Judgment processing method and device for automatic switching of standby pump during electrical soft fault

Abstract

The invention discloses a judgment processing method and device for automatic switching of a standby pump during an electrical soft fault, and relates to the technical field of electrical control. The judgment processing method comprises the steps that whether a system sends a shutdown instruction or not is judged, and if not, the next step is executed; judging whether the normally open contact of the contactor is changed from closed to open or not, and if so, executing the next step; and controlling the working pump to be closed and starting the standby pump. According to the method, the condition of soft fault tripping is accurately judged, and the criterion is used as a condition for starting the standby water pump, so that the influence of conditions such as power grid fluctuation on production is effectively prevented.

Description

Technical Field

[0001] The present invention relates to the field of electrical control technology, in particular to a method and device for judging and processing the automatic switching of a standby pump in the event of an electrical soft fault. Background Art

[0002] During daily operation, motors are often disconnected due to various reasons, such as power grid fluctuations, line phase loss, overcurrent, and poor contact of contactors, which can cause economic losses. For these situations, the following protection methods are currently used: 1. In conventional design, the thermal relay in the water pump motor circuit and the auxiliary contacts of the control circuit switch are used as electrical fault points. When the main circuit is overcurrent, the contacts are activated and the program receives the signal to start the standby water pump motor; 2. For frequency converters and soft starters, after the fault point of the equipment body is triggered, the program receives the signal to start the backup pump; 3. In case of power grid fluctuations, install anti-power sway modules or anti-power sway contactors to avoid tripping caused by instantaneous voltage loss.

[0003] However, after prolonged use, the anti-sway module can become a fault point due to capacitor failure, causing a trip. Soft starters and inverters have also experienced numerous shutdowns without apparent faults.

[0004] In the above-mentioned soft fault tripping situation, no judgment was made in the previous procedure to put the standby pump into use, which is very harmful to production safety. If the operating personnel fail to discover it in time, it will cause an operation accident and bring certain hidden dangers to production. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to overcome the shortcomings of the prior art and provide a method and device for judging and processing the automatic switching of a standby pump in the event of an electrical soft fault.

[0006] In order to solve the above technical problems, the technical solutions of the present invention are as follows: A method for determining whether a standby pump automatically switches on when an electrical soft fault occurs, comprising: Determine whether the system issues a shutdown command, if not, proceed to the next step; Determine whether the normally open contact of the contactor changes from closed to open. If so, proceed to the next step; Control the working pump to shut down and start the standby pump.

[0007] As a preferred solution of the method for determining whether the standby pump automatically switches on when an electrical soft fault occurs in the present invention, after determining whether the system issues a shutdown command and if not, executing the next step, the method further includes: If so, the system will shut down normally.

[0008] As a preferred solution of the method for determining whether the standby pump automatically switches on when an electrical soft fault occurs according to the present invention, the method further comprises: determining whether the normally open contact of the contactor changes from closed to open, and if so, executing the next step; If not, it is determined again whether the normally open contact of the contactor changes from closed to open.

[0009] The present invention also provides a judgment and processing device for automatically switching on a standby pump in the event of an electrical soft fault, comprising: The first judgment module is used to judge whether the system issues a shutdown instruction, and if not, execute the next functional module; The second judgment module is used to judge whether the normally open contact of the contactor changes from closed to open, and if so, execute the next functional module; The pump control module is used to control the shutdown of the working pump and start the standby pump.

[0010] As a preferred solution of the method for judging the automatic switching of the standby pump in the event of an electrical soft fault according to the present invention, the first judgment module is further used to control the system to perform normal shutdown processing after the judgment system issues a shutdown command.

[0011] As a preferred solution of the judgment and processing device for automatically switching on the standby pump during an electrical soft fault as described in the present invention, the second judgment module is also used to judge again whether the normally open contact of the contactor has changed from closed to open after judging that the normally open contact of the contactor has not changed from closed to open.

[0012] The beneficial effects of the present invention are: (1) The present invention prepares for electrical soft faults and optimizes the logic as a starting condition for the standby pump.

[0013] (2) The present invention accurately judges the soft fault tripping situation and uses this judgment criterion as the condition for starting the standby water pump, thereby effectively preventing the influence of power grid fluctuations and the like on production. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0015] Figure 1 A flow chart of a method for determining whether a standby pump automatically switches on when a soft electrical fault occurs, according to the present invention; Figure 2 A ladder diagram of the automatic switching of the standby pump in the method for judging the automatic switching of the standby pump in the event of an electrical soft fault provided by the present invention; Figure 3 A ladder diagram of the automatic switching of the standby pump in the method for judging the automatic switching of the standby pump in the event of an electrical soft fault provided by the present invention; Figure 4 This is a schematic diagram of the judgment and processing device for automatically switching on the standby pump when an electrical soft fault occurs, provided by the present invention. DETAILED DESCRIPTION

[0016] In order to make the contents of the present invention more clearly understood, the present invention is further described below in detail based on specific implementation methods in conjunction with the accompanying drawings.

[0017] Figure 1 This is a flow chart of a method for determining whether a standby pump will automatically start operating when an electrical soft fault occurs, as provided in an embodiment of the present application. The method specifically includes the following steps: Step S101: Determine whether the system issues a shutdown command. If so, the system performs a normal shutdown process. If not, execute the next step, i.e., step S102.

[0018] Step S102: Determine whether the normally open contact of the contactor changes from closed to open. If not, determine again whether the normally open contact of the contactor changes from closed to open. If so, execute the next step, i.e., step S103.

[0019] Step S103: Control the working pump to shut down and start the standby pump.

[0020] Figure 2 This is a soft fault logic judgment ladder diagram in the judgment and processing method for the automatic switching of the standby pump when an electrical soft fault is provided in an embodiment of the present application.

[0021] Figure 3 This is a ladder diagram of the automatic switching of the standby pump in the judgment and processing method of the automatic switching of the standby pump during an electrical soft fault provided in an embodiment of the present application.

[0022] Figure 4 Schematic diagram of a device for determining and processing the automatic switching of a standby pump when an electrical soft fault occurs according to an embodiment of the present application. The device includes a first determination module 201 , a second determination module 202 , and a pump control module 203 .

[0023] The first determination module 201 is used to determine whether the system issues a shutdown instruction. If so, the control system performs a shutdown process normally. If not, the next functional module is executed.

[0024] The second judgment module 202 is used to judge whether the normally open contact of the contactor changes from closed to open. If not, it is judged again whether the normally open contact of the contactor changes from closed to open. If so, the next function module is executed; The pump control module 203 is used to control the working pump to shut down and start the standby pump.

[0025] Therefore, the technical solution of the present application effectively prevents the impact of power grid fluctuations and other situations on production by accurately judging the situation of soft fault tripping and using this judgment criterion as a condition for starting the standby water pump.

[0026] In addition to the above embodiments, the present invention may also have other implementation methods; any technical solutions formed by equivalent replacement or equivalent transformation fall within the protection scope required by the present invention.

Claims

1. A method for determining the automatic switching of a standby pump in the event of an electrical soft fault, characterized in that: include: Determine whether the system issues a shutdown command, if not, proceed to the next step; Determine whether the normally open contact of the contactor changes from closed to open. If so, proceed to the next step; Control the working pump to shut down and start the standby pump.

2. The method for determining the automatic switching of a standby pump during an electrical soft failure according to claim 1, characterized in that: After determining whether the system issues a shutdown instruction and if not, executing the next step, the method further includes: If so, the system will shut down normally.

3. The method for determining the automatic switching of a standby pump during an electrical soft failure according to claim 1, characterized in that: After determining whether the normally open contact of the contactor changes from closed to open, and if so, executing the next step, the method further includes: If not, it is determined again whether the normally open contact of the contactor changes from closed to open.

4. A judgment and processing device for automatically switching on a standby pump in the event of an electrical soft fault, characterized in that: include: The first judgment module is used to judge whether the system issues a shutdown instruction, and if not, execute the next functional module; The second judgment module is used to judge whether the normally open contact of the contactor changes from closed to open, and if so, execute the next functional module; The pump control module is used to control the shutdown of the working pump and start the standby pump.

5. The method for determining whether a standby pump automatically switches on when an electrical soft fault occurs according to claim 4, wherein: The first judgment module is further configured to control the system to perform a normal shutdown process after the judgment system issues a shutdown instruction.

6. The method for determining the automatic switching of a standby pump during an electrical soft failure according to claim 4, characterized in that: The second judgment module is further configured to judge again whether the normally open contact of the contactor changes from closed to open after judging that the normally open contact of the contactor does not change from closed to open.

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