grid-inverter phase angle synchronize.

Hi, we are working on a device that synchronize a pure sinewave inverter to the grid. Is there anyone who know the circuit of such device?

Is the sinewave inverter one you built yourself? Or one you bought?

If you built it yourself, a zero-cross circuit with the grid as its input can be used as a sync signal for the inverter.

jerome21 said:

Hi, we are working on a device that synchronize a pure sinewave inverter to the grid. Is there anyone who know the circuit of such device?

Click to expand...

Hello,

You have to have control over the frequency of the inverter, then you can use a phase locked loop.

In order to have a unity power factor, you have to sync current with grid voltage. You must define your control system specs' Phase error, lock time before going online. All the PLL parameters, lock time, jitter, THD with a step load, steady state, harmonic grid noise rejection ( because phase detectors are harmonic, a current sense feedback filter must reject the harmonic inputs fundamentals without any phase shift. Huawei (2000 model) make the best GTI's so copy their Eng specs. if you can get the detailed ones.

As overvoltage will appear as a short from the grid, the current loop for amplitude and phase must be very stable and have remote control parameters. Your transformerless connection to the grid has an impedance which will define your step load regulation error.