KR102655598B1 - Device providing lagging reactive power and method for controlling temperature correction thereof - Google Patents

Abstract

The present disclosure relates to a method for controlling a terrestrial reactive power supply and its temperature compensation. The device includes a circuit breaker connected to a power system; A thyristor valve including a first thyristor and a second thyristor connected in anti-parallel to the first thyristor; A reactor connected to the thyristor valve; And it may include a control unit configured to adjust the amount of current generated in the reactor by controlling the firing angles of the first thyristor and the second thyristor. The control unit may be configured to receive temperature information of the reactor and, when the temperature of the reactor exceeds a set first temperature, adjust the firing angle until the temperature of the reactor becomes below the first temperature. According to the present disclosure, it is possible to provide a method for controlling the temperature of a reactor applied to a reactive power supply device without disconnecting the reactive power supply device from the power system.

Description

{DEVICE PROVIDING LAGGING REACTIVE POWER AND METHOD FOR CONTROLLING TEMPERATURE CORRECTION THEREOF}

The present disclosure relates to reactive power supplies, and more particularly to methods for controlling terrestrial reactive power supplies and their temperature compensation.

When operating a power system, the number of substations experiencing not only voltage drops due to ground reactive power but also voltage increases due to leading reactive power is increasing. This phenomenon can mainly occur due to the following causes:

- Due to the increase in renewable energy power plants, the power factor is supplied at '1', but the capacitive component increases due to the capacitive component of the underground cable.

- Apartment complexes in new cities exclude the use of ground cables due to microscopic problems and supply power through underground cables, so this occurs due to the capacitive component of the cable.

- In the past, it has become common to insert capacitors, which are capacitive components, at the power receiving end due to the use of a lot of motor-type loads. However, as the high power factor/high efficiency loads using power electronic devices have recently increased, the capacitive components are reduced due to the already inserted capacitors. Oversupplied.

To solve this problem, a stationary ground reactive power supply device that can adjust and supply ground reactive power through thyristor control by applying a reactor in parallel to a high-voltage or extra-high voltage power system can be applied. However, in such a stationary ground reactive power supply device, when high temperature is generated in the reactor due to overheating, etc., if maintenance is performed by opening the circuit breaker applied at the front, the system operation becomes impossible and the reactive power required for the power system cannot be supplied. It can happen.

Therefore, a solution is needed to control the temperature of the reactor applied to the reactive power supply without interrupting system operation.

The present disclosure to solve these problems aims to provide a method for controlling a ground reactive power supply and its temperature compensation.

According to one embodiment of the present disclosure, a ground reactive power supply device is provided. The device includes a circuit breaker connected to a power system; A thyristor valve including a first thyristor and a second thyristor connected in anti-parallel to the first thyristor; A reactor connected to the thyristor valve; And it may include a control unit configured to adjust the amount of current generated in the reactor by controlling the firing angles of the first thyristor and the second thyristor. The control unit may be configured to receive temperature information of the reactor and, when the temperature of the reactor exceeds a set first temperature, adjust the firing angle until the temperature of the reactor becomes below the first temperature.

In addition, the control unit increases the firing angle by a predetermined phase, and compares the generated reactive power value generated at the increased firing angle with the target reactive power value, or the generated voltage value at the increased firing angle and the target voltage. It may be configured to compare values and enter an interrupt mode if the generated reactive power value is not equal to the target reactive power value or the generated voltage value is not equal to the target voltage value.

Additionally, in the interrupt mode, the control unit compares the temperature of the reactor with the first temperature, and if the temperature of the reactor is greater than the first temperature, reduces the firing angle by the predetermined phase, and the temperature of the reactor It may be configured to repeat the operation of comparing with the first temperature and the operation of reducing the firing angle until it becomes below the first temperature.

Additionally, in the interrupt mode, the control unit may be configured to turn off the circuit breaker when the temperature of the reactor exceeds a set second temperature that is higher than the first temperature.

Additionally, when the temperature of the reactor falls below the first temperature, the control unit may be configured to end the interrupt mode and maintain the current firing angle.

In addition, the control unit determines the firing angle when the generated reactive power value is equal to the set maximum reactive power value, the generated reactive power value is equal to the target reactive power value, or the generated voltage value is equal to the target voltage value. It can be configured to maintain .

Additionally, the control unit may be configured to output an alarm or warning signal when the temperature of the reactor exceeds the first temperature.

According to one embodiment of the present disclosure, a method for controlling temperature compensation of a terrestrial reactive power supply is provided. The ground reactive power supply device includes a circuit breaker, a thyristor valve, a reactor connected to the thyristor valve, and a control unit configured to adjust the amount of current generated in the reactor by controlling the firing angle of the thyristor valve and to monitor temperature information of the reactor. The method includes: increasing the firing angle of the thyristor valve by a predetermined phase in the control unit; Comparing the generated reactive power value generated in the reactor at the increased firing angle with a target reactive power value or comparing the generated voltage value at the increased firing angle with a target voltage value; Entering an interrupt mode when the generated reactive power value is not equal to the target reactive power value or the generated voltage value is not equal to the target voltage value; In the interrupt mode, comparing the temperature of the reactor with a set first temperature and reducing the firing angle by the predetermined phase if the temperature of the reactor is greater than the first temperature; It may include terminating the interrupt mode and maintaining the current firing angle when the temperature of the reactor falls below the first temperature.

Additionally, the method may further include maintaining the firing angle when the generated reactive power value is equal to the target reactive power value or when the generated voltage value is equal to the target voltage value.

Additionally, the method may further include turning off the breaker when the temperature of the reactor exceeds a set second temperature that is higher than the first temperature in the interrupt mode.

According to the present disclosure, it is possible to provide a method for controlling the temperature of a reactor applied to a reactive power supply device without disconnecting the reactive power supply device from the grid.

In addition, according to the present disclosure, there is an effect of increasing maintenance efficiency by starting temperature compensation in advance at a set temperature lower than the high temperature at which the reactor of the reactive power supply device needs to be shut off.

In addition, according to the present disclosure, there is an effect of preventing overheating of the reactor of the reactive power supply device and extending the life of the reactor, thereby preventing interruption of ground reactive power supply to the system due to maintenance.

1 is an exemplary conceptual diagram of supplying ground reactive power using a thyristor-controlled reactor.
Figure 2 is an exemplary conceptual diagram of supplying ground reactive power using a magnetic field control reactor.
Figure 3 is an exemplary diagram showing the configuration of a ground reactive power supply device to which a temperature compensation control method is applied according to an embodiment of the present disclosure.
4 is an exemplary flowchart illustrating a method for controlling temperature compensation of a reactor in a ground reactive power supply device according to an embodiment of the present disclosure.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. First, when adding reference numerals to components in each drawing, it should be noted that identical components are given the same reference numerals as much as possible even if they are shown in different drawings. Additionally, in describing the present invention, if it is determined that a detailed description of a related known configuration or function may obscure the gist of the present invention, the detailed description will be omitted.

Various aspects of the invention are described below. It is to be understood that the inventions presented herein may be implemented in a wide variety of forms and that any particular structure, function, or both, presented herein is illustrative only. Based on the inventions presented herein, those skilled in the art will understand that one aspect presented herein can be implemented independently of any other aspects and that two or more of these aspects can be implemented in various ways. You will understand that it can be combined with . For example, an apparatus may be implemented or a method may be practiced using any number of the aspects set forth herein. Additionally, such an apparatus may be implemented or such a method may be practiced using other structure, functionality, or structure and functionality in addition to or other than one or more aspects described herein.

The present disclosure is a Static Var Compensator (SVC) using a thyristor that can be applied to a flexible AC Transmission System (FACTS), a SVC-TCR (Thyristor Controlled Reactor) method that can provide ground reactive power to the power system, or It can be applied to a SVC-MCR (Magnetically Controlled Reactor) type reactive power supply device. Additionally, the power system referred to herein may be a three-phase power system.

1 is an exemplary conceptual diagram of supplying ground reactive power using a thyristor-controlled reactor.

As shown in FIG. 1, the TCR type reactive power supply device may operate by varying the reactor 130 using the thyristor valve 120. The thyristor valve 120 is directly connected to the high-voltage or extra-high-voltage power system 100, and a breaker 110 that can disconnect the reactive power supply device from the system is installed between the power system 100 and the thyristor valve 120. It can be located in . This TCR type reactive power supply device can supply ground reactive power to the power system by adjusting the generated current through phase control (i.e. firing angle control) of the thyristor valve 120.

Figure 2 is an exemplary conceptual diagram of supplying ground reactive power using a magnetic field control reactor.

As shown in FIG. 2, the MCR type reactive power supply device includes a transformer reactor 150 consisting of a primary winding and a secondary winding, and the primary winding side of the reactor 150 is connected to a high-voltage or extra-high-voltage power system. It can be directly connected to (110). The AC-DC converter 140 for supplying direct current (DC) current including a thyristor valve can generate DC current in the secondary winding through phase control of the thyristor. This MCR type reactive power supply device can supply ground reactive power to the power system by using magnetic field saturation characteristics to generate current in the primary winding through DC current in the secondary winding.

As described above, in the TCR or MCR type reactive power supply device, the reactor 130 or 150 is connected to the high voltage or extra high voltage power system 110, so the reactor may exceed the set operating range due to overheating during operation. When the temperature becomes high, it is necessary to open the breaker 110 to prevent failure or damage to the reactor, separate it from the power system 100, and then perform maintenance. However, if the reactive power supply device is separated from the power system 100 for maintenance, the reactive power supply required for the system cannot be supplied, so the present disclosure does not separate the reactive power supply device from the power system 100. We would like to propose a method to control the temperature compensation of the reactor in a non-reactive state (i.e., while maintaining the operation of the reactive power supply).

Figure 3 is an exemplary diagram showing the configuration of a ground reactive power supply device to which a temperature compensation control method is applied according to an embodiment of the present disclosure.

As shown in FIG. 3, the ground reactive power supply device according to the present disclosure includes a circuit breaker 110, a thyristor valve 120, a reactor 130, a control unit 200, and a voltage sensor (PT: Potential Transformer) 210. ), a current sensor (CT: Current Transformer) 220, and HMI (Human Machine Interface) 300.

For example, high voltage or extra-high voltage of 1 kV to 27.5 kV may be applied to the power system 100 depending on the specifications of the corresponding power receiving end. The circuit breaker 110 is directly connected to the power system 100 and may include a fuse and a switch to separate the circuit breaker from the power system 100 in the event of an accident. The thyristor valve 120 may include a first thyristor and a second thyristor connected in anti-parallel with the first thyristor, and this anti-parallel configuration may allow forward and reverse current conduction. The degree of conduction of the first thyristor and the second thyristor may be controlled depending on the phase (ie, firing angle). In one implementation, the thyristor valve 130 may be composed of a plurality of pairs of thyristors connected in anti-parallel, and these pairs of thyristors may be stacked and connected in series to have high voltage resistance. The reactor 130 may be connected to the thyristor valve 120 and may be a large-capacity reactor that meets the standards of the power system to be applied. The reactor may be a reactor 130 as shown in FIG. 1 or a transformer reactor 150 as shown in FIG. 2 depending on the implementation. For convenience of explanation, the present disclosure will be described below based on the reactor 130.

The control unit 200 may be configured to adjust the amount of current generated in the reactor 130 by performing phase control (i.e., firing angle control) of the first thyristor and the second thyristor of the thyristor valve 120. In addition, as will be described in detail later, the control unit 200 can monitor the temperature information of the reactor 130, and when the temperature of the reactor 130 exceeds the first temperature set as the first stage critical temperature, the reactor 130 ) may be configured to adjust the firing angle of the thyristor valve 120 until the temperature becomes below the first temperature. For example, the second temperature, which is a two-stage critical temperature higher than the first temperature, may be set as a temperature at which the reactor 130 applied to the reactive power supply device may fail due to overheating, and the first temperature is the temperature at which the reactor 130 may fail. It is a temperature in the range that can operate normally, but it is a temperature that can be set to a point where temperature compensation is required before overheating to the second temperature. The control unit 200 may be configured to output an alarm or warning signal when the temperature of the reactor 100 exceeds the first temperature, and may be configured to output an alarm or warning signal when the temperature exceeds the second temperature. For example, an alarm or warning signal when the first temperature is exceeded may be set to be output differently so that it can be distinguished from an alarm or warning signal when the second temperature is exceeded. Through this configuration, the temperature range at which the reactor 100 can operate normally is within the range, but an alarm is output when the first temperature is exceeded, thereby performing maintenance in advance before the reactive power supply device needs to be separated from the power system 100 in the power system operating system. It is possible to prepare for.

The voltage sensor (PT) 210 can measure the voltage of the power system 100 and provide the voltage to the control unit 200. The current sensor (CT) 220 can measure the current of the power system 100 and provide it to the control unit 200. The HMI 300 is a device that allows an operator to perform system settings, system status monitoring, and system control, and is connected to the control unit 200 through a predetermined communication network (e.g., a communication network applied to the facility, such as RS-485, etc.). You can. In addition, the HMI 300 can perform monitoring of the power system, and determines the target reactive power value, target voltage value, maximum reactive power amount, first temperature that is the first stage dangerous temperature, and second stage dangerous temperature related to the reactive power supply device. The second temperature, etc. can be predicted or set. In one implementation, upon receiving the target reactive power value or target voltage value from the HMI 300, the controller 200 controls the ground reactive power value or target voltage through control of the thyristor valve 120 to reach the target reactive power value or target voltage. It may be configured to generate power. Additionally, in one implementation, when the state of the power system 100 changes during operation, the target reactive power value, target voltage value, etc. may be changed by the HMI 300, and the control unit 200 may respond to the changed target values. Accordingly, it may be configured to generate ground reactive power.

The control unit 200 may include an interface 201, a control unit 202, a voltage detection unit 203, a current detection unit 204, an input/output unit (IN/OUT) 205, and a display unit 206. The interface 201 may perform an interfacing role for transmitting a thyristor control signal to the thyristor valve 120 and receiving monitoring data such as status information from the thyristor valve 120 . Additionally, the interface 201 may receive temperature information of the reactor 130 measured by a measuring means such as a temperature sensor and transmit it to the control unit 202. The control unit 202 may be configured to control the operation of the control unit 200, and depending on the implementation, may be implemented as a central processing unit (CPU), and other processing units such as FPGA (Field Programmable Gate Array) may be added. It may be in an integrated form. The voltage detection unit 203 may receive the measured voltage value from the voltage sensor 210, and the current detection unit 204 may receive the measured current value from the current sensor 220. The input/output unit 205 may be provided with an input port and an output port for data input/output, and the display unit 206 may display various states (normal state, abnormal state, first temperature) of the reactive power supply device through a light emitting means such as an LED. exceedance notification, second temperature exceedance notification, etc.) can be visually displayed.

When the target reactive power value (Qref), target voltage value (Vref), first-stage reactor temperature (T1), and second-stage reactor temperature (T2) are set by the HMI 300, the control unit 200 operates at the current firing angle. The firing angle of the thyristor valve 120 may be increased by a predetermined phase (eg, 1 degree, etc.). The control unit 200 may determine the current generated in the reactor 130 and the voltage applied to the reactive power supply device at the increased firing angle, and determine the generated reactive power value based on the determined current value and voltage value. If the generated reactive power value is equal to the set maximum reactive power value, the control unit 200 cannot maintain the phase control value (firing angle) of the thyristor valve 120 because additional reactive power supply is not possible from the corresponding reactive power supply device. there is. If the generated reactive power value is smaller than the maximum reactive power value, the control unit 200 compares the generated reactive power value generated at the increased firing angle with the target reactive power value (Qref) or the generated voltage value at the increased firing angle. and the target voltage value (Vref) can be compared. The control unit 200 may be configured to enter an interrupt mode to correct the temperature of the reactor 130 when the generated reactive power value is not equal to the target reactive power value or the generated voltage value is not equal to the target voltage value. In addition, the control unit 200 maintains the phase control value (firing angle) of the thyristor valve 120 because the goal has been achieved when the generated reactive power value is equal to the target reactive power value or the generated voltage value is equal to the target voltage value. You can.

In the interrupt mode, the control unit 200 may compare the temperature of the reactor 130 with the first temperature T1, which is a first-stage critical temperature. When the temperature of the reactor 130 is greater than the first temperature, the control unit 200 reduces the firing angle by a predetermined phase (e.g., 1 degree, etc.), and when the temperature of the reactor 130 is below the first temperature, the control unit 200 reduces the firing angle by a predetermined phase (e.g., 1 degree, etc.). It may be configured to repeat the operation of comparing the above-described first temperature and the operation of reducing the firing angle. Since the reactor 130 may overheat as the generated current increases, the temperature of the reactor 130 can be gradually reduced by gradually reducing the generated current by gradually reducing the firing angle. The control unit 200 may end the interrupt mode and maintain the current firing angle when the temperature of the reactor 130 falls below the first temperature through a gradual decrease in the firing angle in the interrupt mode.

Additionally, in the interrupt mode, the control unit 200 may compare the temperature of the reactor 130 with a second temperature (T2), which is a two-stage critical temperature higher than the first temperature, and the temperature of the reactor 130 may be set to the second temperature. If it exceeds the limit, it may be configured to turn off the circuit breaker 110 of the reactive power supply device to prevent failure of the reactor 130. Accordingly, when the reactor 130 is heated to an extent that exceeds the second temperature, the reactive power supply device can be separated from the power system 100.

Through this configuration, the present disclosure makes it possible to control the temperature of the reactor applied to the reactive power supply without disconnecting the reactive power supply from the power system 100 (i.e., while maintaining the operation of the reactive power supply). can provide a solution. Through this, the present disclosure increases maintenance efficiency and increases maintenance efficiency by starting temperature compensation in advance at a set temperature (first temperature) lower than the high temperature (second temperature) at which the reactor 130 of the reactive power supply device needs to be shut off. (130) The lifespan can be extended.

4 is an exemplary flowchart illustrating a method for controlling temperature compensation of a reactor in a ground reactive power supply device according to an embodiment of the present disclosure.

As shown in FIG. 4, the target reactive power value (Qref), target voltage value (Vref), first temperature (T1), and second temperature (T2) may be set by the HMI 300 (S410). . When setting the target reactive power value (Qref) as the judgment standard in step S415, the control unit 200 may increase the firing angle of the thyristor valve 120 by a predetermined phase (e.g., 1 degree, etc.) ( S420). The control unit 200 may compare the generated reactive power value generated at the increased firing angle with the maximum reactive power value (S425), and if the generated reactive power value is equal to the maximum reactive power value, the firing angle of the thyristor valve 120 may be adjusted. It can be maintained (S450). If the generated reactive power value is not the same as (i.e., smaller than) the maximum reactive power value, the control unit 200 may compare the generated reactive power value and the target reactive power value (Qref) (S430), and if they are not the same, If not, you can enter interrupt mode.

Meanwhile, when setting the target voltage value (Vref) as the judgment standard in step S415, the control unit 200 may increase the firing angle of the thyristor valve 120 by a predetermined phase (e.g., 1 degree, etc.). (S435). The control unit 200 may compare the generated reactive power value generated at the increased firing angle with the maximum reactive power value (S440), and if the generated reactive power value is equal to the maximum reactive power value, the firing angle of the thyristor valve 120 may be adjusted. It can be maintained (S450). If the generated reactive power value is not equal to (i.e., smaller than) the maximum reactive power value, the control unit 200 compares the generated voltage value (or the voltage value of the power system 100) with the target voltage value (Vref). (S445), and if they are not the same, interrupt mode can be entered.

In the interrupt mode, the control unit 200 can compare the temperature of the reactor 130 with the second temperature (T2) (S465), and when it exceeds the second temperature (T2), turns off the breaker 110 to generate reactive power. The supply device can be separated from the power system 100 (S470). If the temperature of the reactor 130 is below the second temperature (T2), the control unit 200 may compare the temperature of the reactor 130 and the first temperature (T1) (S475). When the temperature of the reactor 130 exceeds the first temperature (T1), the control unit 200 reduces the firing angle of the thyristor valve 120 by a predetermined phase (S480), and again increases the temperature and the temperature of the reactor 130. The first temperature (T1) can be compared (S485). Steps S480 and S485 may be repeatedly performed until the temperature of the reactor 130 becomes below the first temperature T1. As a result of repeating S480 and S485, when the temperature of the reactor 130 becomes below the first temperature (T1), the control unit 200 ends the interrupt mode and, if the power system is not turned off in S455, the current point The whistle can be maintained (S450). Meanwhile, in step S475, if the temperature of the reactor 130 is below the first temperature T1, the interrupt mode is immediately terminated, and the control unit 200 may perform steps S420 to S430 or steps S435 to S445 again.

While maintaining the firing angle of the thyristor valve 120 in step S450, if it is determined to turn off the power system (S455), the firing angle may be initialized to 0 (S460) and the process may be terminated.

The description of the presented embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments without departing from the scope of the invention. Thus, the present invention is not limited to the embodiments presented herein, but is to be construed in the broadest scope consistent with the principles and novel features presented herein.

100: power system
110: circuit breaker
120: Thyristor valve
130: reactor
140: AC-DC converter
150: Transformer reactor
200: control unit
201: interface
202: control unit
203: voltage detection unit
204: Current detection unit
205: Input/output unit (IN/OUT)
206: display unit
300: HMI

Claims (10)

As a ground reactive power supply,
Circuit breaker connected to the power system;
A thyristor valve including a first thyristor and a second thyristor connected in anti-parallel to the first thyristor;
A reactor connected to the thyristor valve; and
It includes a control unit configured to adjust the amount of current generated in the reactor by controlling the firing angles of the first thyristor and the second thyristor,
The control unit is configured to monitor temperature information of the reactor,
The control unit increases the firing angle by a predetermined phase, compares the generated reactive power value generated at the increased firing angle with the target reactive power value, or compares the generated voltage value at the increased firing angle with the target voltage value. Compare, and maintain the firing angle if the generated reactive power value is equal to the target reactive power value or the generated voltage value is equal to the target voltage value, and the generated reactive power value is equal to the target reactive power value. Configured to enter interrupt mode if not done or if the generated voltage value is not equal to the target voltage value,
In the interrupt mode, the control unit compares the temperature of the reactor with a set first temperature, and if the temperature of the reactor is greater than the first temperature, decreases the firing angle by the predetermined phase, and the control unit reduces the firing angle by the predetermined phase when the temperature of the reactor is greater than the first temperature. By repeating the operation of comparing the first temperature and the operation of decreasing the firing angle until the temperature falls below the first temperature, when the temperature of the reactor exceeds the first temperature, the temperature of the reactor falls below the first temperature. It is configured to adjust the firing angle until
When the temperature of the reactor falls below the first temperature, the control unit is configured to end the interrupt mode and maintain the current firing angle,
In the interrupt mode, the control unit is configured to turn off the circuit breaker when the temperature of the reactor exceeds a set second temperature that is higher than the first temperature.
Ground reactive power supply. delete delete delete delete delete According to claim 1,
The control unit is configured to output an alarm or warning signal when the temperature of the reactor exceeds the first temperature,
Ground reactive power supply. A method for controlling temperature compensation of a ground reactive power supply, comprising:
The ground reactive power supply device includes a circuit breaker, a thyristor valve, a reactor connected to the thyristor valve, and a control unit configured to adjust the amount of current generated in the reactor by controlling the firing angle of the thyristor valve and to monitor temperature information of the reactor. It includes, and the method includes,
increasing the firing angle of the thyristor valve by a predetermined phase in the control unit;
Comparing the generated reactive power value generated at the increased firing angle with a target reactive power value or comparing the generated voltage value generated at the increased firing angle with a target voltage value; and
maintaining the firing angle when the generated reactive power value is equal to the target reactive power value or the generated voltage value is equal to the target voltage value;
Entering an interrupt mode when the generated reactive power value is not equal to the target reactive power value or the generated voltage value is not equal to the target voltage value;
In the interrupt mode, the temperature of the reactor is reduced by repeating the operation of comparing the temperature of the reactor with a set first temperature and reducing the firing angle by the predetermined phase when the temperature of the reactor is greater than the first temperature. adjusting the firing angle until the first temperature is lower than or equal to the first temperature; and
When the temperature of the reactor falls below the first temperature, terminating the interrupt mode and maintaining the current firing angle,
The above method is,
In the interrupt mode, further comprising turning off the circuit breaker when the temperature of the reactor exceeds a set second temperature that is higher than the first temperature.
Method for controlling temperature compensation of terrestrial reactive power supply. delete delete