I. Basic concepts and classifications of frequency transformers
1. Definition of a varianter: the varianter is a decomposition using electrical semiconductor devices that converts the industrial frequency power source into a continuously modifiable electrical power control device to control the speed of the electrical motor。
2. The voltage type is different from the current-type frequency variant: the voltage-type variant converts the current flow of the voltage source into communication, and the direct flow-repeated filter is electrical; the current-type variant converts the direct flow of the current source into communication, and the direct flow-release filter is electrical。
3. Flower classification: the control can be divided into open and closed rings, most of which are open, and closed loops are controlled by the actual velocity checker (pg) feedback。
Ii. The working principles of the frequency transformer
Integrators: convert communication power into direct current power to provide stable direct current power for subsequent reversers。
5. Reverser function: converting direct current power to a modifiable exchange power, driving the motor。
6. Frequency-voltage relationship: the non-synchronous electric motor rectangular rectangular is produced by the interaction of the electron's magnetic flux with the current flow of the rotor. The frequency and voltage change proportionately at the rated frequency to avoid weak magnetic and magnetic saturation。
7. V/f means of control: reproportion of voltage and frequency, with an appropriate increase in output voltage at low frequency, to obtain a certain roller-and-roller, which is referred to as enhanced start。
Iii. Functions of efficients
8. Energy efficiency is significant: energy efficiency objectives, such as significant energy savings in wind engine and pump applications, can be achieved by adjusting the speed of electrical power。
9. Precise control: accurate acceleration of electrical motors to meet different process and production requirements。
10. Multiple protective features: protective features such as overflow, overpressure, overload to ensure stable operation of equipment。
11. Reduction of start-up shocks: use of low-frequency start-ups to reduce the impact on grids and equipment at the start-up of electrical motors。
12. Extension control functions: multiple control methods, such as multi-slotting speed control, can be achieved by setting parameters and adjusting frequencies。
Iv. Selection and settings for frequency variables
13. Basis for selection: the selection of a suitable control mode for the frequency transformer is based on the type of production machinery, the rate range, the static speed accuracy, and the requirements for the start-up rectangular。
14. Matching of electrical power with a variable: reasonable selection of the power of a variable, taking into account factors such as the number of polars, rectangular properties, electromagnetic compatibility of an electrical power, and the most appropriate value of a general variable power to the power of an electric motor。
Frequency control methods: there are a variety of methods such as operator panels given, functional parameter code presets, functional bit control on the operating panel, external control (simulation control endpoints, nodes control endpoints, numerical control) and control of data lines by the upper slotr。
16. Maximum frequency settings: these include basic frequency and maximum frequency, which are defined in two ways, and in most cases maximum frequency equals basic frequency。
17. Upper and lower frequency: the maximum frequency and minimum frequency allowed for the output of the trans-frequency is set to ensure the safe operation of the equipment, depending on the application of the motor。
18. Accelerator time and speed reduction time setting: the motor driven by the frequency transformer uses a low frequency start, and the acceleration time is required to ensure that normal start-up does not run; the speed reduction time is associated with the drag load and the appropriate speed reduction time is required。
V. Maintenance and troubleshooting of frequency transformers
19. Daily maintenance: periodic inspection of the look, wiring, heat dispersion, etc. Of the frequency transformer to ensure the proper operation of the equipment。
20. Fault removal methods: inspection of power supply, control of electrical circuits and connection to electrical motors when the frequency transformer is unable to start; inspection of the condition of circuits, drives and radiators in case of overloading or short circuit failure; inspection of the correctness of controllers, sensors and connectors when precise control cannot be achieved; inspection of stationary performance, bearing and lubrication of equipment in case of vibration or noise。
Electromagnetic compatibility issues: in order to reduce interference with primary power sources, electrical resistance can be added to the intermediate circuit or to the input circuit of a variable, or pre-installation transformer can be installed; when the generator is more than 50 m away from the variable, the electrical resistor, filter or shielding cable should be inserted in their middle。
Vi. Methodology and technology of rivers
22. Spwm technology: the full name of spwm is sinepulsewidth modification, which is a chord-pulsive width changer, a mode changer that achieves frequency and also changes voltage, and is characterized by a chord pattern of spacing between pulses and pulses。
The principle of straight-flow “reverse transformation” for communication: direct-flow power is converted to communication by switching between switches, and direct-flow power “reverse” can be converted into three-phase communication if six switches work in a pattern of one third of the three-phase exchange。
24. Multi-slotting speed control: the variable is equipped with rh, rrm and rl multi-scop speed control end, which allows flexible speed control for a total of seven tranches through different combinations, with parameters such as pr. 180, pr. 181, pr. 182, etc., that determine the ender control function。
25. Importance of parameter setting: reasonable parameter setting is essential to the operational properties of the mutator, including speed control, output voltage and currents, and precise control and optimization of the electrical velocity can be achieved by adjusting parameters。
Vii. Application and development of efficients
26. The area of application is broad: it is increasingly used in industrial production and in the lives of the population, such as wind machines, pumps, machine beds, elevators, etc。
27. Trends: as technology continues to improve, frequency adapters are moving in the direction of more efficient, intelligent and miniaturized。
28. Use in conjunction with other equipment: for example, with control equipment such as plc to achieve more complex automated controls。
29. Impacts on and attention to electrical power: the process of the use of the frequency transformer may have some impact on the electrical power, such as modulation interference, insulation aging, etc., with regard to the selection of the appropriate electric power and appropriate protective measures。
30. Energy efficiency calculations and efficiency analysis: an understanding of the energy efficiency rationale and methods of the variable, enabling energy efficiency calculations and efficiency analysis to support energy conservation and depletion in enterprises。
Viii. Safe operations and guidelines of efficients
31. Safety protocols: when operating a frequency transformer, relevant safety protocols, such as power outages, prevention of electrocution, etc., must be followed。
32. Electrical connection norms: ensure that electrical connections to the frequency transformer are correct, reliable and consistent with relevant standards and norms。
33. Local requirements: the frequency transformers should be well connected to ensure the safe operation of the equipment and prevent electromagnetic interference。
34. Environmental requirements: frequency transformers should be installed in a meeting environment such as temperature, humidity, ventilation, etc。
35. Fault alert and disposal: when a frequency transformer fails to warn, timely measures should be taken to address the problem in order to avoid further failure。
Ix. Advanced functionality and debugging of frequencies
36. Pid control function: some of the mutators have pid control capability to achieve more precise process control。
37. Communications function: supports multiple communication protocols, such as modbus, profibus and so on, to achieve communication with aircraft or other equipment。
38. Debugging methods and steps: including parameter setting, functional testing, load debugging, etc., to ensure that the variable functions properly and meets actual needs。
39. Optimizing operational strategies: developing sound operational optimization strategies based on specific application scenarios to improve system efficiency and performance。
40. Diagnosis and removal techniques: a number of advanced failure diagnostic and removal techniques are available that can quickly and accurately address various malfunctions in the frequency transformer。
