scholarly journals Automatic Voltage Control of Large-scale Synchronous Condensers in UHV-DC Converter Station

2021 ◽  
Vol 236 ◽  
pp. 01001
Author(s):  
Gang Qu ◽  
Hao Yuan
Keyword(s):  
Large Scale ◽  
Reactive Power ◽  
Voltage Control ◽  
Test Scheme ◽  
Site Testing ◽  
Correct Operation ◽  
Synchronous Condenser ◽  
Synchronous Condensers ◽  
Site Test ◽  
The Relationship

Large-scale synchronous condenser can provide a powerful dynamic reactive power for the Ultra high-voltage (UHV) Direct Current (DC) transmission system. The dynamic characteristics of synchronous condenser ensure the reactive power support capability in the case of grid fault. In this paper, the control strategy and deployment of the synchronous condensers in East China Power Grid are presented. Taking converter station as an example, this paper introduces the main architecture of automatic voltage control (AVC) system, and the relationship between host computers and slave computers. In the substation, it describes the mechanism of several control modes, and designs the on-site test scheme of the control modes. After on-site testing, the correct operation of the large-scale synchronous condensers can be guaranteed.

scholarly journals Reactive Power Optimal Control of a Wind Farm for Minimizing Collector System Losses

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3177 ◽  
Author(s):  
Yunqi Xiao ◽  
Yi Wang ◽  
Yanping Sun
Keyword(s):  
Large Scale ◽  
Wind Farm ◽  
Energy Savings ◽  
Reactive Power ◽  
Voltage Control ◽  
Wind Farms ◽  
Voltage Sensitivity ◽  
Voltage Control Strategy ◽  
Power Sources ◽  
Collector System

A reactive power/voltage control strategy is proposed that uses wind turbines as distributed reactive power sources to optimize the power flow in large-scale wind farms and reduce the overall losses of the collector system. A mathematical model of loss optimization for the wind farm collector systems is proposed based on a reactive power/voltage sensitivity analysis; a genetic algorithm (GA) and particle swarm optimization (PSO) algorithm are used to validate the optimization performances. The simulation model is established based on a large-scale wind farm. The results of multiple scenarios show that the proposed strategy is superior to the traditional methods with regard to the reactive power/voltage control of the wind farm and the loss reduction of the collector system. Furthermore, the advantages in terms of annual energy savings and environmental protection are also estimated.

Testing Study and Numerical Analysis of Dynamic Compaction on the Red Sandstone Rubble Soil

2011 ◽  
Vol 97-98 ◽  
pp. 151-155
Author(s):  
Xi Long Kuang
Keyword(s):  
Numerical Analysis ◽  
Test Data ◽  
Dynamic Compaction ◽  
Site Testing ◽  
Red Sandstone ◽  
Testing Data ◽  
Site Test ◽  
Effective Reinforcement ◽  
The Impact ◽  
The Relationship

The drop distance, times of dynamic compaction and other parameters are studied by on-site testing in order to analyse quantitatively the impact on effective reinforcement depth and radius of the red sandstone rubble soil. Large amounts of on-site test data shows that compactness standard is 93%, strong encryption range is 1.0～4.0m, the effective impact depth is 4～6m and the effective impact radius is 2.5～3.5m. At the same time, through comparison and verification the on-site testing data and numerical analysis, the relationship between times of dynamic compacting and sandstones subside is . Further more, it is revealed that dynamic compaction can restrain effectively the deformation of high fill embankment of the red sandstone rubble soil.

scholarly journals A Quantitative Index to Evaluate the Commutation Failure Probability of LCC-HVDC with a Synchronous Condenser

2019 ◽  
Vol 9 (5) ◽  
pp. 925 ◽  
Author(s):  
Jiangbo Sha ◽  
Chunyi Guo ◽  
Atiq Rehman ◽  
Chengyong Zhao
Keyword(s):  
Failure Probability ◽  
Reactive Power ◽  
Voltage Control ◽  
Capacity Allocation ◽  
Control Device ◽  
Hvdc System ◽  
High Voltage Direct Current ◽  
Synchronous Condenser ◽  
Commutation Failure ◽  
The Impact

Since thyristor cannot turn off automatically, line commutated converter based high voltage direct current (LCC-HVDC) will inevitably fail to commutate and therefore auxiliary controls or voltage control devices are needed to improve the commutation failure immunity of the LCC-HVDC system. The voltage control device, a synchronous condenser (SC), can effectively suppress the commutation failure of the LCC-HVDC system. However, there is a need for a proper evaluation index that can quantitatively assess the ability of the LCC-HVDC system to resist the occurrence of commutation failures. At present, the main quantitative evaluation indicators include the commutation failure immunity index and the commutation failure probability index. Although they can reflect the resistance of the LCC-HVDC system to commutation failures to a certain extent, they are all based on specific working conditions and cannot comprehensively evaluate the impact of SCs on suppressing the commutation failure of the LCC-HVDC system under certain fault ranges. In order to more comprehensively and quantitatively evaluate the influence of SCs on the commutation failure susceptibility of the LCC-HVDC system under certain fault ranges, this paper proposes the area ratio of commutation failure probability. The accuracy of this new index was verified through the PSCAD/EMTDC. Based on the CIGRE benchmark model, the effects of different synchronous condensers on LCC-HVDC commutation failure were analyzed. The results showed that the new index could effectively and more precisely evaluate the effect of SCs on commutation failures. Moreover, the proposed index could provide a theoretical basis for the capacity allocation of SCs in practical projects and it could also be utilized for evaluating the impact of other dynamic reactive power compensators on the commutation failure probability of the LCC-HVDC system under certain fault ranges.

scholarly journals Voltage Control Method for Active Distribution Networks Based on Regional Power Coordination

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4364 ◽  
Author(s):  
Ou-Yang ◽  
Long ◽  
Du ◽  
Diao ◽  
Li
Keyword(s):  
Power Control ◽  
Reactive Power ◽  
Control Method ◽  
Voltage Control ◽  
Distribution Networks ◽  
Active Power ◽  
Reactive Power Control ◽  
Safety Issues ◽  
Bus Voltage ◽  
The Relationship

As loads connected to active distribution network (ADN) grow, ADN’s voltage safety issues are becoming more serious. At present, the solution is mainly to build more distributed generation (DG) or to adjust the reactive power in the whole network, but the former needs a lot of investment while the latter requires a large amount of communication equipment and it takes a long time to calculate the adjustment amount of reactive power and to coordinate reactive power compensation equipment. When the loads are heavy, there will still be drawbacks of insufficient reactive power. Therefore, this paper analyzes the relationship between the active power, reactive power, and the voltage in the ADN. Through the autonomous region (AR) division, a voltage control method based on the active power variation and adjustable power in the AR is proposed. According to the relationship between the amount of active power and the adjustable amount active power, the active power control, the reactive power control, and the coordinated control of active power reactive power control are adopted to adjust the DGs’ output to stabilize the bus voltage. The simulation results show that the proposed method can effectively improve the voltage control capability of ADN and can enable it to operate normally under greater power changes. Through the control method in this paper, the communication requirements are greatly reduced and the calculation time is effectively shortened and is more adaptable.

Quantitative Voltage Control of Large-Scale Wind Base

2013 ◽  
Vol 341-342 ◽  
pp. 1294-1298
Author(s):  
Zheng Jun Xing ◽  
Xiang Yu Kong ◽  
Fei Huang
Keyword(s):  
Large Scale ◽  
Reactive Power ◽  
Voltage Control ◽  
Operating Mode ◽  
Coefficient Matrix ◽  
Sensitivity Coefficient ◽  
Control Flow ◽  
Voltage Fluctuation ◽  
Actual System ◽  
Power Injection

The random variation of wind speed causes active power and reactive power injection of large-scale wind base to fluctuate constantly, this in turn leads to voltage fluctuation and unqualified voltage amplitudes of this area. This article proposes quantitative voltage control to solve this problem. Firstly, analyze the reason and characteristic of voltage fluctuation in large-scale wind base. Then apply sensitivity method to derive voltage/reactive power sensitivity coefficient matrix; this matrix is the product of two special matrices, one is symmetric and the other is diagonal. It can be demonstrated that the symmetric one has a relatively bigger value at the diagonal line; combined with the diagonal one, several simple conclusions can be obtained. According to the conclusions, quantitative voltage control flow can be established. In addition, operating mode of wind turbine generator is taken into account in the simulation process. Simulation results of IEEE 9 nodes system and an actual system demonstrate the validity of proposed measures.

scholarly journals The Application of AVC System in Inner Mongolia Wind Farm

2021 ◽  
Vol 8 (2) ◽  
pp. 42-46
Author(s):  
Junfei Han ◽  
Hua Li
Keyword(s):  
Field Test ◽  
Large Scale ◽  
Wind Farm ◽  
Reactive Power ◽  
Voltage Control ◽  
Wind Farms ◽  
Power Performance ◽  
Control Effect ◽  
Technical Standards ◽  
Response Characteristics

The key technologies of self-regulating voltage control for wind farms are studied, and the technical indicators of the AVC main and sub-stations of wind farms in the field of large-scale wind power generation are defined. Wind farm voltage control (AVC) control strategy, developed a wind farm AVC simulation test platform, prepared a wind farm AVC field test and conducted a field test. According to the actual control effect of wind farm AVC, the dynamic response characteristics of wind farm AVC and the reactive power performance of wind farm AVC are evaluated according to relevant technical standards.

Particle Swarm Optimization Solving Nonlinear Programming Problems in Power System

2013 ◽  
Vol 760-762 ◽  
pp. 1183-1186
Author(s):  
Li Kang ◽  
Xiao Guang Li
Keyword(s):  
Nonlinear Programming ◽  
Power System ◽  
Computational Efficiency ◽  
Optimization Model ◽  
Large Scale ◽  
Voltage Stability ◽  
Reactive Power ◽  
Voltage Control ◽  
Stability Control

In order to improve the control capability of the power system voltage stability and to enhance spatial and temporal coordination of voltage control means, it is essential to establish the model of emergency voltage control that can globally mobilize reactive power support and voltage control potential. Focus on the long-term voltage stability of power system, the paper introduce nonlinear programming into emergency voltage control, settle the problem that how to establish the model of emergency voltage control. Based on detailed models of power system, the receding optimization model of long-term voltage stability control is established under framework of model predictive control. In order to improve the computational efficiency and reduce feedback delays, nonlinear programming sensitivity algorithm is proposed to solve receding optimization model. The proposed method can improve computational efficiency significantly which creates the condition for the emergency voltage control application to large-scale systems.

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