Capacity configuration method and system for reactive power compensation device of multi-machine system

Abstract

The application discloses a capacity configuration method and system of a reactive compensation device of a multi-machine system, which comprises the following steps: constructing a synchronous machine electromagnetic power phase angle characteristic curve equation and a synchronous machine mechanical power phase angle characteristic equation of the multi-machine system before and after fault removal by combining parameters of each element of the multi-machine system configured with the reactive compensation device; calculating a power angle value of the synchronous machine before and after the fault by using the equations; and calculating a capacity demand value of the reactive compensation device of a busbar of the multi-machine system by using an area method according to the equations and the power angle value of the synchronous machine, so as to improve the rationality of the capacity of the reactive compensation device of the multi-machine system, reduce the probability of transient power angle instability of the synchronous machine of the multi-machine system, and solve the problem that the synchronous machine is unstable in transient power angle when the multi-machine system is faulty due to the irrational capacity of the reactive compensation device.

Description

Technical Field

[0001] This invention relates to the field of capacity configuration of reactive power compensation devices, and more particularly to a method and system for capacity configuration of reactive power compensation devices in a multi-machine system. Background Technology

[0002] With the accelerating pace of the global clean and low-carbon energy transition, promoting green and low-carbon technological innovation and developing a modern energy system based on renewable energy has become an international consensus. In actual power grids, with a large number of new energy power generation units combined with thermal power generation units and connected to the grid, a fault in the multi-unit system can lead to transient power angle instability in the synchronous machine. Although existing technologies can improve the transient power angle stability of the synchronous machine by configuring reactive power compensation devices at the busbar of the multi-unit system to maintain the transient voltage of each node, existing technologies typically select reactive power compensation devices with fixed capacity and configure them on the busbar. Due to the unreasonable capacity of the reactive power compensation devices, the existing technology cannot adapt to the faults in the multi-unit system, resulting in transient power angle instability of the synchronous machine when the multi-unit system fails. Summary of the Invention

[0003] This invention provides a method and system for configuring the capacity of a reactive power compensation device in a multi-machine system, which can solve the problem that the existing technology cannot adapt to the failure of the multi-machine system due to the unreasonable capacity configuration of the reactive power compensation device, resulting in the transient power angle instability of the synchronous machine when the multi-machine system fails.

[0004] To address the aforementioned technical problems, one embodiment of the present invention provides a method for configuring the capacity of a reactive power compensation device in a multi-machine system, comprising:

[0005] Based on the system parameters of a multi-machine system equipped with a reactive power compensation device, the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronous machine are constructed before and after the fault is cleared in the multi-machine system.

[0006] Based on the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronizing machine before the multi-machine system failure, calculate the stable power angle of the first synchronizing machine before the multi-machine system failure.

[0007] Calculate the output power angle of the synchronizer when the multi-machine system fault is cleared, based on the stable power angle of the first synchronizer.

[0008] Based on the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronizer after the fault is cleared in the multi-machine system, calculate the stable power angle of the second synchronizer after the fault is cleared in the multi-machine system.

[0009] The area of ​​the first region is calculated based on the stable power angle of the first synchronizer and the output power angle of the synchronizer when the multi-machine system fault is cleared; wherein, the area of ​​the first region is the area enclosed by the change of the mechanical power of the synchronizer from the stable power angle of the first synchronizer to the output power angle of the synchronizer when the multi-machine system fault is cleared.

[0010] The area of ​​the second region is calculated based on the output power angle of the synchronizer when the multi-machine system fault is cleared and the stable power angle of the second synchronizer. The area of ​​the second region is the area enclosed by the electromagnetic power phase angle characteristic curve of the synchronizer after the multi-machine system fault is cleared from the output power angle of the synchronizer when the fault is cleared to the stable power angle of the second synchronizer, and the mechanical power line of the synchronizer.

[0011] Based on the areas of the first and second regions, calculate the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronous machine.

[0012] The capacity requirement of the reactive power compensation device is calculated based on the magnification factor of the phase angle characteristic curve of the electromagnetic power of the synchronous machine, and the capacity of the reactive power compensation device is configured according to the capacity requirement.

[0013] Furthermore, the equation for the phase angle characteristic curve of the electromagnetic power of the synchronizing machine before the fault in the multi-machine system is:

[0014]

[0015] The mechanical power phase angle characteristic equation of the synchronizing machine before the fault in the multi-machine system is:

[0016]

[0017] Wherein, P G The electromagnetic power of the synchronizing machine before the fault is represented; C represents the magnification factor of the phase angle characteristic curve of the electromagnetic power of the synchronizing machine; E G This represents the internal potential voltage of the synchronizer before the fault; the U S This indicates the collected bus voltage before the fault; the P W The Q value represents the active power of the new energy source before the fault; W This indicates the reactive power of the new energy source before the fault; the aforementioned The The X1, X2, and X3 represent the line resistance of the multi-machine system; U W This represents the voltage at the node of the new energy power station before the fault; the δ G Indicates the synchronous motor power angle before the fault; the δ W This indicates the phase angle of the new energy source voltage before the fault; the... The power factor angle represents the power injected by the reactive power compensation device into the grid connection point of the multi-machine system; the PM The δ′0 represents the mechanical power of the synchronizing machine; the δ′0 represents the first stable power angle of the synchronizing machine before the multi-machine system failure; the δ W0 This indicates the voltage phase angle at the new energy terminal during stable operation before a multi-machine system failure.

[0018] Furthermore, the equation for the phase angle characteristic curve of the electromagnetic power of the synchronous machine after the fault clearance of the multi-machine system is as follows:

[0019]

[0020] The mechanical power phase angle characteristic equation of the synchronizer after the fault clearance of the multi-machine system is:

[0021]

[0022] Wherein, P G ′ represents the electromagnetic power of the synchronizer after the fault is cleared; C represents the magnification factor of the phase angle characteristic curve of the electromagnetic power of the synchronizer; E G ′ represents the internal potential voltage of the synchronizer after the fault is cleared; the U S ′ represents the collected bus voltage after fault clearance; the P W ′ represents the active power of the new energy source after the fault is cleared; the Q W ′ represents the reactive power of the new energy source after the fault is cleared; the The The X1, X2, and X3 represent the line resistance of the multi-machine system; X 1c =2X1; the U W ' represents the node voltage of the new energy power station after the fault is cleared; the δ G ′ represents the synchronous motor power angle after the fault is cleared; the δ W ′ represents the phase angle of the new energy terminal voltage after the fault is cleared; the The power factor angle represents the power injected by the reactive power compensation device into the grid connection point of the multi-machine system after the fault is cleared; the P M The δ′ represents the mechanical power of the synchronizing machine; cr The δ represents the stable power angle of the second synchronizer after the fault is cleared in the multi-machine system; Wcr This indicates the phase angle of the new energy terminal voltage after the fault is cleared.

[0023] Furthermore, the synchronous machine output power angle during fault clearing in the multi-machine system satisfies the following calculation formula:

[0024] Wherein, the δ′ c The output power angle of the synchronizer when the multi-machine system fault is cleared; δ′0 represents the first stable power angle of the synchronizer before the multi-machine system fault; PM The ω represents the mechanical power of the synchronizing machine; N The T represents the rated angular velocity of the multi-machine system; J The time constant of the synchronizing machine is represented by Δt; the time of the segmented calculation step is represented by Δt.

[0025] Furthermore, the calculation of the area of ​​the first region satisfies the following formula:

[0026] S ac =P M (δ′ c -δ′0);

[0027] Wherein, the δ′ c The output power angle of the synchronizer when the multi-machine system fault is cleared; δ′0 represents the first stable power angle of the synchronizer before the multi-machine system fault; P M Indicates the mechanical power of the synchronizing machine; the S ac The area of ​​the first region is defined as the area enclosed by the synchronous machine's mechanical power changing from the stable power angle of the first synchronous machine to the output power angle of the synchronous machine when the multi-machine system fault is cleared.

[0028] Furthermore, the calculation of the area of ​​the second region satisfies the following formula:

[0029]

[0030] Wherein, the δ′ c The δ′ represents the output power angle of the synchronizer when a fault is cleared in a multi-machine system; cr The second synchronous machine's stable power angle is indicated by the fault clearing mechanism of the multi-machine system; C represents the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronous machine; E represents the stable power angle of the second synchronous machine after the fault clearing mechanism of the multi-machine system. G ′ represents the internal potential voltage of the synchronizer after the fault is cleared; the U S ′ represents the collected bus voltage after fault clearance; the P M ′ represents the active power of the new energy source after the fault is cleared; the Q W ′ represents the reactive power of the new energy source after the fault is cleared; the X1 and X3 represent the line resistance of the multi-machine system; X 1c =2X1; the U W ' represents the node voltage of the new energy power station after the fault is cleared; the δ G ′ represents the synchronous motor power angle after the fault is cleared; the δ W ′ represents the phase angle of the new energy terminal voltage after the fault is cleared; the S dcThe area of ​​the second region represents the area enclosed by the electromagnetic power phase angle characteristic curve of the synchronizer after the multi-machine system fault is cleared, from the change of the synchronizer output power angle at the time of fault clearing to the stable power angle of the second synchronizer, and the mechanical power line of the synchronizer.

[0031] Furthermore, the calculation of the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronous machine based on the area of ​​the first region and the area of ​​the second region includes:

[0032] Let the area of ​​the first region be equal to the area of ​​the second region, and calculate the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronous machine.

[0033] Furthermore, the step of calculating the capacity requirement of the reactive power compensation device based on the amplification factor of the amplitude of the electromagnetic power phase angle characteristic curve of the synchronous machine, and configuring the capacity of the reactive power compensation device according to the capacity requirement, includes:

[0034] The voltage of the bus before the reactive power compensation device is connected to the multi-level system is obtained. Combined with the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronous machine, the capacity requirement of the reactive power compensation device is calculated, and the capacity of the reactive power compensation device is configured according to the capacity requirement.

[0035] The capacity requirement of the reactive power compensation device is calculated according to the following formula: C represents the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronous machine; U L0 The voltage at the bushead before the reactive power compensation device is connected to the multi-stage system represents the voltage at which the reactive power compensation device is collected; X1 and X3 represent the line resistance of the multi-machine system; Q represents the voltage at the bushead before the reactive power compensation device is connected to the multi-stage system. V This indicates the capacity requirement of the reactive power compensation device.

[0036] Based on the above method embodiments, the present invention provides corresponding system embodiments;

[0037] An embodiment of the present invention provides a capacity configuration system for a reactive power compensation device in a multi-machine system, comprising: an equation construction module, a first calculation module, a second calculation module, a third calculation module, a first area calculation module, a second area calculation module, a multiplication factor calculation module, and a reactive power compensation device capacity configuration module;

[0038] The equation construction module is used to construct the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronous machine before and after the fault is cleared, based on the system parameters of the multi-machine system with a reactive power compensation device.

[0039] The first calculation module is used to calculate the first synchronizer stable power angle before the multi-machine system failure based on the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronizer before the multi-machine system failure.

[0040] The second calculation module is used to calculate the output power angle of the synchronizer when the multi-machine system fault is cleared, based on the stable power angle of the first synchronizer.

[0041] The third calculation module is used to calculate the stable power angle of the second synchronizer after the fault is cleared in the multi-machine system based on the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronizer after the fault is cleared in the multi-machine system.

[0042] The first area calculation module is used to calculate the area of ​​the first region based on the stable power angle of the first synchronizer and the output power angle of the synchronizer when the multi-machine system is cleared of a fault; wherein, the area of ​​the first region is the area enclosed by the change of the mechanical power of the synchronizer from the stable power angle of the first synchronizer to the output power angle of the synchronizer when the multi-machine system is cleared of a fault;

[0043] The second area calculation module is used to calculate the area of ​​the second region based on the output power angle of the synchronizer and the stable power angle of the second synchronizer when the multi-machine system fault is cleared; wherein, the area of ​​the second region is the area enclosed by the electromagnetic power phase angle characteristic curve of the synchronizer after the multi-machine system fault is cleared from the output power angle of the synchronizer when the multi-machine system fault is cleared to the stable power angle of the second synchronizer and the mechanical power line of the synchronizer.

[0044] The magnification factor calculation module is used to calculate the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronous machine based on the area of ​​the first region and the area of ​​the second region.

[0045] The reactive power compensation device capacity configuration module is used to calculate the capacity requirement of the reactive power compensation device based on the magnification factor of the amplitude of the phase angle characteristic curve of the synchronous machine electromagnetic power, and to configure the capacity of the reactive power compensation device according to the capacity requirement.

[0046] Compared with the prior art, the embodiments of the present invention have the following beneficial effects:

[0047] This invention constructs the electromagnetic power phase angle characteristic curve equations and mechanical power phase angle characteristic equations of the synchronizer before and after a multi-machine system fault. Based on these equations, it determines the first stable power angle of the synchronizer before the fault, the output power angle of the synchronizer when the fault is cleared, and the second stable power angle of the synchronizer after the fault is cleared. Then, it calculates the first and second regions of the synchronizer power angle based on these angles. Finally, it calculates the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronizer with a reactive power compensation device based on the first and second regions of the synchronizer power angle. The capacity requirement of the reactive power compensation device is obtained by calculating the magnification factor. That is, the present invention constructs the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronous machine before and after the fault of the multi-machine system by jointly constructing the parameters of each component in the multi-machine system with reactive power compensation device. Based on these equations, the power angle value of the synchronous machine before and after the fault is calculated. The capacity requirement value of the reactive power compensation device configured on the bus of the multi-machine system is calculated by using the area method based on the constructed equations and the power angle value of the synchronous machine. This improves the rationality of the capacity configuration of the reactive power compensation device in the multi-machine system, thereby reducing the probability of transient power angle instability of the synchronous machine in the multi-machine system. It solves the problem of transient power angle instability of the synchronous machine when the multi-machine system fails due to the unreasonable capacity configuration of the reactive power compensation device in the existing technology. Attached Figure Description

[0048] Figure 1 : A flowchart illustrating the steps of a capacity configuration method for a reactive power compensation device in a multi-machine system, as provided in an embodiment of the present invention;

[0049] Figure 2 : A system structure diagram of a capacity configuration system for a reactive power compensation device in a multi-machine system provided in an embodiment of the present invention;

[0050] Figure 3 : Equivalent circuit diagram of a multi-machine system with SVG configured on the bus hub provided in an embodiment of the present invention;

[0051] Figure 4 : A circuit structure diagram of a multi-machine system with an SVG device configured on the busbar, provided in an embodiment of the present invention;

[0052] Figure 5 : A curve showing the power angle characteristics of the synchronizing machine before and after a fault when a reactive power compensation device is configured on the busbar according to an embodiment of the present invention. Detailed Implementation

[0053] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0055] Example 1:

[0056] Reference Figure 1 The flowchart illustrates a method for configuring the capacity of a reactive power compensation device in a multi-machine system, as provided in an embodiment of the present invention. This method includes at least the following steps:

[0057] Step S1: Based on the system parameters of the multi-machine system with reactive power compensation device, construct the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronous machine before and after the fault is cleared.

[0058] In this embodiment, the system parameters can be obtained by measuring electronic measuring elements, as shown in the reference. Figure 3 This is an equivalent circuit diagram of a multi-machine system with SVG configured on a bus hub, provided in an embodiment of the present invention. Figure 3 It can be seen that after configuring SVG (Static Var Compensator) on the busbar, the output current of the synchronous machine is infinite. The results of current injection into node G by the synchronous machine (thermal power unit), new energy power station, and SVG are respectively denoted as: The formulas for each current component are as follows: Based on the formulas for each current component and according to the principle of linear network superposition, the mathematical expression for the output current of the synchronous machine is: The formula for the output electromagnetic power of a synchronous machine during normal operation in a multi-machine system is: By combining the formulas for the output current of the synchronous machine and the electromagnetic power output of the synchronous machine in a multi-machine system during normal operation, the mathematical expression for the electromagnetic power of the synchronous machine in a multi-machine system that combines new energy and synchronous machine power transmission can be obtained as follows:

[0059] Injected current With the voltage at the bus terminal Mathematical expression of the correspondence between them Substituting this into the mathematical expression for the electromagnetic power of the synchronous machine in a multi-machine system that combines new energy sources and synchronous machines for power transmission, we can obtain: Let the effect of configuring a reactive power compensation device on the electromagnetic power of the synchronous machine be: Furthermore, because the new energy source adopts a directional phase-locked loop control method based on d-axis voltage, its terminal voltage d-axis component u d =U W q-axis components The mathematical expressions for the active and reactive power of new energy sources are: Combining the above mathematical expressions, the mathematical expression for the output electromagnetic power of the synchronizing machine before a multi-machine system failure is as follows:

[0060] In this embodiment, according to the principle of linear network superposition, when a multi-machine system is configured with a reactive power compensation device, the bus voltage is collected. It can be regarded as an infinite power supply voltage Synchronous machine internal potential voltage and voltage of new energy power stations The sum of the voltage components at node L is expressed as: Then the voltage of the new energy power station The data expression is: Based on the data expression of the voltage at renewable energy power stations, the voltage at renewable energy power stations is decomposed into dq components to obtain the data expressions for the d-axis and q-axis components of the voltage at renewable energy power stations: Wherein, the U W Voltage for new energy power stations The E G The U is the internal potential voltage of the synchronizing machine; S Infinite power supply voltage Let the data expressions for the d-axis and q-axis components of the voltage at the renewable energy power station be equal to the mathematical expressions for the active and reactive power of the renewable energy, and then simplify and solve them to obtain the mathematical expression for the voltage amplitude at the renewable energy power station after configuring a reactive power compensation device on the busbar: Among them, A V =C 2 [(K1E G ) 2 +(K2U S ) 2 +2K1K2E G U S cosδ G +2Q W X iV ;

[0061] In this embodiment, the mathematical expression for the voltage amplitude at the new energy power station terminal after configuring a reactive power compensation device on the busbar is simplified and solved simultaneously with the data expression for the new energy power station voltage to obtain the phase angle δ of the new energy power station terminal voltage. W With the synchronous machine power angle δ GThe corresponding mathematical expression between them is: Among them, the The power factor angle represents the power injected by the reactive power compensation device into the grid connection point of the multi-machine system; Satisfy the following formula:

[0062] In this embodiment, based on the above mathematical expression, the equation of the phase angle characteristic curve of the synchronous machine's electromagnetic power before the multi-machine system failure is:

[0063]

[0064] The mechanical power phase angle characteristic equation of the synchronizing machine before the failure of the multi-machine system is:

[0065]

[0066] Wherein, P G The electromagnetic power of the synchronizing machine before the fault is represented; C represents the magnification factor of the phase angle characteristic curve of the electromagnetic power of the synchronizing machine; E G This represents the internal potential voltage of the synchronizer before the fault; the U S This indicates the collected bus voltage before the fault; the P W The Q value represents the active power of the new energy source before the fault; W This indicates the reactive power of the new energy source before the fault; the aforementioned The The X1, X2, and X3 represent the line resistance of the multi-machine system; U W This represents the voltage at the node of the new energy power station before the fault; the δ G Indicates the synchronous motor power angle before the fault; the δ W This indicates the phase angle of the new energy source voltage before the fault; the... The power factor angle represents the power injected by the reactive power compensation device into the grid connection point of the multi-machine system; the P M The δ′0 represents the mechanical power of the synchronizing machine; the δ′0 represents the first stable power angle of the synchronizing machine before the multi-machine system failure; the δ W0 This indicates the voltage phase angle at the new energy terminal during stable operation before a multi-machine system failure.

[0067] In this embodiment, refer to Figure 4 This is a line structure diagram of a multi-machine system with an SVG device configured on the busbar, provided in an embodiment of the present invention. The fault condition of the multi-machine system is set as a three-phase short-circuit fault occurring at the busbar L adjacent to line Line 1-II. Compared to the condition before the multi-machine system fault is cleared, the equivalent impedance of line Line 1 changes, and its impedance value X... 1cIt is equal to twice the equivalent impedance of Line 1 before the multi-machine system failure, i.e., X. 1c =2X1, and combining the phase angle characteristic curve equation of the synchronous machine's electromagnetic power before the multi-machine system fault, the phase angle characteristic curve equation of the synchronous machine's electromagnetic power after the multi-machine system fault is cleared is constructed as follows:

[0068]

[0069] The mechanical power phase angle characteristic equation of the synchronizer after fault clearance in a multi-machine system is:

[0070]

[0071] Wherein, P G ′ represents the electromagnetic power of the synchronizer after the fault is cleared; C represents the magnification factor of the phase angle characteristic curve of the electromagnetic power of the synchronizer; E G ′ represents the internal potential voltage of the synchronizer after the fault is cleared; the U S ′ represents the collected bus voltage after fault clearance; the P W ′ represents the active power of the new energy source after the fault is cleared; the Q W ′ represents the reactive power of the new energy source after the fault is cleared; the The The X1, X2, and X3 represent the line resistance of the multi-machine system; X 1c =2X1; the U W ' represents the node voltage of the new energy power station after the fault is cleared; the δ G ′ represents the synchronous motor power angle after the fault is cleared; the δ W ′ represents the phase angle of the new energy terminal voltage after the fault is cleared; the The power factor angle represents the power injected by the reactive power compensation device into the grid connection point of the multi-machine system after the fault is cleared; the P M The δ′ represents the mechanical power of the synchronizing machine; cr The δ represents the stable power angle of the second synchronizer after the fault is cleared in the multi-machine system; Wcr This indicates the phase angle of the new energy terminal voltage after the fault is cleared.

[0072] Step S2: Calculate the first synchronizing power angle before the multi-machine system failure based on the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronizing machine before the failure.

[0073] In this embodiment, the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronizing machine before the multi-machine system failure are solved simultaneously to obtain the first stable power angle (δ) of the synchronizing machine before the multi-machine system failure. ′0); where the first synchronous machine's stable power angle is the synchronous machine's power angle before the fault (δ) in the synchronous machine's electromagnetic power phase angle characteristic curve equation before the multi-machine system fault. G ).

[0074] Step S3: Calculate the output power angle of the synchronizer when the multi-machine system fault is cleared, based on the stable power angle of the first synchronizer.

[0075] In this embodiment, the output power angle of the synchronizer when the multi-machine system fault is cleared is calculated based on the first stable power angle of the synchronizer before the multi-machine system fault, the rated angular velocity of the multi-machine system, the inertial time constant of the synchronizer, the segmented calculation step time, and the mechanical power of the synchronizer.

[0076] The synchronous machine output power angle during fault clearing in the multi-machine system satisfies the following calculation formula:

[0077] The δ′ c The output power angle of the synchronizer when the multi-machine system fault is cleared; δ′0 represents the first stable power angle of the synchronizer before the multi-machine system fault; P M The ω represents the mechanical power of the synchronizing machine; N This represents the rated angular velocity of the multi-machine system, set as w. N =18000° / s; the T J The time constant of the synchronizing machine is represented by Δt; the time of the segmented calculation step is represented by Δt = 0.05s.

[0078] Step S4: Calculate the stable power angle of the second synchronous machine after the fault is cleared, based on the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronous machine after the fault is cleared in the multi-machine system.

[0079] In this embodiment, the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronous machine after the fault clearing of the multi-machine system are solved simultaneously to obtain the stable power angle (δ′) of the second synchronous machine after the fault clearing of the multi-machine system. cr ); where the second synchronous machine stable power angle is the synchronous machine power angle (δ′) after fault clearance in the synchronous machine electromagnetic power phase angle characteristic curve equation after fault clearance in a multi-machine system. G ).

[0080] Step S5: Calculate the area of ​​the first region based on the stable power angle of the first synchronizer and the output power angle of the synchronizer when the multi-machine system fault is cleared; wherein, the area of ​​the first region is the area enclosed by the change of the mechanical power of the synchronizer from the stable power angle of the first synchronizer to the output power angle of the synchronizer when the multi-machine system fault is cleared.

[0081] In this embodiment, please refer to Figure 5This invention provides a diagram showing the synchronous motor power angle characteristic curves before and after a fault when a reactive power compensation device is configured on the busbar. Based on the synchronous motor output power angle during multi-machine system fault clearing, the first stable synchronous motor power angle before the multi-machine system fault, and the synchronous motor mechanical power, the area of ​​the first region is calculated. The calculation of the first region area satisfies the following formula: S ac =P M (δ′c-δ′0); the δ′ c The output power angle of the synchronizer when the multi-machine system fault is cleared; δ′0 represents the first stable power angle of the synchronizer before the multi-machine system fault; P M Indicates the mechanical power of the synchronizing machine; the S ac The area of ​​the first region is defined as the area enclosed by the synchronous machine's mechanical power changing from the stable power angle of the first synchronous machine to the output power angle of the synchronous machine when the multi-machine system fault is cleared.

[0082] Step S6: Calculate the area of ​​the second region based on the output power angle of the synchronizer when the multi-machine system fault is cleared and the stable power angle of the second synchronizer; wherein, the area of ​​the second region is the area enclosed by the electromagnetic power phase angle characteristic curve of the synchronizer after the multi-machine system fault is cleared from the output power angle of the synchronizer when the multi-machine system fault is cleared to the stable power angle of the second synchronizer and the mechanical power line of the synchronizer.

[0083] In this embodiment, please refer to Figure 5 The diagram shows the power angle characteristic curves of the synchronizing machine before and after a fault when a reactive power compensation device is configured on the busbar, as provided in this embodiment of the invention. The area of ​​the second region is calculated according to the following formula:

[0084]

[0085] Wherein, the δ′ C The δ′ represents the output power angle of the synchronizer when a fault is cleared in a multi-machine system; Cr The second synchronous machine's stable power angle is indicated by the fault clearing mechanism of the multi-machine system; C represents the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronous machine; E′ represents the stable power angle of the second synchronous machine after the fault clearing mechanism of the multi-machine system. G U′ represents the internal potential voltage of the synchronizer after the fault is cleared; S This indicates the collected bus voltage after the fault is cleared; the P W ′ represents the active power of the new energy source after the fault is cleared; the G W ′ represents the reactive power of the new energy source after the fault is cleared; the x1 and x3 represent the line resistance of the multi-machine system; X 1c =2X1; the U W ' represents the node voltage of the new energy power station after the fault is cleared; the δ G ′ represents the synchronous motor power angle after the fault is cleared; the δW ′ represents the phase angle of the new energy terminal voltage after the fault is cleared; the s dc The area of ​​the second region represents the area enclosed by the electromagnetic power phase angle characteristic curve of the synchronizer after the multi-machine system fault is cleared, from the change of the synchronizer output power angle at the time of fault clearing to the stable power angle of the second synchronizer, and the mechanical power line of the synchronizer.

[0086] Step S7: Calculate the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronous machine based on the area of ​​the first region and the area of ​​the second region;

[0087] In this embodiment, the area of ​​the first region is equal to the area of ​​the second region, and the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronous machine is calculated.

[0088] Step S8: Calculate the capacity requirement of the reactive power compensation device based on the magnification factor of the phase angle characteristic curve of the synchronous machine electromagnetic power, and configure the capacity of the reactive power compensation device according to the capacity requirement.

[0089] In this embodiment, the bus voltage before the reactive power compensation device is connected to the multi-level system is obtained by electronic measuring elements, and the capacity requirement of the reactive power compensation device is calculated by combining the amplification factor of the phase angle characteristic curve of the synchronous machine electromagnetic power. Finally, the capacity of the reactive power compensation device is configured according to the capacity requirement.

[0090] The capacity requirement of the reactive power compensation device is calculated according to the following formula: C represents the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronous machine; U L0 The voltage at the bushead before the reactive power compensation device is connected to the multi-stage system represents the voltage at which the reactive power compensation device is collected; X1 and X3 represent the line resistance of the multi-machine system; Q represents the voltage at the bushead before the reactive power compensation device is connected to the multi-stage system. V This indicates the capacity requirement of the reactive power compensation device.

[0091] Example 2:

[0092] Reference Figure 2 The present invention provides a system structure diagram of a capacity configuration system for a reactive power compensation device in a multi-machine system. The system includes: an equation construction module, a first calculation module, a second calculation module, a third calculation module, a first area calculation module, a second area calculation module, a multiplication factor calculation module, and a reactive power compensation device capacity configuration module.

[0093] The equation construction module is used to construct the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronous machine before and after the fault is cleared, based on the system parameters of the multi-machine system with a reactive power compensation device.

[0094] The first calculation module is used to calculate the first synchronizer stable power angle before the multi-machine system failure based on the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronizer before the multi-machine system failure.

[0095] The second calculation module is used to calculate the output power angle of the synchronizer when the multi-machine system fault is cleared, based on the stable power angle of the first synchronizer.

[0096] The third calculation module is used to calculate the stable power angle of the second synchronizer after the fault is cleared in the multi-machine system based on the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronizer after the fault is cleared in the multi-machine system.

[0097] The first area calculation module is used to calculate the area of ​​the first region based on the stable power angle of the first synchronizer and the output power angle of the synchronizer when the multi-machine system is cleared of a fault; wherein, the area of ​​the first region is the area enclosed by the change of the mechanical power of the synchronizer from the stable power angle of the first synchronizer to the output power angle of the synchronizer when the multi-machine system is cleared of a fault;

[0098] The second area calculation module is used to calculate the area of ​​the second region based on the output power angle of the synchronizer and the stable power angle of the second synchronizer when the multi-machine system fault is cleared; wherein, the area of ​​the second region is the area enclosed by the electromagnetic power phase angle characteristic curve of the synchronizer after the multi-machine system fault is cleared from the output power angle of the synchronizer when the multi-machine system fault is cleared to the stable power angle of the second synchronizer and the mechanical power line of the synchronizer.

[0099] The magnification factor calculation module is used to calculate the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronous machine based on the area of ​​the first region and the area of ​​the second region.

[0100] The reactive power compensation device capacity configuration module is used to calculate the capacity requirement of the reactive power compensation device based on the magnification factor of the amplitude of the phase angle characteristic curve of the synchronous machine electromagnetic power, and to configure the capacity of the reactive power compensation device according to the capacity requirement.

[0101] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. In particular, it should be noted that any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention for those skilled in the art.

Claims

1. A method for configuring the capacity of a reactive power compensation device in a multi-machine system, characterized in that, include: Based on the system parameters of a multi-machine system equipped with a reactive power compensation device, the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronous machine are constructed before and after the fault is cleared in the multi-machine system. Based on the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronizing machine before the multi-machine system failure, calculate the stable power angle of the first synchronizing machine before the multi-machine system failure. Calculate the output power angle of the synchronizer when the multi-machine system fault is cleared, based on the stable power angle of the first synchronizer. Based on the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronizer after the fault is cleared in the multi-machine system, calculate the stable power angle of the second synchronizer after the fault is cleared in the multi-machine system. The area of ​​the first region is calculated based on the stable power angle of the first synchronizer and the output power angle of the synchronizer when the multi-machine system fault is cleared; wherein, the area of ​​the first region is the area enclosed by the change of the mechanical power of the synchronizer from the stable power angle of the first synchronizer to the output power angle of the synchronizer when the multi-machine system fault is cleared. The area of ​​the second region is calculated based on the output power angle of the synchronizer when the multi-machine system fault is cleared and the stable power angle of the second synchronizer. The area of ​​the second region is the area enclosed by the electromagnetic power phase angle characteristic curve of the synchronizer after the multi-machine system fault is cleared from the output power angle of the synchronizer when the fault is cleared to the stable power angle of the second synchronizer, and the mechanical power line of the synchronizer. The amplification factor of the electromagnetic power phase angle characteristic curve of the synchronizer is calculated based on the area of ​​the first region and the area of ​​the second region; wherein, the calculation of the amplification factor of the electromagnetic power phase angle characteristic curve of the synchronizer based on the area of ​​the first region and the area of ​​the second region includes: setting the area of ​​the first region equal to the area of ​​the second region, and calculating the amplification factor of the electromagnetic power phase angle characteristic curve of the synchronizer. The capacity requirement of the reactive power compensation device is calculated based on the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronous machine, and the capacity of the reactive power compensation device is configured according to the capacity requirement; wherein, the calculation of the capacity requirement of the reactive power compensation device based on the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronous machine, and the configuration of the capacity of the reactive power compensation device according to the capacity requirement, includes: The voltage of the bus before the reactive power compensation device is connected to the multi-machine system is obtained. Combined with the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronous machine, the capacity requirement of the reactive power compensation device is calculated, and the capacity of the reactive power compensation device is configured according to the capacity requirement. The capacity requirement of the reactive power compensation device is calculated according to the following formula: C represents the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronous machine; U L0 The voltage at the bushead before the reactive power compensation device is connected to the multi-machine system represents the voltage at which the reactive power compensation device is collected; X1 and X3 represent the line resistance of the multi-machine system; Q represents the voltage at the bushead before the reactive power compensation device is connected to the multi-machine system. V This indicates the capacity requirement of the reactive power compensation device.

2. The capacity configuration method for a reactive power compensation device in a multi-machine system according to claim 1, characterized in that, The equation for the phase angle characteristic curve of the synchronous machine's electromagnetic power before the fault in the multi-machine system is: The mechanical power phase angle characteristic equation of the synchronizing machine before the fault in the multi-machine system is: Wherein, P G The electromagnetic power of the synchronizing machine before the fault is represented; C represents the magnification factor of the phase angle characteristic curve of the electromagnetic power of the synchronizing machine; E G This represents the internal potential voltage of the synchronizer before the fault; the U S This indicates the collected bus voltage before the fault; the P W The Q value represents the active power of the new energy source before the fault; W This indicates the reactive power of the new energy source before the fault; the aforementioned The The X1, X2, and X3 represent the line resistance of the multi-machine system; U W This represents the voltage at the node of the new energy power station before the fault; the δ G Indicates the synchronous motor power angle before the fault; the δ W This indicates the phase angle of the new energy source voltage before the fault; the... The power factor angle represents the power injected by the reactive power compensation device into the grid connection point of the multi-machine system; the P M The δ′0 represents the mechanical power of the synchronizing machine; the δ′0 represents the first stable power angle of the synchronizing machine before the multi-machine system failure; the δ W0 This indicates the voltage phase angle at the new energy terminal during stable operation before a multi-machine system failure.

3. The capacity configuration method for a reactive power compensation device in a multi-machine system according to claim 1, characterized in that, The equation for the phase angle characteristic curve of the synchronous machine's electromagnetic power after the fault clearance of the multi-machine system is: The mechanical power phase angle characteristic equation of the synchronizer after the fault clearance of the multi-machine system is: Wherein, P′ G The electromagnetic power of the synchronizer after fault clearance is indicated; C represents the magnification factor of the phase angle characteristic curve of the synchronizer's electromagnetic power; E′ G This represents the internal potential voltage of the synchronizer after the fault is cleared; the U S ′ represents the collected bus voltage after fault clearance; the P W ′ represents the active power of the new energy source after the fault is cleared; the Q W ′ represents the reactive power of the new energy source after the fault is cleared; the The The X1, X2, and X3 represent the line resistance of the multi-machine system; X 1c =2X1; the U W This represents the node voltage of the new energy power station after the fault is cleared; the δ G ′ represents the synchronous motor power angle after the fault is cleared; the δ W ′ represents the phase angle of the new energy terminal voltage after the fault is cleared; the The power factor angle represents the power injected by the reactive power compensation device into the grid connection point of the multi-machine system after the fault is cleared; the P M The δ′ represents the mechanical power of the synchronizing machine; cr The δ represents the stable power angle of the second synchronizer after the fault is cleared in the multi-machine system; Wcr This indicates the phase angle of the new energy terminal voltage after the fault is cleared.

4. The capacity configuration method for a reactive power compensation device in a multi-machine system according to claim 1, characterized in that, The synchronous machine output power angle during fault clearing in a multi-machine system satisfies the following calculation formula: Wherein, δ′c represents the output power angle of the synchronizer when the multi-machine system fault is cleared; δ′0 represents the first stable power angle of the synchronizer before the multi-machine system fault; PM represents the mechanical power of the synchronizer; and ω N The T represents the rated angular velocity of the multi-machine system; J The time constant of the synchronizing machine is represented by Δt; the time of the segmented calculation step is represented by Δt.

5. The capacity configuration method for a reactive power compensation device in a multi-machine system according to claim 1, characterized in that, The calculation of the area of ​​the first region satisfies the following formula: S ac =PM(δ′ c -δ′0); Wherein, the δ′ c The output power angle of the synchronizer when the multi-machine system fault is cleared; δ′0 represents the first stable power angle of the synchronizer before the multi-machine system fault; P M Indicates the mechanical power of the synchronizing machine; the S ac The area of ​​the first region is defined as the area enclosed by the synchronous machine's mechanical power changing from the stable power angle of the first synchronous machine to the output power angle of the synchronous machine when the multi-machine system fault is cleared.

6. The capacity configuration method for a reactive power compensation device in a multi-machine system according to claim 1, characterized in that, The calculation of the area of ​​the second region satisfies the following formula: Wherein, the δ′ c The δ′ represents the output power angle of the synchronizer when a fault is cleared in a multi-machine system; cr The second synchronous machine's stable power angle is indicated by the fault clearing mechanism of the multi-machine system; C represents the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronous machine; E represents the stable power angle of the second synchronous machine after the fault clearing mechanism of the multi-machine system. G ′ represents the internal potential voltage of the synchronizer after the fault is cleared; the U S ′ represents the collected bus voltage after fault clearance; the P W ′ represents the active power of the new energy source after the fault is cleared; the Q W ′ represents the reactive power of the new energy source after the fault is cleared; the X1 and X3 represent the line resistance of the multi-machine system; X 1c =2X1; the U W ' represents the node voltage of the new energy power station after the fault is cleared; the δG ′ ′ represents the synchronous motor power angle after the fault is cleared; the δ W ′ represents the phase angle of the new energy terminal voltage after the fault is cleared; the S dc The area of ​​the second region represents the area enclosed by the electromagnetic power phase angle characteristic curve of the synchronizer after the multi-machine system fault is cleared, from the change in the synchronizer's output power angle at the time of fault clearing to the stable power angle of the second synchronizer, and the mechanical power line of the synchronizer; P M This indicates the mechanical power of the synchronizing machine.

7. A capacity configuration system for a reactive power compensation device in a multi-machine system, characterized in that, include: The system includes an equation construction module, a first calculation module, a second calculation module, a third calculation module, a first region area calculation module, a second region area calculation module, a multiplier calculation module, and a reactive power compensation device capacity configuration module. The equation construction module is used to construct the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronous machine before and after the fault is cleared, based on the system parameters of the multi-machine system with a reactive power compensation device. The first calculation module is used to calculate the first synchronizer stable power angle before the multi-machine system failure based on the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronizer before the multi-machine system failure. The second calculation module is used to calculate the output power angle of the synchronizer when the multi-machine system fault is cleared, based on the stable power angle of the first synchronizer. The third calculation module is used to calculate the stable power angle of the second synchronizer after the fault is cleared in the multi-machine system based on the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronizer after the fault is cleared in the multi-machine system. The first area calculation module is used to calculate the area of ​​the first region based on the stable power angle of the first synchronizer and the output power angle of the synchronizer when the multi-machine system is cleared of a fault; wherein, the area of ​​the first region is the area enclosed by the change of the mechanical power of the synchronizer from the stable power angle of the first synchronizer to the output power angle of the synchronizer when the multi-machine system is cleared of a fault; The second area calculation module is used to calculate the area of ​​the second region based on the output power angle of the synchronizer and the stable power angle of the second synchronizer when the multi-machine system fault is cleared; wherein, the area of ​​the second region is the area enclosed by the electromagnetic power phase angle characteristic curve of the synchronizer after the multi-machine system fault is cleared from the output power angle of the synchronizer when the multi-machine system fault is cleared to the stable power angle of the second synchronizer and the mechanical power line of the synchronizer. The magnification factor calculation module is used to calculate the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronous machine based on the area of ​​the first region and the area of ​​the second region; wherein, the calculation of the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronous machine based on the area of ​​the first region and the area of ​​the second region includes: setting the area of ​​the first region equal to the area of ​​the second region, and calculating the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronous machine. The reactive power compensation device capacity configuration module is used to calculate the capacity requirement of the reactive power compensation device based on the magnification factor of the amplitude of the synchronous machine's electromagnetic power phase angle characteristic curve, and to configure the capacity of the reactive power compensation device according to the capacity requirement; wherein, the step of calculating the capacity requirement of the reactive power compensation device based on the magnification factor of the amplitude of the synchronous machine's electromagnetic power phase angle characteristic curve, and configuring the capacity of the reactive power compensation device according to the capacity requirement, includes: The voltage of the bus before the reactive power compensation device is connected to the multi-machine system is obtained. Combined with the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronous machine, the capacity requirement of the reactive power compensation device is calculated, and the capacity of the reactive power compensation device is configured according to the capacity requirement. The capacity requirement of the reactive power compensation device is calculated according to the following formula: C represents the magnification factor of the electromagnetic power phase angle characteristic curve of the synchronous machine; U L0 The voltage at the bushead before the reactive power compensation device is connected to the multi-machine system represents the voltage at which the reactive power compensation device is collected; X1 and X3 represent the line resistance of the multi-machine system; Q represents the voltage at the bushead before the reactive power compensation device is connected to the multi-machine system. V This indicates the capacity requirement of the reactive power compensation device.

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