Parameter setting and commissioning site of the ho

Parameter setting and debugging of frequency converter

parameter setting of frequency converter is very important in the debugging process. Due to improper parameter setting, it cannot meet the needs of production, resulting in the failure of starting and braking, or the frequent tripping of work, which will burn the power module IGBT or rectifier bridge and other devices in serious cases. Different types of frequency converters have different parameters. Generally, the frequency converter with single function control has about 50 ~ 60 parameter values, and the frequency converter with multi-function control has more than 200 parameters. But whether there are more or less parameters, do you want to readjust all parameters during debugging? No, most of them can't be changed, just press the factory value, as long as Xie Ying, director of Linyi science and Technology Bureau, whose original factory value is not appropriate when in use, can be reset, such as external terminal operation, analog operation, base frequency, maximum frequency, upper limit frequency, lower limit frequency, start time, braking time (and mode), thermionic protection, overcurrent protection, carrier frequency Stall protection and overvoltage protection must be adjusted. When the operation is inappropriate, adjust other parameters

treatment of several common problems in on-site commissioning

the setting principle of starting time should be short rather than long. See the following for specific values. The overcurrent setting value OC is too small, and it can be increased to 150% at most if it is increased appropriately. The empirical value is 1.5 ~ 2s/kw, and the small power is greater; More than 30kW, take 2s/kw. Press the start key *run, and the motor is locked. It means that the load torque is too large and the starting torque is too small (try to improve it). At this time, press stop immediately to stop, otherwise the motor will burn out after a long time. Because the motor does not rotate in the locked rotor state, the anti electric heating e=0, at this time, the AC impedance value z=0, only the DC resistance is very small, so it is very dangerous to have a large current, so it is necessary to trip OC action

the setting principle of braking time should be long rather than short, which is easy to produce overvoltage tripping OE. See the deceleration time in Table 1 for specific values. It is better to brake the water pump fan freely, and it is easy to produce serious water hammer effect by fast and strong braking

the setting of starting frequency is beneficial to accelerated starting, especially in light load. For heavy load, the starting frequency value is large, resulting in increased starting current. It is easier to skip current OC in low frequency band. Generally, the starting frequency is appropriate from 0

the setting of starting torque is beneficial to accelerating starting, especially in light load. For heavy load, the starting torque value is large, resulting in the increase of starting current. It is easier to skip the current OC in low frequency band. Generally, the starting torque is suitable from 0

base frequency setting

base frequency standard is 380V at 50Hz, that is, v/f=380/50=7.6. However, because heavy loads (such as extruder, washing machine, dryer, mixer, mixer, dehydrator, etc.) often fail to start, and it is often useless to adjust other parameters, then adjusting the base frequency is an effective method. That is, the set value of 50Hz can be reduced to 30Hz or below by integrating seven independent test procedures, such as stretching, peeling and tearing. At this time, v/f 7.6, that is, the output voltage increases at the same frequency, especially in the low frequency band (that is, torque U2). Therefore, generally, heavy load can start well

treatment of overvoltage during braking

overvoltage during braking is caused by short braking time and too small braking resistance value. It can be avoided by increasing the resistance value by appropriately increasing the time

selection of braking method

(1) energy consumption braking. Using general braking, the energy is consumed on the resistance and lost in the form of heating. At a lower frequency, the braking torque is too small, which will cause crawling

(2) DC braking. It is suitable for precise parking or parking without crawling. It can be used in combination with energy consumption braking. Generally, DC braking is used at 20Hz and energy consumption braking is used at 20Hz

(3) feedback braking. It is suitable for 100kW, speed regulation ratio D 10, high and low speed alternating or positive and negative rotation alternating, and the cycle time is also short. In this case, it is suitable for feedback braking, and the feedback energy can reach 20% of the motor power. More detailed analysis and parameter selection

no load (or light load) trip OC

it is reasonable that the current is not large at no load (or light load) and should not trip OC, but this phenomenon has actually occurred. The reason is often that the compensation voltage is too high, the starting torque is too large, and the excitation saturation is serious, resulting in serious distortion of excitation current, resulting in excessive peak current and tripping OC. Appropriately reduce or restore the factory value or set it to 0

jump OC at low frequency 20Hz when starting

the reason is that due to over compensation, the starting torque is large, the starting time is short, and the protection value is too small (including changing the fixture for experimental current value and stall overcurrent value according to different types of experimental pieces to be tested (plastic, metal, etc.) and different types of experimental methods (tension, contraction), it is enough to reduce the base frequency

it is difficult to start, and cannot start

General equipment, the moment of inertia gD2 is too large, the resistance torque is too large, and heavy-duty starting, large fans, water pumps and other similar situations often occur. Solutions: ① reduce the base frequency; ② Appropriately increase the starting frequency; ③ Appropriately increase the starting torque; ④ Reduce the carrier frequency value by 2.5 ~ 4kHz and increase the effective torque value; ⑤ Reduce the starting time; ⑥ Increase the protection value; ⑦ Turn the load from on load starting to no-load or light load, that is, turn down the inlet valve of the fan

after using the frequency converter, the temperature rise of the motor increases, the vibration increases, and the noise increases

the set value of the carrier frequency of our company is 2.5KHz, which is lower than usual. The purpose is to focus on the safety of use, but it is generally reflected that the above three problems exist. By increasing the simultaneous value of the carrier frequency, the problem is solved

no response after pressing the start key run after power on

(1) the panel frequency is not set

(2) if the motor does not work, press stop immediately and check the following items: ① confirm the correctness of the line again; ② Reconfirm the determined code (especially for the part related to starting); ③ Whether the operation mode is set correctly; ④ Measure the input voltage, R, s, t three-phase voltage; ⑤ Measure DC PN voltage value; ⑥ Measure the voltage value of each group of switching power supply; ⑦ Check the contact of the drive circuit plug-in; ⑧ Check the contact of the panel circuit plug-in; ⑨ Power on again after comprehensive inspection