SINGLE-PHASE FULL-BRIDGE INVERTER Cristian Jhonny Carrion Paladines
[email protected] Jose Enrrique Gaibor Puente
[email protected] Silvia Lilibeth Poalacin Barragan
[email protected] Jaime Vladimir Huara Aguay
[email protected]
Abstract—the main objective of this project is to develop an inverter current and voltage for any system requiring this conversion. An inverter is a power device that converts direct current into AC, this conversion is necessary to inject the power to any electrical circuit, in addition to controlling the modulation inverter uses PWM (this signal is generated by an Arduino 1). The reason PWM is used to make the output current is of the same frequency as power grids to prevent damage to electrical systems, to achieve this switching MOSFET IRF540 is used.
thyristors, power transistors, IGBT, SCR and among others, these act as switches and light according to the design of the control circuit for operation.
Keywords—PWM, inverter current and voltage, transistors, electric power.
I. INTRODUCTION An investor usually handles the conversion of DC - AC, because typically what is sought is to obtain a sinusoidal signal at the load that has the same frequency as electrical network, and to achieve this PWM is used (this signal control can be obtained from any controller or a pulse generator 555), investors are used for multiple applications including feeding AC motors, uninterruptible power systems (UPS), electronic ballasts and others. An inverter full bridge control is more likely, because that can handle twice the power half bridge for the same effort on switches and can work in two ways: control phase slip without phase slip.
Fig.1 Single-phase full-bridge inverter Transistors Q1 and Q2 input voltage then are activated simultaneously at the time that Vs is present in the load. However when Q3 and Q4 are activated, the voltage across the load is -Vs that is the inverse of the input voltage.
II. PREVIOUS WORK Circuit Theory and analyzed in class and review of documents and power electronic books. Review of forums and practices carried out in other institutions of higher education, and contributions by teachers Engineers ESPOCH familiar with the matter. III. THEORETICAL FRAMEWORK DC-AC converter or inverter: Alternating voltage is to obtain a direct voltage supply this is accomplished by using switching devices and driving time variation thereof. The role of an investor is to change a DC input voltage to an output voltage AC, investors use is very common in industrial applications such as AC propulsion motors, variable speed induction heating, power and backup power supplies for discontinued. Single-phase full-bridge inverters: This type of investor has the power circuit comprises four semiconductor which can be
Fig. 2 Waveforms of a single-phase full-bridge inverter
Q1 Q4
on
off
on
Q2 Q3
off
on
off
uS VE Fig. 3 waveforms of an inductive load phase slip control you can adjust the output amplitude (average) by the angle α, obtained waveform is closer to a sine wave. displacement angle α adjusts the fundamental component of the output voltage. the harmonic content depends on the angle α.
-VE Fig. c without displacement Fig. 4 Full investor without scrolling and without displacement a, b y c
Q1
VE
Q3
uS Q2
Q4
FEATURES The output voltage can take three values: VE, VE and 0. Allows control of the output amplitude. Reduces the harmonic content in the output. Voltage stress on the switches are the same as the maximum output voltage.
Fig. a
IV. CONCLUSIONS
Q1 on
off
on
Q2 off
on
off Q3 off
on
off
Q4
on
off
on
Fig. b scrolling
The MOC3021 is a very important within a string inverter circuit optocoupler, because it helps to protect the system from overvoltage and overcurrent occurring by switching thereof. In the circuit is needed for a transistor to allow or not the passage of current, and this is accomplished by sending a voltage to the collector of the transistor and a signal coming from the MOC3021 made qeu switch the transistor, in this case only switched same two MOC3021 to obtain a sinusoidal output, and for this you must change the polarity at a frequency equal to 60 Hz. To obtain a desired output frequency to use our circuit PWM signal Arduino, the same will vary the pulse width to simulate a sine wave output circuit. to appreciate a sine wave at the output of the circuit is made using a transformer of 6-120 V, it should be emphasized that we could not supply a load since the current font was too small was in the range of 200300mA. V. RECOMMENDATIONS
It is recommended when fed a load of 110V inverter, DC power source must have a very strong current in
the order of 5-40A, if they have one of more current is much better as well will be able to connect much more load circuit. to make a good switching to use the MOC of any series, since these devices come with internal diode for overcurrent and overvoltage protection controller and control device which is connected to the gate. consider that to give a pulse to the circuit should consider the MOC that must commute equal, in our case are 1 to 3 and 2 to 4, to achieve can use a gate to invert the signal that activates the MOC this should do it till achieve a frequency of 60Hz, which is the frequency of the electrical networks Ecuador.
VIII.ANNEXES
VI. REFERENCES [1] ANÁLISIS DE CIRCUITOS Y SISTEMAS LINEALES, Universidad Miguel Hernández, Inversor monofásico. [2] ELECTRÓNICA Y CIENCIA, blog técnico sobre proyectos caseros de electrónica, informática y física, El circuito de puente completo con PWM. [3] Presentación en Power Point, Inversores con PWM. VII. ARDUINO PROGRAMMING int pin1=6; int pin2=8; int pin3=5; int pin4=7; int pot=A0; void setup() { Serial.begin(9600); pinMode(pin1,OUTPUT); pinMode(pin2,OUTPUT); pinMode(pin3,OUTPUT); pinMode(pin4,OUTPUT); } void loop() { int espera= analogRead(pot)+10; Serial.println(espera); //Serial.println(pot); digitalWrite(pin3,LOW); digitalWrite(pin4,LOW); delay(10); digitalWrite(pin1,HIGH); digitalWrite(pin2,HIGH); delay(espera); digitalWrite(pin1,LOW); digitalWrite(pin2,LOW); delay(10); digitalWrite(pin3,HIGH); digitalWrite(pin4,HIGH); delay(espera); }
Fig.5 Design of a single-phase full-bridge inverter
