High and low voltage dc output three-stage starter-generator system and design method

Abstract

The application discloses a high-voltage and low-voltage direct-current output three-stage starting generator system and a design method thereof. The system comprises a three-stage starting generator and a controller. The three-stage starting generator comprises a permanent magnet auxiliary exciter, a main exciter and a main motor. The main motor meets the 28V low-voltage and 270V high-voltage direct-current requirements through a low-voltage three-phase winding and a high-voltage three-phase winding. The controller comprises a low-voltage three-phase full bridge and a high-voltage three-phase full bridge. The full bridge supports bidirectional energy flow and is compatible with double-voltage starting. During starting, an alternating current excitation power supply is powered, and the full bridge adjusts the current to make the starting generator output torque. During power generation, the low-voltage side uses synchronous rectification to reduce the MOS tube conduction voltage drop, and the high-voltage side controls the voltage stabilization through voltage boosting or voltage reduction. The three-stage starting generator system provided by the application uses the high-voltage three-phase full bridge power generation voltage stabilization, the switching frequency of which is the same as the output electric frequency of the starting generator, the frequency is low, the system has the characteristics of low loss, low high-frequency ripple spectrum component, weak high-frequency conduction and radiation interference and high power density.

Description

Technical Field

[0001] This invention belongs to the field of generator design technology, specifically relating to a three-stage starting generator system and design method with high voltage and low voltage DC output, and is particularly suitable for aviation hybrid power systems consisting of 28V low voltage DC and 270V high voltage DC. Background Technology

[0002] In the aviation field, three-stage generator-based power generation systems are the mainstream form of main power, auxiliary power, and ramjet turbine emergency power. Early airborne equipment consumed relatively little power and typically used 28V low-voltage DC power systems. However, with the increase in the power consumption of airborne equipment, 28V low-voltage DC power systems are no longer suitable for aircraft with power outputs above 12kW. Therefore, high-voltage systems have become the development direction, replacing the original 28V low-voltage DC power systems with 270V high-voltage DC or 115V AC power systems. Due to the different power requirements of electrical equipment, the main development direction for civil airliners, helicopters, transport aircraft, and high-end reconnaissance UAVs is AC power systems; for fighter jets and high-end strike UAVs, where more electronic equipment and weapon systems use DC power, the main development direction is 270V high-voltage DC power systems. However, aircraft emergency batteries still primarily use 28V low-voltage; at the same time, some mature airborne equipment with lower power consumption does not need to be upgraded entirely to high-voltage DC and AC power, and some airborne equipment still requires 28V low-voltage DC. Therefore, the aviation hybrid power system consisting of 28V low-voltage DC and 270V high-voltage DC is the mainstream form for fighter jets and high-end strike drones.

[0003] Traditional aircraft engines are started using electric starters and air turbine starters. However, once the engine is started, these starters become dead weight, hindering further improvements in aircraft performance. With the development of power electronics technology and the increasing electrification of aircraft, generators that previously only generated electricity can be expanded into starter-generators with both starting and power generation functions, effectively reducing the burden on the engine starting system. For engines smaller than 500kW, a 28V low-voltage DC power supply is the primary power source for engine starting, provided by a 28V battery. For engines larger than 2MW, a 270V high-voltage DC power supply is the primary power source for engine starting, provided by a generator system driven by the auxiliary power unit (APU).

[0004] Existing aviation hybrid power supply systems, consisting of 28V low-voltage DC and 270V high-voltage DC, are generally implemented in the following ways.

[0005] 1. A combination of a high-voltage DC three-stage starter-generator system and a DC bus converter is the primary technical solution used in fighter jets. The engine is only mechanically connected directly to the high-voltage DC three-stage generator system. During startup, the generator system driven by the auxiliary power unit (APU) provides 270V high-voltage DC power, which drives the engine from standstill to ignition speed, thus starting the engine. During power generation, the engine provides mechanical speed input to the high-voltage DC three-stage generator system, which converts the input mechanical energy into 270V AC electrical energy; this is then converted to 28V low-voltage DC via the DC bus converter.

[0006] 2. A combined low-voltage DC brushed starter-generator system and a high-voltage DC three-stage generator system is a standard technical solution primarily used in UAVs. Its power quality, including overload, short-circuit, and high-frequency ripple spectrum protection, fully meets the requirements of aircraft power supply and generation systems. In case of a fault, protection can be achieved through demagnetization, meeting safety requirements. One engine is equipped with two generator systems: a DC brushed starter-generator system and a high-voltage DC three-stage generator system. During startup, a 28V battery serves as the starting power source. The low-voltage DC brushed starter-generator system generates electricity, driving the engine from standstill to ignition speed, thus starting the engine. During power generation, the engine provides mechanical speed input to both the DC brushed starter-generator system and the high-voltage DC three-stage generator system. The DC brushed starter-generator system converts the input mechanical energy into 28V low-voltage DC and 270V high-voltage DC electrical energy, respectively. With the development of power electronics technology, the technical solution of using a low-voltage DC three-stage starter-generator system instead of a low-voltage DC brushed starter-generator system is becoming increasingly mature, and there are already precedents for its application. Because mechanical commutation is replaced by electronic commutation, low-voltage DC three-stage starter generator systems are suitable for high-altitude long-haul flights, export maintenance-free applications, and coastal salt spray environments. However, the power density of low-voltage DC three-stage starter generator systems is much lower than that of DC brushed starter generator systems, which is the main disadvantage of low-voltage DC three-stage starter generator systems.

[0007] 3. A combined high-voltage DC permanent magnet starter-generator system and DC bus converter scheme is the primary technical solution adopted by low-cost UAVs. The engine is only mechanically connected directly to the high-voltage DC permanent magnet starter-generator system. The engine is typically a turbofan engine. Turbofan engines typically start at 5%–8% of their rated speed, exhibiting extremely high drag torque below 10 r / min. Once past this low-speed range, the drag torque decreases significantly, resulting in relatively low starting power. This differs significantly from turbine engines, which typically start at 40%–50% of their rated speed, have low low-speed drag, and exhibit drag that increases quadratically with speed, while also requiring higher starting power. During startup, a 28V battery serves as the starting power source, directly supplying power to the high-voltage DC permanent magnet starter-generator system, or the battery voltage is boosted to 50V–60V via a power converter before supplying power to the system. The high-voltage DC permanent magnet starter-generator system then drives the engine from standstill to ignition speed, thus starting the engine. Since the starting power requirement of a piston engine is not large, and the power converter used to boost the battery voltage to 50V-60V operates for short periods, the added weight of the boost power converter is minimal. During power generation, the engine provides mechanical speed input to the high-voltage DC permanent magnet starter generator system, which converts the input mechanical energy into 270V AC electrical energy; then, a DC bus converter transforms the 270V high-voltage DC into 28V low-voltage DC. Because the permanent magnet starter generator has a simpler structure than a three-stage starter generator, its cost is significantly reduced.

[0008] In Scheme 1, the 28V low-voltage DC is obtained through a two-stage energy conversion. The first stage is a three-stage high-voltage DC starter-generator system that converts the input mechanical energy into 270V high-voltage DC electrical energy. The second stage is a DC bus converter that converts the 270V high-voltage DC into 28V low-voltage DC, resulting in low efficiency in converting to 28V electrical energy. Furthermore, the conversion from 270V high-voltage DC to 28V low-voltage DC is a high-frequency, full-power conversion, and the DC bus converter is also quite heavy. In Scheme 2, the generator system has two mechanical interfaces with the engine, which are more complex, resulting in significant additional weight from the mechanical transmission interface and generator housing. In Scheme 3, because the output voltage of the permanent magnet starter generator changes linearly with the speed and has a high operating frequency, and the 270V voltage regulator has a wide input voltage range and a high switching frequency, the power density and efficiency of the high-voltage DC permanent magnet starter generator system are not superior to those of the high-voltage DC three-stage starter generator system. The power quality of the high-voltage DC permanent magnet starter generator system, such as overload, short circuit, and high-frequency ripple spectrum, is difficult to meet the requirements of aircraft power supply and generation system standards. It cannot be demagnetized after a fault, which does not meet aviation safety requirements. The conversion efficiency of 28V power is low. The DC bus converter that realizes the conversion of 270V high-voltage DC to 28V low-voltage DC is also relatively heavy. Summary of the Invention

[0009] The purpose of this invention is to address the shortcomings of the aforementioned technologies by providing a three-stage starting generator system with high-voltage and low-voltage DC output; the purpose of this invention is also to address the shortcomings of the aforementioned technologies by providing a design method for a three-stage starting generator system with high-voltage and low-voltage DC output.

[0010] The present invention provides a three-stage starter-generator system with high-voltage and low-voltage DC output, comprising a three-stage starter-generator and a controller. The three-stage starter-generator includes a permanent magnet auxiliary exciter, a main exciter, a main motor, a rotating rectifier, and a rotary transformer. The controller includes a low-voltage three-phase full-bridge converter, a high-voltage three-phase full-bridge converter, a voltage regulating circuit, an AC excitation power supply, a control circuit, and a diode D. L and D H Current sensor S F ;

[0011] The rotary transformer outputs a speed and position signal P, which is connected to the control circuit. The winding W of the permanent magnet auxiliary exciter... PMG Terminals A, B, and C are connected to the voltage regulating circuit, and the control circuit outputs a drive signal G. C and G R Connected to a voltage regulating circuit, the output terminal V of the voltage regulating circuit Co The positive and negative terminals are respectively connected to the excitation winding W of the main exciter. EE The F+ and F- terminals are connected, and the low-voltage power supply input terminal V of the AC excitation power supply is connected. iL and high voltage power supply input terminal ViH Connect to the positive terminals of the low-voltage three-phase full-bridge and the high-voltage three-phase full-bridge respectively.

[0012] The ground reference terminal GND of the AC excitation power supply is connected to the negative terminals of both the low-voltage three-phase full-bridge and the high-voltage three-phase full-bridge, respectively, and the control circuit outputs a drive signal G. D and G S Connect to an AC excitation power supply; the output terminal of the AC excitation power supply is V. Bo The * and ~ terminals are respectively connected to the excitation winding W of the main exciter. EE Connect the F+ and F- terminals.

[0013] The current sensor S F Detecting the flow into the main exciter's excitation winding W EE The excitation current i is output after the F+ terminal current. F Connected to the control circuit, the low-voltage three-phase winding W of the main motor L A, B, and C are connected to a low-voltage three-phase full-bridge circuit, and the positive and negative terminals of the low-voltage three-phase full-bridge circuit are connected to the positive and negative terminals of the external low-voltage DC interface, respectively.

[0014] The control circuit outputs a drive signal G. A Connected to a low-voltage three-phase full-bridge, the low-voltage three-phase full-bridge outputs a low-voltage DC voltage V. dcL and low-voltage three-phase alternating current i L Connected to the control circuit, the low-voltage starting power supply terminal V SL via diode D L Anode, diode D L The cathode is connected to the positive terminal of the low-voltage three-phase full-bridge circuit, and the high-voltage three-phase winding W of the main motor... H Terminals A, B, and C are respectively connected to a high-voltage three-phase full-bridge, and the positive and negative terminals of the high-voltage three-phase full-bridge are respectively connected to the positive and negative terminals of the external high-voltage DC interface.

[0015] The output drive signal G of the control circuit B Connected to a high-voltage three-phase full-bridge, the high-voltage three-phase full-bridge outputs a high-voltage DC voltage V. dcH and high voltage three-phase alternating current i H Connected to the control circuit, the high-voltage starting power supply terminal V SH via diode D H Anode, diode D H The cathode is connected to the positive terminal of the high-voltage three-phase full-bridge circuit, and the control circuit outputs a drive signal G. L and G H Respectively with the power generation control circuit breaker GCB L and GCB H Connection, the rotor armature winding W of the main exciter EMvia the rotating rectifier and the main motor rotor excitation winding W ME connect.

[0016] Furthermore, the stator armature winding of the main motor includes a low-voltage three-phase winding W. L and high voltage three-phase winding W H ,

[0017] The low-voltage three-phase winding W L W includes phases A, B, and C respectively. LA W LB and W LC The high-voltage three-phase winding W H W includes phases A, B, and C respectively. HA W HB and W HC ;

[0018] For low-voltage three-phase winding W L Any X-phase winding, where X = A, B, or C, is formed by the 1st, 2nd…pth pole pair windings W LX1 W LX2 …W LXp Parallel connection configuration, low-voltage three-phase winding W L One end of any X-phase winding is connected to the neutral point N. L Connection, low-voltage three-phase winding W L The other end of any X-phase winding is connected to the low-voltage three-phase winding W. L The X-end connection,

[0019] For high-voltage three-phase winding W H Any X-phase winding, where X = A, B, or C, is formed by the 1st, 2nd…pth pole pair windings W HX1 W HX2 …W HXp The high-voltage three-phase winding W is formed by sequentially connecting the windings in series. H One end of any X-phase winding is connected to the neutral point N. H Connection, high-voltage three-phase winding W H The other end of any X-phase winding is connected to the high-voltage three-phase winding W. H The X-end connection,

[0020] Low-voltage three-phase winding W L Any X-phase winding, pole pair W, 1st, 2nd...pth pole pair. LX1 W LX2 …W LXp Respectively connected to the high-voltage three-phase winding W H Any X-phase winding, pole pair W, 1st, 2nd...pth pole pair. HX1 W HX2 …W HXp The structure within the stator slot remains the same.

[0021] Furthermore, the low-voltage three-phase full-bridge includes MOSFET Q. A1 -Q A6 Capacitor C A Voltage sensor A, current sensor S Aa S Ab and S Ac Drive signal G A Includes 6 drive signals G A1 -G A6 ;

[0022] The capacitor C A The two ends are connected to the low-voltage three-phase full bridge and the positive and negative terminals, respectively. The positive terminal of the low-voltage three-phase full bridge is connected via Q. A1 drain, Q A1 The source, Q A2 drain, Q A2 The source terminal is connected to the negative terminal of the low-voltage three-phase full-bridge circuit, and the positive terminal of the low-voltage three-phase full-bridge circuit is connected via Q. A3 drain, Q A3 The source, Q A4 drain, Q A4 The source terminal is connected to the negative terminal of the low-voltage three-phase full-bridge circuit, and the positive terminal of the low-voltage three-phase full-bridge circuit is connected via Q. A5 drain, Q A5 The source, Q A6 drain, Q A6 The source of the MOSFET is connected to the negative terminal of the low-voltage three-phase full-bridge MOSFET, and the MOSFET Q is connected to the negative terminal of the low-voltage three-phase full-bridge MOSFET. A1 -Q A6 The gates are respectively connected to the drive signal G A1 -G A6 Connection, Q A1 source and Q A2 The drain connection point serves as terminal A of the low-voltage three-phase full-bridge, Q. A3 source and Q A4 The drain connection point serves as the B terminal of the low-voltage three-phase full-bridge, Q. A5 source and Q A6 The connection point of the drain electrode as A Terminal C, current sensor S Aa S Ab and S Ac After detecting the current flowing out of terminals A, B, and C of the low-voltage three-phase full bridge, the output AC current i is determined. Aa i Ab and i Ac , by alternating current i Aa i Ab and i Ac constituting low-voltage three-phase alternating current i LThe positive and negative input terminals of voltage sensor A are connected to the positive and negative terminals of a low-voltage three-phase full-bridge circuit, respectively. Voltage sensor A outputs a low-voltage DC voltage V. dcL .

[0023] Furthermore, the high-voltage three-phase full-bridge includes IGBT transistor Q. B1 -Q B6 Q B1A -Q B6A Capacitor C B Voltage sensor B, current sensor S Ba S Bb and S Bc Drive signal G B Includes 6 drive signals G B1 -G B6 and 6-channel drive signal G B1A -G B6A ;

[0024] The capacitor C B The two ends are connected to the positive and negative terminals of the high-voltage three-phase full bridge, respectively. The positive terminal of the high-voltage three-phase full bridge is connected via Q. B1A emitter, Q B1A collector, Q B1 collector, Q B1 emitter, Q B2 collector, Q B2 emitter, Q B2A emitter, Q B2A The collector of the high-voltage three-phase full-bridge is connected to the negative terminal, and the positive terminal of the high-voltage three-phase full-bridge is connected to Q. B3A emitter, Q B3A collector, Q B3 collector, Q B3 emitter, Q B4 collector, Q B4 emitter, Q B4A emitter, Q B4A The collector of the high-voltage three-phase full-bridge is connected to the negative terminal, and the positive terminal of the high-voltage three-phase full-bridge is connected to Q. B5A emitter, Q B5A collector, Q B5 collector, Q B5 emitter, Q B6 collector, Q B6 emitter, Q B6A emitter, Q B6A The collector of the IGBT is connected to the negative terminal of the high-voltage three-phase full-bridge transistor, and the IGBT transistor Q... B1 -Q B6 The gates are respectively connected to the drive signal G B1 -G B6 Connection, QB1A -Q B6A The gates are respectively connected to the drive signal G B1A -G B6A Connection, Q B1 emitter and Q B2 The collector connection point is used as terminal A of the high-voltage three-phase full bridge, Q B3 emitter and Q B4 The collector connection point is used as terminal B of the high-voltage three-phase full bridge, Q B5 emitter and Q B6 The collector connection point serves as the C terminal of the high-voltage three-phase full-bridge, and the current sensor S... Ba S Bb and S Bc After detecting the current flowing out of the A, B, and C terminals of the high-voltage three-phase full bridge, the output AC current i is determined. Ba i Bb and i Bc , by alternating current i Ba i Bb and i Bc Constitutes high-voltage three-phase alternating current i H The positive and negative input terminals of voltage sensor B are connected to the positive and negative terminals of the high-voltage three-phase full-bridge voltage, respectively. Voltage sensor B outputs a high-voltage DC voltage V. dcH .

[0025] The design method for a three-stage starter-generator system with high-voltage and low-voltage DC output includes the following steps:

[0026] Step 1: Calculate the position signal θ based on the speed and position signal P output by the rotary transformer, and make the position signal θ = 0°, and synchronize it with the three-phase armature winding W of the main motor. H The zero-crossing point of the voltage drop segment of phase A under no-load conditions corresponds to the following:

[0027] Step 2: When starting the low-voltage DC power supply, start the low-voltage starting power supply from terminal V. SL Provides the electrical energy required for starting, and supplies it to the main exciter's excitation winding W via AC excitation power supply. EE Provide AC excitation current i F The low-voltage three-phase full-bridge regulation regulates the flow through the three-phase armature winding W of the main motor. L Three-phase alternating current i L This enables the three-stage starter generator to output torque, thereby starting the engine;

[0028] Step 3: When starting the high-voltage DC power supply, the high-voltage starting power supply terminal V... SH Provides the electrical energy required for starting, and supplies it to the main exciter's excitation winding W via AC excitation power supply. EE Provide AC excitation current i F The high-voltage three-phase full-bridge regulator regulates the flow through the three-phase armature windings W of the main motor.H Three-phase alternating current i H This enables the three-stage starter generator to output torque, thereby starting the engine;

[0029] Step 4: During power generation, adjust the flow W through the main exciter's excitation winding via the regulating circuit. EE excitation current i F This enables the low-voltage DC voltage V output by the low-voltage three-phase full-bridge. dcL Stabilize at the desired voltage value;

[0030] Step 5: During power generation, synchronous rectification control is used in the low-voltage three-phase full-bridge converter to reduce the Q of the MOSFET. A1 -Q A6 The on-state voltage drop;

[0031] Step 6: During power generation, the high-voltage DC voltage V output from the high-voltage three-phase full-bridge is controlled by boost and buck voltage control. dcH Stabilize at the desired voltage value;

[0032] Step 7: During power generation, if an abnormality in the high-voltage DC regulation is detected, the drive signal G will be used. B1 -G B6 and G B1A -G B6A Disconnect the high-voltage three-phase full-bridge intermediate power transistor Q B1 -Q B6 and Q B1A -Q B6A Through the driving signal G H To disconnect the power generation control circuit breaker GCB H To achieve fault isolation of high voltage DC regulation;

[0033] Step 8: During power generation, if a low-voltage DC voltage regulation abnormality is detected, the drive signal G will be used. L G H and G R To disconnect the power generation control circuit breaker GCB L Generator control circuit breaker (GCB) H Together with the generator control relay GCR in the voltage regulation circuit, fault protection is achieved.

[0034] Furthermore, the synchronous rectification control in step 5 includes the following steps:

[0035] Step 51: Define the alternating current i Aa i Ab and i Ac The direction of the low-voltage three-phase full-bridge flow is positive, let I... refH and I refL These are +1 / 5 and -1 / 5 of the rated current, respectively;

[0036] Step 52, when iAa >I refH When, make G A2 =1, otherwise G A2 =0;

[0037] Step 53, when i Ab >I refH When, make G A4 =1, otherwise G A4 =0;

[0038] Step 54, when i Ac >I refH When, make G A6 =1, otherwise G A6 =0;

[0039] Step 55, when i Aa refL When, make G A1 =1, otherwise G A1 =0;

[0040] Step 56, when i Ab refL When, make G A3 =1, otherwise G A3 =0;

[0041] Step 57, when i Ac refL When, make G A5 =1, otherwise G A5 =0.

[0042] Furthermore, the boost control in step 6 specifically includes the following steps:

[0043] Step 611: Based on the high voltage DC voltage V dcH And the position signal θ, determine the drive signal G for boost voltage regulation control. B1 -G B6 Define the driving signal G B2 The falling edge corresponds to θ = 240°, and the drive signal G B2 The high-level pulse width is δ1, when the high-voltage DC voltage V dcH When the voltage is lower than the desired value, the DC voltage is stabilized at the desired output voltage by increasing the width of δ1. The adjustment range of δ1 is 0-90°. B1 -G B6 Having the same positive pulse width, according to G B2 G B5 G B4 G B1 G B6 G B3 The driving signal G is generated by sequentially delaying by 60°.​​​B1 -G B6 ;

[0044] Step 612: Determine signal G based on position signal θ. B1i -G B6i When θ = 210° - 360° and 0° - 30°, make G B1i =1, for other θ values, make G B1i =0, press G B1i G B6i G B3i G B2i G B5i G B4i Signal G is formed by sequentially delaying by 60°. B1i -G B6i ;

[0045] Step 613, according to the drive signal G B1 -G B6 Signal G B1i -G B6i Determine the drive signal G B1A -G B6A G B1A =G B2 |G B1i G B6A =G B5 |G B6i G B3A =G B4 |G B3i G B2A =G B1 |G B2i G B5A =G B6 |G B5i G B4A =G B3 |G B4i ;

[0046] Step 614: Transfer the drive signal G B1 -G B6 Send to IGBT Q respectively B1 -Q B6 Drive signal G B1A -G B6A Send to IGBT Q respectively B1A -Q B6A .

[0047] Furthermore, the voltage reduction control in step 6 includes the following steps:

[0048] Step 621: Set the drive signal G B1 -G B6All zeros will drive signal G B1 -G B6 Send to power transistor Q respectively B1 -Q B6 This makes the IGBT transistor Q B1 -Q B6 All are turned off;

[0049] Step 622: Determine signal G based on position signal θ. B1i -G B6i When θ = 210° - 360° and 0° - 30°, make G B1i =1, for other θ values, make G B1i =0, press G B1i G B6i G B3i G B2i G B5i G B4i Signal G is formed by sequentially delaying by 60°. B1i -G B6i ;

[0050] Step 623: Set the drive signal G B1A -G B6A Separately delayed signals G B1i -G B6i The angle is δ2, when the high voltage DC voltage V dcH When the voltage exceeds the desired value, the DC voltage is stabilized at the desired value by increasing the width of δ2.

[0051] Step 624: Transfer the drive signal G B1A -G B6A Send to IGBT Q respectively B1A -Q B6A .

[0052] The beneficial effects of this invention are as follows:

[0053] 1. The high-voltage and low-voltage DC output three-stage starter generator system and design method proposed in this invention are applicable to the field of aviation hybrid power systems consisting of 28V low-voltage DC and 270V high-voltage DC.

[0054] 2. Compared with the combination of high-voltage DC three-stage starter generator system and DC bus converter, the 28V low-voltage DC is obtained by only one stage of energy conversion, which is more efficient in obtaining 28V low-voltage DC; the DC bus power converter that converts 270V high-voltage DC to 28V low-voltage DC is eliminated, and the weight cost of obtaining 28V low-voltage DC is lower.

[0055] 3. Compared to the combination of low-voltage DC brushed starter generator system and high-voltage DC three-stage generator system, and the combination of low-voltage DC three-stage starter generator system and high-voltage DC three-stage generator system, both 28V low-voltage DC and 270V high-voltage DC obtain energy from the same starter generator. The mechanical interface with the engine is reduced from two to one. The starter generator housing, heat dissipation structure, mechanical support structure, etc. are reduced from two to one. The additional weight of mechanical transmission interface and non-effective parts of starter generator is significantly reduced.

[0056] 4. Compared to the combined high-voltage DC permanent magnet starter-generator system and DC bus converter, the 28V low-voltage DC is achieved through excitation voltage regulation, eliminating the need for a DC bus power converter that converts 270V high-voltage DC to 28V low-voltage DC. The 28V low-voltage DC is obtained through only one stage of energy conversion, resulting in significantly lower weight and efficiency costs. The input voltage range of the 270V voltage regulator is significantly narrowed, and the same electrical frequency control as the starter-generator is used, further reducing the weight and efficiency costs of 270V high-voltage DC regulation. Overall power density and efficiency are significantly improved. This overcomes the shortcomings of power quality issues such as overload, short circuit, and high-frequency ripple spectrum, which make it difficult to meet the standards of aircraft power supply and generation systems. It also solves the problem of not being able to demagnetize after a fault, which does not meet aviation safety requirements.

[0057] 5. The main motor uses a low-voltage three-phase winding WL and a high-voltage three-phase winding WH to meet the requirements of 28V low-voltage DC and 270V high-voltage DC respectively.

[0058] 6. When the high-voltage three-phase full-bridge achieves 270V output voltage regulation, the switching frequency used is the same as the output frequency of the starter generator. The frequency is low, and the loss is much lower than that of the traditional high-frequency voltage regulation control scheme.

[0059] 7. When the high-voltage three-phase full-bridge achieves 270V output voltage regulation, the switching frequency used is the same as the output frequency of the starter generator. The frequency is low, and the high-frequency conducted and radiated interference is much lower than that of the traditional high-frequency voltage regulation control scheme. The high-frequency ripple spectrum is more likely to meet the requirements of GJB181B-2012, and it also has better electromagnetic compatibility characteristics.

[0060] 8. When the high-voltage three-phase full bridge achieves 270V output voltage regulation, the switching frequency used is the same as the output frequency of the starting generator. Therefore, the power transistors can be high current-capable but have relatively high switching losses, so that the high-voltage three-phase full bridge has good overload resistance.

[0061] 9. The high-voltage three-phase full-bridge is a step-up / step-down type voltage regulator, which has a faster response speed than the excitation voltage regulator and has a good suppression effect on transient voltage drops or overvoltages caused by loading or shedding.

[0062] 10. The high-voltage three-phase full-bridge converter can perform both boost and buck control. When stabilizing the voltage, the boost and buck control range is relatively narrow, and the efficiency is higher than that of a power converter with simple boost or buck control.

[0063] 11. Both the low-voltage three-phase full bridge for 28V low-voltage DC and the high-voltage three-phase full bridge for 270V high-voltage DC support bidirectional energy flow and are compatible with the functions of 28V low-voltage DC starting and 270V high-voltage DC starting.

[0064] When generating 12.28V low-voltage DC regulated power, the MOSFETs in the low-voltage three-phase full-bridge operate in synchronous rectification mode, making the on-state voltage drop less than 0.2V, which is significantly lower than the diode's 0.7-1.2V, thus significantly improving the efficiency of 28V low-voltage DC regulation. Attached Figure Description

[0065] Figure 1 This is a block diagram of the high-voltage and low-voltage DC output three-stage starter generator system of the present invention;

[0066] Figure 2 Winding diagram of the dual armature windings of the main motor of the present invention;

[0067] Figure 3 The low-voltage three-phase full-bridge circuit diagram of this invention;

[0068] Figure 4 The high-voltage three-phase full-bridge circuit diagram of this invention;

[0069] Figure 5 Circuit diagram of the voltage regulation circuit of the present invention;

[0070] Figure 6 Circuit diagram of the AC excitation power supply of the present invention;

[0071] Figure 7 The position signal θ of this invention is related to the three-phase armature winding W of the main motor. H No-load voltage correspondence diagram;

[0072] Figure 8 The starting control principle diagram of the low-voltage three-phase full-bridge or high-voltage three-phase full-bridge of the present invention;

[0073] Figure 9 Schematic diagram of the low-voltage DC voltage regulation control principle of this invention;

[0074] Figure 10 Schematic diagram of the low-voltage three-phase full-bridge synchronous rectification control principle of the present invention;

[0075] Figure 11 The voltage boost control principle diagram of the high-voltage three-phase full-bridge circuit of the present invention;

[0076] Figure 12 The high-voltage three-phase full-bridge step-down control principle diagram of the present invention. Detailed Implementation

[0077] The technical solution of the present invention is further described below, but the scope of protection is not limited to what is described.

[0078] The following is a further detailed description with reference to the accompanying drawings and embodiments. Figure 1 The diagram shows a three-stage starter-generator system with high-voltage and low-voltage DC outputs, suitable for a hybrid power supply consisting of 28V low-voltage DC and 270V high-voltage DC. During startup, either the 28V low-voltage DC or the 270V high-voltage DC can be used as the starting power source.

[0079] A three-stage starter-generator system with high-voltage and low-voltage DC output, comprising a three-stage starter-generator and a controller. The three-stage starter-generator includes a permanent magnet auxiliary exciter, a main exciter, a main motor, a rotating rectifier, and a rotary transformer. The controller includes a low-voltage three-phase full-bridge converter, a high-voltage three-phase full-bridge converter, a voltage regulating circuit, an AC excitation power supply, a control circuit, and diodes D. L and D H Current sensor S F It consists of a rotary transformer outputting a speed and position signal P connected to the control circuit, and a permanent magnet auxiliary exciter winding W. PMG Terminals A, B, and C are connected to the voltage regulating circuit, and the control circuit outputs a drive signal G. C and G R Connected to a voltage regulator circuit, the output terminal V of the voltage regulator circuit Co The positive and negative terminals are respectively connected to the excitation winding W of the main exciter. EE The F+ and F- terminals are connected, and the low-voltage power supply input terminal V of the AC excitation power supply is connected. iL and high voltage power supply input terminal V iH The AC excitation power supply's ground reference terminal GND is connected to the positive terminals of both the low-voltage and high-voltage three-phase full-bridge circuits, respectively. The control circuit outputs a drive signal G. D and G S Connect to an AC excitation power supply; the output terminal of the AC excitation power supply is V. Bo The * and - terminals are respectively connected to the excitation winding W of the main exciter. EE The F+ and F- terminals are connected, and the current sensor S F Detecting the flow into the main exciter excitation winding W EE The excitation current i is output after the F+ terminal current. F Connected to the control circuit, the low-voltage three-phase winding W of the main motor L A, B, and C are connected to the low-voltage three-phase full-bridge circuit. The positive and negative terminals of the low-voltage three-phase full-bridge circuit are connected to the positive and negative terminals of the external low-voltage DC interface, respectively. The control circuit outputs a drive signal G. AWhen connected to a low-voltage three-phase full-bridge, the low-voltage three-phase full-bridge outputs a low-voltage DC voltage V. dcL and low-voltage three-phase alternating current i L Connected to the control circuit, low-voltage starting power supply terminal V SL via diode D L Anode, diode D L The cathode is connected to the positive terminal of the low-voltage three-phase full-bridge circuit, and the high-voltage three-phase winding W of the main motor is connected to the positive terminal. H A, B, and C are connected to a high-voltage three-phase full-bridge circuit. The positive and negative terminals of the high-voltage three-phase full-bridge circuit are connected to the positive and negative terminals of the external high-voltage DC interface, respectively. The control circuit outputs a drive signal G. B When connected to a high-voltage three-phase full-bridge bridge, the high-voltage three-phase full-bridge bridge outputs a high-voltage DC voltage V. dcH and high voltage three-phase alternating current i H Connected to the control circuit, high-voltage starting power supply terminal V SH via diode D H Anode, diode D H The cathode is connected to the positive terminal of the high-voltage three-phase full-bridge circuit, and the control circuit outputs a drive signal G. L and G H Respectively with the power generation control circuit breaker GCB L and GCB H Connection, main exciter rotor armature winding W EM via the rotating rectifier and the main motor rotor excitation winding W ME Connection constitutes.

[0080] Since the proposed three-stage starter generator with high-voltage and low-voltage DC output does not employ mechanical commutation, it overcomes the shortcomings of combining a DC brushed starter generator system with a high-voltage DC three-stage generator system, which are unsuitable for high-altitude long-haul flights, maintenance-free export operations, and resistance to coastal salt spray environments.

[0081] Compared to the combination of a low-voltage DC brushed starter generator system and a high-voltage DC three-stage generator system, the 28V low-voltage DC and 270V high-voltage DC systems both obtain energy from the same starter generator. The mechanical interfaces with the engine are reduced from two to one. The starter generator housing, heat dissipation structure, and mechanical support structure are also reduced from two to one. The additional weight of the mechanical transmission interface and the non-functional parts of the starter generator is significantly reduced.

[0082] Compared to the combination of a high-voltage DC three-stage starter generator system and a DC bus converter, the 28V low-voltage DC is obtained by only one stage of energy conversion, resulting in higher efficiency in obtaining 28V low-voltage DC. It also eliminates the need for a DC bus power converter that converts 270V high-voltage DC to 28V low-voltage DC, thus reducing the weight cost of obtaining 28V low-voltage DC.

[0083] Figure 2 The diagram shows the dual armature windings of the main motor. The main motor's stator armature windings include a low-voltage three-phase winding W. L and high voltage three-phase winding W H Low-voltage three-phase winding W L W includes phases A, B, and C respectively. LA W LB and W LC High-voltage three-phase winding W H W includes phases A, B, and C respectively. HA W HB and W HC For low-voltage three-phase winding W L Any X-phase winding, where X = A, B, or C, is formed by the 1st, 2nd…pth pole pair windings W LX1 W LX2 …W LXp Parallel connection configuration, low-voltage three-phase winding W L One end of any X-phase winding is connected to the neutral point N. L Connection, low-voltage three-phase winding W L The other end of any X-phase winding is connected to the low-voltage three-phase winding W. L The X-terminal connection is used for the high-voltage three-phase winding W. H Any X-phase winding, where X = A, B, or C, is formed by the 1st, 2nd…pth pole pair windings W HX1 W HX2 …W HXp The high-voltage three-phase winding W is formed by sequentially connecting the windings in series. H One end of any X-phase winding is connected to the neutral point N. H Connection, high-voltage three-phase winding W H The other end of any X-phase winding is connected to the high-voltage three-phase winding W. H The X-terminal connection, low-voltage three-phase winding W L Any X-phase winding, pole pair W, 1st, 2nd...pth pole pair. LX1 W LX2 …W LXp Respectively connected to the high-voltage three-phase winding W H Any X-phase winding, pole pair W, 1st, 2nd...pth pole pair. HX1 W HX2 …W HXp The structure within the stator slot remains the same.

[0084] First, the low-voltage three-phase winding W is achieved by connecting the first, second...p pole pairs of windings in parallel or series. L Or high-voltage three-phase winding W H Voltage regulation, and then by adjusting the winding turns ratio N W Adjustments are made to achieve low-voltage three-phase winding W L Or high-voltage three-phase winding WH Voltage regulation, winding turns ratio N W =W HX1 / W LX1 =W HX2 / W LX2 …=W HXp / W LXp In this embodiment, the number of pole pairs of the main motor is p=5, and the winding turns ratio is selected as N. W =2.

[0085] The main motor uses low-voltage three-phase winding W L and high voltage three-phase winding W H To meet the requirements of 28V low-voltage DC and 270V high-voltage DC respectively.

[0086] Figure 3 The diagram shown is a low-voltage three-phase full-bridge circuit. The low-voltage three-phase full-bridge circuit includes MOSFET Q. A1 -Q A6 Capacitor C A Voltage sensor A, current sensor S Aa S Ab and S Ac Drive signal G A Includes 6 drive signals G A1 -G A6 It is caused by capacitor C A The two ends are connected to the low-voltage three-phase full bridge and the positive and negative terminals, respectively. The positive terminal of the low-voltage three-phase full bridge is connected via Q. A1 drain, Q A1 The source, Q A2 drain, Q A2 The source terminal is connected to the negative terminal of the low-voltage three-phase full-bridge circuit, and the positive terminal of the low-voltage three-phase full-bridge circuit is connected via Q. A3 drain, Q A3 The source, Q A4 drain, Q A4 The source terminal is connected to the negative terminal of the low-voltage three-phase full-bridge circuit, and the positive terminal of the low-voltage three-phase full-bridge circuit is connected via Q. A5 drain, Q A5 The source, Q A6 drain, Q A6 The source of Q is connected to the negative terminal of the low-voltage three-phase full-bridge circuit. A1 -Q A6 The gates are respectively connected to the drive signal G A1 -G A6 Connection, Q A1 source and Q A2 The drain connection point serves as terminal A of the low-voltage three-phase full-bridge, Q. A3 source and Q A4 The drain connection point serves as the B terminal of the low-voltage three-phase full-bridge, Q. A5source and Q A6 The connection point of the drain electrode as A Terminal C, current sensor S Aa S Ab and S Ac After detecting the current flowing out of terminals A, B, and C of the low-voltage three-phase full bridge, the output AC current i is determined. Aa i Ab and i Ac , by alternating current i Aa i Ab and i Ac constituting low-voltage three-phase alternating current i L The positive and negative input terminals of voltage sensor A are connected to the positive and negative terminals of a low-voltage three-phase full-bridge circuit, respectively. Voltage sensor A outputs a low-voltage DC voltage V. dcL constitute.

[0087] For alternating current i Aa i Ab and i Ac Any one of them, when the current flows out of or into the low-voltage three-phase full bridge, has an instantaneous value that is either positive or negative.

[0088] Figure 4 The diagram shown is a high-voltage three-phase full-bridge circuit. The high-voltage three-phase full-bridge includes IGBT transistors Q... B1 -Q B6 Q B1A -Q B6A Capacitor C B Voltage sensor B, current sensor S Ba S Bb and S Bc Drive signal G B Includes 6 drive signals G B1 -G B6 and 6-channel drive signal G B1A -G B6A It is caused by capacitor C B The two ends are connected to the positive and negative terminals of the high-voltage three-phase full bridge, respectively. The positive terminal of the high-voltage three-phase full bridge is connected via Q. B1A emitter, Q B1A collector, Q B1 collector, Q B1 emitter, Q B2 collector, Q B2 emitter, Q B2A emitter, Q B2A The collector of the high-voltage three-phase full-bridge is connected to the negative terminal, and the positive terminal of the high-voltage three-phase full-bridge is connected to Q. B3A emitter, Q B3A collector, Q B3 collector, Q B3emitter, Q B4 collector, Q B4 emitter, Q B4A emitter, Q B4A The collector of the high-voltage three-phase full-bridge is connected to the negative terminal, and the positive terminal of the high-voltage three-phase full-bridge is connected to Q. B5A emitter, Q B5A collector, Q B5 collector, Q B5 emitter, Q B6 collector, Q B6 emitter, Q B6A emitter, Q B6A The collector of Q is connected to the negative terminal of the high-voltage three-phase full-bridge. B1 -Q B6 The gates are respectively connected to the drive signal G B1 -G B6 Connection, Q B1A -Q B6A The gates are respectively connected to the drive signal G B1A -G B6A Connection, Q B1 emitter and Q B2 The collector connection point is used as terminal A of the high-voltage three-phase full bridge, Q B3 emitter and Q B4 The collector connection point is used as terminal B of the high-voltage three-phase full bridge, Q B5 emitter and Q B6 The collector connection point serves as the C terminal of the high-voltage three-phase full-bridge, and the current sensor S... Ba S Bb and S Bc After detecting the current flowing out of the A, B, and C terminals of the high-voltage three-phase full bridge, the output AC current i is determined. Ba i Bb and i Bc , by alternating current i Ba i Bb and i Bc Constitutes high-voltage three-phase alternating current i H The positive and negative input terminals of voltage sensor B are connected to the positive and negative terminals of the high-voltage three-phase full-bridge voltage, respectively. Voltage sensor B outputs a high-voltage DC voltage V. dcH constitute.

[0089] For alternating current i Ba i Bb and i Bc Any one of them, when the current flows out of or into the high-voltage three-phase full bridge, has an instantaneous value that is either positive or negative.

[0090] Figure 5 The diagram shows the circuit diagram of the voltage regulation circuit, with the drive signal G.C Including drive signal G C1 and G C2 , respectively with MOS transistor Q C1 and Q C2 The gate is connected. This is achieved through the drive signal G. C The generator control relay GCR is used to connect the voltage regulating circuit to the main exciter excitation winding W. EE Connecting or disconnecting is controlled by diode D. C1 -D C6 The three-phase rectifier bridge is used to convert the three-phase AC voltage V provided by the permanent magnet exciter into a rectifier bridge. PMG Convert to DC V G When generating electricity, Q C2 Closed, by adjusting Q C1 The duty cycle is used to adjust the flow through the main exciter's excitation winding W. EE excitation current i F .

[0091] Figure 6 The diagram shows the circuit of the AC excitation power supply, with drive signal G. D Includes 4 drive signals G D1 -G D4 , respectively with power transistor Q D1 -Q D4 The gate is connected. When using 28V low-voltage DC as the starting power supply, the 28V low-voltage DC is connected to the low-voltage power supply input terminal V. iL Connection; When using 270V high-voltage DC as the starting power supply, the 270V high-voltage DC is connected to the high-voltage power supply input terminal V. iH Connection. The low-voltage power supply input V is converted via a boost DC / DC module. iL Input 28V low-voltage DC to 270V V SI By adding D D To prevent the high voltage power input terminal V iH The boost DC / DC module is damaged when the input voltage is higher than its output voltage. This is caused by the drive signal G. S The start control relay SCR is controlled by Q D1 -Q D4 The single-phase inverter bridge and the main exciter excitation winding W constitute EE Connect or disconnect, in drive signal G D Under the control of Q D1 -Q D4 The single-phase inverter bridge formed will convert DC V SI Converted to AC, regulating the flow of W through the main exciter's excitation winding during startup. EE excitation current i F .

[0092] The design method for the three-stage starter-generator system with high-voltage and low-voltage DC output includes the following steps:

[0093] Step 1: Calculate the position signal θ based on the speed and position signal P output by the rotary transformer, and make the position signal θ = 0° synchronized with the three-phase armature winding W of the main motor. H The zero-crossing point of the voltage drop segment of phase A under no-load conditions corresponds to the following:

[0094] Step 2: When starting the low-voltage DC power supply, start the low-voltage starting power supply from terminal V. SL Provides the electrical energy required for starting, and supplies it to the main exciter's excitation winding W via AC excitation power supply. EE Provide AC excitation current i F The low-voltage three-phase full-bridge regulation regulates the flow through the three-phase armature winding W of the main motor. L Three-phase alternating current i L This enables the three-stage starter generator to output torque, thereby starting the engine;

[0095] Step 3: When starting the high-voltage DC power supply, the high-voltage starting power supply terminal V... SH Provides the electrical energy required for starting, and supplies it to the main exciter's excitation winding W via AC excitation power supply. EE Provide AC excitation current i F The high-voltage three-phase full-bridge regulator regulates the flow through the three-phase armature windings W of the main motor. H Three-phase alternating current i H This enables the three-stage starter generator to output torque, thereby starting the engine;

[0096] Step 4: During power generation, adjust the flow W through the main exciter's excitation winding via the regulating circuit. EE excitation current i F This enables the low-voltage DC voltage V output by the low-voltage three-phase full-bridge. dcL Stabilize at the desired voltage value;

[0097] Step 5: During power generation, synchronous rectification control is used in the low-voltage three-phase full-bridge converter to reduce the Q of the MOSFET. A1 -Q A6 The on-state voltage drop;

[0098] Step 6: During power generation, the high-voltage DC voltage V output from the high-voltage three-phase full-bridge is controlled by boost and buck voltage control. dcH Stabilize at the desired voltage value;

[0099] Step 7: During power generation, if an abnormality in the high-voltage DC regulation is detected, the drive signal G will be used. B1 -G B6 and G B1A -G B6A Disconnect the high-voltage three-phase full-bridge intermediate power transistor Q B1 -Q B6and Q B1A -Q B6A Through the driving signal G H To disconnect the power generation control circuit breaker GCB H To achieve fault isolation of high voltage DC regulation;

[0100] Step 8: During power generation, if a low-voltage DC voltage regulation abnormality is detected, the drive signal G will be used. L G H and G R To disconnect the power generation control circuit breaker GCB L Generator control circuit breaker (GCB) H Together with the generator control relay GCR in the voltage regulation circuit, fault protection is achieved.

[0101] Combination Figure 7 The position signal θ shown is related to the three-phase armature winding W of the main motor. H The diagram showing the no-load voltage correspondence further illustrates step A. H_A v H_B and v H_C These represent the three-phase armature windings W of the main motor. H The no-load output voltages of phases A, B, and C. In step A, the position signal θ = 0° is set to the no-load voltage. H_A The zero-crossing point of the descent segment is ensured by adjusting the relative position of the resolver rotor and the main motor rotor.

[0102] Figure 8 The diagram shown further illustrates steps B and C of the low-voltage three-phase full-bridge or high-voltage three-phase full-bridge starting control principle. When starting with the low-voltage DC power supply, the low-voltage starting power supply terminal V... SL Connect to 28V low-voltage DC. Figure 8 Three-phase full bridge refers to low-voltage three-phase full bridge, i a and i b i Aa and i Ab A quasi-speed loop is used to adjust the q-axis current reference value i according to the speed change. q * The active current i is adjusted through a current loop. q and reactive current i d The low-voltage three-phase full-bridge drive signal G is generated by space vector pulse width modulation (SVPWM). A1 -G A6 This, in turn, regulates the flow through the three-phase armature winding W of the main motor. L current i L Ultimately, this achieves starting torque regulation. When the high-voltage DC power supply starts, the V at the high-voltage starting power supply terminal... SH Connect to 270V high voltage DC. Figure 8 Three-phase full bridge refers to a high-voltage three-phase full bridge. a and ib i Ba and i Bb The drive signal G is generated through the control circuit. B1A -G B6A To keep the power transistor Q closed B1A -Q B6A It also employs a quasi-speed loop to adjust the q-axis current reference value i as the rotational speed changes. q * The active current i is adjusted through a current loop. q and reactive current i d The drive signal G for the high-performance three-phase full-bridge is generated by space vector pulse width modulation (SVPWM). B1 -G B6 This, in turn, regulates the flow through the three-phase armature winding W of the main motor. H current i H Ultimately, this achieves starting torque regulation.

[0103] Both the low-voltage three-phase full bridge for 28V low-voltage DC and the high-voltage three-phase full bridge for 270V high-voltage DC support bidirectional energy flow and are compatible with the functions of 28V low-voltage DC starting and 270V high-voltage DC starting.

[0104] Combination Figure 9 The low-voltage DC voltage regulator control schematic diagram shown further illustrates step D. Based on the voltage regulation reference value V... refL and low-voltage DC voltage V dcL Voltage loop calculations are performed to generate the reference signal I for the excitation current loop. ref According to the reference signal I of the excitation current loop. ref and excitation current i F Perform excitation current loop calculations to make the excitation current i F With reference signal I of the excitation current loop ref equal.

[0105] Combination Figure 10 The schematic diagram of the low-voltage three-phase full-bridge synchronous rectification control further illustrates step 5. The synchronous rectification control described in step 5 includes the following steps:

[0106] Step 51: Define the alternating current i Aa i Ab and i Ac The direction of the low-voltage three-phase full-bridge flow is positive, let I... refH and I refL These are +1 / 5 and -1 / 5 of the rated current, respectively;

[0107] Step 52, when i Aa >I refH When, make G A2 =1, otherwise GA2 =0;

[0108] Step 53, when i Ab >I refH When, make G A4 =1, otherwise G A4 =0;

[0109] Step 54, when i Ac >I refH When, make G A6 =1, otherwise G A6 =0;

[0110] Step 55, when i Aa refL When, make G A1 =1, otherwise G A1 =0;

[0111] Step 56, when i Ab refL When, make G A3 =1, otherwise G A3 =0;

[0112] Step 57, when i Ac refL When, make G A5 =1, otherwise G A5 =0.

[0113] When generating 28V low-voltage DC regulated power, the MOSFETs in the low-voltage three-phase full-bridge operate in synchronous rectification mode, making the on-state voltage drop less than 0.2V, which is significantly lower than the diode's 0.7-1.2V, thus significantly improving the efficiency of 28V low-voltage DC regulation.

[0114] Since the 28V low-voltage DC stabilization is achieved by adjusting the excitation current in step 4, the main motor three-phase armature winding W H The rectified voltage is usually not the desired 270V, so the auxiliary method in step 5 is needed to achieve 270V high voltage DC regulation.

[0115] Combination Figure 11 The diagram shown illustrates the boost control principle of a high-voltage three-phase full-bridge bridge to further explain the boost control described in step 6. The boost control described in step 6 includes the following steps:

[0116] Step 611: Based on the high voltage DC voltage V dcH And the position signal θ, determine the drive signal G for boost voltage regulation control. B1 -G B6 Define the driving signal G B2 The falling edge corresponds to θ = 240°, and the drive signal G B2 ​​​The high-level pulse width is δ1, when the high-voltage DC voltage V dcH When the voltage is lower than the desired value, the DC voltage is stabilized at the desired output voltage by increasing the width of δ1. The adjustment range of δ1 is 0-90°. B1 -G B6 Having the same positive pulse width, according to G B2 G B5 G B4 G B1 G B6 G B3 The driving signal G is generated by sequentially delaying by 60°. B1 -G B6 ;

[0117] Step 612: Determine signal G based on position signal θ. B1i -G B6i When θ = 210° - 360° and 0° - 30°, make G B1i =1, for other θ values, make G B1i =0, press G B1i G B6i G B3i G B2i G B5i G B4i Signal G is formed by sequentially delaying by 60°. B1i -G B6i ;

[0118] Step 613, according to the drive signal G B1 -G B6 Signal G B1i -G B6i Determine the drive signal G B1A -G B6A G B1A =G B2 |G B1i G B6A =G B5 |G B6i G B3A =G B4 |G B3i G B2A =G B1 |G B2i G B5A =G B6 |G B5i G B4A =G B3 |G B4i ;

[0119] Step 614: Transfer the drive signal G B1 -G B6Send to IGBT Q respectively B1 -Q B6 Drive signal G B1A -G B6A Send to IGBT Q respectively B1A -Q B6A .

[0120] Combination Figure 12 The diagram shown illustrates the voltage reduction control principle of a high-voltage three-phase full-bridge bridge, further explaining the voltage reduction control described in step 6. The voltage reduction control described in step 6 includes the following steps:

[0121] Step 621: Set the drive signal G B1 -G B6 All zeros will drive signal G B1 -G B6 Send to power transistor Q respectively B1 -Q B6 This makes the IGBT transistor Q B1 -Q B6 All are turned off;

[0122] Step 622: Determine signal G based on position signal θ. B1i -G B6i When θ = 210° - 360° and 0° - 30°, make G B1i =1, for other θ values, make G B1i =0, press G B1i G B6i G B3i G B2i G B5i G B4i Signal G is formed by sequentially delaying by 60°. B1i -G B6i ;

[0123] Step 623: Set the drive signal G B1A -G B6A Separately delayed signals G B1i -G B6i The angle is δ2, when the high voltage DC voltage V dcH When the voltage exceeds the desired value, the DC voltage is stabilized at the desired value by increasing the width of δ2.

[0124] Step 624: Transfer the drive signal G B1A -G B6A Send to IGBT Q respectively B1A -Q B6A .

[0125] The design of the high-voltage three-phase full-bridge hardware and control method has the following advantages:

[0126] 1. When the high-voltage three-phase full-bridge achieves 270V output voltage regulation, the switching frequency used is the same as the output frequency of the starter generator. The frequency is low, and the loss is much lower than that of the traditional high-frequency voltage regulation control scheme.

[0127] 2. When the high-voltage three-phase full-bridge achieves 270V output voltage regulation, the switching frequency used is the same as the output frequency of the starter generator. The frequency is low, and the high-frequency conducted and radiated interference is much lower than that of the traditional high-frequency voltage regulation control scheme. The high-frequency ripple spectrum is more likely to meet the requirements of GJB181B-2012, and it also has better electromagnetic compatibility characteristics.

[0128] 3. When the high-voltage three-phase full bridge achieves 270V output voltage regulation, the switching frequency used is the same as the output frequency of the starting generator. Therefore, the power transistors can be high current-capable but have relatively high switching losses, so that the high-voltage three-phase full bridge has good overload resistance.

[0129] 4. The high-voltage three-phase full-bridge is a step-up / step-down type voltage regulator, which has a faster response speed than the excitation voltage regulator and has a good suppression effect on transient voltage drops or overvoltages caused by loading or shedding.

[0130] 5. The high-voltage three-phase full-bridge converter can perform both boost and buck control. When stabilizing the voltage, the boost and buck control range is relatively narrow, and the efficiency is higher than that of power converters with simple boost or buck control.

[0131] Compared to the combined solution of a high-voltage DC permanent magnet starter-generator system and a DC bus converter, the 28V low-voltage DC is achieved through excitation voltage regulation, eliminating the need for a DC bus power converter that converts 270V high-voltage DC to 28V low-voltage DC. The 28V low-voltage DC is obtained through only one stage of energy conversion, resulting in significantly lower weight and efficiency costs. The input voltage range of the 270V voltage regulator is significantly narrowed, and it uses the same electrical frequency control as the starter-generator, further reducing the weight and efficiency costs of 270V high-voltage DC regulation. Overall power density and efficiency are significantly improved. This overcomes the shortcomings of power quality issues such as overload, short circuit, and high-frequency ripple spectrum, which make it difficult to meet the standards of aircraft power supply and generation systems. It also solves the problem of not being able to demagnetize after a fault, which does not meet aviation safety requirements.

Claims

1. A design method for a three-stage starting generator system with high-voltage and low-voltage DC output, characterized in that: The high-voltage and low-voltage DC output three-stage starter-generator system includes a three-stage starter-generator and a controller. The three-stage starter-generator includes a permanent magnet auxiliary exciter, a main exciter, a main motor, a rotating rectifier, and a rotary transformer. The controller includes a low-voltage three-phase full-bridge converter, a high-voltage three-phase full-bridge converter, a voltage regulating circuit, an AC excitation power supply, a control circuit, and diodes D. L and D H Current sensor S F ; The rotary transformer outputs a speed and position signal. P The permanent magnet auxiliary exciter winding W is connected to the control circuit. PMG Terminals A, B, and C are connected to the voltage regulating circuit, and the control circuit outputs drive signals. G C and G R Connected to the voltage regulating circuit, the output terminal of the voltage regulating circuit V Co The positive and negative terminals are respectively connected to the excitation winding W of the main exciter. EE The F+ and F- terminals are connected, and the low-voltage power supply input terminal V of the AC excitation power supply is connected. iL and high voltage power supply input terminal V iH Connect to the positive terminals of the low-voltage three-phase full-bridge and the high-voltage three-phase full-bridge respectively. The ground reference terminal GND of the AC excitation power supply is connected to the negative terminals of both the low-voltage three-phase full-bridge and the high-voltage three-phase full-bridge, respectively, and the control circuit outputs a drive signal. G D and G S Connect to an AC excitation power supply; AC excitation power supply output terminal v Bo The * and ~ terminals are respectively connected to the excitation winding W of the main exciter. EE Connect the F+ and F- terminals. The current sensor S F Detecting the flow into the main exciter excitation winding W EE The excitation current is output after the F+ terminal current. i F Connected to the control circuit, the low-voltage three-phase winding W of the main motor L A, B, and C are connected to a low-voltage three-phase full-bridge circuit, and the positive and negative terminals of the low-voltage three-phase full-bridge circuit are connected to the positive and negative terminals of the external low-voltage DC interface, respectively. The control circuit outputs a drive signal. G A Connected to a low-voltage three-phase full-bridge, the low-voltage three-phase full-bridge outputs a low-voltage DC voltage. V dcL and low-voltage three-phase alternating current i L Connected to the control circuit, low-voltage starting power supply terminal V SL via diode D L Anode, diode D L The cathode is connected to the positive terminal of the low-voltage three-phase full-bridge circuit, and the high-voltage three-phase winding W of the main motor... H Terminals A, B, and C are respectively connected to a high-voltage three-phase full-bridge, and the positive and negative terminals of the high-voltage three-phase full-bridge are respectively connected to the positive and negative terminals of the external high-voltage DC interface. The output drive signal of the control circuit G B Connected to a high-voltage three-phase full-bridge, the high-voltage three-phase full-bridge outputs a high-voltage DC voltage. V dcH and high voltage three-phase alternating current i H Connected to the control circuit, high-voltage starting power supply terminal V SH via diode D H Anode, diode D H The cathode is connected to the positive terminal of the high-voltage three-phase full-bridge circuit, and the control circuit outputs a drive signal. G L and G H Respectively with the power generation control circuit breaker GCB L and GCB H Connection, the rotor armature winding W of the main exciter EM via the rotating rectifier and the main motor rotor excitation winding W ME connect; The high-voltage three-phase full-bridge includes IGBT transistor Q. B1 ~Q B6 Q B1A ~Q B6A ,capacitance C B Voltage sensor B, current sensor S Ba S Bb and S Bc drive signal G B Includes 6 drive signals G B1 ~ G B6 and 6 drive signals G B1A ~ G B6A ; The capacitor C B The two ends are connected to the positive and negative terminals of the high-voltage three-phase full bridge, respectively. The positive terminal of the high-voltage three-phase full bridge is connected via Q. B1A emitter, Q B1A collector, Q B1 collector, Q B1 emitter, Q B2 collector, Q B2 emitter, Q B2A emitter, Q B2A The collector of the high-voltage three-phase full-bridge is connected to the negative terminal, and the positive terminal of the high-voltage three-phase full-bridge is connected to Q. B3A emitter, Q B3A collector, Q B3 collector, Q B3 emitter, Q B4 collector, Q B4 emitter, Q B4A emitter, Q B4A The collector of the high-voltage three-phase full-bridge is connected to the negative terminal, and the positive terminal of the high-voltage three-phase full-bridge is connected to Q. B5A emitter, Q B5A collector, Q B5 collector, Q B5 emitter, Q B6 collector, Q B6 emitter, Q B6A emitter, Q B6A The collector of the IGBT is connected to the negative terminal of the high-voltage three-phase full-bridge transistor Q. B1 ~Q B6 The gates are respectively connected to the drive signal G B1 ~ G B6 Connection, Q B1A ~Q B6A The gates are respectively connected to the drive signal G B1A ~ G B6A Connection, Q B1 emitter and Q B2 The collector connection point is used as terminal A of the high-voltage three-phase full bridge, Q B3 emitter and Q B4 The collector connection point is used as terminal B of the high-voltage three-phase full bridge, Q B5 emitter and Q B6 The collector connection point serves as the C terminal of the high-voltage three-phase full-bridge, and the current sensor S... Ba S Bb and S Bc After detecting the current flowing out of the A, B, and C terminals of the high-voltage three-phase full bridge, the output AC current is determined. i Ba , i Bb and i Bc , by alternating current i Ba , i Bb and i Bc Constitutes high-voltage three-phase alternating current i H The positive and negative input terminals of voltage sensor B are connected to the positive and negative terminals of the high-voltage three-phase full-bridge voltage, respectively, and voltage sensor B outputs a high-voltage DC voltage. V dcH ; The design method for the three-stage starter-generator system with high-voltage and low-voltage DC output includes the following steps: Step 1: Based on the speed and position signal output by the rotary transformer P Calculate the position signal θ , to make the position signal θ =0°, with the three-phase armature winding W of the main motor H The zero-crossing point of the voltage drop segment of phase A under no-load conditions corresponds to the following: Step 2: When starting the low-voltage DC power supply, start the low-voltage starting power supply from terminal V. SL Provides the electrical energy required for starting, and supplies it to the main exciter's excitation winding W via AC excitation power supply. EE Provide AC excitation current i F The low-voltage three-phase full-bridge regulation regulates the flow through the three-phase armature winding W of the main motor. L Three-phase alternating current i L This enables the three-stage starter generator to output torque, thereby starting the engine; Step 3: When starting the high-voltage DC power supply, the high-voltage starting power supply terminal V... SH Provides the electrical energy required for starting, and supplies it to the main exciter's excitation winding W via AC excitation power supply. EE Provide AC excitation current i F The high-voltage three-phase full-bridge regulator regulates the flow through the three-phase armature windings W of the main motor. H Three-phase alternating current i H This enables the three-stage starter generator to output torque, thereby starting the engine; Step 4: During power generation, adjust the flow W through the main exciter's excitation winding via the regulating circuit. EE excitation current i F This enables the low-voltage DC output of the low-voltage three-phase full-bridge circuit. V dcL Stabilize at the desired voltage value; Step 5: During power generation, synchronous rectification control is used in the low-voltage three-phase full-bridge converter to reduce the Q of the MOSFET. A1 ~Q A6 The on-state voltage drop; Step 6: During power generation, the high-voltage DC voltage output from the high-voltage three-phase full-bridge is controlled by boost and buck voltage control. V dcH Stabilize at the desired voltage value; Step 7: During power generation, if an abnormality in the high-voltage DC regulation is detected, a drive signal will be used. G B1 ~ G B6 and G B1A ~ G B6A Disconnect the high-voltage three-phase full-bridge intermediate power transistor Q B1 ~Q B6 and Q B1A ~Q B6A Through drive signal G H To disconnect the power generation control circuit breaker GCB H To achieve fault isolation of high voltage DC regulation; Step 8: During power generation, if a low-voltage DC voltage regulation abnormality is detected, a drive signal will be used. G L , G H and G R To disconnect the power generation control circuit breaker GCB L Generator control circuit breaker (GCB) H The generator control relay GCR in the voltage regulation circuit is used to achieve fault protection; The boost control in step 6 includes the following steps: Step 611: Based on the high voltage DC voltage V dcH and position signal θ Determine the drive signal for boost voltage regulation control. G B1 ~ G B6 Define drive signals G B2 Falling edge corresponding θ = 240°, drive signal G B2 The high-level pulse width is δ 1. When the high voltage DC voltage V dcH When the voltage is less than the expected value, increase δ A width of 1 is used to stabilize the DC voltage at the desired output voltage. δ The adjustment range of 1 is 0~90°. G B1 ~ G B6 Having the same positive pulse width, according to G B2 , G B5 , G B4 , G B1 , G B6 , G B3 The drive signal is generated by sequentially delaying by 60°. G B1 ~ G B6 ; Step 612: Based on the position signal θ , determine signal G B1i ~ G B6i ,when θ = 210°~360° and 0°~30°, making G B1i = 1, the rest θ When the value is [value], make [something] G B1i = 0, press G B1i , G B6i , G B3i , G B2i , G B5i , G B4i Signals are generated by sequentially delaying by 60°. G B1i ~ G B6i ; Step 613, based on the drive signal G B1 ~ G B6 ,Signal G B1i ~ G B6i Determine the drive signal G B1A ~ G B6A , G B1A = G B2 | G B1i , G B6A = G B5 | G B6i , G B3A = G B4 | G B3i , G B2A = G B1 | G B2i , G B5A = G B6 | G B5i , G B4A = G B3 | G B4i ; Step 614: Drive signal G B1 ~ G B6 Send to IGBT Q respectively B1 ~Q B6 drive signal G B1A ~ G B6A Send to IGBT Q respectively B1A ~Q B6A .

2. The design method of the high-voltage and low-voltage DC output three-stage starter-generator system as described in claim 1, characterized in that: The stator armature winding of the main motor includes a low-voltage three-phase winding W. L and high voltage three-phase winding W H , The low-voltage three-phase winding W L W includes phases A, B, and C respectively. LA W LB and W LC The high-voltage three-phase winding W H W includes phases A, B, and C respectively. HA W HB and W HC ; For low-voltage three-phase winding W L Any X-phase winding, where X = A, B, or C, is formed by the 1st, 2nd… p Pole winding W LX1 W LX2 …W LXp Parallel connection configuration, low-voltage three-phase winding W L One end of any X-phase winding is connected to the neutral point N. L Connection, low-voltage three-phase winding W L The other end of any X-phase winding is connected to the low-voltage three-phase winding W. L The X-end connection, For high-voltage three-phase winding W H Any X-phase winding, where X = A, B, or C, is formed by the 1st, 2nd… p Pole winding W HX1 W HX2 …W HXp The high-voltage three-phase winding W is formed by sequentially connecting the windings in series. H One end of any X-phase winding is connected to the neutral point N. H Connection, high-voltage three-phase winding W H The other end of any X-phase winding is connected to the high-voltage three-phase winding W. H The X-end connection, Low-voltage three-phase winding W L Any X-phase winding, 1st, 2nd… p Pole winding W LX1 W LX2 …W LXp Respectively connected to the high-voltage three-phase winding W H Any X-phase winding, 1st, 2nd… p Pole winding W HX1 W HX2 …W HXp The structure within the stator slot remains the same.

3. The design method of the high-voltage and low-voltage DC output three-stage starter-generator system as described in claim 1, characterized in that: The low-voltage three-phase full-bridge includes MOSFET Q. A1 ~Q A6 ,capacitance C A Voltage sensor A, current sensor S Aa S Ab and S Ac drive signal G A Includes 6 drive signals G A1 ~ G A6 ; The capacitor C A The two ends are connected to the positive and negative terminals of the low-voltage three-phase full bridge, respectively. The positive terminal of the low-voltage three-phase full bridge is connected via Q. A1 drain, Q A1 The source, Q A2 drain, Q A2 The source terminal is connected to the negative terminal of the low-voltage three-phase full-bridge circuit, and the positive terminal of the low-voltage three-phase full-bridge circuit is connected via Q. A3 drain, Q A3 The source, Q A4 drain, Q A4 The source terminal is connected to the negative terminal of the low-voltage three-phase full-bridge circuit, and the positive terminal of the low-voltage three-phase full-bridge circuit is connected via Q. A5 drain, Q A5 The source, Q A6 drain, Q A6 The source of the MOSFET is connected to the negative terminal of the low-voltage three-phase full-bridge MOSFET, and the MOSFET Q is connected to the negative terminal of the low-voltage three-phase full-bridge MOSFET. A1 ~Q A6 The gates are respectively connected to the drive signal G A1 ~ G A6 Connection, Q A1 source and Q A2 The drain connection point serves as terminal A of the low-voltage three-phase full-bridge, Q. A3 source and Q A4 The drain connection point serves as the B terminal of the low-voltage three-phase full-bridge, Q. A5 source and Q A6 The connection point of the drain electrode as A Terminal C, current sensor S Aa S Ab and S Ac After detecting the current flowing out of terminals A, B, and C of the low-voltage three-phase full bridge, the output AC current is determined. i Aa , i Ab and i Ac , by alternating current i Aa , i Ab and i Ac Composing a low-voltage three-phase alternating current i L The positive and negative input terminals of voltage sensor A are connected to the positive and negative terminals of a low-voltage three-phase full-bridge circuit, respectively. Voltage sensor A outputs a low-voltage DC voltage. V dcL .

4. The design method of the high-voltage and low-voltage DC output three-stage starter-generator system as described in claim 1, characterized in that, The synchronous rectification control in step 5 includes the following steps: Step 51: Define alternating current i Aa , i Ab and i Ac The direction of the low-voltage three-phase full-bridge flow is positive, so that... I refH and I refL These are +1 / 5 and -1 / 5 of the rated current, respectively; Step 52, when i Aa > I refH At that time, G A2 =1, otherwise G A2 =0; Step 53, when i Ab > I refH At that time, G A4 =1, otherwise G A4 =0; Step 54, when i Ac > I refH At that time, G A6 =1, otherwise G A6 =0; Step 55, when i Aa < I refL At that time, G A1 =1, otherwise G A1 =0; Step 56, when i Ab < I refL At that time, G A3 =1, otherwise G A3 =0; Step 57, when i Ac < I refL At that time, G A5 =1, otherwise G A5 =0.

5. The design method of the high-voltage and low-voltage DC output three-stage starter-generator system as described in claim 1, characterized in that, The voltage reduction control described in step 6 includes the following steps: Step 621: Set the drive signal G B1 ~ G B6 All zeros will drive the signal. G B1 ~ G B6 Send to power transistor Q respectively B1 ~Q B6 This makes the IGBT transistor Q B1 ~Q B6 All are turned off; Step 622: Based on the position signal θ , determine signal G B1i ~ G B6i ,when θ = 210°~360° and 0°~30°, making G B1i = 1, the rest θ When the value is [value], make [something] G B1i = 0, press G B1i , G B6i , G B3i , G B2i , G B5i , G B4i Signals are generated by sequentially delaying by 60°. G B1i ~ G B6i ; Step 623, set the drive signal G B1A ~ G B6A Separate lag signals G B1i ~ G B6i The angle is δ 2. When the high voltage DC voltage V dcH When the voltage exceeds the expected value, increase δ A width of 2 is used to stabilize the DC voltage at the desired voltage value; Step 624: Drive signal G B1A ~ G B6A Send to IGBT Q respectively B1A ~Q B6A .

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