8BCONTROL FUNCTIONS
PROTECTION, CONTROL AND METERING FUNCTIONS
substation, which does not account for pole-mounted devices that might momentarily
interrupt a customer. MAIFI is rarely used in reporting distribution indices because of the
difficulty in knowing when a momentary interruption has occurred. MAIFI is calculated by
summing the number of device operations (opening and reclosing is counted as one
event), multiplying the operations by the number of customers affected (Mi), and dividing
by the total number of customers served (NTC). MAIFI is,
NTC
M
MAIFI
i
=
2.7.6. AVERAGE SERVICE AVAILABILITY INDEX
The Average Service Availability Index (ASAI) is the ratio of the total number of
customer hours that service was available during a given time period to the total
customer hours demanded. This is sometimes called the service reliability index. The
ASAI is usually calculated on either a monthly basis (730 hours) or a yearly basis (8,760
hours), but can be calculated for any time period. The ASAI is found as,
(
)
( )( )
(
)
NTC
T
C
NTC
ASAI
i
i
8760
8760
∑
−
=
2.8. CONTROL FUNCTIONS
2.8.1. NETWORK RECONFIGURATION IN DISTRIBUTION
SYSTEMS
2.8.1.1. INTRODUCTION
Automatic reconfiguration schemes of distribution networks can be made by means
of smART P500 relays. Among which are the following: "with communication",
"without communication", "without communication optimized" and "without
communication: voltage-time coordination". Their purpose is the same one: to clear a
fault in a electrical distribution system and reconfigure the system so that the number
Summary of Contents for smART P500
Page 1: ...Instruction Manual Multifunction Protection Relay smART P500...
Page 23: ...2BTABLES INDEX THIS PAGE HAS BEEN LEFT BLANK INTENTIONALLY...
Page 39: ...5BHARDWARE FEATURES INTRODUCTION Figure 1 9 Wye Wye Connection measured neutral...
Page 40: ...5BHARDWARE FEATURES INTRODUCTION Figure 1 10 Wye Wye Connection sensitive neutral...
Page 41: ...5BHARDWARE FEATURES INTRODUCTION Figure 1 11 Open Delta Connection measured neutral...
Page 42: ...5BHARDWARE FEATURES INTRODUCTION Figure 1 12 Open Delta Connection sensitive neutral...
Page 511: ...2BANSI CURVES 0BCURVES FOR TIME CHARACTERISTICS Figure I 6 Moderately ANSI curve...
Page 513: ...2BANSI CURVES 0BCURVES FOR TIME CHARACTERISTICS Figure I 7 Very inverse ANSI curve...
Page 515: ...2BANSI CURVES 0BCURVES FOR TIME CHARACTERISTICS Figure I 8 Extremely inverse ANSI curve...
Page 532: ...4BRECLOSER CURVES 0BCURVES FOR TIME CHARACTERISTICS Figure I 14 Recloser Curves 101 119...
Page 535: ...4BRECLOSER CURVES 0BCURVES FOR TIME CHARACTERISTICS Figure I 15 Recloser Curves 120 142...
Page 538: ...4BRECLOSER CURVES 0BCURVES FOR TIME CHARACTERISTICS Figure I 16 Recloser Curves 151 202...