A fast-response electronic load circuit and fuel cell system

Abstract

The utility model provides a fast-response electronic load circuit and a fuel cell system, the circuit comprising: a first DC / AC module group, a second DC / AC module group and a first switching circuit; the AC input ends of the first DC / AC module group and the second DC / AC module group are connected to a power grid; the second end of the first DC / AC module group is connected to the first end of the first switching circuit; the second end of the second DC / AC module group is connected to the second end of the first switching circuit; the third end of the first switching circuit is connected to the fuel cell system, and a switching switch for controlling the conduction state between the first end and the third end, and between the second end and the third end of the first switching circuit is configured in the first switching circuit, thereby providing a hardware basis for eliminating the switching time of the feedback electronic load in the prior art.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic circuits, in particular to a fast-response electronic load circuit and a fuel cell system. Background Art

[0002] During the fuel cell test, the power generated by the fuel cell during operation needs to be consumed. Generally, an electronic load is used to consume the electrical energy generated by the fuel cell system. The electronic load used is divided into two modes: consumption electronic load and feedback electronic load.

[0003] The use of consumable electronic loads dissipates electrical energy in the form of heat through resistors. When using consumable electronic loads, it is necessary to provide the system with high-voltage power supply and low-voltage power supply separately to provide consumption for system auxiliary components. For high-power fuel cell systems, feedback loads are more often used to convert the electrical energy output by the fuel cell system into three-phase alternating current, adjust the frequency and phase, and upload it to the power grid for use by other electrical equipment on the same network.

[0004] The feedback electronic load can generally reversely provide the fuel cell system with the power consumed by the accessories. The power provided by the load and the power delivered by the fuel cell system to the load share the power line. This also leads to a certain time interval in the process of switching between the feedback electronic load as a power source and as a load. Utility Model Content

[0005] In view of this, the embodiments of the present invention provide a fast-response electronic load circuit and a fuel cell system to reduce the time interval during the conversion process between the electronic load being used as a power source and being used as a load.

[0006] To achieve the above purpose, the present invention provides the following technical solutions:

[0007] A fast-response electronic load circuit, comprising:

[0008] A first DC / AC module group, a second DC / AC module group and a first switching circuit;

[0009] The AC input ends of the first DC / AC module group and the second DC / AC module group are connected to a power grid;

[0010] The second end of the first DC / AC module group is connected to the first end of the first switching circuit;

[0011] The second end of the second DC / AC module group is connected to the second end of the first switching circuit;

[0012] The third end of the first switching circuit is connected to the fuel cell system. The first switching circuit is provided with a switching switch for controlling the conduction state between the first end and the third end, and between the second end and the third end of the first switching circuit.

[0013] Optionally, in the above-mentioned fast-response electronic load circuit, the first switching circuit is a relay:

[0014] The relay comprises a first moving contact, a second moving contact and a static contact, and the static contact and the first moving contact are in a normally closed state.

[0015] Optionally, the above-mentioned fast response electronic load circuit further includes:

[0016] A second switching circuit, wherein a first end of the second switching circuit is connected to a second end of the first DC / AC module group, and a second end of the second switching circuit is connected to a second end of the second DC / AC module group.

[0017] Optionally, the above-mentioned fast response electronic load circuit further includes:

[0018] A DC / AC controller, wherein a control signal output terminal of the DC / AC controller is connected to a control signal input terminal of the first DC / AC module group.

[0019] Optionally, in the above-mentioned fast-response electronic load circuit, the first DC / AC module group and the second DC / AC module group include at least one DC / AC module.

[0020] Optionally, in the above-mentioned fast-response electronic load circuit, the DC / AC modules in the first DC / AC module group are bidirectional modules, and the DC / AC modules in the second DC / AC module group are unidirectional modules.

[0021] Optionally, the above-mentioned fast response electronic load circuit further includes:

[0022] An energy storage module connected to first ends of the first DC / AC module group and the second DC / AC module group.

[0023] Optionally, the above-mentioned fast response electronic load circuit further includes:

[0024] A switching circuit controller, wherein the first end of the switching circuit controller is used to obtain a fuel cell system use and discharge signal, and the second end of the switching circuit controller is used to output a switching switch control instruction matching the obtained fuel cell system use and discharge signal to the first switching circuit and / or the second switching circuit.

[0025] Optionally, the above-mentioned fast response electronic load circuit further includes:

[0026] A delay circuit is provided between the second terminal of the switching circuit controller and the second switching circuit.

[0027] A fuel cell system comprises any one of the above-mentioned fast-response electronic load circuits.

[0028] Based on the above technical solution, the above solution provided by the embodiment of the utility model includes: a first DC / AC module group, a second DC / AC module group and a first switching circuit; the AC input ends of the first DC / AC module group and the second DC / AC module group are connected to the power grid; the second end of the first DC / AC module group is connected to the first end of the first switching circuit; the second end of the second DC / AC module group is connected to the second end of the first switching circuit; the third end of the first switching circuit is connected to the fuel cell system, and the first switching circuit is configured with a switching switch for controlling the conduction state of the first end and the third end, and the second end and the third end of the first switching circuit, thereby providing a hardware basis for eliminating the switching time of the feedback electronic load in the prior art.

[0029] For example, when the fuel cell system does not output electric energy to the electronic load circuit, the first end and the third end of the first switching circuit are turned on, and the first DC / AC module group loads the direct current converted from the power grid to the fuel cell system through the third end of the first switching circuit. When the fuel cell system outputs electric energy to the electronic load circuit, the second end and the third end of the first switching circuit are turned on, and the fuel cell system can load the output electric energy of the fuel cell to the second DC / AC module group through the second end of the first switching circuit, and after the second DC / AC module group converts the electric energy into alternating current, load it to the power grid. During the switching process, the first switching circuit does not need to wait for the first DC / AC module group to switch to the electronic load state, and can immediately provide discharge service for the fuel cell system, thereby eliminating the switching time of the feedback electronic load in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the embodiments of the utility model 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 in the following description are only embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0031] Figure 1 A schematic diagram of the structure of a fast-response electronic load circuit disclosed in an embodiment of the present application;

[0032] Figure 2A schematic structural diagram of a fast-response electronic load circuit disclosed in another embodiment of the present application;

[0033] Figure 3 A schematic structural diagram of a fast-response electronic load circuit disclosed in another embodiment of the present application;

[0034] Figure 4 A schematic structural diagram of a fast-response electronic load circuit disclosed in another embodiment of the present application;

[0035] Figure 5 A schematic structural diagram of a fast-response electronic load circuit disclosed in another embodiment of the present application;

[0036] Figure 6 A schematic structural diagram of a fast-response electronic load circuit disclosed in another embodiment of the present application;

[0037] Figure 7 This is a schematic structural diagram of a fast-response electronic load circuit disclosed in another embodiment of the present application. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0039] In order to solve the problem in the prior art that there is a certain time interval in the conversion process of the feedback electronic load used as a load, resulting in the inability to provide good discharge service to the fuel cell system within the time interval, the present application discloses a fast-response electronic load circuit, which includes two groups of DC / AC module groups, one of which is specifically used as an electronic load. When the fuel cell system is discharging, the fuel cell system is immediately switched to the group of DC / AC module groups through a first switching circuit, and discharge service can be provided to the fuel cell system immediately without waiting, thereby eliminating the switching time of the feedback electronic load in the prior art.

[0040] See also Figure 1 The fast-response electronic load circuit disclosed in the embodiment of the present application may include: a first DC / AC module group 100 , a second DC / AC module group 200 and a first switching circuit 300 .

[0041] See also Figure 1The AC input terminals of the first DC / AC module group 100 and the second DC / AC module group 200 are connected to the power grid, and the first DC / AC module group 100 can obtain AC power from the power grid, convert the obtained AC power into DC power and output it. The second DC / AC module group 200 can obtain DC power, convert the obtained DC power into AC power and then load it to the power grid.

[0042] The second end of the first DC / AC module group 100 is connected to the first end of the first switching circuit 300;

[0043] The second end of the second DC / AC module group 200 is connected to the second end of the first switching circuit 300;

[0044] The third end of the first switching circuit 300 is connected to the fuel cell system, and a working power supply is applied to the fuel cell system through the third end of the first switching circuit 300, or output power of the fuel cell system is obtained through the third end of the first switching circuit 300. The first switching circuit 300 is configured with a switching switch for controlling the conduction state between the first end and the third end, and between the second end and the third end of the first switching circuit 300.

[0045] In this solution, the first switching circuit 300 has a first conduction state and a second conduction state, wherein when the first switching circuit 300 is in the first conduction state, the third end of the first switching circuit 300 is connected to the first end of the first switching circuit 300, and at this time, the first DC / AC module group 100 can load the direct current converted from the power grid to the fuel cell system through the third end of the first switching circuit 300. When the first switching circuit 300 is in the second conduction state, the third end of the first switching circuit 300 is connected to the second end of the first switching circuit 300, and at this time, the fuel cell system can load the output power of the fuel cell to the second DC / AC module group 200 through the second end of the first switching circuit 300, and after being converted into alternating current by the second DC / AC module group 200, load it to the power grid.

[0046] In the fast-response electronic load circuit disclosed in the above-mentioned embodiment of the present application, when the fuel cell system does not output electric energy to the electronic load circuit, the first end and the third end of the first switching circuit 300 are turned on, and the first DC / AC module group 100 loads the direct current converted from the power grid to the fuel cell system through the third end of the first switching circuit 300. When the fuel cell system outputs electric energy to the electronic load circuit, the second end and the third end of the first switching circuit 300 are turned on, and the fuel cell system can load the output electric energy of the fuel cell to the second DC / AC module group 200 through the second end of the first switching circuit 300, and after being converted into alternating current by the second DC / AC module group 200, load it to the power grid. During the switching process, the first switching circuit 300 does not need to wait for the first DC / AC module group 100 to switch to the electronic load state, and can immediately provide discharge service for the fuel cell system, thereby eliminating the switching time of the feedback electronic load in the prior art.

[0047] In the technical solutions disclosed in the embodiments of this application, see Figure 2 , the first switching circuit 300 can be implemented by a relay, that is, the relay is used as the first switching circuit 300. In this solution, the relay used as the first switching circuit 300 includes a first moving contact, a second moving contact and a static contact. The static contact and the first moving contact are in a normally closed state. When the electromagnetic induction coil of the relay is powered on, the static contact and the second moving contact are connected. In the technical solution disclosed in the embodiment of the present application, the first moving contact serves as the first end of the first switching circuit 300, the second moving contact serves as the second end of the first switching circuit 300, and the static contact serves as the third end of the first switching circuit 300.

[0048] In this solution, the power-on state of the electromagnetic induction coil of the relay is synchronized with the state of the fuel cell system, that is, when electric energy flows out of the fuel cell system, current flows through the electromagnetic induction coil. At this time, the electromagnetic induction coil generates a magnetic field. Under the action of the magnetic field, the static contact of the relay is connected to the second moving contact. When no electric energy flows out of the fuel cell system, no current flows through the electromagnetic induction coil. At this time, the static contact of the relay is connected to the first moving contact.

[0049] In a technical solution disclosed in another embodiment of the present application, the first DC / AC module group 100 can also be used as an electronic load. When the first DC / AC module group 100 is used as an electronic load, the first DC / AC module group 100 can obtain the direct current output by the fuel cell system, convert the obtained direct current into alternating current, and then load it to the power grid.

[0050] In order to use the first DC / AC module group 100 as an electronic load to provide discharge service for the fuel cell system, in the technical solution disclosed in this embodiment, see Figure 3 The fast-response electronic load circuit may further include a second switching circuit 400 , wherein a first end of the second switching circuit 400 is connected to a second end of the first DC / AC module group 100 , and a second end of the second switching circuit 400 is connected to a second end of the second DC / AC module group 200 .

[0051] The switch state switching of the second switching circuit 400 needs to lag behind the preset time length compared with the first switching circuit 300. This is because it is necessary to switch the working state of the first DC / AC module group 100 from the AC-DC state to the DC-AC state within the preset time length, that is, switch the working state of the first DC / AC module group 100 from the AC input and DC output state to the DC input and AC output state. After the working state of the first DC / AC module group 100 is switched from the AC-DC state to the DC-AC state, the first DC / AC module group 100 can provide discharge service for the fuel cell system, and only then can the two ends of the second switching circuit 400 be controlled to be turned on. At this time, in addition to the second DC / AC module group 200 being able to serve as the electronic load of the fuel cell system, the first DC / AC module group 100 can also serve as the electronic load of the fuel cell system.

[0052] In the technical solution disclosed in the present embodiment, see Figure 4 The switching of the working state of the first DC / AC module group 100 can be controlled by a DC / AC controller 500. The control signal output end of the DC / AC controller 500 is connected to the control signal input end of the first DC / AC module group 100. The DC / AC controller 500 is used to obtain a control signal representing the working state of the fuel cell. When the control signal is a control signal used to represent that the fuel cell system has power output, the DC / AC controller 500 controls the working state of the first DC / AC module group 100 to switch to a DC-AC state, that is, controls the first DC / AC controller 500 group to enter an inverter state. At this time, the first DC / AC controller 500 group obtains a DC signal, inverts the DC signal, and outputs an AC signal to the power grid.

[0053] In a technical solution disclosed in another embodiment of the present application, the number of DC / AC modules in the first DC / AC module group 100 and the second DC / AC module group 200 can be set according to user needs. For example, in the technical solution disclosed in an embodiment of the present application, the first DC / AC module group 100 and the second DC / AC module group 200 each include at least one DC / AC module.

[0054] In the technical solution disclosed in this embodiment, the types of the DC / AC modules in the first DC / AC module group 100 and the second DC / AC module group 200 can be the same or different. For example, the DC / AC modules in the first DC / AC module group 100 and the second DC / AC module group 200 can both be DC / AC modules with bidirectional output functions, or the DC / AC modules in the first DC / AC module group 100 are bidirectional modules, and the DC / AC modules in the second DC / AC module group 200 are unidirectional modules that can only achieve DC-AC conversion, or the DC / AC modules in the first DC / AC module group 100 are unidirectional modules that can only achieve AC-DC conversion, and the DC / AC modules in the second DC / AC module group 200 are unidirectional modules that can only achieve DC-AC conversion. Specifically, the type of DC / AC modules selected in the first DC / AC module group 100 and the second DC / AC module group 200 can be determined by the designer.

[0055] In another embodiment of the present application, in order to prevent the fast-response electronic load circuit from being unable to provide working power to the fuel cell system when the power grid suddenly loses power, in this solution, see Figure 5 The fast-response electronic load circuit may further include an energy storage module 600, which is connected to the first ends of the first DC / AC module group 100 and the second DC / AC module group 200. The energy storage module 600 is used to output electric energy to the first DC / AC module group 100 when the power grid is powered off. At this time, the energy storage module 600 may be connected to the first DC / AC module group 100 through an inverter circuit, and the direct current output by the energy storage module 600 is converted into alternating current through the inverter circuit, and then converted into direct current required by the fuel cell through the AC-DC function of the first DC / AC module group 100. Of course, the energy storage module 600 may also be directly connected to the output end of the first DC / AC module group 100.

[0056] In the technical solution disclosed in another embodiment of the present application, see Figure 6, the first switching circuit 300 and / or the second switching circuit 400 in the above-mentioned fast-response electronic load circuit can be controlled by a switching circuit controller 700, the first end of the switching circuit controller 700 is used to obtain the fuel cell system use and discharge signals, and the second end of the switching circuit controller 700 is used to output the switching switch control instruction matching the obtained fuel cell system use and discharge signals to the first switching circuit 300 and / or the second switching circuit 400. That is, when the obtained signal of the fuel cell system is an electric signal, a control instruction for controlling the first end and the third end of the first switching circuit 300 to be turned on is generated, and when the obtained signal of the fuel cell system is a discharge signal, a control instruction for controlling the second end and the third end of the first switching circuit 300 to be turned on is generated, and a control instruction for controlling the two ends of the second switching circuit 400 to be turned on is generated.

[0057] In the technical solution disclosed in another embodiment of the present application, when a control instruction for controlling the two ends of the second switching circuit 400 to be turned on is detected, the second switching circuit 400 cannot be turned on immediately (the DC / AC controller 500 needs to control the first DC / AC module group 100 to switch to the DC-AC state). Figure 7 A delay circuit 800 may be provided between the second end of the switching circuit controller 700 and the second switching circuit 400, so that the second switching circuit 400 has a certain response time, thereby reserving sufficient time for the state switching of the first DC / AC module group 100.

[0058] Corresponding to the above method, the present application also discloses a fuel cell system, which may include any one of the fast-response electronic load circuits described above.

[0059] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0060] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A fast-response electronic load circuit, characterized in that: include: A first DC / AC module group, a second DC / AC module group and a first switching circuit; The AC input ends of the first DC / AC module group and the second DC / AC module group are connected to a power grid; The second end of the first DC / AC module group is connected to the first end of the first switching circuit; The second end of the second DC / AC module group is connected to the second end of the first switching circuit; The third end of the first switching circuit is connected to the fuel cell system. The first switching circuit is provided with a switching switch for controlling the conduction state between the first end and the third end, and between the second end and the third end of the first switching circuit.

2. The fast-response electronic load circuit according to claim 1, characterized in that: The first switching circuit is a relay: The relay comprises a first moving contact, a second moving contact and a stationary contact, and the stationary contact and the first moving contact are in a normally closed state.

3. The fast-response electronic load circuit according to claim 1, characterized in that: Also includes: A second switching circuit, wherein a first end of the second switching circuit is connected to a second end of the first DC / AC module group, and a second end of the second switching circuit is connected to a second end of the second DC / AC module group.

4. The fast-response electronic load circuit according to claim 1, characterized in that: Also includes: A DC / AC controller, wherein a control signal output terminal of the DC / AC controller is connected to a control signal input terminal of the first DC / AC module group.

5. The fast-response electronic load circuit according to claim 1, characterized in that: The first DC / AC module group and the second DC / AC module group include at least one DC / AC module.

6. The fast-response electronic load circuit according to claim 5, characterized in that: The DC / AC modules in the first DC / AC module group are bidirectional modules, and the DC / AC modules in the second DC / AC module group are unidirectional modules.

7. The fast-response electronic load circuit according to claim 5, characterized in that: Also includes: An energy storage module connected to first ends of the first DC / AC module group and the second DC / AC module group.

8. The fast-response electronic load circuit according to claim 3, characterized in that: Also includes: A switching circuit controller, wherein the first end of the switching circuit controller is used to obtain a fuel cell system use and discharge signal, and the second end of the switching circuit controller is used to output a switching switch control instruction matching the obtained fuel cell system use and discharge signal to the first switching circuit and / or the second switching circuit.

9. The fast-response electronic load circuit according to claim 8, characterized in that: Also includes: A delay circuit is provided between the second terminal of the switching circuit controller and the second switching circuit.

10. A fuel cell system, characterized in that: A fast-response electronic load circuit comprising the method described in any one of claims 1 to 9.

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