Raul Santiago Munoz Aguilar

Improving long line stability by integrating renewables using static synchronous generators

Daily increasing in renewable energy sources installed in dispersed location, has led to greater need for long transmission lines to use these green sources. Voltage and phase stability are major challenges for transmission system operators in the operation of these lines. In this paper, a Static Synchronous Generators based in Synchronous Power Controller (SSG-SPC) is presented and implemented in a long AC transmission system in order to reducing stability problems. Power control strategies, compatibility with the grid codes and improvement in voltage and phase stability by SSG-SPC are investigated. Simulations and Experimental test results confirms SSG-SPC capability for participation in reactive compensation, damping active power oscillations and modify stability margins.

Phase stability enhancement in big power networks using renewable generation units controlled by SPC

High penetration of Renewable Generation Units (RGU), has led to that the interaction of this newfound participators in power network with conventional units be more critical challenges for network operators. Effect on the phase stability in emplacement as well as on neighbor generation units is one of this essential challenges. In this paper, a RGU controlled by Synchronous Power Controller (SPC) which behaves as a big Static Synchronous Generation (SSG-SPC) units, are presented as solution to cope with this challenge. Small signal modelling of a power network in presence of SSG-SPC unit is used to analysis this solution. After illustrating SPC dynamic capabilities, study on IEEE-14B test system based on modal analysis, time domain investigation and real time test confirms that a SSG-SPC not only has not damaging impact on phase stability and dynamic of network, but on the contrary can improve it. Moreover, by having at least two dynamic freedom degrees in SPC, the SSG-SPC can adapt itself for keeping this improvement effect.

Synchronous power controller merits for dynamic stability improvement in long line by renewables

Growing universal demand for greater use of renewable energy resources (RES) installed in dispersed location, has caused to more urgent need for long transmission systems to use these green sources. Small signal stability is one of vital challenges for transmission system operators in presence of big RES. In this paper, a Static Synchronous Generators based in Synchronous Power Controller (SSG-SPC) is presented and its capabilities for dynamic stability enhancement in a long AC transmission system is investigated. Dynamic modelling of a long line and then study in Uncompensated and Compensated cases by using time domain simulation and modal analysis, and then experimental test confirms that SSG-SPC can be effective in active damping of power oscillations and reducing small signal stability challenges.

Generation frequency support by renewable SSG SPC unit on interconnected areas

Supporting frequency inside of each generation area as well as keeping proper synchronism condition between interconnected areas are two main challenges for grid operators. In this paper, after analysis of structure of Renewable Static Synchronous Generation unit based on Synchronous Power Controller (RSSG-SPC) for holding and control of frequency, it is shown that how a renewable unit based on SPC can contribute to frequency support inside of generation areas and in this way it will support synchronism of neighbor areas. Results of mathematical analysis and state space modelling, as well as time domain investigation then real time test of two area system in presence of RSSG-SPC confirm that by reducing Rate of Change of Frequency (ROCOF), increasing level of Frequency Nadir (FN) and providing stiffer Center Of Inertia (COI) for whole of the grid, the RSSG-SPC not only supports frequency on the generation areas, furthermore it will cover synchronism of these interconnected areas.

Active power limiter for grid connection of modern renewable SSG SPC

Management of Renewable Static Synchronous Generation units based on Synchronous Power Controller (RSSG-SPC), not only provides grid synchronization without using PLL and gives proper dynamic to output active power, moreover yields simple solution to overcome technical constraints on these units. Control of active power level injected to the grid is one of these key constraints which can overcome by an Active Power Limiter (APL). In this work, an APL designed based on the classic power equation is proposed for this kind of modern RSSG-SPCs. Primary Simulink analysis and real time test results confirm that suggested APL can control and limit both maximum and minimum level of output active power for several grid connection cases.

Grid resonance attenuation in long lines by using renewable energy sources

In this paper the grid harmonic resonance on long lines is studied, in particular the resonance phenomena between the grid series inductance and the line parallel capacitor. Later, the resonance is attenuated by using a renewable energy generator. Experimental results are depicted and the conclusions are stated.In this paper the grid harmonic resonance on long lines is studied, in particular the resonance phenomena between the grid series inductance and the line parallel capacitor. Later, the resonance is attenuated by using a renewable energy generator. Experimental results are depicted and the conclusions are stated.

Analysis on dynamic interaction of renewable SSG SPC with external power grid

Control of renewables by Synchronous Power Controller (SPC) technology provides virtual damping and inertia which results to support phase stability on the grid and keep synchronism of interconnected areas tighter. Serving these benefits needs to have proper dynamic interaction between renewables and grid. In this paper, according to the dynamic modeling of Renewable Static Synchronous Generation unit based on SPC (RSSG-SPC) connected to an external grid, an index is introduced for the study of the dynamic interaction between RSSG-SPC and grid by analysis of synchronization power. Mathematical analysis for weak then stiff external grid confirms that the proposed index can be trustable for both single and two-dimensional design. Modal analysis and detailed time domain test approve that the suggested indices can clarify adjustment range for dynamic parameters aim to have optimal synchronization process between RSSG-SPC and grid, which leads to control this dynamic interaction.