Application of AC300 frequency converter in water supply industry

Overview

With the development of frequency converter speed control technology and people's continuous improvement of the quality requirements of drinking water, frequency conversion water supply equipment has been widely used in multi-story residential community living and high-rise building life water supply, frequency conversion speed water supply has the following advantages:

1. Low equipment investment and reliable system operation;
2. Small footprint, saving electricity and water;
3. High degree of automation, convenient operation and control, etc.

The application of the water supply industry is extremely extensive. The water supply can be controlled by road watering, household water supply, industrial water supply, construction site water supply, etc. The quality of the water supply inverter is uneven, so that our AC300 has a good entrance. The water supply plan is relatively uniform and the maintenance is more convenient.

Equipment composition and working principle of the water supply industry

1. Constant pressure water supply mainly consists of a motor, a water pump, a buffer tank, a remote pressure gauge, and an AC300 inverter. Generally use the terminal to start and stop.
2. The constant pressure water supply system compares the feedback signal of the remote pressure gauge with the given value. When the feedback value is higher than the sleep threshold, the inverter enters the sleep state after entering the sleep time. When the feedback threshold is below the start threshold, the motor is restarted to maintain the pressure near the set point.

Pump unit

Constant pressure water supply system features

1. Pump soft start, stop, no impact and overpressure hazard, no water hammer phenomenon;
2. Reliable operation: the frequency converter realizes the soft start of the pump, prevents the pipe network from impacting, avoids the pipe network pressure exceeding the limit, and the pipe is broken;
3. The equipment has high degree of automation, the water supply is stable and reliable, and the water quality has no secondary pollution;
4. Perfect protection function: a single pump fails, actively sends out alarm information, and starts the standby pump to maintain the water supply balance;

Functions to be realized in the constant pressure water supply industry

The main function of constant pressure water supply is to keep the water pressure constant without large fluctuations.

Mainly implemented features:

1) The pressure is given, that is, the given number of kilograms.
2) The sleep function is implemented, and the motor is maintained at a low speed or a zero speed when no water is used.
3) When the pressure feedback is below a certain value, it is necessary to restart the holding pressure.

AC300 in the constant pressure water supply industry

Parameter settings:

Program

1. F00.03=8 (The frequency reference channel is set to: PID control given).
2. Set the PID controller to give the signal source; (for example: 10 kg water tank, to constant pressure at 6 kg; then the setting is 6/10 + F11.32 (if F11.32 is 5% at this time) = 65% If the constant pressure is not too precise at 6 kg, and the wake-up deviation is small, the setting can be directly set to 6/10=60%).
3. Set the PID controller feedback signal source; (voltage pressure gauge or current pressure gauge, etc.).
4. F11.29=1; (constant pressure water supply sleep is effective).
5. Set the F11.30 sleep frequency according to the scene; (the output frequency is lower than the sleep frequency and goes to sleep after F11.31).
6. Set the F11.31 sleep delay according to the scene.
7. Set F11.32 wake-up deviation; (when PID is given - wake-up deviation > PID feedback, sleep will stop and will start).
8. Set the wake-up delay; (When PID is given - wake-up deviation > PID feedback, the time set by the wake-up delay will no longer sleep, the inverter will start).

Wiring diagram

Conclusion

The constant pressure water supply uses the inverter PID control function. Before the constant pressure water supply mainly uses AC60, AC70 inverter realizes the requirement of constant pressure water supply, but the control performance of AC300 inverter on constant pressure water supply is more perfect, because our company is The PID control algorithm is optimized on the AC300 universal frequency converter, which makes the PID control performance, high precision and fast dynamic response, which can achieve excellent process control and ensure the reliability of process control.