A charging and discharging system includes multiple battery packs and one or more voltage equalization modules. The multiple battery packs are connected in parallel. Each of a subset of the battery packs is connected in series with a voltage equalization module of the one or more voltage equalization modules. The voltage equalization module is configured to adjust, to a target voltage, an output voltage of the corresponding battery pack and the voltage equalization module that are connected in series.

System and method for detecting one or more currents. For example, a system for detecting one or more currents includes: one or more current sampling units coupled to one or more terminal transistors respectively and configured to sample one or more terminal currents that flow between a system terminal of a power management system and one or more port terminals through the one or more terminal transistors respectively; one or more operational amplifiers coupled to the one or more current sampling units respectively and configured to generate one or more detection currents respectively, the one or more detection currents representing one or more magnitudes of the one or more terminal currents respectively; and a signal combiner configured to receive the one or more detection currents, generate a combined detection voltage representing a sum of the one or more magnitudes of the one or more terminal currents.

The system proposed in this invention allows the conversion of energy from an AC/DC source, located on a platform (surface) and transmitted through an umbilical to a robot that operates on flexible lines, converting the electrical voltage to levels suitable for supplying the robotic system, and can also be used for supplying other pieces of equipment that operate with low voltage and require power high-density and protection against voltage transients.

The system of the invention consists of a surface source (2), fed by the platform's three-phase grid (1), an umbilical cable (3), which connects the source to the robot, an overvoltage protection circuit (4), and a two-stage conversion modular system (5 and 6).

A system is provided which comprises a power converter circuit, a plurality of DC-DC converter circuits, and a controller. The power converter circuit is configured to convert an AC voltage to a DC voltage. The DC-DC converter circuits are configured to convert the DC voltage output from the power converter circuit into respective regulated DC voltages. The controller is configured to control and program operations of the DC-DC converter circuits.

A motor control device is provided with a plurality of power converters and a plurality of microcomputers, and controls driving of a motor that has a plurality of sets of windings. The microcomputers perform initial check of components in respective circuits after activation. The microcomputers prohibit driving of the motor by a circuit determined to be abnormal during the initial inspection. When two or more circuits are determined to be normal in the initial check, the microcomputers start driving of the motor by synchronizing the timing between the two or more circuits determined to be normal. When only one circuit is determined to be normal in the initial check, the microcomputers start driving of the motor by the one circuit determined to be normal.

The present disclosure provides a three-phase AC/DC converter aiming for low input current harmonic. The converter includes an input stage for receiving a three-phase AC input voltage, an output stage for at least one load, and one or more switching conversion stages, each stage including a plurality of half bridge modules. The switches in each module operate with a substantially fixed 50% duty cycle and are connected in a specific pattern to couple a DC-link and a neutral node of the input voltage. The AC/DC converter further includes one or more controllers adapted to vary the switching frequency of the switches in the switching conversion stages based on at least one of load voltage, load current, input voltage, and DC-link voltage. The converter can also include one or more decoupling stages, such as, inductive components adapted to decouple the output stage from the switching conversion stages.

The present invention discloses a flying capacitor converter, a short circuit current suppression circuit for the same and an energy storage system. The flying capacitor converter comprises a controller, and has a high voltage side connected to a first power source and a low voltage side connected to a second power source. The short circuit current suppression circuit comprises: at least one current detection unit connected to the low voltage side and/or the high voltage side of the flying capacitor converter; and at least one switch set connected in series to the high voltage side and/or the low voltage side of the flying capacitor converter, wherein the controller controls the switch set to cut off a connection between the flying capacitor converter and the first power source and/or between the flying capacitor converter and the second power source, when the current detection unit detects a short circuit.

Electric machine drive systems, and related electric machine embodiments, include technologies for providing redundancy of shaft information of one or more electric machines between converter controllers of the corresponding system. The converter controllers are configured to control operation of power converters, which control one or more electric machines. The disclosed technologies include establishing one or more communication buses between the converter controllers to share the shaft information, which may be based on analog signals from a single, common resolver and/or from different, redundant resolvers depending on the embodiment. For example, in some embodiments, converter controllers communicatively connected to the same resolver may include separate resolver-to-digital converters (RDCs) to provide redundancy of the RDCs.

A communication device for connection with a power source and a host device is provided. The communication device comprises a device controller and a converter circuit. The device controller is adapted for data communication with the host device and the converter circuit is configured to provide a virtual device ground at least to the device controller, so as to compensate a ground potential difference between the host device and the communication device.

A power supply circuit includes a transformer having a primary winding and secondary windings, a first power conversion circuit configured to convert a DC voltage into an AC voltage and output the AC voltage to the primary winding, a rectifying and smoothing circuit that is connected to the secondary winding and is configured to rectify and smooth an alternating current output from the secondary winding, and a second power conversion circuit configured to boost a direct current output from the rectifying and smoothing circuit and supply to a load a DC voltage lower than a rated voltage of the load set in advance.