Research on Optimal Application of SVG in Substation Regulated Voltage

2014 ◽  
Vol 602-605 ◽  
pp. 2970-2973
Author(s):  
Ying Nan Wang ◽  
Feng Li Han ◽  
Zhe Ren ◽  
Peng Jin ◽  
Hai Sheng Li ◽  
...  
Keyword(s):  
Low Voltage ◽  
Voltage Drop ◽  
Power Grid ◽  
Voltage Stabilization ◽  
Entire Line ◽  
Bus Voltage

In order to solve the problem of low voltage at a terminal rural power grid 66kV substation, a 5000-kilovar SVG is arranged in the substation to elevate and stabilize the 10kV bus voltage. Since put into operation, SVG runs well, solving the problem of low voltage while lowering the loss of the entire line. However, in some cases, people find that while stabilizing the bus voltage, SVG causes voltage drop in adjacent substation, and act of the intelligent capacitor unit in the adjacent substation, thus leading to opposite reactive response of SVG, affecting voltage stabilization of the two substations and adding up to equipment loss. This paper analyzes this phenomenon and has proposed an approach of correction.

Comparative Study on Low Voltage Ride-Through Test Methods for Grid-Connected Photovoltaic Inverter

2014 ◽  
Vol 590 ◽  
pp. 495-499
Author(s):  
Wen Jin Wu ◽  
Jian Hui Su ◽  
Hai Ning Wang
Keyword(s):  
Large Scale ◽  
Low Voltage ◽  
Voltage Drop ◽  
Power Grid ◽  
Design For Test ◽  
Grid Voltage ◽  
Low Voltage Ride Through ◽  
Technical Requirements ◽  
Test Platform ◽  
The Stability

The large scale photovoltaic plants have more effects on the stability of regional power grid with the rapid increase of photovoltaic generation ratio in some areas. According to the grid guideline, the photovoltaic inverter is required to maintain the running status even the grid voltage drops and needs to have the capability to contribute towards the stability of power grid voltage and to support the grid voltage ride through. To test the ability of photovoltaic inverter low voltage ride through (LVRT), the test platform to simulate all kinds of fault for voltage drop needs to be set up. By the low voltage through technical requirements, this paper puts forward three kinds of design for test platform and analyzes respective work principle and characteristics, in order to provide optimization solution for the low voltage ride through test work.

scholarly journals Modeling and Parameter Optimization of Grid-Connected Photovoltaic Systems Considering the Low Voltage Ride-through Control

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3972
Author(s):  
Li Wang ◽  
Teng Qiao ◽  
Bin Zhao ◽  
Xiangjun Zeng ◽  
Qing Yuan
Keyword(s):  
Parameter Optimization ◽  
Low Voltage ◽  
Power Grid ◽  
Current Loop ◽  
Stable Operation ◽  
Power Fluctuation ◽  
Grid Current ◽  
Low Voltage Ride Through ◽  
Dc Bus ◽  
Bus Voltage

The asymmetric faults often cause the power grid current imbalance and power grid oscillation, which brings great instability risk to the power grid. To address this problem, this paper presented a modeling and parameter optimization method of grid-connected photovoltaic (PV) systems, considering the low voltage ride-through (LVRT) control. The harmonics of the grid current under asymmetric faults were analyzed based on the negative-sequence voltage feedforward control method. The notch filter was added to the voltage loop to filter out the harmonic components of the DC bus voltage and reduce the harmonic contents of the given grid current value. The proportional resonant (PR) controller was added to the current loop. The combination of these two components could reduce the 3rd, 5th, and 7th harmonics of the grid current and the output power fluctuation. Then, the parameters of the inverter controller were identified by the adaptive differential evolution (ADE) algorithm based on the sensitivity analysis. The effectiveness of the proposed method was compared with two other strategies under the asymmetric grid faults. The suppression of DC bus voltage fluctuation, power fluctuation, and low-order harmonics of the grid current all had better results, ensuring the safe and stable operation of the PV plant under grid faults.

Low Voltage Ride through (LVRT) Control of Double-Fed Wind-Driven Generator

2012 ◽  
Vol 499 ◽  
pp. 400-404
Author(s):  
Jian Hong Zheng ◽  
Jie Feng Li ◽  
Yu Zhi Gao
Keyword(s):  
Power System ◽  
Wind Turbine ◽  
Wind Power ◽  
Control Method ◽  
Low Voltage ◽  
Voltage Drop ◽  
Power Grid ◽  
Rapid Development ◽  
Low Voltage Ride Through ◽  
The Impact

With the rapid development of the wind power, it is no longer an isolated power system and gradually incorporated in the local power grid. However, as the increasing proportion of the installed wind power capacity in the power grid, the affection of the wind turbine to the region power system is getting heavier, which inevitably bring some new problems to the power system. The low voltage ride through (LVRT) is the direct embodiment of the power quality. In this paper, we fist analyze the impact of the voltage drop on the double-fed wind turbine. Then, a LVRT control method is proposed based on hardware realization. The detailed explanation of the proposed control method is given at last.

Renovating the View of Cost Sharing for the Underground Low Voltage Cable Projects in Hanoi

2019 ◽  
Vol 35 (5E) ◽  
Author(s):  
Pham Thi Thu Ha ◽  
Phan Dieu Huong
Keyword(s):  
Willingness To Pay ◽  
Cost Sharing ◽  
Low Voltage ◽  
Power Grid ◽  
Field Studies ◽  
Power Industry ◽  
Well Field ◽  
The Subject ◽  
Sharing Responsibility ◽  
The Cost

Underground power grid projects in Hanoi is so urgent that it requires immediate implementation. To synchronously and quickly implement the underground power grid projects, people in charge should not follow the outdated perspectives of just including the power industry, but also need to call for the support and cost sharing responsibility from consumers. This paper aims at approaching the subject both from the producers and consumers’ perspectives to together sharing the cost of putting the power grid underground not only in Hanoi but other metropolitans in Vietnam as well. Field studies (including 104 families) at Hoan Kiem District, Hanoi and CBA method were applied to investigate the willingness to pay (WTP) level of consumers to share the cost with the power industry for the underground power grid projects in Hanoi. The overview of the results shows that cost for the underground power grid in Hoan Kiem District ranging from 30,000 VND/household/month to 46,000VND/household/month. On the other hand, the willingness to pay of a typical household of four people within Hoan Kiem District ranges from 17,000VND/month to 24,000VND/month, with the most favorable method of annual payment within a detailed timeline.

Reduction of the Low Voltage Substation Constraints by Inserting Photovoltaic Systems in Underserved Areas

2019 ◽  
Vol 12 (2) ◽  
pp. 105-112
Author(s):  
Benbouza Naima ◽  
Benfarhi Louiza ◽  
Azoui Boubekeur
Keyword(s):  
Low Voltage ◽  
Voltage Drop ◽  
Electrical Energy ◽  
Utilization Rate ◽  
Photovoltaic Systems ◽  
Voltage Distribution ◽  
Medium Voltage ◽  
Pv Systems ◽  
Transformer Substation ◽  
Load Pattern

Background: The improvement of the voltage in power lines and the respect of the low voltage distribution transformer substations constraints (Transformer utilization rate and Voltage drop) are possible by several means: reinforcement of conductor sections, installation of new MV / LV substations (Medium Voltage (MV), Low Voltage (LV)), etc. Methods: Connection of mini-photovoltaic systems (PV) to the network, or to consumers in underserved areas, is a well-adopted solution to solve the problem of voltage drop and lighten the substation transformer, and at the same time provide clean electrical energy. PV systems can therefore contribute to this solution since they produce energy at the deficit site. Results: This paper presents the improvement of transformer substation constraints, supplying an end of low voltage electrical line, by inserting photovoltaic systems at underserved subscribers. Conclusion: This study is applied to a typical load pattern, specified to the consumers region.

scholarly journals Dynamic Low Voltage Ride through Detection and Mitigation in Brushless Doubly Fed Induction Generators

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4461
Author(s):  
Ahsanullah Memon ◽  
Mohd Wazir Mustafa ◽  
Muhammad Naveed Aman ◽  
Mukhtar Ullah ◽  
Tariq Kamal ◽  
...  
Keyword(s):  
Fuzzy Logic ◽  
Fuzzy Logic Controller ◽  
Low Voltage ◽  
Voltage Drop ◽  
Low Voltage Ride Through ◽  
Induction Generators ◽  
Doubly Fed Induction Generators ◽  
Reactive Current ◽  
Doubly Fed ◽  
Rotor Side Converter

Brushless doubly-fed induction generators have higher reliability, making them an attractive choice for not only offshore applications but also for remote locations. These machines are composed of two back-to-back voltage source converters: the grid side converter and the rotor side converter. The rotor side converter is typically used for reactive current control of the power winding using the control winding current. A low voltage ride through (LVRT) fault is detected using a hysterisis comparison of the power winding voltage. This approach leads to two problems, firstly, the use of only voltage to detect faults results in erroneous or slow response, and secondly, sub-optimal control of voltage drop because of static reference values for reactive current compensation. This paper solves these problems by using an analytical model of the voltage drop caused by a short circuit. Moreover, using a fuzzy logic controller, the proposed technique employs the voltage frequency in addition to the power winding voltage magnitude to detect LVRT conditions. The analytical model helps in reducing the power winding voltage drop while the fuzzy logic controller leads to better and faster detection of faults, leading to an overall faster response of the system. Simulations in Matlab/Simulink show that the proposed technique can reduce the voltage drop by up to 0.12 p.u. and result in significantly lower transients in the power winding voltage as compared to existing techniques.

Assessment of power quality parameters and indicators at the point of common coupling in a low voltage power grid with photovoltaic generation emulated

2022 ◽  
Vol 203 ◽  
pp. 107679
Author(s):  
Oscar Pinzón-Quintero ◽  
Daniel Gaviria-Ospina ◽  
Alejandro Parrado-Duque ◽  
Rusber Rodríguez-Velásquez ◽  
German Osma-Pinto
Keyword(s):  
Power Quality ◽  
Low Voltage ◽  
Power Grid ◽  
Quality Parameters ◽  
Photovoltaic Generation ◽  
Point Of Common Coupling ◽  
Common Coupling

scholarly journals MITIGATION OF CURRENT HARMONIC DISTORTIONS STREAMING FROM DOMESTIC NON-LINEAR LOADS USING SINGLE PHASE ACTIVE POWER FILTER.

2018 ◽  
Keyword(s):  
Single Phase ◽  
Low Voltage ◽  
Power Grid ◽  
Power Supplies ◽  
Sleep Mode ◽  
Premature Failure ◽  
Current Harmonic ◽  
Distribution Transformers ◽  
Non Linear ◽  
Harmonic Distortions

This study investigated current harmonic distortions emanating from domestic non-linear loads which have adverse deleterious effects on installed low voltage switchgears such as transformers and conductors. The study examined harmonic distortions emanating from dominant domestic nonlinear loads such as microwave, TV set, radio, fridge, video player and compacted fluorescence bulbs (CFLs) using a power quality equipment. From the results obtained, it was noted that there is need to mitigate harmonic distortions generated by domestic loads at point of common coupling (PCC). It is pertinent to mention that the recent study on supplied loads carried out in Kenya power grid shows that above 67% of power end users are domestic consumers. Under current last mile initiative and Global Partnership on Output Based Aid (GPOBA), unprecedented increase of domestic loads connected to the power grid is predicted. It is worth pointing out that most of these domestic loads have switch mode power supplies (SMPS) which have inherent characteristics of distorting current waveform which causes voltage distortions, over-heating of neutral conductors and premature failure of distribution transformers. Further, most of these loads have two modes; standby/sleep mode and operating mode. Results shows that the two modes generate current harmonic distortions which stream back to power utility network through the service cable. Recently, engineers have designed electronic devices that consume less power. These devices draw current in pulses rather than sinusoidal waveform. As a result, the quality of power supplies continues to deteriorate hence adversely affecting the installed low voltage switchgears such as distribution transformers. Although various mitigation measures exist to reduce the effects of harmonic distortions, this paper proposes a single phase active filter as an optimal solution for attenuating the harmonics emanating from domestic non-linear loads.

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