KR102176532B1 - Controller, controlling method, and recording medium for grid synchronization - Google Patents

Abstract

The present invention relates to a control device, a control method, and a recording medium for system synchronization control. The method includes the following steps of: obtaining a first voltage which is a measurement value of a first time and a second voltage which is a measurement value of a second time, which is just prior to the first time, by measuring voltages at every predetermined time; obtaining first and second voltage vectors by extracting d-q components from the first and second voltages; obtaining a differential phase angle of the first time based on the first voltage vector and the second voltage vector; obtaining an estimated frequency () of the second time; and obtaining an estimated frequency of the first time based on the differential phase angle of the first time and the estimated frequency of the second time.

Description

Control device, control method, and recording medium for system synchronization control {CONTROLLER, CONTROLLING METHOD, AND RECORDING MEDIUM FOR GRID SYNCHRONIZATION}

The present disclosure relates to a control device, a control method, and a recording medium for system synchronization control, and more particularly, to a control device, a control method, and a recording medium for estimating a target frequency to synchronize the frequency of the system.

As the connection of new and renewable energy sources in the power system increases, uncertainty in terms of system stability is increasing, and thus the need for active management of power processed by individual power generation sources and loads is increasing. For such management, it is necessary to supplement the frequency of the system in real time in various system linkage devices to perform a predetermined response according to the degree of change.

In addition, in order for individual power sources or loads connected to the power system to perform a specific response according to system changes, a system synchronization method that estimates the frequency or phase angle from the voltage of the system must be provided. However, the actual grid voltage is not a repetition of an ideal sine wave with a constant size and frequency due to distortion, so the implementation of the grid synchronization method is not simple. Therefore, there is a need for a method capable of achieving continuous grid synchronization even for a grid voltage with some distortion.

)를 획득하는 단계, 제 1 시간의 차분 위상각 및 제 2 시간의 예상 주파수에 기초하여 제 1 시간의 예상 주파수를 획득하는 단계를 포함하는 것을 특징으로 한다.The method for estimating the target frequency according to the present disclosure is for synchronizing the frequency of voltages shared by devices included in the system, and measures the voltage at each predetermined time to measure the first voltage and the first voltage at the first time. Obtaining a second voltage that is a measurement value of a second time that is a time immediately before time, extracting dq components from the first voltage and the second voltage to obtain a first voltage vector and a second voltage vector, a first Obtaining a differential phase angle of the first time based on the voltage vector and the second voltage vector, the expected frequency of the second time (

) Obtaining, obtaining an expected frequency of the first time based on the differential phase angle of the first time and the expected frequency of the second time.

In the method of estimating a target frequency according to the present disclosure, the step of obtaining the differential phase angle of the first time may include obtaining an angle formed by the first voltage vector and the second voltage vector in the dq plane as the differential phase angle of the first time. It characterized in that it comprises a step.

을 획득하는 단계는, 제 1 전압 벡터 및 제 2 전압 벡터의 내적 또는 외적 중 하나에 기초하여 제 1 차분 위상각(

을 획득하는 단계 및 제 1 차분 위상각(

을 제 1 시간의 차분 위상각(

으로 결정하는 단계를 포함하는 것을 특징으로 한다.The differential phase angle of the first time in the method of estimating the target frequency according to the present disclosure (

The step of obtaining is, based on one of the inner product or the outer product of the first voltage vector and the second voltage vector, the first difference phase angle (

And the first difference phase angle (

The difference phase angle of the first time (

It characterized in that it comprises the step of determining.

을 획득하는 단계는, 위상각 보상 함수에 기초하여 제 1 차분 위상각(

을 보상하여 제 2 차분 위상각(

을 획득하는 단계 및 제 2 차분 위상각(

을 제 1 시간의 차분 위상각(

으로 결정하는 단계를 포함하는 것을 특징으로 한다.The differential phase angle of the first time in the method of estimating the target frequency according to the present disclosure (

The step of obtaining is, based on the phase angle compensation function, the first difference phase angle (

By compensating for the second differential phase angle (

And the second differential phase angle (

The difference phase angle of the first time (

It characterized in that it comprises the step of determining.

을 획득하는 단계는, 제 2 시간의 제 2 차분 위상각(

)을 획득하는 단계; 제 1 시간의 제 2 차분 위상각(

)을 제 2 시간의 제 2 차분 위상각(

)에 기초하여 보정하는 단계; 및 보정된 제 2 차분 위상각(

을 제 1 시간의 차분 위상각(

으로 결정하는 단계를 포함하는 것을 특징으로 한다.The differential phase angle of the first time in the method of estimating the target frequency according to the present disclosure (

The step of obtaining is the second differential phase angle of the second time (

Obtaining ); The second differential phase angle of the first time (

) To the second differential phase angle of the second time (

) Correcting based on; And the corrected second differential phase angle (

The difference phase angle of the first time (

It characterized in that it comprises the step of determining.

)를 획득하는 단계, 제 1 시간의 차분 위상각 및 제 2 시간의 예상 주파수에 기초하여 제 1 시간의 예상 주파수를 획득하는 단계를 수행하는 것을 특징으로 한다.The apparatus for estimating a target frequency according to the present disclosure is for synchronizing frequencies of voltages shared by devices included in the system, and the apparatus for estimating the frequency includes a processor and a memory, and the processor is based on instructions stored in the memory. Thus, measuring the voltage at each predetermined time to obtain a first voltage that is a measured value of the first time and a second voltage that is a measured value of a second time that is a time immediately before the first time, the first voltage and the second voltage Extracting the dq component from, obtaining a first voltage vector and a second voltage vector, obtaining a differential phase angle of the first time based on the first voltage vector and the second voltage vector, and predicting the second time frequency(

), obtaining an expected frequency of the first time based on the differential phase angle of the first time and the expected frequency of the second time.

The processor of the apparatus for estimating the target frequency according to the present disclosure performs the step of acquiring the angle formed by the first voltage vector and the second voltage vector in the dq plane as a difference phase angle of a first time based on an instruction stored in a memory. Characterized in that.

을 획득하는 단계, 및 제 1 차분 위상각(

을 제 1 시간의 차분 위상각(

으로 결정하는 단계를 수행하는 것을 특징으로 한다.The processor of the apparatus for estimating a target frequency according to the present disclosure includes a first differential phase angle (1st difference phase angle) based on one of the inner product or the outer product of the first voltage vector and the second voltage vector, based on an instruction stored in a memory.

Obtaining, and a first differential phase angle (

The difference phase angle of the first time (

It characterized in that performing the step of determining.

을 보상하여 제 2 차분 위상각(

을 획득하는 단계 및 제 2 차분 위상각(

을 제 1 시간의 차분 위상각(

으로 결정하는 단계를 수행하는 것을 특징으로 한다.The processor of the apparatus for estimating the target frequency according to the present disclosure includes a first differential phase angle (

By compensating for the second differential phase angle (

And the second differential phase angle (

The difference phase angle of the first time (

It characterized in that performing the step of determining.

)을 획득하는 단계, 제 1 시간의 제 2 차분 위상각(

)을 제 2 시간의 제 2 차분 위상각(

)에 기초하여 보정하는 단계 및 보정된 제 2 차분 위상각(

을 상기 제 1 시간의 차분 위상각(

으로 결정하는 단계를 수행하는 것을 특징으로 한다.The processor of the apparatus for estimating the target frequency according to the present disclosure is based on the instruction stored in the memory, the second differential phase angle of the second time (

), the second differential phase angle of the first time (

) To the second differential phase angle of the second time (

) Based on the correction and the corrected second differential phase angle (

The difference phase angle of the first time (

It characterized in that performing the step of determining.

In addition, a program for implementing the method for estimating the target frequency as described above may be recorded on a computer-readable recording medium.

1 shows a change pattern of an actual three-phase system (system) voltage.
2 is a diagram illustrating a frequency estimation apparatus according to an embodiment of the present disclosure.
3 is a block diagram of an apparatus for synchronizing a grid voltage according to an embodiment of the present disclosure.
4 is a flowchart illustrating an operation of a frequency estimation apparatus according to an embodiment of the present disclosure.
5 is a block diagram illustrating a frequency estimation apparatus according to an embodiment of the present disclosure.
6 is a diagram for explaining dq coordinates of the present disclosure.
7 is a block diagram illustrating a frequency estimation according to an embodiment of the present disclosure.
8 is a graph showing a frequency estimation result according to an embodiment of the present disclosure.
9 is a diagram illustrating backward, forward, and trapezoid according to an embodiment of the present disclosure.

Advantages and features of the disclosed embodiments, and a method of achieving them will become apparent with reference to the embodiments described below together with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below, but may be implemented in a variety of different forms, and only these embodiments make the present disclosure complete, and those skilled in the art to which the present disclosure pertains. It is only provided to inform the person of the scope of the invention completely.

The terms used in the present specification will be briefly described, and the disclosed embodiments will be described in detail.

The terms used in the present specification have selected general terms that are currently widely used as possible while considering functions in the present disclosure, but this may vary according to the intention or precedent of a technician engaged in a related field, the emergence of new technologies, and the like. In addition, in certain cases, there are terms arbitrarily selected by the applicant, and in this case, the meaning of the terms will be described in detail in the description of the corresponding invention. Therefore, the terms used in the present disclosure should be defined based on the meaning of the term and the contents of the present disclosure, not the name of a simple term.

In this specification, expressions in the singular include plural expressions, unless the context clearly specifies that they are singular. In addition, plural expressions include expressions in the singular unless explicitly specified as plural in context.

When a part of the specification is said to "include" a certain component, it means that other components may be further included rather than excluding other components unless otherwise stated.

In addition, the term "unit" used in the specification refers to a software or hardware component, and "unit" performs certain roles. However, "unit" is not meant to be limited to software or hardware. The “unit” may be configured to be in an addressable storage medium or may be configured to reproduce one or more processors. Thus, as an example, "unit" refers to components such as software components, object-oriented software components, class components, and task components, processes, functions, properties, procedures, Includes subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, database, data structures, tables, arrays and variables. The functions provided within the components and "units" may be combined into a smaller number of components and "units" or may be further separated into additional components and "units".

According to an embodiment of the present disclosure, the "unit" may be implemented with a processor and a memory. The term “processor” is to be interpreted broadly to include general purpose processors, central processing units (CPUs), microprocessors, digital signal processors (DSPs), controllers, microcontrollers, state machines, and the like. In some circumstances, “processor” may refer to an application specific application (ASIC), programmable logic device (PLD), field programmable gate array (FPGA), and the like. The term “processor” refers to a combination of processing devices, such as, for example, a combination of a DSP and a microprocessor, a combination of a plurality of microprocessors, a combination of one or more microprocessors in combination with a DSP core, or any other such configuration. You can also refer to it.

The term "memory" should be interpreted broadly to include any electronic component capable of storing electronic information. The term memory refers to random access memory (RAM), read-only memory (ROM), non-volatile random access memory (NVRAM), programmable read-only memory (PROM), erase-programmable read-only memory (EPROM), electrical May refer to various types of processor-readable media such as erasable PROM (EEPROM), flash memory, magnetic or optical data storage, registers, and the like. The memory is said to be in electronic communication with the processor if it can read information from and/or write information to the memory. The memory integrated in the processor is in electronic communication with the processor.

Hereinafter, embodiments will be described in detail with reference to the accompanying drawings so that those of ordinary skill in the art may easily implement the embodiments. In addition, in the drawings, parts not related to the description are omitted in order to clearly describe the present disclosure.

1 shows a change pattern of an actual three-phase system (system) voltage.

1 may represent Va, Vb, and Vc displayed in the abc coordinate system. In the abc coordinate system, the horizontal axis represents time, and the vertical axis represents voltage values. The phase difference between Va, Vb, and Vc in the abc coordinate system may be estimated based on the fact that Va, Vb, and Vc have different voltage values at the same time. In addition, the difference in frequency in the abc coordinate system can be estimated based on the period of voltage values of Va, Vb, and Vc.

Referring to FIG. 1, like waveforms Va, Vb, and Vc after T1, an accident may occur in which the magnitude and frequency of the actual grid voltage do not form an ideal sine wave. In the case of having a system (system) voltage having a distorted sine wave such as Va, Vb, and Vc of FIG. 1, there is a problem in that the devices included in the system cannot operate organically because devices connected to the system cannot easily synchronize.

Various solutions have been proposed to solve this problem and will be described below.

2 is a diagram illustrating a frequency estimation apparatus according to an embodiment of the present disclosure.

The frequency estimation apparatus 100 may include a processor 210 and a memory 220. The processor 210 may execute instructions stored in the memory 220. The frequency estimation apparatus 100 may estimate a target frequency in order to synchronize the frequency of the system based on a command stored in the memory 220. In addition, the frequency estimating device 100 may synchronize voltages of devices included in the system by estimating a target frequency.

Hereinafter, the operation of the frequency estimation apparatus 100 will be described in more detail below.

3 is a block diagram of an apparatus for synchronizing a grid voltage according to an embodiment of the present disclosure.

3 shows a method of synchronizing the grid voltage by a phase-locked loop (PLL).

The frequency estimation apparatus 100 may include a d-q domain change unit 310. In order for the frequency estimating apparatus 100 to convert the single-phase or three-phase system voltage Vabc from the abc coordinate system to the synchronous coordinate system, the estimated phase angle may be substituted for a sine and a cosine function. The grid voltage Vabc according to the abc coordinate system may be the same as the three-phase voltage shown in FIG. 1. The frequency estimating apparatus 100 may convert the abc coordinate system into a stationary coordinate system using Equation (1). In addition, the frequency estimation apparatus 100 may convert the stationary coordinate system into a synchronous coordinate system using Equation (2).

...식 (1)

...Equation (1)

... 식 (2)

... equation (2)

The output of the d-q domain change unit 310 of the frequency estimation apparatus 100 may be a voltage vector including a voltage value Vd of the d-axis and a voltage value Vq of the q-axis.

로 나타낼 수 있다. The frequency estimation apparatus 100 may include a differential phase estimation unit 320. The frequency estimating apparatus 100 may estimate a differential phase according to time of the phase system voltage Vabc from the voltage vector using the differential phase estimating unit 320. The frequency estimating apparatus 100 may estimate a differential phase of the phase system voltage Vabc over time by taking an arc tangent to a voltage vector that is a phase system voltage converted to the dq domain. 3, the estimated value of the differential phase angle is

It can be expressed as

)은 주파수 추정 장치(100)에 포함된 제 1 증폭부(330) 및 제 2 증폭부(340)에 입력될 수 있다. 주파수 추정 장치(100)는 제 1 적분부(350)를 이용하여 제 2 증폭부(340)에 의하여 증폭된 차분 위상을 시간에 대하여 적분할 수 있다. 또한 주파수 추정 장치(100)는 제 1 증폭부(330)의 출력 및 제 1 적분부(350)에 의한 출력을 더하여 추정된 주파수(

)를 획득할 수 있다. 주파수 추정 장치(100)는 추정된 주파수(

)를 출력할 수 있다.Estimated differential phase (

) May be input to the first amplifying unit 330 and the second amplifying unit 340 included in the frequency estimation apparatus 100. The frequency estimation apparatus 100 may integrate the difference phase amplified by the second amplifying unit 340 with respect to time using the first integrating unit 350. In addition, the frequency estimating apparatus 100 adds the output of the first amplifying unit 330 and the output of the first integrating unit 350 to add the estimated frequency (

) Can be obtained. The frequency estimation device 100 is the estimated frequency (

) Can be printed.

)를 적분하여 추정된 위상(

)을 획득할 수 있다. 주파수 추정 장치(100)는 추정된 위상(

)을 출력할 수 있다.The frequency estimation apparatus 100 may further include a second integrating unit 370. The frequency estimating device 100 uses the second integrating unit 370 to determine the estimated frequency (

) And the estimated phase (

) Can be obtained. The frequency estimation device 100 is the estimated phase (

) Can be printed.

) 및 위상(

)을 모두 추정할 수 있는 효과가 있다. The frequency estimating apparatus 100 according to FIG. 3 is a frequency (

) And phase (

) Has the effect of estimating all.

4 is a flowchart illustrating an operation of a frequency estimation apparatus according to an embodiment of the present disclosure. 5 is a block diagram illustrating a frequency estimation apparatus according to an embodiment of the present disclosure. 6 is a diagram for describing d-q coordinates of the present disclosure.

The frequency estimating apparatus 100 measures a voltage at every predetermined time to obtain a first voltage that is a measured value of a first time and a second voltage that is a measured value of a second time that is just before the first time (410) You can do it. The first voltage and the second voltage may be voltage values of the first time and the second time in the abc coordinate system.

The frequency estimating apparatus 100 may measure a first voltage that is a measured value of a first time. The first voltage may be the voltage most recently measured by the frequency estimation apparatus 100. The frequency estimating apparatus 100 may pre-store the second voltage measured at a second time, which is a time immediately before the first time, in a memory. The frequency estimation apparatus 100 may obtain the second voltage measured at the second time from the memory.

)마다 계통 전압(Vg)을 측정할 수있다. 미리 정해진 주기를 샘플 주기라고 할 수 있다. 주파수 추정 장치(100)는 미리 정해진 주기(

)를 메모리에 저장하고 있을 수 있다. 또한 주파수 추정 장치(100)는 미리 정해진 주기(

)를 메모리로부터 획득할 수 있다. 계통 전압은 단상 또는 3상일 수 있다. 제 1 시간은 제 2 시간으로부터 한 샘플 주기(

)가 지난 후를 나타낼 수 있다.The frequency estimating device 100 has a predetermined period (

), the grid voltage (Vg) can be measured. The predetermined period may be referred to as a sample period. The frequency estimating device 100 has a predetermined period (

) May be stored in memory. In addition, the frequency estimating device 100 has a predetermined period (

) Can be obtained from memory. The grid voltage can be single-phase or three-phase. The first time is one sample period from the second time (

) Can indicate after passing.

The frequency estimation apparatus 100 may include a d-q extraction unit 510. The d-q extraction unit 510 may perform step 420 of extracting the d-q component from the first voltage and the second voltage to obtain a first voltage vector and a second voltage vector.

The frequency estimating apparatus 100 may extract the d-q component from the first voltage and the second voltage using at least one of Equation (1) or Equation (2). In addition, the frequency estimating apparatus 100 may obtain a first voltage vector based on the d-q component extracted from the first voltage. Also, the frequency estimation apparatus 100 may obtain a second voltage vector based on the d-q component extracted from the second voltage.

The first voltage is the most recently measured voltage value, and the frequency estimation apparatus 100 may obtain a first voltage vector by extracting the d-q component from the first voltage. In addition, the frequency estimating apparatus 100 may measure the second voltage at a second time, which is a time immediately before the first time, and store it in a memory. Also, the frequency estimating apparatus 100 may obtain a second voltage vector based on the second voltage and store the second voltage vector in the memory in advance. The frequency estimation apparatus 100 may obtain the second voltage vector from the memory.

와 같을 수 있다. 또한 d-q 평면에서 제 2 전압 벡터는

와 같을 수 있다. 여기서 k는 자연수이다. k는 k-1으로부터 하나의 샘플 주기(

)가 지났음을 의미할 수 있다.6, the horizontal axis of the graph represents the voltage value of the d-axis. In addition, the vertical axis of the graph represents the voltage value of the q-axis. The first voltage vector in the dq plane is

Can be the same as Also in the dq plane the second voltage vector is

Can be the same as Where k is a natural number. k is one sample period from k-1 (

) May mean past.

)의 d축 값은 Vd[k]일 수 있다. 또한 제 1 전압 벡터(

)의 q 축 값은 Vq[k]일 수 있다. 제 2 전압 벡터(

)의 d축 값은 Vd[k-1]일 수 있다. 또한 제 2 전압 벡터(

)의 q 축 값은 Vq[k-1]일 수 있다.First voltage vector (

The d-axis value of) may be Vd[k]. Also the first voltage vector (

The q-axis value of) may be Vq[k]. The second voltage vector (

The d-axis value of) may be Vd[k-1]. Also the second voltage vector (

The q-axis value of) may be Vq[k-1].

Referring back to FIG. 5, the frequency estimation apparatus 100 may include a differential phase angle estimation unit 520. The differential phase angle estimator 520 of the frequency estimating apparatus 100 may perform an operation 430 of obtaining a differential phase angle of a first time based on the first voltage vector and the second voltage vector.

The frequency estimating apparatus 100 may perform an operation of obtaining an angle formed by the first voltage vector and the second voltage vector in the d-q plane as a differential phase angle of a first time.

)의 d축 값은 Vd[k]일 수 있다. 또한 제 1 전압 벡터(

)의 q 축 값은 Vq[k]일 수 있다. 제 1 전압 벡터(

)가 d축과 이루는 각은

일 수 있다. 주파수 추정 장치(100)는 제 1 전압 벡터(

)에 아크탄젠트를 취하여

을 획득할 수 있다. 동일한 방식으로 주파수 추정 장치(100)는 제 2 전압 벡터(

)에 아크탄젠트를 취하여

을 획득할 수 있다. 주파수 추정 장치(100)는

와

의 차분을 제 1 시간의 차분 위상각(

)으로 결정할 수 있다.The frequency estimating apparatus 100 may obtain a difference phase angle of the first time by using the arc tangent. As described above, the first voltage vector (

The d-axis value of) may be Vd[k]. Also the first voltage vector (

The q-axis value of) may be Vq[k]. First voltage vector (

The angle between) and the d-axis is

Can be The frequency estimation device 100 is a first voltage vector (

) By taking the arc tangent

Can be obtained. In the same way, the frequency estimating device 100 is configured to a second voltage vector

) By taking the arc tangent

Can be obtained. The frequency estimation device 100

Wow

The difference of the first time difference phase angle (

) Can be determined.

)을 획득할 수 있다. 주파수 추정 장치(100)는 제 1 차분 위상각(

) 또는 제 2 차분 위상각(

)에 기초하여 제 1 시간의 차분 위상각(

)을 결정할 수 있다.In addition, the frequency estimating apparatus 100 uses the outer product or the inner product of the first voltage vector and the second voltage vector to determine the difference phase angle of the first time (

) Can be obtained. The frequency estimating device 100 includes a first differential phase angle (

) Or the second differential phase angle (

The differential phase angle of the first time based on) (

) Can be determined.

The cross product between the first voltage vector and the second voltage vector is given by Equation (3).

... 식 (3)

... Equation (3)

일 수 있다.When the frequency estimating device 100 shortens the voltage measurement period sufficiently, the change in the phase angle is very small.

Can be

)을 획득하기 위하여 식 (4)에 기초하여 제 1 차분 위상각(

)을 획득하는 단계를 수행할 수 있다. Therefore, the frequency estimating device 100 is the difference phase angle of the first time (

In order to obtain ), based on equation (4), the first difference phase angle (

) Can be performed.

...식 (4)

...Equation (4)

)을 제 1 시간의 차분 위상각(

)으로 결정하는 단계를 수행할 수 있다. 여기서,

는 제 1 전압 벡터의 q축 전압값을 나타내고,

는 제 1 전압 벡터의 d축 전압값을 나타내고,

는 제 2 전압 벡터의 q축 전압값을 나타내고,

는 제 2 전압 벡터의 d축 전압값을 나타내고,

는 제 1 전압 벡터의 크기를 나타내고,

는 제 2 전압 벡터의 크기를 나타낼 수 있다. 또한,

와

는 미리 정해둔 상수 값일 수 있다. 주파수 추정 장치(100)는 메모리로부터

및

를 획득할 수 있다. 또한 주파수 추정 장치(100)는 외부의 장치 또는 사용자의 입력으로부터 유무선으로 메모리로부터

및

를 획득할 수 있다.In addition, the frequency estimating apparatus 100 includes a first differential phase angle (

) To the first time difference phase angle (

) Can be performed. here,

Represents the q-axis voltage value of the first voltage vector,

Represents the d-axis voltage value of the first voltage vector,

Represents the q-axis voltage value of the second voltage vector,

Represents the d-axis voltage value of the second voltage vector,

Represents the magnitude of the first voltage vector,

May represent the magnitude of the second voltage vector. In addition,

Wow

May be a predetermined constant value. Frequency estimation device 100 from the memory

And

Can be obtained. In addition, the frequency estimating device 100 may be configured from the memory via wired or wirelessly from an external device or user input.

And

Can be obtained.

)은 실제 제 1 시간의 차분 위상각(

)과 다소 차이가 있을 수 있으나, 그 차이는 무시할 정도로 작을 수 있다.The first difference phase angle (

) Is the difference phase angle of the actual first time (

), but the difference may be negligibly small.

)을 보상하여 제 2 차분 위상각(

)을 획득하는 단계를 수행할 수 있다. 제 2 차분 위상각(

)은 제 1 차분 위상각(

)보다 제 1 시간의 차분 위상각(

)를 정확하게 추정한 값일 수 있다. 주파수 추정 장치(100)는 제 2 차분 위상각(

)을 제 1 시간의 차분 위상각(

)으로 결정하는 단계를 수행할 수 있다.In addition, the frequency estimating apparatus 100 is based on the phase angle compensation function, the first difference phase angle (

) To compensate for the second differential phase angle (

) Can be performed. The second differential phase angle (

) Is the first difference phase angle (

) Than the first time difference phase angle (

) May be an accurate estimate. The frequency estimating device 100 includes a second differential phase angle (

) To the first time difference phase angle (

) Can be performed.

) 및 제 2 시간의 제 2 차분 위상각(

)에 기초하여, 제 1 시간의 차분 위상각(

)을 결정하는 단계를 수행할 수 있다. In addition, the frequency estimating device 100 is the second differential phase angle of the first time (

) And the second differential phase angle of the second time (

) Based on the difference phase angle of the first time (

) Can be performed.

)을 보상 함수를 이용하여 보상하여 제 2 시간의 제 2 차분 위상각(

)을 획득할 수 있다. 또한, 주파수 추정 장치(100)는 제 2 시간의 제 1 전압 벡터 및 제 2 시간의 제 2 전압 벡터의 외적 또는 내적을 이용하여 제 2 시간의 제 1 차분 위상각(

)을 획득할 수 있다. 주파수 추정 장치(100)는 식 (4)를 이용하여 제 2 시간의 제 1 차분 위상각(

)을 획득할 수 있다. 이에 대해서는 제 1 시간의 제 1 차분 위상각(

)을 획득하는 과정과 동일하므로 중복되는 설명은 생략한다.Here, the frequency estimating apparatus 100 is the first difference phase angle of the second time (

) Is compensated using a compensation function to compensate for the second differential phase angle (

) Can be obtained. In addition, the frequency estimating apparatus 100 uses the outer product or the dot product of the first voltage vector of the second time and the second voltage vector of the second time, and the first difference phase angle (

) Can be obtained. The frequency estimating device 100 uses the equation (4) to determine the first difference phase angle of the second time (

) Can be obtained. For this, the first differential phase angle of the first time (

) Is the same as the process of obtaining it, so a duplicate description is omitted.

)에 따른 제 2 차분 위상각(

)을 값을 저장하고 있을 수 있다. 주파수 추정 장치(100)는 테이블 및 제 1 차분 위상각(

)에 기초하여 제 2 차분 위상각(

)을 결정할 수 있다. According to an embodiment of the present disclosure, the frequency estimation apparatus 100 may store a phase angle compensation function as a table. For example, the frequency estimating device 100 may have a first difference phase angle (

The second differential phase angle according to) (

) May be storing the value. The frequency estimation apparatus 100 includes a table and a first differential phase angle (

) Based on the second differential phase angle (

) Can be determined.

According to another embodiment of the present disclosure, the frequency estimating apparatus 100 may define a phase angle compensation function as a linear or quadratic equation. For example, the phase angle compensation function can be given as Equation (5).

= f(

) =

*

...식 (5)

= f(

) =

*

...Equation (5)

는 미리 정해진 실수로써, 주파수 추정 장치(100)는 메모리에

를 저장하고 있을 수 있다.

_는

에 기초하여 변화하는 값일 수 있다. 또는

는 고정된 상수일 수 있고,

이 1일 경우

는 곧바로

로 결정될 수 있다.here

Is a predetermined real number, and the frequency estimating apparatus 100 is

May be saving.

_Is

It may be a value that changes based on. or

Can be a fixed constant,

If is 1

Is straight away

Can be determined as

According to another embodiment of the present disclosure, the frequency estimation apparatus 100 may define a phase angle compensation function as arcsin as shown in Equation (6).

= f(

) =

* arcsin(

)...식 (6)

= f(

) =

* arcsin(

)...Equation (6)

는 미리 정해진 실수로써, 주파수 추정 장치(100)는 메모리에

를 저장하고 있을 수 있다.

는 고정된 상수일 수 있다. here

Is a predetermined real number, and the frequency estimating apparatus 100 is

May be saving.

Can be a fixed constant.

)을 arcsin에 적용한 값들을 메모리에 저장할 수 있다. 주파수 추정 장치(100)는 테이블에 기초하여 제 1 차분 위상각(

)에 대응하는 제 2 차분 위상각(

)을 획득할 수 있다.When the frequency estimating apparatus 100 substantially calculates arcsin, the computational burden of the processor may increase. Accordingly, the frequency estimation apparatus 100 may store a correspondence table in arcsin. That is, the frequency estimation apparatus 100 includes a plurality of first difference phase angles (

) Applied to arcsin can be stored in memory. The frequency estimating device 100 is based on the table, the first difference phase angle (

The second differential phase angle corresponding to) (

) Can be obtained.

)을 획득하는 단계를 수행할 수 있다. 주파수 추정 장치(100)는 제 1 시간의 제 2 차분 위상각(

)과 동일한 방식으로 제 1 시간 이전인 제 2 시간의 제 2 차분 위상각(

)을 획득할 수 있다. 주파수 추정 장치(100)는 제 2 시간의 제 2 차분 위상각(

)을 메모리에 저장하고 있을 수 있다. 주파수 추정 장치(100)는 제 2 시간의 제 2 차분 위상각(

)을 메모리로부터 획득할 수 있다.The frequency estimating device 100 is the second difference phase angle of the second time (

) Can be performed. The frequency estimating device 100 is the second differential phase angle of the first time (

In the same way as ), the second differential phase angle of the second time before the first time (

) Can be obtained. The frequency estimating device 100 is the second difference phase angle of the second time (

) May be stored in memory. The frequency estimating device 100 is the second difference phase angle of the second time (

) Can be obtained from memory.

)을 상기 제 2 시간의 제 2 차분 위상각(

)에 기초하여 아래 식 (7)과 같이 보정하는 단계를 수행할 수 있다. The frequency estimating device 100 is the second differential phase angle of the first time (

) To the second differential phase angle of the second time (

) Based on Equation (7) below.

... 식 (7)

... Equation (7)

와

은 미리 정해진 상수일 수 있다.

Wow

May be a predetermined constant.

을 제 1 시간의 차분 위상각(

으로 결정하는 단계를 수행할 수 있다. 주파수 추정 장치(100)는

와

의 값 중 하나가 1이고 하나가 0이면, 제 1 시간의 제 2 차분 위상각(

) 또는 제 2 시간의 제 2 차분 위상각(

)을 곧바로 제 1시간의 차분 위상각(

)으로 결정할 수 있다. In addition, the frequency estimating device 100 is the corrected second difference phase angle (

The difference phase angle of the first time (

You can perform the steps to determine. The frequency estimation device 100

Wow

If one of the values of is 1 and one is 0, the second differential phase angle of the first time (

) Or the second differential phase angle of the second time (

) Directly to the first hour difference phase angle (

) Can be determined.

) 또는 제 2 차분 위상각(

) 또는 제 2 시간의 1 차분 위상각(

) 또는 제 2 시간의 제 2 차분 위상각(

) 중 하나 이상에 기초하여 제 1 시간의 차분 위상각(

)으로 결정할 수 있다. 예컨대, 제 2 차분 위상각(

)이 제 1 차분 위상각(

)보다 정확한 값이므로, 주파수 추정 장치(100)는 제 2 차분 위상각(

)을 이용하여 제 1 시간의 예상 주파수를 정확하게 추정할 수 있다. 제 1 차분 위상각(

)을 획득하는 과정은 제 2 차분 위상각(

)을 획득하는 과정보다 단순하므로, 주파수 추정 장치(100)는 프로세서의 연산 능력을 적게 사용할 수 있다. 주파수 추정 장치(100)는 제 1 차분 위상각(

)을 이용하여 빠르게 제 1 시간의 예상 주파수를 추정할 수 있다.The frequency estimating device 100 includes a first differential phase angle (

) Or the second differential phase angle (

) Or the first difference phase angle of the second time (

) Or the second differential phase angle of the second time (

) The difference phase angle of the first time based on at least one of (

) Can be determined. For example, the second differential phase angle (

) Is the first difference phase angle (

), so the frequency estimating device 100 has a second differential phase angle (

) Can be used to accurately estimate the expected frequency of the first time. The first difference phase angle (

The process of obtaining) is the second differential phase angle (

Since it is simpler than the process of obtaining ), the frequency estimating apparatus 100 may use less computational power of the processor. The frequency estimating device 100 includes a first differential phase angle (

) Can be used to quickly estimate the expected frequency of the first time.

)를 획득하는 단계(440)를 수행할 수 있다. 제 2 시간의 예상 주파수(

)는 직전 주기에서 미리 계산된 주파수이거나 주파수 추정 장치(100)의 동작을 시작하기 위한 초기 값일 수 있다. 주파수 추정 장치(100)는 제 2 시간의 예상 주파수(

)를 메모리로부터 획득할 수 있다.Referring again to FIG. 4, the frequency estimation apparatus 100 is the expected frequency of the second time (

A step 440 of obtaining) may be performed. The expected frequency of the second time (

) May be a pre-calculated frequency in the previous period or an initial value for starting the operation of the frequency estimation apparatus 100. The frequency estimation device 100 is the expected frequency of the second time (

) Can be obtained from memory.

) 및 제 2 시간의 예상 주파수(

)에 기초하여 제 1 시간의 예상 주파수(

)를 획득하는 단계(450)를 수행할 수 있다.The frequency estimation apparatus 100 may include a frequency estimation unit 530. The frequency estimating unit 530 of the frequency estimating apparatus 100 includes a first time difference phase angle (

) And the expected frequency of the second time (

Based on ), the expected frequency of the first time (

A step 450 of obtaining) may be performed.

)를 획득하는 단계를 수행할 수 있다.Specifically, the frequency estimation apparatus 100 is based on the following equation (8), the expected frequency of the first time (

) Can be performed.

...식 (8)

...Equation (8)

는 제 2 시간의 예상 주파수를 나타내고,

는 미리 결정된 상수를 나타내고,

는 제 1 시간의 차분 위상각을 나타내고,

는 미리 정해진 시간을 나타낸다. 여기서

미리 정해진 실수로써, 주파수 추정 장치(100)는 메모리로부터

를 획득할 수 있다.

는 주파수 추정의 반응성을 조절하기 위한 상수일 수 있다. 또한,

는 이미 설명한 바와 같이 주파수 추정 장치(100)가 계통 전압을 측정하는 샘플 주기를 나타낸다.

는 제 1 시간과 제 2 시간 사이의 시간을 의미할 수 있다. 주파수 추정 장치(100)는 메모리로부터 미리 설정된

를 획득할 수 있다.here

Represents the expected frequency of the second time,

Represents a predetermined constant,

Represents the differential phase angle of the first time,

Represents a predetermined time. here

As a predetermined real number, the frequency estimation apparatus 100

Can be obtained.

May be a constant for adjusting the reactivity of frequency estimation. In addition,

Denotes a sample period in which the frequency estimating apparatus 100 measures the system voltage as described above.

May mean a time between the first time and the second time. The frequency estimation device 100 is preset from the memory

Can be obtained.

)를 획득하는 단계를 수행할 수 있다.In addition, the frequency estimation apparatus 100 is based on the following equation (8-1), the expected frequency of the first time (

) Can be performed.

...식 (8-1)

...Equation (8-1)

및

는 미리 결정된 상수를 나타낸다.

및

는 미리 정해진 실수로써, 주파수 추정 장치(100)는 메모리로부터

및

를 획득할 수 있다. 또한

는

이고,

는

일 수 있다. _{Equation (8-1) may be an equation obtained based on Equation (8).}

And

Represents a predetermined constant.

And

Is a predetermined real number, and the frequency estimation apparatus 100

And

Can be obtained. In addition

Is

ego,

Is

Can be

또는

를 수정할 수 있다. 하지만 이에 한정되는 것은 아니며, 주파수 추정 장치(100)는 미리 정해진 알고리즘에 기초하여 자동으로

또는

를 수정할 수 있다. 주파수 추정 장치(100)는

를 작게 할수록 정확하게 주파수를 추정할 수 있다. 또한 주파수 추정 장치(100)는

를 크게 할수록 빠르게 주파수를 추정할 수 있다. 주파수 추정 장치(100)는

작게 할수록 정확하고 빠르게 주파수를 추정할 수 있다. 또한 주파수 추정 장치(100)는

크게 할수록 프로세서의 연산 부담을 줄일 수 있다.The frequency estimation device 100 is input by the user

or

Can be modified. However, the present invention is not limited thereto, and the frequency estimating apparatus 100 automatically

or

Can be modified. The frequency estimation device 100

The smaller is, the more accurately the frequency can be estimated. In addition, the frequency estimation device 100

The larger is, the faster the frequency can be estimated. The frequency estimation device 100

The smaller it is, the more accurate and faster the frequency can be estimated. In addition, the frequency estimation device 100

The larger it is, the less the computational burden on the processor can be.

) 및 식 (7)에 의하여 획득된 제 1 시간의 차분 위상각(

을 식 (8) 또는 식 (8-1)에 적용하여 제 1 시간의 예상 주파수(

)를 획득할 수 있다.The frequency estimating device 100 is the expected frequency of the second time acquired from the memory (

) And the differential phase angle of the first time obtained by equation (7) (

By applying to Equation (8) or Equation (8-1), the expected frequency of the first time (

) Can be obtained.

)는 다음 주기의 제 2 시간의 예상 주파수로 이용되기 위하여, 주파수 추정 장치(100)는 메모리에 _{제 1 시간의 예상 주파수}(

)를 저장할 수 있다. 또한 주파수 추정 장치(100)는 _{제 1 시간의 예상 주파수}(

)를 d-q 추출부(510)에 피드백(541)할 수 있다. _{Also the estimated frequency of the estimated first time} (

) Is used as the predicted frequency of the second time of the next period, the frequency estimating apparatus 100 in the memory, _{the predicted frequency} of _{the first time} (

) Can be saved. In addition, the frequency estimation device 100 is _{the expected frequency} of _{the first time} (

) May be fed back 541 to the dq extraction unit 510.

Equation (8) can be obtained based on the following method. The phase angle is the integral of the frequency. The phase angle in the discrete domain can be expressed as Equation (9) by the backward method among the backward, forward, and trapezoid methods included in numerical integration.

... 식 (9)

... Equation (9)

In addition, the frequency estimating apparatus 100 may obtain Equation (8) by using a feedback device for estimating a frequency together with Equation (9). The feedback device for estimating the frequency will be described with reference to FIG. 7.

Here, although the backward method is described, it is not limited thereto.

9 is a diagram illustrating backward, forward, and trapezoid according to an embodiment of the present disclosure.

According to the forward method, Equation (9) can be changed as Equation (9-1).

... 식 (9-1)

... Equation (9-1)

Also, according to the trapezoid method, Equation (9) can be changed as Equation (9-2).

... 식 (9-2)

... Equation (9-2)

The frequency estimating apparatus 100 may use Equation (9-1) or Equation (9-2) instead of Equation (9).

7 is a block diagram illustrating a frequency estimation according to an embodiment of the present disclosure.

The frequency estimation apparatus 100 may include a third integrating unit 710. The circuit shown in FIG. 7 is a feedback device using a third integrating unit 710.

)에서 추정 주파수(

)를 차감한 값을 제 3 적분부(710)에 입력할 수 있다. 제 3 적분부(710)는 오차에 기초하여 수정된 추정 주파수(

)를 출력할 수 있다. 주파수 추정 장치(100)는 이러한 과정을 원본 주파수(

)와 추정 주파수(

)가 동일할 때까지 반복할 수 있다. For example, the frequency estimating device 100 is the original frequency (

) At the estimated frequency (

A value obtained by subtracting) may be input to the third integrating unit 710. The third integrating unit 710 is the estimated frequency corrected based on the error (

) Can be printed. The frequency estimation apparatus 100 performs this process as the original frequency (

) And the estimated frequency (

) Can be repeated until the same.

This process is expressed as Equation (10).

... 식 (10)

... equation (10)

)를 신속하고 정확하게 추정할 수 있다.Using equations (9) and (10), equation (8) can be obtained. The frequency estimation device 100 is based on the equation (8), the expected frequency of the first time (

) Can be estimated quickly and accurately.

)를 획득하는 방식과 도 3에 따라 주파수 추정 장치(100)가 예상 주파수(

)를 획득하는 과정은 아래와 같은 차이가 있다. According to FIG. 4, the frequency estimating apparatus 100 is

) And according to FIG. 3, the frequency estimation apparatus 100

The process of obtaining) has the following differences.

When the estimation method of the frequency estimation apparatus 100 according to FIG. 3 is expressed as an equation, it is as shown in equations (11) and (12).

... 식 (11)

... equation (11)

... 식 (12)

... equation (12)

)를 획득하기 위하여 2차 적분부를 이용하여야한다. 2차 적분부는 주파수 추정 장치(100)의 연산 능력을 많이 소모할 수 있다. 또한 도 7을 참조하면 주파수 추정 장치(100)는 식 (8)은 1차 적분부를 이용하여 주파수를 추정할 수 있다. 따라서 주파수 추정 장치(100)는 식 (8)을 이용하여 식 (12)보다 빠르게 제 1 시간의 예상 주파수(

)를 획득할 수 있다.Equations (11) and (12) are quadratic with denominator s. Therefore, the frequency estimation device 100 is the expected frequency (

In order to obtain ), the second integral part must be used. The second integrating unit may consume a lot of computing power of the frequency estimation apparatus 100. In addition, referring to FIG. 7, the frequency estimating apparatus 100 may estimate a frequency using a first-order integrating unit in Equation (8). Therefore, the frequency estimating device 100 uses Equation (8) to be faster than Equation (12).

) Can be obtained.

) 및 위상(

)을 추정하기 위하여 동일한 제어이득(kpp 또는 kip)의 영향을 받을 수 있다. 따라서 주파수 추정 장치(100)가 위상각과 주파수에 대해서 다른 추정 응답성을 갖기 위해서는 도 3과 같은 추가적인 PLL(Phase Lock Loop) 시스템을 더 가져야할 수 있다. In addition, referring to equations (11) and (12), the frequency estimating device 100 is the frequency (

) And phase (

) Can be affected by the same control gain (kpp or kip). Therefore, in order for the frequency estimating apparatus 100 to have different estimation responsiveness with respect to the phase angle and frequency, it may further have an additional PLL (Phase Lock Loop) system as shown in FIG. 3.

If an additional PLL is used, the frequency estimating apparatus 100 must additionally use a sine and cosine, which require a lot of processing resources, such as Equation (2). In addition, the frequency estimating apparatus 100 needs to add two more integral operations for configuring PI (Proportional-Integral) + I (Integral). In addition, the first order term of s in the transfer function numerator of Equation (11) is necessary to estimate the phase angle ramp change without a steady state error, but the first order term of s shown in the transfer function numerator of Equation (12) is It is mainly not essential in frequency estimation showing a step change, and in some cases, an oscillation error of frequency estimation may be caused. Accordingly, the frequency estimating apparatus 100 can more simply estimate the frequency using Equation (8) and efficiently use the processing resources of the frequency estimating apparatus 100.

The frequency estimation apparatus 100 may need an estimated phase angle to precisely control active/reactive power during system synchronization. However, in an application field that controls ON/OFF of a circuit breaker connecting a system and a power/load, since a change in the system is sensed through a frequency, the frequency estimation apparatus 100 may not need to estimate the phase. Accordingly, in the case of using Equation (8), the frequency estimation apparatus 100 does not need to additionally use a PLL and can implement only frequency estimation alone, thereby increasing the efficiency of the apparatus implementation.

8 is a graph showing a frequency estimation result according to an embodiment of the present disclosure.

Referring to FIG. 8, the vertical axis represents frequency and the horizontal axis represents time. Referring to the graph 810 of FIG. 8, the frequency of the system (red line) has been changed in steps from 60Hz to 55Hz. In this case, FIG. 8 shows changes in the system voltage Vg and changes in the estimated voltages Vd and Vq. The graph 821 shows the change of the grid voltage Vg before the frequency of the grid is changed. Since the frequency before the frequency change is 60Hz, it can be seen that one cycle of the system voltage (Vg) appears in 1/60s. Likewise, the graph 831 represents the estimated voltages Vd and Vq before the frequency of the system is changed. Since the frequency before the frequency change is 60Hz, it can be seen that all one period of the estimated voltages (Vd, Vq) appears in 1/60s.

Referring to the graph 822, it can be seen that the grid voltage Vg has been changed to 55 Hz. As the frequency of the grid voltage (Vg) decreases, one cycle of the grid voltage is not included in 1/60 seconds. However, referring to the graph 832, it can be seen that the estimated voltages Vd and Vq have not yet reached 55hz.

Referring to the graph 823 and the graph 833, it can be seen that both the system voltage Vg and the estimated voltages Vd and Vq have been changed to 55 Hz.

The frequency estimating device 100 can follow the slowed frequency of the system voltage Vg by equation (8). The tracking speed can be adjusted through kf, the control gain in equation (8). Referring to FIG. 8, the frequency estimating apparatus 100 shows results so that the following response has a bandwidth of 1 Hz as intended.

So far, we have looked at the center of various embodiments. Those of ordinary skill in the art to which the present disclosure pertains will appreciate that the present invention may be implemented in a modified form without departing from the essential characteristics of the present invention. Therefore, the disclosed embodiments should be considered from an illustrative point of view rather than a limiting point of view. The scope of the present invention is shown in the claims rather than the above description, and all differences within the scope equivalent thereto should be construed as being included in the present invention.

Meanwhile, the above-described embodiments of the present invention can be written as a program that can be executed in a computer, and can be implemented in a general-purpose digital computer that operates the program using a computer-readable recording medium. The computer-readable recording medium includes a storage medium such as a magnetic storage medium (for example, ROM, floppy disk, hard disk, etc.) and an optical reading medium (for example, CD-ROM, DVD, etc.).

Claims (10)

In the method of estimating the target frequency to synchronize the frequency of the voltage shared by devices included in the system,
Measuring a voltage at every predetermined time to obtain a first voltage that is a measured value of a first time and a second voltage that is a measured value of a second time that is a time immediately before the first time;
Extracting a dq component from the first voltage and the second voltage to obtain a first voltage vector and a second voltage vector;
Acquiring a differential phase angle of the first time, which is an angle between the first voltage vector and the second voltage vector;
The expected frequency of the second time (

Obtaining );
Obtaining an expected frequency of the first time based on the sum of a value obtained by multiplying the difference phase angle of the first time by a second constant (Kb) and the product of multiplying the expected frequency of the second time by a first constant (Ka) Frequency estimation method comprising the step.
The method of claim 1,
The step of obtaining the difference phase angle of the first time,
and acquiring an angle formed by the first voltage vector and the second voltage vector in a dq plane as a differential phase angle of a first time.
The method of claim 1,
The difference phase angle of the first time (

The step of obtaining
A first differential phase angle based on one of the inner product or the outer product of the first voltage vector and the second voltage vector (

Obtaining a; And
The first difference phase angle (

The difference phase angle of the first time (

Frequency estimation method comprising the step of determining.
The method of claim 3,
The difference phase angle of the first time (

The step of obtaining
Based on the phase angle compensation function, the first difference phase angle (

By compensating for the second differential phase angle (

Obtaining a; And
The second differential phase angle (

The difference phase angle of the first time (

Frequency estimation method comprising the step of determining.
The method of claim 4,
The difference phase angle of the first time (

The step of obtaining
The second differential phase angle of the second time (

Obtaining );
The second differential phase angle of the first time (

) To the second differential phase angle of the second time (

) Correcting based on; And
The corrected second differential phase angle (

The difference phase angle of the first time (

Frequency estimation method comprising the step of determining.
In the device for estimating a target frequency to synchronize the frequency of the voltage shared by devices included in the system,
The apparatus for estimating the frequency includes a processor and a memory,
The processor based on the instruction stored in the memory,
Measuring a voltage at every predetermined time to obtain a first voltage that is a measured value of a first time and a second voltage that is a measured value of a second time that is a time immediately before the first time;
Extracting a dq component from the first voltage and the second voltage to obtain a first voltage vector and a second voltage vector;
Acquiring a differential phase angle of the first time, which is a stamp between the first voltage vector and the second voltage vector;
The expected frequency of the second time (

Obtaining );
Obtaining an expected frequency of the first time based on the sum of a value obtained by multiplying the difference phase angle of the first time by a second constant (Kb) and the product of multiplying the expected frequency of the second time by a first constant (Ka) Frequency estimation apparatus, characterized in that to perform the step.
The method of claim 6,
The processor based on the instruction stored in the memory,
and acquiring an angle formed by the first voltage vector and the second voltage vector in a dq plane as a differential phase angle of a first time.
The method of claim 6,
The processor based on the instruction stored in the memory,
A first differential phase angle based on one of the inner product or the outer product of the first voltage vector and the second voltage vector (

Obtaining a; And
The first difference phase angle (

The difference phase angle of the first time (

Frequency estimation apparatus, characterized in that performing the step of determining.
The method of claim 8,
The processor based on the instruction stored in the memory,
Based on the phase angle compensation function, the first difference phase angle (

By compensating for the second differential phase angle (

Obtaining a; And
The second differential phase angle (

The difference phase angle of the first time (

Frequency estimation apparatus, characterized in that performing the step of determining.
The method of claim 9,
The processor based on the instruction stored in the memory,
The second differential phase angle of the second time (

Obtaining );
The second differential phase angle of the first time (

) To the second differential phase angle of the second time (

) Correcting based on; And
The corrected second differential phase angle (

The difference phase angle of the first time (

Frequency estimation apparatus, characterized in that performing the step of determining.

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