CN106936148B - Photovoltaic-energy storage converter system and control method thereof - Google Patents
Photovoltaic-energy storage converter system and control method thereof Download PDFInfo
- Publication number
- CN106936148B CN106936148B CN201710084282.1A CN201710084282A CN106936148B CN 106936148 B CN106936148 B CN 106936148B CN 201710084282 A CN201710084282 A CN 201710084282A CN 106936148 B CN106936148 B CN 106936148B
- Authority
- CN
- China
- Prior art keywords
- voltage
- energy storage
- current
- control
- photovoltaic
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000004146 energy storage Methods 0.000 title claims abstract description 89
- 238000000034 method Methods 0.000 title claims abstract description 37
- 230000002457 bidirectional effect Effects 0.000 claims abstract description 35
- 238000013178 mathematical model Methods 0.000 claims description 11
- 239000000969 carrier Substances 0.000 claims description 5
- 230000010354 integration Effects 0.000 claims description 4
- 210000000352 storage cell Anatomy 0.000 claims description 4
- 238000006243 chemical reaction Methods 0.000 abstract description 5
- 230000001276 controlling effect Effects 0.000 description 15
- 239000003990 capacitor Substances 0.000 description 13
- 238000010248 power generation Methods 0.000 description 6
- 238000005070 sampling Methods 0.000 description 6
- 230000009466 transformation Effects 0.000 description 6
- 238000007599 discharging Methods 0.000 description 5
- 230000000903 blocking effect Effects 0.000 description 4
- 238000010586 diagram Methods 0.000 description 4
- 238000004891 communication Methods 0.000 description 3
- 230000001360 synchronised effect Effects 0.000 description 3
- 238000002955 isolation Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 229920006395 saturated elastomer Polymers 0.000 description 2
- 230000003750 conditioning effect Effects 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/28—Arrangements for balancing of the load in a network by storage of energy
- H02J3/32—Arrangements for balancing of the load in a network by storage of energy using batteries with converting means
-
- H02J3/383—
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/34—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering
- H02J7/35—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering with light sensitive cells
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
- H02M3/00—Conversion of dc power input into dc power output
- H02M3/02—Conversion of dc power input into dc power output without intermediate conversion into ac
- H02M3/04—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters
- H02M3/10—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
- H02M3/145—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal
- H02M3/155—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only
- H02M3/156—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators
- H02M3/157—Conversion of dc power input into dc power output without intermediate conversion into ac by static converters using discharge tubes with control electrode or semiconductor devices with control electrode using devices of a triode or transistor type requiring continuous application of a control signal using semiconductor devices only with automatic control of output voltage or current, e.g. switching regulators with digital control
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E70/00—Other energy conversion or management systems reducing GHG emissions
- Y02E70/30—Systems combining energy storage with energy generation of non-fossil origin
Abstract
The invention provides a photovoltaic-energy storage conversion system and a control method thereof, wherein the photovoltaic-energy storage conversion system comprises a bidirectional DC/DC converter, a grid-connected inverter, a DC/DC control module for controlling the bidirectional DC/DC converter and an inverter control module for controlling the grid-connected inverter, the DC/DC control module comprises a voltage control module, a current control module and a comparison module, wherein the current control module is electrically connected with the voltage control module, and the output end of the current control module is electrically connected with the comparison module. The invention provides a photovoltaic-energy storage converter system and a control method thereof, which are used for solving the technical problems that the existing photovoltaic-energy storage converter system needs power failure and unstable direct current bus voltage when an energy storage battery is charged and discharged.
Description
Technical Field
The invention relates to the technical field of photovoltaic energy storage, in particular to a photovoltaic-energy storage converter system and a control method thereof.
Background
Solar energy is widely focused as the cleanest energy source, and a solar power generation system has the characteristics of being influenced by natural environment. In contrast to conventional fossil energy sources, photovoltaic power generation systems are not capable of providing energy stably and continuously. The power of the medium-capacity and small-capacity photovoltaic power generation system is dispersed, the equivalent impedance is larger, the fluctuation of the output power is severe, the photovoltaic power generation system is an impact power supply for a power grid at the location, and the larger the installed capacity is, the larger the hot standby capacity required by the power grid at the location is.
Under the completely isolated operating condition, each photovoltaic power supply lacks the 'supporting' function of the power grid, and strong coordination control is more needed. When the photovoltaic power generation power is greater than the load demand, the electric energy should be stored; when the photovoltaic electric energy can not meet the load requirement, the electric energy should be timely supplied to collect and utilize renewable energy sources with the highest efficiency. Therefore, energy storage is necessary for a distributed independent power generation system based on renewable energy sources, the foundation for improving the power supply reliability is also provided, the photovoltaic energy sources can be utilized to the maximum extent, and the impact and the dependence on a power grid are reduced.
The western China region is wide, residents are scattered, the region is still not completely covered by a large national power grid, and researches show that the photovoltaic-energy storage power supply system is an economic and reliable scheme for solving the problem of power supply of public infrastructures in remote villages, islands and remote areas, so that the research and the opening of the photovoltaic-energy storage power supply system are necessary and significant.
However, in the existing photovoltaic-energy storage power supply system, when the energy storage battery is switched from a charging operation state to a discharging operation state (or the energy storage battery is switched from the discharging operation state to the charging operation state), the photovoltaic-energy storage power supply system usually has power failure firstly, the operation state of the system is manually adjusted, and then the operation is restored, so that inconvenience is brought to practical use; in addition, the existing bidirectional DC/DC converter cannot regulate the voltage of the DC bus, so that the voltage of the DC bus is unstable.
Disclosure of Invention
The invention provides a photovoltaic-energy storage conversion system and a control method thereof, which are used for solving the technical problems that the existing photovoltaic-energy storage conversion system needs power failure and unstable voltage on a direct current bus when an energy storage battery is charged and discharged.
According to one aspect of the present invention, there is provided a photovoltaic-energy storage converter system comprising a bi-directional DC/DC converter and a grid-tie inverter, characterized in that the system comprises: a DC/DC control module for controlling the bidirectional DC/DC converter and an inverter control module for controlling the grid-connected inverter.
The DC/DC control module comprises a voltage control module for obtaining total instruction current, a current control module which is electrically connected with the voltage control module and used for obtaining three-way duty ratio, and a comparison module for obtaining a switch control signal of the bidirectional DC/DC converter, wherein the output end of the current control module is electrically connected with the comparison module.
On the basis of the scheme, the system also comprises an energy storage battery pack and a photovoltaic module, wherein the photovoltaic module is connected with the energy storage battery pack through the bidirectional DC/DC converter; and one end of the grid-connected inverter is connected with the photovoltaic module, and the other end of the grid-connected inverter is connected with a power grid.
On the basis of the scheme, preferably, the voltage control module is used for comparing the terminal voltage of the energy storage battery pack with the command voltage, obtaining voltage deviation and obtaining total command current based on a voltage ring control algorithm.
The invention also provides a control method of the photovoltaic-energy storage converter system,
acquiring a control signal of a bidirectional DC/DC converter based on terminal voltage of an energy storage battery pack;
and acquiring control signals of the grid-connected inverter based on the command voltages of the q axis and the d axis, the direct current bus voltage and the current.
On the basis of the above scheme, preferably, the control signal acquisition method of the bidirectional DC/DC converter includes:
s1, obtaining voltage deviation of an energy storage battery pack by comparing terminal voltage of the energy storage battery pack with command voltage, and obtaining total command current based on a voltage ring control algorithm;
s2, three paths of command dividing currents are respectively obtained based on the total command currents, and three paths of duty ratios are respectively obtained through a current control algorithm;
s3, based on the three-way duty ratios, the three-way duty ratios are respectively compared with carriers to obtain switch control signals of the DC/DC converter.
Preferably, on the basis of the above scheme, the step S1 further includes:
based on the minimum value of the DC bus voltage and the given DC bus voltage, comparing the minimum value of the DC bus voltage and the given DC bus voltage to obtain a voltage deviation value, and obtaining the upper limit value of the total instruction current through a third PI controller;
based on the maximum value of the DC bus voltage and the given DC bus voltage, comparing the maximum value of the DC bus voltage and the given DC bus voltage, obtaining a voltage deviation value, and obtaining a lower limit value for limiting the total instruction current through a third PI controller.
On the basis of the above scheme, preferably, the control mathematical model for obtaining the upper limit value of the total instruction current is:
wherein k is p3 Representing a scaling factor of the third PI controller; k (k) i3 Representing an integral coefficient of the third PI controller;represents the upper limit value of the charging current, and +.>Limited to [1.5C 0.05C]，u dci Represents the DC bus voltage, u dci_min The minimum voltage of the dc bus is indicated, and C represents the capacity of the energy storage battery.
On the basis of the above scheme, preferably, the control mathematical model for obtaining the minimum current value of the total command current is:
wherein k is p3 Representing a scaling factor of the third PI controller; k (k) i3 Representing an integral coefficient of the third PI controller;represents the lower limit value of the charging current and +.>Limited to [ -3C-0.05C]，u dci Represents the voltage across the DC bus, u dci_max The maximum voltage of the dc bus is indicated, and C represents the capacity of the energy storage battery.
On the basis of the above scheme, preferably, the voltage loop control algorithm in step S1 includes obtaining a total command current through a fourth PI controller based on a voltage deviation between a terminal voltage of the energy storage battery pack and the command voltage, where a control mathematical model of the voltage loop control algorithm is:
i dc_ref ＝k p_4 (u dco_ref -u dco )+k i_4 ∫(u dco_ref -u dco )dt；
wherein u is dco_ref Representing a command voltage; k (k) p_4 A scaling factor representing a fourth PI controller; k (k) i_4 An integral coefficient representing the fourth PI controller; u (u) dco Representing the terminal voltage of the energy storage cell.
On the basis of the above scheme, preferably, the current control algorithm in step S2 includes: based on three paths of instruction dividing currents, the three paths of instruction dividing currents are respectively compared with charging currents of an energy storage battery pack to obtain current deviation, three paths of duty ratios are obtained through a fifth PI controller, and a control mathematical model of the current control algorithm is as follows:
wherein d 1 、d 2 、d 3 Representing 3 duty cycles; k (k) p5 A scaling factor representing a fifth PI controller; k (k) i5 An integration coefficient representing a fifth PI controller; current i 1 、i 2 、i 3 Representing the charging current of the energy storage battery.
The invention provides a photovoltaic-energy storage converter system, which controls the charge and discharge of an energy storage battery pack through a DC/DC control module, prevents the energy storage battery pack from being overcharged or overdischarged, and can stabilize the voltage of a direct current bus in a reasonable range by matching with a direct current bus voltage lower limit control module and a direct current bus voltage upper limit control module.
Drawings
Fig. 1 is a block diagram of the overall circuit of the photovoltaic-energy storage converter system of the present invention;
FIG. 2 is a hardware control block diagram of the DC/DC control module and the inverter control module of the present invention;
FIG. 3 is a schematic block diagram of a DC/DC control module of the present invention;
FIG. 4 is a schematic diagram of an inverter control module of the present invention;
FIG. 5 is a flowchart of the operation of the DC/DC control module of the present invention;
fig. 6 is a flowchart of the operation of the inverter control module of the present invention.
Detailed Description
The following describes in further detail the embodiments of the present invention with reference to the drawings and examples. The following examples are illustrative of the invention and are not intended to limit the scope of the invention.
Referring to fig. 1, the invention provides a photovoltaic-energy storage converter system, which comprises an energy storage battery pack, a photovoltaic module, a bidirectional DC/DC converter and a grid-connected inverter, wherein the photovoltaic module is connected with the energy storage battery pack through the bidirectional DC/DC converter, and the direct current input end of the grid-connected inverter is connected with both ends of the photovoltaic module in parallel and then connected with a power grid through an isolation transformer.
Wherein, the bidirectional DC/DC converter comprises six IGBT transistors S' 1 、S′ 2 、S′ 3 、S′ 4 、S′ 5 、S′ 6 Two ends of the photovoltaic module are respectively connected with the left end of a linkage switch K1, and a capacitor C is connected in parallel with the right end of the linkage switch K1 bus Then the right end of the linkage switch K2 is connected with the IGBT transistor S' 1 Collector and IGBT transistor S' 2 Is connected to the emitter of IGBT transistor S' 1 Emitter and IGBT transistor S' 2 Is connected to the collector of IGBT transistor S' 3 Emitter and IGBT transistor S' 4 Is connected to the collector of IGBT transistor S' 5 Emitter and IGBT transistor S' 6 Is connected to the collector of IGBT transistor S' 1 Collector of IGBT transistor S' 3 Collector and IGBT transistor S' 5 The collectors of IGBT transistors S 'are connected together' 2 Emitter, IGBT transistor S' 4 Emitter and IGBT transistor S' 6 The emitters of which are connected together.
An LC filter circuit is also connected between the bidirectional DC/DC converter and the energy storage battery pack, wherein the LC filter circuit comprises three inductors L1, L2 and L3, and the left end of the inductor L1 is connected with an IGBT transistor S' 1 The left end of the inductor L2 is connected with the IGBT transistor S' 3 The left end of the inductor L3 is connected with the IGBT transistor S' 5 An emitter of (a); and the right-end connecting wires of the inductors L1, L2 and L3 respectively pass through the current sensor and then are connected with one end of the energy storage battery pack. Preferably, the LC filter circuit of the present invention further comprises a capacitor C o The capacitor C o And the two ends of the energy storage battery pack are respectively connected in parallel.
Preferably, at the moment of charging, the voltage at two ends of the filter capacitor is different from the end voltage of the energy storage battery, so that larger impact current is caused. Wherein the safety control module comprises a charging switch and a current limiting loop, wherein the right end of the charging switch K3 is connected with one end of the energy storage battery pack, and the left end of the charging switch K3 is connected with the capacitor C O Is connected with one end of the connecting rod; the current limiting loop comprises a current limiting switch K4 and a current limiting resistor connected with the current limiting switch K4 in series, and the current limiting loop is connected with two ends of a charging switch K3 in parallel.
In order to further describe the technical scheme of the present invention in detail, please continue to refer to fig. 1, the circuit structure of the grid-connected inverter of the present invention will be described in detail.
The grid-connected inverter comprises 6 switching tubes S 1 、S 2 、S 3 、S 4 、S 5 、S 6 And switch tube S 1 Emitter and switching tube S of (C) 2 Collector connection of (S) switch tube 3 Emitter junction S of (1) 4 Collector of (d), switch tube S 5 Emitter junction S of (1) 6 A collector electrode of (a); switch tube S 1 Collector, S of 3 Collector and S of (2) 5 The collectors of (a) are connected together, switch tube S 2 Emitter, S of 4 Emitter and S of (2) 6 The emitters of which are connected together. And switch tube S 1 Collector and capacitor C of (2) bus Upper end of (C) switch tube S 2 Emitter-connected capacitance C of (C) bus The grid-connected inverter and the bidirectional branch converter are connected in parallel at two ends of the photovoltaic module; and in the switching tube S 1 Collector of (c) and switch tube S 2 The connection capacitance C between the emitters of (C) Inv 。
Furthermore, the invention also connects with LC filter circuit at the output end of the grid-connected inverter, the LC filter circuit includes three inductances L A 、L B 、L C Wherein, switch tube S is connected 1 Emitter junction inductance L of (a) A Is connected with the left end of the switch tube S 3 Emitter junction inductance L of (a) B Is connected with the left end of the switch tube S 5 Emitter junction inductance L of (a) C Is arranged at the left end of the frame; inductance L A 、L B 、L C The left end of the transformer is respectively connected with an A phase, a B phase and a C phase of the isolation transformer; capacitor C a The upper end of the capacitor is connected with the phase A and the capacitor C of the primary side of the transformer b The upper end of the capacitor is connected with the B phase of the primary side of the transformer, and the capacitor C c The upper end of the transformer is connected with a C phase of the primary side of the transformer; capacitor C a 、C b 、C c Is connected together; 3 Hall current sensors respectively penetrate through the inductor L A 、L B 、L C Left end and capacitor C a 、C b 、C c The contact point between the transformer and the transformer; the a phase, the b phase and the c phase of the secondary side of the transformer are connected with a switch K5, and the switch K5 is respectively connected with the a phase, the b phase and the c phase of the power grid.
The invention further comprises a DC/DC control module for controlling the bidirectional DC/DC converter and an inverter control module for controlling the grid-connected inverter. Wherein, the output end of the DC/DC control module for controlling the bidirectional DC/DC converter is respectively connected with six IGBT transistors S 'of the bidirectional DC/DC converter' 1 、S′ 2 、S′ 3 、S′ 4 、S′ 5 、S′ 6 The base electrode of the transistor is connected with the base electrodes of the six IGBT transistors. The output end of the inverter control module for controlling the grid-connected inverter and the grid-connected inverter respectively comprise 6 switching tubes S 1 、S 2 、S 3 、S 4 、S 5 、S 6 The base electrodes of the switch tubes are connected and used for controlling the on-off of the 6 switch tubes.
With continued reference to fig. 3, in order to accurately control on-off of the bidirectional DC/DC converter and ensure that the energy storage battery pack is not powered off in the process of charge-discharge conversion, the structure of the DC/DC control module for controlling the bidirectional DC/DC converter and the control method thereof will be described in detail.
As shown in fig. 3, the DC/DC control module of the present invention includes a voltage control module, a current control module electrically connected to the voltage control module, and a comparison module, where an output end of the current control module is electrically connected to the comparison module. The voltage control module is used for comparing the terminal voltage of the energy storage battery pack with the command voltage to obtain voltage deviation and obtaining total command current based on a voltage ring control algorithm, wherein the voltage ring control algorithm is that the voltage difference between the terminal voltage of the energy storage battery pack and the command voltage obtains the total command current through a fourth PI controller, and a control model of the voltage ring control algorithm is as follows:
i dc_ref ＝k p_4 (u dco_ref -u dco )+k i_4 ∫(u dco_ref -u dco )dt；
wherein u is dco_ref Representing a command voltage; k (k) p_4 A scaling factor representing a fourth PI controller; k (k) i_4 An integral coefficient representing the fourth PI controller; u (u) dco Representing the terminal voltage of the energy storage cell.
The current control module of the invention obtains three paths of sub-instruction currents respectively through total instruction currents and obtains three paths of duty ratios respectively based on a current control algorithm, wherein the current control algorithm comprises: the three paths of command dividing currents and charging currents are respectively compared to obtain current deviation, the current deviation obtains three paths of duty ratios through a fifth PI controller, and a control model of a current control algorithm is as follows:
wherein d 1 、d 2 、d 3 Representing 3 duty cycles; k (k) p5 A scaling factor representing a fifth PI controller; k (k) i5 An integration coefficient representing a fifth PI controller; current i 1 、i 2 、i 3 Representing the charging current of the energy storage battery.
The comparison module of the invention compares the three paths of duty ratios with carriers with 120 DEG phase difference respectively to obtain the switch control signals of the bidirectional DC/DC converter, and sends the switch control signals to six IGBT transistors S' 1 、S′ 2 、S′ 3 、S′ 4 、S′ 5 、S′ 6 The base of which controls the switching states of the six IGBT transistors.
Furthermore, the DC/DC control module further comprises a direct current bus voltage lower limit control module and a direct current bus voltage upper limit control module which are connected with the output end of the voltage control module, and the direct current bus voltage is limited within a reasonable range by arranging the direct current bus voltage upper limit control module and the direct current bus voltage lower limit control module, so that the grid-connected inverter can work normally.
The control algorithm of the direct current bus voltage upper limit control module is as follows:
wherein k is p3 And k i3 Respectively representing a proportional coefficient and an integral coefficient of the PI_3 algorithm;represents the upper limit value of the charging current, and +.>Limited to [1.5C 0.05C]，u dci Represents the voltage across the DC bus, u dci_min Representing the minimum voltage of the dc bus.
The mathematical model of the direct current bus voltage lower limit control module is as follows:
wherein k is p3 And k i3 Respectively representing a proportional coefficient and an integral coefficient of the PI_3 algorithm;represents the lower limit value of the charging current and +.>Limited to [ -3C-0.05C]，u dci Represents the voltage across the DC bus, u dci_max The maximum voltage of the dc bus is indicated.
The invention also provides a control method of the photovoltaic-energy storage converter system, which comprises the following steps of;
acquiring a control signal of a bidirectional DC/DC converter based on terminal voltage of an energy storage battery pack;
and acquiring control signals of the grid-connected inverter based on the q-axis command voltage, the d-axis command voltage and the voltage and current of the direct current bus.
Referring to fig. 2, in the process of obtaining the control signal of the bidirectional DC/DC converter, first, the sampling conditioning board detects the current i 1 、i 2 And i 3 Voltage u dci 、u dco And temperature and other physical quantities, and send the physical quantities into a sampling port of a control board, the DSP28335 executes a control scheme and a control algorithm to generate 6 paths of PWM signals, and a driving and protecting circuit processes the 6 paths of PWM signals and drives a switching tube S' 1 、S′ 2 、S′ 3 、S′ 4 、S′ 5 And S' 6 The method comprises the steps of carrying out a first treatment on the surface of the And an RS485 serial port on the control board is used for communicating with the photovoltaic inverter and the touch screen.
In the process of obtaining the control signal of the grid-connected inverter, firstly, the detection current i of the board is regulated a 、i b And i c Voltage u dc_pv 、u a (e a )、u b (e b )、u c (e c ) Physical quantities such as temperature and the like are sent into a sampling port of the control panel; DSP28335 execution controlThe control scheme and the control algorithm comprise that a control board outputs 6 SVPWM signals, and after the 6 SVPWM signals are processed by a driving and protecting circuit, the switching tubes S1, S2, S3, S4, S5 and S6 are driven; the RS485 serial port on the control board is used for communicating with the inverter and the touch screen, and the details are shown in fig. 3.
The charging and discharging processes of the energy storage battery pack are controlled by acquiring the control signals of the bidirectional DC/DC converter, and meanwhile, the photovoltaic module is matched with the control signals of the grid-connected inverter to supply power to the power grid or the energy storage battery pack.
In one embodiment of the present invention, please continue to refer to fig. 3, the control signal acquisition method of the bidirectional DC/DC converter of the present invention includes:
s1, obtaining voltage deviation of an energy storage battery pack by comparing terminal voltage of the energy storage battery pack with command voltage, and obtaining total command current based on a voltage ring control algorithm;
s2, three paths of command dividing currents are respectively obtained based on the total command current, and three paths of output duty ratios are respectively obtained through a current control algorithm;
s3, based on three paths of duty ratios, the three paths of duty ratios are respectively compared with carriers with 120 degrees of phase difference, and a switch control signal of the bidirectional DC/DC converter is obtained.
In the control process, the voltage control module controls the terminal voltage u of the energy storage battery pack dco And command voltage u dco-ref Comparing to obtain voltage deviation, processing by using a voltage control algorithm to obtain total command current, dividing the total command current by 3 to obtain an input value of a current control module, namely, each path of command current of the bidirectional DC/DC converter, and respectively controlling i by using three PI_5 algorithms through the current control algorithm 1 、i 2 And i 3 Output three-way duty cycle d 1 、d 2 And d 3 Comparing the three paths of duty ratios with three paths of carriers (triangular waves) with 120 degrees of phase difference to generate a switching signal G' 1 、G′ 2 、G′ 3 G′ 4 、G′ 5 And G' 6 The six paths of switching signals are used for respectively driving the switching tubes S' 1 、S′ 2 、S′ 3 、S′ 4 、S′ 5 And S' 6 。
In another embodiment of the present invention, in order to prevent the battery assembly from being overcharged or overdischarged, which affects the service life of the battery, the step S1 of the present invention further includes:
based on the minimum value of the DC bus voltage and the given DC bus voltage, comparing the minimum value of the DC bus voltage and the given DC bus voltage to obtain voltage deviation, and obtaining the upper limit value of the total instruction current through a third PI controller;
based on the maximum value of the DC bus voltage and the given DC bus voltage, comparing the maximum value of the DC bus voltage and the given DC bus voltage, obtaining a voltage deviation value, and obtaining a lower limit value for limiting the total instruction current through a third PI controller.
The control algorithm for acquiring the upper limit value of the total instruction current is as follows:
wherein k is p3 And k i3 Respectively representing a proportional coefficient and an integral coefficient of the third PI controller;represents the upper limit value of the charging current, and +.>Limited to [1.5C 0.05C]，u dci Represents the DC bus voltage, u dci_min Representing the minimum voltage of the dc bus.
The control algorithm for obtaining the lower limit value of the total instruction current is as follows:
wherein k is p3 And k i3 Respectively represent the ratio of the third PI controllerA number and an integral coefficient;represents the lower limit value of the charging current, and +.>Limited to [ -3C-0.05C]，u dci Represents the DC bus voltage, u dci_max The maximum voltage of the dc bus is indicated.
The invention can achieve the following purposes by obtaining the upper limit value and the lower limit value of the total instruction current, namely, dynamically adjusting the upper limit value and the lower limit value of the charging (discharging) current; second, when the system is running off-grid, command voltage u dco_ref Set to 0.7 times u battery_norm The voltage control algorithm of the DC/DC control module outputs a negative current instruction (the voltage loop control algorithm is in a saturated state), namely the discharge of the energy storage battery is controlled, the voltage of the direct current bus is gradually increased, the upper limit control module gradually exits saturation in the process of gradually increasing the voltage of the direct current bus, and finally the voltage of the direct current bus is controlled, so that the voltage of the direct current bus is stabilized at the highest voltage. In the discharging process of the energy storage battery, the terminal voltage of the energy storage battery is gradually reduced, and the voltage control ring is gradually put into control, so that the energy storage battery can be prevented from being discharged excessively low; when the system is in grid-connected operation, the command voltage u dco_ref Set to 1.05 times u battery_norm The voltage control algorithm of the DC/DC control module outputs a positive current instruction (the voltage loop control algorithm is in a saturated state), so that the bidirectional DC/DC converter charges an energy storage battery, the terminal voltage of the energy storage battery gradually rises along with the progress of the charging process, the voltage loop of the DC/DC control module gradually exits saturation and is put into control to prevent the energy storage battery from being overcharged, the voltage of a direct current bus gradually decreases during the charging process of the energy storage battery, the lower limit control loop of the voltage of the direct current bus gradually exits saturation and is put into operation to prevent the terminal of the direct current bus from being overdischarged, and the voltage of the direct current bus is finally stabilized at u dci _ min 。
Further, the voltage loop control algorithm in step S1 of the present invention includes obtaining a total command current through a fourth PI controller based on a voltage deviation between a terminal voltage of the energy storage battery pack and the command voltage, where a control mathematical model of the voltage loop control algorithm is:
i dc_ref ＝k p_4 (u dco_ref -u dco )+k i_4 ∫(u dco_ref -u dco )dt；
wherein u is dco_ref Representing a command voltage; k (k) p_4 A scaling factor representing a fourth PI controller; k (k) i_4 An integral coefficient representing the fourth PI controller; u (u) dco Representing the terminal voltage of the energy storage cell.
In the working process, when the grid-connected inverter runs in a grid-connected mode, u dco_ref ＝1.05u battery_norm The method comprises the steps of carrying out a first treatment on the surface of the When the grid-connected inverter runs off the grid, u dco_ref ＝0.7u battery_norm ，u battery_norm Is the rated voltage of the energy storage battery.
And the current control algorithm in the step S2 of the invention comprises that three paths of sub-instruction currents are respectively compared with the charging current of the energy storage battery pack to obtain current deviation, the current deviation is processed by a fifth PI controller to obtain three paths of duty ratios, and a control mathematical model of the current control algorithm is as follows:
wherein d 1 、d 2 、d 3 Representing 3 duty cycles; k (k) p5 A scaling factor representing a fifth PI controller; k (k) i5 An integration coefficient representing a fifth PI controller; current i 1 、i 2 、i 3 Representing the charging current of the energy storage battery.
In order to facilitate understanding of the working principle of the DC/DC control module of the present invention, the following describes in detail the implementation steps of the control software of the DC/DC control module of the present invention, and the specific details are shown in fig. 5.
The first step: configuring the functionality of a microprocessor (DSP 28335);
secondly, initializing variables in the bidirectional DC/DC converter;
third, enabling interruption;
fourth step: waiting for an interrupt;
fifth step: if no interruption occurs, the communication is carried out with the touch screen and the control system of the grid-connected inverter, and after the communication is finished, the fourth step is returned to; if an interrupt occurs, sampling is performed to process the sampled data.
Sixth step: judging whether faults such as overcurrent, overvoltage or overheat occur or not, and if one of the faults occurs in the system, blocking the driving signal and stopping the machine; and if the fault condition does not occur, judging whether the direct current bus is under-voltage or not.
Seventh step: if the direct current bus is under voltage, blocking the driving signal, and enabling the bidirectional DC/DC converter to enter a standby state; if the DC voltage is normal, the eighth step is executed.
Eighth step: if the inverter runs off-grid, the command voltage of the bidirectional DC/DC converter is 0.7 times u battery_norm The method comprises the steps of carrying out a first treatment on the surface of the If the inverter is in grid-connected operation, the command voltage of the bidirectional DC/DC converter is 1.05 times u battery_norm ；
Ninth step: executing a lower limit control loop of the DC bus voltage;
tenth step: executing an upper limit control loop of the DC bus voltage;
eleventh step: controlling the charging voltage to obtain a total instruction current;
twelfth step: clipping the total instruction current, and calculating three instruction currents;
twelfth step: controlling a charging current;
thirteenth step: generating six paths of PWM driving signals according to the duty ratio output by the current loop;
fourteenth step: restoring the site;
fifteenth step: an interrupt returns;
the steps 4 to 15 are repeatedly executed every 208.3 microseconds.
In order to further describe the technical solution of the present invention in detail, please continue to refer to fig. 4, the control method of the grid-connected inverter of the present invention will be described in detail below.
When the grid-connected inverter is in grid-connected operation, the switch of the instruction current is switched to the end (1), and a cascade control scheme of MPPT-direct current side voltage ring-inductance current ring is adopted, wherein the specific control process is as follows:
first, the grid voltage [ e ] a e b e c ]' grid-connected current [ i ] a i b i c ]' the equivalent physical quantity is subjected to park transformation to obtain voltage column phasors [ e ] d e q ]' sum current column phasors [ i ] d i q ]' the park transformation formula is:
secondly, sampling the voltage and the current of a direct current bus, tracking the maximum power of a photovoltaic module by using a Maximum Power Point Tracking (MPPT) algorithm, and outputting a command voltage u at the direct current side dci_ref The direct-current side voltage is controlled by a nonlinear proportional-integral control algorithm, and the control algorithm is as follows:
i d_ref ＝k v_pN (u dci_ref -u dci )+k v_iN ∫u dci (u dci_ref -u dci )dt；
wherein: k (k) v_pN And k v_iN Proportional and integral coefficients, u, of the control algorithm NPI, respectively dci Is a direct current side voltage.
Again, the inductor current is controlled. Respectively controlling i in synchronous rotation coordinate system by adopting PI algorithm d And i q The control algorithm is as follows:
m d ＝k p2 (i d_ref -i d )+k i2 ∫(i d_ref -i d )dt-ωLi q +e d ；
m q ＝k p2 (i q_ref -i q )+k i2 ∫(i q_ref -i q )dt+ωLi d +e q ；
wherein: k (k) p2 And k i2 The proportional and integral coefficients of the control algorithm pi_2, respectively.
Fourth, the duty cycle (m d 、m q ) The m is d And m q Obtaining the duty ratio m in the abc coordinate system through inverse park transformation a 、m b And m c The inverse park transform is:
finally, the SVPWM algorithm is used to generate a drive signal (G 1 、G 2 、G 3 、G 4 、G 5 、G 6 ) And a switching tube for driving the inverter.
And (3) when the grid-connected inverter runs off the grid, the switch of the instruction current is switched to the end (2), and the cascade control scheme of an alternating current voltage ring and an inductance current ring is adopted.
First, output voltage [ u ] a u b u c ]' inductor current [ i ] a i b i c ]' the equivalent physical quantity is subjected to park transformation, and the transformation process is as follows:
secondly, adopting an alternating current voltage ring-inductance current ring cascade control scheme in a synchronous rotation coordinate system, wherein a voltage control algorithm is as follows:
i d_ref ＝k p1 (u d_ref -u d )+k i1 ∫(u d_ref -u d )dt
i q_ref ＝k p1 (0-u q )+k i1 ∫(0-u q )dt
in the formula (i),u d_ref is d-axis command voltage, 0 is q-axis command voltage, k p1 Is the proportionality coefficient of the PI_1 algorithm, k i1 Is the integral coefficient of the pi_1 algorithm.
Fourth, the current control scheme and the control algorithm thereof during off-grid operation are completely identical to the current control scheme and the control algorithm thereof during grid-connected operation, and the algorithm for generating the driving signal is also identical, and will not be described again here.
In order to facilitate understanding of the technical scheme of the present invention, the following describes implementation steps of the photovoltaic inverter control software of the present invention, specifically:
the first step: configuring the functionality of a microprocessor (DSP 28335);
secondly, initializing variables in a photovoltaic inverter control system;
third, enabling interruption;
fourth step: waiting for an interrupt;
fifth step: if no interruption is generated, the control system is communicated with the touch screen and the control system of the bidirectional DC/DC converter; if the communication is finished, returning to the fourth step; if the interrupt occurs, executing a sixth step;
sixth step: sampling and processing the sampled data.
Seventh step: judging whether faults such as overcurrent, overvoltage or overheat occur or not, and if one of the faults occurs in the system, blocking the driving signal and stopping the machine; if the fault does not occur, an eighth step is performed.
Eighth step: judging whether the direct current bus is under-voltage or not, if so, blocking the driving signal and entering a standby state; if the direct current bus is normal, executing a ninth step;
ninth step: performing park transformation on the alternating voltage and the alternating current to obtain values of the physical quantities in a synchronous rotation coordinate system;
tenth step: judging whether the photovoltaic inverter runs in a grid-connected mode, if so, executing an MPPT algorithm, and controlling the voltage of a direct current bus; if the network is separated from the network, the network is operated; controlling the ac output voltage of the photovoltaic inverter;
eleventh step: controlling inductance current of photovoltaic inverter and outputting duty cycleRatio m d 、m q ；
Twelfth step: executing SVPWM algorithm, and outputting 6 paths of driving signals (PWM);
thirteenth step: enabling output of six PWM driving signals;
fourteenth step: the scene is restored, and the return is interrupted.
The steps 4 to 14 are repeatedly executed every 208.3 microseconds, and the details are shown in fig. 6.
Finally, the methods of the present application are only preferred embodiments and are not intended to limit the scope of the invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (8)
1. A control method of a photovoltaic-energy storage converter system is characterized by comprising the following steps:
acquiring a control signal of a bidirectional DC/DC converter based on terminal voltage of an energy storage battery pack;
acquiring a control signal of the grid-connected inverter based on the q-axis command voltage, the d-axis command voltage, the direct current bus voltage and the current;
the control signal acquisition method of the bidirectional DC/DC converter comprises the following steps:
s1, obtaining voltage deviation of an energy storage battery pack by comparing terminal voltage of the energy storage battery pack with command voltage, and obtaining total command current based on a voltage ring control algorithm;
s2, three paths of command dividing currents are respectively obtained based on the total command currents, and three paths of duty ratios are respectively obtained through a current control algorithm;
s3, based on three paths of duty ratios, respectively comparing the three paths of duty ratios with carriers to obtain a switch control signal of the DC/DC converter;
the step S1 further includes:
based on the minimum value of the DC bus voltage and the given DC bus voltage, comparing the minimum value of the DC bus voltage and the given DC bus voltage to obtain a voltage deviation value, and obtaining the upper limit value of the total instruction current through a third PI controller;
based on the maximum value of the DC bus voltage and the given DC bus voltage, comparing the maximum value of the DC bus voltage and the given DC bus voltage, obtaining a voltage deviation value, and obtaining a lower limit value for limiting the total instruction current through a third PI controller.
2. The control method of a photovoltaic-energy storage converter system according to claim 1, wherein the control mathematical model for obtaining the upper limit value of the total command current is:
wherein k is p3 Representing a scaling factor of the third PI controller; k (k) i3 Representing an integral coefficient of the third PI controller;indicating the upper limit value of the charging current and the upper limit value of the total command current, u dci Represents the DC bus voltage, u dci _ min Representing the minimum voltage of the dc bus.
3. The control method of a photovoltaic-energy storage converter system according to claim 1, wherein the control mathematical model for obtaining the lower limit value of the total command current is:
wherein k is p3 Representing a scaling factor of the third PI controller; k (k) i3 Representing an integral coefficient of the third PI controller;representing the lower limit value of the charging current and the lower limit value of the total command current, and +.>Limited to [ -3C-0.05C]，u dci Represents the voltage of the DC bus, u dci _ max The maximum voltage of the dc bus is indicated, and C represents the capacity of the energy storage battery.
4. The control method of a photovoltaic-energy storage converter system according to claim 1, wherein the voltage loop control algorithm in step S1 includes obtaining a total command current through a fourth PI controller based on a voltage deviation between a terminal voltage of an energy storage battery pack and a command voltage, and a control mathematical model of the voltage loop control algorithm is as follows:
i dc_ref ＝k p_4 (u dco_ref -u dco )+k i_4 ∫(u dco_ref -u dco )dt；
wherein u is dco_ref Representing a command voltage; k (k) p_4 A scaling factor representing a fourth PI controller; k (k) i_4 An integral coefficient representing the fourth PI controller; u (u) dco Representing the terminal voltage of the energy storage cell.
5. The method of claim 1, wherein the current control algorithm in step S2 comprises: the three paths of instruction dividing currents are respectively compared with the charging current of the energy storage battery pack to obtain current deviation, three paths of duty ratios are obtained through a fifth PI controller, and a control mathematical model of the current control algorithm is as follows:
wherein d 1 、d 2 、d 3 Representing 3 duty cycles; k (k) p5 A scaling factor representing a fifth PI controller; k (k) i5 An integration coefficient representing a fifth PI controller; current i 1 、i 2 、i 3 Representing a charging current of the energy storage battery pack;indicating the fractional command current.
6. A photovoltaic-energy storage converter system employing the control method of the photovoltaic-energy storage converter system of any of claims 1 to 5, comprising a bi-directional DC/DC converter and a grid-tie inverter, characterized in that the system comprises: a DC/DC control module for controlling the bidirectional DC/DC converter and an inverter control module for controlling the grid-connected inverter,
the DC/DC control module comprises a voltage control module for obtaining total instruction current, a current control module which is electrically connected with the voltage control module and used for obtaining three-way duty ratio, and a comparison module for obtaining a switch control signal of the bidirectional DC/DC converter, wherein the output end of the current control module is electrically connected with the comparison module.
7. The photovoltaic-energy storage converter system of claim 6 further comprising an energy storage battery pack, a photovoltaic module, the photovoltaic module connected to the energy storage battery pack through the bi-directional DC/DC converter; and one end of the grid-connected inverter is connected with the photovoltaic module, and the other end of the grid-connected inverter is connected with a power grid.
8. The photovoltaic-energy storage converter system of claim 7 wherein the voltage control module is configured to compare a terminal voltage of the energy storage battery with the command voltage to obtain a voltage deviation and to obtain a total command current based on a voltage loop control algorithm.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710084282.1A CN106936148B (en) | 2017-02-16 | 2017-02-16 | Photovoltaic-energy storage converter system and control method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710084282.1A CN106936148B (en) | 2017-02-16 | 2017-02-16 | Photovoltaic-energy storage converter system and control method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106936148A CN106936148A (en) | 2017-07-07 |
| CN106936148B true CN106936148B (en) | 2023-07-18 |
Family
ID=59424091
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201710084282.1A Active CN106936148B (en) | 2017-02-16 | 2017-02-16 | Photovoltaic-energy storage converter system and control method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106936148B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN108988414A (en) * | 2018-06-28 | 2018-12-11 | 南京理工大学 | Bidirectional DC-DC converter control system and method based on hybrid power RTG |
| CZ2018593A3 (en) * | 2018-10-31 | 2019-11-20 | České vysoké učenà technické v Praze | Device for charging accumulators from a photovoltaic source |
| CN109524970B (en) * | 2018-11-30 | 2023-08-18 | 国网安徽省电力有限公司经济技术研究院 | Distributed optical storage system-based power distribution network voltage control system and method |
| CN112751357B (en) * | 2019-10-31 | 2022-11-11 | 比亚迪股份有限公司 | Photovoltaic energy storage system and control method thereof |
| CN112701753B (en) * | 2020-12-23 | 2024-04-12 | 阳光电源股份有限公司 | Charging and discharging control method and energy storage system |
| CN112994458B (en) * | 2021-03-26 | 2022-08-23 | 潍柴动力股份有限公司 | DC/DC converter, control method thereof, and fuel cell system |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011139576A (en) * | 2009-12-28 | 2011-07-14 | Yaskawa Electric Corp | Motor drive device |
| CN203466613U (en) * | 2013-08-21 | 2014-03-05 | 浙江万向太阳能有限公司 | Household off-network light-storage supplementary electricity generation system compatible with multiple types of energy-storage systems |
| CN104810857B (en) * | 2015-05-22 | 2017-05-10 | 郑州大学 | Single-phase grid-connected photovoltaic power generation system output power smooth control device and control method |
| CN104810858B (en) * | 2015-05-27 | 2017-03-29 | 广西大学 | A kind of light stores up the control method of micro-grid connection electricity generation system |
| CN104993763B (en) * | 2015-06-26 | 2017-11-07 | 华中科技大学 | A kind of no electrolytic capacitor variable frequency drive control system and control method |
| CN105763085B (en) * | 2016-03-04 | 2018-11-20 | 东南大学 | Energy storage grid-connected converter and its control method based on three level of inverse-impedance type |
| CN105958468A (en) * | 2016-05-03 | 2016-09-21 | 北京北变微电网技术有限公司 | V2G direct-current bidirectional energy storage current transformer |
-
2017
- 2017-02-16 CN CN201710084282.1A patent/CN106936148B/en active Active
Non-Patent Citations (1)
| Title |
|---|
| 独立光伏发电直流网能量管理控制策略;徐四勤;王明渝;马兰珍;聂海龙;;现代电力(第04期);全文 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106936148A (en) | 2017-07-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106936148B (en) | Photovoltaic-energy storage converter system and control method thereof | |
| CN105207258B (en) | A kind of photovoltaic direct-current micro-grid energy cooperative control device | |
| Thrimawithana et al. | A novel matrix converter based bi-directional IPT power interface for V2G applications | |
| TWI624147B (en) | A multiple direct current (dc) voltage sources bi-directional energy converter | |
| CN102545257B (en) | Solar photovoltaic generating single-phase grid-connected inverter and control method thereof | |
| TWI387176B (en) | Intelligent hybrid power conversion control system | |
| Park et al. | High-performance transformerless online UPS | |
| TWI497866B (en) | Charging equipment | |
| WO2020186562A1 (en) | Converter and control method therefor | |
| CN103915856B (en) | A kind of base station is grid-connected-charging photovoltaic micro-inverter system and control method thereof | |
| WO2024078198A1 (en) | Energy storage system control method and apparatus, and energy storage system | |
| CN104269914A (en) | Wind-solar complementary control and inversion integrated machine | |
| Fang et al. | Study on bidirectional-charger for electric vehicle applied to power dispatching in smart grid | |
| Dali et al. | Control and energy management of a wind-photovoltaic hybrid system | |
| Rajesh et al. | Predictive control of three level boost converter interfaced SPV system for bi-polar DC micro grid | |
| JP2016039759A (en) | Power supply system and power conversion device | |
| Liu et al. | A bidirectional dual buck-boost voltage balancer with direct coupling based on a burst-mode control scheme for low-voltage bipolar-type DC microgrids | |
| CN104124884A (en) | Photovoltaic inverter and photovoltaic air conditioner system | |
| Fujita | A high-efficiency solar power conditioner using a zigzag-connected chopper converter | |
| Jo et al. | A comparative analysis of stability for battery energy storage system operating with diesel generator in a stand-alone microgrid | |
| CN112436500B (en) | Direct current microgrid power generation, transmission and distribution system | |
| Wu et al. | A dc bus signaling based autonomous power management strategy for a grid-connected pv-battery system | |
| Abraham | Sine Wave Inverter with Three Stage Battery Charger for Solar Photovoltaic Application | |
| Fan et al. | Bi-directional converting technique for Vehicle to Grid | |
| CN203398800U (en) | Energy storing device for clean energy |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP02 | Change in the address of a patent holder |
Address after: No. 296, Luzhong Road, Xiangyang, Hubei Province Patentee after: HUBEI University OF ARTS AND SCIENCE Address before: 441053 No. 296, Longzhong Road, Xiangyang City, Xiangfan City, Hubei Province Patentee before: HUBEI University OF ARTS AND SCIENCE |
|
| CP02 | Change in the address of a patent holder |