Substation electrical cooler control system

Abstract

The invention provides a substation electrical cooler control system, which comprises a power supply automatic switching module used for realizing automatic switching between a main power supply and a standby power supply; the working position cooler control module is connected to the power supply automatic switching module and is used for controlling the cooler at the working position to start and stop; the auxiliary position cooler control module is connected to the power supply automatic switching module and is used for automatically starting an auxiliary cooler according to the oil surface temperature or the load current of the transformer; the standby position cooler control module is connected to the power supply automatic switching module and the working and auxiliary position cooler control module and is used for automatically starting a standby cooler when the working or auxiliary cooler breaks down; and the main transformer signal module is connected with all the modules and is used for monitoring and sending a system operation state signal. By implementing the invention, the reliability of power supply can be improved, the precise control of the cooler is realized, and the operation state monitoring and signal feedback can be perfected, so that the overall stability of the system is enhanced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electrical cooling of transformer substations, and in particular to an electrical cooler control system for transformer substations. BACKGROUND

[0002] In a transformer substation, the stable operation of electrical equipment is of great importance, and the electrical cooling device is a key component to ensure the normal operation of the equipment. During the operation of electrical equipment, a large amount of heat is generated, and if it cannot be cooled in time and effectively, the temperature of the equipment will be too high, which will affect its performance and service life, and even may cause serious failure, endangering the safe and stable operation of the entire transformer substation.

[0003] However, the existing electrical cooling system of transformer substations has many problems. First of all, the circuit design is not reasonable, which makes it difficult to achieve the ideal cooling effect. For example, in terms of power switching, there is a lack of reliable and efficient automatic switching mechanism, and once the main power fails, the standby power cannot be put into use in time, resulting in instantaneous power failure of the cooling device and inability to continuously dissipate heat for electrical equipment. Secondly, the existing system has poor reliability, and the control of working, auxiliary and standby coolers lacks precise and flexible logic. When the working cooler fails, the auxiliary cooler cannot be started in time, or the standby cooler cannot be put into operation at the right time, causing cooling interruption. In addition, the system's monitoring and signal feedback of the running state are not perfect, and the operation and maintenance personnel have difficulty in grasping the running state of the cooling system in time and accurately, which is not conducive to quickly discovering and solving problems, increasing the risk and cost of the operation of the transformer substation. SUMMARY

[0004] The technical problem to be solved by the present application is to provide an electrical cooler control system for transformer substations, which solves the problems of unreliable power switching, inaccurate cooler control and imperfect running state monitoring in the prior art.

[0005] As an aspect of the present application, an electrical cooler control system for transformer substations is provided, which comprises: a power automatic switching module, a working position cooler control module, an auxiliary position cooler control module, a standby position cooler control module and a main transformer signal module; wherein, The power automatic switching module is used to realize automatic switching between the main power and the standby power, ensuring continuous power supply for the cooling device. The working position cooler control module is connected to the power automatic switching module and is used to control the start and stop of the cooler in the working position. The auxiliary position cooler control module is connected to the power automatic switching module and is used to automatically start the auxiliary cooler according to the transformer oil surface temperature or load current. A standby position cooler control module is connected to the power automatic switching module and the working and auxiliary position cooler control modules, and is used to automatically start the standby cooler when the working or auxiliary cooler fails. A main transformer signal module is connected to the above modules, and is used to monitor and send a system running state signal.

[0006] Preferably, the power automatic switching module has an input end connected to a first working power (A1, B1, C1) and a second working power (A2, B2, C2), and an output end connected to a subsequent control module, which contains a power switching handle (wh), intermediate relays (2ZJ, 1ZJ, 1C, 2C) and a switching logic circuit; when the first working power loses power, the intermediate relay 1ZJ loses magnetism, its normally closed contact is closed, the power is automatically switched to the second working power, and power interlocking is realized through the relays 1C and 2C. In the power automatic switching module, the first group of contacts (1-2, 3-4) of the power switching handle (wh) are connected in series with the first working power (C1), the second group of contacts (5-6, 7-8) of the power switching handle (wh) are connected in series with the second working power (C2); the coil of the first intermediate relay (2ZJ) is connected across the phase lines of the first working power, its normally open contact (2ZJ) is connected to the first working power circuit after being connected in series with the coil of the interlocking relay (1ZJ); the normally closed contact of the interlocking relay (1ZJ) is connected to the second working power circuit after being connected in series with the coil of the power selection relay (2C), the normally open contact of the interlocking relay (1ZJ) is connected to the first working power circuit after being connected in series with the coil of the power selection relay (1C); the normally closed contacts of the power selection relays (1C, 2C) are respectively connected into the power supply circuit of the opposite power, to realize interlocking. In the power automatic switching module, a general stop relay (7ZJ) is further connected, the normally closed contact of the general stop relay (7ZJ) is connected in series on the general output line of the power automatic switching module; the coil of the general stop relay (7ZJ) is connected in series after being controlled by the auxiliary normally closed contact of the transformer three-side switch, and when the three-side switch is all tripped, the coil is powered and the normally closed contact is opened.

[0007] Preferably, the working position cooler control module includes a position selection handle (1wn, 1wh), an air switch (1ZK), a thermocouple relay (1RJ, 1RJf1…1RJfm) and a control relay (1Cb, 1Cf); the power input end thereof is connected to the output end of the power automatic switching module, the control signal input end thereof is connected to the contact of the working position selection handle (1wn, 1wh), and the power output end thereof is connected to the oil pump and the fan motor of the cooler; when the cooler is placed in the working position, the handle contacts 1wn (5-6) and 1wh (7-8) are turned on to excite 1Cb and 1Cf, and the oil pump and the fan motor are started. In the working position cooler control module, the contact (5-6) of the working position first selection handle (1wn) is connected in series with the normally closed contact of the thermocouple relay (1RJ) and the coil of the control relay (1Cb, 1Cf), and then connected with the air switch (1ZK) to form a complete control loop.

[0008] Preferably, the auxiliary position cooler control module includes a temperature sensor (1WJ1, 1WJ2), a current relay (BFJ), a time relay (1SJ) and an auxiliary starting relay (5ZJ); the transformer oil temperature contact (1WJ2) is connected in series with the coil of the auxiliary starting relay (5ZJ) to form a temperature direct starting loop. The auxiliary starting relay (5ZJ) is provided with a self-holding loop, which is formed by connecting a pair of normally open contacts of the auxiliary starting relay (5ZJ) in series with a resistor (or an indicator lamp) and then connecting the resistor (or the indicator lamp) in parallel across the transformer oil temperature contact (1WJ2) in the temperature direct starting loop. Meanwhile, the load current relay contact (BFJ) is connected in series with the coil of the time relay (1SJ), and the time-delay closed normally open contact of the time relay (1SJ) is connected in series with the coil of the auxiliary starting relay (5ZJ) to form a current time-delay starting loop; the temperature direct starting loop and the current time-delay starting loop are in parallel relationship; when the oil surface temperature is higher than a predetermined temperature or the load current exceeds a set value, the corresponding contact is closed to excite and self-hold 5ZJ and start the auxiliary cooler.

[0009] Preferably, the standby position cooler control module includes a fault detection unit (the normally closed contact of 1LJ, 1Cb, 1Cf), a time relay (2SJ) and a standby starting relay (6ZJ). The power input end of the standby position cooler control module is connected to the output end of the power automatic switching module, the trigger input end thereof is connected in parallel to the normally closed contact of the working cooler fault contact (1Cb, 1Cf) and the oil flow relay contact (1LJ), and the output end thereof is connected to the control loop of the standby position cooler through the contact of the standby starting relay (6ZJ); The trigger input end of the standby position cooler control module is in parallel structure: the normally closed contacts of the working cooler control relays (1Cb, 1Cf) are connected in parallel with each other, and then connected in parallel with the normally open contact of the oil flow relay (1LJ) to jointly constitute a fault signal acquisition point; the output end of the parallel node is connected in series with the coil of the time relay (2SJ); When the working or auxiliary cooler stops or the oil flow stops, the fault detection unit is turned on, and after 2SJ delay, 6ZJ is excited to start the standby cooler.

[0010] Preferably, the time relay (2SJ) is connected in series with the coil of the standby starting relay (6ZJ) to constitute a delay starting loop of the standby cooler.

[0011] Preferably, the system further comprises a phase failure detection module, which comprises a current balance relay (BLJ), the three-phase coil of which is connected in series in the three-phase power supply (A, B, C) respectively, and the secondary output coil thereof is connected to an execution relay; when the phase fails, the normally open contact of the execution relay is closed and connected to the input end of the main transformer signal module.

[0012] Preferably, the main transformer signal module comprises a plurality of parallel branches, each branch being connected in series by a signal power supply, an indicating device and one or more normally open contacts of relays, and each branch corresponding to a system state signal; when any relay is excited, the corresponding contact is closed, and the phase failure, overload, switching or fault signal is output to the signal loop.

[0013] The embodiment of the present application has the following beneficial effects: The present application provides a substation electrical cooler control system, which realizes automatic and rapid switching between the main power supply and the standby power supply through a power automatic switching module. When the first working power supply loses power, the intermediate relay loses excitation, the normally closed contact thereof is closed, the power supply is automatically switched to the second working power supply, and the power interlocking is realized through a relay to ensure continuous power supply of the cooling device, avoid the problem of cooling interruption caused by power interruption, and improve the reliability of the cooling system.

[0014] The working position cooler control module can accurately control the starting and stopping of the cooler according to the working position of the cooler; the auxiliary position cooler control module can automatically start the auxiliary cooler according to the transformer oil surface temperature or the load current, and sets a temperature direct starting loop and a current delay starting loop to meet the cooling requirements under different working conditions; the standby position cooler control module can automatically start the standby cooler when the working or auxiliary cooler fails, so that the cooling system is always in an effective running state, and the cooling effect is improved.

[0015] The main transformer signal module is connected with each control module, can monitor the system running state in real time, and outputs the signals such as open phase, overload, switching or fault to the signal loop through multiple parallel branches. The operation and maintenance personnel can understand the running condition of the cooling system in time and accurately according to these signals, and take corresponding measures quickly to ensure the safe and stable operation of the substation.

[0016] The substation electrical cooler control system of the application optimizes the running logic of the cooling system, improves the adaptability and anti-interference ability of the system to various working conditions, enhances the stability and reliability of the entire substation electrical cooling system, reduces the equipment failure risk, and reduces the operation and maintenance cost through reasonable design and cooperative work between modules. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, a brief introduction will be given to the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are only some embodiments of the application, and for those skilled in the art, other drawings obtained according to these drawings without creative labor are still within the scope of the application; Figure 1 An embodiment structure schematic diagram of a substation electrical cooler control system provided by the application; Figure 2 The circuit schematic diagram of the power automatic switching module and the open phase detection module involved in the application; Figure 1 Figure 3 The transformer fault protection circuit schematic diagram involved in the power automatic switching module; Figure 4 The control circuit schematic diagram of the working position cooler control module, the auxiliary position cooler control module and the standby position cooler control module involved in the application; Figure 5 The circuit schematic diagram of the cooler input and control loop involved in the application; Figure 6 The circuit schematic diagram of the main transformer module involved in the application. DETAILED DESCRIPTION​

[0018] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be further described in detail below with reference to the drawings.

[0019] As shown in Figure 1 , an embodiment structure schematic diagram of a substation electrical cooler control system provided by the present application is shown; in combination with Figures 2 to 6 , in the embodiment, the substation electrical cooler control system is installed at the installation place of the substation electrical cooling device loop, which comprises a power automatic switching module 1, a working position cooler control module 2, an auxiliary position cooler control module 3, a standby position cooler control module 4, a main transformer signal module 5 and a phase failure detection module 6; wherein: The power automatic switching module 1 is used to realize automatic switching between the main power and the standby power, and ensure continuous power supply of the cooling device; The working position cooler control module 2 is connected to the power automatic switching module, and is used to control the start and stop of the cooler in the working position; The auxiliary position cooler control module 3 is connected to the power automatic switching module, and is used to automatically start the auxiliary cooler according to the transformer oil surface temperature or the load current; The standby position cooler control module 4 is connected to the power automatic switching module and the working and auxiliary position cooler control modules, and is used to automatically start the standby cooler when the working or auxiliary cooler fails; The main transformer signal module 5 is connected with the above modules, and is used to monitor and send system running state signals; The phase failure detection module 6 is used to detect whether there is a phase failure fault in the three-phase power supply.

[0020] The implementation details of the above modules will be described below in combination with specific examples.

[0021] As shown in Figure 2 , in the power automatic switching module 1 shown in the upper part, the input end is connected to the first working power supply (A1, B1, C1) and the second working power supply (A2, B2, C2), and the output end is connected to the subsequent control module, which comprises a power switching handle (wh), intermediate relays (2ZJ, 1ZJ, 1C, 2C) and a switching logic circuit; when the first working power supply loses power, the intermediate relay 1ZJ loses magnetism, and its normally closed contact is closed, so as to automatically switch to the second working power supply for power supply, and realize power interlocking through the relays 1C and 2C; Specifically, in the power automatic switching module, the first group of contacts (1-2, 3-4) of the power switching handle (wh) is connected in series with the first working power supply (C1), and the second group of contacts (5-6, 7-8) of the power switching handle (wh) is connected in series with the second working power supply (C2); the coil of the first intermediate relay (2ZJ) is connected across the phase lines of the first working power supply, and the normally open contact (2ZJ) thereof is connected to the first working power supply loop in series with the coil of the interlocking relay (1ZJ); the normally closed contact of the interlocking relay (1ZJ) is connected to the second working power supply loop in series with the coil of the power selection relay (2C), and the normally open contact of the interlocking relay (1ZJ) is connected to the first working power supply loop in series with the coil of the power selection relay (1C); the normally closed contacts of the power selection relays (1C, 2C) are respectively connected into the power supply loop of the opposite power supply, thereby achieving interlocking. More specifically, in the present embodiment, the power supply adopts a loop dual power design, automatically switches, and improves reliability.

[0022] As shown in Figure 2 , the wh is a power switching handle, which is provided with two gears. When the I working power supply gear is hit, the two pairs of contacts 1-2 and 5-6 are turned on, and the current path is A1 busbar→2ZJ relay normally open contact (the normally open contact is closed and the normally closed contact is disconnected when the I working power supply is normal)→1ZJ relay→1-2 contact→1ZJ relay normally open contact (the normally open contact is closed and the normally closed contact is disconnected when the I working power supply is normal)→2C relay normally closed contact→1C relay (the normally closed contact is closed to disconnect the power supply loop of the working power supply 2 when excited, and the normally open contact is closed to supply power to the cooler)→7ZJ relay normally closed contact→cooler. When it is detected that the I working power supply loses power, the power supply is automatically switched to the II working power supply, and at this time the current path is C2 busbar→5-6 contact→1ZJ relay normally closed contact (the normally closed contact is closed and the normally open contact is disconnected when the I working power supply loses power)→1C relay (the normally closed contact is closed)→2C relay (the normally open contact is closed to disconnect the power supply loop of the working power supply 1 when excited, and the normally open contact is closed to supply power to the cooler)→7ZJ relay normally closed contact→cooler.

[0023] In Figure 2 the phase failure detection module 6 shown in the lower part, a current balance relay (BLJ) is connected in series with the three-phase power supply (A, B, C) through its three-phase coil, and its secondary output coil is connected to an execution relay. When there is a phase failure, the normally open contact of the execution relay is closed and connected to the input of the main transformer signal module 5. Specifically, when in normal operation, the three-phase current is balanced, and the current flowing through the BLJ is zero. When there is a phase failure, the current passing through the BLJ relay will cause the corresponding contact to close, and a phase failure operation signal will be generated.

[0024] As shown in Figure 3As shown, the power automatic switching module 1 is further connected with a general stop relay (7ZJ), the normally closed contact of the general stop relay (7ZJ) is connected in series on the general output line of the power automatic switching module; the coil of the general stop relay (7ZJ) is controlled by the auxiliary normally closed contact of the transformer three-side switch connected in series, when the three-side switch is all tripped, the coil is electrified, and the normally closed contact is disconnected. Specifically, the normally closed contact 7ZJ is disconnected when the transformer three-side switch is all tripped, which is used to disconnect the cooler power supply circuit after the three-side switch is tripped for protection action when the transformer has a serious fault, so that the cooler no longer acts. 2ZH in the figure is a test button, which should be normally closed, and is used when the main transformer is out of operation and the cooler needs to be tested.

[0025] As Figure 4 and in combination Figure 5 As shown, Figure 5 Only one set of cooler input and control circuit is shown, in actual examples, more cooler input and control circuits can be cascaded below, which have similar structures to those shown in Figure 5 not be described here.

[0026] In the embodiment, the working position cooler control module includes a position selection handle (1wn, 1wh), an air switch (ZK), a thermocouple relay (1RJ, 1RJf1…1RJfm) and a control relay (1Cb, 1Cf); the power input end is connected to the output end of the power automatic switching module, the control signal input end is connected to the contact of the working position selection handle (1wn, 1wh), and the power output end is connected to the oil pump and fan motor of the cooler; when the cooler is placed in the working position, the handle contacts 1wn (5-6) and 1wh (7-8) are turned on, so that 1Cb and 1Cf are excited, and the oil pump and fan motor are started; In the working position cooler control module, the contact (5-6) of the working position first selection handle (1wn) is connected in series with the normally closed contact of the thermocouple relay (1RJ) and the coil of the control relay (1Cb, 1Cf), and then connected with the air switch (1ZK), forming a complete control circuit.

[0027] At this time, the start control unit (i.e. Figure 5The specific circuit connection of the input and control circuit is as follows: When the position handle (1wn) is set to the working position and the motor is not overloaded, the air switch (1ZK) is closed, and the current flows through the 5-6 contacts of the position handle (1wn), the normally closed contact of the thermocouple relay (1RJ, etc.), and the coil of the intermediate relay (1Cb, 1Cf), which excites the intermediate relay. After its normally open contact closes, the oil pump and fan are started. When the motor is overloaded or the temperature is too high, the thermocouple relay operates and opens its normally closed contact, thereby disconnecting the power supply circuit of the intermediate relay and stopping the cooler from running.

[0028] like Figure 4 and combined Figure 5 As shown, in this embodiment, the auxiliary control module of the cooler includes a temperature monitoring unit, a current monitoring unit, and an auxiliary start-up unit. The temperature monitoring unit monitors the transformer oil surface temperature through temperature sensors (1WJ1, 1WJ2), and the current monitoring unit monitors the load current through a current sensor (BFJ). The auxiliary start-up unit automatically starts the auxiliary cooler when the temperature or current exceeds a set threshold. Specifically, when the oil surface temperature is higher than 65°C, 1WJ2 closes, and the auxiliary cooler is started by excitation through relay 5ZJ. The auxiliary cooler is maintained through a self-holding circuit (formed by the normally open contact of relay 5ZJ) until the temperature drops below 55°C, at which point both 1WJ1 and 1WJ2 open, the circuit is broken, and the auxiliary cooler stops.

[0029] At this time, the auxiliary start-up unit (i.e. Figure 5 The specific connection relationship of the input and control circuit in the load current start-up is as follows: When the load current exceeds the set value, the auxiliary contact of the current sensor (BFJ) closes, the time relay (1SJ) is energized, and after a delay, its normally open contact closes, energizing the relay 5ZJ and starting the auxiliary cooler; at the same time, a self-holding circuit is formed through the normally open contact of the 5ZJ relay to maintain the operation of the auxiliary cooler until the load current decreases below the set value, at which point the BFJ contact opens, the self-holding circuit is disconnected, and the auxiliary cooler stops.

[0030] Combined Figure 4 As shown, specifically in this example, when the oil surface temperature is above 55°C, 1WJ1 closes; when the oil surface temperature is above 65°C, 1WJ2 closes. When the oil surface temperature is above 65°C, 1WJ2 closes, its corresponding circuit is activated, and relay 5ZJ is energized to start the auxiliary cooler. Simultaneously, the circuit achieves self-holding. When the temperature is below 55°C, both 1WJ1 and 1WJ2 open, the circuit is broken, and the auxiliary cooler stops.

[0031] When the load current exceeds the setting value, the auxiliary contact BFJ is closed, its corresponding circuit is turned on, 1SJ is excited, after a delay, the normally open contact 1SJ is closed, its corresponding circuit is turned on, 5ZJ is excited, and the auxiliary cooler is started. After the 5ZJ relay is excited, the corresponding circuit realizes a self-holding function.

[0032] As Figure 4 and in combination Figure 5 In the embodiment, the standby position cooler control module includes a fault detection unit (the normally closed contact of 1LJ, 1Cb, 1Cf), a time relay (2SJ), and a standby starting relay (6ZJ); the power input end of the standby position cooler control module is connected to the output end of the power automatic switching module, the trigger input end thereof is connected in parallel to the working cooler fault contact (the normally closed contact of 1Cb, 1Cf) and the oil flow relay contact (1LJ), and the output end thereof is connected to the control circuit of the standby position cooler through the contact of the standby starting relay (6ZJ). The trigger input end of the standby position cooler control module is in a parallel structure: the normally closed contacts of the working cooler control relays (1Cb, 1Cf) are connected in parallel with each other, and then connected in parallel with the normally open contact of the oil flow relay (1LJ) to form a fault signal acquisition point; the output end of the parallel node is connected in series with the coil of the time relay (2SJ).

[0033] Specific connection relationship: when the working or auxiliary cooler fails to excite the corresponding relay (1Cb, 1Cf), or the oil flow relay detects that the oil flow stops, its contact is closed, and after a delay by the time relay (2SJ), the 6ZJ is excited to start the standby cooler.

[0034] At this time, the specific circuit connection of the standby starting unit (i.e. Figure 5 The input and control circuit in the standby position cooler control module is as follows: when the working or auxiliary cooler fails, the normally closed contact of the corresponding relay (1Cb, 1Cf) is closed, or the contact of the oil flow relay (1LJ) is closed, forming a current path to start the standby cooler, which, after a delay by the time relay (2SJ), excites the relay 6ZJ, and after the normally open contact of the relay 6ZJ is closed, the standby cooler is started; at the same time, the normally open contact of the 6ZJ relay can also be used to form a self-holding circuit to ensure that the standby cooler continuously operates.

[0035] In the specific work, when a group of coolers hit the standby position, 13-14 contacts of 1wn handle are turned on, and 15-16 contacts of 1wh are turned on. As long as the normally open contact 6ZJ is closed, the circuit can be turned on, so that the cooler in the standby position can be started. The conditions for starting the standby cooler are that the cooler in the working or auxiliary position fails, the 1Cb and 1Cf relays lose magnetism, the corresponding normally closed contact is closed, or the transformer oil stops flowing, and the 1LJ contact of the oil flow relay is closed. As long as one of the conditions is met, the circuit in parallel with 1LJ, 1Cb and 1Cf is used to start the standby cooler and is turned on.

[0036] When the working cooler stops, the time relay 2SJ is magnetized, the corresponding normally open contact 2SJ is delayed to close, so that the relay 6ZJ is magnetized, the corresponding normally open contact is closed, so that the standby cooler starting circuit is turned on, so that the cooler in the standby position is started. At the same time, the circuit for starting the standby cooler when the auxiliary cooler stops is the same as the circuit for starting the standby cooler when the working cooler stops, and will not be described here.

[0037] The time relay (2SJ) is connected in series with the coil of the standby starting relay (6ZJ) through the time delay normally open contact, and a time delay starting circuit of the standby cooler is formed.

[0038] As shown in Figure 6 As shown in the embodiment, the main transformer signal module 5 includes a plurality of parallel branches, each branch is connected in series by a signal power supply, an indicating device and one or more normally open contacts of a relay, and each branch corresponds to a system state signal; when any relay is magnetized, the corresponding contact is closed, and the phase failure, overload, switching or fault signal is output to the signal circuit. The operation and maintenance personnel can understand the running condition of the cooling system in time and accurately, and take corresponding measures quickly to ensure the safe and stable operation of the substation.

[0039] The embodiment of the present application has the following beneficial effects: The present application provides a substation electrical cooler control system, which realizes automatic and rapid switching between the main power supply and the standby power supply through the power supply automatic switching module. When the first working power supply loses power, the intermediate relay loses magnetism, the normally closed contact is closed, the second working power supply is automatically switched to power supply, and the power interlocking is realized through the relay to ensure continuous power supply of the cooling device, avoid the problem of cooling interruption caused by power interruption, and improve the reliability of the cooling system.

[0040] The working position cooler control module can accurately control the starting and stopping of the cooler according to the working position of the cooler; the auxiliary position cooler control module can automatically start the auxiliary cooler according to the transformer oil surface temperature or the load current, and sets a temperature direct starting loop and a current delay starting loop to meet the cooling requirements under different working conditions; the standby position cooler control module can automatically start the standby cooler when the working or auxiliary cooler fails, so as to ensure that the cooling system is always in an effective running state and improve the cooling effect.

[0041] The main transformer signal module is connected with each control module, can monitor the system running state in real time, and outputs the signals such as open phase, overload, switching or fault to the signal loop through multiple parallel branches. The operation and maintenance personnel can understand the running condition of the cooling system in time and accurately according to these signals, and take corresponding measures quickly to ensure the safe and stable operation of the substation.

[0042] The substation electrical cooler control system of the application optimizes the running logic of the cooling system, improves the adaptability and anti-interference ability of the system to various working conditions, enhances the stability and reliability of the entire substation electrical cooling system, reduces the equipment failure risk, and reduces the operation and maintenance cost through reasonable design and cooperative work among the modules.

[0043] The present application is described with reference to flowcharts and / or block diagrams of the method, device (system), and computer program product according to the embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts and / or block diagrams can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 The device that implements the functions specified in one flow or multiple flows and / or blocks Figure 1 The device that implements the functions specified in one flow or multiple flows and / or blocks

[0044] The above disclosure is only a preferred embodiment of the present application, and of course cannot limit the scope of the rights of the present application, so the equivalent changes made according to the claims of the present application still belong to the scope covered by the present application.

Claims

1. A substation electrical cooler control system, characterized in that, include: The system includes an automatic power switching module, a working position cooler control module, an auxiliary position cooler control module, a standby position cooler control module, and a main transformer signal module; among which... The automatic power switching module is used to automatically switch between the main power supply and the backup power supply to ensure that the cooling device is continuously powered. The working position cooler control module is connected to the power automatic switching module and is responsible for controlling the start and stop of the cooler when it is in the working position. The auxiliary position cooler control module is connected to the power automatic switching module and is used to automatically start the auxiliary cooler according to the transformer oil surface temperature or load current. The backup position cooler control module is connected to the power automatic switching module and the working and auxiliary position cooler control modules, and is used to automatically start the backup cooler when the working or auxiliary cooler fails. The main transformer signal module is connected to the above modules and is used to monitor and send out system operating status signals.

2. The system as described in claim 1, characterized in that, The automatic power switching module has its input connected to a first working power supply (A1, B1, C1) and a second working power supply (A2, B2, C2), and its output connected to a subsequent control module. The module includes a power switching handle (wh), intermediate relays (2ZJ, 1ZJ, 1C, 2C), and a switching logic circuit. When the first working power supply fails, the intermediate relay 1ZJ loses its magnetism, its normally closed contact closes, and the system automatically switches to the second working power supply. Power interlocking is achieved through relays 1C and 2C. In the automatic power switching module, the first set of contacts (1-2, 3-4) of the power switching handle (wh) is connected in series with the first working power supply (C1), and the second set of contacts (5-6, 7-8) of the power switching handle (wh) is connected in series with the second working power supply (C2). The coil of the first intermediate relay (2ZJ) is connected across the phase lines of the first working power supply, and its normally open contact (2ZJ) is connected in series with the coil of the interlock relay (1ZJ) and then connected to the first working power supply circuit. The normally closed contact of the interlock relay (1ZJ) is connected in series with the coil of the power selection relay (2C) and then connected to the second working power supply circuit. The normally open contact of the interlock relay (1ZJ) is connected in series with the coil of the power selection relay (1C) and then connected to the first working power supply circuit. The normally closed contacts of the power selection relays (1C, 2C) are respectively connected in series in the power supply circuit of the other power supply to achieve interlocking. The automatic power switching module is also connected to a main stop relay (7ZJ). The normally closed contact of the main stop relay (7ZJ) is connected in series to the main output line of the automatic power switching module. The coil of the main stop relay (7ZJ) is controlled by the auxiliary normally closed contacts of the three-sided switches of the transformer connected in series. When all three-sided switches are tripped, its coil is energized and the normally closed contacts are opened.

3. The system as described in claim 2, characterized in that, The working position cooler control module includes a position selection handle (1wn, 1wh), an air switch (1ZK), thermocouple relays (1RJ, 1RJf1…1RJfm), and control relays (1Cb, 1Cf). Its power input terminal is connected to the output terminal of the automatic power switching module, its control signal input terminal is connected to the contacts of the working position selection handle (1wn, 1wh), and its power output terminal is connected to the oil pump and fan motor of the cooler. When the cooler is in the working position, the handle contacts 1wn (5-6) and 1wh (7-8) are turned on, energizing 1Cb and 1Cf and starting the oil pump and fan motor. In the working position cooler control module, the contacts (5-6) of the first working position selection handle (1wn) are connected in series with the normally closed contacts of the thermocouple relay (1RJ), the coils of the control relays (1Cb, 1Cf) and the air switch (1ZK) to form a complete control circuit.

4. The system as described in claim 3, characterized in that, The auxiliary position cooler control module includes temperature sensors (1WJ1, 1WJ2), a current relay (BFJ), a time relay (1SJ), and an auxiliary start relay (5ZJ); the transformer oil temperature contact (1WJ2) is connected in series with the coil of the auxiliary start relay (5ZJ) to form a direct temperature start circuit.

5. The system as described in claim 4, characterized in that, In the auxiliary position cooler control module, the auxiliary start relay (5ZJ) is provided with a self-holding circuit. This circuit consists of a pair of normally open contacts of the auxiliary start relay (5ZJ) connected in series with a resistor (or indicator light), and then connected in parallel across the transformer oil temperature contact (1WJ2) in the temperature direct start circuit. The load current relay contact (BFJ) is connected in series with the coil of the time relay (1SJ), and the time-delayed normally open contact of the time relay (1SJ) is then connected in series with the coil of the auxiliary starting relay (5ZJ) to form a current-delayed starting circuit; the temperature direct starting circuit and the current-delayed starting circuit are connected in parallel. When the oil surface temperature is higher than the predetermined temperature or the load current exceeds the set value, the corresponding contact closes, energizing and self-holding 5ZJ, and starting the auxiliary cooler.

6. The system as described in claim 5, characterized in that, The backup position cooler control module includes a fault detection unit (normally closed contacts of 1LJ, 1Cb, and 1Cf), a time relay (2SJ), and a backup start relay (6ZJ).

7. The system as described in claim 6, characterized in that, In the standby position cooler control module, its power input terminal is connected to the output terminal of the power automatic switching module, its trigger input terminal is connected in parallel to the working cooler fault contact (normally closed contact of 1Cb, 1Cf) and oil flow relay contact (1LJ), and its output terminal is connected to the control circuit of the standby position cooler through the contact of the standby start relay (6ZJ). The trigger input terminal of the standby position cooler control module has a parallel structure: the normally closed contacts of the working cooler control relays (1Cb, 1Cf) are connected in parallel with each other, and then connected in parallel with the normally open contact of the oil flow relay (1LJ) to form a fault signal acquisition point; the output terminal of this parallel node is connected in series with the coil of the time relay (2SJ). When the working or auxiliary cooler stops or the oil flow stops, the fault detection unit is activated, and after a 2SJ delay, the 6ZJ is energized to start the standby cooler.

8. The system as described in claim 7, characterized in that, The time-delayed normally open contact of the time relay (2SJ) is connected in series with the coil of the backup start relay (6ZJ) to form a time-delayed start circuit for the backup cooler.

9. The system as described in claim 8, characterized in that, The system also includes a phase loss detection module, which contains a current balancing relay (BLJ), whose primary three-phase coils are connected in series in the three-phase power supply (A, B, C), and whose secondary output coil is connected to an execution relay; when a phase loss occurs, the normally open contact of the execution relay closes and is connected to the input terminal of the main transformer signal module.

10. The system as described in claim 9, characterized in that, The main transformer signal module includes multiple parallel branches. Each branch consists of a signal power supply, an indicator device, and one or more normally open contacts of relays connected in series. Each branch corresponds to a system status signal. When any relay is energized, the corresponding contact closes, and a phase loss, overload, switching, or fault signal is output to the signal circuit.

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