Application of the hottest TD3300 frequency conver

2022-07-28
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Application of TD3300 frequency converter in super calender

Abstract:

taking super calender as an example, by introducing TD3300 series frequency converter, this paper introduces the basic mode of tension open loop in variable frequency vector control and TD3300 debugging steps

keyword: frequency converter; TD3300; Calender

1 preface

super calendered paper is abbreviated as SC paper. This new product is independently developed by Bochuang. It is made of low-cost ground wood pulp, chemical mechanical pulp or waste paper deinked pulp and wheat straw pulp as main raw materials, with a small amount of long fiber chemical pulp and more than 30% filler. Its smoothness is more than 500s, opacity is more than 85%, and the average vertical and horizontal fracture length is more than 3000m. Its quality can be compared with that of low weight coated paper, It can be used for color printing of advertisements, catalogues, inserts, etc. Because this process uses a large number of fillers and high yield ground wood pulp or chemical mechanical pulp, it can save fiber and wood resources, so the cost can be greatly reduced. After the paper is calendered by the calender, the smoothness, gloss and tightness of the paper can be improved to make the full thickness of the paper consistent, so as to improve the appearance quality of the paper and reduce the air permeability

the super calender shown in Fig. 1 is mainly divided into unwinding device (also known as paper ejector), calendering roller device (including main motor) and winding device. From the unwinding device, the base paper passes through the paper feed roller and the cold casting roller in turn, and then enters the central winding. This paper discusses how to use frequency conversion control to complete the transmission control of super calender

Figure 1 Schematic diagram of super calender

2 frequency conversion of super calender but great potential in practical utilization in the future control

2.1 open loop tension control scheme

the super calender must ensure constant paper tension during rapid start, rapid stop and intermediate continuous speed regulation, otherwise the collected paper will curl, fold or even break, seriously affecting the production quality and output. In this system, the combination of frequency converters is used to achieve accurate tension control. We know that in general, such requirements can be met in two ways: one is by controlling the speed of the motor, and the other is by controlling the torque of the motor. Considering the cost and conditions of installing the tension sensor, the open-loop tension control is adopted. Of course, under this control mode, the paper tension must be known, but it is obtained through the internal detection and calculation of the frequency converter, which reduces the cost and difficulty of the system

the torque command of the frequency converter can be calculated from the set tension and the winding diameter of the drum. The formula is as follows:

t= (F X D)/(2 x i)

where: t is the output torque command of the frequency converter; F is the tension setting command; D is the winding diameter of the drum; I is the mechanical transmission ratio

the scheme must consider the linear speed detection signal, coil diameter calculation and tension taper control, so as to accurately control the torque output of the motor and maintain the constant tension

2.2 variable frequency structure of super calender

the main drive power of super calender can be calculated according to the following:

p = k x B x V x n

where: P is the motor power (kw); K is a constant coefficient, generally taken as 0.015~0.026; V is the working speed (m/min); N is the number of rolls (PCs.)

taking a paper mill in Sichuan as an example, a 12 roll super calender is used. The rolled paper is 1m wide and 10um thick, and the design speed is 250 m/min. Then the power of the selected main traction motor (frequency converter) is: P = 0.018 x 1 x 250 x 12 = 54kw, so 55kW frequency converter can be selected

the system adopts high-performance vector inverter TD3000, which is configured as follows: main traction inverter: tdt0550g, winding inverter: tdt0055g. In addition, the winding motor adopts variable-frequency motor and is equipped with rotary encoder (Omron, 1024 line output)

Figure 2 electrical configuration diagram of super calender

2.3 variable frequency speed control description

the system uses TD3000 vector open-loop control to drive the main drive motor, and the winding frequency converter TD3300 adopts open-loop tension control mode. The speed setting of the main traction is input from Ai1, and the control accuracy is 1%~0.5 ", said Yang Qingli.". TD3300 uses the analog output port AO2 of the previous main traction converter TD3000, which will inevitably affect the normal operation (output the operating frequency of the TD3000 converter) to obtain the linear speed, and calculate the winding diameter; The tension setting signal is obtained by Ai1; The signals of rotary encoder are respectively connected to pgp/com/a-/b- port

3 commissioning steps for the winding frequency converter of the super calender

3.1 preliminarily check the wiring and nameplate parameters of the frequency converter, motor and rotary encoder

motor nameplate: rated power 5.5kw, rated voltage 380V, rated frequency 50Hz, rated current 11.6a, rated speed 1440rpm

rotary encoder: Omron 1024 line output, Power Supply Voltage 24VDC, abz open collector output

3.2 complete the self identification of motor parameters of the frequency converter

focus on the no-load current of the motor identified by the frequency converter. The normal no-load current of the motor should be within 30% ~ 50% of the rated current of the motor. The TD3300 frequency converter actually identified that the no-load current of the motor is 4.9a, which is 42% of the rated current of the motor, within the normal range

3.3 preliminarily test the drive ability of the frequency converter to the motor

td3000 frequency converter is set as the open-loop vector control mode, TD3300 is set as the closed-loop vector control mode, TD3300 frequency converter should set the encoder parameters (fb.00=1024) in (FB encoder function item), test the drive ability of the frequency converter to the motor in the keyboard control mode, and focus on observing the stability of the output frequency and the output current of the frequency converter, Pay special attention to the output current of TD3300 frequency converter. If the output current is too large and overcurrent fault is reported under no-load condition, the ab phase wiring of rotary encoder should be wrong. Replace the ab phase wiring or change the direction setting of PG wiring in the frequency converter (function code fb.01)

3.4 complete the signal interface test of TD3000 and TD3300

complete the analog output port AO2 (f6.07=1) of TD3000 frequency converter and the analog input port AI2 (f6.01=0) of TD3300 frequency converter

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