JP6982505B2 - Pump device - Google Patents

Description

The present invention relates to a pump device.

Conventionally, as a pump device, for example, a water supply device using a variable speed pump described in Patent Document 1 is known. In the water supply device using the conventional variable speed pump, the operating speed of the motor that drives the pump is changed by the inverter device according to the fluctuation of the demand water amount, and the water supply is continued while keeping the discharge pressure of the pump in a constant relationship. It has become.

In the water supply device incorporating the inverter device in this way, various protection circuits are incorporated in order to protect the inverter device itself. When the inverter device is stopped by the action of the protection circuit, the water is cut off. Therefore, the conventional water supply device is provided with a re-operation means for restarting the inverter device when the inverter device is stopped by the action of the protection circuit. ..

Japanese Unexamined Patent Publication No. 1-190989

By the way, in the above-mentioned conventional water supply device, the restart of the inverter device is tried within the range of the number of operations defined as the number of times of re-operation m, and the value n of the re-operation counter reaches the number of times of re-operation m. In that case, it is judged that it is difficult to restart the inverter device, the failure of the pump is confirmed, the necessary alarm is issued via the interface circuit, and the maintenance manager of the water supply device is urgently contacted. It has become.

In this way, if the cause of the protection stop of the inverter device is eliminated when the restart command is given to the inverter device, the inverter device will be operated again and the inverter device will be completely stopped. It is possible to reduce the probability that it will end up. However, if the cause of the protection stop of the inverter device is not eliminated when the restart command is given to the inverter device, the failure of the pump will be confirmed.

Here, depending on the installation environment and usage of the water supply device, the protection circuit of the inverter device may work due to a transient phenomenon under unstable conditions at the time of starting the pump. In this case, in the above-mentioned conventional water supply device, although the pump can be operated normally when the rotation speed exceeds a certain level and the specified head is reached, it is judged that the cause of the protection stop has not been solved and the failure of the pump is confirmed. There is a risk of doing so. Since the pump device that supplies tap water to the building is a lifeline, it is desirable to avoid the confirmation of failure due to the transient state at the time of starting the pump as much as possible and avoid the water outage.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a highly convenient pump device capable of suppressing a protective stop at the start of a pump and avoiding a water outage as much as possible.

(1) The pump device according to one aspect of the present invention includes a pump, an electric motor for driving the pump, an inverter device for supplying power to the electric motor, and a control device for outputting a control signal of the pump to the inverter device. The control device includes an input unit for inputting the discharge pressure of the pump and a storage unit for storing the values of control parameters related to the drive control of the electric motor. The control device has, as a condition for starting the pump, a first starting condition in which the discharge pressure is lowered from a pressure higher than a predetermined starting pressure to a pressure equal to or lower than the starting pressure, and the first starting condition. Estimates the minimum value of the discharge pressure after the pump is started, sets the value of the control parameter according to the minimum value, and when the first starting condition is satisfied, the minimum value is reached. The pump is started based on the value of the control parameter set accordingly.
According to this configuration, the minimum value of the discharge pressure after the pump is started is estimated under the first starting condition, the value of the control parameter is set according to the minimum value, and then the value of the control parameter is used. Since the pump is started, it is possible to prevent the pump from reaching a protective stop under unstable conditions at the time of starting the pump, and it is possible to avoid water outage as much as possible.

(2) In the pump device according to (1) above, the control device may estimate the minimum value based on the inclination at which the discharge pressure decreases under the first starting condition.
In this case, since the minimum value is estimated based on the slope at which the discharge pressure of the pump drops under the first starting condition, it depends on various conditions such as the height of the water supply destination, the pipeline resistance, or the amount of water used. The corresponding appropriate minimum value can be estimated.

(3) The pump device according to (1) or (2) above, wherein the control parameter includes a torque boost voltage applied to the motor at the start of the pump, and the control device is the control device. The pump may be started by setting the torque boost voltage to a value corresponding to the magnitude of the minimum value.
In this case, the larger the torque boost voltage, the larger the starting torque of the motor. Therefore, the torque boost voltage is set to a value corresponding to the magnitude of the minimum value estimated when the first starting condition is satisfied. As a result, it is possible to eliminate the torque shortage that occurs transiently when the pump is started, and to suppress the protection stop when the pump is started.

(4) In the pump device according to (3) above, the control parameter includes an overcurrent protection level which is a threshold value of an overcurrent trip, and the control device corresponds to the torque boost voltage. The overcurrent protection level may be set to start the pump.
In this case, the larger the torque boost voltage, the larger the current flowing through the inverter device when the pump is started. Therefore, by setting the overcurrent protection level corresponding to the torque boost voltage, the pump is protected by overcurrent protection. It is possible to suppress the stoppage and avoid the water outage as much as possible.

(5) In the pump device according to (1) to (4) above, the control parameter includes a soft start time which is an increase rate of the rotation speed of the electric motor, and the control device is the control device. The pump may be started by setting the soft start time to a value corresponding to the magnitude of the minimum value.
In this case, the longer the soft start time, the more the acceleration of the motor can be suppressed and the current flowing through the inverter device during acceleration can be suppressed. Therefore, when the soft start time is satisfied when the first start condition is satisfied. By setting the value according to the magnitude of the estimated minimum value, it is possible to prevent the current flowing through the inverter device from reaching the overcurrent protection level when the pump is started, and to prevent the protection from stopping when the pump is started. can do.

(6) The pump device according to (1) to (5) above, wherein the control device is a protection for causing the pump to stand by in a stopped state as a protection for the pump device as a condition for starting the pump. After releasing the stop, the second starting condition may be provided in which the discharge pressure is equal to or lower than the starting pressure.
In this case, the water cutoff can be avoided as much as possible by restarting (retrying) the pump that has been protected and stopped according to the second starting condition.

(7) In the pump device according to (6) above, the control device counts the number of times the pump is started under the second starting condition as the number of retries, and sets the size to the minimum value. The value of the control parameter set accordingly is changed according to the number of retries, and when the second start condition is satisfied, the pump is operated based on the value of the control parameter changed according to the number of retries. You may start it.
In this case, in the second starting condition for restarting (retrying) the pump that has stopped protection, the value of the control parameter set according to the magnitude of the minimum value estimated when the first starting condition is satisfied is set. Since the change is made according to the number of retries, the probability that the pump can recover from the protection stop state increases as the number of retries increases.

(8) The pump device according to (7) above, wherein the control device sets a coefficient for changing the value of the control parameter according to the number of retries according to the magnitude of the minimum value. The pump may be started with correction.
In this case, the pump is protected and stopped by correcting the coefficient for changing the value of the control parameter according to the magnitude of the minimum value of the discharge pressure estimated when the first starting condition is satisfied. The probability of recovering from the state can be increased.

(9) The pump device according to (6) to (8) above, wherein the control device counts the number of times the pump is started under the second starting condition as the number of retries, and also counts the number of retries of the pump. The interval time from when the protection stop is released to when the pump is restarted is changed according to the number of retries, and when the second starting condition is satisfied, the interval time is changed according to the number of retries. The pump may be started based on the above.
In this case, the longer the interval time, the lower the discharge pressure of the pump and the lower the starting torque of the motor. Therefore, by changing the interval time according to the number of retries, each time the number of retries increases. , The probability that the pump can recover from the protection stop state increases.

(10) The pump device according to (9) above, wherein the control device corrects a coefficient for changing the interval time according to the number of retries according to the magnitude of the minimum value. The pump may be started.
In this case, by correcting the coefficient for changing the interval time according to the magnitude of the minimum value of the discharge pressure estimated when the first starting condition is satisfied, the pump is protected from the stopped state. You can increase the probability of returning.

(11) The pump device according to (6) to (10) above, wherein the control device counts the number of times the pump is started under the second starting condition as the number of retries, and the number of retries. Depending on the situation, the electric motor may be rotated in a direction opposite to the normal rotation direction.
In this case, in the normal rotation direction, even if the cause of the abnormality (for example, sticking of the impeller or biting of foreign matter) is not removed, the motor is rotated in the direction opposite to the normal rotation direction. , There are cases where the cause of the abnormality is removed. As a result, it is possible to suppress the protection stop of the pump.

(12) The pump device according to the above (6) to (11), wherein the control device sets the value of the control parameter according to the magnitude of the minimum value, and the second start condition is the same. The pump may be started by changing according to the discharge pressure when the filling is performed.
In this case, the value of the control parameter set according to the magnitude of the minimum value estimated when the first starting condition is satisfied is changed according to the discharge pressure when the second starting condition is satisfied. Therefore, the probability that the pump can recover from the protection stop state increases.

(13) The pump device according to (6) to (12) above, wherein the control device has the starting pressure as the discharge pressure after the protection stop is released as a condition for starting the pump. It may have a third starting condition that is less than or equal to the retry start pressure set to less than.
In this case, when the third starting condition is satisfied, the discharge pressure of the pump is lowered to the retry starting pressure or less, so that it is possible to suppress the protection stop due to insufficient torque at the time of starting the pump.

According to the above aspect of the present invention, it is possible to obtain a highly convenient pump device capable of suppressing the protection stop when the pump is started and avoiding water interruption as much as possible.

It is a front view which shows an example of the pump device 1 which concerns on embodiment of this invention. It is a vertical sectional view which shows an example of the internal structure of the pump casing 30 which concerns on embodiment of this invention. It is a block diagram which shows an example of the schematic structure of the pump device 1 which concerns on embodiment of this invention. It is a block diagram which shows an example of the structure of the control unit 4 which concerns on embodiment of this invention. It is a block diagram which shows an example of the structure of the control device 60 which concerns on embodiment of this invention. It is a control flow which shows an example of the automatic control executed by the control device 60 which concerns on embodiment of this invention. It is a time chart which shows an example of the relationship between the discharge pressure PV of a pump 2 and the voltage applied to a motor 3 which concerns on 1st Embodiment. It is a control flow which shows an example of the pump start operation executed by the control device 60 which concerns on 1st Embodiment. 6 is a time chart showing an example of the relationship between the discharge pressure PV of the pump 2 according to the first modification of the first embodiment, the voltage applied to the motor 3, and the current flowing through the inverter device 70. It is a control flow which shows an example of the retry operation executed by the control device 60 which concerns on the 1st modification of 1st Embodiment. 9A is a control flow showing an example of a process of calculating the torque boost voltage in step S13-1 of FIG. 9A. It is a control flow which shows an example of the retry operation executed by the control device 60 which concerns on the 2nd modification of 1st Embodiment. 3 is a time chart showing an example of the relationship between the discharge pressure PV of the pump 2 according to the second embodiment and the command frequency by the inverter control unit 60b of the control device 60. It is a control flow which shows an example of the retry operation executed by the control apparatus 60 which concerns on 2nd Embodiment. It is a control flow which shows an example of the process of calculating the interval time of step S33-1 of FIG. 12A. It is a control flow which shows an example of confirmation of the 3rd start condition executed by the control apparatus 60 which concerns on 1st modification of 2nd Embodiment. It is a flow which shows the modification of the process executed from step S107 (protection stop) to step S109 (retry operation) of FIG. 5B which concerns on the 1st modification of 2nd Embodiment. It is a time chart which shows an example of the relationship between the discharge pressure PV of the pump 2 which concerns on the 2nd modification of 2nd Embodiment, and the command frequency from a control device 60 to an inverter control part 60b. It is a control flow which shows an example of the retry operation executed by the control device 60 which concerns on the 2nd modification of 2nd Embodiment. It is a control flow which shows an example of the process of calculating the soft start time of step S53-1 of FIG. 15A. It is a control flow which shows an example of the retry operation executed by the control device 60 which concerns on the 2nd modification of 2nd Embodiment. It is a control flow which shows an example of the control parameter initialization executed by the control apparatus 60 which concerns on 3rd Embodiment. It is a schematic diagram which shows the 1st use example of the pump device 1 of this disclosure. It is a schematic diagram which shows the 2nd use example of the pump device 1 of this disclosure. It is a schematic diagram which shows the 3rd use example of the pump device 1 of this disclosure.

Hereinafter, an embodiment of the pump device will be described with reference to the drawings.

FIG. 1 is a front view showing an example of a pump device 1 according to an embodiment of the present invention. FIG. 2 is a vertical sectional view showing an example of the internal structure of the pump casing 30 according to the embodiment of the present invention.
As shown in FIG. 1, the pump device 1 includes a pump 2 for pumping water, an electric motor 3 (see FIGS. 3 and 4 described later) provided on the back side of the pump 2 to drive the pump 2, and the pump 2. A control unit 4 that controls the operation, a pressure sensor 42 that detects the discharge pressure of the pump 2 (see FIGS. 2 and 3 described later), and a pressure tank 43 that holds the discharge pressure of the pump 2 (FIG. 3 described later). See) and. The pump 2, the electric motor 3, and the control unit 4 are supported by the unit base 5, and are substantially entirely covered by the unit cover 6.

The pump 2 is a cascade pump also referred to as a friction pump, and as shown in FIG. 2, has an impeller 20 and a pump casing 30 forming a pump chamber 31 for accommodating the impeller 20. As shown in FIG. 1, a pump casing cover 50 is attached to the front side of the pump casing 30, and the impeller 20 can be accessed by removing the cover. As shown in FIG. 2, the impeller 20 is formed in a disk shape having a large number of grooves 21 cut in the peripheral portion, and the peripheral portion causes the water existing in the pump chamber 31 to rotate substantially once. However, it boosts the pressure.

Although the pump 2 is small, a single impeller 20 can obtain a lift comparable to that of a centrifugal pump with several stages, and is suitable for the purpose of small capacity and high lift. Further, since the cascade pump has self-priming property, it is suitable for pumping water or well water stored in a water receiving tank installed at a position lower than the pump 2.

As shown in FIG. 1, a suction port 7 exposed from the unit cover 6 and a discharge port 8 are provided on the front surface of the pump device 1. The suction port 7 communicates with one end 32a of the internal flow path 32 formed inside the pump casing 30 shown in FIG. 2, and the discharge port 8 communicates with the other end 32b of the internal flow path 32. There is. A pump chamber 31 and a steam separation chamber 33 are formed in the internal flow path 32.

A flow check valve 35 is provided in the suction flow path 34 from one end 32a to the pump chamber 31 of the internal flow paths 32. The flow check valve 35 is provided at a position higher than the pump chamber 31, and before driving the pump 2, the inside of the pump chamber 31 is filled with water to secure the water level required for self-priming, and when the pump 2 is stopped. It has a role of preventing backflow of water and always filling the pump chamber 31 with water. That is, the flow check valve 35 closes the suction flow path 34 by its own weight when the pump 2 is stopped, and is pushed up by water (including air at the time of starting) that comes up the suction flow path 34 when the pump 2 is driven. And open the suction flow path 34.

A steam separation chamber 33 is arranged on the downstream side of the pump chamber 31. Of the internal flow paths 32, a baffle 37 with which the liquid discharged from the pump chamber 31 collides is arranged in the connection flow path 36 between the pump chamber 31 and the steam separation chamber 33. At the bottom of the air-water separation chamber 33, a hole 33a communicating with the pump chamber 31 is formed. The hole 33a returns the water separated from the air in the air-water separation chamber 33 to the pump chamber 31 again during the self-priming operation at the start of the pump 2, thereby generating a negative pressure in the pump chamber 31. , Eliminates the air in the suction flow path 34 and sucks up water.

A priming port 38 is formed above the air-water separation chamber 33. The priming port 38 is closed by the priming faucet 39. The priming faucet 39 is opened before the start of the pump 2 in a state where the pump casing 30 is not filled with water at the time of installing the pump 2 or the like, and the priming water is injected from the priming port 38 to generate air water. The separation chamber 33 is full up to the water level 40 at the time of priming. When the self-priming operation is performed by driving the pump 2 described above, the air in the suction flow path 34 disappears, and the water rises, the self-priming operation ends and the air-water separation chamber 33 and the air-water separation chamber 33 After the downstream side is filled with water, the pump 2 is driven to perform the pumping operation.

Of the internal flow paths 32, a pressure sensor 42 is provided in the discharge flow path 41 from the air-water separation chamber 33 to the other end 32b. The pressure sensor 42 is arranged above the priming water level 40, completes the self-priming operation, and detects the pressure (discharge pressure) of the discharge flow path 41 filled with water.

Further, the discharge flow path 41 is provided with a pressure tank 43. The pressure tank 43 has a rubber bladder built in the pressure-resistant container, and when the pressure in the discharge flow path 41 rises, the air outside the bladder is compressed and water is stored in a pressurized state. Further, for example, as the pressure in the discharge flow path 41 decreases with the use of water, the compressed air expands and the stored water is pushed out to the discharge flow path 41. In this way, immediately after the pump 2 is started, water can be supplied from the pressure tank 43 to the discharge flow path 41 for a while even if the rotation speed has not risen sufficiently for water supply.

FIG. 3 is a block diagram showing an example of a schematic configuration of the pump device 1 according to the embodiment of the present invention. FIG. 4 is a block diagram showing an example of the configuration of the control unit 4 according to the embodiment of the present invention. FIG. 5A is a block diagram showing an example of the configuration of the control device 60 according to the embodiment of the present invention.
As shown in FIG. 3, the control unit 4 includes an inverter device 70 that supplies electric power to the electric motor 3, and a control device 60 that outputs a control signal to the inverter device 70 to control the operation of the pump 2. A commercial power source 100 is connected to the inverter device 70, and the AC power supplied from the commercial power source 100 is converted into AC power having a desired frequency by the inverter device 70 and supplied to the electric motor 3. As shown in FIG. 3, the flow check valve 35 described above includes a check valve 35a that prevents backflow of water and a flow sensor 35b that detects a decrease in the flow rate of water flowing through the pump 2 (underwater amount Qmin or less). , Have.

As shown in FIG. 5A, the control device 60 includes an I / O unit 61, a calculation unit 62, and a storage unit 63 (control memory). The I / O unit 61 is connected to various sensors such as a pressure sensor 42, a flow sensor 35b, a voltage sensor 71, a current sensor 72, and temperature sensors 80, 81, 82, and is an input unit for inputting detection results of the various sensors. The 61a is provided, and the detection result input by the input unit 61a is output to the calculation unit 62. Further, the I / O unit 61 includes an output unit 61b, and the control device 60 outputs a command signal (for example, the rotation speed of the pump 2) from the calculation unit 62 to the inverter device 70 via the output unit 61b. Further, the I / O unit 61 may be provided with an external output terminal (not shown) that outputs the state of the pump device 1 to the outside by using a contact signal or communication, or the user selects that the pump device 1 cannot be operated. Alternatively, it may be provided with a contact input that can be released. The arithmetic unit 62 of the control device 60 is realized by, for example, a CPU (central processing unit), and various control programs of the pump device 1 are executed. The calculation unit 62 calculates a command signal to be output to the inverter device 70 based on the detection results of various sensors and the like input via the I / O unit 61, and transmits the command signal to the I / O unit 61. Output. The I / O unit 61 may input / output by a contact signal or an analog signal, or may input / output by wireless or wired communication.

The calculation unit 62 of the control device 60 executes various control programs stored in the storage unit 63 based on the information input from the I / O unit 61 and the information of the storage unit 63. As an example of the control program executed by the calculation unit 62, the operation stop of the pump 2 is instructed by the signal of the discharge pressure PV and the insufficient water amount Qmin of the flow sensor 35b, or the set pressure PA is received by the discharge pressure PV. The known discharge pressure constant control or estimated terminal pressure constant control is calculated, the target pressure SV is calculated, and the rotation speed of the pump 2 is set so that the current discharge pressure PV becomes the target pressure SV. Control. Further, the calculation unit 62 obtains information (discharge pressure, rotation speed, integrated operation time, integrated operation number, etc.) indicating the state of the pump device 1 and stores it in the storage unit 63. The storage unit 63 stores various memories for storing information of the I / O unit 61, various control programs executed by the arithmetic unit 62, various information used by the arithmetic unit 62, various information obtained by the arithmetic unit 62, and the like. Be prepared. The I / O unit 61, the calculation unit 62, and the storage unit 63 of the control device 60 described above may be provided in each of the pump control unit 60a and the inverter control unit 60b, or may be used in combination.

Further, the control device 60 may include an operation panel 64 and a communication unit 65. The operation panel 64 includes a setting unit 64a and a display unit 64b. The setting unit 64a is composed of, for example, an operation button, a switch, a touch panel, or the like, and the user of the pump device 1 can deselect the pump device 1 from being inoperable or change the set pressure via the setting unit 64a. Various information stored in the storage unit 63 of the above can be set and changed. The display unit 64b is composed of, for example, a 7-segment LED, an indicator lamp, a liquid crystal display, or the like, and the user of the pump device 1 visually recognizes various information of the pump device 1 stored in the storage unit 63 via the display unit 64b. be able to.

The communication unit 65 communicates with an external device such as an external terminal 66 by an arbitrary communication method of wired (RS485, RS232C, USB, etc.) or wireless communication (NFC, Bluetooth (registered trademark), Wi-Fi, etc.). .. Examples of information transmitted and received by the communication unit 65 include a control program for controlling the pump device 1, device information of the pump device 1, set value information, maintenance information, history information, abnormality information, operation information, and the like. The operation panel 64 and the communication unit 65 may be provided in each of the pump control unit 60a and the inverter control unit 60b, or may be used in combination. Further, the control device 60 may include a plurality of communication units 65. For example, the arithmetic unit 62 and the operation panel 64 may be composed of separate boards, the operation panel 64 may include a CPU and a communication unit, and may be connected to the arithmetic unit 62 via the communication unit 65. The arithmetic unit 62 and the communication unit 65 may be configured on separate boards.

The external terminal 66 may be, for example, a general-purpose device such as a PDA, or a dedicated terminal such as a remote monitor. The external terminal 66 acquires various information about the pump device 1 stored in the storage unit 63 by communication with the communication unit 65 and displays it on the display operation unit 67. Further, the external terminal 66 transmits a change request of various information stored in the storage unit 63 of the pump device 1 to the communication unit 65 by the operation of the display operation unit 67 of the user.

Here, the various information stored in the storage unit 63 includes at least information for controlling the pump 2 (stop pressure P1, set pressure PA, target pressure SV, starting pressure P0, etc.) and drive control of the electric motor 3 described later. Includes control parameters related to. When the storage unit 63 is provided in each of the pump control unit 60a and the inverter control unit 60b, at least the information for controlling the pump 2 is stored as a set value in the storage unit of the pump control unit 60a, and the inverter control is performed. At least the control parameters related to the drive control may be stored in the storage unit of the unit 60b. The control parameters related to the drive control of the motor 3 include the torque boost voltage, the overcurrent protection level, the soft start time, the interval time, which will be described in detail later, and further, the maximum frequency, the base frequency, the acceleration time, and the like. It is preferable to include the deceleration time, the electronic thermal operation level, the number of electronic thermal retries, the stall prevention operation level, the inverter rated current value, the operation start frequency, and the like.

As shown in FIG. 4, the control device 60 includes a pump control unit 60a and an inverter control unit 60b. The pump control unit 60a and the inverter control unit 60b may be provided with the above-mentioned I / O unit 61, calculation unit 62, storage unit 63 (control memory), operation panel 64, and communication unit 65, respectively. , Partial or all may be used together. The pump control unit 60a and the inverter control unit 60b may be connected by communication or a signal line, or may share various information via a common storage unit.

As described above, the signal of the flow sensor 35b and the measured value of the pressure sensor 42 are input to the pump control unit 60a so that the discharge pressure PV of the pump 2 becomes the target pressure SV. A command for starting, stopping, and target rotation speed of the pump 2 is issued to the inverter control unit 60b. Further, it is preferable to calculate the control parameters related to the drive control of the electric motor 3 described later and send the control parameters to the inverter control unit 60b. Specifically, the inverter control unit 60b starts the pump 2 based on the control parameters related to the drive control of the motor 3, and further commands based on the target rotation speed of the pump 2 sent from the pump control unit 60a. The frequency is calculated, and a PWM signal for minimizing the difference between the command frequency and the actual frequency of the motor 3 is generated.

The inverter device 70 is an inverter circuit that generates an AC voltage based on a PWM signal from the inverter control unit 60b and applies this AC voltage to the electric motor 3. The converter unit 70a, the DC voltage smoothing circuit 70b, and the inverter unit. It includes a 70c and a gate driver 70d. The converter unit 70a has a rectifier circuit composed of a diode or the like in order to convert a three-phase AC voltage supplied from the commercial power source 100 into a DC voltage. The DC voltage smoothing circuit 70b includes a capacitor and smoothes the DC voltage converted by the converter unit 70a.

The inverter unit 70c has a plurality of power elements such as IGBTs (insulated gate bipolar transistors) and diodes connected in parallel to the power elements, and has three phases from the DC voltage smoothed by the DC voltage smoothing circuit 70b. It is configured to generate an AC voltage. The gate driver 70d generates a gate drive signal for switching each power element of the inverter unit 70c based on the PWM signal from the inverter control unit 60b.

A voltage sensor 71 arranged on the secondary side of the inverter circuit and a current sensor 72 are connected to the inverter control unit 60b. The measured values of the voltage and the current obtained by the voltage sensor 71 and the current sensor 72 are input to the inverter control unit 60b. The inverter control unit 60b estimates the actual rotation speed of the motor 3 (and the pump 2) from the measured value of the fed back current, and PWM for minimizing the difference between the estimated rotation speed and the target rotation speed. Generate a signal. If the control device 60 can predict the voltage and current on the secondary side of the inverter circuit, the voltage sensor 71 and the current sensor 72 may be omitted.

Further, although the current flowing through the inverter device 70 used in the following description indicates the current on the secondary side of the inverter circuit, the current flowing through the motor 3 may be used instead. Further, in the present embodiment, "Vf control" may be performed in which the voltage and frequency output from the inverter control unit 60b to the motor 3 are in a substantially direct proportional relationship. Here, when the output frequency becomes low, the influence of the voltage drop becomes large and the torque decreases. Therefore, in order to increase the output voltage in the low frequency region in order to compensate for it, the control device 60 includes the pump control unit 60a and the outside. It has a torque boost voltage as one of the control parameters that can be set and changed by input.

In FIG. 4, temperature sensors 80, 81, and 82 for measuring these temperatures are attached to the pump 2, the electric motor 3, and the inverter device 70, respectively. When the measured value of at least one of the temperature sensors 80, 81, 82 reaches a predetermined upper limit, the pump control unit 60a lowers the rotation speed of the pump 2 or heats the pump as compared with the normal operation. A command may be issued to the inverter control unit 60b to stop the engine as a protection.

The control device 60 described above automatically stops the operation of the pump when the inoperability of the pump device 1 is not selected. Specifically, the control device 60 has a predetermined starting condition for starting the pump 2, and when the starting condition is satisfied, the control device 60 outputs a control signal to the inverter device 70 to start the pump 2. , The operation of the pump 2 is controlled, and the pump 2 is stopped when the stop condition is satisfied.

FIG. 5B is a control flow showing an example of automatic control executed by the control device 60 according to the embodiment of the present invention.
The control flow of FIG. 5B is that the pump 2 is operated after the pump device 1 is installed, after the abnormality is cleared, or after the inoperability of the pump device 1 is cleared by the user, and the like. It is preferable to start after the discharge pressure PV of the pump 2 (see FIG. 6 described later) reaches a predetermined stop pressure P1 (see FIG. 6 described later). Further, when the control flow of FIG. 5B is started, the pump 2 is stopped.

First, the control device 60 determines whether or not the first starting condition is satisfied (step S101). The first starting condition is to start the pump 2 at the time of a small stop restart when the discharge pressure PV of the pump 2 drops from a pressure higher than a predetermined starting pressure P0 (see FIG. 6 described later) to a starting pressure P0 or less. It is a condition. For example, the first starting condition is satisfied by opening the faucet of the water supply destination. The starting pressure P0 may be a set value that can be changed by the user.

When the first start condition is not satisfied (when step S101 is "NO"), the control device 60 waits until the first start condition is satisfied. On the other hand, when the first start condition is satisfied (when step S101 is "YES"), the pump 2 is started as a small stop restart (step S102). Specifically, in the small stop restart in step S102, the control device 60 sets the value of the control parameter related to the drive control of the electric motor 3 described later, and starts the pump 2 based on the value of the control parameter. .. When the pump 2 is stopped and restarted, the torque required at the time of starting differs on the motor 3 side depending on the variation in the performance of the electronic components of the control device 60, the usage status of the pump 2, the installation environment, and the like. Therefore, it is advisable to change the control parameters related to the drive control of the electric motor 3 to restart the pump 2 at a small stop. From the start of the pump 2 to the stop of the pump 2, the control device 60 outputs an operation command to the inverter device 70.

After starting the pump 2 in step S102, when the pump 2 performs a pumping operation and determines that the pump 2 has started normally (when “YES” in step S103), the control device 60 controls the pump 2 with a constant discharge pressure. (Step S104). As an example of the method of controlling the rotation speed of the pump 2 in step S104, the pump 2 is controlled so that the target pressure SV is set to a predetermined set pressure PA and the discharge pressure PV of the pump 2 is set to the set pressure PA. Constant pressure control, estimation that the pump 2 is controlled so that the target pressure SV is calculated so that the pressure at the end of the water supply destination becomes the predetermined set pressure PA, and the discharge pressure PV of the pump 2 is the calculated target pressure SV. Constant end pressure control, constant current control that controls the pump 2 so that the value of the current sensor 72 becomes a predetermined value, and pumping so that the discharge flow rate of the pump 2 becomes a predetermined value using a flow meter (not shown). Examples include constant flow rate control for controlling 2 and constant rotation rate control for controlling the pump 2 so that the rotation speed of the electric motor 3 becomes a predetermined value. In the following description, as an example, it will be described that the discharge pressure is constantly controlled in step S104.

Next, the control device 60 determines whether or not the flow rate of the water flowing through the pump 2 is equal to or less than the insufficient water amount (step S105). Specifically, when the amount of water used at the water supply destination decreases and the flow sensor 35b detects that the amount of water is less than Qmin, the flow rate of water flowing to the pump 2 is less than or equal to the amount of water (YES in step S105). "). When step S105 is "YES", the pump 2 whose flow rate of water flowing to the pump 2 is equal to or less than the insufficient water amount is stopped (step S106).

That is, the stop condition of the pump 2 includes a case where the flow rate of the water flowing through the pump 2 is equal to or less than the insufficient water amount (small water amount stop: step S106). For example, when the faucet of the water supply destination is closed and the amount of water used at the water supply destination decreases, and the flow sensor 35b detects that the water amount is less than Qmin (when step S105 is "YES"), the pump 2 The pump 2 is stopped on the assumption that the stop condition is satisfied.

Here, the small water amount stop in step S106 will be described. In step S106, the control device 60 performs a pressure accumulator operation for controlling the rotation speed of the pump 2 so that the discharge pressure PV reaches the stop pressure P1 in a predetermined time, and when the discharge pressure PV reaches the stop pressure P1 or higher, It is determined that the pressure can be accumulated in the pressure tank 43, the accumulator operation is terminated, and the operation of the pump 2 is stopped. The stop pressure P1, which is the target pressure SV when the small amount of water is stopped, is a set value that can be set and changed by the user, and is set to a value higher than the start pressure P0 and the set pressure PA. Then, after stopping the pump 2 with a small amount of water in step S106, the process returns to step S101.

Then, when water is used again in the building to which the pump 2 is supplied after the small amount of water is stopped, the discharge pressure PV drops to the starting pressure P0 or less, and the first starting condition is satisfied (step S101 is "step S101". YES ”), a small stop restart at which the pump 2 starts (step S102). At the time of restarting the small stop, the discharge pressure PV of the pump 2 can be maintained by supplying water with the water stored in the pressure tank 43 until the pump 2 rises to a rotation speed at which water can be supplied. can. Further, as a method for detecting the underwater amount in step S105, other means such as a low load based on the current value of the motor 3 and a deadline head may be used without using the detection of the underwater amount Qmin or less of the flow sensor 35b.

In step S105, when the flow rate of the water flowing to the pump 2 is not less than or equal to the insufficient amount of water (when step S105 is "NO"), the control device 60 assumes that the water is being used continuously at the water supply destination, and is assumed to be continued in step S105. Judge whether it is a protection stop condition or not in -1. If the protection stop condition is affirmative (step S105-1 is “YES”), the control device 60 protects and stops the pump 2 (step S107). Specifically, the pump 2 is used when a current of a predetermined overcurrent protection level or higher flows through the inverter device 70 (overcurrent trip) or when the temperature of the pump 2 exceeds a predetermined value (pump overheat protection). When it is determined that some kind of trouble has occurred in which the operation cannot be continued at the specified lift, the judgment of affirmation of the protection stop condition is made. If the protection stop condition is negative (step S105-1 is "NO"), the process returns to step S104 to continue water supply.

Here, the explanation is returned to step S103. If it is determined in step S103 that the pump 2 cannot be started when the pump 2 is started (when step S103 is "NO"), the control device 60 stops the pump 2 as a protective stop (step S107). Specifically, when the impeller 20 cannot rotate to a rotation speed at which water can be pumped at a predetermined specified head due to some trouble such as an overcurrent trip or pump overheat protection, the control device 60 determines that the pump 2 cannot be started. (Step S103 is "NO"), and the process proceeds to the protection stop of step S107.

In the protection stop of step S107, the pump 2 is made to stand by in the stopped state in order to protect each device in the pump device 1 such as the electric motor 3, the inverter device 70, and the pump 2. Specifically, regardless of whether or not the impeller 20 of the pump 2 is rotating, the control device 60 stops the operation command and outputs the stop command to the inverter device 70 whose protection is stopped, and determines the predetermined value. The output of the stop command is continued until the cancellation condition of is satisfied. The condition for canceling the protection suspension may be a predetermined time or may be due to a defect leading to the protection suspension. For example, if protection is stopped due to an overcurrent trip, protection is continued for a predetermined time, and if protection is stopped due to pump overheat protection, protection is performed until the temperature of pump 2 falls below a predetermined value. The control device 60 stops the pump 2 until it is determined that the cause of the malfunction has been resolved, such as continuing the stop. Hereinafter, as the protection of the pump device 1, the operation in which the control device 60 puts the pump 2 on standby in the stopped state is referred to as "protection stop".

When the recovery condition for the protection stop is satisfied in step S107 and the protection stop is released, the control device 60 next determines whether or not the second start condition is satisfied (step S108). Until the second start condition is satisfied (step S108 is “NO”), the process returns to step S107 and waits in a protected state (step S107). On the other hand, when the second start condition is satisfied (when step S108 is “YES”), the control device 60 executes a retry operation for restarting the pump 2 (step S109). In this way, by restarting (retrying) the pump 2 that has been protected and stopped according to the second starting condition, the pump device 1 can avoid water outage as much as possible.

Specifically, the second starting condition in step S108 is the starting condition of the pump 2 in which the discharge pressure PV is equal to or less than the starting pressure P0 after the protection stop of the pump 2 is released. After releasing the protection stop, if the discharge pressure PV of the pump 2 is equal to or less than the predetermined starting pressure P0, the control device 60 satisfies the second starting condition (step S108 is “YES”) and sets the pump 2 to A retry operation (step S109) for restarting is performed. Although the details will be described later, in the retry operation in step S109, the control device 60 sets the value of the control parameter related to the drive control of the electric motor 3 according to the number of retries, the discharge pressure PV, and the like, and then controls the set. A signal for starting the pump 2 based on the value of the parameter is output to the inverter device 70. Even when the pump 2 is started by the retry operation, the torque required on the motor 3 side differs depending on the variation in the performance of the electronic components of the control device 60 and the usage status (environment) of the pump 2. Therefore, if the control parameter is changed and the pump 2 is started, the protection stop of the pump 2 can be suppressed. During the retry operation in step S109, at least one of the operation panel 64 and the external terminal 66 may be displayed to indicate that the retry is in progress.

Next, the control device 60 determines whether or not the pump 2 has been normally started by the retry operation (step S110). Specifically, when the impeller 20 rotates to a rotation speed at which water can be pumped and the pump 2 performs the pumping operation, the control device 60 determines that the pump 2 has started normally (step S110 is "YES"). However, if it is determined that the impeller 20 cannot rotate to a rotation speed at which the pump can be pumped due to some trouble such as an overcurrent trip or pump overheat protection, it is determined that the pump 2 does not start normally (step S110 is "NO"). do. When the control device 60 determines that the pump 2 has normally performed the pumping operation at the specified head by the retry operation and has started (when step S110 is "YES"), the control device 60 operates the pump 2 (step S104).

On the other hand, when the pump 2 is not normally started due to the retry operation (when step S110 is "NO"), the control device 60 determines whether or not the retry is completed (step S111). In the retry operation described in detail later, the number of times of continuous retry operation (step S109) is counted as the number of retries, and when the number of retries reaches a predetermined N times, the end of retries is confirmed. When the number of retries is less than N (step S111 is “NO”), the control device 60 returns to the protection stop in step S107. If the retry is completed (the number of retries is N) in step S111 (when step S111 is “YES”), the failure of the pump 2 is confirmed (step S112), and the control flow of FIG. 5B is terminated. Here, after the failure of the pump 2 is confirmed, the control device 60 may display the failure on at least one of the operation panel 64 and the external terminal 66. The failure-determined pump 2 may be disabled until the user presses the reset button or performs a failure reset operation such as restarting the power supply.

Here, as the stop condition of the pump 2, in addition to the conditions leading to the above-mentioned small water volume stop in step S106 and the protection stop in step S107, non-operation is selected by the user's operation, and the control device 60 controls in FIG. 5B. It is good to include the case where the flow is interrupted. That is, even though the pump 2 is operating during the operation of the pump 2 (step S104), the retry operation (step S109), or the accumulator operation of the small water volume stop (step S106), the user can use the operation panel 64. Alternatively, when the non-operation is selected via the I / O unit 61, the control device 60 immediately stops the pump 2 without performing the accumulator operation. Then, the control device 60 makes the pump 2 stand by in a stopped state until the user cancels the inoperability of the pump device 1.

In the following embodiments and modifications, among the operations of the pump device 1 configured as described above (control method of the pump device 1), specifically, the pump 2 is operated due to insufficient torque at the start of the electric motor 3. The control flow of the control device 60 for suppressing the protection stop (step S107) and avoiding the water outage due to the determination of the abnormality in step S112 will be described in detail.

(First Embodiment)
FIG. 6 is a time chart showing an example of the relationship between the discharge pressure PV of the pump 2 and the voltage applied to the motor 3 according to the first embodiment. In the time chart shown in FIG. 6A, the vertical axis represents the pressure and the horizontal axis represents the elapsed time, indicating the change in the discharge pressure PV with the elapsed time. In the time chart shown in FIG. 6B, the vertical axis represents voltage and the horizontal axis represents elapsed time, and shows changes in the voltage applied to the motor 3 by the control device 60 with the passage of time. Further, the solid line and the dotted line in FIG. 6 indicate that water is used at the water supply destination at the time of restarting the small stop and the discharge pressure PV decreases (step S101 is “YES”), and further, the pump 2 is started (step S103 is). “YES”), and the change in the discharge pressure PV when water is supplied by the pumping operation of the pump (step S104) is shown. FIG. 7 is a control flow showing an example of a pump starting operation executed by the control device 60 according to the first embodiment, and is a control flow showing details of the control flow of FIG. 5B from steps S101 to S103. ..

In FIG. 6, when the pump 2 stopped the small amount of water last time (step S106), the discharge pressure PV of the pump 2 pressurized to the stop pressure P1 drops from a pressure higher than the starting pressure P0 to a starting pressure P0 or less. (Step S101 is “YES”), and after the pump 2 is stopped and restarted (step S102), the pump operation (step S104) is exemplified. As shown in FIG. 7, the control device 60 first determines whether or not the discharge pressure PV of the pump 2 drops to the pressure level PL0, which is a predetermined threshold value, based on the measured value of the pressure sensor 42. (Step S1). Here, the pressure level PL0 is preferably a pressure value lower than the stop pressure P1 and a pressure value higher than the start pressure P0.

When the discharge pressure PV of the pump 2 does not drop to the pressure level PL0 (when step S1 is “NO”), the control device 60 waits until the discharge pressure PV of the pump 2 drops to the pressure level PL0. When the discharge pressure PV of the pump 2 drops to the pressure level PL0 (when step S1 is “YES”), the control device 60 starts measuring the time ΔT (step S2). The time ΔT is the time until the discharge pressure PV of the pump 2 drops from the pressure level PL0 to the starting pressure P0. In the next step S3, the control device 60 determines whether or not the discharge pressure PV of the pump 2 drops to the starting pressure P0, and the discharge pressure PV of the pump 2 does not drop to the starting pressure P0. In the case (when step S3 is “NO”), the process returns to step S2, the measurement of the return time ΔT is continued, and the pump 2 waits until the discharge pressure PV drops to the starting pressure P0. That is, the steps S1 to S3 are in a state of stopping the small amount of water waiting until the starting condition of the pump 2 is satisfied (step S101 in FIG. 5B is "YES").

When the first starting condition of the pump 2 is satisfied (step S3 is “YES”) by reducing the discharge pressure PV of the pump 2 to the starting pressure P0, step S101 of FIG. 5B becomes “YES” and is controlled. The device 60 estimates the minimum value of the discharge pressure PV after the pump 2 is started (step S4). Then, the pressure level in the starting discharge pressure PS, which is the lowest value of the estimated discharge pressure PV, is determined (steps S4-1 to S4-2).

Here, in the example shown by the solid line in FIG. 6, the time ΔT from the timing of “YES” in step S1 until the discharge pressure PV of the pump 2 becomes the starting pressure P0 or less is ΔT1 and is discharged at the time of starting. The pressure PS is PS1, and power is supplied to the motor 3 with a delay of ΔT1 from the pressure level PL0. Further, in the example shown by the broken line in FIG. 6, the time ΔT is ΔT2 and the discharge pressure PS at the start is PS2. Then, when the rotational speed of the impeller 20 increases to the rotational speed at which water can be pumped, the discharge pressure PV increases from the decrease. The discharge pressure PV of the pump 2 at the timing when the discharge pressure PV rises from the descent is the minimum value of the discharge pressure PV after the pump 2 is started, and is the discharge pressure PS at the start. That is, the lowest value estimated at the timing of step S3 is the discharge pressure PS at the start.

This starting discharge pressure PS is estimated based on the slope at which the discharge pressure PV decreases from the pressure level PL0 to the starting pressure P0, which is calculated from the time ΔT and the difference between the pressure level PL0 and the starting pressure P0. This inclination depends on the height of the water supply destination, the pipeline resistance, or the amount of water used. The starting discharge pressure PS calculated when the first starting condition is satisfied is stored in the storage unit 63, and the pump 2 normally supplies water, or the retry operation described later is completed and the failure is confirmed. It should be retained until

In the present embodiment, the control device 60 estimates the discharge pressure PS at the start based on the inclination of the discharge pressure PV from the pressure level PL0 to the starting pressure P0, but instead of the pressure level PL0. , May be estimated based on a slope that drops to any pressure PZ (PL0> PZ> P0). In that case, the estimation of PS in step S4 is arbitrary when the discharge pressure PV is pressure PZ or less and the starting pressure P0 or more (starting pressure P0 ≦ discharge pressure PV ≦ pressure PZ) regardless of the condition of step S3 “YES”. It may be carried out at the timing of. As described above, the discharge pressure PS at the time of starting may be estimated based on the slope in which the discharge pressure PV is lowered under the first starting condition.

Next, the control device 60 sets the torque boost voltage to be applied to the motor 3 at the start of the pump 2 according to the magnitude of the discharge pressure PS at the start of the pump 2 (steps S5-1 to S5-2). .. Specifically, if it is determined in step S4-1 that the discharge pressure PS at the start is within the range of PL1 (step S4-1 is "YES"), the torque boost voltage is set to V1 and step S4. At -1, the discharge pressure PS at the start is out of the range of PL1 (step S4-1 is “NO”), and is within the range of PL2 in step S4-2 (step S4-2 is “YES”). If so, the torque boost voltage is set to V2, which is a value larger than V1. The torque boost voltage is one of the control parameters related to the drive control of the motor 3, and the larger the torque boost voltage, the larger the starting torque of the motor 3. The control device 60 sets the torque boost voltage to a value corresponding to the magnitude of the discharge pressure PS at the start of the pump 2.

As shown by the solid line in FIG. 6, when the discharge pressure PS at the start of the pump 2 is calculated to be within the range of the pressure level PL1, the control device 60 sets the torque boost voltage to V1. Further, as shown by the dotted line in FIG. 6, when the discharge pressure PS at the start of the pump 2 is calculated to be within the range of the pressure level PL2 which is a pressure value higher than the pressure level PL1, the control device 60 performs torque boost. The voltage is set to V2, which is a value larger than V1. The pressure levels PL1 and PL2 may be pressure values equal to or lower than the starting pressure P0 and may have a predetermined width.

Next, the control device 60 causes the pump 2 to stop and restart based on the set torque boost voltage (step S6). In steps S5-1 to S5-2, the torque boost voltage applied to the electric motor 3 at the start of the pump 2 is set according to the magnitude of the discharge pressure PS at the start of the pump 2, so that the electric motor 3 is appropriate. A good starting torque can be obtained. That is, in the example shown in FIG. 6, when the discharge pressure PS at the start of the pump 2 is high, the impeller 20 is less likely to start rotating and requires a starting torque. Therefore, if the discharge pressure PS at the start is PS2 and the torque boost voltage is V1 used when the torque boost voltage is PS1, the torque is temporarily insufficient and a current larger than the allowable current flows, and the control device 60 controls the pump 2. When the discharge pressure PS at the start is PS2, the torque boost voltage is set to V2, which is larger than V1. In this way, the torque boost voltage is set to a value corresponding to the magnitude of the discharge pressure PS at the start of the pump 2, and the pump 2 is restarted at a small stop. It is possible to suppress the protection stop of.

Further, when the torque boost voltage is increased, the current flowing through the inverter device 70 when the pump 2 is started also increases, so that the overcurrent protection level may be set according to the torque boost voltage. Specifically, the control device 60 may set an overcurrent protection level proportional to the torque boost voltage. As a result, it is possible to suppress the protection stop due to the overcurrent trip of the pump 2 started under the first starting condition.

As described above, according to the first embodiment described above, the control signal of the pump 2 is output to the pump 2, the electric motor 3 for driving the pump 2, the inverter device 70 for supplying power to the electric motor 3, and the inverter device 70. A pump device 1 including a control device 60 for storing the input unit 61a for inputting the discharge pressure PV of the pump 2 and the values of control parameters related to the drive control of the electric motor 3. The control device 60 includes a storage unit 63, and the control device 60 has a first start in which the discharge pressure PV drops from a pressure higher than a predetermined starting pressure P0 to a starting pressure P0 or less as a condition for starting the pump 2. In addition to having the conditions, the discharge pressure PS at the time of starting, which is the minimum value of the discharge pressure PV after the pump 2 is started under the first start condition, is estimated, and the control parameter is determined according to the discharge pressure PS at the start. By adopting a configuration in which the torque boost voltage, which is one of the values of, is set and the pump 2 is started based on the set torque boost voltage when the first starting condition is satisfied, the pump 2 It is possible to obtain a highly convenient pump device 1 capable of eliminating the torque shortage transiently generated at the time of starting, suppressing the protection stop at the time of starting the pump 2, and avoiding water interruption as much as possible.

In FIG. 6, when the starting discharge pressure PS1 is smaller than the starting discharge pressure PS2, the torque boost voltage V1 is set to a value smaller than V2, but the torque boost voltage V1 is set to a value smaller than V2. The torque boost voltage may be determined according to the pressure PS. Depending on the installation environment of the pump device 1 and the load condition, even though the discharge pressure PS1 at the start is smaller than the discharge pressure PS2 at the start, V1 is set to a larger value than V2 to start. It may be possible to avoid the protection stop at the time.

Therefore, as a program executed by the calculation unit 62, at least one function for calculating an appropriate torque boost voltage from the discharge pressure PS at the start may be stored in the storage unit 63. Further, which of the plurality of functions is used may be stored in the storage unit 63 as a changeable setting value. For example, using the argument that can be set, at least one of addition, subtraction, multiplication, division, etc. is performed using the set argument according to the discharge pressure PS at the start, and the torque boost voltage to be set at the start is determined. You may.

Here, the graph shown by the solid line in FIG. 6 is a case where a flush valve or the like is installed at the water supply destination and a large amount of water is used at the time of restarting a small stop, and the discharge pressure PV shown by the dotted line is It is considered that this indicates a change in the discharge pressure PV when the amount of water is smaller than that of the solid line (a faucet or the like is connected to the water supply destination). The graph shown by the solid line in FIG. 6 is a graph when a large amount of water is used at the time of restarting a small stop, and the discharge pressure PV shown by the dotted line is the discharge pressure PV when the amount of water is smaller than that of the solid line. Show change. In the graph shown by the solid line, since a large amount of water is used at the time of restarting the small stop, the torque may be insufficient by the time the pump 2 is started in step S6 and the discharge pressure PV reaches the vicinity of the target pressure SV. Conceivable.

Specifically, even if the motor 3 obtains an appropriate starting torque at the torque boost voltage V1 and the impeller 20 rotates once, if the torque becomes insufficient due to the subsequent acceleration of the motor 3, the impeller 20 of the pump 2 Stops protection before it rises to a rotation speed at which it can pump water. That is, depending on the environment in which the pump device 1 is installed, the performance of the pump 2, the output and efficiency of the motor 3, etc., the torque is transiently insufficient at the time of starting when the discharge pressure PS at the time of starting the pump 2 is low. As a result, the pump 2 may stop protecting.

In such an environment, the torque boost voltage when the starting discharge pressure PS is estimated to be, for example, PL1, is set to, for example, V11, and the starting discharge pressure PS is estimated to be PL2, which is a value larger than, for example, PL1. For example, the torque boost voltage of V12 may be set to V12, and a value larger than V12 may be set to the value of V11. Since the inverter control unit 60b performs "Vf control", the electric motor 3 can prevent the torque shortage after the impeller 20 has once rotated by increasing the torque boost voltage V11. In this way, by setting the value according to the magnitude of the discharge pressure PS at the start, it is possible to suppress the protection stop of the pump 2 due to the transient shortage of torque at the start, and to the rotation speed at which the water can be pumped at a predetermined specified head. It is possible to increase the rotation speed of the impeller 20.

In this way, by estimating the discharge pressure PS at the start based on the inclination of the discharge pressure PV to the starting pressure P0, it is possible to estimate the torque required for the motor 3 after the pump 2 is started. , The value of the control parameter corresponding to the torque required for the motor 3 after the start of the pump 2 can be set.

Note that step S6 corresponds to step S102 in FIG. 5B, and the control device 60 executes step S103 in FIG. 5B after the control flow of FIG. 7 is completed. As shown in the present embodiment, by setting the torque boost voltage V11 to a value corresponding to the magnitude of the discharge pressure PS at the start, it is possible to suppress the protection stop of the pump 2 due to the transient torque shortage at the start. Can be done.

Further, in the first embodiment, the following modification can be adopted. In the following description, the same or equivalent configurations and steps as those in the above-described embodiment are designated by the same reference numerals, and the description thereof will be simplified or omitted.

FIG. 8 is a time chart showing an example of the relationship between the discharge pressure of the pump 2 according to the first modification of the first embodiment, the voltage applied to the motor 3, and the current flowing through the inverter device 70. In the time chart shown in FIG. 8A, the vertical axis represents the pressure value and the horizontal axis represents the elapsed time, indicating the change in the discharge pressure PV with the passage of time. In the time chart shown in FIG. 8B, the vertical axis represents the voltage and the horizontal axis represents the elapsed time, indicating the change in the voltage applied to the motor 3 by the control device 60 with the elapsed time. In the time chart shown in FIG. 8C, the vertical axis represents the current value and the horizontal axis represents the elapsed time, indicating the change in the current flowing through the inverter device 70 with the elapsed time. FIG. 9A is a control flow showing an example of the retry operation executed by the control device 60 according to the first modification of the first embodiment, and is a detail of the retry operation in step S109 in the control flow of FIG. 5B.

In FIG. 8, in the first embodiment, the discharge pressure PV of the pump 2 drops from the stop pressure P1 to the starting pressure P0 or less (step S101 in FIG. 5B is “YES”), and the pump 2 is started (FIG. 5B). Step S102) When trying, the rotation speed of the impeller 20 could not be increased to the rotation speed at which water can be pumped at a predetermined specified head due to insufficient torque at the start (step S103 in FIG. 5B is "NO"), and the pump. 2 illustrates a case where the protection is stopped (step S107 in FIG. 5B) and then a retry operation for restarting the pump 2 (step S109 in FIG. 5B) is performed.

Specifically, the control device 60 supplies electric power to the motor 3 with the torque boost voltage VL0 at the timing when the discharge pressure PV of the pump 2 becomes equal to or lower than the starting pressure P0 (tr1, step S101 in FIG. 5B is “YES”). Although it was supplied, the impeller 20 of the pump 2 could not rotate normally, and the current flowing through the inverter device 70 reached the overcurrent protection level AL0 (protection level) (tr2, step S103 in FIG. 5B is “NO”). Therefore, the pump 2 was stopped for protection (step S107 in FIG. 5B) from tr2 to tr3 by the overcurrent trip. After that, the control device 60 satisfies the second starting condition that the discharge pressure PV of the pump 2 is equal to or less than the starting pressure P0 after the protection stop of the pump 2 is released (tr3) (step S108 in FIG. 5B is “YES”. ”), And a retry operation (step S109 in FIG. 5B) for restarting the pump 2 was performed. As a result, in the first retry operation (tr3 to tr4), the impeller 20 of the pump 2 cannot rotate normally again, and the current flowing through the inverter device 70 reaches the overcurrent protection level AL1 (protection level) (protection level). tr4, step S110 in FIG. 5B is “NO”) In the overcurrent trip, the pump 2 was stopped for protection between tr4 and tr5 (step S107 in FIG. 5B), but the second retry operation (tr5, FIG. 5B) was performed. In step S109), the pump 2 was normally started (tr6, step S110 in FIG. 5B was “YES”), and water could be supplied at the set pressure PA which is the specified lift (tr7, step S104 in FIG. 5B). Illustrate.

As shown in the time charts of FIGS. 8B and 8C, the control device 60 protects the torque boost voltage and / or overcurrent according to the number of consecutive retry operations (step S109 of FIG. 5B). Increase the level. Specifically, as shown in FIG. 8B, when the number of retries is the 0th (tr1), that is, a small stop restart, the torque boost voltage is VL0, which is a reference value. This VL0 is a torque boost voltage (for example, V1 or V2) applied to the motor 3 at the start of a small stop of the pump 2 according to the magnitude of the discharge pressure PS at the start of the pump 2 in the first embodiment described above. You may. When the number of retries is the first (tr3), the control device 60 sets the torque boost voltage to VL1 which is larger than VL0. Further, when the number of retries is the second time (tr5), the control device 60 sets the torque boost voltage to VL2, which is larger than VL1. Note that VL1 and VL2 may be obtained by adding or multiplying VL0 by a predetermined value according to the number of retries. By increasing the torque boost voltage as the number of retries increases, it is possible to suppress protection stop due to insufficient torque of the pump 2 started under the second starting condition, and to avoid water outage due to abnormal determination as much as possible.

Further, as shown in the time chart of FIG. 8C, the overcurrent protection level is increased in order to correspond to the torque boost voltage that increases with each retry operation. Specifically, the control device 60 sets AL0, AL1, AL2 (AL0 <AL1 <AL2), which are overcurrent protection levels corresponding to the torque boost voltages VL0, VL1, and VL2 (VL0 <VL1 <VL2), respectively. .. When the torque boost voltage is increased, the current flowing through the inverter device 70 when the pump 2 is started also increases. Therefore, by setting the overcurrent protection level corresponding to the torque boost voltage, the pump 2 started under the second starting condition. It is possible to suppress the protection stop due to the overcurrent trip, and to avoid the water outage due to the confirmation of abnormality as much as possible. Further, the overcurrent protection levels AL0, AL1 and AL2 (AL0 <AL1 <AL2) may be set according to the number of retries regardless of the torque boost voltage.

Next, the retry operation in FIG. 8 (step S109 in FIG. 5B) will be described in detail with reference to FIG. 9A. Specifically, in the control flow of the retry operation shown in FIG. 9A, the retry operations of tr3 to tr4 and tr5 to tr6 of the example shown in FIG. 8 will be described in detail. The retry operation shown in FIG. 9A satisfies the second starting condition in which the discharge pressure PV of the pump 2 is equal to or less than the starting pressure P0 after the protection stop of the pump 2 (step S107 in FIG. 5B) is released (tr3, tr5). , Step S108 in FIG. 5B is "YES"). In the retry operation shown in FIG. 8, the control device 60 first counts the number of retries (step S11). The number of retries is the number of times that the protection stop (step S107 in FIG. 5B) is continuously generated and the retry operation is performed. For example, a small stop restart of the pump 2 (step S102 in FIG. 5B) and a normal start of the pump 2 are performed. (Step S110 in FIG. 5B), and resetting may be performed by turning off the power of the pump device 1.

The control device 60 determines the current number of retries (steps S12-1 to S12-N). Then, the control device 60 sets the torque boost voltage applied to the motor 3 at the start of the pump 2 according to the current number of retries (steps S13-1 to S13-N). Specifically, if the number of retries is the first (step S12-1 is “YES”), VL1 having a value larger than the reference value VL0 is set as the torque boost voltage (step S13-1). If the number of retries is the second (“YES” in step S12-2), VL2 is set, which is a value larger than VL1 in which the number of retries is set for the first time in step S13-1 (step S13-2). .. Alternatively, the torque boost voltage may be increased only once every several retries. As described above, the torque boost voltage is one of the control parameters related to the drive control of the motor 3, and the larger the torque boost voltage, the larger the starting torque of the motor 3. Therefore, by increasing the torque boost voltage according to the number of retries, it is possible to suppress the protection stop due to insufficient torque.

Next, the control device 60 increases the overcurrent protection level according to the number of retries (steps S14-1 to S14-N). For example, as shown in FIG. 8, when the number of retries is 0, that is, the small stop restart (tr1, step S102 in FIG. 5B), the overcurrent protection level is AL0, which is a reference value. When the number of retries is the first (tr3, step S12-1 in FIG. 9A is “YES”), the control device 60 sets the overcurrent protection level to AL1 which is larger than AL0 (step S14-1). Further, when the number of retries is the second (tr5, step S12-2 in FIG. 9A is “YES”), the control device 60 sets the overcurrent protection level to AL2, which is larger than AL1 (step S14-2). In addition, AL1 and AL2 may be obtained by adding or multiplying a predetermined value to AL0.

Next, the control device 60 starts the pump 2 using the set torque boost voltage value and the overcurrent protection level value as the retry execution (step S15). Specifically, the control device 60 outputs an operation signal for starting the pump 2 to the inverter device 70 with a set torque boost voltage. Next, in step S16, when the control device 60 determines that the pump 2 is started, pumps water at a specified head, and supplies water normally (step S16 is “YES”), the control device 60 determines that the pump 2 is normally started, as shown in FIG. 9A. End the control flow.

On the other hand, when it is determined in step S16 that the normal start is negative due to overcurrent trip, pump overheat protection, etc. before determining the water supply by the pumping operation at the specified head of the pump 2 (step S16 is "NO"). Case), the control device 60 confirms the number of retries (step S18), and if the number of retries is less than a predetermined N times (when step S18 is “NO”), the control device 60 ends the control flow of FIG. 9A. .. If the number of retries is N or more (when step S18 is “YES”), the end of retries is confirmed (step S100), and the control flow of FIG. 9A ends. After the end of the retry in step S100 is confirmed, the normal start is determined to be "NO" in step S110 of FIG. 5B, the end of the retry is determined to be "YES" in step S111, and the pump 2 is determined in step S112. Failure is confirmed. It is preferable that N, which is the number of retries until the failure of the pump 2 is confirmed, is, for example, about N = 5, and is a set value that can be changed by the user.

Here, in steps S13-1 to S13-N, the torque boost voltage is set high as shown in FIG. 8 according to the number of retries, so that the starting torque increases as the number of retries increases. Further, as the number of retries increases, the time elapses, so that the discharge pressure PV decreases. In the case shown in FIG. 8, the pump 2 could not be restored in the first retry operation due to insufficient starting torque, but in the second retry operation, the torque boost voltage VL2 is higher than the torque boost voltage VL1 in the first retry operation. Is set and the discharge pressure PV is lower than PV1, so that the current flowing through the inverter device 70 reaches the set overcurrent protection level and the water supply by the pump 2 is restored without stopping the protection. Is done. In this way, by increasing the torque boost voltage and / or the overcurrent protection level according to the number of retries, there is a probability that the pump 2 can be normally started by executing the retry in step S15 each time the number of retries increases. It is possible to suppress the protection stop of the pump started under the second starting condition, and to avoid the water outage due to the confirmation of abnormality as much as possible. In the present embodiment, the torque boost voltage is set higher and the overcurrent protection level is increased as the number of retries increases. However, even if only one of the torque boost voltage and the overcurrent protection level is increased, the torque boost voltage is increased. good.

Further, as shown in FIG. 9A, the control device 60 sets the pump 2 in the direction opposite to the normal rotation direction once every several retries (for example, the number of retries is 3 × m: m is a natural number). It may be rotated to (step S17). That is, even if the cause of the abnormality (for example, sticking of the impeller 20 or biting of foreign matter) is not removed in the normal rotation direction, the pump 2 (motor 3) is in the direction opposite to the normal rotation direction. ) Is rotated, the cause of the abnormality is removed, normal starting is possible, and step S16 may be "YES". As a result, it is possible to prevent the pump 2 from reaching a protective stop (step S107 in FIG. 5B) or a failure confirmation (S112 in FIG. 5B). When the pump 2 is rotated in the reverse direction in step S17, the torque boost voltage may be a value corresponding to the number of retries as described above, or a value preset for reverse rotation may be used. good.

As described above, according to the first modification of the first embodiment described above, the control device 60 makes the pump 2 stand by in a stopped state as a protection of the pump device 1 as a condition for starting the pump 2. After releasing (step S107 in FIG. 5B), the control device 60 has a second starting condition (“YES” in step S108 in FIG. 5B) in which the discharge pressure PV is equal to or less than the starting pressure P0, and the control device 60 is shown in FIG. 9A. As shown, the number of times the pump 2 is started under the second starting condition is counted as the number of retries (step S11), and at the same time, according to the magnitude of the discharge pressure PS at the time of starting, which is the lowest value under the first starting condition. The torque boost voltage, which is one of the set control parameter values, is changed according to the number of retries, and when the second start condition is satisfied, the pump 2 is started based on the torque boost voltage changed according to the number of retries. By adopting the configuration of making the pump 2, it is possible to obtain a highly convenient pump device 1 capable of suppressing the protection stop and failure confirmation of the pump 2 and avoiding water interruption as much as possible.

Here, an example of a method for calculating the torque boost voltage in steps S13-1 to S13-N of FIG. 9A will be described with reference to FIG. 9B. The control flow shown in FIG. 9B shows an example of the process of calculating the torque boost voltage in step S13-1 of FIG. 9A. The same process is performed in steps S13-2 to S13-N of FIG. 9A.

The storage unit 63 of the control device 60 has coefficients PL1V and PL2V for changing the torque boost voltage according to the number of retries, and corrects the coefficients PL1V and PL2V according to the magnitude of the discharge pressure PS at the start. May be good. It is assumed that the discharge pressure PS at the time of starting is estimated when the first starting condition is satisfied (step S4 in FIG. 7), and the value is stored in the storage unit 63.

As shown in FIG. 9B, first, the control device 60 determines the pressure level in the starting discharge pressure PS when the first starting condition is satisfied (steps S13-1-1 to S13-1-2). .. Here, the pressure level PL1 shown in step S13-1-1 and the pressure level PL2 shown in step S13-1-2 in the present embodiment are the same as the pressure level PL1 and the pressure level PL2 shown in FIG. 6 (A). However, the present invention is not limited to this, and any range or value may be used. However, it is assumed that PL2 has a higher value than PL1.

Next, the control device 60 is in step S13-1-3 if the pressure level at the starting discharge pressure PS is within the range of PL1, and the pressure level at the starting discharge pressure PS is within the range of PL2. If so, in step S13-1-4, VL1 which is the torque boost voltage applied to the motor 3 when the number of retries is the first start is calculated.

Here, the control device 60 releases the protective stop of the pump 2 (step S107 in FIG. 5B), and then the discharge pressure PV when the second starting condition is satisfied (step S108 in FIG. 5B is “YES”). The torque boost voltage (control parameter) applied at the start of the pump 2 may be set according to the above. Specifically, since the discharge pressure PV at the time of making the determination in step S12-1 is PV1 (see FIG. 8A), in step S13-1-3, the control device 60 uses the discharge pressure PV. The torque boost voltage VL1B corresponding to (PV1) is set. At this time, the torque boost voltage VL1B may be increased in proportion to the difference between the starting pressure P0 and the discharge pressure PV (PV1). Similarly, in steps S12-2 to S12-N, the torque boost voltages VL2B to VLNB may be set according to the discharge pressure PV when determining steps S12-2 to S12-N. As a result, VL0 <VL1B <VL2B <... <VLNB. Since the discharge pressure PV (PV1, PV2 ,,, PVN) at the time of determining steps S12-1 to S12-N differs depending on the supply destination, the installation site, etc., the control device 60 has a torque boost voltage VL1B. It may be calculated by adding or multiplying VL0 by a predetermined value according to the discharge pressure PV (PV1, PV2 ,,, PVN), or a predetermined value according to the number of retries in addition to the discharge pressure PV. May be added to or multiplied by VL0 to calculate the torque boost voltage VL1B.

Next, the control device 60 corrects the coefficients PL1V and PL2V that change the torque boost voltage according to the number of retries according to the magnitude of the discharge pressure PS at the start (steps S13-1-3 to S13-1). -4). Specifically, if the pressure level in the starting discharge pressure PS in step S13-1-1 is within the range of PL1 (step S13-1-1 is "YES"), step S13-1-3 is performed. Run. PL1V shown in steps S13-1-3 is a coefficient for calculating VL1 and is calculated according to the magnitude of the starting discharge pressure PS or the pressure level PL1 when the first starting condition is satisfied. It is good. In steps S13-1-3, the coefficient PL1V is added to VL1B (base value of VL1 in FIG. 9A), which is a torque boost voltage set according to the number of retries and the discharge pressure PV. The coefficient PL1V may be multiplied by VL1B.

Further, if the pressure level in the starting discharge pressure PS in step S13-1-2 is within the range of PL2 (step S13-1-1 is "NO" and step S13-1-2 is "YES"). , Step S13-1--4 is executed. PL2V shown in steps S13-1-4 is a coefficient for calculating VL1, and is calculated according to the magnitude of the starting discharge pressure PS or the pressure level PL2 when the first starting condition is satisfied. It is good. In steps S13-1-4, the control device 60 adds the coefficient PL2V to VL1B, which is a torque boost voltage set according to the number of retries, to calculate VL1. In addition, also in step S13-1-4, the coefficient PL2V may be multiplied by VL1B. As a result, the torque boost voltage VL1 set in step S13-1 can be set to a larger value in the case of PL2, which has a higher discharge pressure PS at the time of starting than in the case of PL1.

The coefficient PL1V and the coefficient PL2V may use different calculation formulas, or may be set to a large value as the number of retries increases. Further, the VL1B and the coefficients PL1V and PL2V may be constant values, and as described above, when the discharge pressure PV at the start of the pump 2 is high, the impeller 20 is less likely to start rotating. When torque is required, it is preferable to increase the torque boost voltage when the discharge pressure PS at the start is PL2 rather than when it is PL1. Specifically, VL1 to VLN when the starting discharge pressure PS is PL2 is larger than VL1 to VLN when the starting discharge pressure PS is PL1 (VLN is the torque boost voltage in the Nth retry). The coefficients PL1V and PL2V that serve as values may be used.

In this way, the coefficients PL1V and PL2V for changing the torque boost value, which is a control parameter, according to the number of retries are set to the magnitude of the starting discharge pressure PS estimated when the first starting condition is satisfied. It may be corrected accordingly. Further, although the starting discharge pressure PS in the present embodiment has been calculated in two ways, the pressure level PL1 and the pressure level PL2, the pressure level can be set to X (X is an arbitrary natural number of 1 or more) regardless of the calculation method. PL1V to PLXV may be calculated as a coefficient corresponding to the pressure levels PL1 to PLX.

Further, in the first embodiment, the following second modification can be adopted.
FIG. 10 is a control flow showing an example of a retry operation executed by the control device 60 according to the second modification of the first embodiment.
The control flow shown in FIG. 10 extends steps S4-1 to S4-2 shown in FIG. 7 of the first embodiment to steps S24-1 to S24-X, and steps S5-1 to S5-2. , Steps S25-1 to S25-X. In addition, "X" of step S24-X and step S25-X referred to here means X (X is an arbitrary one or more) in the pressure range of starting pressure P0 or less divided into two stages of pressure levels PL1 and PL2 in FIG. (Natural number) means the Xth stage when divided into stages. Steps S1, S2, S3, S4-1 to S4-2, S6 shown in FIG. 7, and steps S21, S22, S23, steps S24-1 to S24-X, S26 shown in FIG. 10 are similar processes. Therefore, the description is omitted.

In steps S25-1 to S25-X, the control device 60 sets a soft start time, which is an increase rate of the rotation speed of the electric motor 3, according to the magnitude of the discharge pressure PS at the start of the pump 2. The soft start time is one of the control parameters related to the drive control of the electric motor 3, and when the control device 60 of the present embodiment accelerates the electric motor 3, the rotation speed of the electric motor 3 is based on the soft start time. Limit the increase in. The soft start time may be, for example, the time when the rotation speed of the electric motor 3 reaches a predetermined rotation speed (for example, the maximum output rotation speed) from a value of 0. The longer the soft start time, the more the acceleration of the electric motor 3 can be suppressed, and the current flowing through the inverter device 70 at the time of acceleration can be suppressed. The control device 60 sets the soft start time to a value corresponding to the magnitude of the discharge pressure PS at the start.

For example, as shown in the example of the solid line in FIG. 6A, the control device 60 sets the soft start time to ST1 when the discharge pressure PS at the start of the pump 2 is calculated to be the pressure level PL1. Further, as shown in the example of the solid line in FIG. 6A, the control device 60 is calculated as a pressure level PL2 in which the discharge pressure PS at the start of the pump 2 is a pressure value higher than the pressure level PL1. The control device 60 sets the soft start time to ST2, which is longer than ST1. In this way, by setting the soft start time according to the magnitude of the discharge pressure PS at the start of the pump 2, it is possible to prevent the current flowing through the inverter device 70 at the start of the pump 2 from reaching the overcurrent protection level. Therefore, it is possible to prevent the pump 2 from reaching a protection stop by the time the pump 2 reaches a predetermined predetermined lift.

Here, when the discharge pressure PS at the start is PL1 smaller than PL2, the soft start time ST1 is set to a value smaller than ST2, but regardless of this, the torque boost voltage V1 or V2 described above is the same. The soft start time may be determined according to the discharge pressure PS at the start, such as setting the soft start time ST1 to a value of ST2 or more depending on the installation environment or the like.

The control flow shown in FIG. 10 and the control flow shown in FIG. 7 may be executed in parallel. The control flow shown in FIG. 10 extends steps S4-1 to S4-2 shown in FIG. 7 of the above-described embodiment of the present invention to steps S24-1 to S24-X, and steps S5-1 to S5-2. Is replaced with steps S25-1 to S25-X, but when the control flow shown in FIG. 10 and the control flow shown in FIG. 7 are executed in parallel, steps S25-1 to S25- It becomes a control flow to which the processing of X is added. Specifically, steps S4-1 to S4-2 in FIG. 7 are extended to S4-X, and in addition, steps S5-1 to S5-2 are also extended to S5-X. Then, after steps S5-1 to S5-X, steps S25-1 to S25-X may be added and executed.

For example, when the discharge pressure PS at the start of the pump 2 is calculated as the pressure level PL1 (when step S4-1 is “YES”), the control device 60 sets the torque boost voltage to V1 (step S5-). Together with 1), the soft start time is set to ST1 (step S25-1), and the pump 2 is started (step S6). Further, the control device 60 is a control device when the discharge pressure PS at the start of the pump 2 is calculated to be a pressure level PL2 which is a pressure value higher than the pressure level PL1 (when step S4-2 is “YES”). In 60, the torque boost voltage may be set to V2 higher than V1 (step S5-2) and the soft start time may be set to ST2 longer than ST1 (step S25-2) to start the pump 2 (step). S6).

In this way, by setting the control parameters according to the magnitude of the discharge pressure PS at the start of the pump 2, the current flowing through the inverter device 70 at the start of the pump 2 is suppressed, and the protection stop of the pump 2 is suppressed. It becomes possible. In addition to the first modification in the first embodiment, the second modification may be implemented. Further, the VL0 which is the reference value of the torque boost voltage may be set to a constant value regardless of the discharge pressure PS at the start, or the value and the calculation method may be changed by the user by the setting unit 64a or the like.

The control device 60 sets the above-mentioned control parameter (for example, VL0 shown in FIG. 8) according to the set starting pressure P0 when the setting changeable starting pressure P0 is changed by the user (for example, VL0 shown in FIG. 8). For example, it may be changed (set as the initial value of the control parameter).

(Second Embodiment)
Next, a second embodiment of the present invention will be described. In the following description, the same or equivalent configurations and steps as those in the above-described embodiment are designated by the same reference numerals, and the description thereof will be simplified or omitted.

FIG. 11 is a time chart showing an example of the relationship between the discharge pressure PV of the pump 2 according to the second embodiment and the command frequency by the inverter control unit 60b of the control device 60. In the time chart of FIG. 11A, the vertical axis shows the pressure value, the horizontal axis shows the elapsed time, and the change of the discharge pressure PV with the elapsed time is shown. In the time chart shown in FIG. 11B, the vertical axis indicates the frequency and the horizontal axis indicates the elapsed time, and the change of the command frequency output from the control device 60 to the inverter device 70 according to the elapsed time is shown. FIG. 12A is a control flow showing an example of a retry operation (step S109 in FIG. 5B) executed by the control device 60 according to the second embodiment.

In FIG. 11, after the small amount of water is stopped (tr11, step S106 in FIG. 5B), the discharge pressure PV pressurized to the stop pressure P1 drops to the starting pressure P0 or less (tr12, step S101 in FIG. 5B is “YES”. ), When the pump 2 is about to be restarted at a small stop, the pump 2 is protected and stopped (tr13, step S107 in FIG. 5B) due to a malfunction such as an overcurrent trip (step S103 in FIG. 5B is “NO”). After raising, the pump 2 was started (tr14) by the retry operation (step S109 in FIG. 5B), but the pump 2 could not be started normally (step S110 in FIG. 5B is “NO”), and the retry was not completed. After determining that (step S111 in FIG. 5B is “NO”), the pump 2 causes a protection stop (tr15, step S107 in FIG. 5B) again, and then the pump 2 is started by the second retry operation (tru15, step S107 in FIG. 5B). The case where the pump 2 is normally started (tr17, step S110 in FIG. 5B is “YES”) at the time of tr16, step S109 in FIG. 5B is exemplified.

As shown in FIG. 11, when the number of retries is the first, the control device 60 sets the interval time from the end of the protection stop of the pump 2 (step S107 in FIG. 5B) to the start to T1. Further, when the number of retries is the second time, the control device 60 sets the interval time until the pump 2 is started to T2, which is longer than T1. In this way, the control device 60 increases the interval time according to the number of retries. In the present embodiment, for the sake of simplicity, the protection stop in step S107 of FIG. 5B shall be canceled immediately after the pump 2 is stopped.

Next, the retry operation in FIG. 11 will be described in detail with reference to FIG. 12A. FIG. 12A is a control flow executed at the timing when the protection stop of the pump 2 is released after the pump 2 is stopped at tr13 or tr15 shown in FIG. 11, and the retry operation of step S109 of FIG. 5B is performed. It is a control flow explaining the details. In the control flow of the retry operation shown in FIG. 12A, the control device 60 first counts the number of retries (step S31). Next, the control device 60 determines the current number of retries (steps S32-1 to S32-N). Then, the control device 60 sets the interval time from when the protection stop of the pump 2 is released to when the pump 2 is restarted by executing the retry according to the current number of retries (steps S33-1 to S33). -N).

Specifically, when the number of retries is the first (step S32-1 is "YES"), the interval time is set to the initial value T1 (step S33-1), and the number of retries is the second (step S32-1). Is "NO" and step S32-2 is "YES"), the interval time is set to T2, which is a value larger than T1 (step S33-2). In this way, it is preferable to increase the interval time each time the number of retries increases (T1 <T2 << ... <TN). In addition, T2 to TN may be a value calculated by adding or multiplying a predetermined value to T1 which is an initial value, or may have a table in the storage unit 63 and hold the value.

When the water supply destination pipeline is open (for example, the faucet is open), the pump 2 cannot be started (step S103 in FIG. 5B is “NO”), and the pump 2 is protected and stopped (in FIG. 5B). After step S107), the discharge pressure PV pressurized by the accumulator operation gradually decreases. The starting torque of the motor 3 is reduced by reducing the discharge pressure PV when the pump 2 is started by setting the interval time. Therefore, the interval time is one of the control parameters related to the drive control of the motor 3.

Next, the control device 60 determines whether or not the set interval time has elapsed (step S34). When the interval time has elapsed (step S34 is "YES"), the control device 60 confirms the start condition (step S35a is "YES") and executes a retry (step S35). Specifically, the control device 60 makes the pump 2 stand by in a stopped state in step S34 so that it cannot be operated during the interval time (while step S34 is "NO"). When the interval time has elapsed (step S34 is “YES”), the control device 60 determines whether or not the starting condition is satisfied at the time when the inoperability is canceled. When it is determined that the starting condition is satisfied (when step S35a is "YES"), the pump 2 is started by the process of executing the retry in step S35. Here, in step S35a, when the discharge pressure PV is equal to or less than the starting pressure P0 (second starting condition) after the pump 2 is protected and stopped, or when the third starting condition described later is satisfied, "YES" is set and the second It is advisable to determine step S35a as "NO" and wait until the starting condition or the third starting condition is satisfied. Next, in step S36, the control device 60 confirms the normal start by the pumping operation of the pump 2, and when the water supply of the pump 2 is determined (when the step S36 is “YES”), the retry operation is terminated.

On the other hand, if an overcurrent trip or the like occurs before the rotation speed increases to the rotation speed at which the pump 2 can pump water at the specified head in step S36 (when step S36 is “NO”), the control device 60 may use the control device 60. The number of retries is confirmed (step S38), and if the number of retries is less than N (when step S38 is "NO"), the control flow of FIG. 12A is terminated. If the number of retries is N or more (when step S38 is "YES"), the control flow of FIG. 12A is terminated as the retry end (step S100), and the normal start is "NO" in step S110 of FIG. 5B. Then, in step S111, it is determined that the retry end is "NO", and the protection of step S107 is stopped again. When the retry is completed in step S100, the normal start is set to "NO" in step S110 of FIG. 5B, the determination of "YES" is made in step S111, and the failure of the pump 2 is confirmed (step S112).

Here, in steps S33-1 to S33-N, since the interval time is set longer according to the number of retries, the retry operation is delayed as the number of retries increases. As shown in FIG. 11, since the discharge pressure PV of the pump 2 decreases with the passage of time, the longer the interval time, the smaller the starting torque of the motor 3. In this way, by increasing the interval time according to the number of retries, the pump device 1 defines the pump 2 before the number of retries exceeds the set number of times (for example, N = 5) and the failure of the pump 2 is confirmed. The probability of being able to drive at the lift increases. In the control device 60, as in the first modification of the first embodiment described above, once every several retries (for example, the number of retries is 3 × m: m is a natural number), the pump 2 is used. May be rotated in a direction opposite to the normal rotation direction (step S37).

After determining that the protection of the pump 2 is stopped, the control device 60 disables the operation of the pump 2 for a predetermined period (tr13 to tr14 and tr15 to tr16 in FIG. 11), and causes the pump 2 to stand by in the protection stop state. You may. In this case, the interval time may be set in addition to the inoperable time due to the protection stop.

As described above, according to the second embodiment described above, the control device 60 counts the number of times the pump 2 is started under the second starting condition as the number of retries, and the pump is pumped from the time when the protection stop of the pump 2 is released. The interval time until restarting 2 is changed according to the number of retries, and when the second start condition is satisfied, the pump 2 is started based on the changed interval time according to the number of retries. By adopting the pump device 1, it is possible to obtain a highly convenient pump device 1 capable of suppressing the protection stop of the pump 2 and avoiding water interruption as much as possible.

Further, the control device 60 sets the coefficients PL1T and PL2T for changing the interval time according to the number of retries to the magnitude of the starting discharge pressure PS, which is the minimum value estimated when the first starting condition is satisfied. It may be corrected according to. The starting discharge pressure PS is estimated when the first starting condition is satisfied as described above (step S4 in FIG. 7), and is stored in the storage unit 63. Specifically, this process is executed according to the control flow shown in FIG. 12B. The control flow shown in FIG. 12B shows an example of the process of calculating the interval time in step S33-1 of FIG. 12A. The same process is performed in steps S33-2 to S33-N of FIG. 12A.

As shown in FIG. 12B, first, the control device 60 determines the pressure level in the discharge pressure PS at the start (steps S33-1 to S33-1-2). Here, the pressure level PL1 shown in step S33-1-1 and the pressure level PL2 shown in step S33-1-2 in the present embodiment are the same as the pressure level PL1 and the pressure level PL2 shown in FIG. 6 (A). However, the present invention is not limited to this, and any range or value may be used. However, it is assumed that PL2 has a higher value than PL1.

Next, the control device 60 corrects the coefficients PL1T and PL2T that change the interval time according to the number of retries according to the magnitude of the discharge pressure PS at the time of starting when the first starting condition is satisfied (step). S33-1-3 to S33-1-4). Specifically, if the pressure level in the starting discharge pressure PS in step S33-1-1 is within the range of PL1 (step S33-1-1 is "YES"), step S33-1-3 is performed. Run. PL1T shown in step S33-1-3 is a coefficient for calculating the interval time T1, and depends on the magnitude of the starting discharge pressure PS or the pressure level PL1 when the first starting condition is satisfied. It should be calculated. In step S33-1-3, the coefficient PL1T is added to T1B (base value of T1 in FIG. 12A) which is an interval time set according to the number of retries. The coefficient PL1T may be multiplied by T1B.

Further, if the pressure level in the starting discharge pressure PS in step S33-1-2 is within the range of PL2 (step S33-1-1 is "NO" and step S33-1-2 is "YES"). , Step S33-1-4 is executed. PL2T shown in step S33-1-4 is a coefficient for calculating T1, and is calculated according to the magnitude of the starting discharge pressure PS or the pressure level PL2 when the first starting condition is satisfied. It is good. In steps S33-1-4, the coefficient PL2T is added to T1B, which is an interval time set according to the number of retries. In addition, also in step S33-1-4, the coefficient PL2T may be multiplied by T1B. As a result, the interval time T1 set in step S33-1 can be set to a larger value in the case of PL2, which has a higher discharge pressure PS at the time of starting than in the case of PL1.

It should be noted that the coefficient PL1T and the coefficient PL2T may use different calculation formulas, or may be set to a large value as the number of retries increases. That is, since it can be inferred that the slope of the decrease in the discharge pressure PV when the pump 2 is not operating even though water is used at the water supply destination is constant, the discharge pressure PS at the start is PL1. This is because the discharge pressure PV when the protection stop of the pump 2 is released is larger in the case of PL2 than in the case of PL2. As described above, when the discharge pressure PV at the start of the pump 2 is high, the rotation of the impeller 20 is difficult to start and a start torque is required, when the discharge pressure PS at the start is PL1. It is preferable to make the interval time for PL2 longer than that for PL2. Specifically, T1 to TN when the starting discharge pressure PS is PL2 is larger than T1 to TN when the starting discharge pressure PS is PL1 (TN is the interval time in the Nth retry). The coefficients PL1T and PL2T may be set.

In this way, the coefficients PL1T and PL2T for changing the value of the interval time, which is a control parameter, according to the number of retries are set to the magnitude of the starting discharge pressure PS estimated when the first starting condition is satisfied. It may be corrected accordingly. Further, although the starting discharge pressure PS in the present embodiment has been calculated in two ways, the pressure level PL1 and the pressure level PL2, the pressure level can be set to X (X is an arbitrary natural number of 1 or more) regardless of the calculation method. Then, PL1T to PLXT may be calculated as a coefficient corresponding to the pressure levels PL1 to PLX.

Further, in the second embodiment, the following modification can be adopted. In the following description, the same or equivalent configurations and steps as those in the above-described embodiment are designated by the same reference numerals, and the description thereof will be simplified or omitted.

FIG. 13A is a control flow showing an example of confirmation of a third starting condition executed by the control device 60 according to the first modification of the second embodiment.
The control flow shown in FIG. 13A will be described later, wherein the second starting condition, which is the starting condition of the pump 2 in the retry operation (step S109 in FIG. 5B), is satisfied, and the discharge pressure PV is set to be less than the starting pressure P0. A case is shown in which the third starting condition, which is equal to or less than the retry start pressure RPL, is satisfied. For example, the control flow shown in FIG. 13A may be executed after determining the second starting condition in step S35a shown in FIG. 12A, or may be executed when determining the second starting condition in step S108 of FIG. 5B. .. As a determination of the third start condition, the control device 60 determines whether or not the discharge pressure PV has dropped to the retry start pressure RPL shown in FIG. 11 (step S41).

The retry start pressure RPL is a pressure value lower than the starting pressure P0, and is preferably a pressure at which the starting torque is not insufficient due to the retry operation. The retry start pressure RPL may be a set value that can be set and changed by the user, or may be changed by the control device 60 according to the number of retries. Further, the retry start pressure RPL may be calculated by subtracting or dividing a predetermined value from the discharge pressure PV when the protection is stopped. When the control device 60 changes the retry start pressure RPL according to the number of retries, it is preferable that the retry start pressure RPL becomes a small value as the number of retries increases.

When the discharge pressure PV has not dropped to the retry start pressure RPL or less (when step S41 is “NO”), the control device 60 waits until the discharge pressure PV drops to the retry start pressure RPL or less. When the discharge pressure PV at the start of the pump 2 due to the retry execution is high, it is difficult for the impeller 20 to start rotating and a starting torque is required. Therefore, when the discharge pressure PV drops to the retry start pressure RPL ( By performing the retry operation (step S42) in step S41, it is possible to suppress the protection stop due to insufficient torque at the time of starting the pump 2, as compared with the case where the pump 2 is started at the starting pressure P0. ..

An example of applying the process shown in step S42 of FIG. 13A to the retry operation of step S109 of FIG. 5B described above will be described. This process may be performed according to the flow shown in FIG. 13B. The flow shown in FIG. 13B shows a process executed in place of step S107 (protection stop) to step S109 (retry operation) in FIG. 5B described above. Specifically, when the third starting condition shown in step S41 of FIG. 13A is satisfied in addition to the above-mentioned second starting condition (step S108 is “YES”) (step S108-1 is “YES”). ), The retry operation of step S109 in FIG. 5B may be executed. As a result, since the discharge pressure PV drops below the retry start pressure RPL when the pump 2 is started by executing the retry, it is possible to suppress the protection stop due to the insufficient torque at the start of the pump 2. If the second starting condition is negative (step S108 is “NO”) or the third starting condition shown in step S41 of FIG. 13A is negative (step S108-1 is “NO”), Return to the protection stop in step S107.

Further, an example in which the process shown in step S42 of FIG. 13A is applied to the retry execution of step S35 of FIG. 12A described above will be described. Specifically, in step S35a of FIG. 12A, when the third start condition shown in step S41 of FIG. 13A is satisfied (when step S41 is “YES”), the process of retry execution of step S35 of FIG. 12A is performed. You should do. If the discharge pressure PV is larger than the retry start pressure RPL in step S41 of FIG. 13A, the third start condition is determined to be negative (step S108-1 is “NO”), and the discharge pressure PV is the retry start pressure. Wait until it becomes RPL or less.

As described above, the starting condition of the pump 2 may include, in addition to the second starting condition, a third starting condition in which the discharge pressure PV is equal to or less than the retry starting pressure RPL set to be less than the starting pressure P0. As a result, when the third start condition is satisfied and the pump 2 is started, the discharge pressure PV drops below the retry start pressure RPL, so that protection stop due to insufficient torque at the start of the pump 2 can be suppressed. can.

Further, in the second embodiment, the following second modification can be adopted.
FIG. 14 is a time chart showing an example of the relationship between the discharge pressure PV of the pump 2 and the command frequency from the control device 60 to the inverter control unit 60b according to the second modification of the second embodiment. In the time chart shown in FIG. 14A, the vertical axis represents the pressure and the horizontal axis represents the elapsed time, indicating the change in the discharge pressure PV with the elapsed time. In the time chart shown in FIG. 14B, the vertical axis represents the frequency and the horizontal axis represents the elapsed time, indicating the change in the command frequency from the control device 60 to the inverter device 70 due to the elapsed time. FIG. 15A is a control flow showing an example of a retry operation (step S109 in FIG. 5B) executed by the control device 60 according to the second modification of the second embodiment.

In FIG. 14, as in the second embodiment described above, after the small amount of water is stopped (tr20, step S106 in FIG. 5B), the discharge pressure PV of the pump 2 pressurized to the stop pressure P1 is the starting pressure from the stop pressure P1. When the pressure drops to P0 (tr21, step S101 in FIG. 5B is “YES”), the first starting condition is satisfied, and the pump 2 is attempted to restart at a small stop (step S102 in FIG. 5B), due to insufficient starting torque. When the pump 2 cannot be started (step S103 in FIG. 5B is “NO”), the pump 2 causes a protection stop (tr22, step S107 in FIG. 5B), and then the second starting condition is satisfied and a retry operation (FIG. 5B) is performed. An example is illustrated in which the pump 2 is restarted in step S109) of 5B.

The control device 60 increases the soft start time according to the number of retries for restarting the pump 2. For example, as shown in FIG. 14, when the number of retries is 0 (tr21), that is, when the first start condition is satisfied, the soft start time is ST0, which is a reference value. When the number of retries is the first (tr23), the control device 60 sets the soft start time to ST11, which is longer than ST0. Further, when the number of retries is the second time (tr25), the control device 60 sets the soft start time to ST12, which is longer than ST11. In addition, ST11 and ST12 may be obtained by adding or multiplying ST0 by a predetermined value, or are set values (ST1 to STN) according to the discharge pressure PS at the start of the pump 2 in FIG. 10 described above. May be ST0, and a predetermined value may be added or multiplied to this ST0 to obtain the result.

Here, as described above, the soft start time is one of the control parameters related to the drive control of the electric motor 3, and the longer the soft start time, the more the acceleration of the electric motor 3 can be suppressed, which is necessary at the time of acceleration. The current flowing through the inverter device 70 can be suppressed. In the present embodiment, as an example, as shown in FIG. 14, the soft start time starts from the initial value (zero) when the command frequency by the inverter control unit 60b when the set pressure PA is set is set to PAF. It corresponds to the length of the command time required to reach the PAF (for example, ST12 from tr25 to tr26). However, the soft start time may be, for example, the time when the rotation speed of the electric motor 3 reaches a predetermined rotation speed (for example, the maximum output rotation speed) from a value of 0 (zero) regardless of the command frequency PAF.

Next, the retry operation in FIG. 14 will be described in detail with reference to FIG. 15A. In the control flow of the retry operation shown in FIG. 15A, it is determined that the discharge pressure PV is equal to or less than the starting pressure P0 when the protection stop is released (tr23, tr25) after the protection stop of the pump 2 is released (tr22, tr24). This is a control flow for explaining the details of the retry operation in step S109 of FIG. 5B. In the control flow of the retry operation shown in FIG. 15A, the control device 60 first counts the number of retries (step S51). Next, the control device 60 determines the current number of retries (steps S52-1 to S52-N). Then, the control device 60 sets the soft start time according to the current number of retries (steps S53-1 to S53-N).

Next, the control device 60 performs retry execution based on the set soft start time (step S54). Specifically, the control device 60 starts the pump 2, accelerates the electric motor 3 by the rate of increase in the soft start time, and operates so that the discharge pressure PV of the pump 2 becomes the set pressure PA. Next, in step S55, when the control device 60 confirms the normal start of the pumping operation at the specified head of the pump 2 and determines the water supply of the pump 2 (when the step S55 is “YES”), FIG. 15A. End the control flow of. On the other hand, if normal start cannot be confirmed due to an overcurrent trip or the like (when step S55 is "NO") before determining the water supply by the specified head of the pump 2 in step S55, the control device 60 confirms the number of retries. If the number of retries is less than N (when step S57 is "NO"), the control flow of FIG. 15A is terminated. If the number of retries is N or more (when step S57 is “YES”), the control flow of FIG. 15A is terminated as the retry termination (step S100) in order to confirm the failure of the pump 2.

Here, in steps S53-1 to S53-N, since the soft start time is set longer according to the number of retries, the current accompanying the acceleration of the electric motor 3 can be suppressed as the number of retries increases. It is possible to prevent the current flowing through the inverter device 70 from reaching the set overcurrent protection level and stopping the protection. In this way, by increasing the soft start time according to the number of retries, the probability that the pump 2 can be restored before the number of retries exceeds the set number N increases. In the control device 60, as in the first modification of the first embodiment described above, once every several retries (for example, the number of retries is 3 × m: m is a natural number), the pump 2 is used. May be rotated in a direction opposite to the normal rotation direction (step S56).

As described above, according to the second modification of the second embodiment described above, the control device 60 counts the number of times the pump 2 is started under the second starting condition as the number of retries, as shown in FIG. 15A. In addition to step S51), the soft start time, which is one of the control parameter values set according to the magnitude of the discharge pressure PS at the time of starting, which is the lowest value in the first starting condition, is changed according to the number of retries. By adopting a configuration in which the pump 2 is started based on the soft start time changed according to the number of retries when the second start condition is satisfied, it is possible to suppress the protection stop and failure confirmation of the pump 2. A highly convenient pump device 1 capable of avoiding water outage as much as possible can be obtained.

Further, the control device 60 sets the coefficients PL1ST and PL2ST for changing the soft start time according to the number of retries to the magnitude of the starting discharge pressure PS, which is the minimum value estimated when the first starting condition is satisfied. It may be corrected accordingly. The starting discharge pressure PS is estimated when the first starting condition is satisfied as described above (step S4 in FIG. 7), and is stored in the storage unit 63. Specifically, this process is executed according to the control flow shown in FIG. 15B. The control flow shown in FIG. 15B shows an example of the process of calculating the soft start time in step S53-1 of FIG. 15A. The same process is performed in steps S53-2 to S53-N of FIG. 15A.

As shown in FIG. 15B, first, the control device 60 determines the pressure level in the starting discharge pressure PS when the first starting condition is satisfied (steps S53-1-1 to S53-1-2). .. Here, the pressure level PL1 shown in step S53-1-1 and the pressure level PL2 shown in step S53-1-2 in the present embodiment are the same as the pressure level PL1 and the pressure level PL2 shown in FIG. 6 (A). However, the present invention is not limited to this, and any range or value may be used. However, it is assumed that PL2 has a higher value than PL1.

Next, the control device 60 corrects the coefficients PL1ST and PL2ST that change the soft start time according to the number of retries according to the magnitude of the discharge pressure PS at the time of starting when the first starting condition is satisfied (. Steps S53-1-3 to S53-1-4). Specifically, if the pressure level in the starting discharge pressure PS in step S53-1-1 is within the range of PL1 (step S53-1-1 is "YES"), step S53-1-3 is performed. Run. PL1ST shown in step S53-1-3 is a coefficient for calculating ST11, and is calculated according to the magnitude of the starting discharge pressure PS or the pressure level PL1 when the first starting condition is satisfied. It is good. In step S53-1-3, the coefficient PL1ST is added to ST11B (base value of ST11 in FIG. 15A) which is a soft start time set according to the number of retries. The coefficient PL1ST may be multiplied by ST11B.

Further, if the pressure level in the starting discharge pressure PS in step S53-1-2 is within the range of PL2 (step S53-1-1 is "NO" and step S53-1-2 is "YES"). , Step S53-1--4 is executed. PL2ST shown in step S53-1-4 is a coefficient for calculating ST11, and is calculated according to the magnitude of the starting discharge pressure PS or the pressure level PL2 when the first starting condition is satisfied. It is good. In steps S53-1-4, the coefficient PL2ST is added to ST11B, which is the soft start time set according to the number of retries. In addition, also in step S53-1-4, the coefficient PL2ST may be multiplied by ST11B. As a result, in step S53-1, the soft start time ST11 can be set to a larger value when the discharge pressure PS at the start is PL2 than when it is PL1.

It should be noted that the coefficient PL1ST and the coefficient PL2ST may use different calculation formulas, or may be set to a large value as the number of retries increases. That is, since it can be inferred that the slope of the decrease in the discharge pressure PV when the pump 2 is not operating even though water is used at the water supply destination is constant, the discharge pressure PS at the start is PL1. This is because the discharge pressure PV when the protection stop of the pump 2 is released is larger in the case of PL2 than in the case of PL2. As described above, when the discharge pressure PV at the start of the pump 2 is higher, the rotation of the impeller 20 is more difficult to start and a start torque is required, when the discharge pressure PS at the start is PL1. It is better to lengthen the soft start time at PL2. Specifically, the control device 60 has coefficients PL1ST and PL2ST in which ST11 to ST1N when the starting discharge pressure PS is PL2 is larger than ST11 to ST1N when the starting discharge pressure PS is PL1. And it is sufficient.

In this way, the coefficients PL1ST and PL2ST for changing the value of the soft start time, which is a control parameter, according to the number of retries, are the magnitudes of the discharge pressure PS at the time of starting estimated when the first starting condition is satisfied. It is advisable to correct according to. Further, although the starting discharge pressure PS in the present embodiment has been calculated in two ways, the pressure level PL1 and the pressure level PL2, the pressure level can be set to X (X is an arbitrary natural number of 1 or more) regardless of the calculation method. PL1ST to PLXST may be calculated as coefficients corresponding to the pressure levels PL1 to PLX.

Further, the process of FIG. 15A may be added to the process of FIG. 12A described above. Specifically, as shown in FIG. 15C, steps S53-1 to S53-N are performed after steps S33-1 to S33-N to set ST11 to ST1N for the soft start time, and step S35a is the first step. 2 When the start condition (in the case of “YES”) is satisfied, the retry execution may be performed in step S35. As described above, by changing the interval time and the soft start time according to the number of retries, it is possible to obtain a highly convenient pump device 1 capable of suppressing the protection stop of the pump 2 at the time of starting and avoiding water interruption as much as possible. Further, the process of FIG. 13A may be added to the process of FIG. 15C. Specifically, in step S35a, when the above-mentioned third starting condition is satisfied, the flow shown in FIG. 13A may be executed.

(Third Embodiment)
Next, a third embodiment of the present invention will be described. In the following description, the same or equivalent configurations and steps as those in the above-described embodiment are designated by the same reference numerals, and the description thereof will be simplified or omitted.

FIG. 16 is a control flow showing an example of control parameter initialization executed by the control device 60 according to the third embodiment.
In the third embodiment, a control flow for returning the control parameters changed in each of the above-described embodiments to the initial control parameters used in the small stop restart during the operation of the pump 2 will be described. In the retry operation described above (step S109 in FIG. 5B), protection stop due to a transient state at the time of starting can be avoided (step S110 in FIG. 5B is “YES”), and then water is continuously supplied (step S109 in FIG. 5B). At the time of step S104), the pump 2 can be appropriately operated by returning the control parameter changed by the retry operation to the initial control parameter (control parameter at the time of restarting the small stop).

Specifically, in the case shown in FIG. 8, the torque boost voltage VL2 set in the second retry operation is returned to the torque boost voltage VL0 after the water supply by the pump 2 is restored. In this way, by lowering the torque boost voltage changed at the time of retry to the torque boost voltage at the time of restarting at a small stop, the motor 3 can be driven with the optimum "Vf control", so that the driving energy of the motor 3 can be saved. Can be converted. Further, the soft start times ST11 to ST1N set according to the number of retries shown in FIG. 15A may be returned to ST0 shown in FIG. By shortening the soft start time, the followability of the discharge pressure PV due to the fluctuation of the flow rate at the water supply destination is improved. If the pump 2 stops the small amount of water or protects while the flow of FIG. 16 is being executed, the flow of FIG. 16 is interrupted.

The control flow shown in FIG. 16 is executed after the determination of step S110 “YES” in FIG. 5B, and is executed in parallel with step S104 in FIG. 5B. The determination of step S110 “YES” in FIG. 5B corresponds to the above-mentioned step S16 “YES” in FIG. 9A, step S36 “YES” in FIG. 12A, step S55 “YES” in FIG. 15A, and the like. The control device 60 may check whether the discharge pressure PV has reached the vicinity of the predetermined specified head pressure in order to confirm that the pump 2 is normally supplying water in the pumping operation. Further, it is advisable to confirm that the discharge pressure PV has changed from falling to rising and a predetermined time has elapsed, or that the amount of water is not too small and the discharge pressure PV has reached a predetermined pressure with the flow sensor 35b.

In step S62, the control device 60 determines whether or not the current supplied to the motor 3 (specifically, the measured value of the current sensor 72) is equal to or less than a predetermined current limit level. As shown in tr5 to tr6 in FIG. 8, the current flowing through the inverter device 70 transiently increases when the pump 2 is started. Further, when the load of the electric motor 3 becomes larger than the normal range due to a foreign matter being caught in the impeller 20 of the pump 2 and locking, the current flowing through the inverter device 70 increases, so that the control device 60 is an inverter. When the current flowing through the device 70 is equal to or less than the predetermined current limit level (when step S62 is “YES”), it is determined that the load of the motor 3 is within the normal range, and the process proceeds to the next step S63. On the other hand, when the determination in step S62 is "NO", the control device 60 waits until the current flowing through the inverter device 70 becomes equal to or less than the predetermined current limit level. Here, the current limit level is a value smaller than the overcurrent protection level (for example, AL0, AL1, AL2, etc.) which is the threshold value of the overcurrent trip, and the inverter device 70 when the pump 2 supplies water at the specified head. It is preferable to add a margin to the current flowing through the inverter.

In the next step S63, the control device 60 determines whether or not the amount of water flowing through the pump 2 is equal to or greater than the predetermined amount of water. Specifically, the control device 60 determines whether or not the flow sensor 35b has detected an underwater amount of Qmin or less. When the flow sensor 35b does not detect the underwater amount Qmin and the amount of water flowing to the pump 2 is equal to or greater than the underwater amount (when step S63 is "YES"), the control device 60 supplies water by the pump 2 in the pumping operation. It is determined that this is the case, and the process proceeds to the next step S64. On the other hand, when the determination in step S63 is "NO", the pump 2 is not pumping water, or the water is no longer used at the supply destination and only the pressure is accumulated in the pressure tank 43. The pump 2 is stopped by a small amount of water and exits the control flow. If the determination in step S63 is "NO", the control device 60 returns to the determination in step S62. When the amount of water flowing through the pump 2 is small, the current flowing through the inverter device 70 is small and it is difficult to determine whether or not the water can be pumped normally even if the current is below the current limit level. Therefore, in step S63, The control device 60 confirms the amount of water flowing through the pump 2. However, step S63 may be omitted as long as it can be determined whether or not the water has been pumped normally.

In the next step S64, the control device 60 is in a state where the current flowing through the inverter device 70 is below the current limit level and / or the flow sensor 35b does not detect the insufficient water amount Qmin (step S62 and / or step S63 is "YES". ) To determine whether or not the specified time has passed. When the predetermined time has elapsed (when step S64 is “YES”), the control device 60 proceeds to the next step S65. On the other hand, when the determination in step S64 is "NO", the process returns to step S62, and the control device 60 is in a state where the current flowing through the inverter device 70 is below the current limit level and / or the flow sensor 35b does not detect the insufficient water amount Qmin. While confirming that it has become, wait until the specified time has elapsed.

If "YES" in any of steps S62 to S64, the control device 60 determines that the cause of the abnormality has been removed, and initializes the control parameters (step S65). Specifically, the various control parameters changed in the above-mentioned retry operation (step S109 in FIG. 5B) are returned to the control parameters used in the small stop restart (step S102 in FIG. 5B). On the other hand, if any one of steps S62 to S64 is "NO", the cause of the abnormality may not be removed yet, so that the control device 60 continuously uses the control parameter changed during the retry operation.

As described above, according to the third embodiment described above, the pump 2, the electric motor 3 for driving the pump 2, the inverter device 70 for supplying power to the electric motor 3, and the pump by outputting a control signal to the inverter device 70. A pump device 1 including a control device 60 for controlling the operation of the motor, wherein the control device 60 comprises a control parameter changing means for changing control parameters related to drive control of an electric motor, and a current flowing through the inverter device 70. Reset to return the changed control parameter to the control parameter at the time of restarting the small stop when it stays below the set current limit level for a certain period of time and / or when a certain period of time elapses without detecting the insufficient water amount Qmin. By adopting the configuration of having the means and, it is not necessary for the maintenance worker to bother to go to the site to reset the control parameters after the control parameters are changed, which is convenient for the pump device 1. Will be higher. Further, when the pump 2 is started, a torque shortage occurs due to friction of the sliding surface of the shaft sealing portion of the pump 2, so if the pump 2 starts normally and operates and the current stabilizes for a certain period of time, a retry is performed. Various control parameters changed during operation can be returned to the values at the time of restarting the small stop.

Although preferred embodiments of the present invention have been described and described above, it should be understood that these are exemplary and should not be considered as limiting. Additions, omissions, substitutions, and other modifications may be made without departing from the scope of the invention. Therefore, the present invention should not be considered limited by the above description, but is limited by the claims.

For example, the combination and substitution of the control flows of each of the above-described embodiments can be appropriately performed.

Further, for example, it is preferable that the various control parameters described above are stored in the storage unit 63 of the control device 60 and the settings can be changed from the I / O unit 61. The values of the various control parameters used in the retry operation may be calculated before determining the second starting condition. For example, the control device 60 determines the second start condition (step S108 in FIG. 5B) such as when the protection is stopped (step S107 in FIG. 5B) or the retry is completed (step S111 in FIG. 5B). The value may be calculated and stored in the storage unit 63, and in the retry operation (step S109 in FIG. 5B), the pump 2 may be started based on the value of the control parameter stored in the storage unit 63.

Further, although the pump device 1 described in the above embodiment includes one pump, the number of pumps may be two or more. In that case, the number of the electric motor 3 and the inverter device 70 may be provided according to the number of pumps. Further, the inverter device 70 may be used by switching the connection to the pump to be started. Further, the pump 2 may be a turbo pump regardless of the cascade pump.

FIG. 17 is a schematic view showing a first usage example of the pump device 1 of the present disclosure.
The pump device 1 shown in FIG. 17 is configured to pump water from a well 103a, which is a water supply source, and supply water to a plurality of faucets 102 at different heights in the building 101. The pump device 1 is installed on the ground 103, the faucet 102a is installed at a height h1 from the ground 103, the faucet 102b is installed at a height h2 from the ground 103, and the faucet 102c is installed at a height h3 from the ground 103. Has been done. The higher the installation height of the faucet 102, the higher the discharge pressure PS at the start of the pump 2 at the time of restarting the small stop, and the protection stop of the pump 2 is likely to occur. Therefore, since the optimum control parameters differ depending on which faucet 102a to 102c is opened at the time of restarting the small stop, it is highly effective to install the pump device 1 of the present disclosure in the case of such a usage example.

FIG. 18 is a schematic view showing a second usage example of the pump device 1 of the present disclosure.
The pump device 1 shown in FIG. 18 includes a ground unit 170 and a submersible motor pump 180, and the ground unit 170 and the submersible motor pump 180 are connected by a pumping pipe TB. Such a pump device 1 is provided with the above-mentioned pump 2 and motor 3 as a submersible motor pump 180 outside the unit cover 6, and is suitable for pumping water from, for example, a deep well DW. In the submersible motor pump 180, for example, an electric motor 182, which is a submersible three-phase induction motor, is directly connected to the lower part of a pump 181 which is a single-suction centrifugal type or oblique flow type submersible motor pump for deep wells by a shaft joint.

The ground unit 170 is generally configured by omitting the pump 2 and the electric motor 3 from the pump device 1 described above. Specifically, the ground unit 170 includes a control device 60 and a pressure tank 43 fixed on the unit base 5, a unit cover 6 covering them, a display control unit 140 provided on the upper part of the control device 60, and a unit cover. The display 150 attached to 6 is provided. In FIG. 18, the casing, the pipe, and the pressure tank 43 forming the water flow path in the unit cover 6 are not shown. Such a ground unit 170 supplies water pumped from the submersible motor pump 180 to the water supply destination via the pumping pipe TB and further via the discharge pipe 111.

The ground unit 170 performs the first short-range communication C1 between the display control unit 140 and the display 150, and displays information indicating the state of the pump device 1 on the display 150 attached to the unit cover 6. It is possible. Further, the ground unit 170 can perform the second short-range communication C2 with the external display 160 to display information indicating the state of the pump device 1 on the display screen DP of the external display 160.

The submersible motor pump 180 includes a pump 181 and an electric motor 182 and has a substantially cylindrical outer diameter, and is used in a state of being submerged in water. The pump 181 is, for example, a stainless steel pump and is driven by a motor 182. The electric motor 182 drives the pump 181 under the control of the control device 60. As shown in FIG. 18, for example, the submersible motor pump 180 is arranged so as to be located below the water surface WL (submerged in water) in the deep well DW dug downward from the recess 101, and is arranged via the pumping pipe TB. Water is pumped to the ground unit 170. The electric motor 182 is connected to the ground unit 170 via an underwater cable (not shown) that is wired substantially in parallel with the pumping pipe TB. The control signal calculated by the control device 60 and the electric power of the electric motor 182 are input to the electric motor 182 via the underwater cable. Further, a pressure sensor and a flow detector (not shown) are attached to the pumping pipe TB or the discharge pipe 111 which is the discharge flow path of the pump 181, and the discharge pressure of the pump 181 is detected by the pressure sensor. , The flow rate of the pump 181 (underwater amount Qmin or less) is detected by the flow rate detector. These pressure sensors and the flow rate detector are electrically connected to the I / O unit 61 (see FIG. 5A) of the control device 60.

As described above, in the pump device 1 shown in FIG. 18, the display 150 capable of the first short-range communication C1 and the second short-range communication C2 is attached to the upper surface 115U of the unit cover 6, and information indicating the state of the pump device 1 is shown. Is transmitted from the display 150 to the external display 160 by the second short-range communication C2 and displayed on the display screen DP of the external display 160. As a result, even if the pump device 1 is installed in an environment with poor workability, various information such as an operating state and an alarm can be easily confirmed without removing the unit cover 6. A communication device can be applied instead of the display 150, and further, the window portion 115a of the unit cover 6 formed for the display 150 can be omitted, and NFC with the communication device is possible. It is desirable to put a mark on the upper surface of the unit cover 6 indicating that the part is a visible part (visible part). Even with such a configuration, if the present invention is applied, it is possible to prevent the pump 181 from reaching a protective stop when the pump 181 is started, so that the pump device 1 is highly convenient and can avoid water interruption as much as possible.

FIG. 19 is a schematic view showing a third use example of the pump device 1 of the present disclosure.
The pump device 1 shown in FIG. 19 includes two pumps 2. The two pumps 2 are connected in parallel to the suction flow path 34 branched into two. The upstream side of the suction flow path 34 branched into two merges and communicates with the suction port 7 connected to the water source 110. A check valve 35a and a flow sensor 35b are arranged on the downstream side of the two pumps 2, respectively, and the discharge flow path 41 merges on the downstream side of these two flow sensors 35b, and joins the merged discharge flow path 41. Is provided with a pressure sensor 42 for detecting the discharge pressure PV of the pump 2 and a pressure tank 43. The discharge pressure PV of the pump 2 detected by the pressure sensor 42 is input to the pump control unit 60a (see FIG. 4) via the signal line.

Inside the unit cover 6, two electric motors 3 for driving the two pumps 2 and two inverter devices 70 for supplying electric power to the two electric motors 3 are provided. Two inverter control units 60b are provided corresponding to the two inverter devices 70. On the other hand, the pump control unit 60a is one unit, and controls the two inverter control units 60b in an integrated manner, and outputs control signals of the two pumps 2 to the two inverter devices 70, respectively. In such a configuration, it is preferable that one or a plurality of pumps 2 are started at the time of restarting the small stop in step S102 of FIG. 5B. In addition, it is advisable to add or disconnect the number of pumps 2 in operation as the amount of water used at the supply destination changes. Further, even with such a configuration, if the present invention is applied, it is possible to prevent the pump 2 from reaching a protective stop at the time of starting, so that the pump device 1 is highly convenient and can avoid water interruption as much as possible. The unit cover 6 may accommodate only the inverter device 70 and the pump control unit 60a.

1 Pump device 2 Pump 3 Motor 4 Control unit 5 Unit base 6 Unit cover 7 Suction port 8 Discharge port 20 Impeller 21 Groove 30 Pump casing 31 Pump chamber 32 Internal flow path 32a One end 32b The other end 33 Air-water separation chamber 33a Hole 34 Suction flow path 35 Flow check valve 35a Check valve 35b Flow sensor 36 Connection flow path 37 Baffle 38 Qualifying port 39 Qualifying faucet 40 At priming water level 41 Discharging flow path 42 Pressure sensor 43 Pressure tank 50 Pump casing cover 60 Control device 60a Pump control unit 60b Inverter control unit 61 I / O unit 61a Input unit 61b Output unit 62 Calculation unit 63 Storage unit 64 Operation panel 64a Setting unit 64b Display unit 65 Communication unit 66 External terminal 67 Display operation unit 70 Inverter device 70a Converter unit 70b DC voltage smoothing circuit 70c Inverter 70d Gate driver 71 Voltage sensor 72 Current sensor 80 Temperature sensor 81 Temperature sensor 82 Temperature sensor 100 Commercial power supply 101 Building 102 Faucet 102a Faucet 102b Faucet 102c Faucet 103 Ground 103a Well 110 Water source 111 Discharge pipe 115a Window 115U Top surface 140 Display control unit 150 Display 160 External display 170 Ground unit 180 Submersible motor Pump 181 Pump 182 Motor AL0 Overcurrent protection level AL1 Overcurrent protection level C1 First short-range communication C2 Second short-range communication DP Display screen DW Deep well N Number of retries P0 Start pressure P1 Stop pressure PA Set pressure PAF Command frequency PL0 to PLN Pressure level PL1V Coefficient PL2V Coefficient PS Discharge pressure at start (minimum value)
PV discharge pressure Qmin Underwater amount RPL Retry start pressure S1 Step S2 Step S3 Step S4 Step S4-1 to S4-N Step S5-1 to S5-N Step S5 Step S6 Step S11 Step S12-1 to S12-N Step S13 -1 to S13-N Step S13-1-1 to S13-1-4 Step S14-1 to S14-N Step S15 Step S16 Step S17 Step S18 Step S21 Step S22 Step S23 Step S24-1 to S24-X Step S25 -1 to S25-X Step S25 Step S26 Step S31 Step S32-1 to S32-N Step S33-1 to S33-N Step S33-1 to S33-1-4 Step S34 Step S35 Step S35a Step S36 Step S37 Step S38 Step S41 Step S42 Step S51 Step S52-1 to S52-N Step S53-1 to S53-N Step S53-1-1 to S53-1--4 Step S54 Step S55 Step S56 Step S57 Step S61 Step S62 Step S63 Step S64 Step S65 Step S100 Step S101 Step S102 Step S103 Step S104 Step S105 Step S105-1 Step S106 Step S107 Step S108 Step S108-1 Step S109 Step S110 Step S111 Step S112 Step ST0 to STN Soft start time ST11 to ST1N Soft start Time ST11B Soft start time base value PL1ST coefficient PL2ST coefficient SV Target pressure T1 to TN Interval time T1B Interval time base value TB Pumping pipe PL1T coefficient PL2T coefficient V1 to V2 Torque boost voltage V11 to 1N Torque boost voltage V11B Torque boost voltage Base value VL0 to VLN Torque boost voltage WL Water surface ΔT time ΔT1 hour ΔT2 hours

Claims (13)

With a pump,
The motor that drives the pump and
An inverter device that supplies electric power to the motor and
A pump device including a control device that outputs a control signal of the pump to the inverter device.
The control device is
An input unit for inputting the discharge pressure of the pump and
It is provided with a storage unit for storing the values of control parameters related to the drive control of the electric motor.
The control device is
As a condition for starting the pump, there is a first starting condition in which the discharge pressure is lowered from a pressure higher than a predetermined starting pressure to a pressure lower than the starting pressure.
Under the first starting condition, the minimum value of the discharge pressure after the pump is started is estimated, and the value of the control parameter is set according to the minimum value.
A pump device comprising: when the first starting condition is satisfied, the pump is started based on the value of the control parameter set according to the minimum value. The pump device according to claim 1, wherein the control device estimates the minimum value based on a slope at which the discharge pressure decreases under the first starting condition. The control parameters include a torque boost voltage applied to the motor when the pump is started.
The pump device according to claim 1 or 2, wherein the control device sets the torque boost voltage to a value corresponding to the magnitude of the minimum value to start the pump. The control parameters include an overcurrent protection level, which is a threshold for overcurrent trips.
The pump device according to claim 3, wherein the control device sets the overcurrent protection level according to the torque boost voltage and starts the pump. The control parameters include a soft start time, which is the rate of increase in the rotational speed of the motor.
The pump device according to claim 2 or 3, wherein the control device sets the soft start time to a value corresponding to the magnitude of the minimum value and starts the pump. As a condition for starting the pump, the control device has a second starting condition in which the discharge pressure is equal to or lower than the starting pressure after releasing the protection stop in which the pump is kept in a stopped state to protect the pump device. The pump device according to any one of claims 1 to 5, wherein the pump device comprises. The control device is
The number of times the pump is started under the second starting condition is counted as the number of retries, and the number of retries is counted.
The value of the control parameter set according to the magnitude of the minimum value is changed according to the number of retries.
The pump device according to claim 6, wherein when the second starting condition is satisfied, the pump is started based on the value of the control parameter changed according to the number of retries. 7. The control device is characterized in that the coefficient for changing the value of the control parameter according to the number of retries is corrected according to the magnitude of the minimum value to start the pump. The pump device described in. The control device counts the number of times the pump is started under the second starting condition as the number of retries, and at the same time,
The interval time from when the protection stop of the pump is released to when the pump is restarted is changed according to the number of retries.
The pump according to any one of claims 6 to 8, wherein when the second starting condition is satisfied, the pump is started based on the interval time changed according to the number of retries. Device. The ninth aspect of the present invention is characterized in that the control device corrects a coefficient for changing the interval time according to the number of retries according to the magnitude of the minimum value and starts the pump. Pumping device. The control device is
The number of times the pump is started under the second starting condition is counted as the number of retries, and the number of retries is counted.
The pump device according to any one of claims 6 to 10, wherein the electric motor is rotated in a direction opposite to a normal rotation direction according to the number of retries. The control device changes the value of the control parameter set according to the magnitude of the minimum value according to the discharge pressure when the second starting condition is satisfied, and starts the pump. The pump device according to any one of claims 6 to 11. The control device is characterized by having, as a condition for starting the pump, a third starting condition in which the discharge pressure is equal to or less than the retry start pressure set to be less than the starting pressure after the protection stop is released. The pump device according to any one of claims 6 to 12.

Images