Auxiliary power supply circuit and hybrid off-grid inverter
By introducing a double-pole double-throw relay and rectifier bridge structure into the hybrid grid-connected inverter, the power input switching between the grid and the diesel generator is realized, and a single AC auxiliary power supply is shared. This solves the problem of high design cost in the existing technology, reduces costs, and ensures normal inverter startup.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI PYLON TECH CO LTD
- Filing Date
- 2025-04-28
- Publication Date
- 2026-07-14
AI Technical Summary
In existing hybrid on-grid and off-grid inverter designs, two identical AC auxiliary power supplies are required to connect to the grid and the diesel generator, leading to increased design and component costs.
It adopts a double-pole double-throw relay and rectifier bridge structure, and realizes the power input switching between the grid and the diesel generator through a set of AC auxiliary power supply, which simplifies the design and allows two different power sources to be connected to the same set of AC auxiliary power supply.
This reduces design and component costs while ensuring the inverter can start normally when powered by a separate grid or a separate diesel generator, thus achieving the functional integrity of the inverter.
Smart Images
Figure CN224502929U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of hybrid grid-connected and off-grid inverter technology, and in particular to an auxiliary power supply circuit and a hybrid grid-connected and off-grid inverter. Background Technology
[0002] Hybrid grid-connected inverters can connect to various types of high-voltage power sources, including the grid, diesel generators, PV photovoltaics, and batteries. To ensure that the inverter can start and operate normally when each type of high-voltage power source is connected individually, the inverter needs to be connected to an auxiliary power supply. Specifically, in the conventional auxiliary power supply design of the inverter, the grid interface, diesel generator interface, and battery input interface all need to be connected to the subsequent DC auxiliary power supply through the corresponding auxiliary power supply to supply power to the low-voltage system. Among them, the design parameters of the AC auxiliary power supply corresponding to the diesel generator and the grid are completely identical. The cost of the AC auxiliary power supply is relatively high. Equipping the diesel generator and the grid with corresponding AC auxiliary power supplies increases the design cost and component cost. Utility Model Content
[0003] In view of this, the purpose of this application is to provide at least one auxiliary power supply circuit and a hybrid on-grid inverter. By introducing a power input switching structure that enables switching between different input power sources, two different power inputs can be connected through a single AC auxiliary power supply, simplifying the design and reducing design costs.
[0004] This application mainly includes the following aspects:
[0005] In a first aspect, embodiments of this application provide an auxiliary power supply common circuit, which includes an AC auxiliary power supply and a power input switching structure. A first AC input power supply is connected to a first switching contact of the power input switching structure, and a second AC input power supply is connected to a second switching contact and a switching sensing contact of the power input switching structure. The power output terminal of the power input switching structure is connected to the input terminal of the AC auxiliary power supply.
[0006] In one possible implementation, the power input switching structure is a double-pole double-throw relay, with the first AC input power source being the power grid and the second AC input power source being a diesel generator.
[0007] In one possible implementation, the first normally closed contact of the double-pole double-throw relay is connected to one end of the first AC input power supply, and the second normally closed contact of the double-pole double-throw relay is connected to the other end of the first AC input power supply.
[0008] In one possible implementation, the first normally open contact of the double-pole double-throw relay is connected to one end of the second AC input power supply, and the second normally open contact of the double-pole double-throw relay is connected to the other end of the second AC input power supply.
[0009] In one possible implementation, the first switching contact of the double-pole double-throw relay is connected to the first input terminal of the AC auxiliary power supply, and the second switching contact of the double-pole double-throw relay is connected to the second input terminal of the AC auxiliary power supply.
[0010] In one possible implementation, if the induction coil of the double-pole double-throw relay supports AC, then the induction coil of the double-pole double-throw relay is connected to both ends of a second AC input power supply.
[0011] In one possible implementation, the auxiliary power supply shared circuit further includes a rectifier bridge structure, wherein the induction coil of the double-pole double-throw relay supports DC, and the AC input terminal of the rectifier bridge structure is connected to a second AC input power supply; the DC output terminal of the rectifier bridge structure is connected to the induction coil of the double-pole double-throw relay.
[0012] In one possible implementation, the rectifier bridge structure includes a first diode, a second diode, a third diode, and a fourth diode, wherein the anode of the first diode is connected to the anode of the second diode and one end of the induction coil, the cathode of the first diode is connected to the anode of the third diode and the other end of the second AC input power supply, the cathode of the third diode is connected to the cathode of the fourth diode and the other end of the induction coil, and the anode of the fourth diode is connected to the cathode of the second diode and one end of the second AC input power supply.
[0013] In one possible implementation, the auxiliary power supply common circuit further includes a voltage regulator capacitor, wherein the voltage regulator capacitor is connected in parallel across the induction coil.
[0014] In one possible implementation, the hybrid grid-connected inverter includes a battery auxiliary power supply, a DC auxiliary power supply, an auxiliary power supply common circuit as provided in any of the above embodiments, and a low-voltage power supply system. The input terminal of the DC auxiliary power supply is connected to the photovoltaic input power supply, connected to the battery through the battery auxiliary power supply, and connected to the output terminal of the AC auxiliary power supply in the auxiliary power supply common circuit. The output terminal of the DC auxiliary power supply is connected to the low-voltage power supply system.
[0015] This application provides an auxiliary power supply sharing circuit and a hybrid grid-connected inverter. The auxiliary power supply sharing circuit includes an AC auxiliary power supply, a power input switching structure, a first AC input power supply, and a second AC input power supply. The first AC input power supply is connected to a first switching contact of the power input switching structure, and the second AC input power supply is connected to a second switching contact and a switching sensing contact of the power input switching structure. The power output terminal of the power input switching structure is connected to the input terminal of the AC auxiliary power supply. By introducing a power input switching structure that enables switching between different input power supplies, this application allows two different power inputs to be connected to a single AC auxiliary power supply, simplifying the design and reducing design costs.
[0016] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description
[0017] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0018] Figure 1 A schematic diagram of a traditional auxiliary power supply architecture corresponding to a hybrid on-grid and off-grid inverter is shown.
[0019] Figure 2 This paper shows a schematic diagram of the structure of a hybrid on-grid inverter provided in an embodiment of this application;
[0020] Figure 3 This illustration shows one of the structural schematic diagrams of an auxiliary power supply common circuit provided in an embodiment of this application;
[0021] Figure 4 This is a second schematic diagram of an auxiliary power supply shared circuit provided in an embodiment of this application. Detailed Implementation
[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the drawings in this application are for illustrative and descriptive purposes only and are not intended to limit the scope of protection of this application. Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of this application. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the content of this application, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.
[0023] Furthermore, the described embodiments are merely some, not all, of the embodiments of this application. The components of the embodiments of this application described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0024] Please see Figure 1 , Figure 1 A schematic diagram of a traditional auxiliary power supply architecture corresponding to a hybrid on-grid and off-grid inverter is shown. Figure 1 As shown, the high-voltage input of the hybrid grid-connected inverter includes photovoltaic power, batteries, the power grid, and a diesel generator. The traditional auxiliary power architecture corresponding to the hybrid grid-connected inverter includes a battery auxiliary power supply corresponding to the batteries, a first AC auxiliary power supply corresponding to the power grid, a second AC auxiliary power supply corresponding to the diesel generator, a DC auxiliary power supply, and a low-voltage power supply system. The photovoltaic power supply is connected to the input terminal of the DC auxiliary power supply through a corresponding unidirectional diode. The batteries are connected to the input terminal of the DC auxiliary power supply through the battery auxiliary power supply and a corresponding unidirectional diode. The power grid is connected to the input terminal of the DC auxiliary power supply through the first AC auxiliary power supply and its corresponding unidirectional diode. The diesel generator is connected to the input terminal of the DC auxiliary power supply through the second AC auxiliary power supply and its corresponding unidirectional diode. The output terminal of the DC auxiliary power supply is connected to the low-voltage power supply system. The design parameters of the first AC auxiliary power supply and the second AC auxiliary power supply are completely identical.
[0025] like Figure 1 As shown, in the existing design, two identical AC auxiliary power supplies are required to connect the power grid and the diesel generator to the subsequent circuit. Given the high cost of AC auxiliary power supplies, the existing design method increases the design cost.
[0026] Based on this, the embodiments of this application provide an auxiliary power supply sharing circuit and a hybrid on-grid and off-grid inverter. By introducing a power input switching structure that enables switching between different input power sources, two different power inputs can be connected using a single AC auxiliary power supply, simplifying the design and reducing design costs, as detailed below:
[0027] Please see Figure 2 , Figure 2 A schematic diagram of a hybrid on-grid and off-grid inverter provided in an embodiment of this application is shown. Figure 2 As shown, the hybrid grid-connected inverter provided in this application embodiment includes a battery auxiliary power supply 1, a DC auxiliary power supply 2, an auxiliary power supply common circuit 3, a low-voltage power supply system 4, and a first anti-reverse diode D. S1Second anti-reverse diode D S2 and the third anti-reverse diode D S3 .
[0028] Preferred, such as Figure 1 As shown, the photovoltaic power source passes through the first anti-reverse diode D. S1 Connected to the input terminal of DC auxiliary power supply 2, the battery passes sequentially through battery auxiliary power supply 1 and the second anti-reverse diode D. S2 Connected to the input terminal of DC auxiliary power supply 2, the output terminal of auxiliary power supply common circuit 3 is connected through the third anti-reverse diode D. S3 The DC auxiliary power supply 2 is connected to its input terminal, the DC auxiliary power supply 2 is connected to its output terminal, the low-voltage power supply system 4 is connected to its output terminal, and the low-voltage power supply system 4 is connected to its power supply load.
[0029] In this embodiment, the first input terminal of the auxiliary power supply common circuit 3 is connected to the first AC input power supply, and the second input terminal of the auxiliary power supply common circuit 3 is connected to the second AC input power supply. In one specific embodiment, the first AC input power supply is the power grid, and the second AC input power supply is a diesel generator.
[0030] Please see Figure 3 , Figure 3 This illustration shows one of the structural schematic diagrams of an auxiliary power supply common circuit provided in an embodiment of this application. For example... Figure 3 As shown, the auxiliary power supply common circuit includes an AC auxiliary power supply 31 and a power input switching structure 32. Taking the first AC input power supply as the power grid and the second AC input power supply as a diesel generator as an example, the two ends of the power grid are connected to the first switching contacts (pins ③ and ⑤) of the power input switching structure 32, the two ends of the diesel generator are respectively connected to the second switching contacts (pins ④ and ⑥) of the power input switching structure 32, and the two ends of the diesel generator are also connected to the switching sensing contacts (pins) of the power input switching structure 32. The power output terminals (pins ⑦ and ⑧) of the power input switching structure are connected to the input terminals of the AC auxiliary power supply 31.
[0031] In a preferred embodiment, such as Figure 3 As shown, the power input switching structure 32 is a double-pole double-throw relay, wherein the first normally closed contact (pin ③) of the double-pole double-throw relay is connected to one end of the power grid, and the second normally closed contact (pin ⑤) of the double-pole double-throw relay is connected to the other end of the power grid.
[0032] The first normally open contact (pin ④) of the double-pole double-throw relay is connected to one end of the diesel generator, and the second normally open contact (pin ⑥) of the double-pole double-throw relay is connected to the other end of the diesel generator.
[0033] In another preferred embodiment, the first switching contact (pin ⑦) of the double-pole double-throw relay is connected to the first input terminal of the AC auxiliary power supply 31, and the second switching contact (pin ⑧) of the double-pole double-throw relay is connected to the second input terminal of the AC auxiliary power supply 31.
[0034] like Figure 3 As shown, the induction coil of the double-pole double-throw relay supports AC, so the induction coil 321 of the double-pole double-throw relay is connected to both ends of the diesel generator. In this application, Figure 2 In the connection method shown for the induction coil, the first induction contact (pin ①) of the induction coil is connected to the other end of the diesel generator, and the second induction contact of the induction coil is connected to one end of the diesel generator.
[0035] Alternatively, in another connection method corresponding to induction coil 321 (this connection method) Figure 3 (Not shown in the image), the first sensing contact (pin ①) is connected to one end of the diesel generator, and the second sensing contact corresponding to the induction coil is connected to the other end of the diesel generator.
[0036] In another preferred embodiment, please refer to Figure 4 , Figure 4 This is a second schematic diagram of an auxiliary power supply common circuit provided in an embodiment of this application. For example... Figure 4 As shown, if the induction coil of the double-pole double-throw relay supports DC, the auxiliary power supply common circuit provided in this application also needs to be connected to the rectifier bridge structure 33 and the voltage regulator capacitor C1.
[0037] In one specific embodiment, if the induction coil of the double-pole double-throw relay supports DC, such as Figure 4 As shown, the first AC input terminal of the rectifier bridge structure 33 is connected to one end of the diesel generator, and the second AC input terminal of the rectifier bridge structure 33 is connected to the other end of the diesel generator.
[0038] The first DC output terminal of the rectifier bridge structure 33 is connected to the first sensing contact (pin ①) of the double-pole double-throw relay, and the second DC output terminal of the rectifier bridge structure is connected to the second sensing contact (pin ②) of the double-pole double-throw relay.
[0039] In another preferred embodiment, the voltage regulator capacitor C1 is connected in parallel across the first sensing contact (pin ①) and the second sensing contact (pin ②).
[0040] In a preferred embodiment, the rectifier bridge structure 33 includes a first diode DM1, a second diode DM2, a third diode DM3, and a fourth diode DM4, wherein the first diode DM1, the second diode DM2, the third diode DM3, and the fourth diode DM4 are rectifier diodes.
[0041] Preferably, the anode of the first diode DM1 is connected to the anode of the second diode DM2 and the first sensing contact (pin ①), the cathode of the first diode DM1 is connected to the anode of the third diode DM3 and the other end of the diesel generator, the cathode of the third diode DM3 is connected to the cathode of the fourth diode DM4 and the second sensing contact (pin ②), and the anode of the fourth diode DM4 is connected to the cathode of the second diode DM2 and one end of the diesel generator.
[0042] This application provides, as follows: Figure 3 or Figure 4 The auxiliary power shared circuit shown allows the same AC auxiliary power supply 31 to be reused when the power grid and diesel generator are connected to complete the machine startup.
[0043] like Figure 4 As shown, if the induction coil of the double-pole double-throw relay supports DC but not AC, the AC power output by the diesel generator is converted into DC power after passing through the rectifier bridge structure 33 and the voltage stabilizing capacitor C1, which powers the induction coil of the double-pole double-throw relay.
[0044] If the induction coil of the double-pole double-throw relay supports AC, then as follows Figure 3 As shown, the rectifier bridge structure 33 and voltage regulator C1 are omitted, and the induction coil of the double-pole double-throw relay is directly connected to both ends of the diesel generator. That is, the AC power output by the diesel generator directly powers the induction coil of the double-pole double-throw relay.
[0045] like Figure 3 or Figure 4 As shown, the power grid is connected to the first normally closed contact (pin ③) and the second normally closed contact (pin ⑤). When only the power grid is powered on, the induction coil of the double-pole double-throw relay is not powered. The first switching contact (pin ⑦) of the double-pole double-throw relay is connected to the first normally closed contact (pin ③), and the second switching contact (pin ⑧) of the double-pole double-throw relay is connected to the second normally closed contact (pin ⑤). That is, the power grid is input to the AC auxiliary power supply 31 through the first switching contact (pin ⑦) and the second switching contact (pin ⑧), and the AC auxiliary power supply 31 can work normally.
[0046] When only the diesel generator is powered on, the AC power output by the diesel generator is output to the induction coil through the rectifier bridge (if the relay supports DC) or directly to the induction coil (if the relay supports AC). After the induction coil is energized, the first switching contact (pin ⑦) switches to the first normally open contact (pin ④), and the second switching contact (pin ⑧) switches to the second normally open contact (pin ⑥). The diesel generator output is connected to the AC auxiliary power supply 31, and the AC auxiliary power supply 31 can also work normally.
[0047] As can be seen from the above, the auxiliary power supply circuit provided in this application can enable the hybrid on-grid inverter to start normally when a single grid or a single diesel generator is powered on.
[0048] The advantages of this application are:
[0049] This application enables the system to start normally when a single power grid or a single diesel generator is powered on using a double-pole double-throw relay. This saves the need for a complete AC auxiliary power supply while ensuring the complete start-up function of the hybrid on-grid inverter when a single high-voltage power supply is connected, thus reducing design and component costs.
[0050] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.
Claims
1. An auxiliary power supply circuit, characterized in that, The auxiliary power supply circuit includes an AC auxiliary power supply and a power input switching structure. The first AC input power supply is connected to the first switching contact of the power input switching structure, the second AC input power supply is connected to the second switching contact and the switching sensing contact of the power input switching structure respectively, and the power output terminal of the power input switching structure is connected to the input terminal of the AC auxiliary power supply. The power input switching structure is a double-pole double-throw relay, the first AC input power source is the power grid, and the second AC input power source is a diesel generator; The first normally closed contact of the double-pole double-throw relay is connected to one end of the first AC input power supply, and the second normally closed contact of the double-pole double-throw relay is connected to the other end of the first AC input power supply. The first normally open contact of the double-pole double-throw relay is connected to one end of the second AC input power supply, and the second normally open contact of the double-pole double-throw relay is connected to the other end of the second AC input power supply. The first switching contact of the double-pole double-throw relay is connected to the first input terminal of the AC auxiliary power supply, and the second switching contact of the double-pole double-throw relay is connected to the second input terminal of the AC auxiliary power supply. If the induction coil of the double-pole double-throw relay supports AC, then the induction coil of the double-pole double-throw relay is connected to both ends of the second AC input power supply.
2. The auxiliary power supply circuit according to claim 1, characterized in that, The auxiliary power supply circuit also includes a rectifier bridge structure. Wherein, the induction coil of the double-pole double-throw relay supports DC, and the AC input terminal of the rectifier bridge structure is connected to the second AC input power supply; The DC output terminal of the rectifier bridge structure is connected to the induction coil of the double-pole double-throw relay.
3. The auxiliary power supply circuit according to claim 2, characterized in that, The rectifier bridge structure includes a first diode, a second diode, a third diode, and a fourth diode. The anode of the first diode is connected to the anode of the second diode and one end of the induction coil, the cathode of the first diode is connected to the anode of the third diode and the other end of the second AC input power supply, the cathode of the third diode is connected to the cathode of the fourth diode and the other end of the induction coil, and the anode of the fourth diode is connected to the cathode of the second diode and one end of the second AC input power supply.
4. The auxiliary power supply circuit according to claim 2, characterized in that, The auxiliary power supply circuit also includes a voltage stabilizing capacitor. The voltage stabilizing capacitor is connected in parallel across the induction coil.
5. A hybrid grid-connected inverter, characterized in that, The hybrid on-grid inverter includes a battery auxiliary power supply, a DC auxiliary power supply, an auxiliary power supply circuit as described in any one of claims 1-4, and a low-voltage power supply system. The input terminal of the DC auxiliary power supply is connected to the photovoltaic input power supply, the battery via the battery auxiliary power supply, and the output terminal of the AC auxiliary power supply in the auxiliary power supply circuit. The output terminal of the DC auxiliary power supply is connected to the low-voltage power supply system.