Research on the Large Disturbance Characteristics of the Pumped Storage Motor with the Time-Stepping FEM Consequently

2015 ◽  
Vol 740 ◽  
pp. 339-342
Author(s):  
Sheng Huang ◽  
Jin Ping Kang

In recent years, the proportion of pumped storage power station in the power grid is increasing, which has many special advantages. The pumped storage motor has two kinds of working condition of generator and motor, not only can the system regulate the reactive power, but also can modify the power factor of the grid resulting in the reduction of the investment on the reactive-power-compensation equipment. On the other hand, the above system is able to enhance both the stability and the overall efficiency. Pumped storage motor start-stop and working condition switch frequently. The test will be analysis and researched with the Time-stepping FEM Consequently, this paper analyses the large disturbance characteristics of the pumped storage motor.

2021 ◽  
pp. 53-56
Author(s):  
Evtaleny R Mauboy

Voltage stability is the main focus in supplying the electricity power to the consumer. The power quality is important as the stability and the continuing supply is well maintained. This research aims to regulate the system voltage when the load increased with the addition of wind turbines. The simulation using Simulink/MATLAB with 2x1,5MW wind turbines connected to 2 MVA Synchronous Machine. The load is connected and increased gradually. The voltage stability can be maintained when the load is increased up to 50%. The voltage loses its stability when the load near its full capacity. The control is applied and the voltage can be maintained its stability with the addition of reactive power compensation


2004 ◽  
Vol 261-263 ◽  
pp. 1545-1550
Author(s):  
Shu Cai Li ◽  
Shu Chen Li ◽  
Wei Shen Zhu ◽  
Wei Zhong Chen ◽  
Le Wen Zhang ◽  
...  

Three-dimensional hydro-mechanical coupling analyses have been conducted on the water-tight structure of the cofferdam for both intake and outlet of Taian pumped storage power station, located in Shandong Province of China. In addition, the effects of excavation on the cofferdam and foundation slopes were also studied by using the 3D FLAC. The calculation results show that the central core of high-pressure grouting has a prefect anti-seepage effect and therefore is able to strengthen the stability of the cofferdam and foundation slopes. The excavation process has only some local effects on the cofferdam and does not greatly affect the global stability of the cofferdam. Therefore, no failure takes place around slope toes. The results show that the width of platform left on the excavation side is reasonable.


2013 ◽  
Vol 811 ◽  
pp. 639-642
Author(s):  
Xue Song Zhou ◽  
Chun Ji ◽  
You Jie Ma

Flexible AC transmission technology (FACTS) is a new technology developed in recent years. It use power electronic technology and modern control technology to achieve fast control for AC transmission system parameter and structure [, to achieve the rational allocation of transmission power, reduce the power loss and the cost of power generation, greatly improve the stability and reliability of the system. STATCOM is based on the principle of reactive power compensation, using full-controlled switching devices to compose self-commutated inventer, complemented by small-capacity storage elements constitute reactive power compensation device. Its role in the power system is the compensation of reactive power, maintain the voltage of the connection point, improve system voltage stability, and improve the steady performance and dynamic performance of the system.


Author(s):  
В.В. Бабенко ◽  
И.А. Хайченко ◽  
Ю.В. Нефедов

Рассматривается способ координации настроек локальных систем автоматического регулирования установок компенсации реактивной мощности (РМ) городской системы электроснабжения для достижения оптимального режима работы всей системы по критерию минимума потерь электрической энергии. На основе анализа базы данных автоматизированной системы коммерческого учета электроэнергии МУП «Воронежская горэлектросеть» за пять лет определено, что величина tg φ (коэффициент реактивной мощности) не соответствует нормируемым ГОСТом значениям и требует существенной корректировки для снижения потерь электрической энергии. Оптимальный режим управления рассматриваемой системой электроснабжения по месту подключения и величине реактивной мощности требуемых установок компенсации возможен при правильном соотношении выбранных критериев локальной и системной оптимизации режимов работы ГЭС. Определено, что для получения экономически обоснованного эффекта от оптимизации режима работы ГЭС по критерию достижения tg φ не более 0,35 необходима установка устройств компенсации РМ как минимум на 50% -70% всех параметров реактивной мощности узла нагрузки (РП) энергоемких потребителей. Кроме того, показана целесообразность использования при данном способе компенсации реактивной мощности регрессионного принципа автоматического управления, базирующегося на методе факторного планирования эксперимента. При наличии базы данных параметров городской системы электроснабжения возможно получить серию уравнений регрессии, являющихся основой для настроек локальной системы управления установок компенсации реактивной мощности, которые необходимо установить в основных узловых точках РП МУП «Воронежская горэлектросеть». Установлено, что сформированные на базе уравнений регрессии параметры для системы управления успешно могут быть интегрированы в современные цифровые микропроцессорные регуляторы установок компенсации реактивной мощности сложных систем электроснабжения This article discusses how to coordinate the settings of local automatic control systems of reactive power compensation plants of a city power supply system in order to achieve the optimal mode of operation of the entire system according to the criterion of minimum loss of electric energy. Based on the analysis of the database of the automated system of commercial accounting of electricity of Municipal Unitary Enterprise "Voronezh City Electric Network" for five years, it was determined that the value of tg φ (reactive power factor) does not correspond to the values normalized by GOST and requires significant adjustment to reduce electrical energy losses. The optimal control mode of the considered power supply system at the point of connection and the value of reactive power of the required compensation plants is possible with the correct ratio of the selected criteria of local and system optimization of the hydroelectric power station operation modes. It was determined that in order to obtain an economically justified effect from optimizing the mode of operation of the hydroelectric power station according to the criterion of tg φ reaching a maximum of 0.35, it is necessary to install RM compensation devices at least 50% -70% of all RP energy-intensive consumers. In addition, the utility of using the regression principle of automatic control c based on the factor planning method of the experiment in this reactive power compensation method is shown. At sufficiently low costs for collection, processing of statistical material and optimization calculations, it is possible to obtain a series of regression equations, on which the calculated part of the settings of the control system of reactive power compensation plants, which should be installed in the main nodes of the Voronezh City Electric Network, is based. It was found that the parameters generated on the basis of regression equations for the control system can be successfully integrated into modern digital microprocessor regulators of reactive power compensation plants of complex power supply systems


Energies ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2498 ◽  
Author(s):  
Lei Zhang ◽  
Jian Zhang ◽  
Xiaodong Yu ◽  
Jiawen Lv ◽  
Xiaoying Zhang

In this study, fast Fourier transform and inverse transform are adopted for noise reduction filtering the data of load rejection pressure of a single unit in a one-tube, four-unit pumped storage power station. Five-spot triple smoothing method is used to extract the time-average and pulsation value of the water hammer pressure of the spiral case and draft tube inlet. The reasonable correction formula is put forward, and the pulsating pressure rise rate of the spiral case (4.44%) and the draft tube inlet (−1.22%) are obtained. A mathematical model is also established for the transition process of the water conveyance and power generation system of the pumped storage power station, and the field single-unit load rejection condition is simulated. The simulation results are consistent with the measurements, and the accuracy of the calculation model in predicting the time-average pressure of water hammer is verified. Thus, the extreme successive load rejection conditions can be simulated based on the proposed model. Combining with the pulsating pressure rise rate of unit, the actual extreme value of extreme working condition is reasonably calculated. The conclusion shows that the pressure of spiral case and draft tube inlet after considering pressure pulsation can meet the control requirements, avoid the damage caused by extreme working condition test to unit, and ensure the operation safety of unit.


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