A control device and integrated control method for a high-speed switched reluctance starter-generator

Abstract

This invention discloses a control device and integrated control method for a high-speed switched reluctance starter generator. The control device includes a main power circuit and a control circuit. The main power circuit includes a starter soft-start circuit, a permanent magnet generator rectifier circuit, a dual three-phase unbalanced half-bridge circuit, a bleeder circuit, and a drive circuit. The starter soft-start circuit is connected to the dual three-phase unbalanced half-bridge circuit via the bleeder circuit. The permanent magnet generator rectifier circuit is connected to the dual three-phase unbalanced half-bridge circuit via the permanent magnet generator soft-start circuit and the bleeder circuit. The drive circuit... The input terminal is connected to the control circuit, and the output terminal is connected to each IGBT transistor in the dual three-phase asymmetrical half-bridge circuit. The control circuit is also connected to the contactors and relays in the starting soft-start circuit, permanent magnet motor rectifier circuit, permanent magnet motor soft-start circuit, and discharge circuit in the main power circuit. The control device for the switched reluctance starter generator is used to control the connection and disconnection of each contactor and relay in the main power circuit, as well as the control of the dual three-phase asymmetrical half-bridge circuit, to achieve integrated control of the starting and power generation of the switched reluctance starter generator. The technical solution of this invention solves the problem that existing research on switched reluctance motors is generally focused on low speed and small to medium power, while research and engineering application practice of high-power, high-speed switched reluctance generators are still lacking.

Description

Technical Field

[0001] This invention relates to, but is not limited to, the field of aviation switched reluctance motor control technology, and particularly to a control device and integrated control method for a high-speed switched reluctance starter generator. Background Technology

[0002] In response to the future development trend of all-electric / multi-electric aircraft, and in view of some problems in aircraft DC motor starting / generating systems, such as the limitation of motor speed and maximum power by DC motor brushes and commutators, the large weight and inconvenient installation of the low-voltage DC power grid when transmitting high power, and the increase in the size and weight of the secondary power supply due to the increase of AC electrical equipment, high-voltage DC starting / generating technology has been developed in close line with the needs of the aviation industry for power systems.

[0003] Addressing the electric starting requirements, high-power, high-speed power generation needs, and engine-integrated starting / generating requirements of next-generation aircraft high-thrust turbofan engines, as well as the future aircraft's demand for robust power supply systems, traditional wound-rotor motors, with their rotating diodes and other components, have limited speed and power. Permanent magnet motors, on the other hand, are costly and difficult to demagnetize during power generation. Considering that switched reluctance (SR) motors have no windings or permanent magnets on their rotors, possess excellent high-temperature resistance, are suitable for high-speed operation, and are easily adapted to achieve high capacity and dual starting / generating functions, a solution is proposed.

[0004] Currently, Nanjing University of Aeronautics and Astronautics and Northwestern Polytechnical University have conducted feasibility studies on the application of SR starter / generator systems in aviation. In terms of fundamental theory, they have conducted specialized research on starting characteristics and power generation quality, as well as strong excitation topology circuits, power generation control strategies, and rotorless position sensor technology control strategies. In engineering practice, Nanjing University of Aeronautics and Astronautics has developed two prototypes, 3kW and 6kW, with air-cooled motors. Existing research and applications of switched reluctance motors mainly focus on the motor's operating state, and are concentrated on low speeds and small to medium power. Research on high-power switched reluctance motors is currently very limited, and no engineering applications have been achieved. Summary of the Invention

[0005] The purpose of this invention is to address the aforementioned technical problems by providing a control device and integrated control method for a high-speed switched reluctance starter generator. This addresses the issue that existing research on switched reluctance motors is generally focused on low speeds and small to medium power, while research and engineering applications of high-power, high-speed switched reluctance generators are still lacking.

[0006] The technical solution of the present invention: In a first aspect, the present invention provides a control device for a high-power, high-speed switched reluctance starter generator, characterized in that it includes: a main power circuit and a control circuit;

[0007] The main power circuit includes: a starting soft-start circuit, a permanent magnet motor rectifier circuit, a permanent magnet motor soft-start circuit, a dual three-phase asymmetrical half-bridge circuit, a discharge circuit, and a drive circuit. The starting soft-start circuit is connected to the dual three-phase asymmetrical half-bridge circuit through the discharge circuit. The permanent magnet motor rectifier circuit is connected to the dual three-phase asymmetrical half-bridge circuit through the permanent magnet motor soft-start circuit and the discharge circuit. The input terminal of the drive circuit is connected to the control circuit, and the output terminal is connected to each IGBT in the dual three-phase asymmetrical half-bridge circuit. The control circuit is also connected to the contactors and relays in the starting soft-start circuit, the permanent magnet motor rectifier circuit, the permanent magnet motor soft-start circuit, and the discharge circuit in the main power circuit.

[0008] The control device for the switched reluctance starter generator is used to control the connection and disconnection of each contactor and relay in the main power circuit through the control circuit, as well as the control of the dual three-phase asymmetrical half-bridge circuit, so as to realize the integrated control of the starting and power generation of the switched reluctance starter generator.

[0009] Optionally, in the control device for a high-power, high-speed switched reluctance starter generator described above, the dual three-phase asymmetrical half-bridge circuit adopts a dual-channel three-phase asymmetrical half-bridge structure, including: a bus support capacitor, an output filter capacitor, a generator diode, and two sets of power IGBT modules.

[0010] The bus support capacitor is connected between the starting bus and the power negative line, and is located at the front end of the dual three-phase asymmetrical half-bridge circuit. The output filter capacitor is connected between the generator output bus and the power negative line, and is located at the rear end of the dual three-phase asymmetrical half-bridge circuit. In each power IGBT module, three IGBT bridge arms are connected between the starting bus and the power negative line (to form three-phase positive electricity), and another three IGBT bridge arms are connected between the generator output bus and the power negative line (to form three-phase negative electricity). These three IGBT bridge arms are combined to form three sets of IGBT bridge arms, through which the three-phase current of the generator is output.

[0011] The positive terminal of the power generation diode is connected to the power output bus, and the negative terminal is connected to the starting bus. The power generation diode is located on the side of the output bus closer to the excitation side, so as to transmit the current generated by the generator to the excitation side.

[0012] Optionally, in the control device for a high-power, high-speed switched reluctance starter generator as described above,

[0013] The starting soft-start circuit includes: a series branch of a resistor and a starting soft-start relay, and a starting soft-start contactor connected in parallel with the series branch; the input terminal of the starting soft-start circuit is connected to the power supply through the soft-start relay and the starting contactor, and the output terminal is connected to the starting bus and the discharge circuit.

[0014] The starting soft-start circuit is used to limit the charging current of the bus support capacitor at the moment of power-on, so as to reduce the impact on the power supply and the bus support capacitor; it is also used to connect the starting soft-start contactor under the control of the control circuit after the bus support capacitor has finished charging, so that the control device enters the normal operation state.

[0015] Optionally, in the control device for a high-power, high-speed switched reluctance starter generator as described above,

[0016] The permanent magnet generator rectifier circuit includes a GCR relay and an uncontrolled rectifier bridge connected in series. The input terminal of the generator relay is connected to the permanent magnet generator, and the output terminal of the uncontrolled rectifier bridge is connected to the permanent magnet generator soft power-on circuit and the discharge circuit, respectively. The permanent magnet generator rectifier circuit is used to rectify the three-phase AC power output by the permanent magnet generator into DC power, and the GCR relay controls whether the DC power is connected to the downstream circuit.

[0017] The permanent magnet generator soft power-on circuit includes a generator soft power-on relay and a current-limiting resistor connected in parallel. Its input terminal is connected to one output terminal of an uncontrolled rectifier bridge, and its output terminal is connected to the starting bus. The permanent magnet generator soft power-on circuit is used to achieve soft power-on in the initial excitation voltage building-up stage of the generator generation stage.

[0018] Optionally, in the control device for a high-power, high-speed switched reluctance starter generator as described above,

[0019] The discharge circuit includes a discharge relay and a discharge resistor connected in series; the discharge relay is also connected to the starting bus, and the discharge resistor is connected to another output terminal of the uncontrolled rectifier bridge; the discharge circuit is used to quickly discharge the voltage on the starting bus in a short time when the start-up and power generation are terminated.

[0020] Optionally, in the control device for a high-power, high-speed switched reluctance starter generator as described above, the control circuit includes: a DSP chip, a CPLD chip, and a resolver decoding chip connected in pairs; the CPLD chip is connected to the drive circuit, and the DSP chip is connected to each contactor and relay in the main power circuit;

[0021] The resolver decoding chip is used to decode the motor rotor position signal, and the DSP chip and CPLD chip acquire the motor rotor position signal. The DSP chip is used to calculate the initial position of the motor and send it to the CPLD chip. The CPLD chip counts the incremental encoded signal of the motor rotor position signal based on the initial position of the motor. The DSP chip is also used to calculate the motor speed based on the received position signal, and send the control signal of the drive circuit to the CPLD chip based on the speed calculation result, so as to control the drive circuit to realize the functional control of the power IGBT module in the dual three-phase asymmetrical half-bridge circuit.

[0022] The DSP chip is also connected to the main power circuit through a data acquisition circuit, and controls the connection and disconnection of each relay and contactor by acquiring the voltage signal in the main power circuit.

[0023] Secondly, embodiments of the present invention also provide an integrated control method for a high-power, high-speed switched reluctance starter generator. The integrated control method for the high-power, high-speed switched reluctance starter generator is executed using a control device as described in any of the preceding claims, comprising: start control and power generation control; wherein the start control includes soft-on-start control and generator start control in the initial start phase, and the power generation control includes soft-on-start voltage building control and power generation process control in the initial power generation phase.

[0024] Optionally, in the integrated control method for a high-power, high-speed switched reluctance starter generator as described above, the starting control mode includes:

[0025] First, the starting soft power-on relay is turned on. Through the current limiting effect of the resistor and the starting soft power-on relay, the impact of the bus support capacitor at the moment of power-on is reduced.

[0026] When the voltage of the busbar support capacitor on the starting busbar is greater than 190V, the starting soft power-on contactor is turned on and the starting soft power-on relay is turned off to achieve fast charging and complete the soft power-on of the starting power supply.

[0027] The starting control strategy is pre-configured in the control circuit. The dual three-phase asymmetrical half-bridge circuit is controlled by the drive circuit. According to the motor rotor position and the set turn-on and turn-off angles, the power IGBT module is driven by the drive circuit to convert the 270V DC starting power supply into the three-phase power supply required by the motor, generate power torque, and drive the engine to start.

[0028] Optionally, in the integrated control method for a high-power, high-speed switched reluctance starter generator as described above, the power generation control mode includes:

[0029] First, turn on the GCR relay. When the voltage on the starting bus is greater than 140V, turn on the generator soft power-on relay.

[0030] Under the action of the external voltage-building excitation power supply through the permanent magnet generator, the bus support capacitor is charged after passing through the current-limiting resistor. After passing through the uncontrolled rectifier bridge of the permanent magnet generator rectifier circuit, the permanent magnet generator outputs DC voltage, completing the power generation voltage-building process.

[0031] After the voltage is built up, the pre-configured power generation control strategy in the control circuit is adopted. The dual three-phase asymmetrical half-bridge circuit is controlled by the drive circuit to complete the power generation voltage regulation and stably output 270V DC power.

[0032] When the motor speed reaches the grid connection speed and the generator voltage regulation meets (270±5)V and remains stable for 1s, the generator contactor connected in parallel to the output filter capacitor is turned on to realize grid connection; when the motor speed is lower than the grid connection speed, the dual three-phase asymmetrical half-bridge circuit is controlled to stop the output of the power IGBT module and the generator contactor is turned off to realize grid disconnection.

[0033] The beneficial effects of the present invention: The embodiments of the present invention provide a control device and integrated control method for a high-speed switched reluctance starter generator. The control device includes two parts: a main power circuit and a control circuit. In the main power circuit, the starting soft-on circuit is connected to the dual three-phase unbalanced half-bridge circuit through a bleed circuit; the permanent magnet rectifier circuit is connected to the dual three-phase unbalanced half-bridge circuit through the permanent magnet soft-on circuit and the bleed circuit; the input terminal of the drive circuit is connected to the control circuit, and the output terminal is connected to each IGBT transistor in the dual three-phase unbalanced half-bridge circuit. The control circuit is also connected to each contactor and relay in the main power circuit. The control device controls the connection and disconnection of each contactor and relay in the main power circuit through the control circuit, as well as the control of the dual three-phase unbalanced half-bridge circuit, to achieve integrated control of the starting and power generation of the switched reluctance starter generator. The control device and control strategy for high-speed switched reluctance starter generators provided in this invention are used to achieve integrated starting and generation by switching reluctance starter generators through mode switching. The control strategy of the control circuit realizes the soft start process, the soft voltage building process of generation, and the process of switching generation from external excitation to self-excitation. This method has the advantages of maintaining a relatively stable excitation voltage in external excitation mode, while reducing the weight of the system and improving the system efficiency in self-excitation mode. Attached Figure Description

[0034] The accompanying drawings are provided to further understand the technical solutions of the present invention and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of the present invention and do not constitute a limitation on the technical solutions of the present invention.

[0035] Figure 1 A circuit block diagram of a control device for a high-power, high-speed switched reluctance starter generator provided in an embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of the circuit structure of a control device for a high-power, high-speed switched reluctance starter generator provided in an embodiment of the present invention;

[0037] Figure 3 This is a flowchart illustrating the starting control process of a control device for a high-power, high-speed switched reluctance starter generator provided in an embodiment of the present invention.

[0038] Figure 4 This is a flowchart illustrating the power generation control process of a control device for a high-power, high-speed switched reluctance starter generator provided in an embodiment of the present invention. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

[0040] As explained in the background section, based on the characteristics and high-temperature resistance of switched reluctance motors (SR motors), they can easily achieve both high capacity and dual functions of starting and generating electricity. However, existing research and applications of SR motors mainly focus on the motor's operating state, and are concentrated on low speeds and small to medium power. Research on high-power SR motors is currently very limited, and no engineering applications have been achieved.

[0041] To enable switched reluctance motors to be used in high-power, high-speed starting engines, this invention designs a control device and a corresponding integrated control method for high-power, high-speed switched reluctance starter generators. Specifically, it provides a control device and integrated control method for high-speed switched reluctance starter generators, which has good application prospects in the aviation field.

[0042] The present invention provides the following specific embodiments, which can be combined with each other. For the same or similar concepts or processes, they may not be described again in some embodiments.

[0043] Figure 1 This is a circuit block diagram of a control device for a high-power, high-speed switched reluctance starter generator, provided as an embodiment of the present invention. Figure 1 As shown, the main components of the control device for the switched reluctance starter generator provided in this embodiment of the invention include: a main power circuit and a control circuit.

[0044] like Figure 1 As shown, the main power circuit includes: a starting soft-start circuit, a permanent magnet motor rectifier circuit, a permanent magnet motor soft-start circuit, a dual three-phase asymmetrical half-bridge circuit, a discharge circuit, and a drive circuit; wherein, the starting soft-start circuit is connected to the dual three-phase asymmetrical half-bridge circuit through the discharge circuit; the permanent magnet motor rectifier circuit is connected to the dual three-phase asymmetrical half-bridge circuit through the permanent magnet motor soft-start circuit and the discharge circuit; the input terminal of the drive circuit is connected to the control circuit, and the output terminal is connected to each IGBT transistor in the dual three-phase asymmetrical half-bridge circuit. The control circuit is also connected to the contactors and relays in the starting soft-start circuit, the permanent magnet motor rectifier circuit, the permanent magnet motor soft-start circuit, and the discharge circuit in the main power circuit.

[0045] The control device for the switched reluctance starter generator in this embodiment of the invention is used to control the connection and disconnection of each contactor and relay in the main power circuit through the control circuit, as well as the control of the dual three-phase asymmetrical half-bridge circuit, so as to realize the integrated control of starting and generating of the switched reluctance starter generator.

[0046] The specific structure of each circuit in the control device for the switched reluctance starter generator provided in the embodiments of the present invention will be described below.

[0047] (I) Main Power Circuit

[0048] like Figure 2 The diagram shown is a circuit structure schematic of a control device for a high-power, high-speed switched reluctance starter generator provided in an embodiment of the present invention.

[0049] 1.1 The dual three-phase asymmetrical half-bridge circuit includes: power IGBT modules, bus support capacitors, output filter capacitors, and generator diodes. The IGBT modules are used to build the three-phase asymmetrical half-bridge circuit. Each phase winding is connected to two IGBTs and two freewheeling diodes, enabling independent control of the three stator windings without bridge arm shoot-through. Because the current flowing through the switching devices is large when using a single-channel three-phase asymmetrical half-bridge topology, and to achieve redundant control, a dual-channel three-phase asymmetrical half-bridge topology is used. The generator diodes connect the starting bus and the generator output bus. The bus support capacitor is connected between the starting bus and the power negative line, located at the front end of the circuit. This bus support capacitor is used to stabilize the starting bus current and maintain the starting bus voltage during the starting phase. The output filter capacitor is connected between the starting bus and the power negative line, located at the end of the three-phase asymmetrical half-bridge circuit. The output filter capacitor is used to filter the output pulsating voltage, outputting a quality 270VDC power supply.

[0050] In practical implementation, the dual-channel three-phase asymmetrical half-bridge topology can include: two sets of power IGBT modules, such as... Figure 2 As shown, in each power IGBT module, three IGBT arms are connected between the starting bus and the power negative line (to form three-phase positive electricity), and another three IGBT arms are connected between the generator output bus and the power negative line (to form three-phase negative electricity). These three IGBT arms are combined to form three sets of IGBT arms, through which the three-phase current of the generator is output.

[0051] 1.2 The starting soft-start circuit includes a series branch of a resistor and a starting soft-start relay, and a starting soft-start contact connected in parallel with the aforementioned series branch. The input terminal of the starting soft-start circuit is connected to the power supply through the soft-start relay and the starting contactor, and the output terminal is connected to the starting bus and the discharge circuit. Because the bus support capacitor charges rapidly at the moment of power-on, to reduce the impact on the support capacitor at the moment of power-on and improve the reliability and safety of the product, the charging current of the bus support capacitor needs to be limited during power-on. This reduces the impact on the power supply and the bus support capacitor, thus protecting the capacitor and the power supply circuit. After the bus support capacitor has finished charging, the control circuit sends a connection signal to control the starting soft-start contactor to close, at which point the control device enters normal operation.

[0052] It should be noted that the connection method between the soft start relay and the starting contactor is similar to the connection method between the starting soft power-on relay and the starting soft power-on contactor, such as... Figure 1 As shown, a resistor is connected in series with a soft-start relay, and the whole unit is connected in parallel with the starting contactor.

[0053] 1.3 The permanent magnet generator rectifier circuit includes a series-connected generator relay (GCR relay) and an uncontrolled rectifier bridge. The input terminal of the GCR relay is connected to the permanent magnet generator, and the output terminal of the uncontrolled rectifier bridge is connected to the permanent magnet generator's soft-start circuit and discharge circuit, respectively. The three-phase AC power output from the permanent magnet generator is rectified into DC power. The GCR relay is controlled by a control circuit to determine whether the DC power is connected to the downstream circuit.

[0054] 1.4 The permanent magnet generator soft-start circuit includes a generator soft-start relay and a current-limiting resistor connected in parallel. Its input is connected to one output of an uncontrolled rectifier bridge, and its output is connected to the starting bus. The front-end permanent magnet generator is mainly used in the initial excitation and voltage build-up stage of the power generation phase. Since the excitation power is small and the operating time is short during the excitation and voltage build-up stage, a permanent magnet generator soft-start circuit with a generator soft-start relay and a current-limiting resistor connected in parallel is selected to achieve soft power-up in the initial stage of power generation.

[0055] 1.5 The discharge circuit includes a discharge relay and a discharge resistor connected in series; the discharge relay is also connected to the starting bus, and the discharge resistor is connected to the other output terminal of the uncontrolled rectifier bridge. It is mainly used to quickly discharge voltage in a short time when starting and stopping or when power generation stops.

[0056] (II) Control Circuit

[0057] like Figure 1 As shown, the control circuit includes: a DSP chip, a CPLD chip, and a resolver decoder chip connected in pairs; the CPLD chip is connected to the drive circuit, and the DSP chip is connected to each contactor and relay in the main power circuit. Its main functions include position calculation, start-up control, and power generation control.

[0058] The resolver decoding chip is used to decode the motor rotor position signal, while the DSP chip and CPLD chip simultaneously acquire the generator rotor position signal. The resolver decoding chip feeds back the decoded motor rotor position signal to the DSP chip via a data bus for speed calculation and other data processing. It also sends the initial motor position to the CPLD chip via the data bus, and the CPLD chip counts the incrementally encoded signal of the decoded motor rotor position based on the initial position. The DSP chip calculates the motor speed based on the received position signal and sends control signals for the drive circuit to the CPLD chip based on the speed calculation result. This control enables the drive circuit to perform functional control of the power IGBT modules in the dual three-phase asymmetrical half-bridge circuit. Additionally, the DSP chip is connected to the main power circuit via an acquisition circuit. By acquiring voltage signals from the main power circuit, it controls the switching on and off of relays and contactors. Through the switching control of relays and contactors in the main power circuit, and the control of the dual three-phase asymmetrical half-bridge circuit, it achieves starting control and generation control functions.

[0059] The operation of the control device for the switched reluctance starter generator provided in the above embodiments of the present invention is described as follows:

[0060] When the switched reluctance starter generator enters the starting state, the starting control process is as follows: To avoid current surges to the control device when the starting power supply is powered on, the soft-start relay is first activated. Since the soft-start relay is connected in series with a resistor, it effectively reduces the surge of the bus support capacitor at the moment of power-on. When the voltage of the bus support capacitor on the starting bus is greater than 190V, the soft-start contactor is activated and the soft-start relay is deactivated to achieve rapid charging and complete the soft-start of the starting power supply. Then, the starting control strategy pre-configured in the DSP chip of the control circuit controls the dual three-phase asymmetrical half-bridge circuit through the drive circuit. Based on the motor rotor position and the set turn-on and turn-off angles, the six IGBT bridge arms are driven by the drive circuit to convert the 270V DC starting power supply into the three-phase power supply required by the motor, generating power torque and driving the engine to start. The rotor position signal required during the starting process is provided by the motor.

[0061] The power generation control process is as follows: First, the GCR relay is turned on. When the voltage on the starting bus is greater than 140V, the power generation soft-on relay is turned on. Under the action of the external voltage-building excitation power supply through the permanent magnet generator, the bus support capacitor is charged after passing through the current-limiting resistor. The permanent magnet generator outputs DC voltage after passing through the uncontrolled rectifier bridge of the permanent magnet generator rectifier circuit, completing the power generation voltage building process. After the voltage building is completed, the power generation control strategy pre-configured in the control circuit is adopted. The dual three-phase asymmetrical half-bridge circuit is controlled by the drive circuit to complete the power generation voltage regulation and stably output 270V DC power (power generation output + / -). When the motor speed reaches the grid-connected speed, and the power generation voltage regulation meets (270±5)V and is stable for 1s, the power generation contactor connected in parallel after the output filter capacitor is turned on to realize the power generation grid connection. When the motor speed is lower than the grid-connected speed, the control device stops the output of the power IGBT module and controls the power generation contactor to open, realizing the grid disconnection.

[0062] It should be noted that switched reluctance starter generators employ two regenerative braking modes during operation: self-excited and externally excited. In externally excited mode, the initial excitation is provided by the power supply of an external permanent magnet generator during the initial voltage build-up. In self-excited mode, after voltage build-up, the generator voltage provides its own excitation power, converting mechanical energy into electrical energy output. The generator diodes ensure that current flows only from the generator side to the excitation side. Once the voltage is established, the external excitation power supply is disconnected, and the output filter capacitor provides the excitation energy, achieving system self-excitation.

[0063] This invention provides a control device and integrated control method for a high-speed switched reluctance starter generator. The control device includes a main power circuit and a control circuit. In the main power circuit, a starting soft-start circuit is connected to a dual three-phase asymmetrical half-bridge circuit via a bleed circuit; a permanent magnet rectifier circuit is connected to the dual three-phase asymmetrical half-bridge circuit via a permanent magnet soft-start circuit and a bleed circuit; the input terminal of the drive circuit is connected to the control circuit, and the output terminal is connected to each IGBT transistor in the dual three-phase asymmetrical half-bridge circuit. The control circuit is also connected to each contactor and relay in the main power circuit. The control device controls the connection and disconnection of each contactor and relay in the main power circuit through the control circuit, as well as the control of the dual three-phase asymmetrical half-bridge circuit, to achieve integrated control of the starting and power generation of the switched reluctance starter generator. The control device and control strategy for high-speed switched reluctance starter generators provided in this invention are used to achieve integrated starting and generation by switching reluctance starter generators through mode switching. The control strategy of the control circuit realizes the soft start process, the soft voltage building process of generation, and the process of switching generation from external excitation to self-excitation. This method has the advantages of maintaining a relatively stable excitation voltage in external excitation mode, while reducing the weight of the system and improving the system efficiency in self-excitation mode.

[0064] The following examples illustrate the starting control process and power generation control process of the control device and integrated control method for a high-power, high-speed switched reluctance starter generator provided in this invention.

[0065] Implementation Example 1

[0066] like Figure 3 The diagram shows a flowchart of the starting control process performed by the control device for a high-power, high-speed switched reluctance starter generator provided in an embodiment of the present invention. The starting control process provided in this embodiment 1 includes the following steps:

[0067] 1) When the start command is valid and the motor rotor speed is less than 7200 r / min, switch to start mode.

[0068] 2) Upon entering the start-up mode, first, the soft start relay is activated; after a 500ms delay, the start contactor is activated; upon detecting the activation of the start contactor's auxiliary contacts, the soft start relay is deactivated and the soft power-on relay is activated; when the start bus voltage is greater than or equal to 190V, after a 200ms confirmation period, the soft power-on contactor is closed; after a 30ms delay, both the soft power-on relay and the soft start relay are deactivated, completing the soft power-on control. During the soft power-on process, the bus current does not exceed 200A, and the soft power-on time does not exceed 3 seconds.

[0069] 3) Subsequently, the control circuit, according to the starting control strategy, controls variables such as the motor winding current and the on / off interval through the drive circuit, outputs a drive signal, converts the 270V DC power into the three-phase power required by the motor, generates power torque, controls the motor to drive the engine to rotate, and completes the engine starting control.

[0070] 4) The starting control strategy in this implementation example 1 is:

[0071] a) Controlling the given current: Four speed ranges are set: starting speed 1, starting speed 2, starting speed 3, and starting speed 4. Different given current values ​​are set according to different starting speed ranges. When the motor speed is less than or equal to starting speed 1, if the given current value is less than the given current limit 1, the given current value = given current + 10; otherwise, the given current = given current limit 1. When the motor speed is greater than starting speed 1 and less than or equal to starting speed 2, the given current value increases to the given current limit 2 according to the given curve. When the motor speed is greater than starting speed 2 and less than or equal to starting speed 3, the given current increases to the given current limit 3 according to the given curve. When the motor speed is greater than starting speed 3, the given current value = (starting speed 3 / current speed) * given current limit 3. If the given current value is greater than the given current limit 3, then the given current value = given current limit 3. If the given current value is greater than the given current limit 4, then the given current value = given current limit 4.

[0072] b) Control the turn-on and turn-off angles: Set three speed ranges: angle speed 1, angle speed 2, and angle speed 3.

[0073] When the rotational speed is less than the angular rotational speed 1, set the on-angle 1 and the off-angle 1; when the rotational speed is greater than or equal to the angular rotational speed 1 and less than the angular rotational speed 2, set the on-angle 2 and the off-angle 2; when the rotational speed is greater than or equal to the angular rotational speed 2 and less than the angular rotational speed 3, set the on-angle 3 and the off-angle 3; when the rotational speed is greater than the angular rotational speed 3, set the on-angle 4 and the off-angle 4.

[0074] like Figure 3 As shown, the start-up and termination process also provided in this implementation example 1 includes the following steps:

[0075] 1) When the start command is invalid, the speed is greater than 7200 r / min, or a start failure occurs, disconnect the start contactor and the start soft power-on contactor.

[0076] 2) When the starting bus voltage is below 5V and the control signal of the discharge relay is on, the discharge relay will be disconnected after a delay of 1 second; when the starting bus voltage is above 5V and the control signal of the discharge relay is on, the discharge relay will be disconnected after a delay of 20 seconds.

[0077] Implementation Example 2

[0078] like Figure 4 The diagram shows a flowchart illustrating the power generation control process of a control device for a high-power, high-speed switched reluctance starter generator according to an embodiment of the present invention. The power generation control process provided in this embodiment 2 includes the following steps:

[0079] 1) When the GCS command is valid and the speed is greater than 20,000 r / min, switch to power generation mode.

[0080] 2) First, the control GCR relay is activated; when the starting bus voltage is greater than or equal to 140V, and after a 20ms delay, the generator soft-on relay is activated to complete the generator soft-on control; when the motor rotor speed reaches the voltage-building speed, the control device controls the motor to achieve the generator voltage-building function. During the voltage-building process, the given voltage increases by 10V every 30ms until it reaches 270V, realizing the soft voltage-building function; when the motor speed reaches the grid-connected speed of 22000r / min, and the generator voltage regulation voltage is greater than or equal to 270V, after stabilizing for 50ms, the generator contactor connected in parallel to the output filter capacitor is activated.

[0081] 3) After a 30ms delay, the control GCR relay and the generator soft-power relay are disconnected, realizing the grid connection of the generator. The current flows from the generator side to the excitation side through the generator diode, thereby realizing self-excitation.

[0082] 4) In power generation mode, the control circuit adjusts the voltage through a pre-configured power generation control strategy to ensure that the output voltage is within the required adjustment range.

[0083] 5) The power generation control strategy in this implementation example 2 is as follows: voltage closed-loop control is adopted. The difference between the given voltage regulation and the actual voltage regulation is calculated, and the given current is output through PI regulation to perform excitation control on the motor windings, thereby realizing closed-loop control.

[0084] like Figure 4 As shown, the power generation termination process also provided in this implementation example 2 includes the following steps:

[0085] 1) When the GCS command is invalid, the speed is less than 20000 r / min, or a power generation failure occurs, if the power generation contactor is already connected, the control power generation contactor, GCR relay, and power generation soft-energization relay will disconnect.

[0086] 2) When the starting bus voltage is below 5V and the control signal of the discharge relay is on, the discharge relay will be disconnected after a delay of 1 second; when the starting bus voltage is above 5V and the control signal of the discharge relay is on, the discharge relay will be disconnected after a delay of 20 seconds.

[0087] While the embodiments disclosed in this invention are as described above, they are merely illustrative of the embodiments to facilitate understanding of the invention and are not intended to limit the invention. Any person skilled in the art to which this invention pertains may make any modifications and variations in the form and details of the implementation without departing from the spirit and scope disclosed herein; however, the scope of patent protection for this invention shall still be determined by the scope defined in the appended claims.

Claims

1. A control device for a high-power, high-speed switched reluctance starter generator, characterized in that, include: Main power circuit and control circuit; The main power circuit includes: a starting soft-start circuit, a permanent magnet motor rectifier circuit, a permanent magnet motor soft-start circuit, a dual three-phase asymmetrical half-bridge circuit, a discharge circuit, and a drive circuit. The starting soft-start circuit is connected to the dual three-phase asymmetrical half-bridge circuit through the discharge circuit. The permanent magnet motor rectifier circuit is connected to the dual three-phase asymmetrical half-bridge circuit through the permanent magnet motor soft-start circuit and the discharge circuit. The input terminal of the drive circuit is connected to the control circuit, and the output terminal is connected to each IGBT in the dual three-phase asymmetrical half-bridge circuit. The control circuit is also connected to the contactors and relays in the starting soft-start circuit, the permanent magnet motor rectifier circuit, the permanent magnet motor soft-start circuit, and the discharge circuit in the main power circuit. The starting soft-start circuit includes: a series branch of a resistor and a starting soft-start relay, and a starting soft-start contactor connected in parallel with the series branch; the input terminal of the starting soft-start circuit is connected to the power supply through the soft-start relay and the starting contactor, and the output terminal is connected to the starting bus and the discharge circuit; the permanent magnet generator soft-start circuit includes a generator soft-start relay and a current-limiting resistor connected in parallel, its input terminal is connected to one output terminal of an uncontrolled rectifier bridge, and its output terminal is connected to the starting bus. The control device for the switched reluctance starter generator is used to control the connection and disconnection of each contactor and relay in the main power circuit through the control circuit, as well as the control of the dual three-phase asymmetrical half-bridge circuit, to realize the integrated control of starting and generating of the switched reluctance starter generator, including: starting control and generating control; wherein, the starting control includes starting soft power-on control and generator starting control in the initial stage of starting, and the generating control includes soft power-on voltage building control in the initial stage of generating and control of the generating process; The starting control method includes: First, the starting soft power-on relay is turned on. Through the current limiting effect of the resistor and the starting soft power-on relay, the impact of the bus support capacitor at the moment of power-on is reduced. When the voltage of the busbar support capacitor on the starting busbar is greater than 190V, the starting soft power-on contactor is turned on and the starting soft power-on relay is turned off to achieve fast charging and complete the soft power-on of the starting power supply. The starting control strategy is pre-configured in the control circuit. The dual three-phase asymmetrical half-bridge circuit is controlled by the drive circuit. According to the motor rotor position and the set turn-on and turn-off angles, the power IGBT module is driven by the drive circuit to convert the 270V DC starting power supply into the three-phase power supply required by the motor, generate power torque, and drive the engine to start.

2. The control device for a high-power, high-speed switched reluctance starter generator according to claim 1, characterized in that, The dual three-phase asymmetrical half-bridge circuit adopts a dual-channel three-phase asymmetrical half-bridge structure, including: bus support capacitor, output filter capacitor and power generation diode, as well as two sets of power IGBT modules. The bus support capacitor is connected between the starting bus and the power negative line, and is located at the front end of the dual three-phase asymmetrical half-bridge circuit. The output filter capacitor is connected between the generator output bus and the power negative line, and is located at the rear end of the dual three-phase asymmetrical half-bridge circuit. In each power IGBT module, three IGBT bridge arms are connected between the starting bus and the power negative line to form three-phase positive electricity, and another three IGBT bridge arms are connected between the generator output bus and the power negative line to form three-phase negative electricity. These three IGBT bridge arms are combined to form three sets of IGBT bridge arms, through which the three-phase current of the generator is output. The positive terminal of the power generation diode is connected to the power output bus, and the negative terminal is connected to the starting bus. The power generation diode is located on the side of the output bus closer to the excitation side, so as to transmit the current generated by the generator to the excitation side.

3. The control device for a high-power, high-speed switched reluctance starter generator according to claim 2, characterized in that, The starting soft-start circuit is used to limit the charging current of the bus support capacitor at the moment of power-on, so as to reduce the impact on the power supply and the bus support capacitor; it is also used to connect the starting soft-start contactor under the control of the control circuit after the bus support capacitor has finished charging, so that the control device enters the normal operation state.

4. The control device for a high-power, high-speed switched reluctance starter generator according to claim 3, characterized in that, The permanent magnet generator rectifier circuit includes a GCR relay and an uncontrolled rectifier bridge connected in series. The input terminal of the GCR relay is connected to the permanent magnet generator, and the output terminal of the uncontrolled rectifier bridge is connected to the permanent magnet generator soft power-on circuit and the discharge circuit, respectively. The permanent magnet generator rectifier circuit is used to rectify the three-phase AC power output by the permanent magnet generator into DC power, and the GCR relay controls whether the DC power is connected to the downstream circuit.

5. The control device for a high-power, high-speed switched reluctance starter generator according to claim 4, characterized in that, The discharge circuit includes a discharge relay and a discharge resistor connected in series; the discharge relay is also connected to the starting bus, and the discharge resistor is connected to another output terminal of the uncontrolled rectifier bridge; the discharge circuit is used to quickly discharge the voltage on the starting bus in a short time when the start-up and power generation are terminated.

6. The control device for a high-power, high-speed switched reluctance starter generator according to any one of claims 1 to 5, characterized in that, The control circuit includes: a DSP chip, a CPLD chip, and a resolver decoder chip connected in pairs; the CPLD chip is connected to the drive circuit, and the DSP chip is connected to each contactor and relay in the main power circuit. The resolver decoding chip is used to decode the motor rotor position signal, and the DSP chip and CPLD chip acquire the motor rotor position signal. The DSP chip is used to calculate the initial position of the motor and send it to the CPLD chip. The CPLD chip counts the incremental encoded signal of the motor rotor position signal based on the initial position of the motor. The DSP chip is also used to calculate the motor speed based on the received position signal, and send the control signal of the drive circuit to the CPLD chip based on the speed calculation result, so as to control the drive circuit to realize the functional control of the power IGBT module in the dual three-phase asymmetrical half-bridge circuit. The DSP chip is also connected to the main power circuit through a data acquisition circuit, and controls the connection and disconnection of each relay and contactor by acquiring the voltage signal in the main power circuit.

7. An integrated control method for a high-power, high-speed switched reluctance starter generator, characterized in that, An integrated control method for a high-power, high-speed switched reluctance starter generator, using the control device for a high-power, high-speed switched reluctance starter generator as described in any one of claims 1 to 6, includes: start control and power generation control; wherein the start control includes soft-on power-up control and generator start control in the initial stage of start-up, and the power generation control includes soft-on voltage building-up control in the initial stage of power generation and control of the power generation process.

8. The integrated control method for a high-power, high-speed switched reluctance starter generator according to claim 7, characterized in that, The starting control method includes: First, the starting soft power-on relay is turned on. Through the current limiting effect of the resistor and the starting soft power-on relay, the impact of the bus support capacitor at the moment of power-on is reduced. When the voltage of the busbar support capacitor on the starting busbar is greater than 190V, the starting soft power-on contactor is turned on and the starting soft power-on relay is turned off to achieve fast charging and complete the soft power-on of the starting power supply. The starting control strategy is pre-configured in the control circuit. The dual three-phase asymmetrical half-bridge circuit is controlled by the drive circuit. According to the motor rotor position and the set turn-on and turn-off angles, the power IGBT module is driven by the drive circuit to convert the 270V DC starting power supply into the three-phase power supply required by the motor, generate power torque, and drive the engine to start.

9. The integrated control method for a high-power, high-speed switched reluctance starter generator according to claim 7, characterized in that, The power generation control method includes: First, turn on the GCR relay. When the voltage on the starting bus is greater than 140V, turn on the generator soft power-on relay. Under the action of the external voltage-building excitation power supply through the permanent magnet generator, the bus support capacitor is charged after passing through the current-limiting resistor. After passing through the uncontrolled rectifier bridge of the permanent magnet generator rectifier circuit, the permanent magnet generator outputs DC voltage, completing the power generation voltage-building process. After the voltage is built up, the pre-configured power generation control strategy in the control circuit is adopted. The dual three-phase asymmetrical half-bridge circuit is controlled by the drive circuit to complete the power generation voltage regulation and stably output 270V DC power. When the motor speed reaches the grid connection speed and the generator voltage regulation voltage meets (270±5)V and remains stable for 1s, the generator contactor connected in parallel to the output filter capacitor is turned on to realize grid connection; when the motor speed is lower than the grid connection speed, the dual three-phase asymmetrical half-bridge circuit is controlled to stop the output of the power IGBT module and the generator contactor is controlled to disconnect to realize grid disconnection.

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