Basler Electric DGC-2020HD - Manual (Page 309)

9469300990 Rev B 299
DGC-2020HD Maintenance and Troubleshooting
Control
This screen is useful for debugging load share related issues, and kW and var control related issues. It
gives visibility into the states of the kW, kvar, Speed Trim, and Voltage controllers in the DGC-2020HD.
The Control diagnostics screen is located on the front panel at Metering > Diagnostics > Control.
The following parameters are visible on the Control diagnostics screen:

kW Ramp Status: This indicates the current kW ramp direction as None, Up, or Down.

kW Ramp Demand: This is the normalized kW demand that is ramped from the initial kW loading
upon generator breaker closure to the desired kW set point. The rate at which the ramp occurs is
set by the Ramp Rate (%) in the Governor Bias Control settings. Note the rate is in terms of
percentage of machine capacity, it is not the time to ramp from zero up to the current desired kW
level. Thus, at low loading it may appear that the ramp is skipped. If the system is loaded to only
10% and a unit is brought on line with a ramp rate of 10% per second, it takes only one second to
reach 10% of capacity.

kW Demand: This is the normalized requested kW demand on the generator. It is normalized
such that 1.0 indicates the full kW capacity of the generator, 0.5 indicates 50% of the generator’s
capacity, etc. When the generator breaker is closed, and the kW controller is enabled, the Watt
Demand indicates what level of power should be generated. In an island load share system, this
will correspond to the normalized value read on the load share lines. If the load share lines are at
the 50% point of the load share voltage range, the Watt Demand will be 0.5. If the generator
breaker is closed, and the Parallel To Mains logic element is true, the Watt Demand will be equal
to the base load set point. When the generator breaker is open or the kW controller is disabled,
the Watt Demand will always be equal to the value calculated from the voltage that the DGC-
2020HD sees on its load share line.

Speed PID: This is the output value of the Speed PID controller. It will normally range between
-1.0 and 1.0, and will be zero any time the generator breaker is open, unless synchronization is in
progress. If the Speed Trim is enabled, the Speed PID will be nonzero when the generator
breaker is closed if there is any difference between the machine speed and the Speed Trip Set
Point parameter.

kW PID: This is the output value of the kW PID controller. It will normally range between –1.0 and
1.0, and will be zero any time the generator breaker is open. If the kW Controller is enabled, the
kW PID will be nonzero when the generator breaker is closed if there is any difference between
the normalized kW generation and the Watt Demand value of the machine. If the kW controller is
disabled, the kW PID will always be zero.

Speed Error: This is the normalized difference between the measured generator frequency and
the Speed Trip Set Point. A value of 1.0 means the difference is equal to the speed trip set point;
a value of
–1.0 means the difference is equal to the negative of the speed trim set point. When
the generator breaker is open, or if Speed Trim is disabled, this will always be 0.000 unless
synchronization is in progress. When speed trip is enabled, and the generator breaker is closed,
this will typically be 0.000 or some relatively small number and move a small amount above and
below 0.000 as the speed trim controller corrects for any speed errors.

kW Error: This is the normalized difference between the measured generator kW generation and
the Watt Demand described above. A value of 1.0 means the difference is equal to the Rated kW
of the machine; a value of
–1.0 means the difference is equal to the negative of the Rated kW of
the machine. When the generator breaker is open, or if kW control is disabled, this will always be
0.000. When kW control is enabled, and the generator breaker is closed, this will typically be
0.000 or some relatively small number and move a small amount above and below 0.000 as the
kW controller corrects for kW errors. If a load is added or dropped from the system, the error will
be a non-zero value until the kW controller brings the kW generation to the desired level.

Speed Bias: This is the normalized value to which the governor analog bias output of the DGC-
2020HD will be driven to accomplish desired kW and speed trim control. It is equal to the sum of
the kW PID and the Speed PID. If the value is
–1.0, the speed bias output will be driven to the
minimum value of the governor bias output range. If the value is 1.0, the output will be driven to