Power grid protection via transformer neutral blocking systems and triggered phase disconnection

A protection circuit useable in an alternating current system including a transformer, the circuit comprising:

• a direct current (DC) blocking component electrically connected between a neutral of the transformer and a ground;
• and
• an overvoltage protection device electrically connected in parallel with the DC blocking component, the overvoltage protection device being constructed to repeatably and reliably provide overvoltage protection in response to a voltage at the transformer neutral above a threshold;
• wherein the DC blocking component has an impedance below a predetermined value, thereby effectively grounding the neutral of the transformer;
• and
• wherein the DC blocking component is persistently maintained in connection to the transformer neutral during operation of the protection circuit.