Megawatt power supply system, control method thereof and program product

Abstract

The invention provides a megawatt power supply system, a control method thereof and a program product. The megawatt-level power supply system comprises a container type cabin body, wherein the interior of the container type cabin body is divided into an electrical cabin, a PCS cabin and a battery cabin; the power module is arranged in the PCS cabin; each cluster of battery packs is connected with a grid-connected PCS unit and an off-grid PCS unit in one group of PCS modules; the controller is configured to control the grid-connected PCS unit in the power module to work in a grid-connected mode, and provide energy for the corresponding off-grid PCS unit through the direct current bus; controlling the off-grid PCS unit to work in an off-grid mode so as to convert direct current into alternating current to supply power to a load; monitoring the system state of each cluster battery pack in the energy storage module and dynamically adjusting the charging and discharging power of the grid-connected PCS unit; and when the power grid is powered off, controlling the grid-connected PCS unit to stop running and keeping the off-grid PCS unit to run continuously. Through continuous online operation of the off-grid PCS unit, the zero tolerance requirement for power interruption is met.

Description

Technical Field

[0001] This application relates to the technical field of power grid supply systems, and in particular to a megawatt-level power supply system and its control method and program product. Background Technology

[0002] The global power structure is undergoing fundamental changes, and the energy structure is bound to undergo a historic transformation. Renewable energy will surpass traditional energy to become the world's largest source of electricity. Future new electricity demand will be mainly met by clean energy. Although the transformation is accelerating, challenges still exist. Limited grid capacity and extreme weather events pose challenges to the grid connection of renewable energy and the stable operation of the power system. Therefore, energy storage, with its unique ability to respond quickly to changes and provide stable support for the grid, is becoming a powerful tool for new energy.

[0003] However, the power supply systems provided by related technologies, especially for megawatt-level power supply, require switching times of 10ms or even longer. Therefore, there is an urgent need to provide a megawatt-level power supply system and its control methods and software products. Summary of the Invention

[0004] To address the aforementioned problems in related technologies, this application provides a megawatt-level power supply system and its control method and program product.

[0005] The objective of this application is achieved through the following technical solution: In a first aspect, this application provides a megawatt-level power supply system, comprising: The container-style cabin is internally divided into an electrical compartment, a PCS compartment, and a battery compartment. The power module is located in the PCS compartment and contains multiple PCS modules. Each PCS module includes a grid-connected PCS unit and an off-grid PCS unit. The energy storage module consists of multiple clusters of batteries with a total capacity of megawatts, located in the battery compartment. Each cluster of batteries is connected to a grid-connected PCS unit and an off-grid PCS unit in a set of PCS modules. The controller, located in the electrical compartment and connected to the power module and energy storage module, is configured to: The grid-connected PCS unit in the power module is controlled to operate in grid-connected mode to charge its corresponding battery pack and provide energy to its corresponding off-grid PCS unit through the DC bus. The off-grid PCS unit is controlled to operate in off-grid mode to convert DC power to AC power to supply power to the load; The system monitors the system status of each battery cluster in the energy storage module and dynamically adjusts the charging and discharging power of the grid-connected PCS unit; and controls the grid-connected PCS unit to stop operating and keeps the off-grid PCS unit running continuously when the grid is interrupted, thereby achieving seamless switching between grid connection and off-grid operation.

[0006] In some possible implementations, the containerized hull also includes a temperature control system compartment, and the megawatt-level power supply system further includes a temperature control module disposed in the temperature control system compartment. The temperature control module includes a liquid cooling unit, and the controller is further configured to control the liquid cooling unit to regulate the temperature of the battery compartment through a first liquid cooling pipeline.

[0007] In some possible implementations, when controlling the liquid cooling unit to regulate the temperature of the battery compartment via the first liquid cooling line, the controller is further configured to: The system acquires the lowest and highest cell temperatures of the energy storage module in real time and determines whether the highest cell temperature is greater than a first preset temperature. If it is greater than the first preset temperature, the system starts the cooling mode of the liquid cooling unit until the highest cell temperature is not greater than the second preset temperature. If it is not greater than the first preset temperature, the system determines whether the lowest cell temperature is less than the third preset temperature. If it is less than the third preset temperature, the system starts the heating mode of the liquid cooling unit until the lowest cell temperature is not less than the fourth preset temperature. When the highest cell temperature is not greater than the first preset temperature and the lowest cell temperature is not less than the third preset temperature, the temperature difference between the highest cell temperature and the lowest cell temperature is obtained, and it is determined whether the temperature difference is greater than the first preset temperature difference. If it is greater, the circulation mode of the liquid cooling unit is started until the temperature difference is less than the second preset temperature difference. The temperature values ​​of the first preset temperature, the second preset temperature, the fourth preset temperature, and the third preset temperature are arranged from largest to smallest; the difference between the first preset temperature and the second preset temperature is greater than the difference between the second preset temperature and the first preset temperature.

[0008] In some possible implementations, the controller is further configured to: before acquiring the minimum and maximum cell temperatures of the energy storage module in real time. Two different sets of temperature control parameters corresponding to the current operating mode of the megawatt-level power supply system are obtained; each set of temperature control parameters includes a first preset temperature, a second preset temperature, a third preset temperature, a fourth preset temperature, a first preset temperature difference, and a second preset temperature difference; the operating mode includes an idle operating mode, a normal operating mode, and a full-condition operating mode; Based on the time elapsed since the last operation of the liquid cooling unit, a set of temperature parameters is selected as the target temperature parameters. The liquid cooling unit is controlled using the preset temperature and preset temperature difference in the target temperature parameters, and the temperature of the battery compartment is regulated through the liquid cooling pipeline.

[0009] In some possible implementations, the temperature control module further includes a water-cooled heat exchanger, and the controller is further configured to: control the fan in the PCS compartment to blow out the internal heat of the power module, blow it onto the water-cooled heat exchanger through the air duct in the compartment, and then carry the heat out of the PCS compartment through the second liquid cooling pipeline connected to the water-cooled heat exchanger; the portion of the second liquid cooling pipeline outside the PCS compartment runs parallel to the portion of the first liquid cooling pipeline.

[0010] In some possible implementations, the megawatt-level power supply system also includes an environmental control module and a fire protection module. The environmental control module includes multiple water immersion sensors and temperature and humidity sensors connected to the controller. The water immersion sensors and temperature and humidity sensors are installed in each compartment of the containerized cabin. The fire protection module includes multiple aerosol fire extinguishing devices, and the controller is configured to activate the aerosol fire extinguishing devices in the corresponding areas based on the fire warning status of each battery cluster and each compartment.

[0011] Secondly, this application also provides a control method for a megawatt-level power supply system, applied to the megawatt-level power supply system described in any one of the first aspects, the method comprising: The grid-connected PCS unit in the control power module operates in grid-connected mode to charge its corresponding battery pack and provide energy to its corresponding off-grid PCS unit through the DC bus. The off-grid PCS unit is controlled to operate in off-grid mode to convert DC power to AC power to supply power to the load; The system monitors the system status of each battery cluster in the energy storage module and dynamically adjusts the charging and discharging power of the grid-connected PCS unit; and controls the grid-connected PCS unit to stop operating and keeps the off-grid PCS unit running continuously when the grid is interrupted, thereby achieving seamless switching between grid and off-grid.

[0012] In some possible implementations, the method further includes: The system acquires the lowest and highest cell temperatures of the energy storage module in real time and determines whether the highest cell temperature is greater than a first preset temperature. If it is greater than the first preset temperature, the system starts the cooling mode of the liquid cooling unit until the highest cell temperature is not greater than the second preset temperature. If it is not greater than the first preset temperature, the system determines whether the lowest cell temperature is less than the third preset temperature. If it is less than the third preset temperature, the system starts the heating mode of the liquid cooling unit until the lowest cell temperature is not less than the fourth preset temperature. When the highest cell temperature is not greater than the first preset temperature and the lowest cell temperature is not less than the third preset temperature, the temperature difference between the highest cell temperature and the lowest cell temperature is obtained, and it is determined whether the temperature difference is greater than the first preset temperature difference. If it is greater, the circulation mode of the liquid cooling unit is started until the temperature difference is less than the second preset temperature difference. The temperature values ​​of the first preset temperature, the second preset temperature, the fourth preset temperature, and the third preset temperature are arranged from largest to smallest; the difference between the first preset temperature and the second preset temperature is greater than the difference between the second preset temperature and the first preset temperature.

[0013] In some possible implementations, the method further includes: The liquid cooling unit is controlled to regulate the temperature of the battery compartment through the first liquid cooling pipeline; The fan inside the PCS compartment blows out the internal heat of the power module, which is then blown onto the air-water cooling heat exchanger via the air duct inside the compartment. The heat is then carried out of the PCS compartment through the second liquid cooling pipe connected to the air-water cooling heat exchanger. The portion of the second liquid cooling pipe outside the PCS compartment runs parallel to the portion of the first liquid cooling pipe.

[0014] Thirdly, this application also provides a computer program product comprising a computer program that, when executed by at least one processor, implements the steps of the method described in any one of the third aspects.

[0015] Combining the above-mentioned technical solutions and the technical problems they solve, the technical solution protected in this application differs from the mechanical or electronic switching of traditional STSs. By continuously operating the off-grid PCS unit online, it completely eliminates switching actions, meeting the zero-tolerance requirements for voltage dips (power interruptions) in scenarios such as data centers and precision manufacturing. Furthermore, instead of using conventional static switching switches (STSs) to achieve seamless switching, because STS module power cannot reach the megawatt level, this application uses a controller to connect multiple PCS modules in parallel and continuously operate them in off-grid mode. Important loads are directly connected to the output power distribution circuit of the off-grid PCS unit. When the mains power fails, because the off-grid PCS continuously converts the DC bus power into AC power to supply the load, the mains power will not affect the normal operation of the off-grid load. Attached Figure Description

[0016] The present application will be further described below with reference to the accompanying drawings and embodiments.

[0017] Figure 1 This is a structural schematic diagram of a container-type cabin provided in an embodiment of this application; Figure 2 This is a schematic diagram of an energy storage module and a power module provided in an embodiment of this application; Figure 3 This is a schematic diagram of the connection between a power grid, a battery, and a PCS provided in an embodiment of this application; Figure 4 This is a schematic diagram of the connection between a load, a battery, and a PCS provided in an embodiment of this application; Figure 5 This is a schematic diagram illustrating the connection between a grid-connected PCS, an off-grid PCS, and a battery, provided in an embodiment of this application. Figure 6 This is a schematic diagram of the connection between a grid-connected PCS and a battery provided in an embodiment of this application; Figure 7 This is a schematic diagram of a process for regulating the temperature of the battery compartment according to an embodiment of this application; Figure 8 This is a schematic diagram of heat dissipation in a PCS compartment according to an embodiment of this application; Figure 9 This is a schematic diagram of the structure of a wind-water cooling heat exchanger provided in an embodiment of this application. Detailed Implementation

[0018] The present application will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments. The implementation process of the present application will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present application from the content disclosed in this specification. The present application can also be implemented or applied through other different specific implementation procedures, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present application. It should be understood that the preferred embodiments are only for illustrating the present application and not for limiting the scope of protection of the present application.

[0019] The technical solutions of the embodiments of this application and how the technical solutions of the embodiments of this application solve the above-mentioned technical problems will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that the various embodiments or technical features described below can be arbitrarily combined to form new embodiments, and the same or similar concepts or processes may not be described again in some embodiments. Obviously, the described embodiments are some embodiments of the embodiments of this application, but not all embodiments.

[0020] Example 1.

[0021] See Figure 1 This embodiment provides a megawatt-level power supply system, including: The container-style cabin is internally divided into an electrical compartment, a PCS compartment, and a battery compartment. The power module is located in the PCS compartment and contains multiple PCS modules. Each PCS module includes a grid-connected PCS unit and an off-grid PCS unit. The energy storage module consists of multiple clusters of batteries with a total capacity of megawatts, located in the battery compartment. Each cluster of batteries is connected to a grid-connected PCS unit and an off-grid PCS unit in a set of PCS modules. The controller, located in the electrical compartment and connected to the power module and energy storage module, is configured to: The grid-connected PCS unit in the power module is controlled to operate in grid-connected (PQ) mode to charge its corresponding battery pack and provide energy to its corresponding off-grid PCS unit through the DC bus; The off-grid PCS unit is controlled to operate in off-grid (VF) mode to convert DC power to AC power to supply power to the load; The system monitors the system (SOC) status of each battery cluster in the energy storage module and dynamically adjusts the charging and discharging power of the grid-connected PCS unit; and controls the grid-connected PCS unit to stop operating and keeps the off-grid PCS unit running continuously when the grid is interrupted, thereby achieving seamless switching between grid connection and off-grid operation.

[0022] The technical solution provided in this embodiment achieves seamless megawatt-level power supply through a dual-PCS parallel architecture and zoned control. Its core lies in deconstructing the traditional single power supply path into a physically isolated and dynamically coordinated grid-connected energy path and an off-grid power supply path. Specifically, the containerized cabin physically isolates the three major functions of electrical control, power conversion, and energy storage, forming a zoned layout of electrical compartment (controller), PCS compartment (power module), and battery compartment (energy storage module), reducing mutual interference. Simultaneously, the grid-connected PCS unit and the off-grid PCS unit in each PCS module share the same DC bus of the same battery cluster. However, the grid-connected PCS unit operates in PQ mode, acting only as an energy dispatcher to draw power from the grid to charge the corresponding battery pack while maintaining the voltage stability of the corresponding battery pack. The off-grid PCS unit operates in VF mode, continuously converting energy into AC power to supply the load as a constant power source. The controller can form a negative feedback loop by monitoring the SOC of the energy storage module. For example, when the SOC is greater than its corresponding set threshold, the grid-connected PCS unit is controlled to reduce the charging power, while the off-grid PCS unit increases the discharge power to maintain battery activity. When the SOC is less than its corresponding set threshold, the grid-connected PCS unit automatically increases the charging power to form a dynamic balance.

[0023] When the power grid is normal, the off-grid PCS unit is already in a loaded operating state, with energy derived from the DC bus. At the moment of power failure, the grid-connected PCS unit triggers a protection shutdown due to a voltage drop on the bus, but the DC bus continues to be powered by the battery, and the off-grid PCS unit continues to operate without being affected. This process does not require detecting a power failure signal to trigger the switching logic, achieving a switching time of zero milliseconds from an electrical characteristic perspective.

[0024] Therefore, unlike the mechanical or electronic switching of traditional STSs, this solution completely eliminates switching actions through the continuous online operation of off-grid PCS units, meeting the zero-tolerance requirements for voltage dips (power interruptions) in scenarios such as data centers and precision manufacturing. Furthermore, instead of using conventional static switching switches (STSs) to achieve seamless switching (because STS module power cannot reach megawatt levels), this application uses a controller to connect multiple PCS modules in parallel and continuously operate them in off-grid mode. Important loads are directly connected to the output power distribution circuit of the off-grid PCS unit. When the mains power fails, because the off-grid PCS continuously converts the DC bus power to AC power to supply the load, the mains power will not affect the normal operation of the off-grid load.

[0025] In some embodiments, the containerized cabin further includes a temperature control system compartment, and the megawatt-level power supply system further includes a temperature control module disposed in the temperature control system compartment. The temperature control module includes a liquid cooling unit, and the controller is further configured to control the liquid cooling unit to regulate the temperature of the battery compartment through a first liquid cooling pipeline.

[0026] The liquid-cooled unit may include an electric auxiliary heating module and an air conditioning refrigeration module, and has the functions of heating and cooling. The technical solution provided in this embodiment achieves precise thermal management of megawatt-level energy storage systems through a modular, partitioned temperature control architecture and a closed-loop liquid cooling control mechanism. Specifically, a separate temperature control system compartment is partitioned within the containerized cabin, physically isolating the liquid cooling unit from the controlled object (battery compartment) to prevent vibration, noise, and potential refrigerant leakage from the cooling equipment from interfering with the battery compartment environment. The liquid cooling unit forms an independent circulation loop through a first liquid cooling pipeline. Driven by a circulation pump, the coolant flows through the battery heat dissipation channels within the battery compartment, absorbing the heat generated by the charging and discharging of the battery cells before returning to the temperature control system compartment for heat exchange, forming a closed-loop heat conduction between compartments. The controller can execute temperature control strategies based on real-time data from multi-point temperature sensors in the battery compartment (heating when the temperature is below the set temperature and cooling when the temperature is above the set temperature).

[0027] In some embodiments, when controlling the liquid cooling unit to regulate the temperature of the battery compartment through the first liquid cooling pipeline, the controller is further configured to: The system acquires the lowest and highest cell temperatures of the energy storage module in real time and determines whether the highest cell temperature is greater than a first preset temperature. If it is greater than the first preset temperature, the system starts the cooling mode of the liquid cooling unit until the highest cell temperature is not greater than the second preset temperature. If it is not greater than the first preset temperature, the system determines whether the lowest cell temperature is less than the third preset temperature. If it is less than the third preset temperature, the system starts the heating mode of the liquid cooling unit until the lowest cell temperature is not less than the fourth preset temperature. When the highest cell temperature is not greater than the first preset temperature and the lowest cell temperature is not less than the third preset temperature, the temperature difference between the highest cell temperature and the lowest cell temperature is obtained, and it is determined whether the temperature difference is greater than the first preset temperature difference. If it is greater, the circulation mode of the liquid cooling unit is started until the temperature difference is less than the second preset temperature difference. The temperature values ​​of the first preset temperature, the second preset temperature, the fourth preset temperature, and the third preset temperature are arranged from largest to smallest; the difference between the first preset temperature and the second preset temperature is greater than the difference between the second preset temperature and the first preset temperature.

[0028] The technical solution provided in this embodiment first determines whether the highest cell temperature exceeds a first preset temperature to activate the cooling mode; secondly, it determines whether the lowest cell temperature is lower than a third preset temperature to activate the heating mode; finally, if neither of the first two conditions is met and the temperature difference between the highest and lowest cells exceeds the first preset temperature difference, a circulating temperature equalization mode is activated until the temperature difference is less than the second preset temperature difference. Through progressive judgment logic and multi-threshold gradient control, refined management of the battery compartment temperature can be achieved. In the circulating mode, only the circulating water pump is activated; neither the cooling nor heating device is activated. The above judgment logic ensures that high-energy-consuming cooling / heating modes are activated only when necessary, reducing energy consumption.

[0029] In some embodiments, before acquiring the lowest and highest cell temperatures of the energy storage module in real time, the controller is further configured to: Two different sets of temperature control parameters corresponding to the current operating mode of the megawatt-level power supply system are obtained; each set of temperature control parameters includes a first preset temperature, a second preset temperature, a third preset temperature, a fourth preset temperature, a first preset temperature difference, and a second preset temperature difference; the operating mode includes an idle operating mode, a normal operating mode, and a full-condition operating mode; Based on the time elapsed since the last operation of the liquid cooling unit, a set of temperature parameters is selected as the target temperature parameters. The liquid cooling unit is controlled using the preset temperature and preset temperature difference in the target temperature parameters, and the temperature of the battery compartment is regulated through the liquid cooling pipeline.

[0030] It can be assumed that a parameter database with adaptive operating conditions is stored, and operators can adjust the data in the parameter database. Multiple sets of temperature control parameters and their corresponding operating conditions (operating mode and the downtime since the liquid-cooled unit last started) are stored in the parameter database. Idle operating mode corresponds to low power, standby, and float charging scenarios; normal operating mode corresponds to standard charge-discharge cycle scenarios; full operating mode corresponds to full power, overload, and extreme ambient temperature scenarios. When the liquid-cooled unit has been idle for a long time since its last operation, it corresponds to the cold start parameter set; otherwise, it corresponds to the hot start parameter set.

[0031] See Figure 9 In some embodiments, the temperature control module further includes an air-cooled / water-cooled heat exchanger. The controller is also configured to: control the fan inside the PCS compartment to blow out the internal heat of the power module, blow it onto the air-water cooling heat exchanger through the air duct inside the compartment, and then carry the heat out of the PCS compartment through the second liquid cooling pipeline connected to the air-water cooling heat exchanger; the part of the second liquid cooling pipeline outside the PCS compartment runs parallel to the part of the first liquid cooling pipeline.

[0032] The technical solution provided in this embodiment achieves efficient synergy between the PCS compartment's internal circulating heat dissipation and the battery compartment's liquid cooling system through a wind-liquid heat exchange coupling and parallel pipeline reuse architecture. The second liquid cooling pipeline runs parallel to the first, reducing equipment costs. The PCS compartment can be a fully enclosed internal circulation design, coupled with a wind-liquid cooling heat exchanger, eliminating the need for heat dissipation louvers on the compartment walls, meeting IP66 protection standards, and suitable for harsh environments. Compared to traditional air cooling in related technologies, it offers higher protection levels and is suitable for megawatt-level system integration. It also reduces costs compared to establishing a separate liquid cooling device.

[0033] In some embodiments, the megawatt-level power supply system further includes an environmental control module and a fire protection module. The environmental control module includes multiple water immersion sensors and temperature and humidity sensors connected to the controller. The water immersion sensors and temperature and humidity sensors are installed in each compartment of the containerized cabin. The fire protection module includes multiple aerosol fire extinguishing devices, and the controller is configured to activate the aerosol fire extinguishing devices in the corresponding areas based on the fire warning status of each battery cluster and each compartment.

[0034] In practical applications, water immersion sensors are deployed at the bottom of the electrical compartment, PCS compartment, and temperature control system compartment to monitor water ingress or condensation accumulation in the compartment in real time; temperature and humidity sensors are deployed at the top, middle, and electrical connection points of each battery cluster in the battery compartment.

[0035] As an example, a megawatt-class power supply system is provided, comprising: The container-style structure is internally divided into electrical compartments, PCS compartments, and battery compartments, etc.; it can use standard 20-foot high cube containers to integrate various sub-components internally, facilitating road and sea transportation and making construction convenient. The power module, located in the PCS compartment, contains at least four PCS modules for forming, for example, a 1MW charge-discharge conversion system. Each PCS module includes one grid-connected PCS unit and one off-grid PCS unit. The energy storage module consists of at least four battery clusters with a total capacity of megawatts, located in the battery compartment. Each battery cluster has a capacity of 522 kWh. Each battery cluster is connected to a grid-connected PCS unit and an off-grid PCS unit in a PCS module. A 2 MWh battery stack can be formed by connecting 600+ Ah ​​cells in series and parallel. Temperature control module, which includes a liquid-cooled unit and an air-water-cooled heat exchanger; The environmental control module includes multiple water immersion sensors and temperature and humidity sensors connected to the controller. The water immersion sensors and temperature and humidity sensors are installed in each compartment of the container-type cabin. Firefighting module, which includes multiple aerosol fire extinguishing devices; The controller, located in the electrical compartment and connected to the power module and energy storage module, is configured to: The grid-connected PCS unit in the power module is controlled to operate in grid-connected (PQ) mode to charge its corresponding battery pack and provide energy to its corresponding off-grid PCS unit through the DC bus; The off-grid PCS unit is controlled to operate in off-grid (VF) mode to convert DC power to AC power to supply power to the load; The system monitors the system (SOC) status of each battery cluster in the energy storage module and dynamically adjusts the charging and discharging power of the grid-connected PCS unit; and controls the grid-connected PCS unit to stop operating and keeps the off-grid PCS unit running continuously when the grid is interrupted, thereby achieving seamless switching between grid and off-grid; The liquid cooling unit is controlled to regulate the temperature of the battery compartment through the first liquid cooling pipeline; The fan inside the PCS compartment blows out the internal heat of the power module, which is then blown onto the air-water cooling heat exchanger via the air duct inside the compartment. The heat is then carried out of the PCS compartment through the second liquid cooling pipe connected to the air-water cooling heat exchanger. The portion of the second liquid cooling pipe outside the PCS compartment runs parallel to the portion of the first liquid cooling pipe.

[0036] See Figures 2 to 4 Each grid-connected PCS unit can include two parallel PCS devices (e.g., #1-1PCS and #1-2PCS, #2-1PCS and #2-2PCS, #3-1PCS and #3-2PCS, #4-1PCS and #4-2PCS), and each off-grid PCS unit can include two parallel PCS devices (e.g., #1-3PCS and #1-4PCS, #2-3PCS and #2-4PCS, #3-3PCS and #3-4PCS, #4-3PCS and #4-4PCS). Considering that the entire system has a total of 4 battery clusters, each with a capacity of 522kWh, if 0.5C charge and discharge is performed, each circuit will connect two discharge modules (two parallel PCS devices from the grid-connected PCS unit) and two charging modules (two parallel PCS devices from the off-grid PCS unit), that is, the total charging power is 1MW and the discharge power is 1MW.

[0037] During charging, the power of the discharge module cannot be controlled, and the power of the charging module is determined by the battery's SOC. If the battery's SOC is close to 90-100%, the power of the charging module is reduced to prevent the battery from being overcharged. During discharge, the battery's SOC status is monitored. If the SOC drops, it indicates that the charging module's power is low. In this case, the charging module's power can be increased appropriately. When power is off, the charging module, which operates in parallel with the grid, will report a grid voltage fault and can be commanded to shut down or go into standby mode. The discharging module, on the other hand, will operate normally. During grid-connected and off-grid switching, the system topology design avoids the impact of mains power outages, so the grid-connected and off-grid switching time of this scheme can be considered as 0ms, i.e. seamless switching.

[0038] As an example, when in operation, the provided system can achieve megawatt-level AC / DC integration, highly integrating multiple functional units such as PCS, battery, power distribution, and monitoring management into a single device.

[0039] Specifically, firstly, two 125kW grid-connected PCSs are connected to a battery cluster with an energy of 522kWh, thus forming a 250kW-522kWh energy unit; then, three identical energy units are combined together, and the eight grid-connected PCSs are AC-coupled through the controller in the control cabinet, which can achieve a charging or discharging power of 1MW, with a maximum power of 1.25MW charging and discharging. Using the same principle, firstly, two 125kW off-grid PCS are connected to a battery cluster with an energy of 522kWh, thus forming a 250kW-522kWh energy unit; then, three identical energy units are combined together, and the controller in the control cabinet is used to AC couple the eight off-grid PCS, which can achieve a discharge power of 1MW, with a maximum discharge power of 1.25MW.

[0040] Through the above methods, the system provided in this application can break through the bottleneck of traditional industrial and commercial products only being able to achieve kilowatts; similarly, power can be allocated on demand through control. The controller not only controls the PCS and BMS to perform power allocation operation, but also monitors the environmental control module, effectively manages the air conditioning of the liquid chiller, and communicates with external equipment.

[0041] Seamless switching in this application mainly refers to the system's ability to automatically, quickly, and smoothly switch to backup power when the main power supply or grid fails, without any interruption or significant voltage fluctuation in the power supply to the downstream loads. This application's system does not use a conventional static transfer switch (STS) to achieve seamless switching because STS modules cannot reach megawatt levels. Therefore, the product of this invention uses a controller to connect multiple PCS modules in parallel and continuously operate them in off-grid mode. Important loads are directly connected to the output power distribution circuit of the off-grid PCS. When the grid power fails, because the off-grid PCS continuously converts the DC bus power into AC power to supply the loads, the grid power will not affect the normal operation of the off-grid loads.

[0042] See Figures 5 to 6 During normal operation, the grid-connected PCS charges the batteries in the battery pack and simultaneously provides DC power to the off-grid PCS. The off-grid PCS then converts the DC power into AC power to supply the load. When the batteries in the battery pack are fully charged, the controller controls the charging power of the grid-connected PCS to release some energy from the batteries, thus maintaining battery activity and extending battery life. When the grid loses power, the grid-connected PCS stops operating, and the off-grid PCS converts the DC power back into AC power to supply the load. Because DC power is always available, the off-grid load will not lose power.

[0043] Meanwhile, the system provided in this embodiment uses a fully enclosed design, with all components except the air conditioner and liquid chiller themselves being exposed to the outside air, all of which are installed in a housing with an IP66 protection rating; effectively preventing dust, lint, insects and other particles in the air from entering the equipment, avoiding dust accumulation that could lead to short circuits, signal interference and overheating of components (dust is an insulator), and fundamentally eliminating the risk of downtime caused by dust.

[0044] Regarding the product's heat dissipation, the main components include: a) Since the electrical compartment has relatively little heat, mainly from the copper busbar UPS, wall-mounted small air conditioners are used to dissipate heat from the compartment. The air conditioning in the electrical compartment is kept constant at the set value by the controller. b) Battery compartment heat dissipation is mainly achieved by removing all the heat generated by the PACK through liquid cooling pipes. The controller adjusts the liquid cooling unit. When the PACK temperature reaches the set value, the liquid cooling unit is activated in cooling mode to ensure that the water temperature is kept constant at a reasonable value. When the PACK temperature is too low, the liquid cooling unit is activated in heating mode to similarly ensure that the water temperature is kept constant at a reasonable value. This keeps the cell temperature at its optimal state, which can greatly extend the life of the cell. See Figure 7 A process for regulating the temperature of a battery compartment is provided, including: start; S10, read parameters; execute S11 if the system is in normal working mode (idle working mode, normal working mode and full working mode), otherwise execute S27; S11, determine if the time since the liquid chiller last ran is no more than 0.5 hours; execute S14 instead of S12. S12, determine whether the highest cell temperature is greater than 45℃, otherwise execute S13, otherwise execute S16; S13, determine whether the lowest cell temperature is less than 5℃, otherwise execute S18, otherwise execute S17; S14, determine whether the highest cell temperature is greater than 30℃, otherwise execute S15, otherwise execute S20; S15, determine whether the minimum cell temperature is less than 10℃, otherwise execute S18, otherwise execute S19; S16, the liquid chiller unit starts the cooling mode and executes S21; S17, the liquid-cooled unit starts the heating mode and executes S22; S18, determine whether the temperature difference between the highest cell temperature and the lowest cell temperature is greater than 8℃; if yes, proceed to S23, otherwise proceed to S27. S19, the liquid-cooled unit starts the heating mode and executes S24; S20, the liquid chiller unit starts the cooling mode and executes S25; S21, determine whether the highest cell temperature is not greater than 30℃, otherwise continue to execute S16, otherwise execute S27; S22, determine whether the minimum cell temperature is not less than 10℃, otherwise continue to execute S17, otherwise execute S27; S23, the liquid-cooled unit starts the circulation mode and executes S26; S24, determine whether the minimum cell temperature is not less than 15℃, otherwise continue to execute S19, otherwise execute S27; S25, determine whether the highest cell temperature is not greater than 25℃, otherwise continue to execute S20, otherwise execute S27; S26, determine whether the difference between the highest cell temperature and the lowest cell temperature is less than 5℃. If yes, proceed to S27; otherwise, continue to S23. S27, refrigeration unit stops.

[0045] c) See also Figure 8As mentioned in point 9, the heat dissipation of the PCS compartment is mainly achieved through the PCS's own fan, which blows hot air out of the module and onto the air-liquid cooling heat exchanger through the compartment's air ducts. The air-liquid cooling heat exchanger carries away the heat through the coolant in the liquid cooling pipes. Then, through the airflow in the compartment, the cooled air from the air-liquid cooling heat exchanger is transferred to the air inlet of the PCS, thus forming an airflow circulation to achieve circulating heat dissipation within the compartment. The liquid cooling pipes here are parallel to those in the battery compartment, and the liquid cooling pipes of the entire system can share a single liquid cooler.

[0046] Example 2.

[0047] This embodiment provides a control method for a megawatt-level power supply system, applied to the megawatt-level power supply system described in any one of Embodiments 1. The method includes: The grid-connected PCS unit in the control power module operates in grid-connected PQ mode to charge its corresponding battery pack and provide energy to its corresponding off-grid PCS unit through the DC bus. The off-grid PCS unit is controlled to operate in off-grid VF mode to convert DC power to AC power to supply power to the load; The system monitors the SOC status of each battery cluster in the energy storage module and dynamically adjusts the charging and discharging power of the grid-connected PCS unit; and controls the grid-connected PCS unit to stop operating and keeps the off-grid PCS unit running continuously when the grid is interrupted, thereby achieving seamless switching between grid connection and off-grid operation.

[0048] In some embodiments, the method further includes: The liquid cooling unit is controlled to regulate the temperature of the battery compartment through the first liquid cooling pipeline; The fan inside the PCS compartment blows out the internal heat of the power module, which is then blown onto the air-water cooling heat exchanger via the air duct inside the compartment. The heat is then carried out of the PCS compartment through the second liquid cooling pipe connected to the air-water cooling heat exchanger. The portion of the second liquid cooling pipe outside the PCS compartment runs parallel to the portion of the first liquid cooling pipe.

[0049] Example 3.

[0050] This embodiment provides a computer program product, which includes a computer program that, when executed by at least one processor, implements the steps of any of the methods described in the method embodiment.

[0051] The computer program product may be in the form of a portable compact disc read-only memory (CD-ROM) and include program code, and may run on a terminal device, such as a personal computer. However, the computer program product of this application is not limited thereto, and the computer program product may be in any combination of one or more computer-readable media.

[0052] It should be noted that in the embodiments of this application, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, a and b, a and c, b and c, or a and b and c, where a, b, and c can be single or multiple. It is worth noting that "at least one" can also be interpreted as "one or more".

[0053] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are configured to distinguish similar objects and are not necessarily configured to describe a particular order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0054] This application describes the invention from the perspectives of purpose, performance, progress, and novelty, and it meets the functional enhancement and use requirements emphasized by the Patent Law. The above description and drawings are merely preferred embodiments of this application and are not intended to limit this application. Therefore, all structures, devices, features, etc., that are similar to or identical to those of this application, i.e., all equivalent substitutions or modifications made in accordance with the scope of this patent application, shall fall within the scope of protection of this patent application.

Claims

1. A megawatt-level power supply system, characterized in that, include: The container-style cabin is internally divided into an electrical compartment, a PCS compartment, and a battery compartment. The power module is located in the PCS compartment and contains multiple PCS modules. Each PCS module includes a grid-connected PCS unit and an off-grid PCS unit. The energy storage module consists of multiple clusters of batteries with a total capacity of megawatts, located in the battery compartment. Each cluster of batteries is connected to a grid-connected PCS unit and an off-grid PCS unit in a set of PCS modules. The controller, located in the electrical compartment and connected to the power module and energy storage module, is configured to: The grid-connected PCS unit in the power module is controlled to operate in grid-connected mode to charge its corresponding battery pack and provide energy to its corresponding off-grid PCS unit through the DC bus. The off-grid PCS unit is controlled to operate in off-grid mode to convert DC power to AC power to supply power to the load; Monitor the system status of each battery cluster in the energy storage module and dynamically adjust the charging and discharging power of the grid-connected PCS unit; And when the power grid fails, the grid-connected PCS unit is controlled to stop operating while the off-grid PCS unit continues to operate, thereby achieving seamless switching between grid connection and off-grid operation.

2. The megawatt-level power supply system according to claim 1, characterized in that, The containerized cabin also includes a temperature control system compartment, and the megawatt-level power supply system also includes a temperature control module installed in the temperature control system compartment. The temperature control module includes a liquid cooling unit, and the controller is further configured to control the liquid cooling unit to regulate the temperature of the battery compartment through a first liquid cooling pipeline.

3. The megawatt-level power supply system according to claim 2, characterized in that, When controlling the liquid cooling unit to regulate the temperature of the battery compartment through the first liquid cooling pipeline, the controller is also configured to: The system acquires the lowest and highest cell temperatures of the energy storage module in real time and determines whether the highest cell temperature is greater than a first preset temperature. If it is greater than the first preset temperature, the system starts the cooling mode of the liquid cooling unit until the highest cell temperature is not greater than the second preset temperature. If it is not greater than the first preset temperature, the system determines whether the lowest cell temperature is less than the third preset temperature. If it is less than the third preset temperature, the system starts the heating mode of the liquid cooling unit until the lowest cell temperature is not less than the fourth preset temperature. When the highest cell temperature is not greater than the first preset temperature and the lowest cell temperature is not less than the third preset temperature, the temperature difference between the highest cell temperature and the lowest cell temperature is obtained, and it is determined whether the temperature difference is greater than the first preset temperature difference. If it is greater, the circulation mode of the liquid cooling unit is started until the temperature difference is less than the second preset temperature difference. The temperature values ​​of the first preset temperature, the second preset temperature, the fourth preset temperature, and the third preset temperature are arranged from largest to smallest; the difference between the first preset temperature and the second preset temperature is greater than the difference between the second preset temperature and the first preset temperature.

4. The megawatt-level power supply system according to claim 3, characterized in that, Before acquiring the lowest and highest cell temperatures of the energy storage module in real time, the controller is also configured to: Two different sets of temperature control parameters corresponding to the current operating mode of the megawatt-level power supply system are obtained; each set of temperature control parameters includes a first preset temperature, a second preset temperature, a third preset temperature, a fourth preset temperature, a first preset temperature difference, and a second preset temperature difference; the operating mode includes an idle operating mode, a normal operating mode, and a full-condition operating mode; Based on the time elapsed since the last operation of the liquid cooling unit, a set of temperature parameters is selected as the target temperature parameters. The liquid cooling unit is controlled using the preset temperature and preset temperature difference in the target temperature parameters, and the temperature of the battery compartment is regulated through the liquid cooling pipeline.

5. The megawatt-level power supply system according to claim 2, characterized in that, The temperature control module also includes a water-cooled heat exchanger, and the controller is further configured to: control the fan in the PCS compartment to blow out the internal heat of the power module, blow it onto the water-cooled heat exchanger through the air duct in the compartment, and then carry the heat out of the PCS compartment through the second liquid cooling pipeline connected to the water-cooled heat exchanger; the part of the second liquid cooling pipeline outside the PCS compartment runs parallel to the part of the first liquid cooling pipeline.

6. The megawatt-level power supply system according to claim 1, characterized in that, The megawatt-level power supply system also includes an environmental control module and a fire protection module. The environmental control module includes multiple water immersion sensors and temperature and humidity sensors connected to the controller. The water immersion sensors and temperature and humidity sensors are installed in each compartment of the container-type cabin. The fire protection module includes multiple aerosol fire extinguishing devices, and the controller is configured to activate the aerosol fire extinguishing devices in the corresponding areas based on the fire warning status of each battery cluster and each compartment.

7. A control method for a megawatt-level power supply system, applied to the megawatt-level power supply system according to any one of claims 1-6, characterized in that, The method includes: The grid-connected PCS unit in the control power module operates in grid-connected mode to charge its corresponding battery pack and provide energy to its corresponding off-grid PCS unit through the DC bus. The off-grid PCS unit is controlled to operate in off-grid mode to convert DC power to AC power to supply power to the load; The system monitors the system status of each battery cluster in the energy storage module and dynamically adjusts the charging and discharging power of the grid-connected PCS unit; and controls the grid-connected PCS unit to stop operating and keeps the off-grid PCS unit running continuously when the grid is interrupted, thereby achieving seamless switching between grid and off-grid.

8. The control method according to claim 7, characterized in that, The method further includes: The system acquires the lowest and highest cell temperatures of the energy storage module in real time and determines whether the highest cell temperature is greater than a first preset temperature. If it is greater than the first preset temperature, the system starts the cooling mode of the liquid cooling unit until the highest cell temperature is not greater than the second preset temperature. If it is not greater than the first preset temperature, the system determines whether the lowest cell temperature is less than the third preset temperature. If it is less than the third preset temperature, the system starts the heating mode of the liquid cooling unit until the lowest cell temperature is not less than the fourth preset temperature. When the highest cell temperature is not greater than the first preset temperature and the lowest cell temperature is not less than the third preset temperature, the temperature difference between the highest cell temperature and the lowest cell temperature is obtained, and it is determined whether the temperature difference is greater than the first preset temperature difference. If it is greater, the circulation mode of the liquid cooling unit is started until the temperature difference is less than the second preset temperature difference. The temperature values ​​of the first preset temperature, the second preset temperature, the fourth preset temperature, and the third preset temperature are arranged from largest to smallest; the difference between the first preset temperature and the second preset temperature is greater than the difference between the second preset temperature and the first preset temperature.

9. The control method according to claim 8, characterized in that, The method further includes: The liquid cooling unit is controlled to regulate the temperature of the battery compartment through the first liquid cooling pipeline; The fan inside the PCS compartment blows out the internal heat of the power module, which is then blown onto the air-water cooling heat exchanger via the air duct inside the compartment. The heat is then carried out of the PCS compartment through the second liquid cooling pipe connected to the air-water cooling heat exchanger. The portion of the second liquid cooling pipe outside the PCS compartment runs parallel to the portion of the first liquid cooling pipe.

10. A computer program product, characterized in that, The computer program product includes a computer program that, when executed by at least one processor, implements the steps of the method according to any one of claims 7-9.

Images