Energy storage converter

Abstract

The present invention discloses an energy storage converter, including a control module, a power conversion module, an AC power distribution module and a DC power distribution module; the DC power distribution module is connected to a series battery pack; the power conversion module, the AC power distribution module and the DC power distribution module are connected in sequence, and the AC power distribution module is connected to an AC power grid; the control module includes a DSP unit, an ARM unit and an FPGA unit connected in sequence; the ARM unit communicates with the DSP unit in real time; the ARM unit has a BMU communication port; the ARM unit communicates with the EMS; the DSP unit is connected to the AC power distribution module and the DC power distribution module; the FPGA unit is connected to the power conversion module. The present invention improves the power density of the energy storage system, reduces the complexity of the system and the hardware cost of the system; the internal / external high-speed communication is adopted at the 100-megabit level, which can realize microsecond-level fault alarm and protection, meet the real-time requirements of the host computer data, and have the ability of millisecond-level power scheduling response.

Description

Technical Field

[0001] The invention relates to the technical field of electrochemical energy storage, and in particular to an energy storage converter. Background Art

[0002] With the continuous development of electrochemical energy storage technology, industrial and commercial energy storage, power station-level energy storage and related communication technologies, on the one hand, it is necessary to reduce the cost of energy storage systems and obtain a higher return on investment; on the other hand, it is necessary to increase the data transmission rate, conduct big data analysis, and quickly respond to superior dispatching instructions. Limited by the scale of enterprises and R&D costs, the energy storage converter (PCS) currently used in industrial and commercial and power station levels only has power conversion functions. The battery management system (BMS) and high-voltage AC / DC distribution equipment are independent of the PCS external, and many devices including circuit breakers, contactors, voltage / current sensors, etc. are reused, which increases the hardware cost of the system; in order to ensure the compatibility of communication between equipment from different manufacturers, the communication between energy storage system equipment such as energy management system (EMS), energy storage converter (PCS), battery management system (BMS), battery management unit (BMU) is mostly realized by traditional CAN, RS-485 and other methods, using J1939, Modbus-RTU and other protocols. This data interaction method seriously restricts the improvement of the data transmission rate and control speed of the entire system.

[0003] In order to solve the above problems, it is necessary to optimize energy storage system equipment such as EMS, PCS, BMS, BMU, etc., reduce the number of redundant devices / equipment, and increase the communication rate of equipment. Summary of the invention

[0004] In view of the above-mentioned background technology, the present invention provides an energy storage inverter, which has a built-in battery management system (BMS) and a high-voltage AC / DC power distribution functional module, constructs an energy storage system with the energy storage inverter as the core, improves the overall power density of the energy storage system, reduces the number of discrete devices and hardware costs of the system; adopts 100-megabit high-speed communication to improve the response speed of fault alarm / protection, meets the real-time requirements of background data, and has the ability of millisecond-level scheduling response.

[0005] To achieve the above object, the present invention adopts the following technical solutions:

[0006] An energy storage converter comprises a control module, a power conversion module, an AC power distribution module and a DC power distribution module; the DC power distribution module is connected to a battery pack connected in series; the power conversion module, the AC power distribution module and the DC power distribution module are connected in sequence, and the AC power distribution module is connected to an AC power grid;

[0007] The control module includes a DSP unit, an ARM unit and an FPGA unit connected in sequence;

[0008] The ARM unit communicates with the DSP unit in real time to obtain the DC battery side current data and calculate SOC / SOH; the ARM unit has a BMU communication port to obtain the cell data of each BMU and control it; the ARM unit communicates with the EMS to upload the PCS and BMU data to the EMS and obtain configuration information;

[0009] The DSP unit is connected to the AC power distribution module and the DC power distribution module to obtain battery status information and adjust the charging and discharging mode and current and grid connection control in real time;

[0010] The FPGA unit is connected to the power conversion module and is used to generate a PWM switch signal to control power conversion.

[0011] As a further improvement of the present invention, the power conversion module has a power device, and the PWM switching signal generated by the FPGA unit controls the opening and closing of the power device, performs power conversion between the DC battery side and the AC grid side, and controls the charging and discharging of the series energy storage lithium battery group.

[0012] As a further improvement of the present invention, the AC power distribution module has a power distribution device; the DC power distribution module has a power distribution device.

[0013] The DC power distribution module and the AC power distribution module are connected to the DSP unit for power distribution control, and the voltage and current signals are sent to the DSP unit for grid-connected control.

[0014] As a further improvement of the present invention, the ARM unit communicates with the fire-fighting equipment to obtain the fire-fighting equipment sensor signal and perform fire control; the communication adopts RS-485 bus.

[0015] As a further improvement of the present invention, the FPGA unit has an optical fiber port for parallel connection; the FPGA unit has a hardware fault signal receiving port; and the DSP unit has a software fault signal receiving port.

[0016] As a further improvement of the present invention, the DSP unit, ARM unit and FPGA unit are integrated with the MCU into one chip, or the DSP unit, ARM unit and FPGA unit are respectively independent chips.

[0017] As a further improvement of the present invention, the DSP and ARM units are integrated chips, and the communication adopts an IPC mechanism combined with a shared memory method, and the data exchange rate is 200 Mbit / s.

[0018] As a further improvement of the present invention, the energy storage converter is installed in an outdoor cabinet or container.

[0019] As a further improvement of the present invention, the ARM unit and the BMU adopt a CAN bus form, and the CAN-FD communication rate is 8 Mbit / s.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The energy storage converter of the present invention has an ARM unit to realize the BMS function, and a DSP+FPGA chip to realize the energy storage converter + AC / DC power distribution function, which optimizes the organizational structure of the traditional industrial and commercial / power station energy storage system composed of an energy management system (EMS), an energy storage converter (PCS), a battery management system (BMS), a battery management unit (BMU), and a high-voltage AC / DC power distribution system, integrates the PCS, BMS, and a high-voltage AC / DC power distribution system, simplifies the energy storage system structure, reduces the repeated configuration of AC / DC power distribution equipment, and reduces the complexity of the system and the hardware cost. The communication mode between energy storage system devices is improved, and the data communication and dispatching communication between the PCS and the EMS adopt an independent bus with a speed of 100 megabits, and the communication between the PCS and the BMU adopts an industrial field bus with a speed of megabits. The speed of fault alarm / protection, data transmission between devices, data upload, and the ability of the power station-level system to quickly respond to dispatching instructions are improved, and the accuracy of battery charging and discharging / life management is improved, which has obvious advantages in extending battery life and improving battery utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0023] Figure 1 It is a topological diagram of a traditional commercial / power station-level energy storage system;

[0024] Figure 2 is a topological diagram of the energy storage system of the present invention;

[0025] Figure 3 This is a detailed architecture diagram of the energy storage converter. DETAILED DESCRIPTION

[0026] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] like Figure 2 and 3 As shown, an energy storage converter of the present invention comprises a control module, a power conversion module, an AC power distribution module and a DC power distribution module; the DC power distribution module is connected to a battery pack in series; the power conversion module, the AC power distribution module and the DC power distribution module are connected in sequence, and the AC power distribution module is connected to an AC power grid;

[0028] The control module includes a DSP unit, an ARM unit and an FPGA unit connected in sequence;

[0029] The ARM unit communicates with the DSP unit in real time to obtain the DC battery side current data and calculate SOC / SOH; the ARM unit has a BMU communication port to obtain the cell data of each BMU and control it; the ARM unit communicates with the EMS to upload the PCS and BMU data to the EMS and obtain configuration information;

[0030] The DSP unit is connected to the AC power distribution module and the DC power distribution module to obtain battery status information and adjust the charging and discharging mode and current and grid connection control in real time;

[0031] The FPGA unit is connected to the power conversion module and is used to generate a PWM switch signal to control power conversion.

[0032] The power storage converter (PCS) has the functions of battery management (BMS) and high-voltage AC / DC power distribution. It uses a 100M data interactive bus to achieve high-speed communication. It is mainly composed of a control module, a power conversion module, an AC power distribution module, and a DC power distribution module.

[0033] The control module consists of several processor chips and corresponding peripheral devices, including all the functions of the traditional PCS controller, grid-connected power conversion control algorithm, PWM wave power device control, fault handling and protection, parallel control, etc.; it also includes all the functions of BMS, including battery charging and discharging / life management, SOC / SOH / battery internal resistance calculation, BMU communication, fire equipment communication, EMS data communication / dispatching communication, etc.

[0034] The power conversion module is composed of IGBT power devices, capacitors, inductors and other power devices. The PWM switching signal generated by the control module controls the opening and closing of the IGBT power devices to perform power conversion between the DC battery side and the AC grid side, that is, to control the charging and discharging of the series energy storage lithium battery pack.

[0035] The AC power distribution module is composed of distribution devices such as circuit breakers, contactors, voltage / current sensors, and lightning arresters. The DSP unit is responsible for AC power distribution control, replacing the external high-voltage AC power distribution system.

[0036] The DC power distribution module is composed of circuit breakers, contactors, voltage / current sensors, fuses, leakage current sensors and other devices. The DSP unit is responsible for DC power distribution control, replacing the external high-voltage DC power distribution system.

[0037] The main communication functions of the energy storage converter include chip-level communication within the control module, parallel communication of multiple energy storage converters, communication with EMS, BMU, and fire / sensor equipment.

[0038] Among them, the battery management BMS module has the functions of lithium battery pack charging and discharging / life management, SOC / SOH / battery internal resistance calculation, energy management system (EMS) data communication / dispatching communication, battery management unit (BMU) communication, and cabinet fire equipment communication; the high-voltage AC / DC power distribution function is realized through the PCS built-in contactors, circuit breakers, fuses and other devices in conjunction with software logic.

[0039] The BMS module built into the PCS has functions including but not limited to lithium battery pack charge and discharge / life management, SOC / SOH / battery internal resistance calculation, BMU communication, fire equipment communication, EMS data communication / dispatch communication and other basic functions that a battery management system should have.

[0040] The data communication and scheduling communication between BMS and EMS, depending on the application scenarios, include but are not limited to using two buses to increase the communication rate or sharing one bus to reduce product costs.

[0041] PCS has built-in high-voltage AC / DC power distribution function. Distribution equipment such as contactors, circuit breakers, and fuses can also be realized by leading out contactor control nodes through PCS and placing distribution equipment externally.

[0042] The control system adopts a three-core architecture of DSP+ARM+FPGA, including but not limited to MCU, DSP, ARM, and FPGA cores integrated into one chip, or DSP, ARM, and FPGA using independent chips.

[0043] Energy storage inverters include but are not limited to outdoor cabinets and container installation forms. The DC battery side uses lithium battery cells in series. The typical total DC voltage is DC950V~1500V. The application scenarios are industrial and commercial energy storage and power station-level energy storage.

[0044] The present invention is described in detail below with reference to specific embodiments.

[0045] Example

[0046] according to Figure 1As shown in the figure, in traditional industrial and commercial / power station-level energy storage systems, PCS and BMS use two independent sets of equipment, which are managed and dispatched by EMS respectively; high-voltage AC distribution devices / DC distribution devices are independently configured outside PCS; considering the compatibility of communication between equipment from different manufacturers, traditional low-speed communication methods are adopted.

[0047] according to Figure 2 As shown, the energy storage converter of the present invention modularizes the functions of BMS, AC power distribution device, and DC power distribution device into PCS, and optimizes the communication mode and communication rate with EMS and BMU.

[0048] according to Figure 3 As shown, the energy storage converter proposed by the present invention has a control module using an ARM+DSP+FPGA three-core chip architecture, the ARM chip implements the BMS function, and the DSP+FPGA chip implements the energy storage converter + AC / DC power distribution function. A typical embodiment uses a DSP and ARM unit integrated chip, and the communication adopts an IPC mechanism combined with a shared memory method, and the data exchange rate is 200Mbit / s. The communication between the DSP and the FPGA chip adopts a high-speed serial interface (FSI) communication method, and the communication rate can also reach 200Mbit / s.

[0049] Through high-speed real-time communication between the ARM unit and the DSP unit, the DC battery side current data is obtained, which greatly improves the accuracy of SOC / SOH calculation; the DSP unit obtains battery power, temperature and other status information through high-speed communication, adjusts the charging and discharging mode and current in real time, efficiently utilizes the battery power, and extends the battery life.

[0050] The main function of the communication between the ARM unit and the BMU is to obtain a large amount of data such as voltage, temperature, internal resistance, etc. of hundreds of battery cells of each BMU, and to realize control functions such as active balancing and fan speed regulation. Considering reliability and actual application, an upgraded form based on the CAN bus is used, CAN-FD communication, with a data communication rate of 8Mbit / s.

[0051] The ARM unit communicates with the fire fighting equipment to obtain the fire fighting equipment sensor signals and realize fire fighting control. Considering compatibility and reliability, the RS-485 bus is adopted to be compatible with fire fighting equipment from different manufacturers.

[0052] The data communication between the ARM unit and the EMS is used to upload the data of the PCS and BMU to the EMS, and to obtain configuration information, etc. Considering the requirements of high speed and reliability, industrial Ethernet is used for data transmission with a communication rate of 100Mbit / s.

[0053] The dispatch communication between the ARM unit and the EMS has the main function of quickly responding to the power dispatch instructions from the superior to achieve millisecond-level power station dispatch requirements. To meet this feature, Ethernet control automation technology (EtherCAT) or fiber optic technology (FPC) can be used for dispatch communication, with a communication rate of 100Mbit / s.

[0054] The power distribution control of the DC power distribution module and the AC power distribution module is realized by the DSP unit. At the same time, the voltage and current sensors in the module send the voltage and current signals to the DSP unit to realize the grid-connected control of the energy storage converter.

[0055] The IGBT switching device in the power conversion module is controlled by the PWM switching signal generated by the FPGA unit to achieve power conversion.

[0056] The FPGA unit uses optical fiber as the transmission medium to achieve the PCS high-speed parallel function.

[0057] The FPGA unit receives hardware fault signals to implement fast hardware fault protection; the DSP unit receives software fault signals to implement software fault analysis and protection.

[0058] The DC power distribution module is connected to the lithium battery pack in series, with a voltage range of DC950V to 1500V.

[0059] The AC power distribution module is connected to the AC power grid, and the voltage level is AC800V.

[0060] In summary, the energy storage inverter of the present invention has a built-in battery management system function, and has the functions of charging and discharging / life management of hundreds of lithium battery cells connected in series, SOC / SOH / battery internal resistance calculation, battery management unit (BMU) communication, cabinet fire equipment communication, energy management system (EMS) data communication / dispatching communication, etc.; the energy storage inverter has a built-in high-voltage AC / DC power distribution function, and there is no need to additionally configure high-voltage AC / DC circuit breakers / contactors and voltage and current sensors outside the energy storage inverter; the data interaction between the core chips of the energy storage inverter controller reaches a communication rate of hundreds of megabits, and the data communication and dispatching communication between the energy storage inverter and the energy management system use two independent communication buses, and the communication rate reaches hundreds of megabits.

[0061] Compared with the traditional energy storage system with high cost and low efficiency of each device operating independently, the present invention improves the power density of the energy storage system and reduces the complexity and hardware cost of the system by integrating the battery management system and high-voltage AC / DC power distribution function into the energy storage inverter; both internal and external high-speed communications are adopted at the 100-megabit level, which can realize microsecond-level fault alarm and protection, meet the real-time requirements of the host computer data, and have the ability of millisecond-level power scheduling response.

[0062] All articles and references disclosed above, including patent applications and publications, are incorporated herein by reference for all purposes. The term "consisting essentially of..." describing a combination should include the identified elements, ingredients, parts or steps and other elements, ingredients, parts or steps that do not substantially affect the basic novel features of the combination. The use of the terms "comprising" or "including" to describe the combination of elements, ingredients, parts or steps herein also contemplates embodiments that are essentially composed of these elements, ingredients, parts or steps. By using the term "may", it is intended to illustrate that any attribute described that "may" include is optional.

[0063] Multiple elements, ingredients, parts or steps can be provided by a single integrated element, ingredient, part or step. Alternatively, a single integrated element, ingredient, part or step can be divided into separate multiple elements, ingredients, parts or steps. The disclosure "one" or "an" used to describe an element, ingredient, part or step is not intended to exclude other elements, ingredients, parts or steps.

[0064] It should be understood that the above description is for illustration and not for limitation. Many embodiments and many applications beyond the examples provided will be apparent to those skilled in the art upon reading the above description. Therefore, the scope of the present teachings should not be determined with reference to the above description, but rather with reference to the foregoing claims and the full scope of equivalents to which such claims are entitled. For the purpose of comprehensiveness, all articles and references, including disclosures of patent applications and publications, are incorporated herein by reference. The omission of any aspect of the subject matter disclosed herein in the foregoing claims is not intended to be a waiver of such subject matter, nor should it be considered that the applicant has not considered such subject matter to be part of the disclosed inventive subject matter.

Claims

1. An energy storage converter, characterized in that: It includes a control module, a power conversion module, an AC power distribution module and a DC power distribution module; the DC power distribution module is connected to a battery pack in series; the power conversion module, the AC power distribution module and the DC power distribution module are connected in sequence, and the AC power distribution module is connected to the AC power grid; The control module includes a DSP unit, an ARM unit and an FPGA unit connected in sequence; The ARM unit communicates with the DSP unit in real time to obtain the DC battery side current data and calculate SOC / SOH; the ARM unit has a BMU communication port to obtain the cell data of each BMU and control it; the ARM unit communicates with the EMS to upload the PCS and BMU data to the EMS and obtain configuration information; The DSP unit is connected to the AC power distribution module and the DC power distribution module to obtain battery status information and adjust the charging and discharging mode and current and grid connection control in real time; The FPGA unit is connected to the power conversion module and is used to generate a PWM switch signal to control power conversion; The power conversion module has a power device, and the PWM switch signal generated by the FPGA unit controls the opening and closing of the power device, performs power conversion between the DC battery side and the AC grid side, and controls the charging and discharging of the series energy storage lithium battery pack; The AC power distribution module has a power distribution device; the DC power distribution module has a power distribution device; The DC power distribution module and the AC power distribution module are connected to the DSP unit for power distribution control, and the voltage and current signals are sent to the DSP unit for grid-connected control.

2. The energy storage converter according to claim 1, characterized in that: The ARM unit communicates with the fire-fighting equipment to obtain the fire-fighting equipment sensor signal and perform fire control; the communication adopts RS-485 bus.

3. The energy storage converter according to claim 1, characterized in that: The FPGA unit has an optical fiber port for parallel connection; the FPGA unit has a hardware fault signal receiving port; and the DSP unit has a software fault signal receiving port.

4. The energy storage converter according to claim 1, characterized in that: The DSP unit, ARM unit and FPGA unit are integrated with the MCU in one chip, or the DSP unit, ARM unit and FPGA unit are respectively independent chips.

5. The energy storage converter according to claim 4, characterized in that: The DSP and ARM units are integrated chips, and the communication adopts an IPC mechanism combined with a shared memory method, and the data exchange rate is 200Mbit / s.

6. The energy storage converter according to claim 1, characterized in that: The energy storage converter is installed in an outdoor cabinet or container.

7. The energy storage converter according to claim 1, characterized in that: The ARM unit and the BMU adopt the CAN bus form, and the CAN-FD communication rate is 8Mbit / s.

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