TW201715817A - Apparatus of tandem-type energy storage - Google Patents

Abstract

An apparatus of tandem-type energy storage is provided. The apparatus comprises a plurality of accumulator converter serially connected with each other; a plurality of battery modules each separately connected with one of the accumulator converters; and an alternating-current (AC) power supply connected with at least two of the accumulator converters. Furthermore, each of the accumulator converters can connected with a control module. Thus, the battery module can be replaced during operation without interrupting power supply and affecting operation. According to the status of each battery module, an output right can be assigned to the battery module by the control module for equilibrium. Hence, the apparatus can store energy through a parallel connection with mains or an islanding operation.

Description

Tandem energy storage system

The invention relates to a series-type energy storage system, in particular to a battery module that can be replaced during operation of the system without interrupting the power supply and affecting the normal operation of the system, and can be transmitted according to the state of each battery module. The control module allocates the output weights of the respective battery modules to achieve a balance, thereby achieving the functions of the energy storage system such as the commercial parallel connection and the island operation.

In order to achieve sustainable energy use and solve the energy crisis, the research and application of renewable energy is a hot topic. The common wind power and solar energy are intermittent and unstable. The energy provided in the micro grid is often Discontinuous and unstable, it is necessary to effectively use the energy in the microgrid. In the microgrid system, in addition to renewable energy and load, the energy storage system plays an indispensable role. In addition to improving the power quality of the microsystem, it can also adjust the supply and demand balance of energy in the system. When the energy provided by renewable energy or other energy sources is greater than the load demand, the energy can be stored through the energy storage system; if the renewable energy is insufficient or the energy storage system is required to provide energy, the energy storage system discharges through the battery module to provide energy. . An abnormality in the energy storage system is often caused by an abnormality in the battery module. The battery may be damaged or the voltage of a battery module is too low, causing the battery module to enter a protection state and fail to supply a DC voltage, thereby enabling the energy storage system. It is not working properly, so the balance and stability of the battery module is a very important issue. Nowadays, the common battery module management system on the market mainly focuses on the balance between batteries. The stability is affected by the battery cells of each battery module. However, it is inevitable that the battery will reach its life limit. Occurs during the operation of the battery module. When the battery core fails, it is necessary to stop the operation of the battery module and perform the replacement and maintenance of the battery core. At this time, the energy storage system cannot operate. Therefore, this patent also studies this part, so that the energy storage system can overcome the inherent disadvantages of the battery module and achieve stability and balance in the use of the microgrid. In the past, the common battery module maintenance method was to balance the battery module during the charging process. For example, the Republic of China Patent No. I379486 - Battery Charge Control Device and Battery Balance Charge Controller, the circuit structure diagram is shown in Figure 1. Measure whether the voltage of the adjacent battery modules is different. When the difference is too large, the battery modules are balanced, so that the current of the battery module with a higher voltage flows into the battery module with a lower voltage. This battery module balancing method is the most common balancing method. It is mainly used for battery module balancing during charging, but its limitation can only be used for charging timing, and it cannot be used during battery module balancing. Another method of balancing the battery is to balance the battery module by replacing the parallel battery module. For example, the Republic of China Certificate No. I431896, when one of the battery modules determines that the voltage is too high or too low, the micro control unit is disengaged. And charging or discharging it separately. When the voltage of the battery module is the same as the system reference voltage, it is again incorporated into the battery system through the micro control unit, and the battery module with too high or too low voltage is adjusted. A method of maintaining a balanced and continuous operation of a battery module, but the method is such that the abnormal battery module is disconnected from the battery system for voltage balancing, and the overall battery system voltage is lowered. There is another balancing method for sharing battery modules between battery modules. For example, the Republic of China Patent No. I369381, through the circuit of the shared module and the functional module, is charged and discharged to balance the battery modules. The control method and battery architecture are too complicated, and it may still be difficult to reduce the cost and simplify its structure. Therefore, in order to improve the above-mentioned shortcomings, the inventor of the present invention has devoted himself to research and development of a "series-type energy storage system" to effectively improve the disadvantages of the conventional use.

The main purpose of the present invention is to enable the battery module to be replaced during system operation without interrupting the power supply and affecting the normal operation of the system, and each battery module can be distributed through the control module according to the state of each battery module. The output weights are balanced to achieve the functions of energy storage systems such as parallel power supply and island operation. For the above purposes, the present invention is a series-connected energy storage system, which comprises: a plurality of energy storage converters connected in series with each other; a plurality of battery modules respectively connected to the respective energy storage converters; and one and at least two AC power supply connected to the energy storage converter. In an embodiment of the invention, each of the energy storage converters is a direct current bidirectional converter. In an embodiment of the invention, each of the energy storage converters is further connected to a control module. In an embodiment of the invention, the control module includes a control command processor respectively connected to each energy storage converter, and a digital controller connected to each control command processor. In an embodiment of the invention, each of the battery modules is a lithium battery or a nickel hydrogen battery.

Please refer to FIG. 1 , which is a schematic diagram of the basic architecture of the first embodiment of the present invention. As shown in the figure, the present invention is a series-connected energy storage system 1 comprising at least a plurality of energy storage converters 11, a plurality of battery modules 12, and an AC power source 13. Each of the energy storage converters 11 mentioned above is connected in series with each other, and each of the energy storage converters 11 is a direct current alternating current bidirectional converter. Each of the battery modules 12 is connected to each of the energy storage converters 11, and each of the battery modules 12 is a lithium battery or a nickel-hydrogen battery, and each of the battery modules 2 divides the original high-voltage DC power supply into a plurality of lower voltages. DC power supply. The AC power source 13 is connected to at least two energy storage converters 11. If so, a new series-connected energy storage system is constructed by the above structure. When the series-connected energy storage system 1 of the present invention is in use, if the AC power source 13 charges each of the battery modules 12, each of the energy storage converters 11 converts the AC power into a DC power supply to each of the battery modules 12. Charging; conversely, if each battery module 12 provides DC power, each energy storage converter 11 converts the DC power into an AC power output AC power. For the present embodiment, the tandem energy storage system 1 is divided into a plurality of energy storage system modules a (including an energy storage converter 11 and a battery module 12), if the serial energy storage system 1 It is a 5kW energy storage system, and is divided into 10 small energy storage system modules a. Each battery module 12 is 48V, and then the DC power is converted into AC power through the energy storage system module a and combined with other energy storage system modules. The superposition is performed to output an AC voltage of 220V. When the battery module 12 is abnormal, the energy storage system module a is not output. At this time, an abnormal battery module is transmitted through a disconnecting device (not shown) such as a relay. 12 untie, the other energy storage system module a continuously superimposes and outputs 220V AC voltage, and repairs the battery module 12. After the repair is completed, the 220V AC voltage is superimposed and outputted by all the energy storage system modules a. In this way, the battery module 12 can be replaced without stopping the system during operation. Please refer to FIG. 2, which is a schematic diagram of the basic architecture of the second embodiment of the present invention. As shown in the figure, the series-type energy storage system 1 of the present invention may be the structural type of the second embodiment in addition to the configuration of the first embodiment described above, and the difference lies in Each of the energy storage converters 11 is further connected to a control module 14 , and the control module 14 includes a control command processor 141 respectively connected to each of the energy storage converters 11 , and a control command processor 141 . The digital controller 142 is connected; wherein the digital controller 142 is used as a control center of each energy storage converter 11, each battery module 12, and each control command processor 141, and each control command processor 141 is connected to The digital controller 142 issues a weighting process after issuing the command, and then issues a control command to each of the energy storage converters 11. In the second embodiment, if the voltage of the battery module 12 is high in the discharge mode, after the control command processor 141 detects the message, the control command processor 141 notifies the The energy storage converter 11 of the battery module 12 having a higher voltage increases the discharge power; otherwise, if it is in the charging mode, the energy storage converter 11 of the battery module 12 that reports the higher voltage lowers the output power, thereby balancing the batteries. The voltage between the modules 12. Please refer to the "Fig. 3" for a schematic view of the state of the present invention. As shown in the figure: the present invention can also be applied to the power system 2 for use. When the renewable energy source 21 is incorporated in the power system 2, the unstable and intermittent characteristics of the renewable energy source 21 can be transmitted through the series-connected energy storage system. 1 causing the power system 2 to store the energy provided by the renewable energy 21 for use by the power system 2, and in addition, when the power system 2 is abnormal, the series-type energy storage system 1 can immediately provide a stable voltage source, so that the power system 2 The upper load devices 22, 23 do not disengage. For example, through the series-connected energy storage system 1 in the power system with a voltage of 220V, the charge and discharge are adjusted for the power demand. When the series-type energy storage system 1 is connected to the parallel power supply 24, the renewable energy 21 or the redundant The power is stored in the battery module 12 through the charging mode. If the power system requires a higher power source, the series energy storage system 1 can be discharged into the power network by the battery module 12 to provide additional power demand, and When the utility power 24 is abnormal, the control module 14 of the serial energy storage system 1 detects the fault message, immediately notifies the disconnection from the utility power 24, and enters the island operation mode. At this time, the serial energy storage system 1 establishes a fault. The stabilized voltage source is provided for use by load devices 22, 23 within the power network. In summary, the series-connected energy storage system of the present invention can effectively improve various shortcomings of the conventional use, and can replace the battery module during system operation without interrupting the power supply and affecting the normal operation of the system, and can be based on each battery module. In the state of the group, the output weights of the respective battery modules are distributed through the control module to achieve a balance, thereby achieving the functions of the energy storage system such as the commercial parallel connection and the island operation; thereby making the invention more progressive and practical. More in line with the needs of consumers, it has indeed met the requirements of the invention patent application, and filed a patent application according to law. However, the above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto; therefore, the simple equivalent changes and modifications made in accordance with the scope of the present invention and the contents of the invention are modified. All should remain within the scope of the invention patent.

1‧‧‧Sequential energy storage system 11‧‧‧ Energy storage converter 12‧‧‧Battery module 13‧‧‧AC power supply 14‧‧‧Control module 141‧‧‧Control command processor 142‧‧‧ Digital controller 2‧‧‧Power system 21‧‧Renewable energy 22, 23‧‧‧ Load equipment 24‧‧‧Power
A‧‧‧ energy storage system module

Fig. 1 is a schematic diagram showing the basic structure of a first embodiment of the present invention. Fig. 2 is a schematic diagram showing the basic structure of a second embodiment of the present invention. Fig. 3 is a schematic view showing the state of use of the present invention.

1‧‧‧ tandem energy storage system

11‧‧‧ Energy storage converter

12‧‧‧ battery module

13‧‧‧AC power supply

A‧‧‧ energy storage system module

Claims (5)

A series-connected energy storage system includes: a plurality of energy storage converters, each of the energy storage converters being connected in series; a plurality of battery modules are respectively connected to the energy storage converters; and an AC power supply, at least two Energy storage converter connection. The tandem energy storage system according to claim 1, wherein each of the energy storage converters is a direct current bidirectional converter. The tandem energy storage system of claim 2, wherein each of the energy storage converters is further connected to a control module. The serial energy storage system according to claim 3, wherein the control module comprises a control command processor respectively connected to each energy storage converter, and a control command processor connected thereto. Digital controller. The tandem energy storage system according to claim 1, wherein each battery module is a lithium battery or a nickel hydrogen battery.