In this note, we are going to know about Single Phase Full Bridge Inverter, and about its specifications, circuit diagram, operation, advantages, disadvantages, and applications. Welcome to Poly Notes Hub, a leading destination for engineering notes for diploma and degree engineering students.
Author Name: Arun Paul.
What is Single Phase Full Bridge Inverter?
A Single Phase Full Bridge Inverter is a DC to AC inverter that transforms a set DC voltage to an AC voltage. To control the polarity and magnitude of the output voltage, four switches (transistors or thyristors) are connected in an H-bridge configuration. These inverters are commonly utilized in industrial settings, uninterruptible power supplies (UPS), and renewable energy systems.
📌 Specifications of Single Phase Full Bridge Inverter
- The input voltage is typically ranges from 12V to 400V DC.
- This circuit is generated the AC output voltage from 110V or 230V RMS (depending on the application).
- The generated output frequency is ranges from 50 Hz or 60 Hz.
- Switching devices are used here like MOSFETs, Thyristors, and IGBTs as well.
- The efficiency is high around 90% to 97%.
- The output power is depends on the design, typically from a few watts to several kilowatts.
Single Phase Full Bridge Inverter Circuit Diagram
Here is the circuit diagram of Single Phase Full Bridge Inverter –
- Four switching devices (Q1, Q2, Q3, Q4): Connected in H-Bridge configuration.
- DC Source: It is provides the input DC voltage.
- Load: Connected between the output terminals of the bridge.
- Gate Driving Circuit: Controls the switching of transistors or thyristors.
Single Phase Full Bridge Inverter Working
- The inverter operates by turning on and off the switches in a specific sequence to create an alternating output voltage.
- In one half cycle:
- Q1 and Q4 are turned ON, and Q2 and Q3 are OFF. This applies a positive voltage across the load.
- In the other half cycle:
- Q2 and Q3 are turned ON, and Q1 and Q4 are OFF. This applies a negative voltage across the load.
Output Voltage Equation
The instantaneous output voltage of a single-phase full bridge inverter is stated as:
- For Square Wave Operation, the output voltage is expressed by –
Where;
- Vdc = Input DC Voltage
- ω = Angular Frequency ( ω = 2πf, and f is the output frequency )
- sgn(sin(ωt)) = Signum function that outputs +1 or -1 depending on the sign of sin(ωt).
- For Pulse Width Modulation Operation or PWM Operation, the output voltage is expressed by –
Where;
- Ma = Modulation Index, which ranges from 0 to 1.
- sin(ωt): Desired sinusoidal output waveform.
Output Current Equation
The current depends on the load connected to the inverter. For pure resistive load, the output current is expressed as –
Where;
- V0(t) = Output Voltage
- R = Amount of Load
Advantages of Single Phase Full Bridge Inverter
Here are the lists of single-phase full-bridge inverter advantages –
- The output efficiency is high due to low switching losses.
- This circuit is suitable for portable applications.
- It has low harmonic losses.
- The operation of this circuit is both, like bidirectional operation.
- The power ratings can be adjusted by selecting appropriate switches.
Drawback of Single Phase Full Bridge Inverter
Here are the lists of single-phase full-bridge inverter disadvantages –
- The switching of this circuit can generate Electromagnetic Interference (EMI).
- This circuit is requires a gate driver circuit.
- For high power applications, it requires a power cooling system.
Single Phase Full Bridge Inverter Applications
Here we have listed some important applications of this circuit –
- UPS Systems: Supplies AC power during grid outages.
- Industrial Drives: Drives for AC motors and pumps.
- Renewable Energy Systems: Converts DC from solar panels or batteries to AC.
- Electric Vehicles (EVs): Powers AC motors in Electric Vehicles.
- Household Appliances: Powers devices requiring AC from a DC source.
- Telecommunications: Provides reliable power for communication systems.
