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

Abstract

The invention discloses a high-voltage and low-voltage direct-current dual-output three-stage generator system and a design method. The system comprises a three-stage generator and a controller. The three-stage generator is composed of a permanent magnet auxiliary exciter, a main exciter, a main motor, a rotary transformer and a rotary rectifier. The controller comprises a voltage regulating circuit, a thyristor rectifier bridge, a diode rectifier bridge, a control circuit, a power generation control relay and a current sensor. The main motor is provided with a low-voltage three-phase winding and a high-voltage three-phase winding which respectively meet the requirements of low-voltage direct current and high-voltage direct current. According to the invention, the exciting current of the exciting winding of the main exciter is regulated through the voltage regulating circuit, so that the low-voltage direct-current voltage is stabilized at an expected voltage value; by means of phase-controlled rectification control, the output high-voltage direct-current voltage is stabilized at an expected voltage value, meanwhile, the switching frequency which is the same as the output electric frequency of the generator is adopted for power generation and voltage stabilization of the thyristor rectifier bridge, and the thyristor rectifier bridge has the advantages of being low in loss, low in high-frequency ripple frequency spectrum component, weak in high-frequency conduction and radiation interference, high in power density and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of generator design, and specifically relates to a three-stage generator system with high-voltage and low-voltage DC dual outputs and a design method. The system is particularly suitable for the field of aviation hybrid power systems consisting of 270V high-voltage DC and 28V low-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] The existing aviation hybrid power system composed of 28V low-voltage DC and 270V high-voltage DC is generally implemented in the following way.

[0004] 1. A combination of a high-voltage DC three-stage generator system and a DC bus converter. This solution is primarily used in fighter jets. The engine is directly mechanically connected to the high-voltage DC three-stage generator system, providing mechanical speed input to the system. The system 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.

[0005] 2. A combination of a low-voltage brushed DC 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 brushed DC generator system and a high-voltage DC three-stage generator system. The engine provides mechanical speed input to the brushed DC generator system and the high-voltage DC three-stage generator system, which convert the input mechanical energy into 28V low-voltage DC and 270V high-voltage DC power, respectively. With the advancement of power electronics technology, the use of a low-voltage DC three-stage generator system to replace a brushed DC generator system has matured, with a limited number of applications already in place. Because electronic commutation replaces mechanical commutation, the low-voltage DC three-stage generator system is suitable for high-altitude, long-range flight, maintenance-free export, and coastal salt spray resistance. Furthermore, its power density rivals that of a brushed DC generator system.

[0006] 3. A combination of a high-voltage DC permanent magnet generator system and a DC bus converter. This solution is primarily used in low-cost UAVs. The engine is directly mechanically connected to the HVDC permanent magnet generator system, providing mechanical speed input to the HVDC permanent magnet generator system. The HVDC permanent magnet generator system converts this input mechanical energy into 270V AC power. The DC bus converter then converts the 270V DC power to 28V DC power. Because the permanent magnet generator structure is simpler than a three-stage generator, its cost is significantly reduced.

[0007] 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 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 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 HVDC three-stage generator system, the power density and efficiency of the HVDC permanent magnet generator system are not superior. The power quality of the HVDC permanent magnet generator system, such as overload, short circuit, and high-frequency ripple spectrum, is difficult to meet the requirements of aircraft power supply and power generation system standards. After a fault, demagnetization is not possible, 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

[0008] The purpose of the present invention is to address the deficiencies of the above-mentioned technologies and provide a three-stage generator system with high-voltage and low-voltage DC dual outputs.

[0009] 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 generator system with high-voltage and low-voltage DC dual outputs. The present invention is achieved through the following technical solutions.

[0010] The present invention provides a three-stage generator system with high-voltage and low-voltage DC dual output, comprising a three-stage generator and a controller. The three-stage generator comprises a permanent magnet auxiliary exciter, a main exciter, a main motor, a rotary transformer and a rotary rectifier. The controller comprises a voltage regulating circuit, a thyristor rectifier bridge, a diode rectifier bridge, a control circuit, a power generation control relay GCR and a current sensor S. F ;

[0011] The rotating 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 control circuit are connected to the A, B and C terminals of the voltage regulating circuit respectively, and the control circuit outputs the driving signal G C Connected to the voltage regulating circuit, the output terminal V Co The positive pole of the excitation winding W of the main exciter is connected to the excitation winding W of the main exciter through the power generation control relay GCR. EE The F+ terminal is connected to the output terminal of the voltage regulator circuit V Co The negative pole of the main exciter is connected to the excitation winding W EEThe F-terminal of the power generation control relay GCR is connected to the control circuit output drive signal G R Connection, 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 A, B and C terminals of the thyristor rectifier bridge input are connected to the high voltage three-phase winding W of the main motor respectively. H The positive and negative poles of the thyristor rectifier bridge output are respectively connected to the positive and negative poles of the external high-voltage DC output interface, and the thyristor rectifier bridge outputs a high-voltage DC voltage V dcH Connected to the control circuit, the control circuit outputs a drive signal G A Connected to the thyristor rectifier bridge, the A, B and C terminals of the diode rectifier bridge input are connected to the low voltage three-phase winding W of the main motor respectively. L The positive and negative poles of the diode rectifier bridge output are connected to the positive and negative poles of the external low-voltage DC output interface respectively. The diode rectifier bridge outputs a low-voltage DC voltage V dcL Connected to the control circuit, the control circuit outputs the driving 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 connect.

[0012] 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 , 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 ;

[0013] The 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 LThe other end of any X-phase winding is connected to the low-voltage three-phase winding W L The X-end connection,

[0014] 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 connection,

[0015] 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.

[0016] Furthermore, the thyristor rectifier bridge includes thyristor D A1 ~D A6 , voltage sensor A;

[0017] The positive electrode of the thyristor rectifier bridge output is respectively connected to D A1 、D A3 and D A5 The cathode of the output is connected to D A2 、D A4 and D A6 The anode of the thyristor rectifier bridge is connected to the A end of the AC input of D A1 Anode and D A2 The cathode of the AC input is connected to the B terminal of D A3 Anode and D A4 The cathode of the AC input is connected to the C terminal and the D A5 Anode and D A6 Cathode connection; drive signal G A Respectively with thyristor D A1 ~D A6 The positive and negative input terminals of the voltage sensor A are connected to the positive and negative output terminals of the thyristor rectifier bridge, respectively. The voltage sensor A outputs a high-voltage DC voltage V dcH to the control circuit.

[0018] Furthermore, the diode rectifier bridge includes a diode D B1 ~D B6 , voltage sensor B;

[0019] The positive electrode of the diode rectifier bridge output is respectively connected to D B1 、D B3 and D B5 The cathode of the output is connected to D B2 、D B4 and D B6 The anode of the diode bridge rectifier is connected to the A terminal of the AC input and the D B1 Anode and D B2 The cathode of the AC input is connected to the B terminal of D B3 Anode and D B4 The cathode of the AC input is connected to the C terminal and the D B5 Anode and D B6 The positive and negative input electrodes of the voltage sensor B are connected to the positive and negative output electrodes of the diode rectifier bridge, respectively, and the voltage sensor B outputs a low voltage DC voltage V dcL to the control circuit.

[0020] Furthermore, the control circuit includes a resolver decoding circuit, a field programmable gate array FPGA, and a digital signal processor DSP;

[0021] The speed position signal P is connected to the resolver decoding circuit, and the position lock signal SAM output by the field programmable gate array FPGA is connected to the resolver decoding circuit. The resolver decoding circuit outputs the speed n and the original position φ raw Signal to DSP, external input low voltage DC voltage V dcL , excitation current I F and high voltage DC voltage V dcH Connected to DSP, DSP output drive signal G C , G H , G L and G R , DSP outputs the original position φ raw , angle encryption parameter f scl The phase shift angle θ signal is connected to the field programmable gate array FPGA, and the field programmable gate array FPGA outputs the driving signal G A .

[0022] The design method of a three-stage generator system with high-voltage and low-voltage DC dual outputs includes the following steps:

[0023] Step 1: According to the speed position signal P output by the resolver, the angle signal φ is obtained through the phase-locked loop angle encryption calculation;

[0024] Step 2: Make the angle signal φ=0° and connect it to 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;

[0025] Step 3: Use the voltage regulating circuit to adjust the current flowing through the main exciter excitation winding W EE The excitation current I F , so that the low voltage DC voltage V dcL Stable at the desired voltage value;

[0026] Step 4: Through phase-controlled rectification control, the high-voltage DC voltage V output by the thyristor rectifier bridge is dcH Stable at the desired voltage value;

[0027] Step 5: When generating electricity, if the high voltage DC voltage regulation is abnormal, the drive signal G A Disconnect thyristor D in the thyristor rectifier bridge A1 ~D A6 , through the driving signal G H To disconnect the generator control circuit breaker SCB H , realizing high voltage DC voltage stabilization fault isolation;

[0028] Step 6: When generating electricity, if the low voltage DC voltage regulation is abnormal, the drive signal G L , G H and G C To disconnect the generator control circuit breaker SCB L , Generation Control Circuit Breaker SCB H And the power generation control relay GCR to achieve fault protection.

[0029] Furthermore, the phase-locked loop angle encryption calculation in step 1 includes the following steps:

[0030] Step 11: According to the speed n and the number of pole pairs p of the main motor, press f e =np / 60 to calculate the main motor electrical frequency f e ;

[0031] Step 12: Execute clock frequency f according to FPGA clk and the main motor frequency f e , press f scl =f e / f clk ×2 n+1 ×2 m Calculate the angle encryption parameter f scl , n+1 represents the quantization bit of the main motor electrical angle, that is, through 0 to 2n+1 represents the angle signal φ from 0° to 360°, and m represents the number of bits of the accumulator in the FPGA;

[0032] Step 13: Convert the original position signal φ raw The error signal e is obtained by subtracting the angle signal φ rr ;

[0033] Step 14: Encrypt the angle parameter f scl With the error signal e rr Add up to get the estimated frequency f;

[0034] Step 15: Execute the FPGA clock frequency f clk , the input estimated frequency f is accumulated through the m-bit accumulator;

[0035] Step 16: Shift the data in the m-bit accumulator right by m bits to generate an angle signal φ.

[0036] The beneficial effects of the present invention are:

[0037] 1. The three-stage generator system and design method with high-voltage and low-voltage DC dual outputs proposed in this invention are applicable to the field of aviation hybrid power systems consisting of 270V high-voltage DC and 28V low-voltage DC.

[0038] 2. Compared with the combination of a high-voltage DC three-stage generator system and a DC bus converter, the 28V low-voltage DC is obtained through only one stage of energy conversion, which is more efficient. The DC bus power converter for converting 270V high-voltage DC to 28V low-voltage DC is eliminated, and the weight cost of obtaining 28V low-voltage DC is lower.

[0039] 3. Compared with the combination of a low-voltage DC brushed generator system and a high-voltage DC three-stage generator system, and the combination of a low-voltage DC three-stage 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 generator. The mechanical interface with the engine is reduced from two to one, and the 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 ineffective parts of the generator is significantly reduced.

[0040] 4. Compared to solutions combining a high-voltage DC permanent magnet generator system with a DC bus converter, this system achieves 28V low-voltage DC through excitation regulation, 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 voltage regulator is significantly narrowed, and the same frequency control as the generator is adopted, significantly reducing the weight and efficiency costs of 270V high-voltage DC regulation. 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 for the system 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.

[0041] 5. The main motor uses 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.

[0042] 6. The switching frequency used by the thyristor rectifier bridge to achieve 270V output voltage regulation is the same as the generator output frequency. The frequency is low and the loss is much lower than the traditional solution using high-frequency voltage regulation control.

[0043] 7. The switching frequency used by the thyristor rectifier bridge to achieve 270V output voltage regulation is the same as the generator output frequency. 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.

[0044] 8. The switching frequency used by the thyristor rectifier bridge to achieve 270V output voltage regulation is the same as the generator output frequency. Therefore, the power tube can use a power tube that can withstand large current but has relatively large switching losses, so that the thyristor rectifier bridge has good overload resistance.

[0045] 9. The thyristor rectifier bridge is a step-down voltage stabilization control with a faster response speed than the excitation voltage stabilization control, and has a good suppression effect on transient overvoltage caused by load rejection.

[0046] 10. The thyristor rectifier bridge uses the generator winding inductance to achieve voltage regulation control, eliminating the heavy magnetic components and having a higher power density than conventional power converters.

[0047] 11. The position lock signal SAM output by FPGA is used to control the resolver decoding circuit to ensure the original position φ raw High-precision correspondence with the main motor electrical angle.

[0048] 12. Through the proposed phase-locked loop angle encryption calculation method, an angle signal φ with a step size of less than 1° is obtained, ensuring the accuracy of phase-controlled rectification control. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 This is a structural block diagram of a three-stage generator system with high-voltage and low-voltage DC dual outputs according to the present invention;

[0050] Figure 2 This is the winding diagram of the dual armature windings of the main motor of the present invention;

[0051] Figure 3 This is a thyristor rectifier bridge circuit diagram of the present invention;

[0052] Figure 4 This is a diode rectifier bridge circuit diagram of the present invention;

[0053] Figure 5 is a circuit diagram of a voltage regulating circuit of the present invention;

[0054] Figure 6 is a structural block diagram of the control circuit of the present invention;

[0055] Figure 7 This is a schematic diagram of the voltage stabilization control principle of the thyristor rectifier bridge of the present invention;

[0056] Figure 8 Schematic diagram of the angle encryption function of the control circuit of the present invention. DETAILED DESCRIPTION

[0057] The technical solution of the present invention is further described below, but the scope of protection claimed is not limited to the description.

[0058] The following is a further detailed description with reference to the accompanying drawings and embodiments. Figure 1 The figure shows the structural block diagram of a three-stage generator system with high-voltage and low-voltage DC dual outputs, which is suitable for a hybrid power supply consisting of 270V high-voltage DC and 28V low-voltage DC.

[0059] A three-stage generator system with high-voltage and low-voltage DC dual outputs, including a three-stage generator and a controller. The three-stage generator includes a permanent magnet auxiliary exciter, a main exciter, a main motor, a rotary transformer and a rotary rectifier. The controller includes a voltage regulating circuit, a thyristor rectifier bridge, a diode rectifier bridge, a control circuit, a power generation control relay GCR and a 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 control circuit are connected to the A, B and C terminals of the voltage regulating circuit respectively, and the control circuit outputs the driving signal G C Connected to the voltage regulating circuit, the output terminal V CoThe positive pole of the generator is connected to the main exciter excitation winding W through the generator control relay GCR. EE The F+ terminal is connected to the output terminal of the voltage regulator circuit V Co The negative pole of the main exciter is connected to the excitation winding W EE The F-terminal of the power generation control relay GCR is connected to the control circuit output drive signal G R Connection, 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 A, B and C terminals of the thyristor rectifier bridge input are connected to the high voltage three-phase winding W of the main motor respectively. H The positive and negative poles of the thyristor rectifier bridge output are connected to the positive and negative poles of the external high-voltage DC output interface respectively. The thyristor rectifier bridge outputs a high-voltage DC voltage V dcH Connected to the control circuit, the control circuit outputs the driving signal G A Connected to the thyristor rectifier bridge, the A, B and C terminals of the diode rectifier bridge input are connected to the low voltage three-phase winding W of the main motor respectively. L The positive and negative poles of the diode rectifier bridge output are connected to the positive and negative poles of the external low-voltage DC output interface respectively. The diode rectifier bridge outputs a low-voltage DC voltage V dcL Connected to the control circuit, the control circuit outputs the driving 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.

[0060] Compared with the combination of a high-voltage DC three-stage 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.

[0061] Since the proposed three-stage generator with high-voltage and low-voltage DC dual outputs does not use mechanical commutation, compared with the combination of a low-voltage DC brushed 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.

[0062] Compared with the combination of a low-voltage DC brushed generator system and a high-voltage DC three-stage generator system, and the combination of a low-voltage DC three-stage 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 generator, the mechanical interface with the engine is reduced from two to one, the 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 generator are significantly reduced.

[0063] 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 …WHXp The structure within the stator slots remains the same.

[0064] 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 W H 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 =3.

[0065] Under no-load condition, when the low voltage three-phase winding W L Naturally rectified voltage V dcL When the voltage is 28V, the winding turns ratio N W Designed to ensure high voltage three-phase winding W under 2 times overload function output H Naturally rectified voltage V dcH Higher than 270V.

[0066] 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.

[0067] Figure 3 The thyristor rectifier bridge circuit diagram is shown. The thyristor rectifier bridge includes thyristor D A1 ~D A6 , voltage sensor A, is composed of the positive output and D A1 、D A3 and D A5 The cathode of the output is connected to D A2 、D A4 and D A6 The anode of the AC input is connected to the A terminal of D A1 Anode and D A2 The cathode of the AC input is connected to the B terminal of D A3 Anode and D A4 The cathode of the AC input is connected to the C terminal and the D A5 Anode and D A6 Cathode connection, 6-way drive signal G A Respectively with thyristor DA1 ~D A6 The positive and negative input terminals of the voltage sensor A are connected to the positive and negative output terminals respectively. The voltage sensor A outputs a high-voltage DC voltage V dcH constitute.

[0068] Figure 4 The diode rectifier bridge circuit diagram is shown, and the diode rectifier bridge includes a diode D B1 ~D B6 , voltage sensor B, is composed of the positive output and D B1 、D B3 and D B5 The cathode of the output is connected to D B2 、D B4 and D B6 The anode of the AC input is connected to the A terminal of D B1 Anode and D B2 The cathode of the AC input is connected to the B terminal of D B3 Anode and D B4 The cathode of the AC input is connected to the C terminal and the D B5 Anode and D B6 The cathode of the voltage sensor B is connected, the positive and negative input of the voltage sensor B are connected to the positive and negative output respectively, and the voltage sensor B outputs a low voltage DC voltage V dcL constitute.

[0069] Figure 5 The circuit diagram of the voltage regulator circuit is shown, which consists of 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 .

[0070] Figure 6 The figure shows the structural block diagram of the control circuit, which includes a resolver decoding circuit, a field programmable gate array FPGA, and a digital signal processor DSP. The speed position signal P is connected to the resolver decoding circuit, the FPGA outputs a position lock signal SAM connected to the resolver decoding circuit, and the resolver decoding circuit outputs the speed n and the original position φ raw Connected to DSP, external input low voltage DC voltage V dcL , excitation current I F and high voltage DC voltage V dcHConnected to DSP, DSP outputs driving signal G C , G H , G L and G R , DSP outputs the original position φ raw , angle encryption parameter f scl and the phase shift angle θ are connected to the FPGA, and the FPGA outputs the driving signal G A constitute.

[0071] The resolver decoding circuit is implemented using the integrated circuit AD2S1210CSTZ. The position lock signal SAM is connected to its 10th pin. FPGA can realize precise timing control, and the resolver decoding circuit is controlled by the position lock signal SAM output by FPGA, so that the original position φ raw Maintain high synchronization with the FPGA clock system, thereby ensuring the original position φ raw High-precision correspondence with the electrical angle of the main motor.

[0072] DSP is mainly used to realize the voltage regulation control of low voltage DC output, the phase shift angle θ calculation of high voltage DC output voltage regulation and the angle encryption parameter f scl FPGA is mainly used to complete the angle encryption function and phase-controlled rectification control function.

[0073] The design method of the three-stage generator system with high-voltage and low-voltage DC dual outputs comprises the following steps:

[0074] Step 1: According to the speed position signal P output by the resolver, the angle signal φ is obtained through the phase-locked loop angle encryption calculation;

[0075] Step 2: Make the angle signal φ=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;

[0076] Step 3: Use the voltage regulating circuit to adjust the current flowing through the main exciter excitation winding W EE The excitation current I F , so that the low voltage DC voltage V dcL Stable at the desired voltage value;

[0077] Step 4: Through phase-controlled rectification control, the high-voltage DC voltage V output by the thyristor rectifier bridge is dcH Stable at the desired voltage value;

[0078] Step 5: When generating electricity, if the high voltage DC voltage regulation is abnormal, the drive signal G A Disconnect thyristor D in the thyristor rectifier bridge A1 ~D A6 , through the driving signal GH To disconnect the generator control circuit breaker SCB H , realizing high voltage DC voltage stabilization fault isolation;

[0079] Step 6: When generating electricity, if the low voltage DC voltage regulation is abnormal, the drive signal G L , G H and G C To disconnect the generator control circuit breaker SCB L , Generation Control Circuit Breaker SCB H And the power generation control relay GCR to achieve fault protection.

[0080] Combine Figure 7 The angle signal φ 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 2. 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 2, the angle signal φ = 0°, which is consistent with the no-load v H_A The correspondence of the zero crossing point of the descending section can be ensured by adjusting the relative position of the rotary transformer rotor and the main motor rotor.

[0081] Since the low voltage DC voltage is stabilized by adjusting the excitation current in step 3, the three-phase armature winding W of the main motor is H The voltage after natural rectification is usually not the desired 270V, and the auxiliary means of step 4 is required to achieve 270V high-voltage DC voltage regulation.

[0082] Combine Figure 6 Further explanation of the low voltage DC voltage control described in step 3. In DSP, according to the voltage reference value V refL and low voltage DC voltage V dcL , calculate the voltage loop A 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.

[0083] Combine Figure 7 The thyristor rectifier bridge voltage regulation control principle diagram is shown to explain the phase-controlled rectifier control. High voltage DC voltage V dcH The relationship with the phase shift angle θ is shown in formula (1). The larger the phase shift angle θ, the lower the output voltage.

[0084] V dcH=2.34Ucosθ (1)

[0085] Where U is the three-phase armature winding W H Output phase voltage effective value.

[0086] Combine Figure 6 The reason for the phase shift angle θ is explained. In DSP, according to the voltage reference value V refH and high voltage DC voltage V dcH , calculate the voltage loop B and generate the phase shift angle θ. dcH Greater or less than the voltage reference value V refH When , the output voltage regulation is achieved by increasing or decreasing the phase shift angle θ.

[0087] The thyristor rectifier bridge hardware and control method design has the following advantages:

[0088] 1. The switching frequency used by the thyristor rectifier bridge to achieve 270V output voltage regulation is the same as the generator output frequency. The frequency is low and the loss is much lower than the traditional high-frequency voltage regulation control solution;

[0089] 2. The switching frequency used by the thyristor rectifier bridge to achieve 270V output voltage regulation is the same as the generator output frequency. 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.

[0090] 3. The switching frequency used by the thyristor rectifier bridge to achieve 270V output voltage regulation is the same as the generator output frequency. Therefore, the power tube can be a power tube that can withstand large current but has relatively large switching losses, so that the thyristor rectifier bridge has good overload resistance;

[0091] 4. The thyristor rectifier bridge is a step-down voltage stabilization control with a faster response speed than the excitation voltage stabilization control, and has a good suppression effect on transient overvoltage caused by load rejection;

[0092] 5. The thyristor rectifier bridge uses the generator winding inductance to achieve voltage regulation control, eliminating the heavy magnetic components and having a higher power density than conventional power converters.

[0093] Combine Figure 8 , the function of phase-locked loop angle encryption is explained. Since the original position signal φ collected by DSP raw Is a discrete data, the position signal φ at high frequency raw There is a significant step difference, which will affect the phase-controlled rectifier control drive signal G A Therefore, the phase-locked loop angle encryption calculation is added to realize the continuity of the angle signal, and the original position signal φraw An angle signal φ with a step size of less than 1° is obtained.

[0094] Combine Figure 6 , the principle of phase-locked loop angle encryption calculation is explained. The phase-locked loop angle encryption calculation described in step 1 includes the following steps:

[0095] Step 11: According to the speed n and the number of pole pairs p of the main motor, press f e =np / 60 to calculate the main motor electrical frequency f e ;

[0096] Step 12: Execute clock frequency f according to FPGA clk and the main motor frequency f e , press f scl =f e / f clk ×2 n+1 ×2 m Calculate the angle encryption parameter f scl , n+1 represents the quantization bit of the main motor electrical angle, that is, through 0 to 2 n+1 represents the angle signal φ from 0° to 360°, and m represents the number of bits of the accumulator in the FPGA;

[0097] Step 13: Convert the original position signal φ raw The error signal e is obtained by subtracting the angle signal φ rr ;

[0098] Step 14: Encrypt the angle parameter f scl With the error signal e rr Add up to get the estimated frequency f;

[0099] Step 15: Execute the FPGA clock frequency f clk , the input estimated frequency f is accumulated through the m-bit accumulator;

[0100] Step 16: Shift the data in the m-bit accumulator right by m bits to generate an angle signal φ.

[0101] Steps 11 and 12 are calculated in the DSP. Steps 13 to 16 are calculated in the FPGA and are the implementation steps of the digital phase-locked loop.

[0102] For step 12, the step angle △φ corresponding to one FPGA execution cycle is shown in formula (2); the angle encryption parameter f scl The step angle △φ corresponding to the signal is shown in formula (3). Combining formula (2) and formula (3), we can get f scl The calculation expression of is shown in formula (4).

[0103] △φ=f e / fclk ×2 n+1 (2)

[0104] △φ=f scl / 2 m (3)

[0105] f scl =f e / f clk ×2 n+1 ×2 m (4)

[0106] In step 15, let the data of the previous clock cycle and the current clock cycle in the accumulator be N(x-1) and N(x), then at each clock frequency f clk When it arrives, let N(x) = N(x-1) + f to realize the accumulation operation. The accumulator is equivalent to an integrator, which converts the estimated frequency f into an angle signal φ and also plays a role in smoothing φ. raw The function of stepping stairs.

[0107] From formula (2), we can see that as long as the FPGA execution clock frequency f clk If f is high enough, the step angle Δφ will be small enough. clk =40MHz, n=9, at the main motor electrical frequency f e =2.5kHz, the step angle △φ=0.0225°. The lowest quantization bit of the angle signal φ is 1 / 2 n+1 In this embodiment, the lowest quantization bit corresponds to 0.35°. The accuracy of the angle signal φ depends on the step angle △φ and the lowest quantization bit 1 / 2 n+1 Therefore, the accuracy of the angle signal φ in this embodiment is 0.35°. Therefore, the proposed phase-locked loop angle encryption calculation method can easily obtain an angle signal φ with a step size of less than 1°, ensuring the accuracy of phase-controlled rectification control.

[0108] The above analysis shows that, compared to the combined HVDC permanent magnet generator system and DC bus converter solution, the 28V low-voltage DC is achieved through excitation stabilization, eliminating the need for a DC bus power converter for the 270V to 28V low-voltage DC conversion. 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 regulated converter is significantly narrowed, and the same frequency control as the generator is adopted, 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 does not meet aviation safety requirements.

Claims

1. A three-stage generator system with high-voltage and low-voltage DC dual outputs, characterized by: The three-stage generator includes a permanent magnet auxiliary exciter, a main exciter, a main motor, a rotary transformer and a rotary rectifier. The controller includes a voltage regulating circuit, a thyristor rectifier bridge, a diode rectifier bridge, a control circuit, a power generation control relay GCR and a current sensor S. F ; The rotating 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 control circuit are connected to the A, B and C terminals of the voltage regulating circuit respectively, and the control circuit outputs the driving signal G C Connected to the voltage regulating circuit, the output terminal V Co The positive pole of the excitation winding W of the main exciter is connected to the excitation winding W of the main exciter through the power generation control relay GCR. EE The F+ terminal is connected to the output terminal of the voltage regulator circuit V Co The negative pole of the main exciter is connected to the excitation winding W EE The F-terminal of the power generation control relay GCR is connected to the control circuit output drive signal G R Connection, 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 A, B and C terminals of the thyristor rectifier bridge input are connected to the high voltage three-phase winding W of the main motor respectively. H The positive and negative poles of the thyristor rectifier bridge output are respectively connected to the positive and negative poles of the external high-voltage DC output interface, and the thyristor rectifier bridge outputs a high-voltage DC voltage V dcH Connected to the control circuit, the control circuit outputs a drive signal G A Connected to the thyristor rectifier bridge, the A, B and C terminals of the diode rectifier bridge input are connected to the low voltage three-phase winding W of the main motor respectively. L The positive and negative poles of the diode rectifier bridge output are connected to the positive and negative poles of the external low-voltage DC output interface respectively. The diode rectifier bridge outputs a low-voltage DC voltage V dcL Connected to the control circuit, the control circuit outputs the driving 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 connect.

2. The three-stage generator system with high-voltage and low-voltage DC dual outputs according to claim 1, wherein: 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 ; The 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 X-end connection, 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 X-end connection, 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.

3. The three-stage generator system with high-voltage and low-voltage DC dual outputs as claimed in claim 2, wherein: The thyristor rectifier bridge includes thyristor D A1 ~D A6 , voltage sensor A; The positive electrode of the thyristor rectifier bridge output is respectively connected to D A1 、D A3 and D A5 The cathode of the output is connected to D A2 、D A4 and D A6 The anode of the thyristor rectifier bridge is connected to the A end of the AC input of D A1 Anode and D A2 The cathode of the AC input is connected to the B terminal of D A3 Anode and D A4 The cathode of the AC input is connected to the C terminal and the D A5 Anode and D A6 Cathode connection; drive signal G A Respectively with thyristor D A1 ~D A6 The positive and negative input terminals of the voltage sensor A are connected to the positive and negative output terminals of the thyristor rectifier bridge, respectively. The voltage sensor A outputs a high-voltage DC voltage V dcH to the control circuit.

4. The three-stage generator system with high-voltage and low-voltage DC dual outputs as claimed in claim 3, characterized in that: The diode rectifier bridge includes a diode D B1 ~D B6 , voltage sensor B; The positive electrode of the diode rectifier bridge output is respectively connected to D B1 、D B3 and D B5 The cathode of the output is connected to D B2 、D B4 and D B6 The anode of the diode bridge rectifier is connected to the A terminal of the AC input and the D B1 Anode and D B2 The cathode of the AC input is connected to the B terminal of D B3 Anode and D B4 The cathode of the AC input is connected to the C terminal and the D B5 Anode and D B6 The positive and negative input electrodes of the voltage sensor B are connected to the positive and negative output electrodes of the diode rectifier bridge, respectively, and the voltage sensor B outputs a low voltage DC voltage V dcL to the control circuit.

5. The three-stage generator system with high-voltage and low-voltage DC dual outputs as claimed in claim 4, characterized in that: The control circuit includes a resolver decoding circuit, a field programmable gate array FPGA, and a digital signal processor DSP; The speed position signal P is connected to the resolver decoding circuit, and the position lock signal SAM output by the field programmable gate array FPGA is connected to the resolver decoding circuit. The resolver decoding circuit outputs the speed n and the original position φ raw Signal to DSP, external input low voltage DC voltage V dcL , excitation current I F and high voltage DC voltage V dcH Connected to DSP, DSP output drive signal G C , G H , G L and G R , DSP outputs the original position φ raw , angle encryption parameter f scl The phase shift angle θ signal is connected to the field programmable gate array FPGA, and the field programmable gate array FPGA outputs the driving signal G A .

6. The design method of a three-stage generator system with high-voltage and low-voltage DC dual outputs as claimed in claim 5, characterized in that: Step 1: According to the speed position signal P output by the resolver, the angle signal φ is obtained through the phase-locked loop angle encryption calculation; Step 2: Make the angle signal φ=0° and connect it to 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 3: Use the voltage regulating circuit to adjust the current flowing through the main exciter excitation winding W EE The excitation current I F , so that the low voltage DC voltage V dcL Stable at the desired voltage value; Step 4: Through phase-controlled rectification control, the high-voltage DC voltage V output by the thyristor rectifier bridge is dcH Stable at the desired voltage value; Step 5: When generating electricity, if the high voltage DC voltage regulation is abnormal, the drive signal G A Disconnect thyristor D in the thyristor rectifier bridge A1 ~D A6 , through the driving signal G H To disconnect the generator control circuit breaker SCB H , realizing high voltage DC voltage stabilization fault isolation; Step 6: When generating electricity, if the low voltage DC voltage regulation is abnormal, the drive signal G L , G H and G C To disconnect the generator control circuit breaker SCB L , Generation Control Circuit Breaker SCB H And the power generation control relay GCR to achieve fault protection.

7. The design method of a three-stage generator system with high-voltage and low-voltage DC dual outputs according to claim 6, wherein: The phase-locked loop angle encryption calculation in step 1 includes the following steps: Step 11: According to the speed n and the number of pole pairs p of the main motor, press f e =np / 60 to calculate the main motor electrical frequency f e ; Step 12: Execute clock frequency f according to FPGA clk and the main motor frequency f e , press f scl =f e / f clk ×2 n+1 ×2 m Calculate the angle encryption parameter f scl , n+1 represents the quantization bit of the main motor electrical angle, that is, through 0 to 2 n+1 represents the angle signal φ from 0° to 360°, and m represents the number of bits of the accumulator in the FPGA; Step 13: Convert the original position signal φ raw The error signal e is obtained by subtracting the angle signal φ rr ; Step 14: Encrypt the angle parameter f scl With the error signal e rr Add up to get the estimated frequency f; Step 15: Execute the FPGA clock frequency f clk , the input estimated frequency f is accumulated through the m-bit accumulator; Step 16: Shift the data in the m-bit accumulator right by m bits to generate an angle signal φ.

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