TY - JOUR
T1 - Design of PTP TC/slave over seamless redundancy network for power utility automation
AU - Lee, Soonwoo
AU - Kang, Jimyung
AU - Choi, Sung Soo
AU - Lim, Myo Taeg
N1 - Funding Information:
Manuscript received August 09, 2017; revised October 09, 2017; accepted December 27, 2017. Date of publication February 21, 2018; date of current version June 7, 2018. This work was supported by the Korea Electrotechnology Research Institute Primary Research Program through the National Research Council of Science and Technology funded by the Ministry of Science, ICT and Future Planning under Grant N17-12-N0101-50. The Associate Editor coordinating the review process was Dr. Chao Tan. (Corresponding author: Myo Taeg Lim.) S. Lee is with the School of Mechatronics, Korea University, Seoul 136-701, South Korea, and also with the Power Telecommunication Research Center, Korea Electrotechnology Research Institute, Ansan 426-910, South Korea.
Publisher Copyright:
© 1963-2012 IEEE.
PY - 2018/7
Y1 - 2018/7
N2 - IEC 61850, which drives to digitalize information in the entire system, is being increasingly adopted in the power utility industry, since the last decade. It is necessary for all devices communicating with distributed digital data to have a common understanding of time. As protection and control devices are directly related to the safety of the power system, they are strictly required to have time accuracies. This paper describes the design of a hybrid slave clock with the transparent clock (TC) functionality defined in the IEEE 1588 precision time protocol. The design objective includes not only the synchronization of the time accuracy but also the transient time, as specified in the IEC/IEEE 61850-9-3 precision time profile for power utility automation. To comply with these objectives, we adopt a hardware-software co-design approach. The timestamp of each port is implemented by hardware. Also, they are connected by hardware to calculate the bridge time on the fly, enabling the design to have a one-step TC functionality with low latency. On the other hand, the synchronizing controller is implemented by software for adapting to the varying external conditions. The controller uses the linear quadratic Gaussian (LQG) to achieve stable steady-state performance. Simultaneously, the least-squares estimator is utilized to estimate the initial conditions of the LQG controller for reducing the transition time. Experimental results show the three-sigma time inaccuracies are 15.6 ns for the TC and 149 ns for the slave with an average transition time of 13.5 s, satisfying the IEEE/IEC 61850-9-3 criteria.
AB - IEC 61850, which drives to digitalize information in the entire system, is being increasingly adopted in the power utility industry, since the last decade. It is necessary for all devices communicating with distributed digital data to have a common understanding of time. As protection and control devices are directly related to the safety of the power system, they are strictly required to have time accuracies. This paper describes the design of a hybrid slave clock with the transparent clock (TC) functionality defined in the IEEE 1588 precision time protocol. The design objective includes not only the synchronization of the time accuracy but also the transient time, as specified in the IEC/IEEE 61850-9-3 precision time profile for power utility automation. To comply with these objectives, we adopt a hardware-software co-design approach. The timestamp of each port is implemented by hardware. Also, they are connected by hardware to calculate the bridge time on the fly, enabling the design to have a one-step TC functionality with low latency. On the other hand, the synchronizing controller is implemented by software for adapting to the varying external conditions. The controller uses the linear quadratic Gaussian (LQG) to achieve stable steady-state performance. Simultaneously, the least-squares estimator is utilized to estimate the initial conditions of the LQG controller for reducing the transition time. Experimental results show the three-sigma time inaccuracies are 15.6 ns for the TC and 149 ns for the slave with an average transition time of 13.5 s, satisfying the IEEE/IEC 61850-9-3 criteria.
KW - Finite impulse response (FIR) filter
KW - IEC 62439-3
KW - IEEE 1588
KW - high availability seamless redundancy (HSR)
KW - linear quadratic Gaussian (LQG) controller
KW - power utility automation
KW - precision time protocol (PTP)
KW - redundancy network
KW - time synchronization
UR - http://www.scopus.com/inward/record.url?scp=85042373874&partnerID=8YFLogxK
U2 - 10.1109/TIM.2018.2800858
DO - 10.1109/TIM.2018.2800858
M3 - Article
AN - SCOPUS:85042373874
VL - 67
SP - 1617
EP - 1625
JO - IEEE Transactions on Instrumentation and Measurement
JF - IEEE Transactions on Instrumentation and Measurement
SN - 0018-9456
IS - 7
ER -