Steel industry trade insights

List of contents of this article:

• 1、 Double closed-loop speed regulationIn the given start-up process of the speed system:
• 2,Steel industry trade insights What are the advantages of the speed and current double closed-loop speed regulation system?
• 3, What is the DC closed-loop speed regulation feedback device
• 4, Which ring plays the main regulating role in the double closed-loop speed regulation system? What adjustment should be achieved?
• 5, In the motor speed regulation closed-loop control system, the system is powerless against any disturbance.

In the given start-up process of the double closed-loop speed regulation system:

1. In the speed and current double closed-loop speed regulation system, the speed over-adjustment is due to the inertia and control of the system Caused by the response characteristics of the device. When the system suddenly joins a given startup signal, the current closed-loop controller will immediately adjust the current output to meet the given startup requirements.

2. In a double closed-loop system, the current regulator plays the role of maintaining constant current regulation.The formula is as follows: Feedback link: By sensing the current signal in the circuit, the current regulator compares the actual current with the expected current to obtain the error signal.

3. This is slightly more complicated than that current loop. The double closed loop is generally divided into three stages: current rise, constant current speed, and speed adjustment.

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5. The single-closed-loop speed regulation system using speed negative feedback and PI regulator can achieve no static difference in speed under the condition of ensuring the stability of the system. However, if the dynamic performance requirements of the system are high, such as starting and braking, the dynamic speed reduction of the sudden load is small, etc., it is difficult for a single closed-loop system to meet the requirements.

6. NeedTo transition the engine from a stationary state to a working state, the crankshaft of the engine must first be rotated by external force to make the piston reciprocate. The combustible mixed gas in the cylinder burns and expands to push the piston down to make the crankshaft rotate. Only the engine can run by itself, and the work cycle can proceed automatically.

What are the advantages of the speed and current double closed-loop speed regulation system?

Stability: The double closed-loop control system can achieve stable output. Even in the event of load changes or disturbances, the system can quickly adjust and maintain output stability. A stable system can provide reliable output performance, which is suitable for applications with high stability requirements.

Improve the service life of each equipment. 3) DepartmentIt can comprehensively detect motor faults such as overload, overcurrent and overheating, detect power supply faults such as undervoltage, overvoltage and phase breakage, detect pipeline faults such as leakage and blockage of circulation pipelines and frequency converter faults, and provide alarm signals and fault information in a timely manner.

[Answer]: Steady-state characteristics of the speed regulation system: the double closed-loop system is good and there is no static difference; the steady-state characteristics of the single-closed-loop system with current cut-off link are not as good as the double-closed-loop system.

Overview of DC double closed-loop speed regulation system DC double closed-loop speed regulation system is a widely used, economical and applicable power transmission system. It has the advantages of fast dynamic response and strong anti-interference ability.

What is the DC closed-loop speed regulation feedback device

1. The DC speed controller is designed as a component installed in the cabinet with the supporting control equipment. The speed controller uses a three-phase power supply of 110V to 500V to provide DC output voltage and current, which is suitable for the control of various parallel, other and permanent magnet DC motors.

2. There are three feedback methods: EMF armature voltage speed measurement feedback, analog speed measurement feedback and encoder speed measurement feedback.

3. Speed feedback is the main method of external closed-loop control of the speed controller. The pulse volume of the speed controller is directly controlled through the difference between the given speed and the speed feedback, so that the motor is stable. The speed feedback can be used with optical fiber input to provide high-precision speed control requirements. Control the operation part. Including processor and programming.

fourIn the DC motor speed regulation system, the Hall sensor can detect the size of the current and feedback the detected current signal to the control system. The control system adjusts the size of the current according to the feedback signal, so as to control the speed of the motor. Therefore, Hall sensors play an important role in the DC motor speed regulation system.

Which ring plays the main regulating role in the double closed-loop speed regulation system? What adjustment should be achieved?

1. The mechanism of double closed-loop adjustment is: the rotational speed deviation is large at start-up, the output of the speed regulator is saturated, and the current regulator works; the steady-state speed regulator is the main modulated, and the current loop regulator follows. Therefore, when there is a disturbance, the speed changes, and the speed regulator is the main tune.

2. The inner ring is a current regulator. Its main function (1) The speed regulator is the dominant regulator of the speed regulation system. It makes the speed n quickly follow the given voltage change. In steady state, it can reduce the speed error. If the PI regulator is used, no static difference can be achieved. ( 2) It plays an anti-interference role in load changes.

3. Speed loop: 1. Maintain sufficient accuracy at the speed under the fluctuation of power supply voltage and load fluctuation; 2. Shorten the dynamic over-process of the speed regulation process; 3. If it is a speed loop with a speed cut-off, the maximum speed can also be limited.

In the motor speed regulation closed-loop control system, the system is powerless against any disturbance.

Can be effectively suppressed: As long as the disturbance on the forward channel surrounded by the feedback channel can be effectively suppressed. For example, the change of load, the fluctuation of AC power supply voltage (Kc change), the change of motor excitation (Ce change), the drift of the amplifier output voltage (Kp change), the increase of the main circuit resistance R caused by temperature rise, etc.

The closed-loop system can do nothing about the disturbance in a given signal and detection device.

The feedback closed-loop control system has good anti-interference performance, which can effectively suppress all disturbances on the forward channel of the feedback loop. The single closed-loop speed regulation system using speed negative feedback and PI regulator can achieve no static difference in speed under the condition of ensuring the stability of the system.

Closed-loop system Advantages: It has the ability to suppress interference and improve the response characteristics of the system; Disadvantages: It increases the complexity and instability of the system.

If there is no problem with the load and there is no overload, the abnormal sound of the servo motor may be due to improper rigid adjustment or improper adjustment of gain. Servo motor refers to the engine that controls the operation of mechanical components in the servo system, which is a kind of auxiliary motor indirect transmission device.

This kind of controlled CNC machine tool is called a closed-loop controlled CNC machine tool because the machine tool workbench is included in the control link.The positioning accuracy of the closed-loop control CNC machine tool is high, but the debugging and maintenance are difficult, the system is complex and the cost is high.