2346 results about "DC-BUS" patented technology

The invention discloses a photovoltaic hydrogen production power supply topological structure based on MPPT and a control method, and relates to the technical field of renewable energy electrolysis hydrogen production, and the photovoltaic hydrogen production power supply topological structure mainly comprises a photovoltaic power module, a direct current bus, a water electrolysis hydrogen production unit, an energy storage unit and a control unit. The photovoltaic power modules are connected in parallel to the direct current bus through the independent DC / DC converter, and are matched with the automatic identification and scheduling functions of the control unit, the system operation strategy is automatically adjusted when the modules are newly added or faults exit, and plug-and-play, fault isolation and power reconstruction of the photovoltaic power modules can be supported; the duty ratio change step length of the DC / DC converter is limited when the current rapidly fluctuates due to the change of the photovoltaic output power, the current change rate of the electrolytic cell stack is effectively controlled, the service life protection of the electrolytic cell can be considered, the high modular access capability is achieved, multi-source collaborative scheduling is supported, and bus voltage stabilization and system current sharing optimization can be achieved.

The invention relates to the technical field of flexible direct-current power transmission, in particular to a centralized local energy storage modular multilevel converter MMC-CLES topology which comprises three phase units, each phase unit comprises an upper bridge arm and a lower bridge arm, and each upper bridge arm and each lower bridge arm comprise a bridge arm reactor arranged at one end, close to a power grid, of the bridge arm; a plurality of identical sub-modules SM which are connected to a power grid through a bridge arm reactor; the upper bridge arm and the lower bridge arm form a symmetrical structure; an energy storage sub-module is arranged at the position where the three-phase unit is directly connected with the direct-current bus. According to the invention, the control system is simplified, and the hardware cost and the control complexity are reduced. Voltage stress and current stress are smaller, higher power can be borne, and the high-power capacitor is suitable for being applied to high-power occasions. And moreover, due to the symmetrical layout, the control method is relatively simple, soft switching can be realized, and the power divider can be used as a multi-port component unit.

The invention relates to a reliability evaluation method and system for a flexible AC / DC power distribution network containing an optical storage system in the field of flexible AC / DC power distribution networks. The method comprises the following steps: collecting photovoltaic data, energy storage data, AC / DC bus data and the like in real time; constructing a multi-time scale dynamic topology model, and establishing a failure probability distribution function; load flow calculation based on an improved forward-backward substitution method; adopting an N-1 + N-1-1 composite fault screening strategy to simulate a typical disturbance scene; establishing a vulnerability evaluation matrix to calculate power failure probability and other indexes; designing an optimal scheduling strategy based on model predictive control; multi-time-scale reliability evaluation is carried out; and outputting an evaluation report and a topology reconstruction suggestion. The system comprises a data acquisition unit, a dynamic modeling unit and the like, and an evaluation and analysis unit is internally provided with an algorithm module and is configured with an FPGA acceleration card. The method breaks through the limitation of traditional steady state evaluation in the technology level, improves the load flow calculation speed in the calculation efficiency level, reduces the operation cost in the application value level, improves the energy storage efficiency, and provides support for reliability evaluation of a novel power system.

The invention belongs to the technical field of equipment energy-saving control, and particularly discloses and provides an energy-saving control system based on a direct-current bus system, which comprises a direct-current bus framework module, an equipment state acquisition module, an equipment state analysis module and an energy flow control module. According to the method, the direct current bus voltage and the multi-dimensional operation data of the equipment motor are collected in real time, the motor power state space model is constructed by means of the Kalman filter, and the power sudden change probability of the future preset time period is accurately predicted. And meanwhile, an energy distribution strategy is dynamically adjusted in combination with the total power demand generated by the production schedule and according to the braking type and the power sudden change probability. The defect that dynamic power difference cannot be tracked through fixed threshold value feed-forward compensation in the prior art is effectively overcome, so that bus energy deposition is avoided, braking energy is distributed according to needs, meanwhile, it can be ensured that the braking energy can be recycled timely and correctly, and energy waste caused by misjudgment is reduced.

The invention discloses a multi-mode switching control method suitable for a hydrogen-electricity combined energy storage system, and the method comprises the steps: carrying out the coupling of a plurality of control units through a DC bus, and obtaining a system architecture; according to the operation mode of the system, coordinating the power output of the energy storage unit by using a dynamic collaborative optimization method based on a virtual synchronous machine technology and a variable droop coefficient, and introducing a dynamic energy distribution model and a dynamic energy distribution constraint to obtain a power balance framework of the energy storage unit; performing collaborative optimization and joint optimization on a plurality of energy storage units in the power balance framework by using the optimization model based on the cooperative game and the dynamic power regulation model to obtain a joint dynamic balance mechanism; and iteratively optimizing and improving the combined dynamic balance mechanism by using a distributed dynamic optimization algorithm to obtain the hydrogen-electricity combined energy storage system. The invention relates to a hydrogen-electricity combined energy storage control technology, and solves the technical problems that an existing hydrogen-electricity combined energy storage system is difficult to coordinate and insufficient in dynamic response in the multi-mode switching process.

The invention relates to the field of fault detection, and discloses a fault online diagnosis method for a low-speed large-torque motor control system, and the method comprises the steps: collecting the multi-dimensional parameters of the three-phase current of a motor, the voltage of a DC bus, the position of a motor rotor, the speed of the motor rotor, and the temperature of a radiator based on a sensor group; carrying out data preprocessing on the collected multi-dimensional parameters to remove noise interference; extracting fault features related to current, voltage, rotor motion and temperature from the preprocessed data; a dynamic threshold value is constructed based on fault features, non-fault parameter fluctuation and fault abnormity are distinguished through multi-feature correlation analysis, and online fault diagnosis is achieved; and finally, outputting a diagnosis result containing the fault type and the fault early warning information. Through multi-dimensional parameter acquisition and dynamic correlation diagnosis, the comprehensiveness and accuracy of fault diagnosis are improved, the false alarm rate is effectively reduced, and the method can adapt to the complex working conditions of load fluctuation and rotating speed switching of the low-speed large-torque motor.

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.

The power conversion device provided by the invention comprises a direct current end, a positive direct current bus, a negative direct current bus, a positive bus capacitor, a negative bus capacitor, at least three inverter bridge arms, a switch unit, a controller, filter inductors corresponding to the at least three inverter bridge arms one by one, a filter capacitor and an alternating current end. And the third end of each inverter bridge arm sequentially passes through the filter inductor, the filter capacitor and the switch unit corresponding to each inverter bridge arm and then is connected with the midpoint of the bus. The controller controls the switch unit to be switched off or the impedance of the switch unit to be increased when the voltage of the power grid is smaller than or equal to a first voltage threshold value; and after the switch unit is switched off or the impedance of the switch unit is increased, the modulation wave of each inverter bridge arm is controlled to be the modulation wave after the first common-mode modulation signal is superposed on the initial modulation wave of each inverter bridge arm, so that the amplitude of the modulation wave of each inverter bridge arm is increased. Furthermore, not only can the loss of the switching tube in each inverter bridge arm be balanced, but also the problem of common-mode oscillation caused by modulation wave change can be improved.

The invention relates to a light storage integrated system and a control method, the system comprises a direct current bus, a photovoltaic access unit, an energy storage unit, a power conversion system and an energy management system, the energy storage unit and the photovoltaic access unit are accessed to the direct current bus, and the energy storage unit is provided with a plurality of SOC parameters including a lower discharge limit SOCmin, an upper charge limit SOCmax and an off-grid recovery threshold SOCon; the energy management system configures an energy management strategy in each mode through a plurality of SOC parameters set by an energy storage unit, realizes intelligent control and mode switching in a grid-connected mode and an off-grid mode, and in the grid-connected mode, preferentially utilizes photovoltaic power to supply power to a load, switches to an anti-countercurrent mode after the stored energy is fully charged, and dynamically limits the photovoltaic power to avoid countercurrent; in the off-grid mode, the power conversion system is controlled to operate in a VF mode, and photovoltaic power reduction is triggered when set conditions are met. Compared with the prior art, the method has the advantages that the countercurrent suppression efficiency is improved, and the system safety, reliability and stability are enhanced.

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.

The invention discloses a current reconstruction method for sampling of double Hall current sensors of a permanent magnet synchronous motor, relates to a current reconstruction method, and aims to solve the problems that the cost and the capacity of a control system are increased and a peripheral circuit is more complicated due to the fact that three Hall current sensors need to be adopted for current sampling in a traditional method. The method comprises the following steps: step 1, installing a Hall current sensor H1 and a Hall current sensor H2; step 2, setting sampling moments of the Hall current sensor H1 and the Hall current sensor H2; 3, setting the minimum sampling time of the Hall current sensor H1 and the Hall current sensor H2; 4, current reconstruction is carried out according to the current values is1, is2 and i0 obtained by sampling of the Hall current sensor H1 and the Hall current sensor H2, and the current values of the A phase, the B phase and the C phase are obtained. The invention belongs to the technical field of common direct current bus type open winding permanent magnet synchronous motor control.

The invention provides a railway flexible traction system based on multi-source fusion. The system is composed of a central control unit, a V / v traction transformer unit and a multi-port flexible interconnection unit. The V / v traction transformer unit comprises a first power supply arm, a second power supply arm and a third power supply arm, the input ends of the V / v traction transformer unit are connected with a public power grid, the first and second power supply arms are connected to the multi-port flexible interconnection unit, and the third power supply arm provides passive support for a traction network. The multi-port flexible interconnection unit comprises a two-phase rectification module, a photovoltaic power generation module, an energy storage module and a single-phase inversion module which are commonly connected to a DC bus. The central control unit adjusts the output power of the multi-port flexible interconnection system and the control strategy of the single-phase inversion module in real time so as to realize flexible consumption of new energy and improvement of power supply stability. The system has the advantages of compatibility, cost effectiveness, new energy access and consumption, power supply reliability improvement, electric energy quality optimization, high adaptability and the like, and is suitable for upgrading and reconstruction of newly-built railway lines and existing railway lines.

The present invention provides a battery energy storage parallel equalization converter topology and a control method therefor. The battery energy storage parallel equalization converter topology comprises a series-connected battery energy storage parallel equalization converter, a main converter, and a plurality of groups of filter inductors; in the main converter, the input side of a DC / DC or DC / AC converter is connected in parallel to a parallel voltage-stabilizing capacitor, and the output side of the DC / AC or DC / AC converter is correspondingly connected to an AC or DC source load; the series-connected battery energy storage parallel equalization converter comprises a plurality of groups of small-capacity DC / DC converters and a common DC bus capacitor; the output sides of all the small-capacity DC / DC converters are connected in parallel by means of the common DC bus capacitor to form a common DC bus; the input side of one group of small-capacity DC / DC converters is connected in series to the input side of the main converter, and the input sides of other groups of small-capacity DC / DC converters are connected in series to a battery pack by means of the filter inductors, respectively. According to the present invention, in a battery charging and discharging process, only a small amount of power flows through the converter, reducing the capacity requirements of the converter, and reducing the transmission efficiency.

The invention relates to the technical field of building electrics, and particularly provides a control method and system of an optical storage direct flexible system. The control method comprises the following steps: acquiring power load data of a target building within a preset time; acquiring illumination meteorological data in the preset time; obtaining a power load prediction curve according to the illumination meteorological data and the power load data; based on the power load prediction curve, constructing a control relationship between the direct current bus voltage at the grid-connected part of the optical storage direct-flexible system and the total grid-connected power; and based on the control relationship, performing power regulation according to the voltage change condition of the direct current bus. According to the invention, when the real-time power deviates from the predicted optimal load value, such as the inflection point, the optical storage direct-current flexible system can automatically deploy the power of the energy equipment connected to the direct-current bus. And system power response is completed according to the flexible capacity potential of the equipment, so that the system operation state tends to be economically optimal.

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.

In one embodiment, a method includes receiving DC bus voltage conditions of multiple AC to DC converters of an Input-Series-Output-Parallel power converter during a rectification stage; detecting a peak voltage of each of the DC bus of the multiple AC to DC converters has reached a first threshold voltage, and a Phase Loop Lock locked signal; upon detecting that the PLL locked signal, enabling a first voltage regulation to charge an AC to DC output of each of the multiple AC to DC converters to reach a first reference voltage; determining operating conditions including a load condition and an output voltage condition of multiple Dual Active Bridge (DAB) converters, and a monitored voltage of each of the multiple AC to DC converters; enabling a second voltage regulation of each of the multiple DAB converters to charge a DAB output to reach a second reference voltage based on the operating condition.

The invention discloses a cascade module non-intrusive monitoring method and system, and the method comprises the steps: obtaining a voltage signal of a DC bus in a preset time window length, obtaining a voltage fluctuation time domain signal, carrying out the signal conversion of the voltage fluctuation time domain signal through employing fast Fourier transform, carrying out the extraction, obtaining a plurality of main frequency components, and carrying out the extraction of the main frequency components; obtaining capacitance attenuation degree data according to each main frequency component, then judging whether the coupling strength index is related to the capacitance attenuation degree or not according to voltage fluctuation data of adjacent sub-modules of the direct current bus, and if yes, performing feature extraction on fluctuation coupling information by using a prediction neural network to obtain a monitoring feature vector, the optimized non-intrusive monitoring model is obtained through the monitoring feature vector, the optimized non-intrusive monitoring model is used for analyzing the voltage fluctuation data of the direct-current bus, the capacitance attenuation degree is obtained, and the accuracy and reliability of capacitance attenuation monitoring are improved through the method.

The invention discloses a DC bus interference anomaly detection method based on a dynamic local outlier factor algorithm. The DC bus interference anomaly detection method is especially suitable for real-time operation state monitoring of a complex power system. Aiming at the limitation that a traditional anomaly detection method is high in calculation complexity and limited in detection precision in high-dimensional time series data processing, optimization is carried out on the basis of an outlier detection theory, a dynamic mode updating algorithm is provided, the algorithm evaluates outlier characteristics of time series data through local density, and the detection precision of the time series data is improved. The global calculation overhead is obviously reduced, and the real-time performance and the detection efficiency of the system are improved. Compared with a traditional method, the method consumes manual intervention, is high in detection precision and strong in early warning, can be widely applied to the field of health assessment and intelligent operation maintenance of power equipment, and shows a good engineering application prospect.

The invention provides an arc resistance characteristic-based segmented modeling method of a fuse for a direct current networking system, and relates to the technical field of common direct current bus system design, and the method comprises the steps: calculating the real-time arc resistance data of the fuse according to the continuously collected short-circuit voltage and short-circuit current at the two sides of the fuse in a short-circuit test process, and forming an arc resistance curve; intercepting an arc resistance curve from the peak moment of the short-circuit current to the slope descending moment of the arc resistance curve to obtain an arc starting stage arc resistance curve, and intercepting an arc resistance curve from the slope descending moment to the moment when the short-circuit current is zero to obtain an arc burning stage arc resistance curve; respectively carrying out data fitting according to the arc starting stage arc resistance curve and the arcing stage arc resistance curve to obtain a sectional arc resistance curve equation; and taking the arc resistance curve equation as a control signal to build and obtain a fuse simulation model based on the controlled resistor. The method has the advantages that the arc resistance curve is divided into two sections, the corresponding arc resistance curve equation is designed, the simulation precision is higher, and the method can be better suitable for different working conditions.

The invention provides a power factor correction method and system for AC-DC conversion of a server power supply, and relates to the technical field of server power supplies, and the method comprises the steps: collecting an input AC signal and a DC bus output signal, calculating a real-time power factor value, constructing a compensation function based on the power factor value, and calculating a deviation value; and generating a compensation parameter matrix through recursive calculation, processing a direct current output signal by adopting an adaptive filtering algorithm, fusing the direct current output signal with the compensation parameter matrix, calculating to obtain a current adjusting signal and a duty ratio adjusting signal, and accurately adjusting a power factor.

A bidirectional on-board charger includes a direct current bus, two bus capacitors, a power factor correction circuit, and a controller. The power factor correction circuit includes: a first bridge arm; and three second bridge arms, separately connected in series between the positive electrode and the negative electrode of the direct current bus. The controller is configured to: control the first switch (K1) to be turned off, and control at least one of the second bridge arms to output a direct current to charge a power battery; or control the first switch (K1) to be turned on, and control a midpoint of at least one of the second bridge arms to output an alternating current to supply power to an alternating current load. A Vehicle power system and an electric vehicle are further disclosed. The charger reduces circuit costs.

The invention provides a high-power high-frequency modular battery cluster charging and discharging test device, which is characterized by comprising an alternating current coordination controller connected with a middle computer and used for receiving an instruction transmitted by the middle computer and distributing current to a plurality of isolated ACDC modules; the input ends of the plurality of isolated ACDC modules are connected in parallel and then are connected to the AC co-controller and a three-phase mains supply, and the output ends of the plurality of isolated ACDC modules are connected in parallel and then form a DC bus for converting AC into DC and realizing voltage isolation; and a plurality of BUCK-BOOST modules, the input ends of the plurality of BUCK-BOOST modules are connected in parallel and then are connected to the DC bus, and the output ends of the plurality of BUCK-BOOST modules are connected in parallel and then are connected to a target battery cluster for testing the charging and discharging of the target battery cluster. Modular design is achieved, efficient charging and discharging capacity is achieved, the defects that a traditional scheme is large in size, high in cost, slow in dynamic response and the like are overcome, equipment efficiency and flexibility are improved, and the device is suitable for a high-power scene.

The present disclosure relates to circuits for connecting components of a hydrogen plant to a power grid to power the components in an efficient manner. In one implementation, power-side alternate current (AC) to direct current (DC) converters may be connected to a source power grid without the need for an isolation transformer by providing separate buses between the power-side AC-DC converters and load-side DC-DC converters instead of a shared DC bus between the converters. Other implementations for connecting components of a hydrogen plant to a power grid may include an adjustable transformer, such as a tappable transformer or an autotransformer, to connect any number of auxiliary loads of the plant to the power grid. The adjustable transformer may provide for various types of auxiliary load devices to connect to the power provided by the transformer at the same time, including both three-phase devices and one-phase devices.

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.

The invention provides a power fluctuation suppression method and system based on two-phase virtual phase current regulation and control. The method comprises the steps that S1, a grid-connected current model and a direct-current bus power fluctuation model are constructed; a two-phase virtual phase current regulation and control technology is introduced into the grid-connected current model; the DC bus power fluctuation model corresponds to the grid-connected current model; s2, optimizing a direct current bus power fluctuation model; and S3, solving the optimized direct current bus power fluctuation model to complete the complete suppression of the power fluctuation. On the basis of the single-phase VPCR technology, one of the phases without voltage drop in the three phases is additionally selected as an auxiliary compensation phase, optimization calculation of a two-phase virtual phase current gain coefficient is carried out through a particle swarm optimization algorithm, it is proved from the theoretical level that the two-phase VPCR technology can achieve minimization and zero of direct-current side power fluctuation, and the method is suitable for large-scale popularization and application. The traditional engineering requirements are met, and the design defect of the gain coefficient of the single-phase VPCR technology is improved.

The invention discloses a 5G base station optical storage integrated power supply control system, and relates to the field of 5G base station optical storage integrated power supply control, and the system comprises a detection module which detects the output voltage of a photovoltaic array, the SOC of an energy storage battery and the impedance parameter of a DC bus, and obtains a detection result; and the 5G wireless sensing module monitors reference signal receiving power and channel state information by initializing a 5GNR physical layer chip based on a detection result, transmits the reference signal receiving power to the micro-control unit through an SPI interface, and reads the maximum power point voltage and current of the photovoltaic module to obtain a time sequence and a photovoltaic array. According to the method, the Lyapunov exponent is solved through phase-space reconstruction and the Wolf algorithm, the chaos state flag bit and the load impedance are generated, the parameters of the LLC resonant converter are dynamically matched, the nonlinear dynamics theory is applied to the field of power supply control, the working modes can be adaptively switched through intelligent recognition and utilization of chaos features, and the power supply efficiency is improved. And optimal scheduling of energy is realized while the ZVS state is ensured.

The invention discloses an improved droop control method for a sodium-ion battery parallel system in a micro-grid, and the method comprises the following steps: 1, calculating the actual droop control coefficient of a sodium-ion battery based on the charge state, health state and initial droop control coefficient of the sodium-ion battery, and further calculating the voltage reference of the sodium-ion battery; step 2, obtaining a direct current bus side voltage, and constructing a voltage compensator as a secondary compensation link of a sodium ion battery voltage reference by using a PI regulator, thereby ensuring that the direct current bus side voltage is stabilized at a voltage compensation reference value, and obtaining an actual droop control coefficient meeting the stability and the voltage reference of the sodium ion battery; and step 3, obtaining the actual output voltage and the actual inductive current of the sodium ion battery, and calculating the duty ratio of the bidirectional DC / DC converter by combining the adjusted voltage reference of the sodium ion battery obtained in the step 2. According to the method disclosed by the invention, each sodium-ion battery can be in an optimal working state.

The invention belongs to the technical field of power distribution, and discloses a direct current transformer soft switch and a control method.The direct current transformer soft switch comprises a medium-voltage direct current bus and low-voltage direct current buses, the medium-voltage direct current bus is electrically connected with a modular multi-level multi-port direct current converter, and the modular multi-level multi-port direct current converter is electrically connected with a plurality of low-voltage direct current converters; the plurality of low-voltage direct-current converters are electrically connected with a low-voltage direct-current bus and are used for realizing bidirectional power transmission from medium-voltage direct current to low-voltage direct current; according to the method, the medium-voltage side inductance value is reduced, the medium-voltage side current ripple is enabled to pass zero, the M3DC operates in an approximate critical conduction mode, a constant valley current control strategy is adopted, the minimum value of the medium-voltage side inductance current is controlled to be constant under different working conditions, and then zero-voltage switching-on of a switching device in a wide operation range and zero-current switching-off of an anti-parallel diode are achieved.

The invention provides a zero-carbon battery charging and discharging test system and method. The system comprises a plurality of energy storage energy modules, a plurality of energy allocation modules connected with the plurality of energy storage energy modules, a plurality of non-isolated high-efficiency charging and discharging machines, a plurality of test side intelligent switches connected with the plurality of non-isolated high-efficiency charging and discharging machines, and a plurality of tested batteries connected with the plurality of non-isolated high-efficiency charging and discharging machines. The first controller is used for collecting state information of the plurality of energy storage energy modules and controlling working states of the plurality of energy allocation modules so as to adjust electric energy exchange between the plurality of energy storage energy modules and the direct current bus; the DC bus is connected with the plurality of energy allocation modules and the plurality of test side intelligent switches, and is used for establishing an electric energy transmission path between the plurality of energy storage energy modules and the plurality of tested batteries. And the second controller is connected with the plurality of test-side intelligent switches and is used for controlling on and off of the plurality of test-side intelligent switches so as to realize charging and discharging tests of the plurality of tested batteries.

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.