There are many function parameters of the inverter! There are usually dozens or even hundreds of parameters for the user to choose. In practical applications, it is not necessary to set and debug each parameter, and most of them only need to adopt the factory setting value. However, some parameters have a lot to do with the actual use, and some are also related to each other, so it is necessary to set and debug according to the actual situation. Because the functions of each type of inverter are different, and the names of the same function parameters are also inconsistent, for the convenience of description, this article takes the basic parameter name of Fuji inverter as an example. Since the basic parameters are almost all types of frequency converters, it is completely possible to bypass the class. An acceleration/deceleration time--the acceleration time is the time required for the output frequency to rise from 0 to the maximum frequency. The deceleration time is the time required to fall from the maximum frequency to 0. The acceleration and deceleration time is usually determined by the frequency setting signal rising and falling. When the motor is accelerating, the rate of increase of the frequency setting must be limited to prevent overcurrent, and when decelerating, the rate of decrease is limited to prevent overvoltage. Acceleration time setting requirement: Limit the acceleration current below the overcurrent capacity of the inverter, and do not cause the inverter to trip due to the over-speed. The deceleration time setting point is: prevent the smoothing circuit voltage from being too large, and do not make the regenerative overvoltage stall. Let the frequency converter trip. Acceleration and deceleration time can be calculated according to the load, but in the debugging, it is often set to set the long acceleration/deceleration time according to the load and experience. Observe the overcurrent and overvoltage alarm by starting and stopping the motor; then gradually set the acceleration/deceleration time. Shorten, the principle of no alarm occurs during operation, and repeat the operation several times to determine the optimal acceleration and deceleration time. Fork Type Connecting Terminals Fork Type Connecting Terminals,Terminals,Connecting Terminals Taixing Longyi Terminals Co.,Ltd. , https://www.longyicopperlugs.com
The second torque boost, also called torque compensation, is a method of increasing the low frequency range f/V to compensate for the torque reduction at low speeds caused by the stator winding resistance of the motor. When set to automatic, the voltage during acceleration can be automatically increased to compensate for the starting torque, so that the motor accelerates smoothly. If manual compensation is used, a better curve can be selected by experiment depending on the load characteristics, especially the starting characteristics of the load. For variable torque loads, if the selection is improper, the output voltage will be too high at low speed, and the phenomenon of wasting electric energy may even occur when the motor is loaded with load and the current is large, and the speed is not going up.
Three-Electronic Thermal Overload Protection--This function is set to protect the motor from overheating! It is the CPU inside the inverter calculates the temperature rise of the motor according to the running current value and frequency, thus performing overheat protection. This function is only applicable to the “one-for-one†occasion, and in the case of “one-to-oneâ€, a thermal relay should be added to each motor. Electronic thermal protection set value (%) = [motor rated current (A) / inverter rated output current (A)] × 100%.
Four frequency limits - the upper and lower limits of the inverter output frequency. The frequency limit is a protection function that prevents the device from malfunctioning or the external frequency setting signal source is faulty, causing the output frequency to be too high or too low to prevent damage to the device. In the application, it can be set according to the actual situation. This function can also be used for speed limit. If there are some belt conveyors, because there is not much material to be transported, in order to reduce the wear of machinery and belts, the inverter can be driven and the upper limit frequency of the inverter can be set to a certain frequency value. This allows the belt conveyor to operate at a fixed, low working speed.
Five offset frequencies - some are called deviation frequency or frequency deviation settings. Its purpose is to adjust the output frequency of the lowest frequency setting signal when the frequency is set by external analog signal (voltage or current), as shown in Figure 1. In some inverters, when the frequency setting signal is 0%, the deviation value can be applied in the range of 0 to fmax. Some inverters (such as Mingdianshe and Sanhao) can also set the offset polarity. For example, when the frequency setting signal is 0% during debugging, the inverter output frequency is not 0Hz, but is xHz. At this time, the offset frequency is set to negative xHz to make the inverter output frequency 0Hz.
Six frequency setting signal gain----This function is valid only when the frequency is set with an external analog signal. It is used to compensate for the inconsistency between the external set signal voltage and the internal voltage of the inverter (+10v); at the same time, it is convenient to select the analog set signal voltage. When setting, when the analog input signal is maximum (such as 10v, 5v or 20mA), find the frequency percentage of the f/V pattern that can be output and set it as a parameter; if the external setting signal is 0~5v, if the output frequency of the inverter is 0~50Hz, the gain signal will be Set to 200%.
Seven torque limits---- can be divided into two types: drive torque limit and brake torque limit. It is based on the output voltage and current value of the inverter, and the torque calculation is performed by the CPU, which can significantly improve the shock load recovery characteristics during acceleration and deceleration and constant speed operation. The torque limit function enables automatic acceleration and deceleration control. It is assumed that the acceleration/deceleration time is less than the load inertia time, and the motor can be automatically accelerated and decelerated according to the torque set value. The drive torque function provides a powerful starting torque. During steady-state operation, the torque function will control the motor slip and limit the motor torque to the maximum set value. When the load torque suddenly increases, even When the acceleration time is set too short, it will not cause the inverter to trip. When the acceleration time setting is too short, the motor torque will not exceed the maximum set value. A large driving torque is advantageous for starting, and it is preferable to set it to 80 to 100%. The smaller the brake torque setting value is, the larger the braking force is. It is suitable for the occasion of sudden acceleration and deceleration. If the brake torque setting value is set too high, an overvoltage alarm phenomenon will occur. If the braking torque is set to 0%, the total amount of regeneration applied to the main capacitor can be close to zero, so that when the motor is decelerating, it can be decelerated to stop without tripping without using the braking resistor. However, in some loads, if the braking torque is set to 0%, a short idling phenomenon will occur during deceleration, causing the inverter to start repeatedly, the current fluctuates greatly, and the inverter will trip if it is serious, which should be noticed.
Eight plus deceleration mode selection ---- also called acceleration and deceleration curve selection. Generally, the inverter has three kinds of curves: linear, nonlinear and S. Usually, most of the linear curves are selected; the nonlinear curve is suitable for variable torque loads, such as fans; the S curve is suitable for constant torque loads, and the acceleration and deceleration changes are relatively slow. According to the load torque characteristics, the corresponding curve can be selected according to the load torque characteristics. However, when debugging the inverter of a boiler induced draft fan, the nonlinear curve is selected for the acceleration/deceleration curve, and the inverter is tripped and adjusted together. Changing many parameters has no effect, and then it is normal after changing to the S curve. The reason is: before starting, the induced draft fan rotates by itself due to the flue gas flow, and reverses to become a negative load. Thus, the S curve is selected, so that the frequency of the initial start is slower, thus avoiding the inverter. The occurrence of a trip, of course, is the method used for a frequency converter that does not have a DC braking function.
Nine Torque Vector Control----Vector Control is based on the theory that asynchronous motors have the same torque generation mechanism as DC motors. The vector control method is to decompose the stator current into predetermined magnetic field currents and torque currents, and separately control the stator currents to be output to the motor. Therefore, the same control performance as the DC motor can be obtained in principle. With the torque vector control function, the motor can output the maximum torque under various operating conditions, especially the motor running in the low speed range. Nowadays, almost all inverters adopt non-feedback vector control. Because the inverter can compensate for the slip according to the magnitude and phase of the load current, the motor has very hard mechanical characteristics. For most occasions, the requirements can be met without the need for the inverter. The speed feedback circuit is externally set. The setting of this function can be selected among the valid and invalid according to the actual situation. The function related to this is the slip compensation control, which is used to compensate for the speed deviation caused by the load fluctuation, and the slip frequency corresponding to the load current can be added. This function is mainly used for positioning control.
Ten energy-saving control----fans and pumps are all torque-reducing loads, that is, as the speed decreases, the load torque decreases in proportion to the square of the speed, and the inverter with energy-saving control function is designed with a dedicated V/f. Mode, which improves the efficiency of the motor and the inverter. It can automatically reduce the output voltage of the inverter according to the load current, thus achieving energy saving. It can be set to be effective or invalid depending on the situation. It should be noted that the two parameters of Nine and Ten are very advanced, but some users can not enable these two parameters in the equipment transformation, that is, the inverter trips frequently after being activated, and everything is normal after the deactivation. The reasons are as follows: (1) The difference between the original motor parameters and the motor parameters required by the inverter is too large. (2) The function of setting parameters is not enough. For example, the energy-saving control function can only be used in the V/f control mode, and cannot be used in the vector control mode. (3) The vector control mode is enabled, but the manual setting and automatic reading of the motor parameters are not performed, or the reading method is improper.