Voltage ripple suppression method for DC microgrid under unbalanced load

A DC micro-grid, voltage pulsation technology, applied in parallel operation of DC power supply, DC network circuit device, DC circuit can reduce harmonics/ripples, etc. The effect of simple adjustment of device structure and parameters, reduction of system cost, and avoidance of capacity waste

A DC micro-grid, voltage pulsation technology, applied in parallel operation of DC power supply, DC network circuit device, DC circuit can reduce harmonics/ripples, etc. The effect of simple adjustment of device structure and parameters, reduction of system cost, and avoidance of capacity waste

CN106786485BActive Publication Date: 2020-06-19NORTH CHINA ELECTRIC POWER UNIV (BAODING)
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  • Voltage ripple suppression method for DC microgrid under unbalanced load
  • Voltage ripple suppression method for DC microgrid under unbalanced load
  • Voltage ripple suppression method for DC microgrid under unbalanced load

Examples

Experimental program
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Effect test

Embodiment 1

[0053] Such as figure 1 As shown, a voltage ripple suppression method for DC microgrid under unbalanced load, including the following steps:

[0054] Step 1: Establish a general-purpose DC microgrid: the DC microgrid includes a wind power generation unit composed of wind turbines, wind turbine measuring elements, and AC / DC converters cascaded in sequence. The battery, battery measuring element, and the first DC / DC A battery energy storage unit composed of DC converters cascaded in sequence, a photovoltaic power generation unit composed of a photovoltaic array, a photovoltaic measuring element, and a second DC / DC converter cascaded in sequence, a DC measuring element, a grid-connected inverter, and a second DC / DC converter. A grid-connected unit composed of an AC measuring element and an AC grid connected in sequence, a DC load unit composed of a third DC / DC converter and a DC load connected in sequence, a load inverter, a second AC measuring element, and an AC load in sequence...

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Abstract

The invention discloses a voltage ripple suppression method for a direct-current micro-grid under unbalanced load. The method comprises steps as follows: establishing the direct-current micro-grid, establishing a direct-current voltage control system based on a supercapacitor, performing signal measurement and processing, determining a power expression of the supercapacitor, designing parameters of an energy storage device of the supercapacitor, determining a control error ei, determining a sliding mode surface S, determining a control rate D, judging whether a control target is achieved and performing PWM (pulse-width modulation). The method has the advantages that the structure is simple, the control precision is high, the robustness is high and the like; with the adoption of the method, the control target that the voltage ripple of the direct-current micro-grid is suppressed under the unbalanced load can be achieved under the condition of unbalanced load.

Description

technical field [0001] The invention relates to a voltage pulsation suppression method, in particular to a voltage pulsation suppression method for a DC microgrid under an unbalanced load, and belongs to the technical field of power supply control. Background technique [0002] The DC microgrid uses DC power distribution, which is beneficial to the coordinated control of various distributed power sources and can provide higher power quality, so it has become a new direction of microgrid technology research. However, DC microgrids also have certain stability problems. Since the actual system often contains unbalanced loads, the negative sequence component of the fundamental wave will be introduced on the AC load side, resulting in double frequency pulsation of the DC voltage, which seriously affects the power supply quality of the DC microgrid. In addition, the double frequency pulsation of the inverter output power under unbalanced load will generate secondary ripple curren...

Claims

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Application Information

Patent Timeline
19 Jun 2020
Publication
CN106786485B
IPC
H02J1/02; H02J1/10; H02J1/14; H02J3/38
CPC
H02J1/02; H02J1/102; H02J1/14; H02J3/383; H02J3/386; H02J3/388; Y02E10/56; Y02E10/76
Inventors
朱晓荣; 张雨濛