Historical Data Archiving
ACS takes an Enterprise approach to the input, capture, and dissemination of data in PRISM through our Historical Data Archive (HDA) system. The HDA solution allows for single point of entry & maintenance for the system with respect to archiving, collection, report building, analyzing, and publishing reports The HDA is an operational enterprise solution, in that any point defined in the PRISM system is available within the HDA for archiving, reporting, and backup.
The real-time database can be configured to accommodate different operational objectives. The HDA complements/leverages the PRISM database settings to achieve optimum results. The following feature list is not exhaustive, but demonstrates the flexibility and the breath of options available to the HDA:
- each device point can be set for capture for various intervals
- each device point can be set to capture various attributes
- each device point can capture quality data flags
- each device point can be set to filter based on exceptions
- each device point can be set to filter on reporting bands
Online storage is unlimited and depended on the online storage needs that a utility wishes to have available. The HAD subsystem is then configured and delivered with the processes that automatically archive data offline in a compressed form for efficient storage. The offline storage is limited only by the type and sizing of the media selected. ACS provides all the processes and means to recover offline storage into the online HDA instance in a seamless manner. These processes do not interrupt real time operations.
The HDA is generally deployed in a redundant configuration that allows seamless fail-over capabilities thus minimizing data and access losses. The ability of the HDA to be configured for a seamless fail-over from an archiving standpoint provides for a very robust system. In the event of total loss of the system, the HDA can be readily restored to the last available saved backup. ACS uses various schemes to match the needs to the utility, ranging from cold backups, export/import, and hot backups.
Utility Data Model
ACS built HDA around the unique needs and requirements of utility professionals. The HDA system is unique in that it provides a utility-based data model, or “UDM”.
The Utility Data Model allows each company to customize the data interface to meet the naming convention used across the company. It incorporates the following features:
- Hierarchy – PRISM HDA supports four levels of data hierarchy to allow the users quick access to information that is important to them and their positions. The hierarchies function as follows:
- Organization – Identifies the owner of the data and the highest level of segregation. This level is critical as utilities become more interconnected and receive information from outside sources.
- Region – This level allows the separation of data into operational areas for use by organization within the utility.
- Station – This level defines the physical location of the information and is used to classify the information into substation, or feeder device.
- Point – The attributes associated with each data collection item.
- Readings – The actual data collected. The information includes the readings, date/time, and quality flags.
- Device Groups – The data model supports grouping devices (meters, switches, circuits, etc. into groups that are then related to Organizations. This structural element allows the company to establish collections of data that may be important to key industrial customers, or for special system monitoring or analysis.
- Point Attributes – Each reading in the HDA database is stored with a set of attributes that provides the end-user easy access to specific information from the large data set of historical data. The Data Attributes include:
- Device Name – Utility Specific name for the device (e.g. circuit name, bus name, switch name, etc.) The combination of the station name with the Device Name is unique across the system.
- Device Type – Utility Specific grouping of devices (e.g. Circuit, Bank, Bus, Switch, Transformer, Meteorological, etc.) The attribute allows the company to group a set of readings for easy analysis and reporting.
- Reading Phase –The Phase related to the point (e.g. A, B, C, N, LL, LN, Null, etc.). This attribute allows the company to perform phase loading reports and separate readings by phase.
- Reading Unit of Measurement – The specific units measured at the point (e.g. Amps, Volts, Temperature F, Megawatts, etc.).
Each interval reading includes the following information:
- Reading – The reading level stores the actual information and includes the value and data/time of the reading.
- Quality Flags – Every reading is stored with the complete set of data quality flags from SCADA. These flags include Scan Inhibit, Manual Override, No Data, Channel Out, and FEP Offline.
The combination of the Data Model Hierarchy, Device Groups, Point Attributes, and Reading Attributes provide the end user with the flexibility and power required to turn historical data into useful and problem solving information within the utility enterprise. End users can easily ask the following types of questions directly about historic data:
- Extract the Amp Readings for the individual Circuits in the Downtown Station.
- List all of the kW readings in the system sorted by Station and Bank.
- Identify all of the Amp Circuit Readings in the Southern Region that exceeds 285 Amps.
- Show all historic data values for the XYZ Industrial plant Group.