Depending on the cause of overvoltage, the countermeasures adopted are different. Regarding the overvoltage phenomenon that occurs in the parking process, if there is no special requirement for the parking time or direction, then the extension inverter deceleration time or free parking method can be selected to solve it. The so-called free parking means that the inverter disconnects the main switch equipment and allows the motor to coast freely to stop.
If there are certain requirements for the parking time or parking direction, then the DC braking (DC braking) function can be selected. The function of DC braking is to decelerate the motor to a certain frequency, and then direct current is introduced into the stator winding of the motor to form a stopped magnetic field. The rotor winding of the motor cuts this magnetic field and a braking torque occurs, so that the kinetic energy of the load becomes electrical energy and is consumed in the rotor circuit of the motor in the form of heat, so this kind of braking is also called energy consumption braking. In the process of DC braking, there are actually two processes: regenerative braking and energy braking. The efficiency of this braking method is only 30-60% of that of regenerative braking, and the braking torque is small. Because spending energy in the motor will overheat the motor, the braking moment should not be too long. And the DC braking start frequency, braking time and braking voltage are all set manually, and cannot be actively adjusted according to the concave and convex regeneration voltage, so DC braking can not be used for overvoltage that occurs in normal operation, and can only be used for braking when parking.
In the case of overvoltages that occur when decelerating (switching from high speed to low speed without parking) due to excessive GD2 (flywheel torque) of the load, it is possible to solve the problem by appropriately extending the deceleration time. In fact, this method also uses the principle of regenerative braking, and the extended deceleration time is only to control the regenerative voltage of the load to the charging speed of the inverter, so that 20% of the regenerative braking capacity of the inverter itself can be reasonably used. As for the load that makes the motor in the regenerative state due to the effect of external force (including potential energy decentralization), because of its normal operation in the braking condition, the regenerative energy is too high to be consumed by the inverter itself, so it is impossible to choose the method of DC braking or extending the deceleration time.
Compared with DC braking, regenerative braking has a higher braking torque, and the braking torque can be actively controlled by the braking unit of the inverter according to the braking torque required by the load (i.e., the bump of regenerative energy). Regenerative braking is therefore best suited to provide braking torque to the load during normal operation.
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Inverter maintenance method - hope sunland
1. Look
After taking over a faulty inverter, remove the inverter shell and clean it up, and carefully investigate the appearance, shape, and integrity of the relevant components on the circuit board with both eyes according to the type of inverter fault. This method is about charging resistors, filter electrolytic capacitors, IG ...
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Advantages of Senlan vector control system
Dynamic "fast response" DC motors are rectified constrained and excessively high di/dt is not allowed. The asynchronous motor is only constrained by the capacity of the inverter, and the multiple of the forced current can be very high, so the speed echoes quickly, generally reaching the millisecond level, which has surpassed the DC motor in terms of speed.
At low frequencies ...
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Selection and capacity matching of inverter - Senlan
1. Select the inverter according to the load characteristics
Second, when selecting the inverter, the actual motor current value should be used as the basis for the selection of the inverter, and the extra power of the motor can only be used as a reference. Secondly, it should be fully considered that the output of the inverter contains higher harmonics, which will form the power factor of the motor.
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The method of heat dissipation of small-capacity inverter - Sunland inverter
Natural heat dissipation methods are generally used for heat dissipation of small-capacity inverters, because their operating environment should be well ventilated and free of dust and floating objects. The drag targets of such inverters are mostly household air conditioners, CNC machine tools, etc., and the power is small.
Still...
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Sunland - inverter operation process and factory value restoration
The general operation process is as follows:
Enter the program through the operation panel and set the parameters, and set the relevant parameter groups such as the start-stop method, operation and control form according to the requirements of the industrial control. After confirming that the wiring is correct, the no-load power on test run and ...
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The difference between Sunland inverter and soft starter
What is a frequency converter?
The inverter is a converter that converts the communication electricity with fixed voltage and frequency into the communication electricity with variable voltage and frequency, which is called the inverter. It is mainly used in the local demand for speed regulation, and its output not only changes the voltage but also changes the frequency together; The soft engine is really ...
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Precautions for inverter selection and capacity matching - Senlan
1. Select the inverter according to the load characteristics
Second, when selecting the inverter, the current value of the practical motor should be used as the basis for the selection of the inverter, and the rated power of the motor can only be used as a reference. Secondly, it should be fully considered that the output of the inverter contains higher harmonics, which will form the power factor of the motor.
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Sunland inverter is used in Baotou steel water supply
In recent years, with the development of power electronics skills, the frequency conversion speed regulation skills have been very mature, practice has proved that the use of frequency conversion speed regulation in fans, pumps and loads can save 20%-50% of the electric energy, and the use of frequency conversion speed regulation can bring the following advantages in the future, its biggest advantage is that it has ...
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The difference between a voltage signal and a current signal
The general voltage in industry is 0... 5(10)V or current 0(4)... 20mA is used as an analog signal transmission method, and it is also a method often used by program control machines. So what is the difference between the transmission method of voltage and current, and when to choose what method, the following will be briefly introduced.
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Switching power supply failure maintenance - Senlan
In the process of repairing the switching power supply, the step-down method can be selected. The method is: by connecting the power plug of the display to a communication voltage regulator, and then adjusting the output voltage of the voltage regulator to about 100V, and then repairing it with electricity, and gradually improving the power supply voltage for repair. ...
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The correct wiring of the rail power supply
The rail-rail power supply is a kind of switching power supply that is installed through the rail-type device, which is mainly used to monitor the voltage, current, temperature and other different aspects of the equipment, so that it can play a good maintenance effect. This switching power supply has a variety of different characteristics such as small size and light weight, ...
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Commonly used motor protection method - Hope Sunland
1. Install a reactor at the output of the inverter: This method is the most commonly used, but it should be noted that this method has a certain effect on shorter cables (less than 30 meters), but sometimes the effect is not ideal.
2. In the inverter ...
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Inverter control scheme for fan and water pump - Senlan inverter
There are many control methods for inverters for fans and pumps, which can be selected according to specific conditions. Here are a few common scenarios.
(1) Manual adjustment This is the simplest control method, that is, the operator instructs according to the instrument, ...
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At the physical level, the stable operation of the inverter is guaranteed-Senlan inverter
For the most popular electrical control equipment inverter (Variable-frequency Drive, VFD), as a precision electronic industrial control equipment, in order to run smoothly for a long time, we, as professional and technical personnel, need to be on the VFD device or before the operation.
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Failure of robot contactor and inverter - Senland
Robot contactors are noisy?
Cause:
It is likely that the joint contact surface of the contactor is uneven, and the surface is sand or rust. The result will constitute a phase loss, which will lead to the burnout of contactors, switch frequency conversion and other components.
Solution:
will control the ...
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Sunland inverters are designed for environmental requirements
1. The ambient temperature ---- is generally "-10-+40°C"; Derating between 40 and 50°C, the additional output current must be reduced by 1% for every 1°C increase. If the ambient temperature is too high and the temperature changes greatly, the insulation of the inverter will be greatly reduced, which will affect the life of the inverter.
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Excessive capacity of the inverter causes harm to electrical equipment - Senlan inverter
(1) The harmonic current generated will directly cause the additional heating of the motor, so that the stator of the motor surpasses the additional temperature rise of the motor itself, so that the additional output capacity of the motor will be greatly reduced.
(2) The current output of the inverter ...
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The eight forbidden areas of inverter control loop wiring - Senlan
1. The wires of the inverter control circuit should be strictly distinguished from the main circuit cable (power line) and placed separately. This will help prevent the inverter's control circuit from being disturbed by harmonics in the inverter's main circuit.
2. To separate the connection of the inverter from the terminals or contacts of other control circuits, ...
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The control performance standard of the inverter cabinet
The control specifications of the inverter cabinet include reliability, accuracy, safety, environmental habits and versatility, etc., which are important guarantees to ensure the normal operation and safe production of the inverter cabinet control system.
Reliability specification: The control system should have high reliability and can be used for a long time.
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The inverter is regularly replaced with the device - Sunland inverter
1. Cooling fan
As a prerequisite for ensuring the normal operation of the inverter, efficient and fast in-line cooling fans have become an indispensable conversion configuration of the inverter. Because of the wear of the internal bearings of the cooling fan and the reduction of the grease function in the process of application, the cooling of the fan.
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