Participation of a Pumped-Storage Electric Power Plant with Asynchronous Generator-Motors in Normalized Primary Frequency Regulation

Abstract

The main positive effects on the use of electrical machines with a variable rotation frequency are considered using the example of the Zagorsk pumped-storage power plant. It is shown that the possibility of regulating the electric active power, both in the generator and the pump modes, makes the power plant with asynchronous generator-motors more effective compared with units with synchronous generator-motors and enables it to provide services with normalized primary frequency regulation.Progress in the field of high-powered electronic devices has enabled highly reliable frequency converters to be produced. This, in combination with the development of microprocessor regulation and control devices, construction methods, and the use of new materials and technologies in electrical machines, has enabled electrical machines operating with variable rotation frequency to be designed.Of the variety of electrical machines operating with a variable rotation frequency, the most economical technical designs for a change in the rotation frequency not exceeding ±10% synchronous, is the asynchronous machine [1].The essential advantages of such hydroelectric apparatus with respect to economy, reliability, and controllability compared with hydromachines operating at a constant rotation frequency have been confirmed theoretically and experimentally.For the Russian hydropower system, the use of aggregates with asynchronous machines is important both for reconstructing existing power plants and constructing new ones [2].In this paper we investigate the possibility of pumped storage power plants with asynchronous generator-motors participating in normalized primary frequency regulation.The participation of a pumped-storage power plant with asynchronous generator-motors in normalized primary frequency regulation is considered, taking into account the operating conditions at the Zagorsk pumped-storage power plant when the synchronous generator-motor is replaced by an asynchronous one.The choice of the Zagorsk power plant as the example is governed by the fact that this power plant, practically unique in Russia, has characteristics that are available in the open literature, and in which, in the near future, will have its equipment modernized.The characteristics of the Zagorsk hydroelectric apparatus when operating with a variable rotation frequency. The universal characteristics of hydroelectric equipment operating with turbines and its working characteristic in the pump mode at a rotation frequency of 150 rpm are given in [3,4]. The diameter of the turbine D = 6.3 m, the nominal power in the turbine mode N T = 205 MW, and the nominal power in the pump mode N p = 217 MW.The net pressure heads in the turbine mode are: maximum -111 m, calculated -100 m, and minimum -91 m.The working pressure heads in the pump mode are as follows: maximum -115 m, average -105 m, and minimum -96 m.The rotation frequency n s = 250 rpm is synchronous for apparatus with synchronous generator-motors.

Characteristic Analysis and Optimal Regulation of Primary Frequency Regulation Condition in Low Water Head Area Based on Hydraulic-Mechanical-Electrical Coupling Model of Pumped Storage Unit

“…e fitness function value of each particle is calculated, as shown in equations (18) and (19). Chemotaxis local search operation is carried out for global optimal particles and global worst particles of the current algebra according to a certain number of chemotactic steps and moving steps.…”

“…However, when the PSURS is running at a low water head, it is easy to enter the "S" characteristic area, resulting in widespread range fluctuation and unstable operation of the unit's frequency. Especially when the unit participates in primary frequency regulation [18], the frequency disturbance will greatly increase the probability of wide range fluctuation of the PSU's frequency. e traditional PID controller cannot adjust the frequency fluctuation of PSU well.…”

Load Frequency Control of Pumped Storage Power Station Based on LADRC

“…At present, the rapid control mode conversion by the thermal power plant alone cannot fully meet the control requirements under the high power shortage. Therefore, it is proposed to make full use of the flexibility of the pumped storage units to adjust the resources [4,7].…”