Control Techniques Limited

Nidec Control Techniques Limited

Michael Cade

Simon David Hart

Richard Mark Wain

Gareth Christopher James

Scott Alan Meredith-Jones

Stephen Turner

Embodiments of the present invention relate to an a method, apparatus and computer program product for controlling the operation of a drive unit comprising a plurality of switching modules arranged to receive a DC electricity supply and generate an AC electricity supply for driving a load from the received DC electricity supply, the AC electricity supply being generated by the switching of the plurality of switching modules between a conducting state and a non-conducting state. The method comprises receiving one or more characteristics associated with each of the switching modules, comparing, for each switching module of the plurality of switching modules, a characteristic of the switching module with an equivalent characteristic associated with one or more other switching modules of the plurality of switching modules, and controlling a time period during which one or more of the plurality of switching modules are in the conducting state in accordance with a result of the comparison.

Control system and method

A method for controlling the temperature of a first semiconductor device on an inverter module of a drive configured to drive an electrical machine is disclosed. The method comprises calculating at least one harmonic component of at least one power loss of at least the first semiconductor device; using the at least one harmonic component of the at least one power loss of the at least the first semiconductor device to calculate a temperature of the first semiconductor device; and if the calculated temperature of the first semiconductor device does not meet a predetermined temperature condition, issuing a command to control the operation of the drive such that the temperature of the first semiconductor device is changed to meet the predetermined temperature condition.

Using harmonic component(s) to calculate a temperature of a semiconductor device in an inverter module

A method of managing recovery from an event in an electrical circuit leading to a loss of control of an inverter in the electrical circuit is disclosed, the method comprising sampling a parameter of operation before the event, monitoring for occurrence of the event, calculating an estimated value of the parameter at a time after the event based on an extrapolation of the monitored parameter and controlling the inverter using the estimated value of the parameter.

System and method for managing recovery of control in an electrical system

A method of reducing periodic disturbances in the feedback quantity of a controlled system is disclosed. The method includes receiving a feedback signal and repeatedly deriving respective magnitudes of harmonic components of the feedback signal to produce corresponding error signals. The error signals and harmonic components are used to generate harmonic control signals. The harmonic control signals are used to create a plurality of negative feedback loops acting to reduce the error signals. The present disclosure thus provides negative feedback control in the frequency domain. In one specific disclosed embodiment, the control is tied to the periodic domain resulting from the rotation of an actuator motor shaft.

Reduction of periodic disturbances

A method is provided for determining a value for an electrical output of a converter of renewable energy. The method comprises obtaining a signal representing the electrical output of the converter wherein that electrical output has an initial value. The method further comprises applying a pulse signal to the signal representing the electrical output, wherein the pulse signal comprises a positive portion and a negative portion. The method further comprises obtaining a measurement of electrical power produced by the converter during application of the pulse signal, removing the pulse signal and then obtaining a measurement of electrical power produced by the converter in the absence of the pulse signal. An error value is determined from the obtained electrical power measurements and that error value is applied to the initial value to obtain a target value for the electrical output of the converter.

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Newtown, United Kingdom

Michael Cade