CN111799844A - A virtual synchronous generator control method, device and terminal equipment - Google Patents

Abstract

The invention is suitable for the technical field of micro-grid control, and provides a virtual synchronous generator control method, a device and terminal equipment, wherein the method comprises the following steps: acquiring performance parameters of each virtual synchronous generator unit in the micro-grid system, and calculating the total virtual inertia of the micro-grid system and the weight corresponding to each performance index according to the performance parameters; calculating a positive ideal solution and a negative ideal solution according to each performance parameter and weight, and further calculating a comprehensive evaluation index of each virtual synchronous generator unit; and finally, calculating the virtual inertia of each virtual synchronous generator unit according to the comprehensive evaluation index and the total virtual inertia. By the virtual synchronous generator control method provided by the embodiment, the corresponding virtual inertia can be reasonably determined for each virtual synchronous generator under the condition that the performance parameters of each virtual synchronous generator are different, and the operation stability of the microgrid system is improved.

Description

A virtual synchronous generator control method, device and terminal equipment

technical field

The invention belongs to the technical field of microgrid control, and in particular relates to a virtual synchronous generator control method, device and terminal equipment.

Background technique

The installed capacity of photovoltaic power generation systems in the power grid continues to increase, but the photovoltaic power generation system itself does not have inertia. Therefore, when the photovoltaic power generation system is connected to the power grid through the power electronic converter, the total inertial capacity of the entire system will be reduced. For this problem, virtual synchronous generator control is used to achieve friendly grid connection when photovoltaic and energy storage devices operate together.

The PV-storage unit under the control of the virtual synchronous generator will be restricted by the relevant performance parameters of the system during operation. Factors such as the state of charge of the energy storage, the charge and discharge power control of the energy storage itself, and the rated capacity of the grid-connected converter will all affect Stable operation of PV-storage unit under virtual synchronous generator control. When there are multiple virtual synchronous generator units in the system, and the performance parameters of each virtual synchronous generator unit are different, and the inertial support capacity is also different, there will be problems of unstable operation and low system frequency quality.

SUMMARY OF THE INVENTION

In view of this, embodiments of the present invention provide a virtual synchronous generator control method, device, and terminal device to solve the problem of unstable operation of the microgrid system in the prior art when the performance parameters of each virtual synchronous generator are different. question.

A first aspect of the embodiments of the present invention provides a virtual synchronous generator control method, which is applied to a microgrid system method having at least one virtual synchronous generator unit, including:

Acquiring performance parameters corresponding to at least one performance index of each virtual synchronous generator unit of the microgrid system;

Calculate the total virtual inertia of the microgrid system according to each performance parameter;

Calculate the weight of the corresponding performance index according to each performance parameter;

Calculate the positive ideal solution and the negative ideal solution according to each performance parameter and the weight of the corresponding performance index;

Calculate the comprehensive evaluation index of each virtual synchronous generator unit according to the positive ideal solution, the negative ideal solution and the performance parameters corresponding to each virtual synchronous generator unit;

The virtual inertia of each virtual synchronous generator unit is calculated according to the comprehensive evaluation index of each virtual synchronous generator unit and the total virtual inertia of the microgrid system.

A second aspect of the embodiments of the present invention provides a virtual synchronous generator control device, including:

a performance parameter obtaining module, configured to obtain a performance parameter corresponding to at least one performance index of each virtual synchronous generator unit of the microgrid system;

a total virtual inertia calculation module, configured to calculate the total virtual inertia of the microgrid system according to each performance parameter;

The weight calculation module is used to calculate the weight of the corresponding performance index according to the virtual synchronous generator of each performance parameter;

The ideal solution calculation module is used to calculate the positive ideal solution and the negative ideal solution according to each performance parameter and the weight of the corresponding performance index;

a comprehensive evaluation index calculation module, configured to calculate the comprehensive evaluation index of each virtual synchronous generator unit according to the positive ideal solution, the negative ideal solution and the performance parameters corresponding to each virtual synchronous generator unit;

The virtual inertia calculation module is configured to calculate the virtual inertia of each virtual synchronous generator unit according to the comprehensive evaluation index of each virtual synchronous generator unit and the total virtual inertia of the microgrid system.

A third aspect of the embodiments of the present invention provides a terminal device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, where the processor executes the computer program When implementing the steps of the method described above.

A fourth aspect of the embodiments of the present invention provides a computer-readable storage medium, where the computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, implements the steps of the above method.

Compared with the prior art, the beneficial effect of the embodiment of the present invention is that: this embodiment first obtains a performance parameter corresponding to at least one performance index of each virtual synchronous generator unit in the microgrid system, and calculates the total value of the microgrid system according to the performance parameter. The virtual inertia and the weight corresponding to each performance index; calculate the positive ideal solution and negative ideal solution according to each performance parameter and weight, and calculate the comprehensive evaluation index of each virtual synchronous generator unit according to the positive ideal solution, negative ideal solution and performance parameters; The evaluation index and the total virtual inertia are used to calculate the virtual inertia of each virtual synchronous generator unit, and finally the virtual inertia of each virtual synchronous generator unit is adjusted according to the virtual inertia. The virtual synchronous generator control method provided by this embodiment can reasonably determine the corresponding virtual inertia for each virtual synchronous generator under the condition that the performance parameters of each virtual synchronous generator are different, thereby improving the operation stability of the microgrid system.

Description of drawings

In order to illustrate the technical solutions in the embodiments of the present invention more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only for the present invention. In some embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

1 is a schematic structural diagram of a microgrid system provided by an embodiment of the present invention;

Fig. 2 is the realization flow schematic diagram of the virtual synchronous generator control method provided by the embodiment of the present invention;

3 is an application effect diagram of a virtual synchronous generator control method provided by an embodiment of the present invention;

4 is an application effect diagram of a virtual synchronous generator control method provided by another embodiment of the present invention;

5 is an application effect diagram of a virtual synchronous generator control method provided by another embodiment of the present invention;

6 is an application effect diagram of a virtual synchronous generator control method provided by another embodiment of the present invention;

7 is a schematic structural diagram of a virtual synchronous generator control device provided by an embodiment of the present invention;

FIG. 8 is a schematic diagram of a terminal device provided by an embodiment of the present invention.

Detailed ways

In the following description, for the purpose of illustration rather than limitation, specific details such as specific system structures and technologies are set forth in order to provide a thorough understanding of the embodiments of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present invention with unnecessary detail.

In order to illustrate the technical solutions of the present invention, the following specific embodiments are used for description.

An embodiment of the present invention provides a virtual synchronous generator control method, which is applied to a microgrid system having at least one virtual synchronous generator unit. FIG. 1 shows the structure of the microgrid system.

1, in a specific embodiment, the microgrid system is a six-terminal AC system, including three virtual synchronous generator units, denoted as VSG (virtual synchronous generator, virtual synchronous generator) units: VSG1, VSG2 and VSG3 ; Two conventional generator sets: G ₁ and G ₂ ; AC bus and AC load cells.

Each VSG unit, each conventional generator set, and each AC load unit are respectively connected to the AC bus.

In this embodiment, the traditional generator set G ₁ is used for secondary frequency regulation of the system, the traditional generator set G ₂ is used to maintain the constant power operation of the system, each VSG unit is used for photovoltaic power generation, and the AC load unit is used for Switch the power disturbance of the microgrid system to keep the load constant during normal operation.

In this embodiment, the structure and control strategy of each VSG unit are the same, but the performance parameters may be different.

In this embodiment, each VSG unit includes a grid-connected inverter, a DC bus, a photovoltaic unit (PV) and a corresponding DC-DC converter, and an energy storage unit (BAT) and a corresponding DC -DC converter.

In this embodiment, in each VSG unit, the photovoltaic power generation sub-unit is connected to the DC bus through the corresponding DC-DC converter, the energy storage sub-unit is connected to the DC bus through the corresponding DC-DC converter, and the DC bus is connected to the DC bus through the corresponding DC-DC converter. The grid-tied inverter is connected to the AC bus of the entire microgrid system.

In this embodiment, the photovoltaic power generation sub-unit in each VSG unit operates in the maximum power tracking mode, and the energy storage sub-unit is used to bear the power disturbance caused by load switching during operation, that is, the inertial support required by the system when the power disturbance occurs. Provided jointly by each energy storage sub-unit. Optionally, each energy storage subunit is controlled by a constant DC voltage.

It should be noted that the above is only a specific example, and the number of VSG units in the microgrid system is not limited to three.

Referring to FIG. 2, the virtual synchronous generator control method provided by the embodiment of the present invention includes:

S101: Obtain performance parameters corresponding to at least one performance index of each virtual synchronous generator unit of the microgrid system;

In an embodiment of the present invention, the performance indicators include an energy storage state-of-charge indicator, an inverter adjustable capacity indicator, an energy storage charge-discharge adjustable power indicator, and a system unit time power adjustable amount indicator. Correspondingly, Each VSG unit corresponds to performance parameters: state of charge of energy storage, adjustable capacity of inverter, adjustable power of energy storage charging and discharging, and adjustable amount of system power per unit time.

S101 includes:

Through the formula ΔP _Ni =P _Ni -|P _0i |, the adjustable capacity of the converter of each virtual synchronous generator unit is calculated;

where ΔP _Ni is the inverter adjustable capacity of the i-th virtual synchronous generator unit, P _Ni is the inverter rated capacity of the i-th virtual synchronous generator unit, and P _0i is the ith virtual synchronous generator unit’s inverter capacity. Converter output power;

Calculate the energy storage charging and discharging adjustable power of each virtual synchronous generator by the formula ΔP _bati =P _batNi -|P _bati |;

Among them, ΔP _bati is the energy storage charge and discharge adjustable power of the i-th virtual synchronous generator unit, P _batNi is the upper limit of the energy-storage charge and discharge power of the i-th virtual synchronous generator unit, and P _bati is the i-th virtual synchronous generator unit. The actual charge and discharge power of the unit's energy storage.

In this embodiment, the state of charge of the energy storage may be recorded as SOC (state of charge, state of charge), which is in the form of a percentage, and is used to indicate the current energy storage state of the energy storage subunit in the VSG unit.

In this embodiment, the adjustable amount of system power per unit time is denoted as ΔP _tmax .

In this embodiment, the inertial support capability of each VSG unit can be evaluated through performance parameters corresponding to each performance index, and a VSG unit with a larger inertial support capability will be assigned a larger virtual inertia.

The control expression of the VSG unit is:

为VSG单元的相位，K_d为系统阻尼系数，ω为VSG单元的输出角频率，ω_g为微电网系统交流母线中的电网角频率。In formula (1), H is the virtual inertia of the VSG unit, P _ref is the active power given value of the VSG unit, P _o is the actual output value of the VSG unit,

is the phase of the VSG unit, K _d is the system damping coefficient, ω is the output angular frequency of the VSG unit, and ω _g is the grid angular frequency in the AC bus of the microgrid system.

S102: Calculate the total virtual inertia of the microgrid system according to each performance parameter;

In an embodiment of the present invention, S102 includes:

Calculate the total inertia adjustment coefficient of the microgrid system according to the state of charge of each energy storage;

计算所述微电网系统的总虚拟惯量；by formula

calculating the total virtual inertia of the microgrid system;

Wherein H _T is the total virtual inertia of the microgrid system, α is the total inertia adjustment coefficient, k ₁ and k ₂ are the virtual inertia adjustment coefficients, and f is the system frequency.

In an embodiment of the present invention, the calculating the total inertia adjustment coefficient of the microgrid system according to each energy storage state of charge includes:

Judging the working state of the microgrid system according to the system frequency;

计算所述总惯量调整系数；If the working state of the microgrid system is to be charged, then the formula

calculating the total inertia adjustment coefficient;

计算所述总惯量调整系数；If the working state of the microgrid system is to be discharged, then the formula

calculating the total inertia adjustment coefficient;

where α is the total inertia adjustment coefficient, S _Ni is the rated energy storage capacity of the ith virtual synchronous generator unit, SOC _d is the upper limit of energy storage, SOC _a is the lower limit of energy storage, and SOC _i represents the ith virtual synchronous generator unit The state of charge of the energy storage, SOC _N is the normal reference value of the energy storage.

In this embodiment, when the load of the microgrid system decreases, the working state is to be charged, that is, the excess energy is stored in the energy storage subunit; when the load of the microgrid system increases, the working state is to be discharged, that is, to store energy. The energy stored in the subunit is released.

In this embodiment, the increase of the system frequency means that the load of the microgrid system decreases; the decrease of the system frequency means that the load of the microgrid system increases.

In this embodiment, when the working state of the microgrid system is to be charged, the smaller the SOC _i , the smaller the remaining energy storage capacity of the corresponding VSG unit, the stronger the charging capability, and the greater the virtual inertia that can be provided during charging. .

In this embodiment, when the working state of the microgrid system is to be discharged, the larger the SOC _i , the larger the remaining energy storage capacity of the corresponding VSG unit, the stronger the dischargeable capacity, and the larger the virtual inertia that can be provided during discharge. .

In this embodiment, the working state of the microgrid system depends on the disturbance provided by the AC load unit.

Optionally, SOC _d =90%, SOC _a =10%, SOC _N =50%.

S103: Calculate the weight of the corresponding performance index according to the virtual synchronous generator of each performance parameter;

In an embodiment of the present invention, S103 includes:

计算各个性能指标的变异系数；formula based

Calculate the coefficient of variation of each performance index;

为第j个性能指标对应的各个虚拟同步发电机单元的性能参数的平均数；Among them, V _j is the coefficient of variation of the jth performance index; σ _j is the standard deviation of the performance parameters of each virtual synchronous generator unit corresponding to the jth performance index;

is the average number of performance parameters of each virtual synchronous generator unit corresponding to the jth performance index;

计算各个性能指标的权重；Substitute the coefficient of variation corresponding to each performance index into the formula

Calculate the weight of each performance indicator;

Among them, W _j is the weight corresponding to the j-th performance index, and V _j is the variation coefficient of the j-th performance index.

In this embodiment, the method of calculating the coefficient of variation and then calculating the weight can adjust the weight of each performance index in the virtual inertia allocation process in real time according to the change of each performance parameter, and then adjust the virtual inertia size of each VSG unit in time, Maintain stable operation of each VSG unit.

S104: Calculate the positive ideal solution and the negative ideal solution according to each performance parameter and the weight of the corresponding performance index;

In this embodiment, S104 includes:

Multiply each performance parameter by the weight of the corresponding performance index to obtain the performance update parameter;

The optimal value and the worst value in the performance update parameters corresponding to each performance index are screened out.

The positive ideal solution is a virtual solution obtained by combining the optimal values of the performance update parameters corresponding to each performance index, and the negative ideal solution is a virtual solution obtained by combining the worst values of each performance update parameter.

In this embodiment, for the performance parameters, the adjustable capacity of the current flow device, the adjustable power of the energy storage charging and discharging, and the adjustable amount of the system power per unit time, the larger the better, the smaller the worse.

In this embodiment, when the working state of the microgrid system is to be discharged, the larger the performance parameter SOC, the better, and the smaller the better, the worse;

When the working state of the microgrid system is to be charged, the smaller the performance parameter SOC is, the better it is, and the larger it is, the worse it is.

For example, the performance parameters corresponding to VSG _i are [ΔP _Ni ,ΔP _bati , SOC _i ,ΔP _tmax ];

After multiplying each performance parameter with the weight of the corresponding performance index, the performance update parameter corresponding to VSG _i is obtained as [A _i ,B _i ,C _i ,D _i ]=[W ₁ ΔP _Ni ,W ₂ ΔP _bati ,W ₃ SOC _i ,W ₃ ΔP _tmax ];

When the working state of the microgrid system is to be discharged, we get:

Positive ideal solution Z ^* = [A _max , B _max , C _max , D _max ], negative ideal solution Z ⁰ =[A _min , B _min , C _min , D _min ]

When the working state of the microgrid system is to be charged, we get:

Positive ideal solution Z ^* = [A _max , B _max , C _min , D _max ], negative ideal solution Z ⁰ =[A _min , B _min , C _max , D _min ]

S105: Calculate the comprehensive evaluation index of each virtual synchronous generator unit according to the positive ideal solution, the negative ideal solution and the performance parameters corresponding to each virtual synchronous generator unit;

In an embodiment of the present invention, S105 includes:

计算各个虚拟同步发电机单元的综合评价指数；formula based

Calculate the comprehensive evaluation index of each virtual synchronous generator unit;

where C _i ^* is the comprehensive evaluation index of the ith virtual synchronous generator unit, d _i ^* is the Euclidean distance between the performance parameters of the ith virtual synchronous generator unit and the positive ideal solution, and d _i ^o is the ith virtual synchronous generator unit The Euclidean distance between the performance parameters of the generator unit and the negative ideal solution.

In this embodiment, a sorting method based on approximation to an ideal value is applied to sort the virtual synchronous generator units, which can ensure the accuracy of the calculation.

S106: Calculate the virtual inertia of each virtual synchronous generator unit according to the comprehensive evaluation index of each virtual synchronous generator unit and the total virtual inertia of the microgrid system;

In an embodiment of the present invention, S106 includes:

计算各个虚拟同步发电机单元的虚拟惯量；According to the formula

Calculate the virtual inertia of each virtual synchronous generator unit;

Wherein H _i is the virtual inertia of the ith virtual synchronous generator unit, C _i ^* represents the comprehensive evaluation index of the ith virtual synchronous generator unit, H _T is the total virtual inertia of the microgrid system, and H ₀ is a constant .

Optional, H ₀ =0.2

With the virtual synchronous generator control method provided in this embodiment, a reasonable virtual inertia can be determined for each virtual synchronous generator unit under the condition that the performance parameters of each virtual synchronous generator unit are different, and the virtual inertia can be fully utilized to be flexible and controllable It can improve the operation stability of the microgrid system and improve the frequency quality of the microgrid system.

In a specific embodiment 1, at the initial moment SOC ₁ =80%, SOC ₂ =50%, SOC ₃ =20%, other performance parameters of each VSG unit are the same, and the AC load unit increases the load by 5kW at the moment of 5s. This embodiment The virtual synchronous generator control method provided by the example is denoted as the TOPSIS method.

Fig. 3(a) shows the change of inertia of each VSG unit in this embodiment. Referring to Fig. 3(a), in this embodiment, H ₁ is the largest and H ₃ is the smallest.

Figure 3(b) shows the variation of the active output of each VSG unit in this embodiment. Referring to Figure 3(b), in this embodiment, the active output of the VSG ₁ unit is the largest, and the active output of the VSG ₃ unit is the smallest.

FIG. 3( c ) shows the comparison of SOC ₁ in the virtual synchronous generator control method provided by this embodiment and the existing FVSG control method.

FIG. 3(d) shows the comparison of SOC ₃ in the virtual synchronous generator control method provided by this embodiment and the existing FVSG control method.

It can be seen from Fig. 3(c) and Fig. 3(d) that, compared with the existing FVSG method, the virtual synchronous generator control method provided in this embodiment can reasonably allocate the virtual inertia according to the SOC value of each VSG unit. The more the energy storage subunits in the corresponding VSG unit discharge, the smaller the SOC value, and the less the energy storage subunits discharge in the corresponding VSG unit, so it can effectively avoid overcharge and overdischarge of the energy storage subunits in each VSG unit. occurrence of the phenomenon.

In a specific embodiment 2, at the initial moment P _N1 =2kW, P _N2 =3kW, P _N3 =6kW, other performance parameters of each VSG unit are the same, and the AC load unit increases the load by 5.5kW at the moment of 5S, this embodiment provides The virtual synchronous generator control method is denoted as the TOPSIS method.

Fig. 4(a) shows the change of inertia of each VSG unit in this embodiment, referring to Fig. 4(a), in this embodiment, the virtual inertia of the VSG unit with a large inverter rated capacity is large, and the rated capacity of the inverter is large. Small VSG elements have small virtual inertia.

Fig. 4(b) shows the change of the active output of each VSG unit in this embodiment, and Fig. 4(c) shows the change of the active output of each VSG unit in the existing FVSG control method. 4(c), in this embodiment, the active output of each VSG unit is consistent at the initial moment, and after increasing the load, each VSG unit can run safely; in the existing FVSG control method, after increasing the load, each VSG unit The active power output of the units began to be consistent, which led to the VSG ₁ unit with low safety performance reaching the rated capacity first and out of operation, plus the active power output pressure of the other two VSG units, which led to the VSG ₂ unit also reaching the rated capacity and out of operation.

FIG. 4(d) shows the comparison of the system frequency variation under the virtual synchronous generator control method provided by this embodiment and the existing FVSG control method. Referring to FIG. 4(d), in the method provided in this embodiment, the system frequency changes less violently, which can better provide inertial support for the microgrid system and maintain the frequency quality of the system.

The specific examples 1 and 2 show the optimization effect of the method for one performance index, wherein the embodiment 1 shows the optimization effect when the performance parameter SOC is different, and the embodiment 2 shows the rated capacity of the converter in the performance parameter Optimization effects when there are differences. The virtual synchronous generator control method provided by the embodiment of the present invention can realize reasonable virtual inertia distribution according to the performance parameter difference of each VSG unit, and maintain the stable operation of the microgrid system.

In a specific embodiment 3, at the initial moment SOC ₁ =20%, SOC ₂ =50%, SOC ₃ =50%, P _N1 =2.5KW, P _N2 =2.5KW, P _N3 =3kW, the power of each VSG unit Other performance parameters are the same, the output power of each VSG unit is -1kW, the AC load unit reduces the load by 3kW at 5S, and the energy storage sub-unit of each VSG unit needs to be charged with energy storage. The smaller the performance index SOC, the better. This implementation The virtual synchronous generator control method provided by the example is denoted as the TOPSIS method.

Fig. 5(a) shows the inertia change of each VSG unit in this embodiment, referring to Fig. 5(a), in this embodiment, since the SOC ₁ value is the smallest, the comprehensive evaluation index of the VSG ₁ unit is closest to the optimal solution, Hence _H1 is the largest. After 1S, the active output of the VSG ₁ unit is close to the rated capacity. Due to the change of the output power, the weight of each performance index changes, and the adjustable capacity of the inverter becomes the main factor for evaluating the inertial support capacity. At this time, the VSG ₁ unit is close to Running at rated capacity, away from the positive ideal solution, provides a reduction in the proportion of virtual inertia, that is, _a reduction in H1.

Fig. 5(b) shows the variation of the active output of each VSG unit in this embodiment, referring to Fig. 5(b), in this embodiment, the active output of the VSG ₁ unit starts to be the largest at the start time, and starts to decrease when it is close to the rated capacity. It can be seen that the virtual synchronous generator control method provided in this embodiment adopts the coefficient of variation method to determine the weight of each performance index, and the virtual inertia of each VSG unit can be adjusted in real time according to the change of the performance parameter, so as to maintain the stable operation of the system. .

The specific embodiment 3 shows the effect of using the coefficient of variation method to calculate the weight in this method. The virtual synchronous generator control method provided in this embodiment can comprehensively consider the changes of various performance parameters, and always use the performance parameters corresponding to the greatly different performance parameters. The performance index is used as the main influencing factor, so as to reasonably allocate the virtual inertia to maintain the stable operation of the microgrid system.

In a specific embodiment 4, at the initial moment SOC ₁ =18%, SOC ₂ =21%, SOC ₃ =24%, and other performance parameters of each VSG unit are consistent with those in embodiment 1. The difference in the performance parameter SOC and the total inertia adjustment coefficient α of the two are different, and the AC load unit increases the load by 5kW at 5S. The virtual synchronous generator control method provided in this embodiment is recorded as the TOPSIS method.

Fig. 6(a) shows the change of inertia of each VSG unit in this embodiment, and Fig. 6(b) shows the change of active output of each VSG unit in this embodiment. Referring to Figure 3(a), Figure 3(b), Figure 6(a) and Figure 6(b), when the total energy storage capacity in the microgrid system is low, through the adjustment of the total inertia adjustment coefficient, the The total virtual inertia decreases, the corresponding virtual inertia of each VSG unit decreases, and the active output decreases.

Fig. 6(c), Fig. 6(d) and Fig. 6(e) respectively show the virtual synchronous generator control method and the existing FVSG control provided by the VSG ₁ unit, the VSG ₂ unit and the VSG ₃ unit in this embodiment Comparison of performance parameters SOC in methods. Referring to Fig. 6(c) to Fig. 6(e), compared with the existing FVSG control method, when the virtual synchronous generator control method provided by this embodiment is applied, the change speed of the performance parameter SOC is slower, indicating that this embodiment The provided virtual synchronous generator control method can reasonably adjust the total virtual inertia according to the total residual amount of energy storage in the microgrid system, so as to better maintain the operation of each energy storage sub-unit in a safe state.

The specific embodiment 4 shows the effect of the total inertia adjustment coefficient α on the stable operation of the microgrid system. The total inertia adjustment coefficient is determined by the SOC of each energy storage subunit, and the total virtual inertia of the microgrid system is adjusted according to the capacity of each energy storage subunit to avoid overcharge and overdischarge of each energy storage subunit.

It should be understood that the size of the sequence numbers of the steps in the above embodiments does not mean the sequence of execution, and the execution sequence of each process should be determined by its function and internal logic, and should not constitute any limitation to the implementation process of the embodiments of the present invention.

Referring to FIG. 7, an embodiment of the present invention provides a virtual synchronous generator control device 10, which is applied to a microgrid system having at least one virtual synchronous generator unit, including:

A performance parameter obtaining module 110, configured to obtain a performance parameter corresponding to at least one performance index of each virtual synchronous generator unit of the microgrid system;

a total virtual inertia calculation module 120, configured to calculate the total virtual inertia of the microgrid system according to various performance parameters;

A weight calculation module 130, configured to calculate the weight of the corresponding performance index for the virtual synchronous generator according to each performance parameter;

The ideal solution calculation module 140 is configured to calculate the positive ideal solution and the negative ideal solution according to the weight of each performance parameter and the corresponding performance index;

The comprehensive evaluation index calculation module 150 is configured to calculate the comprehensive evaluation index of each virtual synchronous generator unit according to the positive ideal solution, the negative ideal solution and the performance parameters corresponding to each virtual synchronous generator unit;

The virtual inertia calculation module 160 is configured to calculate the virtual inertia of each virtual synchronous generator unit according to the comprehensive evaluation index of each virtual synchronous generator unit and the total virtual inertia of the microgrid system;

In this embodiment, the performance indicators include the state of charge of the energy storage, the adjustable capacity of the inverter, the adjustable power of the energy storage charging and discharging, and the adjustable amount of power per unit time of the system; the performance parameter acquisition module 110 includes:

The inverter adjustable capacity calculation unit is used to calculate the inverter adjustable capacity of each virtual synchronous generator unit through the formula ΔP _Ni =P _Ni -|P _0i |; where ΔP _Ni is the ith virtual synchronous generator The inverter adjustable capacity of the unit, P _Ni is the inverter rated capacity of the ith virtual synchronous generator unit, and P _0i is the inverter output power of the ith virtual synchronous generator unit;

The energy storage charge and discharge adjustable power calculation unit is used to calculate the energy storage charge and discharge adjustable power according to the formula ΔP _bati =P _batNi -|P _bati |; wherein ΔP _bati is the energy storage of the i-th virtual synchronous generator unit Adjustable charging and discharging power, P _batNi is the upper limit of the energy storage charging and discharging power of the ith virtual synchronous generator unit, and P _bati is the actual charging and discharging power of the energy storage of the ith virtual synchronous generator unit.

The total virtual inertia calculation module 120 includes:

a working state judgment unit, used for judging the working state of the microgrid system according to the system frequency;

计算所述总惯量调整系数；若所述微电网系统的工作状态为待放电，则通过公式

计算所述总惯量调整系数；其中α为总惯量调整系数，S_Ni为第i个虚拟同步发电机单元的额定储能容量，SOC_d为储能上限，SOC_a为储能下限，SOC_i表示第i个虚拟同步发电机单元的实际荷电状态，SOC_N为储能正常参考值总虚拟贯量计算单元，用于通过公式

计算所述微电网系统的总虚拟惯量；其中H_T为所述微电网系统的总虚拟惯量，α为总惯量调整系数，k₁和k₂为虚拟惯量调整系数，f为系统频率。The total inertia adjustment coefficient calculation unit is used to calculate the formula through the formula if the working state of the microgrid system is to be charged

Calculate the adjustment coefficient of the total inertia; if the working state of the microgrid system is to be discharged, then use the formula

Calculate the total inertia adjustment coefficient; where α is the total inertia adjustment coefficient, S _Ni is the rated energy storage capacity of the ith virtual synchronous generator unit, SOC _d is the upper limit of energy storage, SOC _a is the lower limit of energy storage, and SOC _i represents The actual state of charge of the i-th virtual synchronous generator unit, SOC _N is the calculation unit of the total virtual flux of the normal reference value of the energy storage, which is used to pass the formula

Calculate the total virtual inertia of the microgrid system; wherein H _T is the total virtual inertia of the microgrid system, α is the total inertia adjustment coefficient, k ₁ and k ₂ are the virtual inertia adjustment coefficients, and f is the system frequency.

The weight calculation module 130 includes:

计算各个性能指标的变异系数；其中，V_j为第j个性能指标的变异系数；σ_j为第j项性能指标对应的各个虚拟同步发电机单元的性能参数的标准差；

为第j个性能指标对应的各个虚拟同步发电机单元的性能参数的平均数；Coefficient of variation calculation unit for formula-based

Calculate the coefficient of variation of each performance index; wherein, V _j is the coefficient of variation of the jth performance index; σ _j is the standard deviation of the performance parameters of each virtual synchronous generator unit corresponding to the jth performance index;

is the average number of performance parameters of each virtual synchronous generator unit corresponding to the jth performance index;

计算各个性能指标的权重；其中，W_j为第j项性能参数对应的权重，V_j为第j项性能参数的变异系数。The weight calculation unit is used to substitute the coefficient of variation corresponding to each performance index into the formula

Calculate the weight of each performance index; wherein, W _j is the weight corresponding to the j-th performance parameter, and V _j is the variation coefficient of the j-th performance parameter.

计算各个虚拟同步发电机单元的综合评价指数；其中C_i ^*表示第i个虚拟同步发电机单元的综合评价指数，d_i ^*为第i个虚拟同步发电机单元的性能参数与正理想解的欧式距离，d_i ^o为第i个虚拟同步发电机单元的性能参数与负理想解的欧式距离。The comprehensive evaluation index calculation module 150 is used to calculate according to the formula

Calculate the comprehensive evaluation index of each virtual synchronous generator unit; where C _i ^* represents the comprehensive evaluation index of the ith virtual synchronous generator unit, and d _i ^* is the performance parameter of the ith virtual synchronous generator unit and the positive ideal solution. Euclidean distance, d _i ^o is the Euclidean distance between the performance parameters of the ith virtual synchronous generator unit and the negative ideal solution.

计算各个虚拟同步发电机单元的虚拟惯量；其中H_i为第i个虚拟同步发电机单元的虚拟惯量，C_i ^*表示第i个虚拟同步发电机单元的综合评价指数，H_T为所述微电网系统的总虚拟惯量，H₀为常数。The virtual inertia calculation module 160 is used to calculate according to the formula

Calculate the virtual inertia of each virtual synchronous generator unit; wherein H _i is the virtual inertia of the ith virtual synchronous generator unit, C _i ^* represents the comprehensive evaluation index of the ith virtual synchronous generator unit, and H _T is the micro The total virtual inertia of the grid system, H ₀ is a constant.

The virtual synchronous generator control device provided in this embodiment can reasonably determine the corresponding virtual inertia for each virtual synchronous generator when the performance parameters of each virtual synchronous generator are different, thereby improving the operation stability of the microgrid system .

FIG. 8 is a schematic diagram of a terminal device provided by an embodiment of the present invention. As shown in FIG. 8 , the terminal device 8 of this embodiment includes: a processor 80 , a memory 81 , and a computer program 82 stored in the memory 81 and executable on the processor 80 . When the processor 80 executes the computer program 82, the steps in the above embodiments are implemented, for example, steps 101 to 104 shown in FIG. 1 . Alternatively, when the processor 80 executes the computer program 82 , the functions of the modules/units in the foregoing device embodiments, for example, the functions of the modules 110 to 160 shown in FIG. 7 , are implemented.

Exemplarily, the computer program 82 may be divided into one or more modules/units, and the one or more modules/units are stored in the memory 81 and executed by the processor 80 to complete the this invention. The one or more modules/units may be a series of computer program instruction segments capable of performing specific functions, and the instruction segments are used to describe the execution process of the computer program 82 in the terminal device 8 .

The terminal device 8 may be a computing device such as a desktop computer, a notebook, a palmtop computer, and a cloud server. The terminal device may include, but is not limited to, the processor 80 and the memory 81 . Those skilled in the art can understand that FIG. 8 is only an example of the terminal device 8, and does not constitute a limitation on the terminal device 8, and may include more or less components than those shown in the figure, or combine some components, or different components For example, the terminal device may further include an input and output device, a network access device, a bus, and the like.

The so-called processor 80 may be a central processing unit (Central Processing Unit, CPU), and may also be other general-purpose processors, digital signal processors (Digital Signal Processors, DSP), application specific integrated circuits (Application Specific Integrated Circuit, ASIC), Off-the-shelf programmable gate array (Field-Programmable Gate Array, FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, and the like. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.

The memory 81 may be an internal storage unit of the terminal device 8 , such as a hard disk or a memory of the terminal device 8 . The memory 81 may also be an external storage device of the terminal device 8, such as a plug-in hard disk, a smart memory card (Smart Media Card, SMC), a secure digital (Secure Digital, SD) equipped on the terminal device 8. card, flash card (Flash Card) and so on. Further, the memory 81 may also include both an internal storage unit of the terminal device 8 and an external storage device. The memory 81 is used to store the computer program and other programs and data required by the terminal device. The memory 81 can also be used to temporarily store data that has been output or will be output.

Those skilled in the art can clearly understand that, for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example. Module completion, that is, dividing the internal structure of the device into different functional units or modules to complete all or part of the functions described above. Each functional unit and module in the embodiment may be integrated in one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit, and the above-mentioned integrated units may adopt hardware. It can also be realized in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing from each other, and are not used to limit the protection scope of the present application. For the specific working processes of the units and modules in the above-mentioned system, reference may be made to the corresponding processes in the foregoing method embodiments, which will not be repeated here.

In the foregoing embodiments, the description of each embodiment has its own emphasis. For parts that are not described or described in detail in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

Those of ordinary skill in the art can realize that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Skilled artisans may implement the described functionality using different methods for each particular application, but such implementations should not be considered beyond the scope of the present invention.

In the embodiments provided by the present invention, it should be understood that the disclosed apparatus/terminal device and method may be implemented in other manners. For example, the apparatus/terminal device embodiments described above are only illustrative. For example, the division of the modules or units is only a logical function division. In actual implementation, there may be other division methods, such as multiple units. Or components may be combined or may be integrated into another system, or some features may be omitted, or not implemented. On the other hand, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interfaces, indirect coupling or communication connection of devices or units, and may be in electrical, mechanical or other forms.

The units described as separate components may or may not be physically separated, and components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution in this embodiment.

Each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically alone, or two or more units may be integrated into one unit. The above-mentioned integrated units may be implemented in the form of hardware, or may be implemented in the form of software functional units.

The integrated modules/units, if implemented in the form of software functional units and sold or used as independent products, may be stored in a computer-readable storage medium. Based on this understanding, the present invention can implement all or part of the processes in the methods of the above embodiments, and can also be completed by instructing relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium, and the computer When the program is executed by the processor, the steps of the foregoing method embodiments can be implemented. . Wherein, the computer program includes computer program code, and the computer program code may be in the form of source code, object code, executable file or some intermediate form, and the like. The computer-readable medium may include: any entity or device capable of carrying the computer program code, a recording medium, a U disk, a removable hard disk, a magnetic disk, an optical disk, a computer memory, a read-only memory (ROM, Read-Only Memory) , Random Access Memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium, etc. It should be noted that the content contained in the computer-readable media may be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction, for example, in some jurisdictions, according to legislation and patent practice, the computer-readable media Electric carrier signals and telecommunication signals are not included.

The above-mentioned embodiments are only used to illustrate the technical solutions of the present invention, but not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: it can still be used for the foregoing implementations. The technical solutions described in the examples are modified, or some technical features thereof are equivalently replaced; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should be included in the within the protection scope of the present invention.

Claims (10)

1. A virtual synchronous generator control method, applied to a microgrid system with at least one virtual synchronous generator unit, is characterized in that, comprising: Acquiring performance parameters corresponding to at least one performance index of each virtual synchronous generator unit of the microgrid system; Calculate the total virtual inertia of the microgrid system according to each performance parameter; Calculate the weight of the corresponding performance index according to each performance parameter; Calculate the positive ideal solution and the negative ideal solution according to each performance parameter and the weight of the corresponding performance index; Calculate the comprehensive evaluation index of each virtual synchronous generator unit according to the positive ideal solution, the negative ideal solution and the performance parameters corresponding to each virtual synchronous generator unit; The virtual inertia of each virtual synchronous generator unit is calculated according to the comprehensive evaluation index of each virtual synchronous generator unit and the total virtual inertia of the microgrid system. 2. A virtual synchronous generator control method as claimed in claim 1, characterized in that, the performance index comprises an energy storage state-of-charge index, an inverter adjustable capacity index, and an energy storage charge-discharge adjustable power index And the system unit time power adjustable index; The obtaining performance parameters corresponding to at least one performance index of each virtual synchronous generator unit of the microgrid system includes: Through the formula ΔP _Ni =P _Ni -|P _0i |, the adjustable capacity of the converter of each virtual synchronous generator unit is calculated; where ΔP _Ni is the inverter adjustable capacity of the i-th virtual synchronous generator unit, P _Ni is the inverter rated capacity of the i-th virtual synchronous generator unit, and P _0i is the ith virtual synchronous generator unit’s inverter capacity. Converter output power; Calculate the energy storage charging and discharging adjustable power of each virtual synchronous generator unit by the formula ΔP _bati =P _batNi -|P _bati |; Among them, ΔP _bati is the energy storage charge and discharge adjustable power of the i-th virtual synchronous generator unit, P _batNi is the upper limit of the energy-storage charge and discharge power of the i-th virtual synchronous generator unit, and P _bati is the i-th virtual synchronous generator unit. The actual charge and discharge power of the unit's energy storage. 3. A virtual synchronous generator control method according to claim 1, wherein the performance index comprises an energy storage state-of-charge index; The calculating the total virtual inertia of the microgrid system according to each performance parameter includes: Calculate the total inertia adjustment coefficient of the microgrid system according to the state of charge of each energy storage; by formula

calculating the total virtual inertia of the microgrid system; Wherein H _T is the total virtual inertia of the microgrid system, α is the total inertia adjustment coefficient, k ₁ and k ₂ are the virtual inertia adjustment coefficients, and f is the system frequency. 4. A virtual synchronous generator control method according to claim 3, wherein the calculating the total inertia adjustment coefficient of the microgrid system according to each energy storage state of charge comprises: Judging the working state of the microgrid system according to the system frequency; If the working state of the microgrid system is to be charged, according to the formula

calculating the total inertia adjustment coefficient; If the working state of the microgrid system is to be discharged, then according to the formula

calculating the total inertia adjustment coefficient; where α is the total inertia adjustment coefficient, S _Ni is the rated energy storage capacity of the ith virtual synchronous generator unit, SOC _d is the upper limit of energy storage, SOC _a is the lower limit of energy storage, and SOC _i is the ith virtual synchronous generator unit The state of charge of the energy storage, SOC _N is the normal reference value of the energy storage. 5. A virtual synchronous generator control method according to claim 1, wherein the calculating the weight of the corresponding performance index according to each performance parameter comprises: formula based

Calculate the coefficient of variation corresponding to each performance index; Among them, V _j is the coefficient of variation of the jth performance index; σ _j is the standard deviation of the performance parameters of each virtual synchronous generator unit corresponding to the jth performance index;

is the average number of performance parameters of each virtual synchronous generator unit corresponding to the jth performance index; Substitute the coefficient of variation corresponding to each performance index into the formula

Calculate the weight of each performance indicator; Among them, W _j is the weight corresponding to the j-th performance index, and V _j is the variation coefficient corresponding to the j-th performance index. 6 . The virtual synchronous generator control method according to claim 1 , wherein calculating each virtual synchronous generator according to the positive ideal solution, the negative ideal solution and the performance parameters corresponding to each virtual synchronous generator unit. 7 . Comprehensive evaluation index of synchronous generator unit, including: According to the formula

Calculate the comprehensive evaluation index of each virtual synchronous generator unit; where C _i ^* is the comprehensive evaluation index of the ith virtual synchronous generator unit, d _i ^* is the Euclidean distance between the performance parameters of the ith virtual synchronous generator unit and the positive ideal solution, and d _i ^o is the ith virtual synchronous generator unit The Euclidean distance between the performance parameters of the generator unit and the negative ideal solution. 7. A virtual synchronous generator control method as claimed in claim 1, wherein the calculation of each virtual synchronous power generation according to the comprehensive evaluation index of each virtual synchronous generator unit and the total virtual inertia of the microgrid system The virtual inertia of the machine unit, including: According to the formula

Calculate the virtual inertia of each virtual synchronous generator unit; Wherein H _i is the virtual inertia of the ith virtual synchronous generator unit, C _i ^* is the comprehensive evaluation index of the ith virtual synchronous generator unit, H _T is the total virtual inertia of the microgrid system, and H ₀ is a constant . 8. A virtual synchronous generator control device, applied to a microgrid system with at least one virtual synchronous generator unit, characterized in that, comprising: a performance parameter obtaining module, configured to obtain a performance parameter corresponding to at least one performance index of each virtual synchronous generator unit of the microgrid system; a total virtual inertia calculation module, configured to calculate the total virtual inertia of the microgrid system according to each performance parameter; The weight calculation module is used to calculate the weight of the corresponding performance index according to each performance parameter; The ideal solution calculation module is used to calculate the positive ideal solution and the negative ideal solution according to each performance parameter and the weight of the corresponding performance index; a comprehensive evaluation index calculation module, configured to calculate the comprehensive evaluation index of each virtual synchronous generator unit according to the positive ideal solution, the negative ideal solution and the performance parameters corresponding to each virtual synchronous generator unit; The virtual inertia calculation module is configured to calculate the virtual inertia of each virtual synchronous generator unit according to the comprehensive evaluation index of each virtual synchronous generator unit and the total virtual inertia of the microgrid system. 9. A terminal device, comprising a memory, a processor and a computer program stored in the memory and running on the processor, characterized in that, when the processor executes the computer program, the implementation as claimed in the claims The steps of any one of 1 to 7 of the method. 10. A computer-readable storage medium storing a computer program, characterized in that, when the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented .

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