Inverter is a power control device that uses the on-off action of power semiconductor devices to transform a power frequency power supply into another frequency. It can realize soft starting of AC asynchronous motors, frequency conversion speed regulation, improvement of operation accuracy, change of power factor, and overcurrent/ Overvoltage/overload protection and other functions.
2. The difference between PWM and PAMPWM is the abbreviation of Pulse Width Modulation (Pulse Width Modulation) in English. It is a modulation method that changes the pulse width of the pulse train according to a certain rule to adjust the output and waveform. PAM is the abbreviation of Pulse Amplitude Modulation (Pulse Amplitude Modulation) in English. It is a modulation method that changes the pulse amplitude of the pulse train according to a certain rule to adjust the output value and waveform.
3. What is the difference between voltage type and current type?The main circuit of the frequency converter can be roughly divided into two categories: the voltage type is the frequency converter that converts the DC of the voltage source into AC, and the filtering of the DC loop is the capacitor; the current type is the frequency converter that converts the DC of the current source into AC. The DC loop filter is an inductor.
4. Why does the voltage of the inverter change in proportion to the frequency?The electromagnetic torque of any motor is the result of the interaction of current and magnetic flux. The current is not allowed to exceed the rated value, otherwise it will cause the motor to heat up. Therefore, if the magnetic flux is reduced, the electromagnetic torque must also be reduced, resulting in a reduction in load capacity.
From the formula E=4.44*K*F*N*Φ, it can be seen that the magnetic circuit of the motor changes in a considerable range with the operating frequency fX when the frequency conversion speed is adjusted, and it is extremely easy to make the magnetic circuit of the motor serious. Saturation results in severe distortion of the excitation current waveform, resulting in a spike current with a very high peak value.
Therefore, the frequency and the voltage should be changed in proportion, that is, the output voltage of the frequency converter is controlled while changing the frequency, so that the magnetic flux of the motor is kept constant, and the phenomenon of weak magnetic field and magnetic saturation is avoided. This control method is mostly used for energy-saving frequency converters such as fans and pumps.
5. When the motor is driven by a power frequency power supply, the current increases when the voltage drops; for inverter driving, if the voltage drops when the frequency drops, does the current increase?
When the frequency drops (low speed), if the same power is output, the current increases, but under the condition of a constant torque, the current is almost unchanged.
6. What is the starting current and starting torque of the motor when the inverter is used for operation?The inverter is used for operation. With the acceleration of the motor, the frequency and voltage are correspondingly increased, and the starting current is limited to 150% of the rated current (depending on the model, it is 125%~200%). When starting directly with a power frequency power supply, the starting current is 6 to 7 times the rated current, so mechanical and electrical shocks will occur. Using frequency converter drive can start smoothly (starting time becomes longer). The starting current is 1.2~1.5 times of the rated current, and the starting torque is 70%~120% of the rated torque; for the inverter with automatic torque enhancement function, the starting torque is more than 100%, and it can be started with full load.
7. What does V/f mode mean?When the frequency drops, the voltage V also drops proportionally. This question has been explained in answer 4. The proportional relationship between V and f is determined in advance in consideration of the characteristics of the motor. There are usually several characteristics stored in the storage device (ROM) of the controller, which can be selected with a switch or a dial.
8. How does the torque of the motor change when V and f are changed proportionally?When the frequency drops, the voltage is completely reduced in proportion, then the AC impedance becomes smaller and the DC resistance remains unchanged, which will cause the torque generated at low speeds to have a tendency to decrease. Therefore, given V/f at low frequency, the output voltage should be increased to obtain a certain starting torque. This kind of compensation is called enhanced starting. It can be realized by various methods, such as automatic method, selection of V/f mode or adjustment of potentiometer.
9. It is stated in the manual that the speed range is 60~6Hz, that is, 10:1, then there is no output power below 6Hz?The power can still be output below 6Hz, but according to the conditions such as the temperature rise of the motor and the size of the starting torque, the minimum frequency of use is about 6Hz. At this time, the motor can output the rated torque without causing serious heating problems. The actual output frequency (starting frequency) of the inverter is 0.5~3Hz according to the model. .
10. For the combination of general motors, a certain torque is required above 60Hz, is it possible?Usually not possible. Above 60Hz (there are also modes above 50Hz), the voltage remains unchanged, and the characteristic is generally constant power. When the same torque is required at high speed
11. What does the so-called open loop mean?Set a speed detector (PG) for the motor device used, and feedback the actual speed to the control device for control, which is called "closed loop", and the one that runs without PG is called "open loop". Most general-purpose inverters are open-loop mode, and some models use options to perform PG feedback. The speed sensor-less closed-loop control mode is based on the established mathematical model to estimate the actual speed of the motor based on the magnetic flux, which is equivalent to using a virtual speed sensor Form a closed loop control.
12. What should I do if the actual speed deviates from the given speed?In open loop, even if the inverter outputs a given frequency, when the motor is running with a load, the motor's speed will vary within the range of the rated slip (1%~5%). For occasions that require relatively high speed regulation accuracy and require operation at a speed close to a given speed even if the load changes, a frequency converter with PG feedback function (optional) can be used.
13. If a motor with PG is used, can the speed accuracy be improved after feedback?The accuracy of the inverter with PG feedback function is improved. But the value of speed accuracy depends on the accuracy of the PG itself and the resolution of the output frequency of the inverter.
14. What does the stall prevention function mean?If the given acceleration time is too short, the output frequency change of the inverter far exceeds the change of the speed (electrical angle frequency), the inverter will trip due to the overcurrent, and the operation will stop. This is called a stall. In order to prevent the motor from stalling and continuing to run, it is necessary to detect the magnitude of the current for frequency control. When the acceleration current is too large, slow down the acceleration rate appropriately. The same is true when decelerating. The combination of the two is the stall function.
15. There are models for which acceleration time and deceleration time can be given separately, and models for which the acceleration and deceleration time are given together. What's the point of this?Acceleration and deceleration can be given separately for the machine type. It is suitable for short-time acceleration and slow deceleration, or for small machine tools where the production tact time needs to be strictly specified. However, for fan transmission and other occasions, the acceleration and deceleration time is longer. Acceleration time and deceleration time can be given together.
16. What is regenerative braking?If the motor reduces the command frequency during operation, the motor becomes an asynchronous generator and operates as a brake. This is called regenerative (electric) braking.
17. Can it get more braking force?The energy regenerated from the motor is stored in the filter capacitor of the inverter. Due to the relationship between the capacity of the capacitor and the withstand voltage, the regenerative braking force of the general inverter is about 10% to 20% of the rated torque. If the optional brake unit is used, it can reach 50%~100%.
18. Please explain the protection function of the inverter?Protection functions can be divided into the following two categories:
(1) After detecting the abnormal state, it will automatically carry out corrective actions, such as over-current stall prevention and regenerative over-voltage stall prevention.
(2) After detecting the abnormality, block the PWM control signal of the power semiconductor device to make the motor stop automatically. Such as overcurrent cutoff, regeneration overvoltage cutoff, semiconductor cooling fan overheating and instantaneous power failure protection.
19. Why does the protection function of the inverter operate when the clutch is used to connect the load?When the clutch is used to connect the load, the motor changes sharply from the no-load state to the area with large slip at the moment of connection, and the large current flowing causes the inverter to trip over current and fail to operate.
20. In the same factory, large motors move together, and the inverter stops during operation. Why? When the motor starts, the starting current corresponding to the capacity will flow. The transformer on the stator side of the motor produces a voltage drop. When the motor capacity is large, the voltage drop will also have a large impact. The inverter connected to the same transformer will cause undervoltage or instantaneous shutdown. Therefore, sometimes the protection function (IPE) is activated, causing the operation to stop.
For digitally controlled inverters, even if the frequency command is an analog signal, the output frequency is also given in stages. The smallest unit of this level difference is called the frequency conversion resolution. The frequency conversion resolution is usually 0.015~0.5Hz. For example, if the resolution is 0.5Hz, then the upper part of 23Hz can be changed to 23.5 and 24.0 Hz, so the action of the motor is also followed by steps. This causes problems for applications such as continuous winding control. In this case, if the resolution is about 0.015Hz, one step difference for a 4-level motor is 1r/min or less, it can also be fully adapted. In addition, the given resolution of some models is different from the output resolution.
22. Is there any restriction on the installation direction when installing the inverter?The internal and rear structure of the inverter takes into account the cooling effect, and the relationship between the top and bottom is also important for ventilation. Therefore, for the unit type in the panel and hanging on the wall, take the vertical position and install it as vertically as possible.
23. Is it possible to directly input the motor to a fixed frequency inverter without using soft start?It is possible at a very low frequency, but if the given frequency is high, the conditions for direct starting of the power frequency power supply are similar. A large starting current (6~7 times the rated current) will flow, and the motor cannot start because the inverter cuts off the overcurrent.
24. What problems should be paid attention to when the motor is running at more than 60Hz?Pay attention to the following matters when operating at more than 60Hz:
(1) It must be possible for machinery and equipment to operate at this speed (mechanical strength, noise, vibration, etc.).
(2) When the motor enters the constant power output range, its output torque must be able to maintain its work (the output power of the shaft of fans, pumps, etc. increases in proportion to the cube of the speed, so pay attention to a slight increase in the speed).
(3) Bearing life issues must be fully considered.
(4) For motors with medium capacity and above, especially 2-pole motors, carefully discuss with the manufacturer when operating above 60Hz.
Depending on the structure and lubrication method of the reducer, several issues need to be paid attention to. In the structure of the gear, 70~80Hz can usually be considered as the maximum limit. When using oil lubrication, continuous operation at low speed is related to the damage of the gear.
25. Can the inverter be used to drive a single-phase motor? Can single-phase power be used?Basically unusable. For the single-phase motor of the speed governor switch-start type, the auxiliary winding will be burnt when the speed range is below the operating point; for the capacitor start or capacitor operation mode, the capacitor will be induced to explode. The power supply of the inverter is usually three-phase, but for small-capacity models, there are also models that operate with a single-phase power supply.
26. How much power does the inverter consume?It is related to the model, running status, frequency of use, etc. of the inverter, but it is difficult to answer. However, the efficiency of the inverter below 60Hz is about 94%~96%, and the loss can be estimated based on this, but the built-in regenerative braking (FR-K) inverter, if the loss during braking is also taken into account, the power consumption It will become larger, so attention must be paid to the design of the operation panel.
27. Why can't it be used continuously in the whole area of ​​6~60Hz?Generally, the motor uses the outer fan installed on the shaft or the blades on the rotor end ring for cooling. If the speed is reduced, the cooling effect will be reduced. Therefore, it cannot withstand the same heat as high-speed operation. The load torque at low speed must be reduced, or use Combine a large-capacity inverter with a motor, or use a dedicated motor. 29. What should be paid attention to when using a motor with brake?
The power supply of the brake excitation circuit should be taken from the input side of the inverter. If the brake acts when the inverter is outputting power, it will cause the overcurrent to be cut off. Therefore, the brake must be activated after the inverter stops output.
28. I want to use a frequency converter to drive a motor with a capacitor for improving the power factor, but the motor does not move. Please explain the reason.The current of the inverter flows into the capacitor for improving the power factor, and the inverter cannot be started due to the overcurrent (OCT) of the inverter caused by its charging current. As a countermeasure, please remove the capacitor and operate. As for the improvement of the power factor, the input side of the inverter It is effective to connect to AC reactor.
29. How long is the life of the inverter?Although the inverter is a static device, it also has consumables such as filter capacitors and cooling fans. If they are regularly maintained, they are expected to have a life span of more than 10 years.
30. There is a cooling fan in the inverter. What is the direction of the wind? What happens if the fan is broken?There are also models with or without cooling fans for small capacities. For models with fans, the direction of the wind is from bottom to top, so do not place mechanical equipment that hinders suction and exhaust in the place where the inverter is installed. Also, do not place heat-sensitive parts on the top of the inverter. When the fan fails, it is protected by the fan stop detection or the overheat detection on the cooling fan
31. The filter capacitor is a consumable, so how to judge its life?The capacitance of the capacitor used as a filter capacitor gradually decreases over time. The electrostatic capacitance is measured regularly, and the life is judged based on when it reaches 85% of the rated capacity of the product.
32. Is there any restriction on the installation direction when installing the inverter?It should be basically stored in the tray. The problem is that the tray with a fully enclosed structure is large in size, occupies a large space, and has a relatively high cost. The measures include:
(1) The design of the disk should be aimed at the heat dissipation required by the actual device;
(2) Use aluminum fins, fin coolant, etc. to increase the cooling area;
33. What is the function of the inverter DC reactor?Reduce the high-order harmonic interference of the input current and improve the power factor of the input power supply.
36. What is the function of the sine filter attached to the inverter?
The sine filter allows the inverter to run with a longer motor cable, and is also suitable for circuits with an intermediate transformer between the inverter and the motor.
34. What is the resistance value of the given potentiometer of the inverter?The resistance value of a given potentiometer of the frequency converter is generally 1KΩ to 10KΩ.
38. Why can't the inverter be used as a variable frequency power supply?
The entire circuit of the variable frequency power supply is composed of AC DC-AC filtering and other parts, so its output voltage and current waveforms are pure sine waves, very close to the ideal AC power supply. It can output the grid voltage and frequency of any country in the world. The frequency converter is composed of AC DC-AC (modulated wave) and other circuits. The standard name of the frequency converter should be the frequency converter. The waveform of the output voltage is a pulsed square wave, and there are many harmonic components. The voltage and frequency change proportionally at the same time, and cannot be adjusted separately, which does not meet the requirements of AC power. In principle, it cannot be used as a power supply, and is generally only used for speed regulation of three-phase asynchronous motors.
35. What are the interference modes of the inverter and how to deal with it in general?1. Transmission method:
(1) Radiation interference;
(2) Conducted interference
1. Anti-interference measures: For the interference signal transmitted by radiation, it is mainly weakened by wiring and shielding the radioactive source and the interfered line. The interference signal propagated through the line is mainly processed by installing filters, reactors or magnetic rings on the input and output sides of the inverter. The specific methods and precautions are as follows:
(1) The signal line and the power line should be vertically crossed or routed in separate slots.
(2) Do not use wires of different metals to connect to each other.
(3) The shielding tube (layer) should be reliably grounded, and continuous and reliable grounding should be ensured over the entire length.
(4) Use twisted-pair shielded cables in signal circuits.
(5) The grounding point of the shielding layer should be as far away as possible from the inverter and separated from the grounding point of the inverter.
(6) The magnetic ring can be used on the input power line and output line of the inverter. The specific method is: the input line is wound 4 times in the same direction, and the output line is wound 3 times in the same direction. Pay attention when winding, try to put the magnetic ring as close as possible to the inverter.
(7) Generally, shielding and other anti-interference measures can be taken for the interfered equipment and instruments.
36. If I want to increase the speed of the original conveyor belt and run at 80Hz, how to choose the capacity of the inverter?The power consumed by the conveyor belt is proportional to the speed. Therefore, if you want to run at 80HZ, the power of the inverter and the motor must be increased to 80HZ/50HZ in proportion, which means an increase of 60% in capacity.
37. What is the difference between PWM and VVC+?In VVC, the control circuit uses a mathematical model to calculate the best motor excitation when the motor load changes, and to compensate for the load. In addition, the synchronous 60°PWM method integrated on the ASIC circuit determines the optimal switching time of the inverter semiconductor device (IGBTS).
The following principles should be followed to determine the switching time:
1. The phase with the largest value keeps its positive or negative potential unchanged for 1/6 period (60°).
2. The other two phases are changed in proportion to keep the output line voltage sinusoidal and reach the required amplitude.
Unlike sinusoidal control PWM, VVC works according to the digital quantity of the required output voltage. This can ensure that the output of the inverter reaches the rated voltage, the motor current is a sine wave, and the operation of the motor is the same as when the motor is directly connected to power.
Since the constants (stator resistance and inductance) of the motor are considered when the inverter calculates the best output voltage, the best motor excitation can be obtained.
Because the inverter continuously detects the load current, the inverter can adjust the output voltage to match the load, so the motor voltage can adapt to the type of motor and follow the change of the load.
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0.8mm ( 0.031") Female Header Connector
Category:Board To Board Connectors
Sub-Category:Pin Header Female
Type:0.8mm
0.8mm ( 0.031") Female Headers Overview
Whenever there is a need for fitting small-sized connectors in compact devices, the 0.8mm pitch female header, or sometimes referred to as header connector, is ideally suited for this application. Not only does this female header space-savvy, but it is also designed for vacuum pick and place that makes it suitable for high volume automated manufacturing.
Antenk offers these low profile, easy-install, SMT or THM miniature female connector plugs at high quality and affordable China-quoted price, for board-to-board connection, snuggly fitting the pins of a male header and acting as a receptacle.
Assembly and service is simple with either vertical (straight), elevated or at a right angle configuration/orientation, which can dissipate current of about 1.0 A or less in a tape and reel packaging. The filleted corners can also remove shadowing allowing optimization of LED output.
Also, the 0.8mm pitch female headers are made to work in Arduino boards, Arduino Pro and Arduino Mega with either single or double-row female headers, facilitating connections for programming and incorporation into other circuits. They have the perfect height for clearing the USB-B connector and great for stacking multiple shields.
Female header always called as [Header connector", Antenk provide widely range of header connector, from 2.54mm (.100″ inch) pitch to 0.8mm (0.031 inch) pitch. The number of pins (contacts) is from 2 to 40 pins per orw. There are three type: Straight (Dip Vertical), Right angle, SMT (surface mount).
If you can not find the items you interest from above items, welcome to contact us, and you will always get fully responsive from us.
Applications of 0.8mm Pitch Female Headers
Its small size is most suitable for PCB connections of small equipment and devices such as:
Arduino Boards
Architectural and sign lighting
Retail and display lighting
Fluorescent LED retrofit lighting
Cabinet or furniture lighting
Commercial / residential cove lighting
WiFi equipment
Gaming consoles,
Measurement instruments
Medical Diagnostic and Monitoring equipment
Communications: Telecoms and Datacoms
Industrial and Automotive Control and Test
Mount Type: Through-hole vs Surface Mount
At one side of this female header is a series of pins which can either be mounted and soldered directly onto the surface of the PCB (SMT) or placed into drilled holes on the PCB (THM).
Through-Hole (Poke-In)
Best used for high-reliability products that require stronger connections between layers.
Aerospace and military products are most likely to require this type of mounting as these products experience extreme accelerations, collisions, or high temperatures.
Useful in test and prototyping applications that sometimes require manual adjustments and replacements.
0.8mm vertical single row female header, 0.8mm vertical dual row female header, 0.8mm Elevated single row female header, 0.8mm Elevated dual row female Header, 0.8mm right-angle single row female header and 0.8mm right-angle dual row female header are some examples of Antenk products with through-hole mount type.
Surface-Mount
The most common electronic hardware requirements are SMT.
Essential in PCB design and manufacturing, having improved the quality and performance of PCBs overall.
Cost of processing and handling is reduced.
SMT components can be mounted on both side of the board.
Ability to fit a high number of small components on a PCB has allowed for much denser, higher performing, and smaller PCBs.
0.8mm Right-angle Dual Row female header, 0.8mm SMT Single row female header, 0.8mm SMT Dual row female header and 0.8mm Elevated Dual Row female Header are Antenk`s SMT female headers.
Soldering Temperature for 0.8mm Pitch Female Headers
Soldering SMT female connectors can be done at a maximum peak temperature of 260°C for maximum 60 seconds.
Orientation/Pin-Type: Vertical (Straight) and Right-Angle
0.8mm pitch female headers may be further classified into pin orientation as well, such as vertical or straight male header or right-angle female header.
Vertical or Straight Female Header Orientation
One side of the series of pins is connected to PCB board in which the pins can be at a right-angle to the PCB surface (usually called "straight" or [vertical") or.
Right-Angle Female Header Orientation
Parallel to the board's surface (referred to as "right-angle" pins).
Each of these pin-types have different applications that fit with their specific configuration.
PCB Connector Stacking
Profile Above PCB
This type of configuration is the most common way of connecting board-to-board by a connector. First, the stacking height is calculated from one board to another and measured from the printed circuit board face to its highest insulator point above the PCB.
Elevated Sockets/Female Headers
Elevated Sockets aka Stacked sockets/receptacles or Mezzanine are simply stacked female headers providing an exact distance requirement between PCBs that optimizes electrical reliability and performance between PCB boards.
Choosing this type of stacking configuration promotes the following benefits:
Connector Isolation - the contacts are shrouded preventing cable connection mishaps and good guidance for the mating header connectors.
For off-the-shelf wireless PCB module, stacking height is optimized with elevated sockets.
Offers superior strength and rigidity.
Polarisation prevents users from inverted insertion.
Single, Dual or Multiple Number of Rows
For a 1.0mm straight or vertical female header, the standard number of rows that Antenk offers ranges from 1 to 2 rows. However, customization can be available if 3 ,4 or n number of rows is needed by the customer. Also, the number of contacts for the single row is about 2-40 pins while for dual row, the number contacts may vary from 2-80 pins.
Pin Material
The pins of the connector attached to the board have been designed with copper alloy. With customer`s demand the pins can be made gold plated.
Custom 1.0mm Pitch Female Headers
Customizable 1.0 mm pitch female headers are also available, making your manufacturing process way faster as the pins are already inserted in the headers, insulator height is made at the right size and the accurate pin length you require is followed.
Parts are made using semi-automated manufacturing processes that ensure both precision and delicacy in handling the headers before packaging on tape and reel.
Tape and Reel Packaging for SMT Components
Antenk's SMT headers are offered with customizable mating pin lengths, in which each series has multiple number of of circuits, summing up to a thousand individual part number combinations per connector series.
The tape and reel carrier strip ensures that the headers are packaged within accurately sized cavities for its height, width and depth, securing the headers from the environment and maintaining consistent position during transportation.
Antenk also offer a range of custom Tape and reel carrier strip packaging cavities.
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ShenZhen Antenk Electronics Co,Ltd , https://www.antenkelec.com