Micro-grid control method for communication-line-free interconnection based on frequency shift control

A control method and micro-grid technology, applied in electrical components, circuit devices, photovoltaic power generation, etc., can solve problems such as overvoltage, switching "gap closing shock, etc."

Inactive Publication Date: 2017-03-29
STATE GRID CORP OF CHINA +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0021] Through the above analysis: the control of microgrid grid-connected operation, grid-connected to off-grid, off-grid operation, and off-grid to grid-connected con

Method used

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  • Micro-grid control method for communication-line-free interconnection based on frequency shift control
  • Micro-grid control method for communication-line-free interconnection based on frequency shift control
  • Micro-grid control method for communication-line-free interconnection based on frequency shift control

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Embodiment

[0122] Embodiment: what the present invention adopts is a kind of frequency-shift control technology, or is referred to as frequency-shift keying (frequency-shift-keying, FSK) technology again, and it is to use digital signal to modulate the frequency of carrier, in power system protection The field of communication is a well-applied technology, such as: FSK transceiver for high-voltage line protection, rated frequency range 50-400kHz, rated bandwidth of 4kHz, the normal operation is to send the frequency monitoring signal, the signal frequency f G Used for channel monitoring; when a fault occurs, send a command signal, and send the signal frequency f T , used to transmit the specified operation command. The carrier machine for high-voltage line protection adopts FSK technology, switches 5 frequencies in one channel, and normally transmits the monitoring frequency f G , transmit frequency hopping fA, fB, fC, f3 in case of failure. Frequency hopping fA, fB, and fC are divided...

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Abstract

Disclosed is a micro-grid control method for communication-line-free interconnection based on frequency shift control. When a micro-grid runs in an off-grid mode, communication-line-free interconnection micro-grid control is realized with the aid of a power frequency signal of a voltage source, by use of a frequency shift control technology and by taking a frequency signal as a means of communication. No MGCC is needed, and an energy storage device is connected in parallel with DGs autonomously. Specifically, when a micro-grid runs in an off-grid mode, a virtual synchronous generator technology is used in main energy storage. Even if the power fluctuates largely, the system frequency is not beyond an allowed range as long as the maximum charge and discharge power of energy storage is not exceeded. The operation area is divided into three areas according to the SOC (State of Charge): a high-SOC charging sag operation area (50.3-51Hz), a low-SOC discharging sag operation area (47.7-49Hz), and a normal-SOC sag operation area or a high-SOC discharging/low-SOC charging sag operation area (49-50.3Hz).

Description

technical field [0001] The invention relates to a micro-grid control method for frequency-shift control without communication line interconnection, and belongs to the technical field of micro-grid control. Background technique [0002] Distributed generation (distributed generation, DG) is connected near the user side, adopts nearby power generation, and nearby grid connection. When the DG is connected to the distribution network, when the voltage frequency is abnormal due to the disturbance or fault of the power grid, the DG is required to exit the operation, so as to avoid the impact of the DG connection on the safe operation of the distribution network. In order to solve the contradiction of DG access to the distribution network and give full play to the advantages of DG, Lasseter B proposed the concept of micro-grid (MG) 【1】 MG refers to an autonomous system with self-control, management and protection composed of DG (including photovoltaic, wind turbine and other DG), ...

Claims

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Application Information

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IPC IPC(8): H02J3/38H02J3/32
CPCH02J3/32H02J3/385Y02E10/56
Inventor 汪泽州顾卫华刘群朱胜洪黄建伟朱升涛储建新陈宁宁
Owner STATE GRID CORP OF CHINA
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