A Microgrid Privacy Protection Method and System Based on a New Homomorphic Encryption Algorithm

Abstract

The present invention discloses a microgrid privacy protection method and system based on a novel homomorphic encryption algorithm, which relates to the field of microgrid control technology. The method includes: designing a distributed cooperative control method for the microgrid based on the distributed control theory to achieve frequency recovery of each distributed power source in the microgrid; defining the connotation and scope of privacy protection; designing a microgrid privacy protection method based on the novel homomorphic encryption algorithm according to the defined connotation and scope of privacy protection to protect the initial values and real-time values of each distributed power source in the microgrid from being leaked to node neighbors and achieve the goal of distributed cooperative control of the microgrid; and verifying the microgrid privacy protection method based on the novel homomorphic encryption algorithm through simulation experiments. The present invention can improve the trusted perception ability and privacy security of distributed cooperative operation of the microgrid.

Description

Technical Field

[0001] The present invention relates to the technical field of microgrid control, and particularly to a microgrid privacy protection method and system based on a new homomorphic encryption algorithm. Background Art

[0002] With the development of distributed energy technologies, more and more distributed energy resources have been developed and connected to the power grid, such as solar energy, wind energy, biomass energy, etc. The access of these distributed energy resource systems can alleviate the dependence of traditional power grids on large power plants, and at the same time can provide power resources in a decentralized manner, thereby improving the reliability and flexibility of power supply.

[0003] However, with the high-density access of renewable energy, the development of wide-area sensing and intelligent control technologies has deepened the degree of cyber-physical coupling in the microgrid, resulting in an increased risk of privacy leakage in the microgrid, and new challenges will be faced in the stable operation and coordinated control of the system.

[0004] Therefore, proposing a microgrid privacy protection method and system based on a new homomorphic encryption algorithm to solve the difficulties existing in the prior art is an urgent problem to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides a microgrid privacy protection method and system based on a new homomorphic encryption algorithm, which improves the trusted perception ability and privacy security of distributed collaborative operation of the microgrid.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A microgrid privacy protection method based on a new homomorphic encryption algorithm includes:

[0008] S1. Based on the distributed control theory, design a microgrid distributed collaborative control method to achieve the frequency recovery of each distributed power source in the microgrid;

[0009] S2. Define the connotation and scope of privacy protection;

[0010] S3. According to the defined connotation and scope of privacy protection, design a microgrid privacy protection method based on a new homomorphic encryption algorithm to protect the initial values and real-time values of each distributed power source in the microgrid from being leaked to node neighbors, and achieve the goal of microgrid distributed collaborative control;

[0011] S4. Use simulation experiments to verify the microgrid privacy protection method based on the new homomorphic encryption algorithm.

[0012] For the above method, optionally, in S1, when designing the microgrid distributed collaborative control method, it specifically includes:

[0013] The expression of the droop control of the microgrid is as follows:

[0014] ω i = ω ni - m pi P i (1)

[0015] Where, ω i is the output frequency value of distributed power source i, ω ni is the frequency setting of distributed power source i, P i is the output active power value of distributed power source i, m pi is the droop control coefficient of distributed power source i;

[0016] The specific expression of the microgrid frequency recovery target is:

[0017]

[0018] Where, ω ref is the frequency reference value;

[0019] Based on the distributed control theory, the frequency setting value of each distributed power source is only related to its neighbors. The frequency setting point ω ni is designed to enable the frequencies of all distributed power sources to recover to the reference value. The expression of the frequency setting point ω ni is as follows:

[0020] ω i = ω ni - m pi P i + u ωi + u Pi (3)

[0021] Where, u ωi and u Pi are the frequency control quantity and the active power control quantity of distributed power source i respectively;

[0022] u ωi The specific expression is:

[0023]

[0024] Where, ω j is the output frequency value of distributed power source j, k ωi is the frequency control gain of distributed power source i, g i is the frequency root gain of distributed power source i, a ij is the connection gain between distributed power source i and distributed power source j, N i is the neighbor set of distributed power source i;

[0025] uPi The specific expression is:

[0026]

[0027] Among them, P j is the output active power value of distributed power source j, and m pj is the droop control coefficient of distributed power source j, and k Pi is the active power control gain of distributed power source i.

[0028] For the above method, optionally, in S2, the privacy protection connotation and privacy protection scope are defined to protect the data of each distributed power source from being leaked to neighbor nodes during the operation process. The privacy protection scope is the true values of the initial value and real-time value of each distributed power source participating in the operation.

[0029] For the above method, optionally, in S3, the initial value and real-time value of each distributed power source in the microgrid are protected from being leaked to node neighbors, and the connection gain a ij is defined as:

[0030]

[0031] Among them, a i→j ∈Z + and a j→i ∈Z + are the unilateral gains randomly generated by distributed power source i and distributed power source j respectively, z + is the set of positive integers, |N i + | and |N i - | are the in-degree and out-degree matrices of distributed power source i respectively, a and are the minimum and maximum values of the connection gain respectively, n is the total number of distributed power sources.

[0032] For the above method, optionally, use P i κ to represent the data to be encrypted. The new Paillier homomorphic encryption algorithm specifically includes:

[0033] Initialization: The ciphertext C i and the plaintext P i applied in the Paillier homomorphic encryption method are positive integers. Before applying the encryption method, based on the formula P i = 10 κ ·P i κ , convert P i κ to the integer Pi , where k is the number of decimal places to be retained;

[0034] Public key / private key generation: Randomly select two large prime numbers p and q of the same length, satisfying gcd(pq, (p - 1)(q - 1)) = 1

[0035] where gcd(·) is the greatest common divisor function;

[0036] Define the public key as The private key is where, lcm(·) is the least common multiple function, is randomly selected, but satisfies where mod is the modulo function; λ = lcm(p - 1, q - 1);

[0037] Encryption: The ciphertext satisfies where r ∈ Z + , 0 < r < n, E i (·) is the encryption function;

[0038] Decryption: The plaintext satisfies where D i (·) is the decryption function;

[0039] Anti-initialization: According to the plaintext P i Deduce P i κ , and the specific expression is:

[0040]

[0041] For the above method, optionally, the Paillier homomorphic encryption algorithm satisfies the homomorphic addition and homomorphic multiplication properties, and the specific expressions are:

[0042]

[0043] where E i (P i ) τ is the τ-th power of E i (P i );

[0044] The microgrid privacy protection method based on the new homomorphic encryption algorithm specifically includes:

[0045] S301. For distributed power source i and distributed power source j, the connection gain a ij is known to both parties. According to formula (6), divide a ij randomly into a i→j ∈ Z+ and a j→i ∈Z + ;

[0046] S302. Calculate the public key according to the Paillier homomorphic encryption algorithm private key ciphertext E i (ω i (t)), and obtain according to formula (8):

[0047] E i (ω i (t)) -1 = E i (-ω i (t)) (9)

[0048] For distributed power source i, send the data packet to distributed power source j. At the same time, distributed power source j encrypts its own frequency value according to the received public key to obtain E i (ω j (t));

[0049] S303. Use the public key and the unilateral connection gain a j→i ∈Z + , and obtain:[[]]

[0050] E i (-ω i (t))·E i (ω j (t)) = E i (ω j (t)-ω i (t)),

[0051]

[0052] Transmit formula (10) to distributed power source i. Distributed power source i decrypts E i (a j→i ·(ω j (t)-ω i (t))) to a j→i ·(ω j (t)-ω i (t)), then multiply by the unilateral connection gain a i→j ∈Z + , and obtain a i→j ·a j→i ·(ω j (t)-ω i (t)), that is, a ij ·(ω j (t)-ωi (t)), without knowing the information of distributed power source j, distributed power source i realizes the distributed collaborative operation of the microgrid according to the Paillier homomorphic encryption algorithm.

[0053] In the above method, optionally, in S4, in the simulation experiment, the microgrid is established by the MATLAB toolbox, and the Paillier homomorphic cryptography algorithm is executed through Python.

[0054] A microgrid privacy protection system based on a new homomorphic encryption algorithm, which executes a microgrid privacy protection method based on a new homomorphic encryption algorithm as described in any one of the above, includes:

[0055] A distributed control module, which realizes the distributed collaborative control of the microgrid based on the distributed control theory;

[0056] An initialization module, which integerizes the transmitted data;

[0057] A public key / private key generation module, which generates the public key and private key required for data privacy protection;

[0058] An encryption module, which encrypts the transmitted private data;

[0059] A decryption module, which decrypts the transmitted private data;

[0060] An anti-initialization module, which returns the transmitted data to the initial state;

[0061] A verification module, which verifies the proposed method through simulation experiments.

[0062] It can be seen from the above technical solutions that, compared with the prior art, the present invention provides a microgrid privacy protection method and system based on a new homomorphic encryption algorithm, which has the following beneficial effects: on the basis of the traditional homomorphic encryption algorithm, the present invention designs a new homomorphic encryption algorithm to improve the problems of low computing efficiency, few computing types, and large storage overhead existing in the existing privacy protection algorithms, and significantly reduces the overhead in terms of computing efficiency and storage overhead, realizes the collaborative operation of the microgrid while protecting the private data of the interactive subjects, and promotes the development of privacy-secure microgrids. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0064] Figure 1Flowchart of a microgrid privacy protection method based on a new homomorphic encryption algorithm provided by the present invention;

[0065] Figure 2 Block diagram of the structure of a microgrid privacy protection system based on a new homomorphic encryption algorithm provided by the present invention;

[0066] Figure 3 Schematic diagram of the true frequency and encrypted frequency output by each distributed power source in the simulation experiment using the microgrid privacy protection method based on the new homomorphic encryption algorithm provided by the present invention;

[0067] Figure 4 Schematic diagram of the true active power and encrypted active power output by each distributed power source in the simulation experiment using the microgrid privacy protection method based on the new homomorphic encryption algorithm provided by the present invention. Specific implementation manners

[0068] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0069] In this application, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. The terms "include", "comprise" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not expressly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, the element defined by the statement "including a..." does not exclude the existence of additional identical elements in the process, method, article or device including the element.

[0070] Refer to Figure 1 As shown, the present invention discloses a microgrid privacy protection method based on a new homomorphic encryption algorithm, including:

[0071] S1. Based on the distributed control theory, design a microgrid distributed cooperative control method to realize the frequency recovery of each distributed power source in the microgrid;

[0072] S2. Define the connotation and scope of privacy protection;

[0073] S3. Design a privacy protection method for the microgrid based on a new homomorphic encryption algorithm according to the defined privacy protection connotation and scope, so as to protect the initial values and real-time values of each distributed power source in the microgrid from being leaked to node neighbors and achieve the goal of distributed cooperative control of the microgrid;

[0074] S4. Verify the privacy protection method for the microgrid based on the new homomorphic encryption algorithm through simulation experiments.

[0075] Further, in S1, design a distributed cooperative control method for the microgrid, specifically including:

[0076] The expression of the droop control of the microgrid is:

[0077] ω i = ω ni -m pi P i (1)

[0078] where ω i is the output frequency value of distributed power source i, ω ni is the frequency setting of distributed power source i, P i is the output active power value of distributed power source i, and m pi is the droop control coefficient of distributed power source i;

[0079] The specific expression of the microgrid frequency recovery target is:

[0080]

[0081] where ω ref is the frequency reference value;

[0082] Design the frequency setpoint ω ni to achieve the frequency recovery of each distributed power source to the reference value. Based on the distributed control theory, the frequency setting value of each distributed power source is only related to its neighbors. Design the frequency setpoint ω ni to achieve the frequency recovery of each distributed power source to the reference value. The expression of the frequency setpoint ω ni is:

[0083] ω i = ω ni -m pi P i + u ωi + u Pi (3)

[0084] where u ωi and u Pi are the frequency control quantity and active power control quantity of distributed power source i respectively;

[0085] uωi The specific expression is:

[0086]

[0087] where, ω j is the output frequency value of distributed power source j, k ωi is the frequency control gain of distributed power source i, g i is the frequency root gain of distributed power source i, a ij is the connection gain between distributed power source i and distributed power source j, N i is the neighbor set of distributed power source i;

[0088] u Pi The specific expression of is:

[0089]

[0090] where, P j is the output active power value of distributed power source j, m pj is the droop control coefficient of distributed power source j, k Pi is the active power control gain of distributed power source i.

[0091] Furthermore, in S2, the privacy protection connotation and privacy protection scope are defined to protect the data of each distributed power source from being leaked to neighbor nodes during the operation process. The privacy protection scope is the true values of the initial values and real-time values of each distributed power source participating in the operation;

[0092] Define a more specific privacy protection connotation and a wider privacy protection scope to protect the initial values and real-time values of each distributed power source from being leaked to node neighbors, laying a foundation for the design of the microgrid privacy protection method;

[0093] Specifically, eavesdroppers are usually divided into two categories: internal honest but curious eavesdroppers and external malicious eavesdroppers;

[0094] 1) Internal honest but curious eavesdroppers: Steal private or sensitive transmission information and try to calculate the initial and real-time states of other distributed power sources, which is not in the interest of the distributed power source itself;

[0095] 2) External malicious eavesdroppers: Maliciously eavesdrop on private and sensitive messages transmitted on communication links and sensors, tamper with real information and anonymously spread false states, resulting in the microgrid entering a dangerous operating state.

[0096] Furthermore, in S3, considering the problems existing in the existing privacy protection methods, such as low computational efficiency, few computational types, and large storage overhead, a new homomorphic encryption algorithm is designed, and a microgrid privacy protection method based on the new homomorphic encryption algorithm is proposed to protect the initial values and real-time values of each distributed power source in the microgrid from being leaked to node neighbors. And on this premise, the distributed collaborative control goal of the microgrid is still achieved;

[0097] Taking frequency privacy protection as an example, the core privacy leakage problem in the distributed control system is that the real-time value of ω i is leaked to other neighbor nodes of distributed power source i.

[0098] Therefore, the Paillier homomorphic encryption scheme is used to encrypt the transmitted ω i -ω j value. In this case, ω i -ω j in (4) can be effectively calculated without obtaining the actual value of ω j ;

[0099] However, there are loopholes in the above information exchange mechanism. Specifically, distributed power source j cannot obtain the transmission information of distributed power source i. But according to formula (4), the corresponding information of distributed power source j can be inferred from the state information ω i of distributed power source i itself, the decryption result ω i -ω j and the edge weight a ij ;

[0100] To solve the above problems more comprehensively and protect the initial values and real-time values of each distributed power source in the microgrid from being leaked to node neighbors, the connection gain a ij is defined as:

[0101]

[0102] where a i→j ∈Z + and a j→i ∈Z + are the unilateral gains randomly generated by distributed power source i and distributed power source j respectively, Z + is the set of positive integers, |N i + | and |N i - | are the in-degree and out-degree matrices of distributed power source i respectively, a and are the minimum and maximum values of the connection gain respectively, n is the total number of distributed power sources.

[0103] Furthermore, use Pi κ Represents the data to be encrypted. The new Paillier homomorphic encryption algorithm specifically includes:

[0104] Initialization: The ciphertext C applied in the Paillier homomorphic encryption method i and the plaintext P i are positive integers. Before applying the encryption method, based on the formula P i = 10 κ ·P i κ Convert P i κ to the integer P i , where k is the number of decimal places to be retained;

[0105] Public key / private key generation: Randomly select two large prime numbers p and q of the same length, satisfying gcd(pq, (p - 1)(q - 1)) = 1

[0106] where gcd(·) is the greatest common divisor function;

[0107] Define the public key as The private key is where lcm(·) is the least common multiple function, is randomly selected, but satisfies

[0108] where mod is the modulo function; λ = lcm(p - 1, q - 1);

[0109] Encryption: The ciphertext satisfies where r ∈ Z + , 0 < r < n, E i (·) is the encryption function;

[0110] Decryption: The plaintext satisfies where D i (·) is the decryption function;

[0111] Anti-initialization: Derive P i from the plaintext P i κ , and the specific expression is:

[0112]

[0113] Furthermore, the Paillier homomorphic encryption algorithm satisfies the homomorphic addition and homomorphic multiplication properties, and the specific expressions are:

[0114]

[0115] Among them, E i (P i ) τ is the τ-th power of E i (P i );

[0116] The microgrid privacy protection method based on the new homomorphic encryption algorithm specifically includes:

[0117] S301. For distributed power source i and distributed power source j, the connection gain a ij is known to both parties. According to formula (6), a ij is randomly divided into a i→j ∈Z + and a j→i ∈Z + ;

[0118] S302. Calculate the public key private key ciphertext E i (ω i (t)) according to the Paillier homomorphic encryption algorithm. According to formula (8), it can be obtained that:

[0119] E i (ω i (t)) -1 = E i (-ω i (t)) (9)

[0120] For distributed power source i, the data packet is sent to distributed power source j. At the same time, distributed power source j encrypts its own frequency value according to the received public key to obtain E i (ω j (t));

[0121] S303. Use the public key and the unilateral connection gain a j→i ∈Z + , and obtain:

[0122] E i (-ω i (t))·E i (ω j (t)) = E i (ω j (t)-ω i (t)),

[0123]

[0124] Transmit formula (10) to distributed power source i, and distributed power source i will Ei (a j→i ·(ω j (t)-ω i (t))) is decrypted as a j→i ·(ω j (t)-ω i (t)), and then multiplied by the unilateral connection gain a i→j ∈Z + , obtaining a i→j ·a j→i ·(ω j (t)-ω i (t)), that is, a ij ·(ω j (t)-ω i (t)). Without knowing the information of distributed power source j, distributed power source i realizes the distributed collaborative operation of the microgrid according to the Paillier homomorphic encryption algorithm.

[0125] Furthermore, in S4, in the simulation experiment, the microgrid is established by the MATLAB toolbox, and the Paillier homomorphic cryptography algorithm is executed through Python.

[0126] A microgrid privacy protection system based on a new homomorphic encryption algorithm, implementing a microgrid privacy protection method based on a new homomorphic encryption algorithm as described in any one of the above, includes:

[0127] A distributed control module, which realizes the distributed collaborative control of the microgrid based on the distributed control theory;

[0128] An initialization module, which integerizes the transmitted data;

[0129] A public key / private key generation module, which generates the public key and private key required for data privacy protection;

[0130] An encryption module, which encrypts the transmitted private data;

[0131] A decryption module, which decrypts the transmitted private data;

[0132] An anti-initialization module, which returns the transmitted data to the initial state;

[0133] A verification module, which verifies the proposed method through simulation experiments.

[0134] In a specific embodiment, the simulation experiment is carried out on a computer equipped with an Intel i7-12700H CPU and 32G RAM. The microgrid is established by the MATLAB 2021b / Simulink toolbox, and the Paillier homomorphic cryptography algorithm is executed through Python3.8.6;

[0135] To verify the effectiveness of the proposed microgrid privacy protection method based on the new homomorphic encryption algorithm, the simulation process is designed as follows:

[0136] 1) At t = 0 s, the microgrid enters the island operation mode;

[0137] 2) At t = 1.5 s, the microgrid distributed secondary control method is applied;

[0138] 3) At t = 4 s, a load of 3 kW is added;

[0139] 4) At t = 6 s, a load of 3 kW is reduced.

[0140] The total simulation time is 8 s, and the microgrid privacy protection method based on the new homomorphic encryption algorithm proposed in the present invention is applied throughout the simulation.

[0141] Refer to Figure 3 As shown, the convergence diagrams of the distributed power sources under the microgrid privacy protection method based on the new homomorphic encryption algorithm proposed in the present invention are given for the cases of applying the plaintext (real data) and ciphertext (encrypted data) of the frequency of each distributed power source respectively; among them, the ciphertext is calculated according to the Paillier homomorphic encryption method, corresponding to the left y-axis; the plaintext corresponds to the right y-axis; the upper half of the convergence diagram is the ciphertext, and the lower half is the plaintext;

[0142] By comparing the upper and lower parts of each sub-diagram, we can see that the encrypted data of each distributed power source is always different from the real data. In addition, it can be seen that although the real state has converged to the pre-designed reference value, after arbitrarily selecting positive integers r, p, q, the encrypted values of each distributed power source are still random. Therefore, the simulation results are consistent with the theoretical analysis, that is, without the private key, the eavesdropper cannot infer the real state of the distributed power source.

[0143] Refer to Figure 4 As shown, the diagrams of the active power plaintext and ciphertext of each distributed power source under the microgrid privacy protection method based on the new homomorphic encryption algorithm proposed in the present invention are given. The simulation results of the active power are consistent with the frequency. Therefore, the microgrid privacy protection method based on the Paillier homomorphic encryption algorithm effectively prevents the leakage of privacy information to the eavesdropper.

[0144] Each embodiment in this specification is described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other. Each embodiment focuses on the differences from other embodiments. In particular, for a system or system embodiment, since it is basically similar to the method embodiment, the description is relatively simple. For the relevant parts, reference can be made to the description of the method embodiment. The systems and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. A person of ordinary skill in the art can understand and implement it without creative work.

[0145] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A microgrid privacy protection method based on a new homomorphic encryption algorithm, characterized in that: include: S1. Based on distributed control theory, a distributed collaborative control method for microgrids is designed to achieve frequency recovery of each distributed power source in the microgrid; In S1, a distributed collaborative control method for microgrids is designed, including: The expression of microgrid droop control is: oh i =ω ni -m pi P i (1) Among them, ω i is the output frequency value of distributed power source i, ω ni is the frequency setting of distributed power source i, P i is the output active power value of distributed power source i, m pi is the droop control coefficient of distributed generation i; The specific expression of the microgrid frequency restoration target is: Among them, ω ref is the frequency reference value; Based on distributed control theory, the frequency setting value of each distributed power source is only related to its neighbors. The designed frequency setting point ω ni To restore the frequency of each distributed power source to the reference value, the frequency setting point ω ni The expression is: oh i =ω ni -m pi P i +u ωi +u Pi (3) Among them, u ωi and u Pi are the frequency control quantity and active power control quantity of distributed power source i respectively; u ωi The specific expression is: Among them, ω j is the output frequency value of distributed power source j, k ωi is the frequency control gain of distributed power source i, g i is the root frequency gain of distributed power source i, a ij is the connection gain between distributed generation i and distributed generation j, N i is the neighbor set of distributed generation i; u Pi The specific expression is: Among them, P j is the output active power value of distributed generation j, m pj is the droop control coefficient of distributed generation j, k Pi is the active power control gain of distributed power source i; S2. Define the connotation and scope of privacy protection; S3. According to the defined privacy protection connotation and privacy protection scope, a microgrid privacy protection method based on a new homomorphic encryption algorithm is designed to protect the initial value and real-time value of each distributed power source in the microgrid from being leaked to node neighbors, thereby achieving the distributed collaborative control goal of the microgrid; The Paillier homomorphic encryption algorithm satisfies the homomorphic addition and homomorphic multiplication properties. The specific expression is: Among them, E i (P i ) τ For E i (P i ) to the power of τ; The microgrid privacy protection method based on the new homomorphic encryption algorithm specifically includes: S301, for distributed power sources i and j, the connection gain a ij are known to both parties. According to formula (6), a ij Randomly divided into a i→j ∈Z + and a j→i ∈Z + ; S302. Calculate the public key according to the Paillier homomorphic encryption algorithm Private Key Ciphertext E i (ω i (t)), according to formula (8): E i (oh i (t)) -1 =E i (-ω i (t)) (9) For distributed power source i, the data packet Send it to distributed power j. At the same time, distributed power j encrypts its own frequency value according to the received public key to obtain E i (ω j (t)); S303, use public key and single-side connection gain a j→i ∈Z + , we get: E i (-ω i (t))·E i (oh j (t))=E i (oh j (t)-ω i (t)), Transmit formula (10) to distributed generation i, and distributed generation i converts E i (a j→i ·(ω j (t)-ω i (t))) decrypts to a j→i ·(ω j (t)-ω i (t)), and then multiplied by the single-side connection gain a i→j ∈Z + , and we get a i→j ·a j→i ·(ω j (t)-ω i (t)), that is, a ij ·(ω j (t)-ω i (t)), distributed power source i realizes the distributed collaborative operation of microgrid according to the Paillier homomorphic encryption algorithm without knowing the information of distributed power source j; S4. Use simulation experiments to verify the microgrid privacy protection method based on the new homomorphic encryption algorithm.

2. According to a microgrid privacy protection method based on a novel homomorphic encryption algorithm according to claim 1, it is characterized in that: In S2, the privacy protection connotation and privacy protection scope are defined to protect the data of each distributed power source from being leaked to neighboring nodes during the operation. The privacy protection scope is the true value of the initial value and real-time value of each distributed power source participating in the operation.

3. According to a microgrid privacy protection method based on a novel homomorphic encryption algorithm according to claim 1, it is characterized in that: In S3, the initial value and real-time value of each distributed power source in the microgrid are protected from being leaked to node neighbors, and the connection gain a ij Defined as: Among them, a i→j ∈Z + and a j→i ∈Z + are the randomly generated unilateral gains of distributed power sources i and j, Z + is a set of positive integers, and are the in-degree and out-degree matrices of distributed generation i, a and are the minimum and maximum connection gain respectively, V=={1,2,...n}, and n is the total number of distributed power sources.

4. According to a microgrid privacy protection method based on a novel homomorphic encryption algorithm according to claim 3, it is characterized in that: Use P i κ Indicates the data that needs to be encrypted, the new Paillier homomorphic encryption algorithm, specifically including: Initialization: ciphertext C used in Paillier homomorphic encryption method i and plaintext P i Is a positive integer. Before applying the encryption method, based on the formula P i =10 κ ·P i κ , P i κ Convert to integer P i , where k is the number of decimal places retained; Public / private key generation: Randomly select two large prime numbers p and q of the same length, satisfying gcd(pq,(p-1)(q-1))=1 Among them, gcd(·) is the greatest common divisor function; Define the public key as The private key is in, lcm(·) is the least common multiple function, It is chosen randomly, but it satisfies in mod is the modulus function; λ = lcm(p-1,q-1); Encryption: The ciphertext satisfies Among them, r∈Z + ,0<r<n,E i (·) is the encryption function; Decryption: Plaintext satisfies Among them, D i (·) is the decryption function; Deinitialization: According to the plaintext P i Derivation of P i κ , the specific expression is:

5. According to a microgrid privacy protection method based on a novel homomorphic encryption algorithm according to claim 1, it is characterized in that: In S4, in the simulation experiment, the microgrid is established by the MATLAB toolbox, and the Paillier homomorphic cryptographic algorithm is executed by Python.

6. A microgrid privacy protection system based on a novel homomorphic encryption algorithm, executing a microgrid privacy protection method based on a novel homomorphic encryption algorithm as described in any one of claims 1 to 5, comprising: Distributed control module, based on distributed control theory, realizes distributed coordinated control of microgrids; Initialization module, converts the transmission data into integers; Public key / private key generation module, which generates the public key and private key required for data privacy protection; Encryption module, encrypts the transmitted private data; Decryption module, decrypting the transmitted private data; Deinitialization module, returns the transmission data to the initial state; Verification module, uses simulation experiments to verify the proposed method.

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