Soft start control circuit of aviation power distribution system

Abstract

The invention relates to an aviation power distribution system, and provides a soft start control circuit of the aviation power distribution system to realize high-stability grading start of a motor in the power distribution system. The starting circuit comprises a current-limiting starting circuit (1) used for primary starting of the starting all-in-one machine MG; the current limiting circuit (2) is cancelled and is used for secondary starting of the starting all-in-one machine MG; and the current monitoring circuit (3) monitors the working current of the starting and generating all-in-one machine MG through a Hall current sensor CT, transmits data to the controller, and is used for monitoring the starting and generating all-in-one working state and taking the data as a criterion for the controller to send a control instruction. The device is suitable for being used in a high-power motor starting occasion.

Description

Technical Field

[0001] The invention relates to an aviation power distribution system, and in particular to a soft start control circuit for the aviation power distribution system. Background Art

[0002] With the development of all-electric and multi-electric aircraft, the types and quantity of aircraft electrical loads are increasing, and the power supply capacity is also increasing. For motor loads, due to the short-term impact current during the startup process, higher requirements are placed on power supply capacity, grid stability and safety. The design method of highly reliable soft start control circuit is directly related to the stability and safety of the aircraft power distribution system.

[0003] Currently in aircraft power distribution systems, small-capacity motors usually adopt direct starting. The advantages of direct starting are less equipment required and low cost, but it has a certain impact on the power grid and affects the life of the motor. For large-capacity motors, transformer step-down starting is usually adopted, that is, by reducing the working voltage drop of the motor, its starting current is reduced. Its advantages are smooth starting and low starting energy consumption, but it requires the configuration of a transformer, which increases the cost and complexity of the power distribution system.

[0004] In summary, in the aircraft power distribution system, a simple and reliable motor soft start control circuit design method is urgently needed. Summary of the invention

[0005] The purpose of the present invention is to provide a soft start control circuit for an aviation power distribution system to achieve high-stability graded starting of motors in the power distribution system.

[0006] The technical solution of the present invention:

[0007] A soft start control circuit for an aviation power distribution system, comprising:

[0008] The current limiting starting circuit 1 is used for the first-stage starting of the starting integrated machine MG;

[0009] The current limiting circuit 2 is cancelled, and the starting integrated machine MG is used for secondary starting;

[0010] The current monitoring circuit 3 monitors the working current of the starting and starting machine MG through the Hall current sensor CT and transmits the data to the controller for monitoring the working state of the starting and starting machine and serving as a criterion for the controller to send control instructions.

[0011] The current limiting starting circuit 1 comprises: a current limiting starting relay RLY-1, a current limiting starting contactor SPC-1 and a current limiting resistor R1;

[0012] The two groups of normally open contacts of the current limiting starting relay RLY-1 are connected in parallel, the input end thereof is powered by a 28V bus bar, the output end is connected to the positive end of the control coil of the current limiting starting contactor SPC-1, the positive end of the control coil of the current limiting starting relay RLY-1 is connected to the controller, and the negative end of the control coil is grounded;

[0013] The current limiting starting contactor SPC-1 has one end of its normally open main contact connected to the 28V bus bar, and the other end is connected in series with the current limiting resistor R1 and then connected to the power supply end of the starter MG. The negative end of the control coil of the current limiting starting contactor SPC-1 is grounded.

[0014] The current limiting circuit 2 includes: a current limiting relay RLY-2 and a current limiting contactor SPC-2;

[0015] The two groups of normally open contacts of the current limiting relay RLY-2 are connected in parallel, and the output end thereof is powered by a 28V bus bar, and the output end is connected to the positive end of the control coil of the current limiting contactor SPC-2. The positive end of the control coil of the current limiting relay RLY-2 is connected to the controller, and the negative end of the control coil is grounded;

[0016] The current limiting contactor SPC-2 is cancelled, one end of its normally open main contact is connected to the 28V bus bar, and the other end is directly connected to the power supply end of the starter MG, the negative end of its control coil is grounded, one end of its normally open auxiliary contact is connected to the 28V bus bar, and the other end is connected to the controller;

[0017] The current limiting starting relay RLY-1 is controlled by the controller, and the current limiting starting contactor SPC-1 is controlled by the normally open contact of the current limiting starting relay RLY-1. After the positive end of the control coil of the current limiting starting relay RLY-1 receives the current limiting starting control signal of the controller, its normally open contact closes, so that the control coil of the current limiting starting contactor SPC-1 is energized, and the main contact of the current limiting starting contactor SPC-1 is closed to supply power to the starter MG.

[0018] When the controller detects that the operating current of the starter MG is less than the set threshold current, the controller sends a signal to cancel the current limiting control.

[0019] The controller monitors the issuance time of the current-limiting starting control signal and sets a maximum time threshold. When the former reaches the set time threshold, the operating current of the starter MG is still greater than the set threshold current, the controller sends a low-level signal to the current-limiting starting relay RLY-1, controls the current-limiting starting contactor SPC-1 to disconnect, and records that the soft start circuit is in an abnormal state.

[0020] After the positive end of the control coil of the cancel current limiting relay RLY-2 receives the cancel current limiting control signal, its normally open contact closes, so that the control coil of the cancel current limiting contactor SPC-2 is energized, the cancel current limiting contactor SPC-2 is closed, and the secondary starting circuit of the starter MG is connected.

[0021] After the current limiting starting circuit 1 and the current limiting cancellation circuit 2 are both closed, the main circuits of the two are in parallel to supply power to the starter MG, and the current limiting resistor R1 is bypassed to complete the starting process.

[0022] The current limiting contactor SPC-2 transmits a high / open signal to the controller via its normally open auxiliary contact, and the collected contactor on / off status information is used to determine the working status of the starter MG in the power distribution system.

[0023] The beneficial effects of the present invention are as follows: it is simple and reliable, has a strong load-carrying capacity, is suitable for use in high-power motor starting occasions, and simultaneously realizes the function of collecting the motor current and starting status, thereby improving the precision control and reliability of the switching timing of the motor starting. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is the functional block diagram of the soft start control circuit of the aviation power distribution system.

[0025] Figure 2 This is the schematic diagram of the soft start control circuit for the aviation power distribution system. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] like Figure 1 , 2 As shown, the soft start control circuit of the aviation power distribution system includes: a current limiting starting circuit 1, a current limiting cancellation circuit 2 and a current detection circuit 3.

[0028] The current limiting starting circuit 1 and the current limiting cancellation circuit 2 are in parallel relationship, the input ends of the two are connected together, both are powered by the 28V bus, and after the output ends are connected together, the electric energy is transmitted to the main generator after passing through the current detection circuit 3.

[0029] The current limiting starting circuit 1 is used for the first stage starting of the main generator, and is composed of a relay RLY-1, a contactor SPC-1 and a current limiting resistor R1. The control signal of the circuit comes from the controller, and the type of the control signal is "28V / open".

[0030] The two groups of normally open contacts of the current limiting starting relay RLY-1 are connected in parallel, the input end thereof is powered by a 28V bus bar, the output end is connected to the positive end of the control coil of the current limiting starting contactor SPC-1, the positive end of the control coil of the current limiting starting relay RLY-1 is connected to the controller, and the negative end of the control coil is grounded;

[0031] The current limiting starting contactor SPC-1 has one end of its normally open main contact connected to the 28V bus bar, and the other end is connected in series with a current limiting resistor R1 and then connected to the power supply end of the starter MG, and the negative end of its control coil is grounded.

[0032] The function of relay RLY-1 is to enhance the driving ability of the controller control signal. To improve the reliability of the circuit operation, the two groups of normally open contacts of relay RLY-1 are used in parallel. One end of the two groups of normally open contacts is connected together to the 28V bus bar, and the other end is connected together to the positive end of the coil of contactor SPC-1. When the positive end of its coil receives the "28V" control signal, it drives its two groups of normally open contacts to close, so that the positive end of the coil of contactor SPC-1 receives power from the 28V bus bar.

[0033] Contactor SPC-1 is the specific actuator for the on-off control of the current-limiting starting circuit 1. After the positive end of its coil receives the "28V" control signal, it drives its normally open main contacts A1 and A2 to close, and the 28V power is transmitted to the main generator through the series current-limiting resistor R1, realizing its first-level starting and achieving the purpose of reducing the starting current.

[0034] The current limiting circuit 2 is used for the second-stage starting of the main generator, which is composed of relay RLY-2 and contactor SPC-2. The control signal of this circuit comes from the controller, and the type of control signal is "28V / open".

[0035] The two groups of normally open contacts of the current limiting relay RLY-2 are connected in parallel, and the output end thereof is powered by a 28V bus bar, and the output end is connected to the positive end of the control coil of the current limiting contactor SPC-2. The positive end of the control coil of the current limiting relay RLY-2 is connected to the controller, and the negative end of the control coil is grounded;

[0036] The current limiting contactor SPC-2 is cancelled, one end of its normally open main contact is connected to the 28V bus bar, and the other end is directly connected to the power supply end of the starter MG, the negative end of its control coil is grounded, one end of its normally open auxiliary contact is connected to the 28V bus bar, and the other end is connected to the controller;

[0037] The controller is used to collect information such as the on / off status of the contactor in the power distribution system, the power supply current, etc., and after analyzing the data information and implementing the control algorithm, it realizes the on / off control of the relay and contactor by sending relevant control instructions;

[0038] The function, connection and control method of relay RLY-2 are similar to those of relay RLY-1.

[0039] Contactor SPC-2 is the specific actuator for the on-off control of the current-limiting starting circuit 2. When the current-limiting starting circuit 1 is connected for a period of time, the main generator is in a low-speed operation state, and the relay RLY-2 receives the drive signal from the controller, and the normally open contact is connected, thereby driving the normally open main contacts A1 and A2 of the contactor SPC-2 to close, and the 28V power is transmitted to the main generator through the cancellation of the current-limiting circuit 2, bypassing the current-limiting resistor R1 in the current-limiting starting circuit 1, and realizing the secondary start of the main generator. At the same time, the on-off state of the normally open auxiliary contacts C1 and T1 of SPC-2 is transmitted to the controller in the form of a "28V / open" signal, which is used to monitor the on-off state of the cancellation of the current-limiting circuit 2.

[0040] The function of the current monitoring circuit 3 is to monitor the current of the main generator power supply circuit in real time through the current sensor (CT) and transmit it to the controller. The monitored current is used as the basis for determining when the controller sends a command to cancel the current limiting control. When the monitored current is less than the set threshold, the controller immediately issues a command to cancel the current limiting control to prevent the current limiting resistor R1 from working for a long time and burning out; when the monitored current is always greater than the set threshold within the specified time, the controller should directly issue a control command to disconnect the K1 contactor to prevent the current limiting resistor in the rate circuit from working for a long time and causing heating and burning out, and the controller records the abnormal state of the soft start control circuit, and restarts the starter after the subsequent repair is completed.

[0041] The control process of the present invention is as follows:

[0042] The current limiting starting relay RLY-1 is controlled by the controller, and the current limiting starting contactor SPC-1 is controlled by the normally open contact of the current limiting starting relay RLY-1. After the positive end of the control coil of the current limiting starting relay RLY-1 receives the current limiting starting control signal of the controller, its normally open contact closes, so that the control coil of the current limiting starting contactor SPC-1 is energized, and the main contact of the current limiting starting contactor SPC-1 is closed to supply power to the starter MG.

[0043] When the controller detects that the operating current of the starter MG is less than the set threshold current, the controller sends a signal to cancel the current limiting control.

[0044] The controller monitors the issuance time of the current-limiting starting control signal and sets a maximum time threshold. When the former reaches the set time threshold, the operating current of the starter MG is still greater than the set threshold current, the controller sends a low-level signal to the current-limiting starting relay RLY-1, controls the current-limiting starting contactor SPC-1 to disconnect, and records the abnormal state of the soft start circuit to avoid the current-limiting resistor R1 in the power circuit from working for a long time and causing heat and burning.

[0045] After the positive end of the control coil of the cancel current limiting relay RLY-2 receives the cancel current limiting control signal, its normally open contact closes, so that the control coil of the cancel current limiting contactor SPC-2 is energized, the cancel current limiting contactor SPC-2 is closed, and the secondary starting circuit of the starter MG is connected.

[0046] The resistance value of the current limiting resistor R1 should be selected and adapted with reference to the internal resistance of the starter MG. If its resistance value is too large, the starter MG may not be started. If its resistance value is too small, the starting current of the starter MG may not be reduced sufficiently.

[0047] After the current limiting starting circuit 1 and the current limiting cancellation circuit 2 are both closed, the main circuits of the two are in parallel to supply power to the starter MG, and the current limiting resistor R1 is bypassed to complete the starting process.

[0048] The current limiting contactor SPC-2 can transmit a high / open signal to the controller via its normally open auxiliary contact, and the collected contactor on / off status information is used to determine the working status of the starter MG in the power distribution system.

[0049] The above is only a specific embodiment of the present invention, and the present invention is described in detail. The unexplained part is a conventional technology. However, the protection scope of the present invention is not limited to this. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A soft start control circuit for an aviation power distribution system, characterized in that: include: A current-limiting starting circuit (1) is used for first-stage starting of the starter-generator MG; The current limiting circuit (2) is eliminated to achieve secondary starting of the starter-starter MG; The current monitoring circuit (3) monitors the working current of the starting and starting machine MG through the Hall current sensor CT and transmits the data to the controller for monitoring the working state of the starting and starting machine and serving as a criterion for the controller to send a control instruction.

2. The soft start control circuit of an aviation power distribution system according to claim 1, characterized in that: The current limiting starting circuit (1) comprises: a current limiting starting relay RLY-1, a current limiting starting contactor SPC-1 and a current limiting resistor R1; The two groups of normally open contacts of the current limiting starting relay RLY-1 are connected in parallel, the input end thereof is powered by a 28V bus bar, the output end is connected to the positive end of the control coil of the current limiting starting contactor SPC-1, the positive end of the control coil of the current limiting starting relay RLY-1 is connected to the controller, and the negative end of the control coil is grounded; The current limiting starting contactor SPC-1 has one end of its normally open main contact connected to the 28V bus bar, and the other end is connected in series with the current limiting resistor R1 and then connected to the power supply end of the starter MG. The negative end of the control coil of the current limiting starting contactor SPC-1 is grounded.

3. The soft start control circuit of an aviation power distribution system according to claim 1, characterized in that: The current limiting circuit (2) includes: a current limiting relay RLY-2 and a current limiting contactor SPC-2; The two groups of normally open contacts of the current limiting relay RLY-2 are connected in parallel, and the output end thereof is powered by a 28V bus bar, and the output end is connected to the positive end of the control coil of the current limiting contactor SPC-2. The positive end of the control coil of the current limiting relay RLY-2 is connected to the controller, and the negative end of the control coil is grounded; The current limiting contactor SPC-2 is cancelled, one end of its normally open main contact is connected to the 28V bus bar, and the other end is directly connected to the power supply end of the starter MG, the negative end of its control coil is grounded, one end of its normally open auxiliary contact is connected to the 28V bus bar, and the other end is connected to the controller.

4. The soft start control circuit of an aviation power distribution system according to claim 2 or 3, characterized in that: The current limiting starting relay RLY-1 is controlled by the controller, and the current limiting starting contactor SPC-1 is controlled by the normally open contact of the current limiting starting relay RLY-1. After the positive end of the control coil of the current limiting starting relay RLY-1 receives the current limiting starting control signal of the controller, its normally open contact closes, so that the control coil of the current limiting starting contactor SPC-1 is energized, and the main contact of the current limiting starting contactor SPC-1 is closed to supply power to the starter MG.

5. The soft start control circuit of an aviation power distribution system as claimed in claim 4, characterized in that: When the controller detects that the operating current of the starter MG is less than the set threshold current, the controller sends a signal to cancel the current limiting control.

6. The soft start control circuit of an aviation power distribution system as claimed in claim 5, characterized in that: The controller monitors the issuance time of the current-limiting starting control signal and sets a maximum time threshold. When the former reaches the set time threshold, the operating current of the starter MG is still greater than the set threshold current, the controller sends a low-level signal to the current-limiting starting relay RLY-1, controls the current-limiting starting contactor SPC-1 to disconnect, and records that the soft start circuit is in an abnormal state.

7. The soft start control circuit of an aviation power distribution system according to claim 6, characterized in that: After the positive end of the control coil of the cancel current limiting relay RLY-2 receives the cancel current limiting control signal, its normally open contact closes, so that the control coil of the cancel current limiting contactor SPC-2 is energized, the cancel current limiting contactor SPC-2 is closed, and the secondary starting circuit of the starter MG is connected.

8. The soft start control circuit of an aviation power distribution system according to claim 7, characterized in that: After the current limiting starting circuit (1) and the current limiting cancellation circuit (2) are both closed, the main circuits of the two are in a parallel state to supply power to the starting and starting integrated machine MG, and the current limiting resistor R1 is bypassed, completing the starting process.

9. The soft start control circuit of an aviation power distribution system according to claim 8, characterized in that: The current limiting contactor SPC-2 transmits a high / open signal to the controller via its normally open auxiliary contact, and the collected contactor on / off status information is used to determine the working status of the starter MG in the power distribution system.

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