Multi-region micro-grid power frequency oscillation suppression method, device, equipment and medium

Abstract

The invention relates to a multi-region micro-grid power frequency oscillation suppression method, device and equipment and a medium, and the method comprises the steps: collecting the voltage data of an output node of a converter of each micro-grid; based on the voltage data and the active power output equation, extracting coupling damping of each micro-grid; and combining the coupling damping with a coupling damping correlation coefficient to obtain a virtual coupling damping item, and introducing the virtual coupling damping item into a converter control ring to improve the consistency of the output frequencies of the microgrids. According to the method, a transient power compensation strategy can be introduced, transient power compensation amount is dynamically generated and adjusted, and rapid compensation of system power is achieved. According to the invention, the overall optimization control of the multi-region micro-grid can be realized.

Description

Technical Field

[0001] The present invention relates to the field of power electronics and power system control technology, and in particular to a method, device, equipment and medium for suppressing power frequency oscillation of a multi-region microgrid. Background Art

[0002] With the rapid development of renewable energy and the widespread application of distributed generation technology, microgrids, as an important means to achieve efficient energy utilization and improve power supply reliability, have developed rapidly in recent years and have formed a cross-regional microgrid group in the power system. A multi-regional microgrid consists of multiple geographically dispersed but electrically interconnected microgrids, which exchange power through interconnection lines. The topology of a multi-regional microgrid system is as follows: Figure 1 As shown in the figure, due to the different dynamic characteristics and control strategies of the power generation units (such as photovoltaic, wind power, etc.) of each microgrid, as well as the random fluctuations and uncertainties of the load, the multi-regional microgrid is prone to power frequency oscillation during operation. Power frequency oscillation is manifested as periodic fluctuations in system power and frequency. This fluctuation will aggravate the instability of the system and may even trigger a chain reaction, leading to system collapse.

[0003] There are some traditional suppression methods for the power frequency oscillation problem of multi-regional microgrids, such as optimizing control strategies and enhancing system damping. However, these methods often fail to achieve ideal results in the complex environment of multi-regional microgrids. Traditional methods usually only focus on the stability of a single microgrid or a local area, ignoring the interaction and coupling damping effect between multiple microgrids. In addition, traditional methods are also insufficient in dealing with power overshoot problems during transient processes, and it is difficult to quickly and effectively suppress transient oscillations. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a method, device, equipment and medium for suppressing power frequency oscillation of a multi-region microgrid, which can realize the overall optimization control of the multi-region microgrid.

[0005] The technical solution adopted by the present invention to solve the technical problem is: to provide a method for suppressing power frequency oscillation of a multi-region microgrid, comprising the following steps:

[0006] Collecting voltage data of output nodes of converters of each microgrid;

[0007] Extracting coupling damping of each microgrid based on the voltage data and the active output equation;

[0008] The coupling damping is combined with a coupling damping correlation coefficient to obtain a virtual coupling damping term, and the virtual coupling damping term is introduced into a converter control loop to improve the consistency of output frequencies of each microgrid.

[0009] The step of extracting the coupling damping of each microgrid based on the voltage data and the active output equation specifically includes:

[0010] Based on the voltage data, the active power of the output node of the converter of each microgrid is calculated using the active output equation;

[0011] The time derivative of the active power of the output node of the converter of each microgrid is calculated to obtain the active power change rate of each microgrid, and the change rate of the active power of each microgrid is used as the coupling damping of each microgrid.

[0012] The active power of the output node of the microgrid converter is transmitted through Calculated, where P i is the active power of the output node of the converter of the i-th microgrid, U i is the voltage data of the output node of the converter of the i-th microgrid, U j is the voltage data of the output node of the converter of the jth microgrid, Z ij is the mutual magnetic resistance between the nodes of the converter of the i-th microgrid and the converter of the j-th microgrid, δ i is the power angle of the converter of the i-th microgrid, δ j is the power angle of the converter of the jth microgrid, and n is the number of microgrids.

[0013] The active control equation obtained by introducing the virtual coupling damping term into the converter control loop is expressed as: Among them, J i is the moment of inertia of the i-th microgrid, is the output frequency change rate of the i-th microgrid, P refi is the active power reference value of the output node of the converter of the i-th microgrid, ω N is the rated angular frequency, P i is the active power of the output node of the converter of the i-th microgrid, D pi is the damping coefficient of the i-th microgrid, C i is the coupling damping correlation coefficient of the i-th microgrid, is the coupling damping of the i-th microgrid.

[0014] The multi-region microgrid power frequency oscillation suppression method further includes:

[0015] The power-frequency characteristic curve is used to obtain the real-time output frequency response of each microgrid, and the time derivative of the output frequency is calculated to obtain the output frequency change rate of each microgrid. The output frequency change rate of each microgrid is combined with the transient active power reference compensation coefficient to obtain the transient power compensation term of each microgrid.

[0016] The transient power compensation term of the microgrid is introduced into the converter control loop containing the virtual coupling damping term to achieve the power frequency oscillation suppression of multi-area microgrids combining virtual damping with transient compensation.

[0017] The active power control equation obtained by introducing the transient power compensation term of the microgrid into the converter control loop containing the virtual coupling damping term is expressed as: Among them, J i is the moment of inertia of the i-th microgrid, is the output frequency change rate of the i-th microgrid, P refi is the active power reference value of the output node of the converter of the i-th microgrid, ω N is the rated angular frequency, P i is the active power of the output node of the converter of the i-th microgrid, D pi is the damping coefficient of the i-th microgrid, C i is the coupling damping correlation coefficient of the i-th microgrid, is the coupling damping of the i-th microgrid, H i is the transient active power reference compensation coefficient of the i-th microgrid.

[0018] The technical solution adopted by the present invention to solve the technical problem is: to provide a multi-region microgrid power frequency oscillation suppression device, comprising:

[0019] A collection module, used to collect voltage data of output nodes of converters of each microgrid;

[0020] An extraction module, used for extracting coupling damping of each microgrid based on the voltage data and the active output equation;

[0021] The first introduction module is used to combine the coupling damping with the coupling damping correlation coefficient to obtain a virtual coupling damping term, and introduce the virtual coupling damping term into the converter control loop to improve the consistency of the output frequency of each microgrid.

[0022] The extraction module comprises:

[0023] An active power calculation unit, configured to calculate the active power of the output nodes of the converters of each microgrid using an active output equation based on the voltage data;

[0024] The active power change rate calculation unit is used to perform time derivative calculation on the active power of the output node of the converter of each microgrid to obtain the active power change rate of each microgrid, and use the change rate of the active power of each microgrid as the coupling damping of each microgrid.

[0025] The active power calculation unit is Calculate the active power of the output node of each microgrid converter, where Pi is the active power of the output node of the converter of the i-th microgrid, U i is the voltage data of the output node of the converter of the i-th microgrid, U j is the voltage data of the output node of the converter of the jth microgrid, Z ij is the mutual magnetic resistance between the nodes of the converter of the i-th microgrid and the converter of the j-th microgrid, δ i is the power angle of the converter of the i-th microgrid, δ j is the power angle of the converter of the jth microgrid, and n is the number of microgrids.

[0026] The active control equation obtained after the first introduction module introduces the virtual coupling damping term into the converter control loop is expressed as: Among them, J i is the moment of inertia of the i-th microgrid, is the output frequency change rate of the i-th microgrid, P refi is the active power reference value of the output node of the converter of the i-th microgrid, ω N is the rated angular frequency, P i is the active power of the output node of the converter of the i-th microgrid, D pi is the damping coefficient of the i-th microgrid, C i is the coupling damping correlation coefficient of the i-th microgrid, is the coupling damping of the i-th microgrid.

[0027] The multi-region microgrid power frequency oscillation suppression device further includes:

[0028] A calculation module is used to obtain the real-time output frequency response of each microgrid by using the power-frequency characteristic curve, and to perform time derivative calculation on the output frequency to obtain the output frequency change rate of each microgrid, and to combine the output frequency change rate of each microgrid with the transient active power reference compensation coefficient to obtain the transient power compensation item of each microgrid;

[0029] The second introduction module is used to introduce the transient power compensation term of the microgrid into the converter control loop containing the virtual coupling damping term, so as to complete the multi-region microgrid power frequency oscillation suppression combining virtual damping with transient compensation.

[0030] The active power control equation obtained by the second introduction module after introducing the transient power compensation term of the microgrid into the converter control loop containing the virtual coupling damping term is expressed as: Among them, J i is the moment of inertia of the i-th microgrid, is the output frequency change rate of the i-th microgrid, P refi is the active power reference value of the output node of the converter of the i-th microgrid, ωN is the rated angular frequency, P i is the active power of the output node of the converter of the i-th microgrid, D pi is the damping coefficient of the i-th microgrid, C i is the coupling damping correlation coefficient of the i-th microgrid, is the coupling damping of the i-th microgrid, H i is the transient active power reference compensation coefficient of the i-th microgrid.

[0031] The technical solution adopted by the present invention to solve its technical problem is: to provide an electronic device, including a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above-mentioned multi-region microgrid power frequency oscillation suppression method when executing the computer program.

[0032] The technical solution adopted by the present invention to solve its technical problem is: providing a computer-readable storage medium, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above-mentioned multi-region microgrid power frequency oscillation suppression method are implemented.

[0033] Beneficial Effects

[0034] Due to the adoption of the above technical solution, the present invention has the following advantages and positive effects compared with the prior art: the present invention introduces a virtual damping term in the control strategy, so that each microgrid can coordinate with each other and jointly suppress power frequency oscillation during operation. This method not only takes into account the stability of a single microgrid, but also fully considers the interaction and coupling damping effect between multiple microgrids, thereby achieving overall optimization control of multi-regional microgrids. The present invention also reduces power overshoot in the transient process by introducing transient compensation, thereby achieving effective suppression of power frequency oscillations in multi-regional microgrids. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic diagram of the topology of a multi-region microgrid system;

[0036] Figure 2 is a flow chart of a method for suppressing power frequency oscillation of a multi-region microgrid according to an embodiment of the present invention;

[0037] Figure 3 is a topological diagram of a converter control algorithm after a virtual damping mechanism is introduced in an embodiment of the present invention;

[0038] Figure 4 is a topological diagram of a converter control algorithm including virtual damping and transient power compensation in an embodiment of the present invention;

[0039] Figure 5It is the active power output response curve of the multi-area microgrid system under the existing traditional converter control strategy;

[0040] Figure 6 It is a frequency output response curve diagram of a multi-area microgrid system under the existing traditional converter control strategy;

[0041] Figure 7 It is a frequency deviation response diagram of each microgrid in a multi-region microgrid system under the existing traditional converter control strategy;

[0042] Figure 8 is an active power output response curve diagram of a multi-area microgrid system under converter control in an embodiment of the present invention;

[0043] Fig. 9 is a frequency output response curve diagram of a multi-area microgrid system under converter control in an embodiment of the present invention;

[0044] Fig.10 It is a frequency deviation response diagram of each converter of the multi-area microgrid system under the control of the improved converter in the implementation mode of the present invention. DETAILED DESCRIPTION

[0045] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0046] The first embodiment of the present invention relates to a method for suppressing power frequency oscillations in a multi-regional microgrid. The method introduces a virtual damping mechanism and a transient power compensation strategy, and organically integrates them into the control strategy of the multi-regional microgrid converter to achieve power frequency oscillation suppression and transient stability improvement of the multi-regional microgrid.

[0047] The core of the virtual damping mechanism in this implementation is to simulate the mechanism of interaction between components in the physical system through damping force to enhance the stability within the microgrid converter system. In this mechanism, the output node power of each converter not only reflects its own operating state, but also implies the dynamic coupling relationship with other converters. Specifically, the output power of each converter includes the coupling damping generated by their interaction.

[0048] By extracting and analyzing these coupling damping, virtual coupling damping is obtained, which is introduced into the control loop of the microgrid converter as a control signal. These virtual coupling damping reflect the frequency deviation between converters and the imbalance of power distribution, which is an important source of instability within the system. By dynamically adjusting these virtual coupling damping terms, the frequency response speed and output power difference between converters can be finely controlled, thereby enhancing the damping effect within the microgrid and suppressing and reducing the system power frequency oscillation.

[0049] like Figure 2 As shown, the multi-region microgrid power frequency oscillation suppression method of this embodiment specifically includes the following steps:

[0050] Step 1: Collecting voltage data of output nodes of converters of each microgrid. In this step, high-precision sensors are used to collect voltage data of output nodes of converters of each microgrid in real time and accurately.

[0051] Step 2: extract the coupling damping of each microgrid based on the voltage data and the active output equation. This step specifically includes the following steps:

[0052] A. Based on the voltage data obtained in step 1, the active power output equation is used to calculate the active power of the output nodes of the converters of each microgrid.

[0053] It is known that under high inductance line conditions, the active power P of the output node of the converter of the i-th microgrid is i , can be equivalently described as the power injected by the converter at its output node, that is:

[0054]

[0055] Among them, p ij =U i U j Z ij , U i is the voltage data of the output node of the converter of the i-th microgrid, U j is the voltage data of the output node of the converter of the jth microgrid, Z ij is the mutual magnetic resistance between the nodes of the converter of the i-th microgrid and the converter of the j-th microgrid. i is the power angle of the converter of the i-th microgrid, δ j is the power angle of the converter of the jth microgrid, and n is the number of microgrids. The power angle of the converter of the i-th microgrid is expressed as follows:

[0056]

[0057] Among them, ω iis the output angular frequency of the converter of the i-th microgrid; ω pcc is the angular frequency of the common coupling point; δ pcc is the power angle of the common coupling point, and s is the Laplace operator.

[0058] B. Perform time derivative calculation (i.e., open derivative calculation) on the active power of the output nodes of the converters of each microgrid to obtain the active power change rate of each microgrid, and use the change rate of the active power of each microgrid as the coupling damping of each microgrid.

[0059] The active power P of the output node of the converter of each microgrid i The derivative calculation is performed as follows:

[0060]

[0061] Under the assumption that the phase difference between nodes is small and hardly changes significantly over time, the power angle δ of the converter of the i-th microgrid is i The power angle δ of the converter of the jth microgrid j The difference between them can be approximated to zero, that is, δ i -δ j ≈0. At the same time, considering that the output voltage amplitude of the converter changes relatively slowly, it can be reasonably inferred that the last two terms in the original formula can be ignored due to their small influence. Therefore, the rate of change of active power (derivative term) can be simplified to an approximate expression containing only the main contribution terms:

[0062]

[0063] For convenience, define:

[0064] q ij =U i U j Z ij cos(δ i -δ j );

[0065] Among them, q ij > 0. Therefore, the active power change rate of each converter output node can be expressed as:

[0066]

[0067] Step 3: Combine the coupling damping with the coupling damping correlation coefficient to obtain a virtual coupling damping term, and introduce the virtual coupling damping term into the converter control loop to improve the consistency of the output frequency of each microgrid.

[0068] In this step, the coupling damping obtained in step 2 is combined with the coupling damping correlation coefficient to be transformed into a virtual coupling damping term, and the virtual coupling damping term is introduced into the active control loop of each converter to improve the consistency of the output frequency of each microgrid.

[0069] At this time, the virtual coupling damping term of each converter can be expressed as Among them, C i is the coupling damping correlation coefficient of the i-th microgrid. This virtual coupling damping term is cleverly introduced into the converter control loop of the multi-regional microgrid as a key parameter for adjusting the converter behavior. Its main purpose is to improve the power distribution of the multi-regional microgrid system, enhance the stability of the system, and reduce the current impact under fault or load surge conditions.

[0070] By introducing the virtual coupling damping term into each converter control loop, a new control equation and control algorithm topology are obtained. The control algorithm topology diagram is shown in Figure 3 As shown, the active power control equation is expressed as:

[0071]

[0072] Where: J i is the moment of inertia of the i-th microgrid, is the output frequency change rate of the i-th microgrid, P refi is the active power reference value of the output node of the converter of the i-th microgrid, ω N is the rated angular frequency, D pi is the damping coefficient of the i-th microgrid.

[0073] In the power system, the virtual damping mechanism enhances the stability and dynamic response between converters in multi-regional microgrids by simulating the physical damping effect. However, in the transient process of facing load mutation or output fluctuation of distributed power sources, relying solely on the virtual damping mechanism may not be enough to completely eliminate power imbalance and system oscillation. Therefore, this implementation also supplements the transient power compensation mechanism to form a more complete system stability control strategy.

[0074] Transient power compensation aims to solve the power imbalance problem caused by sudden load changes or fluctuations in the output of distributed power sources during transient processes. At this stage, the system needs to quickly adjust its power output to match the new supply and demand relationship. By monitoring the power changes of the system in real time, especially paying attention to the fluctuations of active power, the transient power compensation strategy can calculate the required power compensation amount. Specifically, the strategy achieves compensation by adjusting the active reference power of the converter. When a power shortage is detected in the system, the converter will increase its active power output to make up for the power gap caused by increased load or reduced output of distributed power sources. Conversely, when there is an excess of power in the system, the converter reduces its active power output to avoid overvoltage and overload. This real-time and dynamic power adjustment process ensures that the system can maintain power balance and maintain system stability during transient processes.

[0075] Therefore, the multi-region microgrid power frequency oscillation suppression method of this embodiment may also include the following steps:

[0076] Step 4: Use the power-frequency characteristic curve to obtain the real-time output frequency response of each microgrid, and calculate the time derivative of the output frequency to obtain the output frequency change rate of each microgrid. Combine the output frequency change rate of each microgrid with the transient active power reference compensation coefficient to obtain the transient power compensation item of each microgrid.

[0077] In this step, the output frequency changes of each converter are monitored in real time. This change is an important representation of the transient process of the system. Based on the output frequency induction calculation, combined with the transient compensation algorithm, a transient power compensation term is generated. The transient power compensation term can quickly respond to the transient process of the system and provide the necessary power compensation to maintain the stability of the system. The rotor equation expression of the i-th converter is:

[0078]

[0079] Using the active power-frequency relationship of the converter, the output frequency curve of each converter can be obtained. The transient power compensation term can be expressed as Among them, H i is the transient active power reference compensation coefficient of the i-th microgrid.

[0080] Step 5: Introduce the transient power compensation term of the microgrid into the converter control loop containing the virtual coupling damping term to complete the multi-region microgrid power frequency oscillation suppression combining virtual damping with transient compensation.

[0081] In this step, the transient power compensation term is introduced into the converter control equation with virtual coupling damping to complete the multi-region microgrid power frequency oscillation suppression combining virtual damping and transient compensation. Thus, the control topology diagram of the microgrid multi-parallel converter system oscillation suppression method combining virtual coupling damping and transient power compensation can be obtained, as shown in Figure 4 As shown. The final active power control equation expression is expressed as:

[0082]

[0083] The specific parameters in this embodiment include the moment of inertia J i , the virtual damping coefficient D of the converter pi , coupling damping correlation coefficient C i , and transient active power reference compensation coefficient H i , all of which are tuned and obtained by parameter tuning methods; among them, the preferred parameter tuning method is the parameter tuning method based on the small signal model, specifically: establishing a small signal model of a multi-parallel converter system, and deriving its transfer function, and according to the control theory knowledge, tuning the controller parameters from the two aspects of stability and dynamic response.

[0084] In order to ensure the overall performance of the multi-region microgrid system, it is also necessary to coordinate the control strategies of each converter. This includes adjusting control parameters, optimizing control algorithms, and coordinating the interactions between converters. By comprehensively considering the dynamic characteristics of the system, load conditions, distributed power output and other factors, a more efficient and stable control strategy can be designed.

[0085] This implementation method is verified by simulating four microgrid grid-connected converters to achieve the following preset conditions: the load switching time is set to 1s and 2s. At 1s, the load of each converter is switched from 10kW to 15kW, and at 2s, it is switched from 15kW back to 10kW. Figure 5 , Figure 6 They are respectively represented as the active power output response curve and frequency output response curve of each microgrid under the traditional converter control strategy. It can be seen that when the traditional control strategy is adopted, its active power oscillates during load switching and a large overshoot occurs, with an overshoot of 4% and a recovery stabilization time of 0.5s. Figure 5 ,The frequency response of each microgrid also oscillates, which is the main reason for the active power oscillation. Figure 7 It is expressed as the deviation of the output frequency of each microgrid, showing whether the output frequency response of each microgrid remains consistent.

[0086] Figure 8 , Fig. 9 , Fig.10The following are the response curves of the output active power, frequency and frequency deviation of each microgrid of each converter under the improved converter control strategy with virtual damping mechanism and transient power compensation proposed in this embodiment. The specific results are as follows:

[0087] Effective suppression of active power overshoot: Experimental data show that in the transient process of load switching, after adopting the improved control method of the present invention, the active power output peak of the microgrid is only 15030W (relative to the average of 15kW), and the overshoot is as low as 0.2%. Compared with the overshoot of 4% under the traditional control method, it is reduced by 3.5%. This result demonstrates the excellent performance of the control method proposed in the present invention in stabilizing power output and reducing transient shocks. The significant reduction in overshoot helps protect power grid equipment from excessive current shocks and extend the service life of equipment.

[0088] Significantly shortened system recovery time: Under the traditional control method, the system takes up to 0.55 seconds to recover from transient fluctuations to a stable state. After adopting the improved control method of the present invention, this time is shortened to only 0.35 seconds, and the time efficiency is improved by nearly 40%. This significant improvement means that the power grid can respond to load changes more quickly, improve the dynamic response capability and stability of the system, help maintain the stability of the power grid voltage and frequency, and improve the quality of power supply.

[0089] Significant improvement in frequency regulation capability: In terms of frequency regulation, traditional converter control methods have limitations in dealing with dynamic changes, with the maximum frequency deviation reaching 0.12Hz, affecting the frequency consistency between converters and with the power grid. The improved control method proposed in this invention significantly reduces the frequency deviation in the transient process by optimizing the control logic and parameters, with the maximum deviation value reduced to 0.02Hz. This improvement is crucial to maintaining system frequency stability and promoting the synergy of multiple microgrids operating in parallel, and helps to improve the overall operating efficiency and reliability of distributed power generation systems.

[0090] Energy saving, emission reduction and environmental protection benefits: Since the method of the present invention can respond to load changes quickly and stably, it reduces grid losses and unnecessary energy conversion processes caused by power fluctuations, thereby helping to reduce overall energy consumption and carbon emissions, which is in line with the development trend of green energy and environmental protection requirements.

[0091] Easy operation and reduced cost: The method of the present invention does not require additional complex equipment in hardware, and is mainly implemented through software algorithm optimization, so it has the characteristics of easy implementation and low cost. At the same time, the optimized control logic makes the operation and maintenance of the system more convenient, reducing the labor intensity and technical threshold of operators.

[0092] To sum up, the multi-regional microgrid power frequency oscillation suppression method proposed in this embodiment, which introduces a virtual damping mechanism and transient power compensation, has shown significant effects and advantages in improving the stability of the multi-regional microgrid system, shortening the recovery time, enhancing the frequency regulation capability, promoting energy conservation and emission reduction, and simplifying operations, and provides a new solution for the optimized operation of distributed power generation systems.

[0093] A second embodiment of the present invention relates to a multi-region microgrid power frequency oscillation suppression device, comprising:

[0094] A collection module, used to collect voltage data of output nodes of converters of each microgrid;

[0095] An extraction module, used for extracting coupling damping of each microgrid based on the voltage data and the active output equation;

[0096] The first introduction module is used to combine the coupling damping with the coupling damping correlation coefficient to obtain a virtual coupling damping term, and introduce the virtual coupling damping term into the converter control loop to improve the consistency of the output frequency of each microgrid.

[0097] The extraction module comprises:

[0098] An active power calculation unit, configured to calculate the active power of the output nodes of the converters of each microgrid using an active output equation based on the voltage data;

[0099] The active power change rate calculation unit is used to perform time derivative calculation on the active power of the output node of the converter of each microgrid to obtain the active power change rate of each microgrid, and use the change rate of the active power of each microgrid as the coupling damping of each microgrid.

[0100] The active power calculation unit is Calculate the active power of the output node of each microgrid converter, where P i is the active power of the output node of the converter of the i-th microgrid, U i is the voltage data of the output node of the converter of the i-th microgrid, U j is the voltage data of the output node of the converter of the jth microgrid, Z ij is the mutual magnetic resistance between the nodes of the converter of the i-th microgrid and the converter of the j-th microgrid, δ i is the power angle of the converter of the i-th microgrid, δ j is the power angle of the converter of the jth microgrid, and n is the number of microgrids.

[0101] The active control equation obtained after the first introduction module introduces the virtual coupling damping term into the converter control loop is expressed as: Among them, Ji is the moment of inertia of the i-th microgrid, is the output frequency change rate of the i-th microgrid, P refi is the active power reference value of the output node of the converter of the i-th microgrid, ω N is the rated angular frequency, P i is the active power of the output node of the converter of the i-th microgrid, D pi is the damping coefficient of the i-th microgrid, C i is the coupling damping correlation coefficient of the i-th microgrid, is the coupling damping of the i-th microgrid.

[0102] The multi-region microgrid power frequency oscillation suppression device further includes:

[0103] A calculation module is used to obtain the real-time output frequency response of each microgrid by using the power-frequency characteristic curve, and to perform time derivative calculation on the output frequency to obtain the output frequency change rate of each microgrid, and to combine the output frequency change rate of each microgrid with the transient active power reference compensation coefficient to obtain the transient power compensation item of each microgrid;

[0104] The second introduction module is used to introduce the transient power compensation term of the microgrid into the converter control loop containing the virtual coupling damping term, so as to complete the multi-region microgrid power frequency oscillation suppression combining virtual damping with transient compensation.

[0105] The active power control equation obtained by the second introduction module after introducing the transient power compensation term of the microgrid into the converter control loop containing the virtual coupling damping term is expressed as: Among them, J i is the moment of inertia of the i-th microgrid, is the output frequency change rate of the i-th microgrid, P refi is the active power reference value of the output node of the converter of the i-th microgrid, ω N is the rated angular frequency, P i is the active power of the output node of the converter of the i-th microgrid, D pi is the damping coefficient of the i-th microgrid, C i is the coupling damping correlation coefficient of the i-th microgrid, is the coupling damping of the i-th microgrid, H i is the transient active power reference compensation coefficient of the i-th microgrid.

[0106] A third embodiment of the present invention relates to an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the multi-regional microgrid power frequency oscillation suppression method of the first embodiment when executing the computer program.

[0107] A fourth embodiment of the present invention relates to a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the multi-region microgrid power frequency oscillation suppression method of the first embodiment.

[0108] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage and optical storage, etc.) that contain computer-usable program code.

[0109] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0110] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer-readable memory produce a manufactured product including an instruction method, which is implemented in the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0111] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0112] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for suppressing power frequency oscillation of a multi-region microgrid, characterized in that: The following steps are involved: Collecting voltage data of output nodes of converters of each microgrid; Extracting coupling damping of each microgrid based on the voltage data and the active output equation; The coupling damping is combined with a coupling damping correlation coefficient to obtain a virtual coupling damping term, and the virtual coupling damping term is introduced into a converter control loop to improve the consistency of output frequencies of each microgrid.

2. The method for suppressing power frequency oscillation of a multi-region microgrid according to claim 1, characterized in that: The step of extracting the coupling damping of each microgrid based on the voltage data and the active output equation specifically includes: Based on the voltage data, the active power of the output nodes of the converter of each microgrid is calculated using the active output equation; the time derivative of the active power of the output nodes of the converter of each microgrid is calculated to obtain the active power change rate of each microgrid, and the change rate of the active power of each microgrid is used as the coupling damping of each microgrid.

3. The method for suppressing power frequency oscillation of a multi-region microgrid according to claim 2, characterized in that: The active power of the output node of the microgrid converter is transmitted through Calculated, where P i is the active power of the output node of the converter of the i-th microgrid, U i is the voltage data of the output node of the converter of the i-th microgrid, U j is the voltage data of the output node of the converter of the jth microgrid, Z ij is the mutual magnetic resistance between the nodes of the converter of the i-th microgrid and the converter of the j-th microgrid, δ i is the power angle of the converter of the i-th microgrid, δ j is the power angle of the converter of the jth microgrid, and n is the number of microgrids.

4. The method for suppressing power frequency oscillation of a multi-region microgrid according to claim 1, characterized in that: The active control equation obtained by introducing the virtual coupling damping term into the converter control loop is expressed as: Among them, J i is the moment of inertia of the i-th microgrid, is the output frequency change rate of the i-th microgrid, P refi is the active power reference value of the output node of the converter of the i-th microgrid, ω N is the rated angular frequency, P i is the active power of the output node of the converter of the i-th microgrid, D pi is the damping coefficient of the i-th microgrid, C i is the coupling damping correlation coefficient of the i-th microgrid, is the coupling damping of the i-th microgrid.

5. The method for suppressing power frequency oscillation of a multi-region microgrid according to claim 1, characterized in that: Also includes: The power-frequency characteristic curve is used to obtain the real-time output frequency response of each microgrid, and the time derivative of the output frequency is calculated to obtain the output frequency change rate of each microgrid. The output frequency change rate of each microgrid is combined with the transient active power reference compensation coefficient to obtain the transient power compensation term of each microgrid. The transient power compensation term of the microgrid is introduced into the converter control loop containing the virtual coupling damping term to achieve the power frequency oscillation suppression of multi-area microgrids combining virtual damping with transient compensation.

6. The method for suppressing power frequency oscillation of a multi-region microgrid according to claim 5, characterized in that: The active power control equation obtained by introducing the transient power compensation term of the microgrid into the converter control loop containing the virtual coupling damping term is expressed as: Among them, J i is the moment of inertia of the i-th microgrid, is the output frequency change rate of the i-th microgrid, P refi is the active power reference value of the output node of the converter of the i-th microgrid, ω N is the rated angular frequency, P i is the active power of the output node of the converter of the i-th microgrid, D pi is the damping coefficient of the i-th microgrid, C i is the coupling damping correlation coefficient of the i-th microgrid, is the coupling damping of the i-th microgrid, H i is the transient active power reference compensation coefficient of the i-th microgrid.

7. A multi-region microgrid power frequency oscillation suppression device, characterized in that: include: A collection module, used to collect voltage data of output nodes of converters of each microgrid; An extraction module, used for extracting coupling damping of each microgrid based on the voltage data and the active output equation; The first introduction module is used to combine the coupling damping with the coupling damping correlation coefficient to obtain a virtual coupling damping term, and introduce the virtual coupling damping term into the converter control loop to improve the consistency of the output frequency of each microgrid.

8. The multi-region microgrid power frequency oscillation suppression device according to claim 7, characterized in that: The extraction module comprises: An active power calculation unit, configured to calculate the active power of the output nodes of the converters of each microgrid using an active output equation based on the voltage data; The active power change rate calculation unit is used to perform time derivative calculation on the active power of the output node of the converter of each microgrid to obtain the active power change rate of each microgrid, and use the change rate of the active power of each microgrid as the coupling damping of each microgrid.

9. The multi-region microgrid power frequency oscillation suppression device according to claim 8, characterized in that: The active power calculation unit is Calculate the active power of the output node of each microgrid converter, where P i is the active power of the output node of the converter of the i-th microgrid, U i is the voltage data of the output node of the converter of the i-th microgrid, U j is the voltage data of the output node of the converter of the jth microgrid, Z ij is the mutual magnetic resistance between the nodes of the converter of the i-th microgrid and the converter of the j-th microgrid, δ i is the power angle of the converter of the i-th microgrid, δ j is the power angle of the converter of the jth microgrid, and n is the number of microgrids.

10. The multi-region microgrid power frequency oscillation suppression device according to claim 7, characterized in that: The active control equation obtained after the first introduction module introduces the virtual coupling damping term into the converter control loop is expressed as: Among them, J i is the moment of inertia of the i-th microgrid, is the output frequency change rate of the i-th microgrid, P refi is the active power reference value of the output node of the converter of the i-th microgrid, ω N is the rated angular frequency, P i is the active power of the output node of the converter of the i-th microgrid, D pi is the damping coefficient of the i-th microgrid, C i is the coupling damping correlation coefficient of the i-th microgrid, is the coupling damping of the i-th microgrid.

11. The multi-region microgrid power frequency oscillation suppression device according to claim 7, characterized in that: Also includes: A calculation module is used to obtain the real-time output frequency response of each microgrid by using the power-frequency characteristic curve, and to perform time derivative calculation on the output frequency to obtain the output frequency change rate of each microgrid, and to combine the output frequency change rate of each microgrid with the transient active power reference compensation coefficient to obtain the transient power compensation item of each microgrid; The second introduction module is used to introduce the transient power compensation term of the microgrid into the converter control loop containing the virtual coupling damping term, so as to complete the multi-region microgrid power frequency oscillation suppression combining virtual damping with transient compensation.

12. The multi-region microgrid power frequency oscillation suppression device according to claim 11, characterized in that: The active power control equation obtained by the second introduction module after introducing the transient power compensation term of the microgrid into the converter control loop containing the virtual coupling damping term is expressed as: Among them, J i is the moment of inertia of the i-th microgrid, is the output frequency change rate of the i-th microgrid, P refi is the active power reference value of the output node of the converter of the i-th microgrid, ω N is the rated angular frequency, P i is the active power of the output node of the converter of the i-th microgrid, D pi is the damping coefficient of the i-th microgrid, C i is the coupling damping correlation coefficient of the i-th microgrid, is the coupling damping of the i-th microgrid, H i is the transient active power reference compensation coefficient of the i-th microgrid.

13. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the multi-region microgrid power frequency oscillation suppression method as described in any one of claims 1-6 are implemented.

14. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the multi-region microgrid power frequency oscillation suppression method as claimed in any one of claims 1 to 6 are implemented.

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