Siemens Aktiengesellschaft

Siemens Aktiengesell Schaft

Siemens Aktiengesellscaft

Torsten Kerger

Andreas Jurisch

Robert Matussek

Luc Philippot

Yves Ngounou Ngambo

Matthias Gross

Sven Krueger-Gramatte

Andreas Regenbrecht

Torsten Schumacher

A differential protection device monitors a first object to be protected in an electrical energy supply network. The differential protection device has a measuring unit configured to acquire measurement values at one end of the first object to be protected, a communication unit configured to exchange measurement values with a differential protection device arranged at another end of the first object to be protected, the communication unit has a physical interface for transmitting and receiving the measurement values, and an evaluation unit configured to form a differential value and to generate a fault signal indicating a fault with regard to the first object to be protected if the differential value exceeds a predefined threshold value. Ideally, the differential protection device is configured to monitor further objects to be protected and to exchange respective further measurement values with regard to each further object to be protected.

Differential protection device and protection system for monitoring objects to be protected in a power supply network

A differential protection method for monitoring a line of a power grid. Current phasor measured values are captured at the ends of the line and transmitted to an evaluation device which is used to form a differential current value with current phasor measured values temporally allocated to one another. Time delay information indicating the time delay between local timers of the measuring devices is used for the temporal allocation of the current phasor measured values captured at different ends, and a fault signal indicating a fault affecting the line is generated if the differential current value exceeds a predefined threshold value. The reliability of the time synchronization is further increased by forming a quotient of the current phasor measured values to form an asymmetry variable, that is used to check a transit time difference of messages transmitted via the communication connection in different directions.

Differential protection method, differential protection device, and differential protection system

A differential protection method monitors a line of an electrical energy supply network. Current signals are generated at the ends of the line using inductive current transformers, which current signals are proportional to a current flowing at the respective end. For each end, current measurement values are formed from the respective current signal using measuring devices, which current measurement values indicate a profile of the current flowing at the respective end. For each end, a respective charge value is determined from the current measurement values. The charge values of all the ends are summed to form a charge sum, and a fault signal that indicates an internal fault on the line is generated when the charge sum exceeds a charge threshold value. To perform line differential protection in the case of current transformer saturation, when transformer saturation of a current transformer is present, an estimated charge value is ascertained.

Differential protection method, device and system for monitoring a line of an electrical energy supply network

In a differential protection method for monitoring a line of a power grid, current indicator measured values are measured at the ends of the line and are transmitted to an evaluation device. A differential current value is formed with current indicator measured values temporally allocated to one another. The time delay between local timers of the measuring devices is used for the temporal allocation of the current indicator measured values measured at different ends. A fault signal indicating a fault affecting the line is generated if the differential current value exceeds a predefined threshold value. A check is carried out using electrical measured quantities temporally allocated to one another and a line-specific parameter to determine whether the time delay information indicates the actual time delay between the respective local timers. A time error signal is generated if erroneous time delay information is detected.

Differential protection method, differential protection device and differential protection system

The invention relates to a method for generating an error signal which characterizes a fault current in an electrical conductor provided with two conductor ends and having charge measuring devices which are connected to each other by data lines. At least one device is attached to each end of the conductor. In the invention, charge measuring values are determined using charge measuring devices. The measured charge values take into account the direction of the charge flow and a total measured charge value is formed by addition. The error signal is generated when the total measured charge value exceeds a certain threshold value. In order to be able to detect errors in a more sensitive manner than had previously been possible, the threshold value is formed by taking into account the individual measuring tolerance of the individual charge measuring devices.

Differential protection method for producing a fault signal characteristic of a fault

The invention relates to a method for generating an error signal which characterizes a fault current in an electrical conductor provided with two conductor ends and having charge measuring devices which are connected to each other by data lines. At least one device is attached to each end of the conductor. In the inventive method, charge measuring values are determined using charge measuring devices. The measured charge values take into account the direction of the charge flow a total measured charge value is formed by addition. The error signal is generated when the total measured charge value exceeds a certain threshold value. According to the invention, the measured charge values are determined synchronously and determined repeatedly at regular intervals in such a way that the time interval between each sequential determination is smaller than the predefined measuring period.

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Schoenwalde-Glien, Germany

Torsten Kerger