33results about How to "Convenient redundant design" patented technology

The invention discloses a modular full direct current photovoltaic system and a control method thereof. The system comprises n DC (direct current)-DC converter modules and an MMC (Multi Media Card) centralized inverter, and every DC-DC converter module is connected with an independent control loop and a maximum power tracking control function so as to ensure that a photovoltaic battery pack connected with every DC-DC converter works on the highest point of the output power. According to the modular full direct current photovoltaic system and a control method thereof, a direct current bus is formed by connecting the output ends of a plurality of DC-DC converter modules in series, and the high-power grid-connected power generation function is achieved through the centralized MMC inverter. The direct current bus can effectively reduce the operating loss of the entire system and structurally improve the operating efficiency of the system.

The invention discloses an active power router with an AC/DC through-fault function, comprising a high-voltage rectifier-level MMC-AC/DC (modular multilevel converter-AC/DC) converter connected with ahigh-voltage AC distribution network of an AC/DC distribution network via a high-voltage AC port, and a rectifier-level MMC-AC/DC converter and a transformer isolator-level MMC-DC/DC converter both connected with a high-voltage DC distribution work of a high-voltage DC port. A low-voltage DC port of the transformer isolator-level MMC-DC/DC converter is connected with the DC side of a three-phaseDC/AC converter to form a low-voltage DC interface; a low-voltage AC port of the three-phase DC/AC converter may be connected with a low-voltage AC grid or a single-phase/three-phase AC load. The high-voltage side of the active power router is composed of a hybrid sub-module with negative level output, giving the AC/DC through-fault capacity, and ensuring that the power router can run uninterruptibly and reliably when an external AC/DC grid fails; power generation penetration rate of a distributed clean energy and reliability of power supply can be further improved.

The invention discloses a modularized structure for a three-level inverter for wind power generation, which can simply and quickly form different power levels for wind power generation. The modularized structure comprises an electrical system and a radiating system, wherein the electrical system comprises four direct current capacitors, four IGBTs (Insulated Gate Bipolar Translators), two clamping diodes, two absorption capacitors, a balancing resistor and bus bars; the radiating system comprises a water-cooling base plate and an air water-heat exchanger; a cooling water channel is arranged inside the water cooling base plate; and a water inlet and a water outlet which are connected with the air water-heat exchanger are arranged on in the lower end surface of the water-cooling base plate; the bus bars comprise a direct current capacitor bus bar which is arranged above the water-cooling base plate and a converter loop bus bar which is vertically connected with the direct-current capacitor bus bar, and arranged in front of the water-cooling base plate in parallel; the four direct current capacitors are arranged below the direct current capacitor bus bar, and the wiring terminals of the four direct current capacitors are connected with the direct current capacitor bus bar; the four IGBTs and the two clamping diodes are fixedly arranged on the water-cooling base plate; and the wiring terminals of the four IGBTs and the two clamping diodes and the wiring terminal of the balancing resistor are connected with the converter loop bus bar.

The invention discloses a high-voltage and high-power transducer which comprises a rectifier, a filter unit, an inverter unit and an output transformer unit. The filter unit is connected between the rectifier and the inverter unit, the output transformer unit comprises M transformers, wherein M is larger than or equal to 2, the primary side of each transformer comprises N three-phase windings, the secondary side comprises a three-phase winding, wherein N is larger than or equal to 2, the primary three-phase windings of each transformer have identical voltage and power, the secondary three-phase windings of each transformer have identical voltage and power, the same-phase windings of the M secondary three-phase windings are sequentially connected in series and then connected into star-type three-phase windings or triangular three-phase windings, the inverter unit comprises M*N three-phase inverters which are sequentially connected in series, the output of each three-phase inverter is connected with a primary three-phase winding, phases sequentially shift at 60 degrees/M among the primary three-phase windings of the M transformers, no phase shift happens among the M secondary three-phase windings, and an SPWM (Sinusoidal Pulse Width Modulation) fundamental wave which is output to the primary three-phase windings of the M transformers by the three-phase inverters has no phase shift.

The invention relates to a cascade current converter, which is characterized by comprising at least two current converter bridge arms. Each current converter bridge arm comprises a first bridge arm unit and a second bridge arm unit which are connected in series; the series connection point of the first bridge unit and the second bridge unit in each current converter bridge arm is connected with an alternating current outgoing line; the other two ends of the first bridge arm unit and the second bridge arm unit are respectively connected with the anode and the cathode of a direct current bus; the first bridge arm unit comprises n B-shaped bridges (Mj1) connected in series, and the second bridge arm unit comprises n B-shaped bridges (Mj2) connected in series, wherein ji=1...n, j2=n+1...2n, n is a cascade number and n is not less than 1. The invention is mainly used for high and mid-voltage-grade power grids and loads.

The embodiment of the invention provides a power electronic transformer. The power electronic transformer comprises a high voltage module, a low voltage module and a soft copper bus bar, wherein the high voltage module and the low voltage module realize the functions of a rectifying level, an isolation level and an inverter level, the high voltage module comprises a circuit of the rectifying leveland a high-frequency chopper in the isolation level, an internal connecting terminal of the circuit of the rectifying level is connected with a first wiring terminal of the high-frequency chopper inthe isolation level; the low voltage module comprises a high-frequency transformer in the isolation level and a circuit of the inverter level, and an internal connecting terminal of the circuit of theinverter level is connected with the secondary side of the high-frequency transformer in the isolation level; and a second connecting terminal of the high-frequency chopper in the isolation level isconnected with the primary side of the high-frequency transformer in the isolation level through the soft copper bus bar. According to the power electronic transformer, the overall size, cost and complexity of a system are lowered advantageously, redundant design of the system is facilitated, and the reliability of the system is improved.

The invention relates to a bidirectional multiport non-isolated DC converter and a control method thereof. The DC converter comprises at least two DC converter modules, and one end of each DC converter module is connected with a micro power grid; each DC converter module comprises an upper diode module, a lower diode module, a capacitor C1 connected with the upper diode module in parallel and a capacitor C2 connected with the lower diode module in parallel, and the upper diode module and the lower diode module are connected in series; the upper diode module comprises an upper diode switch T1 and a lower diode switch T2 which are connected in series, and the lower diode switch T2 is connected with a capacitor C3 in parallel; and the lower diode module comprises an upper diode switch T3 and a lower diode switch T4 which are connected in series, and the upper diode switch T3 is connected with a capacitor C4 in parallel. The control method comprises a positive bus voltage control process, a negative bus voltage control process, a positive bus current control process and a negative bus current control process. Each module of the application can achieve bidirectional flow of energy, and can specify voltage or power of a port as needed.

The invention discloses an isolated high-voltage DC/AC converter and a wide-range voltage modulation control method thereof. The isolated high-voltage DC/AC converter comprises a plurality of series-connected modules, wherein each module comprises a half-bridge structure converter, an H-bridge inverter and an output isolation transformer which are sequentially connected, a high-voltage DC voltageis connected to input ends of the plurality of series-connected modules, an AC voltage is output to be connected to two ends of a single-phase load by an LC filter after all transformers of the plurality of modules are connected in series, each half-bridge structure converter comprises a capacitor, the capacitor is connected in parallel with a series branch formed by connecting two isolated gate bipolar transistors (IGBTs) in series, the H-bridge inverter comprises a first IGBT, a second IGBT, a third IGBT and a fourth IGBT, each IGBT is reversely connected in parallel with a diode, the firstIGBT and the second IGBT are connected in series, and the third IGBT and the fourth IGBT are connected in series. By the isolated high-voltage DC/AC converter, the voltage of each sub-module can be stabilized to be an expected voltage, and the voltage stabilization effect is good.

The invention relates to a distribution network high-frequency isolated type flexible direct-current converter. 3n or 6n high-frequency isolated type basic power units are connected with one another so as to form the distribution network high-frequency isolated type flexible direct-current converter; the high-frequency isolated type basic power unit includes a non-isolated type DC/DC converter, anisolated type DC/DC converter and a non-isolated DC/AC converter which are sequentially connected with one another; the input end of the non-isolated type DC/DC converter is adopted as the direct current input end of the high-frequency isolated type basic power unit; the output end of the non-isolated DC/DC converter is connected with the input end of the isolated type DC/DC converter; the outputend of the isolated type DC/DC converter is connected with the input end of the non-isolated type DC/AC converter; and the output end of the non-isolated type DC/AC converter is adopted as the alternating current output end of the high-frequency isolated type basic power unit. With the distribution network high-frequency isolated type flexible direct-current converter of the present invention adopted, functions such as the bi-directional transmission, electrical isolation, and waveform control of medium-voltage direct-current electric energy and medium-voltage alternating-current electric energy can be realized; and modular series and parallel design is adopted, and therefore, expansion can be facilitated, and the requirements of medium-voltage and small- and medium-capacity electric energy conversion can be satisfied.

The invention relates to a topological structure of a medium-voltage direct-hanging photovoltaic power generation system, and the structure comprises a plurality of power modules, wherein each power module is internally composed of a photovoltaic module, a high-frequency isolation DC/DC converter module and a DC/AC converter module; the plurality of power modules are connected in parallel to form the overall topological structure through a cascade H-bridge structure, the power modules are independently designed, the input side of each power module is not connected with the common DC bus, and the output side adopts a series structure. The high-frequency isolation DC/DC converter is adopted in the topological structure, so that the size and weight of the whole machine are reduced, and the cost is reduced; the cascade H-bridge topology is adopted, the number of power electronic devices is reduced, redundancy design and seamless switching redundancy modes are conveniently achieved, and the operation safety and stability of the system are improved; the virtual synchronous motor is adopted for control, voltage and frequency support can be provided for a power grid, the inertia and damping of the system are increased, and safe and stable operation of the power grid can be supported more stably.

The invention relates to a hydraulic winch driving mechanism of a crane. The hydraulic type winch driving mechanism mainly comprises hydraulic motors, speed reducers, a rotary rolling disc, a windingdrum and a structural frame of the winding drum, a bearing seat support and a hydraulic control system. According to the hydraulic winch driving mechanism, the plurality of sets of hydraulic motors and speed reducers are adopted for driving, and small gears of the speed reducers are meshed with a large gear ring of the rotary rolling disc to transfer torque; each group of the speed reducer and thehydraulic motor serves as a driving unit, and the plurality of driving units are uniformly distributed on the circumference of the large gear ring of the rotary rolling disc; a standby unit can be additionally arranged through the driving mechanism, and the driving mechanism has the advantage that when a certain unit breaks down, the fault unit is removed firstly, and a new driving unit can be intervened; and the driving units are controlled by a control valve, and intelligent switching can be realized according to the form of the fault; and the hydraulic control winch driving mechanism has redundant design.

The invention discloses an M * N type modular multi-level AC-AC converter topological structure, which comprises M input ports, N sub-converters and N output ports, the M input ports are connected with each sub-converter at the same time, each sub-converter is connected with one output port, each sub-converter comprises M bridge arm branches, and each bridge arm branch is connected with one output port. Each bridge arm branch is connected with one input port and one output port; each bridge arm branch comprises a bridge arm inductor, one end of each bridge arm inductor is connected with the input port, the other end of each bridge arm inductor is sequentially connected with the K sub-modules in series, and the tail end sub-module is connected with one output port. Different voltage levels are achieved by adjusting the number of modules connected in series in each bridge arm branch, high-voltage high-power direct alternating current-current conversion is achieved through a semiconductor device with a low voltage resistance level, direct current links are reduced, cost and control complexity are reduced, and the power density of the conversion device is improved.