Improvements to the Co-simulation Interface for Geographically - PowerPoint PPT Presentation

Improvements to the Co-simulation Interface for Geographically Distributed Real-time Simulation 45th Annual Conference of the IEEE Industrial Electronics Society (IECON) 15th – 17th October 2019, Lisbon Paper: LD-029874 1 Improvements to the Co-simulation Interface for Geographically Distributed Real-time Simulation M.Sc. Steffen Vogel Steffen Vogel | 16.10.2019

Contents ■ ERIGrid Transnational Access Exchange ■ The concept of Geographically Distributed Co-simulation ■ System Architecture ■ Test case description ■ Main contributions 1. Improved calculation of Dynamic Phasor Coefficients by moving window average 2. Investigation of IETF RTP protocol for streaming real-time simulation data 3. Fidelity Improvements / Bug Fixes 4. CoSiF – A reusable library for distributed real-time simulation ■ Future plans 2 Improvements to the Co-simulation Interface for Geographically Distributed Real-time Simulation Steffen Vogel | 16.10.2019

Geographically Distributed Real-time Simulation (GD-RTS) ■ A single digital real-time simulation spanning multiple simulators / simulation Subsystem 1 Subsystem 2 sites Digital ■ Motivation Real-Time Simulator Subsystem 3 ≡ Large-scale system-level simulatoins (DRTS) ≡ Exchange of Knowledge, Human- and Hardware Ressources From monolithic RTS to GD-RTS ≡ Overcome constraints caused by data confidientiality Subsystem 2 Subsystem 1 Comm. network DRTS 1 DRTS 2 Subsystem 3 DRTS 3 3 Improvements to the Co-simulation Interface for Geographically Distributed Real-time Simulation Steffen Vogel | 16.10.2019

Background / Motivation ■ Global Real-time SuperLab: ≡ 8 sites, 10 simulators, 8 links ■ Simple ITM or P/Q, Vrms, f Interface Algorithms ■ Long setup time ■ Huge variations in network quality M. Stevic et al., “Virtual integration of laboratories over long distance for real-time co-simulation of power systems,” in IECON 2016 - 42nd Annual Conference of the IEEE Industrial Electronics Society , 2016, pp. 6717–6721. 4 Improvements to the Co-simulation Interface for Geographically Distributed Real-time Simulation Steffen Vogel | 16.10.2019

System Architecture ■ 2 Labs: ≡ 2 RTDS Simulators ≡ 2 VILLASnode Gateways ≡ Decentral / Fully-meshed VPN for optimal point-to-point connection with lowest latency 5 Improvements to the Co-simulation Interface for Geographically Distributed Real-time Simulation Steffen Vogel | 16.10.2019

Network Connectivity ■ National Research and Education Networks (NRENs) ≡ DFN, SURFnet, GÉANT ■ Mean Round-trip time: 𝟐𝟑 𝒏𝒕 ■ Routing hops: 𝟐𝟒 ■ Sending rate: ≤ 𝟐𝟏 𝒍𝑸𝒍𝒖/𝒕 1 0.9 0.8 0.7 0.6 Probability 0.5 500 Packets/sec 1000 Packets/sec 2000 Packets/sec 0.4 5000 Packets/sec 10000 Packets/sec 0.3 15000 Packets/sec 17000 Packets/sec 0.2 20000 Packets/sec 0.1 0 10 15 20 25 30 RTT [ms] 6 Improvements to the Co-simulation Interface for Geographically Distributed Real-time Simulation Steffen Vogel | 16.10.2019

Real-time Transport Protocol (RTP) ■ Different co-sim links vary significantly 1 1 1 1 r r r r 8 16 2 4 in quality of serivce (QoS) sending rate [kHz] 3 ■ Adaptive adjustment of communication parameters is helpful 2 ■ Additive Increase – 1 Packet Loss Multiplicate Decrease (AIMD) 0 0 10 20 30 40 50 60 70 10 6 -6.2249 time [s] Sequence Difference -6.22492 ■ Discontinuties in sending rate cause -6.22494 frequency disturbances in simulation -6.22496 -6.22498 ■ Only useful for initial estimation, not 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 during live simulation 60.02 Frequency [Hz] 60 59.98 59.96 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 Time [s] 7 Improvements to the Co-simulation Interface for Geographically Distributed Real-time Simulation Steffen Vogel | 16.10.2019

Test Scenario & Methodology ■ Simple scenario helped debugging and understanding ■ 3 Stages: monolithic, decoupled, distributed 13.8/230 kV 230/115 kV ~ Line 1 Line 2 Load 2 Load 1 a) Monolithic Model 13.8/230 kV 230/115 kV ~ ~ Load 2 Load 1 SS1 SS2 b) Decoupled / Distributed Model 8 Improvements to the Co-simulation Interface for Geographically Distributed Real-time Simulation Steffen Vogel | 16.10.2019

Dynamic Phasor Interface Algorithm (DP-IA) Window Mean Mean Mean . . . . . . Mean Mean Calculation of Dynamic Phasor Coefficients from Time-domain Signals. 9 Improvements to the Co-simulation Interface for Geographically Distributed Real-time Simulation Steffen Vogel | 16.10.2019

Dynamic Phasor Interface Algorithm (DP-IA) Magnitude Cartesian to Phase Polar . . . . . . Magnitude Cartesian to Phase Polar Reconstruction of Time-domain Signals from Dynamic Phasor coefficients. 10 Improvements to the Co-simulation Interface for Geographically Distributed Real-time Simulation Steffen Vogel | 16.10.2019

Simulation Results: Instantaneous V/I ■ Test cases: ≡ Voltage Source in SS1 (left) ����������� ���������������� ����������� ����������� ����������� ��� ≡ Change of magnitude, freuquency, phase ��� �� ■ No error in steady-state � ���� ■ Delayed update of ���� ≡ Voltage magnitude SS1 ����������� ������������ ����������� ����������� ����������� ��� (1/2 RTT) ≡ Current magnitude on left side ���� (1 RTT) � �� ����� ���� � ������� ������� � ������� ������� � 11 Improvements to the Co-simulation Interface for Geographically Distributed Real-time Simulation Steffen Vogel | 16.10.2019

Simulation Results: P/Q RMS ■ Change of source magnitude in SS1 (left side) 20 Original 19 Dcpl. SS1 P [ M W] Dcpl. SS2 18 Dist. SS1 17 Dist. SS2 16 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 8 7.5 Q [ M VAr] 7 6.5 6 0.4 0.5 0.6 0.7 0.8 0.9 1 1.1 1.2 Time [s] 12 Improvements to the Co-simulation Interface for Geographically Distributed Real-time Simulation Steffen Vogel | 16.10.2019

Limits of GD-RTS ■ Phase jump of 𝜌 of 𝑊 ./0 400 SS1 dcpl SS1 dist Original Voltage [kV] 200 SS2 dcpl SS2 dist 0 -200 0.34 0.36 0.38 0.4 0.42 0.44 0.46 0.1 0.05 Current [kA] 0 -0.05 -0.1 0.34 0.36 0.38 0.4 0.42 0.44 0.46 Time [s] 13 Improvements to the Co-simulation Interface for Geographically Distributed Real-time Simulation Steffen Vogel | 16.10.2019

Fidelity Improvements I ■ Mismatch in DFT window length for 60 Hz systems ■ Fundamental period of 60 Hz is not evenly dividable by a 𝑈 . = 50 𝜈𝑡 time-step ■ Optimal Simulation Timestep: ■ Uneven time-steps might cause other issues in relation to synchronization of simulators 14 Improvements to the Co-simulation Interface for Geographically Distributed Real-time Simulation Steffen Vogel | 16.10.2019

Fidelity Improvements II ■ Mismatch in active / reactive power due to internal time-step delays between network solution and control systems of DRTS ■ Phase compensation for controlled sources required Phase Compensation for Controlled Sources dp1_phase Mag 2* (pk) compensation_steps Freq + sin + t X 60.0 (rad) (Hz) AbsPhase X 2* X (rad) compensation dp1_mag recon_dp1 60.0 15 Improvements to the Co-simulation Interface for Geographically Distributed Real-time Simulation Steffen Vogel | 16.10.2019

Usability Improvements ■ Use of GPS time (GTSYNC) to coordinate synchronized simulation start ≡ Alignment of measurements ≡ Synchronized reference phasors ■ Open problem for OPAL-RT systems 16 Improvements to the Co-simulation Interface for Geographically Distributed Real-time Simulation Steffen Vogel | 16.10.2019

Co-Simulation Interface Library: „CoSiF ■ Re-usable library blocks for different: ≡ Interface Algorithms: Dynamic Phasors, PQ + 𝑊 /:. , 𝑔, 𝜚 ≡ Simulation Platforms: RTDS, OPAL+RT Subsystem D - SSD Subsystem H - SSH Processor Assignment Auto IN THIS SUBSYSTEM CONTROL AND MONITOR ssD_SRCBUS ssD_IFBUS fHYKxgK DOKHYPy x_ HdOHbDgg DOKHKKu x_ HyOYHYKd LINE CONSTANTS ssD_VsrcC ssD_VsrcA ssD_VsrcB ifH_phA ifH_phB ifH_phC ssD_TLINE T-LINE NAME CALCULATION BLOCK TLINE ssD_IAtlineSE ssD_IAtlineRE D D GEN ssD_IBtlineSE ssD_IBtlineRE Co-sim interface H H vKOu ssD_ICtlineSE ssD_ICtlineRE Y Y A B C Dynamic Load RxxL dist_ssD_DLD ■ Open Source: GPLv3 ≡ https://fein-aachen.org/projects/cosif/ 17 Improvements to the Co-simulation Interface for Geographically Distributed Real-time Simulation Steffen Vogel | 16.10.2019

Future Plans ■ More tests with off-nominal frequencies at the interface ■ Ongoing ERIGrid Transnational Access with DTU Denmark ≡ Distributed-PHIL with Quasi Stationary Back-to-Back Converter ≡ Energy Based Metric (EBM) for error quantification ■ FPGA / PCIe-based DRTS interfaces ≡ Migration of DP-IA into VILLASnode 18 Improvements to the Co-simulation Interface for Geographically Distributed Real-time Simulation Steffen Vogel | 16.10.2019