A permanent and temporary combined single ring type connection protection system

Abstract

This invention provides a permanent-temporary combined single-loop wiring protection system, relating to the field of power technology. The protection system includes: a first protection circuit and a second protection circuit disposed between a first busbar and a second busbar; the first protection circuit includes: a first protection device and a second protection device; one end of the first protection device is electrically connected to the first busbar via a first circuit breaker and a first current transformer; the other end of the first protection device is electrically connected to the second protection device via a second circuit breaker; one end of the second protection device is electrically connected to the second busbar via a third circuit breaker and a second current transformer; in operation, each of the first and second current transformers is connected to at least one short-lead protection device, the first main transformer is electrically connected to the first protection device, the second main transformer is electrically connected to the second protection circuit, and the converter station is electrically connected to the second protection device. This invention achieves permanent-temporary combined operation of the protection system during use.

Description

Technical Field

[0001] This invention relates to the field of power technology, and more specifically to a single-ring wiring protection system that combines permanent and temporary protection. Background Technology

[0002] In 500kV new energy substations, the construction scale of 500kV often involves a situation of 1 line and 3 transformers. The main electrical wiring scheme is generally selected as a single ring connection or a multi-ring connection according to the actual situation. However, in the current substation, the 500kV short lead protection configuration scheme in both multi-ring and single ring connection schemes cannot be combined with the permanent connection. Especially in the single ring connection scheme, if any bay is out of operation, a loop power supply mode cannot be formed in a short time, which reduces the reliability and flexibility of power supply. In addition, repeated wiring and disconnection are required, which is complicated, expensive, and results in long power outage time during construction. Summary of the Invention

[0003] This invention provides a single-ring wiring protection system that combines permanent and temporary protection. It solves the problems of existing 500kV short-lead protection configurations, which cannot achieve permanent and temporary protection, require repeated wiring and disconnection, are complex to construct, involve high investment, and cause power outages, thus reducing power supply reliability and flexibility.

[0004] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0005] An embodiment of the present invention proposes a single-ring wiring protection system combining permanent and temporary connections, comprising:

[0006] A first protection circuit and a second protection circuit are disposed between the first busbar and the second busbar, and are electrically connected to the first busbar and the second busbar respectively.

[0007] The first protection circuit includes:

[0008] First protection device and second protection device;

[0009] One end of the first protection device is electrically connected to the first busbar through a first circuit breaker and a first current transformer; the other end of the first protection device is electrically connected to the second protection device through a second circuit breaker; one end of the second protection device is electrically connected to the second busbar through a third circuit breaker and a second current transformer.

[0010] In operation, both the first and second current transformers are connected to at least one short lead protection device. The first main transformer is electrically connected to the first protection device, the second main transformer is electrically connected to the second protection circuit, and the converter station is electrically connected to the second protection device.

[0011] Optionally, the first current transformer is provided with at least one first winding, at least one second winding, and a third winding.

[0012] Each of the first windings is electrically connected to a first main transformer protection device, each of the second windings is electrically connected to a first short lead protection device, and the third winding is electrically connected to a first circuit breaker protection device.

[0013] Optionally, the second current transformer is provided with at least one fourth winding, at least one fifth winding, and a sixth winding.

[0014] Each of the fourth windings is electrically connected to a converter station protection device, each of the fifth windings is electrically connected to a second short lead protection device, and the sixth winding is electrically connected to a second circuit breaker protection device.

[0015] Optionally, the first protection device includes:

[0016] A first disconnecting switch electrically connected to the first circuit breaker;

[0017] A third current transformer is installed between the first circuit breaker and the first disconnecting switch;

[0018] The second disconnecting switch has one end electrically connected to the first disconnecting switch and the other end electrically connected to the second circuit breaker.

[0019] A fourth current transformer is installed between the second circuit breaker and the second disconnector;

[0020] The first main transformer is electrically connected to the first disconnect switch and the second disconnect switch via the third disconnect switch.

[0021] Optionally, the second protection device includes:

[0022] The fourth disconnecting switch is electrically connected to the second circuit breaker;

[0023] A fifth current transformer is installed between the fourth disconnector and the second circuit breaker.

[0024] The fifth disconnecting switch has one end electrically connected to the fourth disconnecting switch and the other end electrically connected to the third circuit breaker;

[0025] A sixth current transformer is installed between the third circuit breaker and the fifth disconnecting switch;

[0026] The converter station is electrically connected to the fourth and fifth disconnect switches.

[0027] Optionally, the second protection circuit includes:

[0028] The third and fourth protection devices;

[0029] One end of the third protection device is electrically connected to the first busbar through the fourth circuit breaker and the seventh current transformer; the other end of the third protection device is electrically connected to the fourth protection device through the fifth circuit breaker; one end of the fourth protection device is electrically connected to the second busbar through the sixth circuit breaker and the eighth current transformer.

[0030] In operation, both the seventh and eighth current transformers are connected to at least one short lead protection device, the second main transformer is electrically connected to the third protection device, and the third main transformer is electrically connected to the fourth protection device.

[0031] Optionally, the seventh current transformer is provided with at least one seventh winding, at least one eighth winding, and a ninth winding.

[0032] Each of the seventh windings is electrically connected to a second main transformer protection device, each of the eighth windings is electrically connected to a third short lead protection device, and the ninth winding is electrically connected to a third circuit breaker protection device.

[0033] Optionally, the eighth current transformer is provided with at least one tenth winding, at least one eleventh winding, and a twelfth winding.

[0034] Each of the tenth windings is electrically connected to a third main transformer protection device, each of the eleventh windings is electrically connected to a fourth short lead protection device, and the twelfth winding is electrically connected to a fourth circuit breaker protection device.

[0035] Optionally, the third protection device includes:

[0036] The sixth disconnecting switch is electrically connected to the fourth circuit breaker;

[0037] A ninth current transformer is installed between the fourth circuit breaker and the sixth disconnecting switch.

[0038] The seventh disconnecting switch has one end electrically connected to the sixth disconnecting switch and the other end electrically connected to the fifth circuit breaker;

[0039] The tenth current transformer is installed between the fifth circuit breaker and the seventh disconnecting switch;

[0040] The second main transformer is electrically connected to the sixth and seventh disconnect switches via the eighth disconnect switch.

[0041] Optionally, the second protection device includes:

[0042] The ninth disconnecting switch is electrically connected to the fifth circuit breaker;

[0043] An eleventh current transformer is installed between the ninth disconnecting switch and the fifth circuit breaker.

[0044] The tenth disconnecting switch, one end of which is electrically connected to the ninth disconnecting switch, and the other end of which is electrically connected to the sixth circuit breaker;

[0045] A twelfth current transformer is installed between the sixth circuit breaker and the tenth disconnecting switch;

[0046] The third main transformer is electrically connected to the tenth and ninth disconnect switches via the eleventh disconnect switch.

[0047] The above-described solution of the present invention has at least the following beneficial effects:

[0048] The permanent-temporary combined single-loop wiring protection system of the present invention includes: a first protection circuit and a second protection circuit disposed between a first busbar and a second busbar, and electrically connected to the first busbar and the second busbar respectively; wherein, the first protection circuit includes: a first protection device and a second protection device; one end of the first protection device is electrically connected to the first busbar through a first circuit breaker and a first current transformer; the other end of the first protection device is electrically connected to the second protection device through a second circuit breaker; one end of the second protection device is electrically connected to the second busbar through a third circuit breaker and a second current transformer; in the operating state, each of the first current transformer and the second current transformer is connected to at least one short lead protection device, the first main transformer is electrically connected to the first protection device, the second main transformer is electrically connected to the second protection circuit, and the converter station is electrically connected to the second protection device. The solution of the present invention achieves permanent-temporary combination in the use of the single-loop wiring protection system, ensuring the power supply reliability and flexibility of the power supply system, while reducing the workload of personnel involved in design, construction, commissioning, and operation, and saving investment and construction time. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the overall structure of the permanent and temporary combined single-ring wiring protection system of the present invention;

[0050] Figure 2 This is an enlarged structural diagram of the permanent and temporary combined single-ring wiring protection system of the present invention at the first busbar end;

[0051] Figure 3 This is a magnified structural diagram of the permanent and temporary combined single-ring wiring protection system of the present invention at the second busbar end. Detailed Implementation

[0052] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0053] like Figure 1 and Figure 3 As shown, an embodiment of the present invention provides a single-ring wiring protection system combining permanent and temporary connections, comprising:

[0054] A first protection circuit and a second protection circuit are disposed between the first busbar U1 and the second busbar U2, and are electrically connected to the first busbar U1 and the second busbar U2 respectively.

[0055] The first protection circuit includes:

[0056] First protection device and second protection device;

[0057] One end of the first protection device is electrically connected to the first bus U1 through the first circuit breaker QF1 and the first current transformer CT1; the other end of the first protection device is electrically connected to the second protection device through the second circuit breaker QF2; one end of the second protection device is electrically connected to the second bus U2 through the third circuit breaker QF3 and the second current transformer CT2.

[0058] In operation, the first current transformer CT1 and the second current transformer CT2 are each connected to at least one short lead protection device. The first main transformer T1 is electrically connected to the first protection device, and the converter station E is electrically connected to the second protection device.

[0059] In this embodiment, the first circuit breaker QF1 is electrically connected to the first bus U1 through the twelfth disconnecting switch QS12, and the first current transformer CT1 is disposed between the first circuit breaker QF1 and the twelfth disconnecting switch QS12; the third circuit breaker QF3 is electrically connected to the second bus U2 through the thirteenth disconnecting switch QS13, and the second current transformer CT2 is disposed between the third circuit breaker QF3 and the thirteenth disconnecting switch QS13.

[0060] In this embodiment, when any main transformer needs to be taken out of operation, the corresponding side circuit breaker (i.e., the first circuit breaker QF1 and the third circuit breaker QF3) and the interrupt circuit breaker (i.e., the second circuit breaker QF2) and disconnecting switch can be sequentially disconnected through the control system, and the disconnecting switch at the output of the main transformer can be disconnected to remove the main transformer protection. At this time, the main transformer is taken out of operation. Then, the corresponding side circuit breaker and interrupt circuit breaker and disconnecting switch of this main transformer are closed, the disconnecting switch at the output of the main transformer remains open, and the short lead protection device is activated. At this time, the current circuit can still maintain the series closed loop operation state. When any main transformer needs to be put into operation, the corresponding side circuit breaker and interrupt circuit breaker are disconnected. Close the disconnect switch and the disconnect switch at the output of the main transformer component, then close the corresponding side circuit breaker and interrupt circuit breaker switch and disconnect switch, engage the main transformer protection device, and disengage the short lead protection. At this time, the main transformer is put into operation. The permanent and temporary combined single-ring connection protection system described in this embodiment, through the single-ring connection design and the addition of circuit breaker and short lead protection dedicated current transformer windings in the single-ring connection scheme, achieves a loop power supply mode even when any main transformer is out of operation. The power supply reliability and flexibility are stronger, and there is no need for repeated wiring. The construction is simple, the investment is small, and there is no problem of long construction power outage time. It realizes the permanent and temporary combined protection configuration.

[0061] In an optional embodiment of the present invention, the first current transformer CT1 is provided with at least one first winding W1, at least one second winding W2 and a third winding W3.

[0062] Each of the first windings W1 is electrically connected to a first main transformer protection device, each of the second windings W2 is electrically connected to a first short lead protection device, and the third winding W3 is electrically connected to a first circuit breaker protection device.

[0063] In this embodiment, there are two first windings W1 and two second windings W2; the first current transformer CT1 is also equipped with a main transformer metering winding W0, which is used to connect a current metering device for current detection; the first busbar U1 and the second busbar U2 represent 500kV busbars and are the central nodes for power collection and distribution; the circuit breaker is the core control and protection device of the power system, which can quickly cut off the current when there is a line or equipment fault. In the one-and-a-half circuit breaker wiring of this invention, every two components (such as the first main transformer T1 and the converter station E) are connected to two busbars through three circuit breakers to form a series; the disconnecting switch mainly functions to establish a clear disconnection point during equipment maintenance to ensure personal and equipment safety; the function of the current transformer is to convert the primary current into a secondary current. The high voltage and large current on the secondary side are proportionally converted into low voltage and small current on the secondary side for use by protection and measurement devices. In this embodiment, the current transformer has multiple independent windings, each for use by protection and measurement devices. The first main transformer protection device is used to monitor and protect the main transformer to prevent damage due to internal or external faults. The first circuit breaker protection device is used to monitor and protect the circuit breaker. The short lead protection device protects a conductor between two circuit breakers when the main transformer interval is out of operation and its output isolating switch is open, preventing short circuit faults. Through the independent short lead protection device design, when the main transformer is out of operation and the circuit breaker is closed, allowing the entire circuit system to operate normally, a conductor between two circuit breakers can be protected, thereby ensuring the stability of circuit operation.

[0064] In an optional embodiment of the present invention, the second current transformer CT2 is provided with at least one fourth winding W4, at least one fifth winding W5 and a sixth winding W6.

[0065] Each of the fourth windings W4 is electrically connected to a converter station protection device, each of the fifth windings W5 is electrically connected to a second short lead protection device, and the sixth winding W6 is electrically connected to a second circuit breaker protection device.

[0066] In this embodiment, there are two fourth windings W4 and two fifth windings W5; the second current transformer CT2 is also provided with a converter station metering winding W01, which is used to connect the current metering device.

[0067] In an optional embodiment of the present invention, the first protective device includes:

[0068] The first disconnecting switch QS1 is electrically connected to the first circuit breaker QF1;

[0069] A third current transformer CT3 is installed between the first circuit breaker QF1 and the first disconnecting switch QS1;

[0070] The second disconnecting switch QS2 has one end electrically connected to the first disconnecting switch QS1 and the other end electrically connected to the second circuit breaker QF2.

[0071] A fourth current transformer CT4 is installed between the second circuit breaker QF2 and the second disconnector QS2;

[0072] The first main transformer T1 is electrically connected to the first disconnect switch QS1 and the second disconnect switch QS2 through the third disconnect switch QS3.

[0073] In this embodiment, the third current transformer CT3 is equipped with two first busbar protection windings WO2, each connected to a first busbar protection device for monitoring and protecting the 500kV transmission line. The third current transformer CT3 also includes a circuit breaker protection winding and other measuring windings, which can be configured according to actual project requirements. The fourth current transformer CT4 contains converter station protection windings, circuit breaker backup protection windings, short lead backup protection windings, and other metering equipment windings, primarily used to connect backup protection devices, thereby further enhancing protection capabilities. To enhance the reliability of the entire system, in this embodiment, the third disconnecting switch QS3 is located between the first disconnecting switch QS1 and the second disconnecting switch QS2. In operation, when the first main transformer T1 needs to be taken out of service, the first circuit breaker QF1, the second circuit breaker QF2, and the third circuit breaker QF3 are disconnected sequentially. Then, all disconnecting switches connected to the first main transformer T1 are disconnected, causing the first main transformer T1 to be taken out of service. To ensure the continued operation of the entire circuit, the first circuit breaker QF1, the second circuit breaker QF2, and the third circuit breaker QS3 can be immediately reconnected via the control system. When circuit breaker QF3 and disconnector are closed, the disconnector at the outlet of the first main transformer T1 remains open, meaning the third disconnector QS3 is open. Simultaneously, the short-lead protection device is activated. At this point, the current circuit can still maintain a series-loop operation, and because the short-lead protection device is activated, the safety of the entire system is not affected. Similarly, if it is necessary to connect the first main transformer T1, the corresponding side circuit breaker and interruptor switch and disconnector must be disconnected, then the third disconnector QS3 must be closed, and then the corresponding side circuit breaker and interruptor switch and disconnector must be closed in sequence. When the main transformer protection device is put into use and the short lead protection device is deactivated, the first main transformer T1 is put into operation with the permanent-temporary combined single-loop connection protection system described in this invention. Through the design of the single-loop connection and the short lead protection device, the first main transformer T1 can be quickly deactivated and activated at any time, thereby realizing the rapid repair and maintenance of the first main transformer T1. This achieves permanent-temporary combination during the use of the single-loop connection protection system, ensuring the power supply reliability and flexibility of the power supply system, while reducing the workload of personnel involved in design, construction, commissioning, and operation, and saving investment and construction time.

[0074] In an optional embodiment of the present invention, the second protective device includes:

[0075] The fourth disconnecting switch QS4 is electrically connected to the second circuit breaker QF2;

[0076] The fifth current transformer CT5 is installed between the fourth disconnector QS4 and the second circuit breaker QF2.

[0077] The fifth disconnector switch QS5 has one end electrically connected to the fourth disconnector switch QS4 and the other end electrically connected to the third circuit breaker QF3;

[0078] The sixth current transformer CT6 is installed between the third circuit breaker QF3 and the fifth disconnecting switch QS5.

[0079] The converter station E is electrically connected to the fourth disconnect switch QS4 and the fifth disconnect switch QS5.

[0080] In this embodiment, the sixth current transformer CT6 is equipped with two second busbar protection windings W03, each connected to a second busbar protection device for monitoring and protecting the 500kV transmission line. The sixth current transformer CT6 also includes a circuit breaker protection winding and other measuring windings, the specific configuration of which can be determined according to actual project requirements. The fifth current transformer CT5 is equipped with at least one main transformer protection winding, at least one short lead protection winding, and measuring windings, with each winding connected to a corresponding protection device.

[0081] In this embodiment, the converter station E is located between the fourth disconnecting switch QS4 and the fifth disconnecting switch QS5. The control process for putting the converter station E into operation and taking it out of operation is the same as the process for putting the first main transformer T1 into operation and taking it out of operation, which is to first disconnect the circuit breaker and then disconnect the disconnecting switch.

[0082] In an optional embodiment of the present invention, the second protection circuit includes:

[0083] The third and fourth protection devices;

[0084] One end of the third protection device is electrically connected to the first busbar U1 through the fourth circuit breaker QF4 and the seventh current transformer CT7; the other end of the third protection device is electrically connected to the fourth protection device through the fifth circuit breaker QF5; and one end of the fourth protection device is electrically connected to the second busbar U2 through the sixth circuit breaker QF6 and the eighth current transformer CT8.

[0085] In operation, the seventh current transformer CT7 and the eighth current transformer CT8 are each connected to at least one short lead protection device, the second main transformer T2 is electrically connected to the third protection device, and the third main transformer T3 is electrically connected to the fourth protection device.

[0086] In this embodiment, the second protection circuit is used to increase the number of main transformers and form a loop with the first protection circuit to ensure the normal operation of the entire system. The third and fourth protection devices have the same structure as the first protection device and are equipped with short lead protection devices. Their working principle for putting into use and taking out of operation is the same as that of the first main transformer T1. They first disconnect the circuit breaker, then disconnect the isolating switch, and then start or take out the corresponding short lead protection device.

[0087] In an optional embodiment of the present invention, the seventh current transformer CT7 is provided with at least one seventh winding W7, at least one eighth winding W8, and a ninth winding W9.

[0088] Each of the seventh windings W7 is electrically connected to a second main transformer protection device, each of the eighth windings W8 is electrically connected to a third short lead protection device, and the ninth winding W9 is electrically connected to a third circuit breaker protection device.

[0089] In an optional embodiment of the present invention, the eighth current transformer CT8 is provided with at least one tenth winding W10, at least one eleventh winding W11 and a twelfth winding W12.

[0090] Each of the tenth windings W10 is electrically connected to a third main transformer protection device, each of the eleventh windings W11 is electrically connected to a fourth short lead protection device, and the twelfth winding W12 is electrically connected to a fourth circuit breaker protection device.

[0091] In an optional embodiment of the present invention, the third protection device includes:

[0092] The sixth disconnecting switch QS6 is electrically connected to the fourth circuit breaker QF4;

[0093] The ninth current transformer CT9 is installed between the fourth circuit breaker QF4 and the sixth disconnecting switch QS6.

[0094] The seventh disconnector switch QS7 is electrically connected at one end to the sixth disconnector switch QS6 and at the other end to the fifth circuit breaker QF5.

[0095] The tenth current transformer CT10 is installed between the fifth circuit breaker QF5 and the seventh disconnecting switch QS7.

[0096] The second main transformer T2 is electrically connected to the sixth disconnect switch QS6 and the seventh disconnect switch QS7 through the eighth disconnect switch QS8.

[0097] In an optional embodiment of the present invention, the second protective device includes:

[0098] The ninth disconnecting switch QS9 is electrically connected to the fifth circuit breaker QF5;

[0099] The eleventh current transformer CT11 is installed between the ninth disconnecting switch QS9 and the fifth circuit breaker QF5.

[0100] The tenth disconnector QS10, one end of which is electrically connected to the ninth disconnector QS9, and the other end of which is electrically connected to the sixth circuit breaker QF6;

[0101] The twelfth current transformer CT12 is installed between the sixth circuit breaker QF6 and the tenth disconnecting switch QS10;

[0102] The third main transformer T3 is electrically connected to the tenth disconnector QS10 and the ninth disconnector QS9 via the eleventh disconnector QS11.

[0103] The permanent-temporary combined single-loop wiring protection system described in this invention, when any main transformer is taken out of operation, disconnects the corresponding side circuit breaker, interruptor switch, and disconnector switch, and disconnects the disconnector switch at the transformer outlet, thus taking the main transformer out of operation. Then, the corresponding side circuit breaker, interruptor switch, and disconnector switch of this main transformer are closed, while the disconnector switch at the main transformer outlet remains open, and short-lead protection is activated. At this time, the transformer string can still maintain a closed-loop operation. When any main transformer needs to be put into operation, the corresponding side circuit breaker, interruptor switch, and disconnector switch are disconnected, and the disconnector switch at the main transformer outlet is closed. Then, the corresponding side circuit breaker, interruptor switch, and disconnector switch are closed again, activating the main transformer protection and deactivating the short-lead protection. The main transformer is then put into operation. This invention enables rapid take-off and activation of the main transformer in the single-loop wiring protection system, achieving permanent-temporary combination during the use of the single-loop wiring protection system, ensuring the power supply reliability and flexibility of the power supply system, while reducing the workload of personnel involved in design, construction, commissioning, and operation, and saving investment and construction time.

[0104] The above description represents the preferred embodiments of the present invention. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A permanent and temporary combined single loop type joint protection system, characterized in that, include: A first protection circuit and a second protection circuit are disposed between the first busbar (U1) and the second busbar (U2) and are electrically connected to the first busbar (U1) and the second busbar (U2) respectively. The first protection circuit includes: First protection device and second protection device; One end of the first protection device is electrically connected to the first busbar (U1) through the first circuit breaker (QF1) and the first current transformer (CT1); the other end of the first protection device is electrically connected to the second protection device through the second circuit breaker (QF2); one end of the second protection device is electrically connected to the second busbar (U2) through the third circuit breaker (QF3) and the second current transformer (CT2). In operation, the first current transformer (CT1) and the second current transformer (CT2) are each connected to at least one short lead protection device. The first main transformer (T1) is electrically connected to the first protection device, the second main transformer (T2) is electrically connected to the second protection circuit, and the converter station (E) is electrically connected to the second protection device. The first current transformer (CT1) is provided with at least one first winding (W1), at least one second winding (W2) and a third winding (W3). Each of the first windings (W1) is electrically connected to a first main transformer protection device, each of the second windings (W2) is electrically connected to a first short lead protection device, and the third winding (W3) is electrically connected to a first circuit breaker protection device. The second current transformer (CT2) is provided with at least one fourth winding (W4), at least one fifth winding (W5) and a sixth winding (W6). Each of the fourth windings (W4) is electrically connected to a converter station protection device, each of the fifth windings (W5) is electrically connected to a second short lead protection device, and the sixth winding (W6) is electrically connected to a second circuit breaker protection device. The first protection device includes: The first disconnecting switch (QS1) is electrically connected to the first circuit breaker (QF1); A third current transformer (CT3) is installed between the first circuit breaker (QF1) and the first disconnecting switch (QS1). The second disconnecting switch (QS2) has one end electrically connected to the first disconnecting switch (QS1) and the other end electrically connected to the second circuit breaker (QF2); A fourth current transformer (CT4) is installed between the second circuit breaker (QF2) and the second disconnector (QS2). The first main transformer (T1) is electrically connected to the first disconnect switch (QS1) and the second disconnect switch (QS2) through the third disconnect switch (QS3); The third current transformer (CT3) is equipped with two first busbar protection windings (W02), and the two windings are respectively connected to a first busbar protection device. The third disconnecting switch (QS3) is disposed between the first disconnecting switch (QS1) and the second disconnecting switch (QS2); When the first main transformer (T1) needs to be taken out of operation, the first circuit breaker (QF1), the second circuit breaker (QF2), and the third circuit breaker (QF3) are disconnected in sequence, and all disconnecting switches connected to the first main transformer (T1) are disconnected, so that the first main transformer (T1) is taken out of operation. The control system then closes the switches and disconnecting switches of the first circuit breaker (QF1), the second circuit breaker (QF2), and the third circuit breaker (QF3). At this time, the third disconnecting switch (QS3) at the outlet of the first main transformer (T1) remains open, and the short lead protection device is activated. When the first main transformer (T1) needs to be connected, the corresponding side circuit breaker and interruptor switch and disconnector switch are disconnected, and the third disconnector switch (QS3) is closed. Then, the corresponding side circuit breaker and interruptor switch and disconnector switch are closed in sequence to put the main transformer protection device into use and deactivate the short lead protection device.

2. The permanent temporary combined single loop type joint protection system according to claim 1, characterized in that, The second protection device includes: The fourth disconnecting switch (QS4) is electrically connected to the second circuit breaker (QF2); A fifth current transformer (CT5) is installed between the fourth disconnector (QS4) and the second circuit breaker (QF2). The fifth disconnecting switch (QS5) is electrically connected at one end to the fourth disconnecting switch (QS4) and at the other end to the third circuit breaker (QF3). A sixth current transformer (CT6) is installed between the third circuit breaker (QF3) and the fifth disconnecting switch (QS5). The converter station (E) is electrically connected to the fourth disconnect switch (QS4) and the fifth disconnect switch (QS5).

3. The permanent temporary combined single loop type joint protection system according to claim 1, characterized in that, The second protection circuit includes: The third and fourth protection devices; One end of the third protection device is electrically connected to the first busbar (U1) through the fourth circuit breaker (QF4) and the seventh current transformer (CT7); the other end of the third protection device is electrically connected to the fourth protection device through the fifth circuit breaker (QF5); one end of the fourth protection device is electrically connected to the second busbar (U2) through the sixth circuit breaker (QF6) and the eighth current transformer (CT8). In use, the seventh current transformer (CT7) and the eighth current transformer (CT8) are each connected to at least one short lead protection device, the second main transformer (T2) is electrically connected to the third protection device, and the third main transformer (T3) is electrically connected to the fourth protection device.

4. The permanent and temporary combined single-ring wiring protection system according to claim 3, characterized in that, The seventh current transformer (CT7) is provided with at least one seventh winding (W7), at least one eighth winding (W8), and a ninth winding (W9). Each of the seventh windings (W7) is electrically connected to a second main transformer protection device, each of the eighth windings (W8) is electrically connected to a third short lead protection device, and the ninth winding (W9) is electrically connected to a third circuit breaker protection device.

5. The permanent temporary combined single loop type joint protection system according to claim 3, characterized in that, The eighth current transformer (CT8) is provided with at least one tenth winding (W10), at least one eleventh winding (W11), and a twelfth winding (W12). Each of the tenth windings (W10) is electrically connected to a third main transformer protection device, each of the eleventh windings (W11) is electrically connected to a fourth short lead protection device, and the twelfth winding (W12) is electrically connected to a fourth circuit breaker protection device.

6. The permanent temporary combined single loop type joint protection system according to claim 3, characterized in that, The third protection device includes: The sixth disconnecting switch (QS6) is electrically connected to the fourth circuit breaker (QF4); The ninth current transformer (CT9) is installed between the fourth circuit breaker (QF4) and the sixth disconnecting switch (QS6). The seventh disconnector (QS7) is electrically connected at one end to the sixth disconnector (QS6) and at the other end to the fifth circuit breaker (QF5). The tenth current transformer (CT10) is installed between the fifth circuit breaker (QF5) and the seventh disconnecting switch (QS7). The second main transformer (T2) is electrically connected to the sixth disconnect switch (QS6) and the seventh disconnect switch (QS7) through the eighth disconnect switch (QS8).

7. The permanent and temporary combined single-ring wiring protection system according to claim 3, characterized in that, The second protection device includes: The ninth disconnecting switch (QS9) is electrically connected to the fifth circuit breaker (QF5); The eleventh current transformer (CT11) is installed between the ninth disconnecting switch (QS9) and the fifth circuit breaker (QF5). The tenth disconnector (QS10) has one end electrically connected to the ninth disconnector (QS9) and the other end electrically connected to the sixth circuit breaker (QF6). The twelfth current transformer (CT12) is installed between the sixth circuit breaker (QF6) and the tenth disconnecting switch (QS10). The third main transformer (T3) is electrically connected to the tenth disconnector (QS10) and the ninth disconnector (QS9) via the eleventh disconnector (QS11).

Images