Can a sine wave inverter be used without an H bridge 50

The power frequency transformer turns the voltage of the battery into a modulation waveform of 20kHz similar to the battery voltage through the H bridge, and then connects to the power frequency transformer to boost the voltage, and will feedback the voltage from the transformer secondary to form a closed-loop voltage stabilization, and the transformer is secondary to LC filtering to get the sine wave output.

The principle without power frequency transformer is to turn the battery voltage into alternating current of about 30kHz, and step up to more than 310V through a high-frequency transformer (high-frequency transformer is very small in size and light in weight), and then pass through the H-bridge, and the H-bridge is connected to the LC filter to obtain the D220V sinusoidal AC output, and the H-bridge output is directly sampled and fed back to stabilize the voltage. The sine wave is obtained by SPWM modulation and filtering out the modulated wave.

In the case of the frequency transformer, the H-bridge outputs a modulated waveform, the waveform is a square wave of about 20kHz, you connect a 2UF CBB capacitor and a 2MH inductor in series, and then connect it to the H-bridge, and the sine wave output will be obtained on the two pins of the capacitor, because it constitutes an LC low-pass filter, which filters out the modulated wave and obtains a sine wave similar to the battery voltage.

If the transformer is too small, the output power will not be large.

If the output current of the H-bridge is a certain situation, the larger the transformer, the more wasteful, generally just right, or leave some rich. I've done both power frequency sine and high frequency sine inverters.

As shown in the figure on the right, the working principle of the single-phase bridge inverter circuit is that the switch T1 and T4 are closed, and the T2 and T3 are disconnected: U0=UD; Switches T1 and T4 are disconnected, T2 and T3 are closed: U0 = UD; When switching T1, T4 and T2 and T3 alternately with frequency FS, then the alternating voltage waveform (positive and negative alternating square wave) is obtained on the load resistance r, and its period ts=1 fs, so that the DC voltage E becomes the AC voltage containing each harmonic, and if you want to get the sine wave voltage, it can be obtained by filter filtering.

The main circuit switch T1 T4 is actually an ideal model for various semiconductor switching devices. Switching devices commonly used in inverter circuits include fast thyristors, turn-off thyristors (GTO), power transistors (GTR), power field-effect transistors (MOSFETs), and insulated gate transistors (IGBTs).

In practice, there are losses in switching devices: conduction losses and commutation losses and gate losses. The gate losses are negligible, while the conduction losses and commutation losses increase with the switching frequency.

Last night, two transistors were used to form an oscillator, plus the previous bridge, and they were put together to complete the DC to AC