Low voltage bus interconnection control method based on variable frequency transformer and related products

Abstract

The application relates to the technical field of power distribution network interconnection, and provides a low-voltage bus interconnection control method based on a variable-frequency transformer and related products, the method comprising the following steps: judging the overload condition of each power distribution transformer according to the load condition of the power distribution transformer; judging the overload condition of each power distribution transformer according to the load condition of the power distribution transformer; calculating the power reference value of the variable-frequency transformer according to a power distribution method; judging the overload condition of the variable-frequency transformer according to the power reference value of the variable-frequency transformer; adjusting the power reference value of the variable-frequency transformer according to the judgment result; and transmitting the power reference value of the variable-frequency transformer to the control loop of the variable-frequency transformer to realize coordinated control of the power of two power distribution transformers. The application can solve the problem that some power distribution transformers are overloaded and overloaded due to the limitation of the system structure of the existing distribution network.

Description

Technical Field

[0001] This application relates to the field of power distribution network interconnection technology, and in particular to a low-voltage busbar interconnection control method and related products based on a variable frequency transformer. Background Technology

[0002] Medium-voltage distribution areas are a key link in power distribution systems. They mainly refer to the power supply areas where medium-voltage distribution lines are stepped down to low voltage by distribution transformers. Specifically, they refer to power supply units consisting of one or more medium-voltage distribution transformers and their auxiliary equipment (such as switches, protection devices, metering equipment, etc.), covering a user group within a specific geographical area.

[0003] With the rapid increase in distribution network load, some medium-voltage distribution areas are experiencing serious overload and overload problems. Especially during peak load periods, overload and / or overload of the distribution network will lead to problems such as low voltage and overload tripping, which seriously affects the user's electricity experience and poses a great risk to the safe and stable operation of the power grid.

[0004] In the relevant technologies for dealing with heavy-load and overloaded distribution areas, the main approach is to upgrade the capacity and adjust the grid structure through infrastructure construction. However, since most heavy-load and overload problems are only temporary and generally occur during peak summer seasons and some extreme weather events, the aforementioned methods have problems of poor economic efficiency and slow response speed, and cannot effectively adapt to the development needs of the distribution network. Summary of the Invention

[0005] This application provides a low-voltage busbar interconnection control method and related products based on variable frequency transformers, which can solve the problem of some distribution transformers being overloaded and overloaded due to the limitations of the system structure in existing distribution networks.

[0006] In one aspect, this application provides a low-voltage busbar interconnection control method based on a variable frequency transformer. The method is applied to an interconnected power grid based on a variable frequency transformer. The interconnected power grid includes two distribution transformers, two feeders, two low-voltage buses, and the variable frequency transformer. The high-voltage side of the first distribution transformer is connected to the first feeder, and the low-voltage side of the first distribution transformer is connected to the first low-voltage busbar. The high-voltage side of the second distribution transformer is connected to the second feeder, and the low-voltage side of the second distribution transformer is connected to the second low-voltage busbar. The first low-voltage busbar and the second low-voltage busbar are connected based on the variable frequency transformer. The method includes:

[0007] The load conditions of the two distribution transformers and the variable frequency transformer are collected;

[0008] The overload determination module determines the overload status of each distribution transformer based on its load condition.

[0009] The overload determination module determines the overload status of each distribution transformer based on its load condition.

[0010] The power allocation module obtains the corresponding power allocation method based on the judgment results of the first overload judgment module and the overload judgment module, and calculates the power reference value of the variable frequency transformer based on the power allocation method.

[0011] The overload determination module determines the overload status of the variable frequency transformer based on the power reference value of the variable frequency transformer.

[0012] Based on the judgment result of the second overload determination module, the power reference value of the variable frequency transformer is adjusted;

[0013] The power reference value and load status of the variable frequency transformer are transmitted to the control circuit of the variable frequency transformer to achieve coordinated control of the power of the two distribution transformers.

[0014] On the other hand, this application provides a low-voltage bus interconnection control device for a variable frequency transformer. The device is based on an interconnected power grid of the variable frequency transformer, which includes two distribution transformers, two feeders, two low-voltage buses, and the variable frequency transformer. The high-voltage side of the first distribution transformer is connected to the first feeder, and the low-voltage side of the first distribution transformer is connected to the first low-voltage bus. The high-voltage side of the second distribution transformer is connected to the second feeder, and the low-voltage side of the second distribution transformer is connected to the second low-voltage bus. The first low-voltage bus and the second low-voltage bus are connected based on the variable frequency transformer. The device includes:

[0015] The load status acquisition module is used to acquire the load status of the two distribution transformers and the variable frequency transformer;

[0016] The first overload determination module is used to determine the overload status of each distribution transformer based on the load status of the distribution transformer.

[0017] The overload determination module is used to determine the overload status of each distribution transformer based on the load status of the distribution transformer.

[0018] The power distribution module is used to obtain the corresponding power distribution method based on the judgment results of the overload judgment module and the heavy load judgment module of the distribution transformer, and to calculate the power reference value of the variable frequency transformer based on the power distribution method.

[0019] The second overload determination module is used to determine the overload status of the variable frequency transformer based on the power reference value of the variable frequency transformer.

[0020] The power reference value adjustment module is used to adjust the power reference value of the variable frequency transformer according to the judgment result of the overload judgment module of the variable frequency transformer.

[0021] The coordination control module is used to transmit the power reference value and load status of the variable frequency transformer to the control loop of the variable frequency transformer, so as to realize the coordinated control of the power of the two distribution transformers.

[0022] In another aspect, this application also provides an electronic device, including: a processor, a memory, and a computer program stored in the memory and capable of running on the processor, wherein the computer program, when executed by the processor, implements any of the low-voltage bus interconnection control methods based on variable frequency transformers as described in the present invention.

[0023] In another aspect, this application also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements any of the low-voltage bus interconnection control methods based on variable frequency transformers described in the present invention.

[0024] In another aspect, this application also provides a computer program product containing instructions that, when run on a computer, cause the computer to perform the low-voltage bus interconnection control method based on a variable frequency transformer described in the above aspects.

[0025] This application provides a low-voltage busbar interconnection control method and related products based on variable frequency transformers. This method can be applied to interconnected power grids based on variable frequency transformers. In this interconnected power grid, the high-voltage side of a first distribution transformer is connected to a first feeder, and its low-voltage side is connected to a first low-voltage busbar. The high-voltage side of a second distribution transformer is connected to a second feeder, and its low-voltage side is connected to a second low-voltage busbar. The first and second low-voltage busbars are connected based on variable frequency transformers. The method can collect the load information of the two distribution transformers and the variable frequency transformer. Through a first overload determination module, the overload status of each distribution transformer is determined based on its load information. Furthermore, through a heavy load determination module, the overload status of each distribution transformer is determined based on its load information. The load status of the transformers is used to determine the overload status of each distribution transformer. Then, the power distribution module obtains the corresponding power distribution method based on the judgment results of the first overload judgment module and the overload judgment module. The power reference value of the variable frequency transformer is calculated based on the power distribution method. The second overload judgment module judges the overload status of the variable frequency transformer based on the power reference value. After adjusting the power reference value of the variable frequency transformer based on the judgment result of the overload judgment module, the power reference value and load status of the variable frequency transformer can be transmitted to the control loop of the variable frequency transformer to achieve coordinated power control of the two distribution transformers. Based on the load conditions of distribution transformers and variable frequency transformers, different heavy load and overload conditions are judged, and the power of distribution transformers under different heavy load and overload conditions is coordinated and controlled, making the adjustment methods flexible and varied. Clear and accurate adjustment of heavy load and overload transformers is achieved, effectively adapting to the development needs of the distribution network and solving the problem of some distribution transformers experiencing heavy load and overload conditions due to the limitations of the existing distribution network system structure. Furthermore, it can make full use of the transformer capacity, with advantages of good economy and fast response speed, effectively making up for the shortcomings of the infrastructure construction method. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of an interconnected power grid based on a variable frequency transformer according to an embodiment of this application;

[0027] Figure 2 This is a flowchart illustrating a control console area based on a variable frequency transformer, as provided in an embodiment of this application.

[0028] Figure 3 This is a flowchart illustrating the steps of a low-voltage busbar interconnection control method based on a variable frequency transformer, according to an embodiment of this application.

[0029] Figure 4 This is a schematic diagram of the power distribution of a variable frequency transformer provided in an embodiment of this application;

[0030] Figure 5 This is a schematic diagram of coordinated control provided in an embodiment of this application;

[0031] Figure 6 This is a structural block diagram of a low-voltage busbar interconnection control device for a variable frequency transformer according to an embodiment of this application;

[0032] Figure 7 This is a structural block diagram of an electronic device provided in an embodiment of this application;

[0033] Figure 8 This is a structural block diagram of a computer-readable storage medium provided in an embodiment of this application. Detailed Implementation

[0034] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0035] In the relevant technologies for handling overloaded and overloaded distribution areas, capacity expansion and grid structure adjustment can be achieved through infrastructure construction. However, these methods are not suitable for phased overload and overload problems, and suffer from poor economic efficiency and slow response speed, failing to effectively adapt to the development needs of the distribution network. Alternatively, the distribution network structure can be optimized by controlling the on / off state of tie switches. However, the method of connecting the power supply buses of different distribution transformers through tie switches can only achieve load transfer by switching the tie switches on and off, resulting in a single and inflexible adjustment method.

[0036] This application embodiment uses a variable frequency transformer in the interconnection control of a bilateral same-frequency power grid. In the interconnected power grid formed based on the variable frequency transformer, the high-voltage side of the first distribution transformer is connected to the first feeder, and the low-voltage side of the first distribution transformer is connected to the first low-voltage bus. The high-voltage side of the second distribution transformer is connected to the second feeder, and the low-voltage side of the second distribution transformer is connected to the second low-voltage bus. The first low-voltage bus and the second low-voltage bus are connected based on the variable frequency transformer. Based on the aforementioned interconnected power grid network structure, the real-time power of the distribution transformer, the real-time stator active power of the variable frequency transformer, and the real-time rotor speed are used to judge different heavy load and overload conditions. The power of the distribution transformer under different heavy load and overload conditions is coordinated and controlled, making the adjustment methods flexible and varied. Clear and accurate adjustment of the heavy load and overload transformers is achieved, effectively adapting to the development needs of the distribution network and solving the problem that some distribution transformers in the existing distribution network are subject to heavy load and overload conditions due to the limitations of the system structure. Furthermore, it can make full use of the transformer capacity, has the advantages of good economy and fast response speed, and effectively makes up for the shortcomings of the infrastructure method.

[0037] Reference Figure 1 This illustration shows a schematic diagram of an interconnected power grid based on a variable frequency transformer, according to an embodiment of this application. The interconnected power grid based on a variable frequency transformer can be represented as a low-voltage busbar interconnected power grid based on a variable frequency transformer. This interconnected power grid may include two distribution transformers, two feeders, two low-voltage buses, and a variable frequency transformer, wherein the two distribution transformers, two feeders, and two low-voltage buses can be interconnected based on the variable frequency transformer.

[0038] Specifically, in the interconnected power grid, the high-voltage side of the first distribution transformer is connected to the first feeder, the low-voltage side of the first distribution transformer is connected to the first low-voltage bus, the high-voltage side of the second distribution transformer is connected to the second feeder, the low-voltage side of the second distribution transformer is connected to the second low-voltage bus, and the first low-voltage bus and the second low-voltage bus are connected based on a variable frequency transformer to achieve interconnection.

[0039] The variable frequency transformer may include filter inductors, series transformers, series converters, parallel converters, DC capacitors, converters (such as H-bridge converters), DC motors, and doubly fed motors.

[0040] The specific topology of the first low-voltage bus and the second low-voltage bus connected based on the variable frequency transformer can be represented as follows: the first low-voltage bus is connected to one end of the filter inductor and one end of the output side of the series transformer; the other end of the output side of the series transformer is connected to the stator winding of the doubly-fed motor; the input side of the series transformer is connected to the AC side of the series converter; the other end of the filter inductor is connected to the AC side of the parallel converter; the DC side of the parallel converter is connected to the DC side of the series converter, the DC capacitor, and the DC input side of the converter; the DC output side of the converter is connected to the DC motor; the DC motor is coaxially connected to the doubly-fed motor; and the second low-voltage bus is connected to the rotor winding of the doubly-fed motor.

[0041] Optional, such as Figure 1 As shown, assuming the voltage of the two feeders is 10kV, and the voltage level of the two distribution transformers at the ends of the two feeders is also 10kV, and the capacities of the two distribution transformers, including the preset rated capacity and preset capacity threshold, are the same. The high-voltage side of the first distribution transformer (i.e., distribution transformer 1) can be connected to the first feeder (i.e., 10kV feeder 1), and the low-voltage side of distribution transformer 1 can be connected to the first low-voltage bus (i.e., low-voltage bus 1). Low-voltage bus 1 can be connected to one end of the filter inductor and one end of the output side of the series transformer. The other end of the output side of the series transformer can be connected to the stator winding of the doubly-fed induction generator. The input side of the series transformer can be connected to the AC side of the series converter, and the other end of the filter inductor can be connected to the AC side of the parallel converter. The DC side of the parallel converter can be connected to the DC side of the series converter, the DC capacitor, and the DC input side of the H-bridge converter. The DC output side of the H-bridge converter can be connected to the DC motor. The DC motor can be coaxially connected to the doubly fed motor. The high-voltage side of the second distribution transformer (i.e., distribution transformer 2) can be connected to the second feeder (i.e., 10kV feeder 2). The low-voltage side of distribution transformer 2 can be connected to the second low-voltage bus (i.e., low-voltage bus 2). The low-voltage bus 2 is connected to the rotor winding of the doubly fed motor to form an interconnected power grid.

[0042] Each distribution transformer can generate real-time power, and the variable frequency transformer has a stator side and a rotor side. The stator side of the variable frequency transformer has real-time power (hereinafter referred to as stator real-time active power), and the rotor side of the variable frequency transformer has real-time speed (hereinafter referred to as rotor real-time speed). The embodiments of this application can collect the aforementioned load conditions of two distribution transformers and a variable frequency transformer.

[0043] In some embodiments of this application, based on such Figure 1 The interconnected power grid topology shown can be used to control the low-voltage bus interconnection process as follows: Figure 2 As shown, the process can specifically include the following steps:

[0044] S201. Obtain the real-time power P1 of distribution transformer 1, the real-time power P2 of distribution transformer 2, and the real-time stator active power of the variable frequency transformer. Real-time rotational speed of the variable frequency transformer rotor Then step S202 can be executed;

[0045] S202. Based on the real-time power P1 of distribution transformer 1 and the real-time power P2 of distribution transformer 2, determine whether at least one distribution transformer is overloaded by using a preset first overload determination rule. As an example, if at least one distribution transformer is not overloaded, that is, both distribution transformers are not overloaded, then proceed to step S203. As another example, if at least one distribution transformer is overloaded, then proceed to step S207.

[0046] S203. Based on the real-time power P1 of distribution transformer 1 and the real-time power P2 of distribution transformer 2, determine whether at least one distribution transformer is overloaded by using the preset first overload determination rule. As an example, if at least one distribution transformer is not overloaded, that is, both distribution transformers are not overloaded, then return to step S201. As another example, if at least one distribution transformer is overloaded, then proceed to step S204.

[0047] S204. Based on the real-time power P1 of distribution transformer 1 and the real-time power P2 of distribution transformer 2, determine whether both distribution transformers are under heavy load using the preset second overload determination rule. As an example, if both distribution transformers are under heavy load, proceed to step S205. As another example, if the two distribution transformers are not under heavy load, it means that one distribution transformer is under load and the other distribution transformer is not under load, then proceed to step S206.

[0048] S205. Calculate the power reference value and transmission direction of the variable frequency transformer according to the preset first power distribution formula, and then proceed to step S2011.

[0049] S206. Calculate the power reference value and transmission direction of the variable frequency transformer according to the preset second power distribution formula, and then proceed to step S2011.

[0050] S207. Based on the real-time power P1 of distribution transformer 1 and the real-time power P2 of distribution transformer 2, determine whether both distribution transformers are overloaded by using a preset second overload determination rule. As an example, if both distribution transformers are not overloaded, it means that one distribution transformer is overloaded and the other distribution transformer is not overloaded, then proceed to step S208; if both distribution transformers are overloaded, then proceed to step S2018.

[0051] S208. Based on the real-time power P1 of distribution transformer 1 and the real-time power P2 of distribution transformer 2, determine whether the distribution transformer that is not overloaded is overloaded by using the preset third overload determination rule. As an example, if the distribution transformer that is not overloaded is not overloaded, then proceed to step S209; as another example, if the distribution transformer that is not overloaded is overloaded, then proceed to step S2010.

[0052] S209. Calculate the power reference value of the variable frequency transformer according to the preset third power distribution formula. The size and transmission direction are determined, and then proceed to step S2011;

[0053] S2010. Calculate the power reference value of the variable frequency transformer according to the preset fourth power distribution formula. The size and transmission direction are determined, and then proceed to step S2011;

[0054] S2011, Based on the power reference value of the variable frequency transformer The size of the variable frequency transformer is determined by a preset third overload judgment rule to determine whether the variable frequency transformer is overloaded. As an example, if the variable frequency transformer is not overloaded, step S2012 is executed; as another example, if the variable frequency transformer is overloaded, step S2013 is executed.

[0055] S2012. Maintain the power reference value of the variable frequency transformer. If the size remains unchanged, proceed to step S2014;

[0056] S2013, The power reference value of the variable frequency transformer The size is adjusted to the preset rated capacity P of the variable frequency transformer. N Execute step S2014;

[0057] S2014. Based on the power reference value of the variable frequency transformer The size and transmission direction, and the real-time active power of the stator of the variable frequency transformer. The first armature voltage is calculated by pre-setting the first control equation. And based on the real-time rotor speed of the variable frequency transformer. The second armature voltage is calculated by pre-setting the second control equation. Then, based on the first armature voltage Second armature voltage The total armature voltage was calculated. Execute step S2015;

[0058] S015, Based on the total armature voltage The control signal S for the H-bridge converter switching is obtained through pulse-width modulation (PWM). a Ultimately, through the control signal S a Adjust the DC motor of the variable frequency transformer, and then perform power coordination control on the distribution transformers at the ends of the two 10kV feeders, executing step S2016.

[0059] S2016. Based on the real-time power P1 of distribution transformer 1 and the real-time power P2 of distribution transformer 2, determine whether the overload problem has been resolved. As an example, if the overload problem has been resolved, proceed to step S2017; as another example, if the overload problem has not been resolved, proceed to step S2018.

[0060] S2017. Based on the real-time power P1 of distribution transformer 1 and the real-time power P2 of distribution transformer 2, determine whether the overload problem has been resolved. As an example, if the overload problem has not been resolved, proceed to step S2019; as another example, if the overload problem has been resolved, return to step S201.

[0061] S2018. Generate and issue an overload warning, then return to step S201;

[0062] S2019. Generate and issue an overload warning, then return to step S201.

[0063] The implementation of the low-voltage busbar interconnection control method provided in this application mainly involves coordinating the power control of two distribution transformers at the ends of two feeders in a low-voltage busbar interconnected power grid.

[0064] In some embodiments of this application, the load conditions of two distribution transformers and a variable frequency transformer can be collected so as to determine different heavy load and overload conditions based on the collected load conditions, and to coordinate and control the power of the distribution transformers under different heavy load and overload conditions.

[0065] Specifically, refer to Figure 3 This document illustrates a flowchart of the steps in a low-voltage busbar interconnection control method based on a variable frequency transformer, as provided in an embodiment of this application. This method is applicable to applications such as... Figure 1 The interconnected power grid based on variable frequency transformers shown may specifically include the following steps:

[0066] Step S301: Collect the load information of the two distribution transformers and the variable frequency transformer.

[0067] Optionally, the load condition of the distribution transformer may include the real-time power of the distribution transformer, and the load condition of the variable frequency transformer may include the real-time stator active power and the real-time rotor speed of the variable frequency transformer. The real-time power of the distribution transformer may refer to the active power transmitted at the current moment, i.e., the average instantaneous power consumed by the actual load; the real-time stator active power of the variable frequency transformer may specifically refer to the active power input to the stator windings, i.e., the power absorbed by the motor from the power grid and converted into an electromagnetic field; the real-time rotor speed of the variable frequency transformer may refer to the actual rotational speed of the rotor under the current load and frequency.

[0068] Step S302: The first overload determination module determines the overload status of each distribution transformer based on the load status of the distribution transformer.

[0069] The first overload determination module can be the overload determination module of the distribution transformer.

[0070] Real-time power monitoring of distribution transformers helps ensure that the load does not exceed the rated capacity of the distribution transformer.

[0071] Specifically, the overload situation of distribution transformers can include both distribution transformers not being overloaded, or at least one distribution transformer being overloaded.

[0072] In some embodiments of this application, the overload status of the two distribution transformers can be obtained by determining whether at least one distribution transformer is overloaded based on the real-time power of the two distribution transformers and by using a preset first overload determination rule.

[0073] Optionally, the preset first overload judgment rule can be expressed as follows: if the real-time power of at least one distribution transformer is greater than the preset rated capacity, then it is determined that at least one distribution transformer is overloaded; or, if the real-time power of both distribution transformers is less than or equal to the preset rated capacity, then it is determined that neither distribution transformer is overloaded.

[0074] For example, assume that the real-time power of distribution transformer 1 is P1, the real-time power of distribution transformer 2 is P2, and the preset rated capacity of distribution transformer 1 and distribution transformer 2 are the same, both being P1. N (Where N represents the rated value). The preset first overload judgment rule can be expressed as: if P1 > P N Or P2 > P N If P1 ≤ P2, then it is determined that at least one of the distribution transformers, distribution transformer 1 and distribution transformer 2, is overloaded; N And P2≤P N If the condition is met, then it is determined that neither distribution transformer 1 nor distribution transformer 2 is overloaded.

[0075] In some embodiments of this application, if both distribution transformers are not overloaded, the overload determination module can be entered so that the overload status of each distribution transformer can be determined via the overload determination module.

[0076] In another scenario, if at least one distribution transformer is overloaded, the first step is to determine whether both distribution transformers are overloaded. Specifically, this can be done by using the real-time power of both transformers and a pre-set second overload determination rule. If both transformers are overloaded, an overload warning can be issued, and the process returns to the initial step of collecting load information. Figure 2 As shown in step S201; if one distribution transformer is overloaded, the overload determination module can be entered so that the overload status of each distribution transformer can be determined through the overload determination module.

[0077] Optionally, a second overload determination rule can be preset, which can be expressed as follows: if the real-time power of both distribution transformers is greater than the preset rated capacity, then both distribution transformers are determined to be overloaded; or, if the real-time power of one distribution transformer is greater than the preset rated capacity, and the real-time power of the other distribution transformer is less than the preset rated capacity, then one of the two distribution transformers is determined to be overloaded, and the other distribution transformer is not overloaded.

[0078] For example, the preset second overload determination rule can be expressed as: if P1 > P N And P2 > P N If P1 ≤ P2, then both distribution transformer 1 and distribution transformer 2 are overloaded; N And P2 > P N If distribution transformer 1 is not overloaded, then distribution transformer 2 is overloaded; if P1 > P N And P2≤P N If the distribution transformer 1 is overloaded, then the distribution transformer 2 is not overloaded.

[0079] Step S303: The overload determination module determines the overload status of each distribution transformer based on its load condition.

[0080] The overload determination module can be the overload determination module of the distribution transformer.

[0081] Monitoring the real-time power of a distribution transformer not only helps ensure that the load does not exceed the transformer's rated capacity, but also helps ensure that the load does not exceed a preset capacity threshold. In other words, the overload condition of a distribution transformer can also be determined based on its real-time power.

[0082] In some embodiments of this application, the overload status of the two distribution transformers can be determined by the overload determination module of the distribution transformers, whether both distribution transformers are not overloaded or at least one distribution transformer is overloaded.

[0083] In one scenario, where neither of the two distribution transformers is overloaded, the first step is to determine if at least one transformer is overloaded. If at least one transformer is overloaded, the next step is to determine if both transformers are overloaded, thus achieving the following: Figure 2 The steps S202-S203-S204 shown are a continuous judgment process.

[0084] Specifically, based on the real-time power of the two distribution transformers, a preset first overload determination rule can be used to determine whether at least one distribution transformer is overloaded. If both distribution transformers are not overloaded, the overload determination module can end the determination process and return to the initial step of collecting load information, i.e., return to... Figure 2 As shown in step S201: If at least one distribution transformer is overloaded, the real-time power of the two distribution transformers can be used to determine whether both distribution transformers are overloaded by using a preset second overload determination rule, thereby obtaining the overload status of the two distribution transformers.

[0085] Optionally, the preset first overload determination rule can be expressed as follows: if the real-time power of at least one distribution transformer is greater than the preset capacity threshold and less than or equal to the preset rated capacity, then it is determined that at least one distribution transformer is overloaded; or, if the real-time power of both distribution transformers is less than or equal to the preset capacity threshold, then it is determined that neither distribution transformer is overloaded.

[0086] The preset capacity threshold of the distribution transformer is less than the preset rated capacity of the distribution transformer. Assume the preset rated capacity of the distribution transformer is P. N The preset capacity threshold of the distribution transformer can be nP N n can usually be a decimal greater than 0.5 but less than 1. For example, when n=0.8, the default capacity is 0.8P. N .

[0087] For example, the preset first overload determination rule can be expressed as: if 0.8P N <P1≤P N Or 0.8P N <P2≤P N If P1 ≤ 0.8P, then it is determined that at least one of the distribution transformers, distribution transformer 1 and distribution transformer 2, is overloaded; N And P2≤0.8P N If so, it is determined that both distribution transformer 1 and distribution transformer 2 are not overloaded.

[0088] Optionally, the preset second overload determination rule can be expressed as follows: if the real-time power of both distribution transformers is greater than the preset capacity threshold and less than or equal to the preset rated capacity, then both distribution transformers are determined to be overloaded; or, if the real-time power of one distribution transformer is greater than the preset capacity threshold and less than or equal to the preset rated capacity, and the real-time power of the other distribution transformer is less than the preset capacity threshold, then one distribution transformer is determined to be overloaded and the other distribution transformer is not overloaded.

[0089] For example, the preset second overload determination rule can be expressed as: if 0.8P N <P1≤P N And 0.8P N <P2≤P N If so, then both distribution transformer 1 and distribution transformer 2 are determined to be overloaded; if 0.8P N <P1≤P N And P2≤0.8P N If P1 ≤ 0.8P, then distribution transformer 1 is determined to be overloaded, and distribution transformer 2 is not overloaded; N And 0.8P N <P2≤P N If so, it is determined that distribution transformer 1 is not overloaded, and distribution transformer 2 is overloaded.

[0090] In another scenario, where one of the two distribution transformers is overloaded, it can be further determined whether the un-overloaded distribution transformer is under heavy load, in order to achieve... Figure 2 The steps S202-S207-S208 shown are a continuous judgment process.

[0091] Specifically, based on the real-time power of the two distribution transformers, a preset third overload judgment rule can be used to determine whether the distribution transformer that is not overloaded is overloaded, thus obtaining the overload status of the two distribution transformers.

[0092] Optionally, a third overload determination rule can be preset, which can be expressed as follows: if the real-time power of an unoverloaded distribution transformer is greater than a preset capacity threshold and less than or equal to a preset rated capacity, then the unoverloaded distribution transformer is determined to be overloaded; or, if the real-time power of an unoverloaded distribution transformer is less than or equal to a preset capacity threshold, then the unoverloaded distribution transformer is determined to be not overloaded.

[0093] For example, suppose the preset capacity threshold of the distribution transformer can be nP N n can usually be a decimal greater than 0.5 but less than 1. For example, when n=0.8, the default capacity is 0.8P. N The pre-defined third overload decision rule can be expressed as: when P1≤P N And P2 > PN In this case, the distribution transformer that is not overloaded is distribution transformer 1, and the distribution transformer that is overloaded is distribution transformer 2. Furthermore, as an example, if 0.8P... N <P1≤P N And P2 > P N If P1 ≤ 0.8P, then the distribution transformer 1, which is not overloaded, is determined to be overloaded. In this case, distribution transformer 1 is overloaded, and distribution transformer 2 is overloaded. As another example, if P1 ≤ 0.8P N And P2 > P N If the overload condition is met, then the distribution transformer 1 is determined to be not overloaded. In this case, the distribution transformer 1 is not overloaded, and the distribution transformer 2 is overloaded.

[0094] In P1>P N And P2≤P N In this case, the overloaded distribution transformer is distribution transformer 1, and the unoverloaded distribution transformer is distribution transformer 2. Furthermore, as an example, if P1 > P... N And 0.8P N <P2≤P N If the overloaded distribution transformer 2 is determined to be overloaded, then distribution transformer 1 is overloaded and distribution transformer 2 is overloaded; as another example, if P1 > P N And P2≤0.8P N If the distribution transformer 2 is not overloaded, then it is determined that the distribution transformer 1 is overloaded and the distribution transformer 2 is not overloaded.

[0095] Step S304: The power allocation module obtains the corresponding power allocation method based on the judgment results of the first overload judgment module and the heavy load judgment module, and calculates the power reference value of the variable frequency transformer based on the power allocation method.

[0096] In some embodiments of this application, the power allocation module can be entered after the overload determination module has completed its determination.

[0097] Under different overload and heavy load conditions of the distribution transformer, the power reference value of the variable frequency transformer can be calculated by using the corresponding power allocation method through the power allocation module. The calculated power reference value can be used for subsequent evaluation of the overload condition of the variable frequency transformer.

[0098] Specifically, such as Figure 4 As shown, the power reference value of the variable frequency transformer can be realized based on power allocation. For example, it can be represented by the real-time power of distribution transformer 1. Real-time power of distribution transformer 2 Real-time active power of the stator of a variable frequency transformer and the active power transmitted by the DC motor Power allocation is performed to obtain the power reference value of the variable frequency transformer. .

[0099] Optionally, the power distribution method can be expressed as a power distribution formula, and the power distribution formulas corresponding to different overload and heavy load conditions are different.

[0100] In some embodiments of this application, if both distribution transformers are fully loaded, the power reference value of the variable frequency transformer can be calculated using a preset first power allocation formula.

[0101] For example, when both distribution transformer 1 and distribution transformer 2 are heavily loaded, the preset first power distribution formula can be as follows:

[0102]

[0103]

[0104] in, It can be the power reference value of a variable frequency transformer, specifically referring to the stator active power reference value of a variable frequency transformer. This can be the real-time power of distribution transformer 1; This can be the real-time power of distribution transformer 2; It can transmit active power to a DC motor; It can be a coefficient that describes the power transmission direction of a variable frequency transformer.

[0105] In some embodiments of this application, if one distribution transformer is heavily loaded and the other distribution transformer is not heavily loaded, the power reference value of the variable frequency transformer can be calculated using a preset second power allocation formula.

[0106] For example, when one distribution transformer is overloaded and the other is not overloaded, such as distribution transformer 1 being overloaded but distribution transformer 2 not being overloaded, or distribution transformer 1 not being overloaded but distribution transformer 2 being overloaded, the preset second power allocation formula can be as follows:

[0107]

[0108]

[0109] in, It can be the power reference value of a variable frequency transformer, specifically referring to the stator active power reference value of a variable frequency transformer. This can be the real-time power of distribution transformer 1; This can be the real-time power of distribution transformer 2; The preset rated capacity, i.e., rated power, of the distribution transformer; It can transmit active power to a DC motor; It can be a coefficient used to represent the power transmission direction of a variable frequency transformer.

[0110] In some embodiments of this application, if one distribution transformer is overloaded and the other distribution transformer is not overloaded, the power reference value of the variable frequency transformer can be calculated using a preset third power allocation formula.

[0111] For example, when the unloaded distribution transformer is not overloaded, such as when unloaded distribution transformer 1 is not overloaded (i.e., distribution transformer 1 is not overloaded, and distribution transformer 2 is overloaded), or when unloaded distribution transformer 2 is not overloaded (i.e., distribution transformer 1 is overloaded, and distribution transformer 2 is not overloaded), the preset third power distribution formula can be as follows:

[0112]

[0113]

[0114] in, It can be the power reference value of a variable frequency transformer, specifically referring to the stator active power reference value of a variable frequency transformer. This can be the real-time power of distribution transformer 1; This can be the real-time power of distribution transformer 2; The preset rated capacity, i.e., rated power, of the distribution transformer; It can transmit active power to a DC motor; It can be a coefficient used to represent the power transmission direction of a variable frequency transformer.

[0115] In some embodiments of this application, if one distribution transformer is overloaded and another distribution transformer is heavily loaded, the power reference value of the variable frequency transformer can be calculated using a preset fourth power distribution formula.

[0116] For example, in the case where a non-overloaded distribution transformer is overloaded, such as a non-overloaded distribution transformer 1 being overloaded (i.e., distribution transformer 1 is overloaded and distribution transformer 2 is overloaded), or a non-overloaded distribution transformer 2 being overloaded (i.e., distribution transformer 1 is overloaded and distribution transformer 2 is overloaded), the preset fourth power distribution formula can be as follows:

[0117]

[0118]

[0119] in, It can be the power reference value of a variable frequency transformer, specifically referring to the stator active power reference value of a variable frequency transformer. This can be the real-time power of distribution transformer 1; This can be the real-time power of distribution transformer 2; The preset rated capacity, i.e., rated power, of the distribution transformer; It can transmit active power to a DC motor; It can be a coefficient used to represent the power transmission direction of a variable frequency transformer.

[0120] It should be noted that when calculating the power reference value of a variable frequency transformer, the transmission direction can be determined. The transmission direction can be used to determine the sign of the calculated value of the power distribution formula, such as positive or negative. The determination of the sign of the calculated value can be achieved by the magnitude of k1 in the power distribution formula determined by the transmission direction.

[0121] Step S305: The overload condition of the variable frequency transformer is determined by the second overload determination module based on the power reference value of the variable frequency transformer.

[0122] The second overload determination module can be an overload determination module for a variable frequency transformer.

[0123] The overload condition of a variable frequency transformer can be determined based on the calculated power reference value of the variable frequency transformer, i.e., the stator active power reference value of the variable frequency transformer.

[0124] Specifically, the overload situation of a variable frequency transformer can include either the variable frequency transformer being overloaded or the variable frequency transformer not being overloaded.

[0125] In some embodiments of this application, the overload status of the variable frequency transformer can be obtained by determining whether the variable frequency transformer is overloaded based on the power reference value of the variable frequency transformer and by using a preset third overload determination rule.

[0126] Optionally, a third overload determination rule can be preset, which can be expressed as follows: if the power reference value of the variable frequency transformer is greater than the stator rated active power of the variable frequency transformer, then the variable frequency transformer is determined to be overloaded; or, if the power reference value of the variable frequency transformer is less than or equal to the stator rated active power of the variable frequency transformer, then the variable frequency transformer is determined not to be overloaded.

[0127] For example, assuming the power reference value of the variable frequency transformer is, that is, the stator active power reference value of the variable frequency transformer is... The stator rated active power of the variable frequency transformer is The preset third overload judgment rule can be expressed as: if > If the variable frequency transformer is overloaded; ≤ If so, the variable frequency transformer is not overloaded.

[0128] Step S306: Adjust the power reference value of the variable frequency transformer according to the judgment result of the second overload judgment module.

[0129] In some embodiments of this application, in the case of overload or non-overload of the variable frequency transformer, the power reference value of the variable frequency transformer can be adjusted to determine the power reference value subsequently transmitted to the control circuit of the variable frequency transformer.

[0130] As an example, if the variable frequency transformer is overloaded, the power reference value of the variable frequency transformer can be adjusted to the stator rated active power of the variable frequency transformer; as another example, if the variable frequency transformer is not overloaded, the power reference value of the variable frequency transformer can be kept unchanged.

[0131] Step S307: The power reference value and load status of the variable frequency transformer are transmitted to the control circuit of the variable frequency transformer to achieve coordinated control of the power of the two distribution transformers.

[0132] In some embodiments of this application, the total armature voltage can be calculated based on the power reference value of the variable frequency transformer, the real-time active power of the stator of the variable frequency transformer, and the real-time speed of the rotor. Then, the power of the two distribution transformers at the ends of the two feeders can be coordinated and controlled based on the calculated total armature voltage.

[0133] Specifically, it can be like Figure 5 As shown, the first armature voltage is calculated by using the first preset control equation based on the power reference value of the variable frequency transformer and the real-time active power of the stator of the variable frequency transformer. The second armature voltage is calculated by using the second preset control equation based on the real-time rotor speed of the variable frequency transformer. Finally, the total armature voltage of the interconnected power grid is calculated based on the first and second armature voltages.

[0134] For example, the first governing equation can be preset as follows:

[0135]

[0136] in, It can be the first armature voltage, specifically referring to the reference value of the H-bridge converter voltage corresponding to active power control; It can be the power reference value for a variable frequency transformer, specifically the stator active power reference value; It can be the real-time active power of the stator of a variable frequency transformer; and These are the proportional and integral coefficients of the stator active power controller for the variable frequency transformer, respectively. It can be a Laplace operator.

[0137] The second governing equation can be preset as follows:

[0138]

[0139] in, It can be the second armature voltage, specifically referring to the reference voltage value of the H-bridge converter corresponding to speed control; It can provide the real-time rotational speed of the rotor of a variable frequency transformer; This can be a reference value for the rotor speed of a variable frequency transformer. In this embodiment, the interconnected power grids on both sides operate at the same frequency. ; and These are the proportional and integral coefficients of the rotor speed controller for the variable frequency transformer, respectively. It can be a Laplace operator.

[0140] The formula for calculating the total armature voltage is as follows:

[0141]

[0142] in, It can refer to the total armature voltage of a variable frequency transformer, specifically the total armature voltage of the rotor of the variable frequency transformer.

[0143] The implementation of coordinated control can be manifested as generating a control signal based on the total armature voltage. The generated control signal can be the switching control signal of the converter in the variable frequency transformer. Specifically, the switching control signal of the converter in the variable frequency transformer can be obtained by modulating the total armature voltage. At this time, the switching of the converter can be controlled by the switching control signal to adjust the speed of the DC motor of the variable frequency transformer, so as to coordinate the power of the distribution transformers at the ends of at least two feeders.

[0144] In practical applications, the speed control of a DC motor is mainly achieved through the switching control of the converter. The controlled converter can be an H-bridge converter, such as... Figure 5As shown, the control signal for the H-bridge converter switch can be obtained by PWM modulation based on the total armature voltage. By controlling the speed of the DC motor, the voltage phase on both sides of the variable frequency transformer can be adjusted, thereby affecting the magnitude of the transferred load and consequently the power of the distribution transformers at the ends of at least two feeders. It should be noted that the specific coordination control process is not limited in the embodiments of this application.

[0145] In a preferred embodiment of this application, after power coordination control is performed by control signals, it is also possible to determine whether the overload problem has been resolved based on the real-time power of the two distribution transformers. If at least one distribution transformer is still overloaded, an overload warning can be generated and issued. Furthermore, it is possible to determine whether the overload problem has been resolved based on the real-time power of the two distribution transformers. If at least one distribution transformer is still overloaded, an overload warning can be generated and issued.

[0146] For example, the method for determining whether the overload problem has been resolved can be expressed as follows: if the real-time power P1 of distribution transformer 1 is greater than the preset rated capacity P... N Or the real-time power P2 of distribution transformer 2 is greater than the preset rated capacity P N If the overload problem is not resolved, an overload warning can be generated. If the real-time power P1 of distribution transformer 1 is less than or equal to the preset rated capacity P... N Furthermore, the real-time power P2 of distribution transformer 2 is less than or equal to the preset rated capacity P. N If so, it is determined that the aforementioned overload problem has been resolved after coordination and control.

[0147] The method for determining whether the overload problem has been resolved can be expressed as follows: if the real-time power P1 of distribution transformer 1 is greater than the preset capacity threshold of 0.8P... N And less than or equal to the preset rated capacity P N Or, the real-time power P2 of distribution transformer 2 is greater than the preset capacity threshold of 0.8P. N And less than or equal to the preset rated capacity P N If the real-time power P1 of distribution transformer 1 is less than or equal to the preset capacity threshold of 0.8P, then the overload problem is determined to be unresolved, and an overload warning can be generated. N Furthermore, the real-time power P2 of distribution transformer 2 is less than or equal to the preset capacity threshold of 0.8P. N If so, it is determined that the aforementioned overload problem has been resolved after coordination and control.

[0148] It should be noted that the execution order of the above steps is only an example, and this application embodiment does not limit other execution orders that can achieve the above judgment results.

[0149] In this embodiment, based on the real-time power of the distribution transformer, the real-time stator active power of the variable frequency transformer, and the real-time rotor speed, different heavy load and overload conditions are judged, and the power of the distribution transformer under different heavy load and overload conditions is coordinated and controlled. This makes the adjustment methods flexible and varied, and achieves clear and accurate adjustment of the heavy load and overload transformers, effectively adapting to the development needs of the distribution network and solving the problem that some distribution transformers in the existing distribution network are subject to heavy load and overload conditions due to the limitations of the system structure. Furthermore, it can make full use of the transformer capacity, with the advantages of good economy and fast response speed, effectively making up for the shortcomings of the infrastructure construction method.

[0150] It should be noted that, for the sake of simplicity, the method embodiments are all described as a series of actions. However, those skilled in the art should understand that the embodiments of this application are not limited to the described order of actions, because according to the embodiments of this application, some steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also understand that the embodiments described in the specification are all preferred embodiments, and the actions involved are not necessarily required by the embodiments of this application.

[0151] Reference Figure 6 This diagram illustrates a structural block diagram of a low-voltage busbar interconnection control device for a variable frequency transformer according to an embodiment of this application, which can be applied to applications such as... Figure 1 The interconnected power grid based on variable frequency transformers shown may specifically include the following modules:

[0152] The load status acquisition module 601 is used to acquire the load status of two distribution transformers and a variable frequency transformer.

[0153] The first overload determination module 602 is used to determine the overload status of each distribution transformer based on the load status of the distribution transformer.

[0154] The overload determination module 603 is used to determine the overload status of each distribution transformer based on the load status of the distribution transformer.

[0155] The power distribution module 604 is used to obtain the corresponding power distribution method based on the judgment results of the first overload judgment module and the overload judgment module, and to calculate the power reference value of the variable frequency transformer based on the power distribution method.

[0156] The second overload determination module 605 is used to determine the overload status of the variable frequency transformer based on the power reference value of the variable frequency transformer.

[0157] The power reference value adjustment module 606 is used to adjust the power reference value of the variable frequency transformer according to the judgment result of the second overload judgment module.

[0158] The coordination control module 607 is used to transmit the power reference value and load status of the variable frequency transformer to the control loop of the variable frequency transformer in order to achieve coordinated control of the power of the two distribution transformers.

[0159] In some embodiments of this application, the load status of the distribution transformers includes the real-time power of the two distribution transformers; the first overload determination module 602 may include the following sub-modules:

[0160] The first overload determination submodule is used to determine whether at least one of the two distribution transformers is overloaded based on the real-time power of the two distribution transformers and a preset first overload determination rule; if at least one distribution transformer is overloaded, the process proceeds to the second overload determination submodule; if neither of the two distribution transformers is overloaded, the process proceeds to the overload determination module.

[0161] The second overload determination submodule is used to determine whether both distribution transformers are overloaded when at least one distribution transformer is overloaded, based on the real-time power of the two distribution transformers and a preset second overload determination rule. If both distribution transformers are overloaded, an overload warning is issued and the process returns to the initial step of collecting load information. If one of the two distribution transformers is overloaded and the other is not overloaded, the process proceeds to the overload determination module.

[0162] In some embodiments of this application, the load status of the distribution transformers includes the real-time power of the two distribution transformers; the overload determination module 603 may include the following sub-modules:

[0163] The first overload determination submodule is used to determine whether at least one of the two distribution transformers is overloaded when neither of them is overloaded, based on the real-time power of the two distribution transformers and a preset first overload determination rule. If neither of the two distribution transformers is overloaded, the overload determination module ends the determination process and returns to the initial step of collecting load information. If at least one distribution transformer is overloaded, the module determines whether both distribution transformers are overloaded based on the real-time power of the two distribution transformers and a preset second overload determination rule, and enters the power allocation module after the overload determination module finishes its determination.

[0164] The second overload determination submodule is used to determine whether the unloaded distribution transformer is overloaded when one of the two distribution transformers is overloaded and the other is not overloaded, based on the real-time power of the two distribution transformers and through a preset third overload determination rule. After the overload determination module finishes its determination, it enters the power allocation module.

[0165] In some embodiments of this application, the power distribution module 604 may include the following sub-modules:

[0166] The power allocation submodule is used to calculate the power reference value of the variable frequency transformer using a preset first power allocation formula when both distribution transformers are fully loaded; to calculate the power reference value of the variable frequency transformer using a preset second power allocation formula when one distribution transformer is loaded and the other is not loaded; to calculate the power reference value of the variable frequency transformer using a preset third power allocation formula when one distribution transformer is overloaded and the other is not loaded; and to calculate the power reference value of the variable frequency transformer using a preset fourth power allocation formula when one distribution transformer is overloaded and the other is loaded.

[0167] In some embodiments of this application, the second overload determination module 605 may include the following sub-modules:

[0168] The third overload determination submodule is used to determine whether the variable frequency transformer is overloaded based on the power reference value of the variable frequency transformer and the preset third overload determination rules.

[0169] The power reference value adjustment module 606 may include the following sub-modules:

[0170] The power reference value adjustment submodule is used to adjust the power reference value of the variable frequency transformer to the stator rated active power of the variable frequency transformer when the variable frequency transformer is overloaded; and to keep the power reference value of the variable frequency transformer unchanged when the variable frequency transformer is not overloaded.

[0171] In some embodiments of this application, the load conditions of the variable frequency transformer include the real-time stator active power and the real-time rotor speed of the variable frequency transformer; the coordination control module 607 may include the following sub-modules:

[0172] The coordination control submodule is used in the control loop of the variable frequency transformer to obtain the total armature voltage based on the power reference value of the variable frequency transformer, the real-time active power of the stator and the real-time speed of the rotor; generate control signals based on the total armature voltage; the control signals are the switching control signals of the converter in the variable frequency transformer; and control the switching of the converter through the switching control signals to adjust the speed of the DC motor of the variable frequency transformer, so as to coordinate the power control of the two distribution transformers.

[0173] In some embodiments of this application, the coordination control submodule may include the following units:

[0174] The total armature voltage calculation unit is used to calculate the first armature voltage based on the power reference value of the variable frequency transformer and the real-time active power of the stator of the variable frequency transformer through a preset first control equation; to calculate the second armature voltage based on the real-time rotor speed of the variable frequency transformer through a preset second control equation; and to calculate the total armature voltage using the first armature voltage and the second armature voltage.

[0175] In some embodiments of this application, after coordinating the power control of two distribution transformers, the apparatus provided in this application may further include the following modules:

[0176] The early warning generation module is used to determine whether the overload problem has been resolved based on the real-time power of the two distribution transformers. If at least one distribution transformer is still overloaded, an overload warning is issued. It also determines whether the heavy load problem has been resolved based on the real-time power of the two distribution transformers. If at least one distribution transformer is still overloaded, a heavy load warning is issued.

[0177] In this embodiment, based on the real-time power of the distribution transformer, the real-time stator active power of the variable frequency transformer, and the real-time rotor speed, different heavy load and overload conditions are judged, and the power of the distribution transformer under different heavy load and overload conditions is coordinated and controlled. This makes the adjustment methods flexible and varied, and achieves clear and accurate adjustment of the heavy load and overload transformers, effectively adapting to the development needs of the distribution network and solving the problem that some distribution transformers in the existing distribution network are subject to heavy load and overload conditions due to the limitations of the system structure. Furthermore, it can make full use of the transformer capacity, with the advantages of good economy and fast response speed, effectively making up for the shortcomings of the infrastructure construction method.

[0178] As the device embodiment is basically similar to the method embodiment, the description is relatively simple, and relevant parts can be found in the description of the method embodiment.

[0179] This application also provides an electronic device, see embodiments thereof. Figure 7 The provided electronic device 700 includes a memory 710, a processor 720, and a computer program 711 stored in the memory 710 and capable of running on the processor 720. When the computer program 711 is executed by the processor, it implements the various processes of the above-described embodiments of the low-voltage bus interconnection control method based on a variable frequency transformer and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0180] This application also provides a computer-readable storage medium, see embodiments thereof. Figure 8The computer-readable storage medium 800 provided stores a computer program 711. When the computer program 711 is executed by the processor, it implements the various processes of the above-described embodiments of the low-voltage bus interconnection control method based on a variable frequency transformer and can achieve the same technical effect. To avoid repetition, it will not be described again here.

[0181] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0182] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of the embodiments of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or modules is not necessarily limited to those steps or modules explicitly listed, but may include other steps or modules not explicitly listed or inherent to these processes, methods, products, or devices. The division of modules in the embodiments of this application is merely a logical division; in actual applications, there may be other division methods. For example, multiple modules may be combined into or integrated into another system, or some features may be ignored or not performed. Additionally, the shown or discussed mutual coupling or direct coupling or communication connection may be through some interface, and the indirect coupling or communication connection between modules may be electrical or other similar forms, none of which are limited in the embodiments of this application. Furthermore, the modules or sub-modules described as separate components may or may not be physically separated, may or may not be physical modules, or may be distributed among multiple circuit modules. Some or all of the modules may be selected according to actual needs to achieve the purpose of the embodiments of this application.

[0183] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0184] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and modules described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0185] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple modules or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between devices or modules through some interfaces, and may be electrical, mechanical, or other forms.

[0186] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical modules; that is, they may be located in one place or distributed across multiple network modules. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0187] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can be stored in a computer-readable storage medium.

[0188] In the above embodiments, the implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, in the form of a computer program product.

[0189] The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer may be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, Digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium may be any available medium that a computer can store or a data storage device such as a server or data center that integrates one or more available media. The available medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., a solid-state drive (SSD)).

[0190] This application describes embodiments with reference to flowchart illustrations and / or block diagrams of methods, terminal devices (systems), and computer program products according to embodiments of this application. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing terminal device to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing terminal device, generate instructions for implementing the flowchart illustrations. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0191] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing terminal device to operate in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The functions specified in one or more boxes; these computer program instructions may also be loaded onto a computer or other programmable data processing terminal equipment to cause a series of operational steps to be performed on the computer or other programmable terminal equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable terminal equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0192] Although preferred embodiments of the present application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present application.

[0193] Finally, it should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, data stored, data displayed, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties. Furthermore, the collection, use and processing of the relevant data must comply with the relevant laws, regulations and standards of the relevant countries and regions, and corresponding operation portals are provided for users to choose to authorize or refuse.

[0194] The technical solutions provided in the embodiments of this application have been described in detail above. Specific examples have been used in the embodiments of this application to illustrate the principles and implementation methods of the embodiments of this application. The description of the above embodiments is only for the purpose of helping to understand the methods and core ideas of the embodiments of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the embodiments of this application. Therefore, the content of this specification should not be construed as a limitation on the embodiments of this application.

Claims

1. A low-voltage busbar interconnection control method based on a variable frequency transformer, characterized in that, The method is applied to an interconnected power grid based on a variable frequency transformer. The interconnected power grid includes two distribution transformers, two feeders, two low-voltage buses, and the variable frequency transformer. The high-voltage side of the first distribution transformer is connected to the first feeder, and the low-voltage side of the first distribution transformer is connected to the first low-voltage bus. The high-voltage side of the second distribution transformer is connected to the second feeder, and the low-voltage side of the second distribution transformer is connected to the second low-voltage bus. The first low-voltage bus and the second low-voltage bus are connected based on the variable frequency transformer. The method includes: The load conditions of the two distribution transformers and the variable frequency transformer are collected; The overload determination module determines the overload status of each distribution transformer based on its load condition. The overload determination module determines the overload status of each distribution transformer based on its load condition. The power allocation module obtains the corresponding power allocation method based on the judgment results of the first overload judgment module and the overload judgment module, and calculates the power reference value of the variable frequency transformer based on the power allocation method. The overload determination module determines the overload status of the variable frequency transformer based on the power reference value of the variable frequency transformer. Based on the judgment result of the second overload determination module, the power reference value of the variable frequency transformer is adjusted; The power reference value and load status of the variable frequency transformer are transmitted to the control circuit of the variable frequency transformer to achieve coordinated control of the power of the two distribution transformers.

2. The method according to claim 1, characterized in that, In the interconnected power grid, the voltage level of the two distribution transformers is 10kV, the two distribution transformers have the same capacity, and the variable frequency transformer includes a filter inductor, a series transformer, a series converter, a parallel converter, a DC capacitor, a converter, a DC motor, and a doubly fed motor. The first low-voltage bus is connected to one end of the filter inductor and one end of the output side of the series transformer. The other end of the output side of the series transformer is connected to the stator winding of the doubly-fed motor. The input side of the series transformer is connected to the AC side of the series converter. The other end of the filter inductor is connected to the AC side of the parallel converter. The DC side of the parallel converter is connected to the DC side of the series converter, the DC capacitor, and the DC input side of the converter. The DC output side of the converter is connected to the DC motor. The DC motor is coaxially connected to the doubly-fed motor. The second low-voltage bus is connected to the rotor winding of the doubly-fed motor.

3. The method according to claim 1, characterized in that, The load status of the distribution transformers includes the real-time power of the two distribution transformers; The process of determining the overload status of each distribution transformer through the first overload determination module based on the load status of the distribution transformers includes: Based on the real-time power of the two distribution transformers, a preset first overload determination rule is used to determine whether at least one distribution transformer is overloaded. If neither of the two distribution transformers is overloaded, then the process proceeds to the overload determination module. If at least one distribution transformer is overloaded, then based on the real-time power of the two distribution transformers, a preset second overload determination rule is used to determine whether both distribution transformers are overloaded. If both distribution transformers are overloaded, an overload warning will be issued, and the process will return to the initial step of collecting the load information. If one of the two distribution transformers is overloaded while the other is not overloaded, the system will enter the overload determination module. The preset first overload determination rule is that if the real-time power of at least one distribution transformer is greater than the preset rated capacity, then at least one distribution transformer is determined to be overloaded; or, if the real-time power of both distribution transformers is less than or equal to the preset rated capacity, then both distribution transformers are determined not to be overloaded. The preset second overload determination rule is as follows: if the real-time power of both distribution transformers is greater than the preset rated capacity, then both distribution transformers are determined to be overloaded; or, if the real-time power of one distribution transformer is greater than the preset rated capacity and the real-time power of the other distribution transformer is less than the preset rated capacity, then one of the two distribution transformers is determined to be overloaded and the other distribution transformer is not overloaded.

4. The method according to claim 1, characterized in that, The load status of the distribution transformers includes the real-time power of the two distribution transformers; The overload determination module determines the overload status of each distribution transformer based on its load condition, including: If neither of the two distribution transformers is overloaded, then based on the real-time power of the two distribution transformers, a preset first overload determination rule is used to determine whether at least one distribution transformer is overloaded. If neither of the two distribution transformers is under heavy load, the heavy load determination module ends the determination process and returns to the initial step of collecting the load information. If at least one distribution transformer is overloaded, the system determines whether both distribution transformers are overloaded based on the real-time power of the two distribution transformers using a preset second overload determination rule, and then proceeds to the power allocation module after the overload determination module has completed its determination. If one of the two distribution transformers is overloaded, the non-overloaded distribution transformer is determined to be overloaded based on the real-time power of the two distribution transformers and by using a preset third overload determination rule. After the overload determination module finishes its determination, the process proceeds to the power allocation module. The preset first overload determination rule is as follows: if the real-time power of at least one distribution transformer is greater than the preset capacity threshold and less than or equal to the preset rated capacity, then it is determined that at least one distribution transformer is overloaded; or, if the real-time power of both distribution transformers is less than or equal to the preset capacity threshold, then it is determined that neither distribution transformer is overloaded. The preset second overload determination rule is as follows: if the real-time power of both distribution transformers is greater than a preset capacity threshold and less than or equal to a preset rated capacity, then both distribution transformers are determined to be overloaded; or, if the real-time power of one distribution transformer is greater than a preset capacity threshold and less than or equal to a preset rated capacity, and the real-time power of the other distribution transformer is less than a preset capacity threshold, then one distribution transformer is determined to be overloaded and the other distribution transformer is not overloaded; wherein, the preset capacity threshold of the distribution transformer is less than the preset rated capacity of the distribution transformer. The preset third overload determination rule is as follows: if the real-time power of the unoverloaded distribution transformer is greater than a preset capacity threshold and less than or equal to a preset rated capacity, then the unoverloaded distribution transformer is determined to be overloaded; or, if the real-time power of the unoverloaded distribution transformer is less than or equal to a preset capacity threshold, then the unoverloaded distribution transformer is determined to be not overloaded; wherein, the preset capacity threshold of the distribution transformer is less than the preset rated capacity of the distribution transformer.

5. The method according to claim 1, characterized in that, The step of obtaining a corresponding power allocation method through the power allocation module based on the judgment results of the first overload determination module and the overload determination module, and calculating the power reference value of the variable frequency transformer based on the power allocation method, includes: If both distribution transformers are fully loaded, the power reference value of the variable frequency transformer is calculated using the preset first power allocation formula. If one distribution transformer is overloaded and the other distribution transformer is not overloaded, the power reference value of the variable frequency transformer is calculated using a preset second power allocation formula. If one distribution transformer is overloaded and the other distribution transformer is not overloaded, the power reference value of the variable frequency transformer is calculated using a preset third power distribution formula. If one distribution transformer is overloaded and the other distribution transformer is overloaded, the power reference value of the variable frequency transformer is calculated using the preset fourth power distribution formula. The preset first power allocation formula is as follows: ， The preset second power allocation formula is: ， The preset third power allocation formula is as follows: ， The preset fourth power allocation formula is: ， In the formula, This is the power reference value for the variable frequency transformer; This represents the real-time power of the first distribution transformer; This represents the real-time power of the second distribution transformer; The preset rated capacity of the distribution transformer; The active power transmitted by the DC motor in the variable frequency transformer; This is a coefficient used to indicate the direction of power transmission in a variable frequency transformer.

6. The method according to claim 1, characterized in that, The step of determining the overload status of the variable frequency transformer through the second overload determination module based on the power reference value of the variable frequency transformer includes: Based on the power reference value of the variable frequency transformer, a preset third overload determination rule is used to determine whether the variable frequency transformer is overloaded. Based on the judgment result of the second overload determination module, the power reference value of the variable frequency transformer is adjusted, including: If the variable frequency transformer is overloaded, the power reference value of the variable frequency transformer is adjusted to the stator rated active power of the variable frequency transformer; or, if the variable frequency transformer is not overloaded, the power reference value of the variable frequency transformer is kept unchanged. The preset third overload determination rule is as follows: if the power reference value of the variable frequency transformer is greater than the stator rated active power of the variable frequency transformer, then the variable frequency transformer is determined to be overloaded; or, if the power reference value of the variable frequency transformer is less than or equal to the stator rated active power of the variable frequency transformer, then the variable frequency transformer is determined not to be overloaded.

7. The method according to claim 2, characterized in that, The load condition of the variable frequency transformer includes the real-time active power of the stator and the real-time speed of the rotor. The step of transmitting the power reference value and load status of the variable frequency transformer to the control circuit of the variable frequency transformer to achieve coordinated power control of the two distribution transformers includes: In the control circuit of the variable frequency transformer, the total armature voltage is obtained based on the power reference value of the variable frequency transformer, the real-time active power of the stator and the real-time speed of the rotor. A control signal is generated based on the total armature voltage; the control signal is the switching control signal of the converter in the variable frequency transformer. The switching control signal controls the switching of the converter, adjusts the speed of the DC motor of the variable frequency transformer, and coordinates the power control of the two distribution transformers.

8. The method according to claim 7, characterized in that, The step of obtaining the total armature voltage based on the power reference value of the variable frequency transformer, the real-time stator active power of the variable frequency transformer, and the real-time rotor speed includes: The first armature voltage is calculated by using the power reference value of the variable frequency transformer and the real-time active power of the stator of the variable frequency transformer through a preset first control equation. The second armature voltage is calculated based on the real-time rotor speed of the variable frequency transformer using a preset second control equation. The total armature voltage is calculated using the first armature voltage and the second armature voltage; The preset first governing equation is: In the formula, This is the first armature voltage; This is the power reference value for the variable frequency transformer; The stator active power of the variable frequency transformer is given in real time. and These are the proportional coefficient and integral coefficient of the stator active power controller of the variable frequency transformer, respectively. For the Laplace operator; The preset second control equation is: In the formula, This is the second armature voltage; This refers to the real-time rotor speed of the variable frequency transformer. This is a reference value for the rotor speed of the variable frequency transformer; For and These are the proportional coefficient and integral coefficient of the rotor speed controller for the variable frequency transformer, respectively. For the Laplace operator.

9. The method according to claim 1 or 7, characterized in that, After coordinating the power control of the two distribution transformers, the method further includes: The overload problem is determined based on the real-time power of the two distribution transformers. If at least one distribution transformer is still overloaded, an overload warning is issued. Furthermore, the system determines whether the overload problem has been resolved based on the real-time power of the two distribution transformers. If at least one distribution transformer is still overloaded, an overload warning is issued.

10. An electronic device, characterized in that, include: A processor, a memory, and a computer program stored in the memory and capable of running on the processor, wherein the computer program, when executed by the processor, implements the low-voltage bus interconnection control method based on a variable frequency transformer as described in any one of claims 1 to 9.

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