CN110854980A - Intelligent battery power module applied to distributed energy storage system - Google Patents

Abstract

An intelligent battery power module applied to a distributed energy storage system is suitable for application occasions of the energy storage system with high safety and high dispersity, such as a user side and building combination, and adopts a design scheme of integrating a battery module, isolation transformation, battery management, protection and intellectualization. The battery module in the intelligent battery power module adopts a low-voltage and small-capacity design mode, the voltage level is 48Vdc, and the capacity is about 5-10 kWh; the isolation converter in the intelligent battery power module has a boosting function and also has a charge-discharge control function on the battery module; the controller in the intelligent battery power module has the functions of single voltage acquisition, module temperature acquisition, quick plug connector temperature acquisition, isolation converter voltage and current acquisition, converter drive control and external RS485 and CAN communication. The intelligent battery power module outputs voltage 375Vdc, supports alternating current and direct current application occasions, supports two direct current voltage levels of 375Vdc and 750Vdc, and meets the requirement of future direct current power supply.

Description

An intelligent battery power module applied to distributed energy storage system

technical field

The patent of the present invention relates to the field of energy storage application, especially to the field of distributed energy storage applied by the user side in buildings.

Background technique

With the continuous development of new energy technologies such as wind power generation and photovoltaic power generation, more and more power generation units with poor adjustability are connected to the power grid with high penetration, the power generation side is becoming more and more rigid, and the adjustable performance is getting worse and worse; in the future The proportion of energy consumption on the electricity consumption side of buildings and transportation is getting higher and higher, and the behavior characteristics of these two parts of electricity consumption are very large, the electricity consumption side is becoming more and more rigid, and the adjustability is getting worse and worse. The rigidity and non-adjustment of the power generation side and the power consumption side have brought great challenges to the balance of supply and demand in the power grid. The key to solving this problem is to add energy storage facilities to the power grid to decouple the power generation side and the power consumption side from each other. At present, frequency regulation on the power generation side, peak regulation on the transmission side, and peak shaving and valley filling on the user side are all to solve the above problems, and adding an energy storage system on the user side is the most efficient and direct way to solve the above problems.

Due to the development of related industries such as the electric vehicle industry, electrochemical energy storage systems using lithium-ion batteries as energy storage elements are currently the main choice for energy storage systems. Different from the power generation side and the power transmission side, the user side has higher requirements for the safety of the energy storage system due to the characteristics of being closely integrated with people and buildings. So far, there is no written fire acceptance of the energy storage system. Regulations further hinder the development of energy storage systems. The user side, especially the place where the large users of electricity are located, must also be an area with dense traffic. In addition to safety, spatial location, versatility, intelligence, etc. are all issues that need to be considered and solved by the user-side energy storage system. The DC power supply mode on the distribution side and the user side will also become more and more popular, and the energy storage system on the user side should meet the above relevant requirements. This is also the background of this intelligent battery power module applied to distributed energy storage system.

SUMMARY OF THE INVENTION

In order to solve the problems of safety, space, customization, etc. brought about by the application of the lithium-ion battery energy storage system on the user side, and at the same time consider the intelligentization of the energy storage system and the need to adapt to the future DC power supply, the present invention provides a distributed storage system. Smart battery power modules for energy systems. Using low-voltage, small-capacity battery modules, using isolation converters to isolate the battery modules from each other, and adopting a design scheme that integrates battery modules, isolation converter units, battery management units, protection units and intelligent units, It supports AC and DC applications, and supports two DC voltage levels, 375Vdc and 750Vdc, to meet the needs of future DC power supply.

Technical solutions

The present invention is an intelligent battery power module applied to a distributed energy storage system, which is a battery power module that integrates battery module, isolation conversion, battery management, protection and intelligence, and can be connected in series or in parallel externally. Figure 1.

The internal battery module of an intelligent battery power module applied to a distributed energy storage system of the present invention adopts a lithium iron phosphate battery (which can be a retired battery of an electric vehicle), in the form of 1 parallel 16 series or multiple parallel 16 series, a single cell or After parallel connection, the capacity of the single battery is 100~200Ah, and the capacity of the battery module is about 5kWh~10kWh.

An intelligent battery power module applied to a distributed energy storage system of the present invention includes protection devices such as fuses and DC circuit breakers, wherein the fuses are arranged between two 8-series batteries, and the DC circuit breakers are arranged on the positive and negative sides of the battery module. pole.

The hardware topology of the internal DC/DC converter of an intelligent battery power module applied to a distributed energy storage system of the present invention adopts a full-bridge isolation LLC topology. ) The nominal voltage is 375V, the rated power is 2.5kW, and it has functions such as soft start.

The external connection of an intelligent battery power module applied to a distributed energy storage system of the present invention includes DC+, DC- main circuit terminals, CAN and RS485 communication terminals, all of which adopt a quick-plug design method, and reserve a maintenance interface to support intelligent batteries. The battery module in the power module is externally maintained as required.

An auxiliary power supply of an intelligent battery power module applied to a distributed energy storage system of the present invention adopts the form of a low-voltage battery module and a high-voltage bus to supply power together. The controller integrates functions such as battery management, intelligent control, and communication management, and collects each battery cell Body voltage, battery module temperature collection, quick-plug main circuit output terminal temperature collection, DC/DC converter voltage and current information collection, battery state estimation and DC/DC converter drive control.

The present invention is an intelligent battery power module applied to a distributed energy storage system, which supports parallel 375Vdc operation and series 750Vdc operation, and can realize the automatic voltage equalization control function of the intelligent battery power module during the series operation, as shown in FIG. 2 .

beneficial effect

An intelligent battery power module applied to a distributed energy storage system adopts a distributed arrangement of low-voltage and small-capacity battery modules, which satisfies the safety, layout and safety requirements of the user-side energy storage system in terms of voltage level, unit energy and space requirements. and so on.

Different from the traditional energy storage system in which 200-250 battery cells are connected in series to a very high voltage, the intelligent battery power module applied to the distributed energy storage system of the present invention does not pass the direct series connection of the battery module when it is applied in series and parallel. In parallel, the internal DC/DC converter (using isolation topology) is used to realize series and parallel connection, and the battery modules are isolated from each other through the DC/DC converter, which blocks the channel for fault spread after the battery module has a problem.

An intelligent battery power module applied to a distributed energy storage system of the present invention supports series-parallel combination, supports AC and DC applications, and supports two voltage levels of 375Vdc and 750Vdc. .

Description of drawings

Figure 1 is a system diagram of an intelligent battery power module.

Figure 2 is a series-parallel connection diagram of an intelligent battery power module.

In Figure 1

The DC/DC converter is the internal isolation converter of the intelligent battery power module;

DC+ is the positive terminal for external connection of the intelligent battery power module;

DC- is the negative terminal for external connection of the intelligent battery power module;

RS485 and CAN are the external communication terminals of the intelligent battery power module;

In Figure 2

+375V is the positive bus of bipolar DC bus;

0V is the zero bus of bipolar DC bus;

-375V is the negative bus of bipolar DC bus.

Detailed ways

As shown in Figure 1, the intelligent battery power module includes three parts: battery module, DC/DC converter and controller, which are connected through primary and secondary circuits, and all connecting cables are high-temperature cables.

The battery module adopts lithium iron phosphate battery (can be retired battery of electric vehicle), including 16 battery cells (in the form of 1 parallel 16 series or multi-parallel 16 series), divided into 2 groups of 8 strings, and 2 groups of 8 strings of batteries. They are connected by fuses, the nominal voltage of the battery module is 48Vdc, the capacity of a single cell or a single cell in parallel is 100~200Ah, and the capacity of the battery module is about 5kWh~10kWh.

The DC/DC converter adopts a full-bridge isolation LLC circuit topology. A soft-start device is added on the high-voltage side. The power is 2.5kW. The low-voltage side is connected to the battery module through a DC circuit breaker. The nominal voltage is 48Vdc (supports 45V to 56V). The high-voltage side External connection, nominal voltage 375V.

The controller mainly realizes the functions of battery management, intelligent control and communication management. The controller collects the voltage of the single battery, the temperature of the battery module, the voltage of the low-voltage side of the DC/DC converter, the current of the low-voltage side of the DC/DC converter, and the temperature of the battery module. The high-voltage side voltage of the DC/DC converter, the high-voltage side current of the DC/DC converter, the isolation resonance side current of the DC/DC converter, and the temperature of the external connection quick-plug terminals of the smart battery module are collected. The controller calculates the battery status according to the collected information Judging by SOC, SOE, SOP and SOH, the controller collects information and commands from the host computer according to each part of the DC/DC converter, drives the switching devices in the DC/DC converter based on the internal control strategy, and charges and discharges the DC/DC converter. Take control.

As shown in Figure 1, the external connection of the intelligent battery power module includes the main circuit connection and the communication connection. The main circuit includes two terminals, DC+ and DC-, and the communication connection includes CAN and RS485, which are integrated on one communication terminal. Both main circuit terminals and communication terminals are in the form of screwless quick-plug terminals. A maintenance interface is reserved for the smart battery power module to support external maintenance of the battery modules in the smart battery power module as required.

As shown in Figure 2, the smart battery power module supports series-parallel combination. The output voltage of the smart battery power module is 375V. It can be connected to the 375V DC bus, or two smart battery power modules can be connected to the 750V DC bus in series, and the series can be connected to the 750V DC bus. The intelligent battery power module connected to the 750V DC bus can automatically realize voltage equalization control.

Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, and substitutions can be made in these embodiments without departing from the principle and spirit of the invention and modifications, the scope of the present invention is defined by the appended claims and their equivalents.

Claims (7)

1. An intelligent battery power module applied to a distributed energy storage system is characterized in that: it is a collection of lithium-ion battery modules, isolation conversion, battery management, protection and intelligence in one, and external performance is And the smart battery power module. 2. The intelligent battery power module according to claim 1, wherein the internal battery module adopts a lithium iron phosphate battery (which can be a retired battery of an electric vehicle), in the form of 1 parallel 16 series or multiple parallel 16 series, and the single Or the capacity of the single battery after parallel connection is 100~200Ah, and the capacity of the battery module is about 5kWh~10kWh. 3. The intelligent battery power module according to claim 1, wherein the internal protection includes devices such as fuses and DC circuit breakers, wherein the fuses are arranged between two 8-series cells, and the DC circuit breakers are arranged at Positive and negative poles of the battery module. 4. The intelligent battery power module according to claim 1, wherein the internal DC/DC converter hardware topology adopts a full-bridge isolation LLC topology, the nominal voltage of the battery module side is 48Vdc, and the nominal voltage of the external connection side is 375V, The rated power is 2.5kW, with functions such as soft start. 5. The intelligent battery power module according to claim 1, wherein the external connection includes DC+, DC- main circuit output terminals, CAN and RS485 communication terminals, all adopt a quick-plug design method, and reserve a maintenance interface, Supports maintenance of battery modules in smart battery power modules as required. 6. The intelligent battery power module according to claim 1, characterized in that: the internal auxiliary power supply adopts the form of low-voltage battery module and high-voltage bus to supply power together, and the controller integrates functions such as battery management, intelligent control and communication management, and collects each The voltage of each battery cell, the temperature of the battery module are collected, the temperature of the output terminal of the quick-plug main circuit is collected, the voltage and current of the DC/DC converter are collected, and the battery state estimation and DC/DC converter drive control are performed. 7 . The intelligent battery power module according to claim 5 , wherein: parallel 375Vdc operation and series 750Vdc operation are supported, and the automatic voltage equalization control function of the intelligent battery power module can be realized during the series operation. 8 .

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