Power supply system for electrical devices

Abstract

Power supply system for electrical equipment, characterized in that it comprises the following: an energy manager with an input end connected to a power generation module and an output end connected to a DC bus; at least one inverter assembly, the inverter assembly comprising a rectifier module and an inverter module; the rectifier module having an input end connected to a supply network to rectify AC load power into a DC voltage and output the DC voltage to the DC bus; the inverter module having an input end connected to the DC bus and an output end that outputs AC power to supply power to a load device; wherein the energy manager is configured with an energy management strategy which includes: regulating power coming in from the supply network according to the power generated by the power generation module in order to maintain a DC bus voltage within a preset range to supply power to the consumer device.

Description

AREA OF TECHNOLOGY

[0001] The present application relates to the field of power supply technology and in particular to a power supply system for electrical equipment and a control method thereof. BACKGROUND

[0002] With the changing global energy landscape, renewable energy has become a key area of ​​development for household appliances. For example, photovoltaic air conditioning systems typically integrate solar panels with an outdoor unit of an air conditioner or mount solar panels in a space surrounding the outdoor unit. This allows the power generated by the solar panels to be used when the air conditioner is operating, effectively reducing energy consumption and achieving energy savings and emission reduction goals. Meanwhile, photovoltaic air conditioning systems feed direct current (DC) power generated by the photovoltaic panels directly into the air conditioner.However, existing installed air conditioning systems can only receive alternating current (AC), which means that existing installed air conditioning systems are not able to be directly connected to photovoltaic power generation systems, and existing installed air conditioning systems must be modified before connection, or consumers must purchase new photovoltaic air conditioning systems and build off-grid inverter systems, which significantly increases the modification costs for consumers.

[0003] An off-grid inverter system generally cannot directly power loads without batteries or operate in grid-connected power management mode. Without batteries, the off-grid inverter system switches directly to grid power supply when photovoltaic energy is insufficient. Configuring energy storage devices can fully utilize photovoltaic energy, but requires significant investment. Furthermore, without energy storage devices, switching to grid power supply when photovoltaic energy is insufficient (non-hybrid operation) results in a substantial waste of photovoltaic energy. SUMMARY

[0004] One objective of the present application is to provide a power supply system for electrical equipment and a control procedure thereof in order to solve the aforementioned problems.

[0005] To accomplish the above task, a technical solution is required, which is used in the present application: a power supply system for electrical devices, including: an energy manager with an input end connected to a power generation module and an output end connected to a DC bus; at least one inverter assembly, and the inverter assembly includes a rectifier module and an inverter module; the rectifier module has an input end connected to a supply network to rectify AC consumer power into a DC voltage and output the DC voltage to the DC bus; the inverter module has an input end connected to the DC bus and an output end that outputs AC power to supply power to a consumer device.

[0006] A power management strategy is configured in the power manager, which includes: regulating power coming in from the supply network according to the power generated by the power generation module, in order to maintain a DC bus voltage within a preset range to supply power to the consumer device.

[0007] Furthermore, the power manager is configured to execute a maximum power point tracking control strategy or a maximum current control strategy to keep the DC bus voltage within the preset range.

[0008] Furthermore, if the power generated by the power generation module is greater than or equal to the power required by the consumer device, the maximum power point tracking control strategy is executed below the preset voltage range of the DC bus; and if the energy generated by the power generation module is less than the power required by the consumer device, the maximum current control strategy is executed.

[0009] Furthermore, if the Maximum Power Point Tracking control strategy is executed below the preset DC bus voltage range, a DC voltage value output to the DC bus by the power manager is greater than a voltage value output to the DC bus after rectification of the supply network.

[0010] Furthermore, if the Maximum Power Point Tracking control strategy is executed below the preset DC bus voltage range, a constant voltage control strategy is executed if the DC bus voltage exceeds the preset range.

[0011] Furthermore, a DC-DC module is configured in the system, one end of the DC-DC module is connected to an energy storage module and another end of the DC-DC module is connected to the DC bus; The energy storage module is configured to store excess energy generated by the power generation module when the power generated by the power generation module is greater than or equal to the power required by the consumer device; and to output a DC voltage to the DC bus to maintain the DC bus voltage within the preset range when the power generation module cannot generate power.

[0012] The present application also provides a supply tax procedure for electrical equipment, which includes the following: Monitoring the power output of a power generation module in real time; If the power generated by the power generation module is greater than or equal to the power required by a consumer device, maintain a DC voltage value output by a power manager to a DC bus to be greater than a voltage value output to the DC bus after rectification of a supply network; If the power generated by the power generation module is less than the power required by the consumer device, regulate the power coming in from the mains supply to maintain a DC bus voltage within a preset range for the power supply to the consumer device.

[0013] Furthermore, a maximum power point tracking control strategy or a maximum current control strategy is executed to keep the voltage of the DC bus within the preset range.

[0014] Furthermore, if a maximum power point tracking control strategy is executed, a constant voltage control strategy is executed when the voltage of the DC bus exceeds the preset range.

[0015] Furthermore, the procedure includes: in response to the detection that the power generation module cannot generate power, directly connecting the supply network to the consumer device so that AC power coming in from the supply network powers the consumer device.

[0016] Compared with the prior art, the present application includes at least the following advantageous effects: (1) An inverter assembly is added to the electrical equipment power supply system, and the DC bus voltage is converted by the inverter assembly into AC power and delivered to a consumer appliance, so that existing household appliances can be directly connected to a clean energy generation system, such as a photovoltaic power generation system, without increasing the cost of modifying the household appliances; and all multiple inverter assemblies in the electrical equipment power supply system share an energy microgrid, and energy generated by the power supply flows freely in the energy microgrid. If power generated by clean energy cannot meet the operation of the entire system, the power is supplemented by AC power.Within a well-established microgrid for clean energy, energy can flow freely, enabling household appliances to fully utilize clean energy. (2) The system can regulate an output ratio between energy generated by a power generation module and grid energy according to an actual demand for power generation, so that the energy generated by the power generation module is fully utilized, thereby reducing the waste of photovoltaic energy and lowering costs; (3) An energy storage module is added to the system to be charged and to store excess energy generated when the power generation module supplies sufficient power to a consumer device, and to be discharged to supply power when the power generation module does not supply sufficient power to the consumer device, thereby ensuring that the operation of the consumer device is not affected when the power generation energy is insufficient, maximizing the utilization of energy generated by power generation, and achieving the integration of power generation with clean energy, usage energy, and energy storage through a microgrid; (4) If the power generation module cannot generate power, the system can connect an AC input of the supply network directly to the consumer device, so that the supply network directly supplies power to the consumer device, thereby reducing conversion losses. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] To more clearly illustrate the technical solutions in specific embodiments of the present application or the prior art, the drawings necessary to describe these specific embodiments or the prior art are briefly presented below. Obviously, the drawings in the following description represent some embodiments of the present application. However, a person skilled in the art can easily derive other drawings from these. Fig. Figure 1 is a schematic representation of a power supply system for electrical devices according to one embodiment; Fig. Figure 2 is a topology representation of a power supply system architecture of a photovoltaic microgrid according to one embodiment; Fig. Figure 3 is a topology representation of another architecture of a power supply system of a photovoltaic microgrid according to one embodiment; and Fig. Figure 4 is a flowchart of steps of a power supply control procedure for electrical equipment according to one embodiment. DETAILED DESCRIPTION OF THE EXECUTION FORMS

[0018] The following are specific embodiments of the present application and technical solutions of the present application are described in more detail in conjunction with the drawings; however, the present application is not limited to these embodiments.

[0019] As in Fig. As shown in Figure 1, the embodiment provides a power supply system for electrical equipment, comprising: a power generation module, at least one inverter assembly and a power manager.

[0020] The power manager has an input end connected to the power generation module and an output end connected to a DC bus. The inverter assembly includes a rectifier module and an inverter module. The rectifier module has an input end connected to a utility grid to rectify AC power to a DC voltage and output the DC voltage to the DC bus. The inverter module has an input end connected to the DC bus and an output end that provides AC power to a consumer device.

[0021] The power generation module can be a photovoltaic power generation module, a wind power generation module, or other modules that generate power using clean energy.

[0022] The inverter assembly can be independent. If it is necessary to supply power to multiple devices, only one needs to increase the number of inverter assemblies and connect its input terminals directly to the DC bus.

[0023] Meanwhile, a power management strategy is configured in the power manager and includes the following: regulating the power received from the grid according to the power generated by the power generation module to maintain a DC bus voltage within a preset range to supply power to the consumer device. The power management strategy configured in the power manager regulates the output ratio between power generated by the power generation module and grid power through energy management to preferentially utilize the power generated by the power generation module, thereby ensuring full energy utilization and reducing costs.

[0024] Meanwhile, if the power generation module is unable to generate power, the system can cause the supply network to be connected directly to the consumer device without rectifying the AC input, and power to the consumer device directly, thereby reducing conversion losses.

[0025] Furthermore, using the photovoltaic power generation mode as an example, it includes, as in Fig. Figure 2 shows a schematic representation of the architecture of a power supply system of a photovoltaic microgrid provided by this embodiment, the power supply system of a photovoltaic microgrid: a photovoltaic module, a power manager (corresponding to MPPT1 and MPPT2 in the figure) and an inverter assembly.

[0026] The input end of the power manager is connected to the photovoltaic module, and its output end is connected to a DC bus. The inverter assembly comprises a rectifier module and an inverter module. One input end of the rectifier module is connected to a power supply to rectify AC power to DC voltage and output the DC voltage to the DC bus. One input end of the inverter module is connected to the DC bus, and one output end of the inverter module provides AC power to supply a load.

[0027] Meanwhile, a power management strategy is configured in the power manager and can regulate the power input from the supply network according to the power generated by the power generation module in order to maintain a DC bus voltage within a preset range to supply power to the consumer device.

[0028] Specifically, the energy manager can process the power generated by the photovoltaic module while performing Maximum Power Point Tracking (MPPT), output a DC voltage value to the DC bus that is higher than the voltage value supplied by the power grid after rectification, so that photovoltaic power is preferentially used to supply power to the consumer device.

[0029] Due to the uncertainty of the power levels of household appliance consumers, the energy management strategy configured in the energy manager should execute either a Maximum Power Point Tracking (MPPT) control strategy or a Maximum Current control strategy to keep the voltage of the DC bus within a preset range.

[0030] If the power generated by the photovoltaic module is greater than or equal to the power required by the consumer device, the maximum power point tracking control strategy is executed below the preset voltage range of the DC bus; and if the energy generated by the photovoltaic module is less than the power required by the consumer device, the maximum current control strategy is executed.

[0031] Furthermore, if the Maximum Power Point Tracking control strategy is executed below the preset DC bus voltage range, a constant voltage control strategy is executed if the DC bus voltage exceeds the preset range.

[0032] When photovoltaic energy is sufficient, that is, when there is excess solar energy, the DC bus is controlled with constant voltage (voltage stabilization) and a photovoltaic module is controlled in such a way that it outputs energy based on a given voltage value of the DC bus.However, if the voltage exceeds the voltage after rectification of the supply network by a certain amount, the voltage after rectification of the supply network is limited within a threshold voltage range, thus preventing an overvoltage of the DC bus caused by excess solar energy when the power required by the consumer device is low; if the voltage does not exceed the voltage after rectification of the supply network, Maximum Power Point Tracking control is carried out, that is, the MPPT control strategy in the energy manager fully utilizes photovoltaic energy, thereby reducing waste of photovoltaic energy and lowering costs.

[0033] If photovoltaic energy is insufficient, the energy manager executes the maximum current control strategy, and the maximum current control strategy ensures that if the power required by the consumer device is large and the power generated by a photovoltaic module is insufficient, the energy manager can still control the output current to provide energy to the consumer device.

[0034] Furthermore, the embodiment as described in Fig. Figure 3 shows, and also provides a schematic representation of a system architecture, including a schematic representation of a system architecture in comparison to Fig.2. Furthermore, an energy storage module. Meanwhile, a DC-DC module is configured in the system, with one end of the DC-DC module connected to the energy storage module and another end connected to the DC bus. The DC-DC module can be located independently in the system or integrated into a power manager, and power transfer between the energy storage modules and the DC bus can be carried out by means of a DC-DC conversion.

[0035] The energy storage module is configured to store excess energy generated by a photovoltaic module when the power generated by the power generation module is greater than or equal to the power required by a consumer device; and to output a DC voltage to the DC bus to maintain the DC bus voltage within a preset range when the photovoltaic module cannot generate power.

[0036] In this system architecture, an energy storage module is added to be charged and store excess power generated when the photovoltaic module supplies sufficient power to a consumer device, and to be discharged to supply power when the photovoltaic module does not supply sufficient power to the consumer device, thus ensuring that the operation of the consumer device is not affected when the photovoltaic energy is insufficient, thereby achieving maximum utilization of the photovoltaic energy.

[0037] This embodiment also provides a power supply control procedure for a photovoltaic microgrid, which includes the following steps: S1, Monitoring of power output by a power generation module in real time; S2, if the power generated by the power generation module is greater than or equal to the power required by a consumer device, maintaining a DC voltage value output by a power manager to a DC bus such that it is greater than a voltage value output to the DC bus after rectification of a supply network; S3, if the power generated by the power generation module is less than the power required by the consumer device, regulates the power coming in from the mains supply to maintain a DC bus voltage within a preset range for the power supply to the consumer device.

[0038] A maximum power point tracking control strategy or a maximum current control strategy is executed to keep the voltage of the DC bus within the preset range.

[0039] When photovoltaic energy is sufficient, that is, when there is excess solar energy, the DC bus is controlled with constant voltage (voltage stabilization) and the photovoltaic module is controlled in such a way that it outputs energy based on a given voltage value of the DC bus.However, if the voltage exceeds the voltage after rectification of the supply network by a certain amount, the voltage after rectification of the supply network is limited within a threshold voltage range, thus preventing an overvoltage of the DC bus caused by excess solar energy when the power required by the consumer device is low; if the voltage does not exceed the voltage after rectification of the supply network, maximum power point tracking control is carried out, that is, through an MPPT control strategy in an energy manager, photovoltaic energy is fully utilized, thereby reducing waste of photovoltaic energy and lowering costs.

[0040] If photovoltaic energy is insufficient, the energy manager executes the maximum current control strategy, and the maximum current control strategy ensures that if the power required by the consumer device is large and the power generated by a photovoltaic module is insufficient, the energy manager can still control the output current to provide energy to the consumer device.

[0041] For this reason, the control method provided by this embodiment can regulate an output ratio between the energy generated by the power generation module and grid energy according to an actual demand for photovoltaic power generation, so that the energy generated by the power generation module is fully utilized, thereby reducing energy waste and lowering costs.

[0042] Meanwhile, if the power generation module is unable to generate power, this control method can cause the supply network to be directly connected to the consumer device, so that AC power coming in from the supply network directly supplies power to the consumer device, thereby reducing conversion loss.

[0043] It should be noted that all directional terms (such as up, down, left, right, front, back, etc.) in the embodiments of the present application are used only to explain a relative positional relationship, conditions of movement, etc., between different components in a specific position (as shown in the drawings). If the specific position changes, the directional term changes accordingly.

[0044] Furthermore, in this application, descriptions including "first," "second," "a," etc., are used for descriptive purposes only and are not to be understood as indicating or implying the relative importance of the technical features or implicitly indicating the number of technical features specified. Thus, features defined as "first" and "second" may explicitly or implicitly include at least one such feature. In the description of this application, "a plurality of" means at least two, for example, two, three, etc., unless otherwise clearly and specifically defined.

[0045] In the present application, terms such as "connection" and "fastening" are to be understood in a broad sense, unless otherwise clearly specified and defined. For example, "fastening" may be a permanent connection, a detachable connection, or an integral connection; the connection may be a mechanical connection or an electrical connection; the connection may be a direct connection or an indirect connection through an intermediate medium, or an internal communication between two elements, or an interaction relationship between two elements, unless otherwise clearly defined. The specific meaning of the aforementioned terms in the present application may be understood by the person skilled in the art according to the specific situations.

[0046] Furthermore, technical solutions from different embodiments of the present application can be combined, but the combination must be based on what can be achieved by a person skilled in the art. If a combination of technical solutions is contradictory or cannot be achieved, it must be taken into account that such a combination of technical solutions does not exist and is not within the scope of protection claimed by the present application.

[0047] The specific embodiments described in this document merely illustrate the spirit of the present application. A person skilled in the art in the field to which the present application belongs may make various modifications or additions to the described specific embodiments or use similar alternatives, but such modifications, additions, or similar alternatives shall not deviate from the spirit of the present application and shall not exceed the scope defined by the appended claims.

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