阅读说明：本技术 深井泵控制方法及其驱动装置 (Deep well pump control method and driving device thereof ) 是由 雷发胜 陈伟 陈坤 李柏松 王亮平 李武君 王文宇 于 2020-08-08 设计创作，主要内容包括：一种深井泵控制方法及其控制装置,该深水泵控制方法包括以下步骤：控制深井泵的电机以额定转速运行并获取电机的转矩电流和输出功率,若电机的转矩电流小于预定的转矩电流下限,且电机的输出功率小预定的第一功率阈值,则控制电机停机,否则,判断电机的输出功率是否小于预定的第二功率阈值Pmin2,若大于等于第二功率阈值则返回上一步骤,若小于第二功率阈值Pmin2则执行下一步骤,记录深井泵的出口压力,作为压力阈值；降低电机的转速,获取深井泵的出口压力变化值,根据出口压力变化值判断深水泵是否出现泄露。本发明能够自动实现深水泵的无水保护,并自动识别深水泵停机时的压力阈值,检测出深水泵是否发生泄漏。(A deep-well pump control method and a control device thereof are provided, the deep-well pump control method comprises the following steps: controlling a motor of the deep well pump to operate at a rated rotating speed and obtaining torque current and output power of the motor, if the torque current of the motor is smaller than a preset lower limit of the torque current and the output power of the motor is smaller than a preset first power threshold, controlling the motor to stop, otherwise, judging whether the output power of the motor is smaller than a preset second power threshold Pmin2, if the output power of the motor is larger than or equal to the second power threshold, returning to the previous step, and if the output power of the motor is smaller than the second power threshold Pmin2, executing the next step, and recording outlet pressure of the deep well pump as a pressure threshold; and reducing the rotating speed of the motor, acquiring the outlet pressure change value of the deep well pump, and judging whether the deep well pump leaks or not according to the outlet pressure change value. The invention can automatically realize the waterless protection of the deep water pump, automatically identify the pressure threshold value when the deep water pump is stopped, and detect whether the deep water pump leaks.)

1. A method of controlling a deep well pump, comprising the steps of:

controlling a motor of the deep-well pump to run at a rated rotating speed and obtain the torque current and the output power of the motor, and if the torque current of the motor is smaller than a preset torque current lower limit Tmin and the output power of the motor is smaller than a preset first power threshold Pmin1, controlling the motor to stop so as to implement anhydrous protection; if the torque current of the motor is greater than or equal to a preset torque current lower limit Tmin and the output power of the motor is greater than or equal to a preset first power threshold Pmin1, executing the next step;

judging whether the output power of the motor is smaller than a preset second power threshold value Pmin2, if the output power of the motor is larger than or equal to the second power threshold value Pmin2, returning to the previous step, and if the output power of the motor is smaller than the second power threshold value Pmin2, executing the next step;

recording outlet pressure of the deep well pump as a pressure threshold value Plimit, and setting Plimit n as wake-up pressure Pwake, wherein n is a preset percentage;

reducing the rotating speed of the motor, and obtaining an outlet pressure change value k of the deep well pump; if k is larger than k2, controlling the motor to continue normal operation; if k is less than k1, controlling the motor to stop, monitoring the outlet pressure of the deep well pump in real time, and restarting the motor when the outlet pressure is less than Pwake; if k1< k < k2, the motor is controlled to stop, and the motor is restarted when the outlet pressure is smaller than Pwake, and if the number of times of restarting the motor within preset time t1 from the first time of controlling the motor to stop exceeds a preset number threshold, the motor is controlled to stop until the motor is manually restarted, wherein k1 is a preset first pressure change threshold, and k2 is a preset second pressure change threshold.

2. The deep-well pump control method according to claim 1, wherein the reducing of the rotation speed of the motor and the obtaining of the outlet pressure variation value k of the deep-well pump are realized by:

reducing the rotating speed of the motor by n1, wherein n1 is a preset percentage, and recording the pressure change value of the outlet pressure of the deep well pump before and after speed reduction;

and repeating the steps for N times, averaging the obtained N pressure change values, and taking the average value as an outlet pressure change value k of the deep well pump.

3. The deep-well pump control method according to claim 2, wherein N1 is 8-12% and N is 3-5.

4. The deep-well pump control method of claim 1, wherein after the water-free protection is implemented, the motor is restarted once every predetermined time from when the motor was stopped until the motor was successfully started.

5. The deep-well pump control method according to any one of claims 1 to 4, wherein the locked-rotor determination and processing is performed after the deep-well pump is powered on and before a motor controlling the deep-well pump is operated at a rated rotation speed, and the locked-rotor determination and processing comprises the following steps:

acquiring the torque current and the rotating speed of the motor, and executing the next step if the torque current of the motor is greater than or equal to a preset torque current upper limit Tmax and the rotating speed of the motor is lower than a preset rotating speed lower limit Wmin;

trying to start the motor at the maximum torque for N1 times, controlling the motor to run at the rated rotation speed if the motor is started successfully, and executing the next step if the motor is started for N1 times and fails, wherein N1 is more than or equal to 2;

controlling the motor to rotate reversely by the maximum torque and reach a preset rotating speed so as to remove silt, controlling the motor to rotate forward and start after rotating reversely once, and controlling the motor to operate at a rated rotating speed if the motor is started successfully;

if the starting fails, the previous step is repeatedly executed for N2 times, if the starting still cannot be realized after the repeated execution of N2 times, the deep water pump is controlled to stop, and N2 is more than or equal to 2.

6. A deep well pump drive device, comprising:

a memory for storing a program;

a processor for loading the program to perform the deep well pump control method of any of claims 1 to 5.

Technical Field

The invention relates to a deep well pump control technology.

Background

The deep well pump motor adopts a permanent magnet motor with high rotating speed, the impeller number and the volume of a pump body can be reduced, and the cost and the volume of the pump are reduced, which becomes the development trend of the deep well pump industry. The deep well pump driver, the motor and the impeller are directly connected and sealed and work in a sealed deep well. As the depth of the deep well reaches more than one hundred meters, once the deep well pump fails and stops working normally, the deep well pump is difficult to maintain and the maintenance cost is very high. This requires that the deep well pump drive be intelligent to the extent that it is not only able to identify multiple faults, but also to address them accordingly.

The existing deep-well pump driver can deal with some simple faults, and a better solution is not provided when the following problems are faced:

1) when the impeller is blocked by silt in the deep well, the motor is blocked, so that the water pump cannot be started normally;

2) when the water level in the deep well is low, the motor and the driver are exposed in the air, cannot radiate heat through water cooling, and are easy to damage due to overheating;

3) when the deep-well pump is at different depths, the outlet pressure values of the pumps are different, and the pressure threshold value of shutdown needs to be automatically identified. Because there is no flow sensor, the problem of flow leakage is detected according to the pressure value.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a deep-well pump control method and a deep-well pump control device, which can automatically realize the waterless protection of a deep-well pump, automatically identify the pressure threshold value when the deep-well pump is stopped, and detect whether the deep-well pump leaks.

Another technical problem to be solved by the present invention is to provide a deep-well pump control method and a deep-well pump control device, which can automatically identify whether the deep-well pump is locked by silt and control the deep-well pump motor to perform the operation of removing the locked rotation.

The embodiment of the invention provides a deep-well pump control method, which comprises the following steps:

controlling a motor of the deep-well pump to run at a rated rotating speed and obtain the torque current and the output power of the motor, and if the torque current of the motor is smaller than a preset torque current lower limit Tmin and the output power of the motor is smaller than a preset first power threshold Pmin1, controlling the motor to stop so as to implement anhydrous protection; if the torque current of the motor is greater than or equal to a preset torque current lower limit Tmin and the output power of the motor is greater than or equal to a preset first power threshold Pmin1, executing the next step;

judging whether the output power of the motor is smaller than a preset second power threshold value Pmin2, if the output power of the motor is larger than or equal to the second power threshold value Pmin2, returning to the previous step, and if the output power of the motor is smaller than the second power threshold value Pmin2, executing the next step;

recording outlet pressure of the deep well pump as a pressure threshold value Plimit, and setting Plimit n as wake-up pressure Pwake, wherein n is a preset percentage;

reducing the rotating speed of the motor, and obtaining an outlet pressure change value k of the deep well pump; if k is larger than k2, controlling the motor to continue normal operation; if k is less than k1, controlling the motor to stop, monitoring the outlet pressure of the deep well pump in real time, and restarting the motor when the outlet pressure is less than Pwake; if k1< k < k2, the motor is controlled to stop, and the motor is restarted when the outlet pressure is smaller than Pwake, and if the number of times of restarting the motor within preset time t1 from the first time of controlling the motor to stop exceeds a preset number threshold, the motor is controlled to stop until the motor is manually restarted, wherein k1 is a preset first pressure change threshold, and k2 is a preset second pressure change threshold.

In the above method for controlling a deep-well pump, the locked-rotor determination and processing is performed after the deep-well pump is powered on and before a motor of the deep-well pump is controlled to operate at a rated rotation speed, and the locked-rotor determination and processing includes the following steps:

acquiring the torque current and the rotating speed of the motor, and executing the next step if the torque current of the motor is greater than or equal to a preset torque current upper limit Tmax and the rotating speed of the motor is lower than a preset rotating speed lower limit Wmin;

trying to start the motor at the maximum torque for N1 times, controlling the motor to run at the rated rotation speed if the motor is started successfully, and executing the next step if the motor is started for N1 times and fails, wherein N1 is more than or equal to 2;

controlling the motor to rotate reversely by the maximum torque and reach a preset rotating speed so as to remove silt, controlling the motor to rotate forward and start after rotating reversely once, and controlling the motor to operate at a rated rotating speed if the motor is started successfully;

if the starting fails, the previous step is repeatedly executed for N2 times, if the starting still cannot be realized after the repeated execution of N2 times, the deep water pump is controlled to stop, and N2 is more than or equal to 2.

The invention also provides a deep-well pump driving device, comprising: a memory for storing a program; a processor for loading the program to perform the deep well pump control method as described above.

The invention has at least the following advantages:

1. the outlet pressure threshold of the deep water pump can be automatically identified after the deep water pump is powered on every time, and corresponding actions are carried out according to the state of the water outlet valve; the change of the outlet pressure is obtained through the reduced rotating speed of the motor, and whether the deep water pump leaks or not can be judged;

2. the water level condition can be identified without a liquid level sensor, and the automatic shutdown protection is carried out under the condition of no water until the water is available;

3. the condition that whether silt is locked is detected or not can be automatically identified according to the torque current and the rotating speed of the motor of the deep water pump, and the motor is controlled to do corresponding actions, so that the problem of locked rotor under most conditions can be solved;

4. the deep-well pump control method provided by the embodiment of the invention does not need to add an additional hardware device, can be realized in a pure software mode, and is low in implementation cost.

Drawings

FIG. 1 shows a general flow diagram of a deep-well pump control method according to an embodiment of the invention.

Fig. 2 is a flow chart illustrating a locked rotor determination and processing according to an embodiment of the invention.

Fig. 3 is a flow chart illustrating a waterless determination and protection process according to an embodiment of the present invention.

FIG. 4 shows a flow chart of pressure control and leak detection according to an embodiment of the invention.

Detailed Description

The deep-well pump control method according to an embodiment of the present invention includes the steps of:

controlling a motor of the deep-well pump to run at a rated rotating speed and obtain the torque current and the output power of the motor, and if the torque current of the motor is smaller than a preset torque current lower limit Tmin and the output power of the motor is smaller than a preset first power threshold Pmin1, controlling the motor to stop; if the torque current of the motor is greater than or equal to a preset torque current lower limit Tmin and the output power of the motor is greater than or equal to a preset first power threshold Pmin1, executing the next step;

judging whether the output power of the motor is smaller than a preset second power threshold value Pmin2, if the output power of the motor is larger than or equal to the second power threshold value Pmin2, returning to the previous step, and if the output power of the motor is smaller than the second power threshold value Pmin2, executing the next step, wherein Pmin2 is larger than Pmin 1;

recording outlet pressure of the deep well pump as a pressure threshold value Plimit, and setting Plimit n as wake-up pressure Pwake, wherein n is a preset percentage;

reducing the rotating speed of the motor, and obtaining an outlet pressure change value k of the deep well pump; if k is larger than k2, controlling the motor to continue normal operation; if k is less than k1, controlling the motor to stop, monitoring the outlet pressure of the deep well pump in real time, and restarting the motor when the outlet pressure is less than Pwake; if k1< k < k2, the motor is controlled to stop firstly, and the motor is restarted when the outlet pressure is less than Pwake, and if the number of times of restarting the motor within the preset time t from the first time of controlling the motor to stop exceeds a preset number threshold, the motor is controlled to stop continuously until the motor is manually restarted, wherein k1 is a preset first pressure change threshold, and k2 is a preset second pressure change threshold.

Further, the rotating speed of the motor is reduced, and the outlet pressure change value k of the deep well pump is obtained through the following modes:

reducing the rotating speed of the motor by n1, wherein n1 is a preset percentage, and recording the pressure change value of the outlet pressure of the deep well pump before and after speed reduction;

repeating the steps for N times, averaging the obtained N pressure change values, and taking the average value as an outlet pressure change value k of the deep well pump, wherein N1 is equal to 8% -12%, and N is equal to 3-5.

Further, according to the deep well pump control method of the embodiment of the invention, after the water-free protection is implemented, the motor is restarted once every preset time from the time when the motor is stopped until the motor is started successfully.

Further, according to the deep-well pump control method of an embodiment of the present invention, after the deep-well pump is powered on, and before the deep-well pump is controlled to operate at the rated speed, the method performs locked-rotor determination and processing, and the locked-rotor determination and processing includes the following steps:

acquiring the torque current and the rotating speed of the motor, and executing the next step if the torque current of the motor is greater than or equal to a preset torque current upper limit Tmax and the rotating speed of the motor is lower than a preset rotating speed lower limit Wmin;

starting the motor for N1 times at the maximum torque, controlling the motor to run at the rated rotating speed (namely normal running) if the starting is successful, and executing the next step if the starting is failed for N1 times, wherein N1 is more than or equal to 2;

controlling the motor to rotate reversely by the maximum torque and reach a preset rotating speed so as to remove silt, controlling the motor to rotate forward and start after rotating reversely once, and controlling the motor to operate at a rated rotating speed (namely normal operation) if the starting is successful;

if the starting fails, the previous step is repeatedly executed for N2 times, if the starting still cannot be realized after the repeated execution of N2 times, the deep water pump is controlled to stop to wait for maintenance, and N2 is more than or equal to 2.

In order to make the technical scheme of the invention more clear, the invention is described in detail below with reference to the accompanying drawings and specific application examples. In the application example, the deep-well pump driver is used for controlling the deep-well pump to realize the deep-well pump control method.

Referring to fig. 1-4, in this embodiment, the deep-well pump driver controls the deep-well pump as follows.

After the deep well pump is powered on and started, the judgment and the processing of bus undervoltage or overvoltage are executed. Under the condition that no bus under-voltage or overvoltage exists, locked rotor judgment and processing are executed, and the locked rotor judgment and processing comprise the following steps:

acquiring the torque current and the rotating speed of the motor (for example, the torque current and the rotating speed of the motor can be acquired through a current sensor and a rotating speed sensor respectively), and if the torque current of the motor is greater than or equal to a preset torque current upper limit Tmax and the rotating speed of the motor is lower than a preset rotating speed lower limit Wmin, determining that the deep-well pump has sediment stalling at the moment, executing the next step;

trying to start the motor at the maximum torque for 4 times, if the starting is successful, controlling the motor to run at the rated rotating speed (namely normal running), and if the starting is failed for 4 times, executing the next step;

controlling the motor to rotate reversely by the maximum torque and reach a preset rotating speed so as to remove silt, controlling the motor to rotate forward and start after rotating reversely once, and controlling the motor to operate at a rated rotating speed if the motor is started successfully;

if the starting fails, the silt locked rotor is serious, the last step is repeatedly executed for 4 times, and if the deep water pump cannot be started after being repeatedly executed for 4 times, the deep water pump is controlled to stop to wait for maintenance.

After the locked-rotor judgment and treatment is finished, if the deep water pump is not locked-rotor, the waterless judgment and protection treatment is carried out, and the waterless judgment and protection treatment comprises the following steps:

controlling a motor of the deep-well pump to run at a rated rotating speed and obtaining the torque current and the output power of the motor, if the torque current of the motor is smaller than a preset torque current lower limit Tmin and the output power of the motor is smaller than a preset first power threshold Pmin1, determining that the water level is shallow (namely the situation of no water occurs), the flow of the deep-well pump is small, the heat dissipation cannot be guaranteed, and controlling the motor to stop so as to achieve the purpose of protection;

and restarting the motor once every preset time from the time when the motor is stopped until the motor is successfully started. The next starting interval time is determined according to the number of times of anhydrous protection of the motor within 24 hours, and the motor is restarted after 0.5 hour, 1 hour, 3 hours, 5 hours and 24 hours in sequence, wherein any one time of restarting is successful and the fault is cleared after the motor normally operates for 24 hours, namely when the anhydrous protection is implemented next time, the motor is restarted at an interval of 0.5 hour from the time of stopping the motor.

And after the water-free judgment and protection treatment is finished, further judging whether the deep water pump has the over-current or over-temperature condition, and if the over-current or over-temperature condition occurs, performing shutdown protection. If the motor is restarted for 4 times within 5min and is not restarted successfully after being stopped, the motor is stopped for 1 hour and then restarted, and if the operation of continuously stopping for 5 times and restarting for 1 hour is not restarted successfully, the motor is stopped until being manually powered off and restarted; and if the number of times of restarting the motor within 5min is less than 4 after the machine is stopped, waiting for 5s and then returning to the initial state of electrifying and starting the deep water pump. And if no water exists, no over-current or over-temperature condition exists, performing pressure identification and leakage detection processing.

The deep-well pump is in different depths, the outlet pressure corresponding to the same flow is different, and the outlet pressure corresponding to the tight closing of the water outlet valve of the deep-well pump also changes along with the depth, so that the pressure threshold value is identified every time the deep-well pump is electrified. If the deep-well pump leaks, the outlet pressure can also change, misjudgment is easy to happen, and the deep-well pump is started and stopped frequently. The pressure identification and leak detection process of the present embodiment can solve this problem, and since the output power corresponding to the tight closing of the outlet valve is independent of the depth, the present embodiment utilizes this principle to identify the pressure threshold value by the output power. When the water level is lower than the pump body, the output power is also lower, so the condition of no water is eliminated firstly, and then the pressure identification and the leakage detection processing are executed, and the method comprises the following steps:

keeping the motor running at a rated rotating speed;

judging whether the output power of the motor is smaller than a preset second power threshold value Pmin2, if the output power of the motor is larger than or equal to the second power threshold value Pmin2, performing anhydrous judgment and protection processing, and if the output power of the motor is smaller than the second power threshold value Pmin2, executing the next step, wherein the Pmin2 is not less than the Pmin 1; the output power of the motor being smaller than the second power threshold Pmin2 means that the outlet valve of the deep-water pump may be closed (but not necessarily tightly closed);

recording the outlet pressure of the deep well pump as a pressure threshold value Plimit, setting the Plimit at 70% as a wake-up pressure Pwake, only identifying the pressure threshold value once when electrifying every time, and entering the next step because the depth of the water pump in an electrified state cannot be changed; a deep-well pump outlet pressure equal to or greater than the pressure threshold Plimit means that the outlet valve of the deep-well pump may be closed (but not necessarily tight);

reducing the rated motor speed by 10 percent, obtaining the outlet pressure difference of the deep-well pump when the motor is at the rated speed and is at the rated speed of 90 percent, repeating the process for 3 times, reducing the motor speed to 70 percent of the rated motor speed, and taking the average value of the obtained outlet pressure differences of 3 deep-well pumps (the outlet pressure difference of the 2 nd deep-well pump is the outlet pressure difference when the motor is at the rated speed of 90 percent and the motor is at the rated speed of 80 percent, and so on) as the outlet pressure change value k of the deep-well pump;

if the water outlet valve is closed and the deep well pump has no leakage, the outlet pressure is basically unchanged when the rotating speed is changed; if the water outlet valve is closed but the deep well pump leaks, the outlet pressure changes greatly when the rotating speed changes; if the outlet valve is not closed tightly, the change of the outlet pressure is the largest when the rotating speed is changed. Based on the principle, if k is larger than k2, the outlet valve of the deep water pump is judged not to be tightly closed, and the motor is controlled to continue to normally operate; if k is less than k1, the water valve is judged to be closed and the deep well pump has no leakage, the motor is controlled to stop, the outlet pressure of the deep well pump is monitored in real time, and when the water outlet valve is opened, the motor is restarted when the outlet pressure is less than Pwake; if k1< k < k2, the deep well pump is judged to be possible to leak, the motor is controlled to stop, and the motor is restarted when the outlet pressure is smaller than Pwake (if the leakage exists, the outlet pressure value is quickly lower than Pwake, the deep well pump is restarted, the pressure value exceeds Plimit again after the motor reaches a certain rotating speed due to the fact that a valve is closed, the deep well pump is restarted in a short time), if the number of times of restarting the motor within 5 minutes from the time of first-time motor stopping control exceeds 6 times, the deep well pump is judged to leak, the motor is controlled to stop until the motor is manually restarted, wherein k1 is a preset first pressure change threshold value, k2 is a preset second pressure change threshold value, and k2> k 1.

According to another aspect of embodiments of the present invention, there is also provided a deep-well pump driving apparatus including: a memory for storing a program; a processor for loading the program to perform the deep well pump control method as described above.