

The result value of the conversion unit) 175 is added.

변환부)(178)을 통하여 계산부(177)의 감산기(177-2)에서 상기 계산부(177)의 가산기(177-1)의 결과를 감산함을 통하여 최종적으로 상기 백터제어부(112)의 지령되는 전류값을 계산하게 되며, 이를 통하여 최종적인 보상전류(ic)를 발생하는 것을 가장 큰 기술적 특징으로 한다.In addition, the detected compensation voltage [Vc(abc)] is the eleventh 3-phase-2 phase conversion unit (abc-

By subtracting the result of the adder 177-1 of the calculation unit 177 from the subtractor 177-2 of the calculation unit 177 through the conversion unit) 178, the vector control unit 112 The greatest technical feature is that the commanded current value is calculated, and the final compensation current (ic) is generated through this.

In the present invention, the normal current and the reverse current can be respectively controlled through the controller for controlling the normal and reverse currents of FIG. 15, and finally, a voltage vector is calculated in the stationary coordinate system. In addition, it is a technical feature that the vector control unit 112 is controlled by a spatial vector modulation (SVPWM) method based on the calculated voltage vector.

축과

축의 전압으로 나타내고, 두 좌표계에서 식(17)과 같이 각각의 제어기를 구성한다.Since the current flowing through the power source can be made to be a current of a desired size by the reactor voltage, a controller for controlling the reactor voltage in the circuit of FIG. 14 is configured. Reactance voltage

Axis

It is expressed as the voltage of the axis, and each controller is configured as in Equation (17) in the two coordinate systems.

는 변환기의 직류전압과 PWM 변조율로 결정되므로 제어기에 의하여 전압과 위상을 자유롭게 변화시킬 수 있다. 전력변환기 교류측 전압

는 식(18)과 같이, 전원전압

와, 전류를 제어하기 위한 리액턴스전압

에 의하여 결정된다. 상기 식(18)의

,

및

을 정지좌표계의 두 축성분

축으로 나타내었을 때, 식(19)와 같이 표현된다. 상기 식(19)과 같이 리액턴스전압은, 정상분 전류를 제어하는 정상성분의 전압과, 역상분 전류를 제어하는 역상성분의 전압을 포함하게 된다.14, the voltage on the AC side of the converter

Is determined by the converter's DC voltage and PWM modulation rate, so the voltage and phase can be freely changed by the controller. Voltage on AC side of power converter

Is the power supply voltage as shown in equation (18)

Wow, reactance voltage to control current

Is determined by Of the above equation (18)

,

And

Is the two axis components of the stationary coordinate system

When expressed as an axis, it is expressed as Equation (19). As shown in Equation (19), the reactance voltage includes a voltage of a normal component that controls a normal current and a voltage of a negative phase component that controls a reverse current.

As for the current control of the PWM converter, in FIG. 15, the normal current compensation unit 170 controls the normal current, and the reverse current compensation unit 171 controls the reverse current. The calculation unit 177 of FIG. 15 is a block for calculating Equation (19) based on the voltages of the normal component and the reverse phase component, which are outputs of the normal component current compensating section 170 and the reverse phase current compensating section 171, and the detected power supply voltage. to be. The vector control unit 112 can be driven by the space vector modulator with this voltage calculated in the stationary coordinate system.

As shown in FIG.15, the function of controlling the normal and reverse currents enables stable operation even in the unbalanced AC side reactor of the power supply voltage, and thus the use of leakage transformers with different reactances of each phase in the PWM converter is also possible.

The leakage transformer 110 is insulated from the AC power source, so that the DC side does not need to be electrically insulated. In this case, since the PWM converter is a parallel operation that shares the DC side, it has an improved advantage that can increase the capacity of operating by connecting two or more converters in parallel for AC/DC power conversion.

식(17)

Equation (17)

식(18)

Equation (18)

식(19)

Equation (19)

In addition, in the case of the reactorless unbalance compensation device for power generation of new and renewable energy proposed in the present invention, the current controller 114 can control both the normal current and the reverse current, but if necessary, the reverse current = 0 It is characterized by a technical feature that can be set and controlled. In the case of setting and controlling the reverse-phase current = 0, if the structure of the current control unit 114 is considerably simpler, there is a significant effect of reducing the computational burden on the controller processor because the amount of computation required for control is also reduced.

16 shows the manufactured unbalance (nonlinear) compensation device, and FIG. 17 shows the manufactured leak transformer. Since the manufactured unbalance (nonlinear) compensation device uses the leaky transformer 110 in which the reactor 106 and the general transformer 105 are combined, a reactorless unbalance compensation device in which the reactor 106 is omitted can be completed. . Through this, first, since the leakage transformer 110 that combines the general transformer 105 and the reactor 106 is used, a reactorless unbalance compensation device without the reactor 106 is provided, and second, the price due to the absence of the reactor 106 This is inexpensive and has the advantage of reducing the space of the unbalance compensation device. Third, the power quality is improved, and the power efficiency increases because the unbalanced power is solved. Fourth, the normal current and the reverse phase from the unbalanced three-phase current Since the minute current is detected and controlled in real time, it has a characteristic effect with improved control characteristics.

및 역상분 전류

를 실시간으로 검출하는 것을 특징으로 하는 신재생에너지 발전을 위한 리액터리스 불평형 보상장치를 제안하고자 한다.Therefore, in the present invention, in the reactorless unbalance compensation apparatus for generating renewable energy, the load current detection unit 111 for detecting a three-phase load current of the unbalanced load 103; A load current conversion unit 115 for converting the three-phase load current detected by the load current detection unit 111 into a two-phase current; A current value setting unit and a communication unit 116 for setting a reference current value based on the output of the load current conversion unit 115; A current control unit 114 for controlling a current based on the output of the current value setting unit and the communication unit 116; And a vector control unit 112 for supplying a compensation current ic according to a control command of the current control unit 114; The vector control unit 112 is supplied with electric energy supplied to the solar cell (Cell) 100; The compensation current ic supplied from the vector control unit 112 compensates the unbalanced power of the unbalanced load 103 through the leakage transformer 110; The current control unit 114 is a normal current from the three-phase load current detected by the load current detection unit 111 using the observer 120

And reverse phase current

To propose a reactorless unbalance compensation device for generating new and renewable energy, characterized in that it detects in real time.

The present invention can be applied to a reactorless unbalance compensation device for power generation of new and renewable energy by various modifications by those of ordinary skill in the field, and the scope of the technology to be easily modified technically also falls within the scope of the rights of this patent. You have to admit it.

변환부)
122 : 관측기 이득행렬(L)
123 : 적분기
124 : 상태행렬(A)
125 : 출력행렬(C)
126 : 제1 정상분 전류 변환부(

-

변환부)
127 : 제1 역상분 전류 변환부(

-

변환부)
130 : 전방향 평균필터부
131 : 제2 3상-2상 변환부(abc-

변환부)
132 : 제2 역상분 전류 변환부(

-

변환부)
133 : 제2 정상분 전류 변환부(

-

변환부)
134 : 제1 전방향 평균필터
135 : 제2 전방향 평균필터
136 : 제1

전류 변환부(

-

변환부)
137 : 제2

전류 변환부(

-

변환부)
138 : 제1 감산부
138-1 : 제1 감산부의 제1 감산기
138-2 : 제1 감산부의 제2 감산기
139 : 제3 정상분 전류 변환부(

-

변환부)
140 : 제3 역상분 전류 변환부(

-

변환부)
150 : 역방향 평균필터부
151 : 제11 3상-2상 변환부(abc-

변환부)
152 : 제11 감산부
152-1 : 제11 감산부의 제1 감산기
152-2 : 제11 감산부의 제2 감산기
153 : 제11 역상분 전류 변환부(

-

변환부)
154 : 제11 정상분 전류 변환부(

-

변환부)
155 : 제22 정상분 전류 변환부(

-

변환부)
156 : 제22 역상분 전류 변환부(

-

변환부)
157 : 제1 역방향 평균필터
158 : 제2 역방향 평균필터
161 : 전원전압(V)
162 : 리액턴스 전압(VL)
163 : 불평형(비선형) 부하 보상장치의 출력전압(e)
170 : 정상분 전류 보상부
170-1 : 정상분 전류 보상부의 감산기
171 : 역상분 전류 보상부
171-1 : 역상분 전류 보상부의 감산기
172 : 제1 PI 제어부
173 : 제2 PI 제어부
174 : 제11

전류 변환부(

-

변환부)
175 : 제22

전류 변환부(

-

변환부)
176 : 전류 분해부(Current Decomposer)
177 : 계산부
177-1 : 계산부의 가산기
177-2 : 계산부의 감산기
178 : 제11 3상-2상 변환부(abc-

변환부)

: 제1 관측기 행렬

: 제2 관측기 행렬

: 이득행렬

: 이득행렬의 전치행렬(Transposition Matrix: 행과 열을 바꾸어 놓은 행렬)
ic : 보상전류
is : 보상된 전류
i_L : 불평형(비선형) 부하전류
i_L(abc) : 검출된 불평형(비선형) 부하전류
ic(abc) : 검출된 보상전류
Vc(abc) : 검출된 보상전압90: 3-phase power supply
100: solar cell (Cell)
100-1: first solar cell (Cell)
100-2: second solar cell (Cell)
100-3: 3rd solar cell (Cell)
103: unbalanced load or nonlinear load
104: unbalanced (nonlinear) load compensation device
104-1: First unbalanced (nonlinear) load compensation device
104-2: Second unbalanced (nonlinear) load compensation device
104-3: 3rd unbalanced (nonlinear) load compensation device
105: general transformer
106: reactor
107: passive filter
107-1: Capacitor for passive filter
107-2: Reactor for passive filter
110: leakage transformer
110-1: first leakage transformer
110-2: 2nd leakage transformer
110-3: 3rd leakage transformer
111: load current detection unit
112: vector control unit
113: voltage and current converter
113-1: compensation voltage detection unit
113-2: compensation current detection unit
114: current control unit
115: load current conversion unit
116: current value setting unit and communication unit
117: control computer
118: Transformer Air Gap
120: observer
120-1: subtractor of the observer
120-2: adder of observer
121: first three-phase to two-phase conversion unit (abc-

Conversion unit)
122: Observer gain matrix (L)
123: integrator
124: state matrix (A)
125: output matrix (C)
126: first normal portion current conversion unit (

-

Conversion unit)
127: first reverse-phase current conversion unit (

-

Conversion unit)
130: omnidirectional average filter unit
131: second three-phase to two-phase conversion unit (abc-

Conversion unit)
132: second reverse-phase current conversion unit (

-

Conversion unit)
133: second normal portion current conversion unit (

-

Conversion unit)
134: first omnidirectional average filter
135: second omnidirectional average filter
136: first

Current converter (

-

Conversion unit)
137: second

Current converter (

-

Conversion unit)
138: first subtraction unit
138-1: the first subtractor of the first subtraction unit
138-2: the second subtractor of the first subtraction unit
139: third normal current conversion unit (

-

Conversion unit)
140: third reverse-phase current conversion unit (

-

Conversion unit)
150: reverse average filter unit
151: 11th 3-phase-2 phase conversion unit (abc-

Conversion unit)
152: 11th subtraction section
152-1: the first subtractor of the eleventh subtraction unit
152-2: the second subtractor of the 11th subtraction unit
153: 11th reverse-phase current conversion unit (

-

Conversion unit)
154: 11th normal portion current conversion unit (

-

Conversion unit)
155: 22nd normal portion current conversion unit (

-

Conversion unit)
156: 22nd reverse phase current converter (

-

Conversion unit)
157: first reverse average filter
158: second reverse average filter
161: power supply voltage (V)
162: reactance voltage (VL)
163: Output voltage (e) of the unbalanced (nonlinear) load compensation device
170: normal current compensation unit
170-1: Subtractor of normal current compensation unit
171: reverse phase current compensation unit
171-1: Subtractor of reverse phase current compensation unit
172: first PI control unit
173: second PI control unit
174: the eleventh

Current converter (

-

Conversion unit)
175: the 22nd

Current converter (

-

Conversion unit)
176: Current Decomposer
177: calculation unit
177-1: adder of calculation part
177-2: Subtractor of calculation part
178: 11th 3-phase-2 phase conversion unit (abc-

Conversion unit)

: First observer matrix

: Second observer matrix

: Gain matrix

: Transposition matrix of gain matrix
ic: compensation current
is: compensated current
i _L : Unbalanced (nonlinear) load current
i _L (abc): Detected unbalanced (nonlinear) load current
ic(abc): detected compensation current
Vc(abc): detected compensation voltage

Claims (12)

In the reactorless unbalance compensation device for renewable energy generation,
A load current detection unit 111 for detecting a three-phase load current of the unbalanced load 103;
A load current conversion unit 115 for converting the three-phase load current detected by the load current detection unit 111 into a two-phase current;
A current value setting unit and a communication unit 116 for setting a reference current value based on the output of the load current conversion unit 115;
A current control unit 114 for controlling a current based on the output of the current value setting unit and the communication unit 116;
And a vector control unit 112 for supplying a compensation current ic according to a control command of the current control unit 114;
The vector control unit 112 is supplied with electric energy supplied to the solar cell (Cell) 100;
The compensation current ic supplied from the vector control unit 112 compensates the unbalanced power of the unbalanced load 103 through the leakage transformer 110;
The current control unit 114 is a normal current from the three-phase load current detected by the load current detection unit 111 using the observer 120

And reverse phase current

Reactorless unbalance compensation device for renewable energy generation, characterized in that it detects in real time

The method of claim 1,
Reactorless unbalance compensation device for renewable energy generation, characterized in that the mathematical model of the observer 120 (A)

Equation (A)

here,

: 3-phase-2 phase conversion unit (abc-

Conversion unit)

Current value converted to coordinate side current

: First observer matrix

: Second observer matrix

: Gain matrix
The method of claim 2,
Gain matrix

Transposition Matrix

A reactorless unbalance compensation device for renewable energy generation, characterized in that it has a structure as shown in equation (B).

Equation (B)
The method of claim 3,
The gain matrix in which the state estimation error of the observer 120 converges within 1/4 cycle of the power frequency

Reactorless unbalance compensation device for renewable energy generation, characterized in that
In the reactorless unbalance compensation device for renewable energy generation,
A load current detection unit 111 for detecting a three-phase load current of the unbalanced load 103;
A load current conversion unit 115 for converting the three-phase load current detected by the load current detection unit 111 into a two-phase current;
A current value setting unit and a communication unit 116 for setting a reference current value based on the output of the load current conversion unit 115;
A current control unit 114 for controlling a current based on the output of the current value setting unit and the communication unit 116;
And a vector control unit 112 for supplying a compensation current ic according to a control command of the current control unit 114;
The vector control unit 112 is supplied with electric energy supplied to the solar cell (Cell) 100;
A reactorless unbalance compensation device for renewable energy generation, characterized in that the compensation current ic supplied from the vector control unit 112 compensates the unbalanced power of the unbalanced load 103 through the leakage transformer 110
The method of claim 5,
The current control unit 114 uses a forward average filter to generate a normal current from the three-phase load current detected by the load current detection unit 111

And reverse phase current

Reactorless unbalance compensation device for renewable energy generation, characterized in that it detects in real time
The method of claim 6,
Normal current from the three-phase load current detected by the load current detection unit 111

And reverse phase current

Reactorless unbalance compensation device for renewable energy generation, characterized in that the normal component and the reverse phase component are estimated using coordinate transformation, average filter, and inverse transformation to separate
The method of claim 5,
The current control unit 114 uses a reverse average filter to generate a normal current from the three-phase load current detected by the load current detection unit 111

And reverse phase current

Reactorless unbalance compensation device for renewable energy generation, characterized in that it detects in real time
In the reactorless unbalance compensation device for renewable energy generation,
A load current detection unit 111 for detecting a three-phase load current of the unbalanced load 103;
A load current conversion unit 115 for converting the three-phase load current detected by the load current detection unit 111 into a two-phase current;
A current value setting unit and a communication unit 116 for setting a reference current value based on the output of the load current conversion unit 115;
A current control unit 114 for controlling a current based on the output of the current value setting unit and the communication unit 116;
The current control unit 114 is a normal current from the three-phase load current detected by the load current detection unit 111

And reverse phase current

Reactorless unbalance compensation device for renewable energy generation, characterized in that by detecting in real time to compensate for unbalanced power
The method of claim 9,
A vector control unit 112 for supplying a compensation current ic according to a control command of the current control unit 114;
A reactorless unbalance compensation device for renewable energy generation, characterized in that the compensation current ic supplied from the vector control unit 112 compensates the unbalanced power of the unbalanced load 103 through the leakage transformer 110
The method of claim 10,
The leakage transformer 110 has a structure in which a general transformer 105 and a reactor 106 are electrically combined, and a transformer air gap 118 is present. Compensation device
The method of claim 9,
The current control unit 114 is a reactorless unbalance compensation device for generating renewable energy, characterized in that the state estimation error converges within 1/4 cycle of the power frequency.

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