High-voltage synchronous starting circuit

Abstract

The utility model provides a high-voltage synchronous starting circuit which comprises an energy storage battery, an energy storage power supply module and a synchronous starting module, the positive electrode of the energy storage battery is connected to the first connecting end of the energy storage power supply module, and the negative electrode of the energy storage battery is connected to the second connecting end of the energy storage power supply module and the power ground. The third connecting end of the energy storage power supply module is connected to the input end of the synchronous starting module, and the output end of the synchronous starting module is connected to the input end of the first pulse width modulation chip and the input end of the second pulse width modulation chip; the first pulse width modulation chip outputs a driving signal of the power switch, and the second pulse width modulation chip outputs a driving power supply of the power switch. By introducing the synchronous starting module, the two pulse width modulation chips can be synchronously started under the condition that the same starting circuit and the same starting power supply are shared, and the condition that a subsequent system cannot operate is avoided.

Description

Technical Field

[0001] This application relates to the field of auxiliary power supply starting technology, and in particular to a high-voltage synchronous starting circuit. Background Technology

[0002] In the auxiliary power supply of a high input voltage energy storage system, high-voltage power switching devices (such as SiC MOSFETs) are typically required to start the auxiliary power supply. This requires two pulse width modulation (PWM) chips to jointly drive the SiC MOSFET. One PWM chip generates the drive signal for the SiC MOSFET, while the other provides the drive power for the SiC MOSFET. The two PWM chips share a high-voltage startup circuit, which provides the startup voltage to enable the PWM chips to operate. After the PWM chips start up, the two PWM chips work together on the SiC MOSFET to drive the auxiliary power supply.

[0003] However, in reality, the characteristics of the two pulse width modulation chips cannot be completely identical. After one of the pulse width modulation chips reaches its corresponding start-up threshold voltage and starts up, it begins to consume the current provided by the high-voltage start-up circuit. This will cause the other pulse width modulation chip to fail to start due to insufficient start-up voltage, ultimately causing the auxiliary power supply to fail to operate. Utility Model Content

[0004] In view of this, the purpose of this application is to provide at least one high-voltage synchronous start-up circuit, which, by introducing a synchronous start-up module, enables two pulse width modulation chips to start synchronously when sharing the same start-up circuit and start-up power supply, thereby avoiding the situation where the subsequent system cannot operate.

[0005] This application mainly includes the following aspects:

[0006] In a first aspect, embodiments of this application provide a high-voltage synchronous start-up circuit, which includes an energy storage battery, an energy storage power supply module, and a synchronous start-up module. The positive terminal of the energy storage battery is connected to a first connection terminal of the energy storage power supply module, the negative terminal of the energy storage battery is connected to a second connection terminal of the energy storage power supply module and a power ground, the third connection terminal of the energy storage power supply module is connected to an input terminal of the synchronous start-up module, and the output terminal of the synchronous start-up module is connected to the input terminals of a first pulse width modulation chip and a second pulse width modulation chip. The first pulse width modulation chip outputs a drive signal for a power switch, and the second pulse width modulation chip outputs a drive power supply for the power switch.

[0007] In one possible implementation, the energy storage power supply module includes a power supply capacitor and a high-voltage starting resistor. One end of the high-voltage starting resistor is connected to the positive terminal of the energy storage battery, and the other end of the high-voltage starting resistor is connected to one end of the power supply capacitor and the input terminal of the synchronous starting module. The other end of the power supply capacitor is connected to the negative terminal of the energy storage battery.

[0008] In one possible implementation, the synchronous startup module includes a Zener diode and a startup unit, wherein the cathode of the Zener diode is connected to the third connection terminal of the energy storage power supply module and the first input terminal of the startup unit, respectively, the anode of the Zener diode is connected to the second input terminal of the startup unit and the output terminal of the startup unit, respectively, and the output terminal of the startup unit is also connected to the first pulse width modulation chip and the second pulse width modulation chip, respectively.

[0009] In one possible implementation, the starting unit includes a high-voltage starting switch assembly and a low-voltage starting switch assembly, wherein the control terminal of the high-voltage starting switch assembly is connected to the anode of the Zener diode and the first connection terminal of the low-voltage starting switch assembly, the first connection terminal of the high-voltage starting switch assembly is connected to the control terminal of the low-voltage starting switch assembly, the second connection terminal of the high-voltage starting switch assembly is connected to the power ground, and the second connection terminal of the low-voltage starting switch assembly is connected to the cathode of the Zener diode and the third connection terminal of the energy storage power supply module.

[0010] In one possible implementation, the high-voltage start-up switch assembly includes a first control switch, the control terminal of which is connected to a first connection terminal of the low-voltage start-up switch assembly and the anode of the Zener diode, the first connection terminal of which is connected to the control terminal of the low-voltage start-up switch assembly, and the second connection terminal of which is connected to the power supply ground.

[0011] In one possible implementation, the high-voltage start switch assembly further includes a first on-resistor, wherein one end of the first on-resistor is connected to the first connection terminal of the low-voltage start switch assembly and the anode of the Zener diode, and the other end of the first on-resistor is connected to the control terminal of the first control switch.

[0012] In one possible implementation, the high-voltage start switch assembly further includes a first current-limiting resistor, wherein the first current-limiting resistor is connected in parallel between the control terminal of the first control switch and the second connection terminal of the first control switch.

[0013] In one possible implementation, the low-voltage start-up switch assembly includes a second control switch, the control terminal of which is connected to the first connection terminal of the high-voltage start-up switch assembly. The first connection terminal of the second control switch is connected to the first pulse width modulation chip, the second pulse width modulation chip, the control terminal of the high-voltage start-up switch assembly, and the cathode of the Zener diode. The second connection terminal of the second control switch is connected to the cathode of the Zener diode and the third connection terminal of the energy storage power supply module.

[0014] In one possible implementation, the low-voltage start-up switch assembly further includes a second on-resistor, wherein the second on-resistor is connected in series between the first connection terminal of the high-voltage start-up switch assembly and the gate of the second control switch.

[0015] In one possible implementation, the high-voltage start switch assembly further includes a second current-limiting resistor, wherein the second current-limiting resistor is connected in parallel between the second connection terminal and the control terminal of the second control switch.

[0016] This application provides a high-voltage synchronous start-up circuit, which includes an energy storage battery, an energy storage power supply module, and a synchronous start-up module. The positive terminal of the energy storage battery is connected to a first connection terminal of the energy storage power supply module, and the negative terminal of the energy storage battery is connected to a second connection terminal and a power ground of the energy storage power supply module. The third connection terminal of the energy storage power supply module is connected to the input terminal of the synchronous start-up module, and the output terminal of the synchronous start-up module is connected to the input terminals of a first pulse width modulation (PWM) chip and a second PWM chip. The first PWM chip outputs a drive signal for a power switch, and the second PWM chip outputs a drive power supply for a power switch. By introducing the synchronous start-up module, the two PWM chips can start synchronously while sharing the same start-up circuit and start-up power supply, avoiding situations where the subsequent system cannot operate.

[0017] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This paper shows one of the structural schematic diagrams of a high-voltage synchronous starting circuit provided in an embodiment of this application;

[0020] Figure 2 This is a second schematic diagram of a high-voltage synchronous starting circuit provided in an embodiment of this application;

[0021] Figure 3 The third schematic diagram shows a high-voltage synchronous starting circuit provided in the embodiments of this application. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the drawings in this application are for illustrative and descriptive purposes only and are not intended to limit the scope of protection of this application. Furthermore, it should be understood that the schematic drawings are not drawn to scale. The flowcharts used in this application illustrate operations implemented according to some embodiments of this application. It should be understood that the operations in the flowcharts may not be implemented in sequence, and steps without logical contextual relationships may be reversed or implemented simultaneously. In addition, those skilled in the art, guided by the content of this application, may add one or more other operations to the flowcharts, or remove one or more operations from the flowcharts.

[0023] Furthermore, the described embodiments are merely some, not all, of the embodiments of this application. The components of the embodiments of this application described and illustrated herein can typically be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.

[0024] In the auxiliary power supply of a high input voltage energy storage system, high-voltage power switching devices (such as SiC MOSFETs) are typically required to start the auxiliary power supply. This requires two pulse width modulation (PWM) chips to drive the SiC MOSFET. One PWM chip generates the drive signal for the SiC MOSFET, while the other provides the drive power to the SiC MOSFET. The two PWM chips share a high-voltage startup circuit, which provides the startup voltage to enable the PWM chips to operate. After the PWM chips are started, the two PWM chips work together to drive the SiC MOSFET, thus enabling the auxiliary power supply to be driven by the SiC MOSFET.

[0025] Because the characteristics of the two pulse width modulation chips are not completely consistent, once one of the pulse width modulation chips reaches its corresponding start-up threshold voltage and starts up, it begins to consume the current provided by the high-voltage start-up circuit. This will cause the other pulse width modulation chip to fail to start due to insufficient start-up voltage, ultimately causing the auxiliary power supply to fail to operate.

[0026] Based on this, this application provides a high-voltage synchronous startup circuit. By introducing a synchronous startup module, two pulse width modulation chips can start synchronously while sharing the same startup circuit and startup power supply, thus avoiding the situation where the subsequent system cannot operate. The details are as follows:

[0027] Please see Figure 1 , Figure 1 This illustration shows one of the structural schematic diagrams of a high-voltage synchronous starting circuit provided in an embodiment of this application. For example... Figure 1 As shown, the high-voltage synchronous start-up circuit provided in this application embodiment includes an energy storage battery BAT, an energy storage power supply module 1, and a synchronous start-up module 2. The positive terminal of the energy storage battery BAT is connected to the first connection terminal of the energy storage power supply module 1, and the negative terminal of the energy storage battery BAT is connected to the second connection terminal and the power ground GND of the energy storage power supply module 1. The third connection terminal of the energy storage power supply module 1 is connected to the input terminal of the synchronous start-up module 2, and the output terminal of the synchronous start-up module 2 is connected to the input terminal of the first pulse width modulation chip 31 and the input terminal of the second pulse width modulation chip 32. The first pulse width modulation chip 31 outputs the drive signal of the power switch, and the second pulse width modulation chip 32 outputs the drive power of the power switch.

[0028] In this application, the power switch may be a SiC MOSFET.

[0029] In a preferred embodiment, please refer to Figure 2 , Figure 2 This is a second schematic diagram of a high-voltage synchronous starting circuit provided in an embodiment of this application. For example... Figure 2 As shown, the energy storage power supply module includes a power supply capacitor C1 and a high-voltage starting resistor RM.

[0030] One end of the high-voltage starting resistor RM is connected to the positive terminal of the energy storage battery BAT, and the other end of the high-voltage starting resistor RM is connected to one end of the power supply capacitor C1 and the input terminal of the synchronous starting module 2. The other end of the power supply capacitor C1 is connected to the negative terminal of the energy storage battery and the power ground GND.

[0031] In a preferred embodiment, the synchronous start-up module 2 includes a Zener diode D1 and a start-up unit 21.

[0032] Preferably, the cathode of the Zener diode D1 is connected to the third connection terminal of the energy storage power supply module 1 (i.e., the other end of the high-voltage start-up resistor RM and one end of the power supply capacitor C1) and the first input terminal of the start-up unit 21, respectively. The anode of the Zener diode D1 is connected to the second input terminal and the output terminal of the start-up unit 21, respectively. The output terminal of the start-up unit is also connected to the first pulse width modulation chip 31 and the second pulse width modulation chip 32, respectively.

[0033] In another specific embodiment, such as Figure 2 As shown, the starting unit 21 includes a high-voltage starting switch assembly 211 and a low-voltage starting switch assembly 212.

[0034] The control terminal of the high-voltage start switch assembly 211 is connected to the anode of the Zener diode D1 and the first connection terminal of the low-voltage start switch assembly 212. The first connection terminal of the high-voltage start switch assembly 211 is connected to the control terminal of the low-voltage start switch assembly 212. The second connection terminal of the high-voltage start switch assembly 211 is connected to the power ground GND. The second connection terminal of the low-voltage start switch assembly 212 is connected to the cathode of the Zener diode D1 and the third connection terminal of the energy storage power supply module 1 (i.e., the other end of the high-voltage start resistor RM and one end of the power supply capacitor C1).

[0035] In a preferred embodiment, please refer to Figure 3 , Figure 3 This is shown as a third schematic diagram of a high-voltage synchronous starting circuit provided in an embodiment of this application. Figure 3 As shown, the high-voltage start-up switch assembly 211 includes a first control switch K1, a first on-resistance RQ1, and a first current-limiting resistor RX1.

[0036] The control terminal of the first control switch K1 is connected to the first connection terminal of the low-voltage start switch assembly 212 and the anode of the Zener diode D1 through the first on-resistance RQ1. The first connection terminal of the first control switch K1 is connected to the control terminal of the low-voltage start switch assembly 212. The second connection terminal of the first control switch K1 is connected to the power ground GND. The first current limiting resistor RX1 is connected in parallel between the control terminal of the first control switch K1 and the second connection terminal of the first control switch K1.

[0037] In this circuit, the first control switch K1 is an NPN field-effect transistor, which is turned on when the level is high. The control terminal of the first control switch K1 is the gate of the NPN field-effect transistor, the first connection terminal of the first control switch K1 is the drain of the NPN field-effect transistor, the second connection terminal of the first control switch K1 is the source of the NPN field-effect transistor, and the first current-limiting resistor RX1 and the first on-resistance RQ1 form a voltage divider network.

[0038] In another preferred embodiment, such as Figure 3 As shown, the low-voltage start-up switch assembly 212 includes a second control switch K2, a second on-resistor RQ2, and a second current-limiting resistor RX2.

[0039] Preferably, the control terminal of the second control switch K2 is connected to the first connection terminal of the first control switch K1 through the second on-resistor RQ2. The first connection terminal of the second control switch K2 is connected to the cathodes of the first pulse width modulation chip 31, the second pulse width modulation chip 32, and the Zener diode D1, respectively. The second connection terminal of the second control switch K2 is connected to the cathode of the Zener diode D1 and the third connection terminal of the energy storage power supply module (i.e., the other end of the high-voltage start-up resistor RM and one end of the power supply capacitor C1). The second current-limiting resistor RX2 is connected in parallel between the second connection terminal and the control terminal of the second control switch K2.

[0040] In this circuit, the second control switch K2 is a PNP field-effect transistor, which is turned on when the level is low. The control terminal of the second control switch K2 is the gate of the PNP field-effect transistor, the first connection terminal of the second control switch K2 is the drain of the PNP field-effect transistor, and the second connection terminal of the second control switch K2 is the source of the PNP field-effect transistor. The second on-resistor RQ2 and the second current-limiting resistor RX2 form a voltage divider network.

[0041] In this application, the output terminal of the synchronous start module 3 (i.e. the first connection terminal of the second control switch) outputs the start-up voltage VCC of two pulse width modulation chips. Furthermore, in this application, the first start-up threshold voltage corresponding to the gate and source of the first control switch K1 is opposite to the second start-up threshold voltage corresponding to the gate and source of the second control switch K2.

[0042] Specifically, the first connection terminal (drain) of the second control switch K2 is connected between the cathode of the Zener diode D1 and the first on-resistance RQ1, which ensures that the first control switch K1 and the second control switch K2 form a self-locking mechanism after they are turned on.

[0043] Furthermore, in a preferred embodiment, the high-voltage synchronous starting circuit provided in this application includes:

[0044] The difference between the forward voltage of Zener diode D1 and the first start-up threshold voltage of the first control switch K1, and the start-up voltage threshold of the pulse width modulation chip, is greater than the target given voltage difference.

[0045] The target differential pressure can be 2V.

[0046] by Figure 3 For example, in a specific embodiment, the high-voltage starting resistor RM is 10MΩ (megaohm), the power supply capacitor C1 is 220μF (microfarad), the forward voltage of the Zener diode is 15V, the first on-resistance RQ1 is 1KΩ (megaohm), the first current-limiting resistor RX1 is 20KΩ, and the first starting threshold voltage Vth1 corresponding to the first control switch K1 is 3V.

[0047] The second current-limiting resistor RX2 is 10kΩ, the second on-resistance RQ2 is 10kΩ, and the second start-up threshold voltage Vth2 corresponding to the second control switch K2 is -3V.

[0048] As in the specific embodiments described above, taking a pulse width modulation chip with a startup voltage threshold of 16V as an example, the working process of the high-voltage synchronous startup circuit provided in this application is as follows:

[0049] Initially, the voltage of the power supply capacitor C1 did not reach the conduction voltage of the Zener diode D1. At this time, the Zener diode D1 was not conducting, the first control switch K1 was not conducting, the second control switch K2 was not conducting, and the first pulse width modulation chip 31 and the second pulse width modulation chip 32 did not start.

[0050] When the power supply capacitor C1 is charged to the conduction voltage (15V) corresponding to the Zener diode D1, the Zener diode D1 is broken down and conducts. However, at this time, the voltage across the gate and source of the first control switch K1 has not reached the first start-up threshold voltage Vth1. Therefore, the first control switch K1 is not turned on, the second control switch K2 is not turned on, and the first pulse width modulation chip 31 and the second pulse width modulation chip 32 are not started.

[0051] When the power supply capacitor C1 continues to charge to 18V, the voltage across the gate and source of the first control switch K1 reaches the first start-up threshold voltage Vth1, and the first control switch K1 is turned on. The lower end of the second on-resistor RQ2 is pulled to 0 potential. Based on the voltage divider network formed by the second on-resistor RQ2 and the second current-limiting resistor RX2, the gate and source voltage of the second control switch K2 is -9V, which reaches the second start-up threshold voltage Vth2 corresponding to the second control switch K2, which is -3V. The second control switch K2 is turned on, and the first pulse width modulation chip 31 and the second pulse width modulation chip 32 obtain the start-up voltage VCC = 18V, and the chip starts to work.

[0052] Regarding the high-voltage synchronous startup circuit provided in this application, when one of the pulse width modulation chips starts up first, the voltage of the power supply capacitor C1 begins to decrease. However, the startup voltage VCC provided to the other pulse width modulation chip is still greater than its corresponding startup threshold voltage. That is, the other pulse width modulation chip can still start up and eventually drive the auxiliary power supply to start up smoothly.

[0053] The high-voltage synchronous starting circuit provided in this application has the following advantages:

[0054] After the power supply capacitor C1 is charged by the battery BAT, when the startup voltage VCC provided to the pulse width modulation chip by the synchronous startup module reaches (the startup threshold voltage of the pulse width modulation chip + the given voltage difference), even if one of the pulse width modulation chips starts up first and begins to consume the current provided by the power supply capacitor C1, and the startup voltage VCC begins to drop, the startup voltage VCC is still greater than the startup threshold voltage of the pulse width modulation chip. This ensures that the other pulse width modulation chip starts up smoothly, so that it can ultimately output the drive power supply and drive signal corresponding to the SiC MOSFET, and enable the subsequent auxiliary power supply system to start up and work normally.

[0055] The above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A high-voltage synchronous starting circuit, characterized in that, The high-voltage synchronous start-up circuit includes an energy storage battery, an energy storage power supply module, and a synchronous start-up module. The positive terminal of the energy storage battery is connected to the first connection terminal of the energy storage power supply module, the negative terminal of the energy storage battery is connected to the second connection terminal of the energy storage power supply module and the power ground, the third connection terminal of the energy storage power supply module is connected to the input terminal of the synchronous start module, and the output terminal of the synchronous start module is connected to the input terminal of the first pulse width modulation chip and the input terminal of the second pulse width modulation chip. The first pulse width modulation chip outputs the drive signal for the power switch, and the second pulse width modulation chip outputs the drive power supply for the power switch.

2. The high-voltage synchronous starting circuit according to claim 1, characterized in that, The energy storage power supply module includes a power supply capacitor and a high-voltage starting resistor. One end of the high-voltage starting resistor is connected to the positive terminal of the energy storage battery, and the other end of the high-voltage starting resistor is connected to one end of the power supply capacitor and the input terminal of the synchronous starting module, respectively. The other end of the power supply capacitor is connected to the negative terminal of the energy storage battery.

3. The high-voltage synchronous starting circuit according to claim 1, characterized in that, The synchronous startup module includes a Zener diode and a startup unit. The cathode of the Zener diode is connected to the third connection terminal of the energy storage power supply module and the first input terminal of the startup unit, respectively. The anode of the Zener diode is connected to the second input terminal and the output terminal of the startup unit, respectively. The output terminal of the startup unit is also connected to the first pulse width modulation chip and the second pulse width modulation chip, respectively.

4. The high-voltage synchronous starting circuit according to claim 3, characterized in that, The starting unit includes a high-voltage starting switch assembly and a low-voltage starting switch assembly. The control terminal of the high-voltage start-up switch assembly is connected to the anode of the Zener diode and the first connection terminal of the low-voltage start-up switch assembly, the first connection terminal of the high-voltage start-up switch assembly is connected to the control terminal of the low-voltage start-up switch assembly, the second connection terminal of the high-voltage start-up switch assembly is connected to the power ground, and the second connection terminal of the low-voltage start-up switch assembly is connected to the cathode of the Zener diode and the third connection terminal of the energy storage power supply module.

5. The high-voltage synchronous starting circuit according to claim 4, characterized in that, The high-voltage start-up switch assembly includes a first control switch. The control terminal of the first control switch is connected to the first connection terminal of the low-voltage start switch assembly and the anode of the Zener diode, respectively. The first connection terminal of the first control switch is connected to the control terminal of the low-voltage start switch assembly, and the second connection terminal of the first control switch is connected to the power ground.

6. The high-voltage synchronous starting circuit according to claim 5, characterized in that, The high-voltage start-up switch assembly also includes a first on-resistor. One end of the first on-resistor is connected to the first connection terminal of the low-voltage start-up switch assembly and the anode of the Zener diode, and the other end of the first on-resistor is connected to the control terminal of the first control switch.

7. The high-voltage synchronous starting circuit according to claim 5, characterized in that, The high-voltage start-up switch assembly also includes a first current-limiting resistor. The first current-limiting resistor is connected in parallel between the control terminal of the first control switch and the second connection terminal of the first control switch.

8. The high-voltage synchronous starting circuit according to claim 4, characterized in that, The low-voltage start-up switch assembly includes a second control switch. The control terminal of the second control switch is connected to the first connection terminal of the high-voltage start-up switch assembly. The first connection terminal of the second control switch is connected to the first pulse width modulation chip, the second pulse width modulation chip, the control terminal of the high-voltage start-up switch assembly, and the cathode of the Zener diode. The second connection terminal of the second control switch is connected to the cathode of the Zener diode and the third connection terminal of the energy storage power supply module.

9. The high-voltage synchronous starting circuit according to claim 8, characterized in that, The low-voltage start-up switch assembly also includes a second on-resistor. The second on-resistance is connected in series between the first connection terminal of the high-voltage start-up switch assembly and the gate of the second control switch.

10. The high-voltage synchronous starting circuit according to claim 8, characterized in that, The high-voltage start-up switch assembly also includes a second current-limiting resistor. The second current-limiting resistor is connected in parallel between the second connection terminal and the control terminal of the second control switch.

Images