High Voltage change Over System
Elements of high voltage systems and corresponding electrical isolation needed to contain electric shock hazards are explained.
High voltage: system externalities among the high voltage nodes of a transmission network
The transmission network provider signals the opportunity costs of injection to the different generators located at the different injection nodes. Injection takes place either via import from other transmission networks, import from a distribution network, or at generation locations (nodes) within the network. The sum of generation costs (or import price) and injection charge (according to the system externalities at that node) must not exceed the wholesale price equal to the shadow value of the system balance equation of the transmission network.
Medium voltage: system externalities among the medium voltage nodes of a distribution network
Each distribution network has its own network constraints, and system externalities at the different nodes. Injection takes place either via import from a transmission network or another distribution network, or via injection by a generator at the distribution level, or via a microgrid or Virtual Power Plant. In each injection, a node of the distribution network is used, causing opportunity costs of distribution network usage, according to the system externalities and network loss within the distribution network. The sum of generation costs (or import) and injection charge (according to system externalities at that node) must not exceed the distribution wholesale price, equal to the shadow value of the system balance equation of the distribution network.