Load flow calculation method based on quantum Newton algorithm

Abstract

The invention discloses a load flow calculation method based on a quantum Newton algorithm, and belongs to the field of load flow calculation and analysis. The method comprises the following steps of: firstly, acquiring an electrical parameter corresponding to each network node according to an operation parameter and a network state of a power system, and extracting an input data feature by utilizing adaptive chirp mode decomposition; secondly, constructing a basic equation for load flow calculation; and solving a correction equation of the Newton method containing Jacobian matrix elements again, finally calculating a correction value of the correction equation through a quantum algorithm, and carrying out iterative updating on the voltage until the precision requirement is met, thereby obtaining voltage data. The load flow calculation method provided by the invention can realize rapid convergence on the premise of keeping high precision.

Description

Technical Field

[0001] The invention relates to a power flow calculation method based on quantum Newton algorithm. Background Art

[0002] With the continuous increase in electricity demand, power analysis of distribution networks is particularly important, and power flow calculation is the most basic part of power analysis. It is also a core basis for quantitatively analyzing the safety, rationality of operation mode, reliability and economy of distribution network systems.

[0003] As the complexity of distribution networks continues to increase, various power flow calculation algorithms have been proposed, and traditional solution methods are mostly focused on the traditional Newton-Raphson method or fast decoupling method to complete the calculation of power flow. However, traditional solution methods will have problems such as high number of iterations and slow convergence in complex distribution network analysis, which leads to a sharp drop in calculation efficiency.

[0004] Quantum computing is a new computing framework developed using the basic principles of quantum mechanics. By providing more powerful processing capabilities, it can greatly accelerate the training and execution of machine learning algorithms. This means that larger data sets can be processed, and the accuracy and efficiency of algorithms can be improved, thus showing strong application prospects in image recognition, natural language processing, predictive analysis, etc. Compared with traditional computing methods, it can achieve exponential acceleration in solving linear equations and has faster computing power. Summary of the invention

[0005] The purpose of the present invention is to propose a power flow calculation method based on quantum Newton algorithm, which can achieve fast convergence, fewer convergence times, higher convergence accuracy, and perform fast power flow calculation while maintaining high accuracy.

[0006] To achieve the above object, the technical solution provided by the present invention comprises the following steps: S1. Obtain the electrical parameters corresponding to each network node according to the operating parameters and network status of the power system; S2. Use the current and power relationship of the node to construct n nonlinear complex equations to construct the basic equations for power flow calculation; S3, obtaining a correction equation of Newton's method including Jacobian matrix elements according to the voltage of the node and the admittance matrix of the node, and obtaining a deviation of the calculated value; S4, calculating the correction value of the correction equation by quantum algorithm; S5. Substitute the correction value into the node voltage to update the voltage. When the difference between two iterations is less than the given allowable error value, the voltage of all nodes is output to complete the calculation. Otherwise, continue to iterate and solve.

[0007] The advantages of the present invention are: The power flow calculation method based on the quantum Newton algorithm fully considers the rapidity and accuracy of power flow calculation, and proposes a power flow calculation method based on the quantum Newton algorithm, which uses quantum computing to quickly solve the linear equations deduced by the Newton algorithm, thereby greatly improving the calculation efficiency. Therefore, the present invention greatly improves the detection efficiency while ensuring accuracy. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 The figure is an overall flow chart of the method of the present invention. Specific implementation methods

[0009] The method of the present invention is described in detail below in conjunction with the flow chart. Obviously, the following description is only for example and is not intended to limit the scope of the present invention and its application. Figure 1 Shown is a flow chart of the method of the present invention, and the method of the present invention is specifically described below.

[0010] S1.According to the operating parameters and network status of the power system, obtain the electrical parameters corresponding to each network node.

[0011] Statistics of active power P and reactive power Q of each node in the power system, and construction of the admittance matrix Y of each node ij . The initial value of the given voltage.

[0012] S2. Use the current and power relationship of the nodes to construct n nonlinear complex equations to construct the basic equations for power flow calculation.

[0013] Using the relationship between node power and current Where P i and Q i are the active power and reactive power of each node respectively, is the conjugate of the voltages at each node.

[0014] Obtain the power equation for a node involving n nonlinear complex expressions: where Y ij is the admittance matrix of the node, which reflects the relationship between the voltage and the injected current of each node.

[0015] S3. A correction equation of Newton's method including Jacobian matrix elements is obtained based on the voltage of the node and the admittance matrix of the node to obtain the deviation of the calculated value.

[0016] Substitute the node voltage expression and the node admittance matrix into the node power equation to obtain the error equations of active power and reactive power: Among them G i and B i are the real and imaginary parts of the node’s admittance matrix, respectively.

[0017] P i and Q i Taking partial derivatives, we can compute the modified equations for Newton's method that include elements of the Jacobian matrix: f(X)=JΔX (5) Where J is the Jacobian matrix and f(X) is the calculated deviation.

[0018] Jacobian Matrix in

[0019] S4. Calculate the correction value of the correction equation by quantum algorithm; First, we construct the subprocess O to prepare f(X) b , O b |0〉=f(x) (14); Secondly, we also need to construct the subprocess O of the Jacobian matrix J value A , O A Contains O A1 and O A2 Two processes, O A1 |j,l〉=||j,h(j,l)〉 (15) Where h(j,l) represents the subscript of the lth column and jth row of matrix J.

[0020] By building O b and O A , use the quantum linear solver to solve |Δx〉, and use the quantum amplitude estimation algorithm to calculate the probability of the quantum linear solver: in We execute the quantum linear solver multiple times and use the sampling algorithm to sample |Δx〉 to obtain the mean Δx.

[0021] S5, substituting the correction value into the node voltage to update the voltage, when the difference between two iterations is less than the given allowable error value, output the voltage of all nodes to complete the calculation, otherwise continue to iterate and solve; Substitute the calculated difference into the voltage value of the updated node, and solve the difference between two adjacent voltage values. If it is less than the set threshold, the calculation ends, otherwise continue to superimpose until the requirement is met; The following is verified by combining specific examples to compare the computational efficiency of the traditional Newton method and the quantum Newton method.

[0022] In this embodiment, a simulation experiment is performed based on an IEEE (standard node system) system containing 6 nodes; Constructed admittance matrix The specific parameters after each iteration using the traditional Newton algorithm are listed in the following table: Table 1: Iterations: 0 Wire Voltage Amplitude Voltage phase angle 1 1 0 2 1.1 0 3 1 0 Table 2: Iteration number: 1 Wire Voltage Amplitude Voltage phase angle 1 1 0 2 1.1 0.09163 3 1.02680 -0.26333 Table 3: Iteration number: 2 Wire Voltage Amplitude Voltage phase angle 1 1 0 2 1.1 0.09341 3 0.97552 -0.27473 Table 4: Number of iterations: 3 Wire Voltage Amplitude Voltage phase angle 1 1 0 2 1.1 0.09351 3 0.97229 -0.27641 The specific parameters after each iteration using the quantum Newton algorithm are listed in the following table: Table 5: Iterations: 0 Wire Voltage Amplitude Voltage phase angle 1 1 0 2 1.1 9.38552 3 1.05038 -0.13830 Table 6: Iteration number: 1 Wire Voltage Amplitude Voltage phase angle 1 1 0 2 1.1 0.09420 3 0.97928 -0.27318 Table 7: Iteration number: 2 Wire Voltage Amplitude Voltage phase angle 1 1 0 2 1.1 0.09351 3 0.97233 -0.27638 In summary, by comparing with the traditional Newton algorithm, the quantum Newton algorithm has a faster convergence speed while maintaining the same accuracy.

[0023] The power flow calculation method based on the quantum Newton algorithm fully considers the rapidity and accuracy of power flow calculation, and proposes a power flow calculation method based on the quantum Newton algorithm, which uses quantum computing to quickly solve the linear equations deduced by the Newton algorithm, thereby greatly improving the calculation efficiency. Therefore, the present invention greatly improves the detection efficiency while ensuring accuracy.

Claims

1. A power flow calculation method based on quantum Newton algorithm, characterized in that: The following steps are involved: S1. Obtain the electrical parameters corresponding to each network node according to the operating parameters and network status of the power system; S2. Use the current and power relationship of the node to construct n nonlinear complex equations to construct the basic equations for power flow calculation; S3, obtaining a correction equation of Newton's method including Jacobian matrix elements according to the voltage of the node and the admittance matrix of the node, and obtaining a deviation of the calculated value; S4, calculating the correction value of the correction equation by quantum algorithm; S5. Substitute the correction value into the node voltage to update the voltage. When the difference between two iterations is less than the given allowable error value, the voltage of all nodes is output to complete the calculation. Otherwise, continue to iterate and solve.

2. The power flow calculation method based on quantum Newton algorithm according to claim 1 is characterized in that: In step S1, the active power P and reactive power Q of each node in the power system are counted to construct the admittance matrix Y of each node. ij ; The initial value of the given voltage.

3. The power flow calculation method based on quantum Newton algorithm according to claim 1 is characterized in that: In step S2, the relationship between node power and current is used Where P i and Q i are the active power and reactive power of each node respectively, is the conjugate of the voltages at each node; Obtain the power equation for a node involving n nonlinear complex expressions: where Y ij is the admittance matrix of the node, which reflects the relationship between the voltage and the injected current of each node.

4. The power flow calculation method based on quantum Newton algorithm according to claim 1 is characterized in that: In step S3, the voltage expression of the node and the admittance matrix of the node are substituted into the power equation of the node, thereby obtaining the error equations of active power and reactive power: Among them G i and B i are the real and imaginary parts of the node’s admittance matrix, respectively. i and Q i Find the partial derivatives to calculate the modified equation of Newton's method containing the elements of the Jacobian matrix: f(X) = JΔX Where J is the Jacobian matrix and f(X) is the calculated deviation.

5. The power flow calculation method based on quantum Newton algorithm according to claim 1 is characterized in that: In step S4, we first construct a subprocess O for preparing f(X) b , O b |0>=f(x); Secondly, we also need to construct the sub-process O of the Jacobian matrix J value A , O A Contains O A1 and O A2 Two processes; in: O A1 |j,l〉=|j,h(j,l)〉 Where h(j,l) represents the subscript of the lth column and jth row of matrix J; By building O b and O A , use the quantum linear solver to solve |Δx〉, and use the quantum amplitude estimation algorithm to calculate the probability of the quantum linear solver: in c=k 2 log(k / ε); We execute the quantum linear solver multiple times and use the sampling algorithm to sample |Δx〉 to obtain the mean Δx.

6. The power flow calculation method based on quantum Newton algorithm according to claim 1 is characterized in that: In step S5, the calculated difference is substituted into the voltage value of the update node to solve the difference between two adjacent voltage values. If the difference is less than the set threshold, the calculation ends; otherwise, the superposition continues until the requirement is met.

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