Managing Distributed Energy Resources

Distributed Energy Resources

Minsait ACS offers a robust suite of applications to manage and optimize Distributed Energy Resources (DERs) on the distribution network, and can be deployed with our PRISM ADMS platform, and as an integrated solution with our Centrix Feeder Automation platform.


Managing Distributed Energy Resources

Minsait ACS’s Distributed Energy Resource Management System (DERMS) is a suite of distributed applications built to maximize DER capability and effectiveness, including increased hosting capacity, while mitigating adverse effect on the grid

Minsait ACS provides flexible software solutions that utilize Volt-Var Optimization (VVO), Load Forecasting, and System Reconfiguration that can be integrated with existing systems, cost effective to deploy, and that can scale and expand with the utilities’ needs.

With an ever-growing presence of DERs in the power distribution system, utilities need new solutions to optimize the value of these assets as well as limit the adverse effects on the network. Such challenges include voltage violations and reverse power flow as inverter-based distributed generation increases and load/generation becomes more intermittent.

Minsait ACS deploys a multi-staged solution that combines monitoring and controlling DER assets with system optimization to effectively meet the challenges presented by growing DER penetration and related congestion.

The PRISM DER Integration Solutions Suite provides a utility tools for:

System Voltage Optimization

Real-time VVO
Utilization of smart inverters for fine tuning VVO

Forecasting & System Reconfiguration

Utilize forecasting (weather & loading) to identify potential system issue prior to happening
Provide switching plans to reconfigure system due to DER congestion

Real-Time System Reconfiguration & DER Curtailment

In real-time, dynamically reconfigure system if unexpected injection violations occur
Controlled limited DER curtailment based on injections at Point of Common Coupling (PPC)

  • System Voltage Optimization

    Control scheme is based on three-pass iterative approach:

    Minimize Var losses by controlling distribution capacitor

    Flatten voltage profile after impact of capacitor switching by controlling transformer Load Tap Changers (LTCs) and Voltage Regulators (VRs)

    Fine control of voltage based on ability of smart inverter (if available) to affect voltage at the point of common coupling/injection points

  • Forecasting & System Reconfiguration

    Utilize Forecasting Data

    Look at sliding 24-hour window of forecasting data

    Utilize forecast data to continuously run load flow analysis to identify injection violations

    If it is determined VVO is unable to accommodate injection, DER attempts to identify possible feeder reconfigurations

  • Real-Time System Reconfiguration & DER Curtailment

    If injection limits are violated in real-time, DER will look to reconfigure system in a synchronized fashion

    Voltages across normally open switches will be monitored and adjusted if needed prior to closing switch to an adjacent feeder

    If it is determined violation thresholds cannot be resolved from system reconfiguration, DER will calculate maximum injections allowed at each common coupling point and curtail as necessary

Distributed Architecture

Minsait ACS’ solutions enable a build-as-you-grow approach to begin support gradually while achieving immediate gains in feeder reliability and resiliency—starting while penetration levels may be minimal and have not yet presented operational issues for the network.  The architecture provides utilities with the option of deploying modules with increasing functionality and complexity as their needs dictate, beginning with the introduction of Volt-Var Optimization (VVO).

The available DER application modules include:

  • Real-time VVO, for Volt-Var control extended to include optimization and control capability from inverter-based generation.
  • Energy Storage optimization for charge/discharge
  • Synchronized Load Transfer (SLT) for feeder reconfiguration through remote switching
  • Maximum feeder Injection Capability (MIC) to optimize the injection amount and location

The individual modules are highlighted in the following sections.

Fully Autonomous Operation

The DER applications run in fully automatous mode. During anticipated or real-time violations that DER applications cannot resolve, the system performs a synchronized feeder reconfiguration.  If feeder reconfiguration cannot solve the violations, will curtail the unit injection to the maximum output allowed at the point of common coupling.

During switching where each side of a switch is fed by different buses, voltage is monitored across the open switch and will utilize the VVO function to adjust the voltage within allowable limits prior to operation.  the allowable range needed to safely perform a close may be exceeded.

Volt-Var Optimization (VVO) for distributed energy resources runs in real-time in automatic mode on the platform. The base VVO function manages typical feeder violations by issuing controls in real-time to optimize the voltage profile and to reduce losses (improve the power factor) for each feeder under its control. The user can establish the control objective for each feeder, such as voltage minimization, var loss minimization, or both.  The primary real-time operational objective of VVO is to avoid feeder violations which may threaten the reliability of the feeder’s continued operation.

VVO adds support for control of PV inverters, as well as distributed generation and battery storage.  VVO serves to alleviate voltage issues at the point of common coupling and in reverse flow direction that result from increased DER penetration on the system.  The secondary objective of VVO is to avoid curtailment as much as possible so that the renewable inverter can inject the maximum possible generation.

Energy Storage Optimization

The Energy Storage Optimization function can control the output of Battery Energy Storage Systems (BESS) to inject the proper amount of real and reactive power and to operate in charge and discharge modes as appropriate. For example, where utilities require the power flow to maintain a direction consistent with the relay protection settings, the current flow direction can be enforced with the effective use of the storage system.

Synchronized Load Transfer

The Synchronized Load Transfer (SLT) application runs in conjunction with VVO in real-time.  If the projected or forecast injection is greater than can be effectively managed through VVO control, the system will explore the effect of network switching.

SLT is called by VVO when feeder DER injection is excessive, resulting in voltage violations and reverse power flow.  If VVO cannot resolve the violations in real-time, then SLT will perform feeder switching to transfer load or DER generation to/from another feeder (or a combination of both).  If no possible switching scenarios exist to resolve the violations, then VVO will resort to curtailment of the renewable generation.

Maximum Injection Capability

Voltage and line limit violations due to load and/or generation variations may fall outside of the range of control that IVVC is able to resolve. In these situations, it is necessary to calculate the Maximum Injection Capability (MIC) at each injection point of common coupling on the feeder in terms of watts and vars injection. Curtailment of inverter-based generation is the last resort to protect the feeder by maintaining operation within limits. MIC will supply the VVO with the maximum allowable injection for each controllable DER on the feeder.

What can the PRISM DER Integration Solutions Suite do for you?

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