Dynamic State Estimation in Inverter-Dominated Power Systems

Dynamic State Estimation in Inverter-Dominated Power Systems serves as a valuable tool for power engineers, concentrating on solving the obstacles related to incorporating inverter-based renewable energy sources into traditional power systems.

The document by Sakis MELIOPOULOS, et al., published in IEEE Power & Energy Magazine, delves into the role of dynamic state estimation for monitoring and controlling modern power systems, ensuring grid stability, and maximizing efficiency in the face of growing renewable energy penetration. It offers an in-depth discussion of dynamic state estimation for effectively monitoring and controlling power systems, ensuring grid stability, and maximising efficiency.

Dynamic State Estimation Key Topics:

1. Inverter-Dominated Power Systems: Gain insight into the growing prevalence of inverter-based renewable energy sources, such as solar photovoltaics and wind turbines, and the challenges they pose to traditional power systems. Learn how these sources contribute to grid fluctuations and stability issues, necessitating advanced monitoring and control techniques.
2. Dynamic State Estimation: Understand the critical role of dynamic state estimation in managing inverter-dominated power systems. Explore how it facilitates real-time monitoring, control, and optimization of grid operations, enabling power engineers to make informed decisions and maintain system stability under varying operating conditions.
3. Techniques and Algorithms: Delve into the various techniques and algorithms used in dynamic state estimation, including Kalman filtering, artificial intelligence (AI)-based methods, and machine learning approaches. Discover how these advanced methodologies enhance the accuracy and efficiency of state estimation in complex power systems with high levels of renewable energy penetration.
4. Integration Challenges: Examine the unique challenges and complexities associated with integrating large amounts of inverter-based renewable energy into power systems, such as voltage and frequency fluctuations, harmonic distortions, and the need for advanced protection schemes.
5. Future Outlook and Trends: Assess the future outlook of inverter-dominated power systems, including the impact of emerging technologies like energy storage systems, smart grid solutions, and demand-side management strategies on grid stability and overall power system performance.

Reduce the complexity

The overall approach of using dynamic state estimation to perform protection and supervise the correctness of input data to relays has been organized into the prototype rCSP platform. The system was tested in the laboratory with hardware in the loop and has also been installed in several substations at partner utilities (three substations of the Southern Company system and two substations of NYPA). Prior to the installations the system has been “factory tested” at the Georgia Tech laboratory, with the configuration shown in below.

The laboratory configuration consists of a process and substation bus implemented using managed Ethernet switches. A set of thirteen merging units are connected to both process and substation buses via optical fibers (multimodal 1300 nm). Monitoring and configuration of the merging units is handled via the process bus.

Digital Fault Recorders (DFRs) with PMU capability (shown as USI9000) and numerical relays (not shown) are connected to the substation bus. The system has been designed to interface with merging units as well as with numerical relays, digital fault recorders (DFRs) and other intelligent electronic devices (IEDs). We refer to this system as the hybrid P&C system.

A multi-core personal computer (with Windows 10 operating system) accesses the process and substation buses, respectively. Another computer (power system simulation computer) drives a bank of digital to analog (D/A) converters providing voltage and current signals to the inputs of the amplifiers; the output of the amplifiers is connected to MUs, DFRs, and relays. Note that the voltages and currents are amplified to match MUs, relays, and DFRs analog input range via Omicron amplifiers.

The Power of the Swarm

The VECTO 3 is an intelligent electronic device (IED), although it differs from the usual IED design paradigm in that it is built on a Linux edge-computing architecture. It functions as a broadband multifunction device — DC-50kHz — Synchro-Waveform Measurement Unit (SWMU), monitoring and recording over 9,000 electrical parameters.

The integrated capabilities of the VECTO 3 are comprehensive and include:

1. Power Quality (PQI) monitoring and recording device — IEC 6100-4-30 ED3.0 Class-A
2. Phasor Measurement Unit (PMU) device — Class M & P
3. Higher Harmonics Recorder (up to 25kHz)
4. Digital Fault Recorder (DFR)
5. Small Signal event & trend recorder
6. Sub-station Merging Unit (10kHz streaming)
7. Revenue Metering Device—Class 0.2S
8. SCADA transducer

With local recording and centralised data streaming capabilities, the utility of this multi-function device is comprehensive. With permanent, built-in GPS time synchronisation to within 100ns from absolute time, all recorded data streams are accurately time stamped, regardless of the device’s geolocation.

The local processing capabilities of the VECTO 3 achieve among the following:

1. Data streams are rated and classified to selected industry and custom customer standards on-device before streaming to the central data-store via the built-in secure network connectivity capabilities. This reduces networking infrastructure capacity requirements significantly.
2. Events can be configured to trigger local control signals and alerts via digital and analog interfaces and on the installed SCADA bus.
3. Events are delivered in real-time to designated push capable devices such as mobile phones.
4. Machine Learning derived algorithms can be deployed on the device to identify complex events on the live, full resolution data stream.
5. Trigger full resolution recordings, across multiple devices, when network events occur.

When multiple, geo-distant VECTO 3 devices are deployed, the power grid is monitored — via VECTO Grid OS — as either a single grid-wide virtual instrument, in defined groups of geo-distant virtual instruments, right down to any single instrument.

This multi-function capability and GPS time synchronised fleet capability gives all role players, from power engineers to key account managers to control room engineers and the C-Suite, near real-time access, on the smart device of their choice, access to the data that is relevant to their functions and requirements.

The VECTO 3 and VECTO Grid OS (VECTO System) is the ideal platform to deploy grid-wide Dynamic State Estimation capabilities. The VECTO System platform reduces the complexity required as there is no need to combine multiple bespoke components to achieve the required capabilities. A significant capital and operation cost savings.