On 22/09/2013 16:38, jim wrote:

Please, can someone kindly elucidate how a domestic 240V house system
maintains a stable voltage when connected to an FIT inverter fed from
a pv panel?

One moment it's feeding amps into the local supply, the next it may
be extracting them. To get a reversible current flow, there must be
a pd (potential difference) between the 2 situations. How does it do
this trick? (and avoid flickering lights etc).

The potential difference required actually comes from a phase shift in
the locally generated component. Depending on whether its leading or
lagging the waveform supplied via the grid as to whether its drawing or
feeding current. The RMS voltages of both grid and the output of the
local inverter could actually be the same. The local grid tie inverter
will adjust its generated phase relative to the grid voltage to achieve
the required direction of energy transfer.

Are mirrors involved?

Not usually, and hopefully no smoke either ;-)


--
Cheers,

John.

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