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

Abstract

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.Peer ReviewedPostprint (published version

Electromechanical Design of Synchronous Power Controller in Grid Integration of Renewable Power Converters to Support Dynamic Stability

“…As discussed in [30], the global structure and internal control unit of RSSG-SPC can illustrated as in Figure 1. As a renewable generation unit, the primary source of RSSG-SPC can be supplied from several types of the sources such as wind, solar, and energy storage systems.…”

“…Finally, the PR controller as an internal layer of the controller would provide three phase voltage references (V * abc ) for the PWM module to drive the converter switches. Further details concerning the control layers has been extensively discussed in [30,32].…”

“…Equation (3) gives the internal modes of RSSG-SPC ( = , ). As discussed in [30], RSSG-SPC's dynamic parameters provide high flexibility inside the RSSG-SPC that can be targeted for several applications in grid connection.…”

“…Equations ( 1)-( 5) indicate that the internal dynamics of the RSSG-SPC would be affected by variations in an external power grid which is due to the frequency deviations (ω o ) as a result of the changing in generation level, or small variation of power grid reactance X Grid due to the operation of breakers in transmission lines. Therefore, considering the practical situations of grid connection in our previous research presented in [27][28][29][30][31], a reasonable design consideration is to take a 5% safety margin in tuning D SSG . Therefore, in the grid application of RSSG-SPC illustrated in Figure 7, the damping range (0.45 < D SSG < 0.55 pu) for RSSG-SPC can satisfy the grid operators' requirements.…”

“…This essential point has not been covered in the related previous work. Therefore, an organized and sequenced method for electromechanical design of Renewable Static Synchronous Generators controlled by SPC (RSSG-SPC) in grid application has been proposed briefly in [30]. Later, this methodology has been expanded and investigated from several points of the view in [31].…”