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

Abstract

The invention discloses a capacity configuration method and system for a reactive power compensation device of a multi-machine system. According to the method, a synchronous machine electromagnetic power phase angle characteristic curve equation and a synchronous machine mechanical power phase angle characteristic equation before a fault of the multi-machine system and after the fault is removed are jointly constructed through parameters of all elements in the multi-machine system configured with the reactive power compensation device, and power angle values before and after the fault of the synchronous machine are calculated according to the equation; the capacity demand value of the reactive power compensation device configured by the collection bus in the multi-machine system is calculated by using an area method according to the constructed equation and the power angle value of the synchronous machine, so that the rationality of the capacity of the reactive power compensation device configured by the multi-machine system is improved, and the probability of transient power angle instability transmission of the synchronous machine of the multi-machine system is further reduced. The problem that in the prior art, due to the fact that the capacity of a configured reactive power compensation device is unreasonable and cannot adapt to faults of a multi-machine system, transient state power angle instability occurs when the multi-machine system breaks down is solved.

Description

Technical Field

[0001] The present invention relates to the field of capacity configuration of reactive power compensation devices, and in particular to a capacity configuration method and system for reactive power compensation devices of a multi-machine system. Background Art

[0002] With the acceleration of the global energy clean and low-carbon transformation, it has become the consensus of the international community to promote green and low-carbon technology innovation and develop a modern energy system dominated by renewable energy. In the actual power grid, as a large number of new energy power generation devices are combined with thermal power generation devices to generate electricity and connect to the grid, when a multi-machine system fails, it will cause the synchronous machine to have transient power angle instability. Although the existing technology can improve the transient power angle stability of the synchronous machine by configuring a reactive compensation device at the collection bus in the multi-machine system and maintaining the transient voltage of each node in the system, the existing technology usually selects a fixed capacity reactive compensation device to be configured on the collection bus. The existing technology cannot adapt to the failure of the multi-machine system due to the unreasonable capacity of the reactive compensation device, which causes the synchronous machine to have transient power angle instability when the multi-machine system fails. Summary of the invention

[0003] The present invention provides a capacity configuration method and system for a reactive power compensation device of a multi-machine system, which can solve the problem in the prior art that the capacity of the reactive power compensation device is not reasonably configured and cannot adapt to the failure of the multi-machine system, resulting in transient power angle instability of the synchronous machine when a failure occurs in the multi-machine system.

[0004] In order to solve the above technical problem, an embodiment of the present invention provides a capacity configuration method of a reactive power compensation device of a multi-machine system, comprising:

[0005] According to the system parameters of the multi-machine system equipped with reactive power compensation device, the synchronous machine electromagnetic power phase angle characteristic curve equation and the synchronous machine mechanical power phase angle characteristic equation are constructed before and after the fault of the multi-machine system is removed;

[0006] According to the synchronous machine electromagnetic power phase angle characteristic curve equation and the synchronous machine mechanical power phase angle characteristic equation before the multi-machine system fails, the stable power angle of the first synchronous machine before the multi-machine system fails is calculated;

[0007] Calculating the output power angle of the synchronous machine when a fault in the multi-machine system is removed according to the stable power angle of the first synchronous machine;

[0008] According to the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronous machine after the multi-machine system fault is removed, the stable power angle of the second synchronous machine after the multi-machine system fault is removed is calculated;

[0009] Calculate the area of ​​the first region according to the first synchronous machine stable power angle and the synchronous machine output power angle when the multi-machine system fault is cleared; wherein the first region area is the area enclosed by the synchronous machine mechanical power changing from the first synchronous machine stable power angle to the synchronous machine output power angle when the multi-machine system fault is cleared;

[0010] The area of ​​the second region is calculated according to the output power angle of the synchronous machine when the multi-machine system fault is removed and the stable power angle of the second synchronous machine; wherein the area of ​​the second region is the area enclosed by the synchronous machine mechanical power straight line when the phase angle characteristic curve of the electromagnetic power of the synchronous machine after the multi-machine system fault is removed changes from the output power angle of the synchronous machine when the multi-machine system fault is removed to the stable power angle of the second synchronous machine;

[0011] Calculating the magnification factor of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve according to the area of ​​the first region and the area of ​​the second region;

[0012] According to the magnification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve, the capacity demand value of the reactive power compensation device is calculated, and the capacity of the reactive power compensation device is configured according to the capacity demand value.

[0013] Furthermore, the equation of the synchronous machine electromagnetic power phase angle characteristic curve before the multi-machine system fails is:

[0014]

[0015] The mechanical power phase angle characteristic equation of the synchronous machine before the multi-machine system fails is:

[0016]

[0017] Among them, the P G represents the electromagnetic power of the synchronous machine before the fault; the C represents the magnification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve; the E G represents the internal potential voltage of the synchronous machine before the fault; S Indicates the bus voltage before the fault; W Indicates the active power of the new energy before the fault; W Indicates the reactive power of the new energy before the fault; Said Said X1, X2 and X3 represent the line resistance of the multi-machine system; W Represents the node terminal voltage of the new energy station before the fault; G represents the synchronous machine power angle before the fault; the δ W Indicates the voltage phase angle of the new energy terminal before the fault; Indicates the power factor angle of the reactive power compensation device injecting power into the multi-machine system grid connection point; the PM represents the mechanical power of the synchronous machine; the δ′0 represents the stable power angle of the first synchronous machine before the multi-machine system fails; the δ W0 Indicates the voltage phase angle of the new energy terminal when the multi-machine system is running stably before failure.

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

[0019]

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

[0021]

[0022] Among them, the P G ′ represents the electromagnetic power of the synchronous machine after the fault is removed; C represents the magnification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve; E G ′ represents the internal potential voltage of the synchronous machine after the fault is removed; the U S ′ represents the bus voltage after the fault is removed; the P W ′ represents the active power of the new energy after the fault is removed; W ' represents the reactive power of the new energy after the fault is removed; Said Said X1, X2 and X3 represent the line resistance of the multi-machine system; 1c =2X1; the U W ′ represents the node terminal voltage of the new energy station after the fault is removed; the δ G ′ represents the synchronous machine power angle after fault removal; the δ W ′ represents the voltage phase angle of the new energy terminal after the fault is removed; It indicates the power factor angle of the reactive power compensation device injecting power into the multi-machine system grid connection point after the fault is removed; the P M represents the mechanical power of the synchronous machine; the δ′ cr represents the stable power angle of the second synchronous machine after the multi-machine system fault is removed; the δ Wcr Indicates the voltage phase angle of the new energy terminal after the fault is removed.

[0023] Furthermore, the calculation of the synchronous machine output power angle when the multi-machine system fault is removed satisfies the following calculation formula:

[0024] Among them, the δ′ c represents the output power angle of the synchronous machine when the multi-machine system fault is removed; the δ′0 represents the stable power angle of the first synchronous machine before the multi-machine system fault; the PM Represents the mechanical power of the synchronous machine; N Represents the rated angular velocity of the multi-machine system; J represents the inertia time constant of the synchronous machine; and Δt represents the step time of the segmented calculation.

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

[0026] S ac =P M (δ′ c -δ′0);

[0027] Among them, the δ′ c represents the output power angle of the synchronous machine when the multi-machine system fault is removed; the δ′0 represents the stable power angle of the first synchronous machine before the multi-machine system fault; the P M Represents the mechanical power of the synchronous machine; the S ac It indicates that the area of ​​the first region is the area enclosed by the output power angle of the synchronous machine when the mechanical power of the synchronous machine changes 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 calculation formula:

[0029]

[0030] Among them, the δ′ c Indicates the output power angle of the synchronous machine when the multi-machine system fault is cleared; the δ′ cr represents the stable power angle of the second synchronous machine after the multi-machine system fault is removed; the C represents the magnification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve; the E G ′ represents the internal potential voltage of the synchronous machine after the fault is removed; the U S ′ represents the bus voltage after the fault is removed; the P M ′ represents the active power of the new energy after the fault is removed; W ' represents the reactive power of the new energy after the fault is removed; X1 and X3 represent the line resistance of the multi-machine system; 1c =2X1; the U W ′ represents the node terminal voltage of the new energy station after the fault is removed; the δ G ′ represents the synchronous machine power angle after fault removal; the δ W ′ represents the voltage phase angle of the new energy terminal after the fault is removed; the S dcThe area of ​​the second region is the area enclosed by the synchronous machine mechanical power straight line when the synchronous machine electromagnetic power phase angle characteristic curve after the multi-machine system fault is cleared changes from the synchronous machine output power angle when the multi-machine system fault is cleared to the second synchronous machine stable power angle.

[0031] Furthermore, the calculation of the magnification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve according to the area of ​​the first region and the area of ​​the second region includes:

[0032] Assume that the area of ​​the first region is equal to the area of ​​the second region, and calculate the magnification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve.

[0033] Furthermore, the method of calculating the capacity requirement of the reactive power compensation device according to the magnification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve, and configuring the capacity of the reactive power compensation device according to the capacity requirement, includes:

[0034] Obtain the bus voltage before the reactive power compensation device is connected to the multi-level system, calculate the capacity demand value of the reactive power compensation device in combination with the enlargement multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve, and configure the capacity of the reactive power compensation device according to the capacity demand value;

[0035] The calculation of the capacity requirement value of the reactive power compensation device satisfies the following calculation formula: The C represents the magnification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve; the U L0 represents the bus voltage before the reactive power compensation device is connected to the multi-level system; X1 and X3 represent the line resistance of the multi-machine system; Q V Indicates the capacity requirement value of the reactive power compensation device.

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

[0037] An embodiment of the present invention provides a capacity configuration system for a reactive power compensation device of a multi-machine system, comprising: 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, an expansion multiple calculation module, and a reactive power compensation device capacity configuration module;

[0038] The equation building module is used to build the synchronous machine electromagnetic power phase angle characteristic curve equation and the synchronous machine mechanical power phase angle characteristic equation before and after the fault of the multi-machine system is removed according to the system parameters of the multi-machine system equipped with the reactive power compensation device;

[0039] The first calculation module is used to calculate the stable power angle of the first synchronous machine before the multi-machine system fails according to the synchronous machine electromagnetic power phase angle characteristic curve equation and the synchronous machine mechanical power phase angle characteristic equation before the multi-machine system fails;

[0040] The second calculation module is used to calculate the output power angle of the synchronous machine when the multi-machine system fault is removed according to the stable power angle of the first synchronous machine;

[0041] The third calculation module is used to calculate the stable power angle of the second synchronous machine after the multi-machine system fault is removed according to the synchronous machine electromagnetic power phase angle characteristic curve equation and the synchronous machine mechanical power phase angle characteristic equation after the multi-machine system fault is removed;

[0042] The first region area calculation module is used to calculate the first region area according to the first synchronous machine stable power angle and the synchronous machine output power angle when the multi-machine system fault is cleared; wherein the first region area is the area enclosed by the synchronous machine mechanical power changing from the first synchronous machine stable power angle to the synchronous machine output power angle when the multi-machine system fault is cleared;

[0043] The second region area calculation module is used to calculate the second region area according to the synchronous machine output power angle when the multi-machine system fault is removed and the second synchronous machine stable power angle; wherein the second region area is the area enclosed by the synchronous machine mechanical power straight line when the synchronous machine electromagnetic power phase angle characteristic curve after the multi-machine system fault is removed changes from the synchronous machine output power angle when the multi-machine system fault is removed to the second synchronous machine stable power angle;

[0044] The amplification multiple calculation module is used to calculate the amplification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve according to 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 value of the reactive power compensation device according to the magnification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve, and configure the capacity of the reactive power compensation device according to the capacity requirement value.

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

[0047] The present invention constructs the electromagnetic power phase angle characteristic curve equation of the synchronous machine before and after the fault of the multi-machine system is removed and the mechanical power phase angle characteristic equation of the synchronous machine, and determines the first synchronous machine stable power angle before the multi-machine system fault, the synchronous machine output power angle when the multi-machine system fault is removed and the second synchronous machine stable power angle after the multi-machine system fault is removed according to the electromagnetic power phase angle characteristic curve equation of the synchronous machine before and after the fault of the multi-machine system is removed and the mechanical power phase angle characteristic equation of the synchronous machine, and then calculates the first area and the second area of ​​the synchronous machine power angle according to the first synchronous machine stable power angle, the synchronous machine output power angle and the second synchronous machine stable power angle, calculates the enlargement multiple of the amplitude of the electromagnetic power phase angle characteristic curve of the synchronous machine equipped with a reactive power compensation device according to the first area and the second area, and finally calculates the amplitude of the electromagnetic power phase angle characteristic curve of the synchronous machine according to the amplitude of the synchronous machine electromagnetic power The capacity requirement of the reactive power compensation device is calculated by the enlarged multiple, 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 combining the parameters of each component in the multi-machine system equipped with the reactive power compensation device, and calculates the power angle value of the synchronous machine before and after the fault, and calculates the capacity requirement value of the reactive power compensation device configured for the busbar in the multi-machine system according to the constructed equation and the power angle value of the synchronous machine by the area method, thereby improving the rationality of the capacity of the reactive power compensation device configured in the multi-machine system, thereby reducing the probability of transient power angle instability of the synchronous machine in the multi-machine system, and solving the problem that the capacity of the reactive power compensation device configured in the prior art is unreasonable and cannot adapt to the fault of the multi-machine system, resulting in transient power angle instability of the synchronous machine when the multi-machine system fails. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Figure 1 : A flow chart of the steps of a method for configuring the capacity of a reactive power compensation device of a multi-machine system provided by an embodiment of the present invention;

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

[0050] Figure 3 : An equivalent circuit diagram of a multi-machine system with a busbar configuration SVG provided in an embodiment of the present invention;

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

[0052] Figure 5 : A characteristic curve diagram of the synchronous machine power angle before and after a fault when a reactive compensation device is configured for the collecting bus provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

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

[0055] Embodiment 1:

[0056] Reference Figure 1 , is a flowchart of a method for configuring the capacity of a reactive power compensation device of a multi-machine system provided by an embodiment of the present invention, the method comprising at least the following steps:

[0057] Step S1: constructing an electromagnetic power phase angle characteristic curve equation and a mechanical power phase angle characteristic equation of a synchronous machine before and after a fault of the multi-machine system is removed according to system parameters of the multi-machine system equipped with a reactive power compensation device;

[0058] In this embodiment, the system parameters can be measured and obtained by electronic measuring elements, referring to Figure 3 , which is an equivalent circuit diagram of a multi-machine system with a busbar configuration SVG provided in an embodiment of the present invention, according to Figure 3 It can be seen that after the busbar is equipped with SVG (reactive power compensation device), the output current of the synchronous machine is infinite power supply. The results of the current injected into the node G by the synchronous machine (thermal power unit), the new energy station and the SVG are recorded as The formulas for each current component are as follows: According to the formula of each current component and the linear network superposition principle, the mathematical expression of the synchronous machine output current is: The formula for the electromagnetic power output of the synchronous machine when the multi-machine system is operating normally is: The formula for the output current of the synchronous machine and the formula for the electromagnetic power output of the synchronous machine when the multi-machine system is operating normally can be obtained. The mathematical expression of the electromagnetic power of the synchronous machine in the multi-machine system with new energy and synchronous machine combined power transmission is:

[0059] The injected current The voltage at the bus terminal The corresponding mathematical expression between Substituting this into the mathematical expression of electromagnetic power of the synchronous machine in the multi-machine system of combined power transmission of new energy and synchronous machine, we can get: The influence of the reactive compensation device configured on the busbar on the electromagnetic power of the synchronous machine is: And because the new energy adopts the directional phase-locked control method based on the d-axis voltage, the d-axis component of its terminal voltage u d =U W , q-axis component Then the mathematical expressions of active power and reactive power of new energy are: Combining the above mathematical expressions, the mathematical expression of the electromagnetic power output by the synchronous machine before the multi-machine system fails is:

[0060] In this embodiment, according to the linear network superposition principle, when a multi-machine system is configured with a reactive power compensation device, the bus voltage is collected. Can be regarded as infinite power supply voltage Synchronous machine internal potential voltage And the voltage of new energy stations The sum of the voltage components at the L node is expressed as: The voltage of the new energy station The data expression is: According to the data expression of the new energy station voltage, the new energy station voltage is decomposed into dq, and the data expression of the d-axis component and q-axis component of the new energy station voltage is obtained: Among them, the U W Voltage for new energy stations The E G is the potential voltage inside the synchronous machine; S Infinite power supply voltage Let the data expressions of the d-axis component and q-axis component of the voltage of the new energy station be equal to the mathematical expressions of the active power and reactive power of the new energy, and simplify and solve to obtain the mathematical expression of the voltage amplitude at the new energy station after the collection bus is equipped with a reactive compensation device: 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 voltage amplitude mathematical expression of the new energy station terminal after the collection bus is equipped with a reactive compensation device is simplified and solved together with the data expression of the new energy station voltage to obtain the voltage phase angle δ of the new energy station terminal. W With synchronous machine power angle δ G The corresponding mathematical relationship expression between them is: Among them, the Indicates the power factor angle of the power injected by the reactive power compensation device into the multi-machine system grid connection point; Satisfies the following formula:

[0062] In this embodiment, according to the above mathematical expression, the equation of the synchronous machine electromagnetic power phase angle characteristic curve before the multi-machine system fails is:

[0063]

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

[0065]

[0066] Among them, the P G represents the electromagnetic power of the synchronous machine before the fault; the C represents the magnification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve; the E G represents the internal potential voltage of the synchronous machine before the fault; S Indicates the bus voltage before the fault; W Indicates the active power of the new energy before the fault; W Indicates the reactive power of the new energy before the fault; Said Said X1, X2 and X3 represent the line resistance of the multi-machine system; W Represents the node terminal voltage of the new energy station before the fault; G represents the synchronous machine power angle before the fault; the δ W Indicates the voltage phase angle of the new energy terminal before the fault; Indicates the power factor angle of the reactive power compensation device injecting power into the multi-machine system grid connection point; the P M represents the mechanical power of the synchronous machine; the δ′0 represents the stable power angle of the first synchronous machine before the multi-machine system fails; the δ W0 Indicates the voltage phase angle of the new energy terminal when the multi-machine system is running stably before failure.

[0067] In this embodiment, refer to Figure 4, is a line structure diagram of a multi-machine system with a busbar equipped with an SVG device according to 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 line Line1-ΙΙ near the busbar L. The equivalent impedance of the line Line1 changes after the multi-machine system fault is removed compared with the condition before the multi-machine system fault. The impedance value X 1c It is equal to twice the equivalent impedance of Line 1 before the multi-machine system fails, that is, X 1c =2X1, and combined with the synchronous machine electromagnetic power phase angle characteristic curve equation before the multi-machine system fault, the synchronous machine electromagnetic power phase angle characteristic curve equation after the multi-machine system fault is removed is constructed as follows:

[0068]

[0069] The mechanical power phase angle characteristic equation of the synchronous machine after the multi-machine system fault is removed is:

[0070]

[0071] Among them, the P G ′ represents the electromagnetic power of the synchronous machine after the fault is removed; C represents the magnification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve; E G ′ represents the internal potential voltage of the synchronous machine after the fault is removed; the U S ′ represents the bus voltage after the fault is removed; the P W ′ represents the active power of the new energy after the fault is removed; W ' represents the reactive power of the new energy after the fault is removed; Said Said X1, X2 and X3 represent the line resistance of the multi-machine system; 1c =2X1; the U W ′ represents the node terminal voltage of the new energy station after the fault is removed; the δ G ′ represents the synchronous machine power angle after fault removal; the δ W ′ represents the voltage phase angle of the new energy terminal after the fault is removed; It indicates the power factor angle of the reactive power compensation device injecting power into the multi-machine system grid connection point after the fault is removed; the P M represents the mechanical power of the synchronous machine; the δ′ cr represents the stable power angle of the second synchronous machine after the multi-machine system fault is removed; the δ Wcr Indicates the voltage phase angle of the new energy terminal after the fault is removed.

[0072] Step S2: calculating the stable power angle of the first synchronous machine before the multi-machine system fails according to the synchronous machine electromagnetic power phase angle characteristic curve equation and the synchronous machine mechanical power phase angle characteristic equation before the multi-machine system fails;

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

[0074] Step S3: calculating the output power angle of the synchronous machine when the multi-machine system fault is removed according to the first synchronous machine stable power angle;

[0075] In this embodiment, the output power angle of the synchronous machine when the multi-machine system fault is removed is calculated according to the stable power angle of the first synchronous machine before the multi-machine system fault, the rated angular velocity of the multi-machine system, the inertia time constant of the synchronous machine, the step time of the segmented calculation and the mechanical power of the synchronous machine;

[0076] The calculation of the synchronous machine output power angle when the multi-machine system fault is removed satisfies the following calculation formula:

[0077] The δ′ c represents the output power angle of the synchronous machine when the multi-machine system fault is removed; the δ′0 represents the stable power angle of the first synchronous machine before the multi-machine system fault; the P M Represents the mechanical power of the synchronous machine; N Indicates the rated angular velocity of the multi-machine system, set to w N =18000° / s; T J represents the inertia time constant of the synchronous machine; the Δt represents the step time of the segmented calculation and is set to Δt=0.05s.

[0078] Step S4: calculating the stable power angle of the second synchronous machine after the multi-machine system fault is removed according to the synchronous machine electromagnetic power phase angle characteristic curve equation and the synchronous machine mechanical power phase angle characteristic equation after the multi-machine system fault is removed;

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

[0080] Step S5: calculating the area of ​​the first region according to the first synchronous machine stable power angle and the synchronous machine output power angle when the multi-machine system fault is cleared; wherein the first region is the area enclosed by the synchronous machine mechanical power changing from the first synchronous machine stable power angle to the synchronous machine output power angle when the multi-machine system fault is cleared;

[0081] In this embodiment, please refer to Figure 5 , is a characteristic curve diagram of the synchronous machine power angle before and after the fault when the reactive compensation device is configured for the collection bus provided in an embodiment of the present invention, and the area of ​​the first region is calculated according to the synchronous machine output power angle when the multi-machine system fault is removed, the first synchronous machine stable power angle before the multi-machine system fault, and the synchronous machine mechanical power; wherein, the calculation of the first region area satisfies the following calculation formula: S ac =P M (δ′c-δ′0); the δ′ c represents the output power angle of the synchronous machine when the multi-machine system fault is removed; the δ′0 represents the stable power angle of the first synchronous machine before the multi-machine system fault; the P M Represents the mechanical power of the synchronous machine; the S ac It indicates that the area of ​​the first region is the area enclosed by the output power angle of the synchronous machine when the mechanical power of the synchronous machine changes 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: calculating the area of ​​the second region according to the output power angle of the synchronous machine when the multi-machine system fault is removed and the stable power angle of the second synchronous machine; wherein the area of ​​the second region is the area enclosed by the synchronous machine mechanical power straight line when the phase angle characteristic curve of the electromagnetic power of the synchronous machine after the multi-machine system fault is removed changes from the output power angle of the synchronous machine when the multi-machine system fault is removed to the stable power angle of the second synchronous machine;

[0083] In this embodiment, please refer to Figure 5 , which is a synchronous machine power angle characteristic curve diagram before and after a fault when a reactive compensation device is configured for a collection bus provided by an embodiment of the present invention, and the area of ​​the second region is calculated to satisfy the following calculation formula:

[0084]

[0085] Among them, the δ′ C Indicates the output power angle of the synchronous machine when the multi-machine system fault is cleared; the δ′ Cr represents the stable power angle of the second synchronous machine after the multi-machine system fault is removed; the C represents the enlargement multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve; the E′ G represents the internal potential voltage of the synchronous machine after the fault is removed; the U′ S Indicates the bus voltage after the fault is cleared; the P W′ represents the active power of the new energy after the fault is removed; the G W ' represents the reactive power of the new energy after the fault is removed; The x1 and x3 represent the line resistance of the multi-machine system; 1c =2X1; the U W ′ represents the node terminal voltage of the new energy station after the fault is removed; the δ G ′ represents the synchronous machine power angle after fault removal; the δ W ′ represents the voltage phase angle of the new energy terminal after the fault is removed; the s dc The area of ​​the second region is the area enclosed by the synchronous machine mechanical power straight line when the synchronous machine electromagnetic power phase angle characteristic curve after the multi-machine system fault is cleared changes from the synchronous machine output power angle when the multi-machine system fault is cleared to the second synchronous machine stable power angle.

[0086] Step S7: calculating the magnification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve according to the area of ​​the first region and the area of ​​the second region;

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

[0088] Step S8: Calculate the capacity requirement of the reactive power compensation device according to the magnification factor of the synchronous machine electromagnetic power phase angle characteristic curve amplitude, 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 an electronic measuring element, and the capacity demand value of the reactive power compensation device is calculated in combination with the enlargement multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve, and finally the capacity of the reactive power compensation device is configured according to the capacity demand value;

[0090] The calculation of the capacity requirement value of the reactive power compensation device satisfies the following calculation formula: The C represents the magnification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve; the U L0 represents the bus voltage before the reactive power compensation device is connected to the multi-level system; X1 and X3 represent the line resistance of the multi-machine system; Q V Indicates the capacity requirement value of the reactive power compensation device.

[0091] Embodiment 2:

[0092] Reference Figure 2, which is a system structure diagram of a capacity configuration system for a reactive power compensation device of a multi-machine system provided by an embodiment of the present invention, the system comprises: 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, an expansion multiple calculation module and a reactive power compensation device capacity configuration module;

[0093] The equation building module is used to build the synchronous machine electromagnetic power phase angle characteristic curve equation and the synchronous machine mechanical power phase angle characteristic equation before and after the fault of the multi-machine system is removed according to the system parameters of the multi-machine system equipped with the reactive power compensation device;

[0094] The first calculation module is used to calculate the stable power angle of the first synchronous machine before the multi-machine system fails according to the synchronous machine electromagnetic power phase angle characteristic curve equation and the synchronous machine mechanical power phase angle characteristic equation before the multi-machine system fails;

[0095] The second calculation module is used to calculate the output power angle of the synchronous machine when the multi-machine system fault is removed according to the stable power angle of the first synchronous machine;

[0096] The third calculation module is used to calculate the stable power angle of the second synchronous machine after the multi-machine system fault is removed according to the synchronous machine electromagnetic power phase angle characteristic curve equation and the synchronous machine mechanical power phase angle characteristic equation after the multi-machine system fault is removed;

[0097] The first region area calculation module is used to calculate the first region area according to the first synchronous machine stable power angle and the synchronous machine output power angle when the multi-machine system fault is cleared; wherein the first region area is the area enclosed by the synchronous machine mechanical power changing from the first synchronous machine stable power angle to the synchronous machine output power angle when the multi-machine system fault is cleared;

[0098] The second region area calculation module is used to calculate the second region area according to the synchronous machine output power angle when the multi-machine system fault is removed and the second synchronous machine stable power angle; wherein the second region area is the area enclosed by the synchronous machine mechanical power straight line when the synchronous machine electromagnetic power phase angle characteristic curve after the multi-machine system fault is removed changes from the synchronous machine output power angle when the multi-machine system fault is removed to the second synchronous machine stable power angle;

[0099] The amplification multiple calculation module is used to calculate the amplification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve according to 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 value of the reactive power compensation device according to the magnification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve, and configure the capacity of the reactive power compensation device according to the capacity requirement value.

[0101] The specific embodiments described above further illustrate the purpose, technical solutions and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. It is particularly pointed out that for those skilled in the art, any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A capacity configuration method for a reactive power compensation device of a multi-machine system, characterized in that: include: According to the system parameters of the multi-machine system equipped with reactive power compensation device, the synchronous machine electromagnetic power phase angle characteristic curve equation and the synchronous machine mechanical power phase angle characteristic equation are constructed before and after the fault of the multi-machine system is removed; According to the synchronous machine electromagnetic power phase angle characteristic curve equation and the synchronous machine mechanical power phase angle characteristic equation before the multi-machine system fails, the stable power angle of the first synchronous machine before the multi-machine system fails is calculated; Calculating the output power angle of the synchronous machine when a fault in the multi-machine system is removed according to the stable power angle of the first synchronous machine; According to the electromagnetic power phase angle characteristic curve equation and the mechanical power phase angle characteristic equation of the synchronous machine after the multi-machine system fault is removed, the stable power angle of the second synchronous machine after the multi-machine system fault is removed is calculated; Calculate the area of ​​the first region according to the first synchronous machine stable power angle and the synchronous machine output power angle when the multi-machine system fault is cleared; wherein the first region area is the area enclosed by the synchronous machine mechanical power changing from the first synchronous machine stable power angle to the synchronous machine output power angle when the multi-machine system fault is cleared; The area of ​​the second region is calculated according to the output power angle of the synchronous machine when the multi-machine system fault is removed and the stable power angle of the second synchronous machine; wherein the area of ​​the second region is the area enclosed by the synchronous machine mechanical power straight line when the phase angle characteristic curve of the electromagnetic power of the synchronous machine after the multi-machine system fault is removed changes from the output power angle of the synchronous machine when the multi-machine system fault is removed to the stable power angle of the second synchronous machine; Calculating the magnification factor of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve according to the area of ​​the first region and the area of ​​the second region; According to the magnification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve, the capacity demand value of the reactive power compensation device is calculated, and the capacity of the reactive power compensation device is configured according to the capacity demand value.

2. The capacity configuration method of a reactive power compensation device of a multi-machine system according to claim 1, characterized in that: The equation of the synchronous machine electromagnetic power phase angle characteristic curve before the multi-machine system fails is: The mechanical power phase angle characteristic equation of the synchronous machine before the multi-machine system fails is: Among them, the P G represents the electromagnetic power of the synchronous machine before the fault; the C represents the magnification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve; the E G represents the internal potential voltage of the synchronous machine before the fault; S Indicates the bus voltage before the fault; W Indicates the active power of the new energy before the fault; W Indicates the reactive power of the new energy before the fault; Said Said X1, X2 and X3 represent the line resistance of the multi-machine system; W Represents the node terminal voltage of the new energy station before the fault; G represents the synchronous machine power angle before the fault; the δ W Indicates the voltage phase angle of the new energy terminal before the fault; Indicates the power factor angle of the reactive power compensation device injecting power into the multi-machine system grid connection point; the P M represents the mechanical power of the synchronous machine; the δ′0 represents the stable power angle of the first synchronous machine before the multi-machine system fails; the δ W0 Indicates the voltage phase angle of the new energy terminal when the multi-machine system is running stably before failure.

3. The capacity configuration method of a reactive power compensation device of a multi-machine system according to claim 1, characterized in that: The equation of the synchronous machine electromagnetic power phase angle characteristic curve after the multi-machine system fault is removed is: The mechanical power phase angle characteristic equation of the synchronous machine after the multi-machine system fault is removed is: Among them, the P G ′ represents the electromagnetic power of the synchronous machine after the fault is removed; C represents the enlargement multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve; E G ′ represents the internal potential voltage of the synchronous machine after the fault is removed; the U S ′ represents the bus voltage after the fault is removed; the P W ′ represents the active power of the new energy after the fault is removed; W ' represents the reactive power of the new energy after the fault is removed; Said Said X1, X2 and X3 represent the line resistance of the multi-machine system; lc =2X l ; The U W ′ represents the node terminal voltage of the new energy station after the fault is removed; the δ G ′ represents the synchronous machine power angle after fault removal; the δ W ′ represents the voltage phase angle of the new energy terminal after the fault is removed; It indicates the power factor angle of the reactive power compensation device injecting power into the multi-machine system grid connection point after the fault is removed; the P M represents the mechanical power of the synchronous machine; the δ′ cr represents the stable power angle of the second synchronous machine after the multi-machine system fault is removed; the δ Wcr Indicates the voltage phase angle of the new energy terminal after the fault is removed.

4. The method for configuring the capacity of a reactive power compensation device of a multi-machine system according to claim 1, characterized in that: The calculation of the synchronous machine output power angle when the multi-machine system fault is removed satisfies the following calculation formula: Among them, the δ′ c represents the output power angle of the synchronous machine when the multi-machine system fault is removed; the δ′0 represents the stable power angle of the first synchronous machine before the multi-machine system fault; the P M Represents the mechanical power of the synchronous machine; N Represents the rated angular velocity of the multi-machine system; the T J represents the inertia time constant of the synchronous machine; and Δt represents the step time of the segmented calculation.

5. The method for configuring the capacity of a reactive power compensation device of a multi-machine system according to claim 1, characterized in that: The calculation of the area of ​​the first region satisfies the following calculation formula: S ac =P M (d′ c -δ′0); Among them, the δ′ c represents the output power angle of the synchronous machine when the multi-machine system fault is removed; the δ′0 represents the stable power angle of the first synchronous machine before the multi-machine system fault; the P M Represents the mechanical power of the synchronous machine; the S ac It indicates that the area of ​​the first region is the area enclosed by the output power angle of the synchronous machine when the mechanical power of the synchronous machine changes 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 method for configuring the capacity of a reactive power compensation device of a multi-machine system according to claim 1, characterized in that: The calculation of the area of ​​the second region satisfies the following calculation formula: Among them, the δ′ c Indicates the output power angle of the synchronous machine when the multi-machine system fault is cleared; the δ′ cr represents the stable power angle of the second synchronous machine after the multi-machine system fault is removed; the C represents the magnification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve; the E G ′ represents the internal potential voltage of the synchronous machine after the fault is removed; the U S ′ represents the bus voltage after the fault is removed; the P W ′ represents the active power of the new energy after the fault is removed; W ' represents the reactive power of the new energy after the fault is removed; X1 and X3 represent the line resistance of the multi-machine system; 1c =2X1; the U W ′ represents the node terminal voltage of the new energy station after the fault is removed; the δ G ′ represents the synchronous machine power angle after fault removal; the δ W ′ represents the voltage phase angle of the new energy terminal after the fault is removed; the S dc The area of ​​the second region is the area enclosed by the synchronous machine mechanical power straight line when the synchronous machine electromagnetic power phase angle characteristic curve after the multi-machine system fault is cleared changes from the synchronous machine output power angle when the multi-machine system fault is cleared to the second synchronous machine stable power angle.

7. The method for configuring the capacity of a reactive power compensation device of a multi-machine system according to claim 1, characterized in that: The step of calculating the magnification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve according to the area of ​​the first region and the area of ​​the second region comprises: Assume that the area of ​​the first region is equal to the area of ​​the second region, and calculate the magnification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve.

8. The method for configuring the capacity of a reactive power compensation device of a multi-machine system according to claim 1, characterized in that: The method of calculating the capacity requirement of the reactive power compensation device according to the magnification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve, and configuring the capacity of the reactive power compensation device according to the capacity requirement, comprises: Obtain the bus voltage before the reactive power compensation device is connected to the multi-level system, calculate the capacity demand value of the reactive power compensation device in combination with the enlargement multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve, and configure the capacity of the reactive power compensation device according to the capacity demand value; The calculation of the capacity requirement value of the reactive power compensation device satisfies the following calculation formula: The C represents the magnification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve; the U L0 represents the bus voltage before the reactive power compensation device is connected to the multi-level system; X1 and X3 represent the line resistance of the multi-machine system; Q V Indicates the capacity requirement value of the reactive power compensation device.

9. A capacity configuration system for a reactive power compensation device of a multi-machine system, characterized in that: include: An equation building 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, an expansion multiple calculation module and a reactive power compensation device capacity configuration module; The equation building module is used to build the synchronous machine electromagnetic power phase angle characteristic curve equation and the synchronous machine mechanical power phase angle characteristic equation before and after the fault of the multi-machine system is removed according to the system parameters of the multi-machine system equipped with the reactive power compensation device; The first calculation module is used to calculate the stable power angle of the first synchronous machine before the multi-machine system fails according to the synchronous machine electromagnetic power phase angle characteristic curve equation and the synchronous machine mechanical power phase angle characteristic equation before the multi-machine system fails; The second calculation module is used to calculate the output power angle of the synchronous machine when the multi-machine system fault is removed according to the stable power angle of the first synchronous machine; The third calculation module is used to calculate the stable power angle of the second synchronous machine after the multi-machine system fault is removed according to the synchronous machine electromagnetic power phase angle characteristic curve equation and the synchronous machine mechanical power phase angle characteristic equation after the multi-machine system fault is removed; The first region area calculation module is used to calculate the first region area according to the first synchronous machine stable power angle and the synchronous machine output power angle when the multi-machine system fault is cleared; wherein the first region area is the area enclosed by the synchronous machine mechanical power changing from the first synchronous machine stable power angle to the synchronous machine output power angle when the multi-machine system fault is cleared; The second region area calculation module is used to calculate the second region area according to the synchronous machine output power angle when the multi-machine system fault is removed and the second synchronous machine stable power angle; wherein the second region area is the area enclosed by the synchronous machine mechanical power straight line when the synchronous machine electromagnetic power phase angle characteristic curve after the multi-machine system fault is removed changes from the synchronous machine output power angle when the multi-machine system fault is removed to the second synchronous machine stable power angle; The amplification multiple calculation module is used to calculate the amplification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve according to the area of ​​the first region and the area of ​​the second region; The reactive power compensation device capacity configuration module is used to calculate the capacity requirement value of the reactive power compensation device according to the magnification multiple of the amplitude of the synchronous machine electromagnetic power phase angle characteristic curve, and configure the capacity of the reactive power compensation device according to the capacity requirement value.

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