Abstract: Disclosed is an AC-AC power converter with multiple AC voltage output branches. The AC-AC power converter is bridgeless and contains only one power stage. The AC-AC power converter consists of only one inductor for power conversion and provides a current source for successively feeding multiple output branches one at a time. Each output branch can be selected by the corresponding switch and its resonant circuit turns the input current source into an AC power source.

Abstract: Disclosed is an AC-AC power converter with multiple AC voltage output branches. The AC-AC power converter is bridgeless and contains only one power stage. The AC-AC power converter consists of only one inductor for power conversion and provides a current source for successively feeding multiple output branches one at a time. Each output branch can be selected by the corresponding switch and its resonant circuit turns the input current source into an AC power source.

Abstract: A power converter circuit includes: a direct current (DC) side; a first passive network; a first current switching network; at least one floating capacitor; a second current switching network; a second passive network; and an alternating current (AC) side. The first passive network is connected between the DC side and the first current switching network for linking the DC side and the first current switching network. The first current switching network comprises at least four serially linked switches for switching the power converter circuit between switching cycles. The at least one floating capacitor is connected to the first current switching network. The second current switching network comprises two pairs of switches for providing an interface between the first current switching network and the second passive network. The second passive network is connected between the second current switching network and the AC side.

Abstract: A power converter comprising one or more switch blocks. Each switch block has: a plurality of switch-pairs each having two switches connected in series to each other; a plurality of primary nodes each interconnecting the switches in a respective switch-pair; and a plurality of secondary nodes, each switch-pair being connected in series to an adjacent switch-pair through a said secondary node to form a serial chain of switch-pairs, the secondary nodes including a secondary node at one end of said serial chain and a secondary node at another end of said serial chain. Each adjacent pair of said primary nodes is connectable to a flying capacitor. Each pair of said secondary nodes is connectable to one or more of the following: one or more bypass capacitors, and one or more other said switch blocks.

Abstract: A system and a control method for generating multiple independent alternating current (AC) voltages from a direct current (DC) voltage source in a single-inductor multiple-output (SIMO) inverter are disclosed. The system comprising: a DC voltage source (101) for providing electrical energy; a front-stage DC-DC power converter (105) comprising exactly one inductor as an energy storage element for power conversion and a main switching element; a plurality of selectable output branches (106), wherein each output branch comprises an output selection switch (107), a resonant tank (110), and a transmitter coil (109), wherein the resonant tank converts output power of the DC-DC power converter into AC power for feeding the transmitter coil; and a controller (104) for determining ON/OFF states of the main switching element and the output selection switch of each of the output branches.

Abstract: Switched capacitor (SC) converters with excellent voltage regulation, high conversion efficiency, and good suitability fora wide range of applications are provided. An SC converter can include at least two SC sub-circuits, and at least one of these SC sub-circuits can be of variable gain. One SC sub-circuit can convert the input voltage of the SC converter to an output voltage close to the desired output voltage value for the SC converter, and another SC sub-circuit having variable gain can convert the input voltage to an output voltage with a high resolution of small discrete voltage steps.

Abstract: A system and a control method for generating multiple independent alternating current (AC) voltages from a direct current (DC) voltage source in a single-inductor multiple-output (SIMO) inverter are disclosed. The system comprising: a DC voltage source (101) for providing electrical energy; a front-stage DC-DC power converter (105) comprising exactly one inductor as an energy storage element for power conversion and a main switching element; a plurality of selectable output branches (106), wherein each output branch comprises an output selection switch (107), a resonant tank (110), and a transmitter coil (109), wherein the resonant tank converts output power of the DC-DC power converter into AC power for feeding the transmitter coil; and a controller (104) for determining ON/OFF states of the main switching element and the output selection switch of each of the output branches.

Abstract: In many power electronics systems, there is an intermediate DC-link stage for facilitating the power processing of different sources to their loads. A device called a plug-and-play ripple pacifier (RP) directly plugged into the DC-link, and actively removes undesired DC-link ripple, thereby eliminating the reliance on electrolytes capacitors for stabilizing the system and remove ripple. Importantly, the use of this device is non-invasive to the operation of its host systems, and requires no modification of existing hardware. It is suitable for the protection of DC utilities/systems and can also be used as a direct replacement of ripple-canceling E-Caps in power converters device.

Abstract: A power controller for an AC power converter connected in series with a load and receiving power from or delivering power to a power source, the power controller comprising: a radial control block controlling a radial component of an electrical parameter of the AC power converter; and a chordal control block controlling a chordal component of the electrical parameter of the AC power converter. Also provided is a power system comprising one or more loads each connected in series to a power converter each controlled by a power controller as described above. There is also provided a method of controlling an AC power converter connected in series with a load and receiving power from a power source, the method comprising: controlling a radial component of an electrical parameter of the AC power converter; and controlling a chordal component of the electrical parameter of the AC power converter.

Abstract: In many power electronics systems, there is an intermediate DC-link stage for facilitating the power processing of different sources to their loads. A device called a plug-and-play ripple pacifier (RP) directly plugged into the DC-link, and actively removes undesired DC-link ripple, thereby eliminating the reliance on electrolytes capacitors for stabilizing the system and remove ripple. Importantly, the use of this device is non-invasive to the operation of its host systems, and requires no modification of existing hardware. It is suitable for the protection of DC utilities/systems and can also be used as a direct replacement of ripple-canceling E-Caps in power converters device.

Abstract: Switched capacitor (SC) converters with excellent voltage regulation, high conversion efficiency, and good suitability fora wide range of applications are provided. An SC converter can include at least two SC sub-circuits, and at least one of these SC sub-circuits can be of variable gain. One SC sub-circuit can convert the input voltage of the SC converter to an output voltage close to the desired output voltage value for the SC converter, and another SC sub-circuit having variable gain can convert the input voltage to an output voltage with a high resolution of small discrete voltage steps.

Abstract: A single-stage AC-DC single-inductor multiple-output (SIMO) LED driver uses a single inductor (L) to drive multiple independent LED strings (341-34n) with Power Factor Correction (PFC). The driver uses a diode bridge (20) to achieve initial AC to DC conversion. The output of the bridge (20) is provided to a buck converter whose output is shared with multiple LED strings by a time division multiplex circuit. Feedback is used to separately control the current supplied to each LED string by using a separate reference for each string and controlling the width of the current pulse provided to a string. Current balancing in every LED string can be achieved with the same voltage reference without the need for additional circuitry.

Abstract: A single-stage AC-DC single-inductor multiple-output (SIMO) LED driver uses a single inductor (L) to drive multiple independent LED strings (341-34n) with Power Factor Correction (PFC). The driver uses a diode bridge (20) to achieve initial AC to DC conversion. The output of the bridge (20) is provided to a buck converter whose output is shared with multiple LED strings by a time division multiplex circuit. Feedback is used to separately control the current supplied to each LED string by using a separate reference for each string and controlling the width of the current pulse provided to a string. Current balancing in every LED string can be achieved with the same voltage reference without the need for additional circuitry.

Abstract: A power converter comprising one or more switch blocks. Each switch block has: a plurality of switch-pairs each having two switches connected in series to each other; a plurality of primary nodes each interconnecting the switches in a respective switch-pair; and a plurality of secondary nodes, each switch-pair being connected in series to an adjacent switch-pair through a said secondary node to form a serial chain of switch-pairs, the secondary nodes including a secondary node at one end of said serial chain and a secondary node at another end of said serial chain. Each adjacent pair of said primary nodes is connectable to a flying capacitor. Each pair of said secondary nodes is connectable to one or more of the following: one or more bypass capacitors, and one or more other said switch blocks.

Abstract: A correlated color temperature control system (1) for a LED lighting system (2) having at least two LED sources (3, 4) with different correlated color temperatures. The LED lighting system (2) has a combined correlated color temperature resulting from the combination of the different correlated color temperatures of the at least two LED sources (3, 4), and a combined luminous flux resulting from the combination of the luminous fluxes of the at least two LED sources (3, 4), with each LED source being supplied with a supply current.

Abstract: A power controller for an AC power converter connected in series with a load and receiving power from or delivering power to a power source, the power controller comprising: a radial control block controlling a radial component of an electrical parameter of the AC power converter; and a chordal control block controlling a chordal component of the electrical parameter of the AC power converter. Also provided is a power system comprising one or more loads each connected in series to a power converter each controlled by a power controller as described above. There is also provided a method of controlling an AC power converter connected in series with a load and receiving power from a power source, the method comprising: controlling a radial component of an electrical parameter of the AC power converter; and controlling a chordal component of the electrical parameter of the AC power converter.

Abstract: A correlated colour temperature control system (1) for a LED lighting system (2) having at least two LED sources (3, 4) with different correlated colour temperatures. The LED lighting system (2) has a combined correlated colour temperature resulting from the combination of the different correlated colour temperatures of the at least two LED sources (3, 4), and a combined luminous flux resulting from the combination of the luminous fluxes of the at least two LED sources (3, 4), with each LED source being supplied with a supply current.

Abstract: A driving method for improving luminous efficacy of a light emitting diode (LED), the method comprising: periodically switching a DC current supplied to the LED between a high current level lH and a low current level lL, the low current level lL being fixed at zero or raised above zero to produce a DC offset; and maintaining an average current at a first value If by adjusting the duty cycle acting on the high current level lH and any one from the grouping consisting of: adjusting the high current level lH and adjusting the low current level lL, and adjusting the high current level lH or adjusting the low current level lL.

Abstract: A driving method for improving luminous efficacy of a light emitting diode (LED), the method comprising: periodically switching a DC current supplied to the LED between a high current level lH and a low current level lL, the low current level lL being fixed at zero or raised above zero to produce a DC offset; and maintaining an average current at a first value If by adjusting the duty cycle acting on the high current level lH and any one from the grouping consisting of: adjusting the high current level lH and adjusting the low current level lL, and adjusting the high current level lH or adjusting the low current level lL.