A brushless field synchronous generator

Abstract

This invention relates to the field of power electronics technology, specifically to a brushless excitation synchronous generator, comprising a housing, a rotor assembly installed through the housing, a front cover and a rear cover connected to both ends of the housing, a main PMG disposed inside the front cover, a stator assembly coaxially arranged with the rotor assembly fixed to the inner wall of the housing, a rectifier module disposed outside the housing, and a starting PMG. The main PMG and the starting PMG are respectively connected to two independent three-phase full-wave rectifier bridges, both of which are fixed on the rotor assembly. The starting PMG has a greater number of pole pairs than the main PMG. The beneficial effect of this invention is that the main PMG and the starting PMG constitute a dual excitation source system, serving as backups for each other. An intelligent switching unit automatically cuts off the starting PMG circuit, ensuring it only operates when necessary, avoiding no-load losses and copper losses caused by long-term auxiliary power supply operation. This on-demand power supply mechanism improves the overall efficiency, truly achieving the goal of high-efficiency operation of energy-saving generator sets, and meeting the requirements of green and low-carbon development.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, specifically to a brushless excitation synchronous generator. Background Technology

[0002] The demand for high-efficiency and energy-saving electrical equipment is growing in industries, new energy, ships, emergency power supplies and other fields. As the core device for power conversion, the operating efficiency, starting performance and reliability of synchronous generators are directly related to the stability and energy consumption level of the entire power system. In recent years, energy-saving generator sets have become an important direction for the development of generator technology due to their high efficiency, low loss and intelligent control.

[0003] Traditional brushed synchronous generators rely on carbon brushes and slip rings to introduce excitation current into the rotor windings, which has problems such as high contact resistance, spark interference, frequent maintenance, and short lifespan. They cannot meet the requirements of modern industry for maintenance-free and high reliability. To address this, brushless excitation technology has emerged. By setting an auxiliary exciter and a rotating rectifier on the rotor, contactless transmission of excitation current is achieved, which significantly improves the reliability and service life of the generator.

[0004] However, during the low-speed start-up phase, existing brushless excitation synchronous generators suffer from a starting blind zone because the output voltage of the permanent magnet generator is proportional to the speed. When the generator speed is low, the PMG cannot generate enough voltage to drive the rectifier circuit, resulting in the excitation system failing to establish itself. This severely affects the generator's starting reliability and restricts its widespread application in energy-saving generator sets. Summary of the Invention

[0005] The purpose of this invention is to provide a brushless excitation synchronous generator to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A brushless excitation synchronous generator includes a housing, a rotor assembly installed through the housing, a front cover and a rear cover connected to both ends of the housing, a main PMG disposed inside the front cover, a stator assembly coaxially arranged with the rotor assembly fixed to the inner wall of the housing, a rectifier module disposed outside the housing, and a starting PMG coaxially arranged with the main PMG. The generator also includes a starting PMG connected to two independent three-phase full-wave rectifier bridges, both of which are fixed to the rotor assembly. The starting PMG has a greater number of pole pairs than the main PMG.

[0008] Preferably, the main PMG includes a main stator and a main rotor. The main stator is fixed inside the front end cover. The main rotor includes a first mounting ring that is keyed to the rotor assembly. A first three-phase coil winding is provided on the first mounting ring. The lead wires of the first three-phase coil winding are connected to a three-phase full-wave rectifier bridge on the same side.

[0009] Preferably, the starting PMG includes a starting stator and a starting rotor. The starting stator is fixed inside the housing. The starting rotor includes a second mounting ring that is keyed to the rotor assembly. A second three-phase coil winding is provided on the second mounting ring. The lead wires of the second three-phase coil winding are connected to a three-phase full-wave rectifier bridge on the same side. The magnetic density of the starting stator is higher than that of the main stator.

[0010] Preferably, the rotor assembly includes a main shaft and an excitation rotor fitted in the middle of the main shaft. The excitation rotor is wound with an excitation winding, and the two ends of the excitation winding are electrically connected to the output ends of two three-phase full-wave rectifier bridges, respectively.

[0011] Preferably, the three-phase full-wave rectifier bridge is integrated on a heat dissipation substrate, and the heat dissipation substrate is fixed to the main shaft by an insulating bracket.

[0012] Preferably, it also includes a backflow suppression circuit, which is disposed in the circuit between the starting PMG and the corresponding three-phase full-wave rectifier bridge. The backflow suppression circuit includes a diode and a relay connected in series.

[0013] Preferably, the rectifier module includes an intelligent switching unit and an AVR adjustment unit.

[0014] Preferably, it also includes an energy storage element connected to the output of the AVR regulation unit to provide instantaneous energy support during power switching.

[0015] Compared with the prior art, the beneficial effects of the present invention are:

[0016] 1. The main PMG and the starting PMG constitute a dual excitation source system, which serves as backups for each other. When the main PMG experiences a sudden drop in output voltage due to a fault, the system can automatically switch to the starting PMG to maintain uninterrupted excitation, prevent the generator from losing its excitation and shutting down, buy time for equipment maintenance, and significantly improve the system's robustness and continuous operation capability under complex working conditions.

[0017] 2. The main PMG adopts a four-pole moderate magnetic density design, which can operate efficiently at the rated speed. The intelligent switching unit automatically cuts off the starting PMG circuit, so that it only works when necessary, avoiding no-load loss and copper loss caused by long-term operation of the auxiliary power supply. This on-demand power supply mechanism improves the efficiency of the whole machine, truly achieving the goal of high-efficiency operation of energy-saving motor units, which meets the requirements of green and low-carbon development.

[0018] 3. By integrating energy storage components into the rectifier module, instantaneous energy support is provided to the AVR during power switching, effectively suppressing voltage drops, avoiding output voltage fluctuations caused by sudden changes in excitation current, and improving power quality and control system stability. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the exploded structure of the present invention;

[0021] Figure 3 This is a schematic diagram of the internal structure of the housing of the present invention;

[0022] Figure 4 This is a schematic diagram of the main PMG structure of the present invention;

[0023] Figure 5 This is a schematic diagram of the PMG startup structure of the present invention;

[0024] Figure 6 This is a schematic diagram of the three-phase full-wave rectifier bridge structure of the present invention;

[0025] Figure 7 This is a schematic diagram of the control logic of the intelligent switching unit of the present invention for the rectifier circuits of the main PMG and the starting PMG;

[0026] Figure 8 This is a schematic diagram of the control logic for performing power switching actions according to the present invention.

[0027] The attached diagram lists the components represented by each number as follows:

[0028] 100. Housing; 110. Front cover; 120. Rear cover;

[0029] 200. Rotor assembly; 210. Main shaft; 220. Excitation rotor; 230. Excitation winding; 240. Fan blade;

[0030] 300. Main PMG; 310. Main stator; 320. Main rotor; 321. First mounting ring; 322. First three-phase coil winding;

[0031] 400. Stator assembly;

[0032] 500. Rectifier module; 510. Intelligent switching unit; 520. AVR regulating unit; 530. Energy storage element;

[0033] 600. Start PMG; 610. Start stator; 620. Start rotor; 621. Second mounting ring; 622. Second three-phase coil winding;

[0034] 700. Three-phase full-wave rectifier bridge; 710. Reverse current suppression circuit;

[0035] 800, heat dissipation substrate. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0037] Example: Figure 1 - Figure 8 The illustrated brushless excitation synchronous generator includes a cylindrical housing 100, inside which a rotor assembly 200 is installed. A front cover 110 and a rear cover 120 are bolted to both ends of the housing 100, forming a closed generator cavity. Deep groove ball bearings are provided inside both the front cover 110 and the rear cover 120 to support the rotor assembly 200 and ensure rotational accuracy. A main PMG 300 is located inside the front cover 110. A stator assembly 400, coaxially arranged with the rotor assembly 200, is fixed to the inner wall of the housing 100. The stator assembly 400 consists of a stator core made of stacked silicon steel sheets and embedded in it. The generator is composed of three-phase distributed windings, which are used to induce electromotive force and output AC power during generator operation. A rectifier module 500 is provided on the outside of the housing 100, and a starting PMG 600 is also included, which is coaxially arranged with the main PMG 300. The main PMG 300 and the starting PMG 600 are respectively connected to two independent three-phase full-wave rectifier bridges 700. The three-phase full-wave rectifier bridges 700 are all fixed on the rotor assembly 200 and rotate synchronously with the rotor. The DC output terminals of the three-phase full-wave rectifier bridges 700 are connected in parallel to the rotor assembly 200 to achieve brushless excitation. Crucially, the number of pole pairs of the starting PMG 600 is greater than the number of pole pairs of the main PMG 300.

[0038] During the generator startup phase, the speed is low. Due to insufficient speed, the main PMG300's rotor coil generates a low induced voltage by cutting the magnetic field, which cannot effectively establish excitation. At this time, the starting PMG600, with its more pole pairs, can generate AC power with higher frequency and voltage at the same speed. The second and third phase coil windings 622 of the starting PMG600 output AC power, which is rectified by the three-phase full-wave rectifier bridge 700 on the same side and then supplies power to the excitation winding 230 through the rectifier module 500 to establish the initial magnetic field and ensure low-speed startup reliability.

[0039] As the rotational speed increases, the output voltage of the main PMG300 gradually increases. The rectifier module 500 detects that the voltage of the main PMG300 is close to the rated value and controls the two rectifier outputs of the main PMG300 and the starting PMG600 to supply power in parallel, so as to achieve a smooth transition of the excitation current and avoid voltage fluctuations or magnetic field interruption.

[0040] When the speed reaches the rated value and the main PMG300 output voltage is stable within the set range, the rectifier module 500 determines that the main excitation source has been reliably established. At this time, the starting PMG600 circuit is cut off and its power supply is stopped. Only the main PMG300 provides the excitation current, reducing no-load loss, improving the overall system efficiency, and achieving energy-saving operation.

[0041] If a sudden increase in load or a sharp drop in speed causes a decrease in the voltage of the main PMG300, the rectifier module 500 will restart the PMG600 circuit to ensure uninterrupted excitation and improve system robustness.

[0042] Reference Figure 2 and Figure 3 In order to effectively improve the thermal stability of the generator under high load continuous operation and prevent insulation aging, permanent magnet demagnetization or electronic component failure due to excessive temperature rise, this embodiment further integrates a forced air cooling structure on the rotor assembly 200.

[0043] Specifically, a rotating fan blade 240 is fixedly installed on the side of the rotor assembly 200 near the rear end cover 120. It rotates synchronously with the rotor assembly 200 at high speed. The rotating fan blade 240 has an axial flow blade structure, preferably a multi-blade forward-curved or backward-inclined design, which can generate directional airflow when the generator is running. When the rotor assembly 200 rotates, the fan blade 240 drives the air to be drawn in from the non-driving end of the generator and flows towards the front end along the pre-set ventilation channel inside the housing 100. The airflow is finally discharged outside the machine through the air outlet of the front end cover 110, forming a highly efficient internal circulation forced air cooling system. In addition, the outer wall of the housing 100 is provided with axial heat dissipation fins, which, together with the internal air passage, enhance the heat exchange efficiency with the external environment.

[0044] Reference Figure 3 and Figure 4The main PMG300, as the core power supply component during the rated operation of the generator, includes a main stator 310 and a main rotor 320. The main stator 310 is fixed inside the front cover 110 and is a permanent magnet, specifically located on the side of the deep groove ball bearing near the rotor assembly 200. It is evenly embedded along the circumference and arranged alternately from N pole to S pole, forming a four-pole radial magnetic field structure. The main stator 310 does not rotate with the rotor, and the constant magnetic field it generates is statically distributed in space with stable magnetic flux. When the generator starts, the rotor assembly 200 drives the main rotor 320 to rotate synchronously via a key connection. The main rotor 320 includes... The first mounting ring 321 is keyed to the rotor assembly 200. The first mounting ring 321 is provided with a first three-phase coil winding 322. When the rotor assembly 200 drives the main rotor 320 to rotate, the conductor of the first three-phase coil winding 322 continuously cuts the static radial magnetic field generated by the main stator 310, inducing a three-phase AC electromotive force. The lead wire of the first three-phase coil winding 322 is connected to the three-phase full-wave rectifier bridge 700 on the same side. After the three-phase AC electromotive force is rectified by the rectifier bridge, it is converted into DC voltage. The DC voltage is directly supplied to the rotor assembly 200 to provide a stable power supply for the excitation system when the generator is running under rated load.

[0045] Reference Figure 3 and Figure 5 The PMG600 starter is specifically designed for the initial startup phase of a generator. It includes a starting stator 610 and a starting rotor 620. The starting stator 610 is fixed inside the housing 100. The starting stator 610 has a higher magnetic density than the main stator 310. Fixed to the inner wall of the housing 100, it forms a twelve-pole radial magnetic field. The higher magnetic density means a larger magnetic flux per unit area, allowing sufficient induced electromotive force to be generated even at low speeds through magnetic field cutting. The twelve-pole structure also allows for a higher magnetic field cutting frequency, further improving power generation efficiency at low speeds. The starting rotor 620 also rotates with the rotor assembly 200. The starting rotor 620 includes a second mounting ring 621 keyed to the rotor assembly 200. The second mounting ring 621 is equipped with... The second three-phase coil winding 622 is used to cut the high magnetic density static magnetic field of the starting stator 610. Due to the greater number of pole pairs, the magnetic flux per unit area is greater. Even if the speed decreases, it can still induce a three-phase AC electromotive force that meets the starting requirements. This avoids the problem that the main PMG300 has insufficient magnetic flux and too low frequency at low speeds, which would cause the output voltage to be unable to drive the automatic voltage regulator in the rectifier module 500. The leads of the second three-phase coil winding 622 are connected to the three-phase full-wave rectifier bridge 700 on the same side. After rectification, the AC electromotive force outputs DC power, which prioritizes powering the automatic voltage regulator module. This ensures that the automatic voltage regulator can work normally during the starting phase and avoids starting failure or starting delay caused by the lack of excitation power when the generator starts.

[0046] During the startup phase, the PMG600 generator, due to its high magnetic density and multi-pole structure, prioritizes power generation at low speeds. After rectification, it provides DC power to the automatic voltage regulator, driving the automatic voltage regulator to control the rotor assembly 200 to establish initial excitation and ensure the generator starts smoothly. At this time, the main PMG300 does not participate in power supply because its speed has not reached the rated value, the magnetic flux cutting frequency is insufficient, and the output voltage is low.

[0047] During the rated operation phase, the main PMG300 reaches the specified speed. The first three-phase coil winding 322 cuts the magnetic field to generate an alternating electromotive force, which is rectified to output DC. This voltage is higher than the output of the starting PMG600. Through the three-phase full-wave rectifier bridge 700 and rectifier module 500, it automatically switches to the main power supply to provide a higher power and more stable DC power supply to the rotor assembly 200, meeting the excitation requirements of the generator under rated load.

[0048] When the PMG600 is started, it is still generating electricity, but because its output voltage is lower than that of the main PMG300, it automatically disconnects from the main power supply or serves as a backup redundancy to avoid wasting energy.

[0049] Reference Figure 2 and Figure 3 The rotor assembly 200 includes a main shaft 210 and an excitation rotor 220 fitted in the middle of the main shaft 210. The excitation rotor 220 is made of high permeability silicon steel sheets stacked together. After stacking, it is vacuum impregnated with epoxy resin to form an integral iron core. The integral iron core has the characteristics of low magnetic resistance and high structural strength. An excitation winding 230 is wound on the excitation rotor 220. The two ends of the excitation winding 230 are electrically connected to the output ends of two three-phase full-wave rectifier bridges 700 respectively. When the excitation winding 230 is supplied with DC current provided by the three-phase full-wave rectifier bridge 700, the current generates a closed magnetic circuit in the iron core, forming a radial excitation magnetic field that is uniformly distributed along the circumference. This magnetic field rotates with the main shaft 210, cutting the three-phase distributed windings of the stator assembly 400, and finally inducing a three-phase AC electromotive force in the stator windings.

[0050] Reference Figure 4 - Figure 6 The three-phase full-wave rectifier bridge 700 is integrated on the heat sink substrate 800, which is fixed to the spindle 210 by an insulating bracket.

[0051] When the three-phase full-wave rectifier bridge 700 is working, the diode conduction will generate conduction loss, and the heat will be conducted to the integrated heat dissipation substrate 800 through the pins. The heat dissipation substrate 800 is fixed to the spindle 210 through an insulating bracket. When it rotates synchronously with the spindle 210, the surface of the substrate forms relative motion with the air, generating forced convection heat dissipation.

[0052] Reference Figure 5It also includes a reverse current suppression circuit 710, which is set in the circuit between the starting PMG600 and the corresponding three-phase full-wave rectifier bridge 700. The reverse current suppression circuit 710 includes a diode and a relay connected in series. The diode is a 1N5819WS Schottky diode, which has fast conduction speed and small reverse leakage current and can quickly block reverse current. The relay is a JY-31 electromagnetic relay. The circuit board of the reverse current suppression circuit 710 is mounted on the reserved mounting position of the heat sink 800 by bolts. A thick copper foil is placed between the circuit board and the heat sink 800 so that the heat generated by the diode when it is working can be conducted to the heat sink 800 and dissipated through forced convection of the heat sink 800.

[0053] During the startup phase, the speed is low. At this time, the generator speed has not reached the rated speed of the main PMG300. The AVR module does not supply power to the relay coil, the relay is in the normally closed state, and the contacts are open. The coil winding of the starting PMG600 cuts the high magnetic density stator magnetic field and induces a three-phase AC voltage. The voltage direction causes the diode in the reverse current suppression circuit 710 to be forward biased and the diode to conduct. The three-phase AC current of the starting PMG600 is transmitted through the path from the starting PMG600 to the reverse current suppression circuit 710 and then to the three-phase full-wave rectifier bridge 700. After rectification, the output DC voltage is injected into the excitation winding 230 to establish the initial excitation magnetic field and meet the generator startup requirements.

[0054] During the rated speed range, the relay triggers switching. The DC voltage of the three-phase full-wave rectifier bridge 700 on the main PMG300 side is higher than that on the starting PMG600 side. If not blocked, the current will flow in the reverse path from the rectifier bridge on the main PMG300 side to the rectifier bridge on the starting PMG600 side and then to the starting PMG600 coil winding. At this time, the reverse current direction causes the diode in the reverse current suppression circuit 710 to be reverse biased. The diode is cut off, and the relay contacts are opened, forming a double blocking, preventing the starting PMG600 coil winding from burning out due to overcurrent.

[0055] If the main PMG300 experiences a fault, such as a short circuit in the coil causing a sudden drop in output voltage, the rectifier module 500 will detect the abnormal voltage and immediately cut off the power supply to the relay coil, restoring the relay contacts to their normally closed state. At this time, the output voltage of the starting PMG600 will cause the diode to conduct in the forward direction, and the current will be transferred back to the three-phase full-wave rectifier bridge 700 to provide DC redundant power to the excitation winding 230, maintaining the generator output voltage and ensuring uninterrupted operation during the fault, thus buying time for maintenance.

[0056] Reference Figure 1 and Figure 7 and Figure 8The rectifier module 500 includes an intelligent switching unit 510 and an AVR regulation unit 520, and also includes an energy storage element 530 connected to the output terminal of the AVR regulation unit 520 to provide instantaneous energy support during power switching.

[0057] During the startup phase, the PMG600 is powered on, and the energy storage element 530 is pre-charged to prepare for subsequent power switching. The energy storage element 530 consists of two electrolytic capacitors connected in parallel. The ADC of the intelligent switching unit 510 collects the rectified voltage of the main PMG300 and the rectified voltage of the startup PMG600, determines that the current phase is startup, controls the solid-state relay to switch to the startup PMG600 side, and inputs the rectified voltage into the AVR regulating unit 520. After receiving the power, the AVR regulating unit 520 injects the initial excitation current into the excitation winding 230 to establish the initial magnetic field.

[0058] Under rated conditions, the main PMG300 supplies power, the energy storage element 530 is on standby, the intelligent switching unit 510 detects the voltage threshold and immediately controls the solid-state relay to switch from the starting PMG600 side to the main PMG300 side. After receiving the high voltage, the AVR regulating unit 520 controls the dynamic change of the excitation current according to the generator output voltage feedback. The voltage across the energy storage element 530 rises to a higher level with the main PMG300 supply voltage and is in a fully charged standby state.

[0059] If a fault in the main PMG300 causes a sudden drop in rectified voltage, the intelligent switching unit 510, upon detecting the abnormality, triggers a switch to the starting PMG600 side. The input voltage of the AVR regulating unit 520 experiences a momentary drop. At this time, the energy storage element 530 immediately discharges to maintain stable AVR output voltage and prevent a sudden drop in excitation current. During normal switching from the starting PMG600 to the main PMG300, the intelligent switching unit 510 switches the power supply. During the switching interval, the energy storage element 530 discharges to compensate for the voltage drop and effectively reduce excitation current fluctuations.

[0060] Working principle: The prime mover drives the main shaft 210 of the rotor assembly 200 to rotate. The main shaft 210 synchronously drives the main rotor 320 of the main PMG 300, the starting rotor 620 of the starting PMG 600 and the excitation rotor 220 to rotate. The deep groove ball bearings inside the front cover 110 and the rear cover 120 ensure the rotational accuracy of the main shaft 210 and reduce mechanical losses caused by eccentricity.

[0061] The starting stator 610 of the PMG600 is a twelve-pole high-magnetic-density permanent magnet, with a higher magnetic density than the main stator 310 of the main PMG300. When the starting rotor 620 rotates with the main shaft 210, its second three-phase coil windings 622 cut the stationary magnetism of the starting stator 610. Due to the large number of pole pairs and high magnetic density, even at low speeds, a low-order three-phase AC electromotive force can still be induced, eliminating the need for an additional auxiliary excitation power supply and avoiding the energy waste associated with external battery power during traditional generator startup. In the reverse-current suppression circuit 710, the relay is located where the AVR is not powered. In the normally closed state, there is no additional energy consumption. The low-voltage DC voltage is input to the rectifier module 500 intelligent switching unit 510 outside the housing 100. The voltage is collected by the ADC and it is determined to be in the start-up stage. The solid-state relay is controlled to switch to the start-up PMG600 side and the voltage is input to the AVR regulating unit 520. The AVR regulating unit 520 injects the initial current into the excitation winding 230 of the excitation rotor 220. After the excitation winding 230 is energized, a radial excitation magnetic field is formed in the epoxy resin vacuum impregnated integral iron core. At the same time, the energy storage element 530 is pre-charged.

[0062] The rotating magnetic field of the excitation rotor 220 cuts the stator windings of the stator assembly 400 on the inner wall of the housing 100, inducing an initial AC voltage, marking a successful generator start-up and the entry into the speed-up phase. When the speed reaches the rated speed of the main PMG 300, its first three-phase coil winding 322 cuts the stationary magnetic field of the main stator 310, inducing a higher-order three-phase AC electromotive force. This electromotive force is output as a higher-order DC voltage by the corresponding three-phase full-wave rectifier bridge 700, and the intelligent switching unit 510 of the rectifier module 500 detects the higher-order voltage. Immediately control the solid-state relay to switch to the main PMG300 side, and simultaneously supply power to the relay coil of the reverse-feedback suppression circuit 710. The relay contacts open, and in conjunction with the diode reverse cutoff, a "double blocking" is formed to prevent the high-order voltage of the main PMG300 from flowing back into the starting PMG600 winding. After receiving the high-order power supply from the main PMG300, the AVR regulation unit 520 collects the output voltage of the stator assembly 400 through the voltage transformer and dynamically adjusts the PWM duty cycle. At this time, the energy storage element 530 is fully charged and ready to go.

[0063] If the main PMG300 experiences a short circuit in the coil or demagnetization of the permanent magnet, causing the output voltage to drop sharply below the high-order threshold, the intelligent switching unit 510 of the rectifier module 500 detects the voltage abnormality and immediately cuts off the power supply to the relay coil of the reverse-feedback suppression circuit 710. The relay contacts return to their normally closed state, and the low-order rectified voltage of the starting PMG600 is forward-biased and re-input to the rectifier module 500. This eliminates the need to start the backup generator, resulting in energy savings.

[0064] When the load suddenly increases, the demand for excitation current increases accordingly, and the power supply of the main PMG300 may be delayed. The energy storage element 530 discharges synchronously to supplement the current and relieve the power supply pressure.

[0065] 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 process, method, article, or apparatus.

[0066] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A brushless excitation synchronous generator, comprising a housing (100), characterized in that: A rotor assembly (200) is installed through the housing (100). A front cover (110) and a rear cover (120) are connected to both ends of the housing (100). A main PMG (300) is arranged inside the front cover (110). A stator assembly (400) arranged coaxially with the rotor assembly (200) is fixed to the inner wall of the housing (100). A rectifier module (500) is arranged on the outer side of the housing (100). The housing also includes a starting PMG (600) arranged coaxially with the main PMG (300). The main PMG (300) and the starting PMG (600) are respectively connected to two independent three-phase full-wave rectifier bridges (700). The three-phase full-wave rectifier bridges (700) are all fixed on the rotor assembly (200). The number of pole pairs of the starting PMG (600) is greater than the number of pole pairs of the main PMG (300). The main PMG (300) includes a main stator (310) and a main rotor (320). The main stator (310) is fixed inside the front end cover (110). The main rotor (320) includes a first mounting ring (321) that is keyed to the rotor assembly (200). A first three-phase coil winding (322) is provided on the first mounting ring (321). The lead wires of the first three-phase coil winding (322) are connected to the three-phase full-wave rectifier bridge (700) on the same side. The starting PMG (600) includes a starting stator (610) and a starting rotor (620). The starting stator (610) is fixed inside the housing (100). The starting rotor (620) includes a second mounting ring (621) keyed to the rotor assembly (200). A second three-phase coil winding (622) is provided on the second mounting ring (621). The lead wires of the second three-phase coil winding (622) are connected to a three-phase full-wave rectifier bridge (700) on the same side. The magnetic density of the starting stator (610) is higher than that of the main stator (310). It also includes a backflow suppression circuit (710), which is disposed in the circuit between the starting PMG (600) and the corresponding three-phase full-wave rectifier bridge (700). The backflow suppression circuit (710) includes a diode and a relay connected in series. The rectifier module (500) includes an intelligent switching unit (510) and an AVR adjustment unit (520). It also includes an energy storage element (530) connected to the output of the AVR regulating unit (520) for providing instantaneous energy support during power switching.

2. The brushless excitation synchronous generator according to claim 1, characterized in that: The rotor assembly (200) includes a main shaft (210) and an excitation rotor (220) fitted in the middle of the main shaft (210). An excitation winding (230) is wound on the excitation rotor (220), and the two ends of the excitation winding (230) are electrically connected to the output ends of two three-phase full-wave rectifier bridges (700).

3. A brushless excitation synchronous generator according to claim 1, characterized in that: The three-phase full-wave rectifier bridge (700) is integrated on the heat dissipation substrate (800), which is fixed to the main shaft (210) by an insulating bracket.

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