A power supply circuit, a compensation circuit and a harmonic distortion compensation method thereof are disclosed. The power supply circuit includes a rectifier and filter module, a main power stage module, a voltage waveform detection module and a compensation module. The rectifier and filter module converts an AC voltage into a DC voltage. The main power stage module receives the DC voltage and provides power to a load. The voltage waveform detection module is configured to detect a waveform of the DC voltage and derive, from the waveform, information about each cycle of the DC voltage. The compensation module is configured to generate a compensation signal based on the information about each cycle of the DC voltage and trigger the main power stage module to perform compensation operation based on the compensation signal. The compensation operation is performed to accomplish total harmonic distortion compensation of the power supply circuit.

A power quality compensator device and a control method thereof are provided. The power quality compensator device is electrically connected to a power grid and a nonlinear load, and includes a current controller, a converter, a ripple predictor, a processing unit and a voltage controller. The current controller is configured to receive an instruction current and output a switch control signal. The converter is configured to output an output current and an actual DC bus voltage according to the switch control signal. The ripple predictor is configured to receive an intermediate voltage and a first current and output a predicted ripple voltage. The processing unit is configured to output a processing result according to the actual DC bus voltage, the predicted ripple voltage and a reference DC bus voltage. The voltage controller is configured to receive the processing result and output a voltage control signal to the current controller.

A system for controlling and monitoring electrical energy loads includes a current transducer configured to monitor values of electrical current in the system, wherein neutral and ground lines are monitored via separate current transducers. Additionally, the system includes a centralized programable logic controller (PLC) configured to receive measured values from the current transducer in real time and a local PLC configured to receive the measured values from the centralized PLC. Further, the local PLC periodically compares the measured values of the electrical energy with predetermined thresholds and automatically redistributes the electrical energy to electrical energy loads among three phases based on the comparison.

Various disclosed embodiments include illustrative controller units, direct current fast charging (DCFC) units, and methods. In an illustrative embodiment, a controller unit includes a controller and a memory configured to store computer-executable instructions. The computer-executable instructions are configured to cause the controller to determine status of a power electronics module (PEM) of a direct current fast charging (DCFC) unit, and instruct the PEM to control power quality of a three-phase alternating current (AC) grid power signal in response to the determined status being available.

Techniques, methods, circuits, and systems are provided for providing stabilization for a circuit. One example system includes a switching converter coupled to a power source; a low-pass filter coupled to a load device; a direct current (DC) path; and an alternating current (AC) path, where the DC path and the AC path are provided between the switching converter and the low-pass filter, and where the AC path provides a non-phased information signal to be used to compensate for a phase delay occurring in the DC path. In a more specific implementation, the DC path can be configured to provide control, at low frequency, for an output to the load device. In addition, an error amplifier can be to the DC path and the AC path, where the low-pass filter and the error amplifier can be configured to determine a switchover between the AC path and DC path.

Techniques, methods, circuits, and systems are provided for providing stabilization for a circuit. One example system includes a switching converter coupled to a power source; a low-pass filter coupled to a load device; a direct current (DC) path; and an alternating current (AC) path, where the DC path and the AC path are provided between the switching converter and the low-pass filter, and where the AC path provides a non-phased information signal to be used to compensate for a phase delay occurring in the DC path. In a more specific implementation, the DC path can be configured to provide control, at low frequency, for an output to the load device. In addition, an error amplifier can be to the DC path and the AC path, where the low-pass filter and the error amplifier can be configured to determine a switchover between the AC path and DC path.

Systems and methods are described for active harmonics cancellation. A wireless charging apparatus includes a wireless-power transfer circuit comprising a wireless-power transfer coil configured to generate or couple to a magnetic field to transfer or receive power and a plurality of tuning capacitors electrically coupled to the wireless-power transfer coil. The apparatus also includes a power converter circuit electrically coupled to the wireless-power transfer circuit. Additionally, the apparatus includes a signal generation circuit different from the power converter circuit and electrically coupled to one or more nodes between capacitors of the plurality of tuning capacitors. The signal generation circuit is configured to generate and inject a signal into the wireless-power transfer circuit at the nodes between the capacitors. The signal generation circuit includes a rejection filter tuned to an operating frequency of the wireless-power transfer coil.

A converter apparatus includes a string of electrically interconnected modules that includes a first group of modules comprising a first module and a second group of modules comprising a second module. A first screen is connected to a first defined electric potential and is located adjacent the first group of modules and a second screen is connected to a second defined electric potential and is located adjacent the second group of modules. During operation of the converter apparatus a resonance loop is created from the first module via the first and second screens and the second module back to the first module. A damping unit is located in the resonance loop and is set to dampen electromagnetic noise.

A converter apparatus includes a string of electrically interconnected modules that includes a first group of modules comprising a first module and a second group of modules comprising a second module. A first screen is connected to a first defined electric potential and is located adjacent the first group of modules and a second screen is connected to a second defined electric potential and is located adjacent the second group of modules. During operation of the converter apparatus a resonance loop is created from the first module via the first and second screens and the second module back to the first module. A damping unit is located in the resonance loop and is set to dampen electromagnetic noise.

There is provided an electrical assembly comprising a converter (20) for connection to an electrical network (40), the converter (20) comprising at least one module (44) including at least one switching element (46) and at least one energy storage device (48), the or each switching element (46) and the or each energy storage device (48) in the or each module (44) arranged to be combinable to selectively provide a voltage source, the electrical assembly including a controller (54) configured to selectively control the switching of the or each switching element (46) in the or each module (44), wherein the electrical assembly includes a sensor (56a) configured for measuring a current of the electrical network (40), wherein the controller (54) and sensor (56a) are configured to operate in coordination to carry out a characterisation of an electrical parameter of the electrical network (40) so that, in use: the controller (54) selectively controls the switching of the or each switching element (46) in the or each module (44) to modify an electrical parameter of the converter (20) so as to modify the current of the electrical network (40); the sensor (56a) measures a resultant modified current of the electrical network (40); and the controller (54) processes the measured resultant modified current of the electrical network (40) so as to characterise the electrical parameter of the electrical network (40).