Engineering topics

Chartan, Erol Kevin

Publications and source records attributed to Chartan, Erol Kevin.

4 records

DOE OSTI2019

Frequency Support Enhancement of a Permanent Magnet-Based Adjustable-Speed Pumped Hydropower Plant

When a permanent magnet (PM) -based adjustable-speed pumped storage hydropower (AS-PSH) plant delivers frequency response via the full-scaled power converter, there is power imbalance at the PM generator during the initial stage of the frequency response. This is because the AS-PSH has the different time constants between the power converter and wicket gate in the governor valve. Thus, this imbalance causes a sudden reduction of the rotational speed of the machine during the frequency response. As a result, a voltage deficit arises at the generator terminal in proportion to the decrement in the rotational speed, and thereby it is promising that the current flow at the converter will reach its limit when attempting to inject the commanded active power at a reduced voltage level. Thus, this causes the degradation of the frequency response of the AS-PSH due to the self-demagnetization at a reduced rotational speed. This paper proposes a frequency support scheme of a PM-based AS-PSH to enhance the frequency response by bridging the gap between the different time constants. To achieve this, the frequency support scheme includes a gate opening adjustment in the governor and a dynamic ramp-down in converter controller of the AS-PSH.

13 HYDRO ENERGY↗

DOE OSTI2019

Grid Integration and Market Analysis of Adjustable-Speed Pumped Storage Hydropower: Preprint

Many of the products and services on the electrical grid are currently provided by the conventional power plants, however the response time from conventional power plants is slow compared to hydropower. Similarly, some services such as spinning reserve can be provided by modern renewable generation (wind or PV), however the renewable generation must be curtailed down, thus there is loss of opportunity to harvest clean energy while operating in spinning reserve mode. On the other hand, Adjustable Speed - Pumped Storage Hydropower (AS-PSH) can readily perform these functions while pumping or generating, thus also taking benefit of energy arbitrage which can increase system efficiency. This paper will present results from production cost models showing the effect of adding AS-PSH 50 MW in size to three regional ISO areas which have different ancillary service markets available and different generation mixes. The benefits to these market areas from the ancillary services that can be provided by the AS-PSH and also the load shifting benefits will be measured with cost savings and additional system flexibility in the day-ahead and real-time markets. The main metrics to provide this insight will be savings in the total system production cost and in variable renewable energy curtailment respectively. The simulated operation of the additional hydropower will be analyzed to determine the breakdown of system cost reduction by ancillary services provided and load shifting.

13 HYDRO ENERGY↗

DOE OSTI2019

Grid Integration and Market Analysis of Adjustable-Speed Pumped Storage Hydropower

Variable renewable energy is increasing, affecting variability and range of energy prices and requiring extra power system flexibility. Adjustable-speed pumped storage hydropower (AS-PSH), can provide value to ancillary service markets and take benefit of energy arbitrage. Present results from production cost models showing the effects of adding 50 MW of AS-PSH to three Independent System Operators (ISOs).

24 POWER TRANSMISSION AND DISTRIBUTION↗

DOE OSTI2019

A two-step short-term probabilistic wind forecasting methodology based on predictive distribution optimization

With increasing wind penetrations into electric power systems, probabilistic wind forecasting becomes more critical to power system operations because of its capability of quantifying wind uncertainties. In this paper, a two-step probabilistic wind forecasting approach based on pinball loss optimization is developed. First, a multimodel machine learning-based ensemble deterministic forecasting framework is adopted to generate deterministic forecasts. The deterministic forecast is assumed to be the mean value of the predictive distribution at each forecasting time stamp. Then, the optimal unknown parameter (i.e., standard deviation) of the predictive distribution is estimated by a support vector regression surrogate model based on the deterministic forecasts. Lastly, probabilistic forecasts are generated from the predictive distribution. Numerical results of case studies at eight locations show that the developed two-step probabilistic forecasting methodology has improved the pinball loss metric score by up to 35% compared to a baseline quantile regression forecasting model.

17 WIND ENERGY↗