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Electric Utilities

LOAD MANAGEMENT
This Master Station software is designed to send load reduction commands to TDMS RTUs (for tap changer control) or to a VHF radio system communicating with QEI's low cost load control switches (for temporary shut off of water heaters, air conditioners etc.). Scheduling of load reduction strategy sets, thresholds, operational modes and time periods may be done on a day-of-week basis for each load area, with provisions for holidays. This software package also includes a Power Factor Control program to maintain power factor at each load area within specified limits (by switching capacitor banks into or out of service). The program optimizes the selection of capacitor banks by working to correct the power factor at individual feeders, starting with the feeder that has the worst power factor.

 
SHORT TERM LOAD FORECASTING
Once the system has an established historical database of load versus weather conditions, this package allows the operator to enter forecasted weather conditions (hourly for the next 24 hours or daily for the next month), and receive a load forecast based on a set of the closest historical matches. Weighing factors take into account day types, holidays and annual load growth.


SEQUENCE OF EVENTS
The master station software provides a configurable historical database for Sequence of Events (SOE) data. Each RTU allows the assignment of a large number of inputs for SOE time stamping. Time stamping accuracy is available from 1 to 4 milliseconds. At the master station, about one month's Sequence of Events (SOE) data can be stored. Then, using the standard historical database access tools, reports of sufficient detail can be generated for evaluation long after the operator has responded to and resolved the incident.

 
OPERATIONS AND OUTAGES ACCOUNTING
For each device assigned to Operations and Outage Accounting, the system records the accumulated outage time, associated phase currents just before outages, and the operations count. An alarm can be initiated when the operations count reaches a specific limit to indicate a requirement for maintenance.

 
SYSTEM CONFIGURATION STATUS
This software package automatically displays the power network's connectivity. Making use of the status data reported by the SCADA system (gathered from RTUs or as manually entered by the operator), the software identifies sections of the power network that are 1) without power and 2) looped or paralleled. There is no need to define the network segments into multiple Boolean equations, to define live/dead status, loops or parallels. The software automatically performs this function using only network topology information. It is only necessary to define how the network connects and branches and where switches and breakers are located. With simulation mode, the user is provided with the added capability of performing "what-if" scenarios by simulating changes to network conditions and having the results displayed.

 
AUTOMATIC GENERATION CONTROL (AGC)
This software package provides the capability to regulate the power output of multiple generators to maintain a specified system frequency and/or a scheduled power interchange. The Area Control Error (ACE) is calculated based on the operator-selected mode of constant net interchange, constant frequency or tie-line bias. A nonlinear filter is applied to the ACE to minimize unnecessary control action. The package's capabilities include defining power interchange transactions and taking these into account when computing the ACE. Reserve generation capabilities are calculated and alarmed if low. Economic Dispatch calculations allocate generation capacity to supply a given load in order to minimize the cost of power production.

 
REMOTE TERMINAL UNITS, IED'S, & PROTOCOLS
QEI offers a full line of RTU's - free-standing models to pole-top - with complete systems interoperability. Available in virtually any configuration, utilizing a variety of industry standard protocols, they afford an infinite number of status, analog, and control points to the end-user. The ConfigWiz software package provides a 'drag & drop' Windows interface enabling complete configuration of the RTU - communication ports, Clients, Servers, and mapping of the data points to the Master Station. It provides the ultimate solution to harvesting data from the diversity of protocols used in IED's.

 
COMMAND SEQUENCES SPECIFIC TO ELECTRICAL APPLICATIONS
Command Sequencing allows the creation of scripts to automate anything the operator can do manually. Features of Command Sequencing provide many useful capabilities for electrical utilities. A small sampling follows: · Changing analog alarm limits based on outside temperature or the month of the year. · Simple Load Management: load reduction scenarios can also be edited with command sequences. · Table lookup capability allows nonlinear control parameters to be loaded into the system for use in automatic control loops. One possible use is optimizing generator efficiency based on headwater and tailwater levels. · Using the data supplied with the RIMS interface, or time of day, reasonably accurate calculations of a distribution utility's power bill can be calculated.