Yufan Guan

Intelligent Alarm Processing: From Data Intensive to Information Rich

The requirement for power system operators to respond more efficiently to the stressed power system conditions that may create large number of alarms asks fort advanced alarm processor that can help operators recognize the nature of disturbance quickly and reliably. Many of the conventional alarm processors lack the ability to analyze complex events efficiently within a time constraint. This paper present two novel intelligent alarm processing options. One is a Fuzzy Reasoning Petri-nets diagnosis model which takes advantages of both expert system and fuzzy logic, and the other is an advanced alarm processor that combines alarm processing techniques at both the substation automation system (SAS) and energy management system (EMS) level. Simulation and test results have demonstrated the effectiveness of the proposed alarm processor options.

The 21st century substation design: Vision of the future

This paper discusses the 21st century substation design requirements, which should meet the following criteria: improved reliability, cost, interoperability, reconfigurability, security, controllability and flexibility. Such criteria require designs that use new methodologies quite different from the existing philosophy. The design strategies are focused on reducing cost while maintaining the performance, or maintaining cost while improving performance. Based on the considerations mentioned above, we proposed three design approaches: a) retrofitting the existing substations by replacing legacy equipment with new technologies without disrupting continuity of service, b) implementing brand new substation design using of-the-shelf technologies, and c) envisioning green-filed substation design considering energy market, profit optimization and system-operation/price.

Security-based circuit breaker maintenance management

Circuit breakers play a vital role in maintaining system security since their malfunctioning could result in further component outages and may lead to the insecure operating conditions. This paper proposes a new approach for identifying the most risky circuit breakers using the condition-based monitoring data and security-based impact evaluations. For a given substation configuration, those circuit breakers which cause line outages due to mal-operation during contacts opening are identified and analyzed. The security oriented risk indices taking into account both voltage violations and overloading conditions as the consequence of circuit breaker mal-operations are proposed. A new breaker maintenance prioritization scheme based on the risk factors is elaborated. The proposed security-based risk framework is deemed to be an efficient approach in both breaker maintenance planning and identification of the breakers which are unreliable for reconfiguration plans. The presented methodology is investigated and verified on the IEEE 14-bus test system.

Assessing circuit breaker life cycle using condition-based data

How to make decisions to optimally allocate the resources by deciding when to perform maintenance on power apparatus is a critical issue, especially with present economic scenario in power industry. This paper proposes a new approach to assess the circuit breakers life cycle or deterioration stages using its control circuit data. In this approach, the “classical” healthy, minor and major deterioration stages have been mathematically defined by setting up the limits of various performance indices. The model can be automatically updated as the new real-time condition-based data become available to assess the CBs operation performance using probability distributions. The methodology may also be used to quantify the effect of maintenance making use of the defined performance indices, which further helps in developing system-wide risk-based decision approaches for maintenance optimization. Case studies using field data recorded at different times during operations of circuit breaker are presented at the end.

Implementing Intelligent Techniques for the Advanced Alarm Processing

A major power system disturbance could trigger hundreds and sometimes thousands of individual alarms and events. A better and simpler description of the problems affecting the power system is an urgent need for the operators. The task of an Intelligent Alarm Processor (IAP) is to analyze thousands of alarm messages and extract the information that explains cause- effect sequences associated with the network events. In this sense, Fuzzy Reasoning Petri-nets is a very powerful intelligent technique to deal with the complexities of the power system fault and alarm processing. A graphical FRPN model is build in this paper based on the optimal structure and uses fuzzy logic parameters to effectively tackle the uncertainties. Case studies are presented to demonstrate the capability of the IAP under real fault scenarios.

Signal processing, communication, and networking requirements for synchrophasor systems

The synchrophasor technology has become focus of many theoretical, conceptual and practical studies lately due to an increased opportunity to improve power system reliability and security through enhanced monitoring, protection and control. The paper provides a survey of signal processing, communication and networking issues surrounding this topic so that professionals from related areas can benefit from better understanding the needs for their input and contribution in the overall smart grid integration of synchrophasor technology.

Grid Monitoring and Market Risk Management

The advent of electricity market deregulation has placed great emphasis on information availability and analysis and the subsequent decision making to optimize system operation in a competitive environment. This creates a need for better ways to correlate market activity with the physical grid-operating states in real time and share such information among market participants. Command and control choices might result in different financial consequences for market participants and severely impact their profits. The effects are both short term, as in day-ahead and real-time markets for energy, reserves, and congestion relief, and long term, as in investments in transmission and generation capacity. Be cause of this, new solutions are necessary to integrate grid control and market operations while accounting for both good engineering practices and appropriate economic incentives.

Contingency-Based Nodal Market Operation Using Intelligent Economic Alarm Processor

This paper focuses on system monitoring and alarm processing and the use of those alarms for economic decision in the nodal electricity market. The task of an Intelligent Economic Alarm Processor (IEAP) is to analyze thousands of alarm messages and extract useful information that explains cause-effect sequences associated with the unexpected contingencies. A graphical Fuzzy Reasoning Petri-nets (FRPN) model that uses fuzzy logic parameters to effectively tackle the uncertainties is built. The economic alarm processor module then processes the fault event signal, analyzes the impact on the market operation activities and different participants, and gives recommendations to optimize the total economic impact under fault scenarios. A contingency-based strategic bidding model concept is proposed to help the market participants take advantages of the latest system operation information and maximize their benefits over the competitors.

Verifying interoperability and application performance of PMUs and PMU-enabled IEDs

This paper presents a new test methodology for verifying the interoperability and application performance of PMUs and PMU-enabled IEDs at the device and system level. Two types of tests are defined to evaluate the performance of synchrophasor devices from two different aspects: design and application. The interoperability between PMUs, time synchronization options, and phasor data concentrators (PDCs) can be verified by design test methodology. A fault location algorithm using two-end synchronized measurements is used to evaluate the application performance. A reference PMU algorithm and synchrophasor system test set-up have been developed to perform the tests. Nine commercial PMUs and four GPS receivers with different synchronization options are selected to perform the tests. The test results are summarized at the end.

New concept and solution for monitoring and control system for the 21 st century substation

Development of Intelligent Electronic Devices (IEDs) brings a leap in the development of substations. Large scale deployment of IEDs creates huge amount of data either recorder continuously or captured when IEDs are triggered by an event such as a fault or disturbance. The power system load increased to the point where the systems operate closer to the limits. The new developments enable much better monitoring to make sure the operation does not bring undesirable consequence. New automated monitoring and signal processing in substation has become a powerful feature necessary to assure the system is reliable and secure. In this paper, the new monitoring and signal processing solution in substation based on synchronized sampling technology and multifunctional IEDs (such as protection, controllers and PMUs) is proposed. To illustrate the above concepts new hardware and software solutions are envisioned. The hardware solution fully supports IEC 61850 protocol and takes cyber security into account. The software solution realizes the automated integration of substation IED data.