Can an inverter replace a soft starter - LS generates electricity

1. Soft start function

The soft start function of the inverter is no longer necessary to talk about today, and twenty years ago, it was still a very exciting operation, which is also one of the auxiliary basic functions of the inverter. At the beginning of the birth of the inverter, it was made for the most widely used three-phase asynchronous squirrel cage motor. We know that the speed formula of three-phase asynchronous motor is n=60f(1-s)/p, and changing the speed of the motor by changing the input frequency of the motor is the most thorough, convenient and reliable method. The instantaneous current of the direct start of the motor is 6-8 times of the normal and stable operation, and the step-down start is 4-5 times, and the frequency conversion speed regulation will not exceed 1.5 times the rated current of the inverter, whether it is the impact on the power grid, or the habit of the equipment, its benefits are very outstanding.

Can an inverter replace a soft starter - LS generates electricity

Can an inverter replace a soft starter - LS generates electricity

2. Stepless speed regulation

Stepless speed regulation, is no grade and no step speed regulation, from zero speed start to the highest speed, and from the maximum speed to zero speed, in one go, the speed curve is continuous, smooth, stable, as shown in Figure 1, greatly accustomed to the load inertia, improve the habit ability of multiple mechanical equipment to each other, improve the production power, greatly reduce the mechanical conflict, oscillation and noise, prolong the life of the equipment, reduce the maintenance cost. Generally, the output frequency of the inverter is about 0.00Hz-400.00Hz, the frequency resolution is 0.01Hz, some reach 650.00Hz, and the high-frequency inverter can output up to 5000Hz, which has completely covered all the scales of industrial speed regulation.

3. Energy saving

The energy-saving function of the inverter was originally an unexpected harvest in the process of inverter use, but today, it has been widely used in various industrial and civilian production days, especially when the inverter is used for square torque loads, such as fans, fans, pumps, propeller loads, which is determined by the torque curve of such loads, as shown in Figure 2-a. At low speed, because the flow rate of the fluid is low, the load torque is very small, and with the increase of the motor speed, the flow rate increases, and the load torque and power are also increasing.

However, there are many misunderstandings in the energy-saving use of frequency converters, and some literature claims that frequency converters are power-saving control products, giving people the feeling that only the use of frequency converters can save electricity. In practice, the reason why the variable frequency governor can save electricity is because it can regulate the speed of the motor. If the frequency converter is a power-saving control product, then all the speed control equipment can also be said to be a power-saving control product.

The variable frequency governor is just slightly higher than the power and power factor of other speed control equipment. In addition, as long as the original valve is used to control the flow, and it is not a full-load operation, it is changed to speed control operation, which can achieve power saving. Compared with the DC speed regulation system, the DC motor has higher power and higher power factor than the communication motor, and the power of the digital DC governor is comparable to that of the frequency conversion governor, and even the power of the digital DC governor is slightly higher than that of the frequency conversion governor. Therefore, the claim that the use of AC asynchronous motors and frequency conversion governors is more energy-saving than the use of DC motors and DC governors, which has been proved in theory and practice to be incorrect.

4. Multiple maintenance

We know that in the process of operating the equipment, there are often a variety of factors that lead to various faults and equipment damage, if you can carry out intelligent detection, and active alarm and maintenance, it will be very necessary, such as undervoltage, overvoltage, lightning strike, overload, load stall, high temperature, communication failure, electromagnetic disturbance, power supply phase loss, motor phase loss, load short circuit, ground short circuit, etc., some faults are fatal, once presented, the consequences are unimaginable. In the process of research and development, the inverter first of all, out of consideration for the safety of the inverter's own internal components, multiple detection and maintenance are added, such as the promised maximum current of the inverter inverter module generally does not exceed 2 times of the rating, the maximum temperature of the electrolytic capacitor is 85 °C, electromagnetic compatibility design, etc., coupled with the detection and response of the load side (such as motor temperature detection and maintenance, instantaneous power failure without downtime, etc.), making today's inverter highly intelligent, not only to maintain its own safety and normal operation, It also greatly maintains the safe operation of the front and rear equipment.

In addition, today's excellent inverters have basically passed international certifications or indicators, such as, CE, UL, RoHS, etc., which can be exported to the outside world, and inverter manufacturers also provide all-weather, no regional on-site services and user guidance, providing customers with quality assurance and solving worries.

5. Initiative

The control function of today's inverter is now very complete, and it can cooperate well with other control equipment and instruments to realize real-time monitoring and control of systematic networking, such as cooperative DCS, PLC, sensors, HMI, CNC, host computer, servo drive, etc., which greatly improves the degree of automation of the production line, saves manpower and material resources, improves power, and reduces cost. For example, the inverter can have a variety of frequency given methods, such as digital setting, potentiometer, external analog (0-10V, 4-20mA), multi-stage speed, PID and other methods, can be equipped with a variety of controllers, frequency instructions of response signals, long-distance/local control switching, convenient for the user's various control needs, and some companies, have successively launched a variety of professional special aircraft, for some subdivided professional users for personalized custom development, integrated development, for users to save the problem of selection of troublesome system compatibility, saving money.

In short, the function and role of the inverter is now very complete and mature, is an indispensable member of the industrial automation product family, has an important milestone significance, and is also the basis for the subsequent application of high-end skills and product development, perhaps it is the birth of the inverter, officially opened the prelude to the high-speed development of China's automation industry!

Can an inverter replace a soft starter - LS generates electricity

Sections viewed

Contact

working hours