Distribution Management System
Utilities leverage Survalent’s Demand Response capabilities through three optional applications: Dynamic Voltage Regulation (DVR), Load Curtailment, and Rotational Load Shedding (RLS). Each function is integrated on the SCADA host, and accessible through the SmartVU interface.
Distribution State Estimation
The Distribution State Estimation (DSE) function extends the functionality of Distribution Power Flow (DPF). The DSE function:
- Makes use of SCADA measurements outside the substations
- Perform consistency checks and elimination of time skews on all measurements
- Adds modelling of micro-grids (with use of telemetered data) and distributed generation (e.g. rooftop solar panels) and incorporates these into the DSE calculation, with reverse power flow capability.
Dynamic Voltage Regulation (DVR)
Dynamic Voltage Regulation (DVR) provides capabilities for reducing peak demand and management of optimal feeder voltage limits. It is designed to operate automatically and adjust the voltage regulator set points and/or transformer tap positions to maintain a voltage profile that is within the objective limits without the need for complex programming by the utilities. The advance control algorithm is optimized based on the objective functions, such as minimum control (conservation), or minimum voltage (peak reduction).
Fault Location Isolation and Service Restoration (FLISR)
The SurvalentONE Fault Location Isolation and Service Restoration (FLISR) application helps minimize the downtime caused by outages that trip and lock out devices in a distribution network. FLISR works in conjunction with SCADA, telecommunications, and distribution automation devices to decrease the number of customers affected by a power outage by automatically opening and closing switches to isolate compromised sections of line and to re-energize healthy sections of the system to restore energy distribution. Survalent’s centralized FLISR system consists of a variety of remote telemetered devices, a communication network linking the devices to the control room, and a software application for monitoring and controlling the devices. This type of system can yield outsized benefits for an electric utility.
The Load Curtailment application provides the ability to reduce load in response to event triggers. The application monitors network conditions to determine the control actions to perform. Network conditions can be monitored by command sequences, calculated points, external entities via ICCP, or any other mechanism that can trigger a load shed event. The Load Curtailment application reacts to each control set’s inputs by issuing controls to the appropriate breakers and switches or by issuing load shed commands to load control receivers via load management controllers.
Short-Term Load Forecasting
Load forecasting is an important tool for planning, triggering load management strategies, and for determining unit commitment schedules. Short-term load forecasts are generally more reliable than long-term forecasts due to the variability of weather forecasts. The SurvalentONE Load Forecast application can produce 3 types of forecasts:
- 24-hour forecast based on the full historical load and weather data,
- 7-day (168-hour) forecast based on the full historical load and weather data, and
- 24-hour forecast based on recent load data only (the application will also produce interpolated predictions for 15, 30, 45 and 60 minutes into the upcoming hour)
For utilities that subscribe to weather forecast data, the applications can import both forecast and historical data from text files.
Power Factor Control
The Power Factor Control application reduces power system losses and power factor penalties by monitoring and correcting the power factor at specified locations within the distribution network and issuing controls to the appropriate substation-level and feeder-level capacitor bank controllers.
Distribution Power Flow
The SurvalentONE ADMS supports a Distribution Power Flow (DPF) application that provides a power flow solution for the power system that best fits the power system model and the SCADA feeder measurements in the substations. The DPF application computes and presents phase voltages, currents, and losses on the entire distribution network. The enhanced visibility that DPF provides offers benefits such as improved detection of system problems including overloads and voltage violations, and accurate assessment of line losses.
Protection Settings Manager
The Protection Settings Manager (PSM) application allows the SurvalentONE system to maintain active protection settings in protection relays. By analyzing the current system configuration, and applying user-defined rules, PSM issues controls to the relays to switch to the appropriate protection settings groups (digital and analog output controls are supported). The PSM will verify the need for changes in protection settings in response to any network event, including a load transfer initiated by the operator. As a result, protection settings are always up-to-date across the network according to the as-operated network state.
PSM can function as a standalone application, or as an add-on to the Fault Location, Isolation and Service Restoration (FLISR) and Loss of Voltage (LOV) applications.
- PSM employs a rules-based approach to determine which protection settings to us
- The ‘delay to verify’ setting enables system to ensure the network is in a steady state prior to command execution;
- PSM rules can consist of a combination of parameters relating to line sections, analog or status points;
- PSM can be ‘paused’ when the protection relay is tagged, or if the station is in maintenance mode.
Rotational Load Shedding (RLS)
Rotational Load Shedding (RLS) is used by electric utilities as an emergency measure when electricity demand will exceed electricity supply for an extended period of time. To avoid a full system blackout, different portions of the distribution grid are de-energized and then re-energized on a schedule basis such that the total demand stays within the available supply.
VVO/VAR is an advanced application designed to improve energy efficiency in the distribution system by reducing both energy losses and peak demand. It coordinates control of reactive power and voltage, to optimize user objectives subject to defined constraints. VVO performs optimization and issues controls at both the substation and feeder level.
VVO determines the optimum control actions to achieve operator-specified operating objectives for:
- Loss Minimization: reduce losses at transformers at substations, and at lines along the feeders.
- Energy Conservation: reduce load by minimizing voltage throughout the network within constraints.
- Voltage Reduction
Survalent VVO provides optimized control at the system level, surpassing control through local controllers. As a network-based solution, it addresses more system conditions than a rule-based algorithm.
The Voltage Reduction application provides the ability to reduce, maintain, or restore system voltage in response to event triggers. The application monitors a set of database points to determine the control actions to perform. These database points can be set by command sequences, calculated points, external entities via ICCP, or any other mechanism that can trigger a voltage reduction event.