Abstract: A system for controlling voltage unbalance in a direct current distribution system includes a measurement processor configured to measure a positive load current, and a negative load current at a first load point, including a first load connected to a positive line and a neutral line and a second load connected to the neutral line and a negative line, and at a second load point in a power distribution system; and a control processor configured to determine whether to activate a first load point switching signal based on the positive and negative load currents at the first and second load points to control the first load point to switch the connections of the first load and the second load between the positive line and the negative line.

Abstract: An apparatus and method for controlling adaptive reclosing based on transient stability of a power transmission line are disclosed. The apparatus includes a power angle calculation unit, an integral square error (ISE) second-order differential calculation unit, a stability determination unit, and a disconnection signal generation unit. The power angle calculation unit acquires the instantaneous value of a power angle based on voltage and phase angle measurement signals. The ISE second-order differential calculation unit acquires the instantaneous value of the second-order differential of the ISE of the power angle. The stability determination unit determines whether a system is stable or unstable based on the transitions in the instantaneous value of the second-order differential of the ISE.

Abstract: A system for controlling voltage unbalance in a direct current distribution system includes a measurement processor configured to measure a positive load current, and a negative load current at a first load point, including a first load connected to a positive line and a neutral line and a second load connected to the neutral line and a negative line, and at a second load point in a power distribution system; and a control processor configured to determine whether to activate a first load point switching signal based on the positive and negative load currents at the first and second load points to control the first load point to switch the connections of the first load and the second load between the positive line and the negative line.

Abstract: An apparatus and method for controlling adaptive reclosing based on transient stability of a power transmission line are disclosed. The apparatus includes a power angle calculation unit, an integral square error (ISE) second-order differential calculation unit, a stability determination unit, and a disconnection signal generation unit. The power angle calculation unit acquires the instantaneous value of a power angle based on voltage and phase angle measurement signals. The ISE second-order differential calculation unit acquires the instantaneous value of the second-order differential of the ISE of the power angle. The stability determination unit determines whether a system is stable or unstable based on the transitions in the instantaneous value of the second-order differential of the ISE.