CN116488304A - Energy storage converter of energy storage system and electricity supplementing method - Google Patents

Energy storage converter of energy storage system and electricity supplementing method Download PDF

Info

Publication number
CN116488304A
CN116488304A CN202310651793.2A CN202310651793A CN116488304A CN 116488304 A CN116488304 A CN 116488304A CN 202310651793 A CN202310651793 A CN 202310651793A CN 116488304 A CN116488304 A CN 116488304A
Authority
CN
China
Prior art keywords
branch
energy storage
battery
module
bus
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.)
Pending
Application number
CN202310651793.2A
Other languages
Chinese (zh)
Inventor
邓凯
李乐
申智
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sungrow Power Supply Co Ltd
Original Assignee
Sungrow Power Supply Co Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Sungrow Power Supply Co Ltd filed Critical Sungrow Power Supply Co Ltd
Priority to CN202310651793.2A priority Critical patent/CN116488304A/en
Publication of CN116488304A publication Critical patent/CN116488304A/en
Pending legal-status Critical Current

Links

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
    • H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J7/007—Regulation of charging or discharging current or voltage
    • H02J7/00712—Regulation of charging or discharging current or voltage the cycle being controlled or terminated in response to electric parameters
    • H02J7/007182—Regulation of charging or discharging current or voltage the cycle being controlled or terminated in response to electric parameters in response to battery voltage
    • 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
    • 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
    • H02J7/0042—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries characterised by the mechanical construction
    • H02J7/0045—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries characterised by the mechanical construction concerning the insertion or the connection of the batteries
    • 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
    • H02J7/02—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries for charging batteries from ac mains by converters
    • 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
    • H02M7/00—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output
    • H02M7/66—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal
    • H02M7/68—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal by static converters
    • H02M7/72—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal by static converters using discharge tubes with control electrode or semiconductor devices with control electrode
    • H02M7/79—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal 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
    • H02M7/797—Conversion of ac power input into dc power output; Conversion of dc power input into ac power output with possibility of reversal 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
    • 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
    • H02J2207/00—Indexing scheme relating to details of circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
    • H02J2207/20—Charging or discharging characterised by the power electronics converter

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Supply And Distribution Of Alternating Current (AREA)
  • Charge And Discharge Circuits For Batteries Or The Like (AREA)

Abstract

The invention provides an energy storage converter of an energy storage system and an electricity supplementing method, wherein in the energy storage converter, alternating-current side equipment is connected with an inversion module through a reactor, and the inversion module is connected with the energy storage module so as to input received electric energy of a power grid to the energy storage module; and the energy storage module is connected in parallel with the direct current bus, the first positive electrode and the second positive electrode of the battery are connected with the inversion module to form a first branch and a second branch, when the battery of the second branch is in a power shortage state, the electric energy on the energy storage module is transmitted to the first branch so as to charge the direct current bus, and when the voltage of the bus is greater than or equal to the voltage of the battery, the electric energy on the energy storage module is transmitted to the second branch so as to supplement the electric energy of the battery of the second branch, thereby realizing that the battery is supplemented when the battery is in power shortage under the condition of no slow-starting circuit.

Description

Energy storage converter of energy storage system and electricity supplementing method
Technical Field
The invention relates to the technical field of power electronics, in particular to an energy storage converter of an energy storage system and an electricity supplementing method.
Background
With the large-scale application of the energy storage system, the energy storage system can be divided into PCS systems of different versions according to the discharge time of the battery.
In the related art, as shown in fig. 1, since the ac side is the same, fig. 1 shows only the dc side, and the working logic of the PCS system is to close the BAT1+ branch first, then determine the differential pressure between the BAT2+ voltage and the BAT1+ voltage, and when the differential pressure of the two branches is lower than 15V, the BAT2+ branch can be closed, because the differential pressure is too large, a circulation is generated, and the battery is damaged, so the PCS system has high cost and low efficiency. In practical application, the buffer circuit part (buffer contactor and resistor) on the BAT & lt2+ & gt branch is removed, so that the cost can be reduced and the efficiency can be improved on the premise of not influencing the logic function, but when the battery of the BAT & lt2+ & gt branch is in a power shortage state, the second branch is not provided with the buffer circuit, and the BAT & lt2+ & gt branch cannot be directly switched on to the grid of the direct current contactor to charge the battery.
Therefore, how to supplement the battery with power when the battery is low in power without a slow start circuit, so as to reduce the cost and increase the efficiency is a technical problem that needs to be solved by those skilled in the art.
Disclosure of Invention
Therefore, the embodiment of the invention provides an energy storage converter and a power supplementing method of an energy storage system, so that the power of a battery cannot be supplemented when the battery is in power shortage under the condition of no slow-start circuit, thereby reducing the cost and increasing the efficiency.
In order to achieve the above object, the embodiment of the present invention provides the following technical solutions:
the first aspect of the embodiment of the invention discloses an energy storage converter of an energy storage system, which comprises: a direct current side device and an alternating current side device identical to the direct current side device component; the direct-current side equipment comprises a current transformer, a resistance module, an energy storage module, an inversion module, a reactor and a controller;
the alternating-current side equipment is connected with the inversion module through the reactor;
the inversion module is respectively connected with a first positive electrode and a negative electrode of a battery of the energy storage system through two direct current buses and is connected with the energy storage module;
the energy storage module is connected in parallel with the direct current bus;
a first branch is formed between the first positive electrode of the battery and the inversion module, and the second positive electrode of the battery is connected in parallel with the first branch to form a second branch;
the controller is used for collecting the battery voltage of the second branch when the battery of the second branch is in a power shortage state, controlling the inversion module to receive the power grid electric energy transmitted by the alternating current side equipment through the reactor, inputting the power grid electric energy into the energy storage module, controlling the first branch to charge the direct current bus, collecting the bus voltage of the direct current bus, and controlling the second branch to supplement power to the battery of the second branch when the bus voltage is greater than or equal to the battery voltage.
Optionally, the fuse and the dc contactor are connected in series on the first branch, and the slow-start circuit is connected in parallel, where the slow-start circuit includes a slow-start contactor and a resistor, and the slow-start contactor and the resistor are connected in series and then between the dc contactors.
Optionally, the controller is further configured to: when the battery of the second branch is in a power shortage state, the battery voltage of the second branch is collected, the slow-start contactor of the first branch is controlled to be closed, the inverter module is controlled to receive power grid electric energy transmitted by the alternating-current side equipment through the reactor, the power grid electric energy is input to the energy storage module through the direct-current bus, and the electric energy on the energy storage module is transmitted to the first branch through the current transformer through the direct-current bus so as to charge the direct-current bus.
Optionally, the fuse and the dc contactor are connected in series on the second branch.
Optionally, the controller is further configured to: when the bus voltage is greater than or equal to the battery voltage, the slow-start contactor on the first branch is controlled to be opened, the direct-current contactor of the second branch is closed, the energy storage converter is switched to a grid-connected mode, and electric energy on the energy storage module is transmitted to the second branch through the direct-current bus through the current transformer so as to supplement electricity for the battery of the second branch.
Optionally, the fuse and the dc contactor are connected in series on a dc bus between the negative electrode of the battery and the first side of the inverter module.
Optionally, the ac side device is further connected to a connection line between the inverter module and the energy storage module.
Optionally, the current transformer is connected in series on a direct current bus between the inversion module and the first positive electrode of the battery, and a first branch is formed between the first positive electrode of the battery and the current transformer.
Optionally, the resistor module is connected in parallel to the dc bus, and the resistor module and the energy storage module are correspondingly connected.
Optionally, the inverter module is a DC/AC converter.
Optionally, the DC/AC converter is a bidirectional DC/AC converter;
the controller is further configured to: and controlling the inversion module to convert the received battery electric energy and then output the battery electric energy to the power grid so as to discharge the battery.
Optionally, the method further comprises: an alternating current precharge module;
the first side of the alternating current pre-charging module is connected to a direct current bus between the first side of the inversion module and the current transformer, and the second side of the alternating current pre-charging module is connected with the alternating current side equipment;
the controller is further configured to: when the battery of the second branch is in a power shortage state, the battery voltage of the second branch is collected, the alternating current pre-charging module is controlled to charge the direct current bus, the bus voltage of the direct current bus is collected, and when the bus voltage is greater than or equal to the battery voltage, the second branch is controlled to supplement power to the battery of the second branch.
The second aspect of the embodiment of the invention discloses a power supplementing method of an energy storage system, which is applied to a controller in an energy storage converter of the energy storage system according to any one of the first aspect of the embodiment of the invention, and comprises the following steps:
collecting the battery voltage of the second branch when the battery of the second branch is in a power shortage state;
the method comprises the steps that an inversion module is controlled to receive power grid electric energy transmitted by alternating-current side equipment through a reactor, the power grid electric energy is input to an energy storage module, a first branch is controlled to charge a direct-current bus, and bus voltage of the direct-current bus is collected;
and when the bus voltage is greater than or equal to the battery voltage, controlling the second branch to supplement electricity to the battery of the second branch.
Optionally, the method further comprises:
and when the bus voltage is smaller than the battery voltage, continuously executing the step of controlling the inversion module to receive the power grid electric energy transmitted by the alternating current side equipment through the reactor, inputting the power grid electric energy into the energy storage module, controlling the first branch and charging the direct current bus until the bus voltage of the direct current bus is larger than or equal to the battery voltage.
Optionally, when the battery of the second branch is in a power-deficient state, the method includes:
acquiring a battery charge quantity SOC of a battery of the second branch;
and when the SOC is in a preset lower limit value, determining that the battery of the second branch is in a power shortage state.
Optionally, fuse and direct current contactor are connected in series on the first branch, parallel connection slow-start circuit, slow-start circuit includes slow-start contactor and resistance, slow-start contactor with connect after the resistance is established ties between the direct current contactor, control inverter module receives the electric wire netting electric energy that exchange side equipment passes through the reactor transmission, will electric wire netting electric energy input to energy storage module to control first branch charges the direct current busbar, include:
controlling a slow-start contactor of a first branch to be closed, controlling an inversion module to receive power grid electric energy transmitted by alternating-current side equipment through a reactor, and inputting the power grid electric energy to an energy storage module;
and transmitting the electric energy on the energy storage module to the first branch through the current transformer through the direct current bus so as to charge the direct current bus.
Optionally, the fuse and the dc contactor are connected in series on the second branch, and the controlling the second branch to supplement power to the battery of the second branch includes:
controlling the slow-start contactor of the first branch to be opened, closing the direct-current contactor of the second branch, and switching the energy storage converter to a grid-connected mode;
and transmitting the electric energy on the energy storage module to the second branch through the current transformer through the direct current bus so as to supplement electricity for the battery of the second branch.
Optionally, when the energy storage converter includes an ac precharge module, the controlling the first branch circuit charges the dc bus includes:
and controlling the alternating current pre-charging module to charge the direct current bus.
The energy storage converter and the power supplementing method of the energy storage system provided by the embodiment of the invention are based on the fact that the energy storage converter of the energy storage system comprises: a direct current side device and an alternating current side device identical to the direct current side device component; the direct-current side equipment comprises a current transformer, a resistance module, an energy storage module, an inversion module, a reactor and a controller; the alternating-current side equipment is connected with the inversion module through the reactor; the inversion module is respectively connected with a first positive electrode and a negative electrode of a battery of the energy storage system through two direct current buses and is connected with the energy storage module; the energy storage module is connected in parallel with the direct current bus; a first branch is formed between the first positive electrode of the battery and the inversion module, and the second positive electrode of the battery is connected in parallel with the first branch to form a second branch; the controller is used for collecting the battery voltage of the second branch when the battery of the second branch is in a power shortage state, controlling the inversion module to receive the power grid electric energy transmitted by the alternating current side equipment through the reactor, inputting the power grid electric energy into the energy storage module, controlling the first branch to charge the direct current bus, collecting the bus voltage of the direct current bus, and controlling the second branch to supplement power to the battery of the second branch when the bus voltage is greater than or equal to the battery voltage. In the scheme, the alternating-current side equipment is connected with the inversion module through the reactor, and the inversion module is connected with the energy storage module, so that the received electric energy of the power grid can be input into the energy storage module; and the energy storage module is connected in parallel with the direct current bus, the first positive electrode and the second positive electrode of the battery are connected with the inversion module to form a first branch and a second branch, when the battery of the second branch is in a power shortage state, the electric energy on the energy storage module is transmitted to the first branch so as to charge the direct current bus, and when the voltage of the bus is greater than or equal to the voltage of the battery, the electric energy on the energy storage module is transmitted to the second branch so as to supplement the electric energy of the battery of the second branch, thereby realizing that the battery is supplemented when the battery is in power shortage under the condition of no slow-starting circuit.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are required to be used in the embodiments or the description of the prior art will be briefly described below, and it is obvious that the drawings in the following description are only embodiments of the present invention, and that other drawings can be obtained according to the provided drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic diagram of a PCS system in the prior art according to an embodiment of the present invention;
fig. 2 is a schematic structural diagram of an energy storage converter of an energy storage system according to an embodiment of the present invention;
fig. 3 is a schematic structural diagram of an energy storage converter of another energy storage system according to an embodiment of the present invention;
fig. 4 is a schematic structural diagram of an energy storage converter of another energy storage system according to an embodiment of the present invention;
fig. 5 is a schematic structural diagram of an energy storage converter of another energy storage system according to an embodiment of the present invention;
fig. 6 is a schematic structural diagram of an energy storage converter in a practical application scenario provided by an embodiment of the present invention;
fig. 7 is a schematic flow chart of a power supplementing method of an energy storage system according to an embodiment of the present invention.
Detailed Description
The following description of the embodiments of the present invention will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In this application, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
As known from the background art, the conventional power supply method cannot supply power to the battery when the battery is deficient under the condition that the slow start circuit is not provided.
Therefore, the embodiment of the invention provides an energy storage converter and an electricity supplementing method of an energy storage system, in the scheme, alternating-current side equipment is connected with an inversion module through a reactor, and the inversion module is connected with the energy storage module, so that received electric energy of a power grid can be input into the energy storage module; and the energy storage module is connected in parallel with the direct current bus, the first positive electrode and the second positive electrode of the battery are connected with the inversion module to form a first branch and a second branch, when the battery of the second branch is in a power shortage state, the electric energy on the energy storage module is transmitted to the first branch so as to charge the direct current bus, and when the voltage of the bus is greater than or equal to the voltage of the battery, the electric energy on the energy storage module is transmitted to the second branch so as to supplement the electric energy of the battery of the second branch, thereby realizing that the battery is supplemented when the battery is in power shortage under the condition of no slow-starting circuit.
As shown in fig. 2, a schematic structural diagram of an energy storage converter of an energy storage system according to an embodiment of the present invention is shown, where the energy storage converter 1 includes: a direct-current side device 10 and an alternating-current side device 11.
The components of the ac side device 11 are the same as those of the dc side device 10.
It should be noted that, the specific structure and the working principle of the component parts of the ac side device 11 can be referred to the specific structure and the working principle of the component parts of the dc side device 10 of the present invention, and will not be described in detail herein.
Specifically, the second side of the ac side device 11 is connected to the power grid, and the first side is connected to the dc side device 10.
In a specific implementation, the ac side device 11 receives grid power and inputs the received grid power to the dc side device 10.
The ac side device 11 also receives the electric power of the dc side device 10, and outputs the electric power of the dc side device 10 to the power grid.
In the embodiment of the invention, the direct-current side equipment comprises a current transformer, a resistance module, an energy storage module, an inversion module, a reactor and a controller.
As shown in fig. 3, a schematic structural diagram of an energy storage converter of another energy storage system according to an embodiment of the present invention is shown, where a dc side device 10 includes: a current transformer 100, a resistance module 101, an energy storage module 102, an inverter module 103, a reactor 104, and a controller 105.
In a specific implementation, the ac side device is connected to the inverter module through a reactor.
In detail, the second side of the ac side device 10 is connected to the power grid, the first side is connected to the second side of the reactor 104, and the first side of the reactor 101 is connected to the second side of the inverter module 103.
The first side of the inverter module 103 is connected to the first positive electrode and the negative electrode of the battery of the energy storage system through two dc buses, and is connected to the energy storage module 102.
Specifically, the first side of the inverter module 103 is connected to the first positive electrode and the negative electrode of the battery of the energy storage system via the first dc bus and the second dc bus, respectively.
The energy storage modules 102 are connected in parallel to the dc bus.
In detail, both ends of the energy storage module 102 are connected to the first dc bus and the second dc bus, respectively.
The first side of the ac side device 10 is also connected to a connection between the inverter module 103 and the energy storage module 102.
The power grid can comprise municipal power generation power grids and private enterprise power generation power grids, and particularly, the type of power grid is determined according to the specific application environment, and the power grid is within the protection scope of the application.
The grid may in particular be a 220V ac supply.
And the reactor 104 is used for limiting the voltage fluctuation of the direct current bus to a small range when a short circuit fault occurs, so as to ensure that equipment on a fault-free line can stably operate.
The number of the inverter modules 103 may be plural, where a first side of each inverter module 103 is correspondingly connected to a first positive electrode and a negative electrode of a battery of the energy storage system, and is connected to the energy storage module 102, and a second side is correspondingly connected to the reactor 104.
In some embodiments, the inverter module 103 may be a DC/AC converter or a DC/DC converter.
In some embodiments, the dc bus is preferably the dc bus of a PCS.
In some embodiments, the energy storage module 102 is a bus capacitor, i.e. a dc bus capacitor, and in practical applications, a thin film capacitor and an electrolytic capacitor may be selected, but are not limited thereto, and they are all within the protection scope of the present application depending on the specific application environment.
In a specific implementation, a first branch is formed between the first positive electrode of the battery and the inverter module 103, and the second positive electrode of the battery is connected in parallel to the first branch to form a second branch.
The current transformer 100 is connected in series on the dc bus between the first side of the inverter module 103 and the first positive electrode of the battery.
Specifically, a first branch is formed between the first positive electrode of the battery and the current transformer 100, and the second positive electrode of the battery is connected in parallel to the first branch to form a second branch.
In more detail, the current transformer 100 is connected in series to the first dc bus.
The resistor module 101 is connected in parallel to the direct current bus, and the resistor module 101 and the energy storage module 102 are correspondingly connected.
Specifically, both ends of the resistor module 101 are connected to the first dc bus and the second dc bus, respectively.
Among them, the current transformer 100 (Current transformer, CT) is used to convert the primary side large current into the secondary side small current.
The primary side of the current transformer 100 is the input side of the current transformer 100, and the secondary side of the current transformer 100 is the output side of the current transformer 100.
The resistor module 101 is configured to ensure that the voltages on the energy storage module 102 are equal by using the voltage division principle, that is, the resistor module 101 maintains the voltage of the energy storage module 102 equal.
In some embodiments, the resistor module 101 is preferably a bus voltage equalizing resistor, but is not limited thereto, and is within the scope of the present application depending on the specific application environment.
Specifically, the power grid outputs electric power, and inputs the electric power to the ac side device 11.
The ac side device 11 receives the grid power, and inputs the grid power to the inverter module 103 after processing the grid power by the reactor 104.
Specifically, the ac-side device 11 receives grid power, and inputs the received grid power to the reactor 104. The reactor 104 performs current limiting and filtering processing on the grid power, and then inputs the grid power to the inverter module 103.
The inverter module 103 receives the grid electric energy output after the current limiting and filtering treatment of the reactor 104, and inputs the received grid electric energy to the energy storage module 102 through a direct current bus for supplementing electricity to the battery.
When the battery of the second branch is in a power shortage state, the battery voltage of the second branch is collected, the controller 105 controls the inverter module 103 to receive the power grid power transmitted by the alternating-current side equipment through the reactor 104, the power grid power is input to the energy storage module 102, the first branch is controlled to charge the direct-current bus, and the bus voltage of the direct-current bus is collected.
And when the bus voltage is greater than or equal to the battery voltage, controlling the second branch to supplement electricity to the battery of the second branch.
When the inverter module 103 is a DC/AC converter, the controller 105 is further configured to: the inverter module 103 is controlled to input the received grid power to the energy storage module 102 for recharging the battery.
When the inverter module 103 is a DC/AC converter, the DC/AC converter may be a bidirectional DC/AC converter, and the controller 105 is further configured to: the inverter module 103 is controlled to convert the received battery power and output the converted battery power to the power grid for discharging the battery.
When the battery charge amount of the battery is too low to be charged, the power supply circuit is constructed to supply power from a power supply such as a municipal power generation grid or a private enterprise power generation grid, and the energy storage converter 1 supplements power to the battery so as to prevent the battery from being excessively discharged.
Referring to fig. 2 and fig. 3, fig. 4 is a schematic structural diagram of an energy storage converter of another energy storage system according to an embodiment of the present invention, where a fuse and a dc contactor are connected in series on a first branch, and a snubber circuit is connected in parallel.
Specifically, the slow-start circuit comprises a slow-start contactor and a resistor, and the slow-start contactor and the resistor are connected in series and then connected in parallel between the direct-current contactors.
The contactor is an electric appliance which uses low voltage and small current to control high voltage and large current load, and plays a role of switching on and off the load.
In a specific implementation, when the battery of the second branch is in a power shortage state, the battery voltage of the second branch is collected, the controller 105 controls the slow-start contactor of the first branch to be closed, and controls the inverter module 103 to receive the power grid power transmitted by the ac side device 11 through the reactor 104, the received power grid power is input to the energy storage module 102 through the dc bus, and the power on the energy storage module 102 is transmitted to the first branch through the current transformer 100 through the dc bus to charge the dc bus.
In detail, when the battery of the second branch is in a power shortage state, the controller 105 collects the battery voltage of the second branch, controls the slow-start contactor of the first branch to be closed, and controls the second side of the inverter module 103 to receive the power grid power transmitted by the ac side device 11 through the reactor 104, transmits the power grid power received by the second side to the first side through the dc bus, inputs the power grid power to the energy storage module 102 through the first side, transmits the power on the energy storage module 102 to the second side of the current transformer 100 through the dc bus, transmits the power grid power received by the second side to the first side through the current transformer 100, and inputs the power grid power to the first branch through the first side to charge the dc bus.
Specifically, the second branch is connected with a fuse and a direct current contactor in series.
A fuse and a dc contactor are connected in series on the dc bus between the negative electrode of the battery and the first side of the inverter module 103.
That is, the fuse and the dc contactor are connected in series to the second dc bus.
In a specific implementation, when the bus voltage is greater than or equal to the battery voltage, the controller 105 controls the slow-start contactor on the first branch to be opened, the direct-current contactor on the second branch to be closed, the energy storage converter is switched to the grid-connected mode, and the electric energy on the energy storage module 102 is transmitted to the battery of the second branch through the direct-current bus through the current transformer 100 so as to supplement the electric energy of the battery of the second branch.
In detail, when the bus voltage is greater than or equal to the battery voltage, the controller 105 controls the slow-start contactor on the first branch to open, the dc contactor on the second branch to close, the energy storage converter switches to the grid-connected mode, the power on the energy storage module 102 is transmitted to the second side of the current transformer 100 through the dc bus, the power on the power grid on the second side is transmitted to the first side by the current transformer 100, and the power on the power grid is input to the second branch through the first side to supplement the power to the battery on the second branch.
When the bus voltage is greater than or equal to the battery voltage, the slow-start contactor on the first branch is controlled to be opened, and the direct-current contactor on the second branch is controlled to be closed, at this time, the bus voltage can be reduced within the time range from opening the slow-start contactor of the first branch to closing the direct-current contactor of the second branch, the internal and external pressure difference of the direct-current contactor of the second branch can be controlled within 30V, and the generated impact current is smaller.
Fig. 4 is a schematic structural diagram of an energy storage converter of another energy storage system according to an embodiment of the present invention, where the energy storage converter further includes: alternating current precharge module 106.
Specifically, the first side of the ac pre-charge module 106 is connected to the dc bus between the first side of the inverter module 103 and the current transformer 100, and the second side is connected to the ac side device 11.
That is, the ac pre-charge module 106 is connected on a first dc bus on a first side and connected to the ac side device 11 on a second side.
At this time, the controller 105 is also configured to: when the battery of the second branch is in a power shortage state, the battery voltage of the second branch is collected, the alternating current pre-charging module 106 is controlled to charge the direct current bus, the bus voltage of the direct current bus is collected, and when the bus voltage is greater than or equal to the battery voltage, the second branch is controlled to supplement power to the battery of the second branch.
In a specific implementation, when the battery of the second branch is in a power shortage state, the battery voltage of the second branch is collected, the ac pre-charging module 106 is controlled to charge the dc bus, the dc contactor of the second branch is controlled to be closed, the energy storage converter is switched to a grid-connected mode, and the electric energy on the ac pre-charging module 106 is transmitted to the second branch through the dc bus to supplement the electric energy of the battery of the second branch.
In order to better understand the above-mentioned energy storage converter, as shown in fig. 6, a schematic structural diagram of the energy storage converter in a practical application scenario is provided in an embodiment of the present invention.
In fig. 6, the first positive electrode (BAT 1+) of the battery is connected to the first side of the inverter module through a dc bus to which a Current Transformer (CT) is connected in series.
A first branch is formed between a first positive electrode of the battery and the current transformer, and a second positive electrode (BAT & lt2+ & gt) of the battery is connected in parallel to the first branch to form a second branch.
The first branch is connected with a fuse and a direct current contactor in series, and is connected with a slow-start circuit in parallel.
The slow-start circuit comprises a slow-start contactor and a resistor, and the slow-start contactor and the resistor are connected in series and then connected between the direct-current contactors.
The second branch is connected with the fuse and the direct current contactor in series.
The negative electrode (BAT-) of the battery is connected with the first side of the inversion module through another direct current bus, and the fuse and the direct current contactor are connected in series on the direct current bus.
The bus voltage equalizing resistor and the bus capacitor are connected in parallel with two direct current buses, and the bus voltage equalizing resistor and the energy storage module are correspondingly connected.
The second side of the inversion module is connected with one side of a reactor, the other side of the reactor is connected with one side of alternating current side equipment, and the other side of the alternating current side equipment is connected with a power grid.
The alternating-current side equipment is also connected to a connecting line between the inversion module and the bus capacitor.
In practical application, when the battery of the second branch is in a power shortage state, the battery voltage of the second branch is collected, the inverter module is controlled to receive the power grid electric energy transmitted by the alternating-current side equipment through the reactor, the power grid electric energy is input to the bus capacitor, the first branch is controlled to charge the direct-current bus, the bus voltage of the direct-current bus is collected, and when the bus voltage is greater than or equal to the battery voltage, the second branch is controlled to supplement power to the battery of the second branch.
According to the energy storage converter of the energy storage system, in the energy storage converter, alternating-current side equipment is connected with an inversion module through a reactor, and the inversion module is connected with the energy storage module, so that received electric energy of a power grid can be input into the energy storage module; and the energy storage module is connected in parallel with the direct current bus, the first positive electrode and the second positive electrode of the battery are connected with the inversion module to form a first branch and a second branch, when the battery of the second branch is in a power shortage state, the electric energy on the energy storage module is transmitted to the first branch so as to charge the direct current bus, and when the voltage of the bus is greater than or equal to the voltage of the battery, the electric energy on the energy storage module is transmitted to the second branch so as to supplement the electric energy of the battery of the second branch, thereby realizing that the battery is supplemented when the battery is in power shortage under the condition of no slow-starting circuit.
Corresponding to the energy storage converter of the energy storage system shown in the foregoing embodiments of the present invention, the embodiments of the present invention further correspondingly provide an electricity supplementing method of the energy storage system, which is applied to the controller in the energy storage converter of the energy storage system described in any one of the foregoing embodiments, and the specific structure and the working principle of the energy storage converter of the energy storage system can be referred to the foregoing embodiments, which are not repeated herein.
As shown in fig. 7, the power supplementing method of the energy storage system mainly includes the following steps:
step S701: and judging whether the battery of the second branch is in a power shortage state, if so, executing step S702, and if not, ending the operation.
In step S701, the second leg may be denoted BAT2.
In the specific implementation step S701, it is determined whether the battery of the second branch is in a power shortage state, if so, it is indicated that the battery electric energy of the second branch cannot meet the current electric energy requirement, and power needs to be supplied to the battery of the second branch, then step S702 is executed, if not, it is indicated that the battery of the second branch is in a discharging stage, the battery electric energy can meet the current electric energy requirement, discharging can be performed, no power supply operation is required, and then the operation is ended.
Preferably, the process of judging whether the battery of the second branch is in a power shortage state mainly comprises the following steps:
step S11: the battery charge amount SOC of the battery of the second branch is acquired.
In step S11, the battery charge amount (SOC) refers to the remaining capacity of the battery, that is, the available State of the charge remaining in the battery.
Step S12: and judging whether the SOC is at a preset lower limit value, if so, executing the step S13, and if not, ending the operation.
In step S12, the preset lower limit value may be the charge amount triggering the over-discharge warning, or may be higher than the charge amount, depending on the specific application environment, which is within the protection scope of the present application.
Step S13: and determining that the battery of the second branch is in a power shortage state.
In the specific implementation process of step S13, in the case where it is determined that the battery charge amount SOC of the battery of the second branch is at the preset lower limit value, it is determined that the battery of the second branch is in the power shortage state.
Step S702: and collecting the battery voltage of the second branch.
In step S702, the battery voltage may be represented as VBAT2.
In the specific implementation process of step S702, under the condition that the battery of the second branch is determined to be in a power-deficient state, the battery voltage of the second branch is sampled, and the battery voltage of the second branch is obtained.
Step S703: the control inversion module receives power grid electric energy transmitted by the alternating-current side equipment through the reactor, inputs the power grid electric energy into the energy storage module, controls the first branch circuit, charges the direct-current bus and collects bus voltage of the direct-current bus.
In step S703, the bus voltage may be represented as Vbus.
Preferably, in some embodiments, when the fuse and the dc contactor are connected in series on the first branch, the slow-start circuit is connected in parallel, and the slow-start circuit includes the slow-start contactor and the resistor, and the slow-start contactor and the resistor are connected between the dc contactors after being connected in series, the executing step S703 controls the inverter module to receive the power grid power transmitted by the ac side device through the reactor, inputs the power grid power to the energy storage module, and controls the first branch, and the process of charging the dc bus may include:
the slow-start contactor of the first branch is controlled to be closed, the inverter module is controlled to receive power grid electric energy transmitted by the alternating-current side equipment through the reactor, the power grid electric energy is input to the energy storage module, and the electric energy on the energy storage module is transmitted to the first branch through the current transformer through the direct-current bus to charge the direct-current bus.
Preferably, in some embodiments, when the energy storage converter of the energy storage system includes an ac pre-charging module, in the step S703, controlling the first branch to charge the dc bus may include:
and controlling the alternating current pre-charging module to charge the direct current bus.
Step S704: whether the bus voltage is equal to or higher than the battery voltage is determined, if yes, step S705 is executed, and if not, step S703 is executed again.
In the specific implementation of step S704, the bus voltage is compared with the battery voltage, if the bus voltage is equal to or higher than the battery voltage, step S705 is executed, and if the bus voltage is lower than the battery voltage, step S703 is executed again.
Step S705: and controlling the second branch to supplement electricity to the battery of the second branch.
In the specific implementation process of step S705, under the condition that the bus voltage is greater than or equal to the battery voltage, the second branch is controlled to supplement electricity to the battery of the second branch.
Preferably, in some embodiments, when the fuse and the dc contactor are connected in series on the second branch, performing step S705 to control the second branch to perform a process of recharging the battery of the second branch may include:
and controlling the slow-start contactor of the first branch to be opened, closing the direct-current contactor of the second branch, switching the energy storage converter to a grid-connected mode, and transmitting electric energy on the energy storage module to the second branch through the direct-current bus through the current transformer so as to supplement electricity for the battery of the second branch.
According to the power supplementing method of the energy storage system, when the battery of the second branch is in the power shortage state, electric energy on the energy storage module is transmitted to the first branch so as to charge the direct current bus, and when the voltage of the bus is greater than or equal to the voltage of the battery, the electric energy on the energy storage module is transmitted to the second branch so as to supplement power for the battery of the second branch, so that the battery is supplemented under the condition that a slow starting circuit is not provided, and the battery is in power shortage.
In this specification, each embodiment is described in a progressive manner, and identical and similar parts of each embodiment are all referred to each other, and each embodiment mainly describes differences from other embodiments. In particular, for a system or system embodiment, since it is substantially similar to a method embodiment, the description is relatively simple, with reference to the description of the method embodiment being made in part. The systems and system embodiments described above are merely illustrative, wherein the elements illustrated as separate elements may or may not be physically separate, and the elements shown as elements may or may not be physical elements, may be located in one place, or may be distributed over a plurality of network elements. Some or all of the modules may be selected according to actual needs to achieve the purpose of the solution of this embodiment. Those of ordinary skill in the art will understand and implement the present invention without undue burden.
Those of skill would further appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, computer software, or combinations of both, and that the various illustrative elements and steps are described above generally in terms of functionality in order to clearly illustrate the interchangeability of hardware and software. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.
The previous description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the invention. Thus, the present invention is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (18)

1. An energy storage converter of an energy storage system, comprising: a direct current side device and an alternating current side device identical to the direct current side device component; the direct-current side equipment comprises a current transformer, a resistance module, an energy storage module, an inversion module, a reactor and a controller;
the alternating-current side equipment is connected with the inversion module through the reactor;
the inversion module is respectively connected with a first positive electrode and a negative electrode of a battery of the energy storage system through two direct current buses and is connected with the energy storage module;
the energy storage module is connected in parallel with the direct current bus;
a first branch is formed between the first positive electrode of the battery and the inversion module, and the second positive electrode of the battery is connected in parallel with the first branch to form a second branch;
the controller is used for collecting the battery voltage of the second branch when the battery of the second branch is in a power shortage state, controlling the inversion module to receive the power grid electric energy transmitted by the alternating current side equipment through the reactor, inputting the power grid electric energy into the energy storage module, controlling the first branch to charge the direct current bus, collecting the bus voltage of the direct current bus, and controlling the second branch to supplement power to the battery of the second branch when the bus voltage is greater than or equal to the battery voltage.
2. The energy storage converter of claim 1, wherein the first branch is connected with a fuse and a dc contactor in series, and is connected with a slow-start circuit in parallel, wherein the slow-start circuit comprises a slow-start contactor and a resistor, and the slow-start contactor and the resistor are connected between the dc contactor after being connected in series.
3. The energy storage converter of claim 1 or 2, wherein the controller is further configured to: when the battery of the second branch is in a power shortage state, the battery voltage of the second branch is collected, the slow-start contactor of the first branch is controlled to be closed, the inverter module is controlled to receive power grid electric energy transmitted by the alternating-current side equipment through the reactor, the power grid electric energy is input to the energy storage module through the direct-current bus, and the electric energy on the energy storage module is transmitted to the first branch through the current transformer through the direct-current bus so as to charge the direct-current bus.
4. The energy storage converter of claim 1, wherein the fuse and the dc contactor are connected in series on the second leg.
5. The energy storage converter of claim 1 or 4, wherein the controller is further configured to: when the bus voltage is greater than or equal to the battery voltage, the slow-start contactor on the first branch is controlled to be opened, the direct-current contactor of the second branch is closed, the energy storage converter is switched to a grid-connected mode, and electric energy on the energy storage module is transmitted to the second branch through the direct-current bus through the current transformer so as to supplement electricity for the battery of the second branch.
6. The energy storage converter of claim 1, wherein the fuse and the dc contactor are connected in series on a dc bus between a negative pole of the battery and a first side of the inverter module.
7. The energy storage converter of claim 1, wherein the ac side device is further connected to a connection between the inverter module and the energy storage module.
8. The energy storage converter of claim 1, wherein the current transformer is connected in series on a dc bus between the inverter module and a first positive electrode of the battery, the first positive electrode of the battery and the current transformer forming a first branch therebetween.
9. The energy storage converter of claim 1, wherein the resistor modules are connected in parallel to the dc bus, and the resistor modules and the energy storage modules are connected in correspondence.
10. An energy storage converter according to any of claims 1-9, wherein the inverter module is a DC/AC converter.
11. The energy storage converter of claim 10, wherein the DC/AC converter is a bi-directional DC/AC converter;
the controller is further configured to: and controlling the inversion module to convert the received battery electric energy and then output the battery electric energy to the power grid so as to discharge the battery.
12. The energy storage converter of any of claims 1-7, further comprising: an alternating current precharge module;
the first side of the alternating current pre-charging module is connected to a direct current bus between the first side of the inversion module and the current transformer, and the second side of the alternating current pre-charging module is connected with the alternating current side equipment;
the controller is further configured to: when the battery of the second branch is in a power shortage state, the battery voltage of the second branch is collected, the alternating current pre-charging module is controlled to charge the direct current bus, the bus voltage of the direct current bus is collected, and when the bus voltage is greater than or equal to the battery voltage, the second branch is controlled to supplement power to the battery of the second branch.
13. A method of supplementing power to an energy storage system, characterized by a controller applied in an energy storage converter of an energy storage system according to any one of claims 1 to 12, the method comprising:
collecting the battery voltage of the second branch when the battery of the second branch is in a power shortage state;
the method comprises the steps that an inversion module is controlled to receive power grid electric energy transmitted by alternating-current side equipment through a reactor, the power grid electric energy is input to an energy storage module, a first branch is controlled to charge a direct-current bus, and bus voltage of the direct-current bus is collected;
and when the bus voltage is greater than or equal to the battery voltage, controlling the second branch to supplement electricity to the battery of the second branch.
14. The method of supplementing energy to an energy storage system of claim 13, further comprising:
and when the bus voltage is smaller than the battery voltage, continuously executing the step of controlling the inversion module to receive the power grid electric energy transmitted by the alternating current side equipment through the reactor, inputting the power grid electric energy into the energy storage module, controlling the first branch and charging the direct current bus until the bus voltage of the direct current bus is larger than or equal to the battery voltage.
15. The method of claim 13, wherein when the battery of the second branch is in a power deficient state, comprising:
acquiring a battery charge quantity SOC of a battery of the second branch;
and when the SOC is in a preset lower limit value, determining that the battery of the second branch is in a power shortage state.
16. The method for supplementing power to an energy storage system according to claim 13, wherein a fuse and a dc contactor are connected in series on the first branch, a slow-start circuit is connected in parallel, the slow-start circuit includes a slow-start contactor and a resistor, the slow-start contactor and the resistor are connected in series and then connected between the dc contactor, the control inverter module receives power grid power transmitted by an ac side device through a reactor, the power grid power is input to the energy storage module, and the control first branch charges a dc bus, and the method comprises:
controlling a slow-start contactor of a first branch to be closed, controlling an inversion module to receive power grid electric energy transmitted by alternating-current side equipment through a reactor, and inputting the power grid electric energy to an energy storage module;
and transmitting the electric energy on the energy storage module to the first branch through the current transformer through the direct current bus so as to charge the direct current bus.
17. The method of claim 13, wherein the second branch is connected in series with the fuse and the dc contactor, and wherein controlling the second branch to recharge the battery of the second branch comprises:
controlling the slow-start contactor of the first branch to be opened, closing the direct-current contactor of the second branch, and switching the energy storage converter to a grid-connected mode;
and transmitting the electric energy on the energy storage module to the second branch through the current transformer through the direct current bus so as to supplement electricity for the battery of the second branch.
18. The method of claim 13, wherein when the energy storage converter includes an ac pre-charging module, the controlling the first branch to charge the dc bus includes:
and controlling the alternating current pre-charging module to charge the direct current bus.
CN202310651793.2A 2023-06-01 2023-06-01 Energy storage converter of energy storage system and electricity supplementing method Pending CN116488304A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310651793.2A CN116488304A (en) 2023-06-01 2023-06-01 Energy storage converter of energy storage system and electricity supplementing method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310651793.2A CN116488304A (en) 2023-06-01 2023-06-01 Energy storage converter of energy storage system and electricity supplementing method

Publications (1)

Publication Number Publication Date
CN116488304A true CN116488304A (en) 2023-07-25

Family

ID=87218045

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202310651793.2A Pending CN116488304A (en) 2023-06-01 2023-06-01 Energy storage converter of energy storage system and electricity supplementing method

Country Status (1)

Country Link
CN (1) CN116488304A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116742679A (en) * 2023-08-10 2023-09-12 上海百竹成航新能源有限责任公司 Reverse starting energy storage system and reverse starting method

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN116742679A (en) * 2023-08-10 2023-09-12 上海百竹成航新能源有限责任公司 Reverse starting energy storage system and reverse starting method

Similar Documents

Publication Publication Date Title
EP3503282B1 (en) Quick charging method for parallel battery pack, and related device
EP3506451B1 (en) Quick charging method for series battery pack, and related device
CN105226632B (en) A kind of multi-mode switching control method for coordinating of DC micro power grid system
CN104247201B (en) Accumulating system and box
CN201726205U (en) AC energy storage cabinet and energy storage power station system
CN113270881A (en) Energy storage system, balance control method of energy storage system and photovoltaic power generation system
CN103119822A (en) Electrical storage system and method for controlling electrical storage system
CN108539841A (en) Combination DC-DC converter for hybrid power source system
CN204244092U (en) The charge-discharge circuit of DC bus and converter system
EP4304042A1 (en) Energy storage system, control method for energy storage system, and photovoltaic power generation system
RU53818U1 (en) BATTERY OF ELECTRIC ENERGY STORES
CN116488304A (en) Energy storage converter of energy storage system and electricity supplementing method
CN114301092A (en) Modular optical storage charging detection intelligent system
CN101471576A (en) Charging method and apparatus
CN105186630B (en) A kind of electric energy transfer method and a kind of electric energy bus
Latha et al. Design and implementation of power conditioning for distribution network V2G to electric vehicle and DC charging system
Valchev et al. Improvement on LiFePO4 cell balancing algorithm
CN109274149B (en) Electrical energy exchange device, battery device and battery maintenance system
CN103795116A (en) Power supply change-over and control device, and power supply method and system
Hassan et al. Solar Power Assisted Passive and Active Cell Balancing System: A Comprehensive Analysis
CN116231875A (en) Energy storage system and control method thereof
CN205385295U (en) Electric energy bus
Hamidi et al. Batteries and ultracapacitors for electric power systems with renewable energy sources
CN208015378U (en) Distribution type photovoltaic energy storage system and solar photovoltaic generation system
CN106100095A (en) Photovoltaic inversion energy storage system capable of avoiding frequent charge and discharge switching

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