Shunting circuit for spacecraft and spacecraft power supply system

Abstract

The invention discloses a shunt circuit for a spacecraft and a spacecraft power supply system. The shunting circuit for the spacecraft comprises a solar cell array, a first transistor, a second transistor, a shunting reference generation circuit, a first control module and a second control module. The solar cell array is connected with the first transistor and the second transistor; the shunt reference generation circuit generates a shunt reference signal according to a bus voltage signal and a shunt reference signal; the first control module is connected with the shunt reference generation circuit and the first transistor, and generates a first control signal to control the conduction state of the first transistor; the second control module is connected with the shunt reference generation circuit and the second transistor, and generates a second control signal to control the conduction state of the second transistor. According to the technical scheme, the heat consumption of the shunt circuit is reduced and the reliability of the shunt circuit is improved under the condition of effectively preventing the voltage from flowing backwards.

Description

Technical Field

[0001] This invention relates to the field of spacecraft power supply technology, and in particular to a shunt circuit and a spacecraft power supply system for spacecraft. Background Technology

[0002] During the on-orbit operation of a spacecraft, the stability and reliability of the power supply system directly determine the mission efficiency and on-orbit lifespan. The power supply system mainly relies on solar arrays to convert solar energy into electrical energy, providing continuous power support for the spacecraft. Due to the complex operating conditions faced by the spacecraft during its on-orbit operation, such as changes in sunlight intensity and orbital attitude adjustments, it is necessary to dynamically control the output current of the solar array through a shunt regulation circuit to ensure that the supply voltage and current remain stable within the required range.

[0003] Among them, the sequential switch shunt regulation circuit, with its advantages of high control precision, fast response speed, and adaptability to multiple operating conditions, has become one of the core technical solutions for realizing the current distribution and regulation of solar arrays in the current mainstream power supply system, and is a key component to ensure the long-term stable operation of spacecraft. In traditional sequential switch shunt regulation circuits, when the solar array current supplies power to the load, an isolation diode is usually connected in series in the power supply circuit as a reverse protection element. The isolation diode needs to have forward conduction capability that matches the power supply current of the solar array to meet the power supply requirements of spacecraft under different operating conditions. Currently, traditional silicon-based isolation diodes are widely used in the industry.

[0004] However, traditional isolation diode solutions generate high heat dissipation when used as reverse protection components, which can easily damage the device. Summary of the Invention

[0005] This invention provides a shunt circuit and a spacecraft power supply system to prevent voltage backflow from damaging the shunt circuit, reduce the heat dissipation of the shunt circuit, and improve the reliability of the shunt circuit.

[0006] According to one aspect of the present invention, a shunt circuit for a spacecraft is provided, the shunt circuit comprising: a solar cell array, a first transistor, a second transistor, a shunt reference generation circuit, a first control module, and a second control module;

[0007] The positive terminal of the solar cell array is connected to the first terminal of the first transistor and the first terminal of the second transistor, respectively, and the negative terminal of the solar cell array is connected to the second terminal of the second transistor.

[0008] The second terminal of the first transistor is connected to the first terminal of the shunt circuit, and the negative terminal of the solar cell array is connected to the second terminal of the shunt circuit. The first and second terminals are used to connect to the busbar.

[0009] The input terminal of the shunt reference generation circuit is connected to the first connection terminal. The shunt reference generation circuit is used to generate a shunt reference signal based on the shunt reference reference signal and the bus voltage signal of the first connection terminal.

[0010] The first control module is connected to the output terminal of the shunt reference generation circuit and the control terminal of the first transistor, respectively, and is used to generate a first control signal according to the shunt reference signal to control the conduction state of the first transistor.

[0011] The second control module is connected to the output terminal of the shunt reference generation circuit and the control terminal of the second transistor. It is used to generate a second control signal based on the shunt reference signal to control the conduction state of the second transistor.

[0012] Specifically, when the bus voltage signal is higher than the first voltage threshold or lower than the second voltage threshold, the conduction states of the first transistor and the second transistor are reversed.

[0013] Optionally, the shunt reference generation circuit includes a first PI regulation circuit;

[0014] The first input terminal of the first PI regulation circuit is connected to the first connection terminal. The first input terminal of the first PI regulation circuit is connected to the bus voltage signal. The second input terminal of the first PI regulation circuit is connected to the shunt reference signal. The first PI regulation circuit is used to generate the shunt reference signal according to the bus voltage signal and the shunt reference signal.

[0015] Optionally, the shunt circuit may further include a first drive circuit;

[0016] The first end of the first driving circuit is connected to the first control module, and the other end of the first driving circuit is connected to the control terminal of the first transistor. It is used to generate a first driving signal according to the first control signal. The first driving circuit drives the first transistor according to the first driving signal. The driving capability of the first driving signal is greater than that of the first control signal.

[0017] Optionally, the first control module includes a first comparator;

[0018] The input terminal of the first comparator is connected to the shunt reference generation circuit. The first input terminal of the first comparator is connected to the shunt reference signal, and the second input terminal of the first comparator is connected to the transistor turn-on reference signal. The first comparator generates a first control signal based on the shunt reference signal and the transistor turn-on reference signal.

[0019] Optionally, the second control module includes a second PI adjustment circuit, a second comparator, and a waveform generator;

[0020] The second PI adjustment circuit is connected to the shunt reference generation circuit. The first input terminal of the second PI adjustment circuit is connected to the shunt reference signal, and the second input terminal of the second PI adjustment circuit is connected to the drive reference signal. The second PI adjustment circuit generates an error signal based on the shunt reference signal and the drive reference signal.

[0021] The first input terminal of the second comparator is connected to a waveform generator, which generates a triangular wave. The second input terminal of the second comparator is connected to a second PI adjustment circuit, which generates a second control signal based on the triangular wave and the error signal.

[0022] Optionally, the waveform generator is a PWM controller.

[0023] Optionally, the second control module further includes: a second drive circuit;

[0024] The first end of the second driving circuit is connected to the second comparator. The second driving circuit generates a second driving signal according to the second control signal. The second end of the second driving circuit is connected to the second transistor. The second driving signal is used to drive the second transistor. The driving capability of the second driving signal is greater than that of the second control signal.

[0025] Optionally,

[0026] The shunt circuit also includes a first diode and a second diode;

[0027] The anode of the first diode is connected to the anode of the second diode, the cathode of the first diode is connected to the cathode of the second diode, the anode of the first diode is connected to the first terminal of the first transistor, and the cathode of the first diode is connected to the second terminal of the first transistor.

[0028] According to another aspect of the present invention, a spacecraft power supply system is provided, the spacecraft power supply system including at least one shunt circuit for a spacecraft according to any embodiment of the present invention.

[0029] Optionally, the spacecraft power supply system includes n shunt circuits for the spacecraft in any embodiment of the present invention, where n is a positive integer greater than or equal to 2;

[0030] The voltages of the shunt reference signals corresponding to the n shunt circuits decrease sequentially;

[0031] The first control module includes a first comparator. The input terminal of the first comparator is connected to the shunt reference generation circuit. The first input terminal of the first comparator is connected to the shunt reference signal, and the second input terminal of the first comparator is connected to the transistor turn-on reference signal. The first comparator generates a first control signal based on the shunt reference signal and the transistor turn-on reference signal. The voltages of the transistor turn-on reference signals corresponding to the n shunt circuits decrease sequentially.

[0032] In the technical solution of this invention embodiment, the shunt reference generation circuit generates a shunt reference signal based on the bus voltage magnitude. The first control module and the second control module generate a first control signal and a second control signal based on the shunt reference signal. The first control signal controls the conduction state of the first transistor, and the second control signal controls the conduction state of the second transistor. When the second transistor is off, the drain current is extremely small, which can effectively prevent voltage reverse flow. When the second transistor is on, the on-resistance is extremely small, which reduces heat dissipation, prevents heat damage to the device, and improves the reliability of the shunt circuit.

[0033] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0035] Figure 1 A schematic diagram of a shunt circuit for a spacecraft provided in an embodiment of the present invention;

[0036] Figure 2 This is a schematic diagram of another shunt circuit for a spacecraft provided by an embodiment of the present invention;

[0037] Figure 3 This is a schematic diagram of another shunt circuit for a spacecraft provided by an embodiment of the present invention;

[0038] Figure 4 This is a schematic diagram of a spacecraft power supply system provided in an embodiment of the present invention. Detailed Implementation

[0039] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0040] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0041] Figure 1 This is a schematic diagram of a shunt circuit for a spacecraft provided in an embodiment of the present invention. The shunt circuit for a spacecraft is applied to the spacecraft power supply system. For example, the shunt circuit for a spacecraft adjusts the output power of the power supply system to ensure that the bus voltage remains stable.

[0042] like Figure 1 As shown, the shunt circuit for the spacecraft includes: a solar cell array 110, a first transistor 120, a second transistor 130, a shunt reference generation circuit 140, a first control module 150, and a second control module 160;

[0043] The positive terminal of the solar cell array 110 is connected to the first terminal of the first transistor 120 and the first terminal of the second transistor 130, respectively, and the negative terminal of the solar cell array 110 is connected to the second terminal of the second transistor 130. The second terminal of the first transistor 120 is connected to the first connection terminal A1 of the shunt circuit, and the negative terminal of the solar cell array 110 is connected to the second connection terminal A2 of the shunt circuit. The first connection terminal A1 and the second connection terminal A2 are used to connect to the bus. The input terminal of the shunt reference generation circuit 140 is connected to the first connection terminal A1. The shunt reference generation circuit 140 is used to generate a shunt reference based on the shunt reference reference signal and the bus voltage signal of the first connection terminal A1. The first control module 150 is connected to the output terminal of the shunt reference generation circuit 140 and the control terminal of the first transistor 120, respectively, and is used to generate a first control signal according to the shunt reference signal to control the conduction state of the first transistor 120; the second control module 160 is connected to the output terminal of the shunt reference generation circuit 140 and the control terminal of the second transistor 130, and is used to generate a second control signal according to the shunt reference signal to control the conduction state of the second transistor 130; wherein, when the bus voltage signal is higher than the first voltage threshold or lower than the second voltage threshold, the conduction states of the first transistor 120 and the second transistor 130 are opposite.

[0044] In this embodiment, the solar cell array 110 is a component capable of converting solar energy into electrical energy, and the output current of the solar cell array 110 can be distributed to various loads. The first transistor 120 and the second transistor 130 are switching components in the shunt circuit of the solar cell array 110. The conduction or deactivation of the first transistor 120 and the second transistor 130 can regulate the direction of the output current of the solar cell array 110, thereby ensuring the stability of the bus voltage. For example, if the first transistor 120 is off and the second transistor 130 is on, the output current of the solar cell array 110 is shunt; if the first transistor 120 is on and the second transistor 130 is off, the output current of the solar cell array 110 supplies power to the downstream load.

[0045] The shunt reference generation circuit 140 is a circuit that can generate a shunt reference signal based on the bus voltage signal acquired from the first connection terminal A1 of the shunt circuit. The first control module 150 can generate a first control signal based on the shunt reference signal, and the second control module 160 can generate a second control signal based on the shunt reference signal. The first control signal can control the conduction state of the first transistor 120, and the second control signal can control the conduction state of the second transistor 130.

[0046] The first connection terminal A1 and the second connection terminal A2 of the shunt circuit are used to connect to the bus or load. The current output from the positive terminal of the solar cell array can be delivered to the bus through the first connection terminal A1 of the shunt circuit. After passing through the load, the current flows to the negative terminal of the solar cell array through the second connection terminal A2 of the shunt circuit. When the downstream load demand is low, the bus voltage will increase, shunting the output current of the solar cell array 110 to maintain the stability of the bus voltage. When the downstream load demand is high, the output current of the solar cell array 110 flows to the downstream load, and the bus voltage decreases.

[0047] The first control module 150 is a component capable of generating a first control signal, which is used to control the conduction state of the first transistor 120. The first control module 150 is connected to the shunt reference generation circuit 140 and the control terminal of the first transistor 120. The first control module 150 can generate the first control signal based on the shunt reference signal generated by the shunt reference generation circuit 140. The second control module 160 is a component capable of generating a second control signal, which is used to control the conduction state of the second transistor 130. The second control module 160 is connected to the shunt reference generation circuit 140 and the control terminal of the second transistor 130. The second control module 160 can generate the second control signal based on the shunt reference signal generated by the shunt reference generation circuit 140.

[0048] The first voltage threshold is the target bus voltage value for stabilizing the bus voltage within a certain range. The second voltage threshold is the bus voltage value when the solar array 110 provides the maximum current to the downstream load. When the bus voltage exceeds the first voltage threshold or falls below the second voltage threshold, the conduction states of the first transistor 120 and the second transistor 130 are reversed. For example, when the output current generated by the solar array is entirely diverted, and the bus voltage is higher than the first voltage threshold, the first transistor 120 is off, and the second transistor 130 is on. When the output current of the solar array is entirely supplied to the downstream load, and the bus voltage is lower than the second voltage threshold, the first transistor 120 is on, and the second transistor 130 is off.

[0049] In this design, the first transistor 120 and the second transistor 130 have the same channel type, both being N-type transistors. By using transistors with the same channel type, it can be ensured that when control signals of opposite polarity are applied to the control terminals of the first transistor 120 and the second transistor 130, their conduction states are opposite. For example, the first transistor 120 is on and the second transistor 130 is off, or the first transistor 120 is off and the second transistor 130 is on.

[0050] Specifically, the first transistor 120 has its first terminal as the source, its second terminal as the drain, and its control terminal as the gate. The second transistor 130 has its first terminal as the drain, its second terminal as the source, and its control terminal as the gate. The positive terminal of the solar cell array 110 is connected to the source of the first transistor 120 and the drain of the second transistor 130, while the negative terminal of the solar cell array 110 is connected to the source of the second transistor 130. The first transistor 120 has extremely low on-resistance when it is turned on, reducing heat dissipation and improving the efficiency of the shunt circuit. The first transistor 120 has extremely low drain current when it is turned off, effectively preventing voltage reverse flow.

[0051] The following description uses an example where both the first transistor 120 and the second transistor 130 are turned on under a high-level drive signal and turned off under a low-level drive signal. Exemplarily, the input terminal of the shunt reference generation circuit 140 is connected to the first connection terminal A1. The other input terminal of the shunt reference generation circuit 140 is connected to the bus voltage signal, and the other input terminal is connected to the shunt reference signal. When the bus voltage is higher than a first voltage threshold, the bus voltage is greater than the voltage of the shunt reference signal, and the shunt reference generation circuit 140 outputs a shunt reference signal. The first control module 150 is connected to the control terminals of the shunt reference generation circuit 140 and the first transistor 120. The first control module 150 generates a low-level first control signal based on the shunt reference signal, which controls the first transistor 120 to turn off. The second control module 160 is connected to the control terminals of the shunt reference generation circuit 140 and the second transistor 130. The second control module 160 generates a high-level second control signal based on the shunt reference signal, which controls the second transistor 130 to turn on. When the bus voltage is lower than the first threshold, the first control module 150 generates a high-level first control signal based on the shunt reference signal. The first control signal controls the first transistor 120 to turn on. The second control module 160 generates a low-level second control signal based on the shunt reference signal. The second control signal controls the second transistor 130 to turn off.

[0052] According to the technical solution of the present invention, the shunt reference generation circuit generates a shunt reference signal based on the magnitude of the bus voltage signal. The first control module and the second control module generate a first control signal and a second control signal based on the shunt reference signal. The first control signal controls the conduction state of the first transistor, and the second control signal controls the conduction state of the second transistor. When the first transistor is off, the drain current is extremely small, which can effectively prevent voltage reverse flow. When the first transistor is on, the on-resistance is extremely small, which reduces heat dissipation, prevents heat damage to the device, and improves the reliability of the shunt circuit.

[0053] Figure 2 A schematic diagram of another shunt circuit for a spacecraft provided by an embodiment of the present invention, as shown below. Figure 2 As shown, optionally, the shunt reference generation circuit 140 includes a first proportional-integral (PI) regulation circuit 141;

[0054] The first input terminal of the first PI adjustment circuit 141 is connected to the first connection terminal A1. The first input terminal of the first PI adjustment circuit 141 is connected to the bus voltage signal. The second input terminal of the first PI adjustment circuit 141 is connected to the shunt reference signal VREF1. The first PI adjustment circuit 141 is used to generate a shunt reference signal according to the bus voltage signal and the shunt reference signal VREF1.

[0055] The first PI adjustment circuit 141 is a circuit in the shunt circuit that generates the shunt reference signal. The first PI adjustment circuit 141 includes two input ports and one output port. The two input ports are respectively connected to the bus voltage signal and the shunt reference signal VREF1. The first PI adjustment circuit 141 generates the shunt reference signal according to the two input signals and outputs it.

[0056] For example, the voltage value of the shunt reference signal VREF1 is a fixed value, which can be set according to the actual situation. The bus voltage is a voltage signal collected in real time during the operation of the shunt circuit. The first PI adjustment circuit 141 generates a shunt reference signal by performing proportional-integral operation on the difference between the bus voltage and the voltage of the shunt reference signal VREF1. The shunt reference signal can vary and is positively correlated with the magnitude of the bus voltage. For example, when the bus voltage exceeds the first voltage threshold and reaches its maximum value, the generated shunt reference signal is at its maximum. The bus voltage is reduced by adjusting the conduction state of the front-end second transistor 130. When the bus voltage drops below the second voltage threshold, the bus voltage reaches its minimum, and the generated shunt reference signal is at its minimum. The bus voltage is increased by adjusting the conduction state of the front-end first transistor 120, and finally the bus voltage is kept stable.

[0057] See also Figure 2 Optionally, the first control module 150 includes a first comparator 151;

[0058] The input terminal of the first comparator 151 is connected to the shunt reference generation circuit 140. The first input terminal of the first comparator 151 is connected to the shunt reference signal, and the second input terminal of the first comparator 151 is connected to the transistor turn-on reference signal VREF2. The first comparator 151 generates a first control signal based on the shunt reference signal and the transistor turn-on reference signal VREF2.

[0059] The first comparator 151 is a device that generates a first control signal based on the shunt reference signal. The first comparator 151 includes two input ports and one output port. The two input ports are respectively connected to the shunt reference signal and the transistor turn-on reference signal VREF2. The first comparator 151 outputs a high-level or low-level first control signal based on the magnitude relationship between the shunt reference signal and the transistor turn-on reference signal VREF2. For example, the value of the transistor turn-on reference signal VREF2 can be the value of the turn-on reference of the first transistor 120. When the shunt reference signal is greater than the transistor turn-on reference signal VREF2, the first control signal output by the first comparator 151 is low; when the shunt reference signal is less than the transistor turn-on reference signal VREF2, the first control signal output by the first comparator 151 is high.

[0060] Specifically, the first input terminal of the first PI adjustment circuit 141 is connected to the first connection terminal A1. The first input terminal of the first PI adjustment circuit 141 is connected to the bus voltage. A shunt reference signal is generated based on the difference between the bus voltage and the voltage of the shunt reference signal VREF1. The output terminal of the first PI adjustment circuit 141 is connected to the first comparator 151. The first comparator 151 generates a first control signal based on the relationship between the shunt reference signal and the transistor turn-on reference signal VREF2. The first control signal is either high or low level and is used to control the turn-on or turn-off of the first transistor 120.

[0061] See also Figure 2 Optionally, the second control module 160 includes a second PI adjustment circuit 161, a second comparator 162, and a waveform generator 163;

[0062] The second PI adjustment circuit 161 is connected to the shunt reference generation circuit 140. The first input terminal of the second PI adjustment circuit 161 is connected to the shunt reference signal, and the second input terminal of the second PI adjustment circuit 161 is connected to the drive reference reference signal VREF3. The second PI adjustment circuit 161 generates an error signal based on the shunt reference signal and the drive reference reference signal. The first input terminal of the second comparator 162 is connected to the waveform generator 163, which is used to generate a triangular wave. The second input terminal of the second comparator 162 is connected to the second PI adjustment circuit 161. The second comparator 162 generates a second control signal based on the triangular wave and the error signal.

[0063] The second PI adjustment circuit 161 generates an error signal based on the shunt reference signal, which is used to generate the second control signal. The second PI adjustment circuit 161 includes two input ports and one output port. The two input ports are respectively connected to the shunt reference signal and the drive reference signal VREF3. The second PI adjustment circuit 161 generates the error signal based on the difference between the drive reference signal VREF3 and the shunt reference signal. For example, the drive reference signal VREF3 is a fixed value, which can be set according to actual conditions. The shunt reference signal is a variable signal; as the shunt reference signal increases or decreases, the error signal generated by the second PI adjustment circuit 161 decreases or increases. When the shunt reference signal is at its maximum, the error signal is at its minimum, with a minimum amplitude of 0. When the shunt reference signal is at its minimum, the error signal is at its maximum, with a maximum amplitude of 1. As the shunt reference signal gradually decreases from its maximum, the error signal gradually increases.

[0064] The second comparator 162 is a device that generates a second control signal based on the error signal. The second comparator 162 includes two input ports and one output port. The two input ports are respectively connected to a reference signal and an error signal. The reference signal can be a triangular wave signal with a fixed amplitude and an adjustable duty cycle, generated by the waveform generator 163. The second comparator 162 generates the second control signal based on the triangular wave signal and the error signal. The second control signal is a high- or low-level signal with an adjustable duty cycle. For example, if the amplitude of the triangular wave signal is 1, when the amplitude of the error signal is 0, the second comparator 162 outputs a high-level second control signal with a 100% duty cycle; when the amplitude of the error signal is 1, the second comparator 162 outputs a low-level second control signal with a 0% duty cycle; when the amplitude of the error signal is greater than 0 and less than 1, as the amplitude of the error signal gradually increases from 0 to 1, the second comparator 162 outputs a high- or low-level second control signal with a gradually decreasing duty cycle.

[0065] Optionally, the waveform generator 163 is a pulse width modulation (PWM) controller.

[0066] The PWM controller is used to output a reference waveform, which is a triangular wave.

[0067] Specifically, the second PI adjustment circuit 161 is connected to the first PI adjustment circuit 141. The second PI adjustment circuit 161 receives the shunt reference signal and the drive reference reference signal VREF3 generated by the first PI adjustment circuit 141. An error signal is generated based on the difference between the drive reference reference signal VREF3 and the shunt reference signal. The output of the second PI adjustment circuit 161 is connected to the second comparator 162. The waveform generator 163 is connected to the second comparator 162. The second comparator 162 generates a second control signal with an adjustable duty cycle (high or low level) based on the relationship between the triangular wave and the amplitude of the error signal. When the second control signal is a 100% high-level signal, the second transistor 130 is turned on, and the shunt circuit operates in full shunt mode. When the second control signal is a 0% low-level signal, the second transistor 130 is turned off, and the shunt circuit operates in full power supply mode. When the second control signal is a 30% high / low level signal, within a period of T=10S, the high-level time is 3S and the low-level time is 7S, and the shunt circuit operates in modulation mode.

[0068] Figure 3 A schematic diagram of another shunt circuit for a spacecraft provided by an embodiment of the present invention, as shown below. Figure 3 As shown, the shunt circuit also includes a first drive circuit 210;

[0069] The first end of the first driving circuit 210 is connected to the first control module 150, and the other end of the first driving circuit 210 is connected to the control terminal of the first transistor 120. It is used to generate a first driving signal according to the first control signal. The first driving circuit 210 drives the first transistor 120 according to the first driving signal. The driving capability of the first driving signal is greater than that of the first control signal.

[0070] The first driving circuit 210 is a driving circuit that can enhance the driving capability of the first control signal. For example, the first driving circuit can be a control chip, specifically an LTC4359HS8. By connecting the output of the first comparator 151 in the first control module 150 and the first transistor 120 through the control chip, the driving capability of the first control signal is enhanced, enabling the first transistor 120 to be turned on or off quickly and stably.

[0071] Specifically, one end of the first driving circuit 210 is connected to the output terminal of the first comparator 151 to receive the first control signal output by the first comparator 151. The other end of the first driving circuit 210 is connected to the control terminal of the first transistor 120 to enhance the driving capability of the first control signal and control the first transistor 120 to quickly and stably turn on or off. By driving the first transistor 120 through the first driving circuit 210, the first transistor 120 can be turned on or off quickly and stably, reducing switching losses and improving the efficiency of the shunt circuit.

[0072] Optionally, the second control module 160 further includes: a second drive circuit 164;

[0073] The first end of the second driving circuit 164 is connected to the second comparator 162. The second driving circuit 164 generates a second driving signal according to the second control signal. The second end of the second driving circuit 164 is connected to the second transistor 130. The second driving signal is used to drive the second transistor 130. The driving capability of the second driving signal is greater than that of the second control signal.

[0074] The second driving circuit 164 is a circuit that can enhance the driving capability of the second control signal. For example, the second driving circuit 164 is a push-pull circuit composed of two transistors with opposite polarities. The input terminal of the push-pull circuit is connected to the second control signal generated by the second comparator 162. The push-pull circuit can amplify the power of the second control signal to generate the second driving signal.

[0075] See also Figure 3 Optionally, the shunt circuit further includes a first diode D1 and a second diode D2;

[0076] The anode of the first diode D1 is connected to the anode of the second diode D2, the cathode of the first diode D1 is connected to the cathode of the second diode D2, the anode of the first diode D1 is connected to the first terminal of the first transistor 120, and the cathode of the first diode D1 is connected to the second terminal of the first transistor 120.

[0077] The first diode D1 and the second diode D2 assist the first transistor 120 in supplying power to the downstream load. For example, when the downstream load demand current is at its lowest, the bus voltage signal is higher than the first voltage threshold, the first transistor 120 is completely disconnected, and the shunt circuit operates in full shunt mode. When the downstream load demand current is at its highest, the bus voltage is lower than the second voltage threshold, the first transistor 120 is fully turned on, and the shunt circuit operates in full power supply mode. When the downstream load demand current gradually increases from its lowest value, the bus voltage is lower than the first voltage threshold but not lower than the second voltage threshold, and the shunt circuit operates in modulation mode. That is, part of the output current generated by the solar cell array is used for power supply, and part is shunted. During the modulation stage, the first transistor 120 is continuously disconnected, and the output current of the solar cell array is supplied to the downstream load through the first diode D1 and the second diode D2. The second transistor 130 is turned on or off according to a second control signal with a duty cycle adjustable from 0% to 100%.

[0078] Specifically, the first diode D1 and the second diode D2 are connected in parallel to the first and second terminals of the first transistor 120. When the shunt circuit operates in full shunt mode, the first transistor 120 is quickly and completely turned off. The drain current of the first transistor 120 is extremely small, effectively preventing reverse current and voltage backflow. When the shunt circuit operates in the modulation phase, the first transistor 120 remains off, and current flows to the downstream load through the first diode D1 and the second diode D2. When the shunt circuit operates in full power supply mode, the first transistor 120 is fully turned on. The on-resistance of the first transistor 120 is extremely small, and all current flows to the downstream load through the first transistor 120. When the first transistor 120 is on, the first diodes D1 and D2 are not working. The first transistor 120 reduces the power consumption of the shunt circuit. By connecting the first diode D1 and the second diode D2 in parallel, the frequent switching of the first transistor 120's on / off state during the modulation phase avoids device damage and improves the reliability of the shunt circuit.

[0079] This invention provides a spacecraft power supply system. Figure 4 This is a schematic diagram of a spacecraft power supply system provided in an embodiment of the present invention, as shown below. Figure 4 As shown, the spacecraft power supply system includes at least one shunt circuit of any embodiment of the present invention, and has the beneficial effects of the shunt circuit for spacecraft of any embodiment of the present invention described above.

[0080] Optionally, the spacecraft power supply system includes n shunt circuits, where n is a positive integer greater than or equal to 2;

[0081] The voltages of the shunt reference signals corresponding to the n shunt circuits decrease sequentially;

[0082] The first control module 150 includes a first comparator 151. The input terminal of the first comparator 151 is connected to the shunt reference generation circuit 140. The first input terminal of the first comparator 151 is connected to the shunt reference signal, and the second input terminal of the first comparator 151 is connected to the transistor turn-on reference signal. The first comparator 151 generates a first control signal based on the shunt reference signal and the transistor turn-on reference signal. The voltages of the transistor turn-on reference signals corresponding to the n shunt circuits decrease sequentially.

[0083] Optionally, taking the power supply system with one shunt circuit operating in full power supply mode as an example, the on-resistance of the first transistor 120 is 3mΩ, the full power supply current is 6A, and the heat dissipation is 0.108W. The on-state voltage drop of a traditional isolation diode is about 0.7V, and the heat dissipation is 4.2W. The heat dissipation generated by using the first transistor 120 is much less than 4.2W.

[0084] Taking the power supply system with eight shunt circuits as an example, the shunt circuits are sequentially turned on. When the first to seventh shunt circuits of the power supply system are all in full power supply mode, and the eighth shunt circuit is in modulation mode, the maximum heat dissipation of this invention is... The heat dissipation of a traditional isolation diode would reach 33.6W, therefore the technical solution of the present invention effectively reduces the heat dissipation of the shunt circuit.

[0085] Table 1 shows the operating states of a shunt circuit in a spacecraft power supply system according to an embodiment of the present invention. Taking a spacecraft power supply system comprising three shunt circuits as an example, the three shunt circuits are respectively denoted as the first shunt circuit, the second shunt circuit, and the third shunt circuit. The voltages of the shunt reference signals corresponding to the first shunt circuit, the second shunt circuit, and the third shunt circuit decrease sequentially, as do the voltages of the transistor conduction reference signals corresponding to the first shunt circuit, the second shunt circuit, and the third shunt circuit. Operating state 1 is when the first shunt circuit, the second shunt circuit, and the third shunt circuit are all operating in full shunt state; operating state 2 is when the first shunt circuit is operating in modulation state, while the second shunt circuit and the third shunt circuit remain in full shunt state; operating state 3 is when the first shunt circuit is operating in full power supply state, while the second shunt circuit and the third shunt circuit continue to remain in full shunt state; when the maximum output current of the solar cell array 110 of the first shunt circuit is less than the required current of the downstream load, operating state 4 is when the first shunt circuit is operating in full power supply state, and the second shunt circuit enters modulation state. The third shunt circuit remains in full shunt mode; operating state 5 is when the first shunt circuit operates in full power supply mode, the second shunt circuit also enters full power supply mode, and the third shunt circuit continues to operate in full shunt mode; when the maximum output current of the solar cell array 110 of the first shunt circuit and the second shunt circuit is less than the required current of the downstream load, operating state 6 is when the first and second shunt circuits operate in full power supply mode, and the third shunt circuit enters modulation mode; operating state 7 is when the first, second, and third shunt circuits all operate in full power supply mode. Based on the above seven operating states, it can be seen that the first, second, and third shunt circuits perform sequential shunt modulation. It should be noted that the seven operating states of the shunt circuits in the spacecraft power supply system are for a clearer explanation of the sequential shunt modulation function of the spacecraft power supply system; this embodiment does not limit other operating states in the sequential shunt modulation process of the spacecraft power supply system.

[0086]

[0087] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0088] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A shunt circuit for spacecraft, characterized in that, include: Solar cell array, first transistor, second transistor, shunt reference generation circuit, first control module and second control module; The positive terminal of the solar cell array is connected to the first terminal of the first transistor and the first terminal of the second transistor, respectively, and the negative terminal of the solar cell array is connected to the second terminal of the second transistor. The second terminal of the first transistor is connected to the first terminal of the shunt circuit, and the negative terminal of the solar cell array is connected to the second terminal of the shunt circuit. The first terminal and the second terminal are used to connect to the busbar. The input terminal of the shunt reference generation circuit is connected to the first connection terminal, and the shunt reference generation circuit is used to generate a shunt reference signal based on the shunt reference reference signal and the bus voltage signal of the first connection terminal. The first control module is connected to the output terminal of the shunt reference generation circuit and the control terminal of the first transistor, respectively, and is used to generate a first control signal according to the shunt reference signal to control the conduction state of the first transistor. The second control module is connected to the output terminal of the shunt reference generation circuit and the control terminal of the second transistor, and is used to generate a second control signal according to the shunt reference signal to control the conduction state of the second transistor; Specifically, when the bus voltage signal is higher than the first voltage threshold or lower than the second voltage threshold, the conduction states of the first transistor and the second transistor are reversed.

2. The shunt circuit according to claim 1, characterized in that, The current shunt reference generation circuit includes a first PI adjustment circuit; The first input terminal of the first PI regulation circuit is connected to the first connection terminal. The first input terminal of the first PI regulation circuit is connected to the bus voltage signal. The second input terminal of the first PI regulation circuit is connected to the shunt reference signal. The first PI regulation circuit is used to generate a shunt reference signal based on the bus voltage signal and the shunt reference signal.

3. The shunt circuit according to claim 1, characterized in that, The current shunt circuit also includes a first driving circuit; The first end of the first driving circuit is connected to the first control module, and the other end of the first driving circuit is connected to the control terminal of the first transistor. It is used to generate a first driving signal according to the first control signal. The first driving circuit drives the first transistor according to the first driving signal. The driving capability of the first driving signal is greater than that of the first control signal.

4. The shunt circuit according to claim 1, characterized in that, The first control module includes a first comparator; The input terminal of the first comparator is connected to the shunt reference generation circuit. The first input terminal of the first comparator is connected to the shunt reference signal, and the second input terminal of the first comparator is connected to the transistor turn-on reference signal. The first comparator generates the first control signal based on the shunt reference signal and the transistor turn-on reference signal.

5. The shunt circuit according to claim 1, characterized in that, The second control module includes a second PI adjustment circuit, a second comparator, and a waveform generator; The second PI adjustment circuit is connected to the shunt reference generation circuit. The first input terminal of the second PI adjustment circuit is connected to the shunt reference signal, and the second input terminal of the second PI adjustment circuit is connected to the drive reference signal. The second PI adjustment circuit generates an error signal based on the shunt reference signal and the drive reference signal. The first input terminal of the second comparator is connected to the waveform generator, which generates a triangular wave. The second input terminal of the second comparator is connected to the second PI adjustment circuit. The second comparator generates the second control signal based on the triangular wave and the error signal.

6. The shunt circuit according to claim 5, characterized in that, The waveform generator is a PWM controller.

7. The shunt circuit according to claim 5, characterized in that, The second control module further includes: a second drive circuit; The first end of the second driving circuit is connected to the second comparator. The second driving circuit generates a second driving signal according to the second control signal. The second end of the second driving circuit is connected to the second transistor. The second driving signal is used to drive the second transistor. The driving capability of the second driving signal is greater than that of the second control signal.

8. The shunt circuit according to claim 1, characterized in that, The shunt circuit also includes a first diode and a second diode; The anode of the first diode is connected to the anode of the second diode, the cathode of the first diode is connected to the cathode of the second diode, the anode of the first diode is connected to the first terminal of the first transistor, and the cathode of the first diode is connected to the second terminal of the first transistor.

9. A spacecraft power supply system, characterized in that, It includes at least one shunt circuit as described in any one of claims 1-8.

10. The spacecraft power supply system according to claim 9, characterized in that, It includes n shunt circuits as described in any one of claims 1-8, where n is a positive integer greater than or equal to 2; The voltages of the shunt reference signals corresponding to the n shunt circuits decrease sequentially; The first control module includes a first comparator. The input terminal of the first comparator is connected to the shunt reference generation circuit. The first input terminal of the first comparator is connected to the shunt reference signal, and the second input terminal of the first comparator is connected to the transistor turn-on reference signal. The first comparator generates the first control signal based on the shunt reference signal and the transistor turn-on reference signal. The voltages of the transistor turn-on reference signals corresponding to the n shunt circuits decrease sequentially.

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