JP7508113B2 - Pump device, variable speed control device, and program - Google Patents

Description

The present invention relates to a pump device, a variable speed control device, and a program that variably controls the speed of a motor that drives a pump.

Pump devices equipped with a variable speed control device that drives the motor that drives the impeller at a variable speed have been known for some time. Pump devices of this type are known to perform a protective operation that causes a slower rise in discharge pressure than normal when the pump is started for the first time after power is turned on (see, for example, Patent Document 1). In addition, devices are known that automatically adjust the output frequency command of the variable speed control device so that the variable speed control device does not become an overvoltage or overcurrent (see, for example, Patent Document 2). In addition, a technology is known for such pump devices that starts the pump when the pump is stopped by an overvoltage protection function (see, for example, Patent Document 3).

Patent No. 5417147 JP 2019-80419 A JP 2020-76371 A

In a pump device, in order to ensure that water comes out immediately when the destination of the water supply, for example a faucet, is opened, it is necessary to quickly increase the output frequency of the variable speed control device when the pump is started. However, by increasing the rate at which the output frequency is increased, when the output frequency reaches, for example, the maximum output frequency, the motor may momentarily perform regenerative operation. For this reason, if the voltage inside the variable speed control device is high when the pump is started, there is a risk that an overvoltage will momentarily occur inside the variable speed control device due to the voltage generated by the regenerative operation. This overvoltage will then cause the pump to be stopped by the overvoltage protection function, resulting in a water outage in which the water supply to the destination is cut off.

The present invention aims to provide a pump device, a variable speed control device, and a program that can prevent the variable speed control device from becoming overvoltage.

According to one aspect of the present invention, a pump device includes a pump, a motor that drives the pump, and a variable speed control device that drives the motor to rotate at a variable speed. The variable speed control device includes a voltage measurement unit that measures the voltage in the variable speed control device. If the voltage value detected by the voltage measurement unit when the pump is stopped is less than a threshold value based on a voltage value at which a preset overvoltage may occur, the pump is started using a normal start-up operation. If the voltage value is equal to or greater than the threshold value, the pump is started using a protective start-up operation in which the increase in output frequency is slower than in the normal start-up operation.

According to one aspect of the present invention, the variable speed control device is a variable speed control device that drives a motor that drives a pump at a variable speed, and the variable speed control device includes a voltage measurement unit that measures the voltage within the variable speed control device, and if the voltage value detected by the voltage measurement unit when the pump is stopped is less than a threshold value based on a voltage value at which a preset overvoltage may occur, the pump is started using a normal start-up operation, and if the voltage value is equal to or greater than the threshold value, the pump is started using a protective start-up operation in which the increase in output frequency is slower than in the normal start-up operation.

According to one aspect of the present invention, the program causes the computer to function as: means for comparing the voltage value in the variable speed control device when the pump is stopped with a threshold value based on the voltage value at which an overvoltage may occur; means for starting the pump with a normal start-up operation if the voltage value is less than the threshold; and means for starting the pump with a protective start-up operation in which the increase rate of the output frequency is slower than in the normal start-up operation if the voltage value is equal to or greater than the threshold.

The present invention provides a pump device, a variable speed control device, and a program that can prevent overvoltage from occurring.

1 is an explanatory diagram showing a schematic configuration of a water supply device according to one embodiment of the present invention; FIG. FIG. 2 is an explanatory diagram showing the configuration of an inverter of a pump device used in the water supply system. 4 is a flowchart showing an example of the operation of the water supply device. 4 is a graph showing the increase in speed during the start-up operation of the pump. 4 is a graph showing the deceleration rate during stopping of the pump.

Below, an example of the water supply device 1 according to the embodiment will be described with reference to Figures 1 to 6.

Figure 1 is an explanatory diagram showing a schematic configuration of a water supply device 1 according to one embodiment of the present invention. Figure 2 is an explanatory diagram showing a schematic configuration of the water supply device 1. Figure 3 is an explanatory diagram showing a schematic configuration of an inverter box 51 provided in a pump device used in the water supply device 1. Figure 4 is a flow chart showing an example of the operation of the water supply device 1.

The water supply device 1 is, for example, an automatic water supply device that supplies water to a water tank, a faucet, a shower head, or the like installed in a building. For example, the water supply device 1 is connected to a water tank or the like, and supplies water from the water tank at increased pressure. The water supply device 1 may also be a so-called direct-connected water supply device that is connected to a water distribution pipe installed in a water main pipe, and increases the pressure of the water supplied from the water distribution pipe.

As shown in FIG. 1, the water supply device 1 includes, for example, a pump device 11, a piping unit 12, and an accumulator 13. The water supply device 1 also includes various sensors such as a pressure detection device 15 and a flow rate detection device 16.

As shown in FIG. 1, the pump device 11 includes multiple pump units 20 and a control panel (variable speed control device) 50. The pump device 11 operates each pump unit 20 individually using the control panel 50, and also operates multiple pump units 20 to pump water to the secondary side. In this embodiment, the pump device 11 includes, for example, two pump units 20. The pump unit 20 includes a motor 30 and a pump 40.

The motor 30 is, for example, a PM motor that uses a permanent magnet. The motor 30 is connected to the control panel 50, for example, by a signal line. The motor 30 is driven and controlled by the control panel 50.

The pump 40 is connected to the motor 30. The pump 40 is a single-stage or multi-stage pump having one or more impellers. The impeller of the pump 40 is directly connected to the motor shaft of the motor 30, or is connected to a main shaft that is connected to the motor shaft via a coupling or the like. The pump 40 increases the pressure of the fluid and pumps it to the secondary side by rotating the impeller in conjunction with the rotation of the motor shaft.

As shown in FIG. 2, the control panel 50 is a computer for controlling the motors 30. As shown in FIG. 2, the control panel 50 includes, for example, the same number of inverter boxes 51 as the number of motors 30, and a control device 60.

The inverter box 51 includes, for example, an inverter 52, a voltage measurement unit 54, a current measurement unit 55, a frequency measurement unit 56, and an inverter control board 53.

The inverter 52 receives an inverter control signal from the control device 60 via the inverter control board 53. The inverter 52 operates in response to this inverter control signal. For example, the inverter 52 controls the operation of the motor 30 in response to the inverter control signal from the control device 60.

As shown in FIG. 3, the inverter 52 includes, for example, a converter section 52a including a converter circuit, an inverter section 52b including an inverter circuit, and a smoothing capacitor 52c. The converter section 52a is, for example, a rectifier device configured with a converter circuit including a diode, a control circuit, and the like. The inverter section 52b is, for example, a frequency generating device configured with an inverter circuit including a power semiconductor element such as an IGBT (Insulated Gate Bipolar Transistor) or an IPM (Intelligent Power Module), a control circuit, and the like. The smoothing capacitor 52c is, for example, a film capacitor. Compared to an electrolytic capacitor, a film capacitor has a large ripple current and a small capacitance.

The inverter 52 configured in this manner is connected to a power source 70. Here, the power source 70 is, for example, a three-phase power source. The current flowing from the power source 70 is converted to direct current by the converter unit 52a, rectified by the smoothing capacitor 52c, converted to variable-voltage, variable-frequency alternating current by the inverter unit 52b, and input to the motor 30.

The voltage measurement unit 54 measures the voltage inside the control panel 50. The voltage measurement unit 54 detects the voltage used to determine whether the control panel 50 is overvoltage. The voltage measurement unit 54 also measures the voltage of the control panel 50 used to select the start operation of the pump 40, which will be described later. The voltage measurement unit 54 also measures the voltage to calculate the power of the control panel 50 used to select the stop operation of the pump 40, which will be described later.

The voltage measurement unit 54 measures, for example, the voltage of the inverter box 51, and as a specific example, the voltage of the inverter 52. The voltage measurement unit 54 measures, as the voltage of the inverter 52, for example, a DC intermediate voltage which is the voltage between the converter unit 52a and the inverter unit 52b. The voltage measurement unit 54 transmits a signal corresponding to the measured voltage to the processor 57. Note that the voltage of the inverter box 51 detected by the voltage measurement unit 54 is not limited to the DC intermediate voltage described above. In another example, the voltage measured by the voltage measurement unit 54 may be a power supply AC voltage which is the voltage of the power supply 70 to which the inverter 52 is connected.

The current measuring unit 55 measures the current in the control panel 50. The current measuring unit 55 measures the current in the control panel 50 used to select the stop operation of the pump 40. The current measuring unit 55 also measures the current for calculating the power of the control panel 50 used to select the stop operation of the pump 40.

The current measurement unit 55 measures, for example, the current of the inverter box 51, and as a specific example, the current of the inverter 52. The current measurement unit 55 measures, as the current of the inverter 52, for example, a DC intermediate current that is a current between the converter unit 52a and the inverter unit 52b. The current measurement unit 55 transmits a signal corresponding to the measured current to the processor 57. Note that the current of the inverter box 51 measured by the current measurement unit 55 is not limited to the DC intermediate current. In another example, the current of the inverter 52 measured by the current measurement unit 55 may be a current supplied from the power source 70 to which the inverter 52 is connected.

The frequency measurement unit 56 detects the output frequency of the inverter 52. The frequency measurement unit 56 transmits a signal corresponding to the measured output frequency to the processor 57.

The inverter control board 53 controls the inverter 52 based on an inverter control signal from the control device 60. The inverter control board 53 includes, for example, a processor 57 and a memory 58.

The processor 57 is a control circuit for controlling the inverter 52. The processor 57 is typically a microcomputer, but may also be a CPU (Central Processing Unit), an FPGA (Field Programmable Gate Array), a DSP (Digital Signal Processor), a DSC (Digital Signal Controller), or other general-purpose or dedicated processor. The processor 57 performs any process, such as communication control, frequency control, etc.

As shown in FIG. 2, the processor 57 is connected to the inverter 52, the voltage measurement unit 54, the current measurement unit 55, and the frequency measurement unit 56. The processor 57 includes, for example, a processing circuit and a memory. The processor 57 includes, for example, a non-volatile EEPROM (registered trademark) area and a memory such as a volatile DRAM area. The processor 57 can function as a communication control processor, a frequency processor, etc. by executing a program stored in the memory or the EEPROM area. Note that the internal configuration of the processor 57 and the division of functions among the various units are for convenience and can be changed as appropriate.

The processor 57 outputs, for example, an inverter control signal received from the control device 60 to the inverter 52 to control the motor 30. In this embodiment, the processor 57 controls the pump 40 by operating at a constant target pressure, etc.

Memory 58 stores various data and programs used by processor 57. Memory 58 includes non-volatile memory such as EEPROM (Electrically Erasable Programmable Read-Only Memory) (registered trademark), ROM (Read only memory), or NAND flash memory. Memory 58 also includes an SSD (Solid State Drive) equipped with flash memory. Memory 58 may also include, in addition to non-volatile memory, a RAM having a work area in which data that may be erased when the power is cut off is expanded.

The control device 60 transmits an inverter control signal to the inverter control board 53 based on signals from the pressure detection device 15, the flow detection device 16, the voltage measurement unit 54, the current measurement unit 55, and the frequency measurement unit 56.

For example, the control device 60 stops and starts the motor 30 based on detection signals corresponding to the flow rate detected by the flow rate detection device 16 and the pressure detected by the pressure detection device 15. As a specific example, when the control device 60 detects that the secondary pressure of the pump 40 calculated from the detection signal detected by the pressure detection device 15 has dropped below a predetermined starting pressure, it drives the motor 30 to start the pump 40. When the control device 60 detects that the flow rate is low based on the detection signal from the flow rate detection device 16, it stops the pump 40.

The control device 60 also controls the rotation speed of the motor 30 based on the pressure detected by the pressure detection device 15, and performs variable speed control of the pump 40 by constant target pressure control such as constant discharge pressure control or constant estimated terminal pressure control. The rotation speed of the pump 40 is the same as the rotation speed of the motor 30, and the rotation speed of the pump 40 (motor 30) has a certain relationship with the output frequency of the inverter 52.

When the voltage in the control panel 50 becomes an overvoltage, the control device 60 performs an overvoltage protection operation to stop the output to the motor 30 and stop the pump 40. The overvoltage protection operation is a function to prevent the control panel 50 from continuing to be in an overvoltage state. Specifically, the control device 60 judges the overvoltage based on the voltage measured by the voltage measurement unit 54. When the control device 60 stops the pump 40 during the start-up operation of the pump 40 and during operation excluding the stop operation after the start-up operation of the pump 40 due to the overvoltage protection operation, the control device 60 starts the pump 40. In other words, when the voltage measurement unit 54 detects an overvoltage, the control device 60 stops the pump 40, and when the voltage measurement unit 54 detects an overvoltage during the start-up operation of the pump 40 and during operation excluding the stop operation after the start-up operation of the pump 40, the control device 60 stops the pump 40 once and restarts the pump.

In addition to controlling the pump unit 20, the control device 60 may transmit operation data to the communication terminal 100 as appropriate, for example, by wirelessly connecting to the communication terminal 100. The operation data is data indicating the operating state of the water supply device 1 at a certain operating point, such as the frequency, current, voltage, pressure, flow rate, vibration value, motor insulation resistance, and water tank settings.

As shown in FIG. 2, such a control device 60 includes, for example, a communication unit 61, an input unit 62, an interface 63, a display unit 64, a setting unit 65, a memory 66, and a processor 67.

The communication unit 61 is an arbitrary communication interface that is controlled by the processor 67 and can communicate with an external device such as the communication terminal 100 using wireless communication technology. The communication unit 61 may be implemented, for example, as a communication module or a communication board. The communication module may be detachably provided on the control board of the control device 60 via a connector, for example. Specifically, the communication unit 61 can connect to an external device such as the communication terminal 100 using wireless communication technology such as the Bluetooth (registered trademark) Low Energy standard (hereinafter also referred to as the BLE standard), Wi-Fi (registered trademark), or NFC, or wired communication technology such as USB.

For example, the communication unit 61 broadcasts an advertising packet including identification information of the control device 60. Also, for example, the communication unit 61 may connect communication with the communication terminal 100 when it receives a connection request from the communication terminal 100 that receives the advertising packet. The communication unit 61 is electrically connected to the processor 67 and is an example of a communication means capable of connecting communication with the communication terminal 100. Note that the broadcast communication of the advertising packet may be performed by either the communication unit 61 or the external communication terminal 100 and received by the other.

The input unit 62 has at least one of a device that accepts user input, such as an operation panel including buttons, a touch panel, a keyboard, a mouse, and a sensor such as a pressure sensor, a microphone, a camera, and the like. The input unit 62 is a device that accepts user input, which is an instruction from any user, such as parameter setting, setting of each operation mode, and the like.

For example, the input unit 62 is configured to allow the user to input a command to start the pump 40, and to input a command to stop the pump 40. When the user performs an operation, the input unit 62 transmits a signal corresponding to the operation to the processor 67.

The interface 63 is a terminal or circuit to which the flow rate detection device 16, the pressure detection device 15, and external terminals can be electrically connected.

The display unit 64 has a display device such as a liquid crystal display or an organic EL display. The display unit 64 may have a speaker, an LED (Light Emitting Diode) lighting unit, etc. instead of or in addition to the display device.

The memory 66 is capable of reading and writing data. The memory 66 stores data used by the processor 67, operation data of the pump 40, and various data and programs used to control the pump 40. The memory 66 includes non-volatile memory such as an EEPROM (Electrically Erasable Programmable Read-Only Memory) (registered trademark), a ROM (Read only memory), or a NAND flash memory. The memory 66 also includes an SSD (Solid State Drive) equipped with a flash memory. In addition to non-volatile memory, the memory 66 may include a RAM having a work area in which data that may be erased when the power is cut off is expanded.

Data stored in memory 66 includes, for example, identification information, codes, tables, etc. that identify control device 60. Memory 66 stores, for example, various programs and various reference values and thresholds as information necessary for control. Note that the various thresholds and setting values are configured so that they can be arbitrarily changed by the user, for example, by operational input.

The memory 66 also stores parameters required for controlling the pump 40. For example, the parameters are data related to control targets, such as rated pressure, terminal pressure, starting pressure, and rated flow rate.

The parameters also include data related to the start-up operation of the pump 40. The data related to the start-up operation includes, for example, a first threshold value T1 for selecting a normal start-up operation or a protective start-up operation, which will be described later. The first threshold value T1 is a preset voltage value that is compared with the voltage value measured by the voltage measurement unit 54, and is a value based on a voltage value at which an overvoltage may occur in the control panel 50 if a normal start-up operation is performed. The first threshold value T1 is, for example, a voltage value equal to or greater than a voltage value at which an overvoltage may occur in the control panel 50.

The parameters also include data related to the stopping operation of the pump 40. The data related to the stopping operation includes, for example, a second threshold T2 for selecting a normal stopping operation or a protective stopping operation, which will be described later. In this embodiment, the second threshold T2 includes a third threshold T23 used to determine whether a first condition, which is one of the conditions for performing a protective stopping operation, is satisfied, and a fourth threshold T24 used to determine whether a second condition, which is another condition for performing a protective stopping operation, is satisfied.

The third threshold T23 is a preset frequency of the inverter 52 or a rotation speed of the motor 30, and is a value based on a frequency or rotation speed at which an overvoltage may occur in the control panel 50 if a normal start-up operation is performed. The third threshold T23 is, for example, a value equal to or greater than the output frequency or rotation speed at which an overvoltage may occur in the control panel 50 if a normal stop operation is performed.

The fourth threshold T24 is a preset current value or power value, and is compared with the current value measured by the current measurement unit 55, or the power calculated based on the current value measured by the current measurement unit 55 and the voltage value measured by the voltage measurement unit 54. The fourth threshold T24 is a value based on a current value or power value at which an overvoltage may occur in the control panel 50 when a normal shutdown operation is performed. The fourth threshold T24 is, for example, a value equal to or greater than a current value or power value at which an overvoltage may occur in the control panel 50 when a normal shutdown operation is performed.

The condition for performing the protection stop operation may be only one of the first condition and the second condition. For example, if the condition for performing the protection stop operation is that only the first condition is satisfied, the second threshold T2 includes only the third threshold T23 and does not include the fourth threshold T24. Alternatively, if the condition for performing the protection stop operation is that only the second condition is satisfied, the second threshold T2 includes only the fourth threshold T24 and does not include the third threshold T23.

For example, when the water supply device 1 is being test-run in the manufacturing process or after the water supply device 1 is installed, the initial values of the parameters are set by an operator operating the input section 62 of the control device 60, or by connecting an external terminal to the interface 63 and operating the external terminal.

The processor 67 is a general control unit. The processor 67 is typically a microcomputer, but may be a CPU (Central Processing Unit), an FPGA (Field Programmable Gate Array), a DSP (Digital Signal Processor), or other general-purpose or dedicated processor. The processor 67 performs any process, such as communication control, display control, and pump control. As shown in FIG. 2, the processor 67 is connected to the flow rate detection device 16, the pressure detection device 15, the inverter 52, the voltage measurement unit 54, the current measurement unit 55, and the frequency measurement unit 56, for example, via the interface 63 and the inverter control board 53.

The processor 67 includes, for example, a processing circuit and a memory. The processor 67 includes, for example, a non-volatile EEPROM area 67a and a volatile DRAM area 67b. The processor 67 can also function as a communication control unit 67c and a pump control unit 67d, etc., by executing a program stored in the memory 66 or the EEPROM area 67a. The division of functions among the various parts of the processor 67 is for convenience and can be changed as appropriate.

The communication control unit 67 c controls the communication unit 61 to perform wireless communication with the communication terminal 100 .
The pump control unit 67d acquires operating data indicating the operating state of the water supply device 1 based on detection signals from various sensors including the pressure detection device 15, the flow rate detection device 16, the voltage measurement unit 54, the current measurement unit 55, and the frequency measurement unit 56, and stores the operating data in the memory 66, the EEPROM area 67a and/or the DRAM area 67b.

The pump control unit 67d also generates an inverter control signal based on the program for pump control stored in the memory 66 or the EEPROM area 67a and on each parameter, and outputs the inverter control signal to the inverter 52 via the inverter control board 53 to control the motor 30. As a result, the pump control unit 67d starts the pump 40, controls the pump 40 by, for example, constant target pressure control, and stops the pump 40.

Below, an example of the control function of the pump 40 by the processor 67 is described. Here, the examples of the control function are a control function in which the processor 67 performs a start-up operation to start the pump 40 based on a program, a control function in which the pump 40 operates under constant target pressure control, a control function in which the pump 40 is stopped, and a control function in which the pump 40 is stopped when an overvoltage is determined based on the voltage value measured by the voltage measurement unit 54.

An example of a control function is a control function in which the processor 67, based on a program, determines an overvoltage based on the voltage measured by the voltage measuring unit 54 during the start-up operation of the pump 40 or during operation of the pump 40 after the start-up operation but excluding the stop operation, and then restarts the pump 40.

The processes performed by the pump control unit 67d can be set as appropriate, and therefore will be described below as an example of the processes performed by the processor 67. The memory 66, the EEPROM area 67a, and the DRAM area 67b can be set as appropriate for reading and storing various data, and therefore the reading and storing of various data will be described below as an example using the memory 66.

Based on the program, the processor 67 performs a process of measuring the voltage inside the control panel 50 using the voltage measuring unit 54 when the pump 40 is stopped. The voltage inside the control panel 50 is measured by the voltage measuring unit 54, for example, immediately before the pump 40 is started.

"Immediately before the start of the pump 40" refers to, for example, any point in time during the period from when the user operates the input unit 62 to start the pump 40 and a signal corresponding to the start of the pump 40 is input from the input unit 62 to the processor 67 until the processor 67 transmits an inverter control signal for starting the pump 40 to the inverter 52.

Or, "just before starting the pump 40" refers to, for example, any point in time during the period from when the pressure on the secondary side of the pump 40 drops to the starting pressure and the processor 67 receives a signal from the pressure detection device 15 indicating that the starting pressure has been detected to when the processor 67 transmits an inverter control signal for starting the pump 40 to the inverter 52.

The processor 67 performs a process of comparing the voltage value measured by the voltage measurement unit 54 with the first threshold value T1 when the pump 40 is stopped. If the voltage value measured by the voltage measurement unit 54 is less than the first threshold value T1, the processor 67 performs a normal start-up operation as the start-up operation of the pump 40.

Normal startup operation is a startup operation that increases the output frequency of the inverter 52 from zero at a preset acceleration rate. The preset acceleration rate for normal startup operation is an acceleration rate that does not pose a risk of overvoltage occurring in the control panel 50, and is, for example, an acceleration rate that causes water to come out immediately when a water supply source such as a faucet is turned on.

The normal startup operation is, for example, a startup operation that increases the output frequency of the inverter 52 from zero to the maximum output frequency WM in a preset first acceleration time t1. The first acceleration time t1 is, for example, 0.6 seconds. The normal startup operation increases the output frequency of the inverter 52 at a preset, specific gradient, for example.

Figure 5 shows an example of a setting value for the increase rate of the output frequency of the inverter 52 during normal start-up operation, and an example of a setting value for the increase rate of the output frequency of the inverter 52 during protective start-up operation, which will be described later. In Figure 5, the horizontal axis represents time, and the vertical axis represents the output frequency of the inverter 52.

In addition, the processor 67 performs a protective start-up operation based on the program when the voltage measured by the voltage measuring unit 54 is equal to or greater than the first threshold T1.

The protective start-up operation is a start-up operation in which the rate of increase in the output frequency of the inverter 52 is slower than in the normal start-up operation. A start-up operation in which the rate of increase in the output frequency of the inverter 52 is slower than in the normal start-up operation is a start-up operation in which there is no risk of overvoltage occurring in the control panel 50 even when the voltage in the control panel 50 is equal to or higher than the first threshold value T1.

Making the rate of increase in the output frequency of the inverter 52 slower than in normal startup operation means, for example, making the rate of change in the output frequency of the inverter 52 per unit time during the period in which the output frequency of the inverter 52 increases from zero to the maximum output frequency smaller than in normal startup operation. This rate of change in the output frequency per unit time is the maximum output frequency of the inverter 52 divided by the time it takes for the output frequency of the inverter 52 to increase from zero to the maximum output frequency.

One example of this is to lengthen the period during which the output frequency of the inverter 52 increases from zero to the maximum output frequency compared to normal startup operation. A specific example is to increase the output frequency of the inverter 52 from zero to the maximum output frequency WM in a preset second acceleration time t2 that is longer than the first acceleration time t1. In this example, as shown by output frequency L21 in FIG. 5, the output frequency L2 of the inverter 52 may increase from zero to the maximum output frequency WM in the second acceleration time t2 at a preset predetermined gradient, or may not increase at a predetermined gradient.

There may be, for example, multiple second acceleration times t2. Then, one of the multiple second acceleration times may be selected depending on the result of the comparison between the voltage measured by the voltage measurement unit 54 and the first threshold value T1. For example, t21, t22, t23, and t24 are stored as the second acceleration times t2, where t21<t22<t23<t24. Then, based on the comparison between the voltage in the control panel 50 and the first threshold value T1, one of t21, t22, t23, and t24 is used.

Alternatively, the second acceleration time t2 may be extended, for example, from the time set at the start of the protective start-up operation, depending on the measurement results of the voltage measurement unit 54 during the protective start-up operation.

Another example of slowing down the rate of increase in the output frequency of the inverter 52 compared to normal startup operation is to increase the output frequency of the inverter 52 from zero to the maximum output frequency at multiple slopes, as shown by lines L22 and L23 in Figure 5.

In this example, for example, any of the multiple slopes may be the same as the rate of change per unit time of the output frequency of the inverter 52 in normal startup operation, or may be greater than the rate of change per unit time of the output frequency of the inverter 52 in normal startup operation. Also, in this example, the time it takes to increase the output frequency of the inverter 52 from zero to the maximum output frequency may be the first acceleration time t1 or the second acceleration time t2.

For example, as shown by line L22, after the protective start-up operation begins, the slope of the increase in the output frequency of the inverter 52 in a predetermined period, i.e., the rate of change of the output frequency per unit time, may be greater than that in the normal start-up operation. Alternatively, the slope of the increase in the output frequency of the inverter 52 in this predetermined period may be the same as the rate of change per unit time of the output frequency of the inverter 52 in the normal start-up operation. Alternatively, the slope of the increase in the output frequency of the inverter 52 in a predetermined period including the time when the output frequency of the inverter 52 reaches the maximum output frequency may be greater than that in the normal start-up operation. Alternatively, the slope of the increase in the output frequency of the inverter 52 in this predetermined period may be the same as the rate of change per unit time of the output frequency of the inverter 52 in the normal start-up operation.

In addition, when the processor 67 determines, based on the program, on the voltage measured by the voltage measuring unit 54 that an overvoltage has occurred, it stops the pump 40.

In addition, based on the program, the processor 67 restarts the pump 40 when the pump 40 is stopped by the overvoltage protection function during the start-up operation of the pump 40 and during operation of the pump 40 after the start-up operation, excluding the stop operation of the pump 40.

In addition, in this embodiment, the normal start-up operation is set in the memory 66 etc. as the initial setting for the start-up operation. If the voltage value measured by the voltage measuring unit 54 before starting the pump 40 is equal to or greater than the first threshold value T1, the processor 67 sets the protective start-up operation as the start-up operation. Furthermore, when the processor 67 starts the pump 40 with the protective start-up operation, it returns the start-up operation setting to the normal start-up operation before the next start-up operation of the pump 40 is started.

The processor 67 returns the start-up operation setting to normal start-up operation, for example, when it receives a signal from the pressure detection device 15 that detects the target pressure, when the pump 40 stops, or when the stop conditions for the pump 40 are met.

The time when the pump 40 is stopped is, for example, any point in the period from when the processor 67 starts the stopping operation of the pump 40 to stop the pump 40 to when the processor 67 next starts the starting operation of the pump 40.

The stop condition of the pump 40 is satisfied, for example, when the user operates the input unit 62 to stop the pump 40 and the processor 67 receives a signal from the input unit 62 indicating that the stop operation has been performed. Alternatively, the stop condition of the pump 40 is satisfied, for example, when the flow detection device 16 detects the stop flow rate and the processor 67 receives a signal from the flow detection device 16.

Alternatively, after the protective start-up operation has commenced, when the processor 67 detects a drop in the intermediate current of the inverter 52 based on a signal from the current measurement unit 55, the processor 67 may return the start-up operation of the pump 40 to the normal start-up operation.

Alternatively, the processor 67 may return the setting of the start-up operation of the pump 40 to the normal start-up operation when the pump 40 is started by the protective start-up operation and the control of the output frequency of the inverter 52 is transitioned to PI control. Alternatively, the processor 67 may return the start-up operation of the pump 40 to the normal start-up operation when the output frequency of the inverter 52 is maintained at the maximum output frequency for a preset certain period of time after the protective start-up operation of the pump 40 is initiated.

After the pump 40 starts up, the processor 67 performs water supply processing by operating the pump 40 independently with constant target pressure control based on, for example, a program. The processor 67 controls the output frequency of the inverter 52 based on, for example, the flow rate and pressure detected by the flow rate detection device 16 and the pressure detection device 15, the rotation speed (frequency) of the motor 30, and various data and programs stored in the memory 66, etc., and drives and controls the pump 40 with constant target pressure control. This allows the pump 40 to perform water supply processing by operating alone.

In addition, for example, when the pumps 40 are driven under constant target pressure control, the processor 67 performs an increase process to increase the number of pumps 40 and a decrease process to decrease the number of pumps 40.

Furthermore, the processor 67 performs a process of determining whether or not the stop conditions for the pump 40 are satisfied while the pump 40 is in operation, for example based on a program. Then, when the processor 67 determines that the stop conditions for the pump 40 are satisfied, it performs a process of determining whether or not the conditions for performing a protective start-up operation are satisfied, for example, immediately before starting the stop operation of the pump 40. In this embodiment, the condition for performing the protective stop operation is that both the first condition and the second condition are satisfied. When the processor 67 determines that at least one of the first condition and the second condition is not satisfied, it performs a process of performing a normal start-up operation as the stop operation of the pump 40.

The normal stopping operation is a stopping operation that reduces the output frequency of the inverter 52 to zero at a preset deceleration rate. The preset deceleration rate for the normal stopping operation is a deceleration rate that does not pose a risk of overvoltage occurring in the control panel 50.

The normal stopping operation is, for example, a stopping operation in which the output frequency of the inverter 52 is decreased to zero at a preset, specific rate of change per unit time. This rate of change is the rate at which the output frequency of the inverter 52 is decreased from the maximum output frequency to zero in a preset, specific first deceleration time t3, and is the value obtained by dividing the maximum output frequency by the first deceleration time t3.

Figure 6 shows an example of a set value of the deceleration rate of the output frequency of the inverter 52 in a normal stop operation, and an example of a set value of the deceleration rate of the output frequency of the inverter 52 in a protective stop operation described below. In Figure 6, the horizontal axis indicates time, and the vertical axis indicates frequency. As shown in Figure 6, in the example of this embodiment, the normal stop operation is a deceleration rate that reduces the output frequency of the inverter 52 to zero at a constant slope, as shown by line L3 in Figure 6.

The time immediately before the stopping operation is, for example, when the user operates the input unit 62 to stop the pump 40 and the processor 67 receives a signal from the input unit 62 indicating that the stopping operation has been performed. Or, for example, the time immediately before the stopping operation is when the flow detection device 16 detects the stopping flow rate and the processor 67 receives a signal from the flow detection device 16.

The first condition is that the output frequency of the inverter 52 or the rotation speed of the motor 30 is equal to or greater than the third threshold T23. The third threshold T23 is the output frequency or rotation speed at which performing a normal stop operation may cause an overvoltage in the control panel 50.

The output frequency of the inverter 52 and the rotation speed of the motor 30 may be measured values or command values. The output frequency of the inverter 52 can be measured by the frequency measurement unit 56. Since the rotation speed of the motor 30 has a certain relationship with the output frequency of the inverter 52, the rotation speed of the motor 30 can be detected based on the measurement result of the frequency measurement unit 56.

Note that the rotation speed of the motor 30 is not limited to being detected based on the output frequency of the inverter 52. For example, the processor 67 may use the rotation speed of the motor 30 detected by other means.

The command value for the output frequency of the inverter 52 is the command value for the output frequency transmitted from the inverter control board 53 to the inverter 52. The command value for the rotation speed is calculated, for example, based on the command value for the output frequency transmitted from the inverter control board 53 to the inverter 52.

The second condition is, for example, that the load acting on the motor 30 is a light load. An example of a light load is that the current measured by the current measuring unit 55, or the power calculated based on the current measured by the current measuring unit 55 and the voltage measured by the voltage measuring unit 54, is equal to or less than the fourth threshold value T24. The fourth threshold value T24 is a current value or power value at which an overvoltage may occur in the control panel 50 when a normal stopping operation is performed.

The current measured by the current measuring unit 55 is, for example, a DC intermediate current between the converter unit 52a and the inverter unit 52b. Note that the current in the control panel 50 measured by the current measuring unit 55 is not limited to the DC intermediate current between the converter unit 52a and the inverter unit 52b. In another example, the current measuring unit 55 may measure, for example, the output current from the inverter 52 to the motor 30. The power in the control panel 50 is, for example, the power between the converter unit 52a and the inverter unit 52b. Note that, although measured values are used for the current value and power value in the control panel 50, this is not limiting. In another example, the current value and power value in the control panel 50 may be command values.

Furthermore, when the processor 67 determines based on the program that both the first condition and the second condition are satisfied, it performs a protective stop operation. The protective stop operation is a stop operation in which the deceleration rate of the output frequency of the inverter 52 is slower than that of the normal stop operation. A stop operation in which the deceleration rate of the output frequency of the inverter 52 is slower than that of the normal stop operation is a stop operation in which there is no risk of overvoltage occurring in the control panel 50 even when both the first condition and the second condition are satisfied.

Making the deceleration of the output frequency more gradual compared to normal stopping operation means, for example, making the rate of change of the output frequency of the inverter 52 per unit time during the period from the start of the stopping operation until the output frequency of the inverter 52 drops to zero smaller compared to normal stopping operation.

The output frequency of the inverter 52 at the start of the protective stop operation is greater than the output frequency of the inverter 52 at the start of the normal stop operation. For this reason, the protective stop operation lengthens the time it takes for the output frequency of the inverter 52 to drop to zero from the start of the stop operation compared to the normal stop operation so that the rate of change of the output frequency of the inverter 52 per unit time is smaller than the rate of change of the output frequency of the inverter 52 per unit time in the normal stop operation.

In this embodiment, the rate of change of the output frequency per unit time in the protective stop operation is decelerated at the same rate of change as the rate of change of the output frequency per unit time when the output frequency of the inverter 52 is decreased from the maximum output frequency to zero in a predetermined second deceleration time t4 that is longer than the first deceleration time t3. As another example of this, as shown by line L41 in FIG. 6, the protective stop operation may decrease the output frequency of the inverter 52 at a predetermined slope that is set in advance.

The second deceleration time T4 may be, for example, multiple. Then, one of the multiple second deceleration times may be selected based on the result of comparing the output frequency of the inverter 52 or the rotation speed of the motor 30 with the third threshold T23, and the result of comparing the current value detected by the current measurement unit 55, or the power value based on the current value detected by the current measurement unit 55 and the voltage value measured by the voltage measurement unit 54, with the fourth threshold T24.

For example, t41, t42, t43, and t44 are stored as the second deceleration time t4, where t41<t42<t43<t44. Then, based on the result of comparing the output frequency of the inverter 52 or the rotation speed of the motor 30 with the third threshold value T23, and the result of comparing the current value detected by the current measurement unit 55, or the power value based on the current value detected by the current measurement unit 55 and the voltage value measured by the voltage measurement unit 54, with the fourth threshold value T24, any one of t41, t42, t43, and t44 is used.

Alternatively, the second deceleration time t4 may be extended, for example, from the time set at the start of the protective stop operation, depending on the output frequency of the inverter 52 or the rotation speed of the motor 30 during the protective stop operation, and the current value detected by the current measurement unit 55, or the power value based on the current value detected by the current measurement unit 55 and the voltage value measured by the voltage measurement unit 54.

Another example of deceleration that slows down the output frequency compared to normal stop operation may be to decrease the output frequency of the inverter 52 to zero with multiple slopes. In this example, for example, any of the multiple slopes may be greater than the rate of change of the output frequency per unit time of the output frequency of the inverter 52 in normal stop operation, or may be the same as the rate of change of the output frequency per unit time of the output frequency of the inverter 52 in normal stop operation.

For example, as shown by output frequency L42 in FIG. 6, the rate of change of the output frequency of the inverter 52 per unit time in a predetermined period from the start of the stopping operation of the pump 40 may be greater than that in normal starting operation. Or, in another example, as shown by output frequency L43 in FIG. 5, the rate of change of the output frequency of the inverter 52 per unit time in a predetermined period including the time when the output frequency of the inverter 52 drops to zero may be greater than that in normal starting operation.

In this embodiment, the normal stop operation is set in the memory 66 etc. as the initial setting for the stop operation. When both the first condition and the second condition are satisfied, the processor 67 sets the protective stop operation as the stop operation. When the processor 67 stops the pump 40 by the protective stop operation, or when the start conditions for the pump 40 are satisfied during the protective stop operation and the start operation of the pump 40 is initiated, the processor 67 returns the setting for the stop operation to the normal stop operation.

The state in which the pump 40 is stopped refers to a state in which the output frequency of the inverter 52 is zero, or a state in which the rotation speed of the motor 30 is 0 min ^-1 . Note that the state in which the pump 40 is stopped may also be a state in which the command value for the output frequency of the inverter 52 is zero, or a command value for the rotation speed of the motor 30 is 0 min ^-1 .

In this way, the program functions as a means for performing a process of measuring the voltage inside the control panel 50 using the voltage measurement unit 54, a means for performing a process of comparing the voltage measurement value by the voltage measurement unit 54 with the first threshold value T1, a means for performing a process of performing a normal start-up operation, a means for performing a process of performing a protective start-up operation, and a means for stopping the pump 40 using the overvoltage protection function.

The program also causes the control panel 50 to function as a means for performing a process to restart the pump 40 when the pump 40 is stopped temporarily by the overvoltage protection function during the start-up operation of the pump 40 and during operation after the start-up operation but excluding the stop operation. The program also causes the control panel 50 to function as a means for determining whether the stop condition of the pump 40 is satisfied, a means for performing a process to determine whether both the first condition and the second condition are satisfied, a means for performing a process to perform a normal start-up operation, and a means for performing a protective stop operation.

In this embodiment, the water supply device 1 has a plurality of pump units 20, and therefore the control panel 50 has a control device 60. However, if there is only one pump unit 20, the water supply device 1 does not have the control device 60, and the inverter box 51 has the function of the control device 60, and the inverter box 51 may be configured to control the start and stop operations of the pump 40 as described above based on signals from the pressure detection device 15, the flow detection device 16, the voltage measurement unit 54, the current measurement unit 55, and the frequency measurement unit 56.

As shown in FIG. 1, the piping unit 12 includes, for example, a check valve 12a connected to each pump 40 and a connecting pipe 12b connected to the check valve 12a. The check valve 12a is provided on the secondary side of the pump 40 and prevents backflow of water to the discharge port of the pump 40.

The accumulator 13 is connected to, for example, the connecting pipe 12b. The pressure detection device 15 is configured to be able to detect the starting pressure of the pump 40 of the pump device 11. The pressure detection device 15 is provided on the secondary side of the pump device 11, for example, on the secondary side of the connecting pipe 12b, and detects the pressure on the secondary side of the connecting pipe 12b.

The flow rate detection device 16 is configured to be able to detect the stop flow rate of the pump 40. The flow rate detection device 16 is provided, for example, on the secondary side of each pump 40 and detects the discharge flow rate of each pump 40.

Next, an example of a communication terminal 100 that performs data communication with the water supply device 1 will be described below. The communication terminal 100 is an information processing device that can communicate with the water supply device 1. Examples of the communication terminal 100 include, but are not limited to, a PC or a mobile terminal. As shown in FIG. 2, the communication terminal 100 includes, for example, a communication unit 101, an input unit 102, a memory 103, and a processor 104.

The communication unit 101 is an arbitrary communication interface that is controlled by the processor 104 and can communicate with an external device such as the water supply device 1 using wireless communication technology. The input unit 102 is an input I/F for accepting user input, and may be built into the communication terminal 100 or may be externally attached to the communication terminal 100.

Memory 103 stores programs executed by processor 104 to realize each process, data used by processor 104, etc.

The processor 104 is typically a CPU, but may also be a microcomputer, FPGA, DSP, or other general-purpose or dedicated processor. The processor 104 performs wireless communication with the water supply device 1 via the communication unit 101. The processor 104 can function as the communication terminal 100 by executing a program stored in the memory 103. Note that the division of functions among the various units within the processor 104 is for convenience and can be changed as appropriate.

Next, an example of water supply by constant target pressure control of the water supply device 1 according to this embodiment will be described with reference to the flow chart shown in FIG.
The processor 67 determines whether or not a start condition for the pump 40 is satisfied while the pump 40 is stopped (step ST1). In the example of the present embodiment, the start condition is satisfied when a start signal is received from the input unit 62, or when the secondary pressure of the pump 40 detected by the pressure detection device 15 becomes equal to or lower than a start pressure as a threshold value stored in the memory 66 or the like.

If the start condition is not satisfied (NO in step ST1), the processor 67 keeps the pump 40 stopped. If the processor 67 determines that the start condition is satisfied (YES in step ST1), for example, immediately before starting the pump 40, the processor 67 measures the voltage in the control panel 50 using the voltage measurement unit 54 and compares the measured voltage with the first threshold value T1 (step ST2).

If the voltage detected by the voltage measuring unit 54 is less than the first threshold T1 (YES in step ST2), the processor 67 starts the pump 40 using normal startup operation (step ST3).

When the processor 67 starts the pump 40, it operates the pump 40 with constant target pressure control (step ST4). If the voltage in the control panel 50 is equal to or greater than the first threshold T1 (NO in step ST2), the processor 67 starts the pump 40 with a protective start-up operation (step ST5).

While the pump 40 is operating under constant target pressure control, the processor 67 determines whether the stop condition for the pump 40 is satisfied (step ST6). In the example of this embodiment, the stop condition is satisfied when a signal to stop the pump 40 is received from the input unit 62, or when the flow rate detected by the flow detection device 16 becomes equal to or lower than a threshold stop flow rate stored in the memory 66 or the like.

If the stop condition is not satisfied (NO in step ST6), the processor 67 maintains the operation of the pump 40 and continues to determine whether the stop condition of the pump 40 is satisfied. If the stop condition is satisfied (YES in step ST6), the processor 67 determines whether both the first condition and the second condition are satisfied immediately before stopping the pump 40 (step ST7). If both the first condition and the second condition are satisfied (YES in step ST7), the processor 67 performs a protective stop operation (step ST8).

When the processor 67 determines that at least one of the first condition and the second condition is not satisfied (NO in step ST7), it performs normal start-up operation (step ST9).

According to the water supply device 1 configured in this manner, when the control panel 50 detects that the voltage measured by the voltage measuring unit 54 is equal to or greater than the first threshold value T1 when the pump 40 is stopped, the control panel 50 performs a protective start operation. Since the increase in the output frequency of the inverter 52 due to the protective stop operation is slower than the increase in the output frequency of the inverter due to the normal start operation, even if the motor 30 regenerates after the output frequency of the inverter 52 reaches the maximum output frequency, the voltage generated by the regeneration can be reduced. Therefore, even if the voltage in the control panel 50 is high when the pump 40 is stopped, it is possible to prevent overvoltage from occurring. As a result, it is possible to prevent the pump 40 from stopping due to the overvoltage protection function, and it is possible to prevent a water outage in which the water supply to the water supply destination is cut off. Furthermore, since the voltage generated by the regeneration of the motor 30 can be reduced, a capacitor with a large ripple current and a small capacitance can be used as the smoothing capacitor 52c of the inverter 52. As an example of a capacitor with a large ripple current and a small capacitance, a film capacitor can be used. Furthermore, by using software such as a program, it is possible to prevent overvoltage from occurring in the control panel 50, so overvoltage can be prevented at low cost. Furthermore, by using the above-mentioned program on existing water supply devices 1, overvoltage can be prevented from occurring.

In addition, when the pump 40 is started with the protective start-up operation, the start-up operation setting is returned to the normal start-up operation before the next start-up of the pump 40. Therefore, when the voltage inside the control panel 50 when the pump 40 is stopped is less than the first threshold value T1, the pump 40 can be started with the normal start-up operation without being started with the protective start-up operation. Therefore, when the voltage inside the control panel 50 is less than the first threshold value T1, there is no delay in the supply of water to the destination, and it is possible to prevent the user from feeling uncomfortable.

In addition, even if the pump 40 is stopped by the overvoltage protection function during the start-up operation of the pump 40 or while the pump 40 is operating after the start-up operation but excluding the stop operation of the pump 40, the period of water outage can be shortened by retrying to restart the pump 40.

As described above, the pump device 11 according to this embodiment can prevent overvoltage from occurring within the control panel 50.

The present invention is not limited to the above-described embodiment. For example, the program for implementing the above-described processing, the data related to the normal start-up operation, the data related to the protective start-up operation, the first to fourth thresholds, the data related to the normal stop operation, and the data related to the protective stop operation may be stored in a computer-readable storage medium and provided. The program, the data related to the normal start-up operation, the data related to the protective start-up operation, the first to fourth thresholds, the data related to the normal stop operation, and the data related to the protective stop operation are stored in the storage medium as an installable file or an executable file. Examples of storage media include magnetic disks, optical disks (CD-ROMs, CD-Rs, DVDs, etc.), magneto-optical disks (MOs, etc.), and semiconductor memories. The storage medium may be any medium that can store a program and is readable by a computer. In addition, the program for implementing the above-described processing, the data related to the normal start-up operation, the data related to the protective start-up operation, the first to fourth thresholds, the data related to the normal stop operation, and the data related to the protective stop operation may be stored on a computer (server) connected to a network such as the Internet, and downloaded to a computer (client) via the network.

In the above example, the configuration in which the protective stop operation is performed when the stop condition of the pump 40 is satisfied and both the first condition and the second condition are satisfied before stopping the pump 40 has been described as an example, but is not limited to this. In another example, the protective stop operation may be performed when the stop condition of the pump 40 is satisfied and at least one of the first condition and the second condition is satisfied before stopping the pump 40.
In the above example, a configuration in which it is determined whether the first condition and the second condition are satisfied is described as an example, but this is not limiting. In another example, it may be a configuration in which it is determined whether only the first condition is satisfied, and protection stop operation is performed when the first condition is satisfied. Alternatively, it may be a configuration in which it is determined whether only the second condition is satisfied, and protection stop operation is performed when the first condition is satisfied.

In the above example, the control panel 50 is configured to perform a protective stop operation when the stop condition of the pump 40 is satisfied and both the first condition and the second condition are satisfied, but this is not limiting. In another example, when the stop condition of the pump 40 is satisfied and the control panel 50 detects that the DC intermediate voltage of the inverter 52 is equal to or higher than a threshold, which is a preset voltage value, during deceleration of the output frequency in the normal stop operation, the control panel 50 may switch the stop operation from the normal stop operation to the protective stop operation. The threshold is a value based on a voltage value at which an overvoltage may occur in the control panel 50. The threshold is, for example, a voltage value equal to or higher than a voltage value at which an overvoltage may occur in the control panel 50.

In the above example, the state in which the second condition is satisfied is described as being the current measured by the current measuring unit 55, or the power calculated based on the current measured by the current measuring unit 55 and the voltage measured by the voltage measuring unit 54 being equal to or less than the fourth threshold value T24, but is not limited to this. In another example, the state in which the second condition is satisfied may be, for example, a state in which the pump 40 is running idle. The idling of the pump 40 can be detected, for example, by detecting that the pressure on the secondary side of the pump 40 has dropped below a preset pressure, detecting that the rotation speed of the pump 40 is higher than the preset rotation speed, and detecting that the flow rate detection device 16 is not detecting the stop flow rate.

In the above example, when the pump 40 is started after being stopped by the overvoltage protection function, i.e., when a retry is performed, a normal start-up operation or a protective start-up operation is performed by comparing the voltage measured by the voltage measurement unit 54 with the first threshold value T1. However, this is not limiting. In another example, the start-up operation of the pump 40 due to a retry may be a start-up operation in which the increase in the output frequency of the inverter 52 is slower than in the normal start-up operation.

As an example of this, the start-up operation of the pump 40 due to a retry may be a protective start-up operation. When the start-up operation of the pump 40 due to a retry is performed as a protective start-up operation, after starting the pump 40 with the protective start-up operation, it is not necessary to return the start-up operation setting of the pump 40 to the normal start-up operation before the next start-up operation. Alternatively, the start-up operation of the pump 40 due to a retry may be a start-up operation in which the increase rate of the output frequency from the inverter 52 is slower than in the protective start-up operation.

In the above example, the normal startup operation is initially set as the startup operation in the memory 66, etc., and the protective startup operation is set based on a comparison between the detection value of the voltage measurement unit 54 when the pump 40 is stopped and the first threshold value T1. However, this is not limiting. In other examples, instead of setting the initial startup operation as the startup operation, the normal startup operation or the protective startup operation may be selected based on a comparison between the detection value of the voltage measurement unit 54 when the pump 40 is stopped and the first threshold value T1.

In the above example, the normal start-up operation and the protective start-up operation are described as an example of a configuration in which the output frequency of the inverter 52 is increased from zero to the maximum output frequency, but are not limited to this. In another example, the normal start-up operation and the protective start-up operation may be an operation of increasing the output frequency of the inverter 52 until the pressure on the secondary side of the pump 40 increases to the target pressure.

In the above example, after the pump 40 is stopped by the overvoltage protection function, the pump 40 is started (i.e., retried), and then when the pump 40 is stopped, a normal stop operation or a protective stop operation is performed based on whether or not both the first condition and the second condition are satisfied. However, this is not limiting. In another example, when the pump 40 is stopped after starting the pump 40 by retry, it may be possible to perform a stop operation in which the deceleration of the output frequency of the inverter 52 is slower than that in the normal stop operation, without determining whether or not both the first condition and the second condition are satisfied.

As an example of this, the stopping operation after a retry of the pump 40 may be the same as the protective stopping operation. In this case, for example, if the previous stopping operation was a protective stopping operation, it is not necessary to return the stopping operation setting to the normal starting operation. Alternatively, when stopping the pump 40 after a start operation of the pump 40 due to a retry, the stopping operation may be a stopping operation in which the deceleration rate of the output frequency from the inverter 52 is made gentler than that of the protective stopping operation.

The present invention is not limited to the above-described embodiment, and various modifications can be made in the implementation stage without departing from the gist of the invention. The embodiments may be implemented in appropriate combination, in which case the combined effects can be obtained. Furthermore, the above-described embodiment includes various inventions, and various inventions can be extracted by combinations selected from the multiple constituent elements disclosed. For example, if the problem can be solved and an effect can be obtained even if some constituent elements are deleted from all the constituent elements shown in the embodiment, the configuration from which these constituent elements are deleted can be extracted as an invention.

1...water supply device, 11...pump device, 15...pressure detection device, 16...flow rate detection device, 30...motor, 40...pump, 50...control panel (variable speed control device), 52...inverter, 52c...smoothing capacitor, 54...voltage measurement unit, 55...current measurement unit, 56...frequency measurement unit, 57...processor, 60...control device, 67...processor, 67d...pump control unit.

Claims (9)

A pump,
A motor that drives the pump;
a variable speed control device that drives the motor at a variable speed;
Equipped with
The variable speed control device is equipped with a voltage measuring unit that measures the voltage within the variable speed control device, and if the voltage value detected by the voltage measuring unit when the pump is stopped is less than a threshold value based on a predetermined voltage value at which an overvoltage may occur, the pump is started by a normal start-up operation, and if the voltage value is equal to or greater than the threshold value, the pump is started by a protective start-up operation in which the increase rate of the output frequency is slower than that in the normal start-up operation. The pump device according to claim 1, wherein the normal start-up operation is a start-up operation that increases the output frequency at a preset, predetermined increase rate. The pump device according to claim 2, wherein the variable speed control device measures the voltage value in the variable speed control device with the voltage measuring unit when the pressure on the secondary side of the pump drops to a preset starting pressure. the normal startup operation is a startup operation in which the output frequency is increased from zero to a maximum output frequency in a preset first acceleration time,
the protective start-up operation is a start-up operation for increasing the output frequency from zero to a maximum output frequency in a preset second acceleration time that is longer than the first acceleration time.
A pump device according to any one of claims 1 to 3. The variable speed control device is configured such that the normal start-up operation is initially set as the start-up operation of the pump, and when the voltage value is equal to or greater than the threshold value, the protective start-up operation is set as the start-up operation, and after starting the pump with the protective start-up operation, when the secondary pressure of the pump reaches a target pressure, the setting of the start-up operation of the pump is returned to the normal start-up operation. The pump device according to any one of claims 1 to 4. The variable speed control device is configured such that the normal start-up operation is initially set as the start-up operation of the pump, and when the voltage value is equal to or greater than the threshold value, the protective start-up operation is set as the start-up operation, and after starting the pump with the protective start-up operation, when the pump is stopped or when a stop condition for the pump is satisfied, the setting of the start-up operation of the pump is returned to the normal start-up operation. The pump device according to any one of claims 1 to 5. The variable speed control device according to any one of claims 1 to 6, wherein the variable speed control device stops the pump when the voltage measurement unit detects an overvoltage, and when the voltage measurement unit detects an overvoltage during the start-up operation of the pump and during operation after the start-up operation of the pump but excluding the stop operation, the variable speed control device stops the pump once and restarts the pump. A variable speed control device that drives a motor that drives a pump at a variable speed,
The variable speed control device includes a voltage measuring unit that measures a voltage within the variable speed control device, and if the voltage value detected by the voltage measuring unit when the pump is stopped is less than a threshold value based on a predetermined voltage value at which an overvoltage may occur, the pump is started by a normal start-up operation, and if the voltage value is equal to or greater than the threshold value, the pump is started by a protective start-up operation in which the increase rate of the output frequency is slower than that in the normal start-up operation. Computer,
A means for comparing a voltage value in the variable speed control device when the pump is stopped with a threshold value based on a voltage value at which an overvoltage may occur;
means for starting the pump in a normal start-up mode if the voltage value is less than the threshold value;
means for starting the pump in a protective start-up operation in which the increase rate of an output frequency is slower than that in the normal start-up operation when the voltage value is equal to or greater than the threshold value;
A program to function as a