15results about How to "Solve the circulation problem" patented technology

The invention discloses a non-isolated DC / DC power converter and a power conversion device, the non-isolated DC / DC power converter comprises a power module and an oscillation suppression module, the power module comprises a first power conversion circuit, the first power conversion circuit is a non-isolated DC / DC conversion circuit, a first output terminal of the first power conversion circuit is connected with a first inductor, and a second output terminal of the first power conversion circuit is connected with a second inductor. A second output terminal of the first power conversion circuit is connected with a second inductor; the oscillation suppression module comprises a second power conversion circuit, a first port of the second power conversion circuit is coupled to the input end of the first power conversion circuit in parallel, and the current of the first port of the second power conversion circuit and at least part of alternating components of the input voltage of the oscillation suppression module are in the same phase. The second power conversion circuit is a bidirectional DC / DC conversion circuit.

The invention discloses a bidirectional six-switch buck-boost topology circuit and a control method thereof, and belongs to the technical field of power electronics. According to the scheme, two switch tubes and one inductor are additionally arranged on the basis of a four-switch buck-boost circuit, and an input negative electrode and an output negative electrode are separated through the additionally arranged switch tubes and inductor, so that the problem that when different input source outputs are connected in parallel, a negative bus is directly connected to form circulating current is effectively solved; a loop does not need to judge an input and output voltage relation, the duty ratio of a power switch tube is automatically adjusted directly according to the set voltage, current and energy transfer direction, and the boost-buck state of the topology is determined according to the calculation result of the duty ratio, so that the control on the energy transfer direction is realized; the on / off of the synchronous rectifier tube is determined by the magnitude of the output current. By adopting the scheme of the embodiment of the invention, the circulating current problem caused by multi-path input difference can be solved, the topology control difficulty is reduced, and the control error-tolerant rate is improved.

The invention relates to the field of electric power, in particular to an intelligent grid connection device and method for a wind power photovoltaic power station. The intelligent grid-connected device of the wind power photovoltaic power station can change the operation mode of the voltage stabilizing device according to the energy flow direction to adapt to the energy direction; the self-adaptive flexible voltage stabilizing device comprises a voltage control module and a current control module, and the current control module is located at the front end of the power supply compensation module and used for improving the three-phase imbalance phenomenon in the power transmission line, eliminating higher harmonics and conducting reactive compensation. All current and voltage adjusting devices are connected in parallel in a circuit, or the adjusting devices are separated in a main circuit through an isolation transformer, and the main circuit is not provided with any operation device.

The utility model discloses an energy storage system which comprises a box body, and a battery cluster, an energy storage high-voltage control box, a DC / DC device and an inversion device are arranged in the box body. The number of the battery clusters is multiple, the number of the energy storage high-voltage control boxes is the same as that of the battery clusters, and the input ends of the energy storage high-voltage control boxes are connected with the battery clusters in a one-to-one correspondence mode. The number of the DC / DC devices is multiple, each DC / DC device comprises a DC voltage stabilization channel, the DC voltage stabilization channels included in the multiple DC / DC devices are mutually independent, the number of the DC voltage stabilization channels is the same as that of the energy storage high-voltage control boxes, and the input ends of the DC voltage stabilization channels are connected with the output ends of the energy storage high-voltage control boxes in a one-to-one correspondence mode. The output end of the direct current voltage stabilization channel is electrically connected with the input end of the inversion device. By the adoption of the scheme, the problem of how to reduce circulating current and risks caused by direct-current confluence type design is solved.

This invention discloses a multi-branch battery pack high-voltage system and its control method. The multi-branch battery pack high-voltage system includes: multiple battery pack branches, a charging control module, and a discharging control module. Each battery pack branch includes a battery pack, a battery drain interrupter (BDU), and a bidirectional DC-DC converter module. The battery pack is connected to the input terminal of the BDU. The BDU has a main circuit and an equalization circuit. The main circuit controls the on / off of the main power of the battery pack branch it belongs to. The BDUs of each battery pack branch are connected to each other through the equalization circuit for active equalization between branches. The output terminal of the BDU is connected to the input terminal of the bidirectional DC-DC converter module, which controls the charging and discharging current of its respective battery pack branch. The output terminals of all bidirectional DC-DC converter modules are connected in parallel and then connected to the charging control module and the discharging control module. This invention can solve the circulating current problem between battery packs and improve the stability of the multi-branch battery pack high-voltage system.

The invention provides an energy storage system, a starting control method of the energy storage system and electronic equipment, the energy storage system comprises a main control unit and a plurality of battery cluster units, the main control unit is used for sending a pre-charging control instruction to each sub-control unit to control a battery cluster to pre-charge a DC / DC converter through a pre-charging control circuit; and an output voltage control instruction is sent to each sub-control unit, and after each DC / DC converter controls the output voltage of the DC / DC converter to be adjusted to the target output voltage based on the output voltage control instruction, the main control unit sends a start control instruction to each sub-control unit. According to the invention, all the battery clusters are simultaneously connected with the positive and negative buses, rapid starting of the energy storage system is realized, and the circulating current problem is solved.

The invention provides a permanent magnet synchronous generator parallel control device and method. The device adopts the scheme that the permanent magnet synchronous generator is connected with the controllable rectification direct current side in parallel, eddy current loss of the generator is reduced, and output voltage is improved. According to the output current of each module circuit, the current disturbance coefficient is dynamically adjusted, the given value of the direct current output voltage is dynamically adjusted, the control precision of the parallel current is improved, the problems of circulating current generated by parallel operation of the generator and unbalanced output current are solved, and high power, modularization and modularization of the permanent magnet synchronous generator are realized. Meanwhile, iq after coordinate transformation is adopted as feedback quantity, direct current measurement is not needed, the number of current sensors is reduced, the product cost is reduced, an additional synchronizing device is not needed, and the size, the weight and the complexity of the system are reduced.

The invention relates to the technical field of intelligent power grids and industrial automation control, in particular to a DC power supply coordination control system based on industrial big data. The system comprises a multi-dimensional heterogeneous data sensing module, a feature mapping module, a multi-target collaborative decision-making module and a self-adaptive execution module. The system constructs a load characteristic and electric energy quality correlation model based on the operation state and the power consumption demand, outputs dynamic electrical characteristics and sensitivity characteristics, and solves a power distribution instruction by taking power grid quality, load balance and efficiency as cooperative targets; according to the method, a perception decision-making framework crossing an electrical domain and a physical domain is constructed, hidden physical layer states such as impedance drift are mined through deep learning, the problem that a load physical state is ignored and production quality is disjointed in traditional control is solved, and the industrial yield and energy efficiency are improved while the quality of a power grid is guaranteed.

The embodiment of the invention discloses a rail transit system, power modules applied to the rail transit system and an input control method, and the control method comprises the steps that the rail transit system comprises a plurality of power modules connected in parallel, the direct current ends of the power modules are connected with a direct current traction network, and the alternating current ends of the power modules are connected with an alternating current power grid; the control method comprises the following steps: controlling the working state of a first power module to be switched from an exit state to an operation state within a first duration when a train enters a stable operation stage; wherein the sum of the first time length and the second time length is smaller than or equal to the time length of the stable operation stage, and the second time length is the time length required by the first power module to complete switching of the working state from the quit state to the operation state. The first power module is any one of the power modules which is currently in a quit state and has abnormities eliminated, and the stable operation stage is located between a traction stage when the train is started and a feedback stage when the train is braked.

The invention provides a battery pack parallel operation method, a battery management system, an energy storage system and a storage medium. The battery pack parallel operation method comprises the steps that bus voltage is acquired, and whether the bus voltage is within a preset voltage range or not is judged; when the bus voltage is within a preset voltage range, acquiring a current battery pack voltage, and judging whether the current battery pack voltage is greater than the bus voltage, and if so, entering a high-voltage to low-voltage parallel operation mode; otherwise, entering a low-voltage-to-high-voltage parallel operation mode. The problem of current circulation can be solved, and system parallel operation can be completed under any working condition.

The application discloses an improved distributed collaborative control method for a ship-mounted hybrid energy storage system, and comprises the following steps: obtaining actual current and voltage on a direct-current bus; obtaining current and voltage at an output port of a direct-current converter to obtain output power of the direct-current converter; obtaining voltage output by a storage battery and a super capacitor respectively based on proportional droop and integral droop control methods; obtaining a state of charge of the super capacitor based on the voltage output by the super capacitor; compensating a bus voltage regulation factor to the proportional droop control to accelerate the recovery speed of the state of charge of the super capacitor; obtaining a SoC dynamic adjustment factor based on a novel SoC dynamic adjustment algorithm, so that the storage battery gradually realizes SoC balance in the charging and discharging process, and no circulating current phenomenon occurs; and transient power distribution is realized between the storage battery and the super capacitor, and a high-frequency part of load power change is automatically distributed to the super capacitor, and a low-frequency part is compensated by the storage battery.

The utility model discloses an anti-circulation device of an energy storage system, which is characterized in that two groups of switch modules are arranged on the upper surface of a shell, and each switch module consists of a main switch and a branch switch, so that the two groups of switch modules control charging and discharging of a lithium battery, and mutual influence of a charging circuit and a discharging circuit is avoided; and the main switch is used for controlling the branch switches to be connected with the lithium batteries, so that current circulation caused by parallel connection among multiple groups of lithium batteries is avoided, and the problem of circulation caused by internal resistance change of the lithium batteries in a parallel circuit is solved.

This invention provides an energy storage system, relating to the field of energy storage. The energy storage system includes an inverter device and multiple battery pack devices; each battery pack device includes at least a battery pack unit and a DC-DC converter; the inverter device sends charge / discharge signals to each battery pack device, and the battery pack devices, under the influence of the charge / discharge signals, charge and discharge the battery pack units via the DC-DC converters. This invention solves the problem of output current differences and circulating current issues caused by differences in electrical characteristics between battery pack units by connecting the DC-DC converters and battery pack units in series in each battery pack device. This avoids the deterioration of the electrical characteristics of the battery pack units, reduces the power range and voltage rating requirements of the DC-DC converters, lowers the circuit cost and power consumption of the energy storage system, and ensures the stability and reliability of the energy storage system during operation.

The utility model relates to the technical field of energy storage, and discloses an energy storage converter circuit and an energy storage converter system, a controllable power switch circuit is connected in series on each branch battery pack on the direct current side of a conversion circuit to realize the charge and discharge control of the branch battery packs, so that the circuit module is simple in structure, does not need redundant circuit arrangement, and is convenient to use. Compared with the prior art, according to the scheme provided by the utility model, the circuit structure of the direct current side is simplified, and the controllable power switch circuit is in one-way conduction, so that the problem of circulating current among the multi-branch battery pack is avoided.

The present invention provides a multi-port current source non-common ground type photovoltaic-storage complementary system, comprising: multiple DC ports, an AC port, multiple DC-AC conversion branches, an AC-AC conversion branch and a multi-winding high-frequency transformer. The system establishes a hardware-based power decoupling solution by designing the leakage inductance value, the excitation inductance value and the capacitance value of the AC-AC conversion branch of the multi-port high-frequency transformer, realizes power decoupling between multiple DC ports and AC ports, and solves the circulation problem between the ports. The present invention also provides a control method for the above photovoltaic-storage complementary system, which divides the working state of the photovoltaic-storage complementary system into three application scenarios: standby, grid-connected and independent load according to the connection status of the AC and DC ports and the power flow direction, and changes the corresponding control strategy according to different working conditions, so that the photovoltaic-storage complementary system can still ensure stable operation when facing complex actual working conditions, thereby improving the reliability of the photovoltaic-storage complementary system.