Biblio
The target of security protection of the power distribution automation system (the distribution system for short) is to ensure the security of communication between the distribution terminal (terminal for short) and the distribution master station (master system for short). The encryption and authentication gateway (VPN gateway for short) for distribution system enhances the network layer communication security between the terminal and the VPN gateway. The distribution application layer encryption authentication device (master cipher machine for short) ensures the confidentiality and integrity of data transmission in application layer, and realizes the identity authentication between the master station and the terminal. All these measures are used to prevent malicious damage and attack to the master system by forging terminal identity, replay attack and other illegal operations, in order to prevent the resulting distribution network system accidents. Based on the security protection scheme of the power distribution automation system, this paper carries out the development of multi-chip encapsulation, develops IPSec Protocols software within the security chip, and realizes dual encryption and authentication function in IP layer and application layer supporting the national cryptographic algorithm.
Traditionally, utility crews have used faulted circuit indicators (FCIs) to locate faulted line sections. FCIs monitor current and provide a local visual indication of recent fault activity. When a fault occurs, the FCIs operate, triggering a visual indication that is either a mechanical target (flag) or LED. There are also enhanced FCIs with communications capability, providing fault status to the outage management system (OMS) or supervisory control and data acquisition (SCADA) system. Such quickly communicated information results in faster service restoration and reduced outage times. For distribution system protection, protection devices (such as recloser controls) must coordinate with downstream devices (such as fuses or other recloser controls) to clear faults. Furthermore, if there are laterals on a feeder that are protected by a recloser control, it is desirable to communicate to the recloser control which lateral had the fault in order to enhance tripping schemes. Because line sensors are typically placed along distribution feeders, they are capable of sensing fault status and characteristics closer to the fault. If such information can be communicated quickly to upstream protection devices, at protection speeds, the protection devices can use this information to securely speed up distribution protection scheme operation. With recent advances in low-power electronics, wireless communications, and small-footprint sensor transducers, wireless line sensors can now provide fault information to the protection devices with low latencies that support protection speeds. This paper describes the components of a wireless protection sensor (WPS) system, its integration with protection devices, and how the fault information can be transmitted to such devices. Additionally, this paper discusses how the protection devices use this received fault information to securely speed up the operation speed of and improve the selectivity of distribution protection schemes, in add- tion to locating faulted line sections.