Analog Devices Global

Analog Devices International Unlimited Company

Analog Devices Global Unlimited Company

Analog Devices International Limited Company

Seyed Amir Ali Danesh

Jonathan Ephraim David Hurwitz

William Michael James Holland

John Stuart

Petre Minciunescu

Stephen James Martin Wood

Long Wang

George Redfield Spalding, Jr

Iain Barnett

Shaoli Ye

Luca Martini

William Holland

A three-phase power meter can monitor power on both 3-wire and 4-wire power lines. The power meter measures at least two voltages between phase conductors of the power line, and at least one voltage between a phase conductor and a neutral conductor of the power line when the neutral conductor is available. Using at least some of the measured voltages, the power meter can then operate in a first mode when coupled to a 3-wire power line to determine power on the power line based on the measured voltages, or operate in a second mode when coupled to a 4-wire power line to determine power on the power line based on the measured voltages.

Three-phase power meter monitoring for star and delta configurations

This disclosure relates to monitoring the condition of electrical/electronic switches over time by monitoring the impedance of the switch. The condition of switches can degrade as they age, which can reduce their performance and may ultimately lead to failure. In many applications, particularly high-voltage applications, the reliable operation of switches may be very important and failures can present a safety risk and cause costly unscheduled system downtime for repairs. It has been realised that as the condition of switches change, their impedance changes, so monitoring the impedance can give a good indication of the condition of the switch, enabling potential faults/failures to be identified early and acted upon pre-emptively.

Switch condition monitoring

An apparatus is provided which substantially removes a perturbation signal from a pulse density modulated signal representing a combination of a signal to be measured and a perturbation applied to the signal to be measured. The removal of the perturbation is done by subtracting a correcting signal from the pulse density modulated signal. This approach introduces very little delay as it can be implemented by simple logic gates. It also provided enhanced immunity from the effects of bit errors.

Removing perturbation signal from a serial data stream, and to measurement and/or protection apparatus including same

The present disclosure relates to the determination of impedances in an electrical network. Methods and apparatuses for determining one or more impedances within a root and branch network are disclosed. The impedance of a common root part and the impedance of a branch of the electrical network may be determined based on the current in the common root part, the current in a branch of the electrical network and the voltage across the common root part and the branch. By determining the impedance of different parts of the electrical network in this way, the network may be monitored over time and the location of any faults or impending faults in the network may be identified more exactly without requiring invasive network probing and testing.

Electrical network impedance determination

The present disclosure provides a system and method for the management of a monitor module in an electrical measurement system to determine an estimate of a transfer function of a first measurement sensor in the measurement system. The management comprises outputting a first control instruction for instructing the monitor module to determine an estimate of the transfer function of the first measurement sensor over a first individual run length of time, obtaining a first monitor result from the monitor module, the monitor result comprising the estimate of the transfer function of the first measurement sensor and generating a report based at least in part on the first monitor result.

Managing the determination of a transfer function of a measurement sensor

Current measurement apparatus comprises a measurement arrangement and a signal source. The measurement arrangement is configured to measure a current signal drawn by a load. The signal source is operative to apply a reference input signal to the measurement arrangement whereby an output signal from the measurement arrangement comprises a load output signal corresponding to the load drawn current signal and a reference output signal corresponding to the reference input signal. The signal source comprises a current multiplier which defines first and second current paths and is configured such that: the first path carries a multiplier input current signal; the second path carries a multiplier output current signal which determines the reference input signal and which corresponds to the multiplier input current signal multiplied by a multiplier value determined by the current multiplier; and the multiplier input current signal and the multiplier output current signal are carried on their respective paths in a same direction relative to a power supply voltage. Power drawn through the second path as divided by the multiplier value is less than the power drawn through the first path.

Current measurement

The present invention relates to current measurement apparatus. The current measurement apparatus comprises first and second measurement devices with each of the first and second measurement devices being operative to measure current in a respective one of a live conductor and a neutral conductor substantially simultaneously. The current measurement apparatus is operative to make plural different determinations in dependence on the substantially simultaneous current measurements.

The present disclosure relates to generating a measurement sensor profiling summary in relation to a measurement sensor of an electrical measurement system, the measurement sensor being suitable for measuring an electrical property. The profiling summary is generated by obtaining a plurality of profiling results each comprising an estimate of a transfer function of a measurement sensor of the electrical measurement system and a corresponding certainty value indicative of the accuracy of the estimate of the transfer function, wherein the plurality of profiling results are based on estimates of the transfer function of the measurement sensor and corresponding certainty values that were determined by a monitor module of the electrical measurement system during a profiling period of time; and generating a profiling summary based on at least one of the plurality of profiling results.

Differential sampling circuits may be adversely affected by changes in common mode voltage. Changes in the common mode voltage may alter the on resistance of transistor switches which it turn may mean that small signal changes are not correctly observed against a bigger common mode signal. The present disclosure relates to a way of improving the ability to resolve small differential signal changes by varying the supply or drive voltage to a component to compensate for common mode voltage changes.

Method of and apparatus for reducing the influence of a common mode signal on a differential signal and to systems including such an apparatus

A measurement circuit is arranged to make several measurements, either at different times or in respect of different frequency components of currents measured by current sensors in respective phases of a multiphase supply system. The measurements are then used to correct for discrepancies in the transfer function of the sensors.

The present disclosure relates to the control of an operation of a monitor module of an electrical measurement system, where the monitor module has a plurality of operating states, including a) monitor at least a first measurement sensor of the utility meter to determine a first monitor result comprising an estimate of a transfer function of the first measurement sensor and a corresponding certainty value indicative of the accuracy of the estimate of the transfer function of the first measurement sensor, wherein the first measurement sensor is for measuring a first electrical property, and b) do not monitor any measurement sensor of the electrical measurement system.

There is a need to monitor and control the state of relays and circuit breakers within power distribution systems. The monitoring of a relay state, i.e. open or closed, is often performed by applying a monitoring signal to sensing contacts added to the relay. Manufactures of such systems have chosen many different voltages for their own monitoring systems making it difficult to interconnect dissimilar monitoring systems. A signal conditioning circuit is provided that can cope with a large input voltage range and can be configured to allow may items of equipment (which may be new item or legacy items) to be connected to a controller.

Signal conditioning circuit and a relay/circuit breaker control apparatus including such a signal conditioning circuit

The present invention relates to current measurement apparatus. The current measurement apparatuscomprises a measurement arrangementwhich is configured to be disposed in relation to a loadwhich draws a current signal, the measurement arrangement being operative when so disposed to measure the load drawn current signal. The current measurement apparatusalso comprises a signal sourcewhich is operative to apply a reference input signal to the measurement arrangementwhereby an output signal from the measurement arrangement comprises a load output signal corresponding to the load drawn current signal and a reference output signal corresponding to the reference input signal. The current measurement apparatusfurther comprises processing apparatuswhich is operative to receive the output signal and to make a determination in dependence on the reference output signal and the load output signal, the determination being in respect of at least one of the load drawn current signal and electrical power consumed by the load.

An apparatus is provided that can estimate a transfer function, for example of current measurement systems, voltage measurement systems and power measurement systems, and also provide an estimate of certainty about the transfer function. This enables customers to have confidence that they are not being overcharged for electricity.

Growing community of inventors

Edinburgh, United Kingdom

Seyed Amir Ali Danesh