A high-power low-voltage starting rectifier device

Abstract

The application provides a high-power low-voltage starting rectifying device, which comprises a three-phase input power distribution and filter unit, a three-phase 12-pulse rectifying unit, a DC / DC unit I, a DC / DC unit II and a control module; the three-phase input power distribution and filter unit is connected with the three-phase 12-pulse rectifying unit, the three-phase 12-pulse rectifying unit adopts a differential connection triangle autotransformer 12-pulse rectifying technology and is connected with the DC / DC unit I and the DC / DC unit II respectively; the DC / DC unit I adopts a three-channel staggered parallel phase-shift full-bridge technology, and the DC / DC unit II adopts a single-channel phase-shift full-bridge technology; the control module is connected with the DC / DC unit I and the DC / DC unit II respectively; the control module is used for controlling the DC / DC unit I and the DC / DC unit II to convert direct current voltage and supply a hovercraft gas turbine. The hovercraft gas turbine can be started.

Description

Technical Field

[0001] This invention relates to the power supply system of a gas turbine for hovercraft, and more specifically to a high-power, low-voltage starting rectifier. Background Technology

[0002] Starting the gas turbine of a hovercraft requires a special starting and rectification device.

[0003] The main functions of this starting rectifier include using AC220V / 400Hz three-phase three-wire electric power as input, converting and rectifying it to obtain DC60V and DC50V DC power supplies, which are used to power the starting winding and excitation winding of the DC motor, respectively, to start 5 gas turbines and complete various starting modes such as cold blowing, dummy start, and start-up of the gas turbines.

[0004] Currently, existing rectifiers are typically used to convert three-phase three-wire AC 380V / 50Hz power into DC power. There is no rectifier that can convert three-phase three-wire AC 220V / 400Hz power into DC power.

[0005] Furthermore, the rectifier of the hovercraft's gas turbine requires two DC power supply outputs of different voltages: DC 60V requires an output current of (600A~1000A)±2%; DC 50V requires an output current of 34A±2%, and the DC power supply must have preset parameters such as... Figure 1 The start-up curve shown indicates that current technology cannot start the gas turbine of a hovercraft. Summary of the Invention

[0006] This invention provides a high-power, low-voltage starting rectifier device, which solves the problem that existing technologies cannot start the gas turbine of hovercraft.

[0007] This invention provides a high-power, low-voltage starting rectifier, comprising: a three-phase input power distribution and filtering unit, a three-phase 12-pulse rectifier unit, a DC / DC unit I, a DC / DC unit II, and a control module; wherein,

[0008] The three-phase input power distribution and filtering unit is connected to the three-phase 12-pulse rectifier unit and is used to filter the input AC power and send it to the three-phase 12-pulse rectifier unit.

[0009] The three-phase 12-pulse rectifier unit adopts differential delta autotransformer 12-pulse rectification technology and is connected to the DC / DC unit I and the DC / DC unit II respectively. It is used to rectify the input AC power into DC power and supply it to the DC / DC unit I and the DC / DC unit II.

[0010] The DC / DC unit I adopts a three-channel interleaved parallel phase-shifting full-bridge technology, and the DC / DC unit II adopts a single-channel phase-shifting full-bridge technology; the control module is connected to the DC / DC unit I and the DC / DC unit II respectively;

[0011] The control module is used to control the DC / DC unit I and the DC / DC unit II to perform DC voltage conversion and supply it to the gas turbine of the hovercraft.

[0012] Optionally, the DC / DC unit I includes: 3 H-bridge IGBT modules, 6 transformer rectifier modules, and one output filter inductor-capacitor module;

[0013] The three H-bridge IGBT modules are connected in an interleaved parallel phase-shifting full-bridge wave-by-wave current limiting control manner. The input terminals of the three H-bridge IGBT modules are connected to the three-phase 12-pulse rectifier unit. The output terminals of the three H-bridge IGBT modules are respectively connected to two transformer rectifier modules in a series connection on the primary side and parallel connection on the secondary side.

[0014] The output terminals of the six transformer rectifier modules supply power to the gas turbine of the hovercraft through the output filter inductor-capacitor module.

[0015] Optionally, the control module is further configured to send a synchronization signal to the DC / DC unit I to control the output voltages of the three phase-shifting full-bridge circuits of the DC / DC unit I to be 120° out of phase.

[0016] Optionally, the output filter inductor-capacitor module includes: three inductors and one capacitor;

[0017] The two taps on the secondary side of the transformer rectifier modules in the same group are respectively connected in parallel to an inductor through a rectifier diode; each of the inductors is connected in parallel to the first terminal of the capacitor;

[0018] The center taps of the secondary sides of each transformer rectifier module are connected in parallel and connected to the second terminal of the capacitor.

[0019] Optionally, the control module is also used to provide overload protection and short-circuit protection for the DC / DC unit I and the DC / DC unit II.

[0020] Optionally, the high-power low-voltage starting rectifier also includes: a human-machine interface;

[0021] The human-machine interface is connected to the control module. The control module is also used to receive system protection parameters, output voltage, current and time input by the operator on the human-machine interface, and control the DC voltage conversion of the DC / DC unit I and the DC / DC unit II according to the operator's input.

[0022] Optionally, the three-phase 12-pulse rectifier unit is specifically used to rectify AC220V / 400Hz AC power into DC300V DC power.

[0023] Optionally, the high-power low-voltage starting rectifier also includes: a 24V auxiliary power supply;

[0024] The 24V auxiliary power supply is connected to the three-phase input power distribution and filtering unit and the control module respectively, and is used to rectify the AC power supply into 24V DC power supply to power the control module.

[0025] This invention provides a high-power, low-voltage starting rectifier, comprising: a three-phase input power distribution and filtering unit, a three-phase 12-pulse rectifier unit, a DC / DC unit I, a DC / DC unit II, and a control module; wherein, the three-phase input power distribution and filtering unit is connected to the three-phase 12-pulse rectifier unit, and is used to filter the input AC power supply and send it to the three-phase 12-pulse rectifier unit; the three-phase 12-pulse rectifier unit adopts differential delta autotransformer 12-pulse rectification technology, and is connected to the DC / DC unit I and the DC / DC unit II respectively, for rectifying the input AC power supply into DC power and supplying it to the DC / DC unit I and the DC / DC unit II; the DC / DC unit I adopts a three-channel interleaved parallel phase-shifting full-bridge technology, and the DC / DC unit II adopts a single-channel phase-shifting full-bridge technology; the control module is connected to the DC / DC unit I and the DC / DC unit II respectively; the control module is used to control the DC / DC unit I and the DC / DC unit II to perform DC voltage conversion and supply it to the gas turbine of the hovercraft. It can start the gas turbine of the hovercraft. Attached Figure Description

[0026] Figure 1 The output timing diagram of the starting rectifier for the gas turbine of the hovercraft;

[0027] Figure 2 Circuit configuration block diagram of the high-power low-voltage starting rectifier device provided by the present invention;

[0028] Figure 3 The circuit block diagram of the three-phase input power distribution and filtering unit provided by the present invention;

[0029] Figure 4 This is a structural diagram of the DC / DC unit I (channel I) provided by the present invention;

[0030] Figure 5 This is a structural diagram of the DC / DC unit II (channel II) provided by the present invention;

[0031] Figure 6This is a schematic diagram of the control module provided by the present invention. Detailed Implementation

[0032] The following explanation, in conjunction with the accompanying drawings, compares and contrasts the high-power low-voltage starting rectifier device provided by this invention.

[0033] Reference Figure 1-6 The technical problem to be solved by the present invention is to provide a technical configuration of a high-power low-voltage starting rectifier device and to develop a prototype of a starting rectifier device for a hovercraft gas turbine.

[0034] The technical solution of this invention is the technical design configuration and application of a high-power, low-voltage starting rectifier device; the starting rectifier device for a hovercraft gas turbine includes: three-phase input power distribution and filtering, three-phase 12-pulse rectification, DC / DC unit I, DC / DC unit II, 24V auxiliary power supply, control module, operation display module, and communication module. The circuit configuration block diagram is shown below. Figure 2 .

[0035] The three-phase 12-pulse rectifier unit employs a differential delta autotransformer 12-pulse rectifier technology to rectify the input AC220V power supply into approximately DC300V, simultaneously supplying DC / DC unit I and DC / DC unit II. The three-phase input rectification is as follows: Figure 3 As shown.

[0036] DC / DC Unit I adopts a three-channel interleaved parallel phase-shifted full-bridge scheme, consisting of three H-bridge IGBT modules, six transformer-rectifier modules, and one output filter inductor-capacitor module. The three H-bridge IGBT modules employ an interleaved parallel phase-shifted full-bridge wave-by-wave current-limiting control method, and the output transformer uses a primary-side series connection and a secondary-side parallel connection. The structure of DC-DC Unit I is as follows: Figure 4 As shown.

[0037] DC / DC Unit II (Output Channel II) adopts a single-channel phase-shifted full-bridge design. The structure of DC / DC Unit II is as follows: Figure 5 As shown.

[0038] The control module consists of an ARM microcontroller as the control core, supplemented by multiple dedicated circuits, such as... Figure 6As shown. The main function of the control core is to receive external operation commands, coordinate the actions of multiple functional modules within the power supply, and manage tasks such as summarizing, displaying, and reporting operating status. In addition, an important function of the control core is to send synchronization signals to the three phase-shifting full-bridge circuits of channel I, ensuring that the output voltages of the three interleaved parallel phase-shifting full-bridge circuits differ by 120°, reducing output voltage and current ripple. Furthermore, the control module is responsible for setting and saving system operating parameters. Operators can set system protection parameters and output voltage, current, and time (slope) settings through the human-machine interface (touch panel). Each time the system is powered on, the control module calls up the set values ​​to set the operating parameters of the entire system; parameter setting is completed through the communication bus.

[0039] For example, the technical solution of the present invention includes the following points:

[0040] 1) Employing differential delta autotransformer 12-pulse rectification technology, the rectifier unit boasts advantages such as small size, light weight, low input current THD, low output DC voltage ripple, and strong overload capacity. It can rectify the input AC220V / 400Hz AC power supply into approximately DC300V DC power to supply DC / DC unit I and DC / DC unit II.

[0041] 2) The DC / DC unit I adopts interleaved parallel control, which can effectively reduce input and output current ripple, reduce the size and weight of output filter inductors and capacitors, and improve power output quality; the phase-shifted full-bridge working mode can effectively reduce IGBT switching losses and ensure IGBT working reliability; the wave-by-wave current-limiting feedforward control mode can actively suppress transformer bias magnetization, effectively limit the output short-circuit current within a safe range, and protect the high-frequency rectifier diodes and starter motor.

[0042] 3) Each group of two transformer rectifier modules in DC / DC unit I adopts a primary series and secondary parallel structure to ensure that the two transformer rectifier modules work in a voltage-equal and current-equal manner; at the same time, since multiple groups of diodes on the secondary side work in parallel, the current stress of each diode is reduced, ensuring the overload output capability of the DC gas turbine starting rectifier device.

[0043] 4) In the DC / DC unit I circuit, since the output transformers adopt a series connection on the primary side and a parallel connection on the secondary side, the voltage and current sharing problems of each group of transformers are easily solved. As for the current sharing of the three H-bridge modules, a control strategy using a shared current reference signal can be adopted.

[0044] 5) DC / DC unit II supplies power to the excitation winding of the starter motor. The output power is relatively small. It adopts a phase-shifted full-bridge scheme, which is highly efficient, small in size and weight, mature, widely used, and can well meet the technical requirements of this system.

[0045] 6) The control module fulfills the control and communication requirements of the circuit, can accept external operation commands, coordinate the actions of multiple functional modules inside the power supply, and perform management tasks such as summarizing, displaying and reporting working status.

[0046] 7) The control core can send a synchronization signal to the three phase-shifted full-bridge circuits of channel I to ensure that the output voltages of the three phase-shifted full-bridge circuits connected in parallel are 120° apart, thereby reducing the output voltage and current ripple.

[0047] 8) Under the input power supply conditions of three-phase three-wire AC220V±10% and frequency of 400Hz±5%, the output power supply can meet the requirements of: Channel I: Voltage: DC60V±2%; Current: (600A~1000A)±2%; Channel II: Voltage: DC50V±2%; Current: 34A±2%.

[0048] 9) Efficiency: ≥80% under standard operating conditions; Insulation resistance: not less than 10MΩ when cold and not less than 1MΩ when hot.

[0049] 10) Protection functions:

[0050] a) Overload protection: When the current in channel I exceeds 1200A and the current in channel II exceeds 40A, the delay / duration shall not exceed 6s;

[0051] b) Short circuit protection: When the short circuit current of channel I exceeds (2400±500)A and the short circuit current of channel II exceeds (100±50)A, the delay time shall not exceed 0.1s;

[0052] c) Input over / under voltage protection: Immediate protection when the input voltage fluctuation exceeds 220V±15%;

[0053] Meets research and development requirements;

[0054] 11) The input voltage and current waveforms of the starting device during the entire process of starting turbine No. 1 are shown in [reference needed]. Figure 1As shown; at time t0 when the device receives the start-up signal, channel II immediately outputs the set excitation current (34A) to establish a magnetic field inside the starter motor; simultaneously, channel II gradually increases the starting current according to the set starting current curve, enabling the gas turbine to overcome its internal clearance and begin a smooth start; at time t1, the output current of channel II reaches the given current (600~1000A), switching to a constant current output state, causing the DC starter motor to operate in a near-constant torque mode, driving the gas turbine to accelerate. As the speed increases, the back electromotive force of the motor increases, becoming constant. As the output current increases, the output voltage of this device also increases synchronously. When the output voltage of the device reaches the set voltage (DC60V) of the starter motor at time t2, in order to ensure that the starter motor can continue to rotate, the device adopts a field weakening speed-up control method to gradually reduce the excitation current output by channel II to the set minimum value (time t3). After that, as the gas turbine is successfully ignited, the work done by the gas turbine and the output of the starter motor are superimposed, causing the gas turbine to speed up, the output torque of the starter motor to decrease, and the output current of channel II to automatically decrease. When the current drops to the set value at time t4, the system automatically exits operation.

Claims

1. A high-power, low-voltage starting rectifier device, characterized in that, include: The system comprises a three-phase input power distribution and filtering unit, a three-phase 12-pulse rectifier unit, DC / DC unit I, DC / DC unit II, and a control module; among which... The three-phase input power distribution and filtering unit is connected to the three-phase 12-pulse rectifier unit and is used to filter the input AC power and send it to the three-phase 12-pulse rectifier unit. The three-phase 12-pulse rectifier unit adopts differential delta autotransformer 12-pulse rectification technology and is connected to the DC / DC unit I and the DC / DC unit II respectively. It is used to rectify the input AC power into DC power and supply it to the DC / DC unit I and the DC / DC unit II. The DC / DC unit I adopts a three-channel interleaved parallel phase-shifting full-bridge technology, and the DC / DC unit II adopts a single-channel phase-shifting full-bridge technology; the control module is connected to the DC / DC unit I and the DC / DC unit II respectively; The control module is used to control the DC / DC unit I and the DC / DC unit II to perform DC voltage conversion and supply it to the gas turbine of the hovercraft. The DC / DC unit I includes: 3 H-bridge IGBT modules, 6 transformer rectifier modules, and one output filter inductor-capacitor module; The three H-bridge IGBT modules are connected in an interleaved parallel phase-shifting full-bridge wave-by-wave current limiting control manner. The input terminals of the three H-bridge IGBT modules are connected to the three-phase 12-pulse rectifier unit. The output terminals of the three H-bridge IGBT modules are respectively connected to two transformer rectifier modules in a series connection on the primary side and parallel connection on the secondary side. The output terminals of the six transformer rectifier modules supply power to the gas turbine of the hovercraft through the output filter inductor-capacitor module; The control module is also used to send a synchronization signal to the DC / DC unit I to control the output voltage of the three phase-shifting full-bridge circuits of the DC / DC unit I to be 120° out of phase. The control module is further configured to, upon receiving the start-up time t0, immediately output a set excitation current of 34A from the DC / DC unit II to establish a magnetic field inside the starter motor; simultaneously, the DC / DC unit I gradually increases the starting current according to the set starting current curve, enabling the gas turbine to overcome its internal clearance and begin a smooth start; at time t1, the output current of the DC / DC unit I reaches the given current of 600~1000A, switching to a constant current output state, causing the DC starter motor to operate in a near-constant torque mode, driving the gas turbine to accelerate. As the speed increases, the back electromotive force of the motor increases, providing a constant output current for the DC / DC unit II. As the output current increases, the output voltage of DC / DC unit I rises synchronously. When the output voltage of DC / DC unit I reaches the starter motor's set voltage of DC60V at time t2, to ensure that the starter motor can continue to rotate, DC / DC unit II adopts a field weakening speed-up control method to gradually reduce the excitation current output by DC / DC unit II to the set minimum value at time t3. Afterwards, as the gas turbine is successfully ignited, the work done by the gas turbine and the output of the starter motor are superimposed, causing the gas turbine to accelerate, the output torque of the starter motor to decrease, and the output current of DC / DC unit I to automatically decrease. When the current drops to the set value at time t4, it automatically stops operating.

2. The apparatus according to claim 1, characterized in that, The output filter inductor-capacitor module includes: three inductors and one capacitor; The two taps on the secondary side of the transformer rectifier modules in the same group are respectively connected in parallel to an inductor through a rectifier diode; each of the inductors is connected in parallel to the first terminal of the capacitor; The center taps of the secondary sides of each transformer rectifier module are connected in parallel and connected to the second terminal of the capacitor.

3. The apparatus according to claim 1, characterized in that, The control module is also used to provide overload protection and short-circuit protection for the DC / DC unit I and the DC / DC unit II.

4. The apparatus according to claim 1, characterized in that, Also includes: Human-computer interaction interface; The human-machine interface is connected to the control module. The control module is also used to receive system protection parameters, output voltage, current and time input by the operator on the human-machine interface, and control the DC voltage conversion of the DC / DC unit I and the DC / DC unit II according to the operator's input.

5. The apparatus according to claim 1, characterized in that, The three-phase 12-pulse rectifier unit is specifically used to rectify AC220V / 400Hz AC power into DC300V DC power.

6. The apparatus according to claim 1, characterized in that, It also includes: 24V auxiliary power supply; The 24V auxiliary power supply is connected to the three-phase input power distribution and filtering unit and the control module respectively, and is used to rectify the AC power supply into 24V DC power supply to power the control module.

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