Rolls-royce North American Technologies Inc.

Rolls-royce Singapore Pte. Ltd.

Oki Techno Centre (singapore) Pte Ltd

Yu Yang

Amit Kumar Gupta

Chandana Jayampathi Gajanayake

David Loder

Tomisawa Masayuki

Hu Saigui

Wang Tingwu

Pan Ju Yan

In some examples, an electrical power system includes a solid state power converter including a first set of switches on a source side of the solid state power converter and a second set of switches on a load side of the solid state power converter. The electrical power system also includes a power source connected to the source side of the solid state power converter and also includes a differential bus connected to the load side of the solid state power converter. The electrical power system further includes a controller configured to receive a first signal indicating a current at the source side and receive a second signal indicating a current at the load side. The controller is further configured to detect, based on a time derivative of the first signal and a time derivative of the second signal, a fault in the electrical power system.

Fault detection for a solid state power converter

In some examples, this disclosure describes a method for detecting a fault in an electrical power system comprising a bus connected between a first solid state power converter and a second solid state power converter. The method includes receiving, at a controller of the electrical power system, a first signal indicating a current at a source side of the first solid state power converter, wherein the source side of the first solid state power converter is connected to a power source of the electrical power system. The method also includes receiving, at the controller, a second signal indicating a current at the bus and determining, by the controller, that a fault occurred in the electrical power system based on the first signal and further based on the second signal. The method further includes controlling the first solid state power converter in response to determining that the fault occurred.

A bi-directional direct current (DC) solid state power controller (SSPC) architecture and control method. The SSPC protects a DC distribution system by isolating both the positive and negative buses independently in case of short circuit or ground fault. The SSPC architecture includes two self-heal interleaved capacitors and includes a fast, soft-charging control technique that provides line-isolated charging of the DC bulk capacitor to avoid inrush current when powering up the DC distribution system. The soft-charging function alternately charges one of the two interleaved capacitors, while the other capacitor discharges to the DC bulk capacitor. Repetitive switching results in a charging and discharging process that increases the voltage of the DC bulk capacitor prior to powering up the DC distribution system, while keeping the DC power source isolated from the load.

Topology of a solid state power controller with two mid-capacitors

An apparatus for demodulating an analogue input signal comprises a hard limiter stage () for converting the signal to a two level signal. A digital down converter/low pass filter stage () converts the signal to a base band signal, and a symbol synchronization stage () extracts symbol timing. An instantaneous phase detector () calculates the instantaneous phase of the one or more symbols associated with the input signal. If the input signal has been modulated according to a pi/4DQPSK, pi/2DBPSK, GMSK, or a GFSK modulation scheme, a differential detector () determines a difference in the phase between adjacent symbols, a coarse frequency offset compensation stage () applies a compensation signal to compensate for frequency offset, and a frequency offset estimation stage () updates this compensation signal. A demapper () generates a demodulated output signal after compensation by the frequency offset compensation stage.

Growing community of inventors

Singapore, Singapore

Yu Yang