Invt Frequency Inverter Low Voltage PID control 47Hz - 63Hz

Description

 CHV160A is the enhanced edition of CHV160. It adopts the advanced control theory to adjust speed and switchover of pumps automatically according to the pressure of pipe net, so as to make the pressure to be constant.

Features

1. CHV160A series special for multi-pumps water supply = PLC + pressure sensor + PID regulator + inverter . Supply fixed variable frequency pump mode (can define 1 fixed variable pump at most + 9 grid frequency pumps) and circular variable frequency pump mode(can define 4 circular variable frequency pumps at most + 2 grid frequency pump).
2. Optimized water supply PID regulator can accomplish the switching between two PID parameters.
3. Flexible control logic of add and decrease the pumps, flexible dormancy pumps control.
4.Timing rotation: to avoid pumps being seized by corrosion.
5. Support 8 timeslots timing water-supply and 16 multi-step pressures setting.
6. Built-in water-level detection and control function (for inlet pool and sewage pool).
7. For convenient debugging and maintenance, built-in manual soft-start debugging and manual round-robin debugging function.
8. Monitoring the pressure of pipe net, and alarm at abnormal status. Perfect fault protection: ground fault protection, short phase protection, etc.
9. Built-in standard Modbus communication protocol.

Application

The Application of INVT CHV160 Series Water Supply Specific Frequency Inverter  

Abstract: Compared with traditional water supply system like water tank and water tower, constant pressure water supply system using frequency inverter has many advantages including energy saving, water saving, and no pollution to water resources etc. This paper systematically and comprehensively describes the characteristics of INVT-CHV160, frequency inverter special for water supply, and its application in constant pressure water supply system.

Keywords: frequency inverter   constant pressure water supply     PID control
Foreword:
Water is the most precious resource and the basic condition of survival for human being, as well as the lifeline of national economy, and water industry is a kind of special industry engaging into the sustainable exploring and using of water resource, which treats city and industry as target, and treats water quality as core, and aims to satisfy the water requirement for the social economy sustainable development. In the process of exploring, processing and conveying and using water, water supply equipment is indispensable tool.

Water supply status and constant pressure water supply equipment
Generally, it states that water pressure in city piping network can only guarantee water use in the building below the 6th storey, and it need lifting water pressure to satisfy water use requirements of the higher storey. Conventional method to lift water supply is using pressure increasing equipments like water tower, high position water tank or gas pressure tank, which is of high one-time investment expenses and usually increases the power of pump and energy consumption, because these equipments must use pumps to lift water, always with the pressure higher than actual requirement; meanwhile, it is liable to cause secondary pollution of the water when using the conventional water supply system.
Based on the requirements of water use in industrial production, human living, agriculture water saving irrigation projects etc, it is possible to using CHV160 series water supply specific frequency inverter can quickly assembly constant pressure water supply system, and it integrates frequency inversion speed regulation technology, PLC technology and PID control technology, which can form a complete close-loop automatic control system.

Constant pressure water supply principle
When water supply automation system is working, the equipment tests pressure change in water supply piping network along with the change of water use volume by highly sensitive pressure sensor installed in water supply piping network, which transmits changing signal to frequency inverter continuously, through judging and calculation by micro computer and setting pressure comparison, it will issue the instruction of changing frequency to the controller, and controller can change the rotation and starting set number of water pump motor through changing frequency, and automatically adjust water use volume in the bottom and peak, and guarantee the pressure of water piping network is constant to satisfy the requirements of water use for the users. CHV160 constant pressure water supply principle as follows:

  The advantages of constant pressure water supply
Design conception of CHV160 series water supply specific frequency inverter originates from rich engineering practice, which has advantages as follows:
 1. Multi-section pressure setup: eight-section pressure set every day, which can change pressure giving volume according to different time. E.g. flux wave in 3 water use peak periods in order to adapt to living water supply, and set three high pressure water supplies time periods.

2. Dormancy control function:
It can make the system enter into dormancy control status and control specific dormancy little pump, e.g. parameter setup dormancy waking potential energy, which can wake power and inversion frequency operation; especially suitable for night when water supply is decreasing dramatically.

3. Timing lifting function:

Through setting the time, and let water pump in the system lift, and make all water pumps in the system involved into operation in turn, and prevent rust of the pump effectively, and improve general utility rate of the equipment. Reduce maintenance costs. When pump capacity is basically the same, selecting timing lifting function is more suitable to prevent the vibration of system working.

4. Liquid level testing and control function in suction sump
Test and control liquid level of fresh water pool, when water level of suction sump is changing from the top to the bottom, and water level is higher than lower limit water level, the system is operating according to normal set pressure; when water level is lower than lower limit water level but higher than water short water level, the system is operating according to abnormal backup pressure; when water level is lower than water short water level, the system stops all the operation.

When water level of the pool is changing from the top to the bottom, before water level is lower than lower limit water level, the system can’t operate; when water level is higher than lower limit water level but lower than upper limit water level, the system is operating according to abnormal backup pressure; when it is higher than upper limit water level, the system resumes operating in normal pressure.

5. Adjustment functions in pressure allowance range:
 PID has allowance range, when feedback pressure is under warp limit of pressure value set, pressure adjuster stops adjustment to improve the precision and stability of pressure adjustment system.

6. Smooth water pump switch function:
When accelerating or decelerating the pump, it will constantly keep one frequency inversion pump operating to make the pressure of piping network not changed suddenly. For switching to power frequency pump from frequency inversion pump, it can set frequency inversion pump switch frequency, and frequency inversion pump is operating in higher frequency and then switch to power frequency operation and guarantee stability of piping network pressure.

7. Sewage release pump control function: through control to sewage release pump to realize control to water level of sewage pool and realize automatic sewage release.                            

8. Rich protection function: making all-around protection to the system.

** company uses INVT CHV160 specific water supply frequency inverter, and it requires to drag two sets of water pumps to conduct frequency inversion constant pressure water supply, and it requires to use dormancy function and shield malfunction pump and realize restarting in the moment of stripping. Connection drawing of frequency inverter line is