New energy electric energy complementing circuit and system, electrical equipment and control method thereof

Abstract

The invention discloses a new energy electric energy complementing circuit and system, electrical equipment and a control method thereof, and belongs to the photovoltaic field. Comprising a new energy power generation module, a commercial power supply module, a rectification module and a DC / DC module. The new energy power generation module is connected with a load through the DC / DC module; the commercial power supply module is connected with a load after sequentially passing through the rectifier module and the DC / DC module; when the first voltage of the new energy power generation module is greater than the second voltage of the commercial power supply module after passing through the rectification module, the DC / DC module is used for adjusting the first voltage as the target voltage of the load; and when the first voltage is smaller than or equal to the second voltage, the DC / DC module is used for increasing the power factor of the load. According to the scheme, the new energy power generation module and the commercial power supply module share one DC / DC module to be connected with the load, there is no need to provide a component for each of the new energy power generation module and the commercial power supply module, and the cost is greatly reduced while it is ensured that functions are not changed.

Description

Technical Field

[0001] The present application relates to the field of photovoltaic technology, and in particular, to a new energy electric energy replenishment circuit, system, electrical equipment and a control method thereof. Background Art

[0002] There are two main types of mainstream photovoltaic air conditioners on the market. One is a photovoltaic air conditioner with grid-connected function. In addition to supplying energy to the air conditioner, the excess energy can be fed into the power grid. The other is a photovoltaic air conditioner without grid-connected function. The photovoltaic energy is only used to replenish the air conditioner and cannot be fed into the grid.

[0003] For grid-connected photovoltaic air conditioners, due to the addition of inverter functions and the need to meet relevant grid-connected standards of the power grid, more functional and safety modules need to be added, which increases a lot of costs and causes high costs for grid-connected air conditioners. For non-grid-connected photovoltaic air conditioners, the cost is greatly reduced compared to air conditioners with grid-connected functions. In addition to the cost of the air conditioning part, only a DC / DC module and its voltage and current sampling need to be added to realize the direct connection of the output of the photovoltaic control DC / DC module to the DC bus of the air conditioning control board.

[0004] Common connection topologies of non-grid-connected photovoltaic air conditioners are as follows: Figure 1 As shown, the output of the photovoltaic module is connected to the main control board through a DC chopper, and the AC power supply is connected to the PFC circuit (power factor correction circuit) after passing through the rectifier module, and the PFC circuit is then connected to the main control board.

[0005] However, in the current situation, the photovoltaic and AC power connection main control boards each require a component, which is relatively costly. Summary of the invention

[0006] In order to overcome the deficiencies of the prior art, the present application provides a new energy electric energy replenishment circuit, system, electrical equipment and control method thereof to solve the problem that the existing photovoltaic energy replenishment requires a component each when the photovoltaic and AC power are connected to the load, resulting in high cost.

[0007] The technical solution adopted by this application to solve its technical problem is:

[0008] In a first aspect, a new energy electric energy replenishment circuit is provided, comprising: a new energy power generation module, a mains power supply module, a rectifier module and a DC / DC module;

[0009] The new energy power generation module is connected to the load through the DC / DC module;

[0010] The mains power supply module is connected to the load after passing through the rectifier module and the DC / DC module in sequence;

[0011] When the first voltage of the new energy power generation module is greater than the second voltage of the mains power supply module after passing through the rectifier module, the DC / DC module is used to adjust the first voltage to the target voltage of the load;

[0012] When the first voltage is less than or equal to the second voltage, the DC / DC module is used to improve the power factor of the load.

[0013] Furthermore, the DC / DC module includes any one of the following:

[0014] BOOST circuit and BUCK-BOOST circuit.

[0015] Furthermore, the new energy power generation module includes any one of the following:

[0016] Photovoltaic power generation system and wind power generation system.

[0017] Furthermore, the rectifier module includes a rectifier bridge circuit.

[0018] Furthermore, an anti-backflow component is provided between the new energy power generation module and the DC / DC module;

[0019] The anti-backflow component is used to prevent the current of the commercial power supply module from flowing into the new energy power generation module.

[0020] In a second aspect, a new energy electric energy replenishment system is provided, comprising a circuit as described in any one of the technical solutions of the first aspect.

[0021] In a third aspect, an electrical device is provided, comprising the above-mentioned new energy electric energy replenishment system.

[0022] In a fourth aspect, a new energy electric energy replenishment circuit control method is provided, which is applied to the circuit described in any one of the technical solutions of the first aspect, and the method comprises:

[0023] Obtaining a first voltage output by the new energy power generation module and a second voltage output by the mains power supply module after passing through the rectifier module;

[0024] determining a control strategy for a DC / DC module based on the first voltage and the second voltage;

[0025] Obtaining a target duty cycle of the switch tube in the DC / DC module based on the control strategy;

[0026] The switch tube is controlled according to the target duty cycle.

[0027] Further, determining a control strategy of a DC / DC module based on the first voltage and the second voltage includes:

[0028] When the first voltage is greater than the second voltage, it is determined that the control strategy of the DC / DC module is a first control strategy, and the first control strategy is used to control the DC / DC module to adjust the first voltage to the target voltage of the load.

[0029] Further, determining a control strategy of a DC / DC module based on the first voltage and the second voltage includes:

[0030] When the first voltage is less than or equal to the second voltage, the control strategy of the DC / DC module is determined to be a second control strategy, and the second control strategy is used to control the DC / DC module to improve the power factor of the load.

[0031] Beneficial effects:

[0032] The technical solution of the present application provides a new energy electric energy replenishment circuit, system, electrical equipment and control method thereof. It includes a new energy power generation module, a mains power supply module, a rectifier module and a DC / DC module; the new energy power generation module is connected to the load through a DC / DC module; the mains power supply module is connected to the load after passing through a rectifier module and a DC / DC module in turn; when the first voltage of the new energy power generation module is greater than the second voltage of the mains power supply module after passing through the rectifier module, the DC / DC module is used to adjust the first voltage to the target voltage of the load; when the first voltage is less than or equal to the second voltage, the DC / DC module is used to improve the power factor of the load. That is, in the solution of the present application, the new energy power generation module and the mains power supply module share a DC / DC module to connect the load, and there is no need to provide a component for the new energy power generation module and the mains power supply module respectively, which greatly reduces the cost while ensuring that the functions remain unchanged. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 This is a schematic diagram of the connection topology structure of a common non-grid-connected photovoltaic air conditioner provided in an embodiment of the present application;

[0035] Figure 2 This is a schematic diagram of a new energy electric energy replenishment circuit structure provided in an embodiment of the present application;

[0036] Figure 3 This is a schematic diagram of the connection topology structure of a non-grid-connected photovoltaic air conditioner provided in an embodiment of the present application;

[0037] Figure 4 This is a basic circuit diagram of a new energy electric energy supplement air conditioner provided by this application;

[0038] Figure 5 This is a circuit schematic diagram of a non-grid-connected photovoltaic air conditioner provided in an embodiment of the present application;

[0039] Figure 6 It is a flow chart of a new energy electric energy replenishment circuit control method provided in an embodiment of the present application;

[0040] Figure 7 This is a specific flow chart of a new energy electric energy replenishment circuit control method provided in an embodiment of the present application;

[0041] Figure 8 It is a schematic diagram of a first voltage greater than a second voltage provided by an embodiment of the present application;

[0042] Fig. 9 This is a schematic diagram of a first voltage portion being greater than a second voltage provided by an embodiment of the present application. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme of the present application is described in detail below in conjunction with the accompanying drawings and embodiments. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other implementation methods obtained by ordinary technicians in the field without making creative work belong to the scope of protection of the present application.

[0044] Commonly used new energy power generation methods include photovoltaic power generation and wind power generation. Although they are relatively clean, they have the problem of relatively fluctuating power generation. Therefore, when using new energy electricity, it is necessary to combine it with municipal electricity for auxiliary power supply.

[0045] It should be noted that the loads in this application are generally high-power loads, because low-power loads do not require PFC circuits for power improvement. In addition, for some resistive loads, since no reactive power is generated, a PFC circuit is not required.

[0046] To solve this problem, refer to Figure 2 The embodiment of the present application provides a new energy electric energy replenishment circuit, including: a new energy power generation module, a mains power supply module, a rectifier module and a DC / DC module; wherein the new energy power generation module includes any one of the following: a photovoltaic power generation system and a wind power generation system; the DC / DC module includes any one of the following: a BOOST circuit and a BUCK-BOOST circuit.

[0047] The new energy power generation module is connected to the load through the DC / DC module. Preferably, an anti-backflow component is provided between the new energy power generation module and the DC / DC module. The anti-backflow component is used to prevent the current of the mains power supply module from flowing into the new energy power generation module. Exemplarily, the anti-backflow component is a diode.

[0048] The mains power supply module is connected to the load through the rectifier module and the DC / DC module in sequence, wherein the rectifier module includes a rectifier bridge circuit.

[0049] When the first voltage of the new energy power generation module is greater than the second voltage of the mains power supply module after passing through the rectifier module, the DC / DC module is used to adjust the first voltage to the target voltage of the load;

[0050] When the first voltage is less than or equal to the second voltage, the DC / DC module is used to improve the power factor of the load.

[0051] Figure 4 A basic circuit diagram of a new energy electric energy supplement air conditioner is given. The following provides a load as a photovoltaic air conditioner and a new energy power generation module as a photovoltaic power generation system. Figure 3 As shown in the figure, the output of the photovoltaic module and the rectified mains power supply output are connected to the DC / DC module respectively, and the output of the DC / DC module is connected to the air conditioner main control board, and then flows into the subsequent load (compressor, DC fan and switching power supply). The DC / DC module contains a switch tube, and the control of the photovoltaic or PFC is achieved by controlling the switch tube.

[0052] Figure 5 The DC / DC module is a specific structure of a BOOST circuit. After the grid voltage is rectified by diodes D1 to D4, it is connected to the BOOST circuit (a type of DC / DC circuit, commonly used in air conditioners) inductor L. At the same time, the positive pole of the photovoltaic output is connected to diode D6 to prevent the grid current from flowing back into the photovoltaic panel. The output of diode D6 is connected to the inductor L. One end of the inductor L output is simultaneously connected to the switch tube Q1 and the diode D5. The inductor L, the switch tube Q1 and the diode D5 constitute the only BOOST circuit of this air conditioning system. The output of diode D5 is connected to capacitor C1, which is used to stabilize the DC bus and provide energy for subsequent loads.

[0053] The innovation of the new energy electric energy replenishment circuit of the embodiment of the present application lies in: combining the power devices used for photovoltaic DC / DC and grid PFC into one, and adopting a high voltage priority control strategy to achieve low-cost non-grid-connected photovoltaic air conditioning.

[0054] The new energy electric energy replenishment circuit provided in the embodiment of the present application includes a new energy power generation module, a mains power supply module, a rectifier module and a DC / DC module; the new energy power generation module is connected to the load through the DC / DC module; the mains power supply module is connected to the load after passing through the rectifier module and the DC / DC module in turn; when the first voltage of the new energy power generation module is greater than the second voltage of the mains power supply module after passing through the rectifier module, the DC / DC module is used to adjust the first voltage to the target voltage of the load; when the first voltage is less than or equal to the second voltage, the DC / DC module is used to improve the power factor of the load. That is, in the scheme of the present application, the new energy power generation module and the mains power supply module share a DC / DC module to connect the load, and there is no need to provide a component for the new energy power generation module and the mains power supply module respectively, which greatly reduces the cost while ensuring the function remains unchanged.

[0055] Based on the same inventive concept, an embodiment of the present application provides a new energy electric energy replenishment system, including the new energy electric energy replenishment circuit provided in the above embodiment.

[0056] The new energy electric energy replenishment system provided by the embodiment of the present application includes the new energy electric energy replenishment circuit provided by the above embodiment. The new energy power generation module and the mains power supply module share a DC / DC module to connect the load. It is not necessary to provide a component for the new energy power generation module and the mains power supply module respectively. When the first voltage of the new energy power generation module is greater than the second voltage of the mains power supply module after passing through the rectifier module, the DC / DC module is used to adjust the first voltage to the target voltage of the load; when the first voltage is less than or equal to the second voltage, the DC / DC module is used to improve the power factor of the load. While ensuring that the function remains unchanged, the cost is greatly reduced.

[0057] Based on the same inventive concept, an embodiment of the present application provides an electrical device, including the new energy electric energy replenishment system provided in the above embodiment.

[0058] Based on the same inventive concept, Figure 6 As shown, an embodiment of the present application provides a new energy electric energy replenishment circuit control method, which is applied to the new energy electric energy replenishment circuit provided in the above embodiment, and the method includes:

[0059] S11: Obtain a first voltage output by the new energy power generation module and a second voltage output by the mains power supply module after passing through the rectifier module.

[0060] S12: Determine a control strategy of a DC / DC module based on the first voltage and the second voltage.

[0061] S13: Obtaining a target duty cycle of the switch tube in the DC / DC module based on the control strategy.

[0062] S14: Control the switch tube according to the target duty cycle.

[0063] Wherein, determining a control strategy of a DC / DC module based on the first voltage and the second voltage includes:

[0064] When the first voltage is greater than the second voltage, it is determined that the control strategy of the DC / DC module is a first control strategy, and the first control strategy is used to control the DC / DC module to adjust the first voltage to the target voltage of the load.

[0065] When the first voltage is less than or equal to the second voltage, the control strategy of the DC / DC module is determined to be a second control strategy, and the second control strategy is used to control the DC / DC module to improve the power factor of the load.

[0066] like Figure 7 As shown, the present application provides a specific new energy electric energy replenishment circuit control method, Figure 5 Taking the circuit shown as an example for specific explanation, after receiving the power-on request, the photovoltaic voltage Vpv and the rectified grid voltage Vac are sampled in real time. The control loop decides to run the photovoltaic control or PFC control algorithm according to the high and low voltages of the two, and outputs the duty cycle to control the switch action to complete the input energy control of the air conditioner.

[0067] Photovoltaic energy is a supplement to the energy required by air conditioners, but it is unstable due to the influence of light, temperature, etc. When the photovoltaic output voltage is high, photovoltaic energy is used first to save electricity. When the light intensity decreases or the load increases, if the energy supplied by the photovoltaic side is not enough to maintain the load, its output voltage will drop. When the photovoltaic voltage is lower than the mains voltage, the energy of the power grid is used to supply the air conditioner load, and PFC control is executed at this time.

[0068] Among them, Figure 8 As shown in the figure, the photovoltaic voltage Vpv is greater than the grid voltage Vac. At this time, the grid voltage is clamped by the rectifier bridge composed of diodes D1 to D4, and the grid current cannot flow into the inductor L. At this time, only the photovoltaic output current can flow into the inductor L. At this time, it is only necessary to control the switch tube Q1 according to the photovoltaic control algorithm to stabilize the output voltage of the capacitor C1.

[0069] Fig. 9This is another possible situation of the embodiment of the present application, where the photovoltaic voltage Vpv is partially greater than the grid voltage Vac. Tpv indicates that the photovoltaic voltage Vpv is greater than the grid voltage Vac during this period of time. At this time, the grid voltage is clamped by the rectifier bridge composed of diodes D1 to D4, and the current flowing into the inductor L is the photovoltaic side current. In this case, the photovoltaic control algorithm is executed during this period of time; Tac indicates that the grid voltage Vac is greater than the photovoltaic voltage Vpv during this period of time. At this time, the photovoltaic side voltage is clamped by the diode D5, and the current flowing into the inductor is the grid side current. In this case, the PFC control algorithm is executed during this period of time.

[0070] When the photovoltaic power is high, using PFC control is equivalent to ordinary air conditioning. The photovoltaic energy is not used, which is wasteful and uneconomical.

[0071] There is another possible situation, that is, there is no power on the photovoltaic side. This state is no different from a normal air conditioner, that is, the air conditioner load energy is completely provided by the power grid, and the switch tube also operates according to the PFC control algorithm.

[0072] The embodiment of the present application combines the PFC circuit used in the power grid and the DC / DC circuit used in photovoltaic into one, and combines a unique control algorithm to further reduce the cost of the photovoltaic air conditioning system on the basis of realizing the photovoltaic air conditioning function. Taking a 1.5P air conditioner as an example, reducing a set of DC / DC can reduce the cost by about 25 yuan. The greater the power of the whole machine, the more obvious the cost reduction is.

[0073] It should be noted that, in the description of this application, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" refers to at least two.

[0074] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

Claims

1. A new energy electric energy replenishment circuit, characterized in that: include: New energy power generation module, mains power supply module, rectifier module and DC / DC module; The new energy power generation module is connected to the load through the DC / DC module; The mains power supply module is connected to the load after passing through the rectifier module and the DC / DC module in sequence; When the first voltage of the new energy power generation module is greater than the second voltage of the mains power supply module after passing through the rectifier module, the DC / DC module is used to adjust the first voltage to the target voltage of the load; When the first voltage is less than or equal to the second voltage, the DC / DC module is used to improve the power factor of the load.

2. The circuit according to claim 1, characterized in that: The DC / DC module includes any one of the following: BOOST circuit and BUCK-BOOST circuit.

3. The circuit according to claim 1, characterized in that: The new energy power generation module includes any one of the following: Photovoltaic power generation system and wind power generation system.

4. The circuit according to claim 1, characterized in that: The rectifier module includes a rectifier bridge circuit.

5. The circuit according to claim 1, characterized in that: An anti-backflow component is provided between the new energy power generation module and the DC / DC module; The anti-backflow component is used to prevent the current of the commercial power supply module from flowing into the new energy power generation module.

6. A new energy electric energy replenishment system, characterized in that: Comprising a circuit as claimed in any one of claims 1 to 5.

7. An electrical device, characterized in that: Including the new energy electric energy replenishment system as described in claim 6.

8. A new energy electric energy replenishment circuit control method, characterized in that: Applied to the circuit according to any one of claims 1 to 5, the method comprises: Obtaining a first voltage output by the new energy power generation module and a second voltage output by the mains power supply module after passing through the rectifier module; determining a control strategy for a DC / DC module based on the first voltage and the second voltage; Obtaining a target duty cycle of the switch tube in the DC / DC module based on the control strategy; The switch tube is controlled according to the target duty cycle.

9. The method according to claim 8, characterized in that: The determining a control strategy of the DC / DC module based on the first voltage and the second voltage includes: When the first voltage is greater than the second voltage, it is determined that the control strategy of the DC / DC module is a first control strategy, and the first control strategy is used to control the DC / DC module to adjust the first voltage to the target voltage of the load.

10. The method according to claim 8, characterized in that The determining a control strategy of the DC / DC module based on the first voltage and the second voltage includes: When the first voltage is less than or equal to the second voltage, the control strategy of the DC / DC module is determined to be a second control strategy, and the second control strategy is used to control the DC / DC module to improve the power factor of the load.

Images