A reactive power control method for multiple self-synchronous voltage source units in a new energy station

Abstract

The present invention belongs to the field of reactive power control for renewable energy power generation and discloses a reactive power control method for multiple self-synchronous voltage source units at renewable energy stations. The method comprises the following steps: obtaining a secondary voltage control signal based on a reactive multi-agent consensus algorithm; superimposing the secondary voltage control signal on the reactive voltage control of the self-synchronous voltage source algorithm; generating a reference voltage based on the voltage amplitude of the reactive voltage control output and the phase of the active frequency control output, performing virtual impedance control and current loop control to obtain a modulation signal, and driving the inverter switches after SVPWM. By combining the reactive multi-agent consensus algorithm with the self-synchronous voltage source algorithm, it is possible to achieve reasonable power distribution during grid-connected operation of multiple self-synchronous voltage sources at renewable energy stations, solving the problem of unbalanced reactive power distribution in the case of line impedance mismatch.

Description

Technical Field

[0001] The present invention belongs to the field of reactive power control of renewable energy power generation, and in particular relates to a reactive power control method for multiple self-synchronous voltage source units in a renewable energy station. Background Art

[0002] Under the dual pressures of energy and environmental issues, renewable energy generation has received significant attention. Distributed generation (DG) technology, with its flexible power generation methods, energy conservation, and environmental protection, has become a solution for managing renewable energy. With a high proportion of renewable energy and power electronic equipment connected to the power system, the proportion of synchronous generators has decreased, leading to a gradual decrease in power system inertia and damping, which in turn has led to power stability issues. Self-synchronous voltage source control, by algorithmically simulating the characteristics of synchronous generators, can enhance the ability of renewable energy to actively support the power grid.

[0003] While single-unit self-synchronous voltage source control can achieve balanced active power output according to the rated capacity of the units, when the impedance of the lines connecting the units is mismatched, this can still cause imbalances in reactive power among the units. Amid the rapid development of new energy microgrids, power balancing control during islanded microgrid operation has garnered widespread attention, with extensive research focusing on methods such as virtual impedance. For example, Chinese Patent Publication No. CN106877330B discloses a method for introducing adaptive virtual impedance into distributed micropower sources, which maintains the relative deviation in reactive power between any two micropower sources in the distributed microgrid within a preset range, improving reactive power distribution accuracy. There are also reactive power balancing methods that employ consistency control. For example, Chinese Patent Publication No. CN108964150B discloses a reactive power balancing method for AC / DC hybrid microgrids using finite-time control. Based on droop control, this method proposes distributed secondary reactive power control, resulting in a faster system convergence rate. Each distributed power source only exchanges reactive power information with its neighbors, and a finite-time consistency protocol is used to balance the incremental reactive power output of each distributed power source. Regarding reactive power sharing control for virtual synchronous generators, Chinese Patent Publication No. CN108365639B discloses a reactive power sharing control method for parallel virtual synchronous generators based on online impedance identification. After obtaining the line impedance, the PCC voltage is calculated. A voltage compensation value is added to the virtual synchronous generator control process to eliminate errors caused by power angle interference, thereby achieving reactive power sharing. Whether operating in an islanded system or connected to the grid, a multi-inverter parallel system must ensure that the inverter's output reactive power is properly distributed according to the equipment capacity to ensure safe and economical operation of each unit.

[0004] In grid-connected mode, the output frequency of the multiple self-synchronous voltage sources (MSVs) in a renewable energy station is rated, and the parallel bus voltage is clamped under the support of the main power grid. To ensure that the output frequency of a multi-inverter parallel system can be guaranteed during grid-connected operation, more research has focused on voltage and power control. Currently, there is limited research on power control in grid-connected MSVs. With the promotion of MSV technology and the expansion of renewable energy stations, those skilled in the art need to develop a reactive power control method for MSVs in renewable energy stations. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a reactive power control method for multiple self-synchronous voltage source units in a new energy station, which solves the problem of unbalanced reactive power distribution in the case of line impedance mismatch in the existing technology.

[0006] The purpose of the present invention can be achieved through the following technical solutions:

[0007] A method for controlling reactive power of multiple self-synchronous voltage source units in a new energy station, characterized by comprising the following steps:

[0008] S1 obtains the secondary voltage control signal according to the reactive multi-agent consensus algorithm;

[0009] S2 superimposes the secondary voltage control signal on the reactive voltage control of the self-synchronous voltage source algorithm;

[0010] The voltage amplitude of the S3 reactive voltage control output and the phase of the active frequency control output generate a reference voltage. After virtual impedance control and current loop control, a modulation signal is obtained, which drives the inverter switch after space vector modulation SVPWM.

[0011] Furthermore, the reactive multi-agent consensus algorithm exchanges the reactive power of adjacent units of multiple self-synchronous voltage sources in the new energy station and the intermediate variables introduced in the consistency algorithm, and forms a set of nodes with communication connections with the nodes, and combines the reactive power control and voltage recovery control through the weight coefficient to obtain the secondary voltage control signal.

[0012] Furthermore, the reactive multi-agent consensus algorithm is expressed as:

[0013]

[0014] Among them, the reactive power of adjacent units i and j of the multi-self-synchronous voltage source of the new energy station is Q i and Q j , γ qi and γ qj is the intermediate variable introduced in the consistency algorithm, u qi is the secondary voltage control signal, aq 、b q 、c q is the weight coefficient, N i is the set of nodes that have communication connections with node i, D qi is the reactive voltage droop coefficient.

[0015] Furthermore, the multi-agent consensus algorithm communicates data between adjacent nodes, and only transmits two data, reactive power and intermediate variables, in each communication.

[0016] Furthermore, the reactive multi-agent consensus algorithm normalizes the reactive power with the reactive voltage droop coefficient and uses the normalized reactive power as the consistency control target.

[0017] Furthermore, the secondary voltage control signal output by the reactive multi-agent consensus algorithm is superimposed on the reference voltage of the reactive voltage control; the reactive voltage control simulates the excitation of the synchronous generator, and the difference between the reactive power reference value and the actual reactive power output of the unit is added to the voltage deviation between the voltage reference and the actual voltage to obtain the reactive amount based on the droop control, and after the integration link, the inverter bridge arm voltage amplitude is obtained.

[0018] Furthermore, the secondary voltage control output by the reactive multi-agent consensus algorithm is superimposed on the reactive voltage control unit of the self-synchronous voltage source algorithm, and the expression is:

[0019]

[0020] Among them, 1 / K is the integral coefficient, E m is the voltage amplitude of reactive voltage control output, u q is the secondary voltage control signal, Q ref is the reference value of reactive power; Q is the output reactive power; D q is the reactive voltage droop coefficient; V om is the output voltage amplitude; V n is the rated voltage amplitude.

[0021] Furthermore, the inverter bridge arm midpoint reference voltage expression is:

[0022]

[0023] Among them, e a 、e b 、e c is the reference voltage of the bridge arm midpoint of the self-synchronous voltage source inverter, θ is the phase of the active frequency control output, E m It is the voltage amplitude of reactive voltage control output.

[0024] Furthermore, the virtual impedance control expression is:

[0025]

[0026] Among them, e abc is the inverter arm midpoint reference voltage in the self-synchronous voltage source control, is the reference value of the filter inductor current in the self-synchronous voltage source, v abc is the output voltage of the self-synchronous voltage source, r a Equivalent to the self-synchronous voltage source filter inductor equivalent resistance, L d It is equivalent to the filter inductor of the self-synchronous voltage source.

[0027] Furthermore, the current loop control expression is:

[0028]

[0029] Among them, v* d 、v* q are the d-axis and q-axis components of the SVPWM drive control modulation signal, i* ld 、i* lq are the d-axis and q-axis components of the current loop reference value obtained by the previous stage virtual impedance control, i ld 、i lq They are the d-axis and q-axis components of the filter inductor current of the LC filter, v d 、v q are the d-axis and q-axis components of the inverter output voltage, L f is the filter inductance value of the LC filter, k pi and k ii is the control parameter of the current loop PI controller, and ω is the angular frequency of the self-synchronous voltage source.

[0030] Beneficial effects of the present invention:

[0031] By combining the reactive multi-agent consensus algorithm and the self-synchronous voltage source algorithm, it is possible to achieve reasonable power distribution when multiple self-synchronous voltage sources of new energy stations are connected to the grid, solving the problem of unbalanced reactive power distribution when the line impedance does not match. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0033] Figure 1 This is a control block diagram of a reactive multi-agent consensus algorithm and a self-synchronous voltage source algorithm according to an embodiment of the present invention;

[0034] Figure 2 A schematic diagram of electrical connection and ring communication of a new energy AC grid according to an embodiment of the present invention;

[0035] Figure 3 Schematic diagram of the circuit topology and inverter control method of the inverter system according to an embodiment of the present invention;

[0036] Figure 4 This is a block diagram of multi-agent consistency control in the inverter control method according to an embodiment of the present invention;

[0037] Figure 5 This is a block diagram of an improved reactive voltage control method in an inverter control method according to an embodiment of the present invention;

[0038] Figure 6 This is a diagram showing the active output results of multiple self-synchronous voltage sources according to an embodiment of the present invention;

[0039] Figure 7 This is a diagram showing reactive output results of multiple self-synchronous voltage sources according to an embodiment of the present invention;

[0040] Figure 8 Graph showing the output voltage results of multiple self-synchronous voltage sources according to an embodiment of the present invention. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. 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 making any creative efforts shall fall within the scope of protection of the present invention.

[0042] like Figure 1 As shown, the present invention provides a technical method, a reactive power control method for multiple self-synchronous voltage source units in a new energy station, which specifically includes the following steps:

[0043] S1 obtains the secondary voltage control signal according to the reactive multi-agent consensus algorithm.

[0044] S2 superimposes the secondary voltage control signal on the reactive voltage control of the self-synchronous voltage source algorithm.

[0045] The voltage amplitude of the S3 reactive voltage control output and the phase of the active frequency control output generate a reference voltage. After virtual impedance control and current loop control, a modulation signal is obtained, which drives the inverter switch after space vector modulation SVPWM.

[0046] Each power generation unit in the new energy station is regarded as an intelligent entity. Each self-synchronous voltage source in the station communicates with its adjacent nodes. According to the distance between adjacent units, wired methods such as RS485 or wireless modules can be selected for communication.

[0047] The multi-agent consensus algorithm has lower communication requirements than centralized control. It only needs to communicate data between adjacent nodes and does not require real-time communication. Event-triggered communication can be used to trigger communication when the system operating conditions change, reducing the number and amount of communications.

[0048] The steady-state value of this multi-agent consensus algorithm is unaffected by communication latency, and only two pieces of data—reactive power and intermediate variables—are transmitted in each communication. The communication employed has low requirements for communication rates, and completing data transmission before the next system operating condition change enables stable control, effectively reducing the consumption of communication and computing resources. As long as the communication topology used by the multi-agent consensus algorithm is connected, the consensus algorithm can converge. Even if the connectivity of the communication topology is disrupted, the separate communication components can achieve local convergence, and the system can still operate stably. Therefore, the communication topology of the multi-agent consensus algorithm should be as connected as possible, with bidirectional communication. This local communication approach to achieving global control can significantly reduce the need for long-distance communication transmission, making it suitable for new energy generation forms such as distributed wind power and distributed photovoltaic power generation, and conducive to achieving energy transformation.

[0049] The reactive multi-agent consensus algorithm exchanges the reactive power Q of adjacent units i and j of multiple self-synchronous voltage sources in the new energy station. i and Q j And the intermediate variable γ introduced in the consensus algorithm qi and γ qj , the nodes that have communication connections with node i form a set N i , through the weight coefficient a q 、b q 、c q The reactive power control and voltage recovery control are combined to obtain the secondary voltage control signal u qi The reactive multi-agent consensus algorithm is based on the reactive voltage droop coefficient D qi and D qj The reactive power is normalized and the normalized reactive power is used as the consistency control target. Therefore, the reactive multi-agent consensus algorithm can be expressed as:

[0050]

[0051] Among them, the reactive power of adjacent units i and j of the multi-self-synchronous voltage source of the new energy station is Q i and Q j , γ qi and γ qjis the intermediate variable introduced in the consistency algorithm, u qi is the secondary voltage control signal, a q 、b q 、c q is the weight coefficient, N i is the set of nodes that have communication connections with node i, D qi is the reactive voltage droop coefficient.

[0052] The specific implementation process of self-synchronous voltage control includes:

[0053] The power calculation unit is realized based on the instantaneous power theory, and the collected three-phase voltage signal v a 、v b 、v c And the three-phase current signal i a 、i b 、i c After PARK transformation to the dq coordinate system, the voltage signal v is obtained d 、v q and the current signal i d 、i q , then use the instantaneous power theory to calculate and pass the cutoff frequency ω c After low-pass filtering, the active power P and reactive power Q output by the inverter are obtained. The instantaneous power calculation expression is:

[0054]

[0055] The active frequency control unit simulates the inertia and primary frequency modulation characteristics of the synchronous generator. The mathematical expression of the active frequency is determined based on the rotor motion equation of the synchronous generator. The active power P calculated by instantaneous power theory is used as input, and the synchronous phase θ is output. The expression is:

[0056]

[0057] Among them, P ref is the reference value of active power; P is the electromagnetic power; D p is the active frequency droop coefficient; ω is the angular frequency of the self-synchronous voltage source; ω n is the rated angular frequency; J is the virtual moment of inertia.

[0058] The reactive voltage control unit simulates the primary voltage regulation characteristics of the synchronous generator, with the reactive power calculated by instantaneous power theory as input, the output voltage as feedback, and the reference voltage as output. q Superimposed on the reference voltage V for reactive voltage control n Reactive voltage control simulates synchronous generator excitation, reactive power reference value Q refThe difference between the actual output reactive power Q of the unit and the voltage reference V n +u q The actual voltage V om The voltage deviation is obtained based on the reactive power obtained by droop control, and the inverter bridge arm voltage amplitude E is obtained after the integral link with an integral coefficient of 1 / K. m , the improved reactive voltage control expression is:

[0059]

[0060] Among them, Q ref is the reference value of reactive power; Q is the output reactive power; D q is the reactive voltage droop coefficient; V om is the output voltage amplitude; V n is the rated voltage amplitude.

[0061] The reference voltage generating unit is controlled by the phase θ output by the active frequency control and the voltage amplitude E output by the reactive voltage control. m Composition, self-synchronous voltage source inverter bridge arm midpoint reference voltage e a 、e b 、e c The expression is:

[0062]

[0063] The virtual impedance control unit simulates the stator electrical characteristics of the synchronous generator. The control equation of the unit is determined based on the relationship between the internal potential, stator current and terminal voltage of the synchronous generator, and the expression is:

[0064]

[0065] Among them, e abc is the inverter arm midpoint reference voltage in the self-synchronous voltage source control, is the reference value of the filter inductor current in the self-synchronous voltage source, v abc is the output voltage of the self-synchronous voltage source, r a Equivalent to the self-synchronous voltage source filter inductor equivalent resistance, L d It is equivalent to the filter inductor of the self-synchronous voltage source.

[0066] The current loop control unit is in the dq coordinate system. After the difference between the inductor current reference signal calculated by the virtual impedance control unit and the actual inductor current is controlled by PI, the dq axis components of the output voltage are superimposed. Considering the control method of dq component decoupling, the expression is:

[0067]

[0068] Among them, v*d 、v* q are the d-axis and q-axis components of the SVPWM drive control modulation signal, i* ld 、i* lq are the d-axis and q-axis components of the current loop reference value obtained by the previous stage virtual impedance control, i ld 、i lq They are the d-axis and q-axis components of the filter inductor current of the LC filter, v d 、v q are the d-axis and q-axis components of the inverter output voltage, L f is the filter inductance value of the LC filter, k pi and k ii is the control parameter of the current loop PI controller, and ω is the angular frequency of the self-synchronous voltage source.

[0069] The voltage amplitude of the reactive voltage control output and the generated reference voltage of the active frequency control output are modulated by virtual impedance control and current loop control to obtain the modulation signal, which drives the inverter switch after space vector modulation SVPWM.

[0070] By combining the reactive multi-agent consensus algorithm and the self-synchronous voltage source algorithm, it is possible to achieve reasonable power distribution when multiple self-synchronous voltage sources of new energy stations are connected to the grid, solving the problem of unbalanced reactive power distribution when the line impedance does not match.

[0071] In the following, a simulation experiment is carried out using the above method in conjunction with specific embodiments.

[0072] like Figure 2-7 As shown, the electrical connection and communication connection of the new energy AC grid in this embodiment are as follows Figure 2 As shown in Figure 1, three self-synchronous voltage sources are connected in parallel to the grid. There is line impedance between each unit and the point of common coupling (PCC), and the grid impedance is non-negligible. A ring topology is used for communication between the three units. DG1 and DG3 are two units adjacent to DG2, respectively. Information exchange between adjacent nodes and between the head and tail nodes forms a ring structure, so in this embodiment, the three units communicate with each other.

[0073] Single self-synchronous voltage source circuit topology and control method Figure 3 As shown, the DC side can be regarded as a DC source with constant voltage. The DC-AC conversion is realized by a three-phase full-bridge inverter circuit composed of 6 IGBTs. The current output by the bridge arm flows into the grid after LC filtering. labc is the inductor current, v abc is the output voltage, i abc is the output current, v iabc and v jabcRepresent the output voltages of the i-th inverter and the j-th inverter, respectively. In the inverter control section, the sampled output voltage and current signals undergo PARK transformation and serve as the input to the power calculation unit. The active and reactive powers of the inverter output are calculated using the instantaneous power theory and low-pass filtered. The calculated power is controlled by a self-synchronous voltage source, including active frequency control and reactive voltage control, to obtain the amplitude and phase information required by the voltage reference generation module. The difference between the generated reference voltage and the actual output voltage is applied to the virtual impedance to generate a reference inductor current signal. This signal is then subjected to PI control with the actual inductor current in the dq rotating coordinate system to generate a modulation signal. The controller output undergoes inverse coordinate transformation and space vector modulation (SVPWM) to drive the IGBT. Figure 4 The control block diagram of the reactive multi-agent consensus algorithm is shown below. The output secondary voltage signal of the multi-agent consensus algorithm acts on the reactive voltage control to improve the original control. Figure 5 shown.

[0074] The main parameter values ​​of this embodiment are as follows: DC bus voltage V dc =700V, filter inductor L f =0.15mH, filter capacitor C f =600uF, damping resistor R d =0.2Ω, grid resistance R = 0.01Ω, grid inductance L = 0.15mH, AC bus voltage amplitude AC bus voltage angular frequency ω n =100πrad / s, inverter switching frequency f s =3.2kHz, current loop control proportional coefficient k pi =0.64, current loop control integral coefficient k ii =100.

[0075] In this embodiment, DG1 and DG3 are set to be units with a rated capacity of 500kW, and DG2 is set to be a unit with a rated capacity of 250kW. Control parameters of DG1 and DG3: active power reference value P ref1 =P ref3 =500kW, reactive power reference value Q ref1 =Q ref3 =0, active power droop coefficient D p1 =D p3 =79442, moment of inertia J1=J3=0.3, power filter cutoff frequency f c =30Hz, reactive power droop coefficient D q1 =D q3 =20000, excitation coefficient K1=K3=318; control parameters of DG2: D p2 =39721, J2=0.15, Dq2 =10000, K2=159. Virtual resistance value r a =0.01Ω, virtual inductance value L d =150uH, active power reference value P ref2 =250kW, reactive power reference Q ref2 =0, weight coefficient a q =20, b q =10,g q = 20. Line resistance R1 of DG1 = 0.01Ω, line inductance L1 = 0.1mH, line resistance R2 of DG2 = 0.01Ω, line inductance L2 = 0.1mH, line resistance R3 of DG3 = 0.02Ω, line inductance L3 = 0.2mH.

[0076] The simulation duration is set to 5s. The inverter adopts self-synchronous voltage source control before 2s, and the multi-agent consensus algorithm is added at 2s. Figure 6 、 Figure 7 and Figure 8 The simulation results show that before the multi-agent consensus algorithm was implemented, that is, 2 seconds before the implementation, the active power outputs of the three self-synchronous voltage sources were DG1: 500kW, DG2: 250kW, and DG3: 500kW, meeting the rated capacity ratio of 2:1:2. However, the reactive power outputs were DG1: 104.5kVar, DG2: 96.9kVar, and DG3: 54.7kV, which did not meet the rated capacity of the equipment. After the multi-agent consensus algorithm was implemented at 2 seconds, the active power only fluctuated briefly at the moment of implementation and quickly returned to its original state. The reactive power outputs were DG1: 104kVar, DG2: 52kVar, and DG3: 104kV, meeting the equipment capacity ratio of 2:1:2. When the self-synchronous voltage source control is used 2s ago, the output voltage amplitude is DG1: 250.74V, DG2: 246.28V, DG3: 253.22V, and the average voltage amplitude is 250.08V. After adding the multi-agent consensus algorithm 2s later, the output voltage amplitude is DG1: 254.95V, DG2: 246.8V, DG3: 266.175V, and the average voltage amplitude is 255.975V, of which the rated voltage amplitude is

[0077] Through simulation experiments, the results of this embodiment show that according to the method disclosed in the present invention, the output active power and reactive power of the multi-self-synchronous voltage source of the new energy station can be distributed according to the equipment capacity under the grid-connected working condition, and the output voltage of each unit is close to the rated value and the average voltage reaches the rated value.

[0078] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0079] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications are intended to fall within the scope of the present invention.

Claims

1. A method for controlling reactive power of multiple self-synchronous voltage source units in a new energy station, characterized in that: The steps include: S1 obtains the secondary voltage control signal according to the reactive multi-agent consensus algorithm; S2 superimposes the secondary voltage control signal on the reactive voltage control of the self-synchronous voltage source algorithm; The voltage amplitude of the reactive voltage control output of S3 and the phase of the active frequency control output generate a reference voltage. After virtual impedance control and current loop control, a modulation signal is obtained, which drives the inverter switch after space vector modulation SVPWM. The reactive multi-agent consensus algorithm is expressed as: Among them, the reactive power of adjacent units i and j of the multi-self-synchronous voltage source of the new energy station is Q i and Q j , γ qi and γ qj is the intermediate variable introduced in the consistency algorithm, u qi is the secondary voltage control signal, a q 、b q 、c q is the weight coefficient, N i is the set of nodes that have communication connections with node i, D qi is the reactive voltage droop coefficient; The virtual impedance control expression is: Among them, e abc is the inverter arm midpoint reference voltage in the self-synchronous voltage source control, is the reference value of the filter inductor current in the self-synchronous voltage source, v abc is the output voltage of the self-synchronous voltage source, r a Equivalent to the self-synchronous voltage source filter inductor equivalent resistance, L d Equivalent to the filter inductor of the self-synchronous voltage source; The current loop control expression is: Among them, v* d 、v* q are the d-axis and q-axis components of the SVPWM drive control modulation signal, i* ld 、i* lq are the d-axis and q-axis components of the current loop reference value obtained by the previous stage virtual impedance control, i ld 、i lq They are the d-axis and q-axis components of the filter inductor current of the LC filter, v d 、v q are the d-axis and q-axis components of the inverter output voltage, L f is the filter inductance value of the LC filter, k pi and k ii is the control parameter of the current loop PI controller, and ω is the angular frequency of the self-synchronous voltage source.

2. The reactive power control method of multiple self-synchronous voltage source units in a new energy station according to claim 1 is characterized in that: The reactive multi-agent consensus algorithm exchanges the reactive power of adjacent units of multiple self-synchronous voltage sources in new energy stations and the intermediate variables introduced in the consistency algorithm. It forms a set of nodes that have communication connections with the nodes, and combines reactive power control and voltage recovery control through weight coefficients to obtain a secondary voltage control signal.

3. The reactive power control method of multiple self-synchronous voltage source units in a new energy station according to claim 1 is characterized in that: The multi-agent consensus algorithm communicates data between adjacent nodes, and only transmits two data, reactive power and intermediate variables, in each communication.

4. The reactive power control method of multiple self-synchronous voltage source units in a new energy station according to claim 1 is characterized in that: The reactive multi-agent consensus algorithm normalizes the reactive power with the reactive voltage droop coefficient and takes the normalized reactive power as the consistency control target.

5. The reactive power control method of multiple self-synchronous voltage source units in a new energy station according to claim 1 is characterized in that: The secondary voltage control signal output by the reactive multi-agent consensus algorithm is superimposed on the reference voltage of the reactive voltage control; the reactive voltage control simulates the excitation of the synchronous generator, and the difference between the reactive power reference value and the actual reactive power output of the unit is added to the voltage deviation between the voltage reference and the actual voltage to obtain the reactive amount based on the droop control. After the integration link, the inverter bridge arm voltage amplitude is obtained.

6. A reactive power control method for multiple self-synchronous voltage source units in a new energy station according to claim 5, characterized in that: The secondary voltage control output by the reactive multi-agent consensus algorithm is superimposed on the reactive voltage control unit of the self-synchronous voltage source algorithm, and the expression is: Among them, 1 / K is the integral coefficient, E m is the voltage amplitude of reactive voltage control output, u q is the secondary voltage control signal, Q ref is the reference value of reactive power; Q is the output reactive power; D q is the reactive voltage droop coefficient; V om is the output voltage amplitude; V n is the rated voltage amplitude.

7. The reactive power control method of multiple self-synchronous voltage source units in a new energy station according to claim 6 is characterized in that: The inverter bridge arm midpoint reference voltage expression is: Among them, e a 、e b 、e c is the reference voltage of the bridge arm midpoint of the self-synchronous voltage source inverter, θ is the phase of the active frequency control output, E m It is the voltage amplitude of reactive voltage control output.

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