Research on Detection and Control Strategy for UPQC without PLL in Coal Mine

2013 ◽  
Vol 448-453 ◽  
pp. 3942-3946
Author(s):  
Yan Wen Wang ◽  
Yan Hua Jiang
Keyword(s):  
Power Quality ◽  
Coal Mine ◽  
Control Strategy ◽  
Control Method ◽  
Positive Sequence ◽  
Three Phase ◽  
Park Transformation ◽  
And Control ◽  
Quality Controller

To improve the power quality of power grid in coal mine, a kind of detection and control method for unified power quality controller (UPQC) without phase locked loop (PLL) is put forward. It can get the positive-sequence component of unity fundamental voltage through Park transformation,and then obtains the positive-sequence active component of fundamental current after proper operation . The PLL or filtering of three-phase voltage and the synchronous coordinates transformation for current are cancelled. The control strategy of the system is studied and the effectiveness and validity of UPQC are verified by simulation results.

Performance Improvement of SVPWM-Based Three-Phase Grid-Connected Inverters

2013 ◽  
Vol 732-733 ◽  
pp. 1261-1264
Author(s):  
Zhi Lei Yao ◽  
Lan Xiao ◽  
Jing Xu
Keyword(s):  
Dynamic Response ◽  
Control Strategy ◽  
Pulse Width Modulation ◽  
Control Method ◽  
Grid Current ◽  
Current Controller ◽  
Three Phase ◽  
Reference Grid ◽  
Grid Connected Inverter

An improved control strategy for three-phase grid-connected inverters with space vector pulse width modulation (SVPWM) is proposed. When the grid current contains harmonics, the d-and q-axes grid currents is interacted in the traditional control method, and the waveform quality of the grid current is poor. As the reference output voltage cannot directly reflect the change of the reference grid current with the traditional control strategy, the dynamic response of the grid-connected inverter is slow. In order to solve the aforementioned problems, the d-and q-axes grid currents in the decoupled components of the grid current controller are substituted by the d-and q-axes reference grid currents, respectively. The operating principles of the traditional and proposed control methods are illustrated. Experimental results show that the grid-connected inverter with the improved control strategy has high waveform quality of the grid current and fast dynamic response.

The Selective Harmonic Detection for the Integration Photovoltaic Generation and Active Power Filter

2011 ◽  
Vol 58-60 ◽  
pp. 781-786
Author(s):  
Yan Dan Lin ◽  
Li Qing Tong ◽  
Yao Jie Sun
Keyword(s):  
Control Strategy ◽  
Detection Method ◽  
Active Power Filter ◽  
Active Power ◽  
Positive Sequence ◽  
Harmonic Detection ◽  
Power Filter ◽  
Three Phase ◽  
Frequency Domains ◽  
And Control

To improve the utilization of the inverter of the photovoltaic grid connected systems and decrease the harmonic of the grid, a novel selective harmonic detection method based on the synchronous rotator frame is proposed. Utilizing three-phase Park transform, the rotator vector is transferred to the static vector, and the synchronous harmonic is separated and acquired. The characteristic of negative and positive sequence harmonic is fleetly and exactly presented in all frequency domains. Additional, a new control strategy based on this harmonic detection is proposed for the integration photovoltaic grid connected generation and active power filter. Validity and practicality of the proposed selective harmonic detection method and control strategy are proved.

scholarly journals Control Strategy for Electric Vehicle Charging Station Power Converters with Active Functions

Energies ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3971 ◽  
Author(s):  
Fermín Barrero-González ◽  
María Isabel Milanés-Montero ◽  
Eva González-Romera ◽  
Enrique Romero-Cadaval ◽  
Carlos Roncero-Clemente
Keyword(s):  
Power Quality ◽  
Control Strategy ◽  
Reactive Power ◽  
Power Electronic ◽  
Charging Station ◽  
Electric Vehicle Charging ◽  
Battery Chargers ◽  
Three Phase ◽  
Facility Level

Based on the assumption that vehicles served by petrol stations will be replaced by Electric Vehicles (EV) in the future, EV public charging station facilities, with off-board fast chargers, will be progressively built. The power demand of these installations is expected to cause great impact on the grid, not only in terms of peak power demanded but also in terms of power quality, because most battery chargers behave as non-linear loads. This paper presents the proposal of a novel comprehensive global control strategy for the power electronic converters associated with bidirectional three-phase EV off-board fast chargers. The Charging Station facility Energy Management System (CS-EMS) sends to each individual fast charger the active and reactive power setpoints. Besides, in case the charger has available capacity, it is assigned to compensate a fraction of the harmonic current demanded by other loads at the charging facility. The proposed approach works well under distorted and unbalanced grid voltages. Its implementation results in improvement in the power quality of each fast charger, which contributes to improvement in the power quality at the charging station facility level, which can even provide ancillary services to the distribution network. Simulation tests are conducted, using a 100 kW power electronic converter model, under different load and grid conditions, to validate the effectiveness and the applicability of the proposed control strategy.

scholarly journals Design of a Measuring System for Electricity Quality Monitoring within the SMART Street Lighting Test Polygon: Pilot Study on Adaptive Current Control Strategy for Three-Phase Shunt Active Power Filters

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1718 ◽  
Author(s):  
Radek Martinek ◽  
Petr Bilik ◽  
Jan Baros ◽  
Jindrich Brablik ◽  
Radana Kahankova ◽  
...  
Keyword(s):  
Power Quality ◽  
Control Strategy ◽  
Active Power ◽  
Current Control ◽  
Measuring System ◽  
Street Lighting ◽  
Active Power Filters ◽  
Power Filters ◽  
Three Phase

This study focuses on the design of a measuring system for monitoring the power quality within the SMART street lighting test polygon at university campuses with relation to testing an adaptive current control strategy for three-phase shunt active power filters. Unlike conventional street lighting, SMART elements are powered 24/7. Due to the electronic character of the power part of such mass appliances, there are increased problems with the power quality of the electric energy. Compared to the current concept of street lighting, there is a significant increase in the content of higher current harmonic components, which cause several problems in the distribution system. The test polygon contains 16 luminaires made by various manufacturers and mounted with various SMART components. Using the polygon control and monitoring system, dynamic load scenarios were selected. These scenarios tested the possibilities of different adaptive current control strategies for three-phase shunt active power filters to improve the power quality of electricity. This study focuses on three adaptive algorithms that respond to dynamic changes of current harmonics level in real-time. The possibility of active filter control was tested using FPGA, mainly due to the low latency of the filter control part.

scholarly journals D-PMU and 5G-Network-Based Coordination Control Method for Three-Phase Imbalance Mitigation Units in the LVDN

Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2754
Author(s):  
Mengmeng Xiao ◽  
Shaorong Wang ◽  
Zia Ullah
Keyword(s):  
Mobile Networks ◽  
Control Method ◽  
Low Voltage ◽  
Control Unit ◽  
Distribution Networks ◽  
Optimal Operation ◽  
Positive Sequence ◽  
Measurement Unit ◽  
Control Units ◽  
Three Phase

Three-phase imbalance is a long-term issue existing in low-voltage distribution networks (LVDNs), which consequently has an inverse impact on the safe and optimal operation of LVDNs. Recently, the increasing integration of single-phase distributed generations (DGs) and flexible loads has increased the probability of imbalance occurrence in LVDNs. To overcome the above challenges, this paper proposes a novel methodology based on the concept of "Active Asymmetry Energy-Absorbing (AAEA)" utilizing loads with a back-to-back converter, denoted as “AAEA Unit” in this paper. AAEA Units are deployed and coordinated to actively absorb asymmetry power among three phases for imbalance mitigation in LVDNs based on the high-precision, high-accuracy, and real-time distribution-level phasor measurement unit (D-PMU) data acquisition system and the 5th generation mobile networks (5G) communication channels. Furthermore, the control scheme of the proposed method includes three control units. Specifically, the positive-sequence control unit is designed to maintain the voltage of the DC-capacitor of the back-to-back converter. Likewise, the negative-sequence and zero-sequence control units are expected to mitigate the imbalanced current components. A simple imbalanced LVDN is modeled and tested in Simulink/Matlab (MathWorks, US). The obtained results demonstrate the effectiveness of the proposed methodology.

The Application of S7-200 PLC Reactive Compensation Device in Small Substation

2012 ◽  
Vol 479-481 ◽  
pp. 1476-1480
Author(s):  
Qing He Chu ◽  
Wen Si Cao ◽  
Zhen Nie
Keyword(s):  
Reactive Power ◽  
Control Method ◽  
High Reliability ◽  
Reactive Power Compensation ◽  
Control Device ◽  
Reactive Compensation ◽  
Reconstruction Project ◽  
Compensation Device ◽  
And Control

In the present rural power grid reconstruction project ,according to the problems of capacitor reactive power compensation in rural small substation. Take a small substation for instance, according to its operation and control method, set the criterion of the capacitor bank switching. A new high reliability, flexible reactive power compensation control device based on s7-200 PLC is designed. It plays an important role in improving the power supply , guaranteeing the quality of voltage, reducing the loss of rural power gid.

scholarly journals Research on Transient Power Quality of Large-capacity Electric Arc Furnace

2021 ◽  
Author(s):  
Liu Yang ◽  
Qinyue Tan ◽  
Di Xiong ◽  
Zhengguang Liu
Keyword(s):  
Power Quality ◽  
Reactive Power ◽  
Short Circuit ◽  
Electric Arc Furnace ◽  
Electric Arc ◽  
Normal Operation ◽  
Arc Furnace ◽  
Three Phase ◽  
Transient Power Quality

The overrun of transient power quality index caused by the large-capacity electric arc furnace (EAF) has become a prominent problem affecting the safe and stable operation of the power system. (1) In this paper, the relationship between arc furnace volt-age and current is derived based on the different stages of arc combustion, and the random variation of chaotic phenomenon of the arc voltage are simulated. Established an EAF model suitable for the study of transient power quality problems. (2) Take 50t AC EAF as an example to analyze the reactive power impact and the influence on the point of common coupling (PCC) voltage caused by the three-phase short circuit of the electrode. The results show that the experimental results are consistent with the theoretical analysis, verifying the correctness and effectiveness of the model. (3) When the three-phase short-circuit occurs, the reactive power impact is nearly 6 times that of normal operation, the short-circuit current is 2.66 times that of normal operation, and the effective value of the PCC voltage has dropped by 40.37%, which provides a theoretical basis for real-time compensation of impulsive reactive power and improvement of the transient power quality of the EAF.

scholarly journals Multicriterial Evaluation of the Transport and Logistic System of the Moscow Region

2021 ◽  
Vol 334 ◽  
pp. 02029
Author(s):  
Vasily Demin ◽  
Alexey Terentyev
Keyword(s):  
Radio Frequency ◽  
Control Method ◽  
Complex Structure ◽  
Moscow Region ◽  
Logistics System ◽  
System Parameters ◽  
Complex Problems ◽  
Control Technologies ◽  
And Control

The article deals with the direction of solving complex problems of interaction between the elements of the transport and logistics system of the Moscow region as a complex structure of management methods in multi-criteria systems and technologies for monitoring the quality of processes. The control method should optimize the system parameters, and control technologies (radio frequency cargo identification) implement feedback in the system.

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