DER impact evaluation

DER impact analysis

General

With the objective of speeding up the interconnection process, Eaton's CYME DER Impact Evaluation module automatically performs a comprehensive system impact study that integrates several criteria-based checks and multiple scenarios in order to flag abnormal conditions.

The module improves productivity by reducing the amount of manual work required at each step of the analysis. Relying on a simplified or detailed model of the installation, the module allows the creation of various study cases by combining system loading conditions (e.g. peak and minimum load) with minimum and maximum DER contributions (e.g. 0 and 100%), all defined as simulation parameters. Controlled load flow analyses are then executed on each scenario to assess the impact on the system in terms of steady state voltage, transient voltage variations (flicker), thermal overloads and reverse power flow.

A comprehensive set of colour-coded summaries and detailed reports allows for quick identification of the issues and level of severity.

Scenarios

Scenarios are created as the combination of diverse system loading conditions with minimum and maximum DER contributions.

• Definition of loading conditions using load scaling factors and/or load models
• Inclusion of one or many DER installations in the analysis scope
• Automatic detection or manual selection of point of common coupling (PCC)
• Adjustment of DER minimum and maximum contribution as a percentage of generator rated power, inverter rating or active generation

Verifications

Verification checks stemming from a set of criteria with adjustable thresholds are performed on each scenario.

• Steady-state voltage based on user-defined over and under-voltage limits, applicable globally or by voltage range (LV, MV, HV)
• Voltage variations caused by sudden generation fluctuations (max to min, min to max) based on user-defined limits set by voltage level and at the PCC
• Thermal loading of monitored devices based on user-defined limits set by device type
• Reverse power flow through monitored devices (e.g. voltage regulator, on-load tap changers, etc.)
• Generation ramping from minimum to maximum contribution by user-defined increment
• Power factor ramping from minimum to maximum value by user-defined increment

Results

Analysis results are returned via a series of reports clearly highlighting violations using a simple and intuitive colour-coding.

• A summary report provides an overview of the most severe interconnection impacts for each scenario
• A steady-state report details the system minimum and maximum steady state voltages, including voltage regulator tap position and switchable capacitor bank status
• A voltage variation report presents results for both a rapid increase and decrease in generation