scholarly journals Research on Dynamic Reactive Power Compensation Scheme for Inhibiting Subsequent Commutation Failure of MIDC

2021 ◽  
Vol 13 (14) ◽  
pp. 7829
Author(s):  
Yifan Zhang ◽  
Fei Tang ◽  
Fanghua Qin ◽  
Yu Li ◽  
Xin Gao ◽  
...  
Keyword(s):  
Reactive Power ◽  
Inhibitory Effect ◽  
Economic Benefits ◽  
Reactive Power Compensation ◽  
Normal Operation ◽  
Voltage Fluctuation ◽  
Commutation Failure ◽  
Bus Voltage ◽  
Configuration Scheme ◽  
Voltage Support

Commutation failure at the inverter side of an MIDC (multi-infeed HVDC) is usually caused by AC system faults. Suppose the converter bus voltage cannot recover to the normal operation level in time: in that case, the commutation failure will then develop into more severe subsequent commutation failures or even DC blocking, which will severely threaten the security and stability of the system. Dynamic reactive power compensation equipment (DRPCE) can offer voltage support during accident recovery, stabilize voltage fluctuation and inhibit any subsequent commutation failure risk. This paper proposes the optimal DRPCE configuration scheme for maximizing both inhibitory effect and economic performance. The simulation results on MATLAB-BPA prove the scheme’s correctness and rationality, which can effectively inhibit the risk of subsequent commutation failure and obtain economic benefits.

Reactive Power Compensation Method of HVDC Commutation Failure

2014 ◽  
Vol 536-537 ◽  
pp. 1510-1513
Author(s):  
Xiao Ming Wang ◽  
Qi Zhang ◽  
Bin Qian
Keyword(s):  
Reactive Power ◽  
Voltage Drop ◽  
Critical Value ◽  
Reactive Power Compensation ◽  
Transmission System ◽  
Critical Voltage ◽  
High Voltage Direct Current ◽  
Commutation Failure ◽  
The Difference ◽  
Bus Voltage

In the high-voltage direct current transmission system, the difference value between the landing phase voltage and DC transmission system commutation failure of the critical voltage drop value, as system occurred in the critical value of commutation failure. When commutation voltage lower than the critical value would reduce arc Angle, caused by commutation failure。Therefore, by using the method of reactive power compensation to keep converter bus voltage stability, can avoid commutation failure.

scholarly journals Low-Harmonic DC Ice-Melting Device Capable of Simultaneous Reactive Power Compensation

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2596
Author(s):  
Jiazheng Lu ◽  
Siguo Zhu ◽  
Bo Li ◽  
Yanjun Tan ◽  
Xiudong Zhou ◽  
...  
Keyword(s):  
Transmission Lines ◽  
High Efficiency ◽  
Reactive Power ◽  
Reactive Power Compensation ◽  
Negative Deviation ◽  
Ice Melting ◽  
Voltage Fluctuation ◽  
Small Power ◽  
Supply Capacity ◽  
Bus Voltage

As a result of the high efficiency of ice-melting and the small power supply capacity, DC ice-melting devices are widely used in relation to transmission lines in the power grid. However, it needs to consume reactive power when ice-melting, and voltage fluctuation of the substation may be caused when the demand for reactive power is large. It also generates a large number of 5th and 7th harmonics when ice-melting. In this paper, combined with the demand for ice-melting for transmission lines and the dynamic reactive power of substations, a low-harmonic DC ice-melting device capable of simultaneous reactive power compensation is studied. The function of ice-melting and reactive power compensation can be operated simultaneously and the rectifier’s main harmonics can be eliminated. The simulation and experimental research on the device was carried out in the 500 kV Chuanshan substation. The actual ice melting was carried out on the 500 kV Chuansu I line and took only 68 min to melt the ice. The 500 kV bus voltage had no negative deviation, and the positive deviation decreased from +3.09% to +1.57% within 24 h of testing. The results prove the feasibility of the proposed DC ice-melting device in this paper.

scholarly journals Open-Circuit Fault-Tolerant Design of the Cascaded H-Bridge Rectifier Incorporating Reactive Power Compensation

Electronics ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 1490
Author(s):  
Ting Chen ◽  
Hong Cheng ◽  
Cong Wang ◽  
Wenbo Chen ◽  
Zhihao Zhao
Keyword(s):  
Single Phase ◽  
Reactive Power ◽  
Power Transmission ◽  
Fault Tolerant ◽  
Reactive Power Compensation ◽  
Open Circuit ◽  
Normal Operation ◽  
Bridge Rectifier ◽  
Drive Signals ◽  
Fault Tolerant Design

This paper proposes an open-circuit fault-tolerant design for the cascaded H-Bridge rectifier incorporating reactive power compensation. If one or two switching devices of the H-bridge modules are fault, the drive signals of the faulty H-bridge modules will be artificially redistributed into the bridgeless mode (including the boost bridgeless mode, the symmetric boost bridgeless mode, the totem-pole bridgeless mode and the symmetry totem-pole bridgeless mode) and cooperate with the normally operated H-bridge modules. In this case, the faulty cascaded H-bridge rectifier is not only able to achieve active power transmission, but also can still provide part of reactive power compensation when injecting reactive power from the power grid. Nonetheless, the reactive power that it can supply will be limited, due to the unidirectional characteristics of the bridgeless mode for the faulty modules. Therefore, a method for calculating its adjustable power factor angle range is also presented, which provides the basis for the faulty modules switching to the bridgeless mode. Then, a control strategy of the cascaded H-bridge rectifier incorporating reactive power compensation under the faulty condition and normal operation is presented. Finally, an experimental platform with a single-phase cascaded H-bridge rectifier containing three cells is given to verify the proposed theories.

scholarly journals Multiobjective Reactive Power Optimization of Renewable Energy Power Plants Based on Time-and-Space Grouping Method

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3556
Author(s):  
Linan Qu ◽  
Shujie Zhang ◽  
Hsiung-Cheng Lin ◽  
Ning Chen ◽  
Lingling Li
Keyword(s):  
Renewable Energy ◽  
Power Plants ◽  
Large Scale ◽  
Reactive Power ◽  
Power Optimization ◽  
Reactive Power Compensation ◽  
Mixed Integer ◽  
Reactive Power Optimization ◽  
Time And Space ◽  
Bus Voltage

The large-scale renewable energy power plants connected to a weak grid may cause bus voltage fluctuations in the renewable energy power plant and even power grid. Therefore, reactive power compensation is demanded to stabilize the bus voltage and reduce network loss. For this purpose, time-series characteristics of renewable energy power plants are firstly reflected using K-means++ clustering method. The time group behaviors of renewable energy power plants, spatial behaviors of renewable energy generation units, and a time-and-space grouping model of renewable energy power plants are thus established. Then, a mixed-integer optimization method for reactive power compensation in renewable energy power plants is developed based on the second-order cone programming (SOCP). Accordingly, power flow constraints can be simplified to achieve reactive power optimization more efficiently and quickly. Finally, the feasibility and economy for the proposed method are verified by actual renewable energy power plants.

scholarly journals Analysis and Suppression of Voltage Violation and Fluctuation with Distributed Photovoltaic Integration

Symmetry ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1894
Author(s):  
Yahui Li ◽  
Yuanyuan Sun ◽  
Kejun Li ◽  
Jingru Zhuang ◽  
Yongliang Liang ◽  
...  
Keyword(s):  
Distribution System ◽  
Reactive Power ◽  
Influence Factors ◽  
Integrated System ◽  
Voltage Fluctuation ◽  
Partial Shading ◽  
High Penetration ◽  
Bus Voltage ◽  
Suppression Strategy ◽  
Voltage Violation

In recent years, the violation and fluctuation of system voltage has occurred with greater frequency with the integration of high-penetration distributed photovoltaic generation. In this paper, the voltage violation and fluctuation in a high-penetration distributed photovoltaic integrated system is analyzed, and then a corresponding suppression strategy is proposed. Firstly, based on solar cell and photovoltaic control system models, the influence factors of photovoltaic output are analyzed. Secondly, the voltage violation and fluctuation caused by photovoltaic integration is analyzed, and the quadratic parabola relationship between bus voltage fluctuation and photovoltaic power variation is constructed. Next, according to the virtual synchronous generator characteristic of distributed photovoltaics, a double-hierarchical suppression strategy is proposed to make full use of reactive power regulation capability, which can maintain the symmetry of power supply while meeting standard requirements. The proposed strategy can conveniently realize quick response and support the photovoltaic extensive access. Moreover, with the employment of the proposal, the system voltage violation and fluctuation can be suppressed effectively. Finally, considering the photovoltaic access location, capacity, and partial shading, the effectiveness of the proposed strategy is verified in IEEE 33-bus distribution system with field measured data. After distributed photovoltaic accesses the system, more than 60% of buses appear to have undergone bus voltage violation. With the proposed method, more than 20% of the voltage deviation and more than 6% of the voltage fluctuation are effectively suppressed so that the system voltage can be kept below 1.07 p.u. and the voltage fluctuation can be kept within 4%, meeting the requirements of power quality standards.

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