Degrees conduction, the switches in each phase are turned on for 180 degrees of the input waveform cycle. This means that each switch conducts for half of the input cycle.

During the first 180 degrees of the input waveform cycle, the upper switches in each phase (S1, S3, S5) are turned on, allowing current to flow in one direction through the load. During the next 180 degrees of the input waveform cycle, the lower switches in each phase (S2, S4, S6) are turned on, allowing current to flow in the opposite direction through the load.

By alternating the conduction of the switches, the bridge inverter is able to produce an AC output waveform by converting a DC input voltage into an AC output voltage. The frequency of the output waveform is determined by the frequency of the input waveform.

It is important to note that in a 3 phase bridge inverter, there are 6 switches (S1-S6) that need to be controlled in order to achieve the desired output waveform. This requires a sophisticated control circuit to ensure proper switching of the switches at the right time.

In a 3-phase bridge inverter with 180-degree conduction mode, each phase of the inverter is connected to a pair of power electronic switches, typically insulated gate bipolar transistors (IGBTs) or MOSFETs. The switches are controlled by a pulse width modulation (PWM) signal.

During each half-cycle of the input voltage, two of the switches in each phase are turned on while the other two switches are turned off. This creates a path for the current to flow from the DC power source through the load and back to the source. The switches are controlled in such a way that the output voltage waveform is a pulse train with a frequency equal to the desired output frequency.

In the 180-degree conduction mode, each switch conducts for 180 degrees of the input voltage cycle. This means that for half of the cycle, the switches in one phase are conducting, while the switches in the other two phases are not conducting. Then, in the next half of the cycle, the conducting switches switch off, and the non-conducting switches switch on. This creates a balanced output waveform with three phases.

The output waveform of the 3-phase bridge inverter with 180-degree conduction mode consists of six steps, with each phase outputting a square wave. The output voltage magnitude is determined by the DC input voltage, while the frequency is determined by the switching frequency of the power electronic switches.

The advantage of the 180-degree conduction mode is that it reduces the switching losses in the power electronic switches compared to other conduction modes, such as the 120-degree conduction mode. However, it may result in higher harmonic content in the output voltage waveform, which can cause issues with the load or other connected devices.