scholarly journals Reactive Power Injection to Mitigate Frequency Transients Using Grid Connected PV Systems

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1998
Author(s):  
Yujia Huo ◽  
Simone Barcellona ◽  
Luigi Piegari ◽  
Giambattista Gruosso
Keyword(s):  
Power Systems ◽  
Power Flow ◽  
Reactive Power ◽  
Active Power ◽  
Ancillary Service ◽  
Synchronous Generators ◽  
Pass Filter ◽  
Low Pass Filter ◽  
Reactive Power Flow ◽  
Virtual Inertia

The increasing integration of renewable energies reduces the inertia of power systems and thus adds stiffness to grid dynamics. For this reason, methods to obtain virtual inertia have been proposed to imitate mechanical behavior of rotating generators, but, usually, these methods rely on extra power reserves. In this paper, a novel ancillary service is proposed to alleviate frequency transients by smoothing the electromagnetic torque of synchronous generators due to change of active power consumed by loads. Being implemented by grid-tied inverters of renewables, the ancillary service regulates the reactive power flow in response to frequency transients, thereby demanding no additional power reserves and having little impact on renewables’ active power generation. Differently from the active power compensation by virtual inertia methods, it aims to low-pass filter the transients of the active power required to synchronous generators. The proposed ancillary service is firstly verified in simulation in comparison with the virtual inertia method, and afterwards tested on processor by controller-hardware-in-the-loop simulation, analysing practical issues and providing indications for making the algorithm suitable in real implementation. The ancillary service proves effective in damping frequency transients and appropriate to be used in grid with distributed power generators.

scholarly journals Interphase Power Flow Control via Single-Phase Elements in Distribution Systems

2021 ◽  
Vol 3 (1) ◽  
pp. 37-58
Author(s):  
Piyapath Siratarnsophon ◽  
Vinicius C. Cunha ◽  
Nicholas G. Barry ◽  
Surya Santoso
Keyword(s):  
Power Consumption ◽  
Power Systems ◽  
Power Flow ◽  
Distribution Systems ◽  
Single Phase ◽  
Reactive Power ◽  
Active Power ◽  
Real Power ◽  
Power Flow Control ◽  
Reactive Power Flow

The capability of routing power from one phase to another, interphase power flow (IPPF) control, has the potential to improve power systems efficiency, stability, and operation. To date, existing works on IPPF control focus on unbalanced compensation using three-phase devices. An IPPF model is proposed for capturing the general power flow caused by single-phase elements. The model reveals that the presence of a power quantity in line-to-line single-phase elements causes an IPPF of the opposite quantity; line-to-line reactive power consumption causes real power flow from leading to lagging phase while real power consumption causes reactive power flow from lagging to leading phase. Based on the model, the IPPF control is proposed for line-to-line single-phase power electronic interfaces and static var compensators (SVCs). In addition, the control is also applicable for the line-to-neutral single-phase elements connected at the wye side of delta-wye transformers. Two simulations on a multimicrogrid system and a utility feeder are provided for verification and demonstration. The application of IPPF control allows single-phase elements to route active power between phases, improving system operation and flexibility. A simple IPPF control for active power balancing at the feeder head shows reductions in both voltage unbalances and system losses.

scholarly journals Demodulation of Three-Phase AC Power Transients in the Presence of Harmonic Distortion

Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2341
Author(s):  
Benjamin T. Gwynn ◽  
Raymond de Callafon
Keyword(s):  
Power Systems ◽  
Power Flow ◽  
Reactive Power ◽  
Harmonic Distortion ◽  
Transient Effects ◽  
Active And Reactive Power ◽  
Reactive Power Flow ◽  
Ac Power ◽  
Rlc Circuit ◽  
Smart Inverters

Load switches in power systems may cause oscillations in active and reactive power flow. Such oscillations can be damped by synthetic inertia provided by smart inverters providing power from DC sources such as photovoltaic or battery storage. However, AC current provided by inverters is inherently non-sinusoidal, making measurements of active and reactive power subject to harmonic distortion. As a result, transient effects due to load switching can be obscured by harmonic distortion. An RLC circuit serves as a reference load. The oscillation caused by switching in the load presents as a dual-sideband suppressed-carrier signal. The carrier frequency is available via voltage data but the phase is not. Given a group of candidate signals formed from phase voltages, an algorithm based on Costas Loop that can quickly quantify the phase difference between each candidate and carrier (thus identifying the best signal for demodulation) is presented. Algorithm functionality is demonstrated in the presence of inverter-induced distortion.

scholarly journals Power flow control in parallel transmission lines based on UPFC

2020 ◽  
Vol 9 (5) ◽  
pp. 1755-1765
Author(s):  
Mohammed Y. Suliman ◽  
Mahmood T. Al-Khayyat
Keyword(s):  
Power Systems ◽  
Flow Control ◽  
Transmission Lines ◽  
Power Flow ◽  
Reactive Power ◽  
Unified Power Flow Controller ◽  
Parallel Transmission ◽  
Power Flow Control ◽  
Active And Reactive Power ◽  
Reactive Power Flow

The power flow controlled in the electric power network is one of the main factors that affected the modern power systems development. The unified power flow controller (UPFC) is a FACTS powerful device that can control both active and reactive power flow of parallel transmission lines branches. In this paper, modelling and simulation of active and reactive power flow control in parallel transmission lines using UPFC with adaptive neuro-fuzzy logic is proposed. The mathematical model of UPFC in power flow is also proposed. The results show the ability of UPFC to control the flow of powers components "active and reactive power" in the controlled line and thus the overall power regulated between lines.

Control Methods and Techniques on GIC in Power Systems

2013 ◽  
Vol 805-806 ◽  
pp. 1136-1139
Author(s):  
Yi Yang
Keyword(s):  
Power Systems ◽  
Power Flow ◽  
Reactive Power ◽  
Geomagnetic Storms ◽  
Stable Operation ◽  
Control Methods ◽  
Geomagnetic Disturbances ◽  
Reactive Power Flow ◽  
Methods And Techniques ◽  
And Control

GICs in technological conductor networks are a ground manifestation of space weather. During severe geomagnetic storms, if GICs flow in power systems, real and reactive power flow will swing abnormally, also transformer saturation, over-voltage fluctuation, frequency shift, unnecessary relay trippings and increased harmonic contents, even damage of transformer or a collapse of the whole system may occur. So GIC controlling in power systems is so significant that it can help power systems stand through strong geomagnetic disturbances, as well as ensure safe and stable operation of power systems. In this paper, control methods and techniques on GIC in power systems have been summarized in reference of research achievements and control experience on GIC.

scholarly journals Solution of the Optimal Reactive Power Flow Problem Using a Discrete-Continuous CBGA Implemented in the DigSILENT Programming Language

Computers ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 151
Author(s):  
David Lionel Bernal-Romero ◽  
Oscar Danilo Montoya ◽  
Andres Arias-Londoño
Keyword(s):  
Power Systems ◽  
Programming Language ◽  
Power Flow ◽  
Reactive Power ◽  
Flow Problem ◽  
Computational Effort ◽  
Power Losses ◽  
Reactive Power Flow ◽  
Power Flow Problem ◽  
Optimal Reactive Power Flow

The problem of the optimal reactive power flow in transmission systems is addressed in this research from the point of view of combinatorial optimization. A discrete-continuous version of the Chu & Beasley genetic algorithm (CBGA) is proposed to model continuous variables such as voltage outputs in generators and reactive power injection in capacitor banks, as well as binary variables such as tap positions in transformers. The minimization of the total power losses is considered as the objective performance indicator. The main contribution in this research corresponds to the implementation of the CBGA in the DigSILENT Programming Language (DPL), which exploits the advantages of the power flow tool at a low computational effort. The solution of the optimal reactive power flow problem in power systems is a key task since the efficiency and secure operation of the whole electrical system depend on the adequate distribution of the reactive power in generators, transformers, shunt compensators, and transmission lines. To provide an efficient optimization tool for academics and power system operators, this paper selects the DigSILENT software, since this is widely used for power systems for industries and researchers. Numerical results in three IEEE test feeders composed of 6, 14, and 39 buses demonstrate the efficiency of the proposed CBGA in the DPL environment from DigSILENT to reduce the total grid power losses (between 21.17% to 37.62% of the benchmark case) considering four simulation scenarios regarding voltage regulation bounds and slack voltage outputs. In addition, the total processing times for the IEEE 6-, 14-, and 39-bus systems were 32.33 s, 49.45 s, and 138.88 s, which confirms the low computational effort of the optimization methods directly implemented in the DPL environment.

scholarly journals Active and reactive power flow management in parallel transmission lines using static series compensation (SSC) with energy storage

2019 ◽  
Vol 9 (6) ◽  
pp. 4598
Author(s):  
Mohammed Yahya Suliman
Keyword(s):  
Power Systems ◽  
Transmission Lines ◽  
Power Flow ◽  
Reactive Power ◽  
Parallel Transmission ◽  
Power Flow Control ◽  
Active And Reactive Power ◽  
Reactive Power Flow ◽  
Active Power Flow ◽  
Storage Energy

<p>The power flow controlled in the electric power network is one of the main factors that affected the modern power systems development. The Static Series Compensatior with storage energy, is a FACTS powerful device that can control the active power flow control of multiple transmission lines branches. In this paper, a simulation model of power control using static series compensator with parallel transmission lines is presented.  The control system using adaptive neuro-fuzzy logic is proposed. The results show the ability of static series compensator with storage energy to control the flow of powers components "active and reactive power" in the controlled line and thus the overall power regulated between lines. </p>

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