WO2017132802A1

WO2017132802A1 - Inverter control device and method for energy interconnection and energy storage of ac bus

Info

Publication number: WO2017132802A1
Application number: PCT/CN2016/073083
Authority: WO
Inventors: 牟英峰; 李国利
Original assignee: 无锡美凯能源科技有限公司
Priority date: 2016-02-01
Filing date: 2016-02-01
Publication date: 2017-08-10

Abstract

Disclosed is an inverter control device for energy interconnection and energy storage. The device calculates forward active power, forward reactive power, reverse active power, and reverse reactive power by detecting a flow direction of energy and vectors of electrical parameters such as voltage and current at an electrical energy outflow position, estimates local load and shortage/overage of power generation from a distributed energy source, stores excess energy of the distributed power generation, and automatically releases the stored energy under higher load conditions. A controller controls an output power factor of energy storage grid-connected power generation and performs reactive compensation according to demand of a local grid to optimize electrical energy of the grid. By disposing communication interfaces in a system, the present invention can realize system interconnection, i.e., can carry out energy balancing in micro-grids, and can also, by employing a master-slave approach, realize energy balance in an area through scheduling and management between local micro-grids via an energy interconnection controller composed of a plurality of energy interconnection control devices, and can realize interconnection and energy balance between systems by an energy interconnection control system composed of a plurality of energy interconnection controllers.

Description

Title of Invention: Energy Interconnected Energy Storage Inverter Control Device and Method for AC Busbar

[0001] The present invention belongs to a microgrid system for distributed generation in a power system, and relates to an off-grid microgrid composed of a wind power storage of a microgrid and other distributed energy generation.

Background technique

[0002] Intermittent distributed generation systems, such as wind power generation, photovoltaic power generation, solar thermal power generation, tidal power generation, hydroelectric power generation, and natural gas power generation, are characterized by intermittent and volatility, which exacerbate the peak-to-valley difference of the power grid. It affects the stability of the power grid. Therefore, for some areas, due to the limitation of the capacity of the public power grid, in order to ensure the stability of the power grid, the distributed generation grid-connected mode must adopt all self-use type, and by limiting the output power of distributed power generation, the balance between power generation and power consumption of the user side is The loss of distributed power generation results in waste of energy and limits the proportion of distributed generation access distribution networks.

technical problem

[0003] In order to solve the problem of limiting the power generation of distributed energy in the self-use grid-connected power generation mode, the waste of energy is caused, and the influence of the distributed power generation access distribution network with fluctuation and intermittent on the power grid is reduced. Problem solution

Technical solution

[0004] The energy interconnection energy storage inverter control system of the present invention calculates forward active power, forward reactive power, reverse active power, reverse without detecting a vector of voltage, current, and other electrical parameters at a specific position. Power, calculate the shortage of local load and distributed energy generation, and store the excess energy of distributed generation. At the peak of power consumption, the stored energy is connected to the grid to replenish the energy on the load side. Use electricity to lower the valley, store energy, slow down the peak-to-valley difference of the grid, and optimize the public grid. The device of the present invention can control the power factor of the energy storage grid-connected power generation output, and performs reactive power compensation according to the local power grid demand to optimize the grid power.

Advantageous effects of the invention

Beneficial effect

[0005] The energy interconnection energy storage inverter control device adopts an alternating current bus line in parallel, and can be used on the user side. Low-voltage and medium-voltage distribution networks, including any existing or new intermittent distributed generation systems, such as wind power, photovoltaic power, solar thermal power, tidal power, hydropower and natural gas power generation, etc. The method is connected with the public power grid, or connected in parallel with other independent distributed power generation systems by AC parallel connection. After use, the original power grid configuration on the power side is not required to be changed, and the intermittent distributed power generation system can be compatible, and can be based on the original The power level of distributed generation, paralleling multiple devices to achieve energy interconnection between microgrids, enabling friendly interaction with the public grid, smoothing the volatility of renewable energy, reducing grid peak-to-valley difference, and improving power supply at the end of the grid. Reliability, improve power quality, and effectively increase the proportion of distributed power generation into the power grid.

Brief description of the drawing

DRAWINGS

1 is a composition diagram of an energy interconnection energy storage inverter control device of the present invention.

2 is a composition of an energy interconnected energy storage inverter control device of the present invention. Figure 1. Electrical parameter sampling at a specific location

2. The AC busbar described in this device.

3 is an energy interconnected energy storage inverter control system of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

[0009] The energy interconnection control device of the present invention is composed of a charging module, an inverter module and a control module. The input of the inverter module and the output connection of the charging module constitute a system input end, and the output of the inverter module and the input connection of the charging module The output terminal, the control module and the charging module and the inverter module are connected by a signal line, the input end of the device is connected to the power grid, and the output end of the device is connected with the energy storage battery. The control module in the energy interconnection control device controls the charging module and the inverter module by detecting the electrical parameters of the specific position, thereby realizing intelligent charging and discharging of the energy storage battery, so as to implement the user side single or in the self-use grid-connected mode. The energy balance of the interconnection mode, the composition and connection of the system is as shown in FIG. 1 , wherein the control module controls the power of the charging module and the inverter module, and detects the vector value of the grid side to the user side voltage ¥ and the current I, the present invention The microgrid energy storage inverter system and the power grid adopt the AC bus parallel connection, and the charging part and the inverter part are independent of each other and different. Embodiments of the invention

[0010] The control module determines the magnitudes of the load power (Ρ,) and the distributed power generation (Ρ^) by detecting the vector of the user side voltage and current. When P, <P 吋, judge that the current distributed energy generation exceeds the load power, start the charger, use the battery to store the excess power, the power of the charger! ⁵ ^? ^,. Among them, distributed energy can be intermittent energy such as wind power generation, photovoltaic power generation, and day-to-night power generation that are accessed by the user side. When P, >P 吋, judge that the current distributed power generation is less than the load power, start the inverter, and the battery is sent to the grid through the inverter to meet the load power, the power of the inverter Ρ^Ρ,-Ρ ^

[0011] Since the energy interconnection control device of the present invention is a method in which the AC bus bars are connected in parallel, the parallel connection of the energy storage inverter devices can be performed according to the user side load and the size of the distributed power generation, and the battery capacity in the energy storage system is C. Unit KWH. That is, the number of energy storages to be installed ^ ^) ^, where t is the time of distributed daily power generation, and the device of the present invention is connected to the original system, and can be directly installed on the power side without changing the original line. The access method is shown in Figure 2.

[0012] In the field of expanded microgrid, the controller in the present invention has an interconnection in a region. When it is detected that there is a current in the reverse grid at the transformer, a charging instruction for charging each system is initiated, so that P _C 2+ ...... P _C „=P,;-P /;+P,2-P/2... P, „-P/ _N , so that the energy is balanced in the LAN. When it is detected that there is a current flowing to the load at the transformer, that is, the distributed power generation energy is insufficient to maintain the load, the second controller actively queries the controller in each system to determine the state of each energy storage battery. And perform energy scheduling, such that Ρ,;+ Ρ , 2+ ...... P = Ρ /; -P ,; + P /2-P _g 2... P / „-P _GN , Reach the LAN energy balance.

Industrial applicability

[0013] The device can improve the utilization rate of the volatility distributed energy, and can mitigate the impact of the peak and valley sections on the power grid.

, so that users can use the electricity price of the reserve price to save the user's electricity bill.

Sequence table free content

[0014] None.

[0015]

Claims

Claim

An energy interconnection energy storage inverter control device, which is used in a parallel type and independent type micro power grid including distributed energy generation with intermittent operation characteristics, and is characterized in that it comprises a charging module, an inverter module and a control module, The input end of the charging module is connected to the output end of the inverter and connected to the power grid. The input end of the inverter module is connected to the output end of the charger and connected to the energy storage device, and detects the electrical parameter vector of the specific position on the grid side. To control the power of the charging module _{P f =} P gP , and the power of the inverter module _{P; = P r P} g, thereby achieving the balance and control between the distributed power generation and the power consumption P.

The energy interconnection energy storage inverter control device according to claim 1, characterized in that it further comprises an AC bus, and the AC bus refers to a low-voltage and medium-voltage distribution network on the user side, including any existing or newly built Intermittent distributed generation systems, such as wind power, photovoltaic power, solar thermal power, tidal power, hydropower and natural gas power, are connected to the public grid by AC grid connection, or are connected in parallel with other independent types. The power generation system is connected in parallel.

The energy interconnection energy storage inverter control device according to claim 1, wherein the AC bus bar of claim 2 is connected in the form of one or more energy interconnection control devices, and the voltage of the specific position is detected. The current vector forms a parallel microgrid or a stand-alone microgrid.

The energy interconnection energy storage inverter control device according to claim 1, wherein the electrical parameter vector is current, voltage vector or positive active power, forward reactive power, reverse active power, reverse Reactive power.

The energy interconnected energy storage inverter control device of claim 1 wherein said control module is further coupled to a distributed new energy power generation device.

The energy interconnection energy storage inverter control device according to claim 5, wherein when the distributed energy generation amount is greater than the power consumption amount in the microgrid system in which the energy interconnection control device is located, the control module of the device The charging module is started to charge the energy storage battery, and the distributed energy generation amount is less than the power consumption. The control module of the device starts the inverter module to discharge the energy storage battery. [Claim 7] An energy interconnected energy storage inverter controller, comprising: one or more energy interconnected energy storage inverter control devices according to any one of claims 1-7, and One or more energy storage devices connected.

[Claim 8] An energy interconnected energy storage inverter control system, comprising: one or more energy interconnected energy storage inverter controllers according to claim 7.

[Claim 9] The energy interconnected energy storage inverter control system of claim 8 further comprising a second controller, said second controller and said one or more energy interconnect controllers The energy interconnection control devices are connected.

[Claim 10] The energy interconnection energy storage inverter control system according to claim 9, wherein the distributed energy generation amount is greater than the power consumption amount, the control module of the device starts the charging module, and the energy storage battery Charging, the distributed energy generation amount is less than the power consumption, and the control module of the device starts the inverter module to discharge the energy storage battery.