Power generation controller and power generation system

Abstract

The present application provides a power generation controller and a power generation system, which relate to the technical field of motor power generation and are used to achieve high voltage regulation accuracy and good dynamic characteristics within the full speed range, and improve the power quality and system stability of the power generation system. The power generation controller includes: a plurality of rectification modules, a control and protection module, an excitation switching module, a voltage conditioning module, and an excitation control output module. The input ends of each rectification module are respectively connected to the corresponding stator windings in the permanent magnet machine, and the number of turns of different electronic windings is different; the output ends of all rectification modules and the output end of the control and protection module are respectively connected to the input end of the excitation switching module; the excitation switching module is used to select the DC voltage output by the corresponding rectification module based on the control signal input by the control and protection module; the output end of the excitation switching module and the output end of the voltage conditioning module are respectively connected to the input end of the excitation control output module; the excitation control output module is used to output an excitation voltage.

Description

Technical Field

[0001] This application relates to the technical field of motor power generation, and particularly to a power generation controller and a power generation system. Background Art

[0002] In an aviation high-power AC power supply system, a three-stage electrically excited synchronous motor has been widely used as a generator. In a start / generation integrated system, this motor operates in start and generation modes. In the generation mode of a traditional three-stage electrically excited synchronous motor, the power generation controller rectifies the electrical energy of the permanent magnet machine to provide excitation electrical energy for the exciter. The voltage regulation module uses an integrated control chip to implement "pulse width modulation". The reference voltage of the voltage regulation module is set to be unchanged. When the generator speed or load changes, the output voltage of the main motor changes. By comparing the changing voltage with the reference voltage, the pulse width of the PWM (Pulse Width Modulation) signal output by the voltage regulation module changes. By automatically adjusting the duty cycle of the excitation power switch in a closed loop, the output voltage of the excitation control output module is changed, so as to achieve the purpose of accurately regulating the output voltage of the main motor.

[0003] For traditional constant-frequency or narrow variable-frequency generators, the speed of the generator is almost unchanged or the change range is small, and the output voltage of the permanent magnet machine is almost unchanged or the change range is narrow. For a wide variable-frequency three-stage electrically excited synchronous motor, the higher the generator speed, the higher the output voltage of the permanent magnet machine. Since the excitation current required by the generator is smaller at high speeds or light loads, there will inevitably be the following two problems:

[0004] At low speeds, the voltage output by the permanent magnet machine is low, but at this time the excitation voltage required by the exciter is very large, which will inevitably cause the duty cycle D of the excitation power tube of the power generation controller to be too large, and even insufficient, resulting in the generator being unable to output the reference voltage; at high speeds, the output voltage of the permanent magnet machine is high, and at this time the excitation current required by the exciter is very small, which will inevitably cause the duty cycle D of the excitation power tube of the power generation controller to be very small. A little interference from the outside to the duty cycle D will cause the generator terminal voltage to oscillate, making it difficult to stabilize and the control to be difficult. Therefore, it is very likely that the generator cannot work properly under high-speed and light-load conditions. Summary of the Invention

[0005] Embodiments of this application provide a power generation controller and a power generation system, which are used to achieve high voltage regulation accuracy and good dynamic characteristics within the full speed range, thereby improving the power quality and system stability of the power generation system.

[0006] Embodiments of the present invention provide a power generation controller, and the power generation controller includes: a plurality of rectification modules, a control and protection module, an excitation switching module, a voltage regulation module, and an excitation control output module:

[0007] The input ends of each of the rectification modules are respectively connected to corresponding stator windings in the permanent magnet machine, and the number of turns of different electronic windings is different; the rectification module is used to uncontrollably rectify the output voltage of the corresponding stator winding into a DC voltage;

[0008] The output ends of all the rectification modules and the output end of the control and protection module are respectively connected to the input end of the excitation switching module; the excitation switching module is used to select the DC voltage output by the corresponding rectification module based on the control signal input by the control and protection module;

[0009] The output end of the excitation switching module and the output end of the voltage conditioning module are respectively connected to the input end of the excitation control output module; the excitation control output module is used to output an excitation voltage.

[0010] In an optional embodiment provided by the present invention, the excitation switching module includes n - 1 switching components, where n is the number of rectification modules.

[0011] In an optional embodiment provided by the present invention, the lowest DC voltage output by the rectification module is directly connected to the output end of the excitation switching module; the other DC voltages output by the rectification module are respectively connected to the output end of the excitation switching module through corresponding switching components.

[0012] In an optional embodiment provided by the present invention, the switching component includes: a MOS transistor, a diode, and a resistor;

[0013] The gate (G) of the MOS transistor is connected to the output end of the control and protection module for receiving the control signal output by the control module;

[0014] The drain (D) of the MOS transistor is connected to the output end of the rectification module;

[0015] The source (S) of the MOS transistor is grounded through the resistor and connected to the output end of the excitation switching module through the diode.

[0016] In an optional embodiment provided by the present invention, the control and protection module is connected to the permanent magnet machine motor for obtaining the speed of the three - stage excitation synchronous generator corresponding to the frequency of the output voltage of the permanent magnet machine, and determining the control signal according to the speed of the three - stage excitation synchronous generator.

[0017] In an optional embodiment provided by the present invention, the control and protection module determines the control signal by comparing the engine speed and n - 1 switching speed points, where n is the number of rectification modules.

[0018] In an alternative embodiment provided by the present invention, according to the excitation voltage requirements of the exciter of the three-stage electric excitation generator in the full power generation speed range and full load conditions, the output voltage of the permanent magnet machine is selected in different speed ranges to fit the output voltage curve of the permanent magnet machine, and the n-1 switching speed point is determined according to the output voltage curve of the permanent magnet machine.

[0019] In an alternative embodiment provided by the present invention, the number of turns of the electronic winding is proportional to the output voltage of the stator winding.

[0020] An embodiment of the present invention provides a power generation system, which includes: an aeroengine, a three-stage excitation synchronous motor, airborne electrical equipment, and the above-mentioned power generation controller;

[0021] The three-stage excitation synchronous motor is respectively connected to the aeroengine, the airborne electrical equipment, and the power generation controller;

[0022] Among them, the three-stage excitation synchronous motor includes a permanent magnet machine, and the permanent magnet machine includes a plurality of stator windings, and the number of turns of different electronic windings is different.

[0023] In an alternative embodiment provided by the present invention, the three-stage excitation synchronous motor further includes: an exciter and a main motor;

[0024] The exciter is connected to the excitation control output module in the power generation controller for receiving the excitation voltage output by the excitation control output module;

[0025] The main motor is connected to the airborne electrical equipment.

[0026] The present invention provides a power generation controller and a power generation system. The power generation controller includes: a plurality of rectification modules, a control and protection module, an excitation switching module, a voltage regulation module, and an excitation control output module. Among them, the input end of each rectification module is respectively connected to the corresponding stator winding in the permanent magnet machine, and the number of turns of different stator windings is different; the rectification module is used to uncontrollably rectify the output voltage of the corresponding stator winding into a DC voltage; the output ends of all the rectification modules and the output end of the control and protection module are respectively connected to the input end of the excitation switching module; the excitation switching module is used to select the DC voltage output by the corresponding rectification module based on the control signal input by the control and protection module; the output end of the excitation switching module and the output end of the voltage regulation module are respectively connected to the input end of the excitation control output module; the excitation control output module is used to output an excitation voltage. In the present invention, the stator windings of the permanent magnet machine are designed in multiple sets. After uncontrollable rectification by the corresponding rectification modules, DC voltages are output. Then, the excitation switching module is used to control the selection of the output voltage of the corresponding permanent magnet machine at different speeds, so as to achieve high voltage regulation accuracy and good dynamic characteristics within the full speed range, thereby improving the power quality and system stability of the power generation system. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 FIG. is a schematic structural diagram of a power generation system provided by the present application;

[0028] Figure 2 FIG. is a curve diagram of the output voltage of the permanent magnet machine provided by the present application;

[0029] Figure 3 FIG. is a curve diagram of the output voltage of the permanent magnet machine after fitting provided by the present application;

[0030] Figure 4 FIG. is a comparison diagram of the output duty cycle curves of the present invention and the traditional scheme provided by the present application;

[0031] Figure 5 FIG. is a schematic circuit diagram of the internal circuit of the excitation switching module provided by the present application;

[0032] Figure 6 FIG. is a schematic diagram of the switch state of the excitation switching circuit provided by the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0033] In order to better understand the above technical solutions, the technical solutions of the embodiments of the present application will be described in detail below with reference to the drawings and specific embodiments. It should be understood that the specific features in the embodiments of the present application and the embodiments are detailed descriptions of the technical solutions of the embodiments of the present application, rather than limitations on the technical solutions of the present application. Without conflict, the technical features in the embodiments of the present application and the embodiments can be combined with each other.

[0034] Please refer to Figure 1, a power generation system provided by an embodiment of the present invention, the power generation system includes: an aero-engine, a three-stage excited synchronous motor, airborne electrical equipment, and the above-mentioned power generation controller.

[0035] Wherein, the three-stage excited synchronous motor is respectively connected to the aero-engine, the airborne electrical equipment and the power generation controller; the three-stage excited synchronous motor includes a permanent magnet machine, and the permanent magnet machine includes a plurality of stator windings, and the number of turns of different electronic windings is different.

[0036] Specifically, the three-stage excited synchronous motor further includes: an exciter and a main motor; the exciter is connected to the excitation control output module in the power generation controller for receiving the excitation voltage output by the excitation control output module; the main motor is connected to the airborne electrical equipment.

[0037] As Figure 1 shown, a power generation controller provided by an embodiment of the present invention includes: a plurality of rectification modules, a control and protection module, an excitation switching module, a voltage conditioning module, and an excitation control output module:

[0038] The input end of each rectification module is respectively connected to the corresponding stator winding in the permanent magnet machine, and the number of turns of different electronic windings is different; the rectification module is used to uncontrollably rectify the output voltage of the corresponding stator winding into a DC voltage; the number of turns of the electronic winding is proportional to the output voltage of the stator winding.

[0039] The output ends of all rectification modules and the output end of the control and protection module are respectively connected to the input end of the excitation switching module; the excitation switching module is used to select the DC voltage output by the corresponding rectification module based on the control signal input by the control and protection module;

[0040] The output end of the excitation switching module and the output end of the voltage conditioning module are respectively connected to the input end of the excitation control output module; the excitation control output module is used to output an excitation voltage.

[0041] In this embodiment, according to the excitation power and excitation power supply requirements of the exciter in the three-stage excited synchronous motor, the stator windings of the permanent magnet machine are designed as 2 sets or more sets of windings, and the number of turns of the stator windings are N1, N2,..., Nn respectively. At the same speed, multiple sets of permanent magnet machine voltages with different voltage values can be output: Vpmg1, Vpmg2,..., Vpmgn.

[0042] When the generator is at high speed, the output voltage of the permanent magnet machine is relatively high, and the DC voltage output by the rectification module is also relatively high. However, the exciter only needs a relatively small excitation voltage Vf to adjust the output voltage of the generator to the reference voltage. Since the duty cycle D of the PWM (Pulse Width Modulation) wave output by the voltage conditioning module is D = Vf / Vo, in order to avoid too small a duty cycle, a relatively small excitation DC power supply Vo needs to be selected, which can maintain a relatively high voltage regulation accuracy and good dynamic performance.

[0043] When the generator is at low speed, the output voltage of the permanent magnet machine is relatively low, and the DC voltage output by the rectification module is also relatively low. However, the exciter needs a relatively high excitation voltage Vf to adjust the output voltage of the generator to the reference voltage. Therefore, the PWM wave output by the voltage conditioning module needs to have a relatively high duty cycle to ensure that the excitation control output module outputs sufficient excitation voltage Vf. When the generator is under full load or overload conditions, the demand for excitation current is higher. If the duty cycle is too large, the generator controller cannot output sufficient excitation voltage. Therefore, by selecting a relatively large excitation DC power supply Vo, the duty cycle of the generator at low speed can be reduced, thus ensuring that the generator controller has sufficient excitation output capacity under full load or overload conditions.

[0044] The embodiment of the present invention comprehensively considers the requirements for excitation voltage of the three-stage excitation synchronous motor at different speeds, selects different PMG voltages through the excitation switching module, and fits an actual PMG voltage curve for providing the excitation power supply. The output voltage Vo of the excitation switching module can be controlled within a relatively small range and changes little with the speed. Furthermore, the duty cycle D of the PWM output by the voltage conditioning module can be controlled within an optimal range, which can improve the voltage regulation accuracy and obtain good dynamic performance.

[0045] This embodiment provides a power generation controller and a power generation system. The power generation controller includes: a plurality of rectification modules, a control and protection module, an excitation switching module, a voltage conditioning module, and an excitation control output module. Among them, the input ends of each rectification module are respectively connected to the corresponding stator windings in the permanent magnet machine, and the number of turns of different electronic windings is different; the rectification module is used to uncontrollably rectify the output voltage of the corresponding stator winding into a DC voltage; the output ends of all rectification modules and the output end of the control and protection module are respectively connected to the input end of the excitation switching module; the excitation switching module is used to select the DC voltage output by the corresponding rectification module based on the control signal input by the control and protection module; the output end of the excitation switching module and the output end of the voltage conditioning module are respectively connected to the input end of the excitation control output module; the excitation control output module is used to output an excitation voltage. In the permanent magnet machine of the present invention, the stator windings are designed in multiple sets, and after uncontrollable rectification through the corresponding rectification modules, a DC voltage is output. Then, the excitation switching module is used to control the selection of the output voltage of the corresponding permanent magnet machine at different speeds, so as to achieve a higher voltage regulation accuracy and better dynamic characteristics in the full speed range, thereby improving the power quality and system stability of the power generation system.

[0046] In an alternative embodiment provided by the present invention, the control and protection module is connected to the permanent magnet machine. The control and protection module is used to obtain the speed of the three-stage excitation synchronous generator corresponding to the frequency of the output voltage of the permanent magnet machine, and determine the control signal according to the speed of the three-stage excitation synchronous generator. That is, the switching instruction of the excitation switching module comes from the control and protection module of the power generation controller. The generator speed is obtained by detecting the frequency of the output voltage of the permanent magnet machine, and the output voltage of the permanent magnet machine in the corresponding channel is selected according to the generator speed, that is, the control signal output by the control and protection module to the excitation switching module is determined.

[0047] Specifically, in this embodiment, first, according to the excitation voltage requirements of the exciter of the three-stage electrically excited generator in the full power generation speed range and full load conditions, the output voltage of the corresponding permanent magnet machine is selected in different speed ranges to fit the output voltage curve of the permanent magnet machine, and the n - 1 switching speed points are determined according to the output voltage curve of the permanent magnet machine. Then, the control and protection module determines the control signal by comparing the engine speed with the n - 1 switching speed points, where n is the number of rectification modules.

[0048] In an alternative embodiment provided by the present invention, the excitation switching module includes n - 1 switch components, where n is the number of rectification modules. The lowest DC voltage output by the rectification module is directly connected to the output end of the excitation switching module; the other DC voltages output by the rectification module are respectively connected to the output end of the excitation switching module through the corresponding switch components.

[0049] Among them, the switch component includes: an MOS transistor, a diode, and a resistor; the gate (G) of the MOS transistor is connected to the output end of the control and protection module for receiving the control signal output by the control module; the drain (D) of the MOS transistor is connected to the output end of the rectification module; the source (S) of the MOS transistor is grounded through the resistor and connected to the output end of the excitation switching module through the diode.

[0050] Taking the actual application scenario of an aircraft power system as an example, the power generation controller and power generation system provided by the present invention make up for the deficiencies of the traditional three-stage constant-frequency or narrow-frequency variable generator voltage regulation method, improve the voltage regulation accuracy and dynamic characteristics of a wide-frequency variable generator, and are easy to implement.

[0051] Specifically, the required excitation power and excitation voltage Vf are determined according to the full-speed range and full-load conditions of the exciter. According to the no-load output voltage of the permanent magnet machine Vpmg≈E = 4.44NKfΦ (where: N is the number of turns of the stator winding of the permanent magnet machine; K is a constant coefficient (about 1.1 - 1.25); f is the frequency (n = 60f / p, where: n is the speed of the permanent magnet machine; f is the number of pole pairs of the permanent magnet machine); Φ is the magnetic flux), it can be seen that when the number of turns N of the permanent magnet machine is constant, its output voltage Vpmg is proportional to the speed n of the permanent magnet machine, and when the speed n of the permanent magnet machine is constant, its output voltage Vpmg is proportional to the number of turns N of the stator winding of the permanent magnet machine. The output voltage curves of different permanent magnet machine windings are as Figure 2 shown, where the winding turns corresponding to Vpmg1, Vpmg2, and Vpmg3 are N1, N2, and N3 respectively, and N1 < N2 < N3. Therefore, at the same speed, Vpmg1 < Vpmg2 < Vpmg3.

[0052] Since the required excitation voltage of the generator is smaller at high speeds, a smaller permanent magnet machine voltage is selected; at low speeds, the required excitation voltage is larger, so a larger permanent magnet machine voltage is selected. Two switching speed points ns1 and ns2 are selected. When the generator speed is less than ns1, the output voltage of the permanent magnet machine is taken as Vpmg3; when the generator speed is greater than ns1 and less than ns2, the output voltage of the permanent magnet machine is taken as Vpmg2, and when the generator speed is greater than ns2, the output voltage of the permanent magnet machine is taken as Vpmg1. The fitted output voltage curve of the permanent magnet machine is as Figure 3 shown. Among them, the switching speed points ns1 and ns2 are generally determined by taking the 1 / 3 and 2 / 3 positions between the maximum speed and the minimum speed in the output voltage curve of the permanent magnet machine.

[0053] The output voltages Vpmg1, Vpmg2, and Vpmg3 of the permanent magnet machine are subjected to uncontrolled rectification by the rectification module to obtain Vo1, Vo2, and Vo3 respectively. According to the fitted output voltage curve of the permanent magnet machine, when the generator speed is less than ns1, Vo = Vo3; when the generator speed is greater than ns1 and less than ns2, Vo = Vo2; when the generator speed is greater than ns2, Vo = Vo1. The duty cycle D of the PWM output by the voltage conditioning module is D = Vf / Vo. In the no-load state within the full speed range, the duty cycle curve of the present invention and the duty cycle curve of the traditional scheme are respectively as Figure 4 shown. At high speeds, the duty cycle of the present invention is increased, and better voltage regulation accuracy and dynamic response can be obtained at high speeds; at low speeds, the duty cycle of the present invention is decreased, but it is still within a reasonable duty cycle range, which can meet the requirement that the generator controller has sufficient excitation output capacity under full load or overload conditions.

[0054] Through Figure 1 the excitation switching module in, different output voltages of the permanent magnet machine can be selected. The schematic diagram of the excitation switching circuit is as Figure 5 shown, where Vo1 is the DC voltage output after the uncontrolled rectification of Vpmg1, which is directly connected to the output terminal Vo of the excitation switching circuit; Vo2 is the DC voltage output after the uncontrolled rectification of Vpmg2 by the rectification module, and is connected to the output terminal Vo of the excitation switching circuit through the switching MOS tube Q2; Vo3 is the DC voltage output after the uncontrolled rectification of Vpmg3 by the rectification module, and is connected to the output terminal Vo of the excitation switching circuit through the switching MOS tube Q3.

[0055] The switching of the DC voltage channels output by different rectification modules is achieved through the conduction and cut-off of the MOS tubes Q2 and Q3. The switching logic states are as Figure 6 shown, where state 1 represents conduction and state 0 represents cut-off. When the generator speed is less than ns1, Q3 conducts and Q2 cuts off. Since Vo3 is greater than Vo1, the excitation switching module outputs Vo = Vo3; when the generator speed is greater than ns1 and less than ns2, Q2 conducts and Q3 cuts off after a certain delay. At this time, the excitation switching module outputs Vo = Vo2; when the generator speed is greater than ns2, both Q2 and Q3 cut off. At this time, the excitation switching module outputs Vo = Vo1. To avoid the voltage fluctuation of the generator output caused by the instantaneous power-off during the switching process of the output voltage channels of the permanent magnet machine, the DC voltage Vo1 output after the uncontrolled rectification of the lowest voltage Vpmg1 of the permanent magnet machine output is directly connected to the output terminal, which can avoid the instantaneous power-off of the excitation power supply Vo during the switching process.

[0056] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the various embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. A power generation controller, characterized in that, The power generation controller includes: a plurality of rectification modules, a control and protection module, an excitation switching module, a voltage regulation module, and an excitation control output module: The input ends of each of the rectification modules are respectively connected to the corresponding stator windings in the permanent magnet machine, and the number of turns of different electronic windings is different; the rectification module is used to uncontrollably rectify the output voltage of the corresponding stator winding into a DC voltage; the number of turns of the electronic winding is proportional to the output voltage of the stator winding; The output ends of all the rectification modules and the output end of the control and protection module are respectively connected to the input end of the excitation switching module; the excitation switching module is used to select the DC voltage output by the corresponding rectification module based on the control signal input by the control and protection module; the excitation switching module includes n-1 switch components, where n is the number of rectification modules; the lowest DC voltage output by the rectification module is directly connected to the output end of the excitation switching module; the other DC voltages output by the rectification module are respectively connected to the output end of the excitation switching module through the corresponding switch components; The output end of the excitation switching module and the output end of the voltage regulation module are respectively connected to the input end of the excitation control output module; the excitation control output module is used to output an excitation voltage; The switch component includes: a MOS transistor, a diode, and a resistor; The gate (G) of the MOS transistor is connected to the output end of the control and protection module for receiving the control signal output by the control and protection module; The drain (D) of the MOS transistor is connected to the output end of the rectification module; The source (S) of the MOS transistor is grounded through the resistor and connected to the output end of the excitation switching module through the diode.

2. The power generation controller according to claim 1, wherein The control and protection module is connected to the permanent magnet machine motor for obtaining the speed of the three-stage electrically excited synchronous motor corresponding to the frequency of the output voltage of the permanent magnet machine, and determining the control signal according to the speed of the three-stage electrically excited synchronous motor.

3. The power generation controller according to claim 2, characterized in that, The control and protection module determines the control signal by comparing the speed of the three-stage electrically excited synchronous motor with n-1 switching speed points, where n is the number of rectification modules.

4. The power generation controller according to claim 3, characterized in that, According to the excitation voltage requirements of the exciter of the three-stage electrically excited synchronous motor in the full power generation speed range and full load conditions, select the corresponding output voltage of the permanent magnet machine in different speed ranges to fit the output voltage curve of the permanent magnet machine, and determine the n-1 switching speed points according to the output voltage curve of the permanent magnet machine.

5. A power generation system, characterized in that, The power generation system includes: an aeroengine, a three-stage electrically excited synchronous motor, airborne electrical equipment, and a power generation controller according to any one of claims 1-4; The three-stage electrically excited synchronous motor is respectively connected to the aeroengine, the airborne electrical equipment, and the power generation controller; Among them, the three-stage electrically excited synchronous motor includes a permanent magnet machine, and the permanent magnet machine includes a plurality of stator windings, and the number of turns of different electronic windings is different.

6. The power generation system according to claim 5, characterized in that, The three-stage electrically excited synchronous motor further includes: an exciter and a main motor; The exciter is connected to the excitation control output module in the power generation controller for receiving the excitation voltage output by the excitation control output module; The main motor is connected to the airborne electrical equipment.

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