Incorporating voltage security into the planning, operation and monitoring of restructured electric energy markets

摘要

As open access market principles are applied to power systems, significant changesare happening in their planning, operation and control. In the emerging marketplace,systems are operating under higher loading conditions as markets focus greater attentionto operating costs than stability and security margins. Since operating stability is a basicrequirement for any power system, there is need for newer tools to ensure stability andsecurity margins being strictly enforced in the competitive marketplace. This dissertationinvestigates issues associated with incorporating voltage security into the unbundledoperating environment of electricity markets. It includes addressing voltage security inthe monitoring, operational and planning horizons of restructured power system.This dissertation presents a new decomposition procedure to estimate voltagesecurity usage by transactions. The procedure follows physical law and uses an indexthat can be monitored knowing the state of the system. The expression derived is basedon composite market coordination models that have both PoolCo and OpCo transactions,in a shared stressed transmission grid. Our procedure is able to equitably distinguish theimpacts of individual transactions on voltage stability, at load buses, in a simple and fastmanner.This dissertation formulates a new voltage stability constrained optimal power flow(VSCOPF) using a simple voltage security index. In modern planning, composite powersystem reliability analysis that encompasses both adequacy and security issues is beingdeveloped. We have illustrated the applicability of our VSCOPF into compositereliability analysis.This dissertation also delves into the various applications of voltage security index.Increasingly, FACT devices are being used in restructured markets to mitigate a varietyof operational problems. Their control effects on voltage security would bedemonstrated using our VSCOPF procedure. Further, this dissertation investigates theapplication of steady state voltage stability index to detect potential dynamic voltagecollapse.Finally, this dissertation examines developments in representation, standardization,communication and exchange of power system data. Power system data is the key inputto all analytical engines for system operation, monitoring and control. Data exchangeand dissemination could impact voltage security evaluation and therefore needs to becritically examined.