I. Introduction:   

 

The paper industry occupies an important position in the entire national economy, but the speed control of paper machinery has always been a weak link in the paper industry. The papermaking process requires that the linear speed of each part be absolutely synchronized at their respective synchronization frequency points, so as to ensure that the paper is smooth, uniform in thickness, wrinkle-free, and does not break. The speed, stability, and adjustability of the vehicle directly affect the output and quality of paper. For many years, the DC excitation speed control of the paper industry has accounted for a large proportion. Although the DC excitation speed control motor has good speed control performance, It has advantages such as large moment, but there are many disadvantages: high cost; difficult maintenance of commutators and brushes; difficult to use in harsh situations; large noise is not suitable for operation.

 

In today's energy shortage, most provinces across the country have begun to curtail power, especially in East China. The shortage of power is particularly serious. The paper industry, as a major power consumer, is particularly energy-saving. Therefore, the current rapid development of motor frequency conversion technology provides This possibility, but for low-grade paper, in order to save costs, without expensive foreign equipment imported, the unique control program of Shenzhen Yidrive inverter can meet the requirements of the paper industry. Shenzhen Yidrive inverter realizes total adjustment and fine-tuning control through communication with the host computer, as well as two-channel analog output monitoring speed and load scheme design to complete the papermaking process requirements.

 

2. Analysis of the advantages of using easy-drive frequency converters on pulp pumps 　　 　　

 

1. The frequency conversion technology can effectively control the speed of the motor, and has the advantages of wide speed adjustment range, high speed adjustment accuracy, and fast dynamic response; 　　

 

●Adjustable operating speed: The frequency conversion technology adjusts the output voltage proportionally while adjusting the output frequency, thereby changing the motor speed and realizing stepless speed regulation;

 

●Acceleration controllable: variable frequency speed regulation can be started at zero speed, and correspondingly accelerated according to demand, acceleration curve can be selected according to design requirements;

 

●Using microcomputer control technology to control the frequency converter, it can realize a variety of transmission speed regulation functions: various frequency setting and execution, starting, operation mode selection, torque control setting and operation, acceleration and deceleration design and operation, braking Mode setting and execution make the frequency conversion technology more intelligent, and the application field is broader.

 

2. The protection function of frequency conversion technology is relatively complete, which can effectively control the protection and monitoring of the motor, the life of mechanical parts, and the current and voltage fluctuations of the power grid;

 

In terms of the loss of mechanical parts, the selection of the motor stop mode (deceleration stop, free stop, deceleration stop and DC braking, etc.) of the frequency conversion speed regulation can reduce the impact of the motor and its linked mechanical parts; dynamically adjust the torque limit to avoid mechanical Does not reduce damage.

 

3. Frequency conversion technology has significant advantages in energy saving and maintenance.

 

First, the frequency conversion technology realizes soft start with low starting current. The power of the motor is proportional to the product of current and voltage, and the power consumed by the motor directly started by the industrial frequency will be much higher than the power required for variable frequency start;

 

Second, the variable frequency speed control motor operates at a low slip rate, which reduces the loss of the motor itself and has high working efficiency. At the same time, as application requirements change, the frequency conversion speed regulation system can quickly and dynamically adjust the speed to minimize power consumption.

 

3. Features of Easy Drive CV3100 Inverter

 

1. V/F control mode (one drive multiple) A. Advanced vector control algorithm, optimized SVPWM output, low output harmonics and small motor temperature rise. B. Realize optimal energy-saving operation through motor parameter detection.

 

2. Open-loop vector control (SVC) mode A. Using TI high-speed motor control dedicated DSP processor, it can complete complex vector calculations at high speed and accurately, and achieve complete decoupling of the motor. B. Using advanced motor model algorithm, 0.5Hz can output 150% rated torque, stable speed accuracy 0.5%, speed regulation range 1:100.

 

3. Standard RS485 interface, support MODBUS communication protocol, and can communicate with host computer such as touch screen, PLC, etc.

 

4. Complete protection measures can protect nearly 20 kinds of faults such as overvoltage, undervoltage, input phase loss, output phase loss, overload, overheating, overcurrent, external terminal failure, communication failure, current detection error, motor tuning failure, etc. , Higher reliability.

 

Fourth, the scene picture of the easy drive CV3100 series inverter used in the paper machine