阅读说明：本技术 变频器的控制装置及柱塞泵 (Control device of frequency converter and plunger pump ) 是由 王普军 史军瑞 闫文 易博 徐立鑫 赵学勇 张令利 王翠利 王超 沙泉 姬丙和 于 2019-03-28 设计创作，主要内容包括：本申请公开了一种变频器的控制装置及柱塞泵,属于电力工程领域。该控制装置包括：上电控制模块以及液位检测模块。上电控制模块的第一输入端、第二输入端和第三输入端分别与外接的三相电源连接,上电控制模块的第四输入端与变频器的第一输出端连接,上电控制模块的第五输入端与三相电源中的一相连接,上电控制模块的第六输入端与三相电源中的另一相连接,液位检测模块串联在变频器的第四输入端与上电控制模块的第二输出端之间,用于在检测到液位大于参考液位时使变频器的电机控制端失电。通过本申请提供的变频器的控制装置及柱塞泵,可以解决泵杆依然不停的抽取液体,导致泵房中的设备被液体浸泡的问题。(The application discloses controlling means and plunger pump of converter belongs to the electric power engineering field. The control device includes: the device comprises a power-on control module and a liquid level detection module. The first input end, the second input end and the third input end of the power-on control module are respectively connected with an external three-phase power supply, the fourth input end of the power-on control module is connected with the first output end of the frequency converter, the fifth input end of the power-on control module is connected with one of the three-phase power supplies, the sixth input end of the power-on control module is connected with the other of the three-phase power supplies, and the liquid level detection module is connected between the fourth input end of the frequency converter and the second output end of the power-on control module in series and used for enabling the motor control end of the frequency converter to lose power when the liquid level is detected to be greater than. Through the control device and the plunger pump of converter that this application provided, can solve the pump pole and still extract liquid incessantly, lead to the problem that equipment in the pump house is soaked by liquid.)

1. A control device of a frequency converter, characterized in that the control device comprises: the device comprises an upper electric control module (1) and a liquid level detection module (2);

the first input end (101), the second input end (102) and the third input end (103) of the power-on control module (1) are respectively connected with an external three-phase power supply, the fourth input end (104) of the power-on control module (1) is connected with the first output end (301) of the frequency converter (3), the fifth input end (105) of the power-on control module (1) and the third output end (309) of the frequency converter (3) are respectively connected with one of the three-phase power supplies, the sixth input end (106) of the power-on control module (1) is connected with the other of the three-phase power supplies, the first output end (107) of the power-on control module (1) is connected with the motor control end (302) of the frequency converter (3), and the second output end (108) of the power-on control module (1) is connected with the common end (303) of the frequency converter (3), a third output (109) of the power-on control module (1) is connected to a first input (304) of the frequency converter (3), a fourth output (110) of the power-on control module (1) is connected to a second input (305) of the frequency converter (3), and a fifth output (111) of the power-on control module (1) is connected to a third input (306) of the frequency converter (3);

the liquid level detection module (2) is connected in series between a fourth input end (307) of the frequency converter (3) and a second output end (108) of the power-on control module (1) and is used for enabling a motor control end (302) of the frequency converter (3) to lose power when the liquid level is detected to be larger than a reference liquid level.

2. A control arrangement according to claim 1, characterized in that the control arrangement further comprises an alarm module (4), which alarm module (4) is connected in series between the second output (308) of the frequency converter (3) and the other phase of the three-phase power supply.

3. Control device according to claim 2, characterized in that the alarm module (4) comprises an alarm lamp (41).

4. The control device according to claim 2, characterized in that the alarm module (4) further comprises a buzzer (42).

5. Control device according to claim 1, characterized in that the power-up control module (1) comprises: the relay switch comprises a first switch (112), a contactor coil (113), a contactor switch (114), a relay coil (115), a relay switch (116) and a second switch (117), wherein the first switch (112) is a normally closed switch, and the second switch (117) is a normally open switch;

the first switch (112), the second switch (117), the contactor switch (114) and the relay coil (115) are sequentially connected in series between one phase of the three-phase power supply and the other phase of the three-phase power supply, the relay switch (116) is connected with the second switch (117) in parallel, a first end of the relay switch (116) is connected with a motor control end (302) of the frequency converter (3), and a second end of the relay switch (116) is respectively connected with a common end (303) of a common end frequency converter (3) of the frequency converter and an input end of the liquid level detection module (2);

one end, which is not connected with one of the three-phase power supplies, of the first switch (112) is further connected with a third output end (309) of the frequency converter (3), a first end of the contactor coil (113) is connected with a first output end (301) of the frequency converter (3), and a second end of the contactor coil (113) is connected with the other of the three-phase power supplies.

6. A control arrangement according to claim 5, characterised in that the power-up control module (1) further comprises a third switch (118), the third switch (118) being a normally closed switch, the third switch (118) being connected in series between the first switch (112) and the second switch (117).

7. A control device according to claim 1, characterised in that the liquid level detection module (2) comprises a liquid level sensor (21).

8. A control arrangement according to claim 1, characterized in that the fifth input (310) of the frequency converter (3) is connected to one of the three-phase power sources and the sixth input (311) of the frequency converter (3) is connected to the other of the three-phase power sources.

9. The control device according to claim 1, characterized in that the control device further comprises a reset module (5), the reset module (5) being connected in series between the seventh input (312) of the frequency converter (3) and the common terminal (303) of the frequency converter (3).

10. Plunger pump, characterized in that the plunger pump comprises a plunger pump body (6), a frequency converter (3) connected with the plunger pump body (6), and a control device according to any of claims 1-9, wherein a liquid level detection module (2) in the control device is positioned in an inner cavity of the plunger pump body (6).

11. The plunger pump according to claim 10, characterized in that the liquid level detection module (2) comprises a liquid level sensor (21) and a fixing frame (22), the liquid level sensor (21) being fixed in the inner cavity of the plunger pump body (6) by the fixing frame (22).

Technical Field

The application relates to the field of electric power engineering, in particular to a control device of a frequency converter and a plunger pump.

Background

In the middle and later periods of oil exploitation, along with the reduction of the daily oil production, liquid needs to be injected into the stratum to keep the production and injection balance, and further the daily oil production is improved. In order to achieve the purpose of production-injection balance, at present, the production-injection balance is generally realized by injecting liquid into a stratum through a plunger pump, specifically: the plunger pump pumps the fluid into the formation after pressurizing the fluid. However, when one of the pump rods of the plunger pump is broken, the other pump rods still pump liquid continuously, but the liquid cannot be pumped into the underground by the plunger pump at the moment, but flows into the box body of the plunger pump from the broken part of the broken pump rod, and if the liquid cannot be found in time, the plunger pump which continuously operates not only can cause damage to the plunger pump, but also more and more liquid can overflow into the pump room, so that the equipment in the pump room is soaked by the liquid to cause economic loss, and even the equipment in the pump room can leak electricity to endanger the life safety of people.

Disclosure of Invention

The application provides a controlling means and plunger pump of converter can solve the problem that equipment in the pump house is soaked by liquid. The technical scheme is as follows:

in a first aspect, an embodiment of the present application provides a control device for a frequency converter, where the control device includes: the device comprises an upper electric control module and a liquid level detection module;

the first input end, the second input end and the third input end of the power-on control module are respectively connected with an external three-phase power supply, the fourth input end of the power-on control module is connected with the first output end of the frequency converter, the fifth input end of the power-on control module and the third output end of the frequency converter are both connected with one of the three-phase power supplies, a sixth input end of the power-on control module is connected with the other one of the three-phase power supplies, a first output end of the power-on control module is connected with a motor control end of the frequency converter, the second output end of the power-on control module is connected with the common end of the frequency converter, the third output end of the power-on control module is connected with the first input end of the frequency converter, a fourth output end of the power-on control module is connected with a second input end of the frequency converter, and a fifth output end of the power-on control module is connected with a third input end of the frequency converter;

the liquid level detection module is connected in series between a fourth input end of the frequency converter and a second output end of the power-on control module and used for enabling a motor control end of the frequency converter to lose power when the liquid level is detected to be larger than a reference liquid level.

Optionally, the control device further includes an alarm module, and the alarm module is connected in series between the second output end of the frequency converter and the other phase of the three-phase power supply.

Optionally, the alarm module comprises an alarm lamp.

Optionally, the alarm module further comprises a buzzer.

Optionally, the power-up control module includes: the relay switch comprises a first switch, a contactor coil, a contactor switch, a relay coil, a relay switch and a second switch, wherein the first switch is a normally closed switch, and the second switch is a normally open switch;

the first switch, the second switch, the contactor switch and the relay coil are sequentially connected in series between one phase of the three-phase power supply and the other phase of the three-phase power supply, the relay switch is connected with the second switch in parallel, a first end of the relay switch is connected with a motor control end of the frequency converter, and a second end of the relay switch is respectively connected with a common end of the frequency converter and an input end of the liquid level detection module;

the first switch is connected with one end of the three-phase power supply, the other end of the first switch is connected with the third output end of the frequency converter, the first end of the contactor coil is connected with the first output end of the frequency converter, and the second end of the contactor coil is connected with the other end of the three-phase power supply.

Optionally, the power-on control module further comprises a third switch, the third switch being a normally closed switch, the third switch being connected in series between the first switch and the second switch.

Optionally, the liquid level detection module comprises a liquid level sensor.

Optionally, a fifth input terminal of the frequency converter is connected to one of the three-phase power supplies, and a sixth input terminal of the frequency converter is connected to another of the three-phase power supplies.

Optionally, the control device further includes a reset module, and the reset module is connected in series between the seventh input end of the frequency converter and the common end of the frequency converter.

In a second aspect, an embodiment of the present application provides a plunger pump, the plunger pump includes a plunger pump body, a frequency converter connected to the plunger pump body, and the control device according to any one of the above first aspect, a liquid level detection module in the control device is located in an inner cavity of the plunger pump body.

Optionally, the liquid level detection module includes a liquid level sensor and a fixing frame, and the liquid level sensor is fixed in the inner cavity of the plunger pump body through the fixing frame.

The beneficial effects brought by the technical scheme provided by the embodiment of the application at least can comprise:

because controlling means can make the motor control end of converter get the electricity, again because the liquid level detection module can make the motor control end of converter lose the electricity, also promptly, this controlling means can make the motor control end of converter get the electricity, and then makes converter control motor begin to rotate, also can make the motor control end of converter lose the electricity when detecting the liquid level and being greater than the reference liquid level, and then makes converter control motor stall. Therefore, when one pump rod of the plunger pump is broken, and liquid flows into the box body of the plunger pump from the broken part of the broken pump rod to reach the reference liquid level, the control device can enable the motor control end of the frequency converter to lose power, further enable the motor to stop rotating, and enable the plunger pump to stop pumping the liquid, so that the phenomenon that more and more liquid overflows into the pump room to cause economic loss or endanger life safety of people due to the fact that equipment in the pump room is soaked by the liquid is effectively avoided.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is an electrical schematic diagram of a first control device provided in an embodiment of the present application;

FIG. 2 is an electrical schematic diagram of a second control device provided in an embodiment of the present application;

FIG. 3 is an electrical schematic diagram of an alarm module provided by an embodiment of the present application;

FIG. 4 is an electrical schematic diagram of a first power-on control module and an alarm module provided in an embodiment of the present application;

FIG. 5 is an electrical schematic diagram of a main circuit of a control device according to an embodiment of the present disclosure;

FIG. 6 is an electrical schematic diagram of a second power control module and alarm module provided by an embodiment of the present application;

FIG. 7 is an electrical schematic diagram of a third control device provided in an embodiment of the present application;

FIG. 8 is an electrical schematic diagram of a fourth control device provided in an embodiment of the present application;

FIG. 9 is a schematic structural diagram of a first plunger pump provided in an embodiment of the present application;

fig. 10 is a schematic structural diagram of a second plunger pump according to an embodiment of the present application.

Reference numerals:

1: a power-on control module; 2: a liquid level detection module; 3: a frequency converter; 4: an alarm module; 5: a reset module; 6: a plunger pump body;

21: a liquid level sensor; 22: a fixed mount; 41: an alarm lamp; 42: a buzzer;

101: a first input of the power-on control module; 102: a second input of the power-on control module; 103: a third input of the power-on control module; 104: a fourth input of the power-on control module; 105: a fifth input of the power-on control module; 106: a sixth input of the power-on control module; 107: a first output terminal of the power-on control module; 108: a second output terminal of the power-on control module; 109: a third output end of the power-on control module; 110: a fourth output terminal of the power-on control module; 111: a fifth output terminal of the power-on control module; 112: a first switch; 113: a contactor coil; 114: a contactor switch; 115: a relay coil; 116: a relay switch; 117: a second switch; 118: a third switch;

301: a first output terminal of the frequency converter; 302: a motor control end of the frequency converter; 303: a common terminal of the frequency converter; 304: a first input of a frequency converter; 305: a second input of the frequency converter; 306: a third input of the frequency converter; 307: a fourth input terminal of the frequency converter; 308: a second output terminal of the frequency converter; 309: a third output end of the frequency converter; 310: a fifth input of the frequency converter; 311: a sixth input of the frequency converter; 312: a seventh input of the frequency converter.

Detailed Description

To make the objects, technical solutions and advantages of the present application more clear, embodiments of the present application will be described in further detail below with reference to the accompanying drawings.

Fig. 1 is an electrical schematic diagram of a control device of a frequency converter according to an embodiment of the present application. Referring to fig. 1, the control apparatus includes: an upper electric control module 1 and a liquid level detection module 2. A first input 101 of the power-on control module 1, the second input end 102 and the third input end 103 are respectively connected with an external three-phase power supply, the fourth input end 104 of the power-on control module 1 is connected with the first output end 301 of the frequency converter 3, the fifth input end 105 of the power-on control module 1 and the third output end (309) of the frequency converter (3) are respectively connected with one of the three-phase power supplies, the sixth input end 106 of the power-on control module 1 is connected with the other of the three-phase power supplies, the first output end 107 of the power-on control module 1 is connected with the motor control end 302 of the frequency converter 3, the second output end 108 of the power-on control module 1 is connected with the common end 303 of the frequency converter 3, the third output end 109 of the power-on control module 1 is connected with the first input end 304 of the frequency converter 3, the fourth output end 110 of the power-on control module 1 is connected with the second input end 305 of the frequency converter 3, and the fifth output end 111 of the power-on. The liquid level detection module 2 is connected in series between the fourth input end 307 of the frequency converter 3 and the second output end of the power-on control module 1, and is configured to power down the motor control end 302 of the frequency converter 3 when the liquid level is detected to be greater than the reference liquid level.

Because the first input end 101, the second input end 102, and the third input end 103 of the power-on control module 1 are respectively connected to an external three-phase power supply, the third output end 109 of the power-on control module 1 is connected to the first input end 304 of the frequency converter 3, the fourth output end 110 of the power-on control module 1 is connected to the second input end 305 of the frequency converter 3, the fifth output end 111 of the power-on control module 1 is connected to the third input end 306 of the frequency converter 3, and the first input end 304 of the frequency converter 3, the second input end 305 of the frequency converter 3, and the third input end 306 of the frequency converter 3 are all power supply terminals of the frequency converter 3, the control device can power the frequency converter 3. Since the fourth input end 104 of the power-on control module 1 is connected to the first output end 301 of the frequency converter 3, the fifth input end 105 of the power-on control module 1 and the third output end 309 of the frequency converter 3 are both connected to one of the three-phase power supplies, the sixth input end 106 of the power-on control module 1 is connected to the other of the three-phase power supplies, the first output end 107 of the power-on control module 1 is connected to the motor control end 302 of the frequency converter 3, and the second output end 108 of the power-on control module 1 is connected to the common end 303 of the frequency converter 3, that is, the motor control end 302 is in a closed loop between the power-on control module 1 and the frequency converter 3, the control device can make the motor control end 302 of the frequency converter 3 powered on, so that the frequency converter 3 controls the motor to start to rotate, and the plunger pump starts to pump liquid.

In addition, since the liquid level detection module 2 is connected in series between the fourth input end 307 of the frequency converter 3 and the second output end 108 of the upper electric control module 1, and is used for powering off the motor control end 302 of the frequency converter 3 when the liquid level is detected to be greater than the reference liquid level, the liquid level detection module 2 can enable the frequency converter 3 to control the motor to stop rotating. That is, the control device of the frequency converter can make the motor control end 302 of the frequency converter 3 powered on, so as to make the frequency converter 3 control the motor to start rotating, and can also make the motor control end 302 of the frequency converter 3 powered off when detecting that the liquid level is greater than the reference liquid level, so as to make the frequency converter 3 control the motor to stop rotating. Therefore, when one of the pump rods of the plunger pump is broken, and liquid flows into the box body of the plunger pump from the broken part of the broken pump rod to reach the reference liquid level, the control device can enable the motor control end 302 of the frequency converter 3 to lose power, further enable the motor to stop rotating, and enable the plunger pump to stop pumping the liquid, so that the phenomenon that more and more liquid overflows into a pump room to cause economic loss or endanger the life safety of people due to the fact that equipment in the pump room is soaked by the liquid is effectively avoided.

The main function of the power-on control module 1 is to power on or power off the motor control terminal 302 of the frequency converter 3, so that the frequency converter 3 controls the motor to start rotating or stop rotating. The liquid level detection module 2 is mainly used for powering off the motor control end 302 of the frequency converter 3 when the liquid level is detected to be greater than the reference liquid level, so that the motor stops rotating.

It is noted that in the initial state, the power-up control module 1 may power up the motor control terminal 302 of the frequency converter 3, since the first input terminal 304 of the frequency converter 3 is in the closed state. When the liquid level detection module 2 detects that the liquid level is greater than the reference liquid level, the first input end 304 of the frequency converter 3 is changed from a closed state to an open state, so that the power-on control module 1 can cause the motor control end 302 of the frequency converter 3 to lose power, and further cause the motor to stop rotating and the plunger pump to stop pumping liquid.

It should be noted that, in order to make the control device safer, a fourth switch may also be connected in series between the contactor switch and the external three-phase power supply, and certainly, the fourth switch may not be connected in series, which is not specifically limited in this embodiment of the present application.

It should be noted that, the above-mentioned reference liquid level is artificially set, exemplarily, the reference liquid level can be set to be 10cm, and then when the distance from the water bottom to the water surface is greater than 10cm, that is, when being greater than the reference liquid level, the liquid level detection module 2 can make the motor control end 302 of the frequency converter 3 lose power, and then make the motor stop rotating, make the plunger pump stop extracting liquid, of course, the reference liquid level can also be set to other numerical values, and this application embodiment does not specifically limit the numerical value of the reference liquid level. It should be noted that, in the embodiment of the present application, one phase of the three-phase power and the other phase of the three-phase power may be any one of three phases of the three-phase power L1, L2, and L3, and it is only required to ensure that the one phase of the three-phase power and the other phase of the three-phase power are not the same phase, which is not specifically limited in the embodiment of the present application.

In order to enable a technician to timely find the abnormality after the motor stops rotating and the plunger pump stops pumping liquid, referring to fig. 2, the control device further comprises an alarm module 4, and the alarm module 4 is connected in series between the second output end 308 of the frequency converter 3 and the other phase of the three-phase power supply. Like this, when liquid level detection module 2 detected the liquid level and is greater than the reference liquid level, and then when making motor stall, alarm module 4 can report to the police and then makes the discovery that technical staff can be timely unusual. It should be noted that the alarm module 4 may alarm by flashing the alarm lamp 41, or may alarm by sound, and the alarm mode of the alarm module 4 is not specifically limited in the embodiment of the present application.

In a possible implementation, the alarm module 4 comprises an alarm lamp 41. That is, the alarm module 4 gives an alarm by flashing the alarm lamp 41. In another implementation, in order for the technician to be able to find the abnormality more quickly, see fig. 3, the alarm module 4 further comprises a buzzer 42, so that the technician can signal the abnormality by the sound of the buzzer 42.

It is worth noting that in the initial state, since the second output end 308 of the frequency converter 3 is in the open state, when the liquid level detection module 2 detects that the liquid level is greater than the reference liquid level, the second output end 308 of the frequency converter 3 is changed from the open state to the closed state, so that the alarm module 4 can be powered on to start alarming.

Further, in a possible implementation, referring to fig. 4, the power-on control module 1 includes: the relay switch comprises a first switch 112, a contactor coil 113, a contactor switch 114, a relay coil 115, a relay switch 116 and a second switch 117, wherein the first switch 112 is a normally closed switch, and the second switch 117 is a normally open switch. The first switch 112, the second switch 117, the contactor switch 114 and the relay coil 115 are sequentially connected in series between one phase of the three-phase power supply and the other phase of the three-phase power supply, the relay switch 116 is connected in parallel with the second switch 117, a first end of the relay switch 116 is connected with a motor control end 302 of the frequency converter 3, and a second end of the relay switch 116 is respectively connected with a common end 303 of the frequency converter 3 and an input end of the liquid level detection module 2. The end of the first switch 112 not connected to one of the three-phase power supplies is further connected to a third output 309 of the frequency converter 3, a first end of the contactor coil 113 is connected to the first output 301 of the frequency converter 3, and a second end of the contactor coil 113 is connected to the other of the three-phase power supplies.

Specifically, in a normal operating state, because the first switch 112 is a normally closed switch, one end of the first switch 112, which is not connected to one of the three-phase power supplies, is further connected to the third output terminal 309 of the frequency converter 3, the first end of the contactor coil 113 is connected to the first output terminal 301 of the frequency converter 3, and the second end of the contactor coil 113 is connected to the other end of the three-phase power supply, the contactor coil 113 can be powered on, so that the contactor switch 114 can be actuated, and after the contactor switch 114 is actuated, the frequency converter 3 can be powered on. Because the first switch 112, the second switch 117, the contactor switch 114 and the relay coil 115 are sequentially connected in series between one phase of the three-phase power supply and the other phase of the three-phase power supply, the relay switch 116 is connected in parallel with the second switch 117, the first end of the relay switch 116 is connected with the motor control end 302 of the frequency converter 3, the second end of the relay switch 116 is respectively connected with the common end 303 of the frequency converter 3 and the input end of the liquid level detection module 2, and because the second switch 117 is a normally open switch, the relay coil 115 can be powered by pressing the second switch 117, and then the relay switch 116 is attracted, and after the relay switch 116 is attracted, the motor control end 302 of the frequency converter 3 can be powered, and then the motor starts to rotate. When the motor stops rotating, the first switch 112 is pressed down, the contactor coil 113 can be powered off, the contactor switch 114 and the relay switch 116 are switched off, the motor stops rotating at the moment, and therefore the functions of starting rotating and stopping rotating of the motor in a normal working state are completed. In an abnormal operating state, that is, when the liquid level detection module 2 detects that the liquid level is greater than the reference liquid level, since the first input end 304 of the frequency converter 3 is changed from the closed state to the open state, at this time, the contactor coil 113 is de-energized, and then the contactor switch 114 and the relay switch 116 are both turned off, the motor stops rotating, and thus, the function of automatically stopping rotating the motor in the abnormal operating state is completed.

It should be noted that, in a normal operating state, when the motor needs to stop rotating, the first switch 112 is pressed to disable the power of the contactor coil 113, so that both the contactor switch 114 and the relay switch 116 are turned off, as can be seen from fig. 4 and 5, the motor can stop rotating only by turning off the relay switch 116, and frequent turning off and closing of the contactor switch 114 causes frequent turning on and off of the frequency converter 3 to affect the usability of the frequency converter 3, therefore, referring to fig. 6, the power-on control module 1 further includes a third switch 118, the third switch 118 is a normally closed switch, and the third switch 118 is connected in series between the first switch 112 and the second switch 117. Thus, when the function of stopping the rotation of the motor needs to be completed, the relay coil 115 can be powered off only by pressing the third switch 118, so that the relay switch 116 is turned off, and after the relay switch 116 is turned off, the motor control end 302 of the frequency converter 3 is powered off, the motor stops rotating, and the plunger pump stops pumping liquid.

In a possible implementation, the liquid level detection module 2 comprises a liquid level sensor 21.

In order to avoid a situation in which the frequency converter 3 is de-energized after the contactor switch 114 is opened, and thus the frequency converter 3 is log-lost, the fifth input 310 of the frequency converter 3 is connected to one of the three-phase power supplies, and the sixth input 311 of the frequency converter 3 is connected to the other of the three-phase power supplies, see fig. 7.

In an abnormal working state, when the liquid level detection module 2 detects that the liquid level is greater than the reference liquid level, since the first input end 304 of the frequency converter 3 is changed from the closed state in the initial state to the open state, and the second output end 308 of the frequency converter 3 is changed from the open state in the initial state to the closed state, after the abnormality is removed, the first input end 304 of the frequency converter 3 needs to be restored to the closed state, and the second output end 308 of the frequency converter 3 needs to be restored to the open state, referring to fig. 8, the control device further includes a reset module 5, and the reset module 5 is connected in series between the seventh input end 312 of the frequency converter 3 and the common end 303 of the frequency converter 3. At this time, the reset module 5 is pressed, so that the first input end 304 of the frequency converter 3 and the second output end 308 of the frequency converter 3 can be restored to the initial state.

Fig. 9 is a schematic structural diagram of a plunger pump according to an embodiment of the present application. Referring to fig. 9, the plunger pump comprises a plunger pump body 6, a frequency converter 3 connected with the plunger pump body 6, and the control device of any one of claims 1 to 9, wherein a liquid level detection module 2 in the control device is positioned in an inner cavity of the plunger pump body 6.

In a possible implementation, referring to fig. 10, the liquid level detection module 2 includes a liquid level sensor 21 and a fixing frame 22, and the liquid level sensor 21 is fixed in the inner cavity of the plunger pump body 6 through the fixing frame 22.

It should be noted that the fixing between the fixing frame 22 and the inner cavity of the plunger pump body 6 may be realized by welding, or may be realized by other methods, and the fixing between the fixing frame 22 and the inner cavity of the plunger pump body 6 is not limited in the embodiment of the present application.

In the embodiment of the present application, because the first input terminal 101, the second input terminal 102, and the third input terminal 103 of the power-on control module 1 are respectively connected to an external three-phase power supply, the third output terminal 109 of the power-on control module 1 is connected to the first input terminal 304 of the frequency converter 3, the fourth output terminal 110 of the power-on control module 1 is connected to the second input terminal 305 of the frequency converter 3, the fifth output terminal 111 of the power-on control module 1 is connected to the third input terminal 306 of the frequency converter 3, and the first input terminal 304 of the frequency converter 3, the second input terminal 305 of the frequency converter 3, and the third input terminal 306 of the frequency converter 3 are all power terminals of the frequency converter 3, the control device can power the frequency converter 3. Since the fourth input end 104 of the power-on control module 1 is connected to the first output end 301 of the frequency converter 3, the fifth input end 105 of the power-on control module 1 and the third output end 309 of the frequency converter 3 are both connected to one of the three-phase power supplies, the sixth input end 106 of the power-on control module 1 is connected to the other of the three-phase power supplies, the first output end 107 of the power-on control module 1 is connected to the motor control end 302 of the frequency converter 3, and the second output end 108 of the power-on control module 1 is connected to the common end 303 of the frequency converter 3, that is, the motor control end 302 is in a closed loop between the power-on control module 1 and the frequency converter 3, the control device can make the motor control end 302 of the frequency converter 3 powered on, so that the frequency converter 3 controls the motor to start rotating, and the plunger pump starts to pump liquid. In addition, since the liquid level detection module 2 is connected in series between the fourth input end 307 of the frequency converter 3 and the second output end 108 of the upper electric control module 1, and is used for powering off the motor control end 302 of the frequency converter 3 when the liquid level is detected to be greater than the reference liquid level, the liquid level detection module 2 can enable the frequency converter 3 to control the motor to stop rotating and the plunger pump to stop pumping liquid. In addition, because the control device also comprises the alarm module 4, the alarm module 4 comprises the alarm lamp 41 and the buzzer 42, when the liquid level is detected to be greater than the reference liquid level, the alarm module 4 can start alarming, so that a technician can find abnormality in time, and further the phenomenon that the work period is delayed due to the fact that the plunger pump is idle for a long time is avoided. That is, the controlling means of converter can make the motor control end 302 of converter 3 get electric, and then make converter 3 control motor begin to rotate, make the plunger pump begin to draw liquid, also can make the motor control end 302 of converter 3 lose electricity when detecting that the liquid level is greater than the reference liquid level, and then make converter 3 control motor stall, the plunger pump stops to draw liquid, and in time report to the police after the plunger pump stops to draw liquid, avoid the plunger pump to idle for a long time and lead to delaying the phenomenon of time limit and take place. Therefore, the control device effectively avoids the phenomenon that more and more liquid overflows into the pump room to cause economic loss or endanger life safety of people due to the fact that equipment in the pump room is soaked by the liquid, and also avoids the phenomenon that a work period is delayed due to the fact that the plunger pump is idle for a long time.

The above description is only exemplary of the present application and should not be taken as limiting, as any modification, equivalent replacement, or improvement made within the spirit and principle of the present application should be included in the protection scope of the present application.