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Hi Friends,
I was built this inverter circuit and test it. The circuit works fine.
But there still have some finishing works in software.
I will be complete the software soon, i hope.
I was attach a pictures of the PCB with some soldered components (without power transistors, current transformer and output LC-filter).
Best regards.
Taner
Hi Friends,
I was built this inverter circuit and test it. The circuit works fine.
But there still have some finishing works in software.
I will be complete the software soon, i hope.
I was attach a pictures of the PCB with some soldered components (without power transistors, current transformer and output LC-filter).
Best regards.
Taner
Please see the current transformer secondary cant be open like shown in your schematic. Perhaps you might have the load resistor, but not shown in schematic.
Hi mvs sarma,
Thank you very much, but only the electrical circuit is mine,
PCB was designed from my friend.
Current transformers secondary side has a two load resistors: R8=100 for high range and R18=1.5k for low range. They are in the feedbacks of two OPAMPs (U1A and U1C).
Best regards.
Taner.
Hi mvs sarma,
Thank you very much, but only the electrical circuit is mine,
PCB was designed from my friend.
Current transformers secondary side has a two load resistors: R8=100 for high range and R18=1.5k for low range. They are in the feedbacks of two OPAMPs (U1A and U1C).
Best regards.
Taner.
Hi mvs sarma. i like ur style of criticism. u seem to be very grounded in electronics & this subject. this means that ur active involvement in this topic will encourage Taner to modify his design & finishing touch on time. i'm quite new to sine wave inverter design but have studied alot but still have some doubt which may sound absurd but important to me to clear my head. hence will be grateful if u guys answer subsequent questions in posts. To start with, i know how the 32 PWM signal was got which is similar got from carrier frequency(triangular wave) and reference sine wave. pls, does it mean that for 1 phase of the final sine output, the mosfet pair switches on& off according to PWM for 32 times b4 shifting to the 2nd mosfet pair switching for another 32times to complete the cycle? pls let me know if i'm missing up things.
Hi codewiz
Yes, but carrier frequency is 20kHz (generated with buit-in PWM of the PIC MCU) and each half period (10ms) we have 32 changes in the PWM signal, this makes 64 changes in whole period (20ms). But we generated only the half period of the sine-wave and with the help of the direction signal we can get the whole period of the sine-wave in the output of the inverter.
In this inverter we have a full-bridge power circuits with 4 transistors (paralleled-8 transistors), Q1, Q3, Q5 and Q7.
Two of transistors works with low frequency - 50Hz (Q5 and Q7) depending on the state of the A/B (direction) signal (RC1). Other two transistors (Q1 and Q3) works with high-frequency (20kHz) of the sinewave PWM signal.
Best regards.
Taner
"In this inverter we have a full-bridge power circuits with 4 transistors (paralleled-8 transistors), Q1, Q3, Q5 and Q7.
Two of transistors works with low frequency - 50Hz (Q5 and Q7) depending on the state of the A/B (direction) signal (RC1). Other two transistors (Q1 and Q3) works with high-frequency (20kHz) of the sinewave PWM signal.
Best regards.
Taner "
i appreciate your effort and time. the above explanation has revealed my misconception. To further clarify the above, 1. can i subsequently refer to Q1 and Q3(running on 20khz PWM signal) as High MOSFETS While Q5 and Q7(running 50Hz) as Low MOSFETS. 2. Pls, how is the 50Hz running Q5 and Q7 generated? 3. What are the switching patterns of the 4 transistors?. i mean which group switch on and off together. i will be grateful if these doubts are cleared.
Hi codewiz,
sorry for delay, but i am so busy at work.
I drew a block scheme including the main parts of the inverter.
This will be describe a working mode of the inverter and switching patterns for the
4 transistor.
Best regards: Taner
Wao! great diagram. It explains so much in a stretch. This has cleared most of my misconception. I will now complete building to start experimenting. I do hope you will find time to support me in the subsequent questions during experimenting from your tight schedule. I'm very grateful. i acknowledge that you are busy at work.Hence, appreciate your time input.
The first CT (https://www.es.co.th/Schemetic/PDF/TZ2L9-TAEH.PDF) have a current transfer ratio 1:1000 (50A/0.05A), the inverter output current range is 2.5-5A (550VA/220Vac) in this case you will obtain output current from CT I=2.5-5mA, multiplayed by load resistor=100 Ohm will produce very small voltage 0.25-0,5V. For amplifying this signal you can wind up a 4-5 turns in primary side of the CT (for measure a current in range of 5A). Output voltages of the current amplifiers (U1A and U1C) are centered to 2.5V (full wave signals). Output voltage of the OP AMP U1B (output voltage amplifier) is centeref to 2.5V too.
For the second CT (https://www.es.co.th/Schemetic/PDF/ZCT801.PDF) i can't see the current transfer ratio of the transformer. If it is a similar to first CT (with ratio 1:1000) and suitable for current >=5A, yes you can use it in this inverter design.
Best regards: Taner
Hi, mr Taner. I try build this circuit, but she not work. After restart leds power, but no produce PWM signal. Maybe i wrong? Somebody build this project sucesfull?
p.s. What description status led?
I not wiring all shem, signals from current transformer, Vbat and output voltage i simulate.
Added after 3 minutes:
Г-н Танер, вече бях изпратил въпроса, когато видях, че локацията е България. Така че още един път да попитам тази схема работи ли наистина?
Hi maharadga,
yes, this inverter design works fine.
I was build and test it, but software is not finished yet.
LED status:
1. Green -> Normal operation
2. Green Blinking -> Standby Mode (No load operation)
3. Red -> Low baterry (<10.8V)
4. Red Blinking -> Over Temperature of Power Transistors
5. Orange (Green+Red) Blinking-> Before going in Stanby Mode (for 5 sec).
Best regards.
Да приятелю инвертора работи много добре,
имаме вече произведен един екземпляр от него, но както казах трябва да довърша някои корекции по софтуера, надявам се скоро да го приключа.
Ако ми остане свободно време от работата.
Всичко хубаво ти желая.
Mr. Taner, the idea generally is good , congratulations for you. Must work
Indeed, but I can not let the scheme. Try the hex file that you uploud,
tried and compiled by me. The result is the same. In placing the red LED flashes,
then turn off and then flashes green / red is tied to pin 25 and green for the pin
24 /, in light of the tensions that send Vbat flashes or off.
I think that in your scheme leds are tied back.
There are no generations 50Hz and 20 kHz.I verify sheme several times. I thing
programming that may not be good. So far I successfully programmed PIC16F84A and
PIC16F628A with PIC TEST programmer from site . But PIC16F876A failed to
programming. I called for help, but they are responsive only under contract. And because
microcontrollers work recently, I would like to ask for some help . I did my other programmer / send a link to it/, as
it could be programmed. So if you decide to target me if I proceed correctly
a programmer, you'll be grateful and will treat a bottle of good wine
p.p.I think the appropriate source transformer is ferrite, to
packages of high-frequency pulses. I think that standard will have
large losses.
Благодаря за отговора. Г-н Танер, идеята е по принцип е доста добра, за което Ви поздравявам. Сигурно работи наистина, но аз не мога да пусна схемата. Пробвах с hex файла, който сте ъплоуднали, пробвах и с компилиран от мен. Резултатът е същият. При пускане светва червеният светодиод, след което изгасва и светва зеленият / червеният е вързан за извод 25, а зеления за извод 24 /, като в зависимост от напрежението, което подавам от Vbat светва или изгасва. Предполагам, че във вашата схема светодиодите са вързани обратно. Но това както и да е. Няма никакви генерации- нито 50Hz, нита 20 kHz.Проверих разбира се всичко. Имам опасения, че програмирането може би не е както трябва. Досега съм програмирал успешно PIC16F84A и PIC16F628A с програматора PIC TEST от сайта на Млад конструктор. Но PIC16F876A не успя да програмира. Звънях им за помощ, но те са отзивчиви само при поръчка. И тъй като с микроконтролери се занимавам отскоро, бих искал да помоля за малко помощ, ако не ви притеснявам и имате време. Направих си друг програматор / изпращам линк за него /, като с него успя да се програмира. Така че, ако решите да ме насочите дали съм процедирал правилно с програматорите, ще ви бъда признателен, а и ще почерпя бутилка хубаво вино, нали сме близко
п.п.Мисля си, дали няма да бъде удачно изходният трансформатор да е феритен, предвид високочестотните пакети от импулси. Струва ми се, че стандартните феросилициеви ще имат големи загуби.
Hi maharadga,
the green LED (LED1) is connected to pin25 (RB4) and red LED - to pin26 (RB5).
When inverter turned ON without load, after 5 sec inverter stops and going in standby mode. In this mode inverter starts only for short time for detecting the existence of the load. Time interval between this short start pulses is 1 sec. Before this mode begin to blink Green LED (for 5 sec). And after going in standby mode blinking Green and Red LEDs together (Use a single two color LED - Green and Red) and resulting color is orange.
For the output power transformer i use a low frequency (50Hz) conventional transformer, but decision is yours. Ferrite core transformers are more suitable in other type of inverters with double conversion stages: first stage for boosting the input 12V (or 24V) DC voltage to 350-400Vdc (with HF PWM and ferrite transformer) and second for inverting this voltage to 230Vac (without transformer).
For the programmers, the secon one is better. I use a similar parrallel port programmer and its work fine for all 5V PIC's (PIC16F and PIC18F).
Best regards.
I'm back again. Just built the basic circuit. I tested the microcontroller with the Hex file in it BUT I didn't get any response. What input signals do i put into the controller? and at what pins?. For example, conditions for the PWM & 50Hz to be generated.
Added after 1 minutes:
I'm back again. Just built the basic circuit. I tested the microcontroller with the Hex file in it BUT I didn't get any response. What input signals do i put into the controller? and at what pins?. For example, conditions for the PWM & 50Hz to be generated.
Hi codewiz.
there are many feedback input signal needed for proper work of the inverter:
from input DC voltage, temperature sensor (Rt, NTC-47k), output ac current, output ac voltage (230V), a/b signals (over two low-side power transistor - Q5 and Q7), signals from two POT's (R22 and RT1) and etc. Better look at schematics of the inverter for signals connected to PIC MCU.
When starting the inverter for the first time (before connectin the voltage and current feedback signals to PIC MCU) you must fit (adjust) the polarity of the output signals (I and V) to the polarity of the direction signal A/B (LF, 50Hz signal) from PIC MCU. Signals must be exactly like this: positive output voltage (and high current - curr-h) must be at the same time when signal A/B =5V (log.1) and negative when A/B=0V (log.0). If the voltage (and current) signals are contrariwise you must reverse only input or output pins of the power transformer. For contrariwise current signal you must reverse the pins (inpu or output) of the current transformer. And then you can connect this feedback signals to PIC MCU.
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