The hardware composition of frequency inverter constant pressure water supply system: frequency converter, constant pressure water supply controller, plc, water pump unit and control system.

Working Principle of Frequency Inverter Constant

1. Function introduction of frequency conversion constant pressure water supply system hardware

Inverter: Inverter (Variable-frequency Drive, VFD) is a power control device that uses frequency conversion technology and microelectronics technology to control AC motors by changing the frequency of the motor’s operating power supply. (The speed formula of the three-phase asynchronous motor is: N=60f/p (1-s), f is the power frequency, p is the number of pole pairs, and s is the slip rate) The frequency converter adjusts the output power by switching off the internal IGBT. Voltage and frequency, according to the actual needs of the motor to provide the required power supply voltage, and then achieve the purpose of energy saving and speed regulation.

Constant pressure water supply controller: frequency conversion constant pressure water supply controller, high pressure measurement accuracy, the product and frequency converter can be used together, one for one, one for one standby, one for two, one for three, one for four, etc. Working mode, you can also set the time for water supply. Controllers are widely used in residential areas, petroleum, chemical industry, fire protection, sewage, agricultural irrigation, water supply and other fields.

plc: Programmable logic controller, which uses a type of programmable memory for its internal storage program, executes user-oriented instructions such as logic operations, sequence control, timing, counting and arithmetic operations, and through digital or analog input /Output controls various types of machinery or production processes. The working principle of PLC is to detect the state of external input, calculate and process the input data, and then output the control quantity. It has the characteristics of easy programming, high reliability, and convenient installation and maintenance.

Water pump unit: In the water supply system where the motor and the pipeline are integrated, the output frequency of the inverter is adjusted according to the pressure value detected by the controller to change the speed of the motor to adjust the pressure of the water supply. Usually, multiple water pumps (two for example) are set up in the water supply system, two pumps are turned on when the water supply is large, and one is turned on when the water supply is small. The water pumps in the water pump group work in unison to meet the water supply needs.

2. The control principle of the frequency converter constant pressure water supply system

The frequency conversion constant pressure water supply system takes the water pressure of the pipe network (or the user’s water flow) as the setting parameter, and automatically adjusts the speed of the pump motor through the microcomputer to control the output frequency of the frequency converter, so as to realize the closed-loop adjustment (PID) of the water pressure of the pipe network. The water supply system automatically stabilizes at the set pressure value: that is, when the water consumption increases, the frequency increases, the pump speed increases, and the water supply increases accordingly; when the water consumption decreases, the frequency decreases, the pump speed slows down, and the water supply decreases accordingly Small, so that the water supply efficiency user’s requirements for water pressure and water volume are guaranteed.

In the automatic control, the power frequency and variable frequency operation of the motor are controlled by the plc (two sets as an example). The control system has a water pump to adjust the frequency conversion operation according to the change of water consumption. When the water consumption increases, the pressure in the pipeline system drops. At this time, the pressure sensor The detected signal is transmitted to the microcomputer control unit, and through the operation judgment of the microcomputer, an instruction is sent to the frequency converter to control the water pump motor. The pump is switched to the constant speed operation of the power frequency grid, and the two pumps are started at the same time and enter the frequency conversion operation. The system resumes the closed-loop adjustment of the water pressure until the water pressure reaches the set value; when the water consumption decreases and the water pressure increases, the frequency converter output frequency When the water pressure drops to the starting frequency and the water pressure is still higher than the set value, stop the operation of the water pump, and the system resumes the closed-loop adjustment of the water pressure to make the pressure reach the set value again; When the frequency drops to the starting frequency, stop the pump until the last variable frequency pump is left to run.

The hardware composition of frequency inverter constant pressure water supply system: frequency converter, constant pressure water supply controller, plc, water pump unit and control system.

Working Principle of Frequency Inverter Constant

1. Function introduction of frequency conversion constant pressure water supply system hardware

Inverter: Inverter (Variable-frequency Drive, VFD) is a power control device that uses frequency conversion technology and microelectronics technology to control AC motors by changing the frequency of the motor’s operating power supply. (The speed formula of the three-phase asynchronous motor is: N=60f/p (1-s), f is the power frequency, p is the number of pole pairs, and s is the slip rate) The frequency converter adjusts the output power by switching off the internal IGBT. Voltage and frequency, according to the actual needs of the motor to provide the required power supply voltage, and then achieve the purpose of energy saving and speed regulation.

Constant pressure water supply controller: frequency conversion constant pressure water supply controller, high pressure measurement accuracy, the product and frequency converter can be used together, one for one, one for one standby, one for two, one for three, one for four, etc. Working mode, you can also set the time for water supply. Controllers are widely used in residential areas, petroleum, chemical industry, fire protection, sewage, agricultural irrigation, water supply and other fields.

plc: Programmable logic controller, which uses a type of programmable memory for its internal storage program, executes user-oriented instructions such as logic operations, sequence control, timing, counting and arithmetic operations, and through digital or analog input /Output controls various types of machinery or production processes. The working principle of PLC is to detect the state of external input, calculate and process the input data, and then output the control quantity. It has the characteristics of easy programming, high reliability, and convenient installation and maintenance.

Water pump unit: In the water supply system where the motor and the pipeline are integrated, the output frequency of the inverter is adjusted according to the pressure value detected by the controller to change the speed of the motor to adjust the pressure of the water supply. Usually, multiple water pumps (two for example) are set up in the water supply system, two pumps are turned on when the water supply is large, and one is turned on when the water supply is small. The water pumps in the water pump group work in unison to meet the water supply needs.

2. The control principle of the frequency converter constant pressure water supply system

The frequency conversion constant pressure water supply system takes the water pressure of the pipe network (or the user’s water flow) as the setting parameter, and automatically adjusts the speed of the pump motor through the microcomputer to control the output frequency of the frequency converter, so as to realize the closed-loop adjustment (PID) of the water pressure of the pipe network. The water supply system automatically stabilizes at the set pressure value: that is, when the water consumption increases, the frequency increases, the pump speed increases, and the water supply increases accordingly; when the water consumption decreases, the frequency decreases, the pump speed slows down, and the water supply decreases accordingly Small, so that the water supply efficiency user’s requirements for water pressure and water volume are guaranteed.

In the automatic control, the power frequency and variable frequency operation of the motor are controlled by the plc (two sets as an example). The control system has a water pump to adjust the frequency conversion operation according to the change of water consumption. When the water consumption increases, the pressure in the pipeline system drops. At this time, the pressure sensor The detected signal is transmitted to the microcomputer control unit, and through the operation judgment of the microcomputer, an instruction is sent to the frequency converter to control the water pump motor. The pump is switched to the constant speed operation of the power frequency grid, and the two pumps are started at the same time and enter the frequency conversion operation. The system resumes the closed-loop adjustment of the water pressure until the water pressure reaches the set value; when the water consumption decreases and the water pressure increases, the frequency converter output frequency When the water pressure drops to the starting frequency and the water pressure is still higher than the set value, stop the operation of the water pump, and the system resumes the closed-loop adjustment of the water pressure to make the pressure reach the set value again; When the frequency drops to the starting frequency, stop the pump until the last variable frequency pump is left to run.

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