Island microgrid multi-inverter control system with active filtering function and working method thereof

A control system and inverter technology, which is applied in the parallel control of multiple inverters in an islanded microgrid and in the field of distributed power generation. And other issues

Inactive Publication Date: 2015-05-06
STATE GRID CORP OF CHINA +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The traditional active filtering equipment adopts the current control method, which cannot provide voltage and frequency support for the common bus of the microgrid, and the traditional voltage-controlled inverter cannot compensate the harmonic current of the grid.
The singleness of the functions of the two makes it often contradictory between the safety reserve capacity of the active filter equipment and the design cost of the microgrid when designing a microgrid with a specific capacity

Method used

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  • Island microgrid multi-inverter control system with active filtering function and working method thereof
  • Island microgrid multi-inverter control system with active filtering function and working method thereof
  • Island microgrid multi-inverter control system with active filtering function and working method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0076] An island microgrid multi-inverter control system with active filtering function, including several parallel inverters, linear and nonlinear loads, several parallel inverters connected to a common bus, and the common bus is also connected to the Linear and nonlinear loads, several parallel inverters, the linear and nonlinear loads form an independent microgrid; the inverter includes a main circuit, signal processing and DSP control, the main circuit includes a DC stabilized power supply, H-bridge inverter circuit, LC filter, feeder, the H-bridge inverter circuit includes S 1 -S 4 Four power switch tubes, the DC stabilized power supply, the H-bridge inverter circuit, the LC filter, and the feeder are connected in sequence; the signal processing and DSP control include signal conditioning and A / D conversion, Harmonic extraction, active harmonic control, power droop control, voltage and current control, drive and protection; the signal conditioning and A / D conversion are ...

Embodiment 2

[0079] According to the control system described in Embodiment 1, it is further defined that the DC stabilized power supply is connected to both ends of the input side of the H-bridge inverter circuit, and the midpoints of the left and right bridge arms of the H-bridge inverter circuit are respectively A current tie line is drawn out, the current tie line is connected to the inductance current input end and the capacitor current output end of the LC filter, and the tie lines drawn from both ends of the capacitor of the LC filter are connected to the common bus through the feeder line.

[0080] The control system described in embodiment 1 or 2 is as figure 1 shown.

Embodiment 3

[0082] According to the working method of the control system described in embodiment 1 or 2, the specific steps include:

[0083] (1) At the starting point of each sampling period, signal conditioning and A / D conversion are started, and the inverter feeder grid-connected terminal voltage u pcc Sampling, through harmonic extraction, and sliding window Fourier transform, to obtain the hth common bus harmonic voltage u pcch , and then through active harmonic control, the specific harmonic component u of the reference output voltage of the inverter is output refh ; Active harmonic control calculation formula is:

[0084] u refh = K G Σ h = 3,5,7,9,11 G h u pcch

[0085] Among them, G h is the hth harmonic voltage feedback coefficient; K G is th...

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Abstract

The invention relates to an island microgrid multi-inverter control system with an active filtering function and a working method thereof. The island microgrid multi-inverter control system comprises a plurality of parallelly-connected inverters and linear and nonlinear loads. The working method includes the steps of harmonic extraction, active harmonic control, power droop control and voltage and current control. The island microgrid multi-inverter control system provides energy to the loads; if harmonic distortion rate of voltage and current of a microgrid common bus is overlarge, the inverters start an auxiliary function of active filtering; if the harmonic distortion rate of voltage and current of the microgrid common bus is within a reasonable range, the inverters cut off the auxiliary function of active filtering; start and cut-off of the active filtering auxiliary function of the inverters are completed seamlessly. The island microgrid multi-inverter control system has the active filtering function, so that harmonic current distortion rate and harmonic voltage distortion rate of the island microgrid common bus are lowered, and stability of voltage of a microgrid is guaranteed; spare capacity of active filtering equipment of the microgrid is reduced, and designing cost of a microgrid system is lowered.

Description

technical field [0001] The invention relates to an island micro-grid multi-inverter control system with an active filtering function and a working method thereof, belonging to the technical fields of island micro-grid multi-inverter parallel control and distributed power generation. Background technique [0002] Parallel connection of multiple inverters can realize large-capacity power supply and redundant power supply, which is recognized as one of the important directions for the development of inverter technology today. Compared with a single high-power inverter, multiple low-power inverters connected in parallel can not only reduce costs, facilitate maintenance, but also be more flexible and reliable. By changing the number of parallel inverters, different capacities can be obtained; through redundant parallel inverters, the reliability of the system can be improved. [0003] When the microgrid operates in an isolated island, the distributed power generation can adopt d...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H02J3/38H02M1/12
CPCH02J3/01H02J3/38H02J3/388Y02P80/14
Inventor 张庆海梁甲文王新涛刘安华李洪博蔡军
Owner STATE GRID CORP OF CHINA
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