A control unit rod interface arrangement couples between AC and DC power systems. The interface includes at least two poles for coupling between the DC and AC power systems. Each of the poles includes a converter for conversion between AC and DC power. If a fault has occurred in one of the poles, a transient current, or fault current, may flow through a neutral bus line connected to the pole, the pole's converter and the location of the fault in the pole. Such a transient or fault current should preferably be damped out as quickly as possible, after which the pole may be electrically isolated from the other components of the interface arrangement. Such a transient or fault current may be damped out relatively quickly by opening of a neutral bus switching element of the neutral bus line connected to the pole after the converter has entered a blocking mode and a circuit breaker at the AC side of the converter has been opened so as to effect discontinuation of flow of current between the AC side of the converter and the AC power system.

An apparatus with load dump protection incorporates first and second half-bridge circuits, first and second comparators, and first and second clamping circuits. The first comparator compares a supply voltage with a first set voltage and generates a first comparison signal while the supply voltage exceeds the first set voltage. The second comparator compares the supply voltage with a second set voltage and generates a second comparison signal while the supply voltage exceeds the second set voltage. The first clamping circuit divides the supply voltage and provides a divided voltage to the first half-bridge circuit in response to the second comparison signal. The second clamping circuit divides the supply voltage and provides a divided voltage to the second half-bridge circuit in response to the second comparison signal.

Method for protecting against overvoltage a current fed converter, comprising a switching cell having two or more legs, each leg being provided with at least one switching device, in an open circuit failure condition of a switching device in a leg of said switching cell, comprising measuring current derivative signals in respective upper switching devices or lower switching devices of at least two of said legs where a switching transition occurs, said switching transition comprising a change of current conducting switching device within said upper switching devices or lower switching devices and triggering a protection, based on said current derivative signals, when either: the absolute value of one of said current derivative signal being lower than a first predefined value or null, or a sum of the absolute values of said current derivative signals being lower than a second predefined value,
during said switching transition.

Disclosed are a fault current-suppressing damper topology circuit and a control method thereof and a converter. An anode of a separate diode is connected to a positive electrode of a second switch module, a cathode of the separate diode is connected to one end of an energy storage capacitor, and the other end of the energy storage capacitor is connected to a negative electrode of a first switch module; a damping resistor is connected in parallel with an arrester and then with the first switch module; a bypass switch is connected in parallel between a terminal x1 and a terminal x2 of the damper topology circuit; a power supply system acquires energy from the energy storage capacitor and supplies power to a control system; and the control system controls an operating state of the damper topology circuit by controlling the bypass switch, the first switch module and the second switch module. The fault current-suppressing damper topology circuit is applied to voltage source converters. In case of a DC fault, stress resulting from fault currents is reduced by use of a damping resistor, thereby avoiding damages to a device and achieving self-power supply, modularization and independent control. The fault current-suppressing damper topology circuit can be flexibly applied to various types of voltage source converters and has outstanding economic efficiency and technicality.

To provide improved overvoltage protection for a voltage converter for converting an input voltage into a DC output voltage, a first switch-off unit is provided, which is configured to effect a switch-off of at least a part of the voltage converter if the DC output voltage reaches or exceeds a first voltage threshold, in order to reduce the DC output voltage. Furthermore, a second switch-off unit is provided, which is configured to check whether a mean value of the DC output voltage reaches or exceeds a mean value threshold and, if the mean value threshold is reached or exceeded, to effect a switch-off of at least a part of the voltage converter in order to reduce the DC output voltage.

Disclosed is a short-circuit protection circuit for a voltage sampling resistor of a primary side converter, comprising a high voltage power transistor, a high voltage starting resistor, a first voltage dividing resistor of a port VDD, a second voltage dividing resistor of the port VDD, an NMOS transistor, a diode, a first comparator, a second comparator, a third comparator, a time delay circuit, a filter, a first logic circuit, a second logic circuit, a current supply, a first AND gate and a first inverter. The chip of the present disclosure is capable of correctly and effectively detecting whether the sampling resistor is shorted or not before the chip works normally, thereby avoiding the risk of damaging the chip by large current from the voltage feedback port FB due to turn-on of the switching transistor when the upper voltage sampling resistor is shorted, and greatly reducing the input power.

A circuit system having a voltage converter having an input path, an output path, and having a plurality of phases, each phase having at least one half-bridge and at least one fuse, each branch of the half-bridge having a respective MOSFET. The circuit system recognizes a defective MOSFET and controls the MOSFETs of the intact phases in such a way that a sufficiently large current trips the fuse connected in series with the defective MOSFET in order to enable an emergency operation of the voltage converter. A method for operating such a circuit system is also described.

A first communication line transmits a control signal from an I/F circuit to an n-th drive circuit. A second communication line transmits a state detection signal of semiconductor switches from the n-th drive circuit to the I/F circuit. An i-th drive circuit includes a driver for an i-th semiconductor switch, an abnormality detection circuit for detecting an abnormality of the i-th semiconductor switch, and first and second notification members. The abnormality detection circuit detects the abnormality of the i-th semiconductor switch and an operation state of the i-th semiconductor switch, and notifies a detection result using the first notification member. The abnormality detection circuit generates the state detection signal indicating an operation state of the i-th to n-th semiconductor switches, detects a mismatch between the control signal and the operation state of the i-th to n-th semiconductor switches, and notifies a detection result using the second notification member.

A circuit includes a switching module, a control module, and a driving module. The driving module is electrically coupled between the control module and the switching module for generating a driving signal. The driving module includes a normal driving unit and a fault protection unit. The normal driving unit is for turning on and off the switching module according to a first command signal from the control module. The fault protection unit is for lowering the driving signal from a driving value to a protection value according to a second command signal from the control module during a fault protection period after the control module receives a fault signal.

System and method for protecting a power converter. A system includes a threshold generator configured to generate a threshold signal, and a first comparator configured to receive the threshold signal and a first signal and to generate a comparison signal. The first signal is associated with an input current for a power converter. Additionally, the system includes a pulse-width-modulation generator configured to receive the comparison signal and generate a modulation signal in response to the comparison signal, and a switch configured to receive the modulation signal and adjust the input current for the power converter. The threshold signal is associated with a threshold magnitude as a function of time. The threshold magnitude increases with time at a first slope during a first period, and the threshold magnitude increases with time at a second slope during a second period. The first slope and the second slope are different.