KR20060065742A - Device of detecting phase of system voltage using virtual two phase voltage - Google Patents

Abstract

The present invention relates to a system voltage phase detection device using a virtual two-phase for the PLL control method capable of precise grid linkage with a distributed voltage through fast and accurate phase voltage estimation by converting a single phase voltage into a virtual two-phase voltage. In particular, a first output voltage generator for receiving a single phase input voltage from an AC power supply and a feedback input from a phase estimating means to generate a first output voltage having the same amplitude, phase, and angular frequency as the single phase input voltage; A virtual two-phase voltage generator comprising a second output voltage generator for generating a second output voltage having the same amplitude as the single-phase input voltage and the angular frequency and having a phase difference of? / 2 with the single-phase input voltage; And phase estimating means for receiving the first output voltage and the second output voltage from the virtual two-phase voltage generating means and calculating and outputting the estimated phase. It is possible to synchronize the phase of the grid voltage by detecting, shorten the time required for phase estimation, and because it does not generate errors due to noise or voltage drop and zero disturbance due to harmonic injection, it has a strong characteristic against noise and disturbance. Provide effect.

Grid voltage, single phase voltage, virtual two phase voltage, phase detection, one phase voltage, virtual two phase voltage, phase detection

Description

Device Voltage Detecting Device using Virtual Two-Phase {Device of Detecting Phase of System Voltage Using Virtual Two Phase Voltage}

1 is a block diagram of a grid-tied photovoltaic power generation system according to the prior art.

Figure 2 is a block diagram of a zero point detection system according to the prior art.

3 is a flow chart of a zero detection method according to the prior art.

4 is a block diagram of a system voltage phase detection apparatus using a virtual two-phase according to an embodiment of the present invention.

5 is a block diagram of a virtual two-phase voltage generation means using a memory table according to an embodiment of the present invention.

6 is a block diagram of a virtual two-phase voltage generation means using the estimated phase and the estimated amplitude according to an embodiment of the present invention.

7 is a block diagram of a virtual two-phase voltage generating means using a second order low pass filter in accordance with an embodiment of the present invention.

8 is a block diagram of a virtual two-phase voltage generation means using a first order low pass filter in accordance with an embodiment of the present invention.

9 is a block diagram of a virtual two-phase voltage generation means using a second-order all-pass filter according to an embodiment of the present invention.

10 is a block diagram of the phase estimation means using the arctan function according to an embodiment of the present invention.

11 is a block diagram of a phase estimating means using a synchronous coordinate system according to an embodiment of the present invention.

12 is an overall configuration diagram of a system voltage phase detection apparatus using a virtual two-phase according to the present invention.

13A to 13J are graphs showing an estimated input power, an estimated angular frequency, and an estimated amplitude of a system voltage phase detection device using a virtual two-phase according to an embodiment of the present invention in an initial state.

 14 is a graph showing an estimated input power, an estimated angular frequency, and an estimated amplitude of a system voltage phase detection apparatus using a virtual two-phase according to an embodiment of the present invention in a steady state.

15 is a graph showing an estimated input power, an estimated angular frequency, and an estimated amplitude of a system voltage phase detection apparatus using a virtual two-phase according to an embodiment of the present invention during voltage drop.

16A to 16B are graphs showing an estimated input power, an estimated angular frequency, and an estimated amplitude of a system voltage phase detection device using a virtual two-phase according to an embodiment of the present invention during harmonic injection.

The present invention relates to a grid voltage phase detection device using a virtual two-phase for the PLL control method capable of precise grid linkage with a distributed voltage through fast and accurate phase voltage estimation by converting a single phase voltage into a virtual two-phase voltage. .

In applications such as AC / DC converters, uninterruptible power supplies (UPS), and alternative energy generation systems, accurate and fast grid voltage phase estimation is essential for overall system control. In this case, the phase information of the grid voltage is essential for generating the reference current signal. At this time, even if noise or disturbances are introduced into the grid voltage, the phase of the grid voltage must be detected instantaneously and accurately.

In the case of three-phase voltage, after converting the three-phase voltage to the stationary coordinate system, the phase angle can be easily detected from the vector angle of the voltage. However, in the case of the single-phase voltage, this method cannot be applied. There is a problem that is generally difficult. As a conventional method for detecting a phase of a single phase voltage, a zero detection method is widely used. This method detects a phase only at zero, and thus has a low estimation speed, cannot detect an instantaneous phase, and is sensitive to noise.

)과 인버터 출력 전류(

)를 제어하게 된다. 이 때 인버터의 출력 전류(

)는 계통의 전압과 반드시 동상인 정현파가 되어야하는데, 계통전압과 동상인 정현파를 만들기 위해 PLL제어(40)를 통해 계통 전압의 위상(

)을 검출하여 기준 전류(

)를 생성하여 제어한다.1 shows the overall configuration of a single-phase grid-tied photovoltaic power generation system. The grid-tied photovoltaic power generation system is a system for converting DC power generated in the solar cell 10 into AC power through the inverter 30. In the system, when the generated power is greater than the load power, surplus power is returned to the grid, and in reverse, insufficient power is supplied from the grid. Since the solar cell 10 has a non-linear characteristic according to the amount of solar radiation and temperature, the maximum power point following control is performed through the DC-DC converter 20 to generate the maximum power, and the DC link voltage through the inverter

) And inverter output current (

Will be controlled. At this time, the output current of inverter

) Must be a sinusoid that is in phase with the voltage of the system, and the phase of the system voltage through the PLL control 40 to create a sinusoid in phase with the system voltage.

) To detect the reference current (

) To control.

)을 계산한다. 이때 PI 제어(Proportional-Integral Control)를 사용하여 실제 위상(

)과 추정위상(

)의 오차를 제어하여

를 출력하며 각 주파수 초기 설정치(

)를 더하여 추정 각주파수(

)를 출력한다. 시스템 각 주파수 초기 설정치(

)는 PI제어기(52)의 초기값으로 계통의 알려진 각 주파수인 377rad/s 이다.Figure 2 shows a block diagram of a conventional zero detection method for measuring the frequency and phase of a grid voltage. According to the conventional zero detection method, the zero crossing detector 50 finds a point passing through the zero point every half cycle of the input voltage, detects a phase, and estimates a phase using an estimated angular frequency (

Calculate At this point, you can use Proportional-Integral Control to

) And estimated phase (

Control the error of

Each frequency initial set value (

) Plus the estimated angular frequency (

) Initial frequency setting for each system

) Is the initial value of the PI controller 52 is 377 rad / s, which is the known angular frequency of the system.

3 is a flowchart of a conventional zero point detection method. The grid voltage is sampled and multiplied by the present value and the past value. If the result is a negative value, it is regarded as a zero point (S10). At this time, if the current value is greater than 0, the phase is 0. If the current value is less than 0, the phase is π (S20). However, the conventional zero detection method has a disadvantage in that an error may occur in phase detection of the grid voltage when noise or disturbance is introduced into the grid voltage so as to pass the zero point several times.

The present invention is to solve the above problems, by converting the single-phase system voltage into a virtual two-phase voltage, and by using the phase difference of the virtual two-phase voltage to estimate the phase every moment, the time required for phase estimation is shortened, An object of the present invention is to provide a virtual two-phase phase detection apparatus capable of reducing errors caused by noise or disturbance by converting a single-phase voltage into a virtual two-phase voltage.

In order to achieve the above object, the system voltage phase detection apparatus using a virtual two-phase according to the present invention, the single-phase input voltage is input from an AC power supply and the estimated phase feedback from the phase estimation means, the single-phase input voltage and amplitude A first output voltage generator for generating a first output voltage having the same phase and angular frequency, and a second output voltage having the same amplitude and angular frequency as the single phase input voltage and having a phase difference of π / 2 with the single phase input voltage. A virtual two-phase voltage generator comprising a second output voltage generator for generating; And phase estimating means for receiving the first output voltage and the second output voltage from the virtual two-phase voltage generating means and calculating and outputting the estimated phase.

The above and other objects and features and advantages of the present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

)을 입력받고 위상추정 수단(200)으로부터 추정 위상(

)을 궤환 입력받아, 단상 입력전압(

)과 진폭, 위상, 각주파수가 동일한 제 1 출력전압(

)을 발생하는 제 1 출력전압 발생부 및 상기 단상 입력전압(

)과 진폭, 각주파수가 동일하고 상기 단상 입력전압(

)과 π/2 의 위상차를 가지는 제 2 출력전압(

)을 발생시키는 제 2 출력전압 발생부를 포함하여 구성된다. 위상추정 수단(200)은, 제 1 출력전압(

)과 제 2 출력전압(

)의 두 신호를 이용하여 추정 위상각(

) 및 추정 각주파수(

), 추정 진폭(

) 등을 계산하는 기능을 수행한다. 4 is a block diagram of a system voltage phase detection apparatus using a virtual two-phase according to the present invention. The system voltage phase detection apparatus using the virtual two-phase includes a virtual two-phase voltage generating means 100 and a phase estimating means 200. The virtual two-phase voltage generating means 100 is a single-phase input voltage (from an AC power supply)

) Is inputted, and the estimated phase (

) Feedback input, single-phase input voltage (

) And the first output voltage having the same amplitude, phase, and angular frequency (

And a first output voltage generator for generating the single phase input voltage (

), Amplitude and angular frequency are the same, and the single phase input voltage (

) And a second output voltage having a phase difference of π / 2

It is configured to include a second output voltage generator for generating a). The phase estimating means 200 uses a first output voltage (

) And the second output voltage (

Using two signals of), the estimated phase angle (

) And estimated angular frequency (

), Estimated amplitude (

) To calculate the function.

)이 다음과 같이 주어졌을 때, The virtual two-phase voltage generating means 100 is a single phase input voltage (

) Is given by

)과 제 2 출력전압()을 발생시킨다. The first output voltage with the phase difference π / 2

) And the second output voltage ( ).

)은 단상 입력전압(

)과 동일하므로, 제 2 출력전압(

) 발생부를 구현하는 방법에 따라 메모리 테이블을 이용하는 방법, 추정위상과 추정진폭을 이용하는 방법, 2차 저역 통과 필터를 이용하는 방법, 1차 저역 통과 필터를 이용하는 방법, 및 2차 전역 통과 필터를 이용하는 방법의 5가지의 방법으로 구분할 수 있다. 도 5 내지 도 9는 각각의 방법에 따른 가상 2상 전압발생 수단(100)을 도시한다.At this time, the first output voltage of the two-phase voltage generating means 100 (

) Is the single-phase input voltage (

Is the same as the second output voltage (

) A method of using a memory table, a method of using an estimated phase and an estimated amplitude, a method of using a second order low pass filter, a method of using a first order low pass filter, and a method of using a second order all pass filter according to a method of implementing a generator. It can be divided into five ways. 5 to 9 show the virtual two-phase voltage generating means 100 according to each method.

)을 매 샘플링주기마다 메모리(110)에 저장한다. 이 때 제 1 출력전압(

)은 단상 입력전압(

)과 같고, 제 2 출력전압(

)은 단상 입력전압(

)의 1/4 주기 이전의 값에 -1 을 곱하여 얻을 수 있다. 즉,

이면,An implementation method of the virtual two-phase voltage generator 100 using the memory table will be described with reference to FIG. 5. As shown in FIG. 5, the method using the memory table includes a single-phase input voltage (

) Is stored in the memory 110 at every sampling period. At this time, the first output voltage (

) Is the single-phase input voltage (

), And the second output voltage (

) Is the single-phase input voltage (

This can be obtained by multiplying -1 by the value before 1/4 of the period. In other words,

If,

)과 90°의 위상차를 가지는 제 2 출력전압(

)을 얻을 수 있다.To the first output voltage (

) And a second output voltage having a phase difference of 90 °

) Can be obtained.

)를 더 계산하여 가상 2상 전압발생 수단(100)으로 궤환입력시키도록 한다. 가상 2상 전압발생 수단(100) 중 제 1 출력전압 발생부는 단상 입력전압(

)을 바이패스하여 제 1 출력전압(

)을 발생시키는 바이패스부를 포함하여 구성되도록 하고, 제 2 출력전압 발생부는 특정 샘플링 주기마다 단상 입력전압(

)을 저장하여 위상추정 수단(200)으로부터 입력된 추정 각주파수(

)를 입력받아 단상 입력전압(

)의 1/4 주기 이전의 단상 입력전압(

)을 출력하는 메모리부(100), 및 메모리(100)부로부터의 출력에 -1 을 승산하여 제 2 출력전압(

)을 발생시키는 제 1 승산부(112)를 포함하여 구성되도록 한다.Therefore, when the virtual two-phase voltage generating means is implemented using the memory table, the phase estimating means 200 may estimate the angular frequency (

) Is further calculated to be fed back into the virtual two-phase voltage generating means (100). The first output voltage generating unit of the virtual two-phase voltage generating means 100 is a single phase input voltage (

) Bypasses the first output voltage (

And a bypass portion for generating a second output voltage generator, and the second output voltage generator

) Is estimated and the estimated angular frequency inputted from the phase estimating means 200 (

), The single-phase input voltage (

Single-phase input voltage before 1/4 cycle of

) And the second output voltage () by multiplying -1 by the output from the memory 100 and the output from the memory 100.

It is configured to include a first multiplier 112 for generating a).

)과 추정 진폭(

)을 이용한 가상 2상 전압발생 수단(100)을 설명하면 다음과 같다. 위상추정 수단(200)에서 추정된 추정 진폭(

)과 추정 위상각(

)이 각각 실제 진폭과 실제 위상각을 잘 추정하고 있는 경우는,Referring to FIG. 6, the estimated phase angle (

) And estimated amplitude (

Referring to the virtual two-phase voltage generation means 100 using the following. The estimated amplitude estimated by the phase estimating means 200 (

) And estimated phase angle (

) Estimates the actual amplitude and the actual phase angle, respectively,

)은 제 1 출력전압(

)과 90°의 위상차이를 가지는 신호가 된다. To the second output voltage (

) Is the first output voltage (

) And a signal having a phase difference of 90 °.

)에 추가하여 추정 진폭(

)을 더 계산하여 가상 2상 전압발생 수단(100)으로 더 궤환입력시키도록 한다. 가상 2상 전압발생 수단(100) 중 제 1 출력전압 발생부는 단상 입력전압(

)을 바이패스하여 제 제 1 출력전압(

)을 발생시키는 바이패스부를 포함하여 구성되도록 하고, 제 2 출력전압 발생부는 추정 위상각(

)을 이용하여 단상 입력전압(

)과 π 의 위상차를 가지는 정현파 신호를 발생시키는 정현파 발생부(120), 및 정현파 발생부(120)로부터의 출력에 추정 진폭(

)을 승산하여 제 2 출력전압(

)을 발생시키는 제 2 승산부(122)를 포함하여 구성되도록 한다.Therefore, when implementing the virtual two-phase voltage generation means using the estimated phase angle and the estimated amplitude, the phase estimation means 200, the estimated phase angle (

In addition to),

) Is further calculated to be further fed back into the virtual two-phase voltage generating means (100). The first output voltage generating unit of the virtual two-phase voltage generating means 100 is a single phase input voltage (

) Bypasses the first output voltage (

And a bypass portion for generating the second output voltage generator, and the second output voltage generator

Single-phase input voltage

Sine wave generator 120 for generating a sinusoidal signal having a phase difference of π and an estimated amplitude (a) to an output from the sinusoidal wave generator 120.

) By multiplying the second output voltage (

It is configured to include a second multiplier (122) for generating a).

)이 감 쇄비가

이고 비감쇄 고유주파수(

)가 추정 각주파수(

)인 2차 저역 통과 필터(LPF:130)를 거치게 되면, 추정 각주파수(

)가 실제 각주파수와 일치하는 경우 단상 입력전압(

)과 90°의 위상차를 가지고 진폭이

인 신호를 얻게 된다. 따라서 제 2 출력전압(

)은 아래의 식과 같이 구할 수 있다.Referring to FIG. 7, the virtual two-phase voltage generator 100 using the second order low pass filter 130 will be described. As shown in FIG.

)

And non-attenuated natural frequency (

) Is the estimated angular frequency (

Pass through the second order low pass filter (LPF: 130),

) Matches the actual angular frequency, the single-phase input voltage (

) And the phase difference of 90 °

You get a signal. Therefore, the second output voltage (

) Can be obtained as

)를 더 계산하여 가상 2상 전압발생 수단(100)으로 더 궤환입력시키도록 구성하고, 가상 2상 전압발생 수단(100)의 제 1 출력전압 발생부는 단상 입력전압(

)을 바이패스하여 제 1 출력전압(

)을 발생시키는 바이패스부를 포함하여 구성하고, 제 2 출력전압 발생부는, 고유 각주파수(

)가 추정 각주파수(

)이고, 단상 입력전압(

)을 여과하여 출력하는 2차 저역통과필터(130), 및 2차 저역통과필터(130)의 출력에 2차 저역통과필터(130)의 감쇄비를 보정하여 제 2 출력전압(

)을 발생시키는 제 3 승산부(132)를 포함하여 구성한다.Therefore, the implementation method of the virtual two-phase voltage generation means using the second order low pass filter is as follows. The phase estimating means 200 estimates the angular frequency (

) Is further calculated and fed back into the virtual two-phase voltage generator 100, and the first output voltage generator of the virtual two-phase voltage generator 100 is a single-phase input voltage (

) Bypasses the first output voltage (

And a bypass section for generating a second output voltage generator, and the second output voltage generator

) Is the estimated angular frequency (

), Single-phase input voltage (

) By attenuating the attenuation ratio of the second low pass filter 130 and the second low pass filter 130 at the output of the second low pass filter 130.

It comprises a third multiplier 132 for generating a).

)이 차단주파수가 추정 각주파수 (

)인 1차 저역통과필터(LPF:140)를 통과하도록 하면, 추정 각주파수(

)가 실제 각주파수와 동일한 경우 출력전압은

가 되고, 따라서 제 2 출력전압(

)은 다음의 수식과 같이 구할 수 있다.Referring to FIG. 8, the virtual two-phase voltage generator 100 using the first order low pass filter will be described. Single phase input voltage

) This cutoff frequency is estimated angular frequency (

Pass through the first order lowpass filter (LPF: 140),

Is equal to the actual angular frequency, the output voltage is

And thus the second output voltage (

) Can be found as

)를 더 계산하여 가상 2상 전압발생(100) 수단으로 더 궤환입력시키도록 구성하고, 제 1 출력전압 발생부(100)는 단상 입력전압(

)을 바이패스하여 제 1 출력전압(

)을 발생시키는 바이패스부를 포함하도록 구성하고, 제 2 출력전압 발생부는, 차단각주파수가 추정 각주파수(

)이고 단상 입력전압(

)을 여과하여 출력하는 1차 저역통과필터(140), 1차 저역통과필터(140)의 출력에 -2 를 승산하여 제 2 출력전압(

)을 발생시키는 제 4 승산부(142), 및 제 4 승산부(142)의 출력에 단상 입력전압(

)을 가산하는 제 1 가산부(144)를 포함하도록 구성한다.Therefore, the implementation method of the virtual two-phase voltage generation means using the first order low pass filter is as follows. The phase estimating means 200 estimates the angular frequency (

) And further feedback input to the virtual two-phase voltage generator 100, and the first output voltage generator 100 is a single-phase input voltage (

) Bypasses the first output voltage (

And a bypass unit for generating a second output voltage generator, and the second output voltage generator includes an estimated angular frequency (

) And single-phase input voltage (

) Is multiplied by -2 to the output of the primary low pass filter 140 and the primary low pass filter 140 to filter and output the second output voltage (

) And the single-phase input voltage at the output of the fourth multiplier 142 and the fourth multiplier 142

It is configured to include a first adder (144) for adding).

)이 감쇄비가

이고 비감쇄 고유주파수(

)가 추정 각주파수(

)의

배인 2차 전역 통과 필터(150)를 통과하게 되면 추정 각주파수가 실제 각주파수와 일치하는 경우 입력전압과 위상차가 90°이고 크기가

인 신호를 얻을 수 있다. 따라서 제 2 출력전압(

)은 다음의 식과 같게 된다.Referring to FIG. 9, the virtual two-phase voltage generation means 100 using the second-order all-pass filter is as follows. Single phase input voltage

)

And non-attenuated natural frequency (

) Is the estimated angular frequency (

)of

Passing through the second order all-pass filter 150, if the estimated angular frequency matches the actual angular frequency, the input voltage and the phase difference are 90 ° and the magnitude

Signal can be obtained. Therefore, the second output voltage (

) Becomes the following equation.

)를 더 계산하여 가상 2상 전압발생 수단(100)으로 더 궤환 입력시키도록 구성하고, 제 1 출력전압 발생부는 단상 입력전압(

)을 바이패스하여 제 1 출력전압(

)을 발생시키는 바이패스부를 포함하도록 구성하고, 제 2 출력전압 발생부는 고유 각주파수가 추정 각주파수(

)의

배이고 단상 입력전압(

)을 여과하여 출력하는 2차 전역통과필터(150), 및 2차 전역통과필터(150)의 출력에 2차 전역통과필터(150)의 감쇄비를 보정하여 제 2 출력전압(

)을 발생시키는 제 5 승산부를 포함하도록 구성한다.Therefore, the implementation method of the virtual two-phase voltage generating means 100 using the second-order all-pass filter is as follows. The phase estimating means 200 estimates the angular frequency (

) Is further calculated to further input the feedback to the virtual two-phase voltage generating means 100, and the first output voltage generating unit includes a single phase input voltage (

) Bypasses the first output voltage (

And a bypass portion for generating a second output voltage generator, and the second output voltage generator

)of

Double and single phase input voltage

) By attenuating the attenuation ratio of the second all-pass filter 150 and the second all-pass filter 150 at the output of the second all-pass filter 150 to filter and output the second output voltage (

It is configured to include a fifth multiplier for generating a).

On the other hand, in the case of the phase estimating means 200, there are two methods of calculating the estimated angular frequency, the estimated phase angle and the estimated amplitude using the arctan function, and the method using the synchronous coordinate system. 10 and 11 show the phase estimation means 200 according to each method.

)은 다음의 공식에 의해 계산할 수 있다.Referring to FIG. 10, phase estimation means using an arctan function is described as follows. First command phase angle (

) Can be calculated by the following formula.

)는 상기의 arctan 함수에 의해 계산된 지령 위상각(

)과 피드 백 입력되는 추정 위상각(

)의 차이를 비례적분(PI) 제어하여

를 만들어 내어 이 결과에 각 주파수 설정치(

)를 더하는 방법으로 구할 수 있다. 이때 시스템의 각주파수 초기 설정치(

)는 계통 전압의 각 주파수로 설정한다.Estimated angular frequency (

) Is the command phase angle calculated by the arctan function

) And the estimated phase angle (feedback input)

Control the difference between

To produce the frequency setpoint for each frequency setpoint (

Can be obtained by adding At this time, the initial setting value of each frequency

) Is set to each frequency of the grid voltage.

)은 이미 계산된 추정 각주파수(

)를 적분하는 방법으로 구할 수 있다.Estimated phase angle (

) Is the estimated angular frequency (

Can be obtained by integrating

)은 아래의 식에 의해 구할 수 있다.Estimated amplitude (

) Can be obtained by the following equation.

)에 대한 제 1 출력전압(

)의 비의 arctan 값을 통해 지령 위상각(

)을 계산하여(214) 지령 위상각(

)과 추정 각주파수(

)의 차(215)를 비례적분 제어한 값(216)에 각주파수 설정치(

)를 가산하여(217) 추정 각주파수(

)를 출력하는 추정 각주파수 발생부(214,215,216,217), 추정 각주파수 발생부(214,215,216,217)로부터의 추정 각주파수(

)를 적분하여(218) 추정 위상각(

)을 출력하는 추정 위상각 발생부(218) 및 제 1 출력전압(

)의 제곱값과 제 2 출력전압(

)의 제곱값을 가산한 결과의 제곱근을 계산하여 추정 진폭(

)을 출력하는 추정 진폭 발생부(210)를 포함하여 구성하도록 한다.Therefore, the implementation method of the phase estimating means 200 using the arctan function is as follows. The phase estimating means 100 has a second output voltage (

Output voltage for

The command phase angle (

) And (214) the command phase angle (

) And estimated angular frequency (

The angular frequency set value (

) By adding (217) the estimated angular frequency (

Estimated angular frequencies (214, 215, 216, 217) and estimated angular frequencies (214, 215, 216, 217)

) By integrating (218) the estimated phase angle (

) And an estimated phase angle generator 218 and a first output voltage

Squared value and the second output voltage (

Calculate the square root of the result of adding the squared values of

) Is configured to include an estimated amplitude generator 210 for outputting.

) 및 제 2 출력전 압(

)을 동기 좌표계로 변환하면 다음의 식과 같다.Referring to FIG. 11, the phase detection means 200 using the synchronous coordinate system will be described. A first output voltage input to the phase detecting means 200 (

) And second output voltage (

) Is converted into the synchronous coordinate system.

,

식을 대입하여 정리하면 다음의 식과 같다.On this result

,

Substituting the equation gives the following equation.

)의 오차가 작다면 다음의 식과 같이 근사화 할 수 있다.In this case, the estimated phase angle with respect to the actual phase angle (

If the error of) is small, it can be approximated by the following equation.

는 단상 입력전압(

)의 추정 진폭(

)을 나타내고,

는 추정 위상오 차를 표현한다.

에 추정 진폭(

)을 나누어 추정오차를 구한 다음 비례적분(PI) 제어하여

를 출력하고 주파수 설정치(

)를 더하는 방법으로 추정 각주파수(

)를 구할 수 있다. 추정 위상각(

)은 상기의 추정 각주파수(

)를 적분하는 방법으로 구할 수 있다. 추정 진폭(

)은

를 통해 구할 수 있다.

Is the single-phase input voltage (

Estimated amplitude of

),

Represents the estimated phase error.

Estimated amplitude in

) To obtain the estimated error, then control the proportional integral (PI)

Output and the frequency setpoint (

Add the estimated angular frequency (

) Can be obtained. Estimated phase angle (

) Is the estimated angular frequency (

Can be obtained by integrating Estimated amplitude (

)silver

Available through

)과 제 2 출력전압(

)을 동기 좌표계로 변환하여 추정 진폭(

) 및 추정 위상오차를 계산하는 동기 좌표계 변환부(220), 추정 위상오차를 추정 진폭(

)으로 나누어(223) 이를 비례적분 제어(224)한 값에 설정된 각주파수()를 가산하여(225) 추정 각주파수(

)를 출력하는 추정 각주파수 출력부(223,224,225), 및 추정 각주파수 발생부(223,224,225)로부터의 추정 각주파수(

)를 적분하여(226) 추정 위상각(

)을 출력하는 추정 위상각 발생부(226)를 포함하여 구성하도록 한다.Therefore, the implementation method of the phase estimating means 200 using the synchronous coordinate system is as follows. The phase estimating means 200 uses a first output voltage (

) And the second output voltage (

) Into a synchronous coordinate system,

) And the synchronous coordinate system conversion unit 220 that calculates the estimated phase error, and estimates the estimated phase error

Dividing by (223) and adding the angular frequency () to the value obtained by proportional integral control (224) (225) to estimate the estimated angular frequency (

Estimated angular frequency outputs 223, 224, 225 for outputting the estimated angular frequency (223, 224, 225)

) By integrating (226) the estimated phase angle (

) Is configured to include an estimated phase angle generator 226 for outputting.

)의 크기는 아래의 식과 같다.12 illustrates a system voltage phase detection device using a virtual two-phase according to the present invention implemented in an actual system. In actual implementation, it is preferable to insert the low pass filter 300 in front of the virtual two-phase voltage generating means 100 as shown in order to remove noise of the single phase input voltage. At this time, the gain compensating means 310 is interposed between the low pass filter 300 and the virtual two-phase voltage generating means to perform the function of compensating (K) the attenuation of the amplitude by the low pass filter 300, phase compensation means Is installed at the rear end of the phase estimating means 200 to compensate for the phase delay caused by the low pass filter 300. Gain (K) and compensation phase for compensating attenuation and phase delay by the low pass filter 300 (

) Is the same as

The following ten embodiments can be configured by combining the virtual two-phase voltage generation means by the five methods described above and the phase estimation means by the two methods.

             Division method 2-phase voltage generator Phase estimator     First embodiment How to use a memory table How to use arctan     Second embodiment How to use estimated phase angle and estimated amplitude How to use arctan     Third embodiment How to use a second order filter How to use arctan     Fourth embodiment How to use the primary filter How to use arctan     Fifth Embodiment How to use global filters How to use arctan     Sixth embodiment How to use a memory table How to use synchronous coordinate system     Seventh embodiment How to use estimated phase angle and estimated amplitude How to use synchronous coordinate system     Eighth embodiment How to use a second order filter How to use synchronous coordinate system     9th embodiment How to use the primary filter How to use synchronous coordinate system     10th embodiment  How to use the global filter How to use synchronous coordinate system

)과 추정 위상각(

)을 이용하여 다음과 같이 구하였다.13 to 16 show the actual experimental results for the initial estimation characteristics, the steady state estimation characteristics, the voltage drop estimation characteristics, and the estimation characteristics during the harmonic injection for the ten embodiments. The input voltages used in the experiments were 220 Vms and 60 Hz, and noise (30 Vpeak 1kHz) was injected to verify the robustness against noise during the initial estimation characteristics, steady state estimation characteristics, and voltage drop estimation characteristics. The phase estimation means was operated when the actual phase was π. In harmonic injection, 3 harmonics and 5 harmonics were injected, respectively. The estimated input power is estimated amplitude (

) And estimated phase angle (

) Was obtained as follows.

(1) Initial Estimation Characteristics

)과 추정입력전원(

)을, 두 번째 파형은 추정입력주파수(

)를, 세 번째 파형은 추정진폭(

)을 각각 나타낸다. 도 13b 및 도 13g에 도시된 바와 같이 추정 위상각과 추정 진폭을 이용한 가상 2상 전압발생 수단을 사용하는 경우에는 초기에는 정확한 추정 위상을 얻을 수 없기 때문에 입력전압과 위상차이가 90°인 제 2 출력전압을 얻는 과정에서 상당한 진동이 발생하는 것을 확인할 수 있다. 아래의 표는 제 1 실시예 내지 제 10 실시예의 추정속도를 표시한다. 추정속도는 제어기가 동작한 시점부터 주파수 측정값이 60±0.5Hz 이내에 도달하는데 소요되는 시간으로 정한다. 제 2 실시예와 제 7 실시예의 경우에는 추정 시간이 약 325ms 와 275ms 로 느린 특성을 보이는 반면 나머지 실시예의 경우는 약 110ms 내지 140ms 로 우수한 특성을 가짐을 확인할 수 있다.13A-13J illustrate initial estimation characteristics in accordance with each embodiment. The first waveform of each graph is the input power (

) And estimated input power (

) And the second waveform is the estimated input frequency (

), And the third waveform is estimated amplitude (

) Respectively. As shown in FIGS. 13B and 13G, when the virtual two-phase voltage generator using the estimated phase angle and the estimated amplitude is used, an accurate estimated phase cannot be obtained initially, so that the second output having a phase difference of 90 ° is obtained. It can be seen that significant vibration occurs in the process of obtaining voltage. The table below shows the estimated speeds of the first to tenth embodiments. The estimated speed is determined by the time it takes for the frequency measurement to reach within 60 ± 0.5 Hz from the time the controller is operated. In the case of the second embodiment and the seventh embodiment, the estimated time is slow at about 325 ms and 275 ms, whereas the remaining embodiments have excellent characteristics at about 110 ms to 140 ms.

division Estimated speed (ms) First embodiment 120 Second embodiment 325 Third embodiment 140 Fourth embodiment 130 Fifth Embodiment 130 Sixth embodiment 120 Seventh embodiment 275 Eighth embodiment 120 9th embodiment 110 10th embodiment 120

(2) steady-state estimated characteristics

)을, 두 번째 파형은 추정입력전원(

)을, 세 번째 파형은 추정입력주파수(

)를, 네 번째 파형은 추정진폭(

)을 각각 나타낸다. 정상상태에 서도 노이즈가 있는 경우에도 추정 입력전원이 실제 입력전원을 잘 추정하며 주파수도 60Hz로 정확하게 추정함을 확인할 수 있다. 한편 실험결과 나머지 실시예의 경우도 도 14와 유사한 파형을 나타낸다.FIG. 14 illustrates a case in which noise is included in the input power supply in the eighth embodiment (the embodiment using the secondary filter and the synchronous coordinate system as the virtual two-phase voltage generating means and the phase estimating means, respectively) which showed excellent results in the initial estimation characteristics. The estimated characteristic is shown. The first waveform on the graph is the input power (

), And the second waveform is estimated input power (

), And the third waveform is the estimated input frequency (

), And the fourth waveform is estimated amplitude (

) Respectively. Even in the presence of noise, it can be seen that the estimated input power accurately estimates the actual input power and accurately estimates the frequency to 60Hz. Experimental results show waveforms similar to those of FIG. 14.

(3) Estimation characteristics under voltage drop

)과 추정입력전원(

)을, 두 번째 파형은 추정입력주파수(

)를, 세 번째 파형은 추정진폭(

)을 각각 나타낸다. 아래의 표는 전압강하시의 각 실시예에 따른 추정특성을 표시한다. 제 2 실시예와 제 7 실시예의 경우 추정속도가 다소 느린 반면 나머지 실시예의 경우는 우수한 추정속도를 나타내는 것을 확인할 수 있다.FIG. 15 shows estimation characteristics of the eighth embodiment when the input voltage drops by 50%, and similar results for the remaining embodiments. The first waveform on the graph is the input power (

) And estimated input power (

) And the second waveform is the estimated input frequency (

), And the third waveform is estimated amplitude (

) Respectively. The table below shows estimated characteristics according to each embodiment under voltage drop. In the second and seventh exemplary embodiments, the estimation speed is slightly slower, whereas in the other exemplary embodiments, the estimation speed is excellent.

division Estimated speed (ms) First embodiment 125 Second embodiment 250 Third embodiment 120 Fourth embodiment 130 Fifth Embodiment 140 Sixth embodiment 115 Seventh embodiment 225 Eighth embodiment 100 9th embodiment 130 10th embodiment 130

(4) Estimation Characteristics at High Frequency Injection

)을, 두 번째 파형은 추정입력전원(

)을, 세 번째 파형은 추정입력주파수(

)를, 네 번째 파형은 추정진폭(

)을 각각 나타낸다. 아래의 표는 고조파 주입시의 각 실시예의 추정속도를 나타낸다. 다른 결과와 동일하게 추정 위상각과 추정 진폭을 이용한 방식인 제 2 실시예와 제 7 실시예의 경우는 추정속도가 다소 늦지만 나머지 실시예의 경우 모두 우수한 특성을 나타내는 것을 확인할 수 있다.16 and 17 show estimation characteristics at the time of injecting three harmonics (30 Vpeak) and five harmonics (30 V peak) in the eighth embodiment, respectively. The first waveform of each graph is the input power (

), And the second waveform is estimated input power (

), And the third waveform is the estimated input frequency (

), And the fourth waveform is estimated amplitude (

) Respectively. The table below shows the estimated speed of each embodiment at the time of harmonic injection. As in the other results, the second and seventh exemplary embodiments using the estimated phase angle and the estimated amplitude are slightly slower in estimating speed, but the other examples show excellent characteristics.

division Estimated speed (ms) First embodiment 140 Second embodiment 330 Third embodiment 145 Fourth embodiment 140 Fifth Embodiment 145 Sixth embodiment 135 Seventh embodiment 300 Eighth embodiment 130 9th embodiment 135 10th embodiment 133

As described above, according to the system voltage phase detection device using the virtual two-phase according to the present invention, regardless of whether the input power reaches zero, the phase of the input power can be detected instantaneously to synchronize the phase of the system voltage. Since the time required for phase estimation is shortened, and errors due to zero disturbance due to noise, voltage drop, and harmonic injection do not occur, it provides a remarkable effect having robustness against noise and disturbance.

In addition, preferred embodiments of the present invention are disclosed for the purpose of illustration, those skilled in the art will be able to make various modifications, changes, additions, etc. within the spirit and scope of the present invention, such modifications and modifications belong to the scope of the claims You will have to look.

Claims (9)

A first output voltage generator and the single phase input which receive a single phase input voltage from an AC power source and feedback an estimated phase from a phase estimating means to generate a first output voltage having the same amplitude, phase, and angular frequency as the single phase input voltage. A virtual two-phase voltage generator comprising a second output voltage generator for generating a second output voltage having the same voltage, amplitude, and angular frequency and having a phase difference of? / 2 with the single-phase input voltage; And And a phase estimating means for receiving the first output voltage and the second output voltage from the virtual two-phase voltage generating means and calculating and outputting the estimated phase. . The method of claim 1, The grid voltage phase detection device using the virtual two-phase, A low pass filter disposed between the single phase input voltage and the virtual two phase voltage generating means to remove noise of the single phase input voltage; Gain compensation means for compensating for amplitude reduction in said low pass filter to input an input voltage to said virtual two-phase voltage generating means; The phase estimation means, And a phase compensating means for adding a compensation phase for compensating for the phase delay generated in the low pass filter to the calculated phase. The method according to claim 1 or 2, The phase estimating means further calculates an estimated angular frequency and further feedbacks the input to the virtual two-phase voltage generating means; The first output voltage generator includes a bypass unit configured to bypass the single-phase input voltage to generate a first output voltage; The second output voltage generation unit stores the single-phase input voltage for each specific sampling period, receives the estimated angular frequency input from the phase estimating means, and outputs the single-phase input voltage before a quarter cycle of the single-phase input voltage. And a first multiplier for multiplying the output from the memory by -1 to generate a second output voltage. The method according to claim 1 or 2, The phase estimating means further calculates an estimated amplitude to further feed back the virtual two-phase voltage generating means; The first output voltage generator includes a bypass unit configured to bypass the single-phase input voltage to generate a first output voltage; The second output voltage generator generates a sine wave signal having a phase difference of π with the single phase input voltage using the estimated phase, and multiplies the estimated amplitude by an output of the sinusoidal wave generator to multiply the estimated amplitude by a second. System voltage phase detection apparatus using a virtual two-phase, characterized in that it comprises a second multiplier for generating an output voltage. The method according to claim 1 or 2, The phase estimating means further calculates an estimated angular frequency and further feedbacks the input to the virtual two-phase voltage generating means; The first output voltage generator includes a bypass unit configured to bypass the single-phase input voltage to generate a first output voltage; The second output voltage generation unit includes a second low pass filter for filtering and outputting the single phase input voltage having an intrinsic angular frequency and an estimated angular frequency, and an attenuation ratio of the second low pass filter to an output of the second low pass filter. And a third multiplier for generating a second output voltage by correcting the system voltage phase detection device using the virtual two-phase. The method according to claim 1 or 2 The phase estimating means further calculates an estimated angular frequency and further feedbacks the input to the virtual two-phase voltage generating means; The first output voltage generator includes a bypass unit configured to bypass the single-phase input voltage to generate a first output voltage; The second output voltage generator is configured to multiply -2 by an output of the first low pass filter and the first low pass filter by filtering the single phase input voltage and outputting the second output voltage by filtering the single phase input voltage. And a first multiplier configured to add a single-phase input voltage to the output of the fourth multiplier. The method according to claim 1 or 2 The phase estimating means further calculates an estimated angular frequency and further feedbacks the input to the virtual two-phase voltage generating means; The first output voltage generator includes a bypass unit configured to bypass the single-phase input voltage to generate a first output voltage; The second output voltage generation unit includes a second all-pass filter for filtering the single-phase input voltage and outputting the second full-pass filter at the output of the second full-pass filter by filtering the single-phase input voltage. And a fifth multiplier for correcting the attenuation ratio to generate a second output voltage. The method of claim 1 or 2, wherein the phase estimation means, Calculate a command phase value using an arctan value of the ratio of the first output voltage to the second output voltage, and add an angular frequency set to a value obtained by proportionally integral control of the difference between the command phase value and the estimated phase angle. An estimated angular frequency generator for outputting a frequency; An estimated phase angle generator for integrating an estimated angular frequency from the estimated angular frequency generator and outputting the estimated phase angle; And An estimated amplitude generator configured to calculate a square root of a result of adding the square value of the first output voltage and the square value of the second output voltage to output an estimated amplitude; Grid voltage phase detection device. The method of claim 1 or 2, wherein the phase estimation means, A synchronous coordinate system converter configured to calculate an estimated amplitude and an estimated phase error by converting the first output voltage and the second output voltage into a synchronous coordinate system; An estimated angular frequency generator for dividing the estimated phase error by the estimated amplitude and adding an angular frequency set to a value obtained by proportional integral control to output an estimated angular frequency; And an estimated phase angle generator for integrating the estimated angular frequencies from the estimated angular frequency generator and outputting the estimated phase angle.

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