KR950007520B1 - Control unit of water pump - Google Patents

Abstract

a power supply for providing power to a solid state relay; and a controller including an A/D converter, a central processor, a D/A converter, an operation mode selector switch and logic circuit, a display, an operation condition set switch and a numeric display, wherein the operation mode selector switch selecting one of inverter, automatic and manual operations.

Description

Control device and method of water feed pump system

1 is a mechanical schematic diagram of a conventional pneumatic limit switch.

2 is an inverter controlled schematic diagram for explaining the present invention.

3 is a circuit diagram of the control device of the present invention.

4 shows a block diagram of the central processing unit of FIG.

5 is a flowchart of a control program.

* Explanation of symbols for main parts of the drawings

1: reservoir 2: air supply tank

3: pressure tank 4: air pressure reset switch

5: constant pressure valve 6: control panel

7: pressure sensor 8: inverter

9: Controller IC ₁: Divider Circuit

IC₂: 7 segment SW: Switch

PC: Photocoupler LP: Lamp

M₁, M₂: Motor P: Pump

C: D / A conversion circuit D: Operation mode selection switch and logic circuit

E: Operation condition setting switch and its display circuit

A: A / D converter circuit part B: Central processing circuit part

I / O: I / O SW: Switch

Logic: Logic Circuit

The present invention relates to a control device and a method of a feed pump system.

In the conventional water supply system using a high water tank, it is difficult to secure the height of the water tank chamber, so it is not only able to fundamentally solve the lack of water pressure in the uppermost generation, but also the construction period is long, which is unreasonable in terms of construction cost and sanitation. The present invention provides a computer control system for controlling the speed of a motor, which is a core part of a pressurized water supply system, which uses a pump to feed each generation from an underground water tank to provide practicality and economical efficiency of the water supply system. There is this.

In the present invention, the water supply equipment refers to a facility for supplying pressure and quantity necessary for a place requiring living water in a building without inconvenience, and the most important problem in such a water supply equipment is water conservation as well as securing and proper water quality. The water pressure should be maintained and there should be no noise that is offensive to the user.

Nevertheless, the water supply method using the rooftop water tank, which is applied to most domestic high-rise apartments, is to supply water from the top down by installing concrete water tanks on the roof of the building. Therefore, there must be robustness of the building for water storage. In the case of excessive tops, there is an example where disputes arise due to lack of water pressure.

In recent years, in order to solve such inconveniences, a pressurized water supply type may be adopted. However, in the pressurized water supply method, an inverter control system for detecting a pressure change caused by a load change and controlling a water supply pump has to be installed.

That is, the pump motor is turned on and off by opening and closing the electric circuit by using the air pressure limit switch according to the pressure change in the pressure tank, but the wear of the contact of the magnetic contactor by using the magnetic contact to open and close the electric circuit. And burnout are becoming the source of failure and noise generation.

The present invention is to use the pressure tank to solve the above-mentioned drawbacks of the prior art by injecting water into the water tank by the pump motor to supply water to the necessary place by using the force of the compressed air in the tank, By controlling the pressure as an electronic control device, the error caused by the conventional pressure limit switch is reduced, and the electronic circuit is used to turn the motor power on and off. Standardization and miniaturization are possible.

The present invention will be described below with reference to the drawings of the embodiments.

1 is a view illustrating a known configuration for explaining the present invention. The water in the reservoir 1 opens and closes an electronic contactor (electronic switch) (not shown) of the control panel 6 to the motor M of the feed water pump. By supplying power and driving, the water of the reservoir 1 is sent to the pressure tank 3 through the air supply tank 2, and the air pressure that checks the air pressure in the pressure tank 3 at the top of the pressure tank 3 When the limit switch 4 is installed and the air pressure in the pressure tank 3 becomes higher than the reference pressure, that is, when the water level in the pressure tank 3 becomes a high level, the control panel detects a signal detected by the air pressure limit switch 4. (6) to stop the power supply by turning off the magnetic contactor to stop the power supply. When the water level goes down to a high level, that is, when the pressure drops below the reference value, the air pressure limit switch 4's signal Motor stationary send the signal to Urban (6) is driven so as to again supply power to (M). In this way, the pump motor M is turned on and off by opening and closing the magnetic contactor provided in the control panel 6 in accordance with the operation of the pneumatic limit switch 4.

In addition, the motor may be installed as a spare one, and the pneumatic limit switch 4 has an error from the mechanical operation, the present invention is a piezoelectric element such as a piezoelectric (Piezo Electric), which will be described later. I solved it by using 壓電 素 子). In addition, the present invention instead of the conventional contact type magnetic contactor by using a solid state relay (hereinafter referred to as SSR) can be used as a semi-permanent as well as eliminate the cause of failure or noise caused by contact wear There is this.

On the other hand, the present invention by computerizing the control system of the pump motor, it is possible to connect the communication port (Communication port) as described below, in connection with the central sensing system, remote sensing is possible, It is possible to control a large number of pumps by changing the program, to expand the variable speed operation and the constant speed operation system, and to miniaturize and standardize the control panel.

2 is a diagram of a water supply pump control system using an inverter according to an embodiment of the present invention, in which the same parts as in FIG.

That is, the water in the reservoir 1 is pumped to the pressure tank 3 through the air supply tank 2 to the pump (p) and the water supply to the constant pressure valve (5) is the same as the publicly known description thereof will be omitted. However, in the exemplary embodiment of the present invention, the pressure is sensed by the pressure sensor 7 installed on the upper portion of the pressure tank 3, and the pressure is sent to the control device in which the microprocessor is built in. The output of the control device 9 is the inverter 8 It is arranged to control the pump motor (M) through the electrical circuit diagram for the control device (9) is shown in FIG.

First, the pressure sensor 7 will be described in order to help understanding of the present invention before describing FIG. 3. That is, piezo-electric materials constituting the pressure sensor 7 installed on the pressure tank 3 have electric charges on both sides when there is a pressing or pulling force in the polarizational direction. This causes a potential difference. This potential difference appears in proportion to the magnitude of the external force, that is, the pressing or pulling force, and it is known that the same phenomenon occurs in the piezoelectric element even when a shear force is applied. Therefore, in the embodiment of the present invention, in order to increase the degree of potential difference caused by the pressure variation in the pressure tank 3, a voltage of DC 12V is applied to the pressure sensor 7 which is a piezoelectric element, and outputs DC1-5V, (OKg). / cm² ~ 5Kg / cm² or Okg / cm² ~ 10Kg / cm²).

In addition, the basic circuit of the inverter of FIG. 2 is connected to a large butter portion, a smoothing circuit portion, and an inverter portion between a power supply and an induction motor, and a control circuit is connected between the large butter portion and the inverter portion.

Therefore, in the present invention, a method of changing the output amount of the inverter uses a pulse width modulation (PWM) method in which the amplitude of the pulse is fixed and the pulse width is controlled.

If you show this as the schematic of the basic circuit,

The "converter part" converting AC power to DC power in the above, the "smooth circuit part" consisting of a DC reactor and a capacitor absorbing voltage ripple generated in said converter part and inverter part, and AC power of desired frequency And a control circuit portion for giving a control signal to a main circuit portion for supplying a variable voltage variable frequency power source to an induction motor. The above control circuit portion is provided with an external speed, torque, etc. Comparing and calculating the current and voltage signal from the command and detection circuit unit, and amplifying the control signal from the inverter output frequency, voltage / current detection circuit, and calculation circuit to turn on and off the main circuit elements, and the current and voltage of the main circuit. To stop the inverter and the induction motor in the event of overload or overvoltage. Or it consists of a protection circuit for controlling the voltage or current values.

The control unit in the embodiment of the present invention will be described in detail with reference to FIG. 3.

In FIG. 3, part “A” is a digital signal that can receive an analog signal (DC1 to 5V) generated from a pressure sensor (7) made of a piezoelectric element such as piezoelectric and perform arithmetic processing on the CPU. A / D conversion circuit for converting the circuit into a circuit, and “B” is a central processing unit, which is composed of a central processing unit (CPU), a ROM (ROM), and an input / output unit (I / O). Used.

The 8031 has the following characteristics.

8-Bit CPU for control applications, extensive Bit logic boolean processor capability, 32 bidirectional I / O ports, 128 bytes of data RAM, two 16-Bit timers / counters, full dual Universal Asynchronous Receiver Transmitter (UART) and five interrupts It is possible to have a built-in clock oscillator (osc). 4 shows a block diagram of such a central processing unit.

In FIG. 3, the "C" part is a D / A converter that converts a digital signal into an analog signal of a continuous electronic signal. In this embodiment, the external operation signal of the general-purpose voltage inverter is an analog signal (DC0 to 10V or 4). ~ 20mA) is a D / A circuit that converts the inverter signal calculated by the central processing unit (CPU) into an analog signal.

3 is divided into the operation mode selector switch SW, the logic circuit unit Logic, and the display unit Disp, and the display unit Disp causes the lamp LP to flash by the photocoupler pc. The motor (M₁, M₂) is turned on and off.

In other words, the selector switch (SW) is installed to control the water pump system by inverter, automatic and manual operation. When the inverter operation mode (INVERTER) is selected, the inverter is used to operate the motor (M₁) according to the given operating conditions. If variable speed operation is selected and automatic operation mode (AUTO) is selected, the motor (M₂) is automatically turned on and off according to the given pressure value.If manual operation mode (MANUAL) is selected, the manual operation switch is used. It is designed to operate the motor (M₂) ON-OFF by manual operation by human. In the logic circuit (Logic), when the operation mode is selected by the operation mode selection switch (SW), the selection status is sent to the central processing unit (CPU) and the control command and logic received from the central processing unit (CPU) are calculated to calculate the solid state of the power supply unit. The control signal is sent to the relay SSR, and at the same time, the operation signal is sent to the lamp LP of the operation state display unit Disp. In addition, the operation state display unit displays the current state of the water supply pump system, the ON-OFF state of the power supply, the current pressure operation mode (inverter operation, automatic operation, manual operation) selection state in the tank, and the start and stop states of the motor, etc. Is supposed to appear.

In addition, it is equipped with the operation control setting switch to change the water supply pump system according to the operation pattern, so that various input conditions can be processed variably, and the numerical value is displayed on the display part for the driver to easily identify the variable pressure. The switch is a switch for setting the pressure in the tank, the frequency setting switch is a switch for setting a variable operating range. In addition, the variable speed operation point switch is added to allow the variable speed operation in the proper pressure range between the maximum pressure and the minimum pressure in consideration of the flow rate.The current pressure and the maximum pressure in the “E” of the detailed circuit diagram are added. (Max, pressure), minimum pressure (Min Pressure), frequency pattern (Frequency SP), variable operation point (Variable Operation Point) is displayed as a number.

That is, in Fig. 3, the number “E” is indicated by a parting circuit (IC₁) and 7 segments (IC₂) operated by an operation condition setting switch and an output signal from the display part and the input / output part (I / O). According to the operation pattern, the operation condition setting switch was installed so that the variable result, that is, the maximum pressure and the minimum pressure setting switch were used to set the operating pressure in the tank, and the frequency setting switch was to set the variable speed operating range. Therefore, the 7 segment (IC₂) is to display the current pressure, the maximum pressure minimum pressure, and the frequency pattern, respectively.

On the other hand, the power supply is connected to the solid state relay (SSR), which is a contactless controller is the same as known, so it is omitted for simplicity of the specification.

Therefore, according to the present invention, the inverter operation, the automatic operation, the manual operation is possible according to the operation mode selection, and when the inverter operation and the automatic operation mode selection, it is possible to automatically operate by the control program of the control device.

In addition, since the control device can be installed on a printed circuit board, it can be compactized, so that it is possible to attain a minimum and light weight as compared to a conventional mechanical control panel. In operation, the operation mode switch (inverter operation or automatic operation selection) The set value can be read from the maximum pressure, the minimum pressure, the frequency pattern, and the shift operation point from the operating condition setting switch. In addition, the output signal of the pressure sensor 7 installed above the pressure tank reads the current pressure through the A / D conversion unit from the central control unit with the bus control, the CPU and the RAM, and displays the current pressure value.

In this state, when the inverter operation mode is selected, the inverter is applied to drive the motor M₁ variable speed according to the operation pattern set in the feed water pump system. When the pressure in the pressure tank 7 reaches the maximum pressure, the motor M₁ is stopped. When the pressure in the tank 3 reaches the minimum pressure, the variable speed operation is repeated again and again. In other words, the motor rotates at the rated speed between the minimum pressure value and the shift operation point, and linearly decelerates to the frequency set by the frequency setting switch between the shift point and the maximum pressure value, and stops the motor when the maximum pressure is reached. Once the motor stops at the maximum pressure, the pump motor stops until the minimum pressure is reached even if water is supplied to the consumer side, and when the pressure is below the minimum pressure, the pump motor starts again.

In the automatic operation mode, the motor starts at the minimum pressure, and the motor stops when the maximum pressure is reached, according to the operation pattern set in the water supply pump system. Even if water is supplied to the pump, the pump motor is stopped until the minimum pressure is reached. When the pressure is below the minimum pressure, the pump is restarted and this pattern is repeated.

In the case of malfunction of the controller during inverter operation or automatic operation, by operating the manual operation switch, a person can directly start and stop the motor M2 by manual operation. When the inverter operation and the automatic operation mode are selected, the automatic operation is performed by the control program as shown in FIG. 5 of the control device.

In addition, when an abnormal signal of the system is issued during operation, a signal is generated such that the main solid state relay (SSR) of the power supply unit is turned off.

As described above, according to the present invention, since the control unit is composed of a control unit and a power supply unit, the control unit can be semi-permanently used, but can supply a constant quantity and water pressure.

Claims (3)

In the water supply pump system to sense the pressure of the pressure tank to turn the power of the water supply pump ON-OFF, the control device is composed of a power supply unit and a control unit, the power supply unit to supply power to the solid state relay and the control unit is A / D conversion circuit ("A"), central processing unit ("B"), D / A circuit ("C"), operation mode selection switch and logic circuit, display ("D") and operation condition setting switch and numeric display Control device of a water supply pump system, characterized in that consisting of ("E"). The operating mode selection switch (SW) according to claim 1 is a control method of a feed water pump system to select an inverter, automatic, manual. A control method of a water supply pump system, characterized by sensing the air pressure in a tank by a sensor made of a piezoelectric element such as piezoelectric.