overview
The variable frequency constant pressure (variable voltage) variable current water supply equipment deeply utilizes advanced microcomputer technology and AC variable frequency speed regulation technology to achieve good closed-loop control of the pressure and flow of the water supply system. It automatically adjusts the working state of the water pump unit to maintain stable water supply pressure, making it an advanced and energy-saving electromechanical integrated equipment in water supply equipment.

function and characteristic
The equipment constantly monitors the instantaneous water consumption of the water supply system, and after analyzing and processing the water quantity signal through a microcomputer, the microcomputer controls the working status and speed of each water pump unit, ensuring the required water supply and keeping the water pump unit in energy-saving operation at all times, avoiding the waste of electrical energy. All water pumps in the equipment are soft started under the control of microcomputers and frequency converters, with low starting current and low energy consumption. The entire equipment operates economically and reasonably under microcomputer management, with significant energy-saving effects. If variable voltage control is adopted, the speed range of the water pump is further expanded, and the energy-saving effect is more significant than constant pressure control.
Explanation: When the flow rate of the pipeline network is Q_AChange to Q_BIf a constant speed pump is used, its head will inevitably rise to B 'and the water supply pressure will increase. If a variable frequency constant pressure variable water supply is used, when the set pressure is HA, the microcomputer detects the pressure difference H'B-HB and issues a control command to reduce the output frequency of the frequency converter, causing the pump's operating curve to change from no to n₂Maintain a constant pressure of HA Obviously, it reduces the dynamic pressure loss in the B'B section compared to a constant speed pump, thus having a significant energy-saving effect. If variable pressure water supply is used, the microcomputer sends control instructions to make the pump's operating curve change from n₀Change to n₄Intersection with the working characteristic curve of the pipeline at point B '' reduces the dynamic pressure loss in the BB section compared to constant pressure variable water supply, resulting in more significant energy savings.

Structure and Principle
1. Structure
The variable frequency constant pressure (variable voltage) variable flow water supply equipment mainly consists of a control cabinet, a water pump unit, a small pneumatic water tank, pressure sensors, and pipeline valves. The difference between BTG-I and BTG-II lies in the different controllers used. The BTG-I type adopts the XHG type fully automatic variable frequency constant pressure water supply control (referred to as the controller) for control. The controller is based on the 16 bit 8098 microcontroller from Intel Corporation in the United States. It has the advantages of high integration, high reliability, high control accuracy, high operating speed, and high anti-interference. On this basis, it expands with multifunctional interfaces, thin film buttons, and LED large screen digital display. LCD display provides users with a better control interface. The BTG-II model adopts a programmable logic controller (PLC) control, which makes the control system highly reliable, has strong anti-interference ability, and has flexible and convenient expansion functions.

2. Operation process (taking three pump systems as an example)

In the "variable frequency automatic" operation mode, the microcomputer soft starts the 1 # water pump through the frequency converter, and the 1 # water pump enters the variable frequency operation state, gradually increasing the speed. When the water supply Q is less than 1/3Qmax (Qmax is the flow rate when all three pumps are operating at power frequency), the microcomputer automatically adjusts the speed of pump 1 according to the change in water supply to ensure stable water supply pressure. When 1/3Qmax<Q<2/3Qma, the 1 # pump can no longer meet the required water volume. At this time, the microcomputer will switch the 1 # pump to the power frequency operation state, soft start the 2 # pump, and make it enter the variable frequency operation state. Its speed is determined by the required water volume. When 2/3Qmax<Q, the microcomputer places pumps 1 # and 2 # in power frequency operation, and soft starts pump 3 # in variable frequency operation. When the water supply decreases and 1/3Qmax<Q<2/3 Qmax, the speed of pump 3 gradually drops to zero, stops running, and the microcomputer controls pump 2 to enter the variable frequency state. When the water supply continues to decrease. When 0<Q<1/3Qmax, pump 2 stops working and pump 1 switches to variable frequency operation.

3. System principle

Variable frequency constant pressure (variable voltage) variable flow water supply equipment, with a microcomputer as the core, controls the operation status of the water pump unit through a frequency converter, relay, and touch sensor. Realize the requirements of constant pressure (variable pressure) and variable flow water supply in the pipeline network. When the equipment is running, the pressure sensor continuously converts the water pressure signal of the pipeline network into an electrical signal and sends it to the microcomputer. After processing by the microcomputer, the control parameters are obtained, and the water pump unit is automatically adjusted to operate efficiently through the frequency converter and relay control components, ensuring good water supply quality and limited energy saving.