KR102523830B1 - Apparatus and method for controlling synchronous generator having initial reactive power adjustment function - Google Patents

Abstract

The present invention relates to a synchronous generator control device having an initial input reactive power adjustment function and a method therefor. a reference signal adjusting unit for adjusting the reference signals so that the voltages match; and a reactive power adjusting unit for calculating and providing a reference signal variation for adjusting the terminal voltage of the synchronous generator in addition to the reference signal so that the synchronous generator can adjust the reactive power during initial grid feed-in.

Description

Synchronous generator control device having initial input reactive power adjustment function and method thereof

The present invention relates to a synchronous generator control device having an initial input reactive power adjustment function and a method thereof, and more particularly, to adjust the terminal voltage of a synchronous generator according to the initial value of reactive power set by a power plant manager during initial grid feed-in. Accordingly, the present invention relates to a synchronous generator control device having an initial input reactive power adjustment function and a method thereof for improving the transient stability of the power system by stably supplying reactive power to the power system.

Synchronous generators (or synchronous machines) must be fed in by matching the voltage size, voltage phase, and frequency of the power system in order to feed into the power system. In this way, in order to feed-in operation of the power system by driving the synchronous generator, a synchronous feed-in device for synchronous feed-in (or grid feed-in, grid feed-in, synchronous feed-in) is required.

In general, the synchronizing device is installed independently, and gives terminal voltage control commands to the generator exciter and speed and phase control commands to the governor of the turbine before grid feed-in.

However, when the synchronous feed-in device operates the grid-tied circuit breaker without matching the voltage size, voltage phase, and frequency of the power system with the power system, the main voltage at the output stage of the synchronous generator, peripheral electrical equipment, and turbine equipment are burned out and In this case, it gives a great shock to the power system and gives a great disturbance to the generators operating in parallel in the nearby power system.

1 is a diagram showing the connection between a general synchronizing device and an external controller.

In the case where the synchronous machine and the power system are operated in parallel without matching the voltage levels of the synchronous machine and the power system, a large reactive cross current flows through the generator, which may burn out the synchronous machine.

In addition, when the synchronous machine and the power system are not matched in voltage phase and the synchronous machine is operated in parallel with the power system, an electrical collision phenomenon such as a temporary short circuit occurs due to a large voltage difference between the two systems, which burns out related devices and deteriorates the stability of the power system. It has a huge impact on dropping.

Referring to FIG. 1, the size of the synchronous machine voltage is in charge of adjusting the exciter, and the voltage phase and frequency are in charge of adjusting the speed control system that controls the speed of the turbine that rotates the synchronous machine.

In addition, the synchronous feed-in device detects the voltage magnitude and frequency signal of the power system and the synchronous machine, and after going through the signal processing operation process, detects the voltage magnitude difference, voltage phase difference, phase angle signal, etc. between the two systems, and these values are within the set standard value. When it comes in, it generates a command signal to input synchronism to the grid-tied circuit breaker and operates the synchroniser in parallel with the grid.

And, the synchronous feed-in device generates an increase/decrease command signal to correct the target value of the exciter and speed control system if the voltage, frequency, phase angle, etc. of the synchronous machine to be fed are out of the range of parallel input conditions, It sends a command signal to match the always changing power system signal by modifying the target value.

However, a power plant manager needs to pay attention to the stable supply of reactive power and active power during the initial grid feed-in process of a synchronous generator.

That is, the synchronous feed-in device becomes a closing condition for the grid feed-in circuit breaker when the error between the synchronous generator voltage and the grid voltage is within a certain range. However, in this case, since the amount of injected reactive power is different, it is a time point in which the power plant manager's attention is very necessary.

Therefore, in some cases, it often occurs that the power plant manager hastily increases the voltage due to excessive phase-in operation at the beginning of grid feed-in.

Therefore, it is necessary to provide a method for improving the transient stability of the power system by stably supplying reactive power to the generator by adjusting the generator voltage according to the initial value of reactive power set by the power plant manager during grid feed-in.

Korean Registered Patent Publication No. 10-1063945 (registered on 2011.09.02)

An object of the present invention is to improve the transient stability of the power system by stably supplying reactive power to the power system by adjusting the terminal voltage of the synchronous generator according to the initial value of reactive power set by the power plant manager at the time of initial grid feed-in. To provide a synchronous generator control device and method having an initial input reactive power adjustment function.

A synchronous generator control apparatus having an initial input reactive power adjustment function according to an embodiment of the present invention includes a reference signal adjustment unit for adjusting a reference signal so that a synchronous generator voltage and a grid voltage match; and a reactive power adjusting unit for calculating and providing a reference signal variation for adjusting the terminal voltage of the synchronous generator in addition to the reference signal so that the synchronous generator can adjust the reactive power during initial grid feed-in.

The reactive power adjusting unit may include a reactive power calculation unit for checking a reactive power change and a terminal voltage change using the synchronous generator voltage and current; an impedance calculation unit for calculating system impedance using the reactive power change and the terminal voltage change; and a reference signal variation calculating unit for calculating a reference signal variation using the system impedance and an initial value of reactive power set by a power plant manager.

The reactive power change is calculated as the difference between the first reactive power and the second reactive power, the first reactive power is confirmed when the synchronous generation voltage and the system voltage match, and the second reactive power is initially It may be confirmed when the voltage increase is reflected in the reference signal during grid feed-in.

The terminal voltage change is calculated as a difference between a first terminal voltage and a second terminal voltage, the first terminal voltage is a synchronous generator voltage when the first reactive power is applied, and the second terminal voltage is the second reactive power. When it is power, it can be the synchronous generator voltage.

The terminal voltage change may correspond to the voltage increase.

(여기서, Xe는 계통 임피던스, V1는 제1 단자전압, V2는 제2 단자전압, Q1은 제1 무효전력, Q2는 제2 무효전력)로 계산되는 것일 수 있다.The system impedance is

(Here, Xe is the system impedance, V1 is the first terminal voltage, V2 is the second terminal voltage, Q1 is the first reactive power, Q2 is the second reactive power).

(여기서, △Vsref는 기준신호 변동분, Xe는 계통 임피던스, Qref는 무효전력 초기값)로 계산되는 것일 수 있다.The reference signal variation is

(Here, ΔVsref is a reference signal variation, Xe is a system impedance, and Qref is an initial value of reactive power).

The reference signal variance calculation unit may calculate the reference signal variance by applying a current value of reactive power of another synchronous generator operated in parallel in the vicinity instead of the initial value of reactive power.

The system impedance may be represented by the sum of the main voltage transformer impedance and the interconnection line impedance when representing the after end of the grid-tied circuit breaker by equivalent modeling.

According to the embodiment, a speed adjusting unit for transmitting a speed control command to the governor so that the phase of the synchronous generator voltage and the voltage frequency of the grid voltage coincide.

The reactive power adjustment unit may be installed in an exciter or synchronization device.

In addition, a synchronous generator control method having an initial input reactive power adjustment function according to an embodiment of the present invention includes adjusting a reference signal so that a synchronous generator voltage and a grid voltage match; and calculating and providing a variation of a reference signal for adjusting the terminal voltage of the synchronous generator in addition to the reference signal so that the synchronous generator can adjust reactive power during initial grid feed-in.

The providing may include checking a reactive power change and a terminal voltage change using the synchronous generator voltage and current; calculating system impedance using the reactive power change and the terminal voltage change; and calculating a reference signal variation using the system impedance and an initial value of reactive power set by a power plant manager.

The calculating of the reference signal variation may include calculating the reference signal variation by applying a current value of reactive power of another synchronous generator operated in parallel in the vicinity instead of the initial value of reactive power.

In addition, as a synchronous generator control device according to another embodiment of the present invention, at least one processor; and a memory for storing computer readable instructions, wherein the instructions, when executed by the at least one processor, cause the synchronous generator control device to adjust a reference signal so that the synchronous generator voltage and the grid voltage match. In addition to the reference signal, a reference signal variation for adjusting the terminal voltage of the synchronous generator may be calculated and provided so that the synchronous generator can adjust the reactive power during initial grid feed-in.

According to the present invention, the terminal voltage of the synchronous generator is adjusted according to the initial value of reactive power set by the power plant manager during initial grid feed-in, thereby stably supplying reactive power to the power system, thereby improving the transient stability of the power system.

In addition, the present invention can reduce the space and management cost for installation as an independent device by integrating the synchronizing device with each exciter installed in the power plant.

In addition, the present invention calculates the system impedance by raising the voltage of the synchronous generator after the first grid feed-in after the power plant is built, and the system impedance is already calculated when the grid is fed back after the grid failure, so the reactive power set by the power plant manager The power plant can be stably operated by adjusting the voltage of the synchronous generator based on the initial value.

In addition, in the present invention, when a plurality of synchronous generators are in operation, the synchronous generator that is additionally fed into the grid applies the reactive power current value of other synchronous generators operated in parallel in the vicinity instead of the initial value of the reactive power, thereby It can operate stably together with other synchronous generators.

In addition, the present invention can be simply applied without changing the structures of the current synchronization device and exciter since the synchronizing device and the exciter are not integrated but implemented in an independent form.

*

1 is a diagram showing the connection between a general synchronizing device and an external controller;
2 is a view showing a synchronous generator control device having an initial input reactive power adjustment function according to an embodiment of the present invention;
3 is a view explaining the detailed configuration of the synchronous generator control device of FIG. 2;
4 is a diagram showing impedance disconnection between a synchronous generator and an external device;
5 is a graph explaining operation test results for system impedance calculation;
6 is a diagram showing a method for controlling a synchronous generator having an initial input reactive power adjustment function according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, detailed descriptions of well-known functions or configurations that may obscure the gist of the present invention will be omitted in the following description and accompanying drawings. In addition, it should be noted that the same components are indicated by the same reference numerals throughout the drawings as much as possible.

The terms or words used in this specification and claims described below should not be construed as being limited to ordinary or dictionary meanings, and the inventors are appropriately defined as terms for describing their invention in the best way. It should be interpreted as meaning and concept consistent with the technical idea of the present invention based on the principle that it can be done.

Therefore, the embodiments described in this specification and the configurations shown in the drawings are only one of the most preferred embodiments of the present invention, and do not represent all of the technical ideas of the present invention. It should be understood that there may be equivalents and variations.

In the accompanying drawings, some components are exaggerated, omitted, or schematically illustrated, and the size of each component does not entirely reflect the actual size. The present invention is not limited by the relative sizes or spacings drawn in the accompanying drawings.

When it is said that a certain part "includes" a certain component throughout the specification, it means that it may further include other components without excluding other components unless otherwise stated. In addition, when a part is said to be "connected" to another part, this includes not only the case of being "directly connected" but also the case of being "electrically connected" with another element interposed therebetween.

Singular expressions include plural expressions unless the context clearly dictates otherwise. Terms such as "comprise" or "having" are intended to indicate that a feature, number, step, operation, component, part, or combination thereof described in the specification exists, but that one or more other features, numbers, or steps are present. However, it should be understood that it does not preclude the possibility of existence or addition of operations, components, parts, or combinations thereof.

Also, the term "unit" used in the specification means a hardware component such as software, FPGA or ASIC, and "unit" performs certain roles. However, "unit" is not meant to be limited to software or hardware. A “unit” may be configured to reside in an addressable storage medium and may be configured to reproduce on one or more processors. Thus, as an example, “unit” can refer to components such as software components, object-oriented software components, class components and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays and variables. Functionality provided within components and "parts" may be combined into fewer components and "parts" or further separated into additional components and "parts".

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily carry out the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

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

2 is a diagram showing a synchronous generator control device having an initial input reactive power adjustment function according to an embodiment of the present invention.

As shown in FIG. 2, the synchronous generator control device (hereinafter referred to as 'synchronous generator control device', 100) having an initial input reactive power adjustment function according to an embodiment of the present invention controls the terminal voltage of the synchronous generator. By including and integrating all the functions of the synchronizing device into the exciter in charge, it can be realized in the form of 'exciter with built-in synchronizing device'. That is, the synchronous generator control device 100 may be implemented in a form included in an exciter.

In this case, since the exciter originally receives the generator voltage as a feedback signal, it can sufficiently perform the function of a synchronizing device if it additionally receives the system voltage. This is possible because the signal processing performance of the exciter has been improved.

Thus, the synchronous generator control device 100 can reduce the space and management cost for installation as an independent device by integrating the synchronous feed-in device into each exciter installed in the power plant.

In FIG. 2 , the synchronous generator control device 100 requires a synchronous generator voltage and a line voltage necessary for calculating a synchronous input control signal in order to function as a synchronous feed-in device.

That is, in the synchronous generator control device 100, the voltage signal Vg and the frequency signal of the synchronous generator G are input through the first voltage transformer 20 disposed on the generator side with respect to the grid-connected circuit breaker 10 , The current signal Ig of the synchronous generator G is input through the current transformer 30, and the voltage of the power system through the second voltage transformer 40 disposed on the grid power side with respect to the grid-connected breaker 10 A signal Vt and a frequency signal are input.

Such a synchronous generator control device 100 may be in charge of a synchronizing device function.

First, the synchronous generator control device 100 compares the frequency (phase) of the synchronous generator G and the frequency (phase) of the power system to control the speed of the governor.

In addition, the synchronous generator control device 100 compares the detection signal between the synchronous generator G and the power system and transmits a circuit breaker closing command signal to the grid-connected circuit breaker 10 when it is within a predetermined reference value. At this time, the synchronous generator control device 100 may check the open/closed state of the grid-connected circuit breaker 10 .

And, the synchronous generator control device 100 may be in charge of an exciter control function.

At this time, the synchronous generator control device 100 maintains or adjusts the generator output terminal voltage constant by supplying DC power to the generator field winding C. Here, a stationary exciter control function including a thyristor rectifier 50 that supplies AC power to the generator field winding C as DC power is implemented.

In particular, the synchronous generator control device 100 adjusts the terminal voltage of the synchronous generator (G) based on the initial value of reactive power set by the power plant manager at the time of grid feed-in in which the input condition of the grid-connected breaker 10 is satisfied, It enables synchronous generators to be stably fed into the power system and operated without additional work by the plant manager.

Here, the reactive power is determined by the difference between the synchronous generator voltage and the grid voltage when the synchronous generator is fed into the grid. In order to calculate the reactive power, the system impedance must be confirmed. However, system impedance is difficult to calculate through simulation because numerous generators and system constants are complexly connected.

Therefore, in the embodiment of the present invention, the system impedance was calculated by increasing the synchronous generator voltage after the first grid feed-in after the power plant was built. When synchronous input is resumed after a system failure, since the system impedance has already been calculated, the power plant can be stably operated by adjusting the voltage of the synchronous generator based on the initial value of reactive power set by the plant manager.

Hereinafter, the detailed configuration of the synchronous generator control device 100 will be described in detail with reference to FIG. 3 .

FIG. 3 is a diagram explaining the detailed configuration of the synchronous generator control device of FIG. 2 .

Referring to FIG. 3 , the synchronous generator control device 100 includes a reference signal adjusting unit 110 , a reactive power adjusting unit 120 , and a speed adjusting unit 130 .

First, the reference signal adjusting unit 110 is responsible for controlling the exciter in charge of adjusting the terminal voltage of the synchronous generator (G). That is, the reference signal adjusting unit 110 adjusts the reference signal Vref of the synchronous generator G provided to the PID controller 60 so that the voltage levels of the synchronous generator voltage Vg and the system voltage Vt match. At this time, the reference signal adjusting unit 110 generates a rising or falling command of the reference signal Vref so that |Vg−Vt|=0. Here, the reference signal variation ΔVsref calculated by the reactive power adjusting unit 120 may be reflected in the reference signal Vref.

Next, the reactive power adjusting unit 120 calculates and provides a reference signal variation (Vsref) for adjusting the terminal voltage of the synchronous generator in addition to the reference signal (Vref) so that the synchronous generator can adjust the reactive power during initial grid feed-in. do. Here, the initial value of reactive power (Qref) set by the power plant manager is reflected in the reference signal variation (Vsref).

Accordingly, since the synchronous generator (G) adjusts the terminal voltage according to the reactive power initial value (Qref) set by the power plant manager at the time of initial grid feed-in, it stably supplies reactive power to the power system, thereby reducing the transient stability of the power system. will improve

In other words, the synchronous generator (G) can output reactive power in which the initial reactive power value (Qref) is reflected during the initial grid feed-in.

Specifically, the reactive power adjusting unit 120 includes a reactive power calculating unit 121, an impedance calculating unit 122, and a reference signal variation calculating unit 123.

First, the reactive power calculation unit 121 calculates reactive power using the synchronous generator voltage (Vg) and current (Ig), but calculates the reactive power change and the terminal voltage change for calculating the system impedance (Xe). Check.

At this time, since it is difficult for the reactive power calculation unit 121 to calculate system impedance through simulation, reactive power change that can automatically calculate system impedance by assuming a situation in which a power plant is built and the generator voltage is raised after initial grid feed-in Check the minute and terminal voltage change.

Here, the reactive power change is calculated as the difference (Q1-Q2) between the first reactive power Q1 and the second reactive power Q2, and the terminal voltage change is the first terminal voltage V1 and the second terminal voltage. It is calculated as the difference (V1-V2) of (V2).

Specifically, each of the first reactive power (Q1) and the first terminal voltage (V1) is 'when the power plant is built and initially fed into the grid [ie, when the synchronous generator voltage (Vg) and the grid voltage (Vt) are matched] ' Confirmed.

The first reactive power Q1 is reactive power when the synchronous generator voltage Vg and the grid voltage Vt match. That is, the first reactive power Q1 becomes '0'.

The first terminal voltage V1 is a synchronous generator voltage determined according to a reference signal (ie, a reference signal adjusted to match the synchronous generator voltage and the grid voltage) at the time of initial grid feed-in. That is, the first terminal voltage (V1) is the synchronous generator voltage when the first reactive power (Q1).

In addition, each of the second reactive power Q2 and the second terminal voltage V2 is confirmed 'when the generator voltage rises after being fed into the grid'. Here, the voltage increase (ΔV) may be about 4 to 5%.

The second reactive power Q2 is reactive power when the voltage increase ΔV is reflected in the reference signal at the time of initial grid feed-in.

The second terminal voltage (V2) is a synchronous generator voltage determined by reflecting the voltage increase (ΔV) to the reference signal at the time of initial grid feed-in. That is, the second terminal voltage (V2) is the synchronous generator voltage when the second reactive power (Q2).

Here, since the second terminal voltage V2 is obtained by adding the voltage increase ΔV to the first terminal voltage V1, the terminal voltage change V1-V2 is equal to the voltage increase ΔV.

As a result, the reactive power calculation unit 121 identifies the first reactive power Q1 as '0' and calculates the second reactive power Q2 by reflecting the voltage increase ΔV, thereby changing the reactive power Q1. -Q2) can be checked. Also, the reactive power calculation unit 121 may check the voltage increase (ΔV) as the terminal voltage change (V1-V2).

Next, the impedance calculation unit 122 calculates the system impedance Xe using the reactive power change (Q1-Q2) and the terminal voltage change (V1-V2). That is, since the system impedance Xe is proportional to the reactive power change according to the terminal voltage change, it can be calculated as in Equation 1 below.

Next, the reference signal variation calculation unit 123 calculates the reference signal variation (ΔVsref) using the system impedance (Xe) and the reactive power initial value (Qref) set by the power plant manager. That is, the reference signal variation (ΔVsref) can be calculated as shown in Equation 2 below by multiplying the system impedance (Xe) by the initial reactive power value (Qref) set by the power plant manager.

Here, the reference signal variation (ΔVsref) is added to the reference signal (Vref) of the synchronous generator voltage. Then, the terminal voltage of the synchronous generator (G) is adjusted by the reference signal (Vref + ΔVsref) in which the reference signal variation (ΔVsref) is reflected. At this time, in the synchronous generator (G), the reactive power is automatically changed during synchronous feeding by the reference signal variation (ΔVsref), so that transient stability can be secured at the beginning.

Additionally, when a plurality of synchronous generators are in operation, a 'reactive power current value' of another synchronous generator operated in parallel nearby may be applied instead of a reactive power initial value (Qref) to a synchronous generator that is additionally fed into the grid. Then, since the synchronous generator that is additionally fed into the grid can correct the reactive power in real time and the effect of being fed into the grid can be expected, it can be stably operated together with other synchronous generators operated in parallel nearby.

Next, the speed adjusting unit 130 is responsible for controlling the speed governor, which is responsible for adjusting the voltage frequency and phase of the synchronous generator (G). To this end, the speed adjusting unit 130 calculates the voltage frequency and phase of the synchronous generator (G).

The speed adjusting unit 130 transmits a speed control command to the governor so that the voltage frequency and phase of the synchronous generator voltage Vg and the power system voltage Vt coincide.

As described above, the synchronous generator control device 100 may be implemented in the form of a 'synchronizer built-in exciter'.

However, the synchronous generator control device 100 may be implemented in an independent form rather than an integrated form of a synchronizing device and an exciter. In this case, the reactive power adjusting unit 120 is installed in the synchronizing device, and provides the reference signal variation (ΔVsref) to the exciter. Then, the exciter adjusts the synchronous generator G by using the reference signal in which the reference signal variation is reflected. A detailed description thereof will be omitted since it can be easily understood by those skilled in the art.

Meanwhile, the synchronous generator control apparatus 100 may be implemented with a configuration including at least one processor and a memory for storing computer readable instructions.

That is, each of the reference signal adjusting unit 110, the reactive power adjusting unit 120, and the speed adjusting unit 130 functions to adjust the initial input reactive power according to an embodiment of the present invention when the computer readable instructions stored in the memory are executed by the process. It is possible to perform a synchronous generator control method having.

Here, the processor may also be referred to as a controller, a microcontroller, a microprocessor, a microcomputer, and the like. Also, the processor may be implemented by hardware, firmware, software, or a combination thereof.

Additionally, memory may be a single storage device or may be a collective term for a plurality of storage elements. Computer readable instructions stored in memory may be executable program code or parameters, data, or the like. And, the memory may include RAM (Random Access Memory) or NVRAM (Non-Volatile Memory) such as a magnetic disk storage device or flash memory.

4 is a diagram showing impedance disconnection between a synchronous generator and an external device, and FIG. 5 is a graph explaining operation test results for calculating system impedance.

Referring to FIG. 4, the organic electromotive force (E) and the synchronous impedance (Xs) are parts of the synchronous generator (G) represented by equivalent modeling, and the main voltage generator impedance (Xt) and the link line impedance (Xl) are the grid-tied breaker (10 ) is the part shown by equivalent modeling after the rear end.

Here, the system impedance (Xe) can be expressed as the sum of the main transformer impedance (Xt) and the link line impedance (Xl). That is, Xe=Xt+Xl.

This impedance corresponds to the device, and shows a constant value if the peripheral synchronous generator or line is not changed.

Referring to FIG. 5, a 500 mW synchronous generator was applied to the operation test object. The specifications of the synchronous generator are rated voltage 22,000V, frequency 60Hz (3600rpm), rated output 612㎹A, field voltage 300V, field current 5,224A, field voltage 0.0546@75℃.

Specifically, the system impedance (Xe) can be calculated through Equation 1 above.

First, since the terminal voltage change (V1-V2) is the same as the voltage increase (ΔV), when it is increased by 5%, it becomes -0.05. That is, when the first terminal voltage V1 is 1V, the second terminal voltage V2 becomes 1.05V by adding the first terminal voltage and the voltage increase ΔV. Then, the terminal voltage change (V1-V2) is -0.05.

Next, the first reactive power (Q1) is 0, and the second reactive power (Q2) is reactive power that is confirmed when the voltage increase (ΔV) is reflected in the reference signal (Vref) during initial grid feed-in. The second reactive power Q2 is confirmed to be 0.215.

Therefore, the system impedance (Xe) is calculated as 0.232pu.

이다.in other words,

am.

Then, the reference signal variation (ΔVsref) can be calculated through Equation 2 above. Here, the reactive power initial value Qref may be, for example, 0.2pu.

Therefore, the reference signal variation (ΔVsref) is calculated as 0.0464pu.

이다.in other words,

am.

6 is a diagram showing a method for controlling a synchronous generator having an initial input reactive power adjustment function according to an embodiment of the present invention.

* Referring to FIG. 6, the synchronous generator control device 100 adjusts the reference signal Vref of the synchronous generator G so that the synchronous generator voltage Vg and the grid voltage Vt match (S201). That is, the synchronous generator control device 100 adjusts the reference signal Vref so that |Vg-Vt|=0.

At this time, the synchronous generator control device 100 checks whether the reactive power (Q) is '0' (S202), and if it is satisfied, checks the first terminal voltage (V1) and the first reactive power (Q1) and stores them. It does (S203). Here, the first terminal voltage V1 becomes a synchronous generator voltage when the first reactive power Q1 is '0'.

Thereafter, the synchronous generator control device 100 increases the voltage of the reference signal Vref of the synchronous generator G to check and store the second terminal voltage V2 and the second reactive power Q2 (S204, S205). ). Here, the reference signal Vref is raised by 4 to 5%.

Then, the synchronous generator control apparatus 100 calculates the system impedance Xe using the reactive power change (Q1-Q2) and the terminal voltage change (V1-V2) (S206). Here, the system impedance can be calculated as in Equation 1 above.

Thereafter, the synchronous generator control apparatus 100 calculates and provides a reference signal variation ΔVsref using the system impedance Xe and the reactive power initial value Qref set by the power plant manager (S207). Here, the reference signal variation (ΔVsref) can be calculated as in Equation 2 above.

Accordingly, the synchronous generator (G) can adjust the terminal voltage of the synchronous generator (G) by adding the reference signal variation (ΔVsref) to the reference signal (Vref) (S208).

As described above, the synchronous generator control device 100 is a reference signal variation amount for adjusting the terminal voltage of the synchronous generator (G) in addition to the reference signal (Vref) so that the synchronous generator can adjust the reactive power when the synchronous generator is initially fed into the grid. (ΔVsref) is calculated and provided.

Methods according to some embodiments may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the medium may be those specially designed and configured for the present invention or those known and usable to those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CDROMs and DVDs, and magnetic-optical media such as floptical disks. Included are hardware devices specially configured to store and execute program instructions, such as magneto-optical media and ROM, RAM, flash memory, and the like. Examples of program instructions include high-level language codes that can be executed by a computer using an interpreter, as well as machine language codes such as those produced by a compiler.

Although the foregoing description has been focused on the novel features of the present invention as applied to various embodiments, one skilled in the art will be able to understand the above-described apparatus and method without departing from the scope of the present invention. It will be appreciated that various deletions, substitutions, and changes in the form and detail of are possible. Accordingly, the scope of the present invention is defined by the appended claims rather than by the foregoing description. All modifications that come within the scope of equivalence of the claims are embraced by the scope of the present invention.

10; grid-tied circuit breaker 20 ; 1st voltage transformer
30; current transformer 40; Second voltage transformer
50; thyristor rectifier 60; PID controller
C; generator field winding G ; synchronous generator
110; Reference signal adjusting unit 120; Reactive power adjustment unit
121; Reactive power calculation unit 122; Impedance calculator
123; Reference signal variation calculation unit 130; speed adjuster

Claims (1)

a reference signal adjustment unit 110 for adjusting the reference signal Vref so that the synchronous generator voltage Vg and the grid voltage Vt coincide; and
A reactive power adjustment unit 120 for calculating and providing a reference signal variation (ΔVsref) for adjusting the terminal voltage of the synchronous generator in addition to the reference signal so that the synchronous generator can adjust the reactive power during initial grid feed-in;
The reactive power adjustment unit,
A reactive power calculation unit 121 for checking a reactive power change and a terminal voltage change using the synchronous generator voltage (Vg) and current (Ig);
an impedance calculator 122 for calculating system impedance Xe using the reactive power change and the terminal voltage change; and
A reference signal variation calculation unit 123 for calculating a reference signal variation (ΔVsref) using the system impedance and an initial reactive power value (Qref) set by a power plant manager;
The reactive power change,
It is calculated as the difference between the first reactive power (Q1) and the second reactive power (Q2),
The first reactive power is confirmed when the synchronous power generation voltage and the grid voltage match,
The second reactive power is confirmed when the voltage increase (ΔV) is reflected in the reference signal during initial grid feed-in,
The terminal voltage change is
It is calculated as the difference between the first terminal voltage (V1) and the second terminal voltage (V2), the first terminal voltage is a synchronous generator voltage when the first reactive power is present, and the second terminal voltage is the second reactive power. is the synchronous generator voltage when
The reference signal variation calculation unit,
A synchronous generator control device having an initial input reactive power adjustment function for calculating the reference signal variation by applying the reactive power current value of other synchronous generators operated in parallel in the vicinity instead of the initial reactive power value.

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