A power distribution control system for an AC / DC power supply test bench

Abstract

The application provides an AC-DC power supply test bed power distribution control system, comprising an AC power supply, a switching power supply, a DC power supply, a touch screen, a PLC, a communication interface conversion circuit, a frequency converter and a motor, wherein the AC power supply is connected with the switching power supply, the touch screen and the frequency converter respectively, the switching power supply is connected with the DC power supply, the touch screen, the communication interface conversion circuit and the frequency converter in sequence, the communication interface conversion circuit is connected with the frequency converter and the PLC respectively, and the frequency converter is connected with the motor; the I0.0 input port of the PLC is connected with a change-over switch to select a manual or automatic working mode for the test bed power distribution control system, the I0.1 input port of the PLC is connected with a start button to start the frequency converter of the test bed power distribution control system, the I0.2 input port of the PLC is connected with a stop button to stop the frequency converter of the test bed power distribution control system, and the I0.3 input port of the PLC is connected with an emergency stop button to control the stop of the test bed power distribution control system.

Description

Technical Field

[0001] This invention belongs to the field of aviation electrical equipment testing and control technology, and relates to a power distribution control system for an AC / DC power supply test bench. Background Technology

[0002] Traditional electromechanical aviation power supply test benches are simple in structure and low in precision. They can only perform tests on the power supply system and some of its components. They have limited functions, rely on manual button operation for testing, and are prone to unstable output speed and malfunctions. They also require highly skilled test personnel and cannot achieve automated management and dynamic performance index analysis of AC / DC power supply integrated test benches. Summary of the Invention

[0003] This application provides a power distribution control system for an AC / DC power supply test bench, which can solve the problems of simple structure and low precision of traditional electromechanical aviation power supply test benches.

[0004] Technical solution: This application provides an AC / DC power supply test bench power distribution control system, including an AC power supply, a switching power supply, a DC power supply, a touch screen, a PLC, a communication interface conversion circuit, a frequency converter, and a motor, wherein: The AC power supply is connected to the switching power supply, the touch screen and the frequency converter respectively. The switching power supply is connected to the DC power supply, the touch screen, the communication interface conversion circuit and the frequency converter in sequence. The communication interface conversion circuit is connected to the frequency converter and the PLC respectively. The frequency converter is connected to the motor. The PLC's I0.0 input port, connected to a selector switch, allows selection of manual or automatic operation mode for the test bench's power distribution control system. The PLC's I0.1 input port, connected to a start button, starts the inverter in the power distribution control system. The PLC's I0.2 input port, connected to a stop button, stops the inverter. The PLC's I0.3 input port, connected to an emergency stop button, stops the power distribution control system. The PLC's I0.4 input port, connected to the normally open contact of the inverter's fan, starts the power distribution control system. The system controls the inverter fan; the PLC's I0.5 input port is connected to the normally open contact of the oil pump motor to start the oil pump of the test bench's power distribution control system for lubrication of the motor; the PLC's Q0.0 output port is connected to an external indicator light, which illuminates when this output point is activated; the PLC's Q0.1 output port is connected to an external intermediate relay, which starts the inverter fan when activated; the PLC's Q0.2 output port is connected to an external intermediate relay, which starts the oil pump motor when activated; the PLC's Q0.3 output port is connected to an external intermediate relay, which starts the fan when activated. The PLC's N and L pins are powered by an external AC220V power supply; the PLC's data port 1 is connected to the inverter of the test bench's power distribution control system; and the PLC's data port 2 is connected to the touch screen of the test bench's power distribution control system to enable communication with the outside world.

[0005] Specifically, the AC power supply is equipped with a main power controller. External three-phase AC power is supplied to the main power controller, which distributes the AC power to the corresponding electrical equipment, including frequency converters, touch screens, and switching power supplies.

[0006] Specifically, the AC power supply is also equipped with a phase sequence protector. The external three-phase AC power is first input to the phase sequence protector, and then input to the main power controller by the phase sequence protector. The phase sequence protector is used for phase sequence checking. The main contactor is only connected when the input power phase sequence is correct. There is also a protective relay for automatic phase sequence discrimination to avoid accidents or equipment damage caused by reversed power phase sequence.

[0007] Specifically, the switching power supply provides the required electrical energy to the DC power supply; the DC power supply converts the electrical energy provided by the switching power supply into 24V power and distributes it to the touch screen.

[0008] Specifically, the touch screen provides signals to the PLC and frequency converter through a communication interface conversion circuit.

[0009] Specifically, the PLC communicates with the frequency converter via a communication interface conversion circuit and controls the frequency converter to achieve stepless speed frequency conversion control, thereby controlling the motor and automating the entire power supply test bench power distribution control system.

[0010] Specifically, the frequency converter is connected to the motor via a signal connection, and the motor is directly driven by the frequency converter to achieve stepless speed regulation within the range of 0~5000rpm. The real-time speed of the motor is acquired by multiplying the frequency of the frequency converter by a multiplier. The frequency converter adopts AC-DC-AC variable frequency speed regulation technology. The speed transient change overshoot of the frequency converter under sudden addition and removal of a 50KVA load is <100r / min. The recovery time does not exceed 2s, and the steady-state control accuracy is higher than 0.1%.

[0011] Specifically, after measuring the armature current and voltage of the motor from the output of the inverter, this current is transformed through a motor model with vector transformation to generate two current components equivalent to a DC motor: excitation current Iμ and stator current Iw. The transformed components are used to control the triggering of the IGBT transistors in the inverter, thereby achieving the purpose of torque control and improving the dynamic response characteristics of the speed regulation system. Ultimately, the speed of the motor is controlled, thus forming a speed closed-loop control in the entire control system. A 1024-line incremental pulse encoder is installed on the motor as a speed detection unit for data acquisition, with an error not exceeding 1‰. The encoder has a built-in DB output module, which transmits the data to the PLC through a digital transmission module. The data is compared with the set value, and the PLC outputs a deviation signal to the inverter. The inverter controls the motor speed to achieve motor speed regulation control.

[0012] In summary, this application provides a power distribution control system for an AC / DC power supply test bench. The advantages of this invention are: First, by adopting touch screen control technology, the motor drive, load control and experimental operation process are integrated and managed. It can provide an excellent human-machine interface according to specific test tasks, simplify the operation procedures and improve the safety of the test.

[0013] Secondly, the AC / DC power supply test bench used can simulate the speed of an aircraft engine. In order to achieve miniaturization of the equipment and ease of use and operation, its design adopts a scheme of direct drive of the motor by frequency converter to realize stepless speed regulation of the motor, which can meet the testing requirements of various generators. Attached Figure Description

[0014] Figure 1 This application provides a schematic diagram of the power distribution control system for an AC / DC power supply test bench. Figure 2 The PLC schematic diagram provided for this application. Detailed Implementation

[0015] The purpose of this invention is to develop a power distribution control system for an aircraft AC / DC power supply test bench. This invention employs touchscreen control technology to manage the entire process, providing an excellent human-machine interface based on the test task. It can measure and analyze dynamic performance indicators. The system's main equipment and components are replaceable, and it has complete internal detection interfaces for easy and rapid troubleshooting. It has the advantages of convenient operation, good real-time performance, good scalability, and reliable operation.

[0016] Example 1 like Figure 1 As shown, this application provides an AC / DC power supply test bench power distribution control system, including an AC power supply, a switching power supply, a DC power supply, a touch screen, a PLC, a communication interface conversion circuit, a frequency converter, and a motor, wherein: The AC power supply is connected to the switching power supply, the touch screen and the frequency converter respectively. The switching power supply is connected to the DC power supply, the touch screen, the communication interface conversion circuit and the frequency converter in sequence. The communication interface conversion circuit is connected to the frequency converter and the PLC respectively. The frequency converter is connected to the motor.

[0017] like Figure 2 As shown, the PLC's I0.0 input port is connected to a selector switch to select manual or automatic operating mode for the test bench's power distribution control system. The PLC's I0.1 input port, connected to a start button, can start the test bench's power distribution control system's frequency converter. The PLC's I0.2 input port, connected to a stop button, can stop the test bench's power distribution control system's frequency converter. The PLC's I0.3 input port, connected to an emergency stop button, can control the stop of the test bench's power distribution control system. The PLC's I0.4 input port, connected to the normally open contact of the frequency converter's fan, can start the frequency converter's fan. The PLC's I0.5 input port, connected to the normally open contact of the oil pump motor, can start the test bench's power distribution control system's oil pump to lubricate the motor. The PLC's Q0.0 output port is connected to an external indicator light; when this output point is activated, the fault light illuminates. The PLC's Q0.1 output port is connected to an external intermediate relay; when this output point is activated, the inverter fan starts. The PLC's Q0.2 output port is connected to an external intermediate relay; when this output point is activated, the oil pump motor starts. The PLC's Q0.3 output port is connected to an external intermediate relay; when this output point is activated, the fan starts. The PLC's N and L pins are powered by an external AC220V power supply. The PLC's data port 1 is connected to the inverter of the test bench's power distribution control system, and the PLC's data port 2 is connected to the touchscreen of the test bench's power distribution control system to achieve communication with the outside world.

[0018] Specifically, the AC power supply is equipped with a main power controller. External three-phase AC power is supplied to the main power controller, which distributes the AC power to the corresponding electrical equipment, including frequency converters, touch screens, and switching power supplies.

[0019] Specifically, the AC power supply is also equipped with a phase sequence protector. The external three-phase AC power is first input to the phase sequence protector, and then input to the main power controller. The phase sequence protector is used for phase sequence checking. It only connects the main contactor when the input power phase sequence is correct, and has an automatic phase sequence discrimination protection relay to prevent accidents or equipment damage caused by reversed power phase sequence.

[0020] Specifically, the switching power supply provides the required electrical energy to a DC power source.

[0021] Specifically, the DC power supply converts the electrical energy provided by the switching power supply into 24V power, which is then distributed to the touch screen.

[0022] Specifically, the touchscreen provides signals to the PLC and frequency converter via a communication interface conversion circuit. The touchscreen controls and sets the speed value; displays the setpoint and actual speed values; and monitors motor current, motor temperature, frequency converter temperature, frequency converter frequency, oil tank temperature, and fault alarms.

[0023] It should be noted that the touchscreen allows for convenient operation and control of the test bench, and enables intuitive real-time monitoring of various motor parameters. This avoids malfunctions caused by traditional buttons, improving the reliability of the system's normal operation, offering simpler and more intuitive operation, and providing powerful parameter setting functions. Specifically, the PLC communicates with the frequency converter via a communication interface conversion circuit and controls the frequency converter to achieve stepless speed frequency conversion control, thereby controlling the motor and automating the entire power supply test bench power distribution control system.

[0024] Specifically, the frequency converter is connected to the motor via a signal connection, and the motor is directly driven by the frequency converter to achieve stepless speed regulation within the range of 0~5000rpm. Real-time motor speed is acquired by multiplying the frequency of the frequency converter by a multiplier. The frequency converter adopts AC-DC-AC variable frequency speed control technology; the speed transient change overshoot of the frequency converter under sudden addition and removal of a 50KVA load is <100r / min; the recovery time does not exceed 2s; and the steady-state control accuracy is higher than 0.1%.

[0025] It should be noted that the electric motor combines the advantages of both high-speed and variable frequency motors. High-speed motors are small in size and can be directly connected to high-speed loads, eliminating the need for traditional mechanical speed-increasing devices, reducing system noise while improving transmission efficiency. Their main characteristics are high rotor speed, high stator winding current and magnetic flux frequency in the iron core, and high power density and loss density. Variable frequency motors, on the other hand, are motors that, under standard environmental conditions, operate continuously at 100% rated load within a speed range of 10% to 100% of rated speed without exceeding the motor's rated allowable temperature rise. Combining these two technologies improves the motor's efficiency and thermal performance, making it more suitable for the technical requirements of AC / DC power supply test benches.

[0026] Specifically, the working principle of the power distribution control system of the test bench is as follows: it adopts vector speed closed-loop control, using voltage and current transmitters to detect the output voltage and current, giving the entire speed control system high dynamic characteristics and speed stability accuracy. The system measures the armature current and voltage of the motor from the output of the frequency converter. After transforming this current through a motor model with vector transformation, it generates two current components equivalent to a DC motor: excitation current Iμ and stator current Iw. These transformed components control the triggering of the IGBT transistors in the inverter, thereby controlling the torque and improving the dynamic response characteristics of the speed control system. Ultimately, the speed of the motor is controlled, thus forming a speed closed-loop control in the entire control system. A 1024-line incremental pulse encoder is installed on the motor as a speed detection unit for data acquisition, with an error not exceeding 1‰. The encoder has a built-in DB output module, which transmits the data to the PLC via a digital transmission module. The data is compared with the set value, and the PLC outputs a deviation signal to the frequency converter, which then controls the motor speed to achieve speed control.

[0027] In summary, this application provides a power distribution control system for an AC / DC power supply test bench, which has the following advantages: First: The power distribution control system of the test bench is controlled by a frequency converter, employing AC-DC-AC variable frequency speed regulation technology to meet the requirements of stepless speed regulation within 0~5000rpm, with a speed accuracy of ≤±3 / 1000. A 1024-line incremental pulse encoder is used as the speed detection element to achieve closed-loop speed control. It has protection functions such as overcurrent, overvoltage, undervoltage, overload, overspeed, maximum frequency, minimum frequency limits, and current limits, as well as a fault self-diagnosis function. Relevant parameters can be set and pre-selected via the panel.

[0028] Second: The touch screen serves as the input and output interface for speed parameters. Through the touch screen, the speed setpoint can be set; the speed setpoint and actual value can be displayed; motor current, motor temperature, inverter temperature, inverter frequency, oil tank temperature, fault alarms, etc. are displayed, making the operation interface more convenient and intuitive.

[0029] Third: The test control console has automatic / manual control functions, enabling automatic and manual adjustment of speed and load. Speed ​​adjustment can be achieved in three ways: 1. via touchscreen settings; 2. via the control panel buttons; 3. via the speed adjustment knob on the panel.

[0030] Fourth: This method and apparatus are widely applicable.

[0031] This invention uses a touch screen to control and manage the entire process, providing an excellent human-machine interface according to the test task. The operation is simpler and more intuitive, avoiding the malfunctions of traditional buttons and improving the reliability of the system's normal operation.

Claims

1. A power distribution control system for an AC / DC power supply test bench, characterized in that, This includes AC power supplies, switching power supplies, DC power supplies, touch screens, PLCs, communication interface conversion circuits, frequency converters, and motors, among which: The AC power supply is connected to the switching power supply, the touch screen and the frequency converter respectively. The switching power supply is connected to the DC power supply, the touch screen, the communication interface conversion circuit and the frequency converter in sequence. The communication interface conversion circuit is connected to the frequency converter and the PLC respectively. The frequency converter is connected to the motor.

2. The system according to claim 1, characterized in that, The PLC's I0.0 input port, connected to a selector switch, allows selection of manual or automatic operation mode for the test bench's power distribution control system. The PLC's I0.1 input port, connected to a start button, starts the inverter in the power distribution control system. The PLC's I0.2 input port, connected to a stop button, stops the inverter. The PLC's I0.3 input port, connected to an emergency stop button, stops the power distribution control system. The PLC's I0.4 input port, connected to the normally open contact of the inverter's fan, starts the power distribution control system. The system controls the inverter fan; the PLC's I0.5 input port is connected to the normally open contact of the oil pump motor to start the oil pump of the test bench's power distribution control system for lubrication of the motor; the PLC's Q0.0 output port is connected to an external indicator light, which illuminates when this output point is activated; the PLC's Q0.1 output port is connected to an external intermediate relay, which starts the inverter fan when activated; the PLC's Q0.2 output port is connected to an external intermediate relay, which starts the oil pump motor when activated; the PLC's Q0.3 output port is connected to an external intermediate relay, which starts the fan when activated. The PLC's N and L pins are powered by an external AC220V power supply; the PLC's data port 1 is connected to the inverter of the test bench's power distribution control system; and the PLC's data port 2 is connected to the touch screen of the test bench's power distribution control system to enable communication with the outside world.

3. The system according to claim 1, characterized in that, The AC power supply is equipped with a main power controller. External three-phase AC power is supplied to the main power controller, which distributes the AC power to the corresponding electrical equipment, including frequency converters, touch screens, and switching power supplies.

4. The system according to claim 1, characterized in that, The AC power supply is also equipped with a phase sequence protector. The external three-phase AC power is first input to the phase sequence protector, and then input to the main power controller by the phase sequence protector. The phase sequence protector is used for phase sequence checking. The main contactor is only connected when the input power phase sequence is correct. There is also a protective relay for automatic phase sequence discrimination to avoid accidents or equipment damage caused by reversed power phase sequence.

5. The system according to claim 1, characterized in that, The switching power supply provides the required electrical energy to the DC power supply; the DC power supply converts the electrical energy provided by the switching power supply into 24V power and distributes it to the touch screen.

6. The system according to claim 1, characterized in that, The touchscreen provides signals to the PLC and frequency converter through a communication interface conversion circuit.

7. The system according to claim 1, characterized in that, The PLC communicates with the frequency converter via a communication interface conversion circuit and controls the frequency converter to achieve stepless speed frequency conversion control, thereby controlling the motor and automating the entire power supply test bench power distribution control system.

8. The system according to claim 1, characterized in that, The frequency converter is connected to the motor via a signal connection, and the motor is directly driven by the frequency converter to achieve stepless speed regulation within the range of 0~5000rpm. The real-time speed of the motor is acquired by multiplying the frequency of the frequency converter by a multiplier. The frequency converter adopts AC-DC-AC variable frequency speed regulation technology. The speed transient change overshoot of the frequency converter under sudden addition and removal of a 50KVA load is <100r / min; the recovery time is no more than 2s, and the steady-state control accuracy is higher than 0.1%.

9. The system according to claim 1, characterized in that, After measuring the armature current and voltage of the motor at the output of the inverter, this current is transformed through a motor model with vector transformation to generate two current components equivalent to a DC motor: excitation current Iμ and stator current Iw; the transformed components are used to control the triggering of the IGBT transistors in the inverter.

10. The system according to claim 1, characterized in that, A 1024-line incremental pulse encoder is installed on the motor as a speed detection unit for data acquisition. The encoder has a built-in DB output module, which transmits the data to the PLC through a digital transmission module. The data is compared with the set value, and the PLC outputs a deviation signal to the frequency converter. The frequency converter controls the motor speed to achieve motor speed regulation control.

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