A method for analyzing the power transmission limit of power grid system sections

Abstract

A method for analyzing the power transmission limit of a power grid system section relates to a power grid system transportation power limit analysis technology; in order to simply, quickly and accurately calculate the limit transmission power of the local power grid system section power transmission. The present invention adopts the PSASP platform to analyze the given operating conditions, construct the grid structure, and perform power flow calculation to obtain state parameters; analyze the constraints of the transmission line and perform de-looping on the transmission line; under different load conditions, in combination with different power supply startup schemes, obtain the maximum power of the single-circuit transmission line under the de-looping method; perform transient stability analysis on the local power grid system to obtain the total number of section transmission circuits and perform Prony analysis on the local power grid system to obtain the grid damping ratio; combine the maximum power of the single-circuit transmission line, the total number of section transmission circuits and the grid damping ratio to finally determine the section transmission power limit. The beneficial effect is to improve the ability of the local power grid system section to transmit power.

Description

Technical Field

[0001] The present invention relates to a power grid system transport electric energy limit analysis technology. Background Art

[0002] The power grid system is an important base for power supply. The main sources of electricity for the power grid system include solar energy, wind energy and pumped storage. The surplus electricity of the local power grid system can be transmitted to the power grid systems in other regions for consumption. However, the transmission capacity is limited by the carrying capacity of a single circuit line. With the rapid increase in the installed power capacity of the local power grid system, power grid personnel need to understand and calculate the maximum power that the local power grid system can transmit to the external power grid system under various safety constraints in order to carry out grid scheduling. Therefore, it is urgent to study the maximum transmission power of the power transmission section in the region to improve the power transmission capacity of the region. Summary of the Invention

[0003] The purpose of the present invention is to simply, quickly and accurately calculate the transmission limit power of a local power grid system section, and proposes a power grid system section transmission power limit analysis method.

[0004] The present invention provides a method for analyzing the power transmission limit of a power grid system section, the method comprising the following steps:

[0005] Step 1: Use the PSASP platform to analyze the given operating conditions of the local power grid system and build the grid structure of the local power grid system;

[0006] Step 2: Calculate the power flow using the grid structure constructed in step 1 to obtain the state parameters of the local power grid system in steady state operation;

[0007] Step 3: Analyze the single-circuit transmission line of the local power grid system based on the state parameters obtained in step 2, and obtain the constraints of the single-circuit transmission line of the local power grid system;

[0008] Step 4: Under different load conditions, in accordance with different power startup plans of the local power grid system, and based on the constraints obtained in step 3, de-circuit the local power grid system's transmission lines to obtain the maximum power consumption of a single circuit of the local power grid system's transmission lines;

[0009] Step 5: Perform transient stability analysis on the grid structure of the local power grid system to obtain the total number of outbound transmission circuits in the local power grid system section and perform Prony analysis on the local power grid system to obtain the grid damping ratio;

[0010] Step 6: Combine the maximum value of the local power grid system's single-circuit power transmission line obtained in step 4, the total number of local power grid system section transmission circuits obtained in step 5, and the grid damping ratio obtained in step 5 to finally determine the local power grid system section transmission power limit value.

[0011] Furthermore, the operating conditions given by the local power grid system in step 1 include: the power of each power source in the local power grid system, the power of the load point, the power terminal voltage, the voltage of the balance point, and the phase angle of the balance point voltage.

[0012] Furthermore, the state parameters of the steady-state operation of the local power grid system obtained in step 2 include: the voltage amplitude of each busbar of the local power grid system, the phase angle of each busbar voltage, the power distribution of each branch, and the network power loss of each branch.

[0013] Furthermore, in step five, the transient stability analysis of the local power grid system is performed using a transient stability mathematical model;

[0014] The transient stability mathematical model includes network equations of the power grid, mathematical models of primary equipment and secondary automatic devices, and simulation of disturbance modes.

[0015] The beneficial effects of the present invention are as follows: by utilizing the limit analysis method of the present invention, the influence of different load modes on the power transmission of a single-circuit line of the local power grid system is considered, and the maximum value of the power transmission of a single-circuit line of the local power grid system under the de-looping mode is obtained. By utilizing the maximum value of the single-circuit line power in combination with the total number of cross-section transmission circuits and the grid damping ratio, the limit transmission power of the cross-section power transmission of the local power grid system can be simply, quickly and accurately calculated, thereby improving the cross-section power transmission capacity of the local power grid system. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a flow chart of a method for analyzing the power transmission limit of a power grid system section as described in the first specific implementation method. DETAILED DESCRIPTION

[0017] Specific implementation method 1: Combination Figure 1 This embodiment describes a method for analyzing the power transmission limit of a power grid system section, which includes the following steps:

[0018] Step 1: Use the PSASP platform to analyze the given operating conditions of the local power grid system and build the grid structure of the local power grid system;

[0019] Step 2: Calculate the power flow using the grid structure constructed in step 1 to obtain the state parameters of the local power grid system in steady state operation;

[0020] Step 3: Analyze the single-circuit transmission line of the local power grid system based on the state parameters obtained in step 2, and obtain the constraints of the single-circuit transmission line of the local power grid system;

[0021] Step 4: Under different load conditions, in conjunction with different power startup plans of the local power grid system, and based on the constraints obtained in step 3, the local power grid system's transmission lines are de-looped to obtain the maximum power consumption of a single-circuit transmission line of the local power grid system; wherein, different load conditions refer to two modes: low load in winter and high load in summer.

[0022] Step 5: Perform transient stability analysis on the grid structure of the local power grid system to obtain the total number of outbound transmission circuits in the local power grid system section and perform Prony analysis on the local power grid system to obtain the grid damping ratio;

[0023] Step 6: Combine the maximum value of the local power grid system's single-circuit power transmission line obtained in step 4, the total number of local power grid system section transmission circuits obtained in step 5, and the grid damping ratio obtained in step 5 to finally determine the local power grid system section transmission power limit value.

[0024] In this embodiment, the operating conditions given by the local power grid system in step 1 include: the power of each power source in the local power grid system, the power of the load point, the power terminal voltage, the voltage at the balance point, and the phase angle of the balance point voltage.

[0025] In this embodiment, the state parameters of the steady-state operation of the local power grid system obtained in step 2 include: the voltage amplitude of each busbar of the local power grid system, the phase angle of each busbar voltage, the power distribution of each branch, and the network power loss of each branch.

[0026] In this embodiment, the transient stability analysis of the local power grid system in step five is implemented using a transient stability mathematical model;

[0027] The transient stability mathematical model includes the network equations of the power grid, mathematical models of primary equipment and secondary automatic devices, and simulation of disturbance modes. The mathematical models of primary equipment and secondary automatic devices include mathematical description models of the dynamic characteristics of the generator, the excitation regulator, the speed regulator, the power system stabilizer, the load, the reactive power compensation, the DC transmission, and the relay protection. The disturbance mode simulation includes simple or complex faults in the power grid, as well as impact loads, rapid valve closing, generator shedding, load shedding, and line shedding.

[0028] In this implementation, power flow calculations determine the steady-state operating parameters of each component of the power system based on a given grid structure and parameters, as well as the operating conditions of generators, loads, and other components. Typically, the given operating conditions include the power at each source and load point in the system, the source terminal voltage, and the voltage and phase angle at the equilibrium point. The operating state parameters to be determined include the voltage amplitude and phase angle of each busbar, the power distribution of each branch, and the power loss of the network.

[0029] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included in the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for analyzing the power transmission limit of a power grid system section, characterized in that: The limit analysis method includes the following steps: Step 1: Use the PSASP platform to analyze the given operating conditions of the local power grid system and build the grid structure of the local power grid system; Step 2: Calculate the power flow using the grid structure constructed in step 1 to obtain the state parameters of the local power grid system in steady state operation; Step 3: Analyze the single-circuit transmission line of the local power grid system based on the state parameters obtained in step 2, and obtain the constraints of the single-circuit transmission line of the local power grid system; Step 4: Under different load conditions, in accordance with different power startup plans of the local power grid system, and based on the constraints obtained in step 3, de-circuit the local power grid system's transmission lines to obtain the maximum power consumption of a single circuit of the local power grid system's transmission lines; Step 5: Perform transient stability analysis on the grid structure of the local power grid system to obtain the total number of outbound transmission circuits in the local power grid system section and perform Prony analysis on the local power grid system to obtain the grid damping ratio; Step 6: Combine the maximum value of the local power grid system's single-circuit power transmission line obtained in step 4, the total number of local power grid system section transmission circuits obtained in step 5, and the grid damping ratio obtained in step 5 to finally determine the local power grid system section transmission power limit value.

2. A method for analyzing the power transmission limit of a power grid system section according to claim 1, characterized in that: The operating conditions given by the local power grid system in step 1 include: the power of each power source in the local power grid system, the power of the load point, the power terminal voltage, the voltage at the balance point, and the phase angle of the voltage at the balance point.

3. A method for analyzing the power transmission limit of a power grid system section according to claim 1, characterized in that: The state parameters of the local power grid system steady-state operation obtained in step 2 include: the voltage amplitude of each busbar of the local power grid system, the phase angle of each busbar voltage, the power distribution of each branch, and the network power loss of each branch.

4. A method for analyzing the power transmission limit of a power grid system section according to claim 1, characterized in that: In step five, the transient stability analysis of the local power grid system is carried out using the transient stability mathematical model; The transient stability mathematical model includes network equations of the power grid, mathematical models of primary equipment and secondary automatic devices, and simulation of disturbance modes.

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