Capacity calculating method for power distribution network reactive compensation capacitor containing harmonic waves

A compensation capacitor and calculation method technology, applied in reactive power compensation, reactive power adjustment/elimination/compensation, calculation, etc., can solve problems such as overcompensation

Active Publication Date: 2015-12-09
SICHUAN UNIV
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0008] In formula (2), Q 1 is the fundamental reactive power of the system, Q ND is the background harmonic reactive power of the system, Q NC is the reactive power caused by the load harmonic current; therefore, the reactive power compensation capacity obtained by the traditional reactive power calculation method not only compensates the fundamental reactive power of the system and the background harmonic reactive power in the distribution network containing harmonics, but also compensates However, the reactive power of the load harmonic current in the actual circuit should be compensated by the filter on the load side; therefore, the traditional calculation method of reactive power compensation capacity of the capacitor will cause overcompensation. It is no longer applicable in the distribution network containing harmonics; therefore, it is of great significance to study a capacity calculation method that can be applied to reactive power compensation capacitors in distribution networks containing harmonics

Method used

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  • Capacity calculating method for power distribution network reactive compensation capacitor containing harmonic waves
  • Capacity calculating method for power distribution network reactive compensation capacitor containing harmonic waves
  • Capacity calculating method for power distribution network reactive compensation capacitor containing harmonic waves

Examples

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Effect test

Embodiment 1

[0061] Select a 10kV line in a substation, its power supply voltage is distorted, and the load is a linear load; when the system is not compensated, the three-phase voltage distortion rate of the 10kV bus is 4.66%, and the current distortion rate is 1.08%. Taking phase A as an example, the measured The harmonic content value (phase voltage amplitude) is shown in Table 1.

[0062] Table 1 Bus voltage and current harmonic content values

[0063]

[0064] When the compensation is defined by the traditional sinusoidal reactive power, the calculated capacitance value of the capacitor C 传 =10.262 μF ; When compensated according to the proposed method, the capacitance value of the capacitor is calculated C opt =10.262 μF ; Putting two sets of capacitor banks (with a reactance rate of 5%) calculated by the compensation algorithm, the simulation diagrams of the system’s fundamental reactive power and fundamental power factor changes can be obtained, as shown in the attached ...

Embodiment 2

[0067] Select a 10kV line in a substation, ignore the harmonics of the supply voltage, and the load is a non-linear load; when the system is not compensated, the three-phase voltage distortion rate of the 10kV bus is 1.57%, and the current distortion rate is 35.03%. Taking phase A as an example, The measured harmonic content values ​​(phase voltage amplitude) are shown in Table 2.

[0068] Table 2 Bus Voltage and Current Harmonic Content Values

[0069]

[0070] When the compensation is defined by the traditional sinusoidal reactive power, the calculated capacitance value of the capacitor C 传 =12.954 μF ; When compensated according to the proposed method, the capacitance value of the capacitor is calculated C opt =10.806 μF ; Putting two sets of capacitor banks (with a reactance rate of 5%) calculated by the compensation algorithm, the simulation diagrams of the system’s fundamental reactive power and fundamental power factor changes can be obtained, as shown in the ...

Embodiment 3

[0073] The 10kV line of a substation is selected, the power supply voltage is distorted, and the load is a nonlinear load; when the system is not compensated, the three-phase voltage distortion rate of the 10kV bus is 3.71%, and the current distortion rate is 50.89%. Taking phase A as an example, the measured harmonic content values ​​(phase voltage amplitude) are shown in Table 3.

[0074] Table 3 Bus voltage and current harmonic content values

[0075]

[0076] When the compensation is defined by the traditional sinusoidal reactive power, the calculated capacitance value of the capacitor C 传 =14.497 μF ; When compensated according to the proposed method, the capacitance value of the capacitor is calculated C opt =11.021 μF ; put into the two sets of capacitor banks calculated by the compensation algorithm (the reactance rate is 5%), and the simulation diagram of the change of the fundamental reactive power and fundamental power factor of the system can be obtained ...

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Abstract

The invention relates to a capacity calculating method for a power distribution network reactive compensation capacitor containing harmonic waves. A background harmonic wave voltage and a load harmonic wave current are considered respectively, and a non-sine voltage-non-linear load power distribution network reactive compensation system mathematical model is established. From the perspective of compensation system fundamental wave reactive power and background harmonic wave reactive power, load parameters are combined, and the capacity calculating method for the reactive power compensation capacitor of a compensation system is derived so as to calculate the optimal capacitance of the capacitor. Compared with a conventional capacity calculating method for the compensation capacitor, the method provided by the invention can more pointedly compensate the system reactive power, effectively improve the reactive compensation situation of the power grid and improve the electric energy quality of the power grid.

Description

technical field [0001] The invention relates to a method for calculating the capacity of a reactive power compensation capacitor in a distribution network containing harmonics. Background technique [0002] With the widespread application of non-linear electrical equipment in the power grid, the problems of harmonic pollution, power loss and low power factor in the distribution network are becoming more and more serious. Reactive power compensation has become a key link to achieve safe and economical operation of the power grid. [0003] The traditional reactive power compensation capacitor capacity can be determined by S 2 = P 2 + Q 2 Calculated, that is, the reactive capacitor compensation capacity is: [0004] (1) [0005] In formula (1), Q is the reactive power of the system, P is the active power of the system, S is the apparent power; in a sinusoidal circuit, S , P , Q They are fundamental apparent power, fundamental active power and fundamental reactive...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H02J3/18G06F17/50
CPCY02E40/30
Inventor 赵莉华雷晶晶荣强牛纯春牛帅杰丰瑶刘丹华付荣荣张浩王释颖冯政松徐洪英
Owner SICHUAN UNIV
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