Control method for energy storage battery system in microgrid

　　Author ：Iflowpower – Portable Power Station Supplier

Abstract: The present invention supplies a control method of the energy storage battery system in a microgrid, including steps: 1) establishing a microgrid system, configuring an energy storage battery and a control parameter for load connection through a contact; 2) Measuring the energy storage battery The charged electricity SOC, and calculates the power difference between the load active power and the intermittent power supply. 3) If the power difference between the load active power and the maximum power generation of the intermittent power supply is greater than zero, The battery is operated in the discharge mode; if the power difference between the load active power and the maximum power generation of the intermittent power supply is less than zero, the energy storage battery operates in the charging mode, and selects the charging of the energy storage battery according to the storage battery charge power SOC. Stage; 4) Select the control mode of intermittent power supply based on the control mode in the storing battery charging state.

This method can effectively extend the charging life of the energy storage battery, improve the intermittent energy utilization and stability of charging of the battery. The inventors: Peng Yong Duan Wenhui Wang Peng Jiang Zu Ming Wei Hui Yong Huang Menglan Yan Hui 1. Control Method of Incoming Cell Battery System in Microgrid, including steps: 1) Establish a microgrid system, configure storage battery and pass contact Control parameters of the connection; 2) Measure the load electrical capacity SOC of the energy storage battery and calculate the power difference between the load active power and the intermittent power supply.

3), if the load has power power and the intermittent power supply maximum power generation The power difference between the active power is greater than zero, and the energy storage battery works in the discharge mode; if the power difference between the load has a power power and the maximum power generation power of the intermittent power supply, the energy storage battery works in the charging mode, and according to The energy storage battery charge power SOC selects the charging phase of the energy storage battery; 4) Select the control mode of the intermittent power source according to the control mode in the storing battery. The control method of the energy storage battery system in the microgrid according to claim 1, characterized in that the control parameters of the energy storage battery and the load connection through the contact line include a load of the load into important load and controlled load. , Load active power is the power of important load and controlled load.

The control method of the energy storage battery system in the microgrid according to claim 2, characterized in that the storage battery operates in the discharge mode, and when the charged battery of the battery is used, the controlled load is removed. Only for important load, SOCMIN is 0.5-0.

6. The control method of the energy storage battery system in the microgrid according to claim 3, characterized in that the charging phase of the energy storage battery is selected based on the storage battery charge power SOC, including the charging phase of the energy storage battery. The constant current fast charging phase, constant voltage charging phase and floating charging stage; when the SOCMIN

6-0.7, the SOC2 is 0.7-0.

9, and the value of SOC3 is 0.9-1. The control method of the energy storage battery system in the microgrid according to claim 4, characterized in that the charging stage of the energy storage battery also includes a battery depolarization phase, using a method of penetrating on time, in one day A certain solid press time is balanced to the energy storage battery to eliminate the voltage and capacity of the energy storage battery unit.

The control method of the energy storage battery system in the microgrid according to any one of claims 1 to 5, characterized in that the intermittent power supply works in maximum power tracking MPPT mode when the storage battery operates in the discharge mode; When the storage battery works in the charging mode, the intermittent power supply works in maximum power tracking MPPT mode or constant power control mode. The control method of the energy storage battery system in the microgrid according to claim 6, characterized in that when the energy storage battery is operated in the charging mode, the power difference is less than the charging power required to the energy storage battery, intermittent Sexual power supply works in maximum power tracking MPPT mode; when the storage battery is operating in the charging mode, the power difference is greater than the charge power required to the energy storage battery, the intermittent power supply works in the constant power control mode. TECHNICAL FIELD The present invention relates to the field of micro-grids, and in particular, to a control method of energy storage battery systems.

BACKGROUND OF THE INVENTION Plenty of development and use of renewable energy is an inevitable trend of future grids, but most renewable energy sources cannot be in timely and incorporated into the grid due to geographical dispersion, large fluctuation and high power quality. In recent years, it has been found that establishing a micro-grid is one of the effective ways to solve these distributed energy access grids. The microgrid is a system that is co-constructed by power and load, supply electrical energy and heat for users.

The microgrid has two working modes. Under normal circumstances, the grid connection is implemented in grid network, and when the power network fault or power fluctuation is too large, it is discharged from the grid. Under the island, due to the fluctuations, randomness, miniature gas turbines and fuel power lithium batteries of renewable energy output, fast load fluctuations will bring great problems to the microgrid.

Equipped with a capacity energy storage device can increase system inertia, improve system dynamic response speed, improve power quality, and ensure security and stable operation of the system. In order to solve the problem of large fluctuations in renewable energy, the distributed energy is adequately utilized, and the corresponding energy storage system is included in the microgrid. Battle capacity, such as common lead-acid batteries, lithium-ion batteries, etc.

, have the advantages of high energy density, stable performance, long life, large-scale production and application, and wide application in microgrid systems. In the field of traditional battery applications, such as electric vehicles charging, the discharge power of the battery is randomly changed, but its charging process is very stable to ensure a longer service life. Because the stability of the large grid, the battery is fully charged, constant voltage charging, and floating charging mode.

However, in the microgrid, the intermittent power supply cannot supply a stable energy source, and the energy battery is supplied, and its own charging power is randomly changed with the power generation power of the intermittent power source, and thus the control method of the battery cell. And the control method of the microgrid should be coordinated, reasonable cooperation. Nowadays, intermittent renewable energy is working in MPPT working mode, and the charging current and voltage of the energy storage battery are irrelevant, which seriously affects the service life of the energy storage battery.

In order to solve the problems of the above, people have been seeking an ideal technical solution. SUMMARY OF THE INVENTION It is an object of the present invention to provide a control method of energy storage battery systems in a micro-grid design of the design science, strong design science, strong design science, strong design, high stability, high stability and high utilization rate. In order to achieve the above object, the technical method used in the present invention is to control the control method of the energy storage battery system in a microgrid, including steps: 1) establishing a microgrid system, configuring the energy storage battery and the load of the load connection through the contact Parameters; 2) Measure the load electrical capacity SOC of the energy storage battery and calculate the power difference between the load active power and the maximum power generation of the intermittent power supply; 3) If the load has power and the maximum power generation of the intermittent power supply The power difference is greater than zero, then the energy storage battery is operated in the discharge mode; if the power difference between the load active power and the intermittent power supply is less than zero, the energy storage battery works in the charging mode, and according to the storage battery charge The battery SOC selects the charging phase of the energy storage battery; 4) Select the control mode of the intermittent power source according to the control mode in the storing battery.

Based on the above, the control parameters of the energy storage battery and the load connected through the contact line include the power of the load and the power power of the load and the power of the load and the controlled load. Based on the above, the storage battery operates in the discharge mode, and the power-to-load power SOC of the energy storage battery is only for important load, where SOCMIN is 0.5-0.

6. Based on the above, the charging stage of the energy storage battery is selected according to the energy storage battery charge, including the charging phase of the energy storage battery into a constant current fast charging phase, a constant voltage charging phase, and a floating charging stage; when SOCMIN

6 -0.7, the SOC2 is 0.7-0.

9, and the SOC3 is 0.9-1. Based on the above, the charging stage of the energy storage battery also includes a battery depolarization phase, using a method of penetrating on time, a certain flexible press time in one day, balance the energy storage battery to eliminate the energy storage battery.

Unbalanced phenomenon of voltage and capacity between body. Based on the above, when the storage battery operates in the discharge mode, the intermittent power supply works in maximum power tracking MPPT mode; when the storage battery works in the charging mode, the intermittent power supply works in maximum power tracking MPPT mode or constant power control mode. Based on the above, the intermittent power supply operates in the maximum power tracking MPPT mode when the storage battery is operated in the charging mode, and the power difference is smaller than the charge power required to the energy storage battery; when the battery is operated in the charging mode, the When the power difference is greater than the charging power required to the energy storage battery, the intermittent power supply works in the constant power control mode.

The present invention relates to the prior art having a prominent substantive characteristic and a significant progress, and in particular, the present invention will store the energy storage mode and the microgrid control mode by reasonable design of the inverter capacity, the contact line power, and the load active power. In cooperation, the constant current, constant pressure, floating charging control of the battery in the microgrid is achieved, ensuring precise control of battery charging, extending the battery life, improves stability within the microgrid, which has a design Science, strong practicality, good cooperation, high stability, high utilization rate. BRIEF DESCRIPTION OF DRAWINGS FIG.

1 is a schematic structural diagram of the present invention. 2 is a schematic diagram of the power transmission and control structure of the present invention. Fig.

3 is a schematic structural diagram of the semi-finished product of the present invention. The specific implementation method will further describe the technical method of the present invention in a specific implementation manner. The purpose of microgrid control is to increase the utilization of renewable energy to ensure the stability of the power grid, and ensure that the micro-grid is coordinated with the traditional distribution network, which can use the renewable energy of the distributed power supply, but also within the power grid.

The load supply reliable electricity, even in the case of a traditional large grid, there is still a reliable supply between multiple micro-grids, and the internal network is still reliable, and the necessary conditions for the startup supply of large grids. A typical micro-grid population structure is shown in Figure 1. However, the internal components of the microgrid are numerous, and common distributed power supplies such as wind power, photovoltaic power generation, micro gas power generation, etc.

, their characteristics and operational methods are different, and the control methods and grid structures are varied. For example, the type of microgrid includes DC bus mode, AC bus mode, centralized control mode, dispersion control mode, typical microgrid internal control structure as shown in Figure 2. Between the microgrid and other power grids, and between the microgrid and other micro-grids, it is often connected by a contact line, and between them is a weak coupled relationship, often through the control of the open and closing line of the contact line.

Support each other. The core of the microgrid control is the control of the energy storage system. The energy storage system is a reliable frequency and voltage support for the grid.

It can flexibly adjust the power balance according to the condition of the system, improve stability and economic benefits. However, the control mode of the energy storage battery itself is also affected and restricted by its own performance, and this patent application provides a method of controlling the energy storage battery system in a microgrid, including steps: 1) establish a microgrid system, configuring energy storage batteries and Control parameters of load connection by the contact line; 2) Measure the load capacity SOC of the energy storage battery, and calculate the power difference between the load active power and the intermittent power supply, the maximum power generation active power is calculated; 3) If the load has power and intermittent The power difference between the power supply maximum power generation is greater than zero, then the energy storage battery works in the discharge mode; if the power difference between the load active power and the maximum power generation of the intermittent power supply is less than zero, the energy storage battery works in the charging mode. And according to the storage battery charge power SOC, the charging phase of the energy storage battery is selected; 4) Select the control mode of the intermittent power supply according to the control mode in the state of the storage battery.

Specifically, configure the control parameters of the battery and the load connected through the contact line, including the power of the load and the power of the load and the power of the load and the controllable load. When the power difference is greater than zero, the energy storage battery operates in the discharge mode, and when the battery capacity SOC

6 When the power difference between the load active power and the intermittent power supply, the power difference between power generation is less than zero, the energy storage battery works in the charging mode. During the charging battery charging, the no-load voltage of the energy storage battery is not easy to measure, and the internal resistance of the energy storage battery is also easy to vary, and it is different from the conventional method to determine the battery charging stage according to the charging voltage, and the energy storage battery charge. The power SOC can be relatively easy to measure by the power integration method, and the general energy storage battery voltage has a relatively stable corresponding relationship with the energy storage battery charge amount SOC.

Therefore, the charging stage can be reasonably divided according to the storage battery charge amount SOC. Depending on the storage battery charge power SOC, the charging stage of the energy storage battery is selected, including the charging phase of the energy storage battery into a constant current fast charging phase, a constant voltage charging phase, and a floating charging stage, when the SOCMIN

6-0.7, The value of SOC2 is 0.7-0.

9, and the value of SOC3 is 0.9-1. In practice, the charging stage of the energy storage battery also includes the energy storage battery to the polarization stage, that is, the balanced charging stage.

The method of multi-polarization is used to balance the energy storage battery in a certain fixed press time in one day to eliminate the voltage and capacity of the energy storage battery unit. The imbalance between the storage battery monomer is serious as the use time is severe, the imbalance between the monomers affects the charge and discharge depth and measurement accuracy of the battery cell, and the larger voltage is in a certain period of time. Balanced the battery will reduce the imbalance between the energy storage battery monomers, prevent the energy storage battery polarization, and 1.

3 times the energy storage battery is used as the energy storage battery equilibrium charging voltage in this execution. In the mode of equalization charging, it is still possible to compensate for the unstable intermittent power supply between the intermittent power supply, the contact line power PLEM satisfies the power of the energy storage battery, and the charging power is not As the power generation power of the intermittent power supply is randomly changed, it does not affect the utilization efficiency of intermittent renewable energy. When the storage battery works in the discharge mode, the intermittent power supply works in maximum power tracking MPPT mode; when the storage battery works in the charging mode, the intermittent power supply works in maximum power tracking MPPT mode or constant power control mode.

Specifically, when the storage battery operates in the charging mode, and the power difference is less than the charge power required to the energy storage battery; the intermittent power supply works in the maximum power tracking MPPT mode; when the storage battery is operating in the charging mode, When the power difference is greater than the charging power required to the energy storage battery, the intermittent power supply works in the constant power control mode. In the charging mode, there may be the case where the power difference is greater than the charging power required to the energy storage battery, even the above power difference is greater than the sum of the charging power and the contact line required for the energy storage battery, and the microgrid system There is a severe power generation power surplus, affecting the stability of the system, such as the frequency and voltage of the system and the voltage output, at which time the intermittent power supply works in the constant power control mode to reduce its power generation power to ensure the stability of the system. It will be noted that the above embodiment is intended to illustrate the technical method of the present invention and is not intended to limit the invention.

The specific implementation manner of the invention is modified or part of the technical characteristics of the invention; without departing from the spirit of the technical method of the present invention, it should be included in the scope of the technical method of request protection according to the present invention. Editor: Shan.