36-pulse-wave hydrogen production converter based on controllable pulse wave multiplication balance reactor

Abstract

The invention discloses a 36-pulse-wave hydrogen production converter based on a controllable pulse wave multiplication balance reactor, and belongs to the technical field of power electronics. The problems that the input current THD and the output voltage ripple of an existing 24-pulse thyristor rectification hydrogen production converter are high, and the number of needed large-current thyristors is large are solved. A nine-phase half-wave thyristor bridge, an auxiliary single-phase thyristor rectifier bridge and a balance reactor with a secondary side form a 36-pulse-wave hydrogen production converter, and the balance reactor with the secondary side and the auxiliary single-phase thyristor rectifier bridge form a controllable pulse wave multiplication balance reactor. The hydrogen production converter with 36 pulse waves can be obtained by controlling thyristors in the nine-phase half-wave thyristor bridge and the auxiliary single-phase thyristor rectifier bridge and reasonably designing the turn ratio of primary and secondary side windings of the balance reactor with the secondary side. According to the scheme of the rectifier, only 18 large-current thyristors are needed, and the rectifier is mainly used for new energy hydrogen production and application scenes with high requirements for electric energy quality.

Description

Technical Field

[0001] The invention belongs to the technical field of power electronics. Background Art

[0002] In large-scale renewable energy hydrogen production systems, the power level of hydrogen production converters is usually MW or even GW. In order to meet the high power requirements of hydrogen production rectifiers, thyristor-based 12-pulse rectifiers are usually used. This solution has the advantages of high efficiency, mature technology, and low cost. However, it has problems such as low power factor, high input current harmonic content, and large output voltage ripple. In order to solve the above problems, researchers have proposed a variety of solutions, which can be divided into three types. The first is to use a hydrogen production converter solution based on a 12-pulse uncontrolled rectifier and a DC chopper. This solution can obtain a higher power factor and lower output voltage ripple, but the input current still contains a large amount of harmonics when used alone. The second is to use multiple groups of three-phase PWM rectifiers in parallel to form a high-power hydrogen production rectifier. This solution can obtain a higher power factor and make the input current close to sine, but the parallel operation of multiple three-phase PWM rectifiers will make the control and debugging of the hydrogen production rectifier very complicated, and the overload capacity of the hydrogen production rectifier is weak. The third is to further increase the pulse number of the hydrogen production rectifier to 24 pulses to further suppress the input current harmonics and output voltage ripple. However, this solution still has high input current THD and output voltage ripple, and requires 24 large current thyristors, which is a large number. Therefore, the above problems need to be solved urgently. Summary of the invention

[0003] The purpose of the present invention is to solve the problems of high input current THD and output voltage ripple of the existing 24-pulse thyristor rectified hydrogen production converter and a large number of required high-current thyristors. The present invention provides a 36-pulse hydrogen production converter based on a controllable pulse multiplication balancing reactor.

[0004] The 36-pulse hydrogen production converter based on the controllable pulse multiplication balancing reactor includes a first nine-phase phase-shifting transformer, a second nine-phase phase-shifting transformer, a first nine-phase half-wave thyristor bridge and a second nine-phase half-wave thyristor bridge; the first nine-phase phase-shifting transformer and the second nine-phase phase-shifting transformer are used to shift the phase of the three-phase voltage output by the power grid to generate two groups of nine-phase voltages with the same amplitude and a phase difference of 20°, and the two groups of nine-phase voltages are respectively input to the first nine-phase half-wave thyristor bridge and the second nine-phase half-wave thyristor bridge for rectification;

[0005] The 36-pulse hydrogen production converter also includes an inductor L s , trigger signal generator and controllable pulse multiplication balancing reactor;

[0006] The controllable pulse multiplication balancing reactor is used to multiply the pulse number of the three-phase current output by the power grid from 18 pulses to 36 pulses, and the controllable pulse multiplication balancing reactor includes a balancing reactor with a secondary side and an auxiliary single-phase thyristor rectifier bridge, and the primary and secondary winding turns ratio of the balancing reactor with a secondary side is 33;

[0007] The positive polarity output ends of the first nine-phase half-wave thyristor bridge and the second nine-phase half-wave thyristor bridge are respectively connected to the same-name end and the opposite-name end of the primary winding of the balancing reactor with the secondary side;

[0008] The central output of the primary winding of the balancing reactor with the secondary side is connected to the DC output terminal of the auxiliary single-phase thyristor rectifier bridge and the inductor L s The same-name end and the opposite-name end of the secondary winding of the balancing reactor with the secondary side are respectively connected to the first and second AC input terminals of the auxiliary single-phase thyristor rectifier bridge, the DC input terminal of the auxiliary single-phase thyristor rectifier bridge is simultaneously connected to the neutral point of the first nine-phase phase-shifting transformer and the second nine-phase phase-shifting transformer, and the negative electrode of the electrolytic cell, and the positive electrode of the electrolytic cell is connected to the inductor L s The other end is connected;

[0009] The trigger signal generator is used to perform zero-crossing detection on the phase of the A-phase voltage in the three-phase voltage output by the power grid, and when the phase of the A-phase voltage is 0 during the process of changing from negative to positive, three sets of trigger signals are generated to control the thyristor control ends of the first nine-phase half-wave thyristor bridge, the second nine-phase half-wave thyristor bridge and the auxiliary single-phase thyristor rectifier bridge respectively.

[0010] Preferably, the first group of trigger signals for controlling the first nine-phase half-wave thyristor bridge includes 9 trigger signals, and the 9 trigger signals respectively control the 9 thyristors of the first nine-phase half-wave thyristor bridge;

[0011] There is a one-to-one correspondence between the nine thyristors of the first nine-phase half-wave thyristor bridge and the nine-phase voltage outputted by it, and the conduction angle of the thyristor corresponding to the first phase voltage outputted by the first nine-phase half-wave thyristor bridge is α, and the phase angle of the trigger signal of the thyristor corresponding to the first phase voltage is: obtained by the phase shift α when the phase of the A phase voltage in the three-phase voltage outputted by the power grid is 0 during the process from negative to positive;

[0012] The phase angles of the trigger signals of the nine thyristors corresponding to the nine-phase voltage output by the first nine-phase half-wave thyristor bridge increase from the first phase to the ninth phase, and the phase angles of the trigger signals of the two thyristors corresponding to the two adjacent phase voltages differ by 40°;

[0013] A set of trigger signals for controlling the second nine-phase half-wave thyristor bridge includes nine trigger signals, and the nine trigger signals respectively control the nine thyristors of the second nine-phase half-wave thyristor bridge;

[0014] The phase angle of the trigger signal of the thyristor corresponding to each phase voltage in the second nine-phase half-wave thyristor bridge differs by 20° from the phase angle of the trigger signal of the thyristor corresponding to the corresponding phase voltage in the first nine-phase half-wave thyristor bridge, and the phase angle of the trigger signal of the thyristor in the second nine-phase half-wave thyristor bridge corresponding to the same-phase voltage is greater than the phase angle of the trigger signal of the thyristor in the first nine-phase half-wave thyristor bridge;

[0015] A set of trigger signals for controlling the auxiliary single-phase thyristor rectifier bridge includes four trigger signals, and the four trigger signals respectively control the four thyristors of the auxiliary single-phase thyristor rectifier bridge, and the four thyristors are diagonally turned on, and the trigger signals received by the two thyristors located at the diagonals are the same;

[0016] The phase angle of the trigger signal received by the thyristor in the upper bridge arm of the same bridge arm in the auxiliary single-phase thyristor rectifier bridge is β1, and β1=α+10°, and the phase angle of the trigger signal received by the thyristor in the lower bridge arm of the same bridge arm is β2, and β2=α+30°.

[0017] Preferably, the voltage with the smallest phase output by the first nine-phase half-wave thyristor bridge is used as the first phase voltage output by the first nine-phase half-wave thyristor bridge.

[0018] Preferably, the conduction period of the thyristors in the auxiliary single-phase thyristor rectifier bridge is 1 / 9 of the conduction period of the thyristors in the first nine-phase half-wave thyristor bridge.

[0019] Preferably, the turns ratio between the primary and secondary windings of the balancing reactor with a secondary winding is 33.

[0020] Preferably, the auxiliary single-phase thyristor rectifier bridge includes thyristor T1, thyristor T2, thyristor T3 and thyristor T4;

[0021] After the anode of thyristor T1 is connected to the cathode of thyristor T3, it serves as the first AC input terminal of the auxiliary single-phase thyristor rectifier bridge;

[0022] After the anode of thyristor T2 is connected to the cathode of thyristor T4, it serves as the second AC input terminal of the auxiliary single-phase thyristor rectifier bridge;

[0023] After the cathode of thyristor T1 is connected to the cathode of thyristor T2, it serves as the DC output terminal of the auxiliary single-phase thyristor rectifier bridge;

[0024] After the anode of the thyristor T3 is connected to the anode of the thyristor T4, it serves as the DC input terminal of the auxiliary single-phase thyristor rectifier bridge.

[0025] Preferably, the voltage across the secondary winding of the balancing reactor with a secondary side is u s , the voltage across the electrolytic cell is ud , the controllable pulse multiplication balancing reactor includes three working modes, specifically:

[0026] Working mode Ⅰ: When -u s >u d When the thyristors in the first nine-phase half-wave thyristor bridge connected to the same-name end of the primary winding of the balancing reactor with the secondary side are in the reverse blocking state, and no current flows; the second nine-phase half-wave thyristor bridge connected to the opposite-name end of the primary winding of the balancing reactor with the secondary side is in the forward conduction state, and current flows; at the same time, in the auxiliary single-phase thyristor rectifier bridge connected to the secondary winding of the balancing reactor with the secondary side, thyristors T1 and T4 are in the reverse blocking state, and no current flows, and thyristors T2 and T3 are in the forward conduction state, and current flows, and the auxiliary single-phase thyristor rectifier bridge and the second nine-phase half-wave thyristor bridge jointly supply power to the electrolyzer;

[0027] Working mode II: When |u s | d When the first nine-phase half-wave thyristor bridge connected to the same-name end of the primary winding of the balancing reactor with the secondary side and the second nine-phase half-wave thyristor bridge connected to the opposite-name end of the primary winding of the balancing reactor with the secondary side are both in the forward conduction state, and current flows through them. At the same time, the thyristors T1 to T4 in the auxiliary single-phase thyristor rectifier bridge connected to the secondary winding of the balancing reactor with the secondary side are in the reverse blocking state, and no current flows through them. The first nine-phase half-wave thyristor bridge and the second nine-phase half-wave thyristor bridge jointly supply power to the electrolyzer;

[0028] Working mode III: When u s >u d At this time, the first nine-phase half-wave thyristor bridge connected to the same-name end of the primary winding of the balancing reactor with the secondary side is in the forward conduction state, and current flows through it; the second nine-phase half-wave thyristor bridge connected to the opposite-name end of the primary winding of the balancing reactor with the secondary side is in the reverse blocking state, and no current flows through it. At the same time, in the auxiliary single-phase thyristor rectifier bridge connected to the secondary winding of the balancing reactor with the secondary side, thyristors T2 and T3 are in the reverse blocking state, and no current flows through it, and thyristors T1 and T4 are in the forward conduction state, and current flows through it. The auxiliary single-phase thyristor rectifier bridge and the first nine-phase half-wave thyristor bridge jointly supply power to the electrolyzer.

[0029] Advantages of the present invention:

[0030] ​The present invention provides a 36-pulse hydrogen production converter based on a controllable pulse multiplication balancing reactor, which has the advantages of low input current THD, small conduction loss and low output voltage ripple. It only needs to introduce a controllable pulse multiplication balancing reactor on the DC side of two sets of parallel nine-phase half-wave thyristor bridges to modulate the state number of the output current of the first nine-phase half-wave thyristor bridge and the second nine-phase half-wave thyristor bridge, thereby doubling the pulse number of the parallel 18-pulse rectifier by 2 times, effectively suppressing the input current harmonics and output voltage pulsation of the parallel 18-pulse rectifier, so that the input current THD of the rectifier can meet the requirements of high-power hydrogen production. Among them, the parallel 18-pulse rectifier is composed of the first nine-phase half-wave thyristor bridge, the first nine-phase half-wave thyristor bridge and the balancing reactor with a secondary side.

[0031] Compared with the existing hydrogen production converter based on 24-pulse thyristor rectification, the 36-pulse hydrogen production converter based on controllable pulse multiplication balancing reactor of the present invention has the advantages of less number of high-current thyristors required, better harmonic suppression effect and small output voltage ripple. The present invention only needs to use two simple nine-phase phase-shifting transformers, two nine-phase half-wave thyristor bridges, an auxiliary single-phase thyristor rectifier bridge and a balancing reactor with a secondary side. By reasonably designing the turns ratio of the balancing reactor with a secondary side, the ability to double the pulse number of the rectifier can be obtained. It is mainly used in applications where the power quality requirements of the hydrogen production converter are high. The present invention has the advantages of simple circuit structure, low cost and high reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is a structural schematic diagram of a 36-pulse hydrogen production converter based on a controllable pulse multiplication balancing reactor according to the present invention;

[0033] Figure 2 It is a schematic diagram of the current loop when the controllable pulse multiplication balancing reactor works in mode I;

[0034] Figure 3 It is a schematic diagram of the current loop when the controllable pulse multiplication balancing reactor works in mode II;

[0035] Figure 4 It is a schematic diagram of the current loop when the controllable pulse multiplication balancing reactor works in mode III;

[0036] in, Figures 1 to 4 middle,

[0037] i A 、i B 、i C They are the three-phase currents a, b and c output from the power grid respectively;

[0038] u A 、u B 、u CThey are the three-phase voltages a, b and c output from the power grid respectively;

[0039] i d1 is the current outputted from the positive polarity output terminal of the first nine-phase half-wave thyristor bridge 3;

[0040] i d2 is the current outputted from the positive polarity output terminal of the second nine-phase half-wave thyristor bridge 4;

[0041] I d is the current input to the electrolytic cell 7;

[0042] u d1 is the output voltage of the first nine-phase half-wave thyristor bridge 3;

[0043] u d2 is the output voltage of the second nine-phase half-wave thyristor bridge 4;

[0044] u d is the voltage across the electrolytic cell 7;

[0045] u p is the voltage across the primary winding of the balancing reactor 5 with a secondary side;

[0046] u s is the voltage across the secondary winding of the balancing reactor 5 with a secondary side;

[0047] i s It is the current outputted by the secondary winding of the balancing inductor 5 with a secondary side. DETAILED DESCRIPTION

[0048] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0050] Specific implementation method 1. Combination Figure 1As shown, the 36-pulse hydrogen production converter based on the controllable pulse multiplication balancing reactor described in the first embodiment includes a first nine-phase phase-shifting transformer 1, a second nine-phase phase-shifting transformer 2, a first nine-phase half-wave thyristor bridge 3 and a second nine-phase half-wave thyristor bridge 4; the first nine-phase phase-shifting transformer 1 and the second nine-phase phase-shifting transformer 2 are used to shift the phase of the three-phase voltage output by the power grid to generate two groups of nine-phase voltages with the same amplitude and a phase difference of 20°, and the two groups of nine-phase voltages are respectively input to the first nine-phase half-wave thyristor bridge 3 and the second nine-phase half-wave thyristor bridge 4 for rectification;

[0051] The 36-pulse hydrogen production converter also includes an inductor L s , a trigger signal generator 8 and a controllable pulse wave multiplication balancing reactor;

[0052] The controllable pulse multiplication balancing reactor is used to multiply the pulse number of the three-phase current output by the power grid from 18 pulses to 36 pulses, and the controllable pulse multiplication balancing reactor includes a balancing reactor 5 with a secondary side and an auxiliary single-phase thyristor rectifier bridge 6;

[0053] The positive output ends of the first nine-phase half-wave thyristor bridge 3 and the second nine-phase half-wave thyristor bridge 4 are respectively connected to the same-name end and the opposite-name end of the primary winding of the balancing reactor 5 with a secondary side;

[0054] The central output of the primary winding of the balancing reactor 5 with the secondary side is connected to the DC output end of the auxiliary single-phase thyristor rectifier bridge 6 and the inductor L s The same-name end and the opposite-name end of the secondary winding of the balancing reactor 5 with the secondary side are respectively connected to the first and second AC input ends of the auxiliary single-phase thyristor rectifier bridge 6, and the DC input end of the auxiliary single-phase thyristor rectifier bridge 6 is simultaneously connected to the neutral point of the first nine-phase phase-shifting transformer 1 and the second nine-phase phase-shifting transformer 2, and the negative electrode of the electrolytic cell 7, and the positive electrode of the electrolytic cell 7 is connected to the inductor L s The other end is connected;

[0055] The trigger signal generator 8 is used to perform zero-crossing detection on the phase of the A-phase voltage in the three-phase voltage output by the power grid, and when the phase of the A-phase voltage is 0 during the process of changing from negative to positive, three sets of trigger signals are generated to control the thyristor control ends of each of the first nine-phase half-wave thyristor bridge 3, the second nine-phase half-wave thyristor bridge 4 and the auxiliary single-phase thyristor rectifier bridge 6 respectively.

[0056] In specific application, the turns ratio of the primary winding to the secondary winding of the balancing inductor 5 with a secondary winding is 3:3.

[0057] The 36-pulse hydrogen production converter based on a controllable pulse multiplication balancing reactor described in this embodiment only needs to introduce a controllable pulse multiplication balancing reactor on the DC side of two sets of parallel nine-phase half-wave thyristor bridges to modulate the state number of the output current of the first nine-phase half-wave thyristor bridge and the second nine-phase half-wave thyristor bridge, thereby doubling the pulse number of the parallel 18-pulse rectifier, effectively suppressing the input current harmonics and output voltage pulsation of the parallel 18-pulse rectifier, so that the input current THD of the rectifier can meet the requirements of high-power hydrogen production. It has the advantages of low input current THD, small conduction loss and low output voltage ripple. The parallel 18-pulse rectifier is composed of a first nine-phase half-wave thyristor bridge, a first nine-phase half-wave thyristor bridge and a balancing reactor 5 with a secondary side.

[0058] Compared with the existing hydrogen production converter based on 24-pulse thyristor rectification, the 36-pulse hydrogen production converter based on controllable pulse multiplication balancing reactor of the present invention has the advantages of less number of high-current thyristors required, better harmonic suppression effect and small output voltage ripple. The present invention only needs to use two simple nine-phase phase-shifting transformers, two nine-phase half-wave thyristor bridges, an auxiliary single-phase thyristor rectifier bridge 6 and a balancing reactor 5 with a secondary side. By reasonably designing the turns ratio of the balancing reactor with a secondary side, the ability to double the pulse number of the rectifier can be obtained. It is mainly used in applications where the power quality requirements of the hydrogen production converter are high. The present invention has the advantages of simple circuit structure, low cost and high reliability.

[0059] Further, the first group of trigger signals for controlling the first nine-phase half-wave thyristor bridge 3 includes 9 trigger signals, and the 9 trigger signals respectively control the 9 thyristors of the first nine-phase half-wave thyristor bridge 3;

[0060] There is a one-to-one correspondence between the nine thyristors of the first nine-phase half-wave thyristor bridge 3 and the nine-phase voltage outputted by it, and the conduction angle of the thyristor corresponding to the first phase voltage outputted by the first nine-phase half-wave thyristor bridge 3 is α, and the phase angle of the trigger signal of the thyristor corresponding to the first phase voltage is: obtained by the phase shift α when the phase of the A phase voltage in the three-phase voltage outputted by the power grid is 0 during the process from negative to positive;

[0061] In specific application, the voltage with the smallest phase output by the first nine-phase half-wave thyristor bridge 3 is used as the first phase voltage output by the first nine-phase half-wave thyristor bridge 3;

[0062] The phase angles of the trigger signals of the nine thyristors corresponding to the nine-phase voltage output by the first nine-phase half-wave thyristor bridge 3 increase from the first phase to the ninth phase, and the phase angles of the trigger signals of the two thyristors corresponding to the two adjacent phase voltages differ by 40°;

[0063] A set of trigger signals for controlling the second nine-phase half-wave thyristor bridge 4 includes nine trigger signals, and the nine trigger signals respectively control the nine thyristors of the second nine-phase half-wave thyristor bridge 4;

[0064] The phase angle of the trigger signal of the thyristor corresponding to each phase voltage in the second nine-phase half-wave thyristor bridge 4 differs by 20° from the phase angle of the trigger signal of the thyristor corresponding to the corresponding phase voltage in the first nine-phase half-wave thyristor bridge 3, and the phase angle of the trigger signal of the thyristor in the second nine-phase half-wave thyristor bridge 4 corresponding to the same-phase voltage is greater than the phase angle of the trigger signal of the thyristor in the first nine-phase half-wave thyristor bridge 3;

[0065] A set of trigger signals for controlling the auxiliary single-phase thyristor rectifier bridge 6 includes four trigger signals, and the four trigger signals respectively control the four thyristors of the auxiliary single-phase thyristor rectifier bridge 6, and the four thyristors are diagonally turned on, and the trigger signals received by the two thyristors located at the diagonals are the same;

[0066] The phase angle of the trigger signal received by the thyristor in the upper bridge arm of the same bridge arm in the auxiliary single-phase thyristor rectifier bridge 6 is β1, and β1=α+10°, and the phase angle of the trigger signal received by the thyristor in the lower bridge arm of the same bridge arm is β2, and β2=α+30°.

[0067] In this preferred embodiment, the purpose of setting the phase angle of the trigger signal is to regulate the grid-side input current and DC-side output voltage levels by means of the phase angle of the trigger signal, thereby significantly reducing the complexity of regulating the input current and DC-side output voltage.

[0068] In specific application, the conduction period of the thyristors in the auxiliary single-phase thyristor rectifier bridge 6 is 1 / 9 of the conduction period of the thyristors in the first nine-phase half-wave thyristor bridge 3. This setting keeps the rectifier always working in the standard 36-pulse state.

[0069] See also Figure 1 , further defining the structure of the auxiliary single-phase thyristor rectifier bridge 6, the auxiliary single-phase thyristor rectifier bridge 6 comprising a thyristor T1, a thyristor T2, a thyristor T3 and a thyristor T4;

[0070] After the anode of the thyristor T1 is connected to the cathode of the thyristor T3, it serves as the first AC input terminal of the auxiliary single-phase thyristor rectifier bridge 6;

[0071] After the anode of the thyristor T2 is connected to the cathode of the thyristor T4, it serves as the second AC input terminal of the auxiliary single-phase thyristor rectifier bridge 6;

[0072] After the cathode of thyristor T1 is connected to the cathode of thyristor T2, it serves as the DC output terminal of the auxiliary single-phase thyristor rectifier bridge 6;

[0073] After the anode of the thyristor T3 is connected to the anode of the thyristor T4 , it serves as a DC input terminal of the auxiliary single-phase thyristor rectifier bridge 6 .

[0074] The voltage across the secondary winding of the balancing reactor 5 with a secondary side is u s , the voltage across the electrolytic cell 7 is u d ; The controllable pulse multiplication balancing reactor includes three working modes, specifically:

[0075] Working mode Ⅰ: When -u s >u d At this time, all thyristors in the first nine-phase half-wave thyristor bridge 3 connected to the same-name end of the primary winding of the balancing reactor 5 with the secondary side are in the reverse blocking state, and no current flows; the second nine-phase half-wave thyristor bridge 4 connected to the opposite-name end of the primary winding of the balancing reactor 5 with the secondary side is in the forward conduction state, and current flows; at the same time, in the auxiliary single-phase thyristor rectifier bridge 6 connected to the secondary winding of the balancing reactor 5 with the secondary side, the thyristors T1 and T4 are in the reverse blocking state, and no current flows, and the thyristors T2 and T3 are in the forward conduction state, and current flows, and the auxiliary single-phase thyristor rectifier bridge 6 and the second nine-phase half-wave thyristor bridge 4 jointly supply power to the electrolytic cell 7;

[0076] Working mode II: When |u s | d When the first nine-phase half-wave thyristor bridge 3 connected to the same-name end of the primary winding of the balancing reactor 5 with the secondary side and the second nine-phase half-wave thyristor bridge 4 connected to the opposite-name end of the primary winding of the balancing reactor 5 with the secondary side are both in the forward conduction state, and current flows through them. At the same time, the thyristors T1 to T4 in the auxiliary single-phase thyristor rectifier bridge 6 connected to the secondary winding of the balancing reactor 5 with the secondary side are in the reverse blocking state, and no current flows through them. The first nine-phase half-wave thyristor bridge 3 and the second nine-phase half-wave thyristor bridge 4 jointly supply power to the electrolytic cell 7;

[0077] Working mode III: When u s >u d At this time, the first nine-phase half-wave thyristor bridge 3 connected to the same-name end of the primary winding of the balancing reactor 5 with the secondary side is in the forward conduction state, and current flows through it; the second nine-phase half-wave thyristor bridge 4 connected to the opposite-name end of the primary winding of the balancing reactor 5 with the secondary side is in the reverse blocking state, and no current flows through it. At the same time, in the auxiliary single-phase thyristor rectifier bridge 6 connected to the secondary winding of the balancing reactor 5 with the secondary side, the thyristors T2 and T3 are in the reverse blocking state, and no current flows through it, and the thyristors T1 and T4 are in the forward conduction state, and current flows through it. The auxiliary single-phase thyristor rectifier bridge 6 and the first nine-phase half-wave thyristor bridge 3 jointly supply power to the electrolytic cell 7.

[0078] Principle analysis: ​

[0079] The 36-pulse hydrogen production converter based on controllable pulse multiplication balancing reactor of the present invention modulates the output current of the first nine-phase half-wave thyristor bridge 3 and the second nine-phase half-wave thyristor bridge 4 by constructing a pulse multiplication circuit on the DC side of the parallel 18-pulse thyristor rectifier, and sets the primary and secondary winding turns ratios of the balancing reactor 5 with secondary side, so that the current output by the first nine-phase half-wave thyristor bridge 3 and the second nine-phase half-wave thyristor bridge 4 are both three-level step DC currents. According to the relationship between the AC and DC side voltages and the AC and DC side currents of the 18-pulse rectifier, the pulse number of the 18-pulse rectifier is increased to twice the original, that is, from 18 pulses to 36 pulses, so as to effectively suppress the input current harmonics and output voltage pulsation of the 36-pulse rectifier without substantially increasing the complexity of the rectifier.

[0080] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be used in other described embodiments.

Claims

1. A 36-pulse hydrogen production converter based on a controllable pulse multiplication balancing reactor, comprising a first nine-phase phase-shifting transformer (1), a second nine-phase phase-shifting transformer (2), a first nine-phase half-wave thyristor bridge (3) and a second nine-phase half-wave thyristor bridge (4); the first nine-phase phase-shifting transformer (1) and the second nine-phase phase-shifting transformer (2) are used to shift the phase of the three-phase voltage output by the power grid to generate two groups of nine-phase voltages with the same amplitude and a phase difference of 20°, and the two groups of nine-phase voltages are respectively input to the first nine-phase half-wave thyristor bridge (3) and the second nine-phase half-wave thyristor bridge (4) for rectification; characterized in that: The 36-pulse hydrogen production converter also includes an inductor L s , a trigger signal generator (8) and a controllable pulse wave multiplication balancing reactor; The controllable pulse multiplication balancing reactor is used to multiply the pulse number of the three-phase current output by the power grid from 18 pulses to 36 pulses, and the controllable pulse multiplication balancing reactor comprises a balancing reactor with a secondary side (5) and an auxiliary single-phase thyristor rectifier bridge (6), and the primary and secondary winding turns ratio of the balancing reactor with a secondary side (5) is 33; The positive polarity output ends of the first nine-phase half-wave thyristor bridge (3) and the second nine-phase half-wave thyristor bridge (4) are respectively connected to the same-name end and the opposite-name end of the primary winding of the balancing reactor (5) with a secondary side; The central output of the primary winding of the balancing reactor (5) with the secondary side is connected to the DC output end of the auxiliary single-phase thyristor rectifier bridge (6) and the inductor L s The same-name end and the opposite-name end of the secondary winding of the balancing reactor (5) with a secondary side are respectively connected to the first and second AC input ends of the auxiliary single-phase thyristor rectifier bridge (6); the DC input end of the auxiliary single-phase thyristor rectifier bridge (6) is simultaneously connected to the neutral point of the first nine-phase phase-shifting transformer (1) and the second nine-phase phase-shifting transformer (2), and the negative electrode of the electrolytic cell (7); the positive electrode of the electrolytic cell (7) is connected to the inductor L s The other end is connected; The trigger signal generator (8) is used to perform zero-crossing detection on the phase of the A-phase voltage in the three-phase voltage output by the power grid, and when the phase of the A-phase voltage is 0 during the process of changing from negative to positive, three groups of trigger signals are generated to respectively control the thyristor control ends of the first nine-phase half-wave thyristor bridge (3), the second nine-phase half-wave thyristor bridge (4) and the auxiliary single-phase thyristor rectifier bridge (6).

2. The 36-pulse hydrogen production converter based on a controllable pulse multiplication balancing reactor according to claim 1 is characterized in that: A first group of trigger signals for controlling a first nine-phase half-wave thyristor bridge (3) comprises nine trigger signals, and the nine trigger signals respectively control nine thyristors of the first nine-phase half-wave thyristor bridge (3); There is a one-to-one correspondence between the nine thyristors of the first nine-phase half-wave thyristor bridge (3) and the nine-phase voltage outputted by it, and the conduction angle of the thyristor corresponding to the first phase voltage outputted by the first nine-phase half-wave thyristor bridge (3) is α, and the phase angle of the trigger signal of the thyristor corresponding to the first phase voltage is: obtained by shifting the phase by α when the phase of the A phase voltage in the three-phase voltage outputted by the power grid changes from negative to positive and the phase is 0; The phase angles of the trigger signals of the nine thyristors corresponding to the nine-phase voltage output by the first nine-phase half-wave thyristor bridge (3) increase sequentially from the first phase to the ninth phase, and the phase angles of the trigger signals of the two thyristors corresponding to the two adjacent phase voltages differ by 40°; A group of trigger signals for controlling the second nine-phase half-wave thyristor bridge (4) includes nine trigger signals, and the nine trigger signals respectively control the nine thyristors of the second nine-phase half-wave thyristor bridge (4); The phase angle of the trigger signal of the thyristor corresponding to each phase voltage in the second nine-phase half-wave thyristor bridge (4) differs by 20° from the phase angle of the trigger signal of the thyristor corresponding to the corresponding phase voltage in the first nine-phase half-wave thyristor bridge (3) to which it corresponds, and the phase angle of the trigger signal of the thyristor in the second nine-phase half-wave thyristor bridge (4) corresponding to the same-phase voltage is greater than the phase angle of the trigger signal of the thyristor in the first nine-phase half-wave thyristor bridge (3) to which it corresponds; A set of trigger signals for controlling the auxiliary single-phase thyristor rectifier bridge (6) comprises four trigger signals, the four trigger signals respectively controlling four thyristors of the auxiliary single-phase thyristor rectifier bridge (6), the four thyristors being diagonally conductive, and the trigger signals received by two thyristors located at the diagonals being the same; The phase angle of the trigger signal received by the thyristor in the upper bridge arm of the same bridge arm in the auxiliary single-phase thyristor rectifier bridge (6) is β1, and β1=α+10°, and the phase angle of the trigger signal received by the thyristor in the lower bridge arm of the same bridge arm is β2, and β2=α+30°.

3. The 36-pulse hydrogen production converter based on a controllable pulse multiplication balancing reactor according to claim 2 is characterized in that: The voltage with the smallest phase output by the first nine-phase half-wave thyristor bridge (3) is used as the first phase voltage output by the first nine-phase half-wave thyristor bridge (3).

4. The 36-pulse hydrogen production converter based on a controllable pulse multiplication balancing reactor according to claim 2 is characterized in that: The conduction period of the thyristors in the auxiliary single-phase thyristor rectifier bridge (6) is 1 / 9 of the conduction period of the thyristors in the first nine-phase half-wave thyristor bridge (3).

5. The 36-pulse hydrogen production converter based on controllable pulse multiplication balancing reactor according to claim 1 is characterized in that: The turns ratio between the primary and secondary windings of the balancing inductor (5) with a secondary winding is 3:

3.

6. The 36-pulse hydrogen production converter based on a controllable pulse multiplication balancing reactor according to claim 1 is characterized in that: The auxiliary single-phase thyristor rectifier bridge (6) comprises a thyristor T1, a thyristor T2, a thyristor T3 and a thyristor T4; After the anode of the thyristor T1 is connected to the cathode of the thyristor T3, it serves as the first AC input terminal of the auxiliary single-phase thyristor rectifier bridge (6); After the anode of the thyristor T2 is connected to the cathode of the thyristor T4, it serves as the second AC input terminal of the auxiliary single-phase thyristor rectifier bridge (6); After the cathode of the thyristor T1 is connected to the cathode of the thyristor T2, it serves as the DC output end of the auxiliary single-phase thyristor rectifier bridge (6); After the anode of the thyristor T3 is connected to the anode of the thyristor T4, it serves as the DC input terminal of the auxiliary single-phase thyristor rectifier bridge (6).

7. The 36-pulse hydrogen production converter based on a controllable pulse multiplication balancing reactor according to claim 6 is characterized in that: The voltage across the secondary winding of the balancing reactor (5) with a secondary side is u s , the voltage across the electrolytic cell (7) is u d , the controllable pulse multiplication balancing reactor includes three working modes, specifically: Working mode Ⅰ: When -u s >u d When the thyristors in the first nine-phase half-wave thyristor bridge (3) connected to the same-name end of the primary winding of the balancing reactor (5) with the secondary side are in a reverse blocking state, and no current flows through; the second nine-phase half-wave thyristor bridge (4) connected to the opposite-name end of the primary winding of the balancing reactor (5) with the secondary side is in a forward conduction state, and current flows through; at the same time, in the auxiliary single-phase thyristor rectifier bridge (6) connected to the secondary winding of the balancing reactor (5) with the secondary side, the thyristors T1 and T4 are in a reverse blocking state, and no current flows through, and the thyristors T2 and T3 are in a forward conduction state, and current flows through, and the auxiliary single-phase thyristor rectifier bridge (6) and the second nine-phase half-wave thyristor bridge (4) jointly supply power to the electrolytic cell (7); Working mode II: When |u s | d When the first nine-phase half-wave thyristor bridge (3) connected to the same-name end of the primary winding of the balancing reactor (5) with the secondary side and the second nine-phase half-wave thyristor bridge (4) connected to the opposite-name end of the primary winding of the balancing reactor (5) with the secondary side are both in a forward conduction state, with current flowing through them; at the same time, the thyristors T1 to T4 in the auxiliary single-phase thyristor rectifier bridge (6) connected to the secondary winding of the balancing reactor (5) with the secondary side are in a reverse blocking state, with no current flowing through them; the first nine-phase half-wave thyristor bridge (3) and the second nine-phase half-wave thyristor bridge (4) jointly supply power to the electrolytic cell (7);​ Working mode III: When u s >u d When the first nine-phase half-wave thyristor bridge (3) connected to the same-name end of the primary winding of the balancing reactor (5) with the secondary side is in a forward conduction state, with current flowing through it; the second nine-phase half-wave thyristor bridge (4) connected to the opposite-name end of the primary winding of the balancing reactor (5) with the secondary side is in a reverse blocking state, with no current flowing through it; at the same time, in the auxiliary single-phase thyristor rectifier bridge (6) connected to the secondary winding of the balancing reactor (5) with the secondary side, the thyristors T2 and T3 are in a reverse blocking state, with no current flowing through it, and the thyristors T1 and T4 are in a forward conduction state, with current flowing through it, and the auxiliary single-phase thyristor rectifier bridge (6) and the first nine-phase half-wave thyristor bridge (3) jointly supply power to the electrolytic cell (7).

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