7results about "Constant-current supply ac circuits" patented technology

The invention relates to a supply unit (20) for a DC load (50). The supply unit (20) comprises: - a DC terminal (21) for connecting to the DC load (50), - a first AC terminal (22) which is connected to a DC bus (26) via a first AC / DC converter (24), - a second AC terminal (23) which is designed for connecting to a second AC voltage (U2) and which is connected to the DC terminal (21) via a second AC / DC converter (25), - an energy storage device (29) which is connected to the DC bus (26) via a first DC / DC converter (27), - a second DC / DC converter (28) which connects the DC bus (26) to the DC terminal (21) and which can be operated so as to provide the current with respect to the DC terminal (21), and - a control unit (30) for controlling the supply unit (20). The supply unit is characterized in that - the first DC / DC converter (27) is designed in the form of a bidirectional DC / DC converter, and the control unit (30) is designed to operate the first DC / DC converter (27) so as to provide the voltage with respect to the DC bus (26), and - the first AC / DC converter (24) is designed in the form of a bidirectional AC / DC converter, and the control unit (30) is designed to operate the first AC / DC converter (24) so as to provide the voltage with respect to the first AC terminal (22). The invention additionally relates to an operating and starting method and to an electrolysis system comprising such a supply unit (20).

A control method and an apparatus for a power supply system, and a power supply system are provided. The control method includes: obtaining a current SOC and current charging / discharging power of the energy storage apparatus connected to the first power supply device; and executing a target control policy, in response to the current SOC exceeding a target SOC range, or the current charging / discharging power exceeding a target power range. The executing the target control policy includes: controlling a frequency of the first power supply device; or controlling a contactor connected to the second power supply device to be disconnected, to disconnect the second power supply device from the coupling point.

The application discloses a power supply system control method and device and a power supply system, and belongs to the technical field of power supply. The power supply system control method comprises the following steps: acquiring the current state of charge and the current charging and discharging power of an energy storage device connected to a first power supply device; in the case that the current state of charge is out of a target state of charge range or the current charging and discharging power is out of a target power range, a target control strategy is executed; wherein the execution of the target control strategy comprises: controlling the frequency of the first power supply device; or controlling the disconnection of a contactor connected to the second power supply device, so that the second power supply device is disconnected from the coupling point. The method can realize energy management of multiple power supply devices without establishing communication, and ensure the stable operation of the power supply system.

An uninterruptible power supply system enables versatile power source selection based on present loading. The system comprises: a primary power source selector that is selectable between a plurality of primary power source options; a battery management system comprising a plurality of battery management units; a controller for controlling the primary power source and the battery management system; and a bus subsystem including a controller area network bus for connecting together the primary power source selector, the battery management system and the controller. A primary power source selected by the primary power source selector is determined by the controller based on an analysis of primary power source parameters and peripheral load parameters.

An uninterruptible power supply system can flexibly select a power supply according to a current load. The system includes: a main power selector capable of selecting among a plurality of main power options; a battery management system including a plurality of battery management units; a controller for controlling the main power supply and the battery management system; and a bus subsystem including a controller area network bus for connecting the primary power selector, the battery management system, and the controller together. A primary power source selected by the primary power source selector is determined by the controller based on an analysis of primary power source parameters and peripheral load parameters.

An electrical system includes inverters coupled together in parallel and coupled to a common DC bus. The electrical system also includes a common AC bus coupled between outputs of the inverters and an electrical power grid. The electrical system also includes local controllers coupled to the inverters and decentralized controllers coupled to the local controllers. The decentralized controllers measure voltages and currents of the electrical power grid and the inverters and generate decentralized control signals for the local control controllers based on the measured voltages and currents. The electrical system also includes a centralized controller in communication with the local controllers. The centralized controller predicts a DC load and generates centralized control signals for the local controllers to maintain a constant voltage on the common DC bus based on the predicted DC load.

The embodiment of the invention provides an electrified railway bilateral power supply system, and belongs to the technical field of alternating current electrified railway traction power supply. The power supply and transformation system comprises two power substations, two main substations adopting three-phase and two-phase traction transformers, n voltage reduction substations adopting single-phase wiring traction transformers, a single-phase high-voltage transmission line and a traction network. Wherein the two main substations are connected with a three-phase bus of the power transformer through power transmission lines; the n step-down substations are respectively connected with the single-phase high-voltage transmission line and the traction network; the circuit breaker is arranged between the three-phase bus and the single-phase bus, and bilateral power supply of the traction network is realized through a left-closing and right-opening or left-opening and right-closing control mode. According to the bilateral power supply system, three-phase balance of a superior power grid is realized, and a negative sequence compensation device can be prevented from being arranged; the single-phase high-voltage transmission line and the traction network are erected in parallel, system impedance is reduced, and the traction network power supply distance is effectively prolonged.