Embodiments of the present disclosure provide method, controller and system for regulating a current of a coil. The method comprises: obtaining a first sample value of the current of the coil at a first moment, the first sample value being associated with a duty cycle of a PWM signal applied to a control end of a switch and the switch being coupled in series with the coil; obtaining a second sample value of the current of the coil at a second moment; determining a difference value between the first and the second sample values; and updating the duty cycle of the PWM signal based on the difference value to regulate the current of the coil. According to embodiments of the present disclosure, the inrush current of the coil generated at the moment of closing the contactor can be limited to a target current value, so as to increase the service life of the contactor.

An apparatus and method for minimizing inrush power. The method includes transmitting a load energization signal from a primary microcontroller to a logic latch or secondary microcontroller, transmitting a zero-cross voltage signal from a zero-cross sensor coupled to the load power to the logic latch or secondary microcontroller, and transmitting an energize signal from the logic latch or secondary microcontroller to a relay after the receipt of an energize signal from the primary microcontroller and after receipt of a zero-cross signal.

Techniques are described to slow the turn off of a pass transistor coupled to an inductive load and being controlled by a hot swap or switch controller in the event of a fault on the load side. Active circuitry can control the gate of the pass transistor, e.g., field-effect transistor (FET), as the inductive load de-energizes and a feedback loop can servo the gate voltage of the pass transistor in order to ensure that its source does not go below a reference voltage.

An electronic circuit includes a switch coupled between an input terminal intended to receive a first voltage and an output terminal coupled to a decoupling capacitor and intended to also be coupled to a load. A comparison stage is configured to compare the first voltage and a second voltage that is present at the output terminal. A first adjustment stage is configured to limit a positive inrush current flowing between the input terminal and the output terminal and a second adjustment stage is configured to limit a negative inrush current flowing between the output terminal and the input terminal. A control circuit is configured to activate either the first adjustment stage or the second adjustment stage as a function of a result of the comparison.

An AC-AC power converter, such as a motor soft starter, includes an input connectable to an AC source with a disconnect switch, an output connectable to an AC load, and phase lines connecting the input and output to transmit power. In-line solid-state switching blocks are connected between line terminals and load terminals of the AC source and AC load, respectively, such that each phase line includes a solid-state switching block connected thereto. Free-wheeling solid-state switching blocks are connected to the load terminals at one end and together at a common connection at another end, such that each phase line includes a free-wheeling solid-state switching block connected thereto. Each of the in-line and free-wheeling solid-state switching blocks comprises a bi-directional switching block that selectively controls current and withstands voltage in both directions. The switching blocks also provide soft-starter functions, variable speed control, and integrated circuit breaker protection capability.

An input power supply selection circuit includes a load, at least one input power supply to provide an operation power supply for the load, an input selection circuit to select the at least one input power supply as the operation power supply for the load, a sensing and control module to control the input selection circuit to switch the operation power supply for the load, and a load switch branch to control the load to be connected or disconnected. The sensing and control module controls the load switch branch to be connected or disconnected, and when the load switch branch is disconnected, the load and the at least one input power supply are not electrically coupled. Therefore, a contact protection design is simplified and a switching capacity requirement of the load switch branch is lowered.

Provided is a control module of a converter, in particular a power converter of a wind power installation, which is configured to control the converter in such a way that the converter emulates a behavior of a synchronous machine, comprising an, in particular internal, control loop which has an, in particular adjustable, virtual admittance by means of which the converter is controlled in order to emulate the behavior of the synchronous machine.

Disclosed is a dynamic multi-functional power controller in collocation with a primary side coil, a switching unit, and a current sensing resistor, performing a power control process. An induced current is generated by a secondary side coil coupled with the primary side coil through electromagnetic interaction with a conduction current flowing through the primary side coil, and an output power is generated to supply an external load when the induced current flows through an output rectification unit and an output filter unit. The power control process includes detecting if any abnormal state occurs, sopping a driving signal, waiting for a period of time, and then re-sending the driving signal. Thus, the present invention provides protection for various kinds of peak loading, avoids high power state when abnormal state being not resolved, and further reduces the average output power, thereby implementing power saving.

A power conversion device comprises: a DC link capacitor charged with a DC power supplied from a power supply part; a fuse part, for breaking a current which is output from or supplied to the power supply part and has a first breaking magnitude or greater; a relay part which comprises a first relay for connecting a positive terminal of the fuse part to a positive terminal of the DC link capacitor and a second relay for connecting a negative terminal of the fuse part to a negative terminal of the DC link capacitor; an initial charge part, for charging the DC link capacitor by using DC power supplied from the power supply part; and a power conversion part for converting the direct-current power supplied from the power supply part into AC power when the DC link capacitor has been charged and supplying the alternating-current power to a load terminal.

A shorting cap apparatus is provided for enabling remote application of power, by an external system, to a load connected to the shorting cap apparatus while protecting components of the external system from potential damage due to high inrush current to the load. The shorting cap apparatus comprises a housing, a connector, and inrush current protection circuitry. The connector of the shorting cap apparatus may be connected to a corresponding connector associated with the load. Once the external system applies power, the protection circuitry provides a time delay to allow the load to sufficiently charge via a first set of resistors of the protection circuitry over a period of time before a set of switches of the protection circuitry are transitioned to a conducting state.