A USB Type-C/Power Delivery controller chip includes a first pin for receiving a first voltage, a second pin for receiving a second voltage, and a third pin for coupling to the CC pin of a USB connector. The USB controller chip includes a VCONN power supply circuit having a blocking field effect transistor (BFET) coupled in series with a hot-swap field FET (HSFET) between the first and third pins, and first and second Zener diodes coupled anode-to-anode between the HSFET's source and gate. A cable detection circuit includes a BFET coupled between the second and third pins, and a Zener diode coupled between the BFET's gate and a lower rail. A power delivery physical layer circuit includes a receiver and a transmitter, each coupled to the third pin through a respective BFET, the respective BFETs each having a Zener diode coupled between respective gates and the lower rail.

A ground fault overvoltage relay device is configured to: determine whether or not a first condition is satisfied, the first condition being that at least two of line voltages between respective two phases are less than or equal to a first threshold value; determine whether or not a second condition is satisfied, the second condition being that a ratio between a minimum value of the line voltages between the respective two phases and a minimum value of the respective phase voltages is less than or equal to a second threshold value; determine whether or not a third condition is satisfied, the third condition being that the zero-phase voltage is greater than a third threshold value; and lock a ground fault detection output when the first condition is satisfied, or when the second condition is satisfied and the third condition is not satisfied.

A ground fault overvoltage relay device is configured to: determine whether or not a first condition is satisfied, the first condition being that at least two of line voltages between respective two phases are less than or equal to a first threshold value; determine whether or not a second condition is satisfied, the second condition being that a ratio between a minimum value of the line voltages between the respective two phases and a minimum value of the respective phase voltages is less than or equal to a second threshold value; determine whether or not a third condition is satisfied, the third condition being that the zero-phase voltage is greater than a third threshold value; and lock a ground fault detection output when the first condition is satisfied, or when the second condition is satisfied and the third condition is not satisfied.

A current control device brings, after a target current has been changed to an upper side, a solenoid into a full-on state at a first timing that arrives in a predetermined control transition cycle shorter than an on-off cycle, determines whether an excitation current has become equal to or larger than a full-on threshold larger than the target current, brings the solenoid into a full-off state at a first timing that arrives in a predetermined energization switching cycle shorter than the on-off cycle after the excitation current has become equal to or larger than the full-on threshold, determines whether the excitation current has become equal to or smaller than a full-off threshold smaller than the target current, and causes a transition to a steady control at a first timing that arrives in the control transition cycle after the excitation current has become equal to or smaller than the full-off threshold.

In the field of multi-terminal electrical power network protection, a protection apparatus comprises a measurement apparatus to measure the respective terminal current (I.sub.L, I.sub.R1, I.sub.R2, I.sub.R3, I.sub.R4, I.sub.R5) flowing at each terminal (L, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5) in a multi-terminal network that includes a plurality of electrically interconnected terminals (L, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5). The protection apparatus also includes a control unit that is programmed to process the measured terminal currents (I.sub.L, I.sub.R1, I.sub.R2, I.sub.R3, I.sub.R4, I.sub.R5) to obtain first and second summed values (I.sub.POS(n), I.sub.NEG(n)). The first summed value (I.sub.POS(n)) is the sum at a given time (n) of the or each terminal current (I.sub.L, I.sub.R1, I.sub.R2, I.sub.R3, I.sub.R4, I.sub.R5) flowing in a first direction (Di) relative to a corresponding terminal (L, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5) and the second summed value (I.sub.NEG(n)) is the sum at the same given time (n) of the or each terminal current (I.sub.L, I.sub.R1, I.sub.R2, I.sub.R3, I.sub.R4, I.sub.R5) flowing in a second direction (D.sub.2) opposite the first direction (D.sub.1) relative to the corresponding terminal (L, R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5). The control unit is further programmed to compare the phase of the first summed value (I.sub.POS(n)) with the phase of the second summed value (I.sub.NEG(n)) to determine whether a fault in the multi-terminal network is internal or external to the multi-terminal network and thereafter to produce an internal fault output signal upon the determination of an internal fault.

A method and apparatus for suppressing the impact of a compensator on line distance protection is provided, wherein the method comprises: obtaining a first current of a line connected to a compensator or series converters in the compensator, and a first voltage of a bus connected to the compensator or the line connected to the compensator; exiting the series converters and series transformers if the first current is greater than a preset current threshold and a duration is greater than a first preset time threshold; exiting the series converters and the series transformers if the first voltage is less than or equal to a preset voltage threshold and duration is greater than a second preset time threshold set the output voltage of the series converters to zero, and if a second current of an element corresponding to the first current meets conditions which the first current needs to meet; and otherwise, canceling the setting of the output voltage of the series converters to zero and obtaining a first current if a second voltage of the line corresponding to the first voltage is greater than the preset voltage threshold and the duration is greater than a third preset time threshold.

Distance protection of electric power delivery systems are disclosed herein where a fault within a zone of protection is detected using time-domain fault detection supervised by frequency-domain fault detection. The distance fault detection may be asserted when the real or imaginary parts of the time-domain operating and polarizing quantities are both positive or both negative and an angle between the frequency domain operating and polarizing quantities is within a predetermined range. Additional security may be provided using a level check, a sign consistency check, or a disturbance detector.

Distance protection of electric power delivery systems are disclosed herein where a fault within a zone of protection is detected using time-domain fault detection supervised by frequency-domain fault detection. The distance fault detection may be asserted when the real or imaginary parts of the time-domain operating and polarizing quantities are both positive or both negative and an angle between the frequency domain operating and polarizing quantities is within a predetermined range. Additional security may be provided using a level check, a sign consistency check, or a disturbance detector.

A system level electrostatic discharge (ESD) detection device includes a phase detection unit including at least one phase detector suitable for detecting a phase difference between a plurality of supply voltages or between a plurality of input signals; a storage unit suitable for shifting between a first and a second state, the second state indicating a phase difference detected by the phase detection unit; and an output unit suitable for outputting a system level electrostatic discharge (ESD) detection signal according to the first or second state of the storage unit.

An arc fault detection system includes a high frequency detector module structured to detect first spectral content of power having a frequency in a first frequency range, a number of arc fault circuit interrupters each having separable contacts, a low frequency detector module structured to detect second spectral content of power having a frequency in a second frequency range, a control unit structured to control the separable contacts to trip open, and an arc fault detection unit structured to detect an arc fault based on the detected first and second spectral content of the power and to cause the control unit to control the separable contacts to trip open in response to detecting the arc fault. A communication bus provides communication between the high frequency detector and the arc fault circuit interrupters and the first frequency range includes frequencies that are higher than frequencies in the second frequency range.