7 Cluster Studies – Intended to study multiple requests simultaneously and allocate costs of network upgrades that are beneficial to the group. – All interconnection requests in each queue that are received in a 180 day open season period are studied together. – Allows for all interconnection requests in the queue to commence study process within six months and greatly lessens the queue backlog burden Interconnection Study Measures
8 Cluster Studies (continued) – A set of upgrades that is necessary for the interconnection of the entire cluster of interconnection requests is determined. – The upgrade set’s costs are shared by the entire cluster of interconnection request based on a MW usage basis of each interconnection request. – Upgrades that are required for the interconnection of the cluster (i.e. shared upgrades) cannot be suspended.
9 Low Voltage Ride Through (LVRT) Governed by FERC Order #661 and #661A Comparable requirements for wind generation and thermal based generation. All wind generators are required to be able stay on line and in service for a 3 phase fault at the Point of Interconnection of normal duration and normal clearing time of the fault. Wind generators must be able to comply either through enhanced ride through capabilities from the equipment manufacturers; or must install a dynamic reactive compensation device to help keep the wind farm on line and in service
10 Reactive Power Requirements Governed by FERC Order #661 and #661A If demonstrated in the interconnection study, wind generation plants shall be capable of providing 95% lagging (providing vars) and 95% leading (absorbing vars) power factor at the point of interconnection. Requires wind generation plant to account for any losses in their distribution collector system, substation transformers, and any transmission line they operate. The requirement applies to wind generation plant at 100% nameplate generation. Does not apply to lower values of generation.
11 SCADA Requirements Governed by FERC Order #661 and #661A Wind generation plants required to have SCADA systems Order #661A allows for mutual agreement between the Transmission Owner/Operator and Generation Owner/Operator to decide the requirements
12 Interconnection Study Measures Wind generator developers provide collector system for wind turbines Wind generator developers provide transformer and transmission information Wind generator developers provide a PSS/E dynamic model for the wind generator turbines they are proposing to install. Dynamic Stability Analysis performed using these models LVRT analysis also performed using these models.
Concluding Remarks Renewables are generally not dispatchable, but can be and may need to be managed. Regardless, accurate models and forecasts are critical to optimize integration and deliveries –Significant efforts underway to create and validate appropriate models without sharing proprietary and commercially sensitive details –FERC is proposing that renewable developers need to share real time data to improve forecasting and better manage reliability margins 13