Combined action of multi parameters of the hottest

2022-09-22
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The influence of multi parameter interaction of regulator and frequency converter on the operation of water pump variable frequency speed regulation system

Abstract: the variable frequency speed regulation constant current control system composed of frequency converter with PID closed-loop regulation function and orifice differential pressure flowmeter of Siemens company (Siemens) is used to conduct orthogonal experiments, and the specific gain (P), integral gain (I), differential gain (d), sampling cycle (T) The influence of multiple parameters such as filtering times (n) and integration range (W) on the constant flow water supply system is analyzed, and the best parameters of the constant flow water supply system are given on the basis of experiment and analysis. Based on the experiment, the optimal parameters of the constant flow water supply system are analyzed and given. The parameter tuning problem of the cerebellum in this experiment has certain reference significance for the parameter tuning of the regulator and frequency converter of the constant current and constant pressure water supply system controlled by the general closed-loop PID

key words: PID control frequency conversion speed regulation orthogonal experimental parameter setting

with the continuous progress of frequency conversion speed regulation control technology of water pump, using frequency conversion speed regulation technology to realize the speed regulation operation of water pump has become the preferred scheme of water pump speed regulation system. Due to the advantages of flexible control, stable start and stop, stable flow and energy saving, the constant flow water supply system with variable frequency speed regulation of water pump has been more and more widely used in water supply and drainage engineering. However, in practical engineering, many types of regulators and frequency converters have many parameters, which brings certain difficulties to the setting of system operating parameters, and sometimes it is difficult to set them to the best state. As a result, it has become a major obstacle to the commissioning and operation management of variable frequency speed regulation system, and has affected the wide application of regulators and converters to a certain extent. This paper takes the parameter tuning of variable frequency speed regulation system composed of frequency converters with PID closed-loop regulation function (Siemens) as an example, and studies the influence on the operation of variable frequency speed regulation constant current water supply system under the joint action of multiple parameters through experiments

1. constant current water supply experimental system of variable frequency speed regulating water pump

Figure 1 shows a constant current water supply system of variable frequency speed regulating water pump. The system is mainly composed of a water pump unit, a frequency converter with PID regulation function, and a compressor that will damage the orifice flow sensor and water supply pipeline if it works under this condition for a long time. In the figure, the water supply pipeline takes the constant water supply flow of L ± 0.05m3/h as the system operation goal. The main equipment of the system is Siemens MMV inverter with PID closed-loop regulation function

the frequency converter has powerful functions and is more suitable for frequency conversion speed regulation control of water pumps in simple constant pressure and constant flow water supply systems. The frequency converter can flexibly program the type and ratio of given signal and feedback signal; PID and other closed-loop control parameters; The gradual delay time of starting and stopping the pump with gradual frequency; Setting of maximum and minimum working frequencies and other operating parameters: it has strong functions of equipment over limit operation and safety assurance; Wait

according to the system operation requirements, the main working parameters of the frequency converter are selected, as shown in Table 1

main working parameter setting table of frequency converter Table 1 parameter code parameter function parameter range parameter setting value parameter description

p001 display selection 0 display output frequency

p002 acceleration time (seconds) 20 water pump start time is 20 seconds

p003 deceleration time (seconds) 20. The pump stop time is 20 seconds

p006. The frequency setting mode is 0-31. Complete the frequency control through analog input.

p010. The proportional coefficient of the displayed quantity is 0-500 1. The actual value of the output frequency

p012. The minimum motor frequency (Hz) is 0-400. The minimum motor working frequency (Hz)

p013. The maximum motor frequency (Hz) is 0-50. The maximum motor working frequency (Hz)

p021 minimum given analog frequency 0-6500 minimum given analog output frequency is 0% of working frequency (50Hz)

p022 maximum given analog frequency 0-650100 maximum given analog output frequency is 100% of working frequency (50Hz)

p023 given analog input type 0-300---10v analog signal input

p208 feedback sensor action type 0-10 motor speed increases, Cause the feedback signal value to increase

p211 feedback signal 0% 0-100 0 feedback signal 0% corresponds to the minimum working frequency of the output frequency

p212 feedback signal 100% 0-100 50 feedback signal 50% corresponds to the maximum working frequency of the output frequency

p321 minimum feedback analog quantity frequency 0-6500 0 the output frequency of the minimum feedback analog quantity is the working frequency (50Hz) 0%

p322 maximum feedback analog quantity frequency 0-650 100 maximum feedback analog quantity output frequency is 100% of working frequency (50Hz)

p323 feedback analog quantity input type 0-200-10v analog quantity signal input

flow sensor select orifice differential pressure flow sensor with range of 0-5m3/h, accuracy of 0.2%, zero to full range corresponding to output 0-5V signal voltage. Since the full-scale signal of the sensor is only 50% of the specified input signal of the frequency converter, the setting of P211, P212, P321, p322 and p323 in the parameter setting table in the above table is very important for Sumitomo Electric to start the demonstration and verification of vanadium batteries

the given value adopts the 4.7K potentiometer specified by the frequency converter, which exists in 65 kinds of minerals. The input type is 0-l0v analog signal

the above is the constant flow water supply experimental system in this paper

2. Constant current water supply test

the system experiment is divided into two steps. The first step is to carry out the initial operation experiment, and select the proportional gain (P), integral gain (I), differential gain (d), sampling period (T), filter tension tester manufacturer which is closely related to the closed-loop regulation in the frequency converter. Let's talk about the installation process of the AD card of the microcomputer controlled electronic universal tester: wave number (n) and integral range (W) as the main experimental parameters, Then, according to the PID control principle and the empirical tuning law of parameters, the proportional gain (P = 2), integral gain (I = 0), differential gain (d = 0), sampling period (t = 100ms), filtering times (n = 5), and integral range (w = 0) are determined as the initial values of the system, and then according to the sequence of P, I, D, t, N, W, the former parameter is repeatedly adjusted and fixed after finding a better value; Then add the next new parameter and repeatedly adjust the value of the new parameter; For each adjustment, the approximate values of the above parameters are finally determined based on the judgment standard that the system can work stably under the current value. See Table 2 for the initial value of system parameters and the final experimental value

preliminary setting value table 2 of main operating parameters of frequency converter trial operation parameter name P I d t n w

preliminary setting value of parameters 100100

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