WECC expansions

This new system was successfully operating by May 1997.  It has undergone many improvements and further developments, but the basic system remains at the core.  SCE began using the same PDC in1997, WAPA followed suit in 1998, and BCH started a system in 2000.  The first inter-utility data exchange was started between BPA and SCE in 1999, using communications through LADWP.  In 2000 the WECC DMWG was founded to implement the new NERC disturbance monitoring requirements.  They produced a guideline for the WECC that encouraged but did not require phasor measurements.  As a result of these requirements and the need for better dynamic analysis, PNM, APS/SRP, & PG&E also started the same type of phasor system.  All utilities used the same system architecture used by BPA, but each utility had to solve communication interface, data distribution, and cyber implementation issues.  These problems have slowed system growth.
Interest in regional awareness has steadily increased.  The 2003 blackouts accentuated the need for overall grid awareness, which is of critical importance to security monitors and ISOs. Data exchange between utilities extends the local WAMS to the whole grid. A link from BPA to the California ISO (CAISO)was established in 2002.  This was different than the original BPA-SCE exchange:  it used a high-bandwidth connection (T1 - 1.544 MBPS) that would carry Ethernet traffic.  It uses UDP/IP over Ethernet for minimum bandwidth usage and delay.  Setup and maintenance is simple.  The system has operated very reliably with very little data loss.  In 2004 similar data links from WAPA to BPA and SCE to CAISO were added. In 2005 PG&E began sending to CAISO and BPA.  Figure 6 shows the approximate distribution of PMUs and PDCs in the WECC.  More links between utilities are being explored, but administrative hurdles have slowed the process.  Cost sharing for the high-speed data links needs to be resolved.  More difficult issues are ownership of the data and cyber security.  Links using the Internet need data encryption and secure firewalls.  Leased/private links are less vulnerable, but need firewalls at each utility.  Data should only be exchanged between willing parties, but agreements are still required for how it will be handled and distributed.  The problem quickly moves from engineer to lawyer work.