A compact high speed rotating commutating device with protection redundancy

Abstract

The application discloses a high-speed rotating rectifier device with a compact protection redundancy structure, which comprises a three-phase AC input end, a rectifying part and a DC positive and negative output end. The rectifying part comprises six bridge arms, which form a three-phase uncontrolled bridge rectifier circuit. Each bridge arm is composed of four rectifier diodes. A first rectifier diode and a second rectifier diode are connected in series to form a first branch, and a third rectifier diode and a fourth rectifier diode are connected in series to form a second branch. The first branch and the second branch are connected in parallel to form the bridge arm. The circuit of the rectifier device does not contain a voltage-dependent resistor, a resistance-capacitance buffer circuit or a fuse. The high-speed rotating rectifier device with the compact protection redundancy structure does not need traditional protection elements such as a voltage-dependent resistor, a resistance-capacitance buffer circuit or a fuse. The fault tolerance of the rectifier diode and the system self-protection are realized completely through circuit topology innovation. Meanwhile, the device has the characteristics of compact structure, good heat dissipation and convenient maintenance.

Description

Technical Field

[0001] This invention relates to the field of motor rectification technology, and in particular to a high-speed rotating rectifier device with a compact and redundant protective structure, which is installed on the shaft of a high-speed motor and is used to convert AC power from the exciter armature into DC power. Background Technology

[0002] Three-phase bridge uncontrolled full-wave rectifier circuits are widely used in rotating rectifiers for high-speed motors due to their simple structure and high reliability. In this type of application, the rectifier is directly mounted on the motor shaft and rotates at the same speed as the motor. Its function is to rectify the three-phase AC power generated by the armature winding of the AC exciter into DC power to provide excitation current for the main motor rotor.

[0003] In existing technologies, each arm of a three-phase bridge rectifier circuit typically consists of only a single rectifier diode. To cope with electrical stresses such as overvoltage, overcurrent, and commutation spikes that may occur during motor operation, designers usually add external protection components to the rectifier circuit, mainly in the following ways: (a) Varistor protection: A varistor is connected in parallel at the input or output of the rectifier circuit to absorb overvoltage and surge current energy using its nonlinear voltage-current characteristics. This method has a certain suppression effect on lightning strikes and switching overvoltages, but the varistor's protection function is limited; it can only cope with voltage surges and cannot solve the problem of uneven current distribution, nor can it provide any form of redundancy support when the diode experiences an open circuit or short circuit fault.

[0004] (ii) Protection by RC buffer circuit: A resistor-capacitor snubber circuit (also known as an RC snubber circuit) consisting of a resistor and a capacitor connected in series is connected in parallel across each rectifier diode or at the AC input terminal to suppress voltage spikes caused by line inductance when the diode is turned off. However, this protection method also has limited scope and cannot cope with open-circuit or short-circuit faults of the diode itself. Furthermore, the added resistor and capacitor components themselves may also fail, introducing new failure points.

[0005] (iii) Fuse protection: A fast-acting fuse is connected in series on the AC or DC side of the rectifier circuit. When a severe overcurrent or short-circuit fault occurs, the fuse will trip and cut off the circuit. However, the fuse has a single function and cannot cope with overvoltage or diode parameter variability. Moreover, after the fuse blows, the system must be shut down for replacement, which affects the continuous operation capability of the system.

[0006] While the aforementioned external protection measures can play a role in specific application scenarios, they all belong to the "external remedy" design approach and have the following common problems: (1) The bridge arm itself lacks redundancy: Since each bridge arm is composed of only a single diode, once the diode has an open circuit or short circuit fault, the entire bridge arm will fail directly, the rectification function of the corresponding phase will be lost, and the external protection components will not be able to restore the bridge arm function.

[0007] (2) The protection functions are independent and have a narrow coverage: each protection element is designed only for a specific fault mode and lacks comprehensive protection against multiple electrical stresses such as voltage, current, commutation spikes and diode faults.

[0008] (3) Increased system size, weight and cost: The introduction of external protection components occupies limited installation space, increases the weight and rotational inertia of rotating parts, which is not conducive to the high-speed and stable operation of the motor.

[0009] (4) Reduced reliability: The peripheral protection components themselves are also potential sources of failure. Increasing the number of components may actually reduce the mean time between failures of the overall system.

[0010] (5) Complex mechanical and electrical structure: The arrangement and interconnection of peripheral components make the internal structure of the rectifier device more complex, and the assembly difficulty and maintenance cost increase accordingly.

[0011] To address the aforementioned issues, the art has previously proposed utilizing the reverse breakdown characteristics of avalanche diodes to absorb overvoltage energy, thereby eliminating the need for some RC protection components. However, this approach remains a single-function overvoltage suppression measure and does not solve core problems such as diode redundancy, comprehensive protection, and structural compactness. Summary of the Invention

[0012] The purpose of this invention is to overcome the shortcomings of the prior art and provide a high-speed rotating rectifier device with a compact and redundant protective structure. It is installed on the motor shaft and rotates at the same speed as the motor. It is used to rectify the three-phase AC power generated by the exciter armature into DC power to provide excitation for the main motor rotor. This device does not require traditional protection components such as varistors, RC buffer circuits or fuses. It achieves fault tolerance of rectifier diodes and system self-protection entirely through circuit topology innovation. At the same time, it has the characteristics of compact structure, good heat dissipation and easy maintenance. It is particularly suitable for high-speed excitation systems in aviation, ships, rail transportation and other industries with strict requirements on reliability and size and weight.

[0013] The technical solution to achieve the above objective is: a high-speed rotating rectifier with a compact, redundant protection structure, mounted on the motor shaft and rotating at the same speed as the motor, used to rectify the three-phase AC power generated by the exciter armature into DC power, including a three-phase AC input terminal, a rectifier section, and DC positive and negative output terminals, wherein: The three-phase AC input terminal is connected to the three-phase AC lead-out of the exciter armature, and the DC positive and negative output terminals are connected to the DC excitation conductive copper busbar of the main motor rotor. The rectifier section includes six bridge arms, forming a three-phase uncontrolled bridge rectifier circuit; Each of the bridge arms consists of four rectifier diodes, wherein the first rectifier diode and the second rectifier diode are connected in series to form a first branch, the third rectifier diode and the fourth rectifier diode are connected in series to form a second branch, and the first branch and the second branch are connected in parallel to form the bridge arm. The circuit of the rectifier does not include varistors, RC buffer circuits, or fuses.

[0014] The above-mentioned high-speed rotating rectifier device with a compact protection redundancy structure, wherein the four rectifier diodes in the same bridge arm are selected from the same model and the same production batch, and are grouped according to the forward voltage drop before assembly, so that the total forward voltage drop difference between the first branch and the second branch is not greater than a preset threshold. The equivalent forward voltage drop and reverse recovery characteristics of each of the six bridge arms are kept consistent by selecting and arranging the parameters of the rectifier diodes within each bridge arm.

[0015] The above-mentioned high-speed rotating rectifier with a compact and redundant protective structure includes a total of 24 rectifier diodes in the rectifier section, of which 12 are positive diodes and 12 are negative diodes, and each rectifier diode is a bolt-type diode.

[0016] The aforementioned high-speed rotating rectifier with a compact, redundant protective structure further includes a conductive aluminum block with heat dissipation fins. One end of each pair of rectifier diodes of the same polarity is connected in parallel via a copper busbar, and the conductive aluminum block is connected in series with two rectifier diodes of opposite polarities to form a bridge arm. The conductive aluminum block has two screw holes and two through holes. The two screw holes are used to connect and fix two positive and negative diodes in series, and the two through holes are used to fix the bridge arm to the support plate.

[0017] The above-mentioned high-speed rotating rectifier with a compact and redundant protective structure, wherein the support disk is a single disk structure, and 24 rectifier diodes are evenly distributed along the circumference in the inner and outer layers of the support disk.

[0018] The aforementioned high-speed rotating rectifier with a compact, redundant protective structure includes a support plate with six semi-circular holes. These holes allow cooling air to pass through to form a heat dissipation duct, and also allow the three-phase AC leads of the exciter armature to pass through and connect to the three-phase AC input terminal of the rectifier.

[0019] The aforementioned high-speed rotating rectifier with a compact, redundant protection structure includes a three-phase AC power supply for the exciter, each phase of which has two leads, for a total of six leads. The six semi-circular holes are used for the six leads to pass through, allowing each lead to connect to its corresponding three-phase AC input terminal.

[0020] The aforementioned high-speed rotating rectifier with a compact, redundant protection structure is characterized in that the bridge arm maintains its rectification function even when only one rectifier diode in the same bridge arm experiences an open-circuit or short-circuit fault; the bridge arm loses its rectification function only when at least two branches in the bridge arm fail.

[0021] The aforementioned high-speed rotating rectifier with a compact, redundant protection structure, wherein the rectifier operates in a derating state below its rated value by series voltage division and parallel current division of four rectifier diodes in each bridge arm, so as to withstand reverse overvoltage and surge current during exciter-side faults.

[0022] The present invention relates to a high-speed rotating rectifier device with a compact and redundant protective structure, which is installed on the motor shaft and rotates at the same speed as the motor. It is used to rectify the three-phase AC power generated by the exciter armature into DC power to provide excitation for the main motor rotor. This device does not require traditional protection components such as varistors, RC buffer circuits or fuses. It achieves fault tolerance of rectifier diodes and system self-protection entirely through circuit topology innovation. At the same time, it has the characteristics of compact structure, good heat dissipation and easy maintenance. It is particularly suitable for high-speed excitation systems in aviation, ships, rail transportation and other industries with strict requirements on reliability and size and weight. Attached Figure Description

[0023] Figure 1 This is a circuit diagram of the high-speed rotating rectifier device with a compact protective redundant structure according to the present invention. Figure 2 for Figure 1 A schematic diagram of the redundant structure of a single bridge arm in the rectifier shown. Figure 3a This is a schematic diagram (outer ring view) of the overall structure of the high-speed rotating rectifier device with a compact protective redundant structure according to the present invention. Figure 3b This is a schematic diagram (inner circle view) of the overall structure of the high-speed rotating rectifier device with a compact protective redundant structure according to the present invention. Figure 3c for Figure 3a Sectional view along line AA; Figure 4 This is a structural diagram of the bolt-type diode in this invention; Figure 5a This is a front view of the conductive aluminum block with heat dissipation fins in this invention; Figure 5bThis is a side view of the conductive aluminum block with heat dissipation fins in this invention; Figure 5c This is a top view of the conductive aluminum block with heat dissipation fins in this invention; Figure 6 This is a schematic diagram of the supporting disk structure in this invention. Detailed Implementation

[0024] To enable those skilled in the art to better understand the technical solution of the present invention, its specific embodiments are described in detail below with reference to the accompanying drawings: Please see Figures 1 to 6 In a preferred embodiment of the present invention, a high-speed rotating rectifier with a compact, redundant protective structure is mounted on the motor shaft and rotates at the same speed as the motor. It is used to rectify the three-phase alternating current generated by the exciter armature into direct current. The high-speed rotating rectifier of the present invention includes a three-phase AC input terminal 1, a rectifier section 2, and DC positive and negative output terminals 3.

[0025] The three-phase AC input terminal 1 is connected to the three-phase AC leads of the exciter armature, and the DC positive and negative output terminals 3 are connected to the DC excitation conductive copper busbar of the main motor rotor. The rectifier section 2 includes six bridge arms 20, forming a three-phase uncontrolled bridge rectifier circuit; each bridge arm 20 consists of four rectifier diodes, wherein the first rectifier diode D1 and the second rectifier diode D2 are connected in series to form the first branch, the third rectifier diode D3 and the fourth rectifier diode D4 are connected in series to form the second branch, and the first branch and the second branch are connected in parallel to form the bridge arm 20; the rectifier circuit does not include varistors, RC snubber circuits, and fuses.

[0026] The four rectifier diodes forming the same bridge arm are of the same model and batch to ensure that their forward voltage drop and other parameters are as consistent as possible, achieving better current sharing among the four diodes within the bridge arm. Through the selection and arrangement of diode parameters, the overall conductivity characteristics (such as equivalent forward voltage drop and reverse recovery characteristics) of the six bridge arms are kept consistent, ensuring that each current commutation is almost identical, greatly reducing current spikes and voltage overshoots caused by uneven commutation. Each arm of the rectifier section 2 (three-phase uncontrolled bridge rectifier circuit) is composed of four rectifier diodes connected in a "series-then-parallel" manner, forming a pure diode redundancy structure. When any diode in the arm is short-circuited or open-circuited, the arm can still work normally, and the diodes on the arm can withstand the reverse overvoltage during exciter-side faults without being damaged.

[0027] The rectifier section has a total of 24 rectifier diodes, of which 12 are positive diodes and 12 are negative diodes. Each rectifier diode is a bolt-type diode 21. The positive and negative diodes have the same external structure.

[0028] The high-speed rotating rectifier of the present invention has a compact structure, small outer diameter, and light overall weight. Each pair of rectifier diodes of the same polarity is connected in parallel at one end through a copper busbar, and then connected in series with two rectifier diodes of opposite polarity through conductive aluminum blocks 4, forming a bridge arm 20. The conductive aluminum blocks 4 used for series connection are conductive aluminum blocks with heat dissipation fins 41. Each bridge arm requires two conductive aluminum blocks 4, and the entire high-speed rotating rectifier has a total of 12 conductive aluminum blocks 4.

[0029] The conductive aluminum block 4 has two screw holes 42 and two through holes 43. The two screw holes 42 are used to connect and fix two positive and negative diodes in series, and the two through holes 43 are used to fix the bridge arm 20 to the support plate 5 and have good heat dissipation performance.

[0030] The support disk 5 is a single-disc structure, with 24 rectifier diodes evenly distributed along the circumference in the inner and outer layers of the support disk 5. That is, there are 12 rectifier diodes in the inner ring and 12 rectifier diodes in the outer ring of the support disk 5. This reduces the diameter of the support disk 5. The support disk 5 has screw holes for fixing 12 conductive aluminum blocks and 24 rectifier diodes.

[0031] Please see again Figure 6 The support plate 5 has 24 mounting holes 52 evenly spaced along the same circumference. The 24 mounting holes 52 correspond one-to-one with the through holes 43 of the 12 conductive aluminum blocks 4, which are used to fix the conductive aluminum blocks 4 to the support plate 5, and then fix each bridge arm 20 to the support plate 5.

[0032] The support plate 5 has six semi-circular holes 51. These holes allow cooling air to pass through, forming a heat dissipation channel. They also allow the three-phase AC leads of the exciter armature to pass through and connect to the three-phase AC input terminal 1 of the rectifier. Specifically, each phase of the exciter's three-phase AC power supply has two leads, for a total of six leads. The six semi-circular holes 51 allow these six leads to pass through, connecting each lead to its corresponding three-phase AC input terminal 1, simplifying the electrical connection. The three-phase AC input terminal 1 of the rectifier is a parallel copper busbar with diodes.

[0033] The high-speed rotating rectifier device of the present invention features a compact, redundant protection structure. When only one rectifier diode in the same bridge arm experiences an open-circuit or short-circuit fault, that bridge arm maintains its rectification function; it only loses its rectification function when at least two branches in that bridge arm fail. The rectifier device uses series voltage division and parallel current division of the four rectifier diodes in each bridge arm to ensure that each diode operates at a derating state below its rated value, thus withstanding reverse overvoltage and surge current during exciter-side faults.

[0034] The high-speed rotating rectifier device with a compact, redundant protective structure of the present invention has the following characteristics compared with the prior art: (1) Diode inherent redundancy and strong continuous operation capability: Two independent parallel current paths are formed in each bridge arm. When any diode has an open circuit fault, the series branch containing that diode is broken, but the current will automatically transfer to the other intact parallel branch in the same bridge arm, and the entire bridge arm can still maintain normal operation; when any diode has a short circuit fault, the other diode connected in series with it will maintain the blocking by its reverse withstand voltage margin, and the bridge arm function will not be lost. Only when two or more branches in the same bridge arm fail will the bridge arm lose its rectification function. This redundancy mechanism greatly improves the continuous operation capability and availability of the system.

[0035] (2) Eliminating external protection components and simplifying device structure: This invention abandons the traditional approach of relying on varistors, fuses, or RC circuits for external protection. Through a unique "two-series, two-parallel" diode composite connection method and diode selection with specific parameters, it achieves a fundamental improvement in reliability at the circuit topology level. High reliability operation can be achieved without any varistors or RC circuits, significantly simplifying the system structure and reducing weight, size, cost, and the number of potential failure points.

[0036] (3) Three-phase current sharing, suppression of commutation spikes, and improvement of electromagnetic compatibility: Through strict selection and arrangement of diode parameters, the overall conductivity characteristics of the six bridge arms (such as equivalent forward voltage drop and reverse recovery characteristics) remain highly consistent, so that the turn-on and turn-off speeds of each bridge arm tend to be consistent during the three-phase rectification commutation process, effectively suppressing the commutation voltage and current spikes caused by the difference in diode parameters, reducing the electromagnetic interference generated by the rectifier, and improving the electromagnetic compatibility of the entire motor system.

[0037] (4) Derating Design and Excellent Shock Resistance and Long Lifespan: The "series-then-parallel" topology allows the voltage and current to be shared by four diodes, with each diode actually operating in a derating state below its rated value, significantly reducing electrical and thermal stress. Simultaneously, with more diodes sharing the instantaneous impact energy, the device's resistance to current surges far exceeds that of traditional single-tube structures. Because each diode operates at a lower junction temperature, the overall mean time between failures (MTBF) of the device is greatly extended, making it particularly suitable for uninterrupted operation applications with extremely high reliability requirements.

[0038] (5) Small size and light weight: The single-disc support structure is adopted and 24 rectifier diodes are evenly distributed in a circular pattern on the inner and outer layers of the support disk, which effectively improves the space utilization rate and significantly reduces the outer diameter and overall weight of the rectifier device compared with the traditional single-layer arrangement structure. This design reduces the rotational inertia of the rotating rectifier device, increases the critical speed, and is conducive to the stable operation of the motor at higher speeds.

[0039] (6) Good heat dissipation performance: On the one hand, the conductive aluminum block with heat dissipation fins forms an efficient heat conduction path, which can quickly conduct the heat generated by the diode to the aluminum block and dissipate it through the fins; on the other hand, the six semi-circular holes on the support plate form a smooth axial ventilation channel with the exciter structure, and the cold air can directly penetrate the plate to force convection heat dissipation of the aluminum block and the diode, which greatly enhances the heat dissipation capacity of the device.

[0040] (7) High degree of modularity, reliable connection and easy maintenance: The conductive aluminum block, which combines electrical connection, mechanical fixation and heat dissipation functions, integrates four diodes into a bridge arm module through copper busbar, which simplifies the internal electrical connection. The semi-circular hole on the support plate allows the six leads of the exciter to be directly connected to the three-phase AC input terminal (diodes in parallel copper busbar), which is simple in electrical connection and easy to assemble and maintain.

[0041] In summary, the high-speed rotating rectifier device of this invention, with its compact and redundant protection structure, eliminates the need for traditional protection components such as varistors, RC buffer circuits, or fuses. It achieves fault tolerance of the rectifier diodes and system self-protection entirely through innovative circuit topology. Furthermore, it features a compact structure, excellent heat dissipation, and ease of maintenance. It does not require changes to the overall structural layout of existing motors and can directly replace existing rotating rectifiers, exhibiting excellent compatibility and widespread applicability. It can be widely applied to various synchronous motor excitation systems requiring shaft-fed rectification, and is particularly suitable for applications with stringent requirements regarding reliability, size, and weight, such as aircraft generators, ship generators, nuclear power plant emergency diesel generator sets, rail transit traction motors, and high-speed compressor drive motors.

[0042] Those skilled in the art should recognize that the above embodiments are merely illustrative of the present invention and are not intended to limit the present invention. Any variations or modifications to the above embodiments that are within the spirit and essence of the present invention will fall within the scope of the claims of the present invention.

Claims

1. A high-speed rotating rectifier with a compact, redundant protective structure, mounted on the motor shaft and rotating at the same speed as the motor, used to rectify the three-phase alternating current generated by the exciter armature into direct current, characterized in that, It includes a three-phase AC input terminal, a rectifier section, and DC positive and negative output terminals, wherein: The three-phase AC input terminal is connected to the three-phase AC lead-out of the exciter armature, and the DC positive and negative output terminals are connected to the DC excitation conductive copper busbar of the main motor rotor. The rectifier section includes six bridge arms, forming a three-phase uncontrolled bridge rectifier circuit; Each of the bridge arms consists of four rectifier diodes, wherein the first rectifier diode and the second rectifier diode are connected in series to form a first branch, the third rectifier diode and the fourth rectifier diode are connected in series to form a second branch, and the first branch and the second branch are connected in parallel to form the bridge arm. The circuit of the rectifier does not include varistors, RC buffer circuits, or fuses.

2. The high-speed rotating rectifier with a compact, redundant protection structure according to claim 1, characterized in that, The four rectifier diodes in the same bridge arm are selected from the same model and the same production batch, and are grouped according to the forward voltage drop before assembly, so that the total forward voltage drop difference between the first branch and the second branch is not greater than a preset threshold. The equivalent forward voltage drop and reverse recovery characteristics of each of the six bridge arms are kept consistent by selecting and arranging the parameters of the rectifier diodes within each bridge arm.

3. The high-speed rotating rectifier with a compact, redundant protection structure according to claim 1, characterized in that, The rectifier section has a total of 24 rectifier diodes, of which 12 are positive diodes and 12 are negative diodes. Each rectifier diode is a bolt-type diode.

4. A high-speed rotating rectifier with a compact, redundant protection structure according to claim 3, characterized in that, It also includes a conductive aluminum block with heat dissipation fins. One end of each pair of rectifier diodes of the same polarity is connected in parallel through a copper busbar, and the conductive aluminum block is connected in series with two rectifier diodes of opposite polarities to form a bridge arm. The conductive aluminum block has two screw holes and two through holes. The two screw holes are used to connect and fix the two positive and negative diodes in series, and the two through holes are used to fix the bridge arm to the support plate.

5. A high-speed rotating rectifier with a compact, redundant protection structure according to claim 4, characterized in that, The support disk is a single disk structure, and 24 rectifier diodes are evenly distributed along the circumference in the inner and outer layers of the support disk.

6. A high-speed rotating rectifier with a compact, redundant protection structure according to claim 5, characterized in that, The support plate has six semi-circular holes. These holes allow cooling air to pass through to form a heat dissipation duct, and also allow the three-phase AC leads of the exciter armature to pass through and connect to the three-phase AC input terminal of the rectifier.

7. A high-speed rotating rectifier with a compact, redundant protection structure according to claim 6, characterized in that, The exciter has two leads per phase of its three-phase AC power supply, for a total of six leads; the six semi-circular holes are used for the six leads to pass through, so that each lead is connected to the corresponding three-phase AC input terminal.

8. A high-speed rotating rectifier with a compact, redundant protection structure according to any one of claims 1 to 7, characterized in that, The bridge arm maintains its rectification function when only one rectifier diode in the same bridge arm experiences an open-circuit or short-circuit fault; the bridge arm loses its rectification function only when at least two branches in the bridge arm fail.

9. A high-speed rotating rectifier with a compact, redundant protection structure according to any one of claims 1 to 7, characterized in that, The rectifier device uses the series voltage division and parallel current division of the four rectifier diodes in each bridge arm to make each rectifier diode actually operate in a derating state below its rated value, so as to withstand the reverse overvoltage and surge current when the exciter side fails.

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