CN209731125U - Cement clinker production line kiln owner's driving control system - Google Patents

Abstract

The utility model discloses a kind of cement clinker production line kiln owner driving control systems comprising sequentially connected model-free adaption device, Direct Torque Control module, frequency converter, motor and rotary kiln；The model-free adaption device includes that model-free adaptive controller and single input list go out system, the input terminal of the model-free adaptive controller is manually entered given torque, and the output end of the model-free adaptive controller connects the input terminal of the single-input single-output system；The frequency converter includes that a diode rectifier circuit, intermediate loop and inverter bridge, three are sequentially connected with；The input terminal of the Direct Torque Control module connects the output end of the single-input single-output system, and the output end of the Direct Torque Control module connects the diode rectifier circuit；The output end of the inverter bridge connects the motor, and the motor connects the input terminal of the Direct Torque Control module.The utility model improves the stability of control system, energy conservation.

Description

Cement clinker production line kiln main drive control system

technical field

The utility model relates to the technical field of a cement clinker production line, in particular to a kiln main drive control system for a cement clinker production line.

Background technique

As a high-energy-consuming industry, the cement industry has become a national key industry for compression and rectification. New projects will increasingly focus on large-scale production, thereby reducing unit energy consumption. At present, most domestic rotary kilns adopt DC speed control system. The DC motor used in the DC speed control system needs a high starting current when starting, which will cause a large impact on the power grid, thereby polluting the quality of the power grid. However, when the main transmission of the kiln is running at low speed, due to the characteristics of full-controlled bridge rectification, the harmonic components generated are relatively high, and the power factor is very low, which greatly increases the cost of power consumption, which is not conducive to energy saving and emission reduction. Therefore, a new type is urgently needed. Cement clinker production line kiln main drive control system.

Utility model content

The utility model provides a kiln main drive control system for a cement clinker production line, which improves the stability of the control system, balances the torque during operation, and saves energy.

The utility model adopts the following technical solutions:

Cement clinker production line kiln main drive control system, including: sequentially connected model-free adaptive device, direct torque control module, frequency converter, motor and rotary kiln;

The model-free adaptive device includes a model-free adaptive controller and a single-input-single-output system, the input terminal of the model-free adaptive controller manually inputs a given torque, and the output terminal of the model-free adaptive controller connected to the input of the single-input-single-out system;

The frequency converter includes a diode rectifier circuit, an intermediate circuit and an inverter bridge, and the three are connected in sequence;

The input end of the direct torque control module is connected to the output end of the single-input single-output system, and the output end of the direct torque control module is connected to the diode rectifier circuit;

The output end of the inverter bridge is connected to the motor, and the motor is connected to the input end of the direct torque control module.

Further, the motor is a hysteresis motor.

Further, the direct torque control module includes a motor nameplate data identification module, and the motor nameplate data identification module calculates the magnetic flux vector of the motor according to the nameplate data of the motor.

Preferably, the frequency converter is a 380V frequency converter or a 690V frequency converter.

Beneficial effect

The utility model continuously learns through the model-free adaptive device based on the artificial neural network, and continuously reduces the deviation e(t) between the output torque setting value r(t) and the output torque y(t) in an online manner , so as to adjust the output torque to meet the maximum starting torque of the motor and frequency converter due to the accumulation of cement materials at the bottom and the inertial resistance and frictional resistance of the cylinder when the rotary kiln load starts, so as to realize the soft start of the rotary kiln control system. Eliminate mechanical resonance, realize stepless speed regulation, improve the stability of the control system, and balance the torque during operation. The AC speed regulation system replaces the traditional DC speed regulation system, avoiding a large impact on the power grid, and achieving energy saving effects. In addition, the combination of the model-free adaptive device and the direct torque control module greatly improves the overload characteristics and environmental adaptability of the kiln main drive control system of the cement clinker production line.

Description of drawings

Fig. 1 is a schematic structural view of a cement clinker production line kiln main drive control system provided by an embodiment of the present invention;

Fig. 2 is a schematic structural diagram of the control system of the model-free adaptive control platform in Fig. 1;

Fig. 3 is a schematic diagram of the control structure of the model-free adaptive controller in Fig. 2;

Fig. 4 is a schematic diagram of the circuit structure of the frequency converter in Fig. 1;

FIG. 5 is a schematic structural diagram of the direct torque control module in FIG. 1 .

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the drawings in the embodiments of the present invention.

Referring to Fig. 1 , it is a schematic structural diagram of a kiln main drive control system of a cement clinker production line provided by an embodiment of the present invention.

The kiln main drive control system of a cement clinker production line, including a sequentially connected model-free adaptive device 100, a direct torque control module 200, a frequency converter 300, a motor 400, and a rotary kiln 500, where the motor 400 is a hysteresis motor; optionally , the model-free adaptive device 100 is a computer, a server and/or a device with a computing function from communication.

The model-free adaptive device 100 includes a model-free adaptive controller (MFA, Model-Free Adaptive, hereinafter referred to as "MFA controller") and a single-input single-output system (SISO, Single input single output), and the model-free adaptive controller The output terminal of the system is connected to the input terminal of the single-input-single-output system.

Referring to FIG. 4 , the frequency converter 300 includes a diode rectifier circuit 301 , an intermediate circuit 302 and an inverter bridge 303 , which are connected in sequence. The frequency converter 300 is a 380V frequency converter or a 690V frequency converter, which is used to meet customers' requirements for different mechanical equipment types, load torque characteristics, speed regulation range, static speed accuracy, starting torque and use environment.

The input end of the direct torque control module 200 is connected to the output end of the single-input single-output system, and the output end of the direct torque control module 200 is connected to the input end of the diode rectifier circuit 301; the output end of the inverter bridge 303 is connected to the motor 400, and the motor 400 Connect to the input terminal of the direct torque control module 200 .

Referring to Figure 2, the MFA controller is based on an artificial neural network algorithm, and its algorithm for refreshing weights is based on a single goal, that is, to reduce the deviation between the set value and the process variable. The control objective of the MFA controller is to generate an output u(t), forcing the process variable y(t) to track the set value r(t) even when the set value changes, there are disturbances and process dynamic characteristics change, and That is, the MFA controller continuously reduces the deviation e(t) between the setpoint r(t) and the process variable y(t) in an online manner. Through SISO processing, the effective value is recorded and saved for a period of time through analysis and calculation, and the invalid value of the harmonic component and mechanical resonance generated by part of the diode rectification circuit is eliminated, and then output, which means that when the process is in a stable state , when the deviation is close to zero, there is no need to modify the weight of the MFA controller, that is, the control of the main drive control system of the cement clinker production line kiln tends to be stable. When the system fluctuates due to factors from all walks of life, the MFA system can eliminate the need for complex controller parameter tuning, can control extreme nonlinear processes, control multi-variable processes, and suppress measurable diode rectifier circuits to produce harmonic components, mechanical resonance, etc. A disturbance that forces a process variable to remain within a predetermined range. Users of the MFA controller do not need to design the controller, just select the corresponding controller and simply set the controller parameters to put the MFA controller into use; and the MFA controller based on the artificial neural network saves a part of historical data , to provide valuable information for understanding the process dynamics and thus better control the system.

Referring to Fig. 3, it can also be understood that the MFA controller adopts an artificial neural network (ANN) with a multi-layer perceptron structure, which has an input layer, a hidden layer with N neurons and a single neuron output layer. In this neural network there is a set of weight factors (Wij and hi) that can be changed as needed to tune the behavior of the MFA controller. The algorithm for updating the weighting factors is aimed at reducing the deviation between the set point and the process variable. Because its effect is consistent with the control objective, the use of weight factors can help the MFA controller reduce the deviation when the process dynamic characteristics change.

Input the output torque setting value r(t) of the frequency converter to the MFA controller, and feed back the output torque y(t) of the frequency converter to the input terminal of the MFA controller, and the MFA controller continuously reduces The deviation e(t) between the output torque setting value r(t) and the output torque y(t) is processed by the single-input single-output system to eliminate the harmonic components or mechanical resonance generated by the diode rectifier circuit. When the disturbance d(t) is too large and invalid, the MFA controller automatically changes the weight factors (Wij and hi) to make the deviation e(t) close to zero when the deviation e(t) is close to zero. When e(t) is close to zero, the kiln main drive control system of the cement clinker production line tends to be under stable control.

Referring to FIG. 5 , a direct torque control module 200 (Direct torque control, DTC for short) includes a speed controller, a torque given value control module, a magnetic flux given value control module, a switching frequency control module and a direct torque control chip.

The first input end of the speed controller is the output torque y(t), the second input end of the speed controller is the first output end (actual speed) of the direct torque control chip; the input end of the switching frequency control module is connected directly The second output terminal (actual frequency) of the torque control chip, the output terminal of the switching frequency control module is connected to the first input terminal (hysteresis window terminal) of the direct torque control chip; the input terminal of the magnetic flux given value control module is connected to The second output terminal (actual frequency) of the direct torque control chip, the output terminal of the magnetic flux given value control module is connected to the second input terminal (magnetic flux given value ψ _ref ) of the direct torque control chip; the torque given The first input terminal of the value control module is connected to the output terminal of the speed controller, the second input terminal of the torque given value control module inputs the absolute torque given value, and the output terminal of the torque given value control module is connected to the direct torque The third input terminal of the control chip (torque given value T _ref ); the third output terminal of the direct torque control chip is connected to the power stage of the motor, and the fourth input terminal of the direct torque control chip is connected to the DC circuit voltage of the motor power stage , the fifth input terminal of the direct torque control chip is connected to the switching sequence terminal before the motor power stage, and the sixth input terminal of the direct torque control chip is connected to the motor current feedback terminal.

The direct torque control chip includes a motor nameplate data identification module, and the motor nameplate data identification module calculates the motor's magnetic flux vector ψ _s =∫(u _s -i _s r _s )dt according to the nameplate data of the motor . According to the received output torque and the magnetic flux vector, the direct torque control module calculates and outputs the (sinusoidal) angle proportional relationship between the output torque and the stator magnetic flux in the stator coordinate system. The required torque is maintained within a predetermined hysteresis range, thereby achieving a high gain in speed control.

It can also be understood that the DTC module relies on a powerful digital processor (25μs control loop) and a mathematical model of the motor, without speed feedback, modulator, or switching mode. By using an adaptive motor model, the flux vector of the motor is accurately calculated based on the motor nameplate data, through the (sinusoidal) angular proportional relationship between torque and stator flux. Compares the flux setpoint to flux and maintains it within a predetermined hysteresis, while comparing the torque setpoint to the estimated (i.e. calculated) torque and holds it within a predetermined hysteresis middle. This results in high gains in speed control through fast torque control, improved dynamic and static accuracy, and optimized response to special situations such as power loss, overvoltage and undervoltage, rapid load changes, mechanical vibrations and tripping without interruption And so on, so as to realize the ideal control of cement kiln transmission.

Using the kiln main drive control system of the cement clinker production line of this embodiment, taking the 5000T cement line as an example, the kiln main drive can be started without impact current (starting current is less than the rated current of the motor, and the starting current of the DC motor is as high as about 2 times the rated motor). The annual system maintenance amount (including the motor) is less than 1 time (the annual maintenance amount of the DC control system is more than 5 times), and the overall power factor is increased from 80% to more than 90%.

The foregoing is a preferred embodiment of the present utility model, and it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present utility model, some improvements and modifications can also be made. These improvements and modifications It is also regarded as the protection scope of the present utility model.

Claims (4)

1. cement clinker production line kiln owner's driving control system characterized by comprising sequentially connected model-free adaption dress It sets, Direct Torque Control module, frequency converter, motor and rotary kiln；

The model-free adaption device includes model-free adaptive controller and single-input single-output system, and the model-free is certainly The input terminal of adaptive controller is manually entered given torque, and it is defeated that the output end of the model-free adaptive controller connects the list Enter the input terminal of single output system；

The frequency converter includes that a diode rectifier circuit, intermediate loop and inverter bridge, three are sequentially connected with；

The input terminal of the Direct Torque Control module connects the output end of the single-input single-output system, the Direct Torque The output end of control module connects the diode rectifier circuit；

The output end of the inverter bridge connects the motor, and the motor connects the input terminal of the Direct Torque Control module.

2. cement clinker production line kiln owner driving control system as described in claim 1, which is characterized in that the motor is magnetic Stagnant motor.

3. cement clinker production line kiln owner driving control system as claimed in claim 2, which is characterized in that the Direct Torque Control module includes motor nameplate data identification module, and the motor nameplate data identification module is according to the nameplate number of the motor According to the magnetic flux vector for calculating the motor.

4. cement clinker production line kiln owner driving control system as described in claim 1, which is characterized in that the frequency converter is 380V frequency converter or 690V frequency converter.