Embodiments of this present disclosure may include a system with a first power converter and a control system. The first power converter may supply a first output power to a first backplane at least sometimes concurrent to a second power converter supplying a second output power to a second backplane. The control system may be electrically coupled to the first backplane and the second backplane. The control system may balance a first electrical property and a second electrical property provided to each of one or more load components electrically coupled to the first backplane and the second backplane.

Disclosed are an arc extinguishing control system and method for a relay of an emergency power supply. A relay serves as a main switching circuit for controlling an emergency power supply, and electronic switching tubes are connected in parallel to two ends of the relay, so as to withstand a voltage jump when the relay is disconnected, and common problems of existing relays, such as arc damage and an internal resistance increase, are solved. When a heavy reverse charging current occurs after the vehicle is started, a reverse charging sensing circuit and a reverse charging feedback circuit are used, so that a reverse charging current is directly fed back to a control end of an electronic switching tube when a storage battery is reversely charged by a load, thereby realizing quick disconnection of the electronic switching tube.

A photovoltaic system includes at least one first direct current module, an electromagnetic apparatus, a direct current switch-on/off apparatus, and a second direct current module. First connection ends of all first direct current modules in the at least one first direct current module are connected in parallel and then connected to a first connection end of the electromagnetic apparatus, a second connection end and a third connection end of the electromagnetic apparatus are connected to a first connection end of the second direct current module by using the direct current switch-on/off apparatus, and second connection ends of all the first direct current modules are connected in parallel and then connected to a second connection end of the second direct current module. The electromagnetic apparatus is configured to control the direct current switch-on/off apparatus to disconnect a loop between each first direct current module and the second direct current module.

A method for detecting fault direction of a transmission line of an AC power system and a control system using the same. The method includes sampling current values and voltage values at one end of the transmission line for a series of time points; computing instantaneous voltage values at compensated point on the transmission line from the current value samples and the voltage value samples based on a time domain lumped parameter differential equation for the transmission line for the series of time points; recording the current value samples and the computed instantaneous voltage values at the compensated point; computing at least one voltage fault component each using the recorded computed instantaneous voltage values for at least the at least two of the series of time points; identifying the fault direction in consideration of the at least one computed voltage fault component and the at least one computed current fault component; and generating a fault direction signal indicating the identified fault direction. Where a fault directional element is designed using the voltage fault components at the compensated point, it will work well for the AC power system with strong power source.

Systems and methods, and computing platforms for determining a fault in a power system, executing on a controller are disclosed. Exemplary implementations can receive, from the plurality of system control modules, a plurality of power flow directions as measured by the plurality of line current sensors, receive, from the plurality of system control modules, a plurality of voltage measurements based on measurements of a plurality of potential transformers, determine a location of a power fault using the plurality of power flow directions, and determine a phase of the power fault using the plurality of voltage measurements.

The present invention provides a system and a method for switching a line short-circuit fault section in an inverter-based stand-alone microgrid, the system comprising: multiple intelligent switchgears disposed on a line in a stand-alone microgrid so as to control opening or closing of the line; a battery inverter having a built-in current limiter so as to limit a current output therefrom; and an operating system for receiving short-circuit fault information of the line from the multiple intelligent switchgears, determining a fault section, and controlling the battery inverter to limit the output current. The present invention can quickly and accurately switch a line short-circuit fault section occurring in a stand-alone microgrid which does not include separate cutoff equipment such as a recloser.

Apparatus and associate methods relate to desaturation protection of a metal-oxide-semiconductor field-effect transistor (MOSFET) or an insulated-gate bipolar transistor (IGBT). Desaturation protection circuitry provides desaturation protection to the MOSFET or IGBT as well protection of the desaturation protection circuitry, should such circuitry be connected to reverse power. The desaturation protection circuitry determines a desaturation condition based on a control voltage generated by a Zener-diode-resistor network conductively coupled between first and second conduction nodes of the MOSFET or IGBT. The Zener-diode-resistor network is coupled to first and second conduction nodes via a rectifying diode that is configured to protect the desaturation protection circuitry from reverse bias power. Negative feedback limits current through a signal isolation device that is conductively isolated from the output node, which indicates whether the desaturation condition has been determined.

A DC voltage switch includes a semiconductor-based electronically controllable switching device, a sensor provided upstream of the switching device for determining the DC voltage bus-side voltage level, a sensor provided downstream of the switching device for determining the DC voltage branch-side voltage level, a current sensor for determining current level and direction, a control device designed such that the direction and level of the current are determined, the flow of current is interrupted by the switching device when a first threshold value of the current level is exceeded, and when the first threshold value of the current level is exceeded in the reverse direction: the DC voltage bus-side voltage level is compared with the DC voltage branch-side voltage level, and the switching device is switched on upon a voltage difference being less than a voltage difference value.

A switching system for breaking a current, including a contact arrangement having a first and second terminals, a resonance circuit connectable across the contact arrangement, In the closed state the first switch enables current to flow through the resonance circuit in a first flow direction and into the contact arrangement in a direction opposite to a contact arrangement arc current flow direction. A second switch connected to the resonance circuit and to the second terminal. In the closed state the second switch enables current to flow through the resonance circuit in a second flow direction opposite to the first flow direction. A control system arranged to alternatingly set the first and second switches in the closed state and then in the open state upon a current breaking operation, until a current pulse, emanating from energy supplied by a contact arrangement arc current, flowing through the resonance circuit and into the contact arrangement reaches an amplitude which is equal to or greater than a magnitude of a contact arrangement arc current.

A reverse current protection circuit for a switch circuit includes a reverse current control circuit and an enable/disable circuit coupled to the reverse current control circuit. The reverse current control circuit is coupled to an input terminal and an output terminal of the switch circuit, and disconnects the output terminal of the switch circuit from the input terminal of the switch circuit when an output voltage of the switch circuit is higher than a first predetermined voltage. The enable/disable circuit disables the reverse current control circuit for a first predetermined time period when the output voltage of the switch circuit becomes lower than the first predetermined voltage after being higher than the first predetermined voltage, and enables the reverse current control circuit after the first predetermined time period.