[RE-wrenches] XW / Wind problem to be fixed by firmware update

[Mark Edmunds]

Hi Wrenches -

 

Just to clarify on this a bit... When we designed the XW we were always
assuming there would be some sort of voltage regulation on the input to
the batteries, either with a PV MPPT controller or a diversion regulator
for wind and uHydro systems. So hence while the unit does try to
regulate the battery voltage while selling power to the grid it does
take some time when in sell mode to make sure everything is stable and
compliant  with the UL1741 limits before actually starting to transfer
power.

 

With a typical set up this is just fine, but obviously with a wind
system like this the delay allows the voltage to rise to the point the
inverter thinks it has a lot of power to sell, and with smaller battery
bank sizes quickly pulls the voltage back down to the point it stops
selling. 

 

As mentioned below we think we can speed this start of selling to the
grid when battery voltage rises past the Grid Support Voltage setting,
which should help smooth out this sort of situation. Initially we will
test this in the lab and at  a few sites to ensure we get good
performance, then will roll the change into new units. This all may take
longer than a few weeks, but we will do our best!

 

Yours for a windy future...

 

Mark

 

Mark Edmunds
Director Engineering 
Residential Renewable Energy Markets 
Xantrex Technology Inc. 

p. 604.422.2609 
f.  604.420.1591 
E-mail: mark.edmunds at xantrex.com 
Website: www.xantrex.com <http://www.xantrex.com>  



 

 

 

From: re-wrenches-bounces at lists.re-wrenches.org
[mailto:re-wrenches-bounces at lists.re-wrenches.org] On Behalf Of Michael
Welch
Sent: Friday, January 16, 2009 1:46 PM
To: re-wrenches at lists.re-wrenches.org
Subject: [RE-wrenches] XW / Wind problem to be fixed by firmware update

 

Hi gang. Please contact me OFF LIST if you have any questions.

Dan Lennox asked me to post this to the list:




I have been working with Xantrex customer support for the last couple of
months, concerning an issue when a XW-6048 inverter is connected to a
wind turbine and allows alarmingly high battery voltage.

The inverter Grid Support Volts is set to 55v, and should sell at or
around this voltage. However I have seen issues where the inverter is
not selling and allows the battery voltage to get alarmingly high
(>60v). It would have gone higher (and I have seen 63v) except that my
diversion controller kicks in and diverts power, stopping the voltage
increase.

This situation occurs typically under low wind conditions and it seemed
to take about 15 seconds for the inverter to wake up and load the wind
turbine.  When the inverter did 'kick in' it put a 60amp load onto the
turbine, which caused it to slow down,  quickly lowering the battery
voltage and the inverter stops selling - causing the whole cycle to
happen over again!

I just heard from an Xantrex customer support engineer that the XW
inverter software has a built in 20 second delay (de-bouncing time they
called it) once the Grid Support Voltage is reached, regardless of how
high the voltage may get.

Xantrex has agreed to work on a firmware upgrade that will allow SELL to
occur when BATTV=GSV+4V and this should be available in a few weeks.

Dan Lenox

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