Method for determining delay-dependent stability of new energy power system

A technology of power system and determination method, applied in the field of power system, can solve problems such as the influence of power system stability

Active Publication Date: 2019-04-19
HOHAI UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Studies have shown that even small time delays may have an impact on power system stability

Method used

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  • Method for determining delay-dependent stability of new energy power system
  • Method for determining delay-dependent stability of new energy power system
  • Method for determining delay-dependent stability of new energy power system

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0063] like Figure 1-3 As shown, the present invention first establishes the power system model as a discrete Markov jump linear system model, and constructs a new Lyapunov functional, and then uses the Wirtinger inequality scaling technique to reduce the conservatism of the result. Firstly, the asymptotic stability of the system is analyzed, and then the H of the system ∞ The stability is analyzed, and finally, for the problem that it is difficult to find the global optimal solution in the above inequalities, it is transformed into an eigenvalue solving problem, and at the same time, the maximum time delay that the system can bear is solved.

[0064] The method for judging the stability of the new energy power system under the Wirtinger inequality includes the following steps:

[0065] (1) Establish a time-delay power system model

[0066] x(k+1)=Ax(k)+BK(d s )Cx(k-d s )+Fω(k)

[0067] where: x i (t) = [Δf i ΔP mi ΔP vi ∫ACE i ΔP tie-i ] T , x(t)=[x 1 (t) x ...

Embodiment 2

[0092] The method for determining the stability of the new energy power system under the Wirtinger inequality, the specific process is as follows:

[0093] (1) Establishment of time-delay-dependent new energy power system model based on Markov model

[0094] In general, a power system can be described by a set of differential algebraic equations, which are linearized around the operating point of the system, and the final system can be expressed as:

[0095]

[0096] in:

[0097] x i (t) = [Δf i ΔP mi ΔP vi ∫ACE i ΔP tie-i ] T , x(t)=[x 1 (t) x 2 (t) x 3 (t) … x n (t)] T ,

[0098] u i (t)=-K P ACE i -K I ∫ACE i , u(t)=[u 1 (t) u 2 (t) u 3 (t) ... u n (t)] T ,

[0099] the y i (t)=[ACE i ∫ACE i ] T , y(t)=[y 1 (t) y 2 (t) y 3 (t) ... y n (t)] T ,

[0100] ω i (t) = ΔP di +ΔP windi +ΔP tie-i , ω(t)=[ω 1 (t) ω 2 (t) ω 3 (t) ... ω n (t)] T ,

[0101]

[0102] B d =diag[B 1 B 2 …B n ],

[0103] C d =[C 1 C 2 …C n ]...

Embodiment example

[0216] The multi-area power system load frequency control structure is as follows: figure 1 As shown, the transition probability matrix of the Markov model is set as: The settings of various coefficient items in the dual-area power system model are shown in the table below.

[0217]

[0218] When the power system controller gain is set to: According to the inference, the upper bound of the maximum time delay that the power system can bear at this time can be obtained as: d M =2.2961.

[0219] Figure 4 as well as Figure 5 The frequency error response and ACE signal response of the dual-region power system under random load disturbance are given respectively. It can be seen from the simulation results that under random disturbance conditions, the frequency error response of the system and the response of the ACE signal can both tend to be stable before the next disturbance occurs. To sum up, at this time, the power system (8) is H under the condition of stable perfo...

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Abstract

The invention discloses a method for determining the delay-dependent stability of a new energy power system. The method is based on a Wirtinger inequality and a Markov model, and is used for analyzingthe maximum delay-dependent stability margin that the power system can withstand. The method comprises firstly, establishing delay-dependent new energy power system model based on the Markov model, and forming the system model into a discrete Markov jump linear system model; then, constructing a Lyapunov functional for the established model, and in the derivation process of the functional, scaling down the Wirtinger inequality to reduce the conservation of an criterion; finally, representing a resulting criterion by a set of linear matrix inequalities (LMI). The method of the invention improves the safety and stability of the grid operation.

Description

technical field [0001] The invention belongs to power systems, and in particular relates to a method for judging time-delay-dependent stability of new energy power systems. Background technique [0002] In the power system, the main indicators to measure the power quality are voltage deviation, frequency deviation, harmonics, voltage fluctuation and flicker, three-phase voltage unbalance, etc. In the operation of the power system, it is required that the power generated by the system and the power consumed by the load should be balanced at any time, and the frequency should be at the rated value, and changes in the output of the power plant and changes in the load will cause changes in the frequency. Any sudden disturbance in the power system may cause frequency changes, and the system load may change at any time, and many situations are unpredictable and uncontrollable. Therefore, in order to ensure that the power system can maintain a stable load frequency, an effective l...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H02J3/38
CPCH02J3/382H02J2203/20
Inventor 孙永辉吕欣欣翟苏巍侯栋宸熊俊杰
Owner HOHAI UNIV
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