Dobavitelji zavornih enot vas opominjajo, da so tako frekvenčni pretvorniki kot motorji visokoenergijske električne naprave. Ko tok teče skozi tokokrog, zaradi prisotnosti upora v skladu z Jouleovim zakonom povzročajo toplotne učinke in ustvarjajo toploto. Visokoenergetski tokovi imajo pogosto relativno velik tok in pride do nekaj segrevanja. Na splošno se oceni, da roka ni vroča. Če je zelo vroča, je treba to pravočasno odpraviti.
Bodite pozorni na pravilnost izbire
Motor je srce delovanja opreme in vir energije za skoraj vse obremenitve. Pri načrtovanju izbire opreme je treba celovito upoštevati navor in moč, ki ju zahteva obremenitev, da se izbere ustrezna moč in navor motorja. Če je zmogljivost motorja izbrana premajhna, je to enakovredno vleki težkega vozila z majhnim konjem. Seveda motor sam deluje preobremenjeno in se močno segreva.
Podobno, če so specifikacije frekvenčnega pretvornika izbrane tako majhne, bo frekvenčni pretvornik še vedno močno segreval, če bo dlje časa prehajal tokove, višje od nazivnega toka, in hitro se bodo pojavile težave ter pregorel.
Izbira je premajhna, zato jo lahko le zamenjamo z večjim modelom, da bi se s tem spopadli. To je stroga zahteva in ni bližnjice. Obravnavati jo je treba pravočasno. Tudi če obstoječi model razstavite in ga prodate kot rabljenega, je bolje, da ga še naprej uporabljate. Navsezadnje, če se pojavijo težave, ki zavlačujejo proizvodnjo ali povzročajo eksplozije ali požare zaradi segrevanja in drugih težav, je to velika stvar.
Nekatere obremenitve se morda ne zdijo težke, vendar vključujejo pogosto vklapljanje in ustavljanje, kar zahteva tudi ojačitev moči, sicer se bodo še vedno soočale z zgoraj omenjenimi težavami.
Težave z opremo in obremenitvijo
If there is any abnormality in mechanical equipment or load, such as the gears or bearings of the transmission mechanism being damaged, the resistance will increase and the output of the motor will also increase. In some serious cases, motor stalling may occur, and the current will be very high. Although most frequency converters will cause overload and overcurrent, leading to alarm shutdown, there are also some in critical conditions, or if the protection parameters of the frequency converter are not set properly, it can still cause abnormal phenomena such as heating. In this situation, of course, we need to start with mechanical equipment and loads to solve the problem.
For example, the frequency converter controls some liquid conveying pumps or air supply fans. Due to dirty or bent pipelines, high resistance can cause excessive current in the motor and frequency converter. These need to be cleaned and treated in a timely manner.
Problems with the frequency converter and motor itself
If the motor is used for a long time, it cannot be ruled out that the insulation performance is poor or the bearings are stuck, which may cause high current and heat generation. The connection between the motor and the load may also be worn, or the motor may have three-phase imbalance, loose fixing devices of the motor, etc., which can cause abnormal noise and heating.
Aging of certain components in the frequency converter, deviation between vector parameters and motor matching, excessive setting of parameters such as torque boost, short acceleration and deceleration time, and low carrier frequency of the frequency converter may all cause the motor and frequency converter to heat up together.
The connecting wire between the motor and the frequency converter should generally not be too long, otherwise it will cause attenuation and waveform distortion. If it needs to be used, a dedicated frequency converter and an additional reactor should also be used to handle it.
In some situations where rapid braking is required, it is necessary to select appropriate braking resistors and braking units according to the braking power.
Long term work in low-frequency state
It is generally not advisable to design the motor to operate below 8HZ, even for vector controlled frequency converters, such use should be avoided as much as possible. This is mainly due to severe waveform distortion at low frequencies, which is too far from the sine wave, resulting in poor motor performance, severe torque attenuation, and heat generation. The target can be achieved by increasing the transmission ratio and then raising the output frequency of the frequency converter.
If it is necessary to work in a low-frequency state for a long time, a dedicated variable frequency motor can be used, or the motor can be cooled by forced air cooling or even water cooling.
Optimize the usage environment
V preteklosti zaradi slabih gospodarskih razmer številne majhne tovarne niso načrtovale neodvisnih kontrolnih sob. Tudi če so imele kontrolne sobe, v kontrolne sobe niso namestile klimatskih naprav. Zdaj, ko so razmere dobre, je povsem mogoče namestiti frekvenčne pretvornike in druge komponente v krmilnike s klimatsko napravo. Na ta način je temperatura frekvenčnega pretvornika v optimalnem stanju, zaradi česar je manj verjetno, da bo proizvajal toploto, in se mu je podaljšala življenjska doba zaradi manjšega prahu in drugih dejavnikov. Na splošno je to pravzaprav relativno dobra naložba.