CN111900708A - Soft switch solid-state power controller with current-limiting function - Google Patents

Soft switch solid-state power controller with current-limiting function Download PDF

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Publication number
CN111900708A
CN111900708A CN202010589347.XA CN202010589347A CN111900708A CN 111900708 A CN111900708 A CN 111900708A CN 202010589347 A CN202010589347 A CN 202010589347A CN 111900708 A CN111900708 A CN 111900708A
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Prior art keywords
power
switch tube
power switch
current
state
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CN202010589347.XA
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Chinese (zh)
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嵇保健
赵志宏
孙志超
张天宇
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Nanjing University of Science and Technology
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Nanjing University of Science and Technology
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Priority to CN202010589347.XA priority Critical patent/CN111900708A/en
Publication of CN111900708A publication Critical patent/CN111900708A/en
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    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H9/00—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection
    • H02H9/02—Emergency protective circuit arrangements for limiting excess current or voltage without disconnection responsive to excess current
    • H02H9/025—Current limitation using field effect transistors
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
    • H02H3/00—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection
    • H02H3/08—Emergency protective circuit arrangements for automatic disconnection directly responsive to an undesired change from normal electric working condition with or without subsequent reconnection ; integrated protection responsive to excess current

Abstract

The invention discloses a soft switch solid-state power controller with a current-limiting function, which comprises an alternating-current input power supply, first to fourth power switch tubes, first to fourth power diodes, a power resistor and an induction resistor, wherein the first power switch tube, the second power switch tube, the third power switch tube, the fourth power switch tube, the first power diode, the second power diode, the third power diode, the fourth power diode, the power; the first power switch tube and the second power switch tube are connected in series to form a main branch circuit, and the third power switch tube and the fourth power switch tube are connected in series to form a current-limiting branch circuit; off state when both branches are off; the open state when both branches are open; when the main branch is closed and the current-limiting branch is opened, the current-limiting branch is in a current-limiting state. When the absolute value of the peak current exceeds a threshold value, the SSPC enters a current limiting state; when the alternating current SSPC enters a current limiting state, judging whether a short-circuit fault occurs by using the voltage absolute value at the node power-off position, and if so, entering a closing state; after the current limiting process, when the absolute value of the current is lower than the threshold value, the SSPC recovers the conducting state. The invention improves the capability of SSPC to start large-capacity capacitance load and the safety of short-circuit protection in high-power application.

Description

Soft switch solid-state power controller with current-limiting function
Technical Field
The invention relates to the technical field of solid-state power controllers, in particular to a soft-switching solid-state power controller with a current limiting function.
Background
The Solid-State Power Controller (SSPC) is an intelligent switch device integrating the switching function of a relay and the circuit protection function of a breaker, has the advantages of no contact, no electric arc, no noise, quick response, small electromagnetic interference, long service life, high reliability, convenience for remote control of a computer and the like, and is widely applied to Power distribution systems of airplanes, ships and tanks.
The limitation of transient inrush current caused by capacitive load connections has been a focus and difficulty of SSPC concern in dc power distribution systems. For an ac system, transient inrush current can be significantly reduced or even eliminated due to the ZVS-on functionality of the ac SSPC. However, as power capacity increases, the ac SSPC can control not only one load but also one bus line to power several loads at the same time. Thus, each capacitive load can be connected to the bus at any time with its own switch, for example the peak of a sinusoidal voltage, thereby generating a large overcurrent. Also, as the ac SSPC expands from the aircraft power distribution system to other power distribution systems, severe nonlinear loads such as uncontrolled rectification with large capacitive filters may occur, and the connection of such loads will produce more severe inrush currents. In addition, a short-circuit fault may also cause a continuous surge current.
In order to prevent damage to the power system from overcurrent and inrush current, the ac SSPC must have a current limiting function, and the ac SSPC should have the capability of distinguishing between a short-circuit fault and an inrush load as soon as possible. Conventional ac SSPCs use switching devices, typically MOSFETs, to limit inrush current. However, in this process, the MOSFET must withstand large power losses and high temperatures, so this current limiting method does not operate permanently, otherwise the load capacitor is insufficiently charged or even turned off.
The principle of current limiting is to introduce impedance, which is commonly done by 1, introducing a saturable core current limiter, but the volume of the core and the winding is too large for SSPC, and the non-linear change in the permeability of the core makes impedance control difficult. 2. A whole cabinet control based on an alternating current chopper is introduced, but the control is too complex, and the reliability of the alternating current SSPC is difficult to guarantee. Furthermore, the volume of the transformer is not negligible. Therefore, in order to improve the capability of an alternating current Solid State Power Controller (SSPC) to start a large-capacity capacitive load and improve the safety of short-circuit protection in high-power applications, it is urgently needed to develop a novel topology structure and a control strategy of a soft switch.
Disclosure of Invention
The invention aims to provide a soft switching solid-state power controller with a current limiting function, which has strong capability of starting a large-capacity capacitive load and high safety.
The technical solution for realizing the purpose of the invention is as follows: a soft switch solid-state power controller with a current-limiting function comprises an alternating-current input power supply, a first power switch tube, a first power diode, a second power switch tube, a second power diode, a third power switch tube, a third power diode, a fourth power switch tube, a fourth power diode, a power resistor and an induction resistor;
the drain electrode of the first power switch tube is connected with the drain electrode of the third power switch tube and is connected to the positive end of an input alternating current power supply; the source electrode of the first power switch tube is connected with the source electrode of the second power switch tube, the source electrode of the third power switch tube is connected with the source electrode of the fourth power switch tube, the drain electrode of the fourth power switch tube is connected with one end of a power resistor, the other end of the power resistor is connected with the drain electrode of the second power switch tube and connected to one end of an induction resistor, the other end of the induction resistor is connected with one end of a load, and the other end of the load is connected with the negative end of an input alternating current power supply; the cathode of the first power diode is connected with the drain electrode of the first power switch tube, and the anode of the first power diode is connected with the source electrode of the first power switch tube; the cathode of the second power diode is connected with the drain electrode of the second power switch tube, and the anode of the second power diode is connected with the source electrode of the second power switch tube; the cathode of the third power diode is connected with the drain electrode of the third power switch tube, and the anode of the third power diode is connected with the source electrode of the third power switch tube; the cathode of the fourth power diode is connected with the drain of the fourth power switch tube, and the anode of the fourth power diode is connected with the source of the fourth power switch tube.
Furthermore, the first power switch tube and the second power switch tube are connected in series to form a main branch, and the third power switch tube and the fourth power switch tube are connected in series to form a current-limiting branch;
off state when both branches are off; the open state when both branches are open; when the main branch is closed and the current-limiting branch is opened, the current-limiting branch is in a current-limiting state.
Further, the control strategy for triggering the current limit is specifically as follows:
peak current detection is used to determine when an AC SSPC is switched to a current limiting state when the absolute value of the current exceeds a threshold Uth1When the current limiting signal is locked, the main branch of the SSPC is closed, and the current limiting state is entered; when the current is limited, the absolute value of the current is lower than a threshold value Uth1When so, the SSPC resumes the on state.
Further, the strategy for distinguishing short-circuit fault or surge load is specifically as follows:
when the AC SSPC enters the current limiting state, the absolute value of the voltage | u at the node "power off" is usedPOWEROUTI.e. the load voltage, and if the voltage absolute value | uPOWEROUTL at judgment time TSCInternal lower than threshold value Uth3And if the system is in a short-circuit fault state, judging that the system cannot be opened, and entering a closed state.
Compared with the prior art, the invention has the remarkable advantages that: (1) the peak current detection is adopted to judge when the alternating current SSPC is converted into the current-limiting state, the method is quick and effective, and the capability of starting a large-capacity capacitive load by the SSPC is improved; (2) the load voltage is used for judging whether the short-circuit fault occurs or not, once the short-circuit fault is found, the power supply is cut off immediately, and the safety of the short-circuit protection of the SSPC in high-power application is improved.
Drawings
Fig. 1 is a schematic diagram of a soft-switched solid-state power controller with current limiting capability according to the present invention.
Fig. 2 is a schematic diagram of waveforms of a driving signal, an input voltage and an output current when a soft-switching solid-state power controller with a current limiting function according to an embodiment of the present invention operates.
Fig. 3 is a schematic diagram of a switching mode 1 in an embodiment of the present invention.
Fig. 4 is a schematic diagram of a switching mode 2 in an embodiment of the present invention.
Fig. 5 is a schematic diagram of a switching mode 3 in an embodiment of the present invention.
Fig. 6 is a schematic diagram of a switching mode 4 in an embodiment of the invention.
Fig. 7 is a schematic diagram of a switching mode 5 in an embodiment of the invention.
Fig. 8 is a block diagram of a control circuit for triggering current limiting in an embodiment of the present invention.
Fig. 9 is a schematic diagram of the modal variation of the current limiting process in an embodiment of the invention.
Figure 10 is a schematic diagram of a control circuit in an embodiment of the invention with the short circuit separated from the surge load.
In the figure: u. ofinIs an alternating current input; s1、S2、S3、S4The first, second, third and fourth power switch tubes are respectively arranged; d1, D2, D3 and D4 are S respectively1、S2、S3、S4Diode u connected in parallel across the drain and sourcegs1、ugs2、ugs3、ugs4Are respectively S1、S2、S3、S4Drive signal of RlimitIs a current limiting resistor, RsenseFor sense resistance, LOAD is the LOAD resistance.
Detailed Description
The invention relates to a soft switch solid-state power controller with current-limiting function, which comprises an alternating current input power supply uinA first power switch tube S1A first power diode D1A second power switch tube S2A second power diode D2The third power switch tube S3A third power diode D3The fourth power switch tube S4A fourth power diode D4Power resistor RlimitAnd an induction resistance Rsense；
The first power switch tube S1Drain and third power switch tube S3Drain connected to input AC power supplyuinA positive terminal of; first power switch tube S1Source and second power switch tube S2Source electrode connected, third power switch tube S3Source and fourth power switch tube S4Source electrode connected, fourth power switch tube S4Drain and power resistor RlimitIs connected to one end of a power resistor RlimitAnd the other end of the first power switch tube S2Drain connected to sense resistor RsenseOne end of (1), sense resistor RsenseIs connected with one end of a LOAD, the other end of which is connected with an input alternating current power supply uinIs connected with the negative end of the water tank; first power diode D1Cathode and first power switch tube S1Is connected to the drain of a first power diode D1Anode of and the first power switch tube S1The source electrodes of the two-way transistor are connected; second power diode D2Cathode and second power switch tube S2Is connected to the drain of a second power diode D2Anode of and the second power switch tube S2The source electrodes of the two-way transistor are connected; third power diode D3Cathode and third power switch tube S3Is connected to the drain of the third power diode D3Anode of and third power switch tube S3The source electrodes of the two-way transistor are connected; fourth power diode D4Cathode and fourth power switch tube S4Is connected to the drain of the fourth power diode D4Anode of and fourth power switch tube S4Are connected.
As a specific example, the first power switch tube S1And a second power switch tube S2A third power switch tube S connected in series to form a main branch3And a fourth power switch tube S4The current limiting branches are formed by connecting in series;
off state when both branches are off; the open state when both branches are open; when the main branch is closed and the current-limiting branch is opened, the current-limiting branch is in a current-limiting state.
Further, the control strategy for triggering the current limit is specifically as follows:
peak current detection is used to determine when an AC SSPC is switched to a current limiting state when the current is absoluteThe value exceeds the threshold value Uth1When the current limiting signal is locked, the main branch of the SSPC is closed, and the current limiting state is entered; when the current is limited, the absolute value of the current is lower than a threshold value Uth1When so, the SSPC resumes the on state.
Further, the strategy for distinguishing short-circuit fault or surge load is specifically as follows:
when the AC SSPC enters the current limiting state, the absolute value of the voltage | u at the node "power off" is usedPOWEROUTI.e. the load voltage, and if the voltage absolute value | uPOWEROUTL at judgment time TSCInternal lower than threshold value Uth3And if the system is in a short-circuit fault state, judging that the system cannot be opened, and entering a closed state.
The invention is described in further detail below with reference to the figures and specific embodiments.
Examples
Referring to fig. 1, the soft-switching solid-state power controller with current limiting function according to the present invention comprises an ac input power uinA first power switch tube S1A first power diode D1A second power switch tube S2A second power diode D2The third power switch tube S3A third power diode D3The fourth power switch tube S4A fourth power diode D4Power resistor RlimitAnd an induction resistance Rsense；
The first power switch tube S1Drain and third power switch tube S3Drain connected to input AC power source uinA positive terminal of; first power switch tube S1Source and second power switch tube S2Source electrode connected, third power switch tube S3Source and fourth power switch tube S4Source electrode connected, fourth power switch tube S4Drain and power resistor RlimitIs connected to one end of a power resistor RlimitAnd the other end of the first power switch tube S2Drain connected to sense resistor RsenseOne end of (1), sense resistor RsenseAnother end of (1)Is connected with one end of a LOAD, and the other end of the LOAD is connected with an input alternating current power supply uinIs connected with the negative end of the water tank; first power diode D1Cathode and first power switch tube S1Is connected to the drain of a first power diode D1Anode of and the first power switch tube S1The source electrodes of the two-way transistor are connected; second power diode D2Cathode and second power switch tube S2Is connected to the drain of a second power diode D2Anode of and the second power switch tube S2The source electrodes of the two-way transistor are connected; third power diode D3Cathode and third power switch tube S3Is connected to the drain of the third power diode D3Anode of and third power switch tube S3The source electrodes of the two-way transistor are connected; fourth power diode D4Cathode and fourth power switch tube S4Is connected to the drain of the fourth power diode D4Anode of and fourth power switch tube S4Are connected.
Further, the first power switch tube S1And a second power switch tube S2A third power switch tube S connected in series to form a main branch3And a fourth power switch tube S4The current limiting branches are formed by connecting in series;
off state when both branches are off; the open state when both branches are open; when the main branch is closed and the current-limiting branch is opened, the current-limiting branch is in a current-limiting state.
Further, the control strategy for triggering the current limit is specifically as follows:
peak current detection is used to determine when an AC SSPC is switched to a current limiting state when the absolute value of the current exceeds a threshold Uth1When the current limiting signal is locked, the main branch of the SSPC is closed, and the current limiting state is entered; when the current is limited, the absolute value of the current is lower than a threshold value Uth1When so, the SSPC resumes the on state.
Further, the strategy for distinguishing short-circuit fault or surge load is specifically as follows:
when the AC SSPC enters the current limiting state, the absolute value of the voltage | u at the node "power off" is usedPOWEROUTI.e. load voltage to determine whether short circuit occursWay fault if absolute value of voltage | uPOWEROUTL at judgment time TSCInternal lower than threshold value Uth3And if the system is in a short-circuit fault state, judging that the system cannot be opened, and entering a closed state.
Referring to fig. 1, a first power switch S1And a second power switch tube S2A third power switch tube S connected in series to form a main branch3And a fourth power switch tube S4Are connected in series to form a current-limiting branch circuit.
The different functions of the soft-switching solid-state power controller with the current limiting function of the embodiment are realized by switching among the following three states.
(1) And (3) closing state: both branches are closed.
(2) An open state: both branches are open.
(3) And (3) current limiting state: the main branch is closed and the current-limiting branch is opened.
The following modes of operation can be derived in conjunction with the sspc start-up and stop-operation waveforms of fig. 2:
switched mode 1[ t ]0～t1]As shown in fig. 3: in this mode, the first power switch tube S1The third power switch tube S3The fourth power switch tube S4Off, the second power switch tube S2Closing; because the input voltage is in the positive half cycle, the first power diode D1The circuit plays a role of clamping, so that the circuit does not form a loop.
Switched mode 2[ t ]1～t2]As shown in fig. 4: in this mode, the first power switch tube S1The third power switch tube S3The fourth power switch tube S4Off, the second power switch tube S2Closing; when the input voltage is commutated to the negative half period, the D1 diode is conducted in the forward direction, and the circuit forms a loop
Switching mode 3[ t ]2～t3]As shown in fig. 5: in this mode, the first power switch tube S1A second power switch tube S2The third power switch tube S3The fourth power switch tube S4Closing; due to the first power diode D1Forward conduction is performed, so that the voltage at the two ends is zero, and at the moment, the first power switch tube S1The switching on of zero voltage is realized. At the moment, the solid-state power controller realizes soft switching-on, the circuit works normally, and the current limiting circuit works.
Switch mode 4[ t ]3～t4]As shown in fig. 6: in this mode, the first power switch tube S1The third power switch tube S3The fourth power switch tube S4Closed, second power switch tube S2Disconnecting; the circuit loop continues to work, and the loop current flows from the second power switch tube S2Switching to the second power diode D2And conducting.
Switching mode 5[ t ]4～t5]As shown in fig. 7: in this mode, the first power switch tube S1The third power switch tube S3The fourth power switch tube S4Closed, second power switch tube S2Disconnecting; at time t5, since the input voltage changes from positive to negative and the input current is zero, the first power switch S1The zero current turn-off is realized, at the moment, the solid-state power controller realizes soft turn-off, the circuit stops working, and the current limiting circuit also stops working.
The above working mode is a mode analysis of the working process of the solid-state power controller during switching on and off.
The control strategy for triggering the current limit is specifically as follows:
the peak current detection is adopted to judge when the alternating current SSPC is converted into a current limiting state, and the method is proved to be fast and effective. The control circuit block diagram is shown in fig. 8. When the absolute value of the current exceeds the threshold Uth1When the active current limit signal is locked, the main branch of the SSPC is shut down. Therefore, the surge current receives RlimitThe limit of (2). The modal change of the process is shown in fig. 9.
The strategy for distinguishing short-circuit fault and surge load is as follows:
as shown in FIG. 10, when the AC SSPC enters the current limiting state, the absolute value of the voltage | u at the node "power down" is usedPOWEROUTI.e. the load voltage, to determine whether a short circuit fault has occurred.If | uPOWEROUTL at judgment time TSCInternal lower than threshold value Uth3Then, it is determined as a short-circuit fault or a capacitive load where the system cannot be opened. Using uave，uPOWEROUTBy evaluating whether the surge load is loaded to a stable state by an RC filter, good compatibility with different surge loads is confirmed. Once a short circuit fault is found, the off state is entered. For surge load, after current limiting processing, when the absolute value of current exceeds the threshold Uth1At this time, the SSPC enters the on state.
The method adopts peak current detection to judge when the alternating current SSPC is converted into the current-limiting state, is quick and effective, and improves the capability of starting a large-capacity capacitive load by the SSPC; the load voltage is used for judging whether the short-circuit fault occurs or not, once the short-circuit fault is found, the power supply is cut off immediately, and the safety of the short-circuit protection of the SSPC in high-power application is improved.

Claims (4)

1. A soft-switching solid-state power controller with current-limiting function, comprising an AC input power source (u)in) A first power switch tube (S)1) A first power diode (D)1) A second power switch tube (S)2) A second power diode (D)2) And the third power switch tube (S)3) A third power diode (D)3) And the fourth power switch tube (S)4) And a fourth power diode (D)4) Power resistance (R)limit) And an induction resistance (R)sense)；
The first power switch tube (S)1) Drain and third power switch tube (S)3) Drain connected to input AC power source (u)in) A positive terminal of; first power switch tube (S)1) Source and second power switch tube (S)2) Source electrode connected, third power switch tube (S)3) Source and fourth power switch tube (S)4) Source electrode connected, fourth power switch tube (S)4) Drain and power resistor (R)limit) Is connected to one terminal of a power resistor (R)limit) And the other end of the first power switch tube (S) and a second power switch tube (S)2) The drain electrode is connected with the first electrode,and connected to the sense resistor (R)sense) One end of (2), sense resistor (R)sense) Is connected to one end of a LOAD (LOAD) whose other end is connected to an input ac power source (u)in) Is connected with the negative end of the water tank; a first power diode (D)1) And a first power switch tube (S)1) Is connected to the drain of the first power diode (D)1) And the first power switch tube (S)1) The source electrodes of the two-way transistor are connected; a second power diode (D)2) And a second power switch tube (S)2) Is connected to the drain of the first power diode (D)2) And a second power switch tube (S)2) The source electrodes of the two-way transistor are connected; third power diode (D)3) And a third power switch tube (S)3) Is connected to the drain of the third power diode (D)3) And the third power switch tube (S)3) The source electrodes of the two-way transistor are connected; fourth power diode (D)4) And a fourth power switch tube (S)4) Is connected to the drain of the fourth power diode (D)4) Anode of (2) and a fourth power switch tube (S)4) Are connected.
2. Soft-switched solid-state power controller with current limiting function according to claim 1, characterized in that the first power switch tube (S)1) And a second power switch tube (S)2) A third power switch tube (S) connected in series to form a main branch3) And a fourth power switch tube (S)4) The current limiting branches are formed by connecting in series;
off state when both branches are off; the open state when both branches are open; when the main branch is closed and the current-limiting branch is opened, the current-limiting branch is in a current-limiting state.
3. The soft-switched solid-state power controller with current limiting function according to claim 1, wherein the control strategy for triggering the current limit is as follows:
peak current detection is used to determine when an AC SSPC is switched to a current limiting state when the absolute value of the current exceeds a threshold Uth1While the active current limit signal is locked, the main branch of the SSPCClosing and entering a current limiting state; when the current is limited, the absolute value of the current is lower than a threshold value Uth1When so, the SSPC resumes the on state.
4. A soft-switched solid-state power controller with current limiting capability according to claim 1, wherein the strategy to distinguish short-circuit faults or surge loads is specifically as follows:
when the AC SSPC enters the current limiting state, the absolute value of the voltage | u at the node "power off" is usedPOWEROUTI.e. the load voltage, and if the voltage absolute value | uPOWEROUTL at judgment time TSCInternal lower than threshold value Uth3And if the system is in a short-circuit fault state, judging that the system cannot be opened, and entering a closed state.
CN202010589347.XA 2020-06-24 2020-06-24 Soft switch solid-state power controller with current-limiting function Withdrawn CN111900708A (en)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113852051A (en) * 2021-09-13 2021-12-28 中国科学院电工研究所 Direct-current solid-state circuit breaker with bidirectional breaking and soft starting functions and control method

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113852051A (en) * 2021-09-13 2021-12-28 中国科学院电工研究所 Direct-current solid-state circuit breaker with bidirectional breaking and soft starting functions and control method

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