1288 results about "DC-BUS" patented technology

The invention relates to the technical field of power electronics, in particular to an inverter load feed-forward compensation method and system based on dynamic hysteresis regulation. The method comprises the following steps: acquiring an instantaneous load current signal of an inverter system; wherein when the load current suddenly changes, the bus voltage on the direct current bus fluctuates; performing low-pass filtering on the instantaneous load current signal to extract a direct current component of the load current; determining a dynamic hysteresis limit value according to the instantaneous load current signal, the direct current component and the amplitude adjustment coefficient; comparing the instantaneous load current signal with a historical current feed-forward signal, updating the historical current feed-forward signal according to a comparison result and a dynamic hysteresis limit value, taking the updated historical feed-forward current signal as an updated feed-forward current signal of the current control period, generating a compensation current based on the updated feed-forward current signal, and outputting the compensation current to the current control period. And the compensation current is applied to the corresponding direct-current bus so as to suppress bus voltage fluctuation caused by load abrupt change.

A multiple input converter for outputting power from AC power or a battery to positive and negative direct current (DC) buses is provided. The multiple input converter includes at least one bridge arm unit and a bidirectional DC-DC conversion unit. The bridge arm unit corresponds to one phase of the alternating current (AC) power and includes an upper and lower bridge arms that can independently form a two-level converter. In a battery mode, the upper and lower bridge arms discharge power from the rechargeable battery to the positive and negative DC buses, and the bidirectional DC-DC conversion unit discharges power from the rechargeable battery to the positive and negative DC buses or balances voltages of the positive and negative DC buses. In a mains mode, the bridge arm units are connected to the AC power. The bidirectional DC-DC conversion unit determine whether to charge or discharge according to load conditions.

A converter system, e.g., for vehicle-to-vehicle charging, includes galvanically-isolated modular first and second converters having the same maximum voltage rating, a direct current (DC) voltage bus interconnecting the converters, and an electronic controller. An input voltage to the DC bus is converted into an output voltage via switching control signals to the modular converters. The system's voltage rating may equal the maximum of the input and / or output voltage, or it may equal the maximum input voltage and be about 50-percent of the maximum output voltage. The maximum input and output voltages may be equal. When the voltage rating is about 50-percent of the maximum input voltage, capacitors may be connected in parallel with the modular converters on an input side thereof. Switching circuits may be connected to the bus to control the conversion of the input voltage via switching control signals.

The invention discloses a micro-grid system based on a direct current bus and a control method, the micro-grid system comprises the direct current bus, an energy management unit and a plurality of power conversion modules, when the micro-grid system is in an independent adjusting mode, each power conversion module controls the direct current bus to operate according to bus operation parameters of the direct current bus; and when the micro-grid system is in a centralized regulation mode, the energy management unit issues a control instruction to coordinate the output power and / or the input power of each power conversion module. According to the technical scheme, a unified direct current bus framework is constructed, the photovoltaic energy unit, the energy storage energy unit, the commercial power energy unit, the direct current load and other loads are directly connected to the direct current bus, direct current direct supply and direct current direct charging are achieved, the energy link structure is simplified, the power conversion link is reduced, the overall energy efficiency of the system is improved, and the system cost is reduced. And the phenomena of multiple energy conversion and energy loss caused by dependence on an alternating current bus in the prior art are avoided.

A control system for a direct current (DC) microgrid is described. The control system includes a DC bus with a positive bus line and a negative bus line, DC battery circuits with a positive coupler connected to the positive bus line and a negative coupler connected to the negative bus line, switches including a control input terminal located in each DC battery circuit, a distributed generator circuit connected to the DC bus, a constant load power circuit connected to the DC bus, a computing device connected to each control input terminal, the DC bus, the distributed generator circuit and the constant load power circuit. The computing device includes an electric circuitry, a memory, and at least one processor to determine a DC bus voltage, determine the SoC of the DC battery circuits, generate PWM signals that control the DC bus voltage, and balance the SoC of the DC battery circuits.

The invention discloses a distributed light storage and charging integrated system, which comprises a photovoltaic power generation unit, an energy storage unit, a charging unit, a power grid interface unit, an energy management controller and a direct current bus, the photovoltaic power generation unit comprises a DC / DC converter, and the photovoltaic power generation unit is connected with the DC bus through the DC / DC converter; the energy storage unit comprises a lithium ion battery pack, a flywheel energy storage device, a bidirectional DC converter and a flywheel controller. The lithium ion battery pack and the flywheel energy storage device are connected to the DC bus through the bidirectional DC converter and the flywheel controller respectively. The charging unit comprises at least one direct-current quick charging pile, at least one alternating-current slow charging pile and a DC / AC inverter, the direct-current quick charging pile is directly connected with the direct-current bus, and the alternating-current slow charging pile is connected with the direct-current bus through the DC / AC inverter; the power grid interface unit comprises an AC / DC converter and is connected with the DC bus through the AC / DC converter. According to the invention, through collaborative design of a modular hardware architecture and an intelligent time-sharing strategy, comprehensive improvement of economy, reliability and functionality of the system is realized.

The invention discloses a photovoltaic optimization regulation and control method and device based on an MPPT technology, and particularly relates to the technical field of photovoltaic power generation control, and the method specifically comprises the following steps: S1, full-link operation state synchronous collection, S2, DC bus ripple feature extraction, S3, multi-source disturbance quantitative evaluation, S4, cooperative control parameter decision making, and S5, grid-connected signal synthesis modulation. A multi-source disturbance quantitative evaluation system is adopted, the irradiance change gradient, the frequency ratio and the switching noise contribution ratio are subjected to multi-dimensional fusion, a dynamic weight distribution mechanism is established, and parallel optimization of MPPT mode selection, disturbance step length adjustment and PWM phase shift angle is achieved through a cooperative control parameter decision architecture. A response delay bottleneck existing in a traditional serial decision mode is broken through, and a ripple compensation component is dynamically injected while stable output of fundamental current is maintained based on a grid-connected signal modulation strategy of vector synthesis.

The invention provides a wind power smooth control method, system and equipment based on multi-element energy storage and a medium, belongs to the technical field of wind power generation, and realizes smooth output through multi-step cooperative control. Acquiring original wind power data and a real-time state; and a fluctuation component is extracted through signal decomposition and preprocessing, and a target power instruction is generated. A control strategy input signal is constructed in combination with the state of energy storage equipment, a future multi-cycle power prediction sequence is generated by using a model prediction control algorithm, and power compensation tasks of all energy storage devices are distributed in a differentiated manner. And charging and discharging operation is executed through the converter, compensation power is injected / absorbed to the direct-current bus to offset fluctuation, and finally smooth wind power is output to a power grid. Through multi-element energy storage cooperative control, the wind power fluctuation can be effectively smoothed, and the grid-connected stability is improved; the model prediction control algorithm improves the dynamic response precision, reduces the power grid impact risk, and enhances the overall operation efficiency and reliability of the system.

The invention provides a control method of a photovoltaic energy storage system, the photovoltaic energy storage system and a control circuit. The photovoltaic energy storage system comprises a power supply mechanism, a hybrid energy storage mechanism and a control module. The hybrid energy storage mechanism comprises a super capacitor module and an energy storage module; according to the control method, a hysteresis control threshold value is dynamically adjusted based on real-time state information of multiple dimensions; the method comprises the following steps: collecting power grid side data, photovoltaic side data and load side data in real time, and respectively calculating various different power gap parameters and state abrupt change parameters; when the state abrupt change parameter triggers a transient response strategy in the hybrid energy storage hierarchical control strategy, the super capacitor module is controlled to compensate preferentially; and triggering a steady state control strategy in the hybrid energy storage hierarchical control strategy to control an energy storage module and a super capacitor module to access the DC bus for compensation based on the dynamically adjusted hysteresis control threshold and the matching result of the various different power gap parameters, thereby reducing the state switching frequency of the photovoltaic energy storage system.

The invention relates to an alternating-current and direct-current integrated power supply system and a control method, a power conversion unit comprises a parallel high-frequency rectification module, an inversion module and a communication power supply module, and a direct-current side is connected in parallel to a common direct-current bus; the energy storage unit realizes energy interaction between a storage battery pack and a bus through a bidirectional DC / DC converter, and a matched health monitoring circuit acquires internal resistance, temperature and voltage data in real time; the dynamic voltage support unit is formed by connecting a filter network and a transient suppression device in series and is directly connected with a bus to suppress voltage fluctuation caused by load abrupt change; the electromagnetic protection unit integrates an input-stage surge protector, a cabinet body grounding copper bar and an anti-interference device, so that the electromagnetic compatibility of the system is guaranteed; the intelligent control unit is combined with the communication bus through the main controller, and the functions of multi-mode power supply switching, energy storage unit temperature compensation charging and cooperative fault protection are achieved. The system meets the AC / DC load hybrid power supply requirement through the modular design and the cooperative control strategy, and improves the reliability and adaptability of the power supply system.

The invention discloses an electric power system transient stability rapid response control method and system, and relates to the technical field of electric power systems, and the method comprises the steps: collecting a transient harmonic current signal generated by a power grid fault in real time through a harmonic detection unit connected to a DC bus of an energy storage converter, and calculating the phase offset of the transient harmonic current signal; generating a power control instruction through a pre-configured hardware mapping circuit based on the phase offset; acquiring a current differential signal by using a power grid line current sensor, and identifying a path of transient energy flowing to a key unit based on a power grid topological structure; for the path, dynamically forming a virtual high-impedance wall on the target line; and on a consumption path predefined according to the power grid topological structure, controlling the energy storage converter to operate in a current source mode and configuring a reverse power characteristic so as to absorb the energy flow turned by the virtual high-impedance wall.

The invention discloses a light-diesel hybrid energy storage system and a control method thereof, and belongs to the field of microgrids. The system comprises a photovoltaic power generation unit, a diesel generator set, a hybrid energy storage unit (a storage battery and a super capacitor), an AC / DC bus, a bidirectional AC / DC converter and a system controller. The controller executes hybrid energy storage frequency division control (without sampling load power and distributing power through bus voltage), V / f control and nine multi-mode energy management strategies, and monitors parameters such as photovoltaic output, load power, energy storage charge state and the like in real time to realize intelligent mode switching. The super capacitor preferentially responds to the pulse load, and the voltage fluctuation ratio is smaller than or equal to 5%; the service life of the storage battery is prolonged in combination with energy storage charge state threshold management; photovoltaic maximum utilization enables the system efficiency to be greater than or equal to 90%, and the diesel oil consumption is obviously reduced. The method is suitable for power grid coverage difficulty scenes such as off-network communication base stations, remote sentries and emergency power supply stations, and has high reliability and maneuverability.

The invention provides a direct-current bus type electric vehicle charging system with a source-load-storage cooperative management capability, and belongs to the technical field of electric vehicle charging. Comprising an interface connected with a medium and low voltage power distribution network, a bidirectional AC / DC converter, a common DC bus, a plurality of bidirectional DC / DC converters and a plurality of unidirectional DC / DC converters, the medium and low voltage power distribution network is connected with the AC side of the bidirectional AC / DC converter through a transformer, and the bidirectional AC / DC converter realizes conversion between AC and DC; the direct current side of the bidirectional AC / DC converter is connected to each bidirectional DC / DC converter and each unidirectional DC / DC converter through a common direct current bus; the system takes a direct current bus as a core, has the technical advantages of bidirectional energy flow, modular expansion, multi-scene flexible deployment and the like, and is suitable for various typical application scenes such as intelligent buildings, residential parks, industrial factory areas, micro-grids, power grid energy storage nodes and the like; the defect that an existing electric vehicle charging system cannot be cooperatively managed with a comprehensive energy system can be effectively overcome.

The invention discloses a power module. The power module comprises a direct current busbar, a radiator, an IGBT module I and an IGBT module II, the IGBT module I and the IGBT module II are respectively arranged on a mounting surface I and a mounting surface II of the radiator; the direct-current busbar comprises a direct-current busbar I, a direct-current busbar II, a direct-current busbar III and a direct-current busbar IV; the two ends of a fourth direct-current busbar are connected with the first IGBT module and the second IGBT module respectively, and the middle of the fourth direct-current busbar is connected with the middle of a third direct-current busbar. The two ends of the direct current busbar III are respectively connected with the direct current busbar I and the direct current busbar II; the direct current busbar I and the mounting surface I as well as the direct current busbar II and the mounting surface II are oppositely arranged and parallel to each other; the first direct current capacitor assembly is connected with the first direct current busbar, and the second direct current capacitor assembly is connected with the second direct current busbar. The influence of stray inductance is reduced by optimizing a current path, and the voltage spike at the switching moment is reduced due to the reduction of the stray inductance, so that the switching loss is reduced.

The invention discloses a multi-port DAB energy storage system directly connected with an elevator frequency converter bus and a cooperative control method of the multi-port DAB energy storage system, and is suitable for an elevator frequency converter direct-current bus direct-connection scene. Aiming at the defects in the aspects of elevator bus transient support, multi-branch extension and parallel operation safety access in the prior art, at least two DAB power branches are adopted, the low-voltage sides of the DAB power branches are connected into the same low-voltage direct-current source in parallel to realize current expansion, and the high-voltage sides of the DAB power branches are connected to a VFD direct-current bus through a parallel operation access switch to realize voltage expansion after being connected in series and laminated; the controller adopts fixed frequency phase shift control, and combines a two-line parallel operation or power-off time sequence and a zero-crossing residence strategy; through multi-branch phase interleaving, mutual exclusion amplitude limiting constraint, ZVS guarantee and a fault striding linkage mechanism, branch power balance, circulating current suppression and bus stable support are realized. According to the invention, the millisecond voltage of the bus can be efficiently suppressed, the response speed, the operation efficiency and the reliability of the system are improved, and the core requirements of elevator bus energy recovery and transient stability control are met.

The invention provides a three-phase low-voltage MOSFET (Metal-Oxide-Semiconductor Field Effect Transistor) packaging integrated power module. A driving assembly, a direct-current bus capacitor and other modules are integrated in an aluminum shell package. The three DBC substrates respectively bear U-phase bridge arms, V-phase bridge arms and W-phase bridge arms, an upper bridge arm and a lower bridge arm of each phase are formed by a plurality of parallel MOSFET chips, drain electrodes of the chips are directly welded to a DBC upper copper layer, grid electrodes of the chips are connected with an upper-layer driving circuit board through copper columns, source electrodes of the chips are led out to a direct-current input terminal or an alternating-current output terminal through bonding wires, and a double-layer conductive structure is formed. A plurality of direct-current bus capacitors which are arranged above the aluminum shell in parallel are adjacently coupled with the DBC substrate, so that low-impedance energy buffering is realized; the alternating current output terminal is sleeved on the current sensor, detects the phase current and outputs the phase current through the signal terminal; and a thermistor is mounted on a copper layer on each DBC to monitor the junction temperature of the chip and provide over-temperature protection. The direct-current input terminal, the alternating-current output terminal, the power terminal and the signal terminal are integrally embedded in the aluminum shell and are directly butted with an external busbar and a controller, and additional sampling and driving boards are not needed.

The embodiment of the invention discloses a control system of a multi-voltage bus hybrid micro-grid. The control system comprises a control layer and a hardware layer, wherein the medium-voltage direct-current bus is used for being connected with a distributed energy module of which the power is higher than a first set power value; the low-voltage direct-current bus is used for connecting an equipment assembly of which the power is lower than a second set power value, and the equipment assembly at least comprises a direct-current load of which the power is lower than a set value and a data center load; the AC bus is compatible with a traditional power grid and an AC load; the main control layer is used for realizing closed-loop regulation of voltage and current; the auxiliary control layer realizes the consistency of multi-bus voltage and frequency based on state estimation, bus impedance identification and virtual inertia control; and the comprehensive power management layer realizes cross-bus energy balance and power sharing based on a model predictive control and optimal scheduling algorithm. The technical problems that in the prior art, a control layer and a hardware layer of the multi-voltage bus hybrid micro-grid are independent of each other, a cooperative relation is lacked, and the dynamic self-adaptive adjustment type is poor are solved.

The invention discloses a composite anti-interference voltage stabilization control method for a solid-state transformer rectifier stage, and the method comprises the steps: constructing a discrete full-order voltage model of the rectifier stage, and defining internal parameter change and external disturbance as variables to be observed, and enabling the variables to be equivalent to sum interference; designing a full-order stabilization control law to convert the model into a closed-loop system taking a tracking error as a state; constructing an intermediate observer, determining the gain of the intermediate observer by solving a linear matrix inequality so as to estimate sum interference on line, and solving an optimal solution of a quadratic cost function based on an optimal control theory so as to obtain a state feedback gain; and forming a composite anti-interference control law in combination with the interference estimation value and the state feedback gain, and inversely transforming the composite anti-interference control law into actual control input. According to the invention, through active observation and feed-forward compensation of interference, the voltage fluctuation of the DC bus is effectively suppressed, and the robustness and voltage stabilization precision of the system under complex working conditions are improved.

The invention provides a modular AI optical storage and charging integrated micro-grid control system, and relates to the technical field of smart grids, and the system comprises a sparse communication module which is used for setting three types of core data collection positions at a DC bus convergence point, the output end of each energy storage unit and a charging pile access point, and dynamically generating a sparse communication link through an AI decision module; and the state fusion module is used for exchanging local voltage, power and state-of-charge data through a multi-agent reinforcement learning protocol based on a sparse communication link, and fusing to generate a global bus voltage reference value, a global power distribution reference value and a global average state-of-charge value. Through sparse communication dynamic generation, multi-agent state fusion, adaptive power compensation, AI time sequence prediction, reinforcement learning optimization and communication fault local control, efficient communication, accurate control and energy storage balanced operation of the microgrid are realized.

The invention relates to the technical field of power supplies, and discloses a bidirectional uninterruptible power supply system with a bus neutral-point balance circuit and a control method, the bidirectional uninterruptible power supply system comprises a static bypass unit, a power conversion unit and a controller, a first end of the static bypass unit is connected to an external power grid, and a second end is used as a power grid output end; the first end of the power conversion unit is connected with the energy storage device, the second end of the power conversion unit is connected with the power grid output end of the static bypass unit to form an alternating-current connecting end connected with a load, the power conversion unit comprises a three-level bidirectional DC / AC module, a direct-current bus and a bus neutral-point balance circuit, and the bus neutral-point balance circuit is coupled with the direct-current bus. The direct-current bus comprises a first capacitor and a second capacitor; the controller is configured to control the operation logic of the bus neutral-point balancing circuit according to the voltage difference between the first capacitor and the second capacitor so as to clamp the neutral-point potential of the DC bus. The architecture topology is simple, and the operation stability and the power supply reliability under multiple working conditions are improved.

The invention belongs to the technical field of power system operation and control, and particularly provides a microgrid distributed robust optimization scheduling method considering source load uncertainty and electricity-hydrogen-carbon coupling. Comprising the following steps: constructing an electricity-hydrogen-carbon-heat four-dimensional collaborative micro-grid energy flow framework comprising a multi-port alternating current and direct current bus, a hydrogen production storage and transportation subsystem, a carbon capture methanation subsystem and a cross-stage thermodynamic energy cascade network; establishing an IGDT-based source-load bilateral uncertainty dynamic pricing model, and selecting a risk avoidance or opportunity seeking pricing model as required; a multi-agent game double-layer interaction model with a micro-grid operator as a leader and a load aggregator and a charging station as followers is constructed, and a nested part can observe a Markov decision process; and a privacy protection multi-agent deep reinforcement learning algorithm in which a maximum entropy framework and a CTDE mechanism are introduced is adopted for solving. According to the method, the problem of low-carbon operation of the micro-grid in a source load uncertainty environment is solved, and collaborative improvement of economical efficiency, low-carbon performance and robustness is realized.

The invention relates to a series connection type balance control system, method and device between parallel battery clusters, the system comprises n battery branches which are connected in parallel, and each battery branch comprises a battery cluster, a positive adjusting element, a negative adjusting element, a positive bypass switch and a negative bypass switch, an energy two-way transmission unit is connected in series between one positive pole bypass switch and the other negative pole bypass switch in two adjacent positive pole bypass switches; and an energy two-way transmission unit is also connected in series between the nth positive pole bypass switch and the first negative pole bypass switch. The system makes up the electric quantity difference between the battery clusters through the mutual cooperation of the energy storage element group connected in series with the negative electrodes of the battery clusters and the bypass switch group connected in parallel with the energy storage element group, forms an SOC equalization path, does not involve a high-voltage direct-current bus, only uses a low-voltage energy bidirectional transmission unit, is low in power and low in cost, and improves the reliability of the system. The input and output of the equalization control energy two-way transmission unit can be freely set, and equalization control can be carried out between any two battery clusters.

The invention provides an insulation detection method and device of a photovoltaic system, a controller and the photovoltaic system. The method comprises the following steps: detecting whether the photovoltaic system has an insulation fault; if the photovoltaic system has the insulation fault, determining the position of the insulation fault in the fault photovoltaic string according to the ratio of the voltage to ground of the first pole of the photovoltaic system to the open-circuit voltage of the photovoltaic string; the first electrode is any one of a direct-current bus positive electrode and a direct-current bus negative electrode; and respectively and independently controlling the positive and negative electrodes of the input end of each direct current conversion circuit to be short-circuited, and for each MPPT module, determining whether the insulation fault position is located in the MPPT module based on the change of the voltage to ground of the first electrode before and after the short circuit of the MPPT module. According to the photovoltaic system insulation fault detection method and the photovoltaic system insulation fault detection device, insulation faults from a system level to a component level can be spanned, additional devices are not needed, manpower, time and economic cost required by field troubleshooting is reduced, and the detection efficiency of the photovoltaic system insulation faults is improved.

The invention relates to the field of electrochemical energy storage systems, in particular to a multi-energy complementary electrochemical energy storage system adaptive to load power abrupt change, which comprises a multi-source energy supply component, a power conversion module, an instantaneous power compensation unit (supercapacitor), a direct current bus, an energy storage converter and a central controller. The multi-source energy supply assembly is connected to the direct-current bus through the corresponding power conversion module, the super capacitor is directly connected with the direct-current bus, the energy storage converter is connected with the direct-current bus and the load, and the central controller is connected with all the assemblies. And when the load instantaneous power abrupt change exceeds a threshold value and the bus voltage deviates from an allowable range, the supercapacitor automatically triggers charging and discharging response, releases or absorbs peak current, and fills a power gap. According to the system, instantaneous load compensation is undertaken through the supercapacitor, a low-rate lithium battery and multi-energy priority power supply and dynamic power distribution are matched, an impact load is quickly responded, meanwhile, the system cost is reduced, the power supply stability and safety are improved, and the energy utilization efficiency is optimized.

The invention relates to the technology of power electronics and electric energy quality control, in particular to an energy storage type UPQC and switch state prediction control method based on improved model prediction control, which comprises a series active filter, a parallel active filter, a direct current bus, an energy storage system and a controller, according to the control method, an energy storage power and charge state dynamic equation is introduced into an MPC prediction model, and a multi-objective cost function is designed. And the controller predicts and evaluates the candidate switching vector in each sampling period based on a finite control set model predictive control strategy, and outputs an optimal switching state through value function optimization, thereby realizing collaborative optimization of electric energy quality management and energy storage energy management. According to the method, the dynamic response capability and compensation precision of the UPQC under the working conditions of voltage sag / sag, imbalance, harmonic waves and load fluctuation are remarkably improved, meanwhile, the energy storage utilization efficiency and the system stability are improved, and the method is suitable for a power distribution network with new energy high permeability and large load fluctuation.

A locomotive has DC or AC traction motors, powered by a hydrogen fuel cell, and optionally other sources such as regenerative braking. The traction motors of the locomotive may be connected to a set of independent DC choppers or AC inverters, linked via a common DC bus, configured to regulate power from the one or more power sources. A manager module, among other functions, may receive inputs and signals to coordinate delivery of electricity from the sources to the motor. A method for retrofitting a legacy locomotive may include removing a generator and a control apparatus configured for diesel fuel, and installing a kit of apparatus configured to be powered by a hydrogen fuel cell. A railway system for use by locomotives powered by hydrogen has one or more hydrogen-generation stations deployed near a track of the railway system.

The invention provides a power supply and distribution control method for an offshore wind-solar complementary direct supply type seabed data center, and the method comprises the steps: collecting wind power and photovoltaic electric energy to an ashore substation through a same AC power transmission channel, converting the wind power and photovoltaic electric energy into a first AC voltage, and generating a DC bus voltage; the direct-current bus directly supplies information processing load, and the first alternating-current voltage drives the cooling system; configuring a multi-time-scale energy storage system comprising a super capacitor, a flow battery and a standby power supply, and stabilizing second-level, minute-to-hour-level and longer-period power fluctuations respectively; based on wind and light output prediction and the energy storage charge state, load and charge and discharge are dispatched cooperatively. According to the method, the power transmission cost and conversion loss are reduced, the green power consumption rate and the power supply quality are improved, the dependence on outsourcing power is reduced, and efficient, stable and low-carbon operation is realized.

The present application belongs to the field of flexible AC transmission and distribution and power electronics, and discloses a unified power quality conditioner and method to achieve the goal of power quality management. The device comprises a DC bus and a compensation unit and a regulating unit connected thereto; the compensation unit comprises a series compensation subunit and a parallel compensation subunit; the series compensation subunit is used for compensating the load voltage; the DC bus is used for providing compensation energy for the series compensation subunit; the parallel compensation subunit is used for compensating the load harmonic, three-phase imbalance and reactive current, and also used for providing voltage support for the DC bus and energy for the series compensation subunit; the regulating unit comprises a parallel super capacitor energy storage system and a photovoltaic power generation system; the super capacitor energy storage system comprises a super capacitor and a first DC / DC converter; the photovoltaic power generation system comprises a photovoltaic array and a second DC / DC converter. The present application solves the coupling problem of the series and parallel inverters of the device, and makes the DC side bus voltage stable.

The invention relates to the technical field of power electronics, and particularly provides a double-rectification single-inversion redundant uninterruptible power supply system and a control protection method thereof, and the system comprises a power distribution system, a variable current power module and a control protection system. The power distribution system has double AC inputs, a common DC bus and AC outputs. The converter module comprises three converters, two of which serve as rectifiers and are connected in parallel with the direct current bus, and the other one serves as inverter output. The control method comprises the following steps: in a double-path load balancing mode, realizing power equalization through composite voltage control; in a single-path operation mode, fault seamless switching is realized based on load feedforward and adaptive slope control; in a power distribution mode, triggering according to capacity margin and cooperatively adjusting a droop coefficient based on an optimization target to realize power redistribution; and complete real-time fault protection logic is realized. According to the invention, uninterruptible power supply with high reliability and high electric energy quality is realized, and active regulation and control of power are realized.

The invention provides a UPS (Uninterrupted Power Supply) control method and device, which are used for reducing the power supply cost of a direct current bus. The UPS control method comprises the steps that when it is determined that a bypass module in a UPS works and the UPS has no fault, a first part of power module in the UPS is controlled to work in a harmonic compensation mode, and the UPS comprises the first part of power module and a second part of power module; detecting the bus voltage of each power module in the second part of power modules; an inverter in the target power module is controlled to obtain electric energy from the output end of the bypass module, single-phase rectification processing is conducted on the obtained electric energy, power is supplied to a direct-current bus in the target power module, and the target power module is the power module with the bus voltage smaller than the first set value in the second part of power modules.