A battery energy storage system for microgrid

Abstract

The present invention discloses a battery energy storage system for a microgrid, comprising an isolation filter module, a power module, a charging execution module, an I / O port signal processing and driving module, a battery, a three-phase inverter, a filter, a transformer, a grid voltage acquisition module, a grid power acquisition module, a controller, a PWM drive module and a battery voltage acquisition module; the present invention can provide short-time power supply to meet the power shortage when the microgrid is operating in an isolated island.

Description

Technical Field

[0001] The present invention relates to the technical field of microgrid systems, and in particular to a battery energy storage system for a microgrid. Background Art

[0002] Microgrid refers to a small power generation and distribution system composed of distributed power sources, energy storage devices, energy conversion devices, related loads and monitoring and protection devices. The power sources in microgrids are mostly distributed power sources with smaller capacity, that is, small units with power electronic interfaces, including micro gas turbines, fuel cells, photovoltaic cells, small wind turbines, and energy storage devices such as supercapacitors, flywheels and batteries. They are connected to the user side and have the characteristics of low cost, low voltage and low pollution.

[0003] Due to the dual pressures of environmental protection and energy depletion, we are forced to vigorously develop clean renewable energy. The development potential and profit space of the efficient distributed energy industry (cogeneration) are huge. The requirements for improving power supply reliability and quality and the various constraints brought about by long-distance power transmission are driving the establishment of corresponding power sources close to the load center. The microgrid controller can realize centralized control of the entire power grid. There is no need for distributed local controllers, but only conventional measuring devices, and a fast communication channel is used between the measuring device and the local controller. The local controller of distributed power sources and loads is used to realize transient control of the microgrid, and the microgrid centralized energy management system realizes steady-state safety and economic operation analysis. The microgrid centralized energy management system uses a weak communication connection with the local controller.

[0004] A microgrid is an autonomous system that can achieve self-control, protection and management. As a complete power system, it relies on its own control and management to supply energy to achieve functions such as power balance control, system operation optimization, fault detection and protection, and power quality management.

[0005] Smart microgrid is a small-scale decentralized independent system. It is an autonomous system that can achieve self-control, protection and management. It can operate with the external power grid or in isolation. It is a small power generation and distribution system that integrates distributed power sources, energy storage devices, energy conversion devices, related loads and monitoring and protection devices.

[0006] In recent years, in order to make full use of renewable energy and solve the problem of effective access of distributed generation to the grid, my country has actively carried out research on microgrids and gradually promoted the construction of microgrid demonstration projects. The energy storage system is an important part of the microgrid. The optimal application of advanced energy storage technology in the microgrid is an important means to increase the access capacity of renewable clean energy in the microgrid, which has a positive significance for energy conservation and carbon reduction. At present, the research on advanced energy storage technology and the application of energy storage technology in microgrids in my country is still in its infancy, but it has received widespread attention and attention. In recent years, advanced energy storage technology has been demonstrated and applied in microgrid demonstration projects and achieved good results, with broad application prospects and market space. The key and difficulty of applying energy storage equipment in microgrids lies in the determination of energy storage capacity under different application scenarios. Microgrid voltage sag, voltage drop and other power quality problems, and the uncertainty and instability of distributed generation itself. Summary of the invention

[0007] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a battery energy storage system for a microgrid. The present invention can provide short-term power supply to meet the power shortage when the microgrid is operating in an isolated island.

[0008] The present invention adopts the following technical solutions to solve the above technical problems:

[0009] A battery energy storage system for a microgrid according to the present invention includes an isolation filter module, a power module, a charging execution module, an I / O port signal processing and drive module, a battery, a three-phase inverter, a filter, a transformer, a grid voltage acquisition module, a grid power acquisition module, a controller, a PWM drive module and a battery voltage acquisition module; wherein,

[0010] The isolation filter module, the power module, the charging execution module, the battery, the three-phase inverter, the filter, and the transformer are connected in sequence respectively; the I / O port signal processing and drive module, the battery voltage acquisition module, the PWM drive module, the grid voltage acquisition module, and the grid power acquisition module are connected to the controller respectively; the I / O port signal processing and drive module is connected to the charging execution module, the battery voltage acquisition module is connected to the battery, the PWM drive module is connected to the three-phase inverter, and the grid voltage acquisition module and the grid power acquisition module are connected to the transformer respectively;

[0011] The isolation filter module is used to supply power to the power module, the power module is used to charge the battery under the control of the charging execution module, the three-phase inverter bridge is used to convert the DC power emitted by the battery into three-phase AC power and then send it back to the power grid through the filter and transformer; the power grid voltage acquisition module is used to output the collected power grid voltage to the controller, the power grid power acquisition module is used to output the collected power grid power to the controller, the controller processes and outputs PWM signals to the PWM drive module according to the power grid voltage and power grid, and the PWM drive module is used to control the three-phase inverter according to the PWM signal; the battery voltage acquisition module is used to output the collected battery voltage to the controller, the controller is used to process the battery voltage and then issue control instructions to the I / O port signal processing and drive module; the I / O port signal processing and drive module is used to convert the control instructions into analog control signals and output them to the charging execution module; the charging execution module charges the battery according to the analog control signal.

[0012] As a further optimization solution for a battery energy storage system for a microgrid described in the present invention, the controller is a single-chip microcomputer.

[0013] As a further optimization solution for a battery energy storage system for a microgrid described in the present invention, the controller is a DSP controller.

[0014] As a further optimization solution of a battery energy storage system for a microgrid described in the present invention, the filter is an AC filter.

[0015] As a further optimization solution of a battery energy storage system for a microgrid described in the present invention, the model of the transformer is SZ9-40000 / 110.

[0016] Compared with the prior art, the present invention adopts the above technical solution and has the following technical effects:

[0017] (1) The present invention can provide short-term power supply to meet the power shortage when the microgrid is operating in an isolated island;

[0018] (2) Improving the power quality of the microgrid can solve power quality problems such as voltage sag and voltage drop, and improve stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the present invention. DETAILED DESCRIPTION

[0020] The technical solution of the present invention is further described in detail below in conjunction with the accompanying drawings:

[0021] like Figure 1As shown, a battery energy storage system for a microgrid includes an isolation filter module, a power module, a charging execution module, an I / O port signal processing and drive module, a battery, a three-phase inverter, a filter, a transformer, a grid voltage acquisition module, a grid power acquisition module, a controller, a PWM drive module and a battery voltage acquisition module; wherein,

[0022] The isolation filter module, the power module, the charging execution module, the battery, the three-phase inverter, the filter, and the transformer are connected in sequence respectively; the I / O port signal processing and drive module, the battery voltage acquisition module, the PWM drive module, the grid voltage acquisition module, and the grid power acquisition module are connected to the controller respectively; the I / O port signal processing and drive module is connected to the charging execution module, the battery voltage acquisition module is connected to the battery, the PWM drive module is connected to the three-phase inverter, and the grid voltage acquisition module and the grid power acquisition module are connected to the transformer respectively;

[0023] The isolation filter module is used to supply power to the power module, the power module is used to charge the battery under the control of the charging execution module, the three-phase inverter bridge is used to convert the DC power emitted by the battery into three-phase AC power and then send it back to the power grid through the filter and transformer; the power grid voltage acquisition module is used to output the collected power grid voltage to the controller, the power grid power acquisition module is used to output the collected power grid power to the controller, the controller processes and outputs PWM signals to the PWM drive module according to the power grid voltage and power grid, and the PWM drive module is used to control the three-phase inverter according to the PWM signal; the battery voltage acquisition module is used to output the collected battery voltage to the controller, the controller is used to process the battery voltage and then issue control instructions to the I / O port signal processing and drive module; the I / O port signal processing and drive module is used to convert the control instructions into analog control signals and output them to the charging execution module; the charging execution module charges the battery according to the analog control signal.

[0024] The controller is a single chip microcomputer. The controller is a DSP controller. The filter is an AC filter. The model of the transformer is SZ9-40000 / 110.

[0025] The present invention can provide short-time power supply to meet the power shortage when the microgrid is operating in an isolated island; improve the power quality of the microgrid, solve power quality problems such as voltage sag and voltage drop, and improve stability.

[0026] The above contents are further detailed descriptions of the present invention in combination with specific preferred embodiments, and it cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.

Claims

1. A battery energy storage system for a microgrid, characterized in that: It includes an isolation filter module, a power module, a charging execution module, an I / O port signal processing and drive module, a battery, a three-phase inverter, a filter, a transformer, a grid voltage acquisition module, a grid power acquisition module, a controller, a PWM drive module and a battery voltage acquisition module; wherein, The isolation filter module, the power module, the charging execution module, the battery, the three-phase inverter, the filter, and the transformer are connected in sequence respectively; the I / O port signal processing and drive module, the battery voltage acquisition module, the PWM drive module, the grid voltage acquisition module, and the grid power acquisition module are connected to the controller respectively; the I / O port signal processing and drive module is connected to the charging execution module, the battery voltage acquisition module is connected to the battery, the PWM drive module is connected to the three-phase inverter, and the grid voltage acquisition module and the grid power acquisition module are connected to the transformer respectively; The isolation filter module is used to supply power to the power module, the power module is used to charge the battery under the control of the charging execution module, the three-phase inverter bridge is used to convert the DC power emitted by the battery into three-phase AC power and then send it back to the power grid through the filter and transformer; the power grid voltage acquisition module is used to output the collected power grid voltage to the controller, the power grid power acquisition module is used to output the collected power grid power to the controller, the controller processes and outputs PWM signals to the PWM drive module according to the power grid voltage and power grid, and the PWM drive module is used to control the three-phase inverter according to the PWM signal; the battery voltage acquisition module is used to output the collected battery voltage to the controller, the controller is used to process the battery voltage and then issue control instructions to the I / O port signal processing and drive module; the I / O port signal processing and drive module is used to convert the control instructions into analog control signals and output them to the charging execution module; the charging execution module charges the battery according to the analog control signal.

2. A battery energy storage system for a microgrid according to claim 1, characterized in that: The controller is a single chip microcomputer.

3. A battery energy storage system for a microgrid according to claim 1, characterized in that: The controller is a DSP controller.

4. A battery energy storage system for a microgrid according to claim 1, characterized in that: The filter is an AC filter.

5. A battery energy storage system for a microgrid according to claim 1, characterized in that: The model of the transformer is SZ9-40000 / 110.

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