Tuesday, 15th of August, 09.00 - 15.30
Bygning 101, room S09
DTU Lyngby Campus
We are happy to host the visit of three professors from Tsinghua University. Both teams, the Power System Stability and Control group of Tsinghua and Electric Power Systems research group of Center for Electric Power and Energy, have a long record of research in power system stability issues, and each has their own strengths in this field.
This visit will strengthen the future research of both teams and the scientific cooperation in this field.
Programme:
8:50 Welcome
9:00 Tsinghua presentation #1
"Stability analysis and control of power systems with large-scale wind power generation" By Professor Shen Chen.
9:40 Tsinghua presentation #2
"Evolution Model for Future Power System Under Massive Penetration of New Energy" By Associated Professor Zhang Xuemin.
10:20 Break
10:30 Tsinghua presentation #3
"Fully GPU-Based Electromagnetic Transient Simulation for System-Level Studies" By Assistant Professor Huang Shaowei.
11:10 Tsinghua presentation #4
"Input to State Stability Based Control of Doubly Fed Wind Generator" By Associated Professor Zhang Xuemin.
12:00 Lunch break
Presentation of CEE's research activities and results
13:00 CEE presentation #1
"Overview of CEE's R&D within Power System Stability" By Hjörtur Jóhannsson.
13:40 CEE presentation #2
"Real-time Static-Security Assessment" By Dr. Jakob Glarbo.
14:20 Break
14:30 CEE presentation #3
"Real-Time Early Warning and Early Prevention Against System Blackouts" By Hjörtur Jóhannsson.
15:10 CEE presentation #4
"Economic Dispatch with Stochastic Wind Production and Its Solution by Dual Decomposition and Quasi-Newton Method" By Dr. Shaojun Huang.
15:50 End
All presentations are 40 minute long: 30 minute talk and max 10 minute Q&A.
Abstracts of the presentations by the Tsinghua team:
Title: Stability analysis and control of power systems with large-scale wind power generation
Speaker: Professor Shen Chen
Abstract: China has the largest installed capacity of wind power in the world. In the north part of China and the east coast, there are several large-scale wind farms each with more than 10 GW installed capacity. The wind generation affects power systems in many aspects due to its dynamics and uncertainty. For example, the wind power may deteriorate grid stability in the time span from seconds to minutes within the space range of more than thousands of kilometers. Techniques for stability analysis and control are fundamentals for integrating wind power. This talk introduces the recent findings in small signal stability and transient stability analysis. For the small signal stability, the mechanism by which DFIGs affect the electromechanical modes of power systems will be introduced. For the transient stability, the idea of how to consider the impact of wind power on transient angle stability and how to put the consideration in preventive control will be briefed
Title: Evolution Model for Future Power System Under Massive Penetration of New Energy
Speaker: Associated Professor Zhang Xuemin
Abstract: The expanding clean energy and rapid development of frontier technology will deeply affect the future power grid pattern. However, the existing power system evolution model has neither fully considered the characteristics of clean energy, nor built models for superconducting transmission, energy storage and other new technologies. Referring to electric power system planning, this paper introduces constraints of the power, electricity, peaking, and environmental constraints with the optimize goal of minimizing the construction cost into the evolution model of power system, and establishes a simplified model of several frontier technologies from the perspective of power system operation. Finally, the heuristic rule and the simulated plant growth algorithm are used to solve the evolution model. Through the analysis of the evolution of the State Grid operation area in the next 40 years, this paper analyzed quantitatively the impact of energy policy and the development of new technologies on the power flow, as well as the benefits of reducing the cost of electricity construction. The results show that the model can provide quantitative reference for decision-making on long-term energy policy and power strategy.
Title: Input to State Stability Based Control of Doubly Fed Wind Generator
Speaker: Associated Professor Zhang Xuemin
Abstract: A novel approach on controller design for a doubly fed wind generator based on Input-to-State stability (ISS) theory is proposed. In order to guarantee the stability of the nonlinear system with external disturbances, a systematic methodology for constructing locally input-to-state stabilizing control Lyapunov functions (LISS-CLF) and designing the corresponding LISS control law are proposed. This method avoids the HJI partial differential equation and the limitation of exact linearization. The proposed ISS control law is proved to be inverse optimal and can guarantee the stability of the wind generation system under external disturbances. Since the ISS controller depends on the parameters of the doubly fed wind generator only, it can be considered as a decentralized control. The simulation studies verify the effectiveness of the proposed ISS controller. Compared with conventional PI controller and exact linearization controller, the ISS controller has the ability to enhance the transient stability of the wind generation system during and after faults, and can significantly improve the dynamic performance of the system.
Title: Fully GPU-Based Electromagnetic Transient Simulation for System-Level Studies
Speaker: Assistant Professor Huang Shaowei
Abstract: As more generators and loads are integrated by power electronic converters with complicated controls, electromagnetic transients (EMTs) simulation becomes an important tool for studying dynamic characteristics of large-scale power systems. To accelerate system-level EMTsimulations, a fine-grained parallel algorithm on graphics processing units (GPU) is proposed. By decomposing the computational models of the EMT simulation into heterogeneous, homogeneous and network solution computations, the simulations are mapped into three unified GPU kernels.To incorporate control signals and non-linear features of electrical components, heterogeneous computations are formulated as layered direct acyclic graphs (LDAG) of primitive operations. An LDAG kernel is designed to carry out theses primitive operations efficiently by grouped threads. Then, homogeneous computations for state updates of electrical components are modelled as sets of fused multiply-add (FMA) operations, which are concurrently processed by an FMA kernel. Moreover, a hybrid network solution kernel is designed to solve the network equations, which can adaptively select dense or sparse solvers. Large-scale test systems are created and simulated on an NVIDIA K20x GPU. The results show that the proposed GPU-based EMT simulations are accurate and achieve 10x speedups over the CPU-based ones.