SSPC short-circuit protection self-locking circuit

Abstract

The utility model provides an SSPC short circuit protection self-locking circuit. The circuit comprises a power supply and signal isolation unit, a DCDC boost unit, a driving unit, a power execution unit, a sampling unit and a current acquisition, amplification and comparison unit, the power supply and signal isolation unit inputs and outputs I / O signals, and the power execution unit and the sampling unit respectively input / output power electricity. According to the utility model, through external equipment power supply and related I / O interface control, the power execution device can be controlled to connect and disconnect the power loop, when the current of the power loop reaches a preset short-circuit current value, after automatic short-circuit protection self-locking of the circuit, a short-circuit fault signal is output to the outside, and the outside can control related I / O to unlock the fault according to the fault signal, so that the fault is prevented from being damaged. And after an unlocking fault occurs, the loop can be controlled to be switched on again, so that the reliability of the load driving control system is improved, and power supply and distribution tasks in the power distribution control system can be safely and reliably completed.

Description

Technical Field

[0001] The utility model relates to a SSPC short-circuit protection self-locking circuit. Background Art

[0002] As a new type of power switch device with programmable tripping characteristics that integrates the functions of relays and circuit breakers, the solid-state power controller (SSPC) has many advantages such as integration and intelligence, and can realize the intelligent management and operation of the distribution system. The use of solid-state power controllers reduces the number of components, weight and cost of the distribution system, and improves the reliability and safety of the distribution system.

[0003] At present, solid-state power controllers are not only required to have sensitive short-circuit protection functions, but also to be able to carry capacitive loads. This requires solid-state power controller products to be able to identify whether the back-end load is a capacitive load or a short-circuit state, to avoid false triggering of short-circuit protection at the moment of startup when a capacitive load appears. For example, the solid-state power controller disclosed in publication number CN201571033U uses a control circuit with a microcontroller PIC as the core to control power devices, and prevents power devices from overloading and short-circuiting through a self-locking circuit connected to the drive circuit. Utility Model Content

[0004] In order to solve the above technical problems, the utility model provides a SSPC short-circuit protection self-locking circuit.

[0005] The utility model is realized through the following technical solutions.

[0006] The utility model provides a SSPC short-circuit protection self-locking circuit; a power supply and signal isolation unit, a DCDC boost unit, a drive unit, a power execution unit, a sampling unit and a current acquisition amplification comparison unit, wherein the power supply and signal isolation unit are respectively connected to the DCDC boost unit, the drive unit and the current acquisition amplification comparison unit, the drive unit is respectively connected to the DCDC boost unit, the current acquisition amplification comparison unit and the power execution unit, the power execution unit is connected to the sampling unit, the sampling unit is connected to the current acquisition amplification comparison unit, the power supply and signal isolation unit input and output I / O signals, and the power execution unit and the sampling unit respectively input / output power electricity.

[0007] The power supply and signal isolation unit includes an isolation chip U1, pin 1 of the isolation chip U1 is connected to a 5V power supply and is respectively connected to capacitor C1 and capacitor C2, capacitor C1 and capacitor C2 are grounded with pin 2 of the isolation chip U1, pins 3 and 4 of the isolation chip U1 are connected to an I / O signal, pin 3 is also connected to a 3V3 power supply through a resistor R1, pin 4 is grounded through a resistor R5, pin 5 outputs an I / O signal, pin 7 is connected to a 3V3 power supply, pin 8 is grounded, pins 9 and 15 are grounded, pins 10 and 16 are connected to the positive electrode of the ISO_5V power supply, capacitors C3 and C4 are also connected between pins 15 and 16, pin 12 is respectively connected to a drive unit and a current acquisition and amplification unit, and pins 13 and 14 are respectively connected to a drive unit and a current acquisition and amplification comparison unit.

[0008] The driving unit includes a driving chip U2, wherein pin 1 of the driving chip U2 is connected to an ISO_5V power supply and is grounded through a capacitor C5, pins 2 and 3 are connected to resistors R3 and R8, resistor R3 and the other end of resistor R3 are connected in parallel and are respectively connected to resistors R4 and R9, resistor R4 is connected to a power execution unit, resistor R9 is connected to a sampling unit and is grounded, pin 4 is grounded, pin 5 is connected to pin 12 of an isolation chip U1 and is grounded through a resistor R7, and pin 6 is connected to pin 13 of the isolation chip through a resistor R2 and is grounded through a resistor R6.

[0009] The current acquisition, amplification and comparison unit includes a comparator U4 and an amplifier U5. Pins 5 of the comparator U4 and the amplifier U5 are both connected to the ISO_5V power supply, and pins 2 are both grounded; a capacitor C12 is connected between pins 3 and 4 of the amplifier U5 and is respectively connected to resistors R12 and R16, the other ends of resistors R12 and R16 are respectively connected to the two ends of the sampling resistor R15, pin 1 of the amplifier U5 is connected to pin 3 of the comparator U4 through resistor R14, pin 3 of the comparator U4 is also connected to the positive electrode of the diode D2, the negative electrode of the diode D2 is connected to pin 14 of the isolation chip U1, pin 4 of the comparator U4 is connected to the ISO_5V power supply through resistor R17, and is respectively connected to capacitor C13 and resistor R18, capacitor C13 and resistor R18 are grounded, pin 1 of the comparator U4 is connected to the positive electrode of the diode D3, the negative electrode of the diode D3 is connected to pin 12 of the isolation chip U1, and a resistor R10 is also connected between the negative electrode of the diode D3 and the negative electrode of the diode D1.

[0010] The power execution unit includes a power switch Q1 , a drain of the power switch Q1 inputs power, a source is connected to the sampling unit and grounded, and a gate is connected to the resistor R4 .

[0011] The sampling unit is a sampling resistor R15 , one end of the sampling resistor R15 is connected to the source of the power switch Q1 , and the other end of the sampling resistor R15 outputs power.

[0012] The DCDC boost unit includes a DCDC converter U3, wherein pin 5 of the DCDC converter U3 is connected to an ISO_5V power supply, pin 4 is grounded through a capacitor C11, pin 1 is connected to the positive electrode of a diode D2, the negative electrode of the diode D2 outputs an ISO_15V power supply, pin 3 is connected to pin 1 and pin 2 through resistors R11 and R13 respectively, the negative electrode of the diode D2 is also connected to capacitors C8 and C9 respectively, and capacitors C8 and C9 are grounded, and an inductor L1 is also connected between pin 5 and pin 1 of the DCDC converter U3.

[0013] The beneficial effects of the utility model are as follows: through the power supply of external equipment and the control of related I / O interfaces, the power actuator can be controlled to connect and shut down the power circuit. When the current in the power circuit reaches a preset short-circuit current value, the circuit automatically short-circuit protection self-locks and outputs a short-circuit fault signal to the outside. The outside can unlock the fault by controlling the related I / O according to the fault signal. Only after the fault is unlocked can the circuit be controlled to be connected again, thereby improving the reliability of the load drive control system and realizing the safe and reliable completion of the power supply and distribution tasks in the power distribution control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the principle of the utility model;

[0015] Figure 2 This is a schematic diagram of the circuit principle of the utility model. DETAILED DESCRIPTION

[0016] The technical solution of the utility model is further described below, but the scope of protection required is not limited to the description.

[0017] like Figure 1As shown, a SSPC short-circuit protection self-locking circuit; power supply and signal isolation unit, DCDC boost unit, drive unit, power execution unit, sampling unit and current acquisition amplification comparison unit, the power supply and signal isolation unit are respectively connected to the DCDC boost unit, the drive unit, the current acquisition amplification comparison unit and the power execution unit, the drive unit is respectively connected to the DCDC boost unit, the current acquisition amplification comparison unit and the power execution unit, the power execution unit is connected to the sampling unit, the sampling unit is connected to the current acquisition amplification comparison unit, the power supply and signal isolation unit input and output I / O signals, and the power execution unit and the sampling unit respectively input / output power electricity. The power supply and signal isolation unit supplies power to the drive unit and the current acquisition amplification comparison unit, and interacts with the drive unit after isolating and processing the external I / O signal. It can be controlled by external equipment power supply and related I / O interface control, and the power execution device can be controlled to connect and shut down the power circuit. When the power circuit current reaches the preset short-circuit current value, the circuit automatically short-circuit protection self-locks, and outputs a short-circuit fault signal to the outside. The outside can unlock the fault by controlling the related I / O according to the fault signal, and the circuit can be controlled to connect again after the fault is unlocked. The short-circuit protection self-locking circuit has the characteristics of small package, fast response speed and high reliability; it improves the reliability of the load drive control system and can safely and reliably complete the power supply and distribution tasks in the power distribution control system.

[0018] like Figure 2 As shown, the power and signal isolation unit includes an isolation chip U1, pin 1 of the isolation chip U1 is connected to a 5V power supply and is respectively connected to capacitor C1 and capacitor C2, capacitor C1 and capacitor C2 are grounded with pin 2 of the isolation chip U1, pins 3 and 4 of the isolation chip U1 are connected to I / O signals, pin 3 is also connected to a 3V3 power supply through a resistor R1, pin 4 is grounded through a resistor R5, pin 5 outputs an I / O signal, pin 7 is connected to a 3V3 power supply, pin 8 is grounded, pins 9 and 15 are grounded, pins 10 and 16 are connected to the positive pole of the ISO_5V power supply, capacitors C3 and C4 are also connected between pins 15 and 16, pin 12 is respectively connected to a drive unit and a current acquisition and amplification unit, and pins 13 and 14 are respectively connected to a drive unit and a current acquisition and amplification comparison unit. The power supply and signal isolation unit device includes a four-channel digital isolator with an integrated isolated power supply and its peripheral circuits, which are used to convert the control power supply voltage 5V into isolated ISO_5V through the four-channel digital isolator with an integrated isolated power supply. ISO_5V supplies power to the DCDC boost unit and the current acquisition, amplification and comparison unit; and is used to isolate the external I / O signal from the drive unit signal.

[0019] like Figure 2As shown, the isolation chip U1 converts the external power supply 5V into isolated ISO_5V through U1, ISO_5V is used to power U4 and U5 of the current acquisition, amplification and comparison unit, and ISO_5V is converted into ISO_15V through the DCDC boost unit to power the drive unit U2. INA is the unlocking signal, INB is the drive control signal, and Short_FK is the short-circuit fault feedback signal.

[0020] The driving unit includes a driving chip U2, wherein pin 1 of the driving chip U2 is connected to the ISO_5V power supply and grounded through a capacitor C5, pins 2 and 3 are connected to resistors R3 and R8, resistors R3 and the other end of resistor R3 are connected in parallel and are respectively connected to resistors R4 and R9, resistor R4 is connected to the power execution unit, resistor R9 is connected to the sampling unit and grounded, pin 4 is grounded, pin 5 is connected to pin 12 of the isolation chip U1 and grounded through a resistor R7, and pin 6 is connected to pin 13 of the isolation chip through a resistor R2 and grounded through a resistor R6. The driving unit device is used to realize the external control signal received after the isolation and processing of the power supply and signal isolation unit, drive control and unlock the back-end power execution unit, and if a short circuit occurs, the driving unit will output a short circuit fault feedback signal.

[0021] The driver chip U2 is a single-channel driver chip dedicated to MOSFET with high driving capability. The external INB signal is input to U2 after isolation processing, and the output controls the MOSFET to turn on and off.

[0022] The current acquisition, amplification and comparison unit includes a comparator U4 and an amplifier U5. Pins 5 of the comparator U4 and the amplifier U5 are both connected to the ISO_5V power supply, and pins 2 are both grounded; a capacitor C12 is connected between pins 3 and 4 of the amplifier U5 and is respectively connected to resistors R12 and R16, the other ends of resistors R12 and R16 are respectively connected to the two ends of the sampling resistor R15, pin 1 of the amplifier U5 is connected to pin 3 of the comparator U4 through resistor R14, pin 3 of the comparator U4 is also connected to the positive electrode of the diode D2, the negative electrode of the diode D2 is connected to pin 14 of the isolation chip U1, pin 4 of the comparator U4 is connected to the ISO_5V power supply through resistor R17, and is respectively connected to capacitor C13 and resistor R18, capacitor C13 and resistor R18 are grounded, pin 1 of the comparator U4 is connected to the positive electrode of the diode D3, the negative electrode of the diode D3 is connected to pin 12 of the isolation chip U1, and a resistor R10 is also connected between the negative electrode of the diode D3 and the negative electrode of the diode D1. The acquisition, amplification and comparison unit device is used to acquire the voltage at both ends of the sampling unit and amplify the fixed gain, and then compare it with the short-circuit protection point preset by the high-speed rail-to-rail amplifier and feed it back to the driving unit.

[0023] like Figure 2As shown, the voltage across the sampling resistor R15 is collected after signal processing by the port matching resistors R12, R16 and the filter capacitor C12, and is amplified by the high-side current detection amplifier U5 with a fixed gain of 10 times and then output to the non-inverting input terminal of the high-speed rail-to-rail comparator U4 through R14, and then compared with the preset short-circuit protection point voltage value of the inverting input terminal of U4 formed by the voltage divider R17 and R18, and the output is fed back to the drive unit.

[0024] The power execution unit includes a power switch Q1 , a drain of the power switch Q1 inputs power, a source is connected to the sampling unit and grounded, and a gate is connected to the resistor R4 .

[0025] The sampling unit is a sampling resistor R15, which is a mΩ-level sampling resistor R15. One end of the sampling resistor R15 is connected to the source of the power switch Q1, and the other end outputs power.

[0026] The DCDC boost unit includes a DCDC converter U3, wherein pin 5 of the DCDC converter U3 is connected to an ISO_5V power supply, pin 4 is grounded through a capacitor C11, pin 1 is connected to the positive electrode of a diode D2, the negative electrode of the diode D2 outputs an ISO_15V power supply, pin 3 is connected to pins 1 and 2 through resistors R11 and R13 respectively, the negative electrode of the diode D2 is also connected to capacitors C8 and C9 respectively, the capacitors C8 and C9 are grounded, and an inductor L1 is also connected between pins 5 and 1 of the DCDC converter U3. The DCDC boost unit device includes a non-isolated DCDC converter and its peripheral circuits, which converts the isolated power ISO_5V converted by the power supply and signal isolation unit into ISO_15V through a boost circuit composed of a non-isolated DCDC switch converter U3 and peripheral devices such as an inductor L1, a diode D2, resistors R11, R13, capacitors C8, C9, C11, etc. to power the drive unit U2.

[0027] When a short-circuit fault occurs, the output end of U4 will output a high level through D3, and then through R10 to the in-phase input end of U4 to close the loop and self-lock so that the output end of U4 remains at a high level. At the same time, the high level of the output end of U4 is output to the negative control input end of U2 through D3 and fed back to the fault feedback pin Short_FK of U1 as a high level, causing U2 to turn off the rear-end power switch Q1, achieving the short-circuit protection self-locking function. At the same time, the high level of the in-phase input end of U4 is output through D1 to the isolated output side of U1.

[0028] When Short_FK is high, it means that the short circuit protection is locked. When the circuit returns to normal, the short circuit protection self-locking circuit needs to be unlocked. Simply input a low level to INA, the in-phase input of U4 is pulled low, the output of U4 returns to a low level, and Short_FK returns to a low level.

Claims

1. A SSPC short circuit protection self-locking circuit, characterized in that: A power supply and signal isolation unit, a DCDC boost unit, a drive unit, a power execution unit, a sampling unit and a current acquisition, amplification and comparison unit. The power supply and signal isolation unit are respectively connected to the DCDC boost unit, the drive unit and the current acquisition, amplification and comparison unit. The drive unit is respectively connected to the DCDC boost unit, the current acquisition, amplification and comparison unit and the power execution unit. The power execution unit is connected to the sampling unit. The sampling unit is connected to the current acquisition, amplification and comparison unit. The power supply and signal isolation unit inputs and outputs I / O signals. The power execution unit and the sampling unit respectively input / output power electricity.

2. The SSPC short circuit protection self-locking circuit according to claim 1, characterized in that: The power supply and signal isolation unit includes an isolation chip U1, pin 1 of the isolation chip U1 is connected to a 5V power supply and is respectively connected to capacitor C1 and capacitor C2, capacitor C1 and capacitor C2 are grounded with pin 2 of the isolation chip U1, pins 3 and 4 of the isolation chip U1 are connected to an I / O signal, pin 3 is also connected to a 3V3 power supply through a resistor R1, pin 4 is grounded through a resistor R5, pin 5 outputs an I / O signal, pin 7 is connected to a 3V3 power supply, pin 8 is grounded, pins 9 and 15 are grounded, pins 10 and 16 are connected to the positive electrode of the ISO_5V power supply, capacitors C3 and C4 are also connected between pins 15 and 16, pin 12 is respectively connected to a drive unit and a current acquisition and amplification unit, and pins 13 and 14 are respectively connected to a drive unit and a current acquisition and amplification comparison unit.

3. The SSPC short circuit protection self-locking circuit according to claim 1, characterized in that: The driving unit includes a driving chip U2, wherein pin 1 of the driving chip U2 is connected to an ISO_5V power supply and is grounded through a capacitor C5, pins 2 and 3 are connected to resistors R3 and R8, resistor R3 and the other end of resistor R3 are connected in parallel and are respectively connected to resistors R4 and R9, resistor R4 is connected to a power execution unit, resistor R9 is connected to a sampling unit and is grounded, pin 4 is grounded, pin 5 is connected to pin 12 of an isolation chip U1 and is grounded through a resistor R7, and pin 6 is connected to pin 13 of the isolation chip through a resistor R2 and is grounded through a resistor R6.

4. The SSPC short circuit protection self-locking circuit according to claim 1, characterized in that: The current acquisition, amplification and comparison unit includes a comparator U4 and an amplifier U5. Pins 5 of the comparator U4 and the amplifier U5 are both connected to the ISO_5V power supply, and pins 2 are both grounded; a capacitor C12 is connected between pins 3 and 4 of the amplifier U5 and is respectively connected to resistors R12 and R16, the other ends of resistors R12 and R16 are respectively connected to the two ends of the sampling resistor R15, pin 1 of the amplifier U5 is connected to pin 3 of the comparator U4 through resistor R14, pin 3 of the comparator U4 is also connected to the positive electrode of the diode D2, the negative electrode of the diode D2 is connected to pin 14 of the isolation chip U1, pin 4 of the comparator U4 is connected to the ISO_5V power supply through resistor R17, and is respectively connected to capacitor C13 and resistor R18, capacitor C13 and resistor R18 are grounded, pin 1 of the comparator U4 is connected to the positive electrode of the diode D3, the negative electrode of the diode D3 is connected to pin 12 of the isolation chip U1, and a resistor R10 is also connected between the negative electrode of the diode D3 and the negative electrode of the diode D1.

5. The SSPC short circuit protection self-locking circuit according to claim 1, characterized in that: The power execution unit includes a power switch Q1 , a drain of the power switch Q1 inputs power, a source is connected to the sampling unit and grounded, and a gate is connected to the resistor R4 .

6. The SSPC short circuit protection self-locking circuit according to claim 1, characterized in that: The sampling unit is a sampling resistor R15 , one end of the sampling resistor R15 is connected to the source of the power switch Q1 , and the other end of the sampling resistor R15 outputs power.

7. The SSPC short circuit protection self-locking circuit according to claim 1, characterized in that: The DCDC boost unit includes a DCDC converter U3, wherein pin 5 of the DCDC converter U3 is connected to an ISO_5V power supply, pin 4 is grounded through a capacitor C11, pin 1 is connected to the positive electrode of a diode D2, the negative electrode of the diode D2 outputs an ISO_15V power supply, pin 3 is connected to pin 1 and pin 2 through resistors R11 and R13 respectively, the negative electrode of the diode D2 is also connected to capacitors C8 and C9 respectively, and capacitors C8 and C9 are grounded, and an inductor L1 is also connected between pin 5 and pin 1 of the DCDC converter U3.

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