Power conversion system
By designing an integrated power conversion system, the problem of independent communication between the photovoltaic energy storage system and the electric vehicle charger was solved, realizing overall power management, reducing equipment costs and size, and improving the efficiency of renewable energy use.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- DELTA ELECTRONICS (SHANGHAI) CO LTD
- Filing Date
- 2022-11-03
- Publication Date
- 2026-07-31
AI Technical Summary
Existing photovoltaic energy storage systems and electric vehicle chargers are independent of each other and lack a unified communication protocol, making it difficult to achieve overall power management, resulting in insufficient AC port capacity and high installation and maintenance costs.
Design a power conversion system comprising a power conversion device, a protection device, and a charging device. By integrating multiple input/output ports, it achieves DC/AC conversion, possesses power conversion, communication, and protection functions, and integrates photovoltaic power generation, energy storage, and electric vehicle charging functions.
It enables power management across multiple systems, reduces installation and maintenance costs, lowers equipment size and weight, improves thermal management efficiency, and enhances the efficiency of renewable energy utilization.
Smart Images
Figure CN116154839B_ABST
Abstract
Description
Technical Field
[0001] This case relates to a conversion device, and more particularly to a power conversion system. Background Technology
[0002] Existing photovoltaic-storage-charging systems typically consist of multiple independent subsystems. Photovoltaic energy storage systems usually employ a photovoltaic inverter and a battery inverter, using AC coupling to achieve energy exchange between renewable energy generation and energy storage; or using DC coupling to achieve the same energy exchange. Electric vehicle (EV) chargers are also directly connected to the AC grid.
[0003] If the aforementioned photovoltaic energy storage system and electric vehicle charger are both independent devices, it is difficult to achieve communication between the various subsystems due to the lack of a unified standard and communication protocol, thus hindering overall power management. Furthermore, each system requires its own independent grid connection capacity, resulting in insufficient AC port capacity, high installation costs, and relatively high maintenance costs. Summary of the Invention
[0004] One aspect of this invention relates to a power conversion system, comprising a power conversion device, a protection device, and a charging device. The power conversion device is coupled to a first power source and a second power source. The power conversion device is used to receive power from the first power source and to receive power from the second power source or to charge the second power source. The protection device is coupled to the power conversion device, a load, and a power grid, and is used to switch the electrical connection between the power conversion device, the load, and the power grid. The charging device is coupled to the power conversion device and a third power source. The power conversion device charges the third power source through the charging device, or receives power from the third power source through the charging device. In a first mode, the power conversion device supplies power from the first power source to the load through the protection device, and the power conversion device supplies power from the first power source to the third power source through the charging device. In a second mode, the power conversion device supplies power from the second power source and / or the third power source to the load, or supplies power from the power grid to the load through the protection device.
[0005] In one embodiment, in the first mode, the power conversion device also supplies power provided by the first power source to the second power source.
[0006] In one embodiment, in the first mode, if the power provided by the first power source is greater than the power required by the second power source, the load, and the third power source, the power conversion device will supply the power provided by the first power source to the power grid or reduce the output power of the first power source.
[0007] In one embodiment, in the second mode, if the power provided by the second and third power sources is less than the power required by the load, the power from the grid is supplied to the load through a protection device.
[0008] In one embodiment, in the second mode, if the power supplied by the second power source is greater than or equal to the power required by the load, the power conversion device supplies the power supplied by the second power source to the load.
[0009] In one embodiment, in the second mode, if the energy stored in the third power source is lost after the third power source supplies power to the load, the power conversion device controls the power to be supplied from the grid to the third power source, or controls the power to be supplied from the first power source to the third power source in the first mode.
[0010] In one embodiment, in the third mode, the power conversion device controls the protection device to switch to disconnect from the power grid, and the power conversion device supplies the power provided by the first power source to the load through the protection device.
[0011] In one embodiment, in the third mode, if the power provided by the first power source is greater than the power required by the load, the power conversion device supplies the power provided by the first power source to the second power source, and supplies the power provided by the first power source to the third power source through the charging device.
[0012] In one embodiment, in the third mode, if the power provided by the first power source is greater than the power required by the second power source, the load, and the third power source, the output power of the first power source is reduced.
[0013] In one embodiment, in the third mode, if the power supplied by the first power source is less than the power required by the load, the power conversion device will supply the power supplied by the second or third power source to the load.
[0014] In one embodiment, the first power source includes a photovoltaic panel.
[0015] In one embodiment, the second power source includes an energy storage battery.
[0016] In one embodiment, the third power source includes a mobile energy storage device.
[0017] In one embodiment, the power conversion device includes a converter for performing DC / DC conversion, DC / AC conversion, or AC / DC conversion.
[0018] In one embodiment, the power conversion device includes a controller for controlling a protection device to switch the electrical connection between the power conversion device, the load, and the power grid, and for communicating with a charging device to determine whether to charge a third power source through the charging device or whether to discharge the third power source through the charging device.
[0019] In one embodiment, the power conversion device further includes a sensor that detects at least the state of a third power source and provides the state of the third power source to the controller.
[0020] In one embodiment, the power conversion device further includes a protector that disconnects the connection to the power grid in the event of an overcurrent or leakage current.
[0021] In one embodiment, the protection device includes a switcher for controlling the switching state between the power conversion device, the power grid, and the load.
[0022] In one embodiment, the protection device includes a protector, which disconnects the connection to the power grid in the event of an overcurrent or leakage current.
[0023] In one embodiment, the power conversion device includes a DC bus, a first sub-converter, a second sub-converter, and a third sub-converter. The first sub-converter is coupled to a first power source and the DC bus, and is used to receive and adjust the power provided by the first power source to supply the DC bus. The second sub-converter is coupled to a second power source and the DC bus, wherein the second sub-converter is used to receive and adjust the power provided by the second power source to supply the DC bus, or to charge the second power source. The third sub-converter is coupled to the DC bus and a protection device.
[0024] In one embodiment, the power conversion device includes a DC bus, a first sub-converter, and a third sub-converter. The first sub-converter is coupled to a first power source and the DC bus, and is used to receive and adjust the power provided by the first power source to supply the DC bus, wherein the DC bus is coupled to a second power source. The third sub-converter is coupled to the DC bus and a protection device.
[0025] In one embodiment, the power conversion device includes a DC bus, and the charging device is coupled to the DC bus.
[0026] In one embodiment, the power conversion device includes a fourth sub-converter, and the charging device is coupled to the DC bus through the fourth sub-converter, wherein the fourth sub-converter receives and adjusts the power provided by the third power source to supply the DC bus through the charging device, or charges the third power source through the charging device.
[0027] In one embodiment, the power conversion device further includes a controller and a sensor coupled to the DC bus. The sensor is used to detect a signal that reflects the state of the DC bus and to provide the signal to the controller.
[0028] In one embodiment, the power conversion device further includes a first controller, a second controller, a first sensor, and a second sensor. The first controller is used to control at least a third sub-converter. The second controller is used to control at least a fourth sub-converter. The first sensor is coupled to the DC bus and is used to detect a signal reflecting the state of the DC bus and provide the signal to the first controller. The second sensor is coupled to the DC bus and is used to detect a signal reflecting the state of the DC bus and provide the signal to the second controller. The first sensor is located near the first controller, and the second sensor is located near the second controller. Attached Figure Description
[0029] To make the above and other objects, features, advantages and embodiments disclosed herein more apparent and understandable, the accompanying drawings are described below:
[0030] Figure 1 This is a schematic diagram illustrating a power conversion system according to an embodiment of the present disclosure;
[0031] Figure 2 An embodiment of this disclosure is illustrated as follows: Figure 1 A detailed circuit diagram of the protection device for the power conversion system shown.
[0032] Figure 3 This is a schematic diagram illustrating the operation of a power conversion system according to an embodiment of the present disclosure;
[0033] Figure 4 This is a schematic diagram illustrating the operation of a power conversion system according to an embodiment of the present disclosure;
[0034] Figure 5 This is a schematic diagram illustrating the operation of a power conversion system according to an embodiment of the present disclosure;
[0035] Figure 6 This is a schematic diagram illustrating the operation of a power conversion system according to an embodiment of the present disclosure;
[0036] Figure 7 This is a schematic diagram illustrating a power conversion system according to an embodiment of the present disclosure;
[0037] Figure 8 An embodiment of this disclosure is illustrated as follows: Figure 7 A schematic diagram of the power conversion device in the power conversion system shown.
[0038] Figure 9 This is a schematic diagram illustrating a power conversion system according to an embodiment of the present disclosure;
[0039] Figure 10 An embodiment of this disclosure is illustrated as follows: Figure 9 A schematic diagram of the power conversion device in the power conversion system shown.
[0040] Figure 11 An embodiment of this disclosure is illustrated as follows: Figure 9 A schematic diagram of the power conversion device in the power conversion system shown.
[0041] Figure 12 An embodiment of this disclosure is illustrated as follows: Figure 9 A schematic diagram of the power conversion device in the power conversion system shown.
[0042] Figure 13 An embodiment of this disclosure is illustrated as follows: Figure 12 A detailed circuit diagram of the power conversion device in the power conversion system shown.
[0043] Figure 14 An embodiment of this disclosure is illustrated as follows: Figure 9 The diagram shows a detailed circuit diagram of the power conversion system.
[0044] As is customary practice, the various features and components in the figures are not drawn to scale. The method of drawing is to best represent the specific features and components relevant to this disclosure. Furthermore, similar components / parts are referred to by the same or similar element symbols across different figures. Detailed Implementation
[0045] To make the description of this disclosure more detailed and complete, illustrative descriptions of embodiments and specific implementations of this case are provided below; however, this is not the only form of implementing or using the specific embodiments of this case. The implementation methods cover the features of multiple specific embodiments and the methods, steps, and their order for constructing and operating these specific embodiments. However, other specific embodiments may also be used to achieve the same or equivalent functions and sequence of steps.
[0046] Unless otherwise defined in this specification, the scientific and technical terms used herein have the same meaning as understood and commonly used by one of ordinary skill in the art to which this application pertains. Furthermore, unless conflicting with the context, the singular form of a noun used herein includes its plural form, and vice versa.
[0047] Figure 1 This is a schematic diagram illustrating a power conversion system 100 according to an embodiment of the present disclosure. As shown, the power conversion system 100 includes a power conversion device 110, a protection device 120, and a charging device 130. The power conversion device 110 is electrically connected to the protection device 120 and the charging device 130.
[0048] The aforementioned power conversion device 110 has multiple input / output ports. Two input / output ports of the power conversion device 110 are electrically connected to a first power supply 200 and a second power supply 300. Furthermore, another input / output port of the power conversion device 110 is electrically connected to a protection device 120, through which the power conversion device 110 is electrically connected to the power grid 400 and the load 500. Moreover, yet another input / output port of the power conversion device 110 is electrically connected to a charging device 130, through which the power conversion device 110 is electrically connected to a mobile energy storage device 600.
[0049] For example, the first power source 200 can be a photovoltaic panel, so the first power source 200 can be used to convert solar energy into power and supply it to the power conversion device 110. The second power source 300 can be an energy storage battery, so the second power source 300 can be used to store the electrical energy provided by the power conversion device 110 and supply it to the power conversion device 110 when needed.
[0050] Please see Figure 2 The protection device 120 includes a switch 121, a transformer 123, and a protector 125. The switch 121 can be a contactor or a relay; therefore, the switch 121 can be used to control the switching states between the power conversion device 110, the power grid 400, and the load 500. The transformer 123 can be an isolation transformer or an autotransformer to achieve voltage conversion. The protector 125 can be an overcurrent protection device or a leakage current protection device.
[0051] Please see Figure 1 The charging device 130 can be a charging gun, and the mobile energy storage device 600 can be an electric vehicle. Therefore, the mobile energy storage device 600 can be charged and discharged through the charging device 130. Specifically, the mobile energy storage device 600 includes a second converter 610 and a third power source 620. The third power source 620 can be an energy storage battery. The charging device 130 supplies power to the second converter 610, which converts the electrical energy and stores it in the third power source 620.
[0052] In one embodiment, the power conversion device 110 includes a first converter 111, a controller 113, a sensor 115, and a protector 117. The first converter 111 is electrically connected to the controller 113, the sensor 115, and the protector 117. The controller 113 is electrically connected to the sensor 115 and the protector 117.
[0053] For example, the first converter 111 has multiple input / output ports and can be used for DC / DC conversion, DC / AC conversion, or AC / DC conversion. The controller 113 is used to control the overall system. For example, the controller 113 can communicate with the charging device 130 to control the mobile energy storage device 600 to charge or discharge, or to implement protection functions. The sensor 115 can be a current sampler, a voltage sampler, or a combination of current and voltage samplers. The sensor 115 can detect the current, voltage, and power signals of the mobile energy storage device 600, and provide this information to the controller 113, which calculates the power of the mobile energy storage device 600 accordingly. Furthermore, the sensor 115 can also be used to detect whether the device is in an islanded state. The protector 117 can be a circuit breaker, used for overcurrent and leakage protection, and can also serve as a system protection trigger device. For example, when the sensor 115 detects an islanded state, the protector 117 will be triggered to disconnect the power conversion system 100 from the power grid 400.
[0054] As described above, the power conversion system 100 of this invention integrates the input / output ports of the first converter 111 and the charging device 130, thereby eliminating the need to expand the household power distribution capacity and reducing installation and subsequent maintenance costs. Furthermore, since multiple input / output ports are integrated into a smaller number, the overall size and weight are reduced, achieving better thermal management, simplified wiring, and other benefits. In addition, the power conversion system 100 incorporates an additional sensor 115 to detect the output of the charging device 130 and compensates for a portion of its output through an energy storage inverter, meeting the requirements of the power grid 400 for power consumption, generation, and grid support.
[0055] In one embodiment, the power conversion device 110 is a multi-port conversion controller (for example, it may have four ports: a port connected to the first power supply 200, a port connected to the second power supply 300, a port connected to the charging device 130, and a port connected to the protection device 120; these ports may be selectively configured in the power conversion device 110 depending on the application and the actual system architecture). The power conversion device 110 can realize power conversion, power flow direction control, communication with the internal system, communication with the external system, system protection, and energy management.
[0056] In one embodiment, the controller 113 is the controller and communicator of the entire power conversion system 100, including power conversion control, internal system communication, external system communication, and energy management system. The power conversion control can acquire the voltage and current of the first power source 200 (such as a photovoltaic panel) and calculate power and voltage changes to achieve Maximum Power Point Tracking (MPPT) of the interface of the first power source 200. Simultaneously, the power conversion control can acquire the voltage and current of the first power source 200 (such as a photovoltaic panel) and calculate power and voltage changes to control the active and reactive power of AC, achieving power factor control and frequency control functions. It can communicate with the charging device 130, controlling the voltage, current, or power of the port connected to the charging device to make the mobile energy storage device 600 (such as an electric vehicle) operate in charging or discharging mode. It can obtain the sampling signal from the sensor 115 and calculate the power of the mobile energy storage device 600. It can interact with the protection device 120, synchronize with the conversion controller's state, and switch between grid-connected and off-grid operating modes. It can also connect directly to the cloud via a router to achieve remote data feedback, monitoring, software upgrades, and other functions. These functions can be accomplished using one or more microcontrollers.
[0057] In one embodiment, the charging device 130 includes a power converter, a controller, a relay or contactor, a detector, and a communicator. The charging device 130 may be a connector in the form of an AC charging gun, etc. The power converter is a power conversion section that can perform DC / DC conversion, such as as an auxiliary power supply; the power converter can also perform DC / AC conversion, such as... Figure 1 The second converter can also be located in the charging device. The controller controls the power converter, and the communicator enables communication with the mobile energy storage device 600 and the controller 113. Relays or contactors enable the connection or disconnection of the power conversion device 110 and the mobile energy storage device 600. Detectors detect relevant signals from the charging device 130, including voltage, current, power, and temperature signals.
[0058] The power conversion system 100 in this case can provide the best power management solution under various conditions, as will be explained below. Figures 3 to 6 The above-described power management scheme is described in detail in the embodiments.
[0059] Figure 3This diagram illustrates the operation of a power conversion system 100 according to an embodiment of the present disclosure. In this embodiment, the power conversion system 100 is preset to operate in a first mode. The first mode can be the daytime operation of the power conversion system 100, where the power grid 400 provides power, and it is also in grid-connected operation mode. At this time, the first power source 200 (such as a photovoltaic panel) has a high power output. The power conversion device 110 controls the first power source 200 to charge the second power source 300 (such as an energy storage battery) and the third power source 620 (such as an energy storage battery), and controls the first power source 200 to supply power to the load 500. If there is any excess power, it is transferred to the power grid 400. If the demand of the load 500 cannot be met, the power grid 400 supplies power to the load 500.
[0060] If excess electrical energy is not consumed by the load 500, cannot be stored in the second power source 300 (such as an energy storage battery) and the third power source 620 (such as an energy storage battery), and cannot be transmitted to the power grid 400, then the power conversion device 110 will limit the power output of the first power source 200 (such as a photovoltaic panel).
[0061] Figure 4 This diagram illustrates the operation of a power conversion system 100 according to an embodiment of the present disclosure. In this embodiment, the power conversion system 100 is preset to operate in a second mode. This second mode can be the nighttime operation of the power conversion system 100, where the power grid 400 provides power, also in grid-connected mode. In this mode, the first power source 200 (e.g., a photovoltaic panel) does not generate power. The controller 113 collects voltage and current signals from all power ports in the power conversion system 100 to determine their corresponding status, thereby implementing appropriate power management schemes. For example, the energy stored in the second power source 300 (e.g., an energy storage battery) and the third power source 620 (e.g., an energy storage battery) can supply power to the load 500. If the demand of the load 500 cannot be met, the power grid 400 supplies power to the load 500.
[0062] Furthermore, if the power demand of load 500 is not high, it will be supplied to load 500 by the secondary power source 300 (such as an energy storage battery). This ensures that the mobile energy storage device 600 (such as an electric vehicle) has sufficient power for immediate use. If the power of the mobile energy storage device 600 is used to supply power to load 500, resulting in a higher power consumption for the mobile energy storage device 600, and the mobile energy storage device 600 needs to be used the next day, it can be charged by the power grid 400 during peak nighttime hours, thus achieving greater efficiency.
[0063] Figure 5This diagram illustrates the operation of a power conversion system 100 according to an embodiment of the present disclosure. In this embodiment, the power grid 400 is pre-stopped from supplying power, and the power conversion system 100 operates in off-grid mode. At this time, the controller 113 detects the islanding state through the sensor 115 and controls the protector 117 to disconnect the power conversion system 100 from the power grid 400. The islanding detection method can be either active or passive. Alternatively, islanding detection can be performed by collecting the voltage and frequency of the power grid 400.
[0064] In addition, the protection device 120 can also be accessed via... Figure 2 The switching of switch 121 causes the power conversion system 100 to switch from grid-connected operating mode to off-grid operating mode. This switching between grid-connected and off-grid operating modes can be performed actively by the power conversion system 100 or manually. After switching to off-grid operating mode, the power conversion system 100 can continue to supply power to the load 500 to meet emergency and continuous power needs, such as emergency lighting, refrigerators, and other household appliances.
[0065] In off-grid operation mode, i.e., the power conversion system 100 is preset to operate in the third mode, when the power of the first power source 200 (such as a photovoltaic panel) is high during the day, the power conversion device 110 controls the first power source 200 to prioritize powering the load 500. If there is excess power, it is selectively used to charge the second power source 300 (such as an energy storage battery) and the third power source 620 (such as an energy storage battery). If the excess power is not consumed by the load 500 and cannot be stored in the second power source 300 and the third power source 620, the power conversion device 110 will limit the output power of the first power source 200. In addition, if the power of the first power source 200 is insufficient to power the load 500, the second power source 300 and / or the third power source 620 can supply power to the load 500 to supplement the deficiency.
[0066] Figure 6 This diagram illustrates the operation of a power conversion system 100 according to an embodiment of the present disclosure. The power conversion system 100 is pre-operated in a third mode. In this embodiment, if the first power source 200 operates at night and cannot supply power to the load 500, the load 500 can be supplied by the second power source 300 (such as an energy storage battery) and / or the third power source 620 (such as an energy storage battery). If the power demand of the load 500 is low, the controller 113 can control the second power source 300 to prioritize supplying power to the load 500, thus ensuring that the mobile energy storage device 600 (such as an electric vehicle) retains electrical energy and is readily available for use.
[0067] Figure 7 This is a schematic diagram illustrating a power conversion system 100 according to an embodiment of this disclosure. Compared to Figure 1 The power conversion system 100 shown is... Figure 7 The sensor 115 of the power conversion system 100 is not directly electrically connected to the charging device 130. At this time, the sensor 115 indirectly collects the signal of the common node of the first converter 111 and the charging device 130, and then calculates the relevant information of the charging device 130.
[0068] Figure 8 An embodiment of this disclosure is illustrated as follows: Figure 7 This is a schematic diagram of the first converter 111 of the power conversion device 110 of the power conversion system 100 shown. As shown, the first converter 111 of the power conversion device 110 includes a first sub-converter 112, a second sub-converter 114, a DC bus 116, and a third sub-converter 118.
[0069] In one embodiment, a first sub-converter 112 is coupled to a first power supply 200 and a DC bus 116, and is used to receive and adjust the power provided by the first power supply 200 to supply the DC bus 116. For example, the first sub-converter 112 may be a unidirectional DC-DC converter, such as a boost converter, and the first power supply 200 may be a DC power supply. The unidirectional DC-DC converter 112 is used to receive the power provided by the DC power supply 200 and adapt the port voltage of the DC power supply 200 to the voltage of the DC bus 116.
[0070] In one embodiment, a second sub-converter 114 is coupled to a second power supply 300 and a DC bus 116. The second sub-converter 114 receives and adjusts the power supplied by the second power supply 300 to supply the DC bus 116, or charges the second power supply 300. For example, the second sub-converter 114 may be a bidirectional DC-DC converter, such as a dual active bridge (DAB) series resonant converter, and the second power supply 300 may be a DC power supply. The bidirectional DC-DC converter 114 receives power from the DC power supply 300 or charges the DC power supply 300, and adapts the port voltage of the DC power supply 300 to the voltage of the DC bus 116. A third sub-converter 118 is coupled to the DC bus 116, and the third sub-converter 118 is coupled to a protection device 120 via an inductor 115 and a protector 117. For example, the third sub-converter 118 can be a bidirectional DC-AC converter used to convert DC power to AC power, draw power from the grid 400, or supply power to the grid 400 or the load 500.
[0071] Figure 9 This is a schematic diagram illustrating a power conversion system 100 according to an embodiment of this disclosure. Figure 9As shown, the power conversion device 110 of the power conversion system 100 has multiple input / output ports. Two input / output ports of the power conversion device 110 are electrically connected to the first power supply 200 and the second power supply 300. Furthermore, another input / output port of the power conversion device 110 is electrically connected to the protection device 120, through which the power conversion device 110 is electrically connected to the power grid 400 and the load 500. Moreover, yet another input / output port of the power conversion device 110 is electrically connected to the charging device 130, through which the power conversion device 110 is electrically connected to the mobile energy storage device 600.
[0072] For example, the first power source 200 may be a photovoltaic power generation device, and thus, the first power source 200 may be used to convert solar energy into electrical energy and supply power to the power conversion device 110. The second power source 300 may be an energy storage battery, and thus, the second power source 300 may be used to store the electrical energy provided by the power conversion device 110 and supply power to the power conversion device 110 when needed.
[0073] Figure 1 The charging device 130 is coupled to the protector. For example, in one embodiment, the charging device 130 is coupled to the AC side of the power conversion device 110, electrically connected to the protector through the protector, and then electrically connected to the power grid 400 through the protector. Figure 9 The charging device 130 is coupled to the DC bus 116 of the power conversion device 110, so that... Figure 9 The third power supply 620 does not need to go through Figure 1 The second converter 610 converts DC power into AC power, which can then be directly connected to the power conversion device 110 via the charging device 130. Correspondingly, the controller 113 of the power conversion system 100 can directly control the state of the port connected to the charging device by measuring the current, voltage, and power signals on the DC bus 116, thereby satisfying the operating mode of the mobile energy storage device 600. In this embodiment, the charging device 130 includes a power converter, a controller, a relay or contactor, a detector, and a communicator. The charging device 130 can be a connector in the form of a DC charging gun, etc. The power converter is the power conversion part, which can realize the DC / DC conversion function, such as an auxiliary power supply.
[0074] Compared to existing solutions where the charging device is coupled to the power grid via a distribution panel, in this invention, the charging device 130 is coupled to the AC side or DC bus of the power conversion device 110, eliminating the need for charging equipment (e.g., electric vehicles) to occupy independent grid-connected capacity. The power conversion system of this invention can integrate solar energy, energy storage, and charging energy. When introducing the charging device, the installation of solar energy and energy storage devices is also considered simultaneously, thereby improving the efficiency of renewable energy use, balancing operational benefits, and mitigating the impact on the power grid.
[0075] Figure 10 An embodiment of this disclosure is illustrated as follows: Figure 9 The diagram shows a schematic of the first converter 111 of the power conversion device 110 of the power conversion system 100. As shown, the first converter 111 of the power conversion device 110 includes a first sub-converter 112, a second sub-converter 114, a DC bus 116, a third sub-converter 118, and a fourth sub-converter 119.
[0076] Compared to Figure 8 , Figure 10 The first converter 111 of the power conversion device 110 further includes a fourth sub-converter 119. The fourth sub-converter 119 is coupled to the DC bus 116 and the charging device 130. The fourth sub-converter 119 receives and adjusts the power supplied by the third power source 620 to supply the DC bus 116, or charges the third power source 620 via the charging device 130. For example, the fourth sub-converter 119 may be a bidirectional DC-DC converter, such as a dual active bridge (DAB) series resonant converter, and the third power source 620 may be a DC power source. The bidirectional DC-DC converter 119 is used to receive power supplied by the DC power source 620 or to charge the DC power source 620. In this way, Figure 10 The third power supply 620 no longer needs to go through Figure 1 The second converter 610 converts DC power into AC power, which can then be directly connected to the power conversion device 110 via the charging device 130.
[0077] Figure 11 An embodiment of this disclosure is illustrated as follows: Figure 9 A schematic diagram of the first converter 111 of the power conversion device 110 of the power conversion system 100 shown. Compared to Figure 10 , Figure 11 The first converter 111 of the power conversion device 110 further includes a sensor 121. The sensor 121 is coupled to the DC bus 116. The sensor 121 can be used to detect at least the state of the DC bus 116.
[0078] Figure 12 An embodiment of this disclosure is illustrated as follows: Figure 9 A schematic diagram of the first converter 111 of the power conversion device 110 of the power conversion system 100 shown. Compared to Figure 10 , Figure 12 The power conversion device 110 does not require a second sub-converter 114, and the power from the second power source 300 can be directly transmitted to the DC bus 116.
[0079] Figure 13 An embodiment of this disclosure is illustrated as follows: Figure 12 A detailed circuit diagram of the first converter 111 of the power conversion device 110 of the power conversion system 100 is shown. As shown, the first sub-converter 112 is coupled to the first power supply 200. The DC bus 116 can be directly coupled to the second power supply 300. The third sub-converter 118 is coupled to the DC bus 116, and the third sub-converter 118 is coupled to the protection device 120 through the sensor 115 and the protector 117. The fourth sub-converter 119 is coupled to the DC bus 116 and the charging device 130. The fourth sub-converter 119 receives and adjusts the power provided by the third power supply 620 to supply the DC bus 116 through the charging device 130, or charges the third power supply 620 through the charging device 130.
[0080] In one embodiment, the controller 113 of the first converter 111 of the power conversion device 110 can be implemented by multiple controllers, such as controllers 1111, 1112, and 1113. Controller 1111 can be used to collect signals from nodes N1, N2, and N3, and control the first sub-converter 112 and the third sub-converter 118 accordingly. Controller 1112 can be used to collect signals from nodes N4 and N5, and control the fourth sub-converter 119 accordingly. Controller 1113 is mainly used for communication, for example, it can be used to collect signals from the second power supply 300 and the third power supply 620, and communicate with controllers 1111 and 1112.
[0081] In one embodiment, the first converter 111 of the power conversion device 110 is provided at node N2 or node N5 as follows: Figure 11 The sensor 121 shown is used to detect the signal reflecting the DC bus 116 and transmit the detected signal to the controllers 1111 and 1112. At this time, the third sub-converter 118 and the fourth sub-converter 119 share the sensor 121, saving hardware costs.
[0082] When sensor 121 is installed at node N2, its detection signal is easily interfered with during transmission to the distant controller 1112. Similarly, when sensor 121 is installed at node N5, its detection signal is easily interfered with during transmission to the distant controller 1111. In another embodiment, the first converter 111 of the power conversion device 110 is installed at nodes N2 and N5 respectively as follows: Figure 11 The sensors 121 shown are used to detect signals reflecting the DC bus 116. The sensor 121 at node N2 only needs to transmit the detected signal to the nearby controller 1111, and the sensor 121 at node N2 only needs to transmit the detected signal to the nearby controller 1112, so as to avoid interference when the signal is transmitted over long distances.
[0083] Figure 14 An embodiment of this disclosure is illustrated as follows: Figure 9 The diagram shows a detailed circuit diagram of the power conversion system 100. As shown, the power conversion system includes a first sub-converter 112, a DC bus 116, a third sub-converter 118, and a fourth sub-converter 119. The first power source 200 can be a photovoltaic panel (PV), the second power source 300 can be a battery storage device (BAT), and the grid 400 can be a single-phase AC grid. The charging device 130 is a connector coupled between the mobile energy storage device (electric vehicle) and the fourth sub-converter 119 of the power conversion system 100. The first sub-converter 112 can be a unidirectional DC-DC converter, such as a boost converter. The DC bus 116 can be a capacitor C. bus The third sub-converter 118 can be a bidirectional DC-AC converter. The fourth sub-converter 119 can be a bidirectional DC-DC converter, such as a dual-active-bridge series resonant converter (DAB-SRC).
[0084] As can be seen from the above-described embodiments of this invention, applying this invention has the following advantages. The power conversion system disclosed in this invention can detect the output of the charging device through a sensor and compensate the charging device based on the detection results. Furthermore, the power conversion device can also detect each component through a sensor, and the controller can then control each component based on the detection results, thereby achieving an optimal power management scheme. Moreover, since this invention integrates the input / output ports of the power conversion device and the charging device together, the overall size and weight are reduced, thereby achieving good thermal management, simplified wiring, and other benefits.
[0085] Although the above embodiments disclose specific implementations of this case, they are not intended to limit this case. Those skilled in the art to which this case pertains can make various modifications and alterations without departing from the principles and spirit of this case. Therefore, the scope of protection of this case shall be determined by the scope defined in the appended claims.
Claims
1. A power conversion system, characterized by, Include: A power conversion device is coupled to a first power source and a second power source for receiving power supplied by the first power source and for receiving power supplied by the second power source or charging the second power source. A protection device, coupled to the power conversion device, a load, and a power grid, and used to switch the electrical connection between the power conversion device, the load, and the power grid; and A charging device is coupled to the power conversion device and a third power source, wherein the power conversion device charges the third power source through the charging device, or receives power from the third power source through the charging device. The power conversion device selects at least one of the first power source, the second power source, the third power source, and the power grid according to multiple modes to supply power to the load; In one first mode, the power conversion device supplies the power provided by the first power source to the load through the protection device, and the power conversion device supplies the power provided by the first power source to the third power source through the charging device. In a second mode, the power conversion device supplies the load with the power provided by the second power source and / or the third power source, or supplies the load with the power from the grid through the protection device; The protective device also includes: A switcher is coupled to the power conversion device, wherein the switcher is used to control the switching state between the power conversion device, the power grid and the load; A transformer is coupled to the switcher, wherein the transformer is used to achieve voltage form conversion; as well as A protector is coupled between the power grid and the switch.
2. The power conversion system of claim 1, wherein, In this first mode, the power conversion device also supplies the power provided by the first power source to the second power source.
3. The power conversion system of claim 2, wherein, In the first mode, if the power provided by the first power source is greater than the power required by the second power source, the load, and the third power source, the power conversion device supplies the power provided by the first power source to the power grid or reduces the output power of the first power source.
4. The power conversion system of claim 1, wherein, In the second mode, if the power provided by the second power source and the third power source is less than the power required by the load, the power from the grid is supplied to the load through the protection device.
5. The power conversion system of claim 1, wherein, In the second mode, if the power supplied by the second power source is greater than or equal to the power required by the load, the power conversion device supplies the power supplied by the second power source to the load.
6. The power conversion system of claim 1, wherein, In the second mode, if the third power supply causes energy loss due to power being supplied to the load, the power conversion device controls the power grid to supply the third power supply, or in the first mode, controls the first power supply to supply the third power supply.
7. The power conversion system of claim 1, wherein, In a third mode, the power conversion device controls the protection device to switch to disconnect from the power grid, and the power conversion device supplies the power provided by the first power source to the load through the protection device.
8. The power conversion system of claim 7, wherein, In the third mode, if the power provided by the first power source is greater than the power required by the load, the power conversion device supplies the power provided by the first power source to the second power source, and supplies the power provided by the first power source to the third power source through the charging device.
9. The power conversion system of claim 8, wherein, In the third mode, if the power provided by the first power source is greater than the power required by the second power source, the load, and the third power source, the output power of the first power source is reduced.
10. The power conversion system of claim 7, wherein, In the third mode, if the power provided by the first power source is less than the power required by the load, the power conversion device provides the power provided by the second power source or the third power source to the load.
11. The power conversion system of any one of claims 1 to 10, wherein, The first power source includes a photovoltaic panel.
12. The power conversion system of any one of claims 1 to 10, wherein, The second power source includes an energy storage battery.
13. The power conversion system of any one of claims 1 to 10, wherein, The third power source includes a mobile energy storage device.
14. The power conversion system of any one of claims 1 to 10, wherein, The power conversion device includes: A converter used to perform DC / DC conversion, DC / AC conversion, or AC / DC conversion.
15. The power conversion system of any one of claims 1 to 10, wherein, The power conversion device includes: A controller is used to control the protection device, thereby switching the electrical connection between the power conversion device, the load and the power grid, and communicating with the charging device to determine whether to charge the third power source through the charging device or whether to discharge the third power source through the charging device.
16. The power conversion system of claim 15, wherein, The power conversion device also includes: A sensor detects at least the state of the third power source and provides the state of the third power source to the controller.
17. The power conversion system according to any one of claims 1 to 10, characterized in that, The power conversion device also includes: A protector, in an overcurrent condition or a leakage condition, is used to disconnect from the power grid.
18. The power conversion system according to any one of claims 1 to 10, characterized in that, In an overcurrent condition or a leakage condition, the protector is used to disconnect from the power grid.
19. The power conversion system of claim 1, wherein, The power conversion device includes: A direct current busbar; A first sub-converter is coupled to the first power source and the DC bus, and is used to receive and adjust the power provided by the first power source to supply the DC bus; A second sub-converter, coupled to the second power source and the DC bus, wherein the second sub-converter is used to receive and adjust the power provided by the second power source to supply the DC bus, or to charge the second power source; and A third sub-converter is coupled to the DC bus and the protection device.
20. The power conversion system of claim 1, wherein, The power conversion device includes: A direct current busbar; A first sub-converter, coupled to the first power source and the DC bus, is used to receive and adjust the power supplied by the first power source to supply the DC bus, wherein the DC bus is coupled to the second power source; and A third sub-converter is coupled to the DC bus and the protection device.
21. The power conversion system of claim 1, wherein, The power conversion device includes a DC bus, to which the charging device is coupled.
22. The power conversion system of claim 19 or 20, wherein, The power conversion device also includes a fourth sub-converter, and the charging device is coupled to the DC bus through the fourth sub-converter. The fourth sub-converter receives and adjusts the power provided by the third power source to supply the DC bus through the charging device, or charges the third power source through the charging device.
23. The power conversion system of any of claims 19-21, wherein, The power conversion device further includes: A controller; and A sensor, coupled to the DC bus, is used to detect a signal reflecting the state of the DC bus and to provide the signal to the controller.
24. The power conversion system according to claim 22, characterized in that, The power conversion device further includes: A first controller, for controlling at least the third sub-converter; A second controller, for controlling at least the fourth sub-converter; A first sensor, coupled to the DC bus, is used to detect a signal reflecting the state of the DC bus and provide the signal to the first controller; and A second sensor, coupled to the DC bus, is used to detect a signal reflecting the state of the DC bus and to provide the signal to the second controller; The first sensor is located near the first controller, and the second sensor is located near the second controller.