Maximizing Firm Wind Connection to Security Constrained Transmission Networks

Abstract

Abstract-Prudent use of existing transmission capacity could be achieved by an optimal allocation of wind capacity to distinct transmission nodes. The statistical interdependency of geographically separate wind sites and the partially-dispatchable nature of wind power require a collective analysis of all potential wind farms over an extended time-frame in any optimized transmission planning study. The methodology presented in this paper separates this large optimization problem into smaller subtasks, including a year-long sequential time series hourly integer unit commitment, a linear dc load-flow network model with hourly security constraints, and a linear programming optimization model to estimate the maximum firm wind energy penetration for a given network. A novel maximalvector based constraint redundancy analysis is employed to significantly reduce the linear programming optimization dimensionality. Firm wind capacity connections are facilitated in this paper-i.e., those to which wind curtailment to manage congestion is not applicable within a typical system "planning" timeframe analysis. Each bus is allocated firm capacity on the basis of maximizing the possible firm wind energy penetration in the transmission system as a whole, while preserving traditional network security standards.

On Variable Reverse Power Flow-Part I: Active-Reactive Optimal Power Flow with Reactive Power of Wind Stations

“…As shown in Figure 2, at the high-voltage transmission network (HV-TN), firm [11] and non-firm [12] wind energy penetration can be maximized. It was mentioned in [13] that unit commitment issues and the stability of voltage at a HV-TN have high effects on wind energy losses.…”

“…It was mentioned in [13] that unit commitment issues and the stability of voltage at a HV-TN have high effects on wind energy losses. Based on [11][12][13], other important factors which influence wind energy losses in a HV-TN were studied in [14]. It was shown that the reverse active power flow from a downstream medium-voltage active distribution network (MV-ADN) could be rejected at the HV-TN level.…”

Allocation of wind capacity subject to long term voltage stability constraints

“…Allocation of optimal wind capacity in power systems with an indication of unit commitment has been addressed in several works using both linear and non-linear OPF [10]- [13]. The authors of [10] propose a method that sequentially increases the wind energy penetration target while updating the unit commitment and wind capacity allocation pattern formulated as a linear problem.…”

Optimal allocation of wind generation subject to voltage stability constraints

“…This network is based on the topology of a subset of the Irish transmission system originally introduced in [10]. The line parameters were altered to represent the 110 kV transmission system.…”