DCT power supply for proton exchange membrane hydrogen production

Abstract

The utility model discloses a DCT power supply for proton exchange membrane hydrogen production. The DCT power supply comprises an input port circuit, an inverter circuit, a direct current transformer, a first rectifier circuit and a hydrogen production port circuit which are connected in sequence, the inverter circuit and the first rectifying circuit are connected with the control circuit; the input port circuit is used for externally connecting and inputting a first direct current voltage; the inverter circuit is used for inverting the first direct-current voltage into a first alternating-current voltage and inputting the first alternating-current voltage into a primary side input end of the direct-current transformer; the direct-current transformer is used for converting the first alternating-current voltage into second alternating-current voltage and outputting the second alternating-current voltage through the secondary side output end; the first rectifying circuit is used for receiving and rectifying the second alternating-current voltage into second direct-current voltage; the hydrogen production port circuit is used for receiving and outputting the second direct current voltage. The problem that the service life of a proton membrane is reduced due to the fact that the impact current is too large in the hydrogen production process is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of converters, and more specifically to a DCT power supply for proton exchange membrane hydrogen production. Background Art

[0002] At present, hydrogen is a zero-carbon energy carrier. Making good use of hydrogen can not only solve energy problems, but also accomplish emission reduction tasks. Therefore, how to achieve efficient hydrogen production and make hydrogen inexhaustible is the top priority of current work. In the field of hydrogen production by electrolysis of water, PEM (Proton Exchange Membrane) hydrogen production has become the mainstream hydrogen production mode due to its advantages such as high hydrogen production conversion efficiency, no need for dealkalization, and fast start-stop response. The voltage that the proton exchange membrane of PEM can withstand is generally affected by the number of modules. Under normal circumstances, the voltage level that a proton exchange membrane can withstand is between 1.2V and 2.7V. If the voltage level is exceeded, the PEM proton exchange membrane will break down and fall off. Excessive instantaneous impact current will also affect the life of the proton exchange membrane.

[0003] However, traditional PEM hydrogen production power supplies often use three-phase uncontrolled rectifier power supplies as the main topology for hydrogen production. Due to the topological structure and susceptibility to the influence of grid harmonics, the DC ripple output by traditional PEM hydrogen production power supplies is large, which affects the activation time of the proton membrane and affects the stability and efficiency of hydrogen production. In order to protect the hydrogen production system, the traditional PEM hydrogen production power supply must be started with the start-up of the hydrogen production system in order to achieve the purpose of voltage climbing from 0, and cannot be used in multiple application scenarios.

[0004] Therefore, how to avoid excessive impact current in the hydrogen production process that causes the proton membrane life to decay is an urgent problem that technicians in this field need to solve. Utility Model Content

[0005] In view of this, the utility model provides a DCT power supply for proton exchange membrane hydrogen production, which helps to solve the problem of excessive impact current in the hydrogen production process leading to proton membrane life degradation.

[0006] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A DCT power supply for proton exchange membrane hydrogen production, comprising: an input port circuit, a plurality of inverter circuits connected in series, a plurality of DC transformers, a plurality of first rectifier circuits connected in parallel, a hydrogen production port circuit and a control circuit;

[0008] The input port circuit, the inverter circuit, the DC transformer, the first rectifier circuit and the hydrogen production port circuit are connected in sequence;

[0009] The inverter circuit and the first rectifier circuit are both connected to the control circuit;

[0010] The input port circuit is used to externally connect and input a first DC voltage;

[0011] The inverter circuit is used to invert the first DC voltage into a first AC voltage and input the AC voltage into the primary input terminal of the DC transformer;

[0012] The DC transformer is used to convert the first AC voltage into a second AC voltage and output it through the secondary side output terminal;

[0013] The first rectifier circuit is used to receive and rectify the second AC voltage into a second DC voltage;

[0014] The hydrogen production port circuit is used to receive and output the second DC voltage.

[0015] Preferably, the input port circuit comprises: an input positive branch and an input negative branch;

[0016] The input negative electrode branch includes a first bypass switch and a first pre-charging circuit connected in parallel with the first bypass switch;

[0017] The first pre-charging circuit comprises a first pre-charging switch and a first pre-charging resistor connected in series;

[0018] The input positive electrode branch includes a second bypass switch and a second pre-charging circuit connected in parallel with the second bypass switch;

[0019] The second pre-charging circuit includes a second pre-charging switch and a second pre-charging resistor connected in series.

[0020] Preferably, the input port circuit further includes: an isolating switch and a grounding switch;

[0021] The connection node between the first bypass switch and the first pre-charging circuit close to the power supply, and the connection node between the second bypass switch and the second pre-charging circuit close to the power supply are both connected in series with the grounding switch and the isolating switch in sequence.

[0022] Preferably, the hydrogen production port circuit comprises: a hydrogen production positive electrode branch and a hydrogen production negative electrode branch;

[0023] The hydrogen production positive electrode branch and the hydrogen production negative electrode branch both include a third bypass switch;

[0024] The hydrogen production positive electrode branch further includes a third pre-charging circuit connected in parallel with the third bypass switch;

[0025] A connection node between the third bypass switch and the third pre-charging circuit close to the first rectifier circuit is connected to the cathode of the parallel diode, and the anode of the parallel diode is connected to the first rectifier circuit;

[0026] The third pre-charging circuit comprises a third pre-charging switch and a third pre-charging resistor connected in series;

[0027] The hydrogen production negative electrode branch further includes a fourth pre-charging circuit connected in parallel with the third bypass switch;

[0028] The fourth pre-charging circuit includes a fourth pre-charging switch and a fourth pre-charging resistor connected in series.

[0029] Preferably, the inverter circuit comprises: a first H-bridge circuit and a first capacitor;

[0030] The positive electrode of the input port circuit is respectively connected to one end of the first capacitor and the first input end of the first H-bridge circuit;

[0031] The negative electrode of the input port circuit is connected to the other end of the first capacitor and the second input end of the first H-bridge circuit respectively;

[0032] The first output terminal of the first H-bridge circuit is connected to the first input terminal of the primary side of the DC transformer;

[0033] The second output terminal of the first H-bridge circuit is connected to the second input terminal of the primary side of the DC transformer;

[0034] The first H-bridge circuit includes: a first integrated circuit, a second integrated circuit, a third integrated circuit and a fourth integrated circuit;

[0035] The drain of the first integrated circuit is connected to the drain of the third integrated circuit, and the connection node thereof serves as the first input terminal of the first H-bridge circuit;

[0036] The source of the first integrated circuit is connected to the drain of the second integrated circuit, and the connection node thereof serves as the first output terminal of the first H-bridge circuit;

[0037] The second integrated circuit source is connected to the fourth integrated circuit source, and the connection node thereof serves as the second input terminal of the first H-bridge circuit;

[0038] The source of the third integrated circuit is connected to the drain of the fourth integrated circuit, and the connection node thereof serves as the second output terminal of the first H-bridge circuit;

[0039] The first integrated circuit gate, the second integrated circuit gate, the third integrated circuit gate and the fourth integrated circuit gate are all connected to the control circuit.

[0040] Preferably, the inverter circuit further comprises: a protection integrated circuit and a bypass integrated circuit;

[0041] The protection integrated circuit source is connected to the bypass integrated circuit drain, and the connection node is connected to the positive electrode of the input port circuit;

[0042] The drain of the protection integrated circuit is respectively connected to one end of the first capacitor and the first input end of the first H-bridge circuit;

[0043] The bypass integrated circuit source, the other end of the first capacitor and the second input end of the first H-bridge circuit are all connected to the negative electrode of the input port circuit;

[0044] The protection integrated circuit gate and the bypass integrated circuit gate are both connected to the control circuit.

[0045] Preferably, the first rectifier circuit comprises: a second H-bridge circuit and a second capacitor;

[0046] The first output terminal of the secondary side of the DC transformer is connected to the first input terminal of the second H-bridge circuit;

[0047] The second output terminal of the secondary side of the DC transformer is connected to the second input terminal of the second H-bridge circuit;

[0048] The positive electrode of the hydrogen production port circuit is respectively connected to one end of the second capacitor and the first output end of the second H-bridge circuit;

[0049] The negative electrode of the hydrogen production port circuit is respectively connected to the other end of the second capacitor and the second output end of the second H-bridge circuit;

[0050] The second H-bridge circuit comprises: a fifth integrated circuit, a sixth integrated circuit, a seventh integrated circuit and an eighth integrated circuit;

[0051] The drain of the fifth integrated circuit is connected to the drain of the seventh integrated circuit, and the connection node thereof serves as the first output terminal of the second H-bridge circuit;

[0052] The source of the seventh integrated circuit is connected to the drain of the eighth integrated circuit, and the connection node thereof serves as the first input terminal of the second H-bridge circuit;

[0053] The source electrode of the sixth integrated circuit is connected to the source electrode of the eighth integrated circuit, and the connection node thereof serves as the second output terminal of the second H-bridge circuit;

[0054] The source of the fifth integrated circuit is connected to the drain of the sixth integrated circuit, and the connection node thereof serves as the second input terminal of the second H-bridge circuit;

[0055] The fifth integrated circuit gate, the sixth integrated circuit gate, the seventh integrated circuit gate and the eighth integrated circuit gate are all connected to the control circuit.

[0056] Preferably, it also includes: a secondary side output port circuit;

[0057] The secondary output port circuit comprises: a secondary output positive branch and a secondary output negative branch;

[0058] The secondary output positive branch and the secondary output negative branch both include a fourth bypass switch;

[0059] The secondary side output positive electrode branch further includes a fifth pre-charging circuit connected in parallel with the fourth bypass switch;

[0060] The fifth pre-charging circuit comprises a fifth pre-charging switch and a fifth pre-charging resistor connected in series;

[0061] The secondary side output negative electrode branch further includes a sixth pre-charging circuit connected in parallel with the fourth bypass switch;

[0062] The sixth pre-charging circuit includes a sixth pre-charging switch and a sixth pre-charging resistor connected in series.

[0063] Preferably, it further comprises: a plurality of second rectifier circuits connected in parallel;

[0064] The inverter circuit is connected to the second rectifier circuit via the DC transformer;

[0065] The second rectifying circuit is used for rectifying the second AC voltage into a third DC voltage;

[0066] The second rectifier circuit includes: a third H-bridge circuit and a third capacitor;

[0067] The third output terminal of the secondary side of the DC transformer is connected to the first input terminal of the third H-bridge circuit;

[0068] The fourth output terminal of the secondary side of the DC transformer is connected to the second input terminal of the third H-bridge circuit;

[0069] The positive electrode of the second rectifier circuit is respectively connected to one end of the third capacitor and the first output end of the third H-bridge circuit;

[0070] The negative electrode of the second rectifier circuit is respectively connected to the other end of the third capacitor and the second output end of the third H-bridge circuit;

[0071] The third H-bridge circuit comprises: a ninth integrated circuit, a tenth integrated circuit, an eleventh integrated circuit and a twelfth integrated circuit;

[0072] The drain of the ninth integrated circuit is connected to the drain of the eleventh integrated circuit, and the connection node thereof serves as the first output terminal of the third H-bridge circuit;

[0073] The source of the eleventh integrated circuit is connected to the drain of the twelfth integrated circuit, and the connection node thereof serves as the first input terminal of the third H-bridge circuit;

[0074] The source electrode of the tenth integrated circuit is connected to the source electrode of the twelfth integrated circuit, and the connection node thereof serves as the second output terminal of the third H-bridge circuit;

[0075] The source of the ninth integrated circuit is connected to the drain of the tenth integrated circuit, and the connection node thereof serves as the second input terminal of the third H-bridge circuit;

[0076] The ninth integrated circuit gate, the tenth integrated circuit gate, the eleventh integrated circuit gate and the twelfth integrated circuit gate are all connected to the control circuit.

[0077] Preferably, the first input terminal on the primary side of the DC transformer, the first output terminal on the secondary side of the DC transformer and the third output terminal on the secondary side of the DC transformer are terminals of the same name.

[0078] It can be seen from the above technical solutions that, compared with the prior art, the utility model discloses a DCT power supply for proton exchange membrane hydrogen production, which has the following beneficial effects:

[0079] 1. During the hydrogen production startup phase, the output voltage is limited and the pre-charge current is reduced by delay. The voltage reduction offsets the current impact on the proton exchange membrane during the startup process, which is conducive to the long-term stable use of the proton exchange membrane.

[0080] 2. The characteristics of DCT (direct current transformer) are small harmonic content, small output voltage ripple and current ripple, which helps to accelerate the activation of proton exchange membrane and shorten the commissioning time of hydrogen production system.

[0081] 3. DCT can adopt multiple ports. While meeting the hydrogen production needs, other ports can be used as busbars to support and maintain the DC busbar of the park, reducing the investment in other equipment in the hydrogen production park and saving costs.

[0082] 4. The hydrogen production port of the utility model can be disconnected by a switch when there is no demand for hydrogen production or the hydrogen production system is under maintenance, without the need to shut down the hydrogen production system and cause the entire DCT to shut down.

[0083] 5. Multiple first rectifier circuits are connected in parallel to produce hydrogen through the stable DC voltage output by the hydrogen production port circuit. The DC voltage and current ripples are small, which shortens the activation time of the proton membrane and saves time costs.

[0084] 6. Due to the series voltage-sharing characteristics of multiple inverter circuits, the voltage level requirements of the DC transformer are reduced, saving manufacturing costs.

[0085] 7. The three-port DCT can convert the grid DC±10kV to DC 100~300V with only one level change, which helps to improve the efficiency of PEM hydrogen production.

[0086] 8. The voltage and current of the new hydrogen production port are stable, and the current ripple is ≤3% under rated working conditions. The activation time of the proton exchange membrane is shorter than that of conventional hydrogen production power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0087] 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.

[0088] Figure 1 A schematic diagram of a DCT power supply structure for proton exchange membrane hydrogen production provided by the utility model.

[0089] Figure 2 A schematic diagram of a preferred DCT power supply structure for proton exchange membrane hydrogen production provided by the utility model.

[0090] Figure 3 This is a schematic diagram of the structure and connection relationship of the inverter circuit, DC transformer and first rectifier circuit provided by the utility model.

[0091] Figure 4 This is a schematic diagram of the connection relationship between each inverter circuit, the DC transformer and the first rectifier circuit provided by the utility model.

[0092] Figure 5 This is a schematic diagram of the connection relationship between the inverter circuit and the control circuit provided by the utility model.

[0093] Figure 6 This is a waveform diagram of the grid connection of a DCT power source not of the present utility model and a PEM hydrogen production device.

[0094] Figure 7 It is a waveform diagram of the grid connection of the DCT power supply of the utility model and the PEM hydrogen production equipment. DETAILED DESCRIPTION

[0095] 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.

[0096] Example 1

[0097] like Figure 1As shown, the embodiment of the utility model discloses a DCT power supply for proton exchange membrane hydrogen production, comprising: an input port circuit, a plurality of inverter circuits connected in series, a plurality of DC transformers, a plurality of first rectifier circuits connected in parallel, a hydrogen production port circuit and a control circuit;

[0098] The input port circuit, the inverter circuit, the DC transformer, the first rectifier circuit and the hydrogen production port circuit are connected in sequence;

[0099] The inverter circuit and the first rectifier circuit are both connected to the control circuit;

[0100] An input port circuit, used for externally connecting and inputting a first DC voltage;

[0101] An inverter circuit, used for inverting the first DC voltage into a first AC voltage and inputting the AC voltage into a primary input terminal of a DC transformer;

[0102] A DC transformer, used for converting the first AC voltage into a second AC voltage and outputting the voltage through a secondary output terminal;

[0103] A first rectifying circuit, used for receiving and rectifying a second AC voltage into a second DC voltage;

[0104] The hydrogen production port circuit is used to receive and output a second DC voltage.

[0105] Example 2

[0106] like Figure 2 As shown, an embodiment of the utility model discloses a preferred DCT power supply for proton exchange membrane hydrogen production, including: an input port circuit, a plurality of inverter circuits connected in series, a plurality of DC transformers, a plurality of first rectifier circuits connected in parallel, a hydrogen production port circuit and a control circuit.

[0107] The input port circuit, the inverter circuit, the DC transformer, the first rectifier circuit and the hydrogen production port circuit are connected in sequence.

[0108] The input port circuit is used for externally connecting and inputting a first DC voltage.

[0109] Preferably, the input port circuit comprises: an input positive branch and an input negative branch;

[0110] The input negative electrode branch includes a first bypass switch QF1 and a first pre-charging circuit connected in parallel with the first bypass switch;

[0111] The first pre-charging circuit includes a first pre-charging switch KM1 and a first pre-charging resistor R1 connected in series;

[0112] The input positive electrode branch includes a second bypass switch QF2 and a second pre-charging circuit connected in parallel with the second bypass switch;

[0113] The second pre-charging circuit includes a second pre-charging switch KM2 and a second pre-charging resistor R2 connected in series.

[0114] Preferably, during each DCT startup process, KM1 and KM2 are closed first, and when the module voltage reaches the pre-charge voltage state, QF1 and QF2 are closed, KM1 and KM2 are opened, and the pre-charge resistors R1 and R2 are removed from the circuit.

[0115] Preferably, in this embodiment, the first DC voltage adopts ±10KV, that is, the input port corresponds to the ±10KV port.

[0116] The input port circuit also includes: an isolating switch QS1 and a grounding switch QE1;

[0117] A connection node between the first bypass switch QF1 and the first pre-charging circuit close to the power supply, and a connection node between the second bypass switch QF2 and the second pre-charging circuit close to the power supply are connected in series with a grounding switch QE1 and an isolating switch QS1.

[0118] Preferably, when the DCT is in hot standby or running state, QS1 is always in a closed state, and QE1 is in an open state. When the DCT needs to be repaired, for safety reasons, QS1 is opened and QE1 is closed.

[0119] The inverter circuit is used for inverting the first DC voltage into a first AC voltage and inputting the AC voltage into the primary input terminal of the DC transformer.

[0120] Preferably, Figure 3-Figure 4 As shown, a plurality of inverter circuits GM1-GMn are connected in series. Due to the series voltage-sharing characteristic, the voltage level requirement of the DC transformer is reduced, and the manufacturing cost is saved. The inverter circuits GM1-GMn have the same structure.

[0121] Preferably, the inverter circuit comprises: a first H-bridge circuit and a first capacitor C1;

[0122] The positive electrode of the input port circuit is respectively connected to one end of the first capacitor C1 and the first input end of the first H-bridge circuit;

[0123] The negative electrode of the input port circuit is connected to the other end of the first capacitor C1 and the second input end of the first H-bridge circuit respectively;

[0124] A first output terminal of the first H-bridge circuit is connected to a first input terminal of the primary side of the DC transformer T;

[0125] The second output terminal of the first H-bridge circuit is connected to the second input terminal of the primary side of the DC transformer T;

[0126] The first H-bridge circuit includes: a first integrated circuit S1, a second integrated circuit S2, a third integrated circuit S3 and a fourth integrated circuit S4;

[0127] The drain of the first integrated circuit S1 is connected to the drain of the third integrated circuit S3, and the connection node thereof serves as the first input terminal of the first H-bridge circuit;

[0128] The source of the first integrated circuit S1 is connected to the drain of the second integrated circuit S2, and the connection node between the source of the first integrated circuit S1 and the drain of the second integrated circuit S2 serves as the first output end of the first H-bridge circuit;

[0129] The source of the second integrated circuit S2 is connected to the source of the fourth integrated circuit S4, and the connection node between the source of the second integrated circuit S2 and the source of the fourth integrated circuit S4 serves as the second input terminal of the first H-bridge circuit;

[0130] The source of the third integrated circuit S3 is connected to the drain of the fourth integrated circuit S4, and the connection node between the source of the third integrated circuit S3 and the drain of the fourth integrated circuit S4 serves as the second output end of the first H-bridge circuit;

[0131] The gate of the first integrated circuit S1 , the gate of the second integrated circuit S2 , the gate of the third integrated circuit S3 and the gate of the fourth integrated circuit S4 are all connected to the control circuit.

[0132] Preferably, the first capacitor C1 is used as a supporting capacitor to support the port voltage and stabilize the port voltage.

[0133] Preferably, the first H-bridge circuit is used to invert the first DC voltage U1 into a first AC voltage.

[0134] Preferably, the inverter circuit further comprises: a protection integrated circuit SH and a bypass integrated circuit SP;

[0135] The protection integrated circuit SH is used to prevent the first integrated circuit S1, the second integrated circuit S2, the third integrated circuit S3, and the fourth integrated circuit S4 from overcurrent explosion, and clamp the voltage of the first capacitor C1;

[0136] Bypass integrated circuit SP, used to short-circuit the inverter circuit in case of failure;

[0137] The source of the protection integrated circuit SH is connected to the drain of the bypass integrated circuit SP, and the connection node thereof is connected to the positive electrode of the input port circuit;

[0138] The drain of the protection integrated circuit SH is respectively connected to one end of the first capacitor and the first input end of the first H-bridge circuit;

[0139] The source electrode of the bypass integrated circuit SP, the other end of the first capacitor and the second input end of the first H-bridge circuit are all connected to the negative electrode of the input port circuit;

[0140] The gate of the protection integrated circuit SH and the gate of the bypass integrated circuit SP are both connected to the control circuit.

[0141] Preferably, the current flowing through the protection integrated circuit SH is greater than the current flowing through S1 to S4. When an overcurrent fault occurs, SH will first reach a protection breakdown, so it can serve as a protection switch tube.

[0142] Preferably, when a fault occurs, the switch tube of the bypass integrated circuit SP is closed, and the other switches S1 to S4 are disconnected, the positive and negative poles of the inverter circuit are short-circuited, and the current will no longer pass through the inside of the inverter circuit, forming a bypass.

[0143] A DC transformer, used for converting the first AC voltage into a second AC voltage and outputting the voltage through a secondary output terminal;

[0144] Preferably, the multiple DC transformers BM1 to BMn have the same structure and model, and each DC transformer BM is isolated from each other and has no electrical connection relationship.

[0145] The first rectifier circuit is used to receive and rectify the second AC voltage into a second DC voltage.

[0146] Preferably, multiple first rectifier circuits ZM1 to ZMn are connected in parallel for output, and hydrogen can be produced through a stable DC voltage output by the hydrogen production port circuit. The DC voltage and current ripple are small, which shortens the activation time of the proton membrane and saves time cost.

[0147] Preferably, the first rectifier circuit comprises: a second H-bridge circuit and a second capacitor C2;

[0148] A first output terminal on the secondary side of the DC transformer T is connected to a first input terminal of the second H-bridge circuit;

[0149] The second output terminal of the secondary side of the DC transformer T is connected to the second input terminal of the second H-bridge circuit;

[0150] The positive electrode of the hydrogen production port circuit is respectively connected to one end of the second capacitor C2 and the first output end of the second H-bridge circuit;

[0151] The negative electrode of the hydrogen production port circuit is respectively connected to the other end of the second capacitor C2 and the second output end of the second H-bridge circuit;

[0152] The second H-bridge circuit includes: a fifth integrated circuit S5, a sixth integrated circuit S6, a seventh integrated circuit S7 and an eighth integrated circuit S8;

[0153] The drain of the fifth integrated circuit S5 is connected to the drain of the seventh integrated circuit S7, and the connection node thereof serves as the first output terminal of the second H-bridge circuit;

[0154] The source of the seventh integrated circuit S7 is connected to the drain of the eighth integrated circuit S8, and the connection node thereof serves as the first input terminal of the second H-bridge circuit;

[0155] The source electrode of the sixth integrated circuit S6 is connected to the source electrode of the eighth integrated circuit S8, and the connection node thereof serves as the second output terminal of the second H-bridge circuit;

[0156] The source of the fifth integrated circuit S5 is connected to the drain of the sixth integrated circuit S6, and the connection node thereof serves as the second input terminal of the second H-bridge circuit;

[0157] The gate of the fifth integrated circuit S5 , the gate of the sixth integrated circuit S6 , the gate of the seventh integrated circuit S7 and the gate of the eighth integrated circuit S8 are all connected to the control circuit.

[0158] Preferably, the second capacitor C2 is used as a supporting capacitor to support the port voltage and stabilize the port voltage.

[0159] Preferably, the second H-bridge circuit is used to receive and rectify the second AC voltage into a second DC voltage U2.

[0160] The hydrogen production port circuit is used to receive and output a second DC voltage.

[0161] Preferably, the hydrogen production port circuit comprises: a hydrogen production positive electrode branch and a hydrogen production negative electrode branch;

[0162] The hydrogen production positive electrode branch and the hydrogen production negative electrode branch both include a third bypass switch QF3;

[0163] The hydrogen production positive electrode branch also includes a third pre-charging circuit connected in parallel with the third bypass switch QF3;

[0164] A connection node between the third bypass switch QF3 and the third pre-charging circuit close to the first rectifier circuit is connected to the cathode of the parallel diode D, and the anode of the parallel diode D is connected to the first rectifier circuit;

[0165] The third pre-charging circuit includes a third pre-charging switch KM3 and a third pre-charging resistor R3 connected in series;

[0166] The hydrogen production negative electrode branch also includes a fourth pre-charging circuit connected in parallel with the third bypass switch QF3;

[0167] The fourth pre-charging circuit includes a fourth pre-charging switch KM4 and a fourth pre-charging resistor R4 connected in series.

[0168] Preferably, the hydrogen production port can disconnect QF3, KM3, and KM4 when there is no demand for hydrogen production or the hydrogen production system is under maintenance, without shutting down the entire DCT due to the shutdown of the hydrogen production system.

[0169] Preferably, it further comprises: a plurality of second rectifier circuits DM1 to DMn connected in parallel;

[0170] The inverter circuit is connected to the second rectifier circuit via a DC transformer T;

[0171] A second rectifying circuit, used for rectifying the second AC voltage into a third DC voltage;

[0172] The second rectifier circuit includes: a third H-bridge circuit and a third capacitor C3;

[0173] The third output terminal of the secondary side of the DC transformer T is connected to the first input terminal of the third H-bridge circuit;

[0174] The fourth output terminal of the secondary side of the DC transformer T is connected to the second input terminal of the third H-bridge circuit;

[0175] The positive electrode of the second rectifier circuit is respectively connected to one end of the third capacitor and the first output end of the third H-bridge circuit;

[0176] The cathode of the second rectifier circuit is respectively connected to the other end of the third capacitor C3 and the second output end of the third H-bridge circuit;

[0177] The third H-bridge circuit includes: a ninth integrated circuit S9, a tenth integrated circuit S10, an eleventh integrated circuit S11 and a twelfth integrated circuit S12;

[0178] The drain of the ninth integrated circuit S9 is connected to the drain of the eleventh integrated circuit S11, and the connection node between the drain of the ninth integrated circuit S9 and the drain of the eleventh integrated circuit S11 serves as the first output end of the third H-bridge circuit;

[0179] The source of the eleventh integrated circuit S11 is connected to the drain of the twelfth integrated circuit S12, and the connection node between the source of the eleventh integrated circuit S11 and the drain of the twelfth integrated circuit S12 serves as the first input terminal of the third H-bridge circuit;

[0180] The tenth integrated circuit source S10 is connected to the twelfth integrated circuit source S12, and the connection node between the tenth integrated circuit source S10 and the twelfth integrated circuit source S12 serves as the second output terminal of the third H-bridge circuit;

[0181] The source of the ninth integrated circuit S9 is connected to the drain of the tenth integrated circuit S10, and the connection node between the source of the ninth integrated circuit S9 and the drain of the tenth integrated circuit S10 serves as the second input terminal of the third H-bridge circuit;

[0182] The gate of the ninth integrated circuit S9 , the gate of the tenth integrated circuit S10 , the gate of the eleventh integrated circuit S11 , and the gate of the twelfth integrated circuit S12 are all connected to the control circuit.

[0183] Preferably, the third capacitor C3 is used as a supporting capacitor to support the port voltage and stabilize the port voltage.

[0184] Preferably, the third H-bridge circuit is used to receive and rectify the second AC voltage into a third DC voltage U3.

[0185] Preferably, it also includes: a secondary side output port circuit;

[0186] The secondary output port circuit includes: a secondary output positive branch and a secondary output negative branch;

[0187] The secondary output positive branch and the secondary output negative branch both include a fourth bypass switch QF4;

[0188] The secondary output positive branch also includes a fifth pre-charging circuit connected in parallel with the fourth bypass switch QF4;

[0189] The fifth pre-charging circuit includes a fifth pre-charging switch KM5 and a fifth pre-charging resistor R5 connected in series;

[0190] The secondary output negative electrode branch also includes a sixth pre-charging circuit connected in parallel with the fourth bypass switch QF4;

[0191] The sixth pre-charging circuit includes a sixth pre-charging switch KM6 and a sixth pre-charging resistor R6 connected in series.

[0192] Preferably, the secondary output port circuit is used to output a third DC voltage. In this embodiment, the third DC voltage is 750V, that is, the secondary output port corresponds to a 750V bus voltage port. The DCT adopts multiple ports. While meeting the hydrogen production requirements, other ports can be used as bus supports to maintain the DC bus of the park, reducing the investment in other equipment in the hydrogen production park and saving costs.

[0193] Preferably, during each DCT startup process, KM5 and KM6 are closed first, and when the module voltage reaches the pre-charge voltage state, QF4 is closed, KM5 and KM6 are opened, and the pre-charge resistors R5 and R6 are removed from the circuit.

[0194] Preferably, the selection of the DC transformer is affected by the port voltage. The DC transformer in this embodiment adopts a ratio relationship of U1:U2:U3.

[0195] Preferably, the first input terminal on the primary side of the DC transformer, the first output terminal on the secondary side of the DC transformer and the third output terminal on the secondary side of the DC transformer are terminals of the same name.

[0196] Preferably, the three-port DCT can convert the grid DC±10kV to DC100V~300V with only one level of change, ensuring the high efficiency of PEM hydrogen production.

[0197] Preferably, the integrated circuits S1 to S12, SH and SP of this embodiment have the same structure and all adopt SIC. The specification of SIC type devices is: 1200V / 11mΩ.

[0198] Preferably, each inverter circuit GM1~GMn is correspondingly connected to the primary side of each DC transformer BM1~BMn; each first secondary side of each DC transformer BM1~BMn is correspondingly connected to each first rectifier circuit ZM1~ZMn; each second secondary side of each DC transformer BM1~BMn is correspondingly connected to each second rectifier circuit DM1~DMn.

[0199] The inverter circuit and the first rectifier circuit are both connected to the control circuit;

[0200] Preferably, the gates of the protection integrated circuit SH, bypass integrated circuit SP and integrated circuits S1-S12 are all connected to the control circuit, and the control circuit outputs a PWM wave to control the on and off of the gates of all integrated circuits, so that the primary side outputs an inverted square wave voltage waveform, and the secondary side ensures the voltage of the support capacitor, that is, the port voltage of the secondary side, by opening and closing the gate. Figure 5 As shown, the gates of the protection integrated circuit SH, the bypass integrated circuit SP and the integrated circuits S1-S4 in the inverter circuit of the present invention are respectively connected to the control circuit, wherein all the control circuits have the same structure and function.

[0201] Example 3

[0202] The working principle of hydrogen production of this utility model is:

[0203] During each DCT startup process, KM1 and KM2 in the input port circuit are closed first. When the module voltage reaches the pre-charge voltage state, QF1 and QF2 are closed, KM1 and KM2 are opened, the pre-charge resistors R1 and R2 are removed from the circuit, and the first DC voltage U1 is input to the inverter circuit.

[0204] Based on the output signal of the control circuit, the first H-bridge circuit in the inverter circuit inverts the first DC voltage U1 into a first AC voltage and inputs it into the primary input terminal of the DC transformer; the DC transformer converts the first AC voltage into a second AC voltage and outputs it to the first rectifier circuit through the secondary output terminal; the first rectifier circuit receives and rectifies the second AC voltage into a second DC voltage U2 and inputs it into the hydrogen production port circuit;

[0205] The third bypass switch QF3, the third pre-filling switch KM3 and the fourth pre-filling switch KM4 in the hydrogen production port circuit are all in the disconnected state; after the hydrogen production system receives the DCT unlocking state signal and the DCT state normal feedback, the hydrogen production system synchronously completes the standby start state;

[0206] The hydrogen production system PEM sends a start / stop pulse signal and current target value to the DCT power supply. The pulse signal is greater than 100ms, and the current command ramps from 0A to the target value. The purpose of the pulse signal being greater than 100ms is to prevent false triggering caused by pulse interference signals.

[0207] Based on the output signal of the control circuit, the voltage of the hydrogen production port is adjusted to Ud = 115V, which is less than the maximum tolerable voltage U of the hydrogen production proton module. MAX =120V and the voltage qualified waiting time Ts=3s is met, the third pre-filling switch KM3 and the fourth pre-filling switch KM4 are closed, the hydrogen production port current is less than the current comparison value 3A and lasts for 2s, and the third bypass switch QF3 is closed;

[0208] Based on the output signal of the control circuit, the voltage of the hydrogen production port is adjusted to Ud=105V, which is less than the voltage output limit U MIN =108V, disconnect the third pre-filling switch KM3 and the fourth pre-filling switch KM4, and the DCT power supply adjusts the output current according to the 4-20mA current instruction transmitted by the PEM to achieve hydrogen production. The drop in Ud output voltage can prevent UR from being superimposed on the PEM to trigger a surge current. 4-20mA corresponds to 0 current to full power current of the PEM respectively.

[0209] The voltage U of PEM during charging PEM The voltage of the port Ud gradually increases from 0V to the port Ud. As the voltages at both ends of the port gradually approach each other, the potential difference gradually decreases. The current I of the hydrogen production port will decrease as the pre-charge time increases. The voltage divider U of the pre-charge resistor R3 R =I*R3; Ud=U R +U PEM ; when U R If it is small enough, Ud≈U PEM , the positive circuit of the hydrogen production port is connected to a reverse parallel diode D, at this time U d The voltage will not be reversed to DCT, so U PEM >Ud, similarly, Ud≈U MIN , so U PEM >U MIN At this time, U PEM >U MIN , Ud<U MIN The purpose is to consider the influence of control accuracy. 3V deviation is more conducive to system control and has no effect on the PEM system. MIN The minimum hydrogen production voltage of the PEM of the hydrogen production system. If the PEM voltage is lower than U MIN After a while the PEM will generate oxygen instead of hydrogen.

[0210] The working principle of the utility model outputting 750V bus voltage is:

[0211] During each DCT startup process, KM1 and KM2 in the input port circuit are closed first. When the module voltage reaches the pre-charge voltage state, QF1 and QF2 are closed, KM1 and KM2 are opened, the pre-charge resistors R1 and R2 are removed from the circuit, and the first DC voltage U1 is input to the inverter circuit.

[0212] Based on the output signal of the control circuit, the first H-bridge circuit in the inverter circuit inverts the first DC voltage U1 into a first AC voltage and inputs the first AC voltage into the primary input terminal of the DC transformer; the DC transformer converts the first AC voltage into a second AC voltage and outputs the second AC voltage to the second rectifier circuit through the secondary output terminal;

[0213] Based on the control circuit output signal, the third H-bridge circuit in the second rectifier circuit receives and rectifies the second AC voltage into a third DC voltage U3:

[0214] KM5 and KM6 are closed first. When the module voltage reaches the pre-charge voltage state, QF4 is closed, KM5 and KM6 are opened, and the pre-charge resistors R5 and R6 are removed from the circuit. At this time, the secondary output port circuit is used to output the third DC voltage U3. This embodiment outputs a 750V DC voltage.

[0215] Example 4

[0216] like Figure 6 The figure shows the waveform of the grid connection of a DCT and a PEM hydrogen production device that are not of the present utility model. When a conventional DCT is grid-connected, the bypass switch generates an impact current at the moment of closing. This impact current will be reflected in the PEM electrolyzer, affecting the service life of the proton exchange membrane of the PEM electrolyzer. The impact current is related to the voltage division of the pre-charge resistance circuit, and is positively correlated.

[0217] like Figure 7 As shown, the grid-connected waveform of the DCT and PEM hydrogen production equipment using the utility model. In the grid-connected process, since the DCT drops the voltage at the moment of grid connection, there is no voltage division in the pre-charge resistor when the bypass switch is closed, so there is no current impact on the electrolyzer. After the grid connection is successful, the DCT equipment switches from the voltage control mode to the current control mode, which is friendly to the hydrogen production electrolyzer. The hydrogen production equipment only needs to generate hydrogen production current according to its own electrolyzer conditions to meet the hydrogen production.

[0218] It can be seen from the above technical solutions that, compared with the prior art, the utility model discloses a DCT power supply for proton exchange membrane hydrogen production, which has the following beneficial effects:

[0219] 1. During the hydrogen production startup phase, the output voltage is limited and the pre-charge current is reduced by delay. The voltage reduction offsets the current impact on the proton exchange membrane during the startup process, which is conducive to the long-term stable use of the proton exchange membrane.

[0220] 2. The characteristics of DCT (direct current transformer) are small harmonic content, small output voltage ripple and current ripple, which helps to accelerate the activation of proton exchange membrane and shorten the commissioning time of hydrogen production system.

[0221] 3. DCT can adopt multiple ports. While meeting the hydrogen production needs, other ports can be used as busbars to support and maintain the DC busbar of the park, reducing the investment in other equipment in the hydrogen production park and saving costs.

[0222] 4. The hydrogen production port of the utility model can be disconnected by a switch when there is no demand for hydrogen production or the hydrogen production system is under maintenance, without the need to shut down the hydrogen production system and cause the entire DCT to shut down.

[0223] 5. Multiple first rectifier circuits are connected in parallel to produce hydrogen through the stable DC voltage output by the hydrogen production port circuit. The DC voltage and current ripples are small, which shortens the activation time of the proton membrane and saves time costs.

[0224] 6. Due to the series voltage-sharing characteristics of multiple inverter circuits, the voltage level requirements of the DC transformer are reduced, saving manufacturing costs.

[0225] 7. The three-port DCT can convert the grid DC±10kV to DC 100~300V with only one level change, which helps to improve the efficiency of PEM hydrogen production.

[0226] 8. The voltage and current of the new hydrogen production port are stable, and the current ripple is ≤3% under rated working conditions. The activation time of the proton exchange membrane is shorter than that of conventional hydrogen production power supply.

[0227] 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.

[0228] 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 DCT power supply for proton exchange membrane hydrogen production, characterized in that: include: An input port circuit, a plurality of inverter circuits connected in series, a plurality of DC transformers, a plurality of first rectifier circuits connected in parallel, a hydrogen production port circuit and a control circuit; The input port circuit, the inverter circuit, the DC transformer, the first rectifier circuit and the hydrogen production port circuit are connected in sequence; The inverter circuit and the first rectifier circuit are both connected to the control circuit; The input port circuit is used to externally connect and input a first DC voltage; The inverter circuit is used to invert the first DC voltage into a first AC voltage and input the AC voltage into the primary input terminal of the DC transformer; The DC transformer is used to convert the first AC voltage into a second AC voltage and output it through the secondary side output terminal; The first rectifying circuit is used to receive and rectify the second AC voltage into a second DC voltage; The hydrogen production port circuit is used to receive and output the second DC voltage.

2. A DCT power supply for proton exchange membrane hydrogen production according to claim 1, characterized in that: The input port circuit comprises: an input positive branch and an input negative branch; The input negative electrode branch includes a first bypass switch and a first pre-charging circuit connected in parallel with the first bypass switch; The first pre-charging circuit comprises a first pre-charging switch and a first pre-charging resistor connected in series; The input positive electrode branch includes a second bypass switch and a second pre-charging circuit connected in parallel with the second bypass switch; The second pre-charging circuit includes a second pre-charging switch and a second pre-charging resistor connected in series.

3. A DCT power supply for proton exchange membrane hydrogen production according to claim 2, characterized in that: The input port circuit also includes: an isolating switch and a grounding switch; The connection node between the first bypass switch and the first pre-charging circuit close to the power supply, and the connection node between the second bypass switch and the second pre-charging circuit close to the power supply are both connected in series with the grounding switch and the isolating switch in sequence.

4. A DCT power supply for proton exchange membrane hydrogen production according to claim 1, characterized in that: The hydrogen production port circuit comprises: a hydrogen production positive electrode branch and a hydrogen production negative electrode branch; The hydrogen production positive electrode branch and the hydrogen production negative electrode branch both include a third bypass switch; The hydrogen production positive electrode branch further includes a third pre-charging circuit connected in parallel with the third bypass switch; A connection node between the third bypass switch and the third pre-charging circuit close to the first rectifier circuit is connected to the cathode of the parallel diode, and the anode of the parallel diode is connected to the first rectifier circuit; The third pre-charging circuit comprises a third pre-charging switch and a third pre-charging resistor connected in series; The hydrogen production negative electrode branch further includes a fourth pre-charging circuit connected in parallel with the third bypass switch; The fourth pre-charging circuit includes a fourth pre-charging switch and a fourth pre-charging resistor connected in series.

5. A DCT power supply for proton exchange membrane hydrogen production according to claim 1, characterized in that: The inverter circuit comprises: a first H-bridge circuit and a first capacitor; The positive electrode of the input port circuit is respectively connected to one end of the first capacitor and the first input end of the first H-bridge circuit; The negative electrode of the input port circuit is connected to the other end of the first capacitor and the second input end of the first H-bridge circuit respectively; A first output terminal of the first H-bridge circuit is connected to a first input terminal of the primary side of the DC transformer; The second output terminal of the first H-bridge circuit is connected to the second input terminal of the primary side of the DC transformer; The first H-bridge circuit includes: a first integrated circuit, a second integrated circuit, a third integrated circuit and a fourth integrated circuit; The drain of the first integrated circuit is connected to the drain of the third integrated circuit, and the connection node thereof serves as the first input terminal of the first H-bridge circuit; The source of the first integrated circuit is connected to the drain of the second integrated circuit, and the connection node thereof serves as the first output terminal of the first H-bridge circuit; The second integrated circuit source is connected to the fourth integrated circuit source, and the connection node thereof serves as the second input terminal of the first H-bridge circuit; The source of the third integrated circuit is connected to the drain of the fourth integrated circuit, and the connection node thereof serves as the second output terminal of the first H-bridge circuit; The first integrated circuit gate, the second integrated circuit gate, the third integrated circuit gate and the fourth integrated circuit gate are all connected to the control circuit.

6. A DCT power supply for proton exchange membrane hydrogen production according to claim 5, characterized in that: The inverter circuit also includes: a protection integrated circuit and a bypass integrated circuit; The protection integrated circuit source is connected to the bypass integrated circuit drain, and the connection node is connected to the positive electrode of the input port circuit; The drain of the protection integrated circuit is respectively connected to one end of the first capacitor and the first input end of the first H-bridge circuit; The bypass integrated circuit source, the other end of the first capacitor and the second input end of the first H-bridge circuit are all connected to the negative electrode of the input port circuit; The protection integrated circuit gate and the bypass integrated circuit gate are both connected to the control circuit.

7. A DCT power supply for proton exchange membrane hydrogen production according to claim 5, characterized in that: The first rectifier circuit includes: a second H-bridge circuit and a second capacitor; The first output terminal of the secondary side of the DC transformer is connected to the first input terminal of the second H-bridge circuit; The second output terminal of the secondary side of the DC transformer is connected to the second input terminal of the second H-bridge circuit; The positive electrode of the hydrogen production port circuit is respectively connected to one end of the second capacitor and the first output end of the second H-bridge circuit; The negative electrode of the hydrogen production port circuit is respectively connected to the other end of the second capacitor and the second output end of the second H-bridge circuit; The second H-bridge circuit comprises: a fifth integrated circuit, a sixth integrated circuit, a seventh integrated circuit and an eighth integrated circuit; The drain of the fifth integrated circuit is connected to the drain of the seventh integrated circuit, and the connection node thereof serves as the first output terminal of the second H-bridge circuit; The source of the seventh integrated circuit is connected to the drain of the eighth integrated circuit, and the connection node thereof serves as the first input terminal of the second H-bridge circuit; The source electrode of the sixth integrated circuit is connected to the source electrode of the eighth integrated circuit, and the connection node thereof serves as the second output terminal of the second H-bridge circuit; The source of the fifth integrated circuit is connected to the drain of the sixth integrated circuit, and the connection node thereof serves as the second input terminal of the second H-bridge circuit; The fifth integrated circuit gate, the sixth integrated circuit gate, the seventh integrated circuit gate and the eighth integrated circuit gate are all connected to the control circuit.

8. A DCT power supply for proton exchange membrane hydrogen production according to claim 7, characterized in that: Also includes: Secondary side output port circuit; The secondary output port circuit comprises: a secondary output positive branch and a secondary output negative branch; The secondary output positive branch and the secondary output negative branch both include a fourth bypass switch; The secondary side output positive electrode branch further includes a fifth pre-charging circuit connected in parallel with the fourth bypass switch; The fifth pre-charging circuit comprises a fifth pre-charging switch and a fifth pre-charging resistor connected in series; The secondary side output negative electrode branch further includes a sixth pre-charging circuit connected in parallel with the fourth bypass switch; The sixth pre-charging circuit includes a sixth pre-charging switch and a sixth pre-charging resistor connected in series.

9. A DCT power supply for proton exchange membrane hydrogen production according to claim 8, characterized in that: Also includes: A plurality of second rectifier circuits connected in parallel; The inverter circuit is connected to the second rectifier circuit via the DC transformer; The second rectifying circuit is used for rectifying the second AC voltage into a third DC voltage; The second rectifier circuit includes: a third H-bridge circuit and a third capacitor; The third output terminal of the secondary side of the DC transformer is connected to the first input terminal of the third H-bridge circuit; The fourth output terminal of the secondary side of the DC transformer is connected to the second input terminal of the third H-bridge circuit; The positive electrode of the second rectifier circuit is respectively connected to one end of the third capacitor and the first output end of the third H-bridge circuit; The negative electrode of the second rectifier circuit is respectively connected to the other end of the third capacitor and the second output end of the third H-bridge circuit; The third H-bridge circuit comprises: a ninth integrated circuit, a tenth integrated circuit, an eleventh integrated circuit and a twelfth integrated circuit; The drain of the ninth integrated circuit is connected to the drain of the eleventh integrated circuit, and the connection node thereof serves as the first output terminal of the third H-bridge circuit; The source of the eleventh integrated circuit is connected to the drain of the twelfth integrated circuit, and the connection node thereof serves as the first input terminal of the third H-bridge circuit; The source electrode of the tenth integrated circuit is connected to the source electrode of the twelfth integrated circuit, and the connection node thereof serves as the second output terminal of the third H-bridge circuit; The source of the ninth integrated circuit is connected to the drain of the tenth integrated circuit, and the connection node thereof serves as the second input terminal of the third H-bridge circuit; The ninth integrated circuit gate, the tenth integrated circuit gate, the eleventh integrated circuit gate and the twelfth integrated circuit gate are all connected to the control circuit.

10. A DCT power supply for proton exchange membrane hydrogen production according to claim 9, characterized in that: The first input terminal on the primary side of the DC transformer, the first output terminal on the secondary side of the DC transformer and the third output terminal on the secondary side of the DC transformer are terminals of the same name.

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