Power transmission line ice melting method based on adjustable inductor and adjustable capacitor

Abstract

The invention provides a power transmission line ice melting method based on an adjustable inductor and an adjustable capacitor. The power transmission line ice melting method comprises the steps that the ice coating amount of a power transmission line is detected; judging whether the icing amount of the power transmission line reaches a set value or not, if yes, controlling a circuit breaker of a distribution network where the power transmission line is located to be disconnected, and controlling the power transmission line to exit overcurrent protection and bus differential protection; the inductance value of the adjustable inductor is adjusted to the maximum value, the capacitance value of the adjustable capacitor is adjusted to the minimum value, and the electric control switch I, the electric control switch II and the electric control switch III are controlled to be closed; controlling the adjustable inductance value to be reduced and controlling the capacitance value of the adjustable capacitor to be increased until the ice melting current flowing through the power transmission line reaches a set value; after ice melting is completed, the inductance value of the adjustable inductor is controlled to be increased to the maximum value, the capacitance value of the adjustable capacitor is controlled to be reduced to the minimum value, and the electric control switch I, the electric control switch II and the electric control switch III are switched off; and controlling over-current protection, bus differential protection and distribution network circuit breaker operation of the power transmission line.

Description

Technical Field

[0001] The invention relates to the field of ice melting for power transmission lines, and in particular to an ice melting method for power transmission lines based on adjustable inductance and adjustable capacitance. Background Art

[0002] In the field of power transmission and transformation, icing of transmission lines is one of the serious problems faced. Icing will increase the load on the transmission lines, causing tower collapse or transmission line breakage, resulting in serious economic losses.

[0003] In the prior art, there are mainly the following ways to melt ice on power transmission lines: one is mechanical, that is, to vibrate the transmission line by vibration, thereby causing the ice to fall off, such as by tapping it with a drone. Although this method can remove ice, it will cause the transmission line to generate a greater instantaneous impact load, resulting in a safety hazard. Another method is to use electric current to melt ice. However, in the existing electric current melting method, in order to melt the ice, a large current is required to generate enough heat, and the end of the ice melting needs to be short-circuited to form a loop. The large current can easily cause the protection mechanism in the transmission line to malfunction. Even if the protection is disconnected, a very large current will be generated at the end of the ice melting, causing the transmission line to burn.

[0004] Therefore, in order to solve the above technical problems, it is urgent to propose a new technical means. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a transmission line de-icing method based on adjustable inductance and adjustable capacitance, wherein an adjustable capacitor is arranged at the input end of the de-icing section of the transmission line and an adjustable inductor is arranged at the de-icing end, and during de-icing, the capacitor and the inductor are used to jointly compensate for the reactive power consumption brought by the system to offset each other, so that the transmission line will not be affected during the de-icing process, thereby effectively ensuring the safety of the transmission line during the de-icing process, and the whole process and system are simple, reliable, and easy to operate.

[0006] The present invention provides a transmission line de-icing method based on adjustable inductance and adjustable capacitance, comprising an adjustable capacitor and an adjustable inductance, wherein the input end of the de-icing section of the transmission line is connected to a DC power supply through an electrically controlled switch I, the output end of the de-icing section of the transmission line is connected to one end of the adjustable inductance through an electrically controlled switch II, the other end of the adjustable inductance is grounded, the input end of the de-icing section of the transmission line is connected to one end of the adjustable capacitor through an electrically controlled switch III, the other end of the adjustable capacitor is grounded;

[0007] The ice melting method specifically comprises:

[0008] S1. Detect the amount of ice on the transmission line; wherein, the amount of ice can be detected by an ice monitoring module, and the ice monitoring module can be obtained by using an existing tension sensor, a pull sensor or a high-definition camera. The detection methods of the tension sensor and the pull sensor are both set on the towers at both ends of the transmission line. If there is no ice, the tension or tension is relatively fixed and near an initial value (of course, it will increase to a certain extent under wind speed). Then, at this time, a compensation judgment is made through a temperature sensor. For example, when the tension reaches the set value, it may be caused by ice or wind. Then, the temperature signal output by the temperature sensor is used to judge whether the current ambient temperature will cause ice, so as to make a supplementary judgment. It is more intuitive to obtain images through a high-definition camera, and the amount of ice is analyzed through the existing image processing method;

[0009] S2. Determine whether the ice coverage of the transmission line reaches the set value. If so, control the circuit breaker of the distribution network where the transmission line is located to disconnect, and control the transmission line to exit the overcurrent protection and bus differential protection; that is, make the overcurrent protection device and the bus differential protection device withdraw from the connection with the transmission line;

[0010] S3. Adjust the inductance value of the adjustable inductor to the maximum value and the capacitance value of the adjustable capacitor to the minimum value, and control the electric control switch I, the electric control switch II, and the electric control switch III to close; wherein the adjustable inductor adopts the existing automatic adjustable inductor, and the adjustable capacitor can adopt the existing digital adjustable capacitor, and both are controlled by the control unit;

[0011] S4. Control the adjustable inductance value to decrease and control the adjustable capacitance value to increase until the ice-melting current flowing through the transmission line reaches a set value; the ice-melting current flowing through the transmission line is realized by an existing current sensor, such as a current transformer, an electromagnetic current sensor (such as a TMR tunnel magnetoresistive current sensor), etc.;

[0012] S5. After the ice melting is completed, the inductance value of the adjustable inductor is controlled to increase to the maximum value and the capacitance value of the adjustable capacitor is controlled to decrease to the minimum value, and the electronically controlled switch I, the electronically controlled switch II and the electronically controlled switch III are disconnected; wherein the electronically controlled switch may be realized by an existing relay, contactor, etc., or may be realized by a semiconductor electronic switch such as an IGBT, a MOS tube, etc.;

[0013] S6. Control the overcurrent protection of the transmission line, busbar differential protection and distribution network circuit breaker to be put into operation.

[0014] Furthermore, it also includes a control unit, which is used to control the distribution network circuit breaker, the protection switch, and the electric control switch I, the electric control switch II and the electric control switch III to close or open.

[0015] Furthermore, it also includes an icing monitoring module, which is used to detect the icing status of the target transmission line and output it to the control unit.

[0016] Furthermore, it also includes a current sensor, which is used to monitor the ice melting current of the transmission line and output a current monitoring signal to the control unit.

[0017] Furthermore, it also includes a positioning module, which is used to obtain the current position of the ice-melting section of the transmission line and output it to the control unit, and the control unit uploads the position information for early warning.

[0018] Beneficial effects of the present invention: Through the present invention, an adjustable capacitor is set at the input end of the ice-melting section of the transmission line and an adjustable inductor is set at the ice-melting end. During ice melting, the capacitor and the inductor are used to compensate for the reactive power consumption brought by the system to offset each other, so that the transmission line will not be affected during the ice-melting process, thereby effectively ensuring the safety of the transmission line during the ice-melting process, and the whole process and system are simple, reliable, and easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present invention will be further described below in conjunction with the accompanying drawings and embodiments:

[0020] Figure 1 It is a structural schematic diagram of the present invention.

[0021] Figure 2 It is a schematic diagram of the process of the present invention.

[0022] Figure 3 It is a schematic diagram of an actual three-phase power grid of the present invention.

[0023] Figure 4 It is the equivalent circuit diagram of the present invention. DETAILED DESCRIPTION

[0024] The present invention is further described in detail below:

[0025] The present invention provides a transmission line de-icing method based on adjustable inductance and adjustable capacitance, including an adjustable capacitor and an adjustable inductance, wherein the input end of the de-icing section of the transmission line is connected to a DC power supply via an electrically controlled switch I, the output end of the de-icing section of the transmission line is connected to one end of the adjustable inductance via an electrically controlled switch II, the other end of the adjustable inductance is grounded, the input end of the de-icing section of the transmission line is connected to one end of the adjustable capacitor via an electrically controlled switch III, the other end of the adjustable capacitor is grounded; wherein the input end of the de-icing section of the transmission line is defined as an end connected to a DC power supply, the grounding in the above-mentioned definition is a 0 potential point, which is connected to the negative pole of the DC power supply to form a loop. Figure 3 As shown in the figure, in practice, the transmission line is 3-phase, with adjustable inductance and adjustable capacitance. Figure 4is an equivalent circuit, AC is a DC power supply, CB1 is an electronically controlled switch I, R1 is a line equivalent resistance, L2 is a line equivalent inductance, C1 and C2 are line equivalent capacitances, and L2 and C3 are adjustable inductance and adjustable capacitance.

[0026] The ice melting method specifically comprises:

[0027] S1. Detect the amount of ice on the transmission line; wherein, the amount of ice can be detected by an ice monitoring module, and the ice monitoring module can be obtained by using an existing tension sensor, a pull sensor or a high-definition camera. The detection methods of the tension sensor and the pull sensor are both set on the towers at both ends of the transmission line. If there is no ice, the tension or tension is relatively fixed and near an initial value (of course, it will increase to a certain extent under wind speed). Then, at this time, a compensation judgment is made through a temperature sensor. For example, when the tension reaches the set value, it may be caused by ice or wind. Then, the temperature signal output by the temperature sensor is used to judge whether the current ambient temperature will cause ice, so as to make a supplementary judgment. It is more intuitive to obtain images through a high-definition camera, and the amount of ice is analyzed through the existing image processing method;

[0028] S2. Determine whether the ice coverage of the transmission line reaches the set value. If so, control the circuit breaker of the distribution network where the transmission line is located to disconnect, and control the transmission line to exit the overcurrent protection and bus differential protection; that is, make the overcurrent protection device and the bus differential protection device withdraw from the connection with the transmission line;

[0029] S3. Adjust the inductance value of the adjustable inductor to the maximum value and the capacitance value of the adjustable capacitor to the minimum value, and control the electric control switch I, the electric control switch II, and the electric control switch III to close; wherein the adjustable inductor adopts the existing automatic adjustable inductor, and the adjustable capacitor can adopt the existing digital adjustable capacitor, and both are controlled by the control unit;

[0030] S4. Control the adjustable inductance value to decrease and control the adjustable capacitance value to increase until the ice-melting current flowing through the transmission line reaches a set value; the ice-melting current flowing through the transmission line is realized by an existing current sensor, such as a current transformer, an electromagnetic current sensor (such as a TMR tunnel magnetoresistive current sensor), etc.;

[0031] S5. After the ice melting is completed, the inductance value of the adjustable inductor is controlled to increase to the maximum value and the capacitance value of the adjustable capacitor is controlled to decrease to the minimum value, and the electronically controlled switch I, the electronically controlled switch II and the electronically controlled switch III are disconnected; wherein the electronically controlled switch may be realized by an existing relay, contactor, etc., or may be realized by a semiconductor electronic switch such as an IGBT, a MOS tube, etc.;

[0032] S6. Control the overcurrent protection, bus differential protection and distribution network circuit breaker of the transmission line to be put into operation. Through the above method, an adjustable capacitor is set at the input end of the ice-melting section of the transmission line and an adjustable inductor is set at the ice-melting end. During ice-melting, the capacitor and inductor are used to compensate for the reactive power consumption brought by the system, so that the transmission line will not be affected during the ice-melting process, thereby effectively ensuring the safety of the transmission line during the ice-melting process, and the whole process and system are simple, reliable and easy to operate.

[0033] In this embodiment, a control unit is also included, and the control unit is used to control the distribution network circuit breaker, the protection switch, and the electric control switch I and the electric control switch II to close or open, wherein the protection switch refers to the connection switch between the overcurrent protection device, the bus differential protection device and the transmission line. The control unit adopts an existing control chip, an industrial computer, etc.

[0034] In this embodiment, a positioning module is also included. The positioning module is used to obtain the current position of the ice-melting section of the transmission line and output it to the control unit. The control unit uploads the position information for early warning. The positioning module uses an existing GPS positioning module or a Beidou positioning module to mark the position of the ice-melting section of the transmission line. The control unit uploads the position information, the monitoring information before ice melting, and the ice melting process information to the distribution network operation and maintenance dispatching center for subsequent inspection and tracing.

[0035] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution of the present invention, which should be included in the scope of the claims of the present invention.

Claims

1. A method for melting ice on a power transmission line based on adjustable inductance and adjustable capacitance, characterized in that: It includes an adjustable capacitor and an adjustable inductor, wherein the input end of the ice-melting section of the transmission line is connected to a DC power supply through an electrically controlled switch I, the output end of the ice-melting section of the transmission line is connected to one end of the adjustable inductor through an electrically controlled switch II, the other end of the adjustable inductor is grounded, the input end of the ice-melting section of the transmission line is connected to one end of the adjustable capacitor through an electrically controlled switch III, the other end of the adjustable capacitor is grounded; The ice melting method specifically comprises: S1. Detect the amount of ice on the transmission line; S2. Determine whether the ice coverage of the transmission line reaches the set value. If so, control the circuit breaker of the distribution network where the transmission line is located to disconnect, and control the transmission line to exit the overcurrent protection and bus differential protection; S3. Adjust the inductance value of the adjustable inductor to the maximum value and the capacitance value of the adjustable capacitor to the minimum value, and control the electronically controlled switch I, the electronically controlled switch II, and the electronically controlled switch III to be closed; S4. Control the adjustable inductance value to decrease and control the adjustable capacitance value to increase until the ice-melting current flowing through the transmission line reaches a set value; S5. After the ice melting is completed, the inductance value of the adjustable inductor is controlled to increase to the maximum value and the capacitance value of the adjustable capacitor is controlled to decrease to the minimum value, and the electronically controlled switches I, II and III are disconnected; S6. Control the overcurrent protection of the transmission line, busbar differential protection and distribution network circuit breaker to be put into operation.

2. The method for melting ice on a power transmission line based on adjustable inductance and adjustable capacitance according to claim 1 is characterized in that: It also includes a control unit, which is used to control the distribution network circuit breaker, the protection switch, and the electric control switch I, the electric control switch II and the electric control switch III to close or open.

3. The method for melting ice on a power transmission line based on adjustable inductance and adjustable capacitance according to claim 2 is characterized in that: It also includes an ice-covering monitoring module, which is used to detect the ice-covering state of the target power transmission line and output it to the control unit.

4. The method for melting ice on a power transmission line based on adjustable inductance and adjustable capacitance according to claim 2 is characterized in that: The system also includes a current sensor, which is used to monitor the ice melting current of the power transmission line and output a current monitoring signal to the control unit.

5. The method for melting ice on a power transmission line based on adjustable inductance and adjustable capacitance according to claim 2 is characterized in that: It also includes a positioning module, which is used to obtain the current position of the ice-melting section of the transmission line and output it to the control unit, and the control unit uploads the position information for early warning.

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