Receiving end system transient voltage stability discrimination method and system

A technology of transient voltage stability and transient voltage, which is applied in the field of transient voltage stability discrimination of receiving end systems based on swing characteristic quantities, can solve the problem of fast simulation speed, small simulation scale, and difficult power system transient voltage stability Control and other issues, to achieve the effect of effective voltage stability protection control

Pending Publication Date: 2022-06-14
ELECTRIC POWER RES INST OF STATE GRID ZHEJIANG ELECTRIC POWER COMAPNY +1
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Problems solved by technology

Among them, the electromechanical transient simulation adopts the quasi-steady-state model, which is fast in simulation speed but low in accuracy; the electromagnetic transient simulation is relatively accurate, but its simulation scale is not large, which is not conducive to online applications
The energy function method can use the energy function to directly estimate the transient voltage stability, but the construction of the energy function and the determination of the critical energy are difficult; at the same time, the phenomenon of voltage instability can be explained as the change of the system parameters leading to the stability of the system structure or the change of the characteristics of the equilibrium point. Therefore, bifurcation theory can be used to analyze
[0004] In terms of transient voltage stability criteria, in engineering practice, the transient voltage stability judgment method that uses the transient voltage below a certain threshold and lasts for a certain period of time has been widely used at home and abroad, but it cannot be quantitatively evaluated Transient voltage stability margin is difficult to effectively apply to power system transient voltage stability control

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  • Receiving end system transient voltage stability discrimination method and system
  • Receiving end system transient voltage stability discrimination method and system
  • Receiving end system transient voltage stability discrimination method and system

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Embodiment 1

[0045] The present embodiment provides a transient voltage stability discrimination method of the receiving system, such as Figure 3 As shown, the steps are as follows:

[0046] Step 1: The transient voltage data of the busbar is obtained by the PMU device, based on the difference of the voltage curve, the demarcation point of each pendulum of the voltage curve is divided, and when the difference of the curve changes from positive to negative, it can be used as the demarcation point to form a single swing time range. Specifically, as attached Figure 2 as shown.

[0047] When V(t+5)-V(t)>0 and V(t+6)-V(t+1) <0, the boundary point is V(t+3), and the voltage trajectory between each two boundary points is a "wobble".

[0048] Step 2: According to the voltage stability requirements of the power grid and the type of key busbar (load bus or pivot bus), determine the maximum acceptable duration at different set voltages, and the specific selected criteria can refer to the following table....

Embodiment 2

[0073]The present embodiment provides a transient voltage stability discrimination system of the receiving system, which includes a transient voltage data range division unit, a voltage interval division unit, a weight value calculation unit, a transient voltage stability margin evaluation index calculation unit, a key busbar transient voltage stability judgment unit and a system transient voltage stability judgment unit.

[0074] Transient voltage data range division unit: Obtain the PMU data of the transient process, and divide the time range of the single oscillation of the transient voltage data through the first-order difference of the data.

[0075] The transient voltage data range division unit, first obtain the transient voltage stability data of the PMU, based on the difference of the voltage curve, divide the dividing point of each pendulum of the voltage curve, when the difference of the voltage curve changes from positive to negative, that is, as a demarcation point, s...

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Abstract

The invention discloses a method and a system for judging transient voltage stability of a receiving end system. In the aspect of transient voltage stability criterion, a transient voltage stability judgment method that the transient voltage is lower than a certain threshold value and lasts for a certain time cannot quantitatively evaluate the transient voltage stability margin, and the transient voltage stability judgment method is difficult to be effectively applied to transient voltage stability control of a power system. According to the technical scheme, the method comprises the following steps: firstly, acquiring transient voltage stability data of a bus by a PMU device, and segmenting a voltage curve by using a difference equation; afterwards, corresponding weights are given according to different voltage drop degrees in combination with existing transient voltage practical criteria; further, quantizing the drop accumulation amount by using a weighted integral method; and finally, constructing an evaluation index and forming a complete discrimination method. According to the method, the transient voltage stability of the bus and the power system in the transient time scale can be quantitatively evaluated, so that more effective power system voltage stability protection control can be realized.

Description

Technical field [0001] The present invention relates to the field of power system operation control, in particular a transient voltage stability discrimination method and system based on a receiving system based on a swing characteristic quantity. Background [0002] With the continuous growth of long-distance cross-regional HVDC transmission scale, the characteristics of "strong and weak AC" in China's power system are prominent, and a large amount of DC power is fed in, which reduces the dynamic reactive power supply of the receiving system and weakens the voltage support ability; On the other hand, the fed DC power is equivalent to replacing the synchronous generator of equal capacity, so that the moment of inertia of the power system is greatly reduced, and the anti-interference ability is weakened. In addition, in the low voltage state after the system is disturbed, the dynamic response characteristics of the DC converter and the induction motor load will consume a large amo...

Claims

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Application Information

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IPC IPC(8): G06Q10/06G06Q50/06H02J3/00
CPCG06Q10/06393G06Q50/06H02J3/00H02J2203/20
Inventor熊鸿韬孔贺薛安成杨滢张建承华文楼伯良孙维真倪秋龙王龙飞林进钿张博雄
OwnerELECTRIC POWER RES INST OF STATE GRID ZHEJIANG ELECTRIC POWER COMAPNY