Basler BE1-CDS220, Instruction Manual

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BE1-CDS220 Protection and Control 4-1
SECTION 4
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PROTECTION AND CONTROL
GENERAL
BE1-CDS220 relays provide many functions that can be used for protection and control of power system
equipment in and around the protected zone. Four settings groups are provided for adapting the
coordination under various operating conditions with options for controlling which settings are active by
automatic or programmable logic criteria. Protection and control functions include phase and neutral
differential protection, overcurrent protection, breaker failure protection, general-purpose logic timers and
virtual control switches.
To use a function, three things must occur:
1. The function block must be enabled in the active logic scheme by SL-<function> command or
enabled through BESTCOMS. To enable or disable a function that is part of a preprogrammed
logic scheme, the user must first create a custom name for the new scheme.
2. The inputs and outputs of that function must be connected properly in a logic scheme.
3. Operational characteristics or settings for the function must be programmed by the user and
based on the specific application requirements.
Items 1 and 2 may be skipped if a preprogrammed logic scheme is used for a typical application. Most of
the schemes are general in nature and unneeded capabilities may be disabled by programming the
operational characteristics setting to zero.
Example: The second negative-sequence instantaneous overcurrent function is enabled in the logic
scheme but is not needed for this application. Set the 150TQ function pickup setting to zero
(S#-150TQ=0) or set 150TQ to zero using the Overcurrent Screen in BESTCOMS.
More information on each individual function for item 1 is provided in this section. More information on
Items 2 and 3 is provided in Section 7, BESTlogic Programmable Logic and Section 8, Application.
SETTING GROUPS
BE1-CDS220 relays provide a normal setting group, SG0, and up to three auxiliary setting groups SG1,
SG2, and SG3 (See Figure 4-1). Auxiliary setting groups allow adapting the coordination settings to
optimize them for a predictable situation. Sensitivity and time coordination settings can be adjusted to
optimize sensitivity or clearing time based upon source conditions or to improve security during overload
conditions. The possibilities for improving protection by eliminating compromises in coordination settings
with adaptive setting groups are endless.
0 - Disable
1 - Discrete Input
2 - Binary Input
D2840-21
02/20/02
Figure 4-1. Setting Group Control Logic Block
The group of settings that are active at any point in time is controlled by the setting group control function.
This function allows for manual (logic) or automatic control. When manual control is enabled by the AUTO
logic input not being asserted, the function monitors logic inputs D0, D1, D2, and D3 and changes the
active setting group according to the status of these inputs. These inputs can be connected to logic
expressions such as contact sensing inputs. When automatic control is enabled by the AUTO logic input
being asserted, the relay monitors loading or unbalance conditions and changes the active setting group
according to the switch to and return criteria set. The change criteria for manual and automatic control are
described in more detail later in this section.