A generator system based on high-frequency isolation matrix converter and a regulation method
By using voltage source devices and a simplified commutation strategy, combined with a permanent magnet synchronous generator and a high-frequency matrix converter, the cost and stability issues of high-frequency isolated matrix converters are solved, achieving efficient AC-DC conversion.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- SOUTHEAST UNIV
- Filing Date
- 2022-09-28
- Publication Date
- 2026-06-05
AI Technical Summary
Existing high-frequency isolated matrix converters use bidirectional switching devices, which leads to high cost, increased on-resistance, complex and unstable commutation, affecting system efficiency and reliability.
Using common voltage source devices on the market, avoiding common drain or common source connections, simplifying the commutation strategy, and using a system composed of a permanent magnet synchronous generator, a high-frequency matrix converter and a center-tapped high-frequency matrix transformer, high-efficiency operation is achieved through field-oriented control.
It reduces device costs and on-resistance, simplifies the commutation process, and improves system reliability and stability, making it suitable for AC-powered isolated AC-DC conversion applications.
Smart Images
Figure CN115566913B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the fields of power generation, power transformation or distribution technology, specifically to a generator system and control method based on a high-frequency isolation matrix converter. Background Technology
[0002] High-frequency isolation converters fall into two main categories. One type is the two-stage isolation converter, where the first stage is a rectifier and the second stage is an isolated DC-DC converter, such as resonant converters and full-bridge converters. Electrolytic capacitors are needed between the two stages to decouple energy between the two sides. These electrolytic capacitors limit the converter's operating environment and lifespan, hindering further optimization. The other type of isolation converter is the single-stage high-frequency matrix converter, which eliminates the need for intermediate energy storage, improving system efficiency and extending system lifespan.
[0003] However, existing isolated high-frequency matrix converters require the use of bidirectional switching devices, which brings the following problems. First, due to the characteristics of semiconductor switching devices, both MOSFETs and IGBTs currently have anti-parallel diodes, and there are no commercially available bidirectional switching components on the market. Second, bidirectional switching components require the use of two existing switching transistors connected in a common-source or common-drain configuration, which increases the system's on-resistance and reduces the converter's efficiency. Third, bidirectional switching devices have a large number of switching transistors and a complex commutation method, which poses a risk of commutation failure and is detrimental to the safe and stable operation of the system. Summary of the Invention
[0004] (a) Technical problems to be solved
[0005] To address the shortcomings of existing technologies, this invention provides a generator system and control method based on a high-frequency isolation matrix converter. It uses the most common voltage source devices on the market, ensuring both cost and reliability. It eliminates the need for common-drain or common-source connections of existing devices, reducing the additional on-resistance added by connecting devices in series. It eliminates the need for complex multi-step commutation methods, and the simplified commutation strategy can omit additional controller overhead, reduce the probability of commutation failure, and enhance system reliability.
[0006] (II) Technical Solution
[0007] To achieve the above objectives, the present invention provides the following technical solution:
[0008] On the one hand, a generator system based on a high-frequency isolation matrix converter is provided, the system including a permanent magnet synchronous generator, a high-frequency matrix converter, a center-tapped high-frequency matrix transformer, and a full-bridge converter;
[0009] The output port of the permanent magnet synchronous generator is connected to the subsequent high-frequency matrix converter.
[0010] The three-phase input of the high-frequency matrix converter is connected to the permanent magnet synchronous motor, the positive and negative outputs of the high-frequency matrix converter are connected to the primary side of the center-tapped high-frequency matrix transformer, and the intermediate pole of the high-frequency matrix converter is connected to the center tap of the primary side of the center-tapped high-frequency matrix transformer.
[0011] The primary side of the center-tapped high-frequency matrix transformer connects to the center tap and is connected to the intermediate pole of the high-frequency matrix converter. The secondary side of the center-tapped high-frequency matrix transformer is connected to the midpoint of the bridge arm of the full-bridge converter.
[0012] The midpoint of the input bridge arm of the full-bridge converter is connected to the secondary side of the center-tapped high-frequency matrix transformer, and the output side of the full-bridge converter is connected to a DC load.
[0013] The voltage vector action sequence of the high-frequency matrix converter is determined based on the amplitude of the motor line current.
[0014] Preferably, the high-frequency matrix converter includes a first switch, a second positive switch, a second negative switch, a third switch, a fourth positive switch, a fourth negative switch, a fifth switch, a sixth positive switch, and a sixth negative switch.
[0015] The fourth positive switching transistor and the fourth negative switching transistor are connected by a common drain to form the first bridge arm. The source of the first switching transistor and the a-phase port of the motor are respectively connected to the midpoint of the first bridge arm.
[0016] The sixth positive switch and the sixth negative switch are connected by a common drain to form the second bridge arm. The source of the third switch and the b-phase port of the motor are respectively connected to the midpoint of the second bridge arm.
[0017] The second positive switch and the second negative switch are connected by a common drain to form the third bridge arm. The midpoint of the third bridge arm is connected to the source of the fifth switch and the c-phase port of the motor, respectively.
[0018] The first, third, and fifth switching transistors are connected by their common drains to form a first connection point. The first connection point is the output midpoint of the high-frequency matrix converter and is connected to the center tap of the center-tapped high-frequency matrix transformer.
[0019] The fourth positive switch, the sixth positive switch, and the second positive switch are connected at their common source to form a second connection point. The second connection point is connected to the source of the positive switch. The drain output of the positive switch is connected to the opposite-name terminal of the primary side of the center tap high-frequency matrix transformer.
[0020] The fourth negative switch, the sixth negative switch, and the second negative switch are connected at their common source to form a third connection point. The third connection point is connected to the source of the negative switch, and the drain output of the negative switch is connected to the same-name terminal of the primary side of the center-tapped high-frequency matrix transformer.
[0021] Preferably, the full-bridge converter includes a seventh switch, an eighth switch, a ninth switch, and a tenth switch;
[0022] The fourth bridge arm is formed by the seventh and eighth switches connected in series, and the fifth bridge arm is formed by the ninth and tenth switches connected in series.
[0023] Preferably, the duration of the voltage vector of the high-frequency matrix converter is corrected based on the commutation time of the leakage inductance current of the center-tapped high-frequency matrix transformer. The corrected durations of the three voltage vectors of the high-frequency matrix converter are as follows:
[0024]
[0025] in, T 1, T 2 and T 0 represents the sum of the action times of the first active vector V1, the second active vector V2, the zero vector V7, and V8, respectively. m a and θ i These represent the modulation ratio and angle of space vector modulation, respectively. T s One switching cycle.
[0026] Preferably, the leakage inductance current commutation time of the center-tapped high-frequency matrix transformer is ,in, u dc L is the DC load voltage of the full-bridge converter. kp For the leakage inductance of the center-tapped high-frequency matrix transformer, n p / n s The turns ratio of the center-tapped high-frequency matrix transformer. i b This represents the current in the b-phase winding of the motor.
[0027] Preferably, the high-frequency matrix converter is suitable for other AC-powered isolated AC-DC conversion applications.
[0028] Preferably, the high-frequency matrix converter adopts a field-oriented control scheme and achieves efficient system operation through dual closed-loop control of AC and DC axis currents.
[0029] On the other hand, a control method for the generator system based on the high-frequency isolation matrix converter is provided, the method comprising the following steps:
[0030] During the positive half-cycle of a switch, the four voltage vectors acting on the high-frequency matrix converter are the first zero vector V8, the first active vector V1, the second active vector V2, and the second zero vector V7. These correspond to the input currents of the high-frequency matrix transformer being 0, I1, I2, and 0. When the order of action of the voltage vectors is determined to be V8, V1, V2, and V7 after comparing the motor inductor current, I2 > I1 > 0. Here, I1 and I2 represent the currents of phase a and negative phase c, respectively. i a , -i c Specifically:
[0031] During the second zero vector action phase of the negative half-cycle, before the start of a switching cycle, in the previous switching cycle, the second zero vector V8 of the negative half-cycle acts on the high-frequency matrix converter, and the second, fourth, and sixth negative switches in the high-frequency matrix converter are turned on, with the negative terminal switches having a conduction signal; the eighth and ninth switches in the full-bridge converter also have a conduction signal.
[0032] During the first zero vector action phase of the positive half-cycle, after the start of a switching cycle, the first zero vector V8 of the positive half-cycle acts on the high-frequency matrix converter. The second, fourth, and sixth negative switches are turned off with zero current, while the second, fourth, and sixth positive switches are turned on with zero voltage. The turn-on signal of the negative terminal switches is removed. The state of the full-bridge converter remains unchanged, and the converter does not transfer energy at this time.
[0033] During the transformer leakage inductance current commutation phase, after the first zero vector V8 of the positive half-cycle ends, the first active vector V1 of the positive half-cycle prepares to act. First, the transformer leakage inductance current is increased to prevent voltage spikes caused by the inequality with the inductor phase current. The positive terminal switch is turned on, and a negative voltage is applied to the transformer leakage inductance, causing the leakage inductance current to rise until it is equal to the current corresponding to the first active vector of the next positive half-cycle. At this time, the body diodes of the first, third, and fifth switches freewheel, and the eighth and ninth switches in the full-bridge converter are turned on.
[0034] During the first active vector action phase of the positive half-cycle, after the transformer leakage inductance current commutation is completed, the first zero vector V1 of the positive half-cycle acts on the high-frequency matrix converter, the first switch turns on with zero voltage, removes the drive signals of the eighth and ninth switches in the full-bridge converter, the transformer current is commutated to the anti-parallel diodes of the seventh and tenth switches, the seventh and tenth switches turn on with zero voltage, and at this time energy is transferred from the motor side to the DC load.
[0035] During the second active vector action phase of the positive half-cycle, after the first active vector V1 of the positive half-cycle has finished its action time, the second active vector V2 of the positive half-cycle begins to act. The sixth positive switch is turned off, the third switch is turned on, and the transformer leakage inductance current is naturally commutated. At this time, energy is transferred from the motor side to the DC load.
[0036] After the second active vector V2 of the positive half-cycle ends, the second zero vector of the positive half-cycle begins to act. The second positive switch is turned off, and the fifth switch is turned on. At this time, the motor winding current freewheels in the first, third, and fifth switches. The positive terminal switches of the high-frequency matrix converter and the seventh and tenth switches in the full-bridge converter are turned off because there is no current path. At this time, the converter does not perform energy transfer.
[0037] (III) Beneficial Effects
[0038] This invention discloses a generator system and control method based on a high-frequency isolation matrix converter. It uses the most common voltage source type devices on the market, ensuring the cost and reliability of the devices. It does not require common drain or common source connections of existing devices, reducing the additional on-resistance added by the series connection of devices. It does not require a complex multi-step commutation method. The simplified commutation strategy can eliminate additional controller overhead, reduce the probability of commutation failure, and enhance the reliability of the system. Attached Figure Description
[0039] Figure 1 This is the main circuit topology diagram of a high-frequency matrix converter;
[0040] Figure 2 A voltage space vector diagram of a high-frequency matrix converter;
[0041] Figure 3 A key waveform diagram within one switching cycle;
[0042] Figure 4a This diagram shows the current flow path during the second zero-vector action phase of the converter's negative half-cycle in the first half of the switching cycle.
[0043] Figure 4b The current flow path diagram during the first half of the switching cycle, when the converter is in the positive half-cycle and in the first zero-vector action phase;
[0044] Figure 4c Diagram showing the current flow path during the first half of the switching cycle when the converter is in the transformer leakage inductance current commutation stage;
[0045] Figure 4d The current flow path diagram during the first half of the switching cycle, when the converter is in the positive half-cycle and in the first active vector action phase;
[0046] Figure 4eThe current flow path diagram during the second active vector action phase of the positive half-cycle of the converter in the first half of the switching cycle;
[0047] Figure 4f The current flow path diagram during the second zero-vector action phase of the positive half-cycle of the converter in the first half of the switching cycle;
[0048] Figure 5 A block diagram of the field-oriented control scheme for a high-frequency matrix converter;
[0049] Figure 6 This is a voltage and current diagram of the high-frequency matrix transformer in the embodiment;
[0050] Figure 7a Waveforms of the input and output currents of the high-frequency matrix transformer at different speeds of 1000 rpm;
[0051] Figure 7b The waveforms of the input and output currents of the high-frequency matrix transformer at 750 rpm are shown.
[0052] Figure 7c The waveforms of the input and output currents of the high-frequency matrix transformer at a speed of 500 rpm are shown.
[0053] Figure 8 The dynamic response of motor current and electromagnetic torque under sudden torque changes in the fan;
[0054] Figure 9 The dynamic response of motor current and electromagnetic torque under sudden changes in fan speed;
[0055] Among them, 1. permanent magnet synchronous generator, 2. high-frequency matrix converter, 3. center-tapped high-frequency matrix transformer, 4. full-bridge converter, and 5. DC load. Detailed Implementation
[0056] The technical solutions in the embodiments of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0057] Example
[0058] like Figure 1 As shown, one aspect of this invention provides a generator system based on a high-frequency isolation matrix converter. The system includes a permanent magnet synchronous generator, a high-frequency matrix converter, a center-tapped high-frequency matrix transformer, and a full-bridge converter.
[0059] The output port of the permanent magnet synchronous generator is connected to the subsequent high-frequency matrix converter.
[0060] The three-phase input of the high-frequency matrix converter is connected to the permanent magnet synchronous motor. The positive and negative outputs of the high-frequency matrix converter are connected to the primary side of the center-tapped high-frequency matrix transformer. The intermediate pole of the high-frequency matrix converter is connected to the center tap of the primary side of the high-frequency matrix transformer.
[0061] The primary side of the center-tapped high-frequency matrix transformer connects to the center tap and is connected to the intermediate pole of the high-frequency matrix converter. The secondary side of the center-tapped high-frequency matrix transformer is connected to the midpoint of the bridge arm of the full-bridge converter.
[0062] The input arm midpoint of the full-bridge converter is connected to the secondary side of the center-tapped high-frequency matrix transformer, and the output side of the full-bridge converter is connected to the DC load.
[0063] The voltage vector action sequence of the high-frequency matrix converter is determined based on the amplitude of the motor line current.
[0064] Preferably, the high-frequency matrix converter includes a first switch, a second positive switch, a second negative switch, a third switch, a fourth positive switch, a fourth negative switch, a fifth switch, a sixth positive switch, and a sixth negative switch.
[0065] The fourth positive switching transistor and the fourth negative switching transistor are connected by a common drain to form the first bridge arm. The source of the first switching transistor and the a-phase port of the motor are respectively connected to the midpoint of the first bridge arm.
[0066] The sixth positive switch and the sixth negative switch are connected by a common drain to form the second bridge arm. The source of the third switch and the b-phase port of the motor are respectively connected to the midpoint of the second bridge arm.
[0067] The second positive switch and the second negative switch are connected by a common drain to form the third bridge arm. The midpoint of the third bridge arm is connected to the source of the fifth switch and the c-phase port of the motor, respectively.
[0068] The first, third, and fifth switching transistors are connected by their common drains to form the first connection point, which is the output midpoint of the high-frequency matrix converter. The first connection point is connected to the center tap of the center-tapped high-frequency matrix transformer.
[0069] The fourth positive switch, the sixth positive switch, and the second positive switch are connected at their common source to form the second connection point. The second connection point is connected to the source of the positive switch, and the drain output of the positive switch is connected to the opposite-name terminal of the primary side of the center-tapped high-frequency matrix transformer.
[0070] The fourth negative switch, the sixth negative switch, and the second negative switch are connected at their common source to form the third connection point. The third connection point is connected to the source of the negative switch, and the drain output of the negative switch is connected to the same-name terminal on the primary side of the center-tapped high-frequency matrix transformer.
[0071] Preferably, the full-bridge converter includes a seventh switch, an eighth switch, a ninth switch, and a tenth switch;
[0072] The fourth bridge arm is formed by the seventh and eighth switches connected in series, and the fifth bridge arm is formed by the ninth and tenth switches connected in series.
[0073] Preferably, the duration of the voltage vectors of the high-frequency matrix converter is corrected based on the commutation time of the leakage inductance current of the center-tapped high-frequency matrix transformer. The corrected durations of the three voltage vectors of the high-frequency matrix converter are as follows:
[0074]
[0075] in, T 1, T 2 and T 0 represents the sum of the action times of the first active vector V1, the second active vector V2, the zero vector V7, and V8, respectively. m a and θ i These represent the modulation ratio and angle of space vector modulation, respectively. T s One switching cycle.
[0076] Preferably, the leakage inductance current commutation time of the center-tapped high-frequency matrix transformer is... ,in, u dc L is the DC load voltage of the full-bridge converter. kp For the leakage inductance of the center-tapped high-frequency matrix transformer, n p / n s The turns ratio of the center-tapped high-frequency matrix transformer. i b This represents the current in the b-phase winding of the motor.
[0077] Preferably, the high-frequency matrix converter is suitable for other AC-powered isolated AC-DC conversion applications.
[0078] Please see Figure 5 Preferably, the high-frequency matrix converter adopts a field-oriented control scheme and achieves efficient system operation through dual closed-loop control of AC and DC axis currents.
[0079] On the other hand, a control method for a generator system based on a high-frequency isolation matrix converter is provided, the method comprising the following steps:
[0080] Please see Figure 2During the positive half-cycle of a switch, the four voltage vectors acting on the high-frequency matrix converter are the first zero vector V8, the first active vector V1, the second active vector V2, and the second zero vector V7. The corresponding input currents of the high-frequency matrix transformer are 0, I1, I2, and 0. When the order of action of the voltage vectors is determined to be V8, V1, V2, and V7 after comparing the motor inductor current, I2 > I1 > 0. I1 and I2 are the currents of phase a and negative phase c, respectively. i a , -i c Specifically:
[0081] Please see Figure 3-4f During the second zero vector action phase of the negative half-cycle, before the start of a switching cycle, in the previous switching cycle, the second zero vector V8 of the negative half-cycle acts on the high-frequency matrix converter, and the second, fourth, and sixth negative switches in the high-frequency matrix converter are turned on, with the negative terminal switches having a conduction signal; the eighth and ninth switches in the full-bridge converter also have a conduction signal.
[0082] During the first zero vector action phase of the positive half-cycle, after the start of a switching cycle, the first zero vector V8 of the positive half-cycle acts on the high-frequency matrix converter. The second, fourth, and sixth negative switches are turned off with zero current, while the second, fourth, and sixth positive switches are turned on with zero voltage. The turn-on signal of the negative terminal switches is removed. The state of the full-bridge converter remains unchanged, and the converter does not transfer energy at this time.
[0083] During the transformer leakage inductance current commutation phase, after the first zero vector V8 of the positive half-cycle ends, the first active vector V1 of the positive half-cycle prepares to act. First, the transformer leakage inductance current is increased to prevent voltage spikes caused by the inequality with the inductor phase current. The positive terminal switch is turned on, and a negative voltage is applied to the transformer leakage inductance, causing the leakage inductance current to rise until it is equal to the current corresponding to the first active vector of the next positive half-cycle. At this time, the body diodes of the first, third, and fifth switches freewheel, and the eighth and ninth switches in the full-bridge converter are turned on.
[0084] During the first active vector action phase of the positive half-cycle, after the transformer leakage inductance current commutation is completed, the first zero vector V1 of the positive half-cycle acts on the high-frequency matrix converter, the first switch turns on with zero voltage, removes the drive signals of the eighth and ninth switches in the full-bridge converter, the transformer current is commutated to the anti-parallel diodes of the seventh and tenth switches, the seventh and tenth switches turn on with zero voltage, and at this time energy is transferred from the motor side to the DC load.
[0085] During the second active vector action phase of the positive half-cycle, after the first active vector V1 of the positive half-cycle has finished its action time, the second active vector V2 of the positive half-cycle begins to act. The sixth positive switch is turned off, the third switch is turned on, and the transformer leakage inductance current is naturally commutated. At this time, energy is transferred from the motor side to the DC load.
[0086] After the second active vector V2 of the positive half-cycle ends, the second zero vector of the positive half-cycle begins to act. The second positive switch is turned off, and the fifth switch is turned on. At this time, the motor winding current freewheels in the first, third, and fifth switches. The positive terminal switches of the high-frequency matrix converter and the seventh and tenth switches in the full-bridge converter are turned off because there is no current path. At this time, the converter does not perform energy transfer.
[0087] like Figure 6 As shown, the generator system based on the high-frequency isolation matrix converter without four-quadrant switching devices can operate safely and stably in wind power generation, with low current distortion rate and no significant overcharging of voltage and current in the high-frequency matrix transformer.
[0088] Figure 7a -c represents the primary current of the transformer at different generator speeds. i p , i n and secondary current i s It can be observed that the sum of the currents in the two windings of the primary side of the center-tapped high-frequency matrix transformer is equal to the output current, i.e.
[0089]
[0090] At different speeds, namely 1000 rpm in Figure 7a, 750 rpm in Figure 7b, and 500 rpm in Figure 7c, the amplitude of the transformer current did not change, but the duty cycle changed. This indicates that the high-frequency isolation matrix converter based on four-quadrant switching devices is suitable for applications with large input-output voltage variations.
[0091] Figure 8 This describes the current and electromagnetic torque response of the motor under a sudden change in the torque of the prime mover. Figure 9 By examining the motor's response characteristics when the reference speed drops abruptly from 1000 rpm to 500 rpm and then back to 1000 rpm, it can be observed that the generator system based on a high-frequency isolation matrix converter without four-quadrant switching devices exhibits excellent response characteristics under sudden load changes.
[0092] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
Claims
1. A generator system based on a high-frequency isolation matrix converter, characterized in that, The system includes a permanent magnet synchronous generator, a high-frequency matrix converter, a center-tapped high-frequency matrix transformer, and a full-bridge converter; The output port of the permanent magnet synchronous generator is connected to the subsequent high-frequency matrix converter. The three-phase input of the high-frequency matrix converter is connected to the permanent magnet synchronous motor, the positive and negative outputs of the high-frequency matrix converter are connected to the primary side of the center-tapped high-frequency matrix transformer, and the intermediate pole of the high-frequency matrix converter is connected to the center tap of the primary side of the center-tapped high-frequency matrix transformer. The primary side of the center-tapped high-frequency matrix transformer connects to the center tap and is connected to the intermediate pole of the high-frequency matrix converter. The secondary side of the center-tapped high-frequency matrix transformer is connected to the midpoint of the bridge arm of the full-bridge converter. The midpoint of the input bridge arm of the full-bridge converter is connected to the secondary side of the center-tapped high-frequency matrix transformer, and the output side of the full-bridge converter is connected to a DC load. The voltage vector action sequence of the high-frequency matrix converter is determined according to the amplitude of the motor line current. The duration of the voltage vectors of the high-frequency matrix converter is corrected based on the commutation time of the leakage inductance current of the center-tapped high-frequency matrix transformer. The corrected durations of the three voltage vectors of the high-frequency matrix converter are as follows: in, T 1, T 2 and T 0 represents the sum of the action times of the first active vector V1, the second active vector V2, the zero vector V7, and V8, respectively. m a and θ i These represent the modulation ratio and angle of space vector modulation, respectively. T s One switching cycle The commutation time of the leakage inductance current of the center-tapped high-frequency matrix transformer.
2. The generator system based on a high-frequency isolation matrix converter according to claim 1, characterized in that: The high-frequency matrix converter includes a first switch transistor, a second positive switch transistor, a second negative switch transistor, a third switch transistor, a fourth positive switch transistor, a fourth negative switch transistor, a fifth switch transistor, a sixth positive switch transistor, and a sixth negative switch transistor; The fourth positive switch and the fourth negative switch are connected by a common drain to form the first bridge arm. The source of the first switch and the a-phase port of the motor are respectively connected to the midpoint of the first bridge arm. The sixth positive switch and the sixth negative switch are connected by a common drain to form the second bridge arm. The source of the third switch and the b-phase port of the motor are respectively connected to the midpoint of the second bridge arm. The second positive switch and the second negative switch are connected by a common drain to form the third bridge arm. The midpoint of the third bridge arm is connected to the source of the fifth switch and the c-phase port of the motor, respectively. The first, third, and fifth switching transistors are connected by their common drains to form a first connection point. The first connection point is the output midpoint of the high-frequency matrix converter and is connected to the center tap of the center-tapped high-frequency matrix transformer. The fourth positive switch, the sixth positive switch, and the second positive switch are connected at their common source to form a second connection point. The second connection point is connected to the source of the positive switch. The drain output of the positive switch is connected to the opposite-name terminal of the primary side of the center tap high-frequency matrix transformer. The fourth negative switch, the sixth negative switch, and the second negative switch are connected at their common source to form a third connection point. The third connection point is connected to the source of the negative switch, and the drain output of the negative switch is connected to the same-name terminal of the primary side of the center-tapped high-frequency matrix transformer.
3. A generator system based on a high-frequency isolation matrix converter according to claim 2, characterized in that: The full-bridge converter includes a seventh switch, an eighth switch, a ninth switch, and a tenth switch. The fourth bridge arm is formed by the seventh and eighth switches connected in series, and the fifth bridge arm is formed by the ninth and tenth switches connected in series.
4. A generator system based on a high-frequency isolation matrix converter according to claim 1, characterized in that: The leakage inductance current commutation time of the center-tap high-frequency matrix transformer is ,in, u dc L is the DC load voltage of the full-bridge converter. kp For the leakage inductance of the center-tapped high-frequency matrix transformer, n p / n s The turns ratio of the center-tapped high-frequency matrix transformer. i b This represents the current in the b-phase winding of the motor.
5. A generator system based on a high-frequency isolation matrix converter according to claim 4, characterized in that: The high-frequency matrix converter is suitable for other AC-powered isolated AC-DC conversion applications.
6. A generator system based on a high-frequency isolation matrix converter according to claim 1, characterized in that: The high-frequency matrix converter adopts a field-oriented control scheme and achieves efficient system operation through dual closed-loop control of AC and DC axis currents.
7. A control method for a generator system based on a high-frequency isolation matrix converter as described in any one of claims 1-6, characterized in that, The control method includes the following steps: During the positive half-cycle of a switch, the four voltage vectors acting on the high-frequency matrix converter are the first zero vector V8, the first active vector V1, the second active vector V2, and the second zero vector V7. These correspond to the input currents of the high-frequency matrix transformer being 0, I1, I2, and 0. When the order of action of the voltage vectors is determined to be V8, V1, V2, and V7 after comparing the motor inductor current, then I2 > I1 > 0. I1 and I2 represent the currents of phase a and negative phase c, respectively. i a , -i c Specifically: During the second zero vector action phase of the negative half-cycle, before the start of a switching cycle, in the previous switching cycle, the second zero vector V8 of the negative half-cycle acts on the high-frequency matrix converter, and the second, fourth, and sixth negative switches in the high-frequency matrix converter are turned on, with the negative terminal switches having a conduction signal; the eighth and ninth switches in the full-bridge converter also have a conduction signal. During the first zero vector action phase of the positive half-cycle, after the start of a switching cycle, the first zero vector V8 of the positive half-cycle acts on the high-frequency matrix converter. The second, fourth, and sixth negative switches are turned off with zero current, while the second, fourth, and sixth positive switches are turned on with zero voltage. The turn-on signal of the negative terminal switches is removed. The state of the full-bridge converter remains unchanged, and the converter does not transfer energy at this time. During the transformer leakage inductance current commutation phase, after the first zero vector V8 of the positive half-cycle ends, the first active vector V1 of the positive half-cycle prepares to act. First, the transformer leakage inductance current is increased to prevent voltage spikes caused by the inequality with the inductor phase current. The positive terminal switch is turned on, and a negative voltage is applied to the transformer leakage inductance, causing the leakage inductance current to rise until it is equal to the current corresponding to the first active vector of the next positive half-cycle. At this time, the body diodes of the first, third, and fifth switches freewheel, and the eighth and ninth switches in the full-bridge converter are turned on. During the first active vector action phase of the positive half-cycle, after the transformer leakage inductance current commutation is completed, the first zero vector V1 of the positive half-cycle acts on the high-frequency matrix converter, the first switch turns on with zero voltage, removes the drive signals of the eighth and ninth switches in the full-bridge converter, the transformer current is commutated to the anti-parallel diodes of the seventh and tenth switches, the seventh and tenth switches turn on with zero voltage, and at this time energy is transferred from the motor side to the DC load. During the second active vector action phase of the positive half-cycle, after the first active vector V1 of the positive half-cycle has finished its action time, the second active vector V2 of the positive half-cycle begins to act. The sixth positive switch is turned off, the third switch is turned on, and the transformer leakage inductance current is naturally commutated. At this time, energy is transferred from the motor side to the DC load. After the second active vector V2 of the positive half-cycle ends, the second zero vector of the positive half-cycle begins to act. The second positive switch is turned off, and the fifth switch is turned on. At this time, the motor winding current freewheels in the first, third, and fifth switches. The positive terminal switches of the high-frequency matrix converter and the seventh and tenth switches in the full-bridge converter are turned off because there is no current path. At this time, the converter does not perform energy transfer.