Air cooling cabinet control device and control method thereof

Abstract

The invention belongs to the field of air-cooling cabinet control, and particularly discloses an air-cooling cabinet control device and a control method thereof.The air-cooling cabinet control device comprises a cooling module, the cooling module comprises a plurality of cooling assemblies, each cooling assembly comprises a power source and two fan sets, and each fan set comprises a cooler and a fan. The automatic control mode comprises the following steps that S1, the number n of coolers needing to be put into operation at the current moment is calculated; s2, the number n0 of coolers put into operation at present is obtained, and n0 is compared with n; s3, if n0 is greater than n, quitting (n0-n) coolers which are put into operation; and if n0 is smaller than n, (n-n0) non-running coolers are added. According to the method, the starting number of the coolers is determined according to the top oil temperature and the winding temperature during operation of the transformer, the situation that the hot spot temperature distribution difference of the transformer is large when the top oil temperature rises is fully considered, reliable and effective control over the temperature rise of the transformer is achieved, and safe and stable operation of the transformer can be guaranteed.

Description

Technical Field

[0001] The present invention belongs to the technical field of air cooling cabinet control, and in particular relates to an air cooling cabinet control device and a control method thereof. Background Art

[0002] The traditional transformer cooling system has defects such as complex circuits, large size, and high device failure rate. The conventional temperature control node is small, the capacity is small, and the error is large. The AC contactor that controls the cooler working circuit starts frequently, the contacts are easily burned out, causing poor contact or sticking together, which becomes an important factor that cannot be ignored in the motor phase loss or insulation damage. Modern transformer cooling systems use intelligent control, but there are problems such as unstable operation, low temperature control accuracy, and inability to continuously adjust cooling power, resulting in energy waste. The control logic and frequency conversion adjustment method of the inverter control cabinet or energy-saving air-cooled control cabinet have poor energy-saving effects and poor flexibility.

[0003] At present, most of the control cabinets in the market use relays to control the cooler. Although they can achieve certain energy-saving effects, their control methods all follow the control logic methods of the previous electromagnetic and intelligent control cabinets: the coolers are divided into three working modes: "working group", "auxiliary group", and "standby group", which can be freely set. When the transformer is put into operation, the cooler in the "working group" is put into operation first. When the oil temperature of the upper layer of the transformer is higher than 55 degrees or the current relay on the transformer protection screen is activated (70% load), the cooler in the "auxiliary" state is put into operation. When the temperature drops to 45 degrees, the cooler in the "auxiliary" state is shut down. If any group in the "working" or "auxiliary" state fails during operation, the "standby" cooler is put into operation to repair the fault and the "standby" cooler is shut down; when the oil temperature is between 45 degrees and 55 degrees and the load is below 70%, after the cooler in the working group is put into operation, when the temperature reaches 55 degrees, the two sets of fans are started. Therefore, the control logic method used in the control of the current relay control cabinet or energy-saving air-cooled control cabinet has poor energy-saving effect and poor flexibility. Summary of the invention

[0004] The invention provides an air cooling cabinet control device and a control method thereof, which are used to solve the problems of poor energy saving effect and poor flexibility of the current air cooling control cabinet.

[0005] In order to solve the above technical problems, the technical solution of the present invention is: the air cooling cabinet control device comprises: a power module, a PLC module, a detection module connected to the PLC module, a cooling module connected to the PLC module, and a human-computer interaction module connected to the PLC module;

[0006] The power supply module includes a DC power supply module and an AC control power supply module;

[0007] The cooling module includes a plurality of cooling components, and the cooling components include a power supply and two fan groups, and the fan groups include a cooler and a fan.

[0008] In a preferred embodiment of the present invention, the top oil temperature of the transformer is acquired through the detection module, and the current load of the cooling module is calculated through the human-computer interaction module.

[0009] In a preferred embodiment of the present invention, a fault alarm module connected to the PLC module is also included.

[0010] The present invention also discloses a control method for an air cooling cabinet control device, which includes a manual control mode and an automatic control mode, wherein the automatic control mode includes the following steps:

[0011] S1: Calculate the number of coolers n that need to be put into operation at the current moment;

[0012] S2: Obtain the number n0 of coolers currently in operation, and compare n0 with n;

[0013] S3: If n0>n, exit (n0-n) coolers in operation;

[0014] If n0<n, add (n-n0) coolers that are not in operation.

[0015] In a preferred embodiment of the present invention, in step S3,

[0016] If n0>n, the number of target coolers to be exited is sorted in descending order according to the cumulative operating time of the coolers that have been put into operation;

[0017] If n0<n, the number of target coolers put into operation is sorted in order from shortest to longest according to the cumulative operating time of the coolers that have not been put into operation.

[0018] In a preferred embodiment of the present invention, step S4 is further included: obtaining the top oil temperature in real time, and adjusting the number of fans in operation according to the change of the top oil temperature. In a preferred embodiment of the present invention, step S4 specifically includes: numbering the fans in sequence as fan group 1, fan group 2, fan group 3 and fan group 4, obtaining the top oil temperature T,

[0019] When 65℃<T≤69℃, start one group of fans, and when T<65℃, stop one group of fans;

[0020] When 70℃<T≤74℃, start the two sets of fans; when T<70℃, stop the two sets of fans;

[0021] When 75℃<T≤79℃, start 3 sets of fans; when T<75℃, stop the three sets of fans;

[0022] When T≥80℃, start 4 sets of fans; when T<80℃, stop the four sets of fans.

[0023] In a preferred embodiment of the present invention, the frequency of the frequency converter increases from 30 Hz to 50 Hz.

[0024] In a preferred embodiment of the present invention, when a PLC failure or a DC power failure occurs, all fans are started.

[0025] In a preferred embodiment of the present invention, when any fan unit in the cooling assembly fails, another fan unit in the cooling assembly is started.

[0026] In a preferred embodiment of the present invention, when a blower that has been put into operation fails or an AC control power supply fails, a blower full stop signal is issued after a delay of 20 minutes.

[0027] The technical solution provided by the present invention has the following advantages compared with the prior art:

[0028] The present invention uses PLC to realize the top oil temperature and winding temperature switching management, which mainly includes the control of the fan system and the control selection of fan switching. In the application of PLC in the top oil temperature and winding switching management, it mainly starts and stops the analog quantity and the number of fans, and finally realizes the relevant functions by controlling each fan through the formulated logic setting.

[0029] The present invention determines the number of coolers to be started according to the top oil temperature and the winding temperature when the transformer is running, fully considering the situation that the hot spot temperature distribution of the transformer is greatly different when the top oil temperature rises, and realizes reliable and effective control of the temperature rise of the transformer, which can ensure the safe and stable operation of the transformer and has good on-site detection effect and engineering practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, drawings of other embodiments can be obtained based on these drawings without paying creative work.

[0031] Figure 1 is a schematic diagram of a control device for an air-cooled cabinet according to an embodiment of the present invention;

[0032] Figure 2 It is a logic diagram of a control method of an air cooling cabinet control device described in one embodiment of the present invention. DETAILED DESCRIPTION

[0033] For ease of understanding, an air cooling cabinet control device and a control method thereof are described below in conjunction with embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not used to limit the scope of the present invention.

[0034] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation and positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0035] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0036] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thoroughly understood.

[0037] like Figure 1 As shown, a control device for an air cooling cabinet and a control method thereof, which include: a PLC module, a detection module connected to the PLC module, a cooling module connected to the PLC module, and a human-computer interaction module connected to the PLC module.

[0038] The cooling module includes several cooling components, the cooling components include a power supply and two fan groups, and the fan group includes a cooler and a fan.

[0039] In one embodiment of the present invention, the cooling module includes four cooling components, each cooling component includes two fan groups, one of which is a working fan group and the other is a standby fan group.

[0040] Since the present invention is provided with a detection module and a human-computer interaction module, the top oil temperature of the transformer and the winding temperature in the transformer can be obtained through the detection module, and the current load of the cooling module can be calculated through the human-computer interaction module.

[0041] In addition, an air cooling control device in the present invention also includes a fault alarm module connected to the PLC module, which can alarm for faults in the PLC module, the DC power supply or the AC control power supply.

[0042] A control device for an air cooling cabinet and a control method thereof, which include a manual control mode and an automatic control mode.

[0043] Specifically, refer to Figure 2 , the automatic control mode includes the following steps:

[0044] S1: Calculate the number of coolers n that need to be put into operation at the current moment;

[0045] S2: Obtain the number n0 of coolers currently in operation, and compare n0 with n;

[0046] S3: If n0>n, exit (n0-n) coolers in operation;

[0047] If n0<n, add (n-n0) coolers that are not in operation.

[0048] Specifically, if n0>n, the number of coolers that have been put into operation is sorted from long to short according to the cumulative operation time of the coolers that have been put into operation. If n0<n, the number of coolers that have been put into operation is sorted from short to long according to the cumulative operation time of the coolers that have not been put into operation.

[0049] That is to say, in the present invention, the coolers are sorted according to their cumulative operating time to ensure that the cumulative operating time of each cooler is not much different.

[0050] When the cooler needs to be started, the speed of the cooler circulation oil pump motor and the cooling fan motor to be started are determined according to the harmonic content. The heat dissipation speed of the fan is accurately controlled by the temperature increase to ensure that the fan life and fan power consumption are not wasted.

[0051] The number of coolers to be started is determined based on the top oil temperature during transformer operation. The specific method for determining the interval oil temperature of 65-85°C is as follows:

[0052] The upper end point of the interval is 85℃: The maximum operating temperature allowed by the transformer Class A insulation is 105℃, minus the difference between the hot spot and the oil temperature of 20℃, 105-20=85℃

[0053] The lower end point of the interval is 65°C: The national standard GB 6451 document requires that the blowing device should be put into use when the oil temperature reaches 65°C.

[0054] The cooling fan speed is controlled based on the top oil temperature and the winding temperature.

[0055] The specific control methods are:

[0056] The fans are numbered as fan group 1, fan group 2, fan group 3 and fan group 4 in sequence, and the top layer oil temperature T is obtained.

[0057] When 65℃<T≤69℃, start one group of fans, and when T<65℃, stop one group of fans;

[0058] When 70℃<T≤74℃, start the two sets of fans; when T<70℃, stop the two sets of fans;

[0059] When 75℃<T≤79℃, start 3 sets of fans; when T<75℃, stop the three sets of fans;

[0060] When T≥80℃, start 4 sets of fans; when T<80℃, stop the four sets of fans.

[0061] In the above adjustment process, the inverter frequency increases from 30Hz to 50Hz.

[0062] Specifically, in the first group, 65°C corresponds to 30Hz, 66°C corresponds to 35Hz, and 67°C corresponds to 40Hz;

[0063] 68℃ corresponds to 45Hz, 69℃ corresponds to 50Hz;

[0064] The second group 70℃ corresponds to 30Hz, 71℃ corresponds to 35Hz, and 72℃ corresponds to 40Hz;

[0065] 73℃ corresponds to 45Hz, 74℃ corresponds to 50Hz;

[0066] The third group 75℃ corresponds to 30Hz, 76℃ corresponds to 35Hz, and 77℃ corresponds to 40Hz;

[0067] 78℃ corresponds to 45Hz, 79℃ corresponds to 50Hz;

[0068] The fourth group 80℃ corresponds to 50Hz.

[0069] As the temperature rises, the frequency of the inverter also increases until a balance point between temperature and fan speed is reached.

[0070] When the PLC fails or the DC power supply fails, all fans are started.

[0071] When any fan unit in the cooling assembly fails, another fan unit in the cooling assembly is started. In other words, when one fan unit fails, the standby fan unit is immediately started.

[0072] When a fan in operation fails or the AC control power fails, a fan stop signal will be issued after a delay of 20 minutes.

[0073] Specifically, because the 500kV substation does not allow power outages easily, the configuration is dual power supply. If one power supply fails, it will automatically switch to the second power supply without affecting normal operation. There may be a phase loss fault, and the fault signal will be automatically eliminated after recovery. Therefore, if it is not automatically restored within 20 minutes, the background fault signal will be transmitted.

[0074] The present invention realizes the top oil temperature and winding switching management through PLC, which mainly includes the control of the fan system and the control selection of fan switching. In the application of top oil temperature and winding switching management, PLC mainly starts and stops the analog quantity and the number of fans, and finally realizes the relevant functions through the control of each fan after the formulated logic setting.

[0075] The present invention determines the number of coolers to be started according to the top oil temperature and the winding temperature when the transformer is running, fully considering the situation that the hot spot temperature distribution of the transformer is greatly different when the top oil temperature rises, and realizes reliable and effective control of the temperature rise of the transformer, which can ensure the safe and stable operation of the transformer and has good on-site detection effect and engineering practical value.

[0076] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. Although the present invention has been described in detail with reference to the above embodiments, a person skilled in the art should understand that the technical solutions described in the above embodiments can still be modified, or some or all of the technical features can be replaced by equivalents, and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A control device for an air cooling cabinet, characterized in that: include: A power module, a PLC module, a detection module connected to the PLC module, a cooling module connected to the PLC module, and a human-computer interaction module connected to the PLC module; The power supply module includes a DC power supply module and an AC control power supply module; The cooling module includes a plurality of cooling components, and the cooling components include a power supply and two fan groups, and the fan groups include a cooler and a fan.

2. The air cooling cabinet control device according to claim 1, characterized in that: The top oil temperature of the transformer is acquired through the detection module, and the current load of the cooling module is calculated through the human-computer interaction module.

3. The air cooling cabinet control device according to claim 1, characterized in that: It also includes a fault alarm module connected to the PLC module.

4. A control method for an air cooling cabinet control device according to any one of claims 1 to 3, characterized in that: It includes a manual control mode and an automatic control mode, wherein the automatic control mode includes the following steps: S1: Calculate the number of coolers n that need to be put into operation at the current moment; S2: Obtain the number n0 of coolers currently in operation, and compare n0 with n; S3: If n0>n, exit (n0-n) coolers in operation; If n0<n, add (n-n0) coolers that are not in operation.

5. The control method of the air cooling cabinet control device according to claim 4, characterized in that: In step S3, If n0>n, the number of target coolers to be exited is sorted in descending order according to the cumulative operating time of the coolers that have been put into operation; If n0<n, the number of target coolers put into operation is sorted in order from shortest to longest according to the cumulative operating time of the coolers that have not been put into operation.

6. The control method of the air cooling cabinet control device according to claim 4, characterized in that: The method further includes step S4: obtaining the top layer oil temperature in real time, and adjusting the number of fans put into operation according to the change of the top layer oil temperature.

7. The control method of the air cooling cabinet control device according to claim 6, characterized in that: Step S4 specifically includes: numbering the fans in sequence as fan group 1, fan group 2, fan group 3 and fan group 4, obtaining the top layer oil temperature T, When 65℃<T≤69℃, start one group of fans, and when T<65℃, stop one group of fans; When 70℃<T≤74℃, start the two sets of fans; when T<70℃, stop the two sets of fans; When 75℃<T≤79℃, start 3 sets of fans; when T<75℃, stop the three sets of fans; When T≥80℃, start 4 sets of fans; when T<80℃, stop the four sets of fans.

8. The control method of the air cooling cabinet control device according to claim 7, characterized in that: The inverter frequency increases from 30Hz to 50Hz.

9. The control method of the air cooling cabinet control device according to claim 4, characterized in that: When the PLC fails or the DC power supply fails, all fans are started.

10. The control method of the air cooling cabinet control device according to claim 4, characterized in that: When any fan unit in the cooling assembly fails, another fan unit in the cooling assembly is started.

11. The control method of the air cooling cabinet control device according to claim 4, characterized in that: When a fan in operation fails or the AC control power fails, a fan stop signal will be issued after a delay of 20 minutes.

Images