scholarly journals An Active/Reactive Power Control Strategy for Renewable Generation Systems

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1061
Author(s):  
Iván Andrade ◽  
Rubén Pena ◽  
Ramón Blasco-Gimenez ◽  
Javier Riedemann ◽  
Werner Jara ◽  
...  

The development of distributed generation, mainly based on renewable energies, requires the design of control strategies to allow the regulation of electrical variables, such as power, voltage (V), and frequency (f), and the coordination of multiple generation units in microgrids or islanded systems. This paper presents a strategy to control the active and reactive power flow in the Point of Common Connection (PCC) of a renewable generation system operating in islanded mode. Voltage Source Converters (VSCs) are connected between individual generation units and the PCC to control the voltage and frequency. The voltage and frequency reference values are obtained from the P–V and Q–f droop characteristics curves, where P and Q are the active and reactive power supplied to the load, respectively. Proportional–Integral (PI) controllers process the voltage and frequency errors and set the reference currents (in the dq frame) to be imposed by each VSC. Simulation results considering high-power solar and wind generation systems are presented to validate the proposed control strategy.

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3140 ◽  
Author(s):  
Weiming Liu ◽  
Tingting Zheng ◽  
Ziwen Liu ◽  
Zhihua Fan ◽  
Yilong Kang ◽  
...  

This paper presents a power compensation strategy to suppress the double frequency power ripples of Voltage source converter high-voltage direct current (VSC-HVDC) systems under unbalanced grid voltage conditions. The mathematical control equations of the double frequency ripple power of VSC under unbalanced operating conditions are firstly derived and established, where the dynamic behaviors of the double frequency ripples in active and reactive power are regarded as being driven by current-relevant components and voltage-relevant components, respectively. Based on the equations, a power compensation control strategy of VSC-HVDC is proposed via the passivity-based control with disturbance observer to suppress both the current-relevant and voltage-relevant components in the power ripples. With this control strategy, the double frequency ripples in active and reactive power are suppressed simultaneously and system performance is significantly enhanced with the implementation of the disturbance observer in the passivity-based control. Theoretical stability analysis and simulation cases show the effectiveness and superiority of the proposed strategy.


Author(s):  
A. Naveena ◽  
M.Venkateswara Rao

The equipments based on the power electronics have been improved under the name of Flexible Alternating Current Transmission Systems (FACTS) in the last years. Unified Power Flow Controller (UPFC) is the most widely used FACTS device to control the power flow and to optimize the system stability in the transmission line. UPFC is a FACTS devices that can control active and reactive power flow in transmission line by means of injection controllable series voltage to the transmission line. This paper proposes a new connection for a Unified Power Flow Controller (UPFC) to control the active and reactive power flow control in two sides of a transmission line independently and it regulates bus voltage in the same transmission line, furthermore it is possible to balance line current too. This connection of the UPFC will be called an center node UPFC (C_UPFC). It is one of the newest devices within the FACTS technology. The structure and capability of the C_UPFC is discussed and its control scheme is based on the d-q orthogonal coordinates. According to this, the performance of UPFC for several modes of operations using different control mechanisms based on Proportional-Integral (PI) and PID based controllers has been studied. The obtained simulation results from Matlab/simulink confirm the effective features.


2011 ◽  
Vol 55-57 ◽  
pp. 1361-1364
Author(s):  
Jun Li Zhang ◽  
Xiao Feng Lv ◽  
Chao Li

With the growth of industry manufacturers and population, power quality becomes more and more important issue, and is attracting significant attention due to the increase in the number of sensitive loads. A distribution static compensator (DSTATCOM) is a voltage source inverter (VS1)-based power electronic device, which is usually used to compensate reactive power and sustain the system voltage in distribution power system. Compared with the traditional STATCOM, multilevel STATCOMs exhibit faster dynamic response, smaller volume, lower cost, and higher ratings. A multilevel inverter connected to an energy storage device can control both active and reactive power flow, providing more flexible and versatile power transmission operation. SPWM is actually a kind of multi-pulse trigger mode and used to trigger the switches in DSTATCOM.


Energies ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2341
Author(s):  
Benjamin T. Gwynn ◽  
Raymond de Callafon

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.


2014 ◽  
Vol 19 (4) ◽  
pp. 397-405
Author(s):  
Leonardo Poltronieri Sampaio ◽  
Moacyr Aureliano Gomes de Brito ◽  
Guilherme de Azevedo e Melo ◽  
Carlos Alberto Canesin

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