CN100578882C - Ice-melting system for high-voltage transmission line under load - Google Patents

Abstract

An ice-melting system for high-voltage transmission lines running under load. The transmission lines include at least two transmission wires. The power transmission wire is divided into several subsections; at least two shunts and at least one ice-melting power supply unit are provided with terminals equal in number to the number of power transmission wires; the shunts and the ice-melting power supply unit alternate It is installed at each installation point of the transmission line, and its terminals are connected to the contacts on the transmission wire one by one; the two sub-sections between two adjacent installation points of the transmission line, the shunt and the ice-melting power supply device form a regional ice-melting circuit The ice-melting power supply device is used to connect the two sub-sections in the circuit and provide a loop current to the loop. The switch for gating the sub-sections and the choke to prevent the load current of the transmission wire from passing into the loop are connected in series.

Description

Ice-melting system for high-voltage transmission line under load

technical field

The invention relates to an ice-melting system applied to a high-voltage transmission line running under load in a high-voltage transmission system.

Background technique

In the high-voltage transmission system, the transmission line is erected for a long distance and passes through multiple meteorological regions. Under severe cold and harsh weather conditions, it is easy to cause an icing accident on the high-voltage transmission line, causing transmission interruption, and causing huge losses to enterprises and society.

Among the existing anti-icing and ice-melting solutions, there are over-current ice-melting technology, short-circuit ice-melting technology, heat-resistant alloy wire anti-icing and ice-melting technology, etc. In the anti-icing and ice-melting technology of heat-resistant alloy wires, the characteristics of the wires running at higher temperatures are used to melt the ice and prevent the lines from icing in the high-voltage transmission system, but the disadvantage is that the wires run at high temperatures for a long time In the area, the heat loss is large, and it is not economical. In the line short-circuit ice melting technology, if there is no load, the power transmission will be interrupted; if there is a load, the short-circuit current will cause a great impact on the power grid. In the existing over-current ice-melting technology, no matter whether it is loaded or not, the solution is all lines, and the heat loss is also relatively large. In addition, when the same phase or the same pole of the power transmission system uses a single wire for power transmission, or uses a split wire for power transmission, the existing overcurrent ice melting technology cannot achieve the ice melting when the line is running under load.

For example, in the Chinese utility model patent whose publication number is CN 200944519Y, a kind of transmission line automatic melting ice device is disclosed. When the ice needs to be melted, the current of one wire is zeroed by the current switching switch, and the current of the other wire is doubled. The utility model patent uses over-current technology to realize the melting of ice cubes, but during the ice-melting process, all circuits are in over-current phenomenon, resulting in a large heat loss.

If in the power transmission system, when the wires are covered with ice, an additional current can be applied to the wires in the ice-covered area without affecting the running of the line under load, and a small-scale over-current ice-melting scheme can be implemented. It solves the problem of ice melting of the line with load operation and low heat loss.

Contents of the invention

The technical problem to be solved by the present invention is to provide an ice-melting system for high-voltage transmission lines operating under load. The system can increase the current of the transmission wires in different areas to generate heat and realize ice-melting with low heat loss.

The technical solution of the present invention is as follows: an ice-melting system for a high-voltage transmission line operating under load, the transmission line includes at least two transmission wires, and adopts direct current or alternating current transmission. For the above installation points, a joint is drawn from each power transmission line at each installation point, and the joints divide the power transmission line into several subsections; it also includes at least two shunts and at least one ice-melting power supply unit, the shunt and the melting The ice power supply devices are equipped with terminals equal in number to the number of power transmission wires; the shunts and ice melting power supply devices are alternately arranged on each installation point of the power transmission line, and the terminals are connected to the contacts on the power transmission wires one by one; The two sub-sections belonging to different transmission wires between two adjacent installation points of the transmission line constitute the regional ice-melting circuit with the shunt and the ice-melting power supply unit. The two sub-sections in the loop are connected, and a loop current is provided to the loop, and a switch for gating the sub-sections and a resistor for preventing the load current of the transmission wire from passing into the loop are connected in series.

Preferably, the distances between two adjacent installation points on the power transmission line are equal, so as to balance the current provided by the ice-melting power supply device to the sub-section wires in the loop.

The power transmission line includes a three-phase AC transmission wire, and each phase is transmitted by a single wire; the ice-melting power supply in the ice-melting power supply device adopts a DC power supply; the choke is a reactor; the switch includes a shunt connected in series The shunt switch at the terminal and the power switch connected in series with the terminal of the ice-melting power supply unit. The choke can be arranged in the ice-melting power supply unit, or in the shunt, or in both the ice-melting power supply unit and the shunt.

The power transmission line includes a three-phase AC transmission wire, and each phase is transmitted by a split wire; the ice-melting power supply in the ice-melting power supply device adopts a DC power supply; the choke is a reactor; the switch is connected in series to the ice-melting The power switch of the terminal of the power supply device; the shunt connects the joints of the split wires in the same phase at the same installation point respectively. When the shunt of the technical solution is connected to the joints of the same-phase split conductors, no switch and choke are connected in series, thereby simplifying the connection transformation of the transmission conductors.

The power transmission line includes a single-pole or two-pole DC transmission wire, and each pole adopts a single wire for transmission; the ice-melting power supply in the ice-melting power supply device adopts an AC power supply; the choke is a capacitor; the switch includes a shunt connected in series The shunt switch at the device terminal and the power switch connected in series with the terminal of the ice-melting power supply unit. The choke can be arranged in the ice-melting power supply unit, or in the shunt, or in both the ice-melting power supply unit and the shunt.

The power transmission line includes a single-pole or two-pole DC transmission wire, and each pole is transmitted by a split wire; the ice-melting power supply in the ice-melting power supply device uses an AC power supply; the choke is a capacitor; The power switch of the terminal of the ice power supply device; the shunt connects the contacts of the same polarity split wires at the same installation point respectively. When the shunt of the technical solution is connected to the joints of the same-polarity split conductors, no switch and choke are connected in series, thereby simplifying the transformation of the connection of the transmission conductors.

Due to the installation of multiple ice-melting power supply devices and shunts on the transmission line, when the wires are covered with ice on a certain line, the on-off state of the ice-melting circuit switch in this area is controlled, so that the points in this area belong to different The current of the two sub-sections of the transmission wire is increased to realize overcurrent ice melting in different regions. Moreover, the choke connected in series in the circuit can prevent the load current of the high-voltage transmission wire from entering the circuit: when the high-voltage transmission system adopts three-phase AC transmission, the reactor is used as the choke, and the ice-melting power supply device adopts a DC power supply, thereby Make the regional ice-melting circuit form a DC circuit. As long as the parameters of the reactor are set reasonably, the AC load current of the transmission line can be greatly hindered. The current flowing through the reactor can be ignored, and the transmission line can be blocked. The AC load current enters the regional ice-melting circuit; when the high-voltage power transmission system adopts bipolar DC transmission, a capacitor is used as a choke, and the ice-melting power supply device uses an AC power supply, so that the regional ice-melting circuit forms an AC circuit. By setting the parameters of the high-voltage capacitor, the DC load current of the transmission line can be blocked from entering the regional ice-melting circuit. Therefore, the subsection wire current in the above-mentioned ice melting area is the sum of the load current of the transmission line and the loop current provided by the ice melting power supply device, and the subsection wire current increases obviously and generates heat. When the total current of the conductor in the subsection is greater than or equal to the icing current of the conductor in this power transmission environment, the conductor in the subsection has realized ice melting. Through the switch conversion in the loop, the ice-melting power supply device, the shunt and any other two sub-section wires in the ice-covered area can form a small-area loop. Apply a loop current to the loop according to the above method, and the two sub-sections Sectional conductors have also realized melting ice. After all the wires are thawed once in a cycle, all the wires in the entire power transmission system have been thawed. Since the over-current ice melting is only carried out in the ice-covered area, its heat loss can be reduced to the minimum, so that the transmission line can realize the purpose of low heat loss ice melting on the basis of the load operation.

Description of drawings

Fig. 1 is in the transmission system of high-voltage alternating current single neutral wire, every phase single conductor, the structural representation of the present invention;

Fig. 2 is in high-voltage alternating current without neutral line, in the power transmission system of single-phase single conductor, the structural representation of the present invention;

Fig. 3 is in the transmission system of high-voltage alternating current 2 neutral wires, 2 split wires per phase, the structural representation of the present invention;

Fig. 4 is in the power transmission system of high-voltage alternating current 2 neutral lines, 4 split conductors in each phase, the structural representation of the present invention;

Fig. 5 is a schematic structural diagram of the present invention in a high-voltage direct current 2 neutral line, 4 split conductor power transmission system for each pole;

Fig. 6 is a schematic diagram of the structure of the present invention in a high-voltage direct current 2-neutral line and 6-split wire per pole power transmission system.

Reference signs: L _A ~ L _C are power transmission wires, L _A1 ~ L _A4 , L _B1 ~ L _B4 , L _C1 ~ L _C4 , L ₊₁ ~ L ₊₆ , L _-1 ~ L _-6 are split wires, L _O and L _O1 ~ L _O2 are the midline and split midline; 1, 2, 3, 4, 5 are installation points, a ₁ ~ a ₅ , b ₁ ~ b ₅ , c ₁ ~ c ₅ , o ₁ ~ o ₅ , a ₁₁ ～a ₁₃ , a ₂₁ ～a ₂₃ , a ₃₁ ～a ₃₃ , a ₄₁ ～a ₄₃ , b ₁₁ ～b ₁₃ , b ₂₁ ～b ₂₃ , b ₃₁ ～b ₃₃ , b ₄₁ ～b ₄₃ , c ₁₁ ～c ₁₃ , c ₂₁ ～c ₂₃ , c ₃₁ ～c ₃₃ , c ₄₁ ～c ₄₃ , o ₁₁ ～o ₁₃ , o ₂₁ ～o ₂₃ , + ₁₁ ～+ ₁₃ , + ₂₁ ～+ ₂₃ , + ₃₁ ～ + ₃₃ 、+ ₄₁ ～+ ₄₃ 、+ ₅₁ ～+ ₅₃ 、+ ₆₁ ～+ ₆₃ 、- ₁₁ ～- ₁₃ 、- ₂₁ ～- ₂₃ 、- _{31 ～} - ₃₃ 、- ₄₁ ～- 43 、- ₅₁ ～- ₅₃ , - ₆₁ ~ - ₆₃ are wire contacts, T _A1 ~ T _A5 , T _B1 ~ T _B5 , T _C1 ~ T _C5 , T _O1 ~ T _O5 , T _B11 ~ T _B31 , T _B12 ~ T _B32 , T ₊₁ ~ T ₊₆ , T _-1 ~ T _-6 are switches, R ₁ ~ R ₅ are flow resistors, E ₁ ~ E ₂ are power supplies for melting ice, F ₁ ~ F ₃ are shunts, D ₁ ~ D ₂ are melting ice In the ice power supply device, _Iload is the payload current, _Iback is the effective loop current, and _Imelt is the effective ice-melting current.

Detailed ways

Below in conjunction with the accompanying drawings, the present invention will be further described according to the fact that the high-voltage power transmission system adopts AC or DC power transmission in practical applications, and its transmission wires can have different numbers of split neutral lines and split wires:

Example 1:

As shown in Fig. 1, in this embodiment, the high-voltage power transmission system is a high-voltage AC single-neutral wire, and each phase has a single conductor for power transmission; switches and chokes are provided in the shunt and the ice-melting power supply unit.

In the traditional high-voltage AC power transmission system, there is no wire connection between the phase conductors L _A , L _B , _LC and the neutral line L _O. During power transmission, the conductors L _A , L _B , and _LC run under the safe load current respectively. When the line When a certain section of the wire is covered with ice, because the wire current is a safe load current, which is much lower than the melting current when the ice needs to be melted, such a line design cannot achieve the wire melting.

This embodiment includes 4 conductors in total of phase conductors L _A , L _B , L _C and the neutral line L _O . In areas where icing occurs frequently along the line, at the same time, in order to melt the ice on the center line, the center line is first disconnected from the ground line, and the center line is connected into a wire before and after to form a circuit. Since there is no thunderstorm in the cold winter, the center line and the ground line Disconnection will not cause the problem of being bombarded by lightning. After winter, before thunderstorms come, when the line no longer needs to melt ice, then connect the neutral wire to the ground wire. In the power supply direction of the power transmission system, in the icing-prone area along the power supply side, set up an installation point on the transmission line at intervals of about 50 kilometers, and at each installation point lead out a Contact, the contact divides the transmission wire into several sub-sections, so the whole wire will be divided into several sub-sections by multiple contacts on it. Arrange shunts and ice-melting power supply units alternately at each installation point of the transmission line, wherein the shunt and ice-melting power supply units are provided with terminals equal in number to the number of power transmission wires, and the terminals are connected to the contacts on the power transmission wires. Connect one by one. Fig. 1 shows five installation points 1, 2, 3, 4 and 5, and flow dividers and ice-melting power supply units F ₁ , D ₁ , F ₂ , D ₂ and F ₃ arranged alternately at the five installation points . At installation point 1, the contacts of each wire are a ₁ , b ₁ , c ₁ , o ₁ , and the contacts of other installation points are analogized in turn.

At the installation point 2, the ice-melting power supply E ₁ in the ice-melting power supply device D ₁ is a high-voltage DC power supply, and the choke R ₂ is a high-voltage reactor. As long as the parameters of R ₂ are properly set, the AC between transmission lines can be blocked The load current passes through. The connection relationship between the ice-melting power supply, the choke and the transmission wire is as follows: the ice-melting power supply E ₁ and the choke R ₂ are connected in series. In order to simplify the line transformation, E ₁ and R ₂ are connected at both ends Several terminals of the ice-melting power supply device _D1 are respectively led out through the power switch, and each terminal is connected to the contact points of the wires at the same installation point one by one. Specifically: After the ice-melting power supply E ₁ and the choke R ₂ are connected in series, one end is respectively connected to the terminals of the power switches T _A2 and T _C2 , and the other terminals of the power switches T _A2 and T _C2 are respectively connected to the wire L _A , L _C a ₂ , c ₂ contacts; and the other ends are respectively connected to the terminals of the power switch T _B2 , T _O2 , and the other terminals of the power switches T _B2 , T _O2 are respectively connected to the wires L _B and On the b ₂ and o ₂ contacts of the neutral line L _O. According to the above method, the ice-melting power supply unit D ₂ can be installed at the installation point 4 .

At installation point 1, the resistor _R1 in the shunt _F1 is a high-voltage reactor. As long as the parameters of _R1 are set appropriately, it can block the passage of AC load current between transmission lines. In order to simplify the line transformation, the two ends of _R1 are respectively connected to the contacts of the wires through the shunt switch. To this end, one end of the resistor R ₁ is respectively connected to the terminals of the shunt switches T _A1 and T _C1 , and the other terminals of the shunt switches T _A1 and T _C1 are respectively connected to a ₁ and c of the wires L _A and L _{C 1} , and the other end of the resistor R ₁ is respectively connected to the terminal of the shunt switch T _B1 and T _O1 , and the other terminal of the shunt switch T _B1 and T _O1 is respectively connected to the wire L _B and the neutral line L _O. On b ₁ and o ₁ contacts. According to the method described above, flow splitters F ₃ and F _{5 can be installed at installation points 3 and 5} . When the transmission line is in normal operation, all switches are in the open state.

The deicing principle of the present embodiment is as follows:

In an AC power transmission system, the design load current per phase is 650 amps, and a 720mm ² wire is used for power transmission. Through experiments, in a certain power transmission environment, the ice-melting current of the transmission wire is 1530 amps, and the ice-melting current of the neutral line is 500 amps. When icing occurs on _{the conductors of section 1-3 of the transmission line, first switch T A1 , T B1 , T A2 ,} T _B2 , T _{A3 ,} Close T _B3 and form two E ₁ -T _A2 -a 2 -a ₁ -T A1 -R ₁ -T _B1 -b _{1 -b 2} -T _B2 -R ₂ through the sub-section wires of L _{A and} L _B -E ₁ and E ₁ -T _A2 -a ₂ -a ₃ -T _A3 -R ₃ -T _B3 -b ₃ -b ₂ -T _B2 -R ₂ -E ₁ Small area ice melting circuit. At this time, the effective currents of the wires a ₁ -a ₂ , a ₂ -a ₃ and b ₁ -b ₂ , b ₂ -b ₃ in the subsections are the sum of the wire load AC current _Iload and the loop DC current _Iback respectively. When the current _2I provided by the power supply _E1 >2x(I _melt -I _load )=2x(1530-650)=1760 amps, that is, the total effective current of each sub-section conductor is greater than the deicing current 1530 of the conductor under the power transmission environment at that time When ampere, the conductors a ₁ -a ₂ , a ₂ -a ₃ and b ₁ -b ₂ , b ₂ -b ₃ of each subsection realize ice melting. After the ice melting is completed, the above-mentioned switches T _A1 , T _B1 , T _A2 , T _B2 , T _A3 and T _B3 are turned off. Then, turn on the switches T _C1 , T _O1 , T _C2 , T _O2 , T _C3 , and T _O3 , and form two new E ₁ -T _C2 -c ₂ through the subsection wires of LC and _{L O} -c ₁ -T _C1 -R ₁ -T _O1 -o ₁ -o ₂ -T _O2 -R ₂ -E ₁ and E ₁ -T _C2 -c ₂ -c ₃ -T _C3 -R ₃ -T _O3 -o ₃ -o ₂ -T _O2 -R ₂ -E ₁ Small area ice melting circuit. At this time, the effective currents of the sub-section wires c ₁ -c ₂ , c ₂ -c ₃ are respectively the _sum of the wire load AC current I _load and the loop DC current I; the effective currents of the sub-section wires o ₁ -o ₂ , o ₂ -o ₃ are the loop direct current I _loop respectively. When the current _2Iback provided by the power supply _E1 >2x( _Imelting - _Iload )=2x(1530-650)=1760 amps, that is, the total effective current of the sub-section wire c ₁ -c ₂ and c ₂ -c ₃ is greater than the wire The ice-melting current under the power transmission environment at that time was 1530 amperes; at the same time, the current _{2I circuit} provided by the power supply E1 = 1760 amperes, that is, the effective current of the sub-section conductors o ₁ -o ₂ and o ₂ -o ₃ was also greater than that of the neutral line at that time When the ice-melting current is 500 ampere-hours in the power transmission environment, the conductors c ₁ -c ₂ , c ₂ -c ₃ , o ₁ -o ₂ , and o ₂ -o ₃ in each subsection can melt ice again. Like this, all realized melting ice on 1-3 each subsection wire. After the ice melting is over, the switches T _C1 , T _O1 , T _C2 , T _O2 , T _C3 and T _O3 are turned off. The DC current of the loop is zero, and 650 amps of current flow through the wires respectively, and the normal operation power supply is resumed.

Example 2:

As shown in Figure 2, in this embodiment, the high-voltage power transmission system is a high-voltage AC power transmission system with no neutral line and single-conductor power transmission for each phase; both the shunt and the ice-melting power supply device are equipped with switches and chokes.

This embodiment is similar to Embodiment 1, the difference is that there is no neutral wire, and there are only three wires L _A , L _B , and L _C for power transmission. Figure 2 shows the three installation points 1, 2 and 3, and the shunts and ice-melting power supply units F ₁ , D ₁ and F ₂ respectively located at the three installation points. At the installation point 1, the junctions of the wires are a ₁ , b ₁ , c ₁ , and the contacts of other installation points are deduced in turn. Correspondingly, the connection relationship between the resistor R ₁ in the shunt at the installation point 1 and the transmission wire becomes: the switch T _A1 is connected to the contact a ₁ of the wire L _A , the switch T _C1 is connected to the contact c ₁ of the wire L _C , The junction point _b1 of the wire L _B is connected to both ends of the resistor _R1 in the above-mentioned shunt through two switches T _B11 and T _B12 . At installation point 2, the connection relationship between the ice-melting power supply E ₁ and the choke R ₂ in the ice-melting power supply unit and the L _B transmission wire is: after the ice-melting power supply E ₁ and the choke R ₂ are connected in series, the two ends The switch T _A2 is connected to the contact point a ₂ of the wire L _A , the switch T _C2 is connected to the contact point c ₂ of the wire L _C , and the contact b ₂ of the wire L _B is connected to the above-mentioned ice-melting power supply E ₁ through two switches T _B21 and T _B22 The two ends connected in series with the resistor _R2 . When the transmission line is in normal operation, all switches are in the open state.

The deicing principle of the present embodiment is as follows:

In an AC power transmission system, the design load current per phase is 650 amps, and a 720mm ² wire is used for power transmission. Through experiments, in a certain power transmission environment, the ice-melting current of the power transmission wire is 1530 amps. When icing occurs on the conductors of section 1-3 of the transmission line, _{first switch T A1 , T B12 , T A2 ,} T _{B22 ,} T _A3 , T _B32 is closed, two E ₁ -T _A2 -a _{2 -a 1 -T A1 -R 1 -T B12 -b 1 -b 2 -T B22} -R ₂ are formed through the sub-section wires of L _A and L _B -E ₁ and E ₁ -T _A2 -a ₂ -a ₃ -T _A3 -R ₃ -T _B32 -b ₃ -b ₂ -T _B22 -R ₂ -E ₁ Small area ice melting circuit. At this time, the effective currents of the wires a ₁ -a ₂ , a ₂ -a ₃ and b ₁ -b ₂ , b ₂ -b ₃ in the subsections are the sum of the wire load AC current _Iload and the loop DC current _Iback respectively. When the current _2I provided by the power supply _E1 >2x(I _melt -I _load )=2x(1530-650)=1760 amps, that is, the total effective current of each sub-section wire is greater than the ice melting current 1530 of the wire in the power transmission environment at that time When the temperature is high, the conductors a ₁ -a ₂ , a ₂ -a ₃ and b ₁ -b ₂ , b ₂ -b ₃ of each subsection begin to melt the ice. After the ice is half melted, turn off the switches _TA1 , _TB12 , _TA2 , _TB22 , _TA3 , and _TB32 above, and then turn on the switches _TB11 , _TC1 , _TB21 , _TC2 , _TB31 , and _TC3 . Above, two new small-area ice-melting circuits are formed through the sub-section conductors of L _B and _LC . Similarly, at this time, the effective currents of the sub-section conductors b ₁ -b ₂ , b ₂ -b ₃ and c ₁ -c ₂ , c ₂ -c ₃ are respectively greater than the melting current of 1530 amperes, and the ice melting begins. When the sub-section wires b ₁ -b ₂ , b ₂ -b are completely thawed, and the sub-section wires c ₁ -c ₂ , c ₂ -c ₃ are half-thawed, the above switches T _B11 , T _B21 , T _B31 are turned off. At the same time, turn on the switches T _A1 , T _A2 , and T _A3 , and it is the turn for the subsection wires a ₁ -a ₂ , a ₂ -a ₃ and c ₁ -c ₂ , c ₂ -c ₃ to start melting ice. When the sub-segment wires c ₁ -c ₂ , c ₂ -c ₃ are completely melted, the remaining half of the sub-segment wires a ₁ -a ₂ , a ₂ -a ₃ are also completely melted. Like this, all realized melting ice on 1-3 each subsection wire. After the ice melting is over, the switches T _A1 , T _A2 , T _A3 and T _C1 , T _C2 , T _C3 are turned off. The DC current of the loop is zero, and 650 amps of current flow through the wires respectively, and the normal operation power supply is resumed.

Example 3:

As shown in Figure 3, in this embodiment, the high-voltage power transmission system is a high-voltage AC 2-split neutral line and 2-split conductors for each phase; only switches and chokes are provided in the ice-melting power supply unit.

This embodiment is similar to Embodiment 1, except that the center line is 2-split conductors L _O1 and L _O2 , and each phase is 2-split conductors L _M , L _A2 , L _B1 , L _B2 , L _C1 , and L _C2 . Conductor; The neutral line is also cut off from the ground wire in advance according to the method of embodiment 1, and in order to simplify the structure of the transmission line, no switch and choke are arranged in the shunt, but the same phase or at the same installation point is connected with the connecting line. The contacts of the neutral split wires are connected separately. Figure 3 shows three installation points 1, 2 and 3. At installation points 1 and 3, four connecting wires are used to connect the contacts of the two wires in the same phase and in the same phase, and the connecting wires are connected to The two wires are in the same phase and in the same phase, so it does not affect the normal operation power supply state. At installation point 2, connect the switches at both ends of the ice-melting power supply unit to a ₁₂ , b 12 , _{c 12 of} the wires L _A1 ~ L _A2 , L _B1 ~ L _B2 , L _C1 ~ L _C2 , L _O1 ~ L _O2 respectively , o ₁₂ and a ₂₂ , b ₂₂ , c ₂₂ , o ₂₂ , the contacts of other installation points are analogized in turn. When the transmission line is in normal operation, all switches are in the open state.

The deicing principle of the present embodiment is as follows:

In an AC power transmission system, the load current per phase is designed to be 1300 amps, and 2X720mm ² wires are used for power transmission, that is, the current of each wire is 650 amps. Through experiments, in a certain power transmission environment, the ice-melting current of the transmission wire is 1530 amps, and the ice-melting current of the neutral line is 500 amps. When the wires in section 1-3 of the transmission line are covered with ice, the switches T _O1 and T _O2 of the power supply device _D1 for melting ice in this area are first turned on, and two small areas are formed through the sub-section wires of L _O1 and L _O2 . ice circuit. At this time, the effective currents of the sub-section wires o ₁₁ -o ₁₂ , o ₁₂ -o ₁₃ and o ₂₁ -o ₂₂ , o ₂₂ -o ₂₃ are the loop direct current I _loop respectively. When the current _2I provided by the power source _E1 > _2xImelting =2x500=1000A, that is, the effective current of each sub-section wire is greater than the current 500A of the wire’s melting current under the power transmission environment at that time, each sub-section wire o ₁₁ -o ₁₂ , o ₁₂ -o ₁₃ and o ₂₁ -o ₂₂ , o ₂₂ -o ₂₃ have achieved ice melting, and after the ice melting is completed, the above-mentioned switches T _O1 and T _O2 are turned off. Then, turn on the switches T _A1 and T _A2 again, and form two small area loops through the subsection wires of L _A1 and L _A2 . At this time, the effective currents of the wires a ₁₁ -a ₁₂ , a ₁₂ -a ₁₃ and a ₂₁ -a ₂₂ , a ₂₂ -a ₂ in the subsections are the sum of the wire load AC current I _load and the loop DC current I _back respectively. When the current _2I provided by the power supply _E1 >2x(I _melt -I _load )=2x(1530-650)=1760 amps, that is, the total effective current of each sub-section conductor is greater than the deicing current 1530 of the conductor under the power transmission environment at that time When the ice is on, the wires a ₁₁ -a ₁₂ , a ₁₂ -a ₁₃ and a ₂₁ -a ₂₂ , a ₂₂ -a ₂₃ of each sub-section have realized the ice melting. After the ice melting is over, the above switches T _A1 and T _A2 are disconnected. . Similarly, each subsection of L _B1 , L _B2 and L _C1 , L _C2 is melted in turn according to the above method. When the thawing is complete, turn off all switches. The DC current of the loop is zero, and 650 amps of current flow through the wires respectively, and the normal operation power supply is resumed.

Example 4:

As shown in Fig. 4, in this embodiment, the high-voltage power transmission system is high-voltage AC with 2 split neutral wires and 4 split wires per phase for power transmission; only switches and chokes are provided in the ice-melting power supply unit.

This embodiment is similar to Embodiment 3, except that _each phase has four split conductors L _A1 -LA4 , L _B1 -L _B4 , and L _{C1 -LC4,} a total of 14 conductors. Figure 4 shows three installation points 1, 2 and 3. At installation points 1 and 3, three connecting wires are respectively used in the shunt to connect the joints of the four split wires of the same phase together, and one The connection line connects the contacts of the two split wires in the same line; at the installation point 2, connect the switches at both ends of the ice-melting power supply unit to the wires L _A1 ~ L _A4 , L _B1 ~ L _B4 , L _C1 ~ L respectively Contact points a ₁₂ , a ₃₂ , b ₁₂ , b ₃₂ , c ₁₂ , c ₃₂ , o ₁₂ and a ₂₂ , a ₄₂ , b ₂₂ , b ₄₂ , c ₂₂ , c ₄₂ , o ₂₂ of C4 _, L _O1 ~ L _O2 , the contacts of other installation points and so on. When the transmission line is in normal operation, all switches are in the open state.

The deicing principle of the present embodiment is as follows:

In an AC transmission system, the design load current of each phase is 1500 amps, and 4 split wires of 4X400mm ² are used for power transmission, that is, the current of each wire is 375 amps. Through experiments, in a certain power transmission environment, the ice-melting current of the wire is 800 amps, and the ice-melting current of the neutral line is 500 amps. When the wires in section 1-3 of the transmission line are covered with ice, the switches T _O1 and T _O2 of the ice-melting power supply device _D1 in this area are first turned on, and two small area loops are formed through the sub-section wires of L _O1 and L _O2 . At this time, the effective currents of the sub-section wires o ₁₁ -o ₁₂ , o ₁₂ -o ₁₃ and o ₂₁ -o ₂₂ , o ₂₂ -o ₂₃ are the loop direct current I _loop respectively. When the current _2I provided by the power source _E1 > _2xImelting =2x500=1000A, that is, the effective current of each sub-section wire is greater than the current 500A of the wire’s melting current under the power transmission environment at that time, each sub-section wire o ₁₁ -o ₁₂ , o ₁₂ -o ₁₃ and o ₂₁ -o ₂₂ , o ₂₂ -o ₂₃ have achieved ice melting, and after the ice melting is completed, the above-mentioned switches T _O1 and T _O21 are turned off. Then, turn on the switches T _A1 and T _A2 again, and form two small area loops through the subsection wires of L _A1 and L _A2 . At this time, the effective currents of the wires a ₁₁ -a ₁₂ , a ₁₂ -a ₁₃ and a ₂₁ -a ₂₂ , a ₂₂ -a ₂₃ of the subsections are the sum of the wire load AC current _Iload and the loop DC current _Iback respectively. When the current _2I provided by the power supply _E1 >2x(I _melt -I _load )=2x(800-375)=850 amps, that is, the total effective current of each sub-section conductor is greater than the icing current 800 of the conductor under the power transmission environment at that time When the ice is on, the wires a ₁₁ -a ₁₂ , a ₁₂ -a ₁₃ and a ₂₁ -a ₂₂ , a ₂₂ -a ₂₃ of each sub-section have realized the ice melting. After the ice melting is over, the above switches T _A1 and T _A2 are disconnected. . Similarly, each subsection of L _{A3 and} L _A4 , L _B1 to L B4 and L _C1 to L _C4 is melted in turn according to the above method. When the thawing is complete, turn off all switches. The DC current of the loop is zero, and the wires respectively flow through 375 amps of current, and the normal operation power supply is resumed.

Example 5:

As shown in Figure 5, in this embodiment, the high-voltage power transmission system is two-pole high-voltage direct current with two split neutral wires and four split wires for each pole for power transmission; only switches and chokes are provided in the ice-melting power supply unit.

This embodiment is similar to Embodiment 4, except that the high-voltage power transmission system is DC two-pole power transmission, and each pole has 4 split wires L ₊₁ ˜L ₊₄ , L ₋₁ ˜L _{-4 and} 10 wires in total. Figure 4 shows three installation points 1, 2, and 3. At installation points 1 and 3, 2 connecting wires are respectively used in the shunt to connect the 4 split wires of the same polarity together, and 1 wire is used to connect The line connects the two split wires of the neutral line together; at the installation point 2, correspondingly, the ice-melting power supply E ₁ in the ice-melting power supply device D ₁ is a high-voltage AC power supply, and the choke R ₁ is a high-voltage capacitor, and the high-voltage capacitor can be Block the passage of DC load current between transmission lines; at installation point 2, connect the switches at both ends of the ice-melting power supply device to the wires L ₊₁ ~ L ₊₄ , L _-1 ~ L _-4 , L _O1 ~ L _O2 respectively Contact + ₁₂ , + ₃₂ , - ₁₂ , - ₃₂ , o ₁₂ and + ₂₂ , + ₄₂ , - ₂₂ , - ₄₂ , o ₂₂ , and the contacts of other installation points and so on. When the transmission line is in normal operation, all switches are in the open state.

The deicing principle of the present embodiment is as follows:

In a DC power transmission system, the load current of each pole is designed to be 1500 amps, and 4 split conductors of 4X400mm ² are used for power transmission, that is, the current of each conductor is 375 amps. Through experiments, in a certain power transmission environment, the ice-melting current of the wire is 800 amps, and the ice-melting current of the neutral line is 500 amps. When the wires in section 1-3 of the transmission line are covered with ice, the switches T _O1 and T _O2 of the power supply device _D1 for melting ice in this area are first turned on, and two small areas are formed through the sub-section wires of L _O1 and L _O2 . ice circuit. At this time, the effective currents of the sub-section conductors o ₁₁ -o ₁₂ , o ₁₂ -o ₁₃ and o ₂₁ -o ₂₂ , o ₂₂ -o ₂₃ are the loop alternating current I _times respectively. When the current _2I provided by the power source _E1 > _2xImelting =2x500=1000A, that is, the effective current of each sub-section wire is greater than the current 500A of the wire’s melting current under the power transmission environment at that time, each sub-section wire o ₁₁ -o ₁₂ , o ₁₂ -o ₁₃ and o ₂₁ -o ₂₂ , o ₂₂ -o ₂₃ have achieved ice melting, and after the ice melting is completed, the above-mentioned switches T _O1 and T _O21 are turned off. Then, the switches T ₊₁ and T ₊₂ are turned on again, and the sub-section wires of L ₊₁ and L ₊₂ are used to form two small-area loops. At this time, the effective currents of the wires + ₁₁ -+ ₁₂ , + ₁₂ -+ ₁₃ and + ₂₁ -+ ₂₂ , + ₂₂ -+ ₂₃ are the _sum of the wire load DC _current I and the loop AC current I respectively. When the current _2I provided by the power supply _E1 >2x(I _melt -I _load )=2x(800-375)=850 amps, that is, the total effective current of each sub-section conductor is greater than the icing current 800 of the conductor under the power transmission environment at that time When it is ampere, the wires + ₁₁ - + ₁₂ , + ₁₂ - + ₁₃ and + ₂₁ - + ₂₂ , + ₂₂ - + ₂₃ of each subsection have realized the ice melting. After the ice melting is completed, the above switches T ₊₁ , T ₊₂ disconnect. Similarly, the sub-sections L ₊₃ and L ₊₄ , and L ₋₁ to L ₄ are melted in turn according to the above method. After the ice melting is over, turn off all the switches, the AC current of the loop is zero, and the wires each flow a current of 375 amps to resume normal operation and power supply.

Embodiment 6:

As shown in Figure 6, in this embodiment, the high-voltage power transmission system is two-pole high-voltage DC with two split neutral wires and six split wires for each pole to transmit power; only switches and chokes are provided in the ice-melting power supply unit.

This embodiment is similar to Embodiment 5, except that each pole has 6 split wires L ₊₁ ˜L ₊₆ , and L ₋₁ ˜L _{−6 ,} a total of 14 wires. Figure 4 shows three installation points 1, 2 and 3. At installation points 1 and 3, 2 connecting wires are respectively used in the shunt to connect the 6 split wires of the same polarity together, and 1 connecting wire is respectively used to connect Connect the 2 split conductors of the neutral line together; at the installation point 2, correspondingly connect the switches at both ends of the ice-melting power supply unit to the conductors L ₊₁ ~ L ₊₆ , L _-1 ~ L _-6 , L On the contacts of _O1 ~ L _O2 + ₁₂ , + ₃₂ , + ₅₂ , - ₁₂ , - ₃₂ , - ₅₂ , o ₁₂ and + ₂₂ , + ₄₂ , + ₆₂ , - ₂₂ , - ₄₂ , - ₆₂ , o ₂₂ , The contacts of other installation points can be deduced by analogy. When the transmission line is in normal operation, all switches are in the open state. The ice-melting principle of this embodiment is similar to that of Embodiment 5, the difference is that each pole has 6 split wires in two groups, and the ice is melted three times.

When the transmission line adopts single-pole or two-pole direct current transmission, and each pole adopts a single wire for transmission, the connection structure of the specific embodiment of the ice-melting system of the present invention is similar to the above-mentioned embodiment 1 or 2, the difference is that the ice-melting The ice-melting power supply in the power supply device adopts an AC power supply, and the choke is a capacitor. Those of ordinary skill in the art can obtain the specific embodiment according to the foregoing embodiments 1, 2, 5, and 6, so details are not described here.

When the transmission line adopts unipolar direct current transmission, and each pole adopts split wire transmission, those of ordinary skill in the art can obtain the specific embodiment using the ice-melting system of the present invention according to the above-mentioned embodiments 1, 2, 5, and 6, so in I won't go into details here.

Claims (9)

1. the ice melting system of a high tension power line with load operation, transmission line comprises at least two transmission pressures, adopts direct current or ac transmission, it is characterized in that:

Described transmission line is provided with the mounting points more than three, draws a contact at each mounting points place from each transmission pressure, and contact is divided into the plurality of sub section with transmission pressure;

Also comprise at least two shunts and at least one ice-melt supply unit, shunt and ice-melt supply unit are equipped with the terminal that quantitatively equates with transmission pressure bar number;

Described shunt and ice-melt supply unit are arranged alternately on each mounting points of transmission line, and its terminal is connected one by one with contact on the transmission pressure; The two strip sections that belong to different transmission pressures respectively and shunt, ice-melt supply unit between adjacent two mounting points of transmission line constitute regional ice-melt loop, shunt is used for two strip sections of connected loop, the ice-melt supply unit is used for two strip sections of connected loop, and provide a loop current to the loop, and also be in series with the switch that is used for gating section on the loop and stop the transmission pressure load current to feed the flow plug in this loop.

2. the ice melting system of high tension power line with load operation according to claim 1 is characterized in that: the distance on the described transmission line between adjacent two mounting points equates.

3. the ice melting system of high tension power line with load operation according to claim 1 and 2, it is characterized in that: described transmission line comprises the three-phase alternating current transmission pressure, and whenever adopts the single conductor transmission mutually; The ice-melt power supply adopts DC power supply in the described ice-melt supply unit; Described flow plug is a reactor; Described flow plug is arranged in the ice-melt supply unit, or is arranged in the shunt, or is located at simultaneously in ice-melt supply unit and the shunt; Described switch comprises the diverting switch that is connected on the shunt terminal and is connected on the mains switch of ice-melt supply unit terminal.

4. the ice melting system of high tension power line with load operation according to claim 3 is characterized in that: described transmission line also comprises the center line that adopts the single conductor transmission.

5. the ice melting system of high tension power line with load operation according to claim 1 and 2, it is characterized in that: described transmission line comprises the three-phase alternating current transmission pressure, and whenever adopts the bundle conductor transmission mutually; The ice-melt power supply adopts DC power supply in the described ice-melt supply unit; Described flow plug is a reactor; Described flow plug is arranged in the ice-melt supply unit; Described switch is the mains switch that is connected on ice-melt supply unit terminal; Described shunt couples together the contact of homophase bundle conductor in same mounting points respectively.

6. the ice melting system of high tension power line with load operation according to claim 1 and 2, it is characterized in that: described transmission line comprises one pole or the two poles of the earth direct current transportation lead, and every utmost point adopts the single conductor transmission; The ice-melt power supply adopts AC power in the described ice-melt supply unit; Described flow plug is a capacitor; Described flow plug is arranged in the ice-melt supply unit, or is arranged in the shunt, or is located at simultaneously in ice-melt supply unit and the shunt; Described switch comprises the diverting switch that is connected on the shunt terminal and is connected on the mains switch of ice-melt supply unit terminal.

7. the ice melting system of high tension power line with load operation according to claim 1 and 2, it is characterized in that: described transmission line comprises one pole or the two poles of the earth direct current transportation lead, and every utmost point adopts the bundle conductor transmission; The ice-melt power supply adopts AC power in the described ice-melt supply unit; Described flow plug is a capacitor; Described flow plug is arranged in the ice-melt supply unit; Described switch is the mains switch that is connected on ice-melt supply unit terminal; Described shunt couples together the contact of homopolarity bundle conductor in same mounting points respectively.

8. the ice melting system of high tension power line with load operation according to claim 5 is characterized in that: described transmission line also comprises the center line that adopts the bundle conductor transmission; Described shunt couples together the center line of bundle conductor transmission respectively at the contact of same mounting points.

9. the ice melting system of high tension power line with load operation according to claim 7 is characterized in that: described transmission line also comprises the center line that adopts the bundle conductor transmission; Described shunt couples together the center line of bundle conductor transmission respectively at the contact of same mounting points.

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