Direct current surge suppression circuit

Abstract

The utility model relates to the technical field of current surge suppression, in particular to a direct current surge suppression circuit. Comprising a direct-current power supply assembly, a high-voltage power supply assembly, a control assembly and a load, the direct-current power supply assembly supplies power to the load through the high-voltage power supply assembly, the high-voltage power supply assembly comprises power switch devices Q1 connected in series, a current detection unit I1 for detecting the magnitude of current flowing through the power switch devices Q1 and an inductor L1, and the load is connected with the inductor L1 in series; the high-voltage power supply assembly further comprises a capacitor C1 connected in parallel to the two ends of the load, and a diode D1 of which the negative electrode is connected between the power switch device Q1 and the current detection unit I1 and the positive electrode is connected to the direct-current power supply assembly; according to the utility model, the device of the controller can be effectively protected from being damaged by the impact of current, and the current impact of the power supply assembly is reduced at the same time.

Description

TECHNICAL FIELD

[0001] The utility model relates to current surge suppression technical field, especially a direct current surge suppression circuit. BACKGROUND

[0002] With the development of hydrogen fuel cell, electric automobile, centralized air conditioner, electric tool and other industries, the demand of direct current power supply and motor load is more and more obvious. The controller of this direct current power supply has a large capacity filter capacitor, and the current surge is too large in the power-on moment, which can easily damage the power device or cause interference to make the system work abnormally. The power precharge function is usually needed, which can effectively limit the current surge phenomenon during the power-on process. But the power precharge function generally cannot consider the current limitation of all working time.

[0003] In the prior art, scheme 1:

[0004] As shown in Figure 1 , the traditional power-on moment is charged to C1 capacitor and C2 capacitor through general resistance R2, and after the capacitor is charged, the module of M2 generates 5V power supply to supply power to the MCU control unit of M1, and through time delay (usually delay 0.1-10 seconds), the relay or power switch of S1 is turned on, and the system can work normally.

[0005] E1: direct current power supply, S1: relay or power switch, R2: current surge suppression resistance, M1: MCU control unit, providing driving signal for driving M3, M2: isolating power supply, generating 5V direct current power supply for M1, M3: driving module, sending the driving signal provided by M1 to S1 through isolation and power amplification, C1: direct current system filter energy storage capacitor, C2: filter capacitor of M2 module, M: load, resistive load or inductive load.

[0006] Disadvantages of scheme 1:

[0007] 1. S1 and R2 have large volume;

[0008] 2. R2 current suppression resistance is easy to be damaged if repeatedly charged in a short time;

[0009] 3. After S1 is turned on and works normally, there is no current suppression effect, and this circuit can only play a role in current surge suppression when the power supply is powered on for the first time.

[0010] Scheme 2:

[0011] As shown in Figure 2As shown, in the traditional configuration, upon power-on, the positive temperature coefficient thermistor R3 charges capacitors C1 and C2. After the capacitors are fully charged, module M2 generates a 5V power supply to power the MCU control unit of M1. After a time delay (usually 0.1 to 10 seconds), the relay or power switch of S1 is activated, and the system can then operate normally. R3 is a positive temperature coefficient thermistor. When the current through the resistor is too high (exceeding its normal operating current), the resistor's temperature rises, its resistance increases, and the current flowing through the resistor decreases, thus lowering the resistor's temperature. This ensures that the resistor will not be damaged by excessive temperature rise due to repeated charging and discharging.

[0012] E1: DC power supply; S1: Relay or power switch; R3: Resistor with positive temperature coefficient for current surge suppression; M1: MCU control unit, providing drive signal for driver M3; M2: Isolation switching power supply, generating 5V DC power to power M1; M3: Driver module, which isolates and amplifies the drive signal provided by M1 before sending it to S1; C1: DC system filter energy storage capacitor; C2: Filter capacitor for module M2; M: Load, resistive or inductive load.

[0013] Disadvantages of Option 2:

[0014] 1. S1 and R2 have relatively large volumes;

[0015] 2. After S1 is turned on and working normally, there is no current suppression effect. This circuit can only suppress current surges when the power is first turned on.

[0016] Option 3:

[0017] like Figure 3 As shown, in a traditional circuit, upon power-up, power transistor Q1 charges capacitor C1. Current detection I1 and current conditioning M4 detect and process the current of Q1. When the current of Q1 is too high, the drive module M3 lowers the drive voltage of Q1, increasing the voltage drop across the power transistor (amplification region), thus reducing the current of Q1. Conversely, when the current of Q1 decreases, the drive module M3 raises the drive voltage of Q1, reducing the voltage drop across the power transistor, thus increasing the current of Q1. The current of power transistor Q1 is detected by I1, allowing capacitor C1 to fully charge. Once capacitor C1 is fully charged, the drive voltage of drive module M3 is further increased, turning on Q1 and enabling normal operation. The advantage of this circuit is that it can also ensure current surge suppression during normal operation.

[0018] E1: DC power supply, Q1: power switch, I1: Q1 current detection, M3: Q1 drive module, M4: signal processing after Q1 current detection, C1: DC system filter energy storage capacitor.

[0019] The disadvantage of scheme 3: when Q1 power tube repeatedly charges C1, Q1 works in the amplification zone for a long time, and the power tube of Q1 is easily damaged.

[0020] The direct current current surge suppression circuit is proposed to solve the problems in the prior art. The utility model discloses a direct current current surge suppression circuit

[0021] The utility model aims at providing a direct current current surge suppression circuit to solve the problems in the prior art, direct current power supply, motor as load application occasion, controller internal has large capacity capacitor filter, and the precharge function is needed in the process of power on, and the current limitation of the precharge function generally cannot be considered in all working time.

[0022] The utility model discloses a direct current current surge suppression circuit, including: direct current power supply assembly, high voltage power supply assembly, control assembly, load, direct current power supply assembly is powered with high voltage power supply assembly to load, high voltage power supply assembly includes the power switch device Q1 in series connection, the current detection unit I1 of detecting the current size of flowing through power switch device Q1, inductance L1, load series inductance L1;

[0023] High voltage power supply assembly still includes that capacitor C1 is connected in parallel in the both ends of load, and the diode D1 of negative pole connection between power switch device Q1 and current detection unit I1, positive pole connection on direct current power supply assembly;

[0024] Control assembly obtains the current size of flowing through power switch device Q1 through current detection unit I1, to control the conduction or turn-off of power switch device Q1.

[0025] Preferably, the control assembly includes a current conditioning M4, a control unit M1, and a drive module M3, the current conditioning M4 processes the signal of the current detection unit I1 and transmits it to the control unit M1, the control unit M1 provides corresponding drive signals to the drive module M3 according to the signal transmitted by the current conditioning M4, and the drive module M3 transmits the drive signals provided by the control unit M1 to the power switch device Q1 after isolation and power amplification, so as to control the conduction or turn-off of the power switch device Q1.

[0026] It also includes a low-voltage power supply assembly that supplies power to the control unit M1.

[0027] Preferably, the low-voltage power supply assembly includes an isolated switching power supply M2, a diode D2, a resistor R1, a capacitor C2, and a diode D3, the diode D2, the resistor R1, and the capacitor C2 are connected in series, and the positive electrode of the diode D1 is connected to the first power supply, and the negative electrode is connected to the resistor R1.

[0028] The positive electrode of the diode D3 is connected with a second power supply, and the negative electrode of the diode D3 is connected at a connection point of the resistor R1 and the capacitor C2, which is connected with the isolation switch power supply M2;

[0029] The other end of the capacitor is connected with 0V.

[0030] Preferably, the control unit M1 is a micro control unit MCU.

[0031] Preferably, the current detection unit I1 is a current sensor.

[0032] Preferably, the driving module M3 is a switch driver.

[0033] Compared with the prior art, the direct current surge suppression circuit has the following advantages:

[0034] In the direct current surge suppression circuit, the control unit M1 detects the current of the power switch device Q1, and cooperates with the inductor L1 and the diode D1 to realize the power pre-charging function and prevent the current overshoot phenomenon in the power-on process. In the normal working process, the current flowing through the power switch device Q1 is detected in real time, and the current detection unit I1 controls the conduction or turn-off of the power switch device Q1, so that the input current can be prevented from being too large to damage the device. By detecting the current of the main circuit and the principle that the current of the inductor cannot be suddenly changed, the current of the control circuit is not suddenly changed in the power-on moment and the whole process of normal working. The device of the controller can be effectively protected from damage caused by the impact of the current, and the current impact of the power supply assembly is also reduced. BRIEF DESCRIPTION OF DRAWINGS

[0035] The utility model will be further described in connection with the drawings and examples:

[0036] Figure 1 It is the direct current surge suppression circuit structure schematic drawing of prior art scheme 1;

[0037] Figure 2 It is the direct current surge suppression circuit structure schematic drawing of prior art scheme 2;

[0038] Figure 3 It is the direct current surge suppression circuit structure schematic drawing of prior art scheme 3;

[0039] Figure 4 It is the circuit structure schematic drawing of the direct current surge suppression circuit of the embodiment;

[0040] Figure 5 In the direct current surge suppression circuit, the circuit structure schematic diagram of the initial power-on of the control unit M1 is shown in the figure;

[0041] Figure 6 For the direct current surge suppression circuit described in this embodiment, the strong electric pre-charge power switch device Q1 is in the on state;

[0042] Figure 7 For the direct current surge suppression circuit described in this embodiment, the strong electric pre-charge power switch device Q1 is in the off state;

[0043] Figure 8 For the direct current surge suppression circuit described in this embodiment, the circuit structure schematic diagram in the normal working state.

[0044] Wherein: 1, direct current power supply component, 2, high-voltage power supply component, 3, load, 4, low-voltage power supply component, 5, control component. DETAILED DESCRIPTION

[0045] The content of the utility model will be further described in detail below in combination with specific embodiments:

[0046] In the description of the utility model, it should be understood that the orientation or positional relationship indicated by the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" and the like is the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the indicated device or element must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model.

[0047] As Figure 4 shown, a direct current surge suppression circuit, comprising: direct current power supply component 1, high-voltage power supply component 2, control component 5, load 3, the direct current power supply component 1 supplies power to the load through the high-voltage power supply component 2, the high-voltage power supply component 2 is a direct current power supply E1 in this embodiment, which is 600VA; the high-voltage power supply component 2 includes a power switch device Q1 in series, a current detection unit I1 for detecting the current flowing through the power switch device Q1, and an inductor L1, and the load 3 is connected in series with the inductor L1; the high-voltage power supply component 2 further includes a capacitor C1 connected in parallel across the load 3, and a diode D1 having a negative electrode connected between the power switch device Q1 and the current detection unit I1 and a positive electrode connected to the direct current power supply component 1; the control component 5 obtains the current flowing through the power switch device Q1 through the current detection unit I1 to control the conduction or turn-off of the power switch device Q1.

[0048] Control component 5 includes a current conditioning unit M4, a control unit M1, a drive module M3, and a low-voltage power supply component 4, which supplies power to the control unit M1. The current conditioning unit M4 processes the signal from the current detection unit I1 and transmits it to the control unit M1. The control unit M1 provides the corresponding drive signal to the drive module M3 based on the signal transmitted from the current conditioning unit M4. The drive module M3 isolates and amplifies the drive signal provided by the control unit M1 before transmitting it to the power switching device Q1, thereby controlling the power switching device Q1 to turn on or off. The control unit M1 is a microcontroller unit (MCU). The current detection unit I1 is a current sensor. The drive module M3 is a switch driver.

[0049] The low-voltage power supply assembly 4 includes an isolating switch power supply M2, diode D2, resistor R1, capacitor C2, and diode D3. Diode D2, resistor R1, and capacitor C2 are connected in series. The anode of diode D1 is connected to a first power supply (600VA in this embodiment), and the cathode is connected to resistor R1. The anode of diode D3 is connected to a second power supply (600VB in this embodiment), and the cathode of diode D3 is connected to the junction of resistor R1 and capacitor C2, which is connected to the isolating switch power supply M2. The other end of the capacitor is connected to 0V. Diode D2, resistor R1, and capacitor C2 form a pre-charge function for the isolating switch power supply M2. Diodes D2 and D3 can automatically switch the power supply of the isolating switch power supply M2 from 600VA or 600VB. After the 600VA power is cut off, the capacity stored in capacitor C1 can form a rapid passive discharge function through the diode D3 and isolating switch power supply M2 circuit. Normally, the passive discharge time is about 120 seconds; with this function, the passive discharge time is only about 30 seconds.

[0050] The working principle of the DC current surge suppression circuit in this utility model is as follows:

[0051] (1) As Figure 5 As shown, the initial power-on operation process of control unit M1

[0052] When the S1-1, 600VA power supply is powered on, because the control unit M1 has no low-voltage circuit, the power switching device Q1 is in the off state. The 600VA power supply has 600V, while the 600VB power supply has no voltage.

[0053] S1-2, 600VA precharges capacitor C2 through diode D2 and resistor R1. After the precharge is completed (usually 0.1 seconds to 1 second), capacitor C2 has a voltage of 600V.

[0054] After S1-3 and capacitor C2 have a voltage of 600V, they supply power to the isolation switching power supply M2. That is, the isolation switching power supply M2 can work normally and generate a 5V weak current to supply power to the control unit M1 module.

[0055] S1-4, after the control unit M1 module works normally, the current flowing through the power switch device Q1 is detected by the current regulating M4 and the current detection unit I1, and the conduction or turn-off of the power switch device Q1 power tube is controlled by the size of the current flowing through the power switch device Q1;

[0056] S1-5, the control unit M1 controls the conduction or turn-off of the power switch device Q1 power tube.

[0057] (2) strong electric pre-charging working state

[0058] S2-1, after the control unit M1 completes the initial power-on working process, the strong electric pre-charging working state is entered;

[0059] S2-2, the control unit M1 turns on the power switch device Q1 through the driving module M3;

[0060] S2-3, when the power switch device Q1 is turned on, the 600VA power supply charges the capacitor C1 through the power switch device Q1, the current detection unit I1 and the inductor L1; because of the existence of the inductor L1 (the current cannot be suddenly changed), the current increases linearly, as shown in Figure 6 ;

[0061] S2-4, when the control unit M1 detects that the current of the power switch device Q1 is too large through the current regulating M4 and the current detection unit I1, the power switch device Q1 is turned off;

[0062] S2-5, after the power switch device Q1 is turned off, because of the existence of the energy of the inductor L1, the capacitor C1 is continuously charged through the diode D1 and the inductor L1; the current of the inductor L1 decreases linearly, as shown in Figure 7 ,

[0063] S2-6, when the current of the inductor L1 decreases to a certain extent, the power switch device Q1 is turned on again, and the charging state returns to step S2-3;

[0064] S2-7, after the power switch device Q1 is turned on / off repeatedly for several times, the voltage of the capacitor C1 600VB approaches the voltage of the power supply E1 600VA, and the strong electric pre-charging is completed.

[0065] (3) as shown in Figure 8 , the normal working state

[0066] S3-1, when the capacitor C1 is charged, it is the normal working state;

[0067] S3-2, in the normal working state, when the control unit M1 detects that the current of the current detection unit I1 is ≤ the peak current of the controller, the control unit M1 turns on the power switch device Q1;

[0068] S3-3, when the control unit M1 detects that the current of the current detection unit I1 is greater than the controller peak current, the control unit M1 turns off the power switch device Q1;

[0069] S3-4, after the power switch device Q1 is turned off, the control unit M1 detects that the current of the current detection unit I1 is too small, and then turns on the power switch device Q1 again; this state returns to the strong electricity pre-charging state.

[0070] (4) Strong electricity normal shutdown power-off working state

[0071] S4-1, the system stops working, and the load M has no load current;

[0072] S4-2, after the DC power supply E1 is powered off, i.e. 600VA has no voltage.

[0073] S4-3, the energy stored in the capacitor C1 is discharged through the diode D3 and the switching power supply M2;

[0074] S4-4, until the voltage of the capacitor C1 cannot support the switching power supply M2 power supply to work, the M1 control module stops working.

[0075] (5) Strong electricity abnormal shutdown power-off working state

[0076] S5-1, when the load M is in normal working, the DC power supply E1 is disconnected, i.e. 600VA has no voltage;

[0077] S5-2, the energy stored in the capacitor C1 continues to provide energy for the load M;

[0078] S5-3, when the voltage of the capacitor C1 cannot continue to provide energy for the load M, the energy stored in the capacitor C1 continues to be discharged through the diode D3 and the isolation switching power supply M2;

[0079] S5-4, until the voltage of the capacitor C1 cannot support the switching power supply M2 power supply to work, the control unit M1 control module stops working.

[0080] The above examples are only for illustrating the technical concept and characteristics of the present application, and the purpose is to enable those skilled in the art to understand the content of the present application and to implement it, and cannot limit the protection scope of the present application. For those skilled in the art, it is obvious that the present application is not limited to the details of the above exemplary embodiments, and the present application can be implemented in other specific forms without departing from the spirit or basic characteristics of the present application, therefore, from any point of view, the examples should be regarded as exemplary and non-limiting, the scope of the present application is defined by the appended claims rather than the above description, therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present application.

Claims

1. A direct current inrush suppression circuit, characterized by, The application relates to a high-voltage power supply assembly, a control assembly and a low-voltage power supply assembly. The high-voltage power supply assembly comprises a power switch device Q1, a current detection unit I1 and an inductor L1 which are connected in series, and the load is connected in series with the inductor L1. The high-voltage power supply assembly further comprises a capacitor C1 connected in parallel with the load, and a diode D1 with a negative electrode connected between the power switch device Q1 and the current detection unit I1 and a positive electrode connected to the direct-current power supply assembly. The control assembly obtains the current flowing through the power switch device Q1 through the current detection unit I1 to control the on or off of the power switch device Q1.

2. A direct current inrush suppression circuit according to claim 1, characterized in that: The control assembly comprises a current conditioning M4, a control unit M1 and a driving module M3, the current conditioning M4 processes the signal of the current detection unit I1 and transmits the signal to the control unit M1, the control unit M1 provides corresponding driving signals for the driving module M3 according to the signal transmitted by the current conditioning M4, and the driving module M3 transmits the driving signals provided by the control unit M1 to the power switch device Q1 after isolation and power amplification to control the on or off of the power switch device Q1. The low-voltage power supply assembly supplies power to the control unit M1.

3. A direct current inrush suppression circuit according to claim 2, characterized in that: The low-voltage power supply assembly comprises an isolation switch power supply M2, a diode D2, a resistor R1, a capacitor C2 and a diode D3, the diode D2, the resistor R1 and the capacitor C2 are connected in series, the positive electrode of the diode D1 is connected to a first power supply, and the negative electrode is connected to the resistor R1. The positive electrode of the diode D3 is connected to a second power supply, the negative electrode of the diode D3 is connected to the connection point of the resistor R1 and the capacitor C2, and the connection point is connected to the isolation switch power supply M2. The other end of the capacitor is connected to 0V.

4. A direct current inrush suppression circuit according to claim 2, characterized in that: The control unit M1 is a micro control unit MCU.

5. A direct current inrush suppression circuit according to claim 1, characterized in that: The current detection unit I1 is a current sensor.

6. A direct current inrush suppression circuit according to claim 2, characterized in that: The driving module M3 is a switch driver.

Images