A high-voltage battery switch activation circuit

Abstract

This invention discloses a high-voltage battery switch activation circuit, comprising: an MCU module; a main power supply circuit connected to the MCU module, the main power supply circuit being used to supply power to the MCU module; a high-voltage activation circuit connected to the MCU module and the main power supply circuit, the MCU module driving the high-voltage activation circuit to operate, the high-voltage activation circuit being used to drive the main power supply circuit; and a power-on detection circuit connected to the MCU module, the MCU module driving the power-on detection circuit to realize the switching between a high-voltage activation signal and a low-voltage drive signal. This invention supports the power-on and activation of a wide-range high-voltage BMS, can reasonably control the voltage of the high-voltage activation circuit, and accelerate the start-up speed of the high-voltage activation circuit to avoid the high-voltage activation circuit being subjected to impact or increased losses, and can ensure fast and low-cost safe startup of the BMS under a wide input voltage range.

Description

Technical Field

[0001] This invention relates to the field of battery technology, and in particular to a high-voltage battery switch activation circuit. Background Technology

[0002] In recent years, with the widespread use of clean energy sources such as solar power, high-voltage home energy storage systems have gradually come into focus. Energy storage systems convert clean energy into electrical energy for storage, supplying power to household / industrial equipment. To reduce power line losses, battery voltage is increased when designing energy storage systems of the same capacity. The Battery Management System (BMS) is a crucial component for protecting and monitoring the battery's safety status; higher supply voltages place higher demands on the BMS's normal operation. For high-voltage input BMSs, proper startup becomes a key control factor. To facilitate operation and avoid voltage oscillations during startup, a common approach is to use disconnect switches, relays, or other devices to use the high-voltage level as an activation signal. This signal is then converted to a low-voltage signal to activate the switching transistors / IGBTs in the main power supply circuit, thus powering on the entire system. Therefore, a suitable power-on activation circuit needs to be configured on the BMS.

[0003] For this activation circuit, since the battery voltage is not fixed, it is necessary to ensure that the BMS can be triggered at different voltages. Furthermore, based on the characteristics of the high-voltage switching transistor, excessively high drive voltage can easily lead to gate-source overvoltage breakdown and damage to the transistor. If the voltage rise time is slow, it can cause the transistor to enter the Miller plateau and be damaged. Therefore, the trigger voltage needs to be kept within a reasonable range, and the trigger time needs to be as fast as possible. Existing trigger circuits mostly use complex ICs in conjunction with external circuits for control, converting the high-voltage signal into a suitable voltage drive signal for control, which is very costly. Summary of the Invention

[0004] The main objective of this invention is to propose a high-voltage battery switch activation circuit that aims to ensure fast and low-cost safe startup of the BMS over a wide input voltage range.

[0005] To achieve the above objectives, the present invention provides a high-voltage battery switch activation circuit, comprising:

[0006] MCU module;

[0007] The main power supply circuit is connected to the MCU module and is used to supply power to the MCU module.

[0008] A high-voltage activation circuit is connected to the MCU module and the main power supply circuit. The MCU module drives the high-voltage activation circuit to work, and the high-voltage activation circuit is used to drive the main power supply circuit.

[0009] A power-on detection circuit is connected to the MCU module, and the MCU module drives the power-on detection circuit to switch between high-voltage activation signal and low-voltage drive signal.

[0010] In one embodiment, the high-voltage activation circuit includes an isolation dual-channel switch, a first resistor, a second resistor, a first capacitor, a second capacitor, a first diode, and a second diode. The isolation dual-channel switch is connected to one end of the first resistor, the other end of the first resistor is connected to one end of the second resistor, the other end of the second resistor is connected to the first capacitor, the first capacitor and the second capacitor are connected in series, and the first diode, the second diode, and the second capacitor are connected in parallel.

[0011] In one embodiment, the first diode and the second diode are transient suppression diodes.

[0012] In one embodiment, the high-voltage activation circuit further includes a third resistor, a fourth resistor, a first switching transistor, and a third diode. The third resistor is connected in parallel across the high-voltage battery. One end of the fourth resistor is connected to the source of the first switching transistor, and the other end of the fourth resistor is connected to the second diode. The gate of the first switching transistor is connected to the second diode, and the drain of the first switching transistor is connected to the anode of the third diode. The cathode of the third diode outputs a drive signal to the main power supply circuit.

[0013] In one embodiment, the main power supply circuit includes a second switch, a fifth resistor, a sixth resistor, and a seventh resistor. One end of the fifth resistor is connected to the negative terminal of the first diode, and the other end of the fifth resistor is connected to the gate of the second switch. One end of the sixth resistor is connected to the other end of the fifth resistor and the gate of the second switch, and the other end of the sixth resistor is connected to the seventh resistor.

[0014] In one embodiment, the power-on detection circuit includes an eighth resistor, the isolated dual-channel switch is connected to the eighth resistor, the eighth resistor collects the switch status signal of the isolated dual-channel switch and transmits the switch status signal to the MCU module.

[0015] In one embodiment, the power-on detection circuit further includes an isolating switch, a ninth resistor, a tenth resistor, an eleventh resistor, a third switching transistor, and a fourth diode. The MCU module is connected to the isolating switch. The isolating switch is connected to one end of the ninth resistor and one end of the tenth resistor. The other end of the ninth resistor is connected to the source of the third switching transistor. The other end of the tenth resistor is connected to the gate of the third switching transistor. The drain of the third switching transistor is connected to one end of the eleventh resistor. The other end of the eleventh resistor is connected to the anode of the fourth diode. The cathode of the fourth diode outputs a drive signal.

[0016] In one embodiment, when the isolation dual-path switch is closed, the voltage across the first capacitor is inversely proportional to the capacitance value of the first capacitor, and the voltage across the second capacitor is inversely proportional to the capacitance value of the second capacitor.

[0017] In one embodiment, when the first switch is turned on, the gate-source voltage of the second switch is equal to the voltage across the second diode plus the voltage across the fourth resistor.

[0018] In one embodiment, when the high-voltage battery switch activation circuit is operating normally, the minimum voltage required by the high-voltage battery is:

[0019]

[0020] Wherein, VINmin is the minimum voltage required by the high-voltage battery, VtvsC is the clamping voltage of the first diode, C1 is the capacitance of the first capacitor, and C2 is the capacitance of the second capacitor.

[0021] This invention employs an MCU module to drive the high-voltage activation circuit, which in turn drives the main power supply circuit. This supports power-on and activation of a wide-range high-voltage BMS, featuring a simple topology that eliminates the need for other high-voltage ICs and complex components. The high-voltage activation circuit voltage can be effectively controlled, accelerating its startup and preventing it from being impacted or experiencing increased losses. A subsequent power-on detection circuit switches between the high-voltage activation signal and the low-voltage drive signal, preventing repeated switching and ensuring a safe and reliable startup process. This allows for fast and cost-effective safe startup of the BMS across a wide input voltage range. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of a high-voltage battery switch activation circuit module.

[0024] Figure 2 This is a high-voltage activation circuit diagram;

[0025] Figure 3 This is the circuit diagram for power-on detection.

[0026] Figure 4 This is a schematic diagram of the main circuit.

[0027] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0028] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] It should be noted that if the embodiments of the present invention involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0030] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, if the word "and / or" appears throughout the text, it means including three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution that simultaneously satisfies A and B. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0031] This invention proposes a high-voltage battery switch activation circuit, comprising:

[0032] MCU module 1; main power supply circuit 3, connected to MCU module 1, the main power supply circuit 3 is used to power MCU module 1; high-voltage activation circuit 2, connected to MCU module 1 and main power supply circuit 3, MCU module 1 drives the high-voltage activation circuit 2 to work, the high-voltage activation circuit 2 is used to drive the main power supply circuit 3; power-on detection circuit 4, connected to MCU module 1, MCU module 1 drives the power-on detection circuit 4 to realize the switching between high-voltage activation signal and low-voltage drive signal.

[0033] In embodiments of the present invention, such as Figure 1As shown, this invention uses an MCU module 1 to drive the high-voltage activation circuit 2, which in turn drives the main power supply circuit 3. This supports power-on and activation of a wide-range high-voltage BMS, with a simple topology that eliminates the need for other high-voltage ICs and complex components. The voltage of the high-voltage activation circuit 2 can be reasonably controlled, and its startup speed can be accelerated to prevent it from being impacted or experiencing increased losses. The subsequent power-on detection circuit 4 switches between the high-voltage activation signal and the low-voltage drive signal, preventing repeated switching and ensuring a safe and reliable startup process. This allows for fast and low-cost safe startup of the BMS across a wide input voltage range.

[0034] like Figure 2 As shown, the high-voltage activation circuit 2 includes an isolation dual-channel switch S1, a first resistor R1, a second resistor R2, a first capacitor C1, a second capacitor C2, a first diode TVS1, and a second diode TVS2. The isolation dual-channel switch S1 is connected to one end of the first resistor R1, the other end of the first resistor R1 is connected to one end of the second resistor R2, the other end of the second resistor R2 is connected to the first capacitor C1, the first capacitor C1 and the second capacitor C2 are connected in series, and the first diode TVS1, the second diode TVS2 and the second capacitor C2 are connected in parallel. The function of the first resistor R1 and the second resistor R2 is to limit current.

[0035] The first diode TVS1 and the second diode TVS2 are transient suppression diodes.

[0036] The high-voltage activation circuit 2 also includes a third resistor R3, a fourth resistor R4, a first switching transistor Q1, and a third diode D1. The third resistor R3 is connected in parallel across the high-voltage battery. One end of the fourth resistor R4 is connected to the source of the first switching transistor Q1, and the other end of the fourth resistor R4 is connected to the second diode TVS2. The gate of the first switching transistor Q1 is connected to the second diode TVS2, and the drain of the first switching transistor Q1 is connected to the anode of the third diode D1. The cathode of the third diode D1 outputs a drive signal to the main power supply circuit 3.

[0037] The main power supply circuit 3 includes a second switch Q2, a fifth resistor R5, a sixth resistor R6, and a seventh resistor R7. One end of the fifth resistor R5 is connected to the negative terminal of the first diode TVS1, and the other end of the fifth resistor R5 is connected to the gate of the second switch Q2. One end of the sixth resistor R6 is connected to the other end of the fifth resistor R5 and the gate of the second switch Q2, and the other end of the sixth resistor R6 is connected to the seventh resistor R7. The function of the seventh resistor R7 is also to limit current.

[0038] like Figure 2As shown, after the isolation dual-circuit switch S1 is closed, the main power supply circuit 3 forms a circuit between the positive and negative terminals of the high-voltage battery through the first resistor R1, the second resistor R2, the first capacitor C1, and the second capacitor C2. The first diode TVS1 is connected in parallel with the second capacitor C2. At the midpoint between the first capacitor C1 and the second capacitor C2, a lead wire is connected to the source of the first switching transistor Q1. The fourth resistor R4 is connected in parallel between the gate and the source of the first switching transistor Q1. The gate of the first switching transistor Q1 is connected in series with the second diode TVS2 to the negative terminal of the high-voltage battery. The drain of the first switching transistor Q1 is connected in series with the second diode TVS2. The second switching transistor Q2 is driven by the output voltage drive of the second diode TVS2.

[0039] The power-on detection circuit 4 includes an eighth resistor R8. The isolated dual-channel switch S1 is connected to the eighth resistor R8. The eighth resistor R8 collects the switch status signal of the isolated dual-channel switch S1 and transmits the switch status signal to the MCU module 1.

[0040] like Figure 3 As shown, the power-on detection circuit 4 also includes an isolating switch S2, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a third switch Q3, and a fourth diode D2. The MCU module 1 is connected to the isolating switch S2. The isolating switch S2 is connected to one end of the ninth resistor R9 and one end of the tenth resistor R10. The other end of the ninth resistor R9 is connected to the source of the third switch Q3. The other end of the tenth resistor R10 is connected to the gate of the third switch Q3. The drain of the third switch Q3 is connected to one end of the eleventh resistor R11. The other end of the eleventh resistor R11 is connected to the anode of the fourth diode D2. The cathode of the fourth diode D2 outputs a drive signal. The power-on detection circuit 4, composed of the isolated dual-channel switch S1 and the eighth resistor R8, forms a switch state judgment circuit to confirm the switch state. The MCU module 1 drives the isolating switch S2, the ninth resistor R9, the tenth resistor R10, the eleventh resistor R11, the third switch Q3, and the fourth diode D2 to output the drive voltage of the second switch Q2.

[0041] When the isolation switch S1 is closed, the positive terminal of the high-voltage battery charges the first capacitor C1 and the second capacitor C2 through the first resistor R1 and the second resistor R2. When the first diode TVS1 is not activated, it is approximately assumed that the voltage drop across the first capacitor C1 and the second capacitor C2 is inversely proportional to their capacitance values. Let the voltage across the first capacitor C1 be VC1 and the voltage across the second capacitor C2 be VC2. It is then found that the voltage across the first capacitor C1 is inversely proportional to its capacitance value, and the voltage across the second capacitor C2 is inversely proportional to its capacitance value.

[0042]

[0043] Where C1 is the capacitance value of the first capacitor C1, and C2 is the capacitance value of the second capacitor C2.

[0044] Then it proceeds to the following stage:

[0045] Phase 1: As the voltage VC2 across the second capacitor C2 gradually increases, the second capacitor C2 charges the second diode TVS2 through the fourth resistor R4. The voltage across the second diode TVS2 gradually increases. The clamping voltage of the first diode TVS1 is higher than the clamping voltage of the second diode TVS2, so the protection will not be triggered. As the current provided by the second capacitor C2 flows through the fourth resistor R4, the current of the second diode TVS2 increases. At this time, the voltage across the gate and source of the first switch Q1 rises to the turn-on voltage threshold, and the first switch Q1 gradually turns on.

[0046] Second stage: When the voltage across the second capacitor C2 reaches a certain value, the gate-source voltage of the first switch Q1 reaches the threshold voltage, and the first switch Q1 turns on. Let the voltage across the second diode TVS2 be Vtvs2, and the voltage across the fourth resistor R4 be Vr4. The gate-source voltage of the second switch Q2 is Vq2gs. At this time, the gate-source voltage of the second switch Q2 is:

[0047] Vq2gs=Vtvs2+Vr4

[0048] That is, when the first switch Q1 is turned on, the gate-source voltage of the second switch Q2 is equal to the voltage across the second diode TVS2 plus the voltage across the fourth resistor R4.

[0049] At this time, the voltage Vr4 across the fourth resistor R4 has reached the turn-on voltage of the second switch Q2, and the current Ir4 flowing through the fourth resistor R4 and the second diode TVS2 is:

[0050]

[0051] Where r4 is the resistance value of the fourth resistor R4.

[0052] At this point, the current flowing through the second diode TVS2 has risen to a certain value, therefore the voltage Vtvs4 across the fourth resistor R4 will also rise. Thus, when the first switch Q1 turns on, the gate-source voltage of the second switch Q2 will jump to a high value in a very short time, surpassing the Miller plateau stage of the second switch Q2. At this time, the second switch Q2 can quickly turn on, avoiding impact or increased losses on the second switch Q2.

[0053] Third stage: As the voltage across the second capacitor C2 continues to rise, the current flowing through the second diode TVS2 reaches the threshold, and the second diode TVS2 begins to clamp. At this time, the voltage Vr4 across the fourth resistor R4 and the gate-source voltage of the second switch Q2 continue to rise until the voltage of the second capacitor C2 reaches the maximum clamping voltage of the first diode TVS1. The first diode TVS1 clamps the voltage, and at this time, both the first switch Q1 and the second switch Q2 can conduct normally.

[0054] Fourth stage: After the second capacitor C2 stores energy to its peak value, the first diode TVS1 clamps and stabilizes the voltage of the second capacitor C2 for a period of time. The energy stored in the second capacitor C2 is released to the fourth resistor R4, the first diode TVS1, the first switch Q1, and the second switch Q2. The energy stored in the second capacitor C2 will gradually decrease. At the same time, the first capacitor C1, since it has no discharge circuit, will continue to charge and store energy, causing the voltage of the first capacitor C1 to gradually rise and the voltage of the second capacitor C2 to gradually decrease. When the voltage across the second capacitor C2 can no longer maintain the conduction of the first switch Q1, the first switch Q1 is turned off. Whether the second switch Q2 is turned on at this time is determined by the power-on detection circuit 4.

[0055] Through these four stages, when the high-voltage battery switch activation circuit is working normally, the minimum voltage value required by the high-voltage battery is:

[0056]

[0057] Wherein, VINmin is the minimum voltage required by the high-voltage battery, VtvsC is the clamping voltage of the first diode TVS1, C1 is the capacitance of the first capacitor C1, and C2 is the capacitance of the second capacitor C2.

[0058] As described above, as long as the withstand voltage of the resistors and capacitors allows, the activation of this high-voltage battery switch will not limit the maximum voltage of the high-voltage battery, thus satisfying power-on activation across a wide range of battery voltages. Simultaneously, this high-voltage battery switch activation circuit ensures that the drive voltage of the second switch transistor Q2 is within a reasonable range, guaranteeing its rapid and safe startup without damaging or increasing the switching losses of Q2.

[0059] like Figure 4 As shown, the high-voltage battery switch activation circuit also includes a DC / DC circuit 5 and an isolated DC / DC circuit 6. Both the DC / DC circuit 5 and the isolated DC / DC circuit 6 are connected to the input terminal of the high-voltage battery switch activation circuit, and the isolated DC / DC circuit 6 is connected to the MCU module 1.

[0060] When the second capacitor C2 is charging and the second switch Q2 is turned on for the first time, the main circuit is turned on, allowing the DC / DC circuit 5 in the main circuit to operate normally. Figure 3 and Figure 4 As shown, when the second switch Q2 is turned on, the internal VIN12V voltage will start normally. At the same time, MCU module 1 will also start through the isolated DC / DC circuit 6. Since the isolation dual-channel switch S1 is closed, the low-voltage drive voltage VIN12V, the eighth resistor R8, and VIN- will form a loop, feeding the signal back to MCU module 1. After MCU module 1 starts up and confirms that the BMS is working correctly, it will immediately control the power-on detection circuit 4 to close the isolation switch S2. At this time, VIN12V forms a loop with the ninth resistor R9, the tenth resistor R10, and the third switch Q3. The circuit turns on the third switch Q3, outputting VIN12V to the drive through the fourth diode D2. If the high-voltage activation circuit 2 also has an output voltage, VIN12V is compared with its output voltage. The third diode D1 and the fourth diode D2 bear the voltage difference between VIN12V and the output voltage of the high-voltage activation circuit 2. When the activation part cannot drive the third switch Q3, this output voltage can continue to provide a drive voltage for the second switch Q2, maintaining its normal conduction and ensuring the main circuit works normally. When the BMS is not working and the isolation dual-path switch S1 is open, the first capacitor C1 can discharge through the circuit formed by the first capacitor C1, the second resistor R2, the first resistor R1, the third resistor R3, the second capacitor C2, and back to the first capacitor C1. This ensures that during the next activation start-up, the first capacitor C1 and the second capacitor C2 have no additional energy interference and will not affect the activation effect.

[0061] The above description is merely an optional embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A high-voltage battery switch activation circuit, characterized in that, include: MCU module; The main power supply circuit is connected to the MCU module and is used to supply power to the MCU module. A high-voltage activation circuit is connected to the MCU module and the main power supply circuit. The MCU module drives the high-voltage activation circuit to work, and the high-voltage activation circuit is used to drive the main power supply circuit. A power-on detection circuit is connected to the MCU module, and the MCU module drives the power-on detection circuit to switch between high-voltage activation signal and low-voltage drive signal; The high-voltage activation circuit includes an isolation dual-channel switch, a first resistor, a second resistor, a first capacitor, a second capacitor, a first diode, and a second diode. The isolation dual-channel switch is connected to one end of the first resistor, the other end of the first resistor is connected to one end of the second resistor, the other end of the second resistor is connected to the first capacitor, the first capacitor and the second capacitor are connected in series, and the first diode, the second diode, and the second capacitor are connected in parallel. The high-voltage activation circuit further includes a third resistor, a fourth resistor, a first switching transistor, and a third diode. The third resistor is connected in parallel across the high-voltage battery. One end of the fourth resistor is connected to the source of the first switching transistor, and the other end of the fourth resistor is connected to the second diode. The gate of the first switching transistor is connected to the second diode, and the drain of the first switching transistor is connected to the anode of the third diode. The cathode of the third diode outputs a drive signal to the main power supply circuit.

2. The high-voltage battery switch activation circuit as described in claim 1, characterized in that, The first diode and the second diode are transient suppression diodes.

3. The high-voltage battery switch activation circuit as described in claim 1, characterized in that, The main power supply circuit includes a second switch, a fifth resistor, a sixth resistor, and a seventh resistor. One end of the fifth resistor is connected to the negative terminal of the first diode, and the other end of the fifth resistor is connected to the gate of the second switch. One end of the sixth resistor is connected to the other end of the fifth resistor and the gate of the second switch, and the other end of the sixth resistor is connected to the seventh resistor.

4. The high-voltage battery switch activation circuit as described in claim 1, characterized in that, The power-on detection circuit includes an eighth resistor, and the isolated dual-channel switch is connected to the eighth resistor. The eighth resistor collects the switch status signal of the isolated dual-channel switch and transmits the switch status signal to the MCU module.

5. The high-voltage battery switch activation circuit as described in claim 4, characterized in that, The power-on detection circuit further includes an isolating switch, a ninth resistor, a tenth resistor, an eleventh resistor, a third switching transistor, and a fourth diode. The MCU module is connected to the isolating switch. The isolating switch is connected to one end of the ninth resistor and one end of the tenth resistor. The other end of the ninth resistor is connected to the source of the third switching transistor. The other end of the tenth resistor is connected to the gate of the third switching transistor. The drain of the third switching transistor is connected to one end of the eleventh resistor. The other end of the eleventh resistor is connected to the anode of the fourth diode. The cathode of the fourth diode outputs a drive signal.

6. The high-voltage battery switch activation circuit as described in claim 1, characterized in that, When the isolation dual-circuit switch is closed, the voltage across the first capacitor is inversely proportional to the capacitance value of the first capacitor, and the voltage across the second capacitor is inversely proportional to the capacitance value of the second capacitor.

7. The high-voltage battery switch activation circuit as described in claim 3, characterized in that, When the first switch is turned on, the gate-source voltage of the second switch is equal to the voltage across the second diode plus the voltage across the fourth resistor.

8. The high-voltage battery switch activation circuit as described in claim 1, characterized in that, When the high-voltage battery switch activation circuit is working normally, the minimum voltage required by the high-voltage battery is: Wherein, VINmin is the minimum voltage required by the high-voltage battery, VtvsC is the clamping voltage of the first diode, C1 is the capacitance of the first capacitor, and C2 is the capacitance of the second capacitor.

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