Siemens Aktiengesellschaft

Feng Du

Yue Zhuo

Zhen Yu Liu

Yi Zhu

Mario Dankert

Thomas Beckert

Shivansh Batra

Michael Hein

Ling Fu

Sebastian Haas

Ying Zong Min

Wei Gang Chen

An electric grid includes feed-ins, loads, and a distribution grid, which is arranged therebetween. The distribution grid comprises at least one busbar and at least one device for opening or closing a DC circuit. The at least one device includes an electric switch for opening or closing the DC circuit, a fault current detector, a trigger unit, a precharging device, and a control unit for automatically closing the electric switch after the precharging process. The electric switch opens the DC circuit via the trigger unit if a fault current is detected by the fault current detector, and the precharging device restores the voltage on the busbar prior to closing the electric switch.

Electric grid and method for operating an electric grid

A hybrid circuit breaker includes a semiconductor circuit breaker, connected between a first output end of a converter of a power supply or a source branch and a first end of a damping module; a first mechanical circuit breaker, connected in parallel to the semiconductor circuit breaker, an energy absorber, connected in parallel to the semiconductor circuit breaker, and a controller coupled to the semiconductor circuit breaker and the first mechanical circuit breaker, and when a current flowing through the converter is greater than a safe current, the controller is configured to control the first mechanical circuit breaker to be disconnected, and control the semiconductor circuit breaker to be closed.

Hybrid circuit breaker, hybrid circuit breaking system, and circuit breaking method

A method for controlling a solid state circuit breaker includes detecting a direction of a current flowing through the solid state circuit breaker, obtaining a breaking current value of the solid state circuit breaker according to the detected direction of the current, obtaining a value of a maximum threshold current to flow through the solid state circuit breaker, obtaining a predicted current value within a next sampling period of a present sampling period of the solid state circuit breaker, comparing the predicted current value with the breaking current value, and upon the predicted current value being greater than the breaking current value, delaying the solid state circuit breaker, and upon the predicted current value being greater than the maximum threshold current value, controlling the solid state circuit breaker to disconnect a circuit in which the solid state circuit breaker resides.

Method and apparatus for controlling solid state circuit breaker, and solid state circuit breaker

Provided are a grid fault detection method and a device. The grid includes at least one AC power source provided by a public grid. The AC power source is coupled to a plurality of parallel circuits, each including a plurality of parallel branches. The parallel branches are each connected with a load and/or a DC power source. The grid fault detection method having the distributed energy resource includes: selecting a first collection point between the AC power source and the plurality of parallel circuits, and collecting a current value and a current direction of the first collection point; comparing an output current and an input current of the first collection point, and upon the input current being greater than the output current, it is determined that the plurality of parallel circuits are faulty. Accordingly, the plurality of collection points check the fault, so as to trigger a protection device.

Power grid fault detection method and device with distributed energy resource

A nanogrid and a virtual inverter controller for the nanogrid are disclosed. The nanogrid includes at least one parallel branch, and at least one branch is equipped with a protector. At least one of the protectors is equipped with one virtual inverter controller. The virtual inverter controller includes a sensor component configured to detect at least one characteristic parameter on the branch, and a control component affecting the electrical connection state of the corresponding protector of the virtual inverter controller according to the characteristic parameter.

Virtual inverter controller for a nanogrid and the nanogrid thereof

Provided is a nano grid protection device for a nano grid including a distributed power supply, a large power grid including the nano grid protection device, and a method for controlling the nano grid protection device. In an embodiment, the nano grid is connected with a bus through the nano grid protection device and a main grid is connected with the bus through a main grid protection device. In an embodiment, the nano grid protection device includes: a signal unit, configured to detect and send current information passing through the nano grid protection device, the current information including the magnitude and direction of the current; a controller, configured to determine, based upon the received current information, whether to send a trip signal or not; and an execution mechanism, configured to execute a trip operation of the nano grid protection device upon receiving the trip signal.

Nano grid protection device, large power grid and a method for controlling a nano grid protection device

A solid-state circuit breaker and breaking method are disclosed. In an embodiment, the solid-state circuit breaker includes a semiconductor switch; a controller, connected to the semiconductor switch; and an energy absorber, connected in parallel with the semiconductor switch. The controller is configured to obtain an equivalent inductance of a circuit of the solid-state circuit breaker upon a fault occurring in a line. Further, upon the equivalent inductance being greater than an inductance estimated value, the controller is configured to set a second current fault threshold. Finally, upon a fault current of the line reaching the second current fault threshold, the semiconductor switch is controlled to execute a closing operation.

Solid-state circuit breaker and breaking method for solid-state circuit breaker

A current transformer and a direct current source based on a current transformer are disclosed. In an embodiment, the current transformer includes two output ends; a first winding and a second winding connected in series between the two output ends; a main core; a bypass core, arranged to be magnetically coupled with the main core. The first winding is wound on a part of the main core and a part of the bypass core, and the second winding is wound on apart of the bypass core. In an embodiment, the current transformer also includes a high-frequency bypass, connected in parallel with the first winding, and used to filter a high-frequency signal. The high-frequency bypass provides a low-impedance path for a high-frequency signal in a primary conductor under measurement, such that the bypass core with the second winding presents less obstruction to the main core, thereby reducing heating.

Current transformer and direct current source based on current transformer

A method and device are disclosed for determining the direction of current flowing through a circuit breaker. An embodiment includes obtaining a sample value of current flowing through the circuit breaker and a differential value of current; obtaining a sample value of voltage at the circuit breaker; on the basis of a relationship between voltage and current in an equivalent circuit in which the circuit breaker lies at the present time and at a previous time, obtaining an equivalent resistance and an equivalent inductance in the equivalent circuit; if the equivalent resistance and equivalent inductance are both greater than zero, determining that the direction of current flowing through the circuit breaker is the same as the current reference direction, and if the equivalent resistance and equivalent inductance are both less than zero, determining that the direction of current flowing through the circuit breaker is opposite to the current reference direction.

Method and device for determining direction of current flowing through circuit breaker

A zone selective interlocking device includes a first port, a second port, an input bus, an output bus and a query signal receiving branch. The first and second port each are switchable between two states, connected to the input bus and connected to the output bus, and the zone selective interlocking device is operable in a first mode. In the first mode, the query signal receiving branch is turned on. Within a preset timeslot, a link fault query signal is permitted to be inputted to the query signal receiving branch through the first port, while a link fault query signal is prevented from being inputted to the query signal receiving branch through the second port. Based on whether a link fault query signal is received within the timeslot, a judgment is made on whether a fault has occurred in a communication link connected to a corresponding port.

Zone selective interlocking device

A fault arc detection method includes: sampling an instantaneous current value of a circuit; using the instantaneous current value to predict a current peak value and, when the predicted current peak value is greater than a predetermined threshold, determining that a first energy fault arc is to appear; and comparing a time domain or frequency domain feature of the instantaneous current value with a reference time domain feature or a reference frequency domain feature of the current of a fault arc of the circuit. When the similarity between the time domain or frequency domain feature and the reference time or reference frequency domain feature of the current of the fault arc reaches a predetermined range, a second energy fault arc is determined to appear. The method and detection device detect the occurrence of a fault arc early and they are able to distinguish different types of fault arcs.

Fault arc detection method and detection device

A method is disclosed for diagnosing faults on a communication bus used to transmit zone selective interlocking signals in a power distribution network. The method includes configuring interfaces of all protection devices connected to the same communication bus to be input ports within a first diagnosis time period; detecting, at each protection device connected to the communication bus, an input signal received by the input port thereof; and if abnormality is detected in the input signal, the protection device issuing a first alert associated with the corresponding interface.

Protection device with communication bus fault diagnosis function, system and method

A power supply device is disclosed for use in electronic equipment. In an embodiment, the power supply device includes: a current transformer with N secondary winding parts connected in series, an energy storage capacitor and a winding selector, in which N is an integral number and N&#x2267;2, wherein the winding selector selectively enables one or more serially connected winding parts of the N secondary winding parts to output an electrical current, in response to a state signal indicating the operating state of the electronic equipment; and the energy storage capacitor is charged by the output current, and supplies power to a main circuit of the electronic equipment. In the embodiments of the present invention, there is also provided corresponding electronic equipment and a corresponding method. By way of the embodiments of the present invention, it is possible to supply electrical energy at relatively low power loss.

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Shanghai, China

Feng Du