Impact of Connecting Reactor on Stable Operation of Chain SVG Device

2014 ◽  
Vol 644-650 ◽  
pp. 794-797
Author(s):  
Zheng Dao Liu ◽  
De Sheng Xi ◽  
Qiang Liu ◽  
Lei Shi ◽  
Shu Han Wang ◽  
...  
Keyword(s):  
Electrical Property ◽  
Design Principle ◽  
Reactive Power ◽  
Power Grid ◽  
Stable Operation ◽  
Grid System ◽  
Reactive Compensation ◽  
Actual Operation ◽  
Design Requirements ◽  
The Impact

Chain SVG device is connected to the power grid via the reactor which is also referred to as connection reactor. Compared with other reactors of reactive compensation devices, It’s not like the serial filtering reactor which simply provides a specific quantity of inductive reactive power, or parallel phase control reactor which provides continuously adjustable inductive reactive power. The connection reactor in SVG is related to the impact of SVG on the power grid, the impact of the power grid system on SVG, and in particular, the compensation capacity and effect of SVG. Therefore, during design, requirements of SVG and electrical property of the compensated system should both be considered. In this paper, the impact of the connection reactor on SVG stable operation is analyzed in detail. The design principle that when choosing the reactor parameters, the impact on power unit DC side voltage should be prioritized is proposed, and simulation verification is conducted by using of PSCAD software. A reasonable reactor is selected for a 10kV SVG based on the conclusion. The actual operation result verifies the rationality of design.

Reactive Power Loss Index for Identification of Weak Nodes and Reactive Compensation Analysis to Improve Steady State Voltage Stability

2020 ◽  
pp. 177-237
Author(s):  
Tukaram Moger ◽  
Thukaram Dhadbanjan
Keyword(s):  
Steady State ◽  
Power Loss ◽  
Voltage Stability ◽  
Reactive Power ◽  
Power Grid ◽  
Southern Region ◽  
Equivalent System ◽  
Reactive Compensation ◽  
Simulation Results ◽  
Loss Index

This chapter presents a new reactive power loss index for identification of weak buses in the system. This index can be used for identification of weak buses in the systems. The new reactive power loss index is illustrated on sample 5-bus system, and tested on sample 10-bus equivalent system and 72-bus equivalent system of Indian southern region power grid. The validation of the weak buses identification from the reactive power loss index with that from other existing methods in the literature is carried out to demonstrate the effectiveness of the index. Simulation results show that the identification of weak buses in the system from the new reactive power loss index is completely non-iterative, and thus requires minimal computational efforts as compared with other existing methods in the literature.

scholarly journals Control of MMC-Based STATCOM as an Effective Interface between Energy Sources and the Power Grid

Electronics ◽  
2019 ◽  
Vol 8 (11) ◽  
pp. 1264 ◽  
Author(s):  
Fatemeh Shahnazian ◽  
Ebrahim Adabi ◽  
Jafar Adabi ◽  
Edris Pouresmaeil ◽  
Kumars Rouzbehi ◽  
...  
Keyword(s):  
Reactive Power ◽  
Control Method ◽  
Second Harmonic ◽  
Power Grid ◽  
Harmonic Component ◽  
Current Control ◽  
Energy Sources ◽  
Stable Operation ◽  
Multilevel Converters ◽  
Steady State Operation

This paper presents a dynamic model of modular multilevel converters (MMCs), which are considered as an effective interface between energy sources and the power grid. By improving the converter performance, appropriate reactive power compensation is guaranteed. Modulation indices are calculated based on detailed harmonic evaluations of both dynamic and steady-state operation modes, which is considered as the main contribution of this paper in comparison with other methods. As another novelty of this paper, circulating current control is accomplished by embedding an additional second harmonic component in the modulation process. The proposed control method leads to an effective reduction in capacitor voltage fluctuation and losses. Finally, converter’s maximum stable operation range is modified, which provides efficiency enhancements and also stability assurance. The proficiency and functionality of the proposed controller are demonstrated through detailed theoretical analysis and simulations with MATLAB/Simulink.

Harmonic Analyses of Power Grid in Large-Capacity Groups of AC-DC-AC Frequency Speed Drag System

2013 ◽  
Vol 448-453 ◽  
pp. 1988-1993
Author(s):  
Ji Zhong Wang ◽  
Chao Nan Tong ◽  
Rui Li
Keyword(s):  
Power Supply ◽  
Pulse Width Modulation ◽  
Reactive Power ◽  
Power Grid ◽  
Harmonic Distortion ◽  
Power Load ◽  
Grid Side ◽  
Lc Filter ◽  
Harmonic Analyses ◽  
The Impact

Based on the synchronous machine in AC-DC-AC Frequency speed drag System, a new power supply method of phase shifting combination is proposed by a detailed study of the impact in the power grid harmonics. With regard to the main Motor drive system of hot-rolling finishing mills, a large number of varying parameters quantitative analysis is made respectively for power load, LC filter, pulse-width modulation circuit and transformer, in which the grid side harmonic rate and waveform distortion rate is focused on. The simulation results show that the power supply method with reasonable parameters design of the drag system can be drastically reduce the grid side harmonic interference that the total harmonic distortion is suppressed within 4.0%. Results of this study provides an effective method for the design of the factory drag system, reactive power compensation system as well as fault diagnosis of electric drag system.

The Research of the New High Voltage Reactive Power Compensation Device Based on the Compound Switch

2014 ◽  
Vol 496-500 ◽  
pp. 1097-1100 ◽  
Author(s):  
Yin Sheng Wang ◽  
Xue Di Qiao
Keyword(s):  
Reactive Power ◽  
Power Grid ◽  
Reactive Power Compensation ◽  
Parallel Capacitor ◽  
Thyristor Switch ◽  
Compensation Device ◽  
Equipment Utilization ◽  
Contact Switch ◽  
Current Zero ◽  
The Impact

With the increase of power system load, the demand for reactive power is also increasing. In order to ensure the power quality and improve equipment utilization, transmission of reactive power in power grid can lead to network loss and the voltage of the electricity. Installing reactive power compensation device in power grid is the essential means to meet the demand of power grid reactive power [1].The parallel capacitor reactive power compensation device is equipped in the coal mine 3.3 kV system reactive power compensation [2]. Introducing the parallel capacitor reactive power compensation principle and related problems, analysis of the current commonly uses contactor, relay and thyristor switch device, chooses the contactor and breaks pipe parallel composite switch which can have contact and non-contact switch to solve their problems [3]. Using software EMTP simulation composite switch voltage zero input, the result is very good to restrain the impact flow; Compound switch off after current zero avoids the contactor breaking arc, the simulation thyristor compound switch and diode in parallel.

scholarly journals Determination of Minimum Reactive Power Compensation for the Stable Operation of Type-1 WTG in Grid-Connected Mode

2020 ◽  
Vol 8 (5) ◽  
pp. 4656-4660
Keyword(s):  
Wind Farm ◽  
Reactive Power ◽  
Reactive Power Compensation ◽  
Induction Generator ◽  
Stable Operation ◽  
Squirrel Cage ◽  
Squirrel Cage Induction Generator ◽  
Reactive Power Compensator ◽  
The Impact

The current energy demand scenario leads to tremendous increase in the renewable energy sector, but the integration of these renewable causes various stability issues of the system. Increasing share Wind energy has several shortages due to its energy harnessed from the wind. These shortages can be improved by compensating reactive power into the wind plant. The wind farm consist of fixed speed squirrel cage Induction generator absorbs reactive power from the grid for stable operation and it can be injected using reactive power compensator. In this context, the main aim of the research is to find the minimum reactive power compensation required for stable operation for different rating of Type-1 WTG in grid connected mode. In this paper, a detailed model of constant speed Squirrel Cage Induction Generator is carried out in MATLAB/SIMULINK-2017a to analyze the need of reactive power compensation to maintain voltage and frequency stability of the system during normal condition. The work also focuses on to investigate the impact of induction generator inertia level on compensation level. The modified IEEE 5-bus radial distribution system is used to conduct these investigations and the simulation results clearly show that: (1) The necessity and minimum additional reactive power support to the wind farm to improve and maintain stability of the system; (2) the inertia level of wind farm and reactive power compensator level both are independent each other.

The Quality Analysis of Electric Energy after Wind Power Grid Integration

2012 ◽  
Vol 485 ◽  
pp. 502-505 ◽  
Author(s):  
Gui Hua Cai ◽  
Tao Han
Keyword(s):  
Wind Power ◽  
Wind Farm ◽  
Harmonic Wave ◽  
Power Grid ◽  
Electric Energy ◽  
Quality Analysis ◽  
Grid Integration ◽  
Reactive Compensation ◽  
Trial Test ◽  
The Impact

The electric energy quality problems caused by the running of wind power grid integration such as flicker and harmonic wave are increasingly prominent with the increase of the proportion of wind power. This paper describes the impact of the wind turbine connected to the power grid on the electric energy quality and conducts a trial test and proposes measures to improve the quality of electric energy such as improving the grid structure, improving voltage level of wind farm access system and the application of dynamic reactive compensation to the SVC and so on.

scholarly journals The Application and Practice of the Voltage Reactive Power Optimization Automatic Control System (AVC)in the Power Grid of Wuhu Region

2016 ◽  
Vol 12 (02) ◽  
pp. 10
Author(s):  
Liang Sun ◽  
Xusheng Jian ◽  
Wenqiang Yuan
Keyword(s):  
Reactive Power ◽  
Power Optimization ◽  
Power Grid ◽  
Active Power Filter ◽  
Optimization Method ◽  
Active Power ◽  
Reactive Power Optimization ◽  
Control Plan ◽  
Power Filter ◽  
The Impact

In the paper, the influence of harmonic was taken into consideration during the realization of the AVC system in the power grid of Wuhu region, relevant study and development were conducted from the perspective of application and practice, and concrete proposal of practicable reactive voltage power optimization was put forward. The system adopted two-layer control plan: whole-network coordination layer and execution layer within transformer substation. Optimization algorithm adopted the reactive power optimization method with relaxed constraints so as to improve the convergence and computation speed of reactive power optimization. To control the impact of harmonic, a hybrid active power filter scheme which was made up of passive power filter and active power filter was adopted, thus improving the cost performance of the AVC system. The result of applying the AVC system in the power grid of Wuhu region shows that the system is stable and reliable, obviously decreasing the operation times of equipment and improving the voltage qualified rate and power factor of panel point.

scholarly journals A Speed-Governing System Model with Over-Frequency Protection for Nuclear Power Generating Units

Energies ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 173 ◽  
Author(s):  
Li Wang ◽  
Wentao Sun ◽  
Jie Zhao ◽  
Dichen Liu
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Power Grid ◽  
Simulation Software ◽  
System Model ◽  
Total Power ◽  
Stable Operation ◽  
Thermal System ◽  
Governing System ◽  
The Impact

Overspeed is more likely to occur in the process of load rejection or large disturbances for nuclear steam turbines due to the large parameter range and low steam parameters, as well as the power of the low-pressure cylinder accounting for a high proportion of the total power. It is of great significance to study the overspeed characteristics of nuclear power plants (NPPs) to ensure the safe and stable operation of the unit and power grid. According to the characteristics of NPPs, the overspeed protection model and the super-acceleration protection model were established, which were added to the speed-governing system model. The response characteristics of the reactor, thermal system, steam turbine and speed-governing system in the process of load rejection or large disturbances of the power grid were analyzed and simulated. The results were compared using the simulation software personal computer transient analyzer (PCTRAN). The simulation results showed that quickly closing both the high and medium pressure regulating valves could effectively realize frequency control when load rejection or a large grid disturbance occurred. The over-acceleration protection cooperates with the super-acceleration protection to avoid the repeated opening/closing of the valves due to overspeed protection. This could effectively reduce the impact of large disturbances on the reactor, thermal system, and turbine.

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