TY - JOUR
T1 - Instantaneous penetration level limits of non-synchronous devices in the British power system
AU - Yu, Mengran
AU - Roscoe, Andrew J.
AU - Dyśko, Adam
AU - Booth, Campbell D.
AU - Ierna, Richard
AU - Zhu, Jiebei
AU - Urdal, Helge
N1 - This paper is a postprint of a paper submitted to and accepted for publication in IET Renewable Power Generation and is subject to Institution of Engineering and Technology Copyright. The copy of record is available at IET Digital Library
PY - 2016/9/29
Y1 - 2016/9/29
N2 - The installed capacity of non-synchronous devices (NSD), including renewable energy generation and other converter-interfaced equipment such as energy storage, bi-directional transfer links, electric vehicles, etc., is expected to increase and contribute a large proportion of total generation capacity in future power systems. Concerns have been expressed relating to operability and stability of systems with high penetrations of NSD, since NSD are typically decoupled from the grid via power electronic devices and consequently reduce the “natural” inertia, short-circuit levels and damping effects which are inherently provided by synchronous machines. It is therefore crucial to ensure secure and stable operation of power systems with high penetrations of NSD. This paper will show and quantify the instantaneous penetration level (IPL) limits of NSD connected to a simple example power system in terms of steady-state stability beyond which the system can become unstable or unacceptable, defined as “unviable”. The NSD used in this example will be a conventional dq-axis current injection (DQCI) convertor model. The paper will introduce a set of criteria relating to locking signal in converter phase-locked loop, frequency, rate of change of frequency and voltage magnitude, which will be used to determine the system viability and the IPL limit. It will also be shown that there are several factors that can potentially affect the IPL limits. Frequency and voltage droop slopes and filter time-constant for DQCI converter are varied and it is shown how these settings influence the IPL limits. Finally, to provide additional insight into network viability under high penetrations of NSD, a visualisation method referred here as “network frequency perturbation” is introduced to investigate responses of individual generators to a change in network frequency.
AB - The installed capacity of non-synchronous devices (NSD), including renewable energy generation and other converter-interfaced equipment such as energy storage, bi-directional transfer links, electric vehicles, etc., is expected to increase and contribute a large proportion of total generation capacity in future power systems. Concerns have been expressed relating to operability and stability of systems with high penetrations of NSD, since NSD are typically decoupled from the grid via power electronic devices and consequently reduce the “natural” inertia, short-circuit levels and damping effects which are inherently provided by synchronous machines. It is therefore crucial to ensure secure and stable operation of power systems with high penetrations of NSD. This paper will show and quantify the instantaneous penetration level (IPL) limits of NSD connected to a simple example power system in terms of steady-state stability beyond which the system can become unstable or unacceptable, defined as “unviable”. The NSD used in this example will be a conventional dq-axis current injection (DQCI) convertor model. The paper will introduce a set of criteria relating to locking signal in converter phase-locked loop, frequency, rate of change of frequency and voltage magnitude, which will be used to determine the system viability and the IPL limit. It will also be shown that there are several factors that can potentially affect the IPL limits. Frequency and voltage droop slopes and filter time-constant for DQCI converter are varied and it is shown how these settings influence the IPL limits. Finally, to provide additional insight into network viability under high penetrations of NSD, a visualisation method referred here as “network frequency perturbation” is introduced to investigate responses of individual generators to a change in network frequency.
KW - non-synchronous devices
KW - renewable energy generation
KW - instantaneous penetration level
KW - dq-axis current injection
KW - locking signal
KW - converter phase-locked loop,
KW - system viability
KW - IPL limit.
KW - network frequency perturbation
UR - http://digital-library.theiet.org/content/journals/iet-rpg
U2 - 10.1049/iet-rpg.2016.0352
DO - 10.1049/iet-rpg.2016.0352
M3 - Article
SN - 1752-1416
JO - IET Renewable Power Generation
JF - IET Renewable Power Generation
ER -