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miticamy

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    Metrou Costin Georgian

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  1. miticamy

    LLC in simulari

  2. miticamy

    LLC in simulari

    Daca esti mai atent si ai timp de pierdut vezi ca nu difera prea mult cele 2 programe. Insa LT vede un max in jur de 71,2kHz in timp ce TINA il vede la 71kHz. EDIT1: am reusit si cu gen de curent al TINA
  3. miticamy

    LLC in simulari

  4. miticamy

    LLC in simulari

    CITAT: Este o diferenta la modul de reprezentare a marimilor, Tina are semnal din generator "virf la virf" si LTspice doar "virf", imagehost
  5. miticamy

    LLC in simulari

    Am zis, ce atatea comenzi, tranzistoare...Am folosit un generator sinusoidal si verific raspunsul circuitului LC serie functie de frecventa sau de valorile L si C din tancul rezonant.
  6. miticamy

    LLC in simulari

    Pe care sa te bazezi, la aceeasi simulare diferenta de 4:1
  7. miticamy

    LLC in simulari

    Ca sa nu mai caut prin calculator pun aici o selectie din cartea lui Xiang Fang: Xiang Fang ian19 Series Resonant Converter The SRC circuit is illustrated in Figure 1.7. The resonant tank of SRC consists of a resonant capacitor and a resonant inductor connected in series. The output load resistance is in series with the resonant tank and the impedance of the resonant tank is a function of the switching frequency, and hence the voltage across the output impedance can be modulated by the switching frequency. At resonant frequency ( √ ), the resonant impedance reaches its minimum and the normalized output voltage gain ( , the transformer turns ratio is included as if is equal to 1) becomes unity. It is the max gain of SRC, since magnitude becomes larger for the switching frequency above or below resonance and the voltage divided to output accordingly will decrease. The DC characteristic plot is shown in Figure 1.8. For the frequency region above the resonance, the total input impedance will appear inductive, which makes the input current lag the input voltage, and thus ZVS condition is attainable. ZVS is preferable for converters that use MOSFETs and diodes, since it minimizes the switching losses and the EMI effect. On the other hand, below the resonant frequency is the capacitive impedance region, where ZCS can be achieved. ZCS condition is more favorable for reducing the switching losses for IGBT devices, but cannot reduce the switching loss in MOSFET converters. Also, the resonant behavior in the ZCS region of SRC is more complicated than in ZVS due to the sub-harmonic effect. The resonant tank responds to the signal with the resonant frequency component more strongly than other frequency, and it is possible that some high order harmonic of a low switching frequency input coincides with the resonance. In this case, the gain and frequency relationship is no longer monotonic for low switching frequency and therefore these operation regions should be generally avoided. It can be observed from the DC characteristic plot (Figure 1.8) that the gain curves are less steep for lighter load condition. In other words, in order to regulate an increased input voltage, the required frequency variation range will be wider for light load comparing to heavy load. In theory, the gain curve becomes flat for zero load condition, which makes SRC incapable of zero load regulation. Another problem for the high frequency operation (above the resonance) is that the turn-off switching loss is increased. Therefore, SRC is not suitable for wide input and load applications. Parallel Resonant Converter The parallel resonant converter (PRC) topology is shown in Figure 1.9. Its resonant tank also has two resonant components as SRC, but the capacitor is in parallel with the output rectifier. Another difference is that the output stage is an L-C filter rather than a capacitor filter, which is an inductively coupled output and equivalent to a current source. The peak gain of PRC is affected by the load resistance, whereas for SRC the peak gain at resonance is unity and load-independent. The peak gains occur at a frequency below the resonant frequency, and the peak frequency will be lower for a heavier load condition. The peak value can be larger or smaller than 1, which allows the converter to work in a wider gain range if properly designed. The DC gain plot is shown in Figure 1.10. The same analysis can be applied to PRC that in order to achieve ZVS the converter should be limited in the above peak gain frequency region. However, the peak frequency is variable depending on the load condition and the tank parameters: the peak point shifts to lower frequency and smaller gain value as the load increases. Another notable feature of the DC gain is that the curve slope is steeper for lighter load condition in contrary to SRC. Provided the same input and load range, the required frequency variation to regulate the voltage is narrower for PRC than for SRC. The drawback of PRC is the same circulating current problem causing high conduction loss and poor efficiency for light load condition, since the input impedance is inductive for ZVS condition, which is dominated by the inductive part and less affected by the load resistance resulted in a relatively large resonant current even for large load resistance. LCC Resonant Converter The SPRC, also known as the LCC resonant converter, is a combination of SRC and PRC as seen in Figure 1.11[36-38]. The resonant tank has three resonant elements: and in series, in parallel with the rectifier input. Consequently, the converter has two resonant frequencies: ( √ ) is the short circuit resonant frequency, and ( √ ) is the open circuit resonant frequency, where ( ) The DC gain of the SPRC is illustrated in Figure 1.12 (where ). It can be seen that at it is the load-independent operating point similar to the SRC where all the gain curves cross the unity point. However, affected by the presence of the gain may reach its peak at a higher frequency above . As aforementioned, in order to operate in the preferable ZVS region, the converter with MOSFET switches should be working on the right slope of a gain curve. Therefore, the LCC cannot operate at the open circuit resonant frequency, which is the highest efficacious point for the series part of the resonant tank impedance is at its minimum magnitude with the inductance and capacitance canceled each other. The LCC possesses the advantages of PRC that it is capable of handling zero load condition and the gain-frequency curves have steep slope for light load condition. In the meantime, the resonant current is not as large as PRC and thus the circulating energy is limited, which is one of the merits of SRC. LLC Resonant Converter The LLC resonant converter is also a three-resonant-component converter as shown in Figure 1.13. Unlike the LCC, the LLC resonant tank has an inductor in parallel to the transformer primary side (or rectifier input) instead of a capacitor. The parallel inductor is denoted as for the reason that it is usually implemented by the magnetizing inductor of the transformer. Although the magnetizing inductor exists for every transformer, which makes SRC look the same as LLC, in SRC is much larger than the resonant inductor and will not participate in the resonance, while in the LLC has comparable inductance with and can no longer be ignored in the resonance. Since the magnetizing inductor is embodied in the transformer and the resonant inductor can be implemented by the leakage inductance of the transformer as well, the SRC circuit structure can be converted to the LLC topology at no extra costs [39-41]. The LLC converter has likewise two resonant frequencies: ( √ ) is the short circuit resonant frequency, and ( √( ) ) is the open circuit resonant frequency. But is larger than , which indicates that the load-independent unity gain point occurs at a higher frequency than the peak gain point based on the previous LCC analysis as shown in Figure 1.14 (where ). This feature of the LLC grants the highest efficiency operation point reachable within ZVS region to the converter, which is given up by the LCC in consideration of ensuring ZVS. Besides, the LLC combines the advantages of SRC and PRC: the range of gain is wide as the gain can be above or below 1; the span of operation frequency is contracted as different gain curves for different load condition converge to the unity gain point at . 1.3 Objectives and Outline The primary objective of this dissertation is to give a thorough and systematic analysis of the operation of the resonant converter, particularly the LLC resonant converter, whose topology has the potential to achieve high power density and high power efficiency for wide input range applications.
  8. miticamy

    Robot pornire masina

    CITAT: Tiristorul odata aprins nu se poate stinge decat in mod natural Eu cred ca SSB se referea la siguranta aprinderii unui tiristor. Citate din teorie poate posta aproape oricine, in practica sunt si cazuri ce creaza probleme. 1) 1980--1985 era la moda aprinderea electronica cu tiristor. Nu am avut niciodata masina si nu m-a interesat problema dar colegii au trecut serios la treaba si toata ziua se auzeau descarcarile bobinei(aveau un motoras cu distributia si bobina de Dacia). Tot dadeau rateuri si intro zi un inginer a adaugat un 555 si un traf pe ferita si aprinderea era ferma. 2) Calculatorul Felix a fost adus de la francezi in 72 care il luasera de la americani. Va dati seama ca proiectul este din anii 60. Sursele de 5V erau de 50A si 100A. Protectia la supratensiune era cu un tiristor si o siguranta rapida pusa pe tensiunea de intrare. M-am angajat in 78 si mi se parea cam mult 4 tranzistori pt comanda in poarta, ultimii 2 fiind un triger SCH. Un inginer de la Coral a folosit protectia cu tiristor direct pe iesire si a pus schema simpla din Tehnium-un zener in poarta de la iesire. Rezultatul? Tiristorul nu se amorsa suficient si se incalzea de nu puteai sa-l atingi. Nu stiu schema finala dar langa zener au mai pus tranzistori.
  9. miticamy

    LLC in simulari

    Diferente la sarcini in raport 1/2: Diferente la grupul rezonant 1/2:
  10. miticamy

    Robot pornire masina

  11. miticamy

    LLC in simulari

    Am mers la postarea de inceput a lui FRobert; Membru FRobert Posted December 8, 2015 Citind postarea anterioara a lui maxente am observat o greseala de a mea de la postul 7, unde am scris dielectric in loc de intrefier. Am sa postez si fisierul excel, dar mai intai trebuie sa-l traduc ca l-am luat de pe forumul din ungaria, unde un membru a construit sursa rezonanta conform AN1160 avand la baza integratul IRS27951s. Nu cunosc cat de corect este fisierul, eu am introdus datele pentru un ETD39 de la care doresc 100V (2*50V) la un curent de 8A, excelul mi-a calculat: inductanta totala de: 116.7uH - si mi-a iesit la B=0.19 ales pentru miez 3C90 - 18 spire a 27buc fire Cu de 0.2 inductanta de scapari:16uH - care mi-a iesit la 21uH cred ca trebuia sa fie mai mare pe carcasa partea de secundar. Am inpartit egal carcasa Iar intrefierul mi-a calculat de 0.23mm, si a fost ok. Pot sa zic ca mi-a dat in mare parte si fizic valorile calculate. Toate le pot confirma dupa realizarea sursei, dar pana acum pare promitator??. Posted January 29, 2016 Intr-un final am reusit sa termin sursa rezonanta cu IRS27951 conform AN1160. Am pornit sursa de pe o sursa de laborator cu o tensiune de 20V, respectiv 15V pentru controler (IRS27951) si driver(IR2110). Pe iesire s-a generat o tensiune de aprox 5V, i-am pus si o sarcina de 6 ohmi, si am masurat cu clampmetru un consum de 800mA. Pe condensatorul de rezonanta am forma de unda sinusoidala. La mers in gol pe iesirile de la IRS 27951 am factorul de umplere egala, dar la conectarea rezistentei de sarcina ( cei 6 ohmi) se modifica factorul de umplere. Pe HO creste si pe LO scade factorul de uplere, respectiv dupa driver treaba devine si mai urata. Masurand pe G mosului de sus, la coborare pe la mijlocul pantei semnalul se lateste si se suprapune cu cel de urcare de pe G mosului de jos. Ma poate cineva lamurii cu fenomenul? Posted January 29, 2016 Am pus driver pentru putere mai mare. Doresc sa trag din sursa aprox 800W. Pentru mosi am folosit SPP20N60C3 (in schema am IRFP460 pentru capsula TO243, pentru care am desenat cablajul). C11 este liber, si valoarea lui C10= 330pF. Stau si ma gandesc ce ar fi daca as inparti condensatorul de rezonanta in doua. +310 - traf = 44nF si traf - GND = 44nF. Vedem maine. A doua chestie ce ma mai intereseaza, este daca reusesc sa indrept, si sa stabilizez semnalul de comanda pe G mosilor la tensiune mica de alimentare (alimentare de la 30V pe rail de exemplu, aici ma refer la tensiunea dintre D mosului de sus si S mosului de jos. controler-ul + dirverul de finali vor fi alimentati de la 15V stabilizat), atunci semnalul acela de comanda va ramane si la tensiune de lucru 310V? - se va schimba comportamentul elementelor de comutare la 310V fata de 30V, s-au nu? Posted January 30, 2016 (edited) Inductanta primarului 116uH, si inductanta de scapari cu secundarul forta in scurt 19uH (conform calculelor acesta trebuia sa fie de 16.7uH). Montajul alimentat de la 20V, cu sarcina de 5.8ohm pe iesire cu consum de 900mA, masurat cu clampmetru Am simulat cu valori apropiate putin sub rezonanta si putin peste rezonanta: Edit: am pus mos-urile cu capacitatea iesire mai mica si m-am apropiat de rezonanta: Dar asa arata foarte bine si sub rezonanta: Stiu ca asa ar fi mai bine dar mananca timp:
  12. miticamy

    LLC in simulari

    De marti am o ameteala suspecta care s-a agravat ieri. nu stiu cat este de vina calculatorul ca stau cu orele la el dar o sa pun ceva poze fara prea multe explicatii. Cine este interesat vede cum lucreaza LTC si poate deduce usor ce reprezinta oscilogramele. EDIT: schema este LLC semipunte ca si pana acum...
  13. miticamy

    Schema invertor Fimer 180

    Cum masori tensiunea in primar driver? Pui sonda pe cei 2 pini ai primarului? Se pune oscul pe DC, masa sondei la masa montaj si sonda pe drena MOS driver. Nu se foloseste in impulsuri oscul pe AC.
  14. miticamy

    LLC in simulari

    Cred ca LTS nu ia in considerare capacitatile MOS-ului. Am pus eu la intamplare cate 2n si am prins iesirea din ZVS cu sarcina. EDIT: Am vazut si influenta timpului mort:
  15. miticamy

    LLC in simulari

    Este topicul meu de pensionar si doresc liniste. Pt problema de care intrebi deschide un topic separat, ex. "Sursele mele--practica si teorie". Nu de alta dar o sa incepi si aici sa pui filme cu realizarile dumitale. La topicul lui Maxente s-a scris destul despre rezonanta serie ZCS, si acolo s-au dus lupte fara niciun rezultat. Cauta in acel topic si vezi ce ti-am scris de cateva ori: oscilogramele lui UNIT au lamurit total cum fac vesticii surse rezonante ZCS. Aici vorbim de LLC care sunt surse stabilizate nu ca cele din audio. Te rog sa nu raspunzi aici, deschide un topic cum am spus pe care il voi citi cum citesc totul la alimentatoare si daca binevoiesti sa-mi pui o intrebare punctuala si ma pricep sigur voi raspunde. Deci trimite un MP d-lui Sabac si continuati discutia eventual pe topicul lui Maxente care se potriveste cu sursele pe care le-ai construit. PUNCT!
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