PLC-based hardware-in-the-loop simulator of a centrifugal pump

Abstract

A hardware-in-the-loop (HIL) model of a centrifugal pump is proposed. The HIL simulator consists of the pump and pipeline imitators built on the basis of the variable speed drives (VSD) connected via the programmable logical controller (PLC, and profibus communication components. The mathematical description of the pressure maintenance represents a core of the simulation methodology. To study the system, a series of tests have been conducted that proved the designed system flexibility and accuracy in pressure imitation at both the static and the dynamic modes.

Energy Efficiency of Chilled Water Pumping System Using Wireless Sensor Controller

“…The power input adjustment base on the changes of the pump speed is define as [5] : (11) where : PI1 : motor pump power input at rated speed (watt) PI2 : motor pump power input at speed executed (watt) N1 : pump speed at rated speed (Rpm) N2 : pump speed at speed executed (Rpm) So PI2 is :…”

“…The head and the pressure alter with the squared pump speed as follows [3] : (1) The power varies with the cube of the pump rotational speed as follows [3]: (2) To govern the relationships between the pressure (p) variables at the changing pump speed n, every hydraulic system is described with the affinity laws [5]: (3) With the pump speed will be controlled in the certain pressure, so the speed required (n2) can be determined from (3) as follows : (4) where :…”

“…So the conjunction between the change of flow rate and pump speed as follows: (6) where : m˚1 : actual flow rate at duty point, Kg/s m˚2 : flow rate required at certain heat load, Kg/s with the flow rate is proportional with heat load, the pump speed refer to change of heat load can defined from (9) as follow : (7) So the required pump speed (n2) is : (8) where : Q1 : Load at duty point (watts) Q2 : Actual load (watts) E. Propose Method This paper proposed Thermomechanical method to control the chilled water pump speed. Thermomechanical method is combining the bernoulli laws (refer to [3] and [5]) to determine the pump speed required base on the pressure changing and the thermodynamic law to determine the pump speed required base on the AC load changing. The flowchart of thermomechanical method is shown in fig.…”

“…PLC is used for data processing and the result of the algorithm is use to control the pump speed. The other method is proposed in [5]. Combination method between mathematics and physic model is use to control the pump speed.…”

“…Affinity transformation of Bernoulli equations is used to determine the speed required base on the actual torque and combine with speed sensor, pressure sensor and torque sensor for the physic model. The result in the [5] is the system have more flexibility and accurate in the static and dynamic condition.…”