Power System Stability with Power-Electronic Converter Interfaced Renewable Power Generation: Present Issues and Future Trends

Abstract

<jats:p>The energy sector is currently undergoing a rapid transformation with the integration of power electronic converter (PEC)-interfaced renewable energy sources (RES), such as wind and solar photovoltaic (PV) systems, at both the transmission and distribution networks. Power system stability has been significantly influenced by this power grid transformation. This paper comprehensively reviews major power system stability issues affected due to large-scale integration of PEC-interfaced RES in power grids, with some example case studies relevant for each stability category. According to the review, stability issues are mainly originating from reduction in synchronous inertia, reduction in reactive power reserve, low short-circuit strength of the power network, and fault ride-through (FRT) strategy/capability of the PEC-interfaced RES. Decrease in synchronous inertia could affect both the rotor angle stability and the frequency stability, while decrease in short-circuit strength and reactive power reserve could cause voltage stability and rotor angle stability issues in power networks. Sub-synchronous control interactions are also receiving a lot of attention by the power industry due to increasing oscillatory stability incidents reported in power networks with PEC-interfaced RES. FRT capabilities/strategies of PEC-interfaced RES are also playing a pivotal role in power grid stability due to its influence on active and reactive power, hence more emphasis should be placed on FRT schemes of PEC-interfaced RES, since future power grids are expected to operate with 100% PEC-interfaced generation sources. Stability improvement strategies could be implemented to address multiple stability issues in PEC-interfaced power networks; however, rigorous stability studies are required to identify the optimal conditions to implement these improvement strategies. Furthermore, ongoing structural changes in power grids to accommodate remotely sited PEC-interfaced RES are also influencing the stability of power grids. Therefore, all these factors must be carefully considered by system operators when planning and operating power grids in a secure and stable manner with high penetration levels of PEC-interfaced RES.</jats:p>

Power system stability in the transition to a low carbon grid: A techno‐economic perspective on challenges and opportunities

“…Attempts are also being made to identify suitable substitutes for inertia, for instance via pre‐programmed synthetic responses that could be provided by some PEC‐interfaced technologies (known by different technical terms, such as synthetic inertia, emulated inertial response, FFR, etc.). Three main techniques are proposed within the literature, and indeed commercial offerings implemented by OEMs (Meegahapola, Sguarezi, et al, 2020), to achieve an FFR; (1) response based on frequency error (Δ f ), (2) response based on ROCOF ( df / dt ), (3) fixed trajectory response (fixed trapezoidal response) when the frequency excursion exceeds a certain threshold (Ruttledge & Flynn, 2016). By providing a very fast active power response—in the same timescale as an inertial response (basically, sub‐second response)—these technologies can help to stabilize the system frequency during frequency excursions (Ruttledge et al, 2013; Tan et al, 2017).…”

A study of the transient processes in the physical model of the electric power systems with predominant part of the renewable energy sources

“…From the other hand, the quality of the generated energy also is important factor for system stability. For example, the output voltage shape of the inverters and noise in the system are one of the strongest factors for system failures [1]. Having in mind upper reasons and facts it will be correct the parameters of the model transient process to be defined as follows [11]:…”

“…During the last few decades, the scale of renewable energy sources (RES) integrated into the electric power system (EPS) has been rapidly increasing. In the global EPS, there is a real possibility to appear a case with a predominant part of the renewable energy in a large region or during a long time period [1,2,3]. In the global EPS there exist the regions with predominant part of RES [2].…”

“…The most often cases of RES types are: wind power turbines and photovoltaic modules [4]. All of RES electrical schemes incorporate inverter, with switch-mode power supply (SMPS) module, which creates a high level of high frequency powerful harmonics, decreasing the power factor in the circuit, quality of the power energy, sustainability and reliability of the system [1,4,5]. These effects increase the risk of unpredictable and unprovoked failures and collapse of the system.…”

A Review of Control Techniques in Photovoltaic Systems

“…Each article focuses on a particular study objective, generally addressing topics at a single hierarchical level. The reviews associated with the first level were presented in [100][101][102][103], while in [102][103][104][105] the reviews of the controllers located at the second level are addressed and the reviews that study control topics at the third level are developed in [106][107][108][109][110]. In special cases the study objective has been approached at two levels.…”