JPH0925874A - Variable speed pumping system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify constitution, to reduce cost, to simplify wiring and to downsize a control panel by controlling pumps by inverters. SOLUTION: A variable speed pumping system consists of n-number of pumps 7-9 with the discharge side respectively connected to a fluid feed pipeline, n- number of motors 4-6 provided one to one to the respective pumps 7-9, n-number of inverters 4i-6i provided one to one to the respective motors 4-6, and signal lines connected from one inverter to the remaining (n-1) inverters so as to transmit linkage operation signals.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a variable speed pump device for alternately operating, increasing or decreasing the number of pumps.

[0002]

2. Description of the Related Art FIG. 1 shows a conventional variable speed pump device.
9 and FIG. 20. In FIG. 19, 1
Is an inverter, 4 to 6 are electric motors, 7 to 9 are pumps, 10
12 to a water suction pipe, 13 to a water supply pipe, 14 to a water pressure detecting means,
15 is a flow rate detecting means, 16 is a pressure tank, 17a to 22
Reference characters a are contacts of the electromagnetic switches 17 to 22, reference numeral 23 is a microcomputer, reference numeral 24 is a backup operation circuit at the time of microcomputer failure, and reference numeral 25 is a pressure switch.

The pumps 7-9 are driven by electric motors 4-6, respectively, and deliver the fluid flowing in from the water suction pipes 10-12 to the water supply pipe 13. The pressure detecting means 14 detects the pressure of the water supply pipe 13 and outputs a signal h corresponding to the pressure to the microcomputer 23.

The flow rate detecting means 15 detects the flow rate of the water supply pipe 13 and outputs a signal q corresponding to the flow rate to the microcomputer 2
Output to 3. The microcomputer 23 turns on the electromagnetic switch 17 and closes the contact 17a. Then, the start signal s and the speed signal f are output to the inverter 1.

The inverter 1 supplies electric power of variable frequency to the electric motor 4. With this electric power, the electric motor 4 is started and the pump 7 is rotated. Microcomputer 23
Compares the pressure signal h from the pressure detection means 14 with a preset target pressure state, and outputs the pressure signal h
Adjusts the speed signal f so that approaches the target pressure. That is, the microcomputer 23 determines that the state of the pressure signal h is
When the pressure is higher than the target, the speed signal f is decreased, and when the state of the pressure signal h is lower than the target, the speed signal f is increased.

When the flow rate used by the water supply pipe 13 decreases and the flow rate detecting means 15 detects a minimum flow rate below a predetermined level, the microcomputer 23 causes the flow rate signal q from the flow rate detecting means 15 to cause the start signal s to the inverter 1. Is stopped and the speed signal f is made zero. As a result, the inverter 1 stops outputting the variable frequency power. As a result, the electric motor 4
Is stopped and the pump 7 is stopped.

By the way, water is supplied from the pressure tank 16 while the pump 7 is stopped. As the water is supplied, the pressure in the pressure tank 16 and the water supply pipe 13 decreases. When the pressure of the water supply pipe 13 falls below a predetermined pressure, the microcomputer 23 turns on the electromagnetic switch 19 and closes the contact 19a by the signal h of the pressure detecting means 14. And the activation signal s,
The speed signal f is output to the inverter 1 to activate the pump 8. Every time the pump is stopped in this way, pump 7 → 8
Control is performed to switch to → 9 → 7 and rotary.

On the other hand, when the flow rate used increases and exceeds the capacity of one pump, the electromagnetic switch 18, 20 or 2
2 is turned on to close the contacts 18a, 20a, or 22a of the electromagnetic switch, and the electric motor 4, 5 or 6 is operated at a constant speed with a commercial power source, so that the variable speed operation and the constant speed operation are performed in parallel. Drive.

When the inverter 1 fails, the electromagnetic switch 18, 20 or 22 is turned on and the contact 18a, 20a or 22a of the electromagnetic switch is closed, and the motor 4, 5 or 6 is closed. Backup operation is carried out by operating at constant speed with commercial power supply.

When the microcomputer 23 fails, the backup operation circuit 24 and the pressure switch 2
5 and the flow rate detection means 15 automatically perform backup operation.

When the microcomputer 23 fails,
The backup operation circuit detects a pressure equal to or lower than a predetermined pressure of the pressure switch 25, starts the pump 7, and detects the flow rate detecting means 1
When 5 detects a flow rate below a predetermined flow rate, the pump 7 is stopped.

When the pump 7 fails, the pump 8 is operated, and when the pump 8 also fails, the pump 9 is operated.
This will be described with reference to FIGS. 19 and 20. When the microcomputer 23 of FIG. 19 fails, a relay E (not shown) operates and its contact E-a shown in FIG. 20 closes. When the pressures in the pressure tank 16 and the water supply pipe 13 decrease and the pressure switch 25 detects a pressure equal to or lower than a predetermined pressure, the contact P of the pressure switch is closed and the relay Ry is turned ON, so that the electromagnetic switch 18 is turned ON and the pump 7 Starts and runs at a constant speed.

Then, the flow rate detecting means 15 detects a predetermined flow rate or more, the contact q thereof is turned on, and the relay Ry is held by itself. At the same time as the pump is started, the pressure in the water supply pipe 13 rises, and the contact P of the pressure switch 25 opens.

Next, when the flow rate detecting means 15 detects a predetermined flow rate or less and the contact q of the flow rate detecting means is turned off, Ry is turned off, the electromagnetic switch 18 is turned off, and the pump 7 is stopped.

When the pump 7 breaks down and a protection relay (not shown) operates, its contact TH1 operates and the electromagnetic switch 1
Instead of 8, the electromagnetic switch 20 is turned on and the pump 8 is operated. When the pump 8 also breaks down and a protection relay (not shown) of the pump 8 operates, its contact TH2 operates and the pump 9 operates.

[0016]

However, in such a conventional method, the inverter 1 and the microcomputer 23 have the backup operation circuit 24 and the electromagnetic switches 17-2.
2 must be used, which complicates the configuration and wiring. Therefore, both manufacturing and inspection can be done only by an expert with special expertise, and the cost, delivery time, and production system were difficult.

Further, since the conventional variable speed pump device is composed of a large number of parts, if a failure occurs, it is difficult to find the failure location. For this reason, unless you are an expert with special expertise, you can not determine the failure point,
If the failure location is abandoned, the maintenance service is difficult because the process is repeated many times.

Furthermore, the conventional apparatus has many parts and wirings, and thus requires a large space, which inevitably increases the size of the control panel. The present invention has been made in view of the above points, and an object thereof is to provide an inexpensive inverter for each pump so that the inverter can control the pump, thereby simplifying the configuration and reducing the cost. It is an object of the present invention to provide a variable speed pump device capable of downsizing, simplifying wiring, and downsizing a control panel.

[0019]

According to a first aspect of the present invention, there is provided a variable speed pump device comprising n pumps each having a discharge side connected to a fluid supply pipe, and n pumps provided in a one-to-one correspondence with the respective pumps. One motor and one to one for each motor
, And a signal line connected from the one inverter to the remaining (n-1) inverters and transmitting a link operation signal.
The pump is equipped with a rotation speed control means for controlling the rotation speed of the corresponding pump, an automatic start / stop control means for the pump, and a link operation control means for controlling the link operation of each pump.

In the variable speed pump device according to claim 2, the link operation signal of claim 1 means that the corresponding pump is operating at H level and the corresponding pump is stopped at L level, and the link operation signal is By outputting an L level signal from the H level for a predetermined time, it is output as an operation request signal for the remaining (n-1) pumps, and one of the (n-1) pumps that has received this operation request signal By changing the link operation signal of the pump from the L level to the H level, the operation request signal is output as the operation approval signal for the pump, and the pump that outputs the operation approval signal determines the cooperation operation signal of another pump. , The operating mode of its own pump is determined.

According to another aspect of the variable speed pump device of the present invention, when it is determined that all the other pumps are stopped by another link operation signal according to the second aspect, the pumps of their own are made to wait for activation. In the operation mode, when it is determined that one of the other pumps is in operation by the above-mentioned other cooperation operation signal, the own pump is immediately started to perform the multiple mount operation.

A variable speed pump device according to a fourth aspect outputs the operation consent signal by controlling a time interval from the receipt of the operation request signal according to the second claim to the output of the operation consent signal. It is characterized in that the state of the pump is output.

In the variable speed pump device according to a fifth aspect of the present invention, the inverter according to the first aspect has a timer that counts from when the link operation signal of its own pump is turned on to when it is turned off. It is characterized in that the main engine for shifting operation is determined based on time.

In the variable speed pump device according to the sixth aspect, when it is determined that all the other pumps are stopped by the other linked operation signal, the variable speed pump device is set to the alternate operation mode in which its own pump is on standby. , If it is determined that any of the other pumps is operating by the above-mentioned other link operation signal, immediately start its own pump to increase the number of the pumps. The inverter is characterized in that the rotational speed of the pump is controlled so that the pressure in the flow rate supply pipe is slightly higher than the target pressure.

According to the first aspect of the present invention, the invertor is provided corresponding to n pumps whose discharge sides are connected to the fluid supply pipes.
Each inverter is used to control the rotation speed of the pump, automatically start and stop the pump, and control the linked operation of each pump.

In the second aspect of the present invention, the respective inverters are linked with each other regarding the operation of the pumps by exchanging the operation request signal and the operation approval signal. In claim 3, when it is determined that all the other pumps are stopped by the other link operation signal, the alternate operation mode in which the own pump is on standby is set, and the other link operation signal causes the other When it is determined that any of the above pumps is in operation, it immediately starts its own pump to perform the multiple mount operation.

In the fourth aspect, the state of the pump that has output the operation approval signal is output by controlling the time interval from the reception of the operation request signal to the output of the operation approval signal.

In the fifth aspect of the present invention, the inverter has a timer for counting from when the link operation signal of its own pump is turned on to when it is turned off, and determines the main engine for variable speed operation based on the counted time of each timer. I am trying.

In the sixth aspect of the present invention, during the increase operation of the own pump after the increase operation of the pump, the inverter of the own pump pumps the pressure of the flow rate supply pipe to a pressure slightly higher than the target pressure. The rotation speed of is controlled.

[0030]

BEST MODE FOR CARRYING OUT THE INVENTION The first embodiment of the present invention will now be described with reference to the drawings.
An embodiment will be described. In FIG.
The same numbers are given to the same parts as those in FIG. In FIG. 1, pumps 7 to 9 are motors 4 to 4, respectively.
It is driven by 6 and sends out the fluid flowing in from the water absorption pipes 10 to 12 to the water supply pipe 13.

The water supply pipe 13 has a pressure sensor 14 for detecting the pressure of the water supply pipe 13 and outputting an analog pressure signal h.
Is provided. Further, this water supply pipe 13 has a water supply pipe 1
A flow rate sensor 15 is provided which detects the flow rate of No. 3 and outputs a flow rate signal q which changes on and off when the flow rate reaches a stop flow rate.

Further, a pressure tank 16 is connected to the water supply pipe 13. The pressure tank 16 is provided for supplying water while the pumps 7 to 9 are stopped. Also, 21
Is a control panel. The control panel 21 is provided with inverters 4i to 6i corresponding to the electric motors 4 to 6 one to one. The detailed configuration of these inverters 4i to 6i will be described later with reference to FIG. These inverters 4i-6
The pressure signal h and the flow rate signal q from the pressure sensor 14 and the flow rate sensor 15 are input to i, respectively.

Inverters 4i to 5i are also provided.
And 6i the linking operation signal r1, and the inverter 5i sends the linking operation signal r2 to the inverters 4i and 6i.
The signal lines for outputting the link operation signal r3 from the inverter 6i to the inverters 4i, 5i are the inverters 4i-6.
It is provided between each i.

Next, referring to FIG. 2, the inverters 4i-6 are
The detailed configuration of i will be described. Inverters 4i-6
Since i has the same configuration except that the input / output relations of the link operation signals r1 to r3 are different, the configuration will be described on behalf of the inverter 4i.

The inverter 4i comprises a controller 31 and an operating frequency controller 32 which variably controls the operating frequency of the electric motor 4. The control unit 31 is provided with a CPU (central processing unit) 33 that centrally controls the inverter 4i.

The CPU 33 has an A / D converter 34 for converting an analog pressure signal h into a digital signal, an input port 35 for inputting a flow rate signal q, and a link operation signal r1.
Output port 36 for outputting, input ports 37, 38 for inputting link operation signals r2, r3, and the flow chart shown in the flow charts of FIGS. 3 to 8 are stored. An output port 41 for outputting the frequency signal f to be output to the memory 39 and the operating frequency controller 32 is connected.

The linked operation signals r1 to r3 are signals indicating the operating states of the electric motors 4 to 6, respectively.
The H level signal is output when the vehicle is operating and the L level signal is output when the vehicle is stopped.

Furthermore, these linked operation signals r1 to r3 are transmitted and received as operation request signals and operation approval signals between the inverters 4i to 6i. Further, the AC power supply 42 is converted into a DC voltage through the full-wave rectification circuit 43 and the smoothing circuit 44, and then converted into a variable frequency power through the switching transistor 45 and output to the electric motor 4. The frequency signal f is input to the gate of the switching transistor 45.

Next, the operation of the first embodiment of the present invention configured as above will be described. As described above, the memory 39 stores the programs for controlling the inverters 4i to 6i shown in the flowchart of FIG.

That is, each of the inverters 4i to 6i is provided with a pump rotation speed control program for controlling the pump rotation speed, a pump automatic start / stop control program, a pump linkage operation control program, and an inverter control program. Remembered

As shown in the flowchart of FIG. 4, the pump rotation speed control program causes the electric motors 4, 5 so that the pressure signal h from the pressure sensor 14 reaches a preset target state. , Or 6 by controlling the frequency of the variable frequency power to the pump 7, 8, or 9
To control the number of revolutions. Specifically, when the pressure signal h is lower than the target pressure, the frequency of the frequency signal f is increased, and when the pressure signal h is higher than the target pressure, the frequency of the frequency signal f is decreased.

The automatic start / stop control program for the pump is shown in FIG.
When the flow rate used through the water supply pipe 13 decreases and the flow rate signal q from the flow rate sensor 15 detects a minimum flow rate below a predetermined level, the electric motor 4, 5 or 6 is stopped as shown in the flowchart of FIG. When the control is performed and water is supplied from the pressure tank 16 while the pump is stopped, the pressure drops as the water is supplied, and when the pressure sensor 14 detects a starting pressure below a predetermined pressure, variable frequency power is supplied to the electric motor 4, 5 or 6. It is supplied and is controlled to start the pump 7, 8 or 9.

The linked operation control program of the pump is shown in FIG.
Pump 7 → 8 → 9 → 7 as shown in the flow chart
Alternate operation, or when the flow rate used exceeds the capacity of the pump, the number of pumps is increased to operate in parallel.When the flow rate used decreases, the number of pumps is decreased. Control to switch to other pump.

As described above, the link operation signals r1 to r3
Is a link operation signal provided corresponding to the pumps 7-9. A driving request and a driving approval are transmitted and received between the respective inverters 4i to 6i by the linked driving signals r1 to r3.

That is, the link operation signals r1 to r3
Operates as an operation request signal when requesting operation to other pumps for alternate operation or increasing the number of machines, and as an operation approval signal when operation is accepted in response to operation requests from other pumps. .

The coordinated operation control program transmits / receives the coordinated operation signals r1 to r3 to perform the alternate operation of the pumps 7 to 9, the increase / decrease of the number of pumps, and the alternative operation of the pumps. First, the alternating operation will be described with reference to the flowcharts of FIGS. 7 and 8 and the timing chart of FIG. In FIG. 9, solid lines indicate the link operation signals r1 to r3 of the pumps 7 to 9, and broken lines r1 ′ to r3 ′ indicate ON / OF of the pumps 7 to 9, respectively.
The F state is shown. In the ON state, the pumps 7 to 9 are operating, and in the OFF state, the pumps 7 to 9 are stopped.

The alternation operation will be described below with reference to the flowcharts of FIGS. 7 and 8. At time t1, the pump 7 is operating and the pump 8 is stopped. Then, the pump 7 is brought into an operating state by the control of the inverter 4i corresponding to the pump 7, and the link operation signal r1 is turned on, which indicates that the pump 7 is in operation and is in operation ( Step S11).

Then, during operation of the pump 7, the flow rate detecting means 15 of FIG. 1 detects whether or not the flow rate is a predetermined minimum flow rate or less (step S12). If this determination is "YES", the inverter 4i stops the pump 7 (step S13).

At the same time, the link operation signal r1 is transmitted at time t.
It is turned off at 2, and this off state continues for a predetermined time from time t2 to t3 (step S14). The OFF state of the link operation signal r1 for a predetermined time from time t2 to t3 becomes an operation request signal for another pump. Hereinafter, turning off the linked operation signal for a predetermined time to request an operation will be referred to as an operation request signal REQ.

The operation request signal REQ of the pump 7 is input to the CPUs 33 of all the other pumps 8 and 9. Upon receiving the operation request signal REQ, the CPU 33 of the pump turns on / off the input operation signals r1 to r3 of the other pumps.
The link operation signals r1 to r3 are output based on the OFF state, that is, whether or not the pumps are in operation and are operating.

Here, the operation when the pump 8 receives the operation request signal REQ will be described with reference to the flowchart of FIG. First, it is determined whether the link operation signal r1 output from the pump 7 has been turned off for a predetermined time (step S20).

Then, the pump next to the pump which is in operation and is in operation turns on the link operation signals r1 to r3 to acknowledge the operation. In this example, since the pump 7 is in operation and the linkage operation signal r1 of the pump 7 is ON, the linkage signal r2 of the next pump 8 in the numerical order is turned ON at time t4 (step S21). In this way, the operation request signal RE
For Q, the linked operation signal that is turned on and output when the operation is approved is hereinafter referred to as an operation approval signal ACK.

This operation acknowledge signal ACK is the CP of the pump 7.
Although input to U33, the pump 7 determines whether or not the link operation signals r2 and r3 of the other pumps are turned on (step S15 in the flowchart of FIG. 7). And
If the determination in step S15 is "YES", that is, if it is determined that the operation acceptance signal ACK from another pump 8 is received, the CPU 33 of the pump 7 turns off the link operation signal r1 at time t5 (step S16).

Here, the ON state of the link operation signal r1 between times t3 and t5 is a period in which the pump 8 selects its own pump at time t4. That is, the CPU 33 of the pump 8 determines the link operation signal r in step S21.
2 is turned on, and it is determined in step S22 that the predetermined time has elapsed, the link operation signal r of another pump
The ON / OFF state of 1 and r3 is determined (step S2
3). If all the other linked operation signals r1 and r3 are in the OFF state in the determination of step S23, the pumps other than the own pump are stopped, so the operation request signal RE
It is determined that Q is an operation request signal for requesting alternate operation, and a standby state is entered after time t6.

This start-up waiting state is based on the processing from step S24 onward, and it is determined whether the pressure signal h has dropped to the start-up pressure or less (step S24). If the determination in step S24 is "YES", the pump 8 is started at time t7 (step S25). Then, thereafter, the pump 8 and the link operation signal r2 operate in the same manner as the pump 7 and the signal r1 described above. In this way,
Every time it is stopped by a small amount of water, the pumps 7 → 8 → 9 → 7 are operated alternately one by one.

By the way, in step S23, when the number of pumps is increased and it is determined that the link operation signals r1 and r3 are not all in the OFF state, the number of pumps is increased in parallel. This will be described with reference to the steps S17 and S18 of the chart and the timing chart of FIG. First, as shown in FIG.
In FIG. 1, it is assumed that only the pump 7 is in operation.

During operation of the pump 7, the pump 7 is operated as shown in FIG.
As shown in step S17, it is determined whether the pressure detected by the pressure sensor 14 is smaller than the target pressure (step S17). In the determination of step S17, "Y
When it is determined to be “ES”, the CPU 33 of the pump 7 exceeds the capacity of the pump 7 alone, and therefore, in order to increase the number of other pumps, the cooperation operation signal r1 is turned off only for a predetermined time from time t2 to t3. And output (step S1
8). The linked operation signal r1 is input to the CPUs 33 of all the other pumps 8 and 9 as the operation request signal REQ.

The operation of the pump 8 in response to the operation request signal REQ will be described below with reference to step S23 and subsequent steps in the flowchart of FIG. As described above, the CPU 33 of each pump turns ON / OFF the link operation signals r1 to r3.
A pump that outputs a linked operation signal based on the OFF state, that is, whether or not each pump is operating and operating.
That is, the pump next to the pump in operation is the link operation signal,
That is, the driving approval signal ACK is turned on.

In this case, since the pump 7 is in operation and the link operation signal r1 of the pump 7 is ON, the operation acceptance signal r2 of the next pump 8 is turned ON at the time t4 in numerical order.
To

The CPU 33 of the pump 8 sends the operation approval signal A
After a predetermined time from outputting CK, it is confirmed whether or not the linked operation signals r1 and r3 of the other pumps 7 and 9 are ON / OFF, that is, whether or not the other pump is operating, and if it is ON, other pumps are also operating. Therefore, it is determined that the above operation request signal is a signal requesting an increase in number of units for parallel operation, and at time t6, the pump 8 is immediately started to operate at a constant speed (step S2).
6).

In this way, the number of pumps is increased and the pumps are operated in parallel. When the usage flow rate further increases, the number of pumps is increased in the same manner, and the number of pumps is increased within a range not exceeding the preset maximum number of parallel operation units.

As described above, it is possible to perform the linked operation control such as the alternating operation and the increase in the number of signals with a small number of signals. In a system with only two pumps 7 and 8, the operation request destination is always the other pump, so step S1 in FIG.
As described in 4, the cooperation operation signal r1 is set to O for a predetermined time.
There is no need to use FF. Therefore, as shown in FIG. 11, at the time t2, the link operation signal r1 is switched from the ON state to the OFF state to become the operation request signal REQ.

When the pressure signal h becomes smaller than the target pressure in the determination of step S17 in FIG. 7, the pump 7 turns off the link operation signal r1 for a predetermined time (step S18), and outputs an operation request signal to another pump. However, the link operation signal r1 may be switched from ON to OFF as shown at time t2 in FIG. The OFF state of the link operation signal r1 is C of the other pump 8.
It is input to PU33. CPU 33 of the other pump 8
On the basis of the switching of the link operation signal r1 from ON to OFF, the link operation signal r2 is turned ON at time t4, and the driving approval signal ACK is output to the pump 7.

When the CPU 33 of the pump 7 receives the operation acknowledge signal ACK, it turns the link operation signal r1 ON again at time t5. The CPU 33 of the pump 8 sends the operation approval signal r
After a predetermined time from outputting 2, the ON / OFF state of the linked operation signal of the other pump 7 is confirmed. If ON, the other pump 7 is also in operation, so the operation request signal REQ
Determines that the signal requires an increase in the number of units for parallel operation, and starts immediately. That is, the pump 8 is started at time t6. In a system with only two pumps, the pumps may be operated in this way.

In the above description, the linked operation control signal r1,
r2 and r3 were used corresponding to the pumps 8 and 9, and were also used as the operation request signal and the operation approval signal. As another method, the driving request signal and the driving approval signal may be provided for each.

The link operation signal is also used as the pump operation signal because it is linked to the pump operating state except when the operation request and the operation consent are exchanged with other pumps. You can

Further, the operation request signal and the operation approval signal are turned on.
Although the operation request destination and the operation request content are determined based on the ON / OFF state, the operation request signal itself may include such information such as the length of the operation request signal.

Next, a first modification of the flow chart of FIG. 8 according to the first embodiment of the present invention will be described with reference to the flow chart of FIG. In the flowchart of FIG. 13, steps performing the same processing as in FIG. 8 are given the same step numbers, and detailed description thereof will be omitted.

In this first modification, the operation request signal REQ
When the pump that has received the response to the operation approval signal ACK responds with the operation approval signal ACK, the operation approval signal A
When all the surroundings of the control unit that outputs CK are normal, and when there is any problem and the gear change operation as the main machine cannot be performed but the constant speed operation as the slave machine is possible, the operation completion signal A
Change the timing of issuing CK. For example, in the flowchart of FIG. 13, when it is determined to be "YES" in step S20, when it is determined that the operation request signal REQ is received, and when it is normal, the operation request signal REQ is received. After a predetermined time, which is a short time after
If CK is output and only constant speed operation is possible, step S20a may be added which outputs an operation acceptance signal ACK after a predetermined time longer than that.

By detecting the difference in time until the pump that has output the operation request signal REQ receives this operation approval signal ACK, it is possible to determine that the pump that has completed operation can only operate at a constant speed as a slave. CPU3 of pump
3 can recognize.

By doing so, even if a failure occurs in any of the pumps, it is not necessary to immediately prohibit the operation of the pump. For example, even if the pump cannot be operated as the main engine, The effect can be minimized by making the best use of the remaining functions such as performing the operation of, and automatically continuing the operation. Conventionally, when such a problem occurs, the corresponding pump stops and automatically switches to the operation with the remaining pump, but even in such a case, a service person is required when parallel operation is required. According to the above, the driving operation is switched to perform the driving, but by the method as described above, the optimal driving is automatically performed on behalf of the service person, so that the service becomes easy.

Although the amount of information is increased by the time difference method of outputting the operation acceptance signal ACK, the amount of information may be increased by another method such as pulse width. Further, the information content may be enriched such as a fault location and a backup operation method.

Next, a second modification of the flow chart of FIG. 8 according to the first embodiment of the present invention will be described with reference to the flow chart of FIG. In the flow chart of FIG. 8 described above, it is determined whether all the linked operation signals r1 and r3 from the other pumps are OFF (step S23), and if either is ON, the pump 8 is started. The parallel operation was performed at a constant speed (step S25).

In this second modification, when all the linked operation signals from other pumps are not zero, the pump 8 is started to operate at a constant speed (step S26a). And
After that, when the flow rate used is drastically reduced and the pressure detected by the pressure detection means 14 is still too high even if the rotation speed of the main engine 7 is set to "0", the rotation speed of the pump 8 is controlled and the pressure detection means 1 is operated.
The pressure detected by No. 4 is controlled to be slightly higher than the preset target pressure (step S26).
a). By doing this, even if the operating flow rate suddenly decreases, it is possible to prevent the pressure from rising rapidly, and at the same time, the pressure is limited to a pressure slightly higher than the target pressure. Is possible.

Next, a second embodiment of the present invention will be described with reference to FIGS. The configurations of FIGS. 1 to 6 of the first embodiment described above are also used in the second embodiment.

Description will be made with reference to FIGS. 1, 2, 15, and 16. The timers T1 to T3 in FIG.
Three timers, each of which is provided on the memory 39 of the U33 microcomputer, are operated by software.

The timers T1 to T3 are associated with the link operation signals r1 to r1.
Operates corresponding to r3. The timer T1 starts time measurement when the link operation signal r1 of the pump 7 is turned on, and is cleared to zero and stopped when the link operation signal r1 is turned off. The timer T2 operates in the same manner as the link operation signal r2, and the timer T3 operates in the same manner as the link operation signal r3.

In FIG. 16 (a), all three pumps are in operation, and T1, T2, and T3 are in time measurement. The horizontal axis represents the measured time, that is, the time when r1 to r3 are ON.

In FIG. 16B, the pumps 7 and 8 are operating and the timers T1 and T2 are measuring time. The pump 9 is stopped and the timer T3 is cleared to zero and stopped.

In the example of FIG. 16A, the timer T1 is the longest and the timer T3 is the shortest. This represents that the pump 7 started first and the pump 9 started last. (a) When the pump flow is reduced due to a decrease in the flow rate used during parallel operation of the pumps, stopping the earliest starting pump among the pumps operating in parallel will result in averaging the operating time. Become. Therefore, the pump 7 corresponding to the longest timer T1 is stopped.

Further, in parallel operation, there is a method in which one pump is used as a main machine for variable speed operation and another pump is used as a slave machine for constant speed operation. In this way, when the usage flow rate decreases and falls below the gear shift range of the main machine, the slave machine does not shift, so it is easy to determine that the pressure has risen above the target pressure and has reached the operating point where the number of units should be reduced.

In such a case, the main engine is defined based on the timers T1 to T3. (b) In the second embodiment, of the timers T1 to T3, the one having the longest measurement time is the main engine.

From the above-mentioned items (a) and (b), among the pumps operating in parallel, the pump which is started first is the pump to be operated in the variable speed mode as the main engine, and the pump to be stopped next. Becomes Therefore, if the methods (a) and (b) above are used, the flow rate used will decrease, and when reducing the number of pumps, it is sufficient for the main engine to stop as it is. There is no need for a control such as issuing.

Now, as shown in FIG. 16 (a), the timer T1 is the longest, the pump 7 is the main engine (shift operation), and
When the flow rate to be used is reduced when the pump is to be stopped next, the pump 7 is stopped and the timer T1 is cleared to zero and then stopped, as shown in FIG. 16 (c). Then, as described above, the pump having the longest operating time becomes the new main engine, and therefore the pump 8 corresponding to the timer T2 becomes the main engine. in this way,
When the number of units is reduced, the main engine is simply stopped and the new main engine is automatically replaced.

On the other hand, in addition to the automatic stop due to the reduction of the number of units, a description will be given of the case where the power supply switch is shut down or a failure occurs. In the state of FIG. 16 (a), if the pump 7 suddenly stops due to a power switch failure or a failure, the link operation signal r1 is turned off, the timer T1 is cleared to zero, and the state of FIG. 16 (c) is obtained. . Then, the control units of the operating pumps 8 and 9 determine that the pump 8 corresponding to the longest timer T2 is the new main engine. In this way, even when the pump is stopped due to a failure or power failure, it automatically switches. After that, when the stop factor such as the disconnection of the power supply switch or the failure of the pump 7 is released, the timers T1 to T3 of the pump 7 start with a blank sheet,
It becomes like FIG.16 (d). That is, since the pumps 8 and 9 are already in operation at the start time, the timers T2 and T3 start measuring at the same time. Moreover, the time is shorter than the actual time because it is measured from the middle.

Therefore, the CPUs 33 of the pumps 8 and 9 measure FIG. 16 (e), and the pump 7 measures FIG. 16 (d), resulting in inconsistency in the measured contents. However, when using the above-mentioned methods (a) and (b), that is, the method in which the first pump started is the main engine and then the pump that stops is used, what is necessary for each pump is that It is whether it started. The pumps 8 and 9 are based on FIG. 16 (e), and the main engine is the pump 8 corresponding to the timer T2.
When the pump 8 is stopped, the pump 9 corresponding to the timer T3 becomes the main engine, and if the pump 7 becomes the main engine, it is determined that it will be thereafter.

On the other hand, based on FIG. 16 (d), the pump 7 first becomes the main engine by the pump 8 or 9 corresponding to the timer T2 or the timer T3.
Since it will be judged that the main machine will be after that, even if the contents of the timer do not match, the judgment based on the contents of the timer will match.

As described above, even if the memories of the timers T1 to T3 of a certain pump are lost due to the power failure or the failure, the judgments of the control units do not become inconsistent and the linked operation can be performed without any trouble. .

Further, when the power supply switch is stopped due to disconnection or failure, the linked operation signals r1 to r3 are kept off, and therefore the operation request signal is turned off only for a predetermined time. Absent.

When one pump is operating and the pump is stopped due to a power switch failure or failure, the operation request signal is not output. Therefore, the linked operation signals of all the pumps are turned off.

In such a case, the pumps 7, 8 and 9 are provided with waiting times in advance in a predetermined priority order, and when all the link operation signals are OFF, the pump 7 is first activated. If the pump 7 does not start even after waiting for a predetermined time, the pump 8 is started. If the pump 8 does not start after waiting for a predetermined time, the pump 9 is started.

The same applies when the link operation signals of all pumps are OFF immediately after the power is turned on. In addition, even if the power switch of each pump is turned on in a random order such as the order of the pumps 8, 7, and 9, when the pumps are stopped and then restarted, they are started in a predetermined priority order. Return to rotary operation in the correct order.

As described above, the pump 7 can be easily operated with a simple signal.
Alternate operation can be performed in a rotary in the order of → 8 → 9 → 7. Also, since it is not necessary to rely on past memories,
Even if one of the pumps is turned ON / OFF during operation, the rotary operation automatically returns to the normal order.

When stopping the pump,
As described above, if the pumps are not stopped in the order in which they are started but are stopped in the order of the pump numbers, it is difficult to determine the pump to be stopped next. For example, if all three pumps are normal and two pumps 7 and 8 are in operation, it can be easily estimated that the pump 7 started first and then the pump 8 started. Good.
However, when all three pumps are in operation, it cannot be estimated from the pump number which pump started first. So I don't know which pump to stop. Also, when one unit is out of order and the remaining two units are in parallel operation, it is not known which one started first and which one to stop.

In the above-mentioned linked operation control, when the operation request signal is not output in response to the operation request signal output, the operation request is stopped and the operation request signal is output again after a predetermined time. repeat. The output side of the operation request signal does not perform operations such as alternate operation or increase of the number of units while the output of the operation approval signal is not confirmed, so there is no obstacle to operation even if the output of the operation request signal is repeated many times. .

Although the control unit 31 has shown the embodiment in which the control circuit of the operating frequency control unit 32 is also used, a control circuit other than the control circuit of the operating frequency control unit 32 may be provided for the control unit. The control circuit may be built in the operating frequency control unit 32 or may be provided outside the operating frequency control unit 32. Further, one part of the control circuit of the operating frequency control part 32 may be used in common and the rest may be added.

By thus providing the control unit 31 of the present application other than the control circuit of the inverters 4i to 5i, the present application can be easily implemented even when the processing capacity and memory capacity of the inverter itself are not sufficient.

In addition, the control unit 31 of the present application is connected to the inverter 4i.
If provided outside of 5i, the present application can be easily implemented even when the inverter is extremely small and it is difficult to add a control circuit.

Although the pressure control is performed in the above embodiment, the liquid level may be controlled by using a water tank or a liquid level detecting means instead of the pressure tank 16 and the pressure sensor 14. Further, in the above embodiment, the linked operation signal is an ON / OFF signal, but any signal line, communication line, bus, or any other transmission means may be used. The signal may be a code, a method of expressing the transmission destination or transmission content with a predetermined pulse width, or any method. If communication or pulse width is used, r1 to r in FIG.
The number of input terminals of 3 is one for each CPU of the pumps regardless of the number of pumps.

An example thereof is shown in FIG. The signal is composed of a head mark and the output signals of r1 to r3 that follow at a predetermined time interval. When the control unit of any pump outputs ON of the head mark, it is the CPU of all pumps.
33 is input. Then, after the head mark, the output from the CPU 33 of each pump is assigned at a predetermined time interval. When the CPU 33 of the pump 7 outputs the link operation signal, after outputting the head mark, r1 in FIG.
Output the link operation signal, and the pump 8 CP
When U outputs the cooperation operation signal, after outputting the head mark, nothing is done during the time period of the output of r1 and the cooperation operation signal is output at the output of r2. Even when the head marks are output from the control units of a plurality of pumps at the same time, the respective pumps output the linked operation signal in accordance with the allocation of the time zone following the head marks, so that there is no collision between the outputs.

The method of outputting the linked operation signals of r1 to r3 is as follows:
An ON / OFF signal may be used, communication may be used, or any method such as a method of determining the content of information by the length of the pulse width may be used. Also, a diagram of the system in this case is shown in FIG.
It becomes as shown in.

In the above embodiment, the system having three pumps has been described, but the number of pumps may be other than three. In the two-pump system, only two link operation signals r1 and r2 are required. Further, the number of terminals for the link operation signal is only one input and one output for each inverter.

In the above embodiment, the order in which the pumps are started is determined by using the timers T1 to T3 in FIG. 16, but the method need not be a timer as long as the order can be determined. For example, a stack or a first-in first-out structure may be provided on the memory to store the order of activation. Alternatively, a method in which only the user himself or herself starts up may be used.

As described above, by providing an inexpensive inverter for each pump, a large number of electromagnetic switches are not required, and a highly functional inverter is also used to control the pump. By eliminating the need for a backup circuit for a computer or a microcomputer, a conventional inverter that is complicatedly composed of one inverter, a microcomputer, a backup circuit for a microcomputer, and many electromagnetic switches has been replaced by an inverter for each pump. It is possible to reduce the cost, simplify the wiring, and reduce the size of the control panel.

Further, by eliminating the complexity of the conventional structure and wiring and providing a single inverter for each pump, even if a failure occurs, the failed inverter can be replaced. It only needs to be replaced, there is no need to investigate the failure point, and it can be easily processed by anyone, even if you are not a veteran with special expertise.

In addition, the parts inventory for the service system,
It is not necessary to prepare many different parts, only an inverter is required. Even when the ON / OFF signal is used as the link operation signal as in the embodiment, the number of signal terminals of the inverter may be the same as the number of pumps. For two pumps, two terminals and four pumps are used. 4 terminals are enough.

If a simple ON / OFF signal is used,
Operation can be checked with a normal tester, no special equipment is required, and maintenance is easy. Furthermore, it is not necessary to consider compatibility due to the difference in communication methods as compared with communication methods.
Further, it is not necessary to provide a special circuit such as communication, and the ON / OFF input / output terminal generally provided in the inverter can be easily used.

[0108]

As described above in detail, according to the present invention, it is possible to simplify the configuration by allowing the inverter to control the pump, reduce the cost, simplify the wiring, and downsize the control panel. A variable speed pump device capable of being provided can be provided.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a variable speed pump device according to first and second embodiments of the present invention.

2 is a diagram showing a detailed configuration of the inverter shown in FIG.

3 is a flowchart showing an outline of program contents of the inverter shown in FIG.

4 is a flow chart for explaining a rotation speed control function of the pump of FIG.

5 is a flowchart for explaining an automatic start / stop control function of the pump of FIG.

FIG. 6 is a flowchart for explaining a linked operation function of the pump of FIG.

FIG. 7 is a flowchart for explaining the control contents of the pump 7 according to the first embodiment.

FIG. 8 is a flow chart for explaining the control contents of the pump 8 according to the first embodiment.

FIG. 9 is a timing chart for explaining the operation of the alternating operation according to the first embodiment.

FIG. 10 is a timing chart for explaining the operation of the multiple mount operation according to the first embodiment.

FIG. 11 is a flowchart for explaining the operation of the alternate operation of the variable speed pump device when there are two pumps.

FIG. 12 is a flowchart for explaining the operation of increasing the number of variable speed pump devices when there are two pumps.

FIG. 13 is a flowchart for explaining the operation of the first modification of the first embodiment.

FIG. 14 is a flowchart for explaining the operation of the second modification of the first embodiment.

FIG. 15 is a flowchart for explaining the operation of the second embodiment of the present invention.

FIG. 16 is a diagram for explaining changes in the contents of counters T1 to T3.

FIG. 17 is a timing chart for explaining a modified example.

FIG. 18 is a block diagram showing a modification of the variable speed pump device of FIG. 1.

FIG. 19 is a block diagram showing the configuration of a conventional variable speed pump device.

20 is a circuit diagram showing a configuration of a main part of FIG.

[Explanation of symbols]

7-9 ... Pump, 10-12 ... Water absorption pipe, 13 ... Water supply pipe,
14 ... Pressure sensor, 15 ... Flow rate sensor, 16 ... Pressure tank, 21 ... Control panel.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshihisa Shimada No. 1 Goryota, Hashime-cho, Okazaki-shi, Aichi Stock Company Kawamoto Works Okazaki Plant

Claims (6)

[Claims] 1. N pumps each having a discharge side connected to a fluid supply pipe, n electric motors provided in a one-to-one correspondence with each of the pumps, and one-to-one correspondence with each of the electric motors. Inverter of n provided
And a signal line connected to the remaining (n-1) inverter from the one inverter and transmitting a link operation signal, the inverter being the rotational speed of the corresponding pump. A variable speed pump device, comprising: a rotation speed control unit for controlling the pump, an automatic start / stop control unit for the pump, and a link operation control unit for controlling the link operation of each pump. 2. The linked operation signal means that the corresponding pump is operating at the H level and the corresponding pump is stopped at the L level, and the linked operation signal outputs the L level signal for a predetermined time from the H level. The remaining (n-1)
Is output as an operation request signal to the pump, and the operation request signal is output by changing the linked operation signal of one of the (n-1) pumps that received this operation request signal from the L level to the H level. A pump that has output an operation-acknowledgement signal to the selected pump and determines the operation mode of its own pump by judging the linked operation signal of another pump.
Variable speed pump device described. 3. When it is determined by the other link operation signal that all the other pumps are stopped, the alternate operation mode in which the own pump is on standby is set, and the other link operation signal is used. 3. The variable speed pump device according to claim 2, wherein when it is determined that one of the other pumps is in operation, its own pump is immediately started to perform an additional mount operation. 4. The state of the pump that has output the operation approval signal is output by controlling the time interval from the reception of the operation request signal to the output of the operation approval signal. The variable speed pump device according to claim 2. 5. Each of the inverters has a timer that counts from when the link operation signal of its own pump is turned on to when it is turned off. The variable speed pump device according to claim 1, wherein 6. When it is determined by the other link operation signal that all the other pumps are stopped, the alternate operation mode in which the own pump is on standby is set, and the other link operation signal is used. If it is determined that one of the other pumps is in operation, it immediately starts its own pump to increase the number of the pumps, and during this increase of the number of pumps, the inversion of its own pump is performed.
The variable speed pump device according to claim 2, wherein the pump controls the rotational speed of the pump so that the pressure in the flow rate supply pipe is slightly higher than the target pressure.