JPS5965591A - Water supply device - Google Patents

Abstract

PURPOSE:To assure time delay necessary for preventing chattering, by comparing pressure with delivery target pressure of pump and increasing/decreasing a speed command by predetermined width which provide variable speed driving means when both pressures will not match. CONSTITUTION:When not reach to target pressure H0, a microcomputer will execute required operating steps again. Consequently, rotation of a variable speed motor will further decrease by DELTAN to shift the operating point of pump 4 from O2 to O3 to bring pressure in a water supply pipe to H3 and continue until the result of decision will be O0 thus to produce rotation of N4 while to maintain target pressure H0 thus to assure time delay required for preventing chattering or water hammer.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to an operation and control device for a pump device driven in a variable speed mode, and particularly to a device suitable for digital control by using a microcomputer. It relates to a driving device and a control device.

[Prior art]

Conventionally, by installing a pressure sensor in the water supply pipe of a pump device driven by a variable speed mode, measuring the discharge pressure, and constantly comparing the auxiliary pressure to ensure that the discharge pressure is maintained at the target discharge pressure, There are seven methods for continuously variable operation of a pump based on a control signal whose magnitude corresponds to the deviation. This method will now be explained using FIGS. 1 to 6.

Figure 1 is a configuration diagram of the pump device. 1&''i water receiving box, 2 suction pipe, 3.6 gate valve, 4 pump, 5-piece check valve, 7
8 is a water supply pipe, 8 is a pressure sensor installed in the water supply pipe, and 9 is a variable speed motor. The sensor 8 detects the pressure of the fluid flowing through the water supply pipe, and generates f'C, a direct current electric signal (current or voltage), in response to the pressure. FIG. 2 is an operating characteristic diagram when the pump 4f of the pump device is operated at variable speed, with the horizontal axis representing the water amount Q and the vertical axis representing the deka H. Curve a shows the Q-H performance when the rotational speed of pump 4 is ≠; maximum rotational speed (1oo%) and operation 1 to 1 (similar to -1, curve e
The Q and -H performances are shown when the td7 Jr. rotation speed is operating at the minimum rotation speed. The rotational speed of the pump is continuously variable.
d.

FIG. 3 is a block diagram showing the control flow of the control device for variable speed operation of the pump system.

It consists of an integrator and an adder A. CTL indicates a control device for operating the variable speed mode 9 at variable speeds, and FIG. 4 shows a time chart from the proportional-integral circuit P. In Figures 1 to 4, the amount of water used is Q.

Assume that the pump 4 is operating at a rotational speed N and a point 01 on the pump performance curve C. In this state, the amount of water used changes, and when it is reduced to Q, the operating point moves to Oj, and the pressure inside the water supply pipe 7 increases to 1 dH. At this time, the pressure sensor 8 detects the pressure and generates a corresponding electric signal (DC current or voltage). The error amplification circuit O
The amplified signals are amplified by P, and the amplified signals are respectively applied to a comparator circuit P and an integrator circuit, and the output signal EP of the proportional circuit P and the integrator circuit is
E is added by an adder A, and this signal EP+Eik is outputted to the control device CTL of the variable speed mode 9 as a control signal EP+Eik.

In other words, as shown in Fig. 4, the electrical signal E1 emitted from the pressure sensor is larger than the electrical signal E0, which is the target value corresponding to the target pressure HoK, and the deviation between the two Es=(EゎOne disease)
becomes negative. Therefore, the control signal Ep+F21rfi becomes smaller, and the speeds of the bonder 4 and the variable speed mode 9 decrease, and when the deviation Es=(E0~) becomes ZO, the control signal Ep+Ei becomes stable, and the operation is performed at a speed according to the signal. Ru. As a result, as shown in Fig. 2, the speed motor 9 and the pump 4 are decelerated to the rotational speed N4, the pump performance curve becomes f, the pump operation starts from Oj to ○, and the target pressure H0 keep constant. Also, water consumption ≠: increases, Q
, the operating point moves to ○ and the pressure inside the water supply pipe 7 decreases to -zH1, as described above. At this time, the pressure sensor 8 detects the pressure of the cigarette and emits an electric signal E.
The variable speed mode 9 is changed so that the deviation from the target value becomes ES (E, -E, )/;0. In this case, the deviation E
Since s is positive, the speed increases and the rotational speed becomes N, and the pump performance curve becomes G. As a result, the pump operating point moves from O1 to O8, and the target pressure is kept constant at Ho. However, the above conventional techniques have the following problems.

(1) In order to prevent the rotational speed of the variable speed mode and pump from falling below the minimum rotational speed and from running out of control beyond the maximum speed, the proportional-integral circuit P is used to reduce the offset of automatic control. Jz was necessary.

(2) - This proportional-integral circuit P is analog controlled, and there are many adjustment parts such as target value setting and proportional-integral time setting, which may cause a delay with respect to the target value.

(3) It is economically more expensive than this P, and it is difficult to apply it to other purposes. For example, if you want to use a data logger to measure the amount of water used each day, you will need a computer in addition to a flow meter. Having a computer perform only this data logger is uneconomical as cost performance decreases.

In addition, in recent years, the digitalization of control has progressed, and there is no consideration of replacing the conventional analog configuration with a digital configuration. (equivalent to the PiD circuit) is required. In order to realize this control step, it is necessary to calculate a previously stored mathematical formula, or to follow a predetermined control pattern according to the control process. However, this LV
C requires software development tailored to the pump's discharge characteristics and piping characteristics, or an increase in memory capacity, and e1c
This is very disadvantageous when applied to low-priced products.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a water supply device that can maintain a substantially constant discharge pressure at a low cost.

[Summary of the invention]

The present invention includes a pump, a variable speed drive means for driving the pump, a pressure sensor for detecting the total pressure in a water supply pipe connected to the pump, and a comparison pressure generation means for generating a comparison pressure from time to time. Compare this comparison pressure with the pressure measured by the pressure sensor to determine the self-pressure; when a certain relationship is reached, the comparison pressure value is further compared with the pump discharge target pressure, and if the self-pressure does not match The present invention provides a water supply device equipped with an operation control device that increases or decreases a speed command given to a variable speed drive means by a fixed range.

To explain in more detail, the present invention changes the number of revolutions of the pump in stages according to the amount of water used to keep the discharge pressure of the pump almost constant. The pressure is detected, an electrical signal corresponding to this is extracted, this signal is amplified and sent to the input terminal of the comparator, and arbitrary data is sent from the microcomputer to the comparator via the D/A converter. Output to the other input terminal, increment or decrement the microcomputer data until the comparator output goes from 0 to 1, store the data as the pressure sensor detection signal, and use it as the initial rotation speed. In addition to storing arbitrary rotation speed data and shift width data, the output device of the microcomputer converts the initial rotation speed data into an analog control signal via a D/A converter. After outputting the output to the control device of the variable speed mode and operating at the initial speed, compare the target pressure data and the detection data of the pressure sensor, and if the target pressure data is greater than the initial rotation speed data. If the target pressure data is smaller by ≠2, the shift width data is subtracted from the initial rotation speed data, and the result is outputted from the output device to the variable speed via the D/A converter. It is equipped with an operation control device that outputs the data to the control device of the modle, stores the data as new rotation speed data, repeats the above process until the target pressure data and the detected data of the pressure sensor match, and obtains the target rotation speed. It is something.

[Embodiments of the invention]

The present invention will be explained in detail below. FIG. 5 shows the control circuit of the operation control device according to the embodiment of the present invention, where MOB is the breaker for the main circuit, MO is the coil of the electromagnetic contactor, M (3a is its contact, and NV is the variable speed mode). A variable frequency inverter device for changing the rotation speed of the pump 4 (2!c) In the embodiment, the inverter device is used as a variable frequency inverter device 11 for changing the rotation speed of the driving mode of the pump 4, but primary voltage control, eddy current (Couplings, other speed change control devices may also be used).49
is a thermal relay for overload prevention, μC0n (7: is a central processing unit CPU (hereinafter abbreviated as CPU), Memo I
JM, Yoigen terminal E, input device ND, output device 0UTA
, 0UTB, and ○UTC - 1F and F are respectively D/Af converters LL OPH that convert digital signals such as hexadecimal numbers into analog signals.
Opean 7-CP is a comparator, and R1-R6 are resistors.

Output device ou' of the microcomputer μCON
The rc port is connected to the 10 input terminal of the comparator CP via the D/Af converter F1, and the 8bj-t data r is output from the port of the output device 0UTC, and this 8bi
The data of t is converted into a 7-narrow amount using an example D/A converter. The output of the comparator CP is the least significant bit b of the input device ND port of the microcomputer μCOL'1. (any bits may be used) and the microcomputer.
The μcon output device 0UTB boat outputs the speed change command signal through the D/A conversion converter to the variable frequency inverter device IN.
The connection is configured so that it is sent to V.

CTLId) Lanste. Power supply unit z, start s, stop switch SS, electromagnetic contactor MO, I-run sister Tr,
A control circuit consisting of a relay X is shown. The control device CTL
When the circuit breaker MCB- is turned on and the start/stop switch SS is closed, the power supply unit Z is connected via the transformer T.
The rectification is sent to the power supply terminal E of the smoothed and stable power supply microcomputer-μCON, and operation preparation is completed.

Next, the relationship between the electrical signals emitted from the pressure sensor 8 will be explained. Now, the pressure sensor indicates that the pressure inside the water supply pipe 7 is P.
When , an electric signal is generated, and the input voltage of the operational amplifier ○P is ftui, and the output voltage is vo, the output voltage is given by the equation 0.

By the way, the input voltage ■i of the operational amplifier is the pressure sensor 8
Expressed in terms of the electric signal emitted by vi=engine・R1・・・・・・・・・・・・・・・・・・
・・・・・・Represented by ■.

Here, R8 is the input resistance of the operational amplifier OP.

By transforming equations ① and ②, we obtain the following 0 equation.

Here, the resistors R, R, can be selected appropriately, but for convenience, E? , =R, then formula 0 is vo-2・engine・R1・・・・・・・・・・・・・・・・
・・・・・・■ becomes.

In general, the electrical signal emitted by a pressure sensor is on the order of rnA, so in formula (2), R1 is set to 1 for convenience (Ω(R,
You can also choose appropriately. ), the ■ expression is further vo-2・engine・・・・・・・・・・・・・
・・・・・・・・・■.

In other words, Equation 0 indicates that the output voltage of the operational amplifier OP is proportional to 2@VC of the electrical signal generated by the pressure sensor. In other words, the pressure P in the water supply pipe and the output voltage V of the operational amplifier have a one-to-one correspondence.

6 and 7 are flowcharts showing the control procedure of the operation control device.

FIG. 8 shows the relationship between the pressure detected by the pressure sensor 8 and the electrical signal outputted by the pressure sensor 8, and shows the process until the pressure is reached.

To explain in more detail with reference to these drawings, the memory MIC [611] of the microcomputer μCOJ'l stores a program for operating the pump device according to the flowchart shown in FIG.

First, in three steps, target rotation speed data (data obtained by converting the electrical signal 2 shown in FIG. 8 into hexadecimal or the like) is loaded into the CPU's jC-CBC register.

Next, write data 01 to the CPU0A register in 4 steps.
(hexadecimal number), and in 5 steps, data row 1 (16) was loaded into the A register from the port of the output device 0UTA of the microcomputer μCON.
Output. This output state is the control circuit CTL1 in Fig. 5.
7) Shown in OUTA.

In other words, since only the least significant bit b0 of boat 0UTA is 1, transistor Tr becomes conductive and relay X is energized, so that one electromagnetic contactor MC is energized and its contact Mca is closed.

Next is the initial rotation speed data in 6 steps? It is loaded into the A register, and in 7 steps, the data in the A register is output from the port of the output device ○UTB to the variable frequency inverter device NV, which is the control device of the variable speed mode, via the D/A converter F1. Therefore, the variable speed mode starts operating at the initial speed. Note that this speed can be arbitrarily determined. Further, data of this initial rotational speed is stored in the memory M in Hs steps.

Further, in the 9th step, data on the shift control width (data corresponding to ΔN shown in FIGS. 9 and 10) is loaded into the A register, and in the 10th step, the data loaded into the A register is stored in the memory M.

Similarly, in steps 11, 12, 13, and 14, memory M is set.

Note the data corresponding to the minimum rotational speed Nm1n+)
Store the data corresponding to the maximum rotational speed N I'll a X in M.

To continue the explanation, it is assumed that the motor is now operating at the 00 point of the characteristic curves C and I: at a pressure H8 and a rotational speed of the electromagnetic speed mode 9 and the pump 4 shown in FIG. 9, N, as shown in FIG. Under these conditions, when the amount of water used decreases and reaches Q, the pressure increases. The pressure increases and moves from the operating point ≠ 80° to Oo, and when the pressure in the water supply pipe 7 reaches ≠ (Hl), the pressure sensor 8 detects this and emits an acid gas signal.

As a result, the output voltage of operational amplifier ○P is 2I from formula 0.
, =V. This signal V, yM comparator C
It is sent to one input terminal of P. Next, the microcomputer μCON executes the processing from step 15 onwards. In other words, data 00 (16) (
Alternatively, it may be FF (16) or other data. )
and output the data in the I) E register to the output device 0'UTC. Here, the output bag [0U
The digital signal output from the TC boat is transferred to the D/A converter F.
Convert it to an analog signal with □, and send the signal (initial value is 00 (16) for the wood grain side) to the plus input of the comparator CP. This comparator OF inverts its output signal from 0 to 1 when the positive input signal is equal to or greater than the negative input signal.

Therefore, as a result, the input device I of the microcomputer
The least significant bit b of the ND vote becomes 0.

Next, in step 17 of the microcomputer μ0Oni input the data 00 (16) of the input device ND boat and read it into the A register, and in step 18 it is determined whether the data taken into the A register is /:01 (16) or not. If the result is 01 (i6+) tare, jump 20 steps, and if Do (16), 1
Proceed to step 9, increment (or decrement) the data in the DE register, jump to step 17, repeat the loop of steps 17, 18, and 19 until the A register becomes 01 (16), and then move to D.
The data in the E register is sequentially incremented (or decremented if FF (16) is loaded into the DE register first).

As a result, the data of A register /;01 (16)
(!: If so, the data in the DE register will be shifted to the right in 20 steps, reducing the data to 1/2. This is because the above-mentioned formula 0 is twice the signal emitted by the pressure sensor, so the target value and level This is to match the target value.Instead of halving, the target value may be doubled and matched.

Then, in step 21, the data in the DE register (the detected value of the pressure sensor) is subtracted from the data in the BC register (target pressure value), and the result is stored in the A register.

The data stored in this A register is the deviation H, -H between the target pressure H0 and the measured pressure H1 of the pressure sensor.
This is digital data corresponding to □.

Next, in step 22, it is determined whether the data stored in the A register is 00 (16). If it is 00 (16), the target pressure and the measured pressure match, so the data stored in the A register is 00 (16).
Jump to the step, wait for a certain period of time, and proceed to step 65.

If it is not DO (16), it is determined in the next 23 steps whether the data in the A register is positive. In the example of FIG. 9, H, -H, is negative, so it is determined that frUaJJ2a
Jump to the step, transfer the initial rotation speed data in the memory M1 to the A register, compare the data in the A register with the data in the memory IJM (minimum rotation speed data) in step 26, and if they are equal to 1 or smaller. , without changing gears, jumps to the next step and waits for a certain period of time to proceed with the process, otherwise transfers the rotation speed data of M to the A register in 27 steps.

This is because as the speed continues to decelerate and the speed decreases, the Q-H curve of the pump also decreases, causing the pump cut-off pressure PS to fall below the target pressure H6, resulting in the inconvenience of control runaway -A=. This is taken into account because the rotational speed does not drop below the minimum rotational speed Nm,in.

Then, in 28 steps, the data in the memo IJM containing the shift control width ΔN is subtracted from the data in the A register, and stored in the A register, and! In step 12, the data in the A register is transferred to the memory M as a new rotational speed 3 node and stored therein. Next, in 33 steps, the data in the A register is output from the port of the output device ○UTB, and the data is converted into an analog quantity by the D/A converter F, and is sent as a control signal to the variable frequency control device of the variable speed mode. Send to inverter equipment engineer NV. As a result, the rotational speeds of the variable speed moder 9 and the pump 40 become N, which is reduced by ΔN. Therefore,
The pressure in the water supply pipe 7 becomes H as the pump 4 moves from the M6-lit Ol to Ol. However, since the target pressure H6 has not been reached, the microcomputer μCOn proceeds with the processing further and executes a waiting time for a certain period of time in the da step.
It is determined whether the start/stop switch SS is closed or not, and if it is open, the operation is stopped.As the result of the determination is that it is closed, both microcomputers μCON are set to 15 steps 7' to 14'. As a result, the rotational speed I of the variable speed mode is further reduced by △N, and the operating point of the pump 4...
It moves from S○ to O8, the pressure inside the water supply pipe becomes H8, and in the end, the judgment result of the 22 steps mentioned above becomes D[)(1
6), the rotational speed in °C becomes H4, and the target pressure is maintained at Hok. Also, if the amount of water used increases and becomes Q4' as shown in Figure 10, the microcomputer μCON will continue processing as described above, or in this case 2
Since the judgment result at 3 steps is positive (plus), it is 25.
Jump to the step and memo the initial rotation speed data.
JM transfers the data to the A register, and in the next 29 steps, compares the data in the A register with the data in memory M (maximum rotational speed data), and if they are equal or larger, shift in 34 steps without changing gears. Wait for a certain period of time and proceed with the process. Otherwise, the memory M is executed in 60 steps.

Transfer the rotation speed data to the A register.

This is because as the speed continues to increase, the rotational speed becomes too large.
This is to prevent the Q and -H curves of the pump from becoming large, which would not only result in overload operation but also adversely affect the control device of the variable speed mode. Therefore, the rotational speed of the variable speed mode and the pump is kept below Nmax.

Then, in step 31, add the data in the A register and memory M containing the data of the speed change control width ΔN, and store the result in the A register.In step 32, add the data in the A register as new rotational speed data. The data is transferred to memory M and stored. Then, in 36 steps, the data of the A register is output from the port of the output device 0UTB to the variable frequency inverter device NV via the D/Af converter Fat-, and the rotational speed of the variable speed moder 9 and the pump 4 is changed to N, The speed is increased by ΔN until the result of determination at 22 steps becomes 00 (16). As a result, the operating point of pump 4 is 00-40,'-
40, '-〇, / -Q, /, the pressure inside the water supply pipe 7 changes to H, -H, -H, -Ho, and the target pressure H0 is kept constant. . 9th and 10th
In order to make the explanation easier to understand, the figure shows the pressure change in a large scale, but in reality, the change is extremely small.

Furthermore, the shift control width △N can be appropriately determined by the offset to the target pressure H0, the time to reach the target pressure H0≠2, and the waiting time t can also be appropriately determined by the time to reach the target pressure, etc.≠ ;It is possible. Also, microcomputer-μcon CPU
While the wait time is running, a flow meter (not shown) is installed in the water supply pipe on the wood flow side, and the signal from this flow meter is read into the microcomputer μCON, and the signal is read into the microcomputer μCON for one day or one month. It is also possible to log data such as water usage and power consumption. Furthermore, since these data are in digital quantities, they can be easily transmitted to distant observation rooms.

Although FIGS. 6 and 7 of the Kino-style drawings show an example in which an 8080 or equivalent microcomputer is used as the instruction system, the present invention is not limited to this.

As described above, according to the Kimi style, the proportional-integral circuit P for the speed command of the variable speed mode is not required, which not only makes it economically cheaper, but also reduces the speed change control interval ΔN and waiting time t.
By appropriately determining , the offset with respect to the target pressure can be reduced and responsiveness can be improved.

That is, if the speed change control range ΔN is selected to be small, the operating speed of the variable speed pump can be varied almost continuously.

Furthermore, since the microcomputer can be used for multiple purposes, cost performance is improved. In addition, in order to prevent runaway, a minimum rotational speed Nln'in and a maximum rotational speed Nmax are set, and the operation is set between these values, so there is no pressure drop and pressure changes are small, making it suitable for the control device of the variable speed mode. No adverse effects.

In this embodiment, since the comparative numerical value is incremented or decremented in order to input the measured pressure data of the pressure sensor 8 into the entire microcomputer μcon, an appropriate delay time is required. Water hammer in the pipe line or chattering in the control system can be prevented without adding any other steps.

In the embodiment described above, the comparative pressure generating means is provided as a software, and the sampling operation of the measured pressure is performed in the microcomputer μCON by first turning the hexadecimal data OFF or ○.
By setting ○ and decrementing or incrementing this n, the microcomputer μCON
This was done by generating a comparison signal corresponding to the comparison pressure outputted from the output device OUT of the converter CP via the D/A converter F1 to the controller CP. It can also be configured such that it converges toward the measured pressure.

In addition, in the embodiment, the digital number r- and D output from the output device dOUTc of the microcomputer μC○n is
/ Ayr converter F11 converts the analog to the number, and the comparator CPV sends 7 analog l/be! ”C comparison a δ
Measurement signal of pressure sensor 8 input through operational amplifier OP? I matched it, but this is a digital code output! Place D/A using a pressure sensor that can be obtained
It is possible to compare both town numbers without using a converter. Furthermore, as an example, the microcomputer μCON
Once the S degree command signal from the digital code output from the output 9 position 0 'U T r1711 degree /Af converter 3
+, converts it into an analog signal and inputs it to the speed control device INV, but recently, digitally controlled inverter devices have become popular7, so the speed command from the output device 0UTB is directly input to the speed control device INV. It is also conceivable to input it to the speed control device INV.

Furthermore, in the water supply system of the present invention, if it is possible to change the pump capacity or the discharge pressure due to an increase or decrease in the number of customers, a new memo is written in the memo IJM of the microcomputer μCON before operation of the pump. the desired discharge target pressure, the speed change control range for increasing or decreasing the pump operating speed, the pump operating limit speed (maximum rotation speed and minimum rotation speed), and the initial pump initial setting that is provisionally determined when the water supply system is initially started. It is convenient to add a control step for inputting data such as rotation speed.

〔Effect of the invention〕

The water supply device of the present invention includes a pump, a variable speed drive means for driving the pump, a pressure sensor for detecting the pressure in the water supply pipe connected to the pump, and a comparison pressure generation means for generating a comparison pressure that is variable at any time. The comparison pressure of this comparison pressure detection means is compared with the pressure measured by the pressure sensor, and when the same pressure reaches a certain relationship, the value of the comparison pressure is further compared with the target discharge pressure of the pump, and the same pressure is determined to match. Since the water supply device of the present invention is fully equipped with an operation control device that constantly increases/decreases the speed command given to the variable speed drive means when the variable speed drive means does not operate, the water hammer or Since it is possible to secure the delay time necessary to prevent chattering, it is possible to provide inexpensive AM products by simplifying control operations and reducing memory costs.

[Brief explanation of the drawing]

Fig. 1 is a block diagram for explaining the configuration of one embodiment of the present invention, Fig. 2 is a characteristic curve diagram for explaining the operation of a conventional water supply device, and Fig. 3 is a control system of the conventional device. 4 is a timing diagram for explaining the control characteristics of the conventional device, FIG. 5 is a block diagram for explaining the configuration of the operation control device of the embodiment, and FIGS. FIG. 7 is a flowchart for explaining the control procedure of the embodiment device, FIG. 8 is a diagram showing the output characteristics of the pressure sensor, and FIGS. 9 to 10 are characteristic curves for explaining the operation operation of the embodiment device. It is a diagram. 4...Pump, 7...Water supply pipe, 8...Pressure sensor. Engineering NV...Variable speed drive means, Ho...Target pressure boiling
2 Figure θ--A 3rd Figure 4 Zo

Claims (1)

[Claims] 1. A pump, a variable speed drive means for driving the pump, a pressure sensor for detecting the pressure in a water supply pipe connected to the pump, and a comparison device that generates a variable comparison pressure at any time. The pressure generating means compares the comparative pressure of the comparative pressure generating means with the pressure measured by the pressure sensor, and the value of the comparative pressure when the same pressure reaches a predetermined constant relationship is further set as the discharge target of the pump. A water supply device equipped with an operation control device that increases or decreases a speed command given to a variable speed drive means by a fixed range when two pressures do not match when compared with a target pressure. 2. In claim 1, the comparative pressure generating means is provided for generating a comparative pressure that is increased by a certain width from time to time, and the comparative pressure of the comparative pressure generating means is compared with the pressure measured by the pressure sensor, and the comparative pressure is The value of the comparison pressure when the pressure exceeds the measured pressure is further compared with the target pressure that is the discharge target of the pump, and if the comparison pressure exceeds the target pressure, the speed command given to the variable speed drive means is set within a certain range. 2. A water supply device comprising an operation control device that increases a speed command given to a variable speed drive means by a certain width when the comparative pressure≠2 target pressure has not been reached. 3. In claim 1, the comparative pressure generating means is provided for generating a comparative pressure that is reduced by a constant width from time to time, and the comparative pressure of the comparative pressure generating means is compared with the pressure measured by the pressure sensor, and the comparative pressure is The value of the comparison pressure when the pressure becomes less than the measured pressure is further compared with the target pressure for pump discharge, and if the comparison pressure exceeds the target pressure, the speed command given to the variable speed drive means is set within a certain range. 1. A water supply device comprising an operation control device that increases a speed command given to a speed drive means by a certain width when the comparative pressure has decreased and the comparative pressure has not reached the target pressure. 4. The pump, the variable speed drive that drives the pump, the comparative pressure generating means that generates the comparative pressure generating means, and the comparative pressure of the comparative pressure generating means and the pressure measured by the pressure sensor are compared, and both pressures reach a predetermined constant relationship. Then, compare the area of comparative pressure when A water supply device equipped with an operation control device that sets the speed command as the operating limit speed when the predetermined operating limit speed of the variable speed drive means is exceeded.