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

Abstract

The application 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 meet the requirements of low-voltage direct current and high-voltage direct current respectively. The application adjusts the excitation current of the excitation winding of the main exciter through the voltage regulating circuit, so as to realize the stable voltage of the low-voltage direct current at the expected voltage value. The output high-voltage direct current is stabilized at the expected voltage value by means of phase control rectification control. Meanwhile, the thyristor rectifier bridge generates power and stabilizes voltage by adopting the same switching frequency as the output frequency of the generator, and has the characteristics of low loss, low high-frequency ripple spectrum component, weak high-frequency conduction and radiation interference and high power density.

Description

Technical Field

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

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

[0003] Existing aviation hybrid power supply systems, consisting of 28V low-voltage DC and 270V high-voltage DC, are generally implemented in the following ways.

[0004] 1. A combination of a high-voltage direct current (HVDC) three-stage generator system and a DC bus converter is the primary technical solution used in fighter jets. The engine is directly mechanically connected to the HVDC three-stage generator system, which provides mechanical speed input. The HVDC three-stage generator system converts the input mechanical energy into 270V AC electrical energy; then, the DC bus converter converts the 270V high-voltage DC into 28V low-voltage DC.

[0005] 2. A combined low-voltage DC brushed generator system and a high-voltage DC three-stage generator system is the main technical solution adopted by standard UAVs. Its power quality, including overload, short-circuit, and high-frequency ripple spectrum protection, fully meets the requirements of aircraft power supply and generation systems. Protection is achieved through demagnetization after a fault, meeting safety requirements. One engine is equipped with two generator systems: a DC brushed generator system and a high-voltage DC three-stage generator system. The engine provides mechanical speed input to both systems, which convert the mechanical energy into 28V low-voltage DC and 270V high-voltage DC electrical energy, respectively. With the development of power electronics technology, the technology of using a low-voltage DC three-stage generator system to replace the low-voltage DC brushed generator system is becoming increasingly mature, with a few application precedents. Because mechanical commutation is replaced by electronic commutation, the low-voltage DC three-stage generator system is suitable for high-altitude long-haul flights, maintenance-free export applications, and environments resistant to coastal salt spray, while maintaining a power density comparable to that of a DC brushed generator system.

[0006] 3. A combined high-voltage DC permanent magnet generator system and DC bus converter scheme is the primary technical solution adopted by low-cost UAVs. The engine is only mechanically connected directly to the high-voltage DC permanent magnet generator system, providing mechanical speed input. The high-voltage DC permanent magnet generator system converts the input mechanical energy into 270V AC electrical energy; then, the DC bus converter converts the 270V high-voltage DC into 28V low-voltage DC. Because the permanent magnet generator structure is simpler than a three-stage generator, the cost is significantly reduced.

[0007] In Scheme 1, the 28V low-voltage DC is obtained through a two-stage energy conversion. The first stage is a three-stage high-voltage DC generator system that converts the input mechanical energy into 270V high-voltage DC electrical energy. The second stage is a DC bus converter that converts the 270V high-voltage DC into 28V low-voltage DC, resulting in low efficiency in converting to 28V electrical energy. Furthermore, the conversion from 270V high-voltage DC to 28V low-voltage DC is a high-frequency, full-power conversion, and the DC bus converter is also quite heavy. In Scheme 2, the generator system has two mechanical interfaces with the engine, which are more complex, resulting in significant additional weight from the mechanical transmission interface, generator housing, etc. In Scheme 3, due to the linear change of the permanent magnet generator's output voltage with rotational speed and its high operating frequency, and the wide input voltage range and high switching frequency of the 270V voltage regulator converter, the power density and efficiency of the high-voltage DC permanent magnet generator system are not superior to those of the high-voltage DC three-stage generator system. The power quality of the high-voltage DC 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 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 of 270V high-voltage DC to 28V low-voltage DC is also relatively heavy. Summary of the Invention

[0008] The purpose of this invention is to address the shortcomings of the above-mentioned technologies by providing a three-stage generator system with both high-voltage and low-voltage DC dual outputs.

[0009] The purpose of this invention is to address the shortcomings of the aforementioned technologies by providing a design method for a three-stage generator system with both high-voltage and low-voltage DC dual outputs. This invention is achieved through the following technical solutions.

[0010] The present invention provides a three-stage generator system with dual high-voltage and low-voltage DC outputs, comprising 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 rotating rectifier. The controller includes a voltage regulating circuit, a thyristor rectifier bridge, a diode rectifier bridge, a control circuit, a generator control relay (GCR), and a current sensor (S). F ;

[0011] The rotary transformer outputs a speed and position signal. P Connected to the control circuit, the winding W of the permanent magnet auxiliary exciter PMG Terminals A, B, and C are connected to terminals A, B, and C of the voltage regulator circuit, respectively, and the control circuit outputs drive signals. G C Connected to the voltage regulator circuit, the output terminal of the voltage regulator circuit V Co The positive terminal is connected to the excitation winding W of the main exciter via the generator control relay GCR. EE The F+ terminal is connected to the output terminal of the voltage regulator circuit.V Co The negative terminal is connected to the excitation winding W of the main exciter. EE The F- terminal is connected to the control terminal of the power generation control relay GCR and the drive signal output by the control circuit. G R Connection, current sensor S F Detecting the flow into the main exciter excitation winding W EE The excitation current is output after the F+ terminal current. I F Connected to the control circuit, the A, B, and C terminals of the thyristor rectifier bridge input are respectively connected to the W phase of the high-voltage three-phase winding of the main motor. H The A, B, and C connections are made, and the positive and negative terminals of the thyristor rectifier bridge output are connected to the positive and negative terminals of the external high-voltage DC output interface, respectively. The thyristor rectifier bridge outputs a high-voltage DC voltage. V dcH Connected to a 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 respectively connected to the low-voltage three-phase winding W of the main motor. L Connect A, B, and C. Connect the positive and negative terminals of the diode rectifier bridge output to the positive and negative terminals 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 a drive signal. G L and G H Respectively with the power generation control circuit breaker GCB L and GCB H Connection, main exciter rotor armature winding W EM via the rotating rectifier and the main motor rotor excitation winding W ME 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 W includes phases A, B, and C respectively. LA W LB and W LC The high-voltage three-phase winding W H W includes phases A, B, and C respectively. HA W HB and W HC ;

[0013] For the low-voltage three-phase winding W LAny X-phase winding, where X = A, B, or C, is formed by the 1st, 2nd… p Pole winding W LX1 W LX2 …W LXp Parallel connection configuration, low-voltage three-phase winding W L One end of any X-phase winding is connected to the neutral point N. L Connection, low-voltage three-phase winding W L The other end of any X-phase winding is connected to the low-voltage three-phase winding W. L The X-end connection,

[0014] For the high-voltage three-phase winding W H Any X-phase winding, where X = A, B, or C, is formed by the 1st, 2nd… p Pole winding W HX1 W HX2 …W HXp The high-voltage three-phase winding W is formed by sequentially connecting the windings in series. H One end of any X-phase winding is connected to the neutral point N. H Connection, high-voltage three-phase winding W H The other end of any X-phase winding is connected to the high-voltage three-phase winding W. H The X-end connection,

[0015] The low-voltage three-phase winding W L Any X-phase winding, 1st, 2nd… p Pole winding W LX1 W LX2 …W LXp Respectively connected to the high-voltage three-phase winding W H Any X-phase winding, 1st, 2nd… p Pole winding W HX1 W HX2 …W HXp The structure within the stator slot remains the same.

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

[0017] The positive terminal of the output of the thyristor rectifier bridge is respectively connected to D A1 D A3 and D A5 The cathode is connected, and the output negative terminal is connected to D. A2 D A4 and D A6 The anode connection is as follows: the A terminal of the AC input of the thyristor rectifier bridge is connected to the D terminal. A1 anode and D A2 The cathode is connected, and the B terminal of the AC input is connected to the D terminal respectively. A3 anode and DA4 The cathode is connected, and the C terminal of the AC input is connected to the D terminal respectively. A5 anode and D A6 Cathode connection; drive signal G A respectively with thyristor D A1 ~D A6 The control terminal of the voltage sensor A is connected, and the positive and negative input terminals of the voltage sensor A are respectively connected to the positive and negative output terminals of the thyristor rectifier bridge. The voltage sensor A outputs a high-voltage DC voltage. V dcH To the control circuit.

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

[0019] The positive terminal of the diode rectifier bridge output is respectively connected to D B1 D B3 and D B5 The cathode is connected, and the output negative terminal is connected to D. B2 D B4 and D B6 The anode of the diode is connected, and the A terminal of the AC input of the diode rectifier bridge is respectively connected to the D... B1 anode and D B2 The cathode is connected, and the B terminal of the AC input is connected to the D terminal respectively. B3 anode and D B4 The cathode is connected, and the C terminal of the AC input is connected to the D terminal respectively. B5 anode and D B6 The cathode of voltage sensor B is connected; the positive and negative input terminals of voltage sensor B are connected to the positive and negative output terminals of the diode rectifier bridge, respectively, and 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 rotational speed position signal P Connected to the resolver decoding circuit, the position locking signal output by the field-programmable gate array (FPGA) SAM Connected to a resolver decoding circuit, the resolver decoding circuit outputs a rotational speed. n and original location Signal to DSP, externally input low-voltage DC voltage V dcL Excitation current I F and high voltage DC voltage VdcH Connected to the DSP, the DSP outputs drive signals. G C , G H , G L and G R DSP output raw position Angle encryption parameters f scl and phase shift angle θ The signal is connected to the Field Programmable Gate Array (FPGA), and the FPGA outputs a drive signal. G A .

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

[0023] Step 1: Based on the speed and position signal output by the rotary transformer P Angle signals are obtained through phase-locked loop angle encryption calculation. ;

[0024] Step 2: Activate the angle signal =0°, with the three-phase armature winding W of the main motor H The zero-crossing point of the voltage drop segment of phase A under no-load conditions corresponds to the following:

[0025] Step 3: Adjust the current flowing through the excitation winding W of the main exciter using the voltage regulating circuit. EE excitation current I F This makes the low-voltage DC voltage V dcL Stabilize at the desired voltage value;

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

[0027] Step 5: During power generation, if an abnormality in the high-voltage DC regulation is detected, a drive signal will be used. G A Disconnect thyristor D in the thyristor rectifier bridge A1 ~D A6 Through drive signal G H To disconnect the power generation control circuit breaker GCB H To achieve fault isolation of high voltage DC regulation;

[0028] Step 6: During power generation, if an abnormality in low-voltage DC regulation is detected, a drive signal will be used. GL , G H and G C To disconnect the power generation control circuit breaker GCB L Generator control circuit breaker (GCB) H Together with the power generation control relay GCR, fault protection is achieved.

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

[0030] Step 11: Based on the rotational speed n and the number of pole pairs of the main motor p ,according to f e = np / 60 Calculate the main motor frequency f e ;

[0031] Step 12: Execute according to the FPGA clock frequency f clk and main motor frequency f e ,according to f scl = f e / f clk ×2 n+1 ×2 m Calculate angle encryption parameters f scl , n +1 indicates the number of quantization bits for the main motor's electrical angle, i.e., through 0~2 n+1 Represents an angle signal from 0° to 360°. , m Indicates the number of bits in the accumulator in the FPGA;

[0032] Step 13: Transfer the original position signal With angle signal Obtaining the error signal by subtraction e rr ;

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

[0034] Step 15: Execute according to the FPGA clock frequency f clk ,pass mThe bit accumulator estimates the frequency of the input. f Accumulate;

[0035] Step 16, m Right-shift the data in the bit accumulator m Position generates angle signal .

[0036] The beneficial effects of this invention are as follows:

[0037] 1. The three-stage generator system and design method with dual output of high voltage and low voltage DC 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 high-voltage DC three-stage generator system and DC bus converter, the 28V low-voltage DC is obtained by only one stage of energy conversion, which is more efficient in obtaining 28V low-voltage DC; the DC bus power converter that converts 270V high-voltage DC to 28V low-voltage DC is eliminated, and the weight cost of obtaining 28V low-voltage DC is lower.

[0039] 3. Compared to the combination of low-voltage DC brushed generator system and high-voltage DC three-stage generator system, the 28V low-voltage DC and 270V high-voltage DC both obtain energy from the same generator. The mechanical interfaces with the engine are reduced from two to one. The generator housing, heat dissipation structure, and mechanical support structure are also reduced from two to one. The additional weight of the mechanical transmission interface and the non-effective parts of the generator is significantly reduced.

[0040] 4. Compared to the combined solution of high-voltage DC permanent magnet generator system and DC bus converter, the 28V low-voltage DC is achieved through excitation voltage regulation, eliminating the need for a DC bus power converter that converts 270V high-voltage DC to 28V low-voltage DC. The 28V low-voltage DC is obtained through only one stage of energy conversion, resulting in significantly lower weight and efficiency costs. The input voltage range of the 270V voltage regulator is significantly narrowed, and it adopts the same electrical frequency control as the generator, further reducing the weight and efficiency costs of 270V high-voltage DC regulation. Overall power density and efficiency are significantly improved. This overcomes the shortcomings of power quality that is difficult to meet the standards of aircraft power supply and generation systems, such as overload, short circuit, and high-frequency ripple spectrum. It also solves the problem of not being able to demagnetize after a fault, which does not meet aviation safety requirements.

[0041] 5. The main motor uses low-voltage three-phase windings W L and high voltage three-phase winding W H To meet the requirements of 28V low-voltage DC and 270V high-voltage DC respectively.

[0042] 6. When the thyristor rectifier bridge achieves 270V output voltage regulation, the switching frequency used is the same as the generator output frequency. The frequency is low, and the loss is much lower than that of the traditional high-frequency voltage regulation control scheme.

[0043] 7. When the thyristor rectifier bridge achieves 270V output voltage regulation, the switching frequency used is the same as the generator output frequency. The frequency is low, and the high-frequency conducted and radiated interference is much lower than that of the traditional high-frequency voltage regulation control scheme. The high-frequency ripple spectrum is more likely to meet the requirements of GJB181B-2012, and it also has better electromagnetic compatibility characteristics.

[0044] 8. When the thyristor rectifier bridge achieves 270V output voltage regulation, the switching frequency used is the same as the generator output frequency. Therefore, the power transistors can be high current-capable but have relatively high switching losses, so that the thyristor rectifier bridge has good overload resistance.

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

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

[0047] 11. Position locking signal output by FPGA SAM To control the resolver decoding circuit and ensure its original position High-precision correspondence with the electrical angle of the main motor.

[0048] 12. Using the proposed phase-locked loop angle encryption calculation method, angle signals with a step size of less than 1° are obtained. This ensures the accuracy of phase-controlled rectification control. Attached Figure Description

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

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

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

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

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

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

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

[0056] Figure 8 This is a schematic diagram of the angle encryption function of the control circuit of the present invention. Detailed Implementation

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

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

[0059] A three-stage generator system with dual high-voltage and low-voltage DC outputs includes 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 generator control relay (GCR), and a current sensor (S). F It is the speed and position signal output by the rotary transformer. P Connected to the control circuit, the permanent magnet auxiliary exciter winding W PMG Terminals A, B, and C are connected to terminals A, B, and C of the voltage regulator circuit, respectively, and the control circuit outputs drive signals. G C Connected to the voltage regulator circuit, the output terminal of the voltage regulator circuit V Co The positive terminal is connected to the generator control relay GCR and the main exciter excitation winding W. EE The F+ terminal is connected to the output terminal of the voltage regulator circuit. V Co The negative terminal is connected to the main exciter excitation winding W. EE The F- terminal is connected to the control terminal of the power generation control relay GCR and the drive signal output by the control circuit. G R Connection, current sensor S F Detecting the flow into the main exciter excitation winding W EE The excitation current is output after the F+ terminal current. I F Connected to the control circuit, the A, B, and C terminals of the thyristor rectifier bridge input are respectively connected to the W phase of the high-voltage three-phase winding of the main motor. H Connect A, B, and C. Connect the positive and negative terminals of the thyristor rectifier bridge output to the positive and negative terminals 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 a drive signal. G A Connected to the thyristor rectifier bridge, the A, B, and C terminals of the diode rectifier bridge input are respectively connected to the low-voltage three-phase winding W of the main motor. L Connect A, B, and C. Connect the positive and negative terminals of the diode rectifier bridge output to the positive and negative terminals 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 a drive signal. G L and G H Respectively with the power generation control circuit breaker GCB L and GCB H Connection, main exciter rotor armature winding W EM via the rotating rectifier and the main motor rotor excitation winding W ME Connection constitutes.

[0060] Compared to 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, resulting in higher efficiency in obtaining 28V low-voltage DC. It also eliminates the need for a DC bus power converter that converts 270V high-voltage DC to 28V low-voltage DC, thus reducing the weight cost of obtaining 28V low-voltage DC.

[0061] Since the proposed three-stage generator with dual output of high-voltage and low-voltage DC does not employ mechanical commutation, it overcomes the shortcomings of combining a low-voltage DC brushed generator system with a high-voltage DC three-stage generator system, such as being unsuitable for high-altitude long-haul flights, maintenance-free export operations, and resistance to coastal salt spray environments.

[0062] Compared to the combination of a low-voltage DC brushed generator system and a high-voltage DC three-stage generator system, the 28V low-voltage DC and 270V high-voltage DC both obtain energy from the same generator. The mechanical interfaces with the engine are reduced from two to one. The generator housing, heat dissipation structure, and mechanical support structure are also reduced from two to one. The additional weight of the mechanical transmission interface and the non-effective parts of the generator is significantly reduced.

[0063] Figure 2 The diagram shows the dual armature windings of the main motor. The main motor's stator armature windings include a low-voltage three-phase winding W. L and high voltage three-phase winding W H Low-voltage three-phase winding W L W includes phases A, B, and C respectively. LA W LBand W LC High-voltage three-phase winding W H W includes phases A, B, and C respectively. HA W HB and W HC For low-voltage three-phase winding W L Any X-phase winding, where X = A, B, or C, is formed by the 1st, 2nd… p Pole winding W LX1 W LX2 …W LXp Parallel connection configuration, low-voltage three-phase winding W L One end of any X-phase winding is connected to the neutral point N. L Connection, low-voltage three-phase winding W L The other end of any X-phase winding is connected to the low-voltage three-phase winding W. L The X-terminal connection is used for the high-voltage three-phase winding W. H Any X-phase winding, where X = A, B, or C, is formed by the 1st, 2nd… p Pole winding W HX1 W HX2 …W HXp The high-voltage three-phase winding W is formed by sequentially connecting the windings in series. H One end of any X-phase winding is connected to the neutral point N. H Connection, high-voltage three-phase winding W H The other end of any X-phase winding is connected to the high-voltage three-phase winding W. H The X-terminal connection, low-voltage three-phase winding W L Any X-phase winding, 1st, 2nd… p Pole winding W LX1 W LX2 …W LXp Respectively connected to the high-voltage three-phase winding W H Any X-phase winding, 1st, 2nd… p Pole winding W HX1 W HX2 …W HXp The structure within the stator slot remains the same.

[0064] First, through steps 1, 2… p The low-voltage three-phase winding W is achieved by connecting the pole windings in parallel or series. L Or high-voltage three-phase winding W H Voltage regulation, and then by adjusting the winding turns ratio N W Adjustments are made to achieve low-voltage three-phase winding W L Or high-voltage three-phase winding W H Voltage regulation, winding turns ratio N W =W HX1 / W LX1 =WHX2 / W LX2 …=W HXp / W LXp This implementation increases the number of pole pairs of the main motor. p =5, select the winding turns ratio as N W =3.

[0065] Under no-load conditions, when the low-voltage three-phase winding W L Voltage after natural rectification V dcL When the voltage is 28V, the winding turns ratio needs to be considered. N W Designed to ensure high-voltage three-phase winding W under 2x overload output H Voltage after natural rectification V dcH Above 270V.

[0066] The main motor uses low-voltage three-phase winding W L and high voltage three-phase winding W H To meet the requirements of 28V low-voltage DC and 270V high-voltage DC respectively.

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

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

[0069] Figure 5 The diagram shown is of a voltage regulator circuit, consisting of diode D. C1 ~D C6 The constructed three-phase rectifier bridge is used to convert the three-phase AC voltage provided by the permanent magnet exciter. v PMG Convert to DC V G When generating electricity, Q C2 Closed, by adjusting Q C1 The duty cycle is used to adjust the flow through the main exciter's excitation winding W. EE excitation current I F .

[0070] Figure 6 The diagram shown is a block diagram of the control circuit, which includes a resolver decoding circuit, a field-programmable gate array (FPGA), and a digital signal processor (DSP); it is based on the rotation speed and position signal. P Connected to the resolver decoding circuit, the FPGA outputs a position lock signal. SAM Connected to a resolver decoding circuit, the resolver decoding circuit outputs the rotational speed. n and original location Connects to the DSP, with an external low-voltage DC input. V dcL Excitation current I F and high voltage DC voltage V dcH Connected to a DSP, the DSP outputs drive signals. G C , GH , G L and G R DSP output raw position Angle encryption parameters f scl and phase shift angle θ Connected to an FPGA, the FPGA outputs drive signals. G A constitute.

[0071] The resolver decoding circuit is implemented using the integrated circuit AD2S1210CSTZ, with a position locking signal. SAM With its 10th pin Connection. FPGAs can achieve precise timing control through position locking signals output by the FPGA. SAM To control the resolver decoding circuit, the obtained original position can be... Maintaining a high degree of synchronization with the FPGA's clock system ensures the original position. High-precision correspondence with the electrical angle of the main motor.

[0072] DSPs are mainly used to implement voltage regulation control for low-voltage DC output and phase shift angle control for high-voltage DC output. θ Calculation and angle encryption parameters f scl The calculations are performed using FPGAs. FPGAs are mainly used to perform angle encryption and phase-controlled rectification control functions.

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

[0074] Step 1: Based on the speed and position signal output by the rotary transformer P Angle signals are obtained through phase-locked loop angle encryption calculation. ;

[0075] Step 2: Activate the angle signal =0° and the three-phase armature winding of the main motor W H The zero-crossing point of the voltage drop segment of phase A under no-load conditions corresponds to the following:

[0076] Step 3: Adjust the current flowing through the excitation winding W of the main exciter using the voltage regulating circuit. EE excitation current I F This makes the low-voltage DC voltage V dcL Stabilize at the desired voltage value;

[0077] Step 4: Through phase-controlled rectification control, the high-voltage DC voltage output by the thyristor rectifier bridge is made... VdcH Stabilize at the desired voltage value;

[0078] Step 5: During power generation, if an abnormality in the high-voltage DC regulation is detected, a drive signal will be used. G A Disconnect thyristor D in the thyristor rectifier bridge A1 ~D A6 Through drive signal G H To disconnect the power generation control circuit breaker GCB H To achieve fault isolation of high voltage DC regulation;

[0079] Step 6: During power generation, if an abnormality in low-voltage DC regulation is detected, a drive signal will be used. G L , G H and G C To disconnect the power generation control circuit breaker GCB L Generator control circuit breaker (GCB) H Together with the power generation control relay GCR, fault protection is achieved.

[0080] Combination Figure 7 The angle signal shown With the three-phase armature winding W of the main motor H The diagram showing the no-load voltage correspondence further illustrates step 2. v H_A , v H_B and v H_C These represent the three-phase armature windings W of the main motor. H The no-load output voltages of phases A, B, and C. In step 2, the angle signal... =0°, under no-load conditions v H_A The zero-crossing point of the descent segment should correspond to the position of the rotor of the rotary transformer and the rotor of the main motor, which can be ensured by adjusting the relative position of the rotor of the rotary transformer and the rotor of the main motor.

[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 H The voltage after natural rectification is usually not the desired 270V, so the auxiliary means in step 4 are needed to achieve 270V high voltage DC regulation.

[0082] Combination Figure 6 The low-voltage DC voltage control described in step 3 is further explained. In the DSP, based on the regulated reference value... V refL and low voltage DC voltage V dcLPerform voltage loop A calculation to generate a reference signal for the excitation current loop. I ref Based on the reference signal of the excitation current loop. I ref and excitation current I F Perform excitation current loop calculations to ensure the excitation current... I F Reference signal of the excitation current loop I ref equal.

[0083] Combination Figure 7 The diagram shown illustrates the voltage regulation control principle of a thyristor rectifier bridge, explaining the phase-controlled rectification control. High-voltage DC voltage. V dcH With phase angle θ The relationship is shown in equation (1). Phase shift angle θ The larger the value, the lower the output voltage.

[0084] V dcH =2.34 U cos θ (1)

[0085] In the formula, U For three-phase armature winding W H Effective value of output phase voltage.

[0086] Combination Figure 6 phase shift angle θ The cause will be explained. In the DSP, based on the regulated reference value... V refH and high voltage DC voltage V dcH Perform voltage loop B calculation to generate phase shift angle. θ When the high voltage DC voltage V dcH Greater than or less than the regulated reference value V refH At that time, by increasing or decreasing the phase shift angle θ To achieve output voltage regulation.

[0087] The hardware and control methods for thyristor rectifier bridges have the following advantages:

[0088] 1. When the thyristor rectifier bridge achieves 270V output voltage regulation, the switching frequency used is the same as the generator output frequency. The frequency is low, and the loss is much lower than that of the traditional high-frequency voltage regulation control scheme.

[0089] 2. When the thyristor rectifier bridge achieves 270V output voltage regulation, the switching frequency used is the same as the generator output frequency. The frequency is low, and the high-frequency conducted and radiated interference is much lower than that of the traditional high-frequency voltage regulation control scheme. The high-frequency ripple spectrum is more likely to meet the requirements of GJB181B-2012, and it also has better electromagnetic compatibility characteristics.

[0090] 3. When the thyristor rectifier bridge achieves 270V output voltage regulation, the switching frequency used is the same as the generator output frequency. Therefore, the power transistors can be high current-capable but have relatively high switching losses, so that the thyristor rectifier bridge has good overload resistance.

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

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

[0093] Combination Figure 8 The function of phase-locked loop angle encryption is explained. This is because the original position signal acquired by the DSP... It is discrete data, a position signal at high frequencies. Significant step difference will affect the phase-controlled rectifier control drive signal. G A To improve the accuracy of the generated angle signal, a phase-locked loop (PLL) is added for angle encryption calculation to achieve continuity of the angle signal, based on the stepped original position signal. Obtain angle signals with a step of less than 1° .

[0094] Combination Figure 6 The principle of phase-locked loop (PLL) angle encryption calculation is explained. Step 1, the PLL angle encryption calculation, includes the following steps:

[0095] Step 11: Based on the rotational speed n and the number of pole pairs of the main motor p ,according to f e = np / 60 Calculate the main motor frequency f e ;

[0096] Step 12: Execute according to the FPGA clock frequency f clk and main motor frequency f e ,according to f scl = fe / f clk ×2 n+1 ×2 m Calculate angle encryption parameters f scl , n +1 indicates the number of quantization bits for the main motor's electrical angle, i.e., through 0~2 n+1 Represents an angle signal from 0° to 360°. , m Indicates the number of bits in the accumulator in the FPGA;

[0097] Step 13: Transfer the original position signal With angle signal Obtaining the error signal by subtraction e rr ;

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

[0099] Step 15: Execute according to the FPGA clock frequency f clk ,pass m The bit accumulator estimates the frequency of the input. f Accumulate;

[0100] Step 16, m Right-shift the data in the bit accumulator m Position generates angle signal .

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

[0102] For step 12, the step angle Δ corresponding to one FPGA execution cycle is... As shown in equation (2); angle encryption parameters f scl The step angle Δ corresponding to the signal As shown in equation (3). Combining equations (2) and (3), we can obtain... f scl The calculation expression is shown in equation (4).

[0103] △ = f e / f clk ×2 n+1(2)

[0104] △ = 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, N ( x )= N ( x -1)+ f This is used to perform accumulation operations. The accumulator is equivalent to an integrator, which estimates the frequency... f Converted into angle signal It also serves to smooth The function of steps.

[0107] As can be seen from equation (2), as long as the FPGA execution clock frequency is... f clk If it is high enough, then the step angle △ It will be small enough. In this embodiment, f clk =40MHz, n =9, at the main motor frequency f e At 2.5kHz, the step angle Δ =0.0225°. angle signal The lowest quantization bit is 1 / 2 n+1 In this embodiment, the lowest value corresponds to 0.35°. Angle signal. The accuracy depends on the step angle Δ and the lowest quantization bit 1 / 2 n+1 The maximum value in the range, therefore, in this embodiment, the angle signal The accuracy is 0.35°. Therefore, the proposed phase-locked loop angle encryption calculation method can easily obtain angle signals with a step size of less than 1°. This ensures the accuracy of phase-controlled rectification control.

[0108] The above analysis shows that, compared to the combined high-voltage DC permanent magnet generator system and DC bus converter scheme, the 28V low-voltage DC is achieved through excitation regulation, eliminating the need for a DC bus power converter that converts 270V high-voltage DC to 28V low-voltage DC. The 28V low-voltage DC is obtained through only one stage of energy conversion, resulting in significantly lower weight and efficiency costs. The input voltage range of the 270V voltage regulator is significantly narrowed, and it adopts the same electrical frequency control as the generator, further reducing the weight and efficiency costs of 270V high-voltage DC regulation. Overall power density and efficiency are significantly improved. This overcomes the shortcomings of power quality issues such as overload, short circuit, and high-frequency ripple spectrum, which make it difficult to meet the standards of aircraft power supply and generation systems. It also solves the problem of not being able to demagnetize after a fault, which does not meet aviation safety requirements.

Claims

1. A three-stage generator system with dual high-voltage and low-voltage DC outputs, characterized in that: The system includes 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 includes a voltage regulating circuit, a thyristor rectifier bridge, a diode rectifier bridge, a control circuit, a generator control relay (GCR), and a current sensor (S). F ; The rotary transformer outputs a speed and position signal. P Connected to the control circuit, the winding W of the permanent magnet auxiliary exciter PMG Terminals A, B, and C are connected to terminals A, B, and C of the voltage regulator circuit, respectively, and the control circuit outputs drive signals. G C Connected to the voltage regulator circuit, the output terminal of the voltage regulator circuit V Co The positive terminal is connected to the excitation winding W of the main exciter via the generator control relay GCR. EE The F+ terminal is connected to the output terminal of the voltage regulator circuit. V Co The negative terminal is connected to the excitation winding W of the main exciter. EE The F- terminal is connected to the control terminal of the power generation control relay GCR and the drive signal output by the control circuit. G R Connection, current sensor S F Detecting the flow into the main exciter's excitation winding W EE The excitation current is output after the F+ terminal current. I F Connected to the control circuit, the A, B, and C terminals of the thyristor rectifier bridge input are respectively connected to the W phase of the high-voltage three-phase winding of the main motor. H The A, B, and C connections are made, and the positive and negative terminals of the thyristor rectifier bridge output are connected to the positive and negative terminals of the external high-voltage DC output interface, respectively. The thyristor rectifier bridge outputs a high-voltage DC voltage. V dcH Connected to a 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 respectively connected to the low-voltage three-phase winding W of the main motor. L Connect A, B, and C. Connect the positive and negative terminals of the diode rectifier bridge output to the positive and negative terminals 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 a drive signal. G L and G H Respectively with the power generation control circuit breaker GCB L and GCB H Connection, main exciter rotor armature winding W EM via the rotating rectifier and the main motor rotor excitation winding W ME connect.

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

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

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

5. The three-stage generator system with dual high-voltage and low-voltage DC outputs as described 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 rotational speed position signal P Connected to the resolver decoding circuit, the position locking signal output by the field-programmable gate array (FPGA) SAM Connected to a resolver decoding circuit, the resolver decoding circuit outputs a rotational speed. n and original location Signal to DSP, externally input low-voltage DC voltage V dcL Excitation current I F and high voltage DC voltage V dcH Connected to the DSP, the DSP outputs drive signals. G C , G H , G L and G R DSP output raw position Angle encryption parameters f scl and phase shift angle θ The signal is connected to the Field Programmable Gate Array (FPGA), and the FPGA outputs a drive signal. G A .

6. The design method of the three-stage generator system with high-voltage and low-voltage DC dual output as described in claim 5, characterized in that: Step 1: Based on the speed and position signal output by the rotary transformer P Angle signals are obtained through phase-locked loop angle encryption calculation. ; Step 2: Activate the angle signal =0°, with the three-phase armature winding W of the main motor H The zero-crossing point of the voltage drop segment of phase A under no-load conditions corresponds to the following: Step 3: Adjust the current flowing through the excitation winding W of the main exciter using the voltage regulating circuit. EE excitation current I F This makes the low-voltage DC voltage V dcL Stabilize at the desired voltage value; Step 4: Through phase-controlled rectification control, the high-voltage DC voltage output by the thyristor rectifier bridge is made... V dcH Stabilize at the desired voltage value; Step 5: During power generation, if an abnormality in the high-voltage DC regulation is detected, a drive signal will be used. G A Disconnect thyristor D in the thyristor rectifier bridge A1 ~D A6 Through drive signal G H To disconnect the power generation control circuit breaker GCB H To achieve fault isolation of high voltage DC regulation; Step 6: During power generation, if an abnormality in low-voltage DC regulation is detected, a drive signal will be used. G L , G H and G C To disconnect the power generation control circuit breaker GCB L Generator control circuit breaker (GCB) H Together with the power generation control relay GCR, fault protection is achieved.

7. The design method of the three-stage generator system with dual high-voltage and low-voltage DC output as described in claim 6, characterized in that, The phase-locked loop angle encryption calculation in step 1 includes the following steps: Step 11: Based on the rotational speed n and the number of pole pairs of the main motor p ,according to f e = np / 60 Calculate the main motor frequency f e ; Step 12: Execute according to the FPGA clock frequency f clk and main motor frequency f e ,according to f scl = f e / f clk ×2 n+1 ×2 m Calculate angle encryption parameters f scl , n +1 indicates the number of quantization bits for the main motor's electrical angle, i.e., through 0~2 n+1 Represents an angle signal from 0° to 360°. , m Indicates the number of bits in the accumulator in the FPGA; Step 13: Transfer the original position signal With angle signal Obtain the error signal by subtraction. e rr ; Step 14: Encrypt the angle parameters f scl With error signal e rr Add to obtain the estimated frequency f ; Step 15: Execute according to the FPGA clock frequency f clk ,pass m The bit accumulator estimates the frequency of the input. f Accumulate; Step 16, m Right-shift the data in the bit accumulator m Position generates angle signal .

Images