Park electric energy quality cooperative treatment system and method

Abstract

The embodiment of the invention relates to the technical field of energy, in particular to a park electric energy quality collaborative treatment system and method. The system comprises a monitoring device, a plurality of energy storage converter cabinets, an active power filter and a control device, each energy storage converter cabinet comprises a cabinet body for accommodating a device therein, and an in-cabinet controller, an inverter, an energy storage battery, an energy storage element, a voltage stabilization module and a voltage transformation module which are arranged in the cabinet body; an input junction box, a direct-current output junction box, an alternating-current output junction box and a communication device are installed on the cabinet body, the energy storage battery is connected with the energy storage element through a bidirectional charging circuit, the energy storage element is connected with the input junction box through a self-adaptive charging circuit arranged in the cabinet body, and the alternating-current output junction box is connected with the energy storage element through an inverter arranged in the cabinet body. The direct current output junction box is connected with the energy storage battery through a voltage stabilization module and a voltage transformation module which are arranged in the cabinet body, and the input end of the active power filter is powered by an inverter of an energy storage converter cabinet.

Description

Technical Field

[0001] Multiple embodiments of this specification relate to the field of energy technology, and specifically to a system and method for collaborative management of power quality in a park. Background Art

[0002] With the acceleration of industrialization, in order to solve many problems in industrial development, such as low land utilization efficiency, environmental pollution, and low resource utilization efficiency. Industrial parks concentrate a large number of industrial enterprises in one area, so that they can concentrate on the construction of infrastructure and solve or reduce these problems through intensive management. It is of great significance to promote economic development, optimize resource allocation, and enhance industrial competitiveness. Through planning and management, industrial parks can achieve efficient use of resources such as land, electricity, and manpower. And they can carry out special planning and construction in combination with the characteristics of industrial parks to provide higher quality services. For power supply, the loads in industrial parks are usually more complex, including a large number of LED lighting, variable frequency drive equipment and other nonlinear loads, which will generate harmonic pollution. The instability of the loads in the park will lead to problems such as voltage fluctuations and frequency changes. For this reason, it is necessary to study the power management technology of industrial parks. Summary of the invention

[0003] Multiple embodiments of this specification describe a system and method for collaborative management of power quality in a park.

[0004] In the first aspect, the embodiments of this specification provide a park power quality collaborative management system, including monitoring equipment, several energy storage converter cabinets, active power filters, and control equipment. The monitoring device monitors the voltage, frequency and harmonics of the power supply ring network of the park. A plurality of energy storage converter cabinets are respectively connected to a plurality of power supply branches. The energy storage converter cabinets include a cabinet body for accommodating the device therein, and an in-cabinet controller, an inverter, an energy storage battery, an energy storage element, a voltage stabilizing module and a voltage transformation module arranged in the cabinet body. An input junction box, a DC output junction box, an AC output junction box and a communication device are installed on the cabinet body. The energy storage battery is connected to the energy storage element via a bidirectional charging circuit, the energy storage element is connected to the input connection box via an adaptive charging circuit arranged in the cabinet, the input connection box is connected to an external power supply, the AC output connection box is connected to a load, the AC output connection box is connected to the energy storage element via an inverter arranged in the cabinet, the DC output connection box is connected to the energy storage battery via a voltage stabilizing module and a voltage transformation module arranged in the cabinet, an in-cabinet monitoring device is arranged in the cabinet, the in-cabinet monitoring device monitors the temperature and humidity in the cabinet, and the working status of the energy storage battery and the energy storage element, The input end of the active power filter is powered by an inverter of an energy storage converter cabinet. When the voltage and frequency of the power supply ring network fluctuate beyond a preset threshold, the controller in the cabinet controls the energy storage converter cabinet to smooth the voltage and frequency fluctuations of the power supply ring network.

[0005] In a second aspect, the embodiments of this specification provide a method for collaboratively managing power quality in a park, including the following steps: It includes setting up monitoring equipment, several energy storage converter cabinets, active power filters and control equipment, and the monitoring equipment monitors the voltage, frequency and harmonics of the power supply ring network of the park; A plurality of energy storage converter cabinets are configured to be connected to a plurality of power supply branches respectively. The energy storage converter cabinets include a cabinet body for accommodating the device therein, and an in-cabinet controller, an inverter, an energy storage battery, an energy storage element, a voltage stabilizing module and a voltage transformation module arranged in the cabinet body. An input junction box, a DC output junction box, an AC output junction box and a communication device are installed on the cabinet body; The energy storage battery is connected to the energy storage element via a bidirectional charging circuit, the energy storage element is connected to the input connection box via an adaptive charging circuit arranged in the cabinet, the input connection box is connected to an external power supply, the AC output connection box is connected to a load, the AC output connection box is connected to the energy storage element via an inverter arranged in the cabinet, the DC output connection box is connected to the energy storage battery via a voltage stabilizing module and a voltage transformation module arranged in the cabinet, and an in-cabinet monitoring device is arranged in the cabinet, the in-cabinet monitoring device monitors the temperature and humidity in the cabinet, and the working status of the energy storage battery and the energy storage element; The input end of the active power filter is configured to be powered by an inverter of an energy storage converter cabinet; When the voltage and frequency of the power supply ring network fluctuate beyond a preset threshold, the in-cabinet controller controls the energy storage converter cabinet to smooth the voltage and frequency fluctuations of the power supply ring network.

[0006] The beneficial effects brought by the technical solutions provided by some embodiments of this specification include at least: In multiple embodiments of this specification, the provided park power quality collaborative management system can manage harmonics in the power supply ring network through active power filters, which is conducive to the normal operation of electronic equipment in the park. The energy storage converter cabinet can smooth the peak-to-valley difference of the distribution network, which helps to improve the stability of the distribution network and ensure the power supply safety of the park. The energy storage converter cabinet combined with photovoltaic panels can smooth the fluctuation of photovoltaic power generation output, reduce abandoned light and improve the power quality of the power supply ring network.

[0007] Other features and advantages of the various embodiments of the present specification will be further disclosed in the following detailed description and drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] In order to more clearly illustrate the technical solutions in the embodiments of this specification, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0009] Figure 1 This is a schematic diagram of the campus power supply structure provided in the embodiments of this specification.

[0010] Figure 2 This is a schematic diagram of the structure of the energy storage converter cabinet provided in the embodiments of this specification.

[0011] Figure 3 This is a schematic diagram of the electrical connection of the energy storage converter cabinet provided in the embodiments of this specification.

[0012] Figure 4 This is a schematic diagram of the circuit connection principle of the energy storage converter cabinet provided in the embodiments of this specification.

[0013] Figure 5 A schematic diagram of a method for generating online control instructions provided in an embodiment of this specification.

[0014] Figure 6 A schematic diagram of a method for smoothing voltage and frequency fluctuations provided in an embodiment of this specification. DETAILED DESCRIPTION

[0015] The following is an explanation and description of the technical solutions of the embodiments of this specification in conjunction with the drawings of the embodiments of this specification, but the following embodiments are only preferred embodiments of this specification, not all. Based on the embodiments in the implementation mode, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of this specification.

[0016] The terms "first", "second", "third", etc. in the description and claims of this specification and the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices.

[0017] In the following description, terms such as "inside", "outside", "up", "down", "left", "right", etc. that indicate directions or positional relationships are only used to facilitate the description of the embodiments and simplify the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation of this specification.

[0018] The data involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection of relevant data complies with the relevant laws, regulations and standards of relevant countries and regions.

[0019] Before describing the technical solution in this specification, an introduction is given to the application scenarios and related technologies of the technical solution.

[0020] The accelerated industrialization process has led to a series of problems, including inefficient land use, serious environmental pollution, and waste of resources. Industrial parks can achieve intensive production and environmental protection through unified planning and management. Centralized treatment of industrial waste can reduce environmental pollution. Through centralized management, resource allocation can be optimized and production efficiency can be improved. Infrastructure such as roads, water and power supply, and communication networks within the park can be shared, reducing the cost of individual construction for each enterprise. By installing advanced waste gas treatment equipment and technology, the emission of harmful gases can be reduced.

[0021] The industrial park will also use clean energy, such as solar energy and wind energy, to reduce the use of fossil fuels. Figure 1 , install solar photovoltaic panels 102 on the roof of the park or other open areas to generate electricity using solar energy. This method can not only meet part of the park's own electricity needs, but also sell excess electricity to power grid companies. Install wind turbines in areas with abundant wind resources to convert wind energy into electrical energy. It is suitable for open areas or areas with strong winds such as the seaside. Due to the unstable supply of natural energy such as solar energy and wind energy, this poses a challenge to the stable operation of the power grid. At present, the park uses a ring network cabinet 101 with higher power supply stability as the main power supply method. The ring network cabinet 101 forms a power supply ring network, and the outgoing line of each ring network cabinet 101 is connected to a power supply branch 104, and the load 105 of the park is connected to the power supply branch 104.

[0022] There are also a large number of nonlinear loads105 (such as inverters, switching power supplies, etc.) in the industrial park. These devices generate harmonic currents, causing distortion of the grid voltage waveform. When high-power equipment starts or stops, it causes voltage fluctuations, affecting the normal operation of sensitive equipment, especially for precision instruments and automated production lines. Fluctuations in grid frequency can affect the stability of motor speed and have an adverse effect on the production process. Due to external grid failures or other factors, the park may experience a brief voltage drop or complete interruption, which is particularly detrimental to the process of continuous production.

[0023] Therefore, power management in industrial parks is a key task in the parks. Good power quality can ensure the normal operation of production equipment, extend the service life of equipment, and reduce maintenance and replacement costs. Power quality problems may lead to production interruptions, product quality degradation, etc., which in turn lead to economic losses. These losses can be avoided by improving power quality.

[0024] Energy storage and power conversion systems can store excess electricity and release the stored electricity during peak power demand periods or when renewable energy generation is insufficient, thereby balancing power supply and demand and improving the overall stability of the power grid. In addition, energy storage and power conversion systems help improve power quality, reduce power losses, and in some cases, can also serve as the core component of microgrids to achieve power autonomy in local areas. See attached Figure 2 , which is a common application type of current energy storage and conversion systems. That is, it is set in a cabinet 10 similar to a container, and the batteries and related equipment are installed in the cabinet 10. It has the characteristics of convenient transportation. And it can be placed directly in an open space outdoors, without the need to build a building specifically for it or divide the space indoors. It can be deployed and put into use by wiring through the cable interface outside the cabinet 10.

[0025] The park is an area with a certain scale, clear functional positioning and intensive management, usually including industrial parks, science and technology parks, logistics parks and other types. There are many enterprises in the park, often involving enterprises with large energy demand. At the same time, the park itself also has high energy management requirements. With the popularization of the concept of sustainable development and the advancement of technology, many parks have begun to deploy containerized energy storage and conversion systems in the park, which can play a role in energy conservation and emission reduction, improving energy utilization efficiency and exploring new energy. Specifically, the electricity demand in the park changes with time and season. The energy storage system can store excess electricity during the low-power period and release it during the peak period, thereby balancing the power supply and demand in the park and reducing the pressure on the power grid. The energy storage system can also serve as a backup emergency power supply to provide emergency power support in emergencies and ensure continuous operation in the park, which is especially important for key equipment and services. Combined with an intelligent management system, the energy storage system can monitor and adjust energy distribution in real time to maximize the use of renewable energy in the park, such as electricity generated by solar photovoltaic panels 102. By shaving peaks and filling valleys, the park can also store electricity when the electricity price is low and use the stored electricity when the electricity price is high, thereby saving electricity expenses. In addition, some parks may also enjoy subsidies or incentive policies for energy storage projects from relevant competent authorities.

[0026] The energy storage system is one of the important tools for achieving energy structure adjustment, which helps the park to develop in the direction of low-carbon and environmental protection, and is in line with the national sustainable development strategy. The deployment of containerized energy storage and conversion systems in the park can not only solve the energy management problems faced by the park itself, but also drive the optimization and upgrading of the energy structure in the entire region and even a larger range. It is an important part of realizing the construction of green and intelligent parks. However, the energy storage system also has some disadvantages, such as high initial investment, high maintenance costs and technical requirements, and efficiency losses in the energy conversion process. Secondly, the battery life of the energy storage device is limited and needs to be replaced regularly, and if it is not handled properly. When the energy storage and conversion system in the park is not properly controlled, it will cause the battery to frequently switch between charging and discharging states, further reducing the life and stability of the energy storage and conversion system. For this reason, this manual discusses the improvement technology of the energy storage and conversion system used in the park.

[0027] Since this application involves some professional terms, these professional terms will be introduced below.

[0028] Energy Storage Batteries Energy storage batteries are devices used to store electrical energy and release it when needed. They are widely used in many fields such as homes, industries, power grids, etc. to achieve functions such as smooth power supply, peak shaving and valley filling, and backup power supply. Energy storage batteries 31 can be divided into many types according to their chemical composition, purpose of use and scale. Lithium-ion batteries, lead-acid batteries, sodium-sulfur batteries, flow batteries, nickel-cadmium batteries and nickel-metal hydride batteries. As an important energy management tool, energy storage batteries 31 play an indispensable role in parks and other application scenarios. With the advancement of technology and the reduction of costs, the application scope of energy storage batteries 31 will continue to expand, becoming one of the key factors in realizing smart grids and promoting energy transformation.

[0029] Energy storage components An energy storage element refers to a device or component that can store energy for a certain period of time and release the energy when needed. Energy storage elements 32 are widely used in many fields such as power systems, electronic equipment, transportation, etc. Common energy storage elements 32 mainly include capacitors (including supercapacitors), flywheel energy storage devices, etc. In a park environment, the energy storage element 32 can be flexibly configured according to specific needs. For example, supercapacitors can be used to provide instantaneous large current requirements and are suitable for equipment that is frequently started and stopped. Flywheel energy storage devices can be used as a fast-response backup power supply to ensure that the park can still maintain the operation of key facilities when the power grid is interrupted. Relatively speaking, the use of supercapacitors in energy storage elements 32 can achieve better results.

[0030] This specification first provides a park power quality collaborative management system, the park includes a power supply ring network and a plurality of power supply branches 104, including monitoring equipment, a plurality of energy storage converter cabinets, active power filters, control equipment, The monitoring device monitors the voltage, frequency and harmonics of the power supply ring network of the park. The plurality of energy storage converter cabinets are connected to a plurality of power supply branches 104 respectively. Figure 3 The energy storage converter cabinet includes a cabinet body for accommodating the device therein, and an in-cabinet controller, an inverter, an energy storage battery, an energy storage element, a voltage stabilizing module and a voltage transformation module arranged in the cabinet body. An input junction box, a DC output junction box, an AC output junction box and a communication device are installed on the cabinet body. The energy storage battery is connected to the energy storage element via a bidirectional charging circuit, the energy storage element is connected to the input connection box via an adaptive charging circuit disposed in the cabinet, the input junction box is connected to an external power supply, the AC output junction box is connected to a load 105, the AC output junction box is connected to the energy storage element via an inverter disposed in the cabinet, the DC output junction box is connected to the energy storage battery via a voltage stabilizing module and a voltage transformation module disposed in the cabinet, the input junction box 11, the DC output junction box 121, and the AC output junction box 122 can be implemented using the technology disclosed in the art, and can be implemented as long as they have the function of establishing an electrical connection.

[0031] The cabinet is provided with an in-cabinet monitoring device, which monitors the temperature and humidity in the cabinet, the working status of the energy storage battery and the energy storage element. The input end of the active power filter is powered by an inverter of an energy storage converter cabinet. When the voltage and frequency of the power supply ring network fluctuate beyond a preset threshold, the in-cabinet controller controls the energy storage converter cabinet to smooth the voltage and frequency fluctuations of the power supply ring network.

[0032] The cabinet 10 is provided with an in-cabinet monitoring device 41, and the in-cabinet monitoring device 41 monitors the temperature and humidity in the cabinet 10, the power of the energy storage battery 31, the power of the energy storage element 32, the voltage of the energy storage battery 31, the voltage of the energy storage element 32, the current of the energy storage battery 31, the current of the energy storage element 32, and the external power supply voltage. The bidirectional charging circuit 22, the adaptive charging circuit 21, the inverter 42, the in-cabinet monitoring device 41, and the communication device are all connected to the controller.

[0033] The voltage, frequency and harmonics of the power supply ring network can be monitored and obtained by monitoring equipment. When there are many harmonics in the power supply ring network, the active power filter can generate opposite harmonics and inject them into the power supply ring network, thereby suppressing the harmonics and improving the power quality of the power supply ring network. The active power filter can be implemented using the technology disclosed in the art. The active power filter can be powered by the power supply ring network, by the inverter of the energy storage converter cabinet, or by the energy storage battery of the energy storage converter.

[0034] The energy storage battery 31 establishes a distributed energy storage system to help the park to achieve peak shaving and valley filling and smooth the load curve. The energy storage element 32 can meet the power demand of special equipment in the park. For equipment with frequent power fluctuations, the energy storage element 32 can smooth its fluctuations, which is beneficial to improving the power supply quality of the park. The bidirectional charging circuit 22 can exchange energy between the energy storage battery 31 and the energy storage element 32. When there is photovoltaic power generation equipment in the park, when the photovoltaic power generation equipment charges the energy storage battery 31, if constant current charging is used, it is easy to cause fluctuations in the park's distribution network or cause obvious problems of abandoned light. The use of energy storage elements 32 can achieve constant current charging, protect the energy storage battery 31, and at the same time can smooth the output fluctuations of photovoltaic power generation equipment, reduce the fluctuation pressure of the park's distribution network, and improve the power supply quality of the park.

[0035] For details, please refer to the attached Figure 4 , the adaptive charging circuit 21 includes a DC charging circuit, an AC charging circuit and a detection module, the detection module detects the voltage and type of the external power supply, when the external power supply is a DC power supply, the DC charging circuit charges the energy storage element 32, when the external power supply is an AC power supply, the AC charging circuit charges the energy storage element 32, the input junction box 11 also includes a photovoltaic input module, a mains input module and a switching device, the photovoltaic input module is connected to the external photovoltaic panel 102, the mains input module is connected to the power supply ring network, and the adaptive charging circuit 21 is connected to the photovoltaic input module and the mains input module through the switching device. When the park is equipped with photovoltaic power generation equipment and the output of the photovoltaic power generation equipment is greater than the preset threshold value, the photovoltaic power generation equipment supplies power to the park's load 105 through the energy storage converter box provided in this embodiment, rather than directly supplying power to the park's load 105. When the output of the photovoltaic power generation equipment is not greater than the power of the park's load 105, the photovoltaic power generation equipment charges the energy storage element 32 through the connected DC charging circuit, and transfers the electric energy generated by the photovoltaic power generation equipment to the energy storage element 32.

[0036] The energy storage element 32 supplies power to the inverter 42. When the inverter 42 completes the voltage boost and is phase-locked with the power grid, it generates AC power for the park load 105. The energy storage element 32 has the characteristics of fast charging and fast discharging, which can smooth the fluctuation of the output of the photovoltaic power generation equipment and ensure the stable power supply of the inverter 42. For example, when the energy storage element 32 uses a supercapacitor, the power generated by the photovoltaic power generation equipment is used to charge the supercapacitor, and the voltage of the supercapacitor is slightly increased. At this time, a voltage stabilizing circuit 43 is equipped according to the prior art to stabilize the voltage, and then the inverter 42 is supplied to work, which can ensure that the input voltage of the inverter 42 is stable. When the power generated by the photovoltaic power generation equipment is low or the park load 105 increases suddenly, the voltage of the supercapacitor will drop slightly, but through the voltage stabilizing effect of the voltage stabilizing circuit 43, the input voltage of the inverter 42 can still be guaranteed to be stable.

[0037] When the output of the photovoltaic power generation equipment is greater than the park load 105, the photovoltaic power generation equipment charges the energy storage element 32 through the DC charging circuit. After the energy storage element 32 supplies power to the inverter 42 and generates power for the park load 105, there is still residual power. At this time, the power of the energy storage element 32 will be supplemented to the energy storage battery 31 through the bidirectional charging circuit 22. The bidirectional charging circuit 22 uses a constant current method or a constant voltage method for charging. When the output of the photovoltaic power generation equipment increases slightly, the energy storage element 32 will store more power, but the voltage of the energy storage element 32 will not rise much. When the output of the photovoltaic power generation equipment decreases slightly, the energy storage element 32 will store less power, but the voltage of the energy storage element 32 will not drop much. Thereby ensuring that the bidirectional charging circuit 22 can work smoothly, and at the same time realizing constant current charging or constant voltage charging of the energy storage battery 31, it helps to protect the energy storage battery 31 and extend the life of the energy storage battery 31.

[0038] When the photovoltaic power generation equipment has no output or the output is lower than the threshold power, the power grid is used to supply power to the park load 105. However, if the energy storage battery 31 has a large amount of electricity stored at this time, or the current power grid is in the peak power consumption period, the energy storage battery 31 is used to charge the energy storage element 32, and then the energy storage element 32 supplies power to the inverter 42, generating AC power that can share the park load 105 and relieve the peak power consumption pressure of the power grid.

[0039] Specifically, the bidirectional charging circuit 22 includes a forward charging circuit 221 and a reverse charging circuit 222. The forward charging circuit 221 uses the power of the energy storage battery 31 to charge the energy storage element 32, and the reverse charging circuit 222 uses the power of the energy storage element 32 to charge the energy storage battery 31. The controller reads the power of the energy storage element 32. When the power of the energy storage element 32 is higher than a preset first threshold, the reverse charging circuit 222 is controlled to operate until the power of the energy storage element 32 is lower than a preset second threshold. When the power of the energy storage element 32 is lower than a preset fourth threshold, the controller controls the forward charging circuit 221 to operate until the power of the energy storage element 32 is higher than a preset third threshold.

[0040] As the electricity stored in the energy storage element 32 is gradually transferred to the energy storage battery 31 by the reverse charging circuit 222, the electricity of the energy storage element 32 will gradually drop below the second threshold, and the reverse charging circuit 222 will be controlled to stop working. If at this time, the output power of the photovoltaic power generation equipment is still high, in addition to supplying the load 105, the energy storage element 32 will also be charged until the power returns to a state where the electricity exceeds the first threshold. At this time, the charging of the energy storage battery 31 can be restarted, that is, the reverse charging circuit 222 is restarted. In this way, when the output power of the photovoltaic power generation equipment is large, in addition to supplying the user load 105, the energy storage battery 31 is charged.

[0041] When the output power of the photovoltaic power generation equipment is relatively low, such as on cloudy days or at night, the power of the energy storage element 32 will decrease due to the use of the user's load 105. When the power of the energy storage element 32 drops below the fourth threshold, it indicates that the power of the energy storage element 32 is low. At this time, the forward charging circuit 221 is operated, and the power of the energy storage battery 31 will charge the energy storage element 32 through the forward charging circuit 221, so that the power of the energy storage element 32 gradually increases and reaches the third threshold. At this time, the forward charging circuit 221 is controlled to stop working. Then, the output power of the photovoltaic power generation equipment is still relatively low, or the power of the user's load 105 is relatively large, and the power of the energy storage element 32 will be gradually consumed until it is lower than the fourth threshold again.

[0042] Among them, the controller periodically calculates the charge and discharge power of the energy storage element 32 until the power of the energy storage element 32 is lower than the preset fourth threshold, calculates the equivalent discharge power of the energy storage element 32 during the period when the power drops from the third threshold to the fourth threshold, and the controller calculates the ratio of the equivalent discharge power to the preset reference discharge power. When the ratio is greater than 1, the square of the ratio is calculated as the adjustment coefficient, and the third threshold is adjusted to the product of the preset initial threshold and the adjustment coefficient. When the ratio is not greater than 1, the third threshold is adjusted to the preset initial threshold. The controller controls the forward charging circuit 221 to work until the power of the energy storage element 32 reaches the preset third threshold. According to the park load 105, the third threshold is dynamically adjusted to reduce the number of switching times of the forward charging circuit 221 in the working or stopping state, ensuring a more stable power supply and helping to ensure the life of the energy storage battery 31.

[0043] On the other hand, when the controller calculates the equivalent discharge power during the period when the electric quantity of the energy storage element 32 decreases from the third threshold value to the fourth threshold value, the controller performs the following steps: The read charge and discharge power of the energy storage element 32 is compared with the preset reference power, and after deleting the charge and discharge power that is less than the preset reference power, the average value of the remaining charge and discharge power is calculated as the equivalent discharge power.

[0044] On the other hand, in another embodiment, the system further includes a server, the communication device is communicatively connected to the server, the controller reports the data monitored by the cabinet monitoring device 41 to the server through the communication device, and the server runs a remote control interface and a report interface, the report interface displays the data monitored by the cabinet monitoring device 41, and the remote control interface is used to receive user control instructions for the controller. The server in this specification can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, content distribution networks, and big data and artificial intelligence platforms.

[0045] Among them, the server runs an online control module, and the online control module generates online control instructions based on the data reported by the controllers of multiple energy storage inverter cabinets 103. The online control instructions are executed by the controllers of multiple energy storage inverter cabinets 103, and multiple energy storage inverter cabinets 103 are connected to the same load 105 and the same external power supply.

[0046] Specifically, when the online control module generates an online control instruction according to the data reported by the controllers of the multiple energy storage converter cabinets 103, please refer to the attached Figure 5 , perform the following steps: Step S101) obtaining the power of the energy storage battery 31 of each energy storage converter cabinet 103; Step S102) When the load 105 exceeds a preset high threshold, the inverter 42 of the energy storage converter cabinet 103 whose power level of the energy storage battery 31 is higher than a first reference power level is controlled to operate to supply power to the load 105; Step S103 ) When the load 105 is lower than a preset low threshold, the adaptive charging circuit 21 of the energy storage converter cabinet 103 controls the power level of the energy storage battery 31 to be lower than a second reference power level to operate and charge the energy storage battery 31 .

[0047] By controlling the online energy storage converter cabinet 103, when the park load 105 is high, the energy storage converter cabinet 103 with more stored electricity is used to preferentially supply power to the park load 105. When the park load 105 is low, such as when the power grid is in a low period, the energy storage converter cabinet 103 with less stored electricity is preferentially charged to achieve online control.

[0048] On the other hand, please see the attached Figure 6 When the in-cabinet controller controls the energy storage converter cabinet to smooth the voltage and frequency fluctuations of the power supply ring network, the following steps are performed: Step S201) calculating the voltage deviation value and the frequency deviation value of the power supply ring network, and generating the adjustment power according to the voltage deviation value and the frequency deviation value; Step S202) When the voltage or frequency of the power supply ring network is low, the in-cabinet controller controls the inverter to supply power to the power supply ring network with the adjusted power; Step S203) When the voltage or frequency of the power supply ring network is high, the in-cabinet controller controls the adaptive charging circuit to charge the energy storage element with the adjusted power.

[0049] The technology for generating adjustment power according to the voltage deviation value and the frequency deviation value has been disclosed in the art. For example, it can be referred to the adjustment scheme of the power plant for the output of the generator set.

[0050] On the other hand, this specification provides a method for collaboratively managing power quality in a park, including the steps of: It includes setting up monitoring equipment, several energy storage converter cabinets, active power filters and control equipment, and the monitoring equipment monitors the voltage, frequency and harmonics of the power supply ring network of the park; A plurality of energy storage converter cabinets are configured to be connected to a plurality of power supply branches 104 respectively. The energy storage converter cabinet comprises a cabinet body for accommodating the device therein and an in-cabinet controller, an inverter, an energy storage battery, an energy storage element, a voltage stabilizing module and a voltage transformation module arranged in the cabinet body. An input junction box, a DC output junction box, an AC output junction box and a communication device are installed on the cabinet body; The energy storage battery is connected to the energy storage element via a bidirectional charging circuit, the energy storage element is connected to the input connection box via an adaptive charging circuit arranged in the cabinet, the input connection box is connected to an external power supply, the AC output connection box is connected to a load, the AC output connection box is connected to the energy storage element via an inverter arranged in the cabinet, the DC output connection box is connected to the energy storage battery via a voltage stabilizing module and a voltage transformation module arranged in the cabinet, and an in-cabinet monitoring device is arranged in the cabinet, the in-cabinet monitoring device monitors the temperature and humidity in the cabinet, and the working status of the energy storage battery and the energy storage element; The input end of the active power filter is configured to be powered by an inverter of an energy storage converter cabinet; When the voltage and frequency of the power supply ring network fluctuate beyond a preset threshold, the in-cabinet controller controls the energy storage converter cabinet to smooth the voltage and frequency fluctuations of the power supply ring network.

[0051] On the other hand, in another embodiment, the bidirectional charging circuit is configured to include a forward charging circuit and a reverse charging circuit, wherein the forward charging circuit uses the power of the energy storage battery to charge the energy storage element, and the reverse charging circuit uses the power of the energy storage element to charge the energy storage battery. Reading the power of the energy storage element, and when the power of the energy storage element is higher than a preset first threshold, controlling the reverse charging circuit to operate until the power of the energy storage element is lower than a preset second threshold; When the power level of the energy storage element is lower than a preset fourth threshold, the controller controls the forward charging circuit to operate until the power level of the energy storage element is higher than a preset third threshold.

[0052] On the other hand, in another embodiment, the park power quality collaborative management method further includes the following steps: Periodically calculating the charge and discharge power of the energy storage element until the power level of the energy storage element is lower than a preset fourth threshold; Calculating the equivalent discharge power during a period in which the electric quantity of the energy storage element decreases from the third threshold value to a fourth threshold value; Calculating a ratio of the equivalent discharge power to a preset reference discharge power; When the ratio is greater than 1, the square of the ratio is calculated as an adjustment coefficient, and the third threshold is adjusted to the product of a preset initial threshold and the adjustment coefficient; When the ratio is not greater than 1, the third threshold is adjusted to a preset initial threshold, and the controller controls the forward charging circuit to operate until the power of the energy storage element reaches a preset third threshold.

[0053] On the other hand, in another embodiment, the method for calculating the equivalent discharge power during the period when the electric quantity of the energy storage element decreases from the third threshold to the fourth threshold comprises the steps of: The read charge and discharge power of the energy storage element is compared with the preset reference power, and after deleting the charge and discharge power that is less than the preset reference power, the average value of the remaining charge and discharge power is calculated as the equivalent discharge power.

[0054] The embodiments described above are merely preferred embodiments of this specification and are not intended to limit the scope of this specification. Without departing from the design spirit of this specification, various modifications and improvements made to the technical solutions of this specification by ordinary technicians in this field should fall within the scope of protection determined by the claims of this specification.

Claims

1. A park power quality collaborative management system, the park includes a power supply ring network and a plurality of power supply branches, characterized in that: Including monitoring equipment, several energy storage converters, active power filters, control equipment, The monitoring device monitors the voltage, frequency and harmonics of the power supply ring network of the park. A plurality of energy storage converter cabinets are respectively connected to a plurality of power supply branches. The energy storage converter cabinets include a cabinet body for accommodating the device therein, and an in-cabinet controller, an inverter, an energy storage battery, an energy storage element, a voltage stabilizing module and a voltage transformation module arranged in the cabinet body. An input junction box, a DC output junction box, an AC output junction box and a communication device are installed on the cabinet body. The energy storage battery is connected to the energy storage element via a bidirectional charging circuit, the energy storage element is connected to the input connection box via an adaptive charging circuit arranged in the cabinet, the input connection box is connected to an external power supply, the AC output connection box is connected to a load, the AC output connection box is connected to the energy storage element via an inverter arranged in the cabinet, the DC output connection box is connected to the energy storage battery via a voltage stabilizing module and a voltage transformation module arranged in the cabinet, an in-cabinet monitoring device is arranged in the cabinet, the in-cabinet monitoring device monitors the temperature and humidity in the cabinet, and the working status of the energy storage battery and the energy storage element, The input end of the active power filter is powered by an inverter of an energy storage converter cabinet. When the voltage and frequency of the power supply ring network fluctuate beyond a preset threshold, the controller in the cabinet controls the energy storage converter cabinet to smooth the voltage and frequency fluctuations of the power supply ring network.

2. A park power quality collaborative management system according to claim 1, characterized in that: The bidirectional charging circuit includes a forward charging circuit and a reverse charging circuit. The forward charging circuit uses the power of the energy storage battery to charge the energy storage element, and the reverse charging circuit uses the power of the energy storage element to charge the energy storage battery. The in-cabinet controller reads the power of the energy storage element. When the power of the energy storage element is higher than a preset first threshold, the in-cabinet controller controls the reverse charging circuit to operate until the power of the energy storage element is lower than a preset second threshold. When the power of the energy storage element is lower than a preset fourth threshold, the in-cabinet controller controls the forward charging circuit to operate until the power of the energy storage element is higher than a preset third threshold.

3. A park power quality collaborative management system according to claim 2, characterized in that: The in-cabinet controller periodically calculates the charging and discharging power of the energy storage element until the power level of the energy storage element is lower than a preset fourth threshold, calculates the equivalent discharge power during the period when the power level of the energy storage element drops from the third threshold to the fourth threshold, and calculates the ratio of the equivalent discharge power to a preset reference discharge power. When the ratio is greater than 1, the square of the ratio is calculated as an adjustment coefficient, and the third threshold is adjusted to the product of a preset initial threshold and the adjustment coefficient. When the ratio is not greater than 1, the third threshold is adjusted to the preset initial threshold. The in-cabinet controller controls the forward charging circuit to operate until the power level of the energy storage element reaches a preset third threshold.

4. A park power quality collaborative management system according to claim 3, characterized in that: When the in-cabinet controller calculates the equivalent discharge power during the period when the electric quantity of the energy storage element decreases from the third threshold value to the fourth threshold value, the following steps are performed: The read charge and discharge power of the energy storage element is compared with the preset reference power, and after deleting the charge and discharge power that is less than the preset reference power, the average value of the remaining charge and discharge power is calculated as the equivalent discharge power.

5. A park power quality collaborative management system according to any one of claims 1 to 4, characterized in that: The adaptive charging circuit of the energy storage converter cabinet includes a DC charging circuit, an AC charging circuit and a detection module. The detection module detects the voltage and type of the external power supply. When the external power supply is a DC power supply, the DC charging circuit charges the energy storage element. When the external power supply is an AC power supply, the AC charging circuit charges the energy storage element. The input junction box also includes a photovoltaic input module, a mains input module and a switching device. The photovoltaic input module is connected to an external photovoltaic panel, the mains input module is connected to a power supply ring network, and the adaptive charging circuit is connected to the photovoltaic input module and the mains input module via the switching device.

6. A park power quality collaborative management system according to any one of claims 1 to 4, characterized in that: When the in-cabinet controller controls the energy storage converter cabinet to smooth the voltage and frequency fluctuations of the power supply ring network, the following steps are performed: Calculating the voltage deviation value and the frequency deviation value of the power supply ring network, and generating the adjustment power according to the voltage deviation value and the frequency deviation value; When the voltage or frequency of the power supply ring network is low, the in-cabinet controller controls the inverter to supply power to the power supply ring network with the adjusted power; When the voltage or frequency of the power supply ring network is high, the in-cabinet controller controls the adaptive charging circuit to charge the energy storage element with the adjusted power.

7. A method for collaborative management of power quality in a park, characterized in that: Includes steps: It includes setting up monitoring equipment, several energy storage converter cabinets, active power filters and control equipment, and the monitoring equipment monitors the voltage, frequency and harmonics of the power supply ring network of the park; A plurality of energy storage converter cabinets are configured to be connected to a plurality of power supply branches respectively. The energy storage converter cabinets include a cabinet body for accommodating the device therein, and an in-cabinet controller, an inverter, an energy storage battery, an energy storage element, a voltage stabilizing module and a voltage transformation module arranged in the cabinet body. An input junction box, a DC output junction box, an AC output junction box and a communication device are installed on the cabinet body; The energy storage battery is connected to the energy storage element via a bidirectional charging circuit, the energy storage element is connected to the input connection box via an adaptive charging circuit arranged in the cabinet, the input connection box is connected to an external power supply, the AC output connection box is connected to a load, the AC output connection box is connected to the energy storage element via an inverter arranged in the cabinet, the DC output connection box is connected to the energy storage battery via a voltage stabilizing module and a voltage transformation module arranged in the cabinet, and an in-cabinet monitoring device is arranged in the cabinet, the in-cabinet monitoring device monitors the temperature and humidity in the cabinet, and the working status of the energy storage battery and the energy storage element; The input end of the active power filter is configured to be powered by an inverter of an energy storage converter cabinet; When the voltage and frequency of the power supply ring network fluctuate beyond a preset threshold, the in-cabinet controller controls the energy storage converter cabinet to smooth the voltage and frequency fluctuations of the power supply ring network.

8. A method for collaboratively managing power quality in a park according to claim 7, characterized in that: The bidirectional charging circuit is configured to include a forward charging circuit and a reverse charging circuit, wherein the forward charging circuit uses the power of the energy storage battery to charge the energy storage element, and the reverse charging circuit uses the power of the energy storage element to charge the energy storage battery. Reading the power of the energy storage element, and when the power of the energy storage element is higher than a preset first threshold, controlling the reverse charging circuit to operate until the power of the energy storage element is lower than a preset second threshold; When the power level of the energy storage element is lower than a preset fourth threshold, the controller controls the forward charging circuit to operate until the power level of the energy storage element is higher than a preset third threshold.

9. A method for collaboratively managing power quality in a park according to claim 8, characterized in that: The following steps are also included: Periodically calculating the charge and discharge power of the energy storage element until the power level of the energy storage element is lower than a preset fourth threshold; Calculating the equivalent discharge power during a period in which the electric quantity of the energy storage element decreases from the third threshold value to a fourth threshold value; Calculating a ratio of the equivalent discharge power to a preset reference discharge power; When the ratio is greater than 1, the square of the ratio is calculated as an adjustment coefficient, and the third threshold is adjusted to the product of a preset initial threshold and the adjustment coefficient; When the ratio is not greater than 1, the third threshold is adjusted to a preset initial threshold, and the controller controls the forward charging circuit to operate until the power of the energy storage element reaches the preset third threshold.

10. A method for collaboratively managing power quality in a park according to claim 9, characterized in that: The method for calculating the equivalent discharge power of the energy storage element during the period when the electric quantity of the energy storage element decreases from the third threshold to the fourth threshold comprises the steps of: The read charge and discharge power of the energy storage element is compared with the preset reference power, and after deleting the charge and discharge power that is less than the preset reference power, the average value of the remaining charge and discharge power is calculated as the equivalent discharge power.

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