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

Abstract

The invention discloses a high-voltage and low-voltage direct current output three-stage starter generator system and a design method, the system comprises a three-stage starter generator and a controller, the three-stage starter generator comprises a permanent magnet auxiliary exciter, a main exciter, a main motor and the like, and the main motor meets 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, a high-voltage three-phase full bridge and the like, and the full bridges support bidirectional energy flow and are compatible with double-voltage starting. During starting, the alternating-current excitation power supply supplies power, and full-bridge current regulation enables the generator to output torque; during power generation, the low-voltage side uses synchronous rectification to reduce the conduction voltage drop of the MOS tube, and the high-voltage side controls voltage stabilization through voltage boosting or voltage reduction. According to the three-stage starter generator system provided by the invention, the switching frequency adopted by the high-voltage three-phase full-bridge power generation voltage stabilization is the same as the output power frequency of the starter generator, and the frequency is relatively low; the high-frequency power supply has the characteristics of low loss, low high-frequency ripple frequency spectrum component, weak high-frequency conduction and radiation interference and high power density.

Description

Technical Field

[0001] The present invention belongs to the technical field of generator design, and specifically relates to a three-stage starter generator system with high-voltage and low-voltage DC output and a design method. The system is particularly suitable for an aviation hybrid power system consisting of a 28V low-voltage DC and a 270V high-voltage DC. Background Art

[0002] In the aviation sector, power generation systems based on three-stage generators are the mainstream form of main power, auxiliary power, and ram air turbine emergency power. Early airborne equipment typically used low-power 28V DC power systems. However, as power consumption increased, 28V DC systems became unsuitable for aircraft with power outputs exceeding 12kW. Consequently, the trend toward higher voltages became clear: replacing the original 28V DC with 270V HVDC or 115V AC power systems. Due to the varying power requirements of power-consuming equipment, AC power systems were the primary focus for civil airliners, helicopters, transport aircraft, and high-end reconnaissance drones. For fighter jets and high-end strike drones, 270V HVDC systems were the primary focus due to the preponderance of DC-powered electronic equipment and weapon systems. However, aircraft emergency batteries still primarily utilize 28V. Furthermore, some mature airborne equipment with lower power consumption does not necessarily require full upgrade to HVDC or AC power; some still require 28V 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 an electric starter and an air turbine starter. However, after the engine is started, the electric starter and air turbine starter become dead weight, hindering further improvement of aircraft performance. With the advancement of power electronics technology and the electrification of aircraft, the original generator with only power generation function has been expanded to a starter-generator with both starting and power generation functions, effectively reducing the weight of the engine starting system. For engines less than 500kW, a 28V low-voltage DC power supply is the primary power source for engine starting, with power provided by a 28V battery. For engines greater than 2MW, a 270V high-voltage DC power supply is the primary power source for engine starting, with power provided by the auxiliary power unit (APU)-driven power generation system.

[0004] The existing aviation hybrid power system composed of 28V low-voltage DC and 270V high-voltage DC is generally implemented in the following way.

[0005] 1. A combination of a high-voltage DC three-stage starter-generator system and a DC bus converter. This solution is primarily used in fighter aircraft. The engine is directly mechanically connected only 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. The high-voltage DC three-stage starter-generator system drives the engine from standstill to ignition speed, achieving engine start. 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 power. The DC bus converter then converts the 270V high-voltage DC to 28V low-voltage DC.

[0006] 2. A combination of a low-voltage DC brushless starter-generator system and a high-voltage DC three-stage generator system. This solution is primarily used in standard UAVs. Its power quality, including overload, short-circuit, and high-frequency ripple spectrum, fully meets the standards for aircraft power and power generation systems. Fault protection is achieved through demagnetization, meeting safety requirements. Each engine is equipped with two power generation systems: a DC brushless starter-generator system and a high-voltage DC three-stage generator system. During starting, a 28V battery provides the starting power. The low-voltage DC brushless starter-generator system generates power, driving the engine from standstill to ignition speed, achieving engine start. During power generation, the engine provides mechanical speed input to the DC brushless starter-generator system and the high-voltage DC three-stage generator system. The DC brushless starter-generator system converts the input mechanical energy into 28V low-voltage DC and 270V high-voltage DC energy, respectively. With the advancement of power electronics technology, the technical solution of replacing low-voltage DC brushless starter-generator systems with low-voltage DC three-stage generator systems has matured, and pilot applications have already been implemented. Since mechanical commutation is replaced by electronic commutation, the low-voltage DC three-stage starter-generator system can be applied to high-altitude long-distance flight, export maintenance-free and coastal salt spray environment resistance. However, the power density of the low-voltage DC three-stage starter-generator system is much lower than that of the DC brush starter-generator system, which is the main disadvantage of the low-voltage DC three-stage starter-generator system.

[0007] 3. A combination of a high-voltage DC permanent magnet starter-generator system and a DC bus converter is the primary technical solution for low-cost UAVs. The engine is only directly mechanically connected to the high-voltage DC permanent magnet generator system. Turbopump engines typically use turboplug engines, which typically start at 5% to 8% of rated speed and exhibit extremely high drag torque below 10 rpm. This drag torque decreases significantly beyond the low-speed range, resulting in low starting power consumption. This is significantly different from turbine engines, which typically start at 40% to 50% of rated speed, have low drag at low speeds, increase drag by the square of the speed as speed increases, and require high starting power consumption. During starting, a 28V battery serves as the starting power source, either directly powering the high-voltage DC permanent magnet starter-generator system or boosting the battery voltage to 50V to 60V via a power converter. The high-voltage DC permanent magnet starter-generator system then drives the engine from a standstill to ignition speed, achieving engine start. Since piston engines require minimal starting power, and the power converter used to boost the battery voltage to 50-60V operates for a short period, the added weight of a step-up power converter is minimal. During power generation, the engine provides mechanical speed input to the HVDC permanent magnet starter-generator system, which converts this input mechanical energy into 270V AC power. The DC bus converter then converts the 270V DC power to a low-voltage 28V DC power. Because the permanent magnet starter-generator structure is simpler than a three-stage starter-generator, its cost is significantly reduced.

[0008] In Option 1, 28V low-voltage DC is generated through a two-stage energy conversion process. The first stage is a high-voltage DC three-stage starter-generator system that converts the input mechanical energy into 270V high-voltage DC electricity. The second stage is a DC bus converter that converts the 270V high-voltage DC into 28V low-voltage DC. This results in low efficiency in converting the 28V electricity. Furthermore, the 270V high-voltage DC to 28V low-voltage DC conversion is a high-frequency, full-power conversion, and the DC bus converter is also heavy. In Option 2, the power generation system has two mechanical interfaces with the engine, which are more complex and result in significant additional weight for the mechanical transmission interface, generator housing, and other components. In Option 3, the output voltage of the permanent magnet starter generator varies linearly with the speed and has a high operating frequency. The 270V voltage-stabilizing converter has a wide input voltage range and a high switching frequency. Compared with the high-voltage DC three-stage starter generator system, the power density and efficiency of the high-voltage DC permanent magnet starter generator system are not superior. 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 system and power generation system standards. It cannot be demagnetized after a fault, which does not meet aviation safety requirements. The conversion efficiency of 28V electrical energy is low. The DC bus converter that realizes the conversion from 270V high-voltage DC to 28V low-voltage DC is also heavy. Summary of the Invention

[0009] The purpose of the present invention is to address the deficiencies of the above-mentioned technologies and provide a three-stage starter-generator system with high-voltage and low-voltage DC outputs; the purpose of the present invention is to address the deficiencies of the above-mentioned technologies and provide a design method for a three-stage starter-generator system with high-voltage and low-voltage DC outputs.

[0010] The present invention provides a high-voltage and low-voltage DC output three-stage starter generator system, including 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 rotating transformer. The controller includes a low-voltage three-phase full-bridge, a high-voltage three-phase full-bridge, a voltage regulating circuit, an AC excitation power supply, a control circuit, a diode D L and D H , current sensor S F ;

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

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

[0013] The current sensor S F Detect the current flowing into the main exciter excitation winding W EE The F+ terminal current outputs the excitation 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, and the positive and negative poles of the low-voltage three-phase full bridge are respectively connected to the positive and negative poles of the external low-voltage DC interface terminal.

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

[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 AC current i H Connected to the control circuit, the high voltage starting power supply terminal V SH Through diode D H Anode, diode D H The cathode is connected to the positive pole of the high-voltage three-phase full bridge, and the control circuit outputs the drive signal G L and G H Generator control circuit breaker GCB L and GCB H Connect the rotor armature winding W of the main exciter EMThrough 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 Includes A, B and C phase windings W respectively LA 、W LB and W LC , the high voltage three-phase winding W H Includes A, B and C phase windings W respectively HA 、W HB and W HC ;

[0018] For low voltage three-phase winding W L Any X-phase winding, X=A, B or C, is composed of the 1st, 2nd…pth pole winding W LX1 、W LX2 …W LXp Parallel connection, low voltage three-phase winding W L Any X-phase winding end and 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, X=A, B or C, is composed of the 1st, 2nd…pth pole winding W HX1 、W HX2 …W HXp The high voltage three-phase winding W is connected in series. H Any X-phase winding end and 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 1, 2…p pole winding W LX1 、W LX2 …W LXp Respectively with the high voltage three-phase winding W H Any X-phase winding 1, 2…p pole winding W HX1 、W HX2 …W HXp The structure within the stator slots remains the same.

[0021] Furthermore, the low voltage three-phase full bridge includes a MOS tube Q A1 -Q A6 , capacitor C A , voltage sensor A, current sensor S Aa 、S Ab and S Ac , driving signal G A Including 6-way drive signal G A1 -G A6 ;

[0022] The capacitor C A The two ends of the low voltage three-phase full bridge are connected to the positive and negative poles respectively, and the positive pole of the low voltage three-phase full bridge is connected to the positive pole of the low voltage three-phase full bridge through Q A1 The drain, Q A1 Source, Q A2 The drain, Q A2 The source of the low voltage three-phase full bridge is connected to the negative pole of the low voltage three-phase full bridge, and the positive pole of the low voltage three-phase full bridge is connected to the negative pole of the low voltage three-phase full bridge through Q A3 The drain, Q A3 Source, Q A4 The drain, Q A4 The source of the low voltage three-phase full bridge is connected to the negative pole of the low voltage three-phase full bridge, and the positive pole of the low voltage three-phase full bridge is connected to the negative pole of the low voltage three-phase full bridge through Q A5 The drain, Q A5 Source, Q A6 The drain, Q A6 The source is connected to the negative electrode of the low voltage three-phase full bridge, and the MOS tube Q A1 -Q A6 The gates are respectively connected to the driving signal G A1 -G A6 Connect, Q A1 source and Q A2 The connection point of the drain is used as the A terminal of the low voltage three-phase full bridge, Q A3 source and Q A4 The drain connection point is used as the B terminal of the low voltage three-phase full bridge, Q A5 source and Q A6 The drain connection point serves as A C terminal, current sensor S Aa 、S Ab and S Ac After detecting the current flowing out of the A, B and C terminals of the low-voltage three-phase full bridge, the AC current i is output. Aa 、i Ab and i Ac , by the AC current i Aa 、i Ab and i Ac Constitutes low voltage three-phase AC current i LThe positive and negative input electrodes of the voltage sensor A are connected to the positive and negative electrodes of the low-voltage three-phase full-bridge respectively, and the voltage sensor A outputs a low-voltage DC voltage V dcL .

[0023] Furthermore, the high voltage three-phase full bridge includes an IGBT tube Q B1 -Q B6 , Q B1A -Q B6A , capacitor C B , voltage sensor B, current sensor S Ba 、S Bb and S Bc , driving signal G B Including 6-way drive signal G B1 -G B6 and 6-way drive signal G B1A -G B6A ;

[0024] The capacitor C B The two ends of the high voltage three-phase full bridge are connected to the positive and negative poles respectively. The positive pole of the high voltage three-phase full bridge is connected to the positive pole of the high voltage three-phase full bridge through Q B1A The emitter, Q B1A The collector, Q B1 The collector, Q B1 The emitter, Q B2 The collector, Q B2 The emitter, Q B2A The emitter, Q B2A The collector is connected to the negative electrode of the high voltage three-phase full bridge, and the positive electrode of the high voltage three-phase full bridge is connected to the negative electrode of the high voltage three-phase full bridge through Q B3A The emitter, Q B3A The collector, Q B3 The collector, Q B3 The emitter, Q B4 The collector, Q B4 The emitter, Q B4A The emitter, Q B4A The collector is connected to the negative electrode of the high voltage three-phase full bridge, and the positive electrode of the high voltage three-phase full bridge is connected to the negative electrode of the high voltage three-phase full bridge through Q B5A The emitter, Q B5A The collector, Q B5 The collector, Q B5 The emitter, Q B6 The collector, Q B6 The emitter, Q B6A The emitter, Q B6A The collector is connected to the negative electrode of the high voltage three-phase full bridge, the IGBT tube Q B1 -Q B6 The gates are respectively connected to the driving signal G B1 -G B6 Connect, QB1A -Q B6A The gates are respectively connected to the driving signal G B1A -G B6A Connect, Q B1 The emitter and Q B2 The connection point of the collector is used as the A terminal of the high voltage three-phase full bridge, Q B3 The emitter and Q B4 The connection point of the collector is used as the B terminal of the high voltage three-phase full bridge, Q B5 The emitter and Q B6 The connection point of the collector is used 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 AC current i is output. Ba 、i Bb and i Bc , by the AC current i Ba 、i Bb and i Bc Constitutes high voltage three-phase alternating current i H The positive and negative input electrodes of voltage sensor B are connected to the positive and negative electrodes of the high-voltage three-phase full bridge respectively, and voltage sensor B outputs a high-voltage DC voltage V dcH .

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

[0026] Step 1: Calculate the position signal θ according to the speed position signal P output by the rotary transformer, make the position signal θ=0°, and compare it with the three-phase armature winding W of the main motor. H It corresponds to the zero crossing point of the voltage drop section of phase A under no-load;

[0027] Step 2: When the low voltage DC power supply starts, the low voltage starting power supply terminal V SL Provide the electric energy required for starting, and supply the main exciter excitation winding W through the AC excitation power supply EE Provide AC excitation current i F , the low voltage three-phase full bridge regulates the current flowing through the three-phase armature winding W of the main motor L The three-phase AC current i L , so that the three-stage starter generator outputs torque to start the engine;

[0028] Step 3: When the high voltage DC power supply starts, the high voltage starting power supply terminal V SH Provide the electric energy required for starting, and supply the main exciter excitation winding W through the AC excitation power supply EE Provide AC excitation current i F , the high voltage three-phase full bridge regulates the current flowing through the three-phase armature winding W of the main motorH The three-phase AC current i H , so that the three-stage starter generator outputs torque to start the engine;

[0029] Step 4: When generating electricity, adjust the current flowing through the main exciter excitation winding W through the regulating circuit. EE The excitation current i F , so that the low voltage DC voltage V output by the low voltage three-phase full bridge dcL Stable at the desired voltage value;

[0030] Step 5: When generating electricity, the low-voltage three-phase full-bridge adopts synchronous rectification control to reduce the MOS tube Q A1 -Q A6 The conduction voltage drop;

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

[0032] Step 7: When generating electricity, if the high voltage DC voltage regulation is abnormal, the drive signal G B1 -G B6 and G B1A -G B6A Disconnect the high-voltage three-phase full-bridge medium power tube Q B1 -Q B6 and Q B1A -Q B6A , through the driving signal G H To disconnect the generator control circuit breaker GCB H , realizing high voltage DC voltage stabilization fault isolation;

[0033] Step 8: When generating electricity, if the low voltage DC voltage regulation is abnormal, the drive signal G L , G H and G R To disconnect the generator control circuit breaker GCB L , Generation Control Circuit Breaker GCB H And the power generation control relay GCR in the voltage regulation circuit to achieve fault protection.

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

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

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

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

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

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

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

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

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

[0043] Step 611: According to the high voltage DC voltage V dcH and position signal θ, determine the driving 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 driving signal G B2 The high level pulse width is δ1, when the high voltage DC voltage V dcH When the voltage is less than the expected value, the DC voltage is stabilized at the expected output voltage by increasing the width of δ1. The adjustment range of δ1 is 0-90°. B1 -G B6 With the same positive pulse width, press G B2 , G B5 , G B4 , G B1 , G B6 , G B3 The driving signal G is formed by lagging 60 degrees in sequence.​​​B1 -G B6 ;

[0044] Step 612: Determine the signal G according to the position signal θ. B1i -G B6i , when θ=210°-360° and 0°-30°, 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 lagging 60° in sequence B1i -G B6i ;

[0045] Step 613: According to the driving signal G B1 -G B6 , signal G B1i -G B6i , determine the driving 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: The driving signal G B1 -G B6 Sent to IGBT tube Q respectively B1 -Q B6 , driving signal G B1A -G B6A Sent to IGBT tube Q respectively B1A -Q B6A .

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

[0048] Step 621: Set the driving signal G B1 -G B6All are 0, the drive signal G B1 -G B6 Sent to power tube Q respectively B1 -Q B6 , so that the IGBT tube Q B1 -Q B6 All are turned off;

[0049] Step 622: Determine the signal G according to the position signal θ. B1i -G B6i , when θ=210°-360° and 0°-30°, 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 lagging 60° in sequence B1i -G B6i ;

[0050] Step 623: Set the driving signal G B1A -G B6A Lag signal G B1i -G B6i The angle is δ2, when the high voltage DC voltage V dcH When it is greater than the expected voltage value, the DC voltage is stabilized at the expected voltage value by increasing the width of δ2;

[0051] Step 624: The driving signal G B1A -G B6A Sent to IGBT tube Q respectively B1A -Q B6A .

[0052] The beneficial effects of the present invention are:

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

[0054] 2. Compared with 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, and the efficiency of obtaining the 28V low-voltage DC is higher. The DC bus power converter for converting 270V high-voltage DC to 28V low-voltage DC is eliminated, and the weight cost of obtaining the 28V low-voltage DC is lower.

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

[0056] 4. Compared to a solution combining a high-voltage DC permanent magnet starter generator system and a DC bus converter, this system achieves 28V low-voltage DC through excitation stabilization, eliminating the need for a DC bus power converter for converting 270V high-voltage DC to 28V low-voltage DC. The 28V low-voltage DC is obtained through a single energy conversion stage, significantly reducing the weight and efficiency costs of achieving 28V low-voltage DC. The input voltage range of the 270V regulated converter is significantly narrowed, and the same electrical frequency control as the starter generator is used, significantly reducing the weight and efficiency costs of 270V high-voltage DC stabilization. Overall power density and efficiency are significantly improved. This overcomes the drawbacks of power quality due to overload, short circuit, and high-frequency ripple spectrum, which make it difficult to meet aircraft power supply and power generation system standards. It also addresses the issue of inability to demagnetize after a fault, which would not meet aviation safety requirements.

[0057] 5. The main motor meets the requirements of 28V low-voltage DC and 270V high-voltage DC respectively by using low-voltage three-phase winding WL and high-voltage three-phase winding WH.

[0058] 6. The switching frequency used by the high-voltage three-phase full-bridge to achieve 270V output voltage regulation is the same as the output frequency of the starter generator. The frequency is low and the loss is much lower than the traditional solution using high-frequency voltage regulation control.

[0059] 7. The switching frequency used by the high-voltage three-phase full-bridge to achieve 270V output voltage regulation is the same as the output frequency of the starter generator. The frequency is low, and the high-frequency conduction and radiation interference is much lower than the traditional high-frequency voltage regulation control solution. The high-frequency ripple spectrum is more likely to comply with the requirements of GJB181B-2012, and it also has better electromagnetic compatibility characteristics.

[0060] 8. The switching frequency used by the high-voltage three-phase full-bridge to achieve 270V output voltage regulation is the same as the output frequency of the starter generator. Therefore, the power tube can use a power tube that can withstand large current but has relatively large 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 buck-boost voltage stabilization control with a faster response speed than the excitation voltage stabilization control. It has a good suppression effect on transient voltage drops or overvoltages caused by loading or dumping.

[0062] 10. The high-voltage three-phase full-bridge can perform boost and buck control. The boost and buck control range is narrow during voltage regulation, 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 both 28V low-voltage DC starting and 270V high-voltage DC starting functions.

[0064] When 12.28V low-voltage DC is used for regulated power generation, the MOS tubes in the low-voltage three-phase full-bridge operate in a synchronous rectification state, so that the conduction voltage drop is only below 0.2V, which is significantly lower than the 0.7-1.2V of the diode, significantly improving the efficiency of the 28V low-voltage DC regulation. BRIEF DESCRIPTION OF THE DRAWINGS

[0065] Figure 1 This is a structural 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 the present invention;

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

[0069] Figure 5 A circuit diagram of the voltage regulating circuit of the present invention;

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

[0071] Figure 7 The position signal θ of the present invention is related to the three-phase armature winding W of the main motor. H No-load voltage corresponding 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 The low voltage DC voltage stabilization control principle diagram of the present invention;

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

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

[0076] Figure 12 Schematic diagram of the voltage reduction control principle of the high-voltage three-phase full-bridge of the present invention. DETAILED DESCRIPTION

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

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

[0079] High-voltage and low-voltage DC output three-stage starter generator system device, including 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 rotating transformer. The controller includes a low-voltage three-phase full-bridge, a high-voltage three-phase full-bridge, a voltage regulating circuit, an AC excitation power supply, a control circuit, a diode D L and D H , current sensor S F The rotary transformer outputs the speed position signal P which is connected to the control circuit, and the permanent magnet auxiliary exciter winding W PMG The A, B and C terminals of the controller are connected to the voltage regulating circuit, and the control circuit outputs the driving signal G C and G R Connected to the voltage regulating circuit, the output terminal V Co The positive and negative poles are connected to the main exciter excitation winding W EE The F+ and F- terminals of the AC excitation power supply are connected to the low voltage power supply input terminal V iL and the high voltage power supply input terminal V iH They are connected to the positive poles 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 poles of the low-voltage three-phase full bridge and the high-voltage three-phase full bridge respectively. The control circuit outputs the drive signal G D and G S Connected to the AC excitation power supply, the AC excitation power supply output terminal v Bo The * and - ends are connected to the main exciter excitation winding W EE The F+ and F- terminals of the current sensor S F Detect the current flowing into the main exciter excitation winding W EE The F+ terminal current outputs the excitation current i F Connected to the control circuit, the main motor low voltage three-phase winding W L A, B and C are connected to the low-voltage three-phase full bridge, and the positive and negative poles of the low-voltage three-phase full bridge are connected to the positive and negative poles of the external low-voltage DC interface respectively. The control circuit outputs the drive signal G AConnected to the 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 AC current i L Connected to the control circuit, low voltage starting power supply terminal V SL Through diode D L Anode, diode D L The cathode is connected to the positive pole of the low-voltage three-phase full bridge, and the high-voltage three-phase winding W of the main motor H A, B and C are connected to the high-voltage three-phase full bridge, and the positive and negative poles of the high-voltage three-phase full bridge are connected to the positive and negative poles of the external high-voltage DC interface respectively. The control circuit outputs the drive signal G B Connected to the 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 AC current i H Connected to the control circuit, high voltage starting power supply terminal V SH Through diode D H Anode, diode D H The cathode is connected to the positive pole of the high-voltage three-phase full bridge, and the control circuit outputs the drive signal G L and G H Generator control circuit breaker GCB L and GCB H Connection, main exciter rotor armature winding W EM Through the rotating rectifier and the main motor rotor excitation winding W ME Connection composition.

[0080] Since the proposed high-voltage and low-voltage DC output three-stage starter generator does not use mechanical commutation, compared with the combination of a DC brush starter generator system and a high-voltage DC three-stage generator system, it overcomes the shortcomings of being unsuitable for high-altitude long-distance flight, maintenance-free export, and resistant to coastal salt spray environments.

[0081] Compared with the combination of a low-voltage DC brushed starter generator system and a high-voltage DC three-stage generator system, and the combination of a low-voltage DC three-stage starter generator system and a high-voltage DC three-stage generator system, both the 28V low-voltage DC and the 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 casing, heat dissipation structure, mechanical support structure, etc. are reduced from two to one, and the additional weight of the mechanical transmission interface and the non-effective parts of the starter generator are significantly reduced.

[0082] Compared with 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, and the efficiency of obtaining the 28V low-voltage DC is higher; the DC bus power converter for converting 270V high-voltage DC to 28V low-voltage DC is eliminated, and the weight cost of obtaining the 28V low-voltage DC is lower.

[0083] Figure 2 The main motor stator armature winding includes a low voltage three-phase winding W L and high voltage three-phase winding W H , low voltage three-phase winding W L Includes A, B and C phase windings W respectively LA 、W LB and W LC , high voltage three-phase winding W H Includes A, B and C phase windings W respectively HA 、W HB and W HC ; For low voltage three-phase winding W L Any X-phase winding, X=A, B or C, is composed of the 1st, 2nd…pth pole winding W LX1 、W LX2 …W LXp Parallel connection, low voltage three-phase winding W L Any X-phase winding end and 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 is connected to the high voltage three-phase winding W H Any X-phase winding, X=A, B or C, is composed of the 1st, 2nd…pth pole winding W HX1 、W HX2 …W HXp The high voltage three-phase winding W is connected in series. H Any X-phase winding end and 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 is connected to the low voltage three-phase winding W L Any X-phase winding 1, 2…p pole winding W LX1 、W LX2 …W LXp Respectively with the high voltage three-phase winding W H Any X-phase winding 1, 2…p pole winding W HX1 、W HX2 …W HXp The structure within the stator slots remains the same.

[0084] First, the low-voltage three-phase winding W is realized by connecting the 1st, 2nd, ...p pole pairs in parallel or in series. L Or high voltage three-phase winding W H The voltage regulation is then achieved by changing the winding turns ratio N W Adjust 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 turn ratio is selected as N W =2.

[0085] The main motor is connected by using a low voltage three-phase winding W L and high voltage three-phase winding W H To meet the needs of 28V low voltage DC and 270V high voltage DC respectively.

[0086] Figure 3 The low voltage three-phase full bridge circuit diagram is shown. The low voltage three-phase full bridge includes MOS tube Q A1 -Q A6 , capacitor C A , voltage sensor A, current sensor S Aa 、S Ab and S Ac , driving signal G A Including 6-way drive signal G A1 -G A6 ; is composed of capacitor C A The two ends of the low voltage three-phase full bridge are connected to the positive and negative poles respectively, and the positive pole of the low voltage three-phase full bridge is connected to the positive pole of the low voltage three-phase full bridge through Q A1 The drain, Q A1 Source, Q A2 The drain, Q A2 The source of the low voltage three-phase full bridge is connected to the negative pole of the low voltage three-phase full bridge, and the positive pole of the low voltage three-phase full bridge is connected to the negative pole of the low voltage three-phase full bridge through Q A3 The drain, Q A3 Source, Q A4 The drain, Q A4 The source of the low voltage three-phase full bridge is connected to the negative pole of the low voltage three-phase full bridge, and the positive pole of the low voltage three-phase full bridge is connected to the negative pole of the low voltage three-phase full bridge through Q A5 The drain, Q A5 Source, Q A6 The drain, Q A6 The source is connected to the negative pole of the low voltage three-phase full bridge, Q A1 -Q A6 The gates are respectively connected to the driving signal G A1 -G A6 Connect, Q A1 source and Q A2 The connection point of the drain is used as the A terminal of the low voltage three-phase full bridge, Q A3 source and Q A4 The drain connection point is used as the B terminal of the low voltage three-phase full bridge, Q A5source and Q A6 The drain connection point serves as A C terminal, current sensor S Aa 、S Ab and S Ac After detecting the current flowing out of the A, B and C terminals of the low-voltage three-phase full bridge, the AC current i is output. Aa 、i Ab and i Ac , by the AC current i Aa 、i Ab and i Ac Constitutes low voltage three-phase AC current i L The positive and negative input electrodes of the voltage sensor A are connected to the positive and negative electrodes of the low-voltage three-phase full-bridge respectively, and the voltage sensor A outputs a low-voltage DC voltage V dcL constitute.

[0087] For the alternating current i Aa 、i Ab and i Ac When the current flows out of or into the low-voltage three-phase full-bridge, the instantaneous value is positive or negative respectively.

[0088] Figure 4 The high voltage three-phase full bridge circuit diagram is shown. The high voltage three-phase full bridge includes IGBT tube Q B1 -Q B6 , Q B1A -Q B6A , capacitor C B , voltage sensor B, current sensor S Ba 、S Bb and S Bc , driving signal G B Including 6-way drive signal G B1 -G B6 and 6-way drive signal G B1A -G B6A ; is composed of capacitor C B The two ends of the high voltage three-phase full bridge are connected to the positive and negative poles respectively. The positive pole of the high voltage three-phase full bridge is connected to the positive pole of the high voltage three-phase full bridge through Q B1A The emitter, Q B1A The collector, Q B1 The collector, Q B1 The emitter, Q B2 The collector, Q B2 The emitter, Q B2A The emitter, Q B2A The collector is connected to the negative electrode of the high voltage three-phase full bridge, and the positive electrode of the high voltage three-phase full bridge is connected to the negative electrode of the high voltage three-phase full bridge through Q B3A The emitter, Q B3A The collector, Q B3 The collector, Q B3The emitter, Q B4 The collector, Q B4 The emitter, Q B4A The emitter, Q B4A The collector is connected to the negative electrode of the high voltage three-phase full bridge, and the positive electrode of the high voltage three-phase full bridge is connected to the negative electrode of the high voltage three-phase full bridge through Q B5A The emitter, Q B5A The collector, Q B5 The collector, Q B5 The emitter, Q B6 The collector, Q B6 The emitter, Q B6A The emitter, Q B6A The collector is connected to the negative electrode of the high voltage three-phase full bridge, Q B1 -Q B6 The gates are respectively connected to the driving signal G B1 -G B6 Connect, Q B1A -Q B6A The gates are respectively connected to the driving signal G B1A -G B6A Connect, Q B1 The emitter and Q B2 The connection point of the collector is used as the A terminal of the high voltage three-phase full bridge, Q B3 The emitter and Q B4 The connection point of the collector is used as the B terminal of the high voltage three-phase full bridge, Q B5 The emitter and Q B6 The connection point of the collector is used 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 AC current i is output. Ba 、i Bb and i Bc , by the AC current i Ba 、i Bb and i Bc Constitutes high voltage three-phase alternating current i H The positive and negative input electrodes of voltage sensor B are connected to the positive and negative electrodes of the high-voltage three-phase full bridge respectively, and voltage sensor B outputs a high-voltage DC voltage V dcH constitute.

[0089] For the alternating current i Ba 、i Bb and i Bc When the current flows out of or into the high-voltage three-phase full-bridge, the instantaneous value is positive or negative respectively.

[0090] Figure 5 The circuit diagram of the voltage regulator circuit is shown, and the driving signal GC Including driving signal G C1 and G C2 , respectively with MOS tube Q C1 and Q C2 The gate is connected to the C Control the generator control relay GCR to connect the voltage regulating circuit with the main exciter excitation winding W EE Connect or disconnect, 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 auxiliary exciter PMG Converted to DC V G When generating electricity, Q C2 Closed, by adjusting Q C1 The duty cycle is used to adjust the current flowing through the main exciter excitation winding W EE The excitation current i F .

[0091] Figure 6 The circuit diagram of AC excitation power supply is shown, and the driving signal G D Including 4-way drive signal G D1 -G D4 , respectively with the power tube Q D1 -Q D4 When 28V low voltage DC is used as the starting power supply, the 28V low voltage DC is connected to the low voltage power supply input terminal V iL When 270V high voltage DC is used as the starting power supply, the 270V high voltage DC is connected to the high voltage power supply input terminal V iH Connect. Through the step-up DC / DC module, the low voltage power supply input terminal V iL Input 28V low voltage DC is converted to 270V V SI , by adding D D To prevent the high voltage power supply input terminal V iH When the input voltage is higher than the output voltage of the boost DC / DC module, the boost DC / DC module will be damaged. S Control the start control relay SCR to turn on Q D1 -Q D4 The single-phase inverter bridge and the main exciter excitation winding W EE Connect or disconnect, the drive signal G D Under the control of Q D1 -Q D4 The single-phase inverter bridge formed converts DC V SI Converted into AC, regulating the current flowing through the main exciter excitation winding W during starting EE The excitation current i F .

[0092] The design method of the three-stage starter generator system with high-voltage and low-voltage DC outputs comprises the following steps:

[0093] Step 1: Calculate the position signal θ according to the speed position signal P output by the rotary transformer, so that the position signal θ = 0° and the three-phase armature winding W of the main motor H It corresponds to the zero crossing point of the voltage drop section of phase A under no-load;

[0094] Step 2: When the low voltage DC power supply starts, the low voltage starting power supply terminal V SL Provide the electric energy required for starting, and supply the main exciter excitation winding W through the AC excitation power supply EE Provide AC excitation current i F , the low voltage three-phase full bridge regulates the current flowing through the three-phase armature winding W of the main motor L The three-phase AC current i L , so that the three-stage starter generator outputs torque to start the engine;

[0095] Step 3: When the high voltage DC power supply starts, the high voltage starting power supply terminal V SH Provide the electric energy required for starting, and supply the main exciter excitation winding W through the AC excitation power supply EE Provide AC excitation current i F , the high voltage three-phase full bridge regulates the current flowing through the three-phase armature winding W of the main motor H The three-phase AC current i H , so that the three-stage starter generator outputs torque to start the engine;

[0096] Step 4: When generating electricity, adjust the current flowing through the main exciter excitation winding W through the regulating circuit. EE The excitation current i F , so that the low voltage DC voltage V output by the low voltage three-phase full bridge dcL Stable at the desired voltage value;

[0097] Step 5: When generating electricity, the low-voltage three-phase full-bridge adopts synchronous rectification control to reduce the MOS tube Q A1 -Q A6 The conduction voltage drop;

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

[0099] Step 7: When generating electricity, if the high voltage DC voltage regulation is abnormal, the drive signal G B1 -G B6 and G B1A -G B6A Disconnect the high-voltage three-phase full-bridge medium power tube Q B1 -Q B6and Q B1A -Q B6A , through the driving signal G H To disconnect the generator control circuit breaker GCB H , realizing high voltage DC voltage stabilization fault isolation;

[0100] Step 8: When generating electricity, if the low voltage DC voltage regulation is abnormal, the drive signal G L , G H and G R To disconnect the generator control circuit breaker GCB L , Generation Control Circuit Breaker GCB H And the power generation control relay GCR in the voltage regulation circuit to achieve fault protection.

[0101] Combine Figure 7 The position signal θ shown is related to the three-phase armature winding W of the main motor. H The no-load voltage corresponding diagram is used to further illustrate step A. In the figure, v H_A 、v H_B and v H_C Represent the three-phase armature winding W of the main motor H The no-load output voltage of phases A, B and C. In step A, the position signal θ = 0° and the no-load v H_A The correspondence of the zero crossing point of the descending section is ensured by adjusting the relative position of the resolver transformer rotor and the main motor rotor.

[0102] Figure 8 The figure shows the control principle of low voltage three-phase full bridge or high voltage three-phase full bridge starting, which further explains step B and step C. When the low voltage DC power supply is started, the low voltage starting power supply terminal V SL Connected to 28V low voltage DC, Figure 8 The medium three-phase full bridge refers to the low voltage three-phase full bridge, i a and i b I Aa and i Ab , using a quasi-speed loop to adjust the q-axis current reference value i as the speed changes q *, adjust the active current i through the current loop q and reactive current i d , using space vector pulse width modulation (SVPWM) to generate the low voltage three-phase full bridge drive signal G A1 -G A6 , and then adjust the current flowing through the three-phase armature winding W of the main motor L The current i L , and finally realize the starting torque adjustment. When the high voltage DC power supply starts, the high voltage starting power supply terminal V SH Connected to 270V high voltage DC, Figure 8 The three-phase full bridge in the middle refers to the high-voltage three-phase full bridge, i a and ib I Ba and i Bb , the drive signal G is generated by the control circuit B1A -G B6A To keep the power tube Q closed B1A -Q B6A , also uses the quasi-speed loop to adjust the q-axis current reference value i as the speed changes q *, adjust the active current i through the current loop q and reactive current i d , using space vector pulse width modulation (SVPWM) to generate a high three-phase full-bridge drive signal G B1 -G B6 , and then adjust the current flowing through the three-phase armature winding W of the main motor H The current i H , and finally realize starting torque adjustment.

[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] Combine Figure 9 The low voltage DC voltage regulation control principle diagram shown in the figure further explains step D. According to the voltage regulation reference value V refL and low voltage DC voltage V dcL , calculate the voltage loop and generate the reference signal I of the excitation current loop ref According to the reference signal I of the excitation current loop ref and the excitation current i F , calculate the excitation current loop so that the excitation current i F The reference signal I of the excitation current loop ref equal.

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

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

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

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

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

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

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

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

[0113] During 28V low-voltage DC regulated power generation, the MOS tubes in the low-voltage three-phase full-bridge operate in a synchronous rectification state, so that the conduction voltage drop is only below 0.2V, which is significantly lower than the diode 0.7-1.2V, significantly improving the efficiency of 28V low-voltage DC regulated power generation.

[0114] Since the 28V low voltage DC voltage regulation is achieved by adjusting the excitation current in step 4, the three-phase armature winding W of the main motor H The voltage after rectification is usually not the desired 270V, and the auxiliary means of step 5 is required to achieve 270V high-voltage DC voltage regulation.

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

[0116] Step 611: According to the high voltage DC voltage V dcH and position signal θ, determine the driving 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 driving signal G B2 ​​​The high level pulse width is δ1, when the high voltage DC voltage V dcH When the voltage is less than the expected value, the DC voltage is stabilized at the expected output voltage by increasing the width of δ1. The adjustment range of δ1 is 0-90°. B1 -G B6 With the same positive pulse width, press G B2 , G B5 , G B4 , G B1 , G B6 , G B3 The driving signal G is formed by lagging 60 degrees in sequence. B1 -G B6 ;

[0117] Step 612: Determine the signal G according to the position signal θ. B1i -G B6i , when θ=210°-360° and 0°-30°, 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 lagging 60° in sequence B1i -G B6i ;

[0118] Step 613: According to the driving signal G B1 -G B6 , signal G B1i -G B6i , determine the driving 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: The driving signal G B1 -G B6Sent to IGBT tube Q respectively B1 -Q B6 , driving signal G B1A -G B6A Sent to IGBT tube Q respectively B1A -Q B6A .

[0120] Combine Figure 12 The step-down control principle diagram of the high-voltage three-phase full-bridge is shown to further illustrate the step-down control described in step 6. The step-down control described in step 6 includes the following steps:

[0121] Step 621: Set the driving signal G B1 -G B6 All are 0, the drive signal G B1 -G B6 Sent to power tube Q respectively B1 -Q B6 , so that the IGBT tube Q B1 -Q B6 All are turned off;

[0122] Step 622: Determine the signal G according to the position signal θ. B1i -G B6i , when θ=210°-360° and 0°-30°, 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 lagging 60° in sequence B1i -G B6i ;

[0123] Step 623: Set the driving signal G B1A -G B6A Lag signal G B1i -G B6i The angle is δ2, when the high voltage DC voltage V dcH When it is greater than the expected voltage value, the DC voltage is stabilized at the expected voltage value by increasing the width of δ2;

[0124] Step 624: The driving signal G B1A -G B6A Sent to IGBT tube Q respectively B1A -Q B6A .

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

[0126] 1. The switching frequency used by the high-voltage three-phase full-bridge to achieve 270V output voltage regulation is the same as the output frequency of the starter generator. The frequency is low, and the loss is much lower than the traditional solution using high-frequency voltage regulation control;

[0127] 2. The switching frequency used by the high-voltage three-phase full-bridge to achieve 270V output voltage regulation is the same as the output frequency of the starter generator. This lower frequency results in much lower high-frequency conducted and radiated interference than with traditional high-frequency voltage regulation control solutions. The high-frequency ripple spectrum is more likely to comply with GJB181B-2012 requirements and has better electromagnetic compatibility characteristics.

[0128] 3. The switching frequency used by the high-voltage three-phase full-bridge to achieve 270V output voltage regulation is the same as the output frequency of the starter generator. Therefore, the power tube can be a power tube that can withstand large current but has relatively large switching losses, so that the high-voltage three-phase full-bridge has good anti-overload capability;

[0129] 4. The high-voltage three-phase full-bridge adopts a buck-boost voltage stabilization control, which has a faster response speed than the excitation voltage stabilization control and has a good suppression effect on transient voltage drops or overvoltages caused by loading or load rejection;

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

[0131] Compared to a solution combining a high-voltage DC permanent magnet starter generator system and a DC bus converter, this 28V low-voltage DC is achieved through excitation stabilization, eliminating the need for a DC bus power converter for converting 270V high-voltage DC to 28V low-voltage DC. The 28V low-voltage DC is obtained through only one energy conversion stage, significantly reducing the weight and efficiency costs of achieving 28V low-voltage DC. The input voltage range of the 270V voltage regulator is significantly narrowed, and the same electrical frequency control as the starter generator is used, significantly reducing the weight and efficiency costs of 270V high-voltage DC stabilization. Overall power density and efficiency are significantly improved. This overcomes the drawbacks of power quality due to overload, short circuit, and high-frequency ripple spectrum, which make it difficult to meet aircraft power supply and power generation system standards. It also addresses the issue of inability to demagnetize after a fault, which would not meet aviation safety requirements.

Claims

1. High-voltage and low-voltage DC output three-stage starter generator system, characterized by: The three-stage starter generator and controller include a permanent magnet auxiliary exciter, a main exciter, a main motor, a rotary rectifier and a rotary transformer. The controller includes a low-voltage three-phase full-bridge, a high-voltage three-phase full-bridge, a voltage regulating circuit, an AC excitation power supply, a control circuit, a diode D L and D H , current sensor S F ; The rotary transformer outputs a speed position signal P which is connected to the control circuit, and the winding W of the permanent magnet auxiliary exciter is connected to the control circuit. PMG The A, B and C terminals of the controller are connected to the voltage regulating circuit, and the control circuit outputs the driving signal G C and G R connected to the voltage regulating circuit, the output terminal V Co The positive and negative poles are connected to the excitation winding W of the main exciter respectively. EE The F+ and F- terminals of the AC excitation power supply are connected to the low voltage power supply input terminal V iL and the high voltage power supply input terminal V iH They are respectively connected to the positive poles of the low-voltage three-phase full bridge and the high-voltage three-phase full bridge. The ground reference terminal GND of the AC excitation power supply is connected to the negative poles of the low-voltage three-phase full bridge and the high-voltage three-phase full bridge respectively, and the control circuit outputs the driving signal G D and G S Connected to the AC excitation power supply, the AC excitation power supply output terminal v Bo The * and ~ ends are connected to the excitation winding W of the main exciter respectively EE The F+ and F- terminals are connected. The current sensor S F Detect the current flowing into the main exciter excitation winding W EE The F+ terminal current outputs the excitation 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, and the positive and negative poles of the low-voltage three-phase full bridge are respectively connected to the positive and negative poles of the external low-voltage DC interface terminal. The control circuit outputs a driving signal G A Connected to a low voltage three-phase full bridge, the output low voltage DC voltage V dcL and low voltage three-phase AC current i L Connected to the control circuit, the low voltage starting power supply terminal V SL Through diode D L Anode, diode D L The cathode is connected to the positive pole of the low-voltage three-phase full bridge, and the high-voltage three-phase winding W of the main motor H The A, B and C terminals are connected to the high-voltage three-phase full bridge respectively, and the positive and negative poles of the high-voltage three-phase full bridge are connected to the positive and negative poles of the external high-voltage DC interface respectively. 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 AC current i H Connected to the control circuit, the high voltage starting power supply terminal V SH Through diode D H Anode, diode D H The cathode is connected to the positive pole of the high-voltage three-phase full bridge, and the control circuit outputs the drive signal G L and G H Generator control circuit breaker GCB L and GCB H Connect the rotor armature winding W of the main exciter EM Through the rotating rectifier and the main motor rotor excitation winding W ME connect.

2. The three-stage starter generator system with high-voltage and low-voltage DC outputs as claimed 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 Includes A, B and C phase windings W respectively LA 、W LB and W LC , the high voltage three-phase winding W H Includes A, B and C phase windings W respectively HA 、W HB and W HC ; For low voltage three-phase winding W L Any X-phase winding, X=A, B or C, is composed of the 1st, 2nd…pth pole winding W LX1 、W LX2 …W LXp Parallel connection, low voltage three-phase winding W L Any X-phase winding end and 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, X=A, B or C, is composed of the 1st, 2nd…pth pole winding W HX1 、W HX2 …W HXp The high voltage three-phase winding W is connected in series. H Any X-phase winding end and 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 1, 2…p pole winding W LX1 、W LX2 …W LXp Respectively with the high voltage three-phase winding W H Any X-phase winding 1, 2…p pole winding W HX1 、W HX2 …W HXp The structure within the stator slots remains the same.

3. The three-stage starter generator system with high-voltage and low-voltage DC outputs as claimed in claim 2, characterized in that: The low voltage three-phase full bridge includes MOS tube Q A1 -Q A6 , capacitor C A , voltage sensor A, current sensor S Aa 、S Ab and S Ac , driving signal G A Including 6-way drive signal G A1 -G A6 ; The capacitor C A The two ends of the low voltage three-phase full bridge are connected to the positive and negative poles respectively, and the positive pole of the low voltage three-phase full bridge is connected to the positive pole of the low voltage three-phase full bridge through Q A1 The drain, Q A1 Source, Q A2 The drain, Q A2 The source of the low voltage three-phase full bridge is connected to the negative pole of the low voltage three-phase full bridge, and the positive pole of the low voltage three-phase full bridge is connected to the negative pole of the low voltage three-phase full bridge through Q A3 The drain, Q A3 Source, Q A4 The drain, Q A4 The source of the low voltage three-phase full bridge is connected to the negative pole of the low voltage three-phase full bridge, and the positive pole of the low voltage three-phase full bridge is connected to the negative pole of the low voltage three-phase full bridge through Q A5 The drain, Q A5 Source, Q A6 The drain, Q A6 The source is connected to the negative electrode of the low voltage three-phase full bridge, and the MOS tube Q A1 -Q A6 The gates are respectively connected to the driving signal G A1 -G A6 Connect, Q A1 source and Q A2 The connection point of the drain is used as the A terminal of the low voltage three-phase full bridge, Q A3 source and Q A4 The drain connection point is used as the B terminal of the low voltage three-phase full bridge, Q A5 source and Q A6 The drain connection point serves as A C terminal, current sensor S Aa 、S Ab and S Ac After detecting the current flowing out of the A, B and C terminals of the low-voltage three-phase full bridge, the AC current i is output. Aa 、i Ab and i Ac , by the AC current i Aa 、i Ab and i Ac Constitutes low voltage three-phase AC current i L The positive and negative input electrodes of the voltage sensor A are connected to the positive and negative electrodes of the low-voltage three-phase full-bridge respectively, and the voltage sensor A outputs a low-voltage DC voltage V dcL .

4. The high-voltage and low-voltage DC output three-stage starter-generator system according to claim 3, characterized in that: The high voltage three-phase full bridge includes IGBT tube Q B1 -Q B6 , Q B1A -Q B6A , capacitor C B , voltage sensor B, current sensor S Ba 、S Bb and S Bc , driving signal G B Including 6-way drive signal G B1 -G B6 and 6-way drive signal G B1A -G B6A ; The capacitor C B The two ends of the high voltage three-phase full bridge are connected to the positive and negative poles respectively. The positive pole of the high voltage three-phase full bridge is connected to the positive pole of the high voltage three-phase full bridge through Q B1A The emitter, Q B1A The collector, Q B1 The collector, Q B1 The emitter, Q B2 The collector, Q B2 The emitter, Q B2A The emitter, Q B2A The collector is connected to the negative electrode of the high voltage three-phase full bridge, and the positive electrode of the high voltage three-phase full bridge is connected to the negative electrode of the high voltage three-phase full bridge through Q B3A The emitter, Q B3A The collector, Q B3 The collector, Q B3 The emitter, Q B4 The collector, Q B4 The emitter, Q B4A The emitter, Q B4A The collector is connected to the negative electrode of the high voltage three-phase full bridge, and the positive electrode of the high voltage three-phase full bridge is connected to the negative electrode of the high voltage three-phase full bridge through Q B5A The emitter, Q B5A The collector, Q B5 The collector, Q B5 The emitter, Q B6 The collector, Q B6 The emitter, Q B6A The emitter, Q B6A The collector is connected to the negative electrode of the high voltage three-phase full bridge, the IGBT tube Q B1 -Q B6 The gates are respectively connected to the driving signal G B1 -G B6 Connect, Q B1A -Q B6A The gates are respectively connected to the driving signal G B1A -G B6A Connect, Q B1 The emitter and Q B2 The connection point of the collector is used as the A terminal of the high voltage three-phase full bridge, Q B3 The emitter and Q B4 The connection point of the collector is used as the B terminal of the high voltage three-phase full bridge, Q B5 The emitter and Q B6 The connection point of the collector is used 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 AC current i is output. Ba 、i Bb and i Bc , by the AC current i Ba 、i Bb and i Bc Constitutes high voltage three-phase alternating current i H The positive and negative input electrodes of voltage sensor B are connected to the positive and negative electrodes of the high-voltage three-phase full bridge respectively, and voltage sensor B outputs a high-voltage DC voltage V dcH .

5. The design method of the high-voltage and low-voltage DC output three-stage starter generator system according to claim 4, characterized in that: The following steps are involved: Step 1: Calculate the position signal θ according to the speed position signal P output by the rotary transformer, make the position signal θ=0°, and compare it with the three-phase armature winding W of the main motor. H It corresponds to the zero crossing point of the voltage drop section of phase A under no-load; Step 2: When the low voltage DC power supply starts, the low voltage starting power supply terminal V SL Provide the electric energy required for starting, and supply the main exciter excitation winding W through the AC excitation power supply EE Provide AC excitation current i F , the low voltage three-phase full bridge regulates the current flowing through the three-phase armature winding W of the main motor L The three-phase AC current i L , so that the three-stage starter generator outputs torque to start the engine; Step 3: When the high voltage DC power supply starts, the high voltage starting power supply terminal V SH Provide the electric energy required for starting, and supply the main exciter excitation winding W through the AC excitation power supply EE Provide AC excitation current i F , the high voltage three-phase full bridge regulates the current flowing through the three-phase armature winding W of the main motor H The three-phase AC current i H , so that the three-stage starter generator outputs torque to start the engine; Step 4: When generating electricity, adjust the current flowing through the main exciter excitation winding W through the regulating circuit. EE The excitation current i F , so that the low voltage DC voltage V output by the low voltage three-phase full bridge dcL Stable at the desired voltage value; Step 5: When generating electricity, the low-voltage three-phase full-bridge adopts synchronous rectification control to reduce the MOS tube Q A1 -Q A6 The conduction voltage drop; Step 6: During power generation, the high voltage DC voltage V output by the high voltage three-phase full bridge is controlled by boost control and buck control. dcH Stable at the desired voltage value; Step 7: When generating electricity, if the high voltage DC voltage regulation is abnormal, the drive signal G B1 -G B6 and G B1A -G B6A Disconnect the high-voltage three-phase full-bridge medium power tube Q B1 -Q B6 and Q B1A -Q B6A , through the driving signal G H To disconnect the generator control circuit breaker GCB H , realizing high voltage DC voltage stabilization fault isolation; Step 8: When generating electricity, if the low voltage DC voltage regulation is abnormal, the drive signal G L , G H and G R To disconnect the generator control circuit breaker GCB L , Generation Control Circuit Breaker GCB H And the power generation control relay GCR in the voltage regulation circuit to achieve fault protection.

6. The design method of the high-voltage and low-voltage DC output three-stage starter generator system according to claim 5, characterized in that: The synchronous rectification control in step 5 includes the following steps: Step 51: Define the AC current i Aa 、i Ab and i Ac The direction of outflow of low voltage three-phase full bridge is positive direction, let I refH and I refL +1 / 5 and -1 / 5 of the rated current respectively; Step 52: When i Aa >I refH When G A2 =1, otherwise G A2 =0; Step 53: When i Ab >I refH When G A4 =1, otherwise G A4 =0; Step 54: When i Ac >I refH When G A6 =1, otherwise G A6 =0; Step 55: When i Aa refL When G A1 =1, otherwise G A1 =0;​ Step 56: When i Ab refL When G A3 =1, otherwise G A3 =0;​ Step 57: When i Ac refL When G A5 =1, otherwise G A5 =0.​ 7. The design method of the high-voltage and low-voltage DC output three-stage starter generator system according to claim 5, characterized in that: The boost control in step 6 includes the following steps: Step 611: According to the high voltage DC voltage V dcH and position signal θ, determine the driving 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 driving signal G B2 The high level pulse width is δ1, when the high voltage DC voltage V dcH When the voltage is less than the expected value, the DC voltage is stabilized at the expected output voltage by increasing the width of δ1. The adjustment range of δ1 is 0-90°. B1 -G B6 With the same positive pulse width, press G B2 , G B5 , G B4 , G B1 , G B6 , G B3 The driving signal G is formed by lagging 60 degrees in sequence. B1 -G B6 ; Step 612: Determine the signal G according to the position signal θ. B1i -G B6i , when θ=210°-360° and 0°-30°, 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 lagging 60° in sequence B1i -G B6i ; Step 613: According to the driving signal G B1 -G B6 , signal G B1i -G B6i , determine the driving 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: The driving signal G B1 -G B6 Sent to IGBT tube Q respectively B1 -Q B6 , driving signal G B1A -G B6A Sent to IGBT tube Q respectively B1A -Q B6A .

8. The high-voltage and low-voltage DC output three-stage starter generator system and design method as claimed in claim 5, characterized in that: The voltage reduction control described in step 6 includes the following steps: Step 621: Set the driving signal G B1 -G B6 All are 0, the drive signal G B1 -G B6 Sent to power tube Q respectively B1 -Q B6 , so that the IGBT tube Q B1 -Q B6 All are turned off; Step 622: Determine the signal G according to the position signal θ. B1i -G B6i , when θ=210°-360° and 0°-30°, 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 lagging 60° in sequence B1i -G B6i ; Step 623: Set the driving signal G B1A -G B6A Lag signal G B1i -G B6i The angle is δ2, when the high voltage DC voltage V dcH When it is greater than the expected voltage value, the DC voltage is stabilized at the expected voltage value by increasing the width of δ2; Step 624: The driving signal G B1A -G B6A Sent to IGBT tube Q respectively B1A -Q B6A .

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