36-pulse rectifier with passive tripler auxiliary circuit on dc side

Abstract

The 36-pulse rectifier with passive three-multiplication auxiliary circuit on the DC side belongs to the technical field of power electronics. The problem of the existing 36-pulse rectifier is solved, that is, the turns ratio of the secondary side to the primary side of the auxiliary transformer in the pulse multiplication circuit is large, which leads to the increase of leakage inductance, reduces the harmonic suppression effect, and further leads to the problem of large input current harmonics of the rectifier and the increase of manufacturing difficulty. The passive three-multiplication auxiliary circuit is added to the DC side of the existing series type 12-pulse rectifier, the turns ratio of the primary winding and the secondary winding of the auxiliary transformer with multiple taps is optimized, so that the conduction time of the auxiliary diode D f1 and the auxiliary diode D f2 is 1 / 6 of the input voltage period, respectively, the output current of the first diode rectifier bridge and the second diode rectifier bridge is four-level current with equal width, and then the pulse number is multiplied to 36 according to the AC / DC side current relationship and the DC side voltage relationship. The present application is mainly used for realizing pulse multiplication.

Description

Technical Field

[0001] This invention belongs to the field of power electronics technology. Background Technology

[0002] Series-type 12-pulse rectifiers are widely used in medium- and high-voltage, high-power applications such as ship electric propulsion, high-voltage direct current transmission, and metal smelting due to their advantages of simple circuit structure, high reliability, and low cost. However, due to the nonlinearity of the rectifier devices and the limitations of the rectifier structure, series-type 12-pulse rectifiers not only have high input current harmonic content (THD not less than 10%), but also large output voltage ripple, which increases the weight and cost of the DC-side filter.

[0003] To effectively suppress input current harmonics and output voltage ripple in a series-type 12-pulse rectifier, increasing the rectifier's pulse count is a common method. Existing technologies involve introducing a pulse multiplier circuit on the DC side of the series-type 12-pulse rectifier to increase the pulse count and achieve a 36-pulse rectifier. However, the auxiliary transformer in this DC-side pulse multiplier circuit has a large turns ratio between the secondary and primary sides, resulting in significant leakage inductance and reduced harmonic suppression. This leads to relatively high input current harmonics. Furthermore, the large turns ratio increases the manufacturing difficulty of the transformer. Additionally, the pulse multiplier circuit on the DC side requires two single-phase auxiliary rectifier bridges to achieve the multiplication function, necessitating eight additional diodes. This complicates the overall structure of the 36-pulse rectifier. Therefore, these problems urgently need to be addressed. Summary of the Invention

[0004] The purpose of this invention is to address the problem in existing 36-pulse rectifiers where the secondary and primary windings of the auxiliary transformer have a large turns ratio, leading to increased leakage inductance, reduced harmonic suppression, higher input current harmonics, and increased manufacturing difficulty. This invention provides three different structures for 36-pulse rectifiers with passive tripler auxiliary circuits on the DC side.

[0005] First structure:

[0006] A 36-pulse rectifier with a passive tripler auxiliary circuit on the DC side includes a series-type 12-pulse rectifier and a passive tripler auxiliary circuit. The passive tripler auxiliary circuit triples the 12 pulses of the series-type 12-pulse rectifier by a factor of 3 to obtain a 36-pulse rectifier. The series-type 12-pulse rectifier includes a phase-shifting transformer, a first diode rectifier bridge, and a second diode rectifier bridge. The passive tripler auxiliary circuit includes an auxiliary single-phase rectifier bridge, a three-winding auxiliary transformer with double taps, a balancing reactor, and an auxiliary diode D. f1 and auxiliary diode D f2 Capacitors C1 and C2;

[0007] A phase-shifting transformer is used to shift the three-phase voltage input from the power grid to generate two three-phase voltages with a phase difference of 30° and the same amplitude. The two three-phase voltages generated by the phase-shifting transformer are then sent to the first diode rectifier bridge and the second diode rectifier bridge, respectively.

[0008] The positive output terminal of the first diode rectifier bridge is connected to one end of capacitor C1 and auxiliary diode D. f1 After the cathodes are connected simultaneously, they are connected to the positive output terminal of the 36-pulse rectifier and the positive terminal of the load.

[0009] The negative output terminal of the second diode rectifier bridge is connected to one end of capacitor C2 and auxiliary diode D. f2 After the anodes are connected simultaneously, they are connected to the negative output terminal of the 36-pulse rectifier and the negative polarity terminal of the load.

[0010] The positive output terminal of the auxiliary single-phase rectifier bridge is connected to the negative output terminal of the first diode rectifier bridge, and the negative output terminal of the auxiliary single-phase rectifier bridge is connected to the positive output terminal of the second diode rectifier bridge.

[0011] The opposite-named terminal A of the primary winding AB of the three-winding auxiliary transformer with double taps is connected to the same-named terminal D of the secondary winding CD of the three-winding auxiliary transformer with double taps, and then connected as the first tap of the three-winding auxiliary transformer with double taps to one input terminal of the auxiliary single-phase rectifier bridge.

[0012] The same-name terminal B of the primary winding AB of the three-winding auxiliary transformer with double taps is connected to the opposite-name terminal E of the secondary winding EF of the three-winding auxiliary transformer with double taps, and then connected to the center tap of the balancing reactor as the second tap of the three-winding auxiliary transformer with double taps.

[0013] The opposite-name terminal C of the secondary winding CD of the three-winding auxiliary transformer with double taps is connected to the other input terminal of the auxiliary single-phase rectifier bridge.

[0014] The corresponding terminal F of the secondary winding EF of the three-winding auxiliary transformer with double taps is connected to the auxiliary diode D. f1 anode and auxiliary diode D f2 The cathodes are connected simultaneously;

[0015] One end of the balancing reactor is connected to the other end of capacitor C1, and the other end of the balancing reactor is connected to the other end of capacitor C2.

[0016] By setting the turns ratio of the secondary winding CD to the primary winding AB of the three-winding auxiliary transformer with double taps, and the turns ratio of the secondary winding EF to the primary winding AB of the three-winding auxiliary transformer with double taps, the auxiliary diode D is made... f1 and auxiliary diode D f2The conduction time of each is 1 / 6 of the output voltage period of the secondary winding EF of the three-winding auxiliary transformer with double taps, so that the first diode rectifier bridge and the second diode rectifier bridge work simultaneously or alternately. When the first diode rectifier bridge and / or the second diode rectifier bridge are working, the current output by their rectifier bridge is a 4-level stepped DC current with equal width.

[0017] The second structure:

[0018] A 36-pulse rectifier with a passive tripler auxiliary circuit on the DC side includes a series 12-pulse rectifier and a passive tripler auxiliary circuit. The passive tripler auxiliary circuit is used to triple the 12 pulses of the series 12-pulse rectifier to obtain a 36-pulse rectifier. The series 12-pulse rectifier includes a phase-shifting transformer, a first diode rectifier bridge, and a second diode rectifier bridge.

[0019] The passive tripler auxiliary circuit includes an auxiliary full-wave rectifier, a three-winding auxiliary transformer with double taps, a balancing reactor, and an auxiliary diode D. f1 Auxiliary diode D f2 Capacitors C1 and C2;

[0020] A phase-shifting transformer is used to shift the three-phase voltage input from the power grid to generate two three-phase voltages with a phase difference of 30° and the same amplitude. The two three-phase voltages generated by the phase-shifting transformer are then sent to the first diode rectifier bridge and the second diode rectifier bridge, respectively.

[0021] The positive output terminal of the first diode rectifier bridge is connected to one end of capacitor C1 and auxiliary diode D. f1 After the cathodes are connected simultaneously, they are connected to the positive output terminal of the 36-pulse rectifier and the positive terminal of the load.

[0022] The negative output terminal of the first diode rectifier bridge is connected to the positive output terminal of the second diode rectifier bridge and the opposite terminal A of the primary winding AB of the three-winding auxiliary transformer with double taps.

[0023] The negative output terminal of the second diode rectifier bridge is connected to the output terminal of the auxiliary full-wave rectifier, one end of capacitor C2, and the auxiliary diode D. f2 The anodes are connected simultaneously;

[0024] The two input terminals of the auxiliary full-wave rectifier are connected to the opposite-name terminal E and the same-name terminal G of the secondary winding EG of the three-winding auxiliary transformer with double taps, respectively. The center tap F of the secondary winding EG of the three-winding auxiliary transformer with double taps is connected to the negative polarity terminal of the load as the negative output terminal of the 36-pulse rectifier; wherein, the center tap F is one tap of the three-winding auxiliary transformer with double taps.

[0025] After the same-name terminal B of the primary winding AB of the three-winding auxiliary transformer with double taps is connected to the opposite-name terminal C of its secondary winding CD, it is connected to the center tap of the balancing reactor as another tap of the three-winding auxiliary transformer with double taps.

[0026] The corresponding terminal D of the secondary winding CD of the three-winding auxiliary transformer with double taps and the auxiliary diode D f1 anode and auxiliary diode D f2 The cathodes are connected simultaneously;

[0027] One end of the balancing reactor is connected to the other end of capacitor C1, and the other end of the balancing reactor is connected to the other end of capacitor C2.

[0028] By setting the turns ratio of the secondary winding CD of the three-winding auxiliary transformer with double taps to its primary winding AB, and the turns ratio of the secondary winding EF or FG of the three-winding auxiliary transformer with double taps to its primary winding AB, the auxiliary diode D is made... f1 and auxiliary diode D f2 The conduction time of each diode rectifier bridge is 1 / 6 of the output voltage period of the secondary winding CD of the three-winding auxiliary transformer with double taps, thereby enabling the first diode rectifier bridge and the second diode rectifier bridge to work simultaneously or alternately. When the first diode rectifier bridge and / or the second diode rectifier bridge are working, the output current of their rectifier bridges is a 4-level stepped DC current with equal width.

[0029] The secondary winding EF is the winding between the opposite terminal E of the secondary winding EG and the center tap F of the secondary winding EG.

[0030] The secondary winding FG is the winding between the center tap F of the secondary winding EG and its corresponding terminal G.

[0031] The third structure:

[0032] A 36-pulse rectifier with a passive tripler auxiliary circuit on the DC side includes a series 12-pulse rectifier and a passive tripler auxiliary circuit. The passive tripler auxiliary circuit is used to triple the 12 pulses of the series 12-pulse rectifier to obtain a 36-pulse rectifier. The series 12-pulse rectifier includes a phase-shifting transformer, a first diode rectifier bridge, and a second diode rectifier bridge.

[0033] The passive tripler auxiliary circuit includes an auxiliary full-wave rectifier, a multi-winding auxiliary transformer with three taps, a balancing reactor, and an auxiliary diode D. f1 Auxiliary diode D f2 Capacitors C1 and C2;

[0034] A phase-shifting transformer is used to shift the three-phase voltage input from the power grid to generate two three-phase voltages with a phase difference of 30° and the same amplitude. The two three-phase voltages generated by the phase-shifting transformer are then sent to the first diode rectifier bridge and the second diode rectifier bridge, respectively.

[0035] The negative output terminal of the first diode rectifier bridge is connected to the positive output terminal of the second diode rectifier bridge and the opposite terminal A of the primary winding AB of the three-tap multi-winding auxiliary transformer.

[0036] The negative output terminal of the second diode rectifier bridge is connected to the output terminal of the auxiliary full-wave rectifier and one end of capacitor C2 at the same time.

[0037] The positive output terminal of the first diode rectifier bridge and the auxiliary diode D f1 Cathode, auxiliary diode D f2 After the cathode and one end of capacitor C1 are connected simultaneously, they are connected to the positive output terminal of the 36-pulse rectifier and the positive terminal of the load.

[0038] The two input terminals of the auxiliary full-wave rectifier are connected to the opposite-name terminal E and the same-name terminal G of the secondary winding EG of the three-tap multi-winding auxiliary transformer, respectively.

[0039] The center tap F of the secondary winding EG of the three-tap multi-winding auxiliary transformer is connected to the negative polarity terminal of the load as the negative output terminal of the 36-pulse rectifier; the center tap F is the No. 1 tap of the three-tap multi-winding auxiliary transformer.

[0040] The opposite terminal C of the secondary winding AC of a three-tap multi-winding auxiliary transformer and the auxiliary diode D f1 The anode connection of the secondary winding AC of the three-tapped multi-winding auxiliary transformer is such that the same-name terminal of AC is connected to the opposite-name terminal A of AC of AC and the primary winding AB, which is then used as the No. 2 tap of the three-tapped multi-winding auxiliary transformer.

[0041] The corresponding terminal D of the secondary winding BD of a three-tap multi-winding auxiliary transformer and the auxiliary diode D f2 The anode connection; after the opposite end of the secondary winding BD of the three-tapped multi-winding auxiliary transformer is connected to the same end B of its primary winding AB, it is connected to the center tap of the balancing reactor as the No. 3 tap of the three-tapped multi-winding auxiliary transformer.

[0042] By setting the turns ratio of the secondary winding AC to the primary winding AB of the three-tapped multi-winding auxiliary transformer, the turns ratio of the secondary winding EF or FG to the primary winding AB of the three-tapped multi-winding auxiliary transformer, and the turns ratio of the secondary winding BD to the primary winding AB of the three-tapped multi-winding auxiliary transformer, the auxiliary diode D is made... f1The conduction time is 1 / 6 of the output voltage period of the secondary winding AC of the three-tap multi-winding auxiliary transformer, causing the auxiliary diode D to... f2 The conduction time of each is 1 / 6 of the output voltage period of the secondary winding BD of the multi-winding auxiliary transformer with three taps, so that the first diode rectifier bridge and the second diode rectifier bridge work simultaneously or alternately. When the first diode rectifier bridge and / or the second diode rectifier bridge are working, the current output by the rectifier bridge is a 4-level stepped DC current with equal width.

[0043] Among them, the secondary winding EF is the winding between the opposite terminal E of the secondary winding EG and the center tap F of the secondary winding EG.

[0044] The secondary winding FG is the winding between the center tap F of the secondary winding EG and its corresponding terminal G.

[0045] The beneficial effects of this invention are:

[0046] This invention provides three types of 36-pulse rectifiers with passive tripling auxiliary circuits on the DC side. These rectifiers have advantages such as simple circuit structure, high reliability, effective suppression of input current harmonics, and low cost. The core idea is that by simply adding a passive tripling auxiliary circuit to the DC side of an existing series-type 12-pulse rectifier, the pulse count of the conventional series-type 12-pulse rectifier can be multiplied to 36 pulses. This effectively suppresses the input current harmonics and output voltage ripple of the series-type 12-pulse rectifier, allowing the rectifier's input current THD to meet the requirements of most industrial applications.

[0047] Compared to the prior art method of increasing the pulse count of a rectifier to 36 pulses by introducing a pulse multiplier circuit on the DC side of a series-type 12-pulse rectifier, the 36-pulse rectifier described in this invention reduces the turns ratio of the secondary to primary side of the auxiliary voltage transformer in the passive tripler auxiliary circuit introduced on the DC side. This reduces the impact of leakage inductance caused by excessive transformer turns ratio on input current harmonics, while also reducing the manufacturing difficulty of the transformer. Furthermore, the passive tripler auxiliary circuit proposed in this invention only requires 4 or 6 diodes, simplifying the overall structure of the rectifier and reducing manufacturing costs.

[0048] The 36-pulse rectifier with a passive tripler auxiliary circuit on the DC side described in this invention can achieve a tripler of the rectifier pulse number without using a phase-shifting transformer with multi-phase output windings or any active switching devices. Compared with existing 36-pulse rectifiers obtained through phase-shifting multiple connections, it has the advantages of simple circuit structure, ease of implementation, and low cost.

[0049] The 36-pulse rectifier with a passive tripler auxiliary circuit on the DC side described in this invention eliminates the need for an inductor in series on the input side of the rectifier, avoiding the problem of needing a large inductor in series on the AC side of the rectifier when using an auxiliary voltage injection circuit. This allows the rectifier to obtain a higher displacement factor and a stable output voltage, making it more promising for medium- and high-voltage high-power applications. Attached Figure Description

[0050] Figure 1 This is a schematic diagram of the 36-pulse rectifier with a passive tripler auxiliary circuit on the DC side, as described in the first embodiment of the present invention.

[0051] Figure 2 This is a schematic diagram of the current loop of the passive tripler auxiliary circuit in the first type of 36-pulse rectifier when it is operating in mode I.

[0052] Figure 3 This is a schematic diagram of the current loop of the passive tripler auxiliary circuit in the first type of 36-pulse rectifier when it is operating in Mode II.

[0053] Figure 4 This is a schematic diagram of the current loop of the passive tripler auxiliary circuit in the first type of 36-pulse rectifier when it is operating in Mode III.

[0054] Figure 5 This is a schematic diagram of the current loop of the passive tripler auxiliary circuit in the first type of 36-pulse rectifier when it is operating in mode IV.

[0055] Figure 6 This is a schematic diagram of the 36-pulse rectifier with a passive tripler auxiliary circuit on the DC side, as described in the second structure of Specific Implementation Method 4.

[0056] Figure 7 This is a schematic diagram of the current loop of the passive tripler auxiliary circuit in the second type of 36-pulse rectifier when it is operating in mode I.

[0057] Figure 8 This is a schematic diagram of the current loop of the passive tripler auxiliary circuit in the second type of 36-pulse rectifier when it is operating in Mode II.

[0058] Figure 9 This is a schematic diagram of the current loop of the passive tripler auxiliary circuit in the second type of 36-pulse rectifier when it is operating in Mode III.

[0059] Figure 10 This is a schematic diagram of the current loop of the passive tripler auxiliary circuit in the second type of 36-pulse rectifier when it is operating in mode IV.

[0060] Figure 11This is a schematic diagram of the 36-pulse rectifier with a passive tripler auxiliary circuit on the DC side, as described in the seventh specific embodiment.

[0061] Figure 12 This is a schematic diagram of the current loop of the passive tripler auxiliary circuit in the third type of 36-pulse rectifier when it is operating in mode I.

[0062] Figure 13 This is a schematic diagram of the current loop of the passive tripler auxiliary circuit in the third type of 36-pulse rectifier when it is operating in Mode II.

[0063] Figure 14 This is a schematic diagram of the current loop of the passive tripler auxiliary circuit in the third type of 36-pulse rectifier when it is operating in Mode III.

[0064] Figure 15 This is a schematic diagram of the current loop of the passive tripler auxiliary circuit in the third type of 36-pulse rectifier when it is operating in mode IV.

[0065] in, Figures 1 to 15 middle,

[0066] i a i b i c These are the three-phase input currents a, b, and c of phase-shifting transformer 1, respectively.

[0067] u a u b u c The three-phase AC voltage sources a, b, and c, respectively, are input from the power grid to the phase-shifting transformer 1; a1 i b1 i c1 These are the three-phase currents a, b, and c input to the first diode rectifier bridge 2, respectively.

[0068] i a2 i b2 i c2 These are the three-phase currents a, b, and c input to the second diode rectifier bridge 3, respectively.

[0069] i c1 This is the current flowing through capacitor C1;

[0070] i c2 This is the current flowing through capacitor C2;

[0071] i d1 This is the current output from the positive terminal of the first diode rectifier bridge 2;

[0072] i d2 This is the current input to the negative terminal of the second diode rectifier bridge 3;

[0073] i d The current input to the positive terminal of load 7;

[0074] u d1 This is the output voltage of the first diode rectifier bridge 2;

[0075] u d2 This is the output voltage of the second diode rectifier bridge 3;

[0076] u d This is the voltage across load 7;

[0077] Figures 1 to 5 middle,

[0078] i s This refers to the current flowing through the auxiliary single-phase rectifier bridge 4;

[0079] i p The current flowing through the primary winding AB of the three-winding auxiliary transformer 5 with double taps;

[0080] i f The current flowing through the secondary winding EF of the three-winding auxiliary transformer 5 with double taps;

[0081] i f1 For the flow through auxiliary diode D f1 The current;

[0082] i f2 For the flow through auxiliary diode D f2 The current;

[0083] u p This refers to the voltage across the primary winding AB of the three-winding auxiliary transformer 5 with double taps;

[0084] u s This refers to the voltage across the secondary winding CD of the three-winding auxiliary transformer 5 with double taps.

[0085] u f This refers to the voltage across the secondary winding EF of the three-winding auxiliary transformer 5 with double taps.

[0086] N p The number of turns AB in the primary winding of the three-winding auxiliary transformer 5 with double taps;

[0087] N s The number of turns of the secondary winding CD of the three-winding auxiliary transformer 5 with double taps;

[0088] N f The number of turns of the secondary winding EF of the three-winding auxiliary transformer 5 with double taps;

[0089] Figures 6 to 10 middle,

[0090] i s For the current flowing through the auxiliary full-wave rectifier 4;

[0091] i o The current flowing through the primary winding AB of the three-winding auxiliary transformer 5 with double taps;

[0092] i p The current flowing through the secondary winding CD of the three-winding auxiliary transformer 5 with double taps;

[0093] i f1 For the flow through auxiliary diode D f1 The current;

[0094] i f2 For the flow through auxiliary diode D f2 The current;

[0095] u o This refers to the voltage across the primary winding AB of the three-winding auxiliary transformer 5 with double taps;

[0096] u p This refers to the voltage across the secondary winding CD of the three-winding auxiliary transformer 5 with double taps.

[0097] u s This refers to the voltage across winding EF or FG of the three-winding auxiliary transformer 5 with double taps.

[0098] N o This refers to the number of turns of the primary winding AB of the three-winding auxiliary transformer 5 with double taps;

[0099] N p This refers to the number of turns of the secondary winding CD of the three-winding auxiliary transformer 5 with double taps;

[0100] N s The number of turns of winding EF or FG of the three-winding auxiliary transformer 5 with double taps;

[0101] Figures 11 to 15 middle,

[0102] u o The voltage across the primary winding AB of the multi-winding auxiliary transformer 5 with three taps;

[0103] u p1 The voltage across AC of the secondary winding of the multi-winding auxiliary transformer 5 with three taps;

[0104] u p2 The voltage across the secondary winding BD of the multi-winding auxiliary transformer 5 with three taps;

[0105] u s The voltage across windings EF or FG of the multi-winding auxiliary transformer 5 with three taps;

[0106] i o1 This is the sum of the currents flowing through the primary winding AB and the secondary winding AC of the multi-winding auxiliary transformer 5 with three taps;

[0107] i o2 This is the sum of the currents in the primary winding AB and the secondary winding BD of the multi-winding auxiliary transformer 5 with three taps;

[0108] i p1 For the flow through auxiliary diode D f1 The current;

[0109] i p2 For the flow through auxiliary diode D f2 The current;

[0110] i p For i p1 with i p2 sum;

[0111] i s The current flowing through the auxiliary full-wave rectifier 4;

[0112] N o The number of turns of the primary winding AB of the multi-winding auxiliary transformer 5 with three taps;

[0113] N p1 The number of turns of the secondary winding AC of the multi-winding auxiliary transformer 5 with three taps;

[0114] N p2 The number of turns of the secondary winding BD of the multi-winding auxiliary transformer 5 with three taps;

[0115] N s This refers to the number of turns in the secondary winding EF or FG of the multi-winding auxiliary transformer 5 with three taps. Detailed Implementation

[0116] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0117] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other.

[0118] This invention provides three structures of 36-pulse rectifiers with passive tripler auxiliary circuits on the DC side, and the three structures are respectively described in [reference 1]. Figure 1 , Figure 6 and Figure 11 The first type of 36-pulse rectifier is described in specific embodiments one to three; the second type of 36-pulse rectifier is described in specific embodiments four to six; and the third type of 36-pulse rectifier is described in specific embodiments seven to ten, as detailed below:

[0119] The first structure, as detailed in embodiments one through three, is as follows:

[0120] Specific Implementation Method 1: The following is combined with... Figure 1 This embodiment describes a 36-pulse rectifier with a passive tripler auxiliary circuit on the DC side, based on the first structure of this embodiment. The rectifier includes a series-connected 12-pulse rectifier and a passive tripler auxiliary circuit. The passive tripler auxiliary circuit triples the 12 pulses of the series-connected 12-pulse rectifier to obtain a 36-pulse rectifier. The series-connected 12-pulse rectifier includes a phase-shifting transformer 1, a first diode rectifier bridge 2, and a second diode rectifier bridge 3.

[0121] The passive tripler auxiliary circuit includes an auxiliary single-phase rectifier bridge (4), a three-winding auxiliary transformer with double taps (5), a balancing reactor (6), and an auxiliary diode (D). f1 and auxiliary diode D f2 Capacitors C1 and C2;

[0122] Phase-shifting transformer 1 is used to shift the three-phase voltage input from the power grid to generate two three-phase voltages with a phase difference of 30° and the same amplitude. The two three-phase voltages generated by phase-shifting transformer 1 are sent to the first diode rectifier bridge 2 and the second diode rectifier bridge 3, respectively.

[0123] The positive output terminal of the first diode rectifier bridge 2 is connected to one end of capacitor C1 and auxiliary diode D. f1 After the cathodes are connected simultaneously, they are connected to the positive output terminal of the 36-pulse rectifier and the positive terminal of the load 7.

[0124] The negative output terminal of the second diode rectifier bridge 3 is connected to one end of capacitor C2 and auxiliary diode D. f2 After the anodes are connected simultaneously, they are connected to the negative output terminal of the 36-pulse rectifier and the negative polarity terminal of the load 7.

[0125] The positive output terminal of the auxiliary single-phase rectifier bridge 4 is connected to the negative output terminal of the first diode rectifier bridge 2, and the negative output terminal of the auxiliary single-phase rectifier bridge 4 is connected to the positive output terminal of the second diode rectifier bridge 3.

[0126] The opposite-named terminal A of the primary winding AB of the three-winding auxiliary transformer 5 with double taps is connected to the same-named terminal D of the secondary winding CD of the three-winding auxiliary transformer 5 with double taps, and then connected as the first tap of the three-winding auxiliary transformer 5 with double taps to one input terminal of the auxiliary single-phase rectifier bridge 4.

[0127] The same-name terminal B of the primary winding AB of the three-winding auxiliary transformer 5 with double taps is connected to the opposite-name terminal E of the secondary winding EF of the three-winding auxiliary transformer 5 with double taps, and then connected to the center tap of the balancing reactor 6 as the second tap of the three-winding auxiliary transformer 5 with double taps.

[0128] The opposite-name terminal C of the secondary winding CD of the three-winding auxiliary transformer 5 with double taps is connected to the other input terminal of the auxiliary single-phase rectifier bridge 4.

[0129] The corresponding terminal F of the secondary winding EF of the three-winding auxiliary transformer 5 with double taps is connected to the auxiliary diode D. f1 anode and auxiliary diode D f2 The cathodes are connected simultaneously;

[0130] One end of the balancing reactor 6 is connected to the other end of capacitor C1, and the other end of the balancing reactor 6 is connected to the other end of capacitor C2;

[0131] By setting the turns ratio of the secondary winding CD of the three-winding auxiliary transformer 5 with double taps to its primary winding AB, and the turns ratio of the secondary winding EF of the three-winding auxiliary transformer 5 with double taps to its primary winding AB, the auxiliary diode D is made... f1 and auxiliary diode D f2 The conduction time of each is 1 / 6 of the output voltage cycle of the secondary winding EF of the three-winding auxiliary transformer 5 with double taps, so that the first diode rectifier bridge 2 and the second diode rectifier bridge 3 work simultaneously or alternately. When the first diode rectifier bridge 2 and / or the second diode rectifier bridge 3 are working, the current output by their rectifier bridges is a 4-level stepped DC current with equal width.

[0132] In this embodiment, the current output by the rectifier bridge is the "4-level stepped DC" in the equal-width 4-level stepped DC, which means that there are four different current states in one cycle, and the current value output by the rectifier bridge is constant in the same current state. "Equal width" means that the duration of each current state is the same.

[0133] In practical applications, the three-winding auxiliary transformer 5 with double taps is a single-phase transformer, and the optimal turns ratio is: N s / N p =0.97; N f / N p=31.91, which provides the best doubling effect at the current turns ratio, minimizing the input current THD to 5.04%. N p The number of turns AB in the primary winding of the three-winding auxiliary transformer 5 with double taps;

[0134] N s The number of turns of the secondary winding CD of the three-winding auxiliary transformer 5 with double taps;

[0135] N f The number of turns of the secondary winding EF of the three-winding auxiliary transformer 5 with double taps;

[0136] This invention, under the current structure of a 36-pulse rectifier, achieves this by reasonably setting the turns ratio of the primary and secondary windings of the three-winding auxiliary transformer 5 with double taps, and by keeping the number of turns relatively small, thereby enabling the auxiliary diode D... f1 and auxiliary diode D f2 The conduction time of each diode is 1 / 6 of its input voltage cycle. When the output currents of the first diode rectifier bridge 2 and the second diode rectifier bridge 3 are equal-width 4-level stepped DC currents, the passive tripler auxiliary circuit precisely multiplies the series-type 12-pulse rectifier into a series-type 36-pulse rectifier. At this time, the passive tripler auxiliary circuit has the strongest ability to suppress input current harmonics and output voltage ripple. This invention reduces the impact of leakage inductance caused by excessive transformer turns ratio on input current harmonics, while also reducing the manufacturing difficulty of the transformer.

[0137] Specific Implementation Method Two: The following is combined with... Figure 1 This embodiment further describes the 36-pulse rectifier with the first structure described in Embodiment 1. The auxiliary single-phase rectifier bridge 4 includes diode D. m1 Diode D m2 Diode D m3 and diode D m4 ,

[0138] Diode D m1 Cathode and diode D m2 After the cathode is connected, it serves as the positive output terminal of the auxiliary single-phase rectifier bridge 4;

[0139] Diode D m3 anode and diode D m4 After the anode is connected, it serves as the negative output terminal of the auxiliary single-phase rectifier bridge 4;

[0140] Diode D m2 anode and diode D m4 After the cathode is connected, it serves as one input terminal of the auxiliary single-phase rectifier bridge 4;

[0141] Diode D m1anode and diode D m3 After the cathode is connected, it serves as another input terminal of the auxiliary single-phase rectifier bridge 4.

[0142] In this preferred embodiment, a specific structure of the auxiliary single-phase rectifier bridge 4 is provided, which contains only 4 diodes. This means that the passive tripler auxiliary circuit proposed in this invention only requires 6 diodes to achieve pulse multiplication, which simplifies the structure of the passive tripler auxiliary circuit, further simplifies the overall structure of the rectifier, and reduces manufacturing costs.

[0143] Specific Implementation Method Three: The following is combined with... Figures 2 to 5 This embodiment further describes the 36-pulse rectifier with the first structure described in Embodiment 2. The passive tripler auxiliary circuit includes four operating modes, specifically:

[0144] Working Mode I: See Figure 2 , when u d1 >u d2 、|u f | d / 2andu f When >0, diode D in auxiliary single-phase rectifier bridge 4 m1 and diode D m4 Reverse bias cutoff, diode D m2 and diode D m3 When the transformer is in forward conduction, the secondary winding EF of the three-winding auxiliary transformer 5 with double taps is in a non-operating state, while the secondary winding CD and primary winding AB of the three-winding auxiliary transformer 5 with double taps are both in an operating state. At this time, the auxiliary diode D is connected to the same-name terminal F of the secondary winding EF of the three-winding auxiliary transformer 5 with double taps. f1 and auxiliary diode D f2 Both are reverse-biased and cut off, so that the first diode rectifier bridge 2 and the second diode rectifier bridge 3 together supply power to the two ends of the load 7; wherein,

[0145] u d1 This is the output voltage of the first diode rectifier bridge 2;

[0146] u d2 This is the output voltage of the second diode rectifier bridge 3;

[0147] u d This is the voltage across load 7;

[0148] u f This refers to the voltage across the secondary winding EF of the three-winding auxiliary transformer 5 with double taps;

[0149] Working Mode II: See Figure 3 , when u d1 >u​d2 u f >u d When / 2, diode D in auxiliary single-phase rectifier bridge 4 m1 Diode D m3 and diode D m4 All are reverse biased and cut off, diode D m2 With forward conduction, the secondary winding CD of the three-winding auxiliary transformer 5 with double taps is in a non-operating state, while the primary winding AB and secondary winding EF of the three-winding auxiliary transformer 5 with double taps are both in an operating state. Simultaneously, the auxiliary diode D is connected to the same-name terminal F of the secondary winding EF of the three-winding auxiliary transformer 5 with double taps. f2 Reverse bias cutoff, auxiliary diode D f1 Forward conduction, current flows through auxiliary diode D f1 current i f1 >0, current i f1 The current is injected into the positive output terminal of the first diode rectifier bridge 2. At this time, the second diode rectifier bridge 3 does not work, and its output current is zero. The first diode rectifier bridge 2 supplies power to the two ends of the load 7 alone.

[0150] u d1 This is the output voltage of the first diode rectifier bridge 2;

[0151] u d2 This is the output voltage of the second diode rectifier bridge 3;

[0152] u d This is the voltage across load 7;

[0153] u f This refers to the voltage across the secondary winding EF of the three-winding auxiliary transformer 5 with double taps;

[0154] Working Mode III: See Figure 4 , when u d1 d2 、|u f | d / 2, and u f When <0, diode D in auxiliary single-phase rectifier bridge 4 m2 and diode D m3 Reverse bias cutoff, diode D m1 and diode D m4 Forward conduction; the secondary winding EF of the three-winding auxiliary transformer 5 with double taps is in a non-operating state, while the primary winding AB and secondary winding CD of the three-winding auxiliary transformer 5 with double taps are both in an operating state. Simultaneously,

[0155] The auxiliary diode D is connected to the same-name terminal F of the secondary winding EF of the three-winding auxiliary transformer 5 with double taps. f1 ​​and auxiliary diode D f2 Both are reverse-biased and cut off. At this time, the first diode rectifier bridge 2 and the second diode rectifier bridge 3 together supply power to the two ends of the load 7; among which,

[0156] u d1 This is the output voltage of the first diode rectifier bridge 2;

[0157] u d2 This is the output voltage of the second diode rectifier bridge 3;

[0158] u d This is the voltage across load 7;

[0159] u f This refers to the voltage across the secondary winding EF of the three-winding auxiliary transformer 5 with double taps;

[0160] Working Mode IV: See Figure 5 , when u d1 d2 -u f >u d When / 2, diode D in auxiliary single-phase rectifier bridge 4 m1 Diode D m2 and diode D m3 All are reverse biased and cut off, diode D m4 Forward conduction; the secondary winding CD of the three-winding auxiliary transformer 5 with double taps is in a non-operating state, while the primary winding AB and secondary winding EF of the three-winding auxiliary transformer 5 with double taps are both in an operating state. Simultaneously, the auxiliary diode D connected to the F terminal of the secondary winding EF... f1 Reverse bias cutoff, auxiliary diode D f2 Forward conduction, current flows through auxiliary diode D f2 current i f2 >0, current i f2 The current is injected into the center tap of the balancing reactor 6. At this time, the first diode rectifier bridge 2 is not working and its output current is zero. The second diode rectifier bridge 3 supplies power to the two ends of the load 7 alone.

[0161] u d1 This is the output voltage of the first diode rectifier bridge 2;

[0162] u d2 This is the output voltage of the second diode rectifier bridge 3;

[0163] u d This is the voltage across load 7;

[0164] u f This is the voltage across the secondary winding EF of the three-winding auxiliary transformer 5 with double taps.

[0165] ​The second structure, as detailed in embodiments four to six, is as follows:

[0166] Specific Implementation Method Four: The following is combined with... Figure 6 This embodiment describes a 36-pulse rectifier with a passive tripler auxiliary circuit on the DC side, which is the second type of structure in this embodiment. It includes a series-connected 12-pulse rectifier and a passive tripler auxiliary circuit. The passive tripler auxiliary circuit is used to triple the 12 pulses of the series-connected 12-pulse rectifier to obtain a 36-pulse rectifier. The series-connected 12-pulse rectifier includes a phase-shifting transformer 1, a first diode rectifier bridge 2, and a second diode rectifier bridge 3.

[0167] The passive tripler auxiliary circuit includes an auxiliary full-wave rectifier 4, a three-winding auxiliary transformer with double taps 5, a balancing reactor 6, and an auxiliary diode D. f1 Auxiliary diode D f2 Capacitors C1 and C2;

[0168] Phase-shifting transformer 1 is used to shift the three-phase voltage input from the power grid to generate two three-phase voltages with a phase difference of 30° and the same amplitude. The two three-phase voltages generated by phase-shifting transformer 1 are sent to the first diode rectifier bridge 2 and the second diode rectifier bridge 3, respectively.

[0169] The positive output terminal of the first diode rectifier bridge 2 is connected to one end of capacitor C1 and auxiliary diode D. f1 After the cathodes are connected simultaneously, they are connected to the positive output terminal of the 36-pulse rectifier and the positive terminal of the load 7.

[0170] The negative output terminal of the first diode rectifier bridge 2 is simultaneously connected to the positive output terminal of the second diode rectifier bridge 3 and the opposite terminal A of the primary winding AB of the three-winding auxiliary transformer 5 with double taps.

[0171] The negative output terminal of the second diode rectifier bridge 3 is connected to the output terminal of the auxiliary full-wave rectifier 4, one end of capacitor C2, and the auxiliary diode D. f2 The anodes are connected simultaneously;

[0172] The two input terminals of the auxiliary full-wave rectifier 4 are respectively connected to the opposite-name terminal E and the same-name terminal G of the secondary winding EG of the three-winding auxiliary transformer 5 with double taps. The center tap F of the secondary winding EG of the three-winding auxiliary transformer 5 with double taps is connected to the negative polarity terminal of the load 7 as the negative output terminal of the 36-pulse rectifier; wherein, the center tap F is one tap of the three-winding auxiliary transformer 5 with double taps.

[0173] After the same-name terminal B of the primary winding AB of the three-winding auxiliary transformer 5 with double taps is connected to the opposite-name terminal C of its secondary winding CD, it is connected to the center tap of the balancing reactor 6 as another tap of the three-winding auxiliary transformer 5 with double taps.

[0174] The corresponding terminal D of the secondary winding CD of the three-winding auxiliary transformer 5 with double taps and the auxiliary diode D f1 anode and auxiliary diode D f2 The cathodes are connected simultaneously;

[0175] One end of the balancing reactor 6 is connected to the other end of capacitor C1, and the other end of the balancing reactor 6 is connected to the other end of capacitor C2;

[0176] By setting the turns ratio of the secondary winding CD of the three-winding auxiliary transformer 5 with double taps to its primary winding AB, and the turns ratio of the secondary winding EF or FG of the three-winding auxiliary transformer 5 with double taps to its primary winding AB, the auxiliary diode D is made... f1 and auxiliary diode D f2 The conduction time of each is 1 / 6 of the output voltage period of the secondary winding CD of the three-winding auxiliary transformer 5 with double taps, thereby enabling the first diode rectifier bridge 2 and the second diode rectifier bridge 3 to work simultaneously or alternately. When the first diode rectifier bridge 2 and / or the second diode rectifier bridge 3 are working, the output current of their rectifier bridges is a 4-level stepped DC current with equal width.

[0177] The secondary winding EF is the winding between the opposite terminal E of the secondary winding EG and the center tap F of the secondary winding EG.

[0178] The secondary winding FG is the winding between the center tap F of the secondary winding EG and its corresponding terminal G.

[0179] In this embodiment, the current output by the rectifier bridge is the "4-level stepped DC" in the equal-width 4-level stepped DC, which means that there are four different current states in one cycle, and the current value output by the rectifier bridge is constant in the same current state. "Equal width" means that the duration of each current state is the same.

[0180] In practical applications, the three-winding auxiliary transformer 5 with double taps is a single-phase transformer. And the optimal turns ratio is: N s / N o =0.653; N p / N o =21.17, which provides the best doubling effect at the current turns ratio, minimizing the input current THD to 5.04%. N o N represents the number of turns in the primary winding AB of a three-winding auxiliary transformer 5 with double taps; pN represents the number of turns in the secondary winding CD of a three-winding auxiliary transformer 5 with double taps. s This refers to the number of turns in winding EF or FG of the three-winding auxiliary transformer 5 with double taps.

[0181] This invention, under the current structure of a 36-pulse rectifier, achieves this by reasonably setting the turns ratio of the primary and secondary windings of the three-winding auxiliary transformer 5 with double taps, and by keeping the number of turns relatively small, thereby enabling the auxiliary diode D... f1 and auxiliary diode D f2 The conduction time of each diode is 1 / 6 of its input voltage cycle. When the output currents of the first diode rectifier bridge 2 and the second diode rectifier bridge 3 are equal-width 4-level stepped DC currents, the passive tripler auxiliary circuit precisely multiplies the series-type 12-pulse rectifier into a series-type 36-pulse rectifier. At this time, the passive tripler auxiliary circuit has the strongest ability to suppress input current harmonics and output voltage ripple. This invention reduces the impact of leakage inductance caused by excessive transformer turns ratio on input current harmonics, while also reducing the manufacturing difficulty of the transformer.

[0182] Specific Implementation Method Five: The following is combined with... Figure 6 This embodiment further describes the 36-pulse rectifier with the second structure described in Embodiment 4. The auxiliary full-wave rectifier 4 includes a diode D. m1 and diode D m2 ;

[0183] Diode D m1 Cathode and diode D m2 When the cathodes are connected simultaneously, they serve as the output terminals of the auxiliary full-wave rectifier 4.

[0184] Diode D m1 anode and diode D m2 The anodes are respectively connected to the opposite-named terminal E and the same-named terminal G in the secondary winding EG of the three-winding auxiliary transformer 5 with double taps; wherein,

[0185] Diode D m1 The anode serves as the first input terminal of the auxiliary full-wave rectifier 4;

[0186] Diode D m2 The anode serves as the second input terminal of the auxiliary full-wave rectifier 4.

[0187] Specific Implementation Method Six: The following is combined with... Figures 7 to 10 This embodiment further describes the 36-pulse rectifier with the second structure described in Embodiment 5. The passive tripler auxiliary circuit includes four operating modes, specifically:

[0188] Working Mode I: See Figure 7 , when ud1 >u d2 、|u p |<(u d1 +u d2 ) / 2, and u p When >0, diode D in auxiliary full-wave rectifier 4 m1 Reverse bias cutoff, diode D m2 Forward conduction; the secondary winding EF of the three-winding auxiliary transformer 5 with double taps is in a non-operating state, the secondary winding FG of the three-winding auxiliary transformer 5 with double taps is in an operating state, and the secondary winding CD of the three-winding auxiliary transformer 5 with double taps is in a non-operating state. At the same time, the auxiliary diode D connected to the same-name terminal D of the secondary winding CD of the three-winding auxiliary transformer 5 with double taps is in a non-operating state. f1 and auxiliary diode D f2 When reverse biased and cut off, the first diode rectifier bridge 2 and the second diode rectifier bridge 3 together supply power to the two ends of the load 7; among which,

[0189] u d1 This is the output voltage of the first diode rectifier bridge 2;

[0190] u d2 This is the output voltage of the second diode rectifier bridge 3;

[0191] u p This refers to the voltage across the secondary winding CD of the three-winding auxiliary transformer 5 with double taps;

[0192] Working Mode II: See Figure 8 , when u d1 >u d2 u p >(u d1 +u d2 When ) / 2, diode D in auxiliary single-phase rectifier 4 m1 Reverse bias cutoff, diode D m2 Forward conduction; the secondary winding EF of the three-winding auxiliary transformer 5 with double taps is in a non-operating state, the secondary winding FG of the three-winding auxiliary transformer 5 with double taps is in an operating state, the secondary winding CD of the three-winding auxiliary transformer 5 with double taps is in an operating state, and the auxiliary diode D connected to the same-name terminal D of the secondary winding CD of the three-winding auxiliary transformer 5 with double taps... f1 Forward conduction, auxiliary diode D f2 Reverse bias cutoff, current flows through auxiliary diode D f1 current i f1 >0, current i f1 The current is injected into the positive output terminal of the first diode rectifier bridge 2. At this time, the second diode rectifier bridge 3 is not working, and its output current is zero. The first diode rectifier bridge 2 supplies power to both ends of the load 7.

[0193] u d1 This is the output voltage of the first diode rectifier bridge 2;

[0194] u d2 This is the output voltage of the second diode rectifier bridge 3;

[0195] u p This refers to the voltage across the secondary winding CD of the three-winding auxiliary transformer 5 with double taps;

[0196] Working Mode III: See Figure 9 , when u d1 d2 、|u p |<(u d1 +u d2 ) / 2, and u p <0, u s When <0, diode D in auxiliary full-wave rectifier 4 m2 Reverse bias cutoff, diode D m1 Forward conduction; the secondary winding FG of the three-winding auxiliary transformer 5 with double taps is in a non-operating state, the secondary winding EF of the three-winding auxiliary transformer 5 with double taps is in an operating state, and the secondary winding CD of the three-winding auxiliary transformer 5 with double taps is in a non-operating state. At the same time, the auxiliary diode D connected to the same-name terminal D of the secondary winding CD of the three-winding auxiliary transformer 5 with double taps is in a non-operating state. f1 and auxiliary diode D f2 Reverse bias cutoff: at this time, the first diode rectifier bridge 2 and the second diode rectifier bridge 3 together supply power to the two ends of the load 7; where u d1 This is the output voltage of the first diode rectifier bridge 2;

[0197] u d2 This is the output voltage of the second diode rectifier bridge 3;

[0198] u p This refers to the voltage across the secondary winding CD of the three-winding auxiliary transformer 5 with double taps;

[0199] u s The voltage across the secondary winding EF of the three-winding auxiliary transformer 5 with double taps or the voltage across the secondary winding FG of the three-winding auxiliary transformer 5 with double taps.

[0200] Working Mode IV: See Figure 10 , when u d1 d2 -u p >(u d1 +u d2 ) / 2andu p <0, u​​s When <0, diode D in auxiliary full-wave rectifier 4 m2 Reverse bias cutoff, diode D m1 Forward conduction; the secondary winding FG of the three-winding auxiliary transformer 5 with double taps is in a non-operating state, the secondary winding EF of the three-winding auxiliary transformer 5 with double taps is in an operating state, the secondary winding CD of the three-winding auxiliary transformer 5 with double taps is in an operating state, and the auxiliary diode D connected to the same-name terminal D of the secondary winding CD of the three-winding auxiliary transformer 5 with double taps is in a forward conduction state. f2 Forward conduction, auxiliary diode D f1 Reverse bias cutoff, current flows through auxiliary diode D f2 current i f2 >0, current i f2 The current is injected into the center tap of the balancing reactor 6. At this time, the first diode rectifier bridge 2 is not working and its output current is zero. The second diode rectifier bridge 3 supplies power to both ends of the load 7.

[0201] u d1 This is the output voltage of the first diode rectifier bridge 2;

[0202] u d2 This is the output voltage of the second diode rectifier bridge 3;

[0203] u p This refers to the voltage across the secondary winding CD of the three-winding auxiliary transformer 5 with double taps;

[0204] u s This refers to the voltage across the secondary winding EF of the three-winding auxiliary transformer 5 with double taps, or the voltage across the secondary winding FG of the three-winding auxiliary transformer 5 with double taps.

[0205] The third structure, as detailed in Implementation Methods VII to X, is as follows:

[0206] Specific Implementation Method Seven: The following is combined with... Figure 11 This embodiment describes a 36-pulse rectifier with a passive tripler auxiliary circuit on the DC side, comprising a series-connected 12-pulse rectifier and a passive tripler auxiliary circuit. The passive tripler auxiliary circuit triples the 12 pulses of the series-connected 12-pulse rectifier by a factor of 3 to obtain a 36-pulse rectifier. The series-connected 12-pulse rectifier includes a phase-shifting transformer 1, a first diode rectifier bridge 2, and a second diode rectifier bridge 3.

[0207] The passive tripler auxiliary circuit includes an auxiliary full-wave rectifier 4, a multi-winding auxiliary transformer with three taps 5, a balancing reactor 6, and an auxiliary diode D. f1 Auxiliary diode D f2 Capacitors C1 and C2;

[0208] Phase-shifting transformer 1 is used to shift the three-phase voltage input from the power grid to generate two three-phase voltages with a phase difference of 30° and the same amplitude. The two three-phase voltages generated by phase-shifting transformer 1 are sent to the first diode rectifier bridge 2 and the second diode rectifier bridge 3, respectively.

[0209] The negative output terminal of the first diode rectifier bridge 2 is simultaneously connected to the positive output terminal of the second diode rectifier bridge 3 and the opposite terminal A of the primary winding AB of the three-tap multi-winding auxiliary transformer 5.

[0210] The negative output terminal of the second diode rectifier bridge 3 is connected to the output terminal of the auxiliary full-wave rectifier 4 and one end of the capacitor C2 at the same time.

[0211] The positive output terminal of the first diode rectifier bridge 2 is connected to the auxiliary diode D. f1 Cathode, auxiliary diode D f2 After the cathode and one end of capacitor C1 are connected simultaneously, they are connected to the positive output terminal of the 36-pulse rectifier and the positive terminal of the load 7.

[0212] The two input terminals of the auxiliary full-wave rectifier 4 are respectively connected to the opposite-name terminal E and the same-name terminal G of the secondary winding EG of the three-tap multi-winding auxiliary transformer 5.

[0213] The center tap F of the secondary winding EG of the three-tapped multi-winding auxiliary transformer 5 is connected to the negative polarity terminal of the load 7 as the negative output terminal of the 36-pulse rectifier; the center tap F is the No. 1 tap of the three-tapped multi-winding auxiliary transformer 5.

[0214] The opposite terminal C of the secondary winding AC of the three-tap multi-winding auxiliary transformer 5 is connected to the auxiliary diode D. f1 The anode connection of the secondary winding AC of the three-tapped multi-winding auxiliary transformer 5 is such that the same-name terminal of AC is connected to the opposite-name terminal A of AC of AC and the primary winding AB, which serves as the No. 2 tap of the three-tapped multi-winding auxiliary transformer 5.

[0215] The corresponding terminal D of the secondary winding BD of the three-tap multi-winding auxiliary transformer 5 and the auxiliary diode D f2 The anode connection; after the opposite end of the secondary winding BD of the three-tapped multi-winding auxiliary transformer 5 is connected to the same end B of its primary winding AB, it is connected to the center tap of the balancing reactor 6 as the No. 3 tap of the three-tapped multi-winding auxiliary transformer 5.

[0216] By setting the turns ratio of the secondary winding AC to the primary winding AB of the multi-winding auxiliary transformer 5 with three taps, the turns ratio of the secondary winding EF or FG to the primary winding AB of the multi-winding auxiliary transformer 5 with three taps, and the turns ratio of the secondary winding BD to the primary winding AB of the multi-winding auxiliary transformer 5 with three taps, the auxiliary diode D is made to... f1 The conduction time is 1 / 6 of the output voltage period of the secondary winding AC of the three-tap multi-winding auxiliary transformer 5, causing the auxiliary diode D to... f2 The conduction time of each is 1 / 6 of the output voltage period of the secondary winding BD of the multi-winding auxiliary transformer 5 with three taps, so that the first diode rectifier bridge 2 and the second diode rectifier bridge 3 work simultaneously or alternately. When the first diode rectifier bridge 2 and / or the second diode rectifier bridge 3 work, the current output by the rectifier bridge is a 4-level stepped DC current with equal width.

[0217] Among them, the secondary winding EF is the winding between the opposite terminal E of the secondary winding EG and the center tap F of the secondary winding EG.

[0218] The secondary winding FG is the winding between the center tap F of the secondary winding EG and its corresponding terminal G.

[0219] In this embodiment, the current output by the rectifier bridge is the "4-level stepped DC" in the equal-width 4-level stepped DC, which means that there are four different current states in one cycle, and the current value output by the rectifier bridge is constant in the same current state. "Equal width" means that the duration of each current state is the same.

[0220] In practical applications, the three-winding auxiliary transformer 5 with double taps is a single-phase transformer.

[0221] This invention, under the current structure of a 36-pulse rectifier, achieves this by reasonably setting the turns ratio of the primary and secondary windings of the three-winding auxiliary transformer 5 with double taps, and by keeping the number of turns relatively small, thereby enabling the auxiliary diode D... f1 and auxiliary diode D f2 The conduction time of each diode is 1 / 6 of its input voltage cycle. When the output currents of the first diode rectifier bridge 2 and the second diode rectifier bridge 3 are equal-width 4-level stepped DC currents, the passive tripler auxiliary circuit precisely multiplies the series-type 12-pulse rectifier into a series-type 36-pulse rectifier. At this time, the passive tripler auxiliary circuit has the strongest ability to suppress input current harmonics and output voltage ripple. This invention reduces the impact of leakage inductance caused by excessive transformer turns ratio on input current harmonics, while also reducing the manufacturing difficulty of the transformer.

[0222] Detailed Implementation Method Eight: The following is combined with... Figure 11This embodiment further describes the 36-pulse rectifier with the third structure described in Embodiment 7. The auxiliary full-wave rectifier 4 includes a diode D. m1 and diode D m2 ,

[0223] Diode D m1 anode and diode D m2 The anodes of diodes D and D are respectively used as the two input terminals of the auxiliary full-wave rectifier 4. m1 anode and diode D m2 The anodes are respectively connected to the opposite-named terminal E and the same-named terminal G of the secondary winding EG of the multi-winding auxiliary transformer 5 with three taps.

[0224] Diode D m1 Cathode and diode D m2 After the cathode is connected, it serves as the output terminal of the auxiliary full-wave rectifier 4.

[0225] Specific Implementation Method Nine: The following is combined with... Figures 12 to 15 This embodiment further describes the 36-pulse rectifier with the third structure described in Embodiment Eight. The passive tripler auxiliary circuit includes four operating modes, specifically:

[0226] Working Mode I: See Figure 12 , when u o >0 and u p2 <(u d1 -u o When ), diode D in auxiliary full-wave rectifier 4 m1 Reverse bias cutoff, diode D m2 Forward conduction; the primary winding AB and secondary winding FG of the multi-winding auxiliary transformer 5 with three taps are both in working state, while the secondary windings AC, BD and EF of the multi-winding auxiliary transformer 5 with three taps are all in non-working state.

[0227] Meanwhile, the auxiliary diode D is connected to the secondary winding AC of the three-tap multi-winding auxiliary transformer 5. f1 And the auxiliary diode D connected to the secondary winding BD of the multi-winding auxiliary transformer 5 with three taps f2 When reverse biased and cut off, the first diode rectifier bridge 2 and the second diode rectifier bridge 3 together supply power to the two ends of the load 7; among which,

[0228] u d1 This is the output voltage of the first diode rectifier bridge 2;

[0229] u o This refers to the voltage across the primary winding AB of the multi-winding auxiliary transformer 5 with three taps;

[0230] u p2 This refers to the voltage across the secondary winding BD of the multi-winding auxiliary transformer 5 with three taps;

[0231] Working Mode II: See Figure 13 , when u o >0 and u p2 >(u d1 -u o When ), diode D in auxiliary full-wave rectifier 4 m1 Reverse bias cutoff, diode D m2 Forward conduction; the primary winding AB, secondary winding BD, and secondary winding FG of the multi-winding auxiliary transformer 5 with three taps are all in working condition;

[0232] Meanwhile, the auxiliary diode D is connected to the secondary winding BD of the three-tap multi-winding auxiliary transformer 5. f2 Forward conduction, current flows through auxiliary diode D f2 current i p2 >0, current i p2 The current is injected into the positive output terminal of the first diode rectifier bridge 2; the secondary windings AC and EF of the three-tap multi-winding auxiliary transformer 5 are in a non-operating state.

[0233] Simultaneously, the auxiliary diode D is connected to the secondary winding AC of the three-tap multi-winding auxiliary transformer 5. f1 When reverse biased and cut off, the first diode rectifier bridge 2 supplies power to the two ends of load 7; where,

[0234] u d1 This is the output voltage of the first diode rectifier bridge 2;

[0235] u o This refers to the voltage across the primary winding AB of the multi-winding auxiliary transformer 5 with three taps;

[0236] u p2 This refers to the voltage across the secondary winding BD of the multi-winding auxiliary transformer 5 with three taps;

[0237] Working Mode III: See Figure 14 , when u o <0 and -u p1 d1 At that time, diode D in auxiliary full-wave rectifier 4 m2 Reverse bias cutoff, diode D m1 Forward conduction; the primary winding AB and secondary winding EF of the three-tapped multi-winding auxiliary transformer 5 are both in working condition, while the secondary windings AC, BD, and FG of the three-tapped multi-winding auxiliary transformer 5 are in non-working condition. ​

[0238] Meanwhile, the auxiliary diode D is connected to the secondary winding AC of the three-tap multi-winding auxiliary transformer 5. f1 And the auxiliary diode D connected to the secondary winding BD of the multi-winding auxiliary transformer 5 with three taps f2 Both are reverse-biased and cut off. At this time, the first diode rectifier bridge 2 and the second diode rectifier bridge 3 together supply power to the two ends of the load 7; among which,

[0239] u d1 This is the output voltage of the first diode rectifier bridge 2;

[0240] u o This refers to the voltage across the primary winding AB of the multi-winding auxiliary transformer 5 with three taps;

[0241] u p1 This refers to the voltage across the AC terminals of the secondary winding of the multi-winding auxiliary transformer 5 with three taps.

[0242] Working Mode IV: See Figure 15 , when u o <0 and -u p1 >u d1 At that time, diode D in auxiliary full-wave rectifier 4 m2 Reverse bias cutoff, diode D m1 Forward conduction; the primary winding AB, secondary winding AC, and secondary winding EF of the three-tapped multi-winding auxiliary transformer 5 are all in working condition, while the secondary winding BD and secondary winding FG of the three-tapped multi-winding auxiliary transformer 5 are in non-working condition. Simultaneously,

[0243] The auxiliary diode D is connected to the secondary winding AC of the three-tap multi-winding auxiliary transformer 5. f1 Forward conduction, current flows through auxiliary diode D f1 current i p1 >0; Auxiliary diode D connected to the secondary winding BD of the three-tap multi-winding auxiliary transformer 5. f2 When reverse biased and cut off, the second diode rectifier bridge 3 supplies power to the two ends of load 7; where,

[0244] u d1 This is the output voltage of the first diode rectifier bridge 2;

[0245] u o This refers to the voltage across the primary winding AB of the multi-winding auxiliary transformer 5 with three taps;

[0246] u p1 This refers to the voltage across the AC terminals of the secondary winding of the multi-winding auxiliary transformer 5 with three taps.

[0247] Specific Implementation Method Ten: The following is combined with... Figure 11 This embodiment further describes the 36-pulse rectifier with the third structure described in Embodiment Seven. s / N o =0.653; N p1 / N o =20.17; N p2 / N o =21.17;

[0248] Where, N o The number of turns of the primary winding AB of the multi-winding auxiliary transformer 5 with three taps;

[0249] N p1 The number of turns of the secondary winding AC of the multi-winding auxiliary transformer 5 with three taps;

[0250] N p2 The number of turns of the secondary winding BD of the multi-winding auxiliary transformer 5 with three taps;

[0251] N s This refers to the number of turns in the secondary winding EF or FG of the multi-winding auxiliary transformer 5 with three taps.

[0252] In this preferred embodiment, an optimal turns ratio is provided, which yields the best multiplication effect under the current turns ratio, minimizing the THD of the input current to 5.04%. With a relatively small number of turns, the auxiliary diode D... f1 and auxiliary diode D f2 The conduction time of each diode is 1 / 6 of its input voltage cycle. The output currents of the first diode rectifier bridge 2 and the second diode rectifier bridge 3 are equal-width 4-level stepped DC currents, achieving a 36-pulse multiplication. At this time, the passive tripler auxiliary circuit has the strongest ability to suppress rectifier input current harmonics and output voltage ripple. This invention reduces the impact of leakage inductance caused by excessive transformer turns ratio on input current harmonics, while also reducing the manufacturing difficulty of the transformer.

[0253] Principle Analysis:

[0254] The overall concept of the three 36-pulse rectifier structures of this invention is to add a passive tripler auxiliary circuit to the DC side of a conventional series-type 12-pulse rectifier to extract the 4-level stepped wave current of the primary winding AB from the DC side of the series-type 12-pulse rectifier, thereby modulating and increasing the output current level of the first diode rectifier bridge 2 and the second diode rectifier bridge 3. Specifically:

[0255] By optimizing the turns ratio of the primary and secondary windings of the multi-tap auxiliary transformer, the auxiliary diode D... f1 and auxiliary diode D f2The conduction time of each diode is 1 / 6 of its input voltage cycle. The output current of the first diode rectifier bridge 2 and the second diode rectifier bridge 3 is a four-level current with equal width. Then, according to the AC / DC side current relationship and the DC side voltage relationship, the pulse number of the rectifier is increased from 12 to 36, which effectively suppresses the input current harmonics and the output voltage ripple. That is, the present invention solves the problems of high input current harmonic content and large output voltage ripple of the existing series-type 12-pulse rectifier without increasing the complexity of the rectifier or reducing the stability of the output voltage. Moreover, the 36-pulse rectifier of the present invention, compared with the 36-pulse rectifier implemented by the pulse multiplier circuit in the prior art, reduces the turns ratio of the secondary side to the primary side of the auxiliary voltage transformer in the passive triple multiplier auxiliary circuit introduced on the DC side, reduces the influence of leakage inductance caused by excessive transformer turns ratio on the input current harmonics, and reduces the manufacturing difficulty of the transformer. In addition, the passive triple multiplier auxiliary circuit proposed in the present invention only requires 4 or 6 diodes, which simplifies the overall structure of the rectifier and reduces the manufacturing cost.

[0256] While the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that different dependent claims and features described herein can be combined in ways different from those described in the original claims. It is also understood that features described in conjunction with individual embodiments can be used in other described embodiments.

Claims

1. A 36-pulse rectifier with a passive tripler auxiliary circuit on the DC side, comprising a series-connected 12-pulse rectifier and a passive tripler auxiliary circuit, wherein the passive tripler auxiliary circuit is used to triple the 12 pulses of the series-connected 12-pulse rectifier to obtain a 36-pulse rectifier; the series-connected 12-pulse rectifier comprises a phase-shifting transformer (1), a first diode rectifier bridge (2), and a second diode rectifier bridge (3); characterized in that... ； The passive tripler auxiliary circuit includes an auxiliary single-phase rectifier bridge (4), a three-winding auxiliary transformer with double taps (5), a balancing reactor (6), and an auxiliary diode D. f1 and auxiliary diode D f2 Capacitors C1 and C2; The phase-shifting transformer (1) is used to shift the three-phase voltage input from the power grid to generate two three-phase voltages with a phase difference of 30° and the same amplitude. The two three-phase voltages generated by the phase-shifting transformer (1) are sent to the first diode rectifier bridge (2) and the second diode rectifier bridge (3) respectively. The positive output terminal of the first diode rectifier bridge (2) is connected to one end of capacitor C1 and auxiliary diode D. f1 After the cathodes are connected simultaneously, they are connected to the positive output terminal of the 36-pulse rectifier and the positive terminal of the load (7). The negative output terminal of the second diode rectifier bridge (3) is connected to one end of capacitor C2 and auxiliary diode D. f2 After the anodes are connected simultaneously, they are connected to the negative output terminal of the 36-pulse rectifier and the negative polarity terminal of the load (7). The positive output terminal of the auxiliary single-phase rectifier bridge (4) is connected to the negative output terminal of the first diode rectifier bridge (2), and the negative output terminal of the auxiliary single-phase rectifier bridge (4) is connected to the positive output terminal of the second diode rectifier bridge (3). The opposite-named terminal A of the primary winding AB of the three-winding auxiliary transformer (5) with double taps is connected to the same-named terminal D of the secondary winding CD of the three-winding auxiliary transformer (5) with double taps, and then connected as the first tap of the three-winding auxiliary transformer (5) with double taps to one input terminal of the auxiliary single-phase rectifier bridge (4). The same-name terminal B of the primary winding AB of the three-winding auxiliary transformer (5) with double taps is connected to the opposite-name terminal E of the secondary winding EF of the three-winding auxiliary transformer (5) with double taps, and then connected to the center tap of the balancing reactor (6) as the second tap of the three-winding auxiliary transformer (5) with double taps. The opposite-name terminal C of the secondary winding CD of the three-winding auxiliary transformer (5) with double taps is connected to the other input terminal of the auxiliary single-phase rectifier bridge (4); The corresponding terminal F of the secondary winding EF of the three-winding auxiliary transformer (5) with double taps is connected to the auxiliary diode D. f1 anode and auxiliary diode D f2 The cathodes are connected simultaneously; One end of the balancing reactor (6) is connected to the other end of capacitor C1, and the other end of the balancing reactor (6) is connected to the other end of capacitor C2; By setting the turns ratio of the secondary winding CD of the three-winding auxiliary transformer (5) with double taps to its primary winding AB, and the turns ratio of the secondary winding EF of the three-winding auxiliary transformer (5) with double taps to its primary winding AB, the auxiliary diode D is made to... f1 and auxiliary diode D f2 The conduction time of each is 1 / 6 of the output voltage period of the secondary winding EF of the three-winding auxiliary transformer (5) with double taps, so that the first diode rectifier bridge (2) and the second diode rectifier bridge (3) work simultaneously or alternately, and when the first diode rectifier bridge (2) and / or the second diode rectifier bridge (3) are working, the current output by their rectifier bridge is a 4-level stepped DC current with equal width.

2. The 36-pulse rectifier with a passive tripler auxiliary circuit on the DC side according to claim 1, characterized in that, The auxiliary single-phase rectifier bridge 4 includes diode D. m1 Diode D m2 diode D m3 and diode D m4 ; Diode D m1 Cathode and diode D m2 After the cathode is connected, it serves as the positive output terminal of the auxiliary single-phase rectifier bridge (4); Diode D m3 anode and diode D m4 After the anode is connected, it serves as the negative output terminal of the auxiliary single-phase rectifier bridge (4); Diode D m2 anode and diode D m4 After the cathode is connected, it serves as an input terminal of the auxiliary single-phase rectifier bridge (4); Diode D m1 anode and diode D m3 After the cathode is connected, it serves as another input terminal of the auxiliary single-phase rectifier bridge (4).

3. The 36-pulse rectifier with a passive tripler auxiliary circuit on the DC side according to claim 2, characterized in that, The passive tripler auxiliary circuit includes four operating modes, specifically: Working Mode I: When u d1 >u d2 、|u f | d / 2andu f When >0, diode D in the auxiliary single-phase rectifier bridge (4) m1 and diode D m4 Reverse bias cutoff, diode D m2 and diode D m3 When the transformer is in forward conduction, the secondary winding EF of the three-winding auxiliary transformer (5) with double taps is in a non-operating state, while the secondary winding CD and primary winding AB of the three-winding auxiliary transformer (5) with double taps are both in an operating state. At this time, the auxiliary diode D is connected to the same-name terminal F of the secondary winding EF of the three-winding auxiliary transformer (5) with double taps. f1 and auxiliary diode D f2 Both are reverse-biased and cut off, so that the first diode rectifier bridge (2) and the second diode rectifier bridge (3) jointly supply power to both ends of the load (7); among which,​ u d1 The output voltage of the first diode rectifier bridge (2); u d2 The output voltage of the second diode rectifier bridge (3); u d The voltage across the load (7); u f The voltage across the secondary winding EF of the three-winding auxiliary transformer (5) with double taps; Working Mode II: When u d1 >u d2 u f >u d When / 2, diode D in the auxiliary single-phase rectifier bridge (4) m1 diode D m3 and diode D m4 All are reverse biased and cut off, diode D m2 With forward conduction, the secondary winding CD of the three-winding auxiliary transformer (5) with double taps is in a non-operating state, while the primary winding AB and secondary winding EF of the three-winding auxiliary transformer (5) with double taps are both in an operating state. At the same time, the auxiliary diode D is connected to the same-name terminal F of the secondary winding EF of the three-winding auxiliary transformer (5) with double taps. f2 Reverse bias cutoff, auxiliary diode D f1 Forward conduction, current flows through auxiliary diode D f1 current i f1 >0, current i f1 The current is injected into the positive output terminal of the first diode rectifier bridge (2). At this time, the second diode rectifier bridge (3) does not work, and its output current is zero. The first diode rectifier bridge (2) supplies power to the two ends of the load (7) alone. u d1 The output voltage of the first diode rectifier bridge (2); u d2 The output voltage of the second diode rectifier bridge (3); u d The voltage across the load (7); u f The voltage across the secondary winding EF of the three-winding auxiliary transformer (5) with double taps; Working Mode III: When u d1 d2 、|u f | d / 2, and u f When <0, diode D in the auxiliary single-phase rectifier bridge (4) m2 and diode D m3 Reverse bias cutoff, diode D m1 and diode D m4 Forward conduction; the secondary winding EF of the three-winding auxiliary transformer (5) with double taps is in a non-operating state, while the primary winding AB and secondary winding CD of the three-winding auxiliary transformer (5) with double taps are both in an operating state. At the same time, the auxiliary diode D is connected to the same-name terminal F of the secondary winding EF of the three-winding auxiliary transformer (5) with double taps. f1 and auxiliary diode D f2 Both are reverse biased and cut off. At this time, the first diode rectifier bridge (2) and the second diode rectifier bridge (3) jointly supply power to both ends of the load (7); among them,​​ u d1 The output voltage of the first diode rectifier bridge (2); u d2 The output voltage of the second diode rectifier bridge (3); u d The voltage across the load (7); u f The voltage across the secondary winding EF of the three-winding auxiliary transformer (5) with double taps; Working mode IV: When u d1 d2 -u f >u d When / 2, diode D in the auxiliary single-phase rectifier bridge (4) m1 diode D m2 and diode D m3 All are reverse biased and cut off, diode D m4 Forward conduction; the secondary winding CD of the three-winding auxiliary transformer (5) with double taps is in a non-working state, while the primary winding AB and the secondary winding EF of the three-winding auxiliary transformer (5) with double taps are both in a working state. At the same time, the auxiliary diode D connected to the F terminal of the secondary winding EF is in a working state. f1 Reverse bias cutoff, auxiliary diode D f2 Forward conduction, current flows through auxiliary diode D f2 current i f2 >0, current i f2 The current is injected into the center tap of the balancing reactor (6). At this time, the first diode rectifier bridge (2) is not working and its output current is zero. The second diode rectifier bridge (3) supplies power to both ends of the load (7) alone.​ u d1 The output voltage of the first diode rectifier bridge (2); u d2 The output voltage of the second diode rectifier bridge (3); u d The voltage across the load (7); u f The voltage across the secondary winding EF of the three-winding auxiliary transformer (5) with double taps.

4. A 36-pulse rectifier with a passive tripler auxiliary circuit on the DC side, comprising a series-connected 12-pulse rectifier and a passive tripler auxiliary circuit, wherein the passive tripler auxiliary circuit is used to triple the 12 pulses of the series-connected 12-pulse rectifier to obtain a 36-pulse rectifier; the series-connected 12-pulse rectifier comprises a phase-shifting transformer (1), a first diode rectifier bridge (2), and a second diode rectifier bridge (3); characterized in that... ； The passive tripler auxiliary circuit includes an auxiliary full-wave rectifier (4), a three-winding auxiliary transformer with double taps (5), a balancing reactor (6), and an auxiliary diode D. f1 Auxiliary diode D f2 Capacitors C1 and C2; The phase-shifting transformer (1) is used to shift the three-phase voltage input from the power grid to generate two three-phase voltages with a phase difference of 30° and the same amplitude. The two three-phase voltages generated by the phase-shifting transformer (1) are sent to the first diode rectifier bridge (2) and the second diode rectifier bridge (3) respectively. The positive output terminal of the first diode rectifier bridge (2) is connected to one end of capacitor C1 and auxiliary diode D. f1 After the cathodes are connected simultaneously, they are connected to the positive output terminal of the 36-pulse rectifier and the positive terminal of the load (7). The negative output terminal of the first diode rectifier bridge (2) is connected to the positive output terminal of the second diode rectifier bridge (3) and the opposite terminal A of the primary winding AB of the three-winding auxiliary transformer (5) with double taps. The negative output terminal of the second diode rectifier bridge (3) is connected to the output terminal of the auxiliary full-wave rectifier (4), one end of capacitor C2, and the auxiliary diode D. f2 The anodes are connected simultaneously; The two input terminals of the auxiliary full-wave rectifier (4) are respectively connected to the opposite-name terminal E and the same-name terminal G of the secondary winding EG of the three-winding auxiliary transformer (5) with double taps. The center tap F of the secondary winding EG of the three-winding auxiliary transformer (5) with double taps is connected to the negative polarity terminal of the load (7) as the negative output terminal of the 36-pulse rectifier. The center tap F is one tap of the three-winding auxiliary transformer (5) with double taps. After the same-name terminal B of the primary winding AB of the three-winding auxiliary transformer (5) with double taps is connected to the opposite-name terminal C of its secondary winding CD, it is connected to the center tap of the balancing reactor (6) as another tap of the three-winding auxiliary transformer (5) with double taps. The corresponding terminal D of the secondary winding CD of the three-winding auxiliary transformer (5) with double taps and the auxiliary diode D f1 anode and auxiliary diode D f2 The cathodes are connected simultaneously; One end of the balancing reactor (6) is connected to the other end of capacitor C1, and the other end of the balancing reactor (6) is connected to the other end of capacitor C2; By setting the turns ratio of the secondary winding CD of the three-winding auxiliary transformer (5) with double taps to its primary winding AB, and the turns ratio of the secondary winding EF or FG of the three-winding auxiliary transformer (5) with double taps to its primary winding AB, the auxiliary diode D is made to... f1 and auxiliary diode D f2 The conduction time of each is 1 / 6 of the output voltage period of the secondary winding CD of the three-winding auxiliary transformer (5) with double taps, so that the first diode rectifier bridge (2) and the second diode rectifier bridge (3) work simultaneously or alternately, and when the first diode rectifier bridge (2) and / or the second diode rectifier bridge (3) are working, the current output by their rectifier bridges is a 4-level stepped DC current of equal width; among which, The secondary winding EF is the winding between the opposite terminal E of the secondary winding EG and the center tap F of the secondary winding EG. The secondary winding FG is the winding between the center tap F of the secondary winding EG and its corresponding terminal G of the secondary winding EG.

5. The 36-pulse rectifier with a passive tripler auxiliary circuit on the DC side according to claim 4, characterized in that, The auxiliary full-wave rectifier (4) includes diode D. m1 and diode D m2 ; Diode D m1 Cathode and diode D m2 After the cathodes are connected simultaneously, they serve as the output terminals of the auxiliary full-wave rectifier (4); Diode D m1 anode and diode D m2 The anodes are respectively connected to the opposite-named terminal E and the same-named terminal G in the secondary winding EG of the three-winding auxiliary transformer (5) with double taps; wherein, Diode D m1 The anode is used as the first input terminal of the auxiliary full-wave rectifier (4); Diode D m2 The anode is used as the second input terminal of the auxiliary full-wave rectifier (4).

6. The 36-pulse rectifier with a passive tripler auxiliary circuit on the DC side according to claim 5, characterized in that, The passive tripler auxiliary circuit includes four operating modes, specifically: Working Mode I: When u d1 >u d2 、|u p |<(u d1 +u d2 ) / 2, and u p When >0, diode D in the auxiliary full-wave rectifier (4) m1 Reverse bias cutoff, diode D m2 Forward conduction; the secondary winding EF of the three-winding auxiliary transformer (5) with double taps is in a non-operating state, the secondary winding FG of the three-winding auxiliary transformer (5) with double taps is in an operating state, the secondary winding CD of the three-winding auxiliary transformer (5) with double taps is in a non-operating state, and at the same time, the auxiliary diode D connected to the same-name terminal D of the secondary winding CD of the three-winding auxiliary transformer (5) with double taps is in a non-operating state. f1 and auxiliary diode D f2 When reverse biased and cut off, the first diode rectifier bridge (2) and the second diode rectifier bridge (3) together supply power to both ends of the load (7); among them, u d1 The output voltage of the first diode rectifier bridge (2); u d2 The output voltage of the second diode rectifier bridge (3); u p The voltage across the secondary winding CD of the three-winding auxiliary transformer (5) with double taps; Working Mode II: When u d1 >u d2 u p >(u d1 +u d2 When ) / 2, diode D in auxiliary single-phase rectifier 4 m1 Reverse bias cutoff, diode D m2 Forward conduction; the secondary winding EF of the three-winding auxiliary transformer (5) with double taps is in a non-operating state, the secondary winding FG of the three-winding auxiliary transformer (5) with double taps is in an operating state, the secondary winding CD of the three-winding auxiliary transformer (5) with double taps is in an operating state, and the auxiliary diode D connected to the same-name terminal D of the secondary winding CD of the three-winding auxiliary transformer (5) with double taps is in a forward conduction state. f1 Forward conduction, auxiliary diode D f2 Reverse bias cutoff, current flows through auxiliary diode D f1 current i f1 >0, current i f1 The current is injected into the positive output terminal of the first diode rectifier bridge (2). At this time, the second diode rectifier bridge (3) does not work, and its output current is zero. The first diode rectifier bridge (2) supplies power to both ends of the load (7). u d1 The output voltage of the first diode rectifier bridge (2); u d2 The output voltage of the second diode rectifier bridge (3); u p The voltage across the secondary winding CD of the three-winding auxiliary transformer (5) with double taps; Working Mode III: When u d1 d2 、|u p |<(u d1 +u d2 ) / 2, and u p <0, u s When <0, diode D in the auxiliary full-wave rectifier (4) m2 Reverse bias cutoff, diode D m1 Forward conduction; the secondary winding FG of the three-winding auxiliary transformer (5) with double taps is in a non-operating state, the secondary winding EF of the three-winding auxiliary transformer (5) with double taps is in an operating state, the secondary winding CD of the three-winding auxiliary transformer (5) with double taps is in a non-operating state, and at the same time, the auxiliary diode D connected to the same-name terminal D of the secondary winding CD of the three-winding auxiliary transformer (5) with double taps is in a non-operating state. f1 and auxiliary diode D f2 When reverse biased and cut off, the first diode rectifier bridge (2) and the second diode rectifier bridge (3) together supply power to both ends of the load (7); among them,​ u d1 The output voltage of the first diode rectifier bridge (2); u d2 The output voltage of the second diode rectifier bridge (3); u p The voltage across the secondary winding CD of the three-winding auxiliary transformer (5) with double taps; u s The voltage across the secondary winding EF of the three-winding auxiliary transformer (5) with double taps or the voltage across the secondary winding FG of the three-winding auxiliary transformer (5) with double taps. Working mode IV: When u d1 d2 -u p >(u d1 +u d2 ) / 2andu p <0, u s When <0, diode D in the auxiliary full-wave rectifier (4) m2 Reverse bias cutoff, diode D m1 Forward conduction; the secondary winding FG of the three-winding auxiliary transformer (5) with double taps is in a non-operating state, the secondary winding EF of the three-winding auxiliary transformer (5) with double taps is in an operating state, the secondary winding CD of the three-winding auxiliary transformer (5) with double taps is in an operating state, and the auxiliary diode D connected to the same-name terminal D of the secondary winding CD of the three-winding auxiliary transformer (5) with double taps is in a forward conduction state. f2 Forward conduction, auxiliary diode D f1 Reverse bias cutoff, current flows through auxiliary diode D f2 current i f2 >0, current i f2 The current is injected into the center tap of the balancing reactor (6). At this time, the first diode rectifier bridge (2) is not working and its output current is zero. The second diode rectifier bridge (3) supplies power to both ends of the load (7).​ u d1 The output voltage of the first diode rectifier bridge (2); u d2 The output voltage of the second diode rectifier bridge (3); u p The voltage across the secondary winding CD of the three-winding auxiliary transformer (5) with double taps; u s The voltage across the secondary winding EF of a three-winding auxiliary transformer (5) with double taps or the voltage across the secondary winding FG of a three-winding auxiliary transformer (5) with double taps.

7. A 36-pulse rectifier with a passive tripler auxiliary circuit on the DC side, comprising a series 12-pulse rectifier and a passive tripler auxiliary circuit, wherein the passive tripler auxiliary circuit is used to triple the 12 pulses of the series 12-pulse rectifier to obtain a 36-pulse rectifier; wherein the series 12-pulse rectifier comprises a phase-shifting transformer (1), a first diode rectifier bridge (2), and a second diode rectifier bridge (3); The passive tripler auxiliary circuit includes an auxiliary full-wave rectifier (4), a multi-winding auxiliary transformer with three taps (5), a balancing reactor (6), and an auxiliary diode D. f1 Auxiliary diode D f2 Capacitors C1 and C2; The phase-shifting transformer (1) is used to shift the three-phase voltage input from the power grid to generate two three-phase voltages with a phase difference of 30° and the same amplitude. The two three-phase voltages generated by the phase-shifting transformer (1) are sent to the first diode rectifier bridge (2) and the second diode rectifier bridge (3) respectively. The negative output terminal of the first diode rectifier bridge (2) is connected to the positive output terminal of the second diode rectifier bridge (3) and the opposite terminal A of the primary winding AB of the multi-winding auxiliary transformer (5) with three taps. The negative output terminal of the second diode rectifier bridge (3) is connected to the output terminal of the auxiliary full-wave rectifier (4) and one end of the capacitor C2 at the same time; The positive output terminal of the first diode rectifier bridge (2) is connected to the auxiliary diode D. f1 Cathode, auxiliary diode D f2 After the cathode and one end of capacitor C1 are connected at the same time, they are connected to the positive output terminal of the 36-pulse rectifier and the positive terminal of the load (7). The two input terminals of the auxiliary full-wave rectifier (4) are respectively connected to the opposite-name terminal E and the same-name terminal G of the secondary winding EG of the three-tap multi-winding auxiliary transformer (5); The center tap F of the secondary winding EG of the three-tapped multi-winding auxiliary transformer (5) is connected to the negative polarity terminal of the load (7) as the negative output terminal of the 36-pulse rectifier; the center tap F is the No. 1 tap of the three-tapped multi-winding auxiliary transformer (5). The opposite terminal C of the secondary winding AC of the three-tap multi-winding auxiliary transformer (5) is connected to the auxiliary diode D. f1 The anode connection of the secondary winding AC of the three-tapped multi-winding auxiliary transformer (5) is connected to the opposite terminal A of its primary winding AB, which serves as the No. 2 tap of the three-tapped multi-winding auxiliary transformer (5). The corresponding terminal D of the secondary winding BD of the three-tap multi-winding auxiliary transformer (5) and the auxiliary diode D f2 The anode connection; After the opposite end of the secondary winding BD of the three-tapped multi-winding auxiliary transformer (5) is connected to the same end B of its primary winding AB, it is connected to the center tap of the balancing reactor (6) as the No. 3 tap of the three-tapped multi-winding auxiliary transformer (5). By setting the turns ratio of the secondary winding AC of the three-tapped multi-winding auxiliary transformer (5) to its primary winding AB, the turns ratio of the secondary winding EF or FG of the three-tapped multi-winding auxiliary transformer (5) to its primary winding AB, and the turns ratio of the secondary winding BD of the three-tapped multi-winding auxiliary transformer (5) to its primary winding AB, the auxiliary diode D is made to... f1 The conduction time is 1 / 6 of the output voltage period of the secondary winding AC of the three-tap multi-winding auxiliary transformer (5), causing the auxiliary diode D to... f2 The conduction time of each is 1 / 6 of the output voltage period of the secondary winding BD of the multi-winding auxiliary transformer (5) with three taps, so that the first diode rectifier bridge (2) and the second diode rectifier bridge (3) work simultaneously or alternately, and when the first diode rectifier bridge (2) and / or the second diode rectifier bridge (3) work, the current output by the rectifier bridge is a 4-level stepped DC current with equal width. in, The secondary winding EF is the winding between the opposite terminal E of the secondary winding EG and the center tap F of the secondary winding EG. The secondary winding FG is the winding between the center tap F of the secondary winding EG and its corresponding terminal G of the secondary winding EG.

8. The 36-pulse rectifier with a passive tripler auxiliary circuit on the DC side according to claim 7, characterized in that, The auxiliary full-wave rectifier (4) includes diode D m1 and diode D m2 , Diode D m1 anode and diode D m2 The anodes of the diodes are respectively used as the two input terminals of the auxiliary full-wave rectifier (4), and diode D m1 anode and diode D m2 The anodes are respectively connected to the opposite-named terminal E and the same-named terminal G of the secondary winding EG of the three-tap multi-winding auxiliary transformer (5); Diode D m1 Cathode and diode D m2 After the cathode is connected, it serves as the output terminal of the auxiliary full-wave rectifier (4).

9. The 36-pulse rectifier with a passive tripler auxiliary circuit on the DC side according to claim 8, characterized in that, The passive tripler auxiliary circuit includes four operating modes, specifically: Working Mode I: When u o >0 and u p2 <(u d1 -u o When ), the diode D in the auxiliary full-wave rectifier (4) m1 Reverse bias cutoff, diode D m2 Forward conduction; the primary winding AB and secondary winding FG of the multi-winding auxiliary transformer (5) with three taps are both in working state, while the secondary windings AC, BD and EF of the multi-winding auxiliary transformer (5) with three taps are all in non-working state. Meanwhile, the auxiliary diode D is connected to the secondary winding AC of the multi-winding auxiliary transformer (5) with three taps. f1 And the auxiliary diode D connected to the secondary winding BD of the multi-winding auxiliary transformer (5) with three taps. f2 When reverse biased and cut off, the first diode rectifier bridge (2) and the second diode rectifier bridge (3) together supply power to both ends of the load (7); among them, u d1 The output voltage of the first diode rectifier bridge (2); u o The voltage across the primary winding AB of the multi-winding auxiliary transformer (5) with three taps; u p2 The voltage across the secondary winding BD of the multi-winding auxiliary transformer (5) with three taps; Working Mode II: When u o >0 and u p2 >(u d1 -u o When ), the diode D in the auxiliary full-wave rectifier (4) m1 Reverse bias cutoff, diode D m2 Forward conduction; the primary winding AB, secondary winding BD and secondary winding FG of the multi-winding auxiliary transformer (5) with three taps are all in working condition; Meanwhile, the auxiliary diode D is connected to the secondary winding BD of the multi-winding auxiliary transformer (5) with three taps. f2 Forward conduction, current flows through auxiliary diode D f2 current i p2 >0, current i p2 Injected into the positive output terminal of the first diode rectifier bridge (2); the secondary windings AC and EF of the multi-winding auxiliary transformer (5) with three taps are in a non-working state. Simultaneously, the auxiliary diode D is connected to the secondary winding AC of the multi-winding auxiliary transformer (5) with three taps. f1 When reverse biased and cut off, the first diode rectifier bridge (2) supplies power to both ends of the load (7); among which, u d1 The output voltage of the first diode rectifier bridge (2); u o The voltage across the primary winding AB of the multi-winding auxiliary transformer (5) with three taps; u p2 The voltage across the secondary winding BD of the multi-winding auxiliary transformer (5) with three taps; Working Mode III: When u o <0 and -u p1 d1 At that time, diode D in the auxiliary full-wave rectifier (4) m2 Reverse bias cutoff, diode D m1 Forward conduction; the primary winding AB and secondary winding EF of the multi-winding auxiliary transformer (5) with three taps are both in working state, while the secondary windings AC, BD and FG of the multi-winding auxiliary transformer (5) with three taps are in non-working state.​ Meanwhile, the auxiliary diode D is connected to the secondary winding AC of the multi-winding auxiliary transformer (5) with three taps. f1 And the auxiliary diode D connected to the secondary winding BD of the multi-winding auxiliary transformer (5) with three taps. f2 Both are reverse biased and cut off. At this time, the first diode rectifier bridge (2) and the second diode rectifier bridge (3) jointly supply power to both ends of the load (7); among them, u d1 The output voltage of the first diode rectifier bridge (2); u o The voltage across the primary winding AB of the multi-winding auxiliary transformer (5) with three taps; u p1 The voltage across the AC terminals of the secondary winding of the multi-winding auxiliary transformer (5) with three taps; Working mode IV: When u o <0 and -u p1 >u d1 At that time, diode D in the auxiliary full-wave rectifier (4) m2 Reverse bias cutoff, diode D m1 Forward conduction; the primary winding AB, secondary winding AC, and secondary winding EF of the multi-winding auxiliary transformer (5) with three taps are all in working condition, while the secondary windings BD and FG of the multi-winding auxiliary transformer (5) with three taps are in non-working condition. The auxiliary diode D is connected to the secondary winding AC of the multi-winding auxiliary transformer (5) with three taps. f1 Forward conduction, current flows through auxiliary diode D f1 current i p1 >0; Auxiliary diode D connected to the secondary winding BD of the multi-winding auxiliary transformer (5) with three taps. f2 When reverse biased and cut off, the second diode rectifier bridge (3) supplies power to both ends of the load (7); where, u d1 The output voltage of the first diode rectifier bridge (2); u o The voltage across the primary winding AB of the multi-winding auxiliary transformer (5) with three taps; u p1 The voltage across AC terminals of the secondary winding of the multi-winding auxiliary transformer (5) with three taps.

10. The 36-pulse rectifier with a passive tripler auxiliary circuit on the DC side according to claim 7, characterized in that, N s / N o =0.653;N p1 / N o =20.17;N p2 / N o =21.17; Where, N o The number of turns of the primary winding AB of the multi-winding auxiliary transformer (5) with three taps; N p1 The number of turns of the secondary winding AC of the multi-winding auxiliary transformer (5) with three taps; N p2 The number of turns of the secondary winding BD of the multi-winding auxiliary transformer (5) with three taps; N s The number of turns of the secondary winding EF or FG of the multi-winding auxiliary transformer (5) with three taps.

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