Current limiting circuit based on solid-state power controller and operation method thereof

Abstract

The invention discloses a current limiting circuit based on a solid-state power controller and an operation method thereof, and relates to the technical field of aviation power distribution. According to the protection implementation strategy based on the current limiting circuit of the solid-state power controller, a current limiting, short-circuit and overcurrent cooperation strategy is utilized, it is guaranteed that the impulse current is controllable in the short-circuit process through the current limiting circuit, and the situation that the voltage of a 28V bus bar is lowered due to the fact that the short-circuit impulse current is too high is avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of aviation power distribution systems, and in particular relates to a current limiting circuit based on a solid-state power controller and an operating method thereof. Background Art

[0002] Since the 1980s, the rapid development of MOSFET technology using Si materials has attracted widespread attention to this new generation of power devices. At present, the 28V solid-state power controller circuit based on MOSFET has become mature. Since the power margin of MOSFET is large enough, auxiliary circuits are generally not designed in the circuit, but a single MOSFET is used to limit the short circuit. During the short circuit or capacitive load process, the self-current limiting of MOSFET is completed in a relatively short time. Since the current limiting capability of MOSFET is limited, the capacitive load current limiting process needs to be released after the current limiting, resulting in a current shock. This current shock is related to factors such as the response time of the solid-state power controller, the power supply capability, and the cable impedance. Therefore, the peak value of the current shock is somewhat uncontrollable during the entire process. Summary of the invention

[0003] The purpose of the present invention is to complete the assessment of discrete quantity acquisition function in the test and verification of aircraft power distribution system and related equipment, and in particular to provide a general discrete quantity acquisition circuit boundary test method.

[0004] In view of this, according to one aspect of an embodiment of the present invention, a current limiting circuit based on a solid-state power controller is provided, comprising: a main solid-state power controller circuit and an auxiliary solid-state power controller circuit;

[0005] The main solid-state power controller circuit also includes a main loop MOS tube and a sampling resistor R2, the drain D1 of the main loop MOS tube is used for power input, the gate G1 is used to receive the main loop drive signal DRV1, the source S1 is connected to one end of the sampling resistor R2, the other end of the sampling resistor R2 is connected to one end of the load M, and the other end of the load M is connected to the ground PGND;

[0006] The auxiliary solid-state power controller circuit also includes an auxiliary loop MOS tube and a current limiting resistor R1, one end of the current limiting resistor R1 is used for power input, and the other end of the current limiting resistor R1 is connected to the drain D2 of the auxiliary loop MOS tube, the gate G2 of the auxiliary loop MOS tube is used to receive the auxiliary loop drive signal DRV2, and the source S2 is connected to the source level S1 of the main loop MOS tube.

[0007] Optionally, the switching action of the main loop MOS tube is controlled by the main loop drive signal DRV1, and whether the main loop drive signal DRV1 is an on signal or an off signal is determined according to the voltage difference between AMP and QGND at both ends of the sampling resistor R2.

[0008] Optionally, the switching action of the auxiliary loop MOS switch circuit is controlled by the auxiliary loop drive signal DRV2, and the voltage difference between AMP and QGND at both ends of the sampling resistor R2 determines whether the main loop drive signal DRV2 is an on signal or an off signal.

[0009] Optionally, the power input voltage is 28V,

[0010] Optionally, the current limiting resistor has a resistance of 0.2 to 0.4Ω.

[0011] Optionally, the resistance of the sampling resistor is 1-5 mΩ.

[0012] According to another aspect of an embodiment of the present invention, there is also provided an operation method of a current limiting circuit based on a solid-state power controller, based on any of the above circuits, comprising: a sampling resistor R2 converts a load current I in the loop into a voltage signal, which is used to determine the normal, overcurrent, short-circuit and other states of the current, wherein the rated current of the load M is the normal state, the multiple rated current of the load M is the short-circuit state, and the overcurrent state is between the normal state and the short-circuit state; the main loop MOS tube receives the main loop drive signal DRV1, and the MOS tube performs switching according to the main loop drive signal DRV1; the auxiliary loop MOS tube receives the auxiliary loop drive signal DRV2, and the MOS tube performs switching according to the auxiliary loop drive signal DRV2, which is used for current limiting during the startup process of the short circuit and the capacitive load M;

[0013] When the current I is in a normal state, the capacitive load M is started, the main solid-state power controller circuit is turned on, and the auxiliary solid-state power controller circuit is turned off;

[0014] When the current I state is an overcurrent state, the main solid-state power controller circuit is turned on, the auxiliary solid-state power controller circuit is turned off, and trips according to the inverse delay curve;

[0015] When the current I is in a short-circuit state, the auxiliary solid-state power controller circuit is turned on, the main solid-state power controller circuit is turned off, and the circuit is tripped with a time delay.

[0016] Optionally, the short-circuit current is adjusted by a current-limiting resistor R1.

[0017] Optionally, when the current I exceeds the overcurrent threshold, the main solid-state power controller circuit is turned off and the auxiliary solid-state power controller circuit is turned on, and the current I is detected after a delay. If the current I exceeds the short-circuit threshold, it is determined to be a short-circuit state, the auxiliary solid-state power controller circuit is turned off, and the circuit is tripped with a delay; if the current I is lower than the short-circuit threshold, it is determined to be an overcurrent state, the auxiliary solid-state power controller circuit is turned off and the main power controller circuit is turned on, and the circuit is tripped according to the inverse delay curve.

[0018] Optionally, the overcurrent threshold is 3 times the normal current value, and the short-circuit threshold is 10 times the normal current value.

[0019] The beneficial effects achieved by the present invention are as follows: by using the current limiting and short-circuit and overcurrent coordination strategies, the current limiting circuit can ensure that the impact current during the short-circuit process is controllable, and avoid the short-circuit impact current being too high to pull down the 28V bus voltage. The current limiting circuit can ensure that the impact current during the short-circuit process is controllable, ensuring that the power input is stable under abnormal load conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 FIG. 4 is a block diagram of a current limiting circuit according to the present invention. DETAILED DESCRIPTION

[0021] 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.

[0022] According to one aspect of an embodiment of the present invention, a current limiting circuit based on a solid-state power controller is provided, comprising: a main solid-state power controller circuit and an auxiliary solid-state power controller circuit;

[0023] The main solid-state power controller circuit also includes a main loop MOS tube and a sampling resistor R2, the drain D1 of the main loop MOS tube is used for power input, the gate G1 is used to receive the main loop drive signal DRV1, the source S1 is connected to one end of the sampling resistor R2, the other end of the sampling resistor R2 is connected to one end of the load M, and the other end of the load M is connected to the ground PGND;

[0024] The auxiliary solid-state power controller circuit also includes an auxiliary loop MOS tube and a current limiting resistor R1, one end of the current limiting resistor R1 is used for power input, and the other end of the current limiting resistor R1 is connected to the drain D2 of the auxiliary loop MOS tube, the gate G2 of the auxiliary loop MOS tube is used to receive the auxiliary loop drive signal DRV2, and the source S2 is connected to the source level S1 of the main loop MOS tube.

[0025] Furthermore, the switching action of the main circuit MOS tube is controlled by the main circuit driving signal DRV1, and the main circuit driving signal DRV1 is determined to be an on signal or an off signal according to the voltage difference between AMP and QGND at both ends of the sampling resistor R2.

[0026] Furthermore, the switching action of the auxiliary loop MOS switch circuit is controlled by the auxiliary loop drive signal DRV2, and the voltage difference between AMP and QGND at both ends of the sampling resistor R2 determines whether the main loop drive signal DRV2 is an on signal or an off signal.

[0027] Furthermore, the power input voltage is 28V,

[0028] Furthermore, the resistance of the current limiting resistor is 0.2-0.4Ω.

[0029] Furthermore, the resistance of the sampling resistor is 1-5 mΩ.

[0030] According to another aspect of an embodiment of the present invention, there is also provided an operation method of a current limiting circuit based on a solid-state power controller, based on any of the above circuits, comprising: a sampling resistor R2 converts a load current I in the loop into a voltage signal, which is used to determine the normal, overcurrent, short-circuit and other states of the current, wherein the rated current of the load M is the normal state, the multiple rated current of the load M is the short-circuit state, and the overcurrent state is between the normal state and the short-circuit state; the main loop MOS tube receives the main loop drive signal DRV1, and the MOS tube performs switching according to the main loop drive signal DRV1; the auxiliary loop MOS tube receives the auxiliary loop drive signal DRV2, and the MOS tube performs switching according to the auxiliary loop drive signal DRV2, which is used for current limiting during the startup process of the short circuit and the capacitive load M;

[0031] When the current I is in a normal state, the capacitive load M is started, the main solid-state power controller circuit is turned on, and the auxiliary solid-state power controller circuit is turned off;

[0032] When the current I state is an overcurrent state, the main solid-state power controller circuit is turned on, the auxiliary solid-state power controller circuit is turned off, and trips according to the inverse delay curve;

[0033] When the current I is in a short-circuit state, the auxiliary solid-state power controller circuit is turned on, the main solid-state power controller circuit is turned off, and the circuit is tripped with a time delay.

[0034] Furthermore, the short-circuit current is adjusted by the current-limiting resistor R1.

[0035] Furthermore, when the current I exceeds the overcurrent threshold, the main solid-state power controller circuit is turned off and the auxiliary solid-state power controller circuit is turned on. The current I is detected after a delay. If the current I exceeds the short-circuit threshold, it is determined to be a short-circuit state, the auxiliary solid-state power controller circuit is turned off, and the circuit is tripped with a delay; if the current I is lower than the short-circuit threshold, it is determined to be an overcurrent state, the auxiliary solid-state power controller circuit is turned off and the main power controller circuit is turned on, and the circuit is tripped according to the inverse delay curve.

[0036] Furthermore, the overcurrent threshold is 3 times the normal current value, and the short-circuit threshold is 10 times the normal current value.

[0037] Example 1

[0038] The present invention provides a protection implementation strategy based on a solid-state power controller current limiting circuit, comprising: a 28V main solid-state power controller circuit and a 28V auxiliary solid-state power controller circuit;

[0039] The 28V main solid-state power controller circuit is composed of a main circuit MOS tube switch circuit and a sampling resistor. The main circuit MOS tube switch circuit receives the main circuit drive signal to turn on and off the 28V main solid-state power controller circuit; the sampling resistor converts the current signal in the circuit into a voltage signal, which is used to determine the current current status such as normal, overcurrent, short circuit, etc.

[0040] The 28V auxiliary solid-state power controller circuit is composed of an auxiliary loop MOS tube switch circuit and a current limiting resistor, and is used for channel current limiting during short circuit and capacitive load startup.

[0041] The switching action of the main circuit MOS tube switch circuit is controlled by the main circuit drive signal, where 1 is on and 0 is off; the type of the main circuit drive signal is determined by the voltage difference between AMP and QGND at both ends of the sampling resistor.

[0042] The switching action of the auxiliary loop MOS tube switch circuit is controlled by the auxiliary loop drive signal, where 1 is on and 0 is off; the type of the auxiliary loop drive signal is determined by the voltage difference between AMP and QGND at both ends of the sampling resistor.

[0043] The sampling resistor converts the current signal in the loop into a voltage signal, which is used to determine the current state of the current, such as normal, overcurrent, and short circuit. The channel is in a normal state with the rated current of the load M, a short circuit state with the current value of 28V divided by the current limiting resistor, and an overcurrent state between the normal state and the short circuit state. The short circuit state can be adjusted by the current limiting resistor, and is usually a short circuit state with a value of more than 8 times the normal state.

[0044] When the channel current state is normal, the 28V main solid-state power controller circuit is connected and can work for a long time; when the channel current state is overcurrent, the 28V main solid-state power controller circuit is connected and trips according to the inverse delay curve; when the channel current state is short-circuit, the 28V auxiliary solid-state power controller circuit is connected, the 28V main solid-state power controller circuit is turned off, and trips with a delay.

[0045] Example 2

[0046] like Figure 1 As shown, it is a functional circuit block diagram of the present invention, including a main solid-state power controller circuit and an auxiliary solid-state power controller circuit.

[0047] The drain D1 of the main loop MOS tube switch circuit in the main solid-state power controller circuit is connected to the 28V power input, the gate G1 is connected to the main loop drive signal DRV1, the source S1 is connected to one end of the sampling resistor R2, the other end of the sampling resistor R2 is connected to one end of the load, and the other end of the load is connected to the 28V ground PGND.

[0048] The 28V power input in the auxiliary solid-state power controller circuit is connected to one end of the current limiting resistor R1, the other end of the current limiting resistor is connected to the drain D2 of the auxiliary loop MOS, the gate G2 of the auxiliary loop MOS is connected to the output end of the drive circuit, and the source S2 is connected to the source level S1 of the main loop MOS tube.

[0049] The sampling resistor R2 converts the load current I in the loop into a voltage signal, which is used to determine the current state of normal, overcurrent, short circuit, etc. The rated current of the load M is the normal state of the channel, the rated current of the load M is the short circuit state, and the overcurrent state is between the normal state and the short circuit state; the short circuit state can be adjusted by the current limiting resistor;

[0050] When the channel current state is normal, the main circuit drive signal DRV1 drives the main solid-state power controller circuit to turn on, and the auxiliary circuit drive signal DRV2 drives the auxiliary solid-state power controller circuit to turn off;

[0051] When the channel current state is in the overcurrent state, the main circuit drive signal DRV1 drives the main solid-state power controller circuit to turn on, and the auxiliary circuit drive signal DRV2 drives the auxiliary solid-state power controller circuit to turn off and trip according to the inverse delay curve.

[0052] When the channel current state is short-circuited, the auxiliary circuit drive signal DRV2 drives the auxiliary solid-state power controller circuit to turn on, and the main circuit drive signal DRV1 drives the main solid-state power controller circuit to turn off and delay tripping. The power input voltage is 28V, the current limiting resistor is 0.4Ω, and the short-circuit current is limited to 70A.

[0053] When the load current I exceeds 3 times the rated current, the main solid-state power controller circuit is turned off and the auxiliary solid-state power controller circuit is turned on. The current I is detected after a delay. If the current I exceeds 10 times the rated current, it is determined to be a short-circuit state, the auxiliary solid-state power controller circuit is turned off, and the circuit is tripped with a delay; if the current I is lower than 10 times the rated current, it is determined to be an overcurrent state, the auxiliary solid-state power controller circuit is turned off and the main power controller circuit is turned on, and tripping is carried out according to the inverse delay curve in Table 1.

[0054] Table 1 28V SSPC reverse delay curve characteristic points

[0055]

[0056] 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 current limiting circuit based on a solid-state power controller, characterized in that: include: a main solid-state power controller circuit and an auxiliary solid-state power controller circuit; The main solid-state power controller circuit also includes a main loop MOS tube and a sampling resistor R2, the drain D1 of the main loop MOS tube is used for power input, the gate G1 is used to receive the main loop drive signal DRV1, the source S1 is connected to one end of the sampling resistor R2, the other end of the sampling resistor R2 is connected to one end of the load M, and the other end of the load M is connected to the ground PGND; The auxiliary solid-state power controller circuit also includes an auxiliary loop MOS tube and a current limiting resistor R1, one end of the current limiting resistor R1 is used for power input, and the other end of the current limiting resistor R1 is connected to the drain D2 of the auxiliary loop MOS tube, the gate G2 of the auxiliary loop MOS tube is used to receive the auxiliary loop drive signal DRV2, and the source S2 is connected to the source level S1 of the main loop MOS tube.

2. The circuit according to claim 1, characterized in that: The switching action of the main circuit MOS tube is controlled by the main circuit drive signal DRV1. The voltage difference between AMP and QGND at both ends of the sampling resistor R2 determines whether the main circuit drive signal DRV1 is an on signal or an off signal.

3. The circuit according to claim 1, characterized in that: The switching action of the auxiliary loop MOS switch circuit is controlled by the auxiliary loop drive signal DRV2, and the voltage difference between AMP and QGND at both ends of the sampling resistor R2 determines whether the main loop drive signal DRV2 is an on signal or an off signal.

4. The circuit according to claim 1, characterized in that: The power input voltage is 28V.

5. The circuit according to claim 1, characterized in that: The resistance of the current limiting resistor is 0.2~0.4Ω.

6. The circuit according to claim 1, characterized in that: The sampling resistor has a resistance of 1 to 5 mΩ.

7. A method for operating a current limiting circuit based on a solid-state power controller, characterized in that: Based on any circuit described in claims 1-6, comprising: a sampling resistor R2 converts the load current I in the loop into a voltage signal, which is used to judge the normal, overcurrent, short-circuit and other states of the current, wherein the rated current of the load M is the normal state, the multiple rated current of the load M is the short-circuit state, and the overcurrent state is between the normal state and the short-circuit state; the main loop MOS tube receives the main loop drive signal DRV1, and the MOS tube is turned on and off according to the main loop drive signal DRV1; the auxiliary loop MOS tube receives the auxiliary loop drive signal DRV2, and the MOS tube is turned on and off according to the auxiliary loop drive signal DRV2, which is used for current limiting during the startup process of the short circuit and the capacitive load M; When the current I is in a normal state, the capacitive load M is started, the main solid-state power controller circuit is turned on, and the auxiliary solid-state power controller circuit is turned off; When the current I state is an overcurrent state, the main solid-state power controller circuit is turned on, the auxiliary solid-state power controller circuit is turned off, and trips according to the inverse delay curve; When the current I is in a short-circuit state, the auxiliary solid-state power controller circuit is turned on, the main solid-state power controller circuit is turned off, and the circuit is tripped with a time delay.

8. The operating method according to claim 7, characterized in that: The short-circuit current is adjusted by the current-limiting resistor R1.

9. The operating method according to claim 7, characterized in that: When the current I exceeds the overcurrent threshold, the main solid-state power controller circuit is turned off and the auxiliary solid-state power controller circuit is turned on. The current I is detected after a delay. If the current I exceeds the short-circuit threshold, it is determined to be a short-circuit state, the auxiliary solid-state power controller circuit is turned off, and the tripping is delayed; If the current I is lower than the short-circuit threshold, it is determined to be an overcurrent state, the auxiliary solid-state power controller circuit is turned off and the main power controller circuit is turned on, and tripping occurs according to the inverse delay curve.

10. The operating method according to claim 9, characterized in that: The overcurrent threshold is 3 times the normal current value, and the short-circuit threshold is 10 times the normal current value.

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