High-frequency link matrix rectifier and method based on reverse blocking IGBT (Insulated Gate Bipolar Translator)

Abstract

The invention relates to a high-frequency link matrix rectifier and method based on a reverse blocking type IGBT, and belongs to the technical field of power electronic converters. The rectifier comprises an input LC filter, a reverse blocking type IGBT matrix converter, a high-frequency transformer, a diode rectifier bridge and an output LC filter. The reverse blocking type IGBT matrix converter is composed of nine reverse blocking type IGBT switch tubes which are divided into a positive electrode switch group, a negative electrode switch group and a middle switch group, and the primary side of the high-frequency transformer is of a double-winding structure with a center tap. The reverse blocking type IGBT matrix converter is controlled to be switched on and switched off through a three-wire SPWM modulation strategy, a corresponding switch combination is controlled according to an input voltage sector, positive and negative alternating high-frequency pulse voltage is synthesized on a primary winding of a transformer, and direct current is obtained after the high-frequency pulse voltage is isolated and rectified through the transformer. According to the invention, the commutation process is simplified through switch multiplexing, and the converter has the advantages of few switching devices, simple commutation, high reliability and high efficiency.

Description

Technical Field

[0001] This invention relates to a high-frequency chain matrix rectifier and method based on reverse-resistance IGBTs, belonging to the field of power electronic converter technology, and particularly to a three-phase AC / DC converter with electrical isolation function suitable for microgrid interfaces. Background Technology

[0002] With the international community placing increasing emphasis on ensuring energy security, protecting the ecological environment, and addressing climate change, developing low-carbon, clean, and renewable energy has become a global consensus. As an effective form of integrating distributed energy resources, microgrids rely heavily on their core component—the three-phase AC / DC converter—which plays a crucial role in connecting the AC grid, DC bus, or energy storage devices. The converter performs multiple functions, including power factor correction, harmonic suppression, and voltage stabilization, and is essential for improving the overall performance of the microgrid.

[0003] Three-phase AC / DC converters can be divided into two-stage and single-stage types. Two-stage structures offer flexible control, but the presence of an intermediate energy storage capacitor limits further improvements in efficiency and power density. Single-stage structures, by sharing active components, eliminate the intermediate capacitor and have become a research hotspot in recent years. The high-frequency chain matrix rectifier (HFLMR), as a type of single-stage converter, combines the advantages of matrix converters and high-frequency transformers, offering advantages such as compact structure, no DC energy storage stage, adjustable power factor, and low input current harmonics.

[0004] However, traditional matrix converters and the high-frequency chain matrix rectifiers derived from them have some inherent drawbacks: First, they use a large number of switching transistors, resulting in a large number of switching devices, high system cost, and complex control; second, the commutation process of the switching transistors is cumbersome and prone to voltage spikes and electromagnetic interference, placing stringent requirements on the voltage withstand capability and drive performance of the switching devices; third, significant switching losses reduce system efficiency; in addition, existing modulation strategies (such as Wien method, virtual rectification-inverter PWM, etc.) either have problems such as low voltage utilization or computational complexity and weak anti-interference capability.

[0005] While existing technologies have made some improvements to traditional matrix converters, such as using reverse-resistance IGBTs or new wide-bandgap devices to reduce losses from parallel diodes, or proposing new topologies like Swiss rectifiers to reduce the number of switches, most of these improvements are still based on the concept of bidirectional switching and have not fundamentally solved the problems of complex topology and difficult commutation. The patent "Isolation Matrix AC / DC Converter" proposes a topology based on a voltage-source converter (VSC), which reduces the number of switches and simplifies commutation, but there is still room for optimization in the number of switches used, and circulating currents and voltage spikes may still exist during commutation.

[0006] In summary, the analysis above shows that if a three-phase AC / DC converter topology with fewer switching devices, a simpler commutation process, and good high-frequency isolation and input / output characteristics can be constructed, the reliability, efficiency, and power density of the system can be significantly improved. Summary of the Invention

[0007] This invention addresses the problems of high-frequency chain matrix rectifiers, such as a large number of switching devices, complex commutation process, high switching losses, and the resulting system efficiency and reliability issues. It provides a high-frequency chain matrix rectifier and method based on reverse-resistance IGBTs. This topology reduces the number of switching transistors, simplifies the commutation steps, and improves the system's energy transfer efficiency.

[0008] A high-frequency chain matrix rectifier based on reverse-resistance IGBTs is characterized by comprising: an input LC filter, a reverse-resistance IGBT matrix converter, a high-frequency transformer, a diode rectifier bridge, and an output LC filter.

[0009] The improved matrix converter consists of nine switching transistors, divided into three groups. The positive switching group contains three switching transistors S. ap S bp S cp Its collectors are connected to the A, B, and C phases after three-phase input filtering, respectively, and its emitters are all connected to the positive terminal of the primary winding of the high-frequency transformer. The negative switch group contains three switching transistors S. an S bn S cn Its collectors are connected to phases A, B, and C after the three-phase input filtering, respectively, and its emitters are all connected to the negative terminal of the primary winding of the high-frequency transformer. The intermediate switching group contains three switching transistors S. a S b S c Its emitters are connected to the A, B, and C phases after the three-phase input filtering, respectively, and its collectors are connected to the center tap of the primary winding of the high-frequency transformer.

[0010] The primary winding of the high-frequency transformer adopts a double-winding structure with a center tap, while the secondary winding is a single winding. The diode rectifier bridge is a full-bridge structure, with its AC input terminal connected to the secondary winding of the transformer and its DC output terminal connected to the load after passing through an output LC filter.

[0011] Furthermore, the switching transistor S ap S bp S cp S an S bn S cn S a S b S cThe preferred type is the reverse-resistance IGBT, which can withstand reverse voltage and avoid the use of anti-parallel diodes, thereby reducing conduction losses.

[0012] The high-frequency chain matrix rectifier described in this invention operates by controlling the on / off state of the nine switching transistors to convert the mains frequency three-phase AC power into high-frequency AC power. After transformer isolation and voltage transformation, the AC power is converted into DC power by a diode rectifier bridge. When the positive switch group (S... ap ,S bp ,S cp ) and the intermediate switch group (S a ,S b ,S c The negative switch group (S) performs a switching action. an ,S bn ,S cn When all switches are turned off, the circuit is said to be operating in a positive cycle. By controlling the combination of the positive switch and the intermediate switch, a positive high-frequency pulse voltage is synthesized on the positive half-winding of the primary side of the transformer; when the negative switch group (S) is turned off... an ,S bn ,S cn ) and the intermediate switch group (S a ,S b ,S c The positive electrode switch group (S) performs a switching action. ap ,S bp ,S cp When all switches are off, the circuit is said to operate in the negative cycle. By controlling the combination of the negative switch and the intermediate switch, a negative high-frequency pulse voltage is synthesized on the negative half-winding of the primary side of the transformer. The switching action of the switching transistors is driven by a three-wire SPWM modulation strategy.

[0013] The three-wire SPWM modulation strategy divides each power frequency cycle into 12 sectors based on the instantaneous values ​​of the three-phase input line voltages. The three-phase reference modulation is obtained from the three-phase input voltages via a controller. Within each sector, three modulation waves (i1) are calculated based on the three-phase reference modulation. * i2 * i3 * The signal is compared with a triangular carrier wave to generate the corresponding drive signal for the switching transistor. The principle is that only the switching transistor with the largest absolute value of the phase voltage in the three switching groups is always on, while the other switching groups are turned on in turn according to the comparison result of the modulation wave and the carrier wave, so as to output zero voltage, maximum line voltage, and second largest line voltage in sequence, and finally obtain a positive and negative symmetrical high-frequency AC voltage on the secondary side of the transformer. Beneficial effects

[0014] The beneficial effects of this invention are multifaceted: First, structurally, by decoupling the switching transistors of a traditional matrix converter and reusing intermediate switches, the number of switching transistors is reduced from 12 to 9, significantly simplifying the structure and reducing system cost, complexity, and the need for drive circuitry. Second, this structure optimizes the topology of the traditional matrix converter, avoiding its complex four-step commutation process. The commutation logic is clearer, reducing the risk of commutation failure, alleviating switching stress, and improving the overall reliability of the system. Furthermore, due to the presence of transformer leakage inductance and the zero-voltage switching (ZVS) condition during the switching process, optimized modulation and control strategies significantly reduce switching losses and improve system efficiency. Regarding the modulation strategy, the proposed three-wire SPWM modulation combines the strong anti-interference capabilities of two-wire voltage modulation with the ease of implementation of SPWM, achieving high voltage utilization and unity power factor operation. Finally, the structure incorporates a high-frequency transformer, achieving electrical isolation and voltage matching between input and output, meeting safety regulations. Simultaneously, the single-stage design and reduced component count contribute to achieving higher power density. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall topology of the high-frequency chain matrix rectifier based on reverse-resistance IGBT proposed in this invention.

[0016] Figure 2 This is a schematic diagram of the input voltage sector division (12 sectors) in the modulation strategy of this invention.

[0017] Figure 3 In the first specific implementation method, in the first sector (u a >0>u b >u c When ), the three modulated waves (i1) * i2 * i3 * The diagram shows the comparison logic with the triangular carrier wave, the generation of the switch drive signal, and the waveforms of the transformer secondary voltage during the positive and negative half-cycles within a transformer cycle. Detailed Implementation

[0018] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0019] Combination Figure 1 , Figure 2 and Figure 3 This embodiment demonstrates the topology of the high-frequency chain matrix rectifier and its high-frequency switching operation. By controlling the on and off of the nine switching transistors, the power frequency three-phase AC power is converted into high-frequency AC power. A three-wire SPWM modulation strategy is adopted, and the three-phase input line voltage can be divided into 12 sectors within one power frequency cycle according to the magnitude relationship of the three-phase input line voltage.

[0020] The three-phase reference modulation i given by the controller a * i b * i c * With three-phase input voltage u a u b u c In phase, i is determined according to the sector situation. a * i b * i c * Three modulation waves i1 were obtained * i2 * i3 * Within each sector, take i a * i b * i c * The reference modulation with the largest absolute value is used as i1. * The absolute value of the remaining two reference modulation differences is taken as i2. * i1 * Invert as i3 * The three modulation waves i1 * i2 * i3 * Comparing with a triangular carrier wave, a drive signal is generated, when the modulated wave i3 * Greater than the carrier or modulated wave i1 * When the voltage is less than the carrier wave, the output voltage is zero; when the modulated wave i3 * Less than the carrier and modulated wave i2 * The maximum value of the output line voltage when the modulated wave i2 is greater than the carrier wave; * Less than the carrier and modulated wave i1 * When the voltage is greater than the carrier wave, it is the second largest value of the output line voltage.

[0021] During the positive half-cycle, only one switch in the positive switch group and the intermediate switch group is always on, while the remaining switch groups are turned on in turn according to the comparison result of the modulation wave and the carrier wave. All the negative switch groups are turned off. On the positive winding of the primary side of the transformer, the positive high-frequency pulse voltage is synthesized by the positive maximum line voltage and the positive second maximum line voltage.

[0022] During the negative half-cycle, only one switch in the negative switch group and the intermediate switch group is constantly conducting, while the remaining switch groups are turned on in turn according to the comparison result of the modulation wave and the carrier wave. All the positive switch groups are turned off, and the negative high-frequency pulse voltage is synthesized by the negative maximum line voltage and the negative second maximum line voltage on the primary side negative winding of the transformer.

[0023] Specific implementation method one: When the input voltage is in the first sector (u a >0>u b >u c When ), the modulated wave i1 * = i a * i2 * =i b * - i c * i3 * =- i a * The circuit operates during the positive half-cycle, and the transformer's primary side outputs the maximum forward voltage u. ac Second largest forward voltage u ab Zero voltage u aa When the circuit operates in the negative half-cycle, the maximum negative voltage u is output from the negative terminal of the transformer primary side. ca Second largest negative voltage u ba Zero voltage u aa .by Figure 3 For example, let's explain the working status:

[0024] t0-t1: S ap and S a When the circuit is turned on, the positive half of the primary winding of the transformer is short-circuited, and the secondary voltage u s =0;

[0025] t1-t2: S ap and S c When the circuit is turned on, the secondary voltage u s =u ac (Maximum forward line voltage);

[0026] t2-t3: S ap and S b When the circuit is turned on, the secondary voltage u s =u ab (Forward submaximum line voltage);

[0027] t3-t4: S ap and S a When the circuit is turned on, the positive half of the primary winding of the transformer is short-circuited, and the secondary voltage u s =0;

[0028] t4-t5: San and S a When the transformer is turned on, the negative half of the primary winding is short-circuited, and the secondary voltage u s =0;

[0029] t5-t6: S an and S c When the circuit is turned on, the secondary voltage u s =u ca (Negative maximum line voltage);

[0030] t6-t7: S an and S b When the circuit is turned on, the secondary voltage u s =u ba (Negative second largest line voltage);

[0031] t7-t8: S an and S a When the transformer is turned on, the negative half of the primary winding is short-circuited, and the secondary voltage u s =0.

[0032] Specific implementation method two: When the input voltage is in the second sector (u a >u b >0 >u c When ), the modulated wave i1 * =- i c * i2 * = i a * - i b * i3 * = i c * The circuit operates during the positive half-cycle, and the transformer's primary side outputs the maximum forward voltage u. ac Second largest forward voltage u bc Zero voltage u cc When the circuit operates in the negative half-cycle, the maximum negative voltage u is output from the negative terminal of the transformer primary side. ca Second largest negative voltage u cb Zero voltage u cc .

[0033] t0-t1: S cp and S c When the circuit is turned on, the positive half of the primary winding of the transformer is short-circuited, and the secondary voltage u s =0;

[0034] t1-t2: S ap and S c When the circuit is turned on, the secondary voltage u s =u ac(Maximum forward line voltage);

[0035] t2-t3: S bp and S c When the circuit is turned on, the secondary voltage u s =u bc (Forward submaximum line voltage);

[0036] t3-t4: S cp and S a When the circuit is turned on, the positive half of the primary winding of the transformer is short-circuited, and the secondary voltage u s =0;

[0037] t4-t5: S cn and S c When the transformer is turned on, the negative half of the primary winding is short-circuited, and the secondary voltage u s =0;

[0038] t5-t6: S an and S c When the circuit is turned on, the secondary voltage u s =u ca (Negative maximum line voltage);

[0039] t6-t7: S bn and S c When the circuit is turned on, the secondary voltage u s =u cb (Negative second largest line voltage);

[0040] t7-t8: S cn and S c When the transformer is turned on, the negative half of the primary winding is short-circuited, and the secondary voltage u s =0.

Claims

1. A high-frequency chain matrix rectifier based on reverse-resistance IGBTs, characterized in that, It contains 3 input filter inductors L fa L fb L fc 3 input filter capacitors C fa C fb C fc 9 switching transistors S ap S bp S cp S an S bn S cn S a S b S c The converter consists of a reverse-resistance IGBT matrix converter, a three-winding transformer T with a center tap, a diode rectifier bridge composed of four diodes D1, D2, D3, and D4, and an output filter inductor L. f One output filter capacitor C f The three-phase input power supply passes through a star-connected input filter inductor and a delta-connected input filter capacitor to obtain three-phase A, B, and C after input filtering. The improved matrix converter consists of nine switching transistors, divided into three groups. The positive switch assembly contains three switching transistors S ap S bp S cp Its collectors are respectively connected to the A, B, and C phases after the three-phase input filtering, and its emitters are all connected to the positive terminal of the primary winding of the high-frequency transformer. The negative switch assembly contains three switching transistors S. an S bn S cn Its collectors are respectively connected to the A, B, and C phases after the three-phase input filtering, and its emitters are all connected to the negative terminal of the primary winding of the high-frequency transformer. The intermediate switching group contains three switching transistors S a S b S c Its emitter is connected to the A, B, and C phases after the three-phase input filtering, and its collector is connected to the center tap of the primary winding of the high-frequency transformer. The primary winding of the three-winding transformer has a double-winding structure with a center tap, and the secondary winding has a single winding. The AC input terminal of the diode rectifier bridge is connected to the secondary winding of the transformer, and the DC output terminal is connected to the load after passing through the output LC filter.

2. The modulation method for a high-frequency chain matrix rectifier based on a reverse-resistance IGBT according to claim 1, characterized in that, By controlling the on and off of the nine switching transistors, the three-phase AC power at the power frequency is converted into high-frequency AC power. A three-wire SPWM modulation strategy is adopted. Based on the relationship between the three-phase input line voltages, the power frequency cycle can be divided into 12 sectors. The three-phase reference modulation i given by the controller a * i b * i c * With three-phase input voltage u a u b u c In phase, i is determined according to the sector situation. a * i b * i c * Three modulation waves i1 were obtained * i2 * i3 * Within each sector, take i a * i b * i c * The reference modulation with the largest absolute value is used as i1. * The absolute value of the remaining two reference modulation differences is taken as i2. * i1 * Invert as i3 * The three modulation waves i1 * i2 * i3 * Comparing with a triangular carrier wave, a drive signal is generated, when the modulated wave i3 * Greater than the carrier or modulated wave i1 * When the voltage is less than the carrier wave, the output voltage is zero; when the modulated wave i3 * Less than the carrier and modulated wave i2 * The maximum value of the output line voltage when the modulated wave i2 is greater than the carrier wave; * Less than the carrier and modulated wave i1 * When the voltage is greater than the carrier wave, it is the second largest value of the output line voltage. Of the three switching groups, only the switch tube with the largest absolute value of the phase voltage is always on, while the other switching groups are turned on in turn according to the comparison result of the modulation wave and the carrier wave, thus outputting zero voltage, maximum line voltage, and second largest line voltage in sequence. During the positive half-cycle, only one switch in the positive switch group and the intermediate switch group is always on, while the remaining switch groups are turned on in turn according to the comparison result of the modulation wave and the carrier wave. All the negative switch groups are turned off. On the positive winding of the primary side of the transformer, the positive high-frequency pulse voltage is synthesized by the positive maximum line voltage and the positive second maximum line voltage. During the negative half-cycle, only one switch in the negative switch group and the intermediate switch group is constantly conducting, while the remaining switch groups are turned on in turn according to the comparison result of the modulation wave and the carrier wave. All the positive switch groups are turned off, and the negative high-frequency pulse voltage is synthesized on the negative winding of the primary side of the transformer by the negative maximum line voltage and the negative second maximum line voltage.

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