Abstract: There is provided a method of configuring a closed-loop control system, the control system comprising a controller and a plant, the controller configured to provide an actuator signal to the plant, the controller configured to receive a reference signal (r) and a feedback signal (y), the feedback signal (y) derived from a state (x) of the plant, wherein a first state space representation of the control system includes at least one system delay, the method comprising the steps of: transforming the first state space representation of the control system into a second, augmented state space representation of the control system; configuring a control law (uT) based on the augmented state space representation of the control system, wherein the control law (uT) is configured to include at least one control term configured to compensate for at least one disturbance (d) to the control system, wherein the control law (uT) is configured to include a time-advanced or predicted reference signal (r) configured so that the

Abstract: A voltage source converter for interconnecting first and second electrical networks, including first and second terminals for connection to the first electrical network, and a primary converter limb extending between the first and second terminals including first and second primary limb portions separated by a third terminal connectable to the second electrical network. The converter further including a second chain-link converter connected to the third terminal and a control unit configured to selectively operate one or more chain-link modules to generate a discontinuous pulse width modulation voltage waveform. The converter further including a controller configured to selectively operate each chain-link converter to control the configuration of a discontinuous pulse width modulation voltage waveform at the third terminal.

Abstract: A synthetic test circuit, comprising: a device under test including a chain-link converter under test, comprising a plurality of test modules, each test module including module switches connected with an energy storage device; a terminal connected to the device under test; at least one injection circuit operably connected to the terminal, the injection circuit including a source, the source including a source chain-link converter, which includes a plurality of source modules, each source module including a plurality of module switches connected with at least one energy storage device; a controller being configured to operate each source module to selectively bypass the corresponding energy storage device and insert the corresponding energy storage device into the corresponding source chain-link converter so as to generate a voltage across the source chain-link converter and thereby operate the injection circuit to inject a current waveform and/or a voltage waveform into the chain-link converter under test.

Abstract: A synthetic test circuit, for performing an electrical test on a device under test, is provided. The circuit includes a terminal connectable to the device under test; a voltage injection circuit-operably connected to the terminal, the voltage injection circuit including a voltage source, the voltage source including a chain-link converter, the chain-link converter including a plurality of modules, each module including a plurality of module switches connected with at least one energy storage device; and a controller-configured to operate each module of the voltage injection circuit to selectively bypass the or each corresponding energy storage device and insert the or each corresponding energy storage device into the chain-link converter so as to generate a voltage across the chain-link converter and thereby operate the voltage injection circuit to inject a unidirectional voltage waveform into the device under test.

Abstract: A method is provided for controlling a converter including at least one converter limb corresponding to a respective phase of the converter, the or each converter limb extending between first and second DC terminals and including first and second limb portions separated by an AC terminal, each limb portion including a converter arm, at least one of the limb portions including at least one director arm, the or each director arm including a director switch. The method comprises the steps of obtaining a respective AC current demand phase waveform for the or each converter limb, and a DC current demand, both of which the or each converter limb is required to track; determining a limb portion current; timing the current ramp profile of the determined director arm current for the director arm or the one of the director arms; and providing a limb portion voltage source for each limb portion.

Abstract: A voltage source converter for interconnecting first and second electrical networks, including first and second terminals for connection to the first electrical network, and a primary converter limb extending between the first and second terminals including first and second primary limb portions separated by a third terminal connectable to the second electrical network. The converter further including a second chain-link converter connected to the third terminal and a control unit configured to selectively operate one or more chain-link modules to generate a discontinuous pulse width modulation voltage waveform. The converter further including a controller configured to selectively operate each chain-link converter to control the configuration of a discontinuous pulse width modulation voltage waveform at the third terminal.