Main transformer cooler control circuit and system

Abstract

The utility model relates to a main transformer cooler control circuit and system, and relates to the technical field of main transformer cooler control. The main transformer cooler control circuit comprises a three-phase power supply and a plurality of control branches, the three-phase power supply is connected with each control branch, and the control branches are used for being connected with the main transformer coolers in a one-to-one correspondence mode. According to the main transformer cooler control circuit, the control branch circuit is independently arranged for each main transformer cooler, so that the independent control of a plurality of main transformer coolers can be realized, and the problem that the rest main transformer coolers are shut down due to failure shutdown of one main transformer cooler is avoided.

Description

Technical Field

[0001] The present disclosure relates to the technical field of main transformer cooler control, and specifically, to a main transformer cooler control circuit and system. Background Art

[0002] Main transformer coolers are very important equipment in the power system and are responsible for cooling the main transformer. In the related art, there are coupled parts in the control branches of multiple main transformer coolers, which results in all main transformer coolers shutting down when one main transformer cooler fails, and independent control of the main transformer coolers cannot be achieved. Therefore, the related art has problems of high single-point failure risk and poor reliability. Summary of the Utility Model

[0003] To solve the above problems, the present disclosure provides a main transformer cooler control circuit and system.

[0004] In a first aspect, the present disclosure provides a main transformer cooler control circuit, including: a three-phase power supply and multiple control branches, the three-phase power supply is connected to each of the control branches, and the multiple control branches are used to be connected to the multiple main transformer coolers in one-to-one correspondence.

[0005] Optionally, each of the control branches includes: a three-phase circuit breaker, a single-pole switch, and a change-over switch, a first end of the three-phase circuit breaker is connected to the single-pole switch, and the single-pole switch is connected to the change-over switch.

[0006] Optionally, each of the control branches includes: a contactor, the three-phase power supply is connected to a second end of the three-phase circuit breaker, a third end of the three-phase circuit breaker is connected to a main contact of the contactor, the main contact of the contactor is used to be connected to the main transformer cooler corresponding to the control branch where it is located, and the change-over switch is connected to a coil of the contactor.

[0007] Optionally, the third end of the three-phase circuit breaker includes three sub-ends, the three sub-ends correspond to the three phase lines of the three-phase power supply one by one, and the first end is any one of the sub-ends of the third end.

[0008] Optionally, it further includes an alarm circuit, the alarm circuit is connected to an auxiliary normally closed contact of each of the single-pole switches; the alarm circuit includes a display screen for displaying the main transformer cooler fault alarm information.

[0009] Optionally, the model of the single-pole switch is ABB S201 C3.

[0010] Optionally, the auxiliary normally closed contacts of each of the single-pole switches are connected in parallel and then connected to the alarm circuit.

[0011] Optionally, the alarm circuit is connected to an auxiliary normally closed contact of each of the three-phase circuit breakers.

[0012] Optionally, the auxiliary normally closed contacts of each of the three-phase circuit breakers are connected in parallel and then connected to the alarm circuit.

[0013] In a second aspect, the present disclosure further provides a main transformer cooler control system, including a plurality of main transformer coolers and a main transformer cooler control branch as described in any one of the first aspects, and the plurality of main transformer coolers are connected to the main transformer cooler control branch.

[0014] In the above technical solution, a control branch is separately provided for each main transformer cooler and connected to a three-phase power supply. When a problem occurs in a single main transformer cooler, it will not affect the normal operation of other main transformer coolers, thereby realizing independent control of the main transformer coolers and improving the reliability and stability of the operation of the main transformer coolers.

[0015] Other features and advantages of the present disclosure will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings are used to provide a further understanding of the present disclosure, and constitute a part of the specification, and are used to explain the present disclosure together with the following specific implementation manners, but do not constitute a limitation to the present disclosure. In the accompanying drawings:

[0017] Figure 1 is a structural diagram of a main transformer cooler control circuit shown according to an exemplary embodiment;

[0018] Figure 2 is a structural diagram of each control branch shown according to an exemplary embodiment;

[0019] Figure 3 is a structural diagram of a main transformer cooler control circuit shown according to an exemplary embodiment;

[0020] Figure 4 is a structural diagram of an alarm circuit shown according to an exemplary embodiment.

[0021] DESCRIPTION OF THE REFERENCE NUMERALS

[0022] Main transformer cooler control circuit 100, three-phase power supply 200, control branch 300, main transformer cooler 400, three-phase circuit breaker 3i1, first end 3i11 of the three-phase circuit breaker, second end 3i12 of the three-phase circuit breaker, third end 3i13 of the three-phase circuit breaker, auxiliary normally closed contact 3i14 of the three-phase circuit breaker, single-pole switch 3i2, auxiliary normally closed contact 3i21 of the single-pole switch, change-over switch 3i3, main contact 3i41 of the contactor, coil 3i42 of the contactor, alarm circuit 500. DETAILED DESCRIPTION OF THE INVENTION

[0023] The following will describe in detail the specific embodiments of the present disclosure with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for illustrating and explaining the present disclosure, and are not used to limit the present disclosure.

[0024] The main transformer cooler is an important device used to cool the main transformer in the power system. The main transformer is the core component in the power system, responsible for voltage conversion and playing a key role in connecting the power plant and the power consumption side. During operation, the main transformer generates a large amount of heat, which needs to be cooled by a cooling system to ensure the continuous and stable operation of the main transformer. The main transformer cooler is a key part of such a cooling system. It can adopt single or combined cooling methods such as water cooling, oil cooling or air cooling to timely export the heat generated by the main transformer and ensure the reliable operation of the main transformer.

[0025] There are some problems in the control circuit of the main transformer cooler in the related art. Specifically, multiple main transformer coolers share the same branch from the three-phase power supply to the transfer switch. This design has a risk of single-point failure. Once there is a problem with this branch, all main transformer coolers will stop operating simultaneously. This centralized control method lacks independent control of each main transformer cooler. Once a certain cooler has a problem, it will affect the operation stability of the main transformer cooler and cannot achieve reliable and flexible control of the main transformer cooler. That is, the related art has problems such as high single-point failure risk and poor reliability.

[0026] The good operation of the main transformer cooler is crucial for the reliable power supply of the entire power system. Therefore, how to design a reliable control circuit for the main transformer cooler is one of the technical problems that the power industry urgently needs to solve.

[0027] Figure 1 is a structural diagram of the main transformer cooler control circuit 100 shown according to an exemplary embodiment. As Figure 1 shown, the main transformer cooler control circuit 100 includes: a three-phase power supply 200 and a plurality of control branches 300. The three-phase power supply 200 is connected to each of the control branches 300, and the plurality of control branches 300 are used to be connected to the plurality of main transformer coolers 400 in one-to-one correspondence.

[0028] Here, the three-phase power supply 200 refers to a power supply that provides three-phase alternating current and is used to supply power to the main transformer, a high-power device. The control branch 300 refers to a separate circuit branched from the three-phase power supply 200 and is used to connect and control a single main transformer cooler 400. Exemplarily, as Figure 2As shown in the figure, there are n (n≥3) control branches 300, including the first control branch 310, the second control branch 320, ……, the i-th control branch 3i0 (1≤i≤n), ……, the n-th control branch 3n0. Correspondingly, there are also n main transformer coolers 400, including the first main transformer cooler 410, the second main transformer cooler 420, ……, the i-th main transformer cooler 4i0, ……, the n-th main transformer cooler 400. The control branches 300 are connected to the main transformer coolers 400 in a one-to-one correspondence.

[0029] The three-phase power supply 200 is connected to each control branch 3i0, which can ensure that each main transformer cooler 4i0 can obtain an independent power supply from the three-phase power supply 200. Thus, the problem of all main transformer coolers shutting down due to the failure of a single control branch 3i0 can be avoided. The specific connection method between the three-phase power supply 200 and the control branch 300 can be: the three-phase AC outputs of the three-phase power supply 200 are respectively connected to the three input ends of each control branch 3i0.

[0030] The one-to-one correspondence connection between the control branches 300 and the main transformer coolers 400 can achieve independent control of each main transformer cooler 400. Once a certain main transformer cooler 4i0 fails, it only affects that device and does not affect the normal operation of other main transformer coolers 400.

[0031] In the above technical solution, a control branch 3i0 is set separately for each main transformer cooler 4i0 and is connected to the three-phase power supply 200. When a problem occurs in a single main transformer cooler 4i0, it does not affect the normal operation of other main transformer coolers, thereby realizing independent control of the main transformer coolers 400 and improving the reliability and stability of the operation of the main transformer coolers 400.

[0032] Figure 2 is a structural diagram of each control branch 300 shown according to an exemplary embodiment. Figure 3 is a structural diagram of the main transformer cooler control circuit 100 shown according to an exemplary embodiment. In one embodiment, as Figure 2 and Figure 3 shown, each of the control branches 300 includes: a three-phase circuit breaker 3i1, a single-pole switch 3i2, and a changeover switch 3i3. The first end 3i11 of the three-phase circuit breaker is connected to the single-pole switch 3i2, and the single-pole switch 3i2 is connected to the changeover switch 3i3.

[0033] Here, the three-phase circuit breaker 3i1 is a circuit breaker used to protect the three-phase circuit (the circuit connecting to the three-phase power supply 200), which can quickly cut off the circuit in case of overload or short circuit of the circuit, protecting the circuit and the main transformer cooler 400 safely. The single-pole switch 3i2 is a switch used for a single-phase circuit (a circuit that only connects to one phase of the three-phase power supply 200). The changeover switch 3i3 is used to switch the operation mode of the main transformer cooler, including standby mode, stop mode, working mode, auxiliary mode, etc. The first end 3i11 of the three-phase circuit breaker refers to a single output end of the three-phase circuit breaker 3i1.

[0034] In the related art, the changeover switch 3i3 of all control branches 300 is directly connected to the three-phase power supply 200 and shares one branch. Therefore, when a fault occurs in a certain branch, it will affect the normal operation of other branches, reducing the reliability.

[0035] The first end 3i11 of the three-phase circuit breaker is connected to the single-pole switch 3i2, and the single-pole switch 3i2 is connected to the changeover switch 3i3, which can enable each control branch 3i0 to have an independent power supply path from the three-phase power supply 200 to the changeover switch 3i3, thereby avoiding problems that may be caused by sharing branches. Setting the single-pole switch 3i2 on the independent branch from the three-phase power supply 200 to the changeover switch 3i3 can conveniently manually control the on / off of the entire three-phase circuit. When a fault occurs, the corresponding branch can be quickly isolated from the three-phase power supply 200 through the single-pole switch 3i2. Even if the changeover switch 3i3 itself fails, the single-pole switch 3i2 can independently cut off the power supply.

[0036] In one embodiment, as Figure 2 and Figure 3 shown, each of the control branches 300 includes: a contactor. The three-phase power supply 200 is connected to the second end 3i12 of the three-phase circuit breaker. The third end 3i13 of the three-phase circuit breaker is connected to the main contact 3i41 of the contactor. The main contact 3i41 of the contactor is used to connect to the main transformer cooler 400 corresponding to the control branch 300 where it is located. The changeover switch 3i3 is connected to the coil 3i42 of the contactor.

[0037] Here, a contactor is an electromagnetic switch device used to control the on / off of a circuit, mainly composed of a coil and a main contact. The main contact 3i41 of the contactor is the electrical contact point for actually cutting off or connecting the circuit, undertaking the on / off function of the main circuit of the circuit. The coil 3i42 of the contactor is an electromagnetic coil. When current passes through the coil, a magnetic field will be generated, attracting the movable iron core of the contactor, thereby driving the main contact 3i41 of the contactor to close and completing the connection of the circuit. The second end 3i12 of the three-phase circuit breaker is its input end, connecting to the three-phase power supply 200. The third end 3i13 of the three-phase circuit breaker is its output end, used to supply power to the main transformer cooler 400.

[0038] Connect the output terminal (the third terminal) of the three - phase circuit breaker 3i1 to the main contact 3i41 of the contactor. The opening and closing function of the contactor can be used to control the operation and shutdown of the main transformer cooler 4i0. Connect the change - over switch 3i3 to the coil 3i42 of the contactor. By operating the change - over switch 3i3, the energization and de - energization of the coil 3i42 of the contactor can be controlled, thereby controlling the attraction and separation of the main contact 3i41 of the contactor, and thus realizing the control of the operation and shutdown of the main transformer cooler 4i0.

[0039] In one embodiment, the third terminal 3i13 of the three - phase circuit breaker includes three sub - terminals, which correspond one - to - one with the three phase lines of the three - phase power supply 200, and the first terminal is any one of the sub - terminals of the third terminal.

[0040] Here, the third terminal 3i13 of the three - phase circuit breaker includes three sub - terminals, corresponding to the three phase lines of the three - phase power supply 200 respectively. The first terminal, as the input terminal of the contactor coil, only needs to be connected to one of the phases of the three - phase power supply 200 to realize the control of the contactor. Therefore, any one of the sub - terminals of the third terminal is used as the first terminal. Exemplarily, as Figure 2 and Figure 3 shown, the first terminal is the terminal corresponding to phase A in the three - phase power supply 200 among the third terminals.

[0041] Figure 4 is a structural diagram of the alarm circuit 500 shown according to an exemplary embodiment. In one embodiment, as Figure 3 and 4 shown, the main transformer cooler control circuit 100 further includes an alarm circuit 500, and the alarm circuit 500 is connected to the auxiliary normally - closed contact 3i21 of each single - pole switch; the alarm circuit 500 includes a display screen for displaying the fault alarm information of the main transformer cooler 4i0.

[0042] Here, the alarm circuit 500 is an independent circuit for detecting whether the main transformer cooler 400 fails and giving an alarm prompt. In addition to the main breaking function, the single - pole switch 3i2 has a pair of auxiliary normally - closed contacts that remain open when the single - pole switch 3i2 is normally closed and close when the single - pole switch 3i2 trips. This auxiliary normally - closed contact can be used to detect the tripping state of the single - pole switch 3i2. The display screen is a device in the alarm circuit 500 for displaying the fault alarm information of the main transformer cooler 4i0.

[0043] When the single - pole switch 3i2 trips due to a fault, its auxiliary normally - closed contact closes, thereby conducting the alarm circuit 500, enabling the display screen to display the fault alarm information, so that the fault of the main transformer cooler 4i0 can be detected and processed in time. Through the linkage between the alarm circuit 500 and the auxiliary contact of the single - pole switch 3i2, the fault of the main transformer cooler 4i0 can be detected and displayed in time.

[0044] In one embodiment, the model of the single-pole switch 3i2 is ABB S201 C3.

[0045] Here, the ABB S201 C3 model single-pole switch is a single-pole switch with an auxiliary normally-closed contact.

[0046] In one embodiment, as Figure 3 and 4 shown, the auxiliary normally-closed contacts 3i21 of each single-pole switch are connected in parallel to the alarm circuit 500.

[0047] Here, the auxiliary normally-closed contacts 3i21 of all single-pole switches are connected together in parallel and connected to the alarm circuit 500. When any single-pole switch 3i2 trips due to a fault, its auxiliary normally-closed contact will close, conducting the alarm circuit 500 and triggering an alarm. Thus, any main transformer cooler 4i0 and its control branch 3i0 can be monitored in a timely manner for faults.

[0048] Corresponding to the number of control branches 300, there are n single-pole switches 3i2, and each single-pole switch 3i2 has a corresponding auxiliary normally-closed contact. Exemplarily, as Figure 4 shown, the auxiliary normally-closed contact 3121 of the first single-pole switch, the auxiliary normally-closed contact 3221 of the second single-pole switch,..., the auxiliary normally-closed contact 3i21 of the i-th single-pole switch,..., the auxiliary normally-closed contact 3n21 of the n-th single-pole switch are all connected in parallel to the alarm circuit 500 to jointly control the conduction and closing of the alarm circuit 500. When the auxiliary normally-closed contact 3i21 of any single-pole switch closes, the alarm circuit 500 closes.

[0049] In one embodiment, as Figure 3 and Figure 4 shown, the alarm circuit 500 is connected to the auxiliary normally-closed contact 3i14 of each three-phase circuit breaker.

[0050] Here, like the single-pole switch 3i2, the three-phase circuit breaker 3i1 also has an auxiliary normally-closed contact. When the three-phase circuit breaker 3i1 is normally closed, its auxiliary normally-closed contact is open, and when it trips, its auxiliary normally-closed contact closes. Connecting the auxiliary normally-closed contact 3i14 of the three-phase circuit breaker to the alarm circuit 500 can achieve fault monitoring of the main transformer cooler 4i0 and its control branch 3i0.

[0051] In one embodiment, as Figure 3 and Figure 4 shown, the auxiliary normally-closed contacts 3i14 of each three-phase circuit breaker are connected in parallel to the alarm circuit 500.

[0052] Here, the auxiliary normally closed contacts 3i14 of all three-phase circuit breakers are paralleled together and connected to the alarm circuit 500. When any one of the three-phase circuit breakers 3i1 trips due to a fault, its auxiliary normally closed contact will close, conducting the alarm circuit 500 and triggering an alarm. Thus, faults in any main transformer cooler 4i0 and its control branch 30i0 can be monitored in a timely manner.

[0053] Corresponding to the number of control branches 300, there are n three-phase circuit breakers 3i1, and each three-phase circuit breaker 3i1 has a corresponding auxiliary normally closed contact. By way of example, as Figure 4 shown, the auxiliary normally closed contacts 3114 of the first three-phase circuit breaker, 3214 of the second three-phase circuit breaker,..., 3i14 of the i-th three-phase circuit breaker,..., 3n14 of the n-th three-phase circuit breaker are all paralleled and connected to the alarm circuit 500, jointly controlling the conduction and closing of the alarm circuit 500. When the auxiliary normally closed contact 3i14 of any one of the three-phase circuit breakers closes, the alarm circuit 500 closes.

[0054] The present disclosure also provides a main transformer cooler control system, including a plurality of main transformer coolers and the main transformer cooler control branch as described in any one of the first aspect, and the plurality of main transformer coolers are connected to the main transformer cooler control branch.

[0055] The preferred embodiments of the present disclosure have been described in detail above in conjunction with the accompanying drawings. However, the present disclosure is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present disclosure, various simple modifications can be made to the technical solutions of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

[0056] In addition, it should be noted that, in the case of no contradiction, the various specific technical features described in the above specific embodiments can be combined in any suitable manner. To avoid unnecessary repetition, the present disclosure will not separately describe various possible combination manners.

[0057] Furthermore, any combination can be made between different embodiments of the present disclosure, as long as it does not violate the idea of the present disclosure, and it should also be regarded as the content disclosed by the present disclosure.

Claims

1. A main transformer cooler control circuit for controlling multiple main transformer coolers, characterized in that, Comprising: A three-phase power supply (200) and a plurality of control branches (300), the three-phase power supply (200) is connected to each of the control branches (300), and the plurality of control branches (300) are used to be connected to the plurality of main transformer coolers (400) in a one-to-one correspondence.

2. The main transformer cooler control circuit according to claim 1, wherein, Each of the control branches (300) includes: a three-phase circuit breaker (3i1), a single-pole switch (3i2), and a change-over switch (3i3). The first end (3i11) of the three-phase circuit breaker is connected to the single-pole switch (3i2), and the single-pole switch (3i2) is connected to the change-over switch (3i3).

3. The main transformer cooler control circuit according to claim 2, characterized in that, Each of the control branches (300) includes: a contactor. The three-phase power supply (200) is connected to the second end (3i12) of the three-phase circuit breaker, the third end (3i13) of the three-phase circuit breaker is connected to the main contact (3i41) of the contactor, and the main contact (3i41) of the contactor is used to be connected to the main transformer cooler (400) corresponding to the control branch (300) where it is located. The change-over switch (3i3) is connected to the coil (3i42) of the contactor.

4. The main transformer cooler control circuit according to claim 3, characterized in that, The third end (3i13) of the three-phase circuit breaker includes three sub-ends, and the three sub-ends correspond to the three phase lines of the three-phase power supply (200) in a one-to-one manner. The first end is any one of the sub-ends of the third end.

5. The main transformer cooler control circuit according to any one of claims 2-4, characterized in that It further includes an alarm circuit (500), and the alarm circuit (500) is connected to the auxiliary normally closed contact (3i21) of each of the single-pole switches; the alarm circuit (500) includes a display screen for displaying the fault alarm information of the main transformer cooler (400).

6. The main transformer cooler control circuit according to claim 5, characterized in that, The model of the single-pole switch (3i2) is ABB S201 C3.

7. The main transformer cooler control circuit according to claim 5, wherein The auxiliary normally closed contacts (3i21) of each of the single-pole switches are connected in parallel and then connected to the alarm circuit (500).

8. The main transformer cooler control circuit according to claim 5, wherein The alarm circuit (500) is connected to the auxiliary normally closed contact (3i14) of each of the three-phase circuit breakers.

9. The main transformer cooler control circuit according to claim 8, characterized in that, The auxiliary normally closed contacts (3i14) of each of the three-phase circuit breakers are connected in parallel and then connected to the alarm circuit (500).

10. A main transformer cooler control system, characterized in that, Comprising a plurality of main transformer coolers and the main transformer cooler control branch as described in any one of claims 1-9, and the plurality of main transformer coolers are connected to the main transformer cooler control branch.

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