Abstract: An operating condition monitor (100) for monitoring an operating condition of a transistor-based power converter (102), comprising: a sensing apparatus (106) configured to measure a turn-off transient energy of the power converter (102), a processor (108) in communication with the sensing apparatus (106) to receive the measurement of the turn-off transient energy, the processor being configured to: compare the measurement of the turn-off transient energy to a threshold; and issue an event signal based on the comparison to the threshold meeting a comparison criterion. A method (200, 200?) of monitoring an operating state of a transistor-based power converter is also disclosed.

Abstract: A system, method and machine-readable instructions for monitoring a power electronics device. The system involves a semiconductor device, at least one sensor and a processor. The processor is configured to monitor a junction temperature of the semiconductor device by determining from the at least one sensor an on-state resistance of the semiconductor device and calculating the junction temperature of the semiconductor device according to a relationship between the on-state resistance of the semiconductor device and the junction temperature of the semiconductor device. The processor may apply an ageing coefficient to the on-state resistance.

Abstract: A power system includes a synchronous electrical generator having a rotor driven by a shaft; a permanent magnet signaling generator, coupled to the shaft; and an angle computation unit configured to calculate a rotor angle or load angle based on a voltage from the permanent magnet signaling generator and a voltage from the synchronous electrical generator.

Abstract: A power system, including: a synchronous electrical generator having a rotor; and an angle computation unit configured to: determine a rotor angle in a steady state period of the synchronous electrical generator, determine a change in rotor angle in a transient period of the synchronous electrical generator, and estimate the rotor angle in the transient period based on the steady state rotor angle and the change in rotor angle.

Abstract: A method determines a generator system load and/or rotor angle. The generator system has a generator with a generator terminal outputting electrical power generated by the generator, a transformer and a point of common coupling, PCC, terminal. The transformer is between the generator and PCC terminals. The method includes: determining the generator field current; determining the output voltage, the output current and the power factor and/or angle of the output voltage and output current from the generator terminal, and determining the load angle of the generator system, output voltage from the generator terminal, output current from the generator terminal and the power factor and/or angle; and/or determining the output voltage, the output current and the power factor and/or angle of the output voltage and output current, and determining the rotor angle of the generator system, output voltage, output current from the PCC terminal and the power factor and/or angle.

Abstract: There is disclosed a fault ride-through system for use in a power system comprising a synchronous generator driven by a prime mover. The fault ride-through system comprises a mechanical switch connected in parallel with a dynamic power dissipater, wherein the dynamic power dissipater comprises a solid-state switch connected in series with a braking resistor. A controller is configured to control the mechanical switch and the solid-state switch to control the current through the braking resistor, based on received data indicative of one or more operation parameters of the power system.

Abstract: A method for diagnosing a fault condition in an electric machine includes measuring at least one physical parameter generated during operation of the electric machine; analyzing the or each measured parameter in a frequency domain; and determining whether the electric machine has a stator or rotor winding fault based on a comparison of an amplitude of the or each analyzed parameter at a first predetermined frequency and a first threshold amplitude for the first frequency. The at least one physical parameter includes a sound generated by the electric machine.

Abstract: A fault condition is diagnosed in an electric machine that includes a rotor and a plurality of permanent magnets. To do so, the rotor is rotated so that each of the plurality of permanent magnets passes a magnetic flux density sensor, and the values of magnetic flux density are measured using the magnetic flux density sensor at a plurality of positions of the rotor. The measured values of magnetic flux density are analyzed and a magnitude of a peak amplitude is compared in a time or frequency domain with a reference value. If the peak amplitude is below the reference value, the electric machine is determined to have a fault condition.

Abstract: A rectifier diode failure detection apparatus for an electrical machine (10), the electrical machine (10) comprising an exciter armature winding (28a-c), a rotor main field winding (24) and first and second rectifiers (34a, 34b) arranged in parallel, each rectifier (34a, 34b) comprising at least first and second diodes (38a, 38b), each rectifier being configured to independently supply the rotor main field winding (24) with DC electrical current, the failure detection apparatus comprising: a controller (40) comprising at least two current sensors (42a, 42b), each current sensor (42a, 42b) being configured to measure output current (If1, If2) of a respective one of the rectifiers (34a, 34b), and the controller (40) being configured to determine a harmonic of the measured rectifier output currents; the controller (40) being further configured to determine a ratio of the magnitude of the first rectifier (34a) output current harmonic to the magnitude of the second rectifier (34b) output current harmonic, wherein

Abstract: An electrical system including a three phase AC input supply and three or more H-bridge converter cells. Each H-bridge converter cell has: an active front end rectifier for receiving the three phase AC input supply and transforming it into a DC supply, thereby providing a rectifier current ii; a capacitor suitable to receive a capacitor current iC, the capacitor smoothing the DC supply; and an inverter suitable to receive an inverter current io, wherein io=ii?iC, said inverter transforming the received inverter current io into a single phase AC supply. The system also including a control subsystem, which provides a signal to each active front end rectifier to vary its respective rectifier current ii such that the difference between the rectifier current ii, provided by the active front end rectifier, and the inverter current io, received by the inverter, is substantially zero.

Abstract: There is disclosed a method for diagnosing a fault condition in an electric machine 4. The method comprises measuring S2 at least one physical parameter generated during operation of the electric machine 4; analysing S4 the or each measured parameter in a frequency domain; and determining S12 whether the electric machine 4 has a stator or rotor winding fault based on a comparison of an amplitude of the or each analysed parameter at a first predetermined frequency and a first threshold amplitude for the first frequency. The at least one physical parameter comprises a sound generated by the electric machine 4.

Abstract: There is disclosed a method for diagnosing a fault condition in an electric machine 4, the electric machine 4 comprising a rotor 10 having an axis of rotation 14 and comprising a plurality of permanent magnets M1-M8. The method comprises: rotating the rotor 10 so that each of the plurality of permanent magnets M1-M8 passes a magnetic flux density sensor 6; measuring values of magnetic flux density using the magnetic flux density sensor 6 at a plurality of positions of the rotor 10; analysing the measured values of magnetic flux density and comparing a magnitude of a peak amplitude in a time or frequency domain with a reference value; and if the peak amplitude is below the reference value, determining that the electric machine 4 has a fault condition.

Abstract: An electrical system including a three phase AC input supply and three or more H-bridge converter cells. Each H-bridge converter cell has: an active front end rectifier for receiving the three phase AC input supply and transforming it into a DC supply, thereby providing a rectifier current ii; a capacitor suitable to receive a capacitor current iC, the capacitor smoothing the DC supply; and an inverter suitable to receive an inverter current io, wherein io=ii?iC, said inverter transforming the received inverter current io into a single phase AC supply. The system also including a control subsystem, which provides a signal to each active front end rectifier to vary its respective rectifier current ii such that the difference between the rectifier current ii, provided by the active front end rectifier, and the inverter current io, received by the inverter, is substantially zero.

Abstract: A delta-sigma Analog-to-Digital Converter (ADC) (IC) which includes an input feed-forward path extending from an input to the ADC to a feed-forward summing circuit disposed between a loop filter and quantizer of the ADC, and a filter disposed in the feed-forward path as an apparatus for improving distortion performance in the delta-sigma ADC. The filter may be a low pass filter, for example, a Resistor-Capacitor (RC) circuit. The filter may have a cut-off frequency outside the ADC's passband. The filtering provided may be continuous-time filtering, even if the delta-sigma ADC is a discrete-time delta-sigma ADC.

Abstract: A delta-sigma Analog-to-Digital Converter (ADC) (IC) which includes an input feed-forward path extending from an input to the ADC to a feed-forward summing circuit disposed between a loop filter and quantizer of the ADC, and a filter disposed in the feed-forward path as an apparatus for improving distortion performance in the delta-sigma ADC. The filter may be a low pass filter, for example, a Resistor-Capacitor (RC) circuit. The filter may have a cut-off frequency outside the ADC's passband. The filtering provided may be continuous-time filtering, even if the delta-sigma ADC is a discrete-time delta-sigma ADC.

Abstract: A method of controlling an inverter, in which the inverter includes a single-phase inverter arrangement having a complementary pair of power switches, including the steps of: controlling the complementary pair of power switches with a modulating signal to output an AC signal; monitoring a collector-emitter voltage of each of the pair of power switches; if the collector-emitter voltage exceeds a predetermined value, the corresponding one of the pair of power switches is judged to be in a short circuit condition; and if either one of the pair of power switches is judged to be in a short circuit condition, executing a shutdown operation to switch off the corresponding one of the pair of power switches.

Abstract: A rectifier diode failure detection apparatus for an electrical machine (10), the electrical machine (10) comprising an exciter armature winding (28a-c), a rotor main field winding (24) and first and second rectifiers (34a, 34b) arranged in parallel, each rectifier (34a, 34b) comprising at least first and second diodes (38a, 38b), each rectifier being configured to independently supply the rotor main field winding (24) with DC electrical current, the failure detection apparatus comprising: a controller (40) comprising at least two current sensors (42a, 42b), each current sensor (42a, 42b) being configured to measure output current (If1, If2) of a respective one of the rectifiers (34a, 34b), and the controller (40) being configured to determine a harmonic of the measured rectifier output currents; the controller (40) being further configured to determine a ratio of the magnitude of the first rectifier (34a) output current harmonic to the magnitude of the second rectifier (34b) output current harmonic, wherein

Abstract: Embodiments of the present disclosure provide a method of valuing an individual or group of individual's social contributions. This involves an individual first joining or being selected to join a community. The community may be created by a creator who selects the individuals to the community. The individuals participate in activities and as well as challenges of the community. In exchange for their participation and completion, the individual may receive rewards or points associated with the activities and challenges. The individual develops a score based on their social engagement. This score is a Social Engagement Reward Value (SERV) and represents their social engagement within the community. The rewards provided by the creator are awarded by the creator based on the individual's social engagement i.e. SERV and may come from a contributor. Additionally the community may be associated with a sponsor.

Abstract: A delta-sigma Analog-to-Digital Converter (ADC) (IC) which includes an input feed-forward path extending from an input to the ADC to a feed-forward summing circuit disposed between a loop filter and quantizer of the ADC, and a filter disposed in the feed-forward path as an apparatus for improving distortion performance in the delta-sigma ADC. The filter may be a low pass filter, for example, a Resistor-Capacitor (RC) circuit. The filter may have a cut-off frequency outside the ADC's passband. The filtering provided may be continuous-time filtering, even if the delta-sigma ADC is a discrete-time delta-sigma ADC.

Abstract: A method of detecting a stator fault in a multi-phase current induction machine including the steps of: obtaining a respective frequency spectrum for each of the current phases in the induction machine; deriving, from each frequency spectrum, a value for the ITHD (Inverse current Total Harmonic Distortion) for the respective current phase; calculating an ITHD deviation value corresponding to the maximum deviation for the derived ITHD values; judging whether the calculated ITHD deviation value differs from a reference deviation value; and determining, in response to a positive judgement, that there is a stator fault.