A space power system with controllable power flow direction and its control method

Abstract

This invention relates to the field of spacecraft power technology, and in particular to a space power system with controllable power flow and its control method. It includes a spacecraft primary bus, a power electronic converter with controllable power flow, an energy storage unit, a logic control unit, a load, and a power distribution switch. The positive terminal of the spacecraft primary bus is connected to one end of the power distribution switch and one input terminal of the power electronic converter with controllable power flow. One end of the load is connected to the other end of the power distribution switch. The other input terminal of the power electronic converter with controllable power flow is connected to the other end of the load and the negative terminal of the spacecraft primary bus. The input terminal of the energy storage unit is connected to the output terminal of the power electronic converter with controllable power flow. The logic control unit is used to collect the voltage at the positive and negative terminals of the spacecraft primary bus and the current of the load. This invention features high power density, fast dynamic response, simple circuit structure, and avoids severe electromagnetic interference.

Description

Technical Field

[0001] This invention relates to the field of spacecraft power technology, and in particular to a space power system with controllable power flow and its control method. Background Technology

[0002] With the rapid development of my country's aerospace industry and the increasingly fierce international space race, high-power, short-term operational payloads are being used more and more frequently. The short-term peak power of the payload differs significantly from the long-term load power of the satellite platform. For example, a certain satellite currently has a short-term peak power of 12kW, while its long-term stable power requirement is only around 1500W, resulting in a payload-to-platform power ratio of 8:1. Even more extreme, the payload-to-platform power ratio can reach as high as 20:1. Calculations show that a fourfold increase in current leads to a nearly 10% increase in line loss; a 20-fold increase in load power would result in unbearable line losses. Furthermore, the increased power consumption of the load also brings the challenge of increased weight for power distribution cables.

[0003] Furthermore, the peak power of the load lasts for a very short time. The pulse repetition frequency of synthetic aperture radar (SAR) is up to 5kHz (a single pulse is about 0.2 to 1ms). At the moment of power change of a high-power pulse load, the current input to the DC bus will reach hundreds of amperes or even more, which is very similar to the characteristics of short-circuit current. This will cause a series of power quality problems: the increase in load power consumption from 0 to 50% will cause a voltage drop of 12.5% ​​during transient response. The primary bus voltage "dip" is very serious, which will cause strong electromagnetic interference (EMI) problems to other equipment powered by the same bus voltage.

[0004] Currently, the power system design of spacecraft in orbit, both domestically and internationally, is relatively simple, with the vast majority still employing the traditional "solar cell power generation + power regulation + battery energy storage" single-bus centralized power supply system design. However, traditional power system designs are inadequate for powering such short-duration, high-power pulsed payloads. Simply increasing the area of ​​the solar panels or adding parallel capacity to lithium-ion batteries is not the optimal design and may even render the system unusable due to its enormous size and weight. Therefore, a novel space power system is needed that can automatically control power flow, meet the power supply requirements of short-term, ultra-high-power pulsed payloads, and quickly alleviate the primary bus voltage dip problem based on payload characteristics. This would be a significant innovation in the existing space power system architecture. Summary of the Invention

[0005] In view of the shortcomings of the prior art described above, the purpose of this invention is to provide a space power supply system with controllable power flow and its control method, which solves the problems of voltage drop on the primary bus, severe electromagnetic interference, heavy power transmission cables, and large transmission loss caused by the instantaneous large current start-up of the load in traditional space centralized power supply systems. It also has the characteristics of high power density, fast dynamic response, and simple circuit structure.

[0006] To achieve the above and other related objectives, the present invention provides a space power system with controllable power flow, comprising: a spacecraft primary bus, a power electronic converter with controllable power flow, an energy storage unit, a logic control unit, a load, and a power distribution switch, wherein...

[0007] The positive terminal of the spacecraft's primary bus is connected to one end of the power distribution switch and one input terminal of the power electronic converter with controllable power flow, respectively.

[0008] The load has one end connected to the other end of the power distribution switch;

[0009] The other input terminal of the power electronic converter with controllable power flow is connected to the other end of the load and the negative terminal of the primary bus of the spacecraft.

[0010] The energy storage unit has its input terminal connected to the output terminal of the power electronic converter with controllable power flow.

[0011] The logic control unit is used to collect the voltage of the positive and negative terminals of the primary bus of the spacecraft, as well as the current of the load, and the output terminal of the logic control unit is connected to the input terminal of the power electronic converter with controllable power flow and the power distribution switch, respectively.

[0012] In one embodiment of the present invention, the spacecraft primary bus includes: a solar cell array, a power controller, and a battery pack, wherein,

[0013] The output terminal of the solar cell array is connected to the input terminal of the power controller;

[0014] The power controller's output terminals serve as the positive and negative terminals of the spacecraft's primary bus.

[0015] The battery pack has a bidirectional communication connection with the power controller.

[0016] In one embodiment of the present invention, the power electronic converter with controllable power flow includes: a first semiconductor switch, a second semiconductor switch, and an inductor, wherein,

[0017] The collector of the first semiconductor switch is respectively connected to the positive pole of the primary bus of the spacecraft and one end of the power distribution switch, and the source of the first semiconductor switch is respectively connected to the collector of the second semiconductor switch and one end of the inductor;

[0018] The source of the second semiconductor switch is respectively connected to the other end of the load, the negative terminal of the primary bus of the spacecraft, and the negative input terminal of the energy storage unit;

[0019] The other end of the inductor is connected to the positive input terminal of the energy storage unit.

[0020] The present invention also provides a control method for a space power supply system with controllable power flow direction, including the above-mentioned space power supply system with controllable power flow direction. The control method for the space power supply system with controllable power flow direction includes:

[0021] The logic control unit collects the voltages at the positive and negative terminals of the primary bus of the spacecraft, and collects the current of the load, and processes the voltages and currents to make the voltage value distributed within the interval [V1, V4] and the current value distributed within the interval [I1, I3], where the voltage value V1 < V2 < V3 < V4 and the current value I1 < I2 < I3, and controls the power flow direction according to the voltage value and the current value;

[0022] When the voltage value is within the interval [V1, V2), control the power flow direction path to be the first path;

[0023] When the voltage value is within the interval (V3, V4], control the power flow direction path to be the third path;

[0024] When the voltage value is within the interval [V2, V3] and the current value is within the interval [I2, I3], control the power flow direction path to be the second path;

[0025] When the voltage value is within the interval [V2, V3] and the current value is within the interval [I1, I2), control the power flow direction path to be the third path.

[0026] In an embodiment of the present invention, when the logic control unit controls the power flow direction path to be the third path, if the voltage between the positive input terminal and the negative input terminal of the energy storage unit is greater than the set safety voltage threshold, then control the power flow direction path to be converted from the third path to the fourth path.

[0027] In an embodiment of the present invention, when the logic control unit controls the power flow direction path to be the first path, the logic control unit sends an instruction to the power distribution switch, and the power distribution switch disconnects;

[0028] When the logic control unit controls the power flow path to be the second path, the third path, or the fourth path, the logic control unit sends a command to the power distribution switch, and the power distribution switch is turned on.

[0029] In one embodiment of the present invention, when the logic control unit controls the power flow path to be the first path, the logic control unit adopts a voltage feedback closed-loop control strategy for the positive and negative terminals of the spacecraft's primary bus, the voltage feedback closed-loop control strategy including:

[0030] The logic control unit performs low-pass filtering on the voltages at the positive and negative terminals of the spacecraft's primary bus to obtain the processed voltage V. in ;

[0031] Set reference voltage V in_ref The reference voltage V in_ref With the processed voltage V in Subtract them to get the difference;

[0032] The difference obtained after subtraction is subjected to linear control adjustment and amplitude limiting control to obtain the adjusted voltage V. in_PI ;

[0033] The adjusted voltage V in_PI The pulse signal is obtained by comparing it with the triangular carrier signal.

[0034] The pulse signal is inverted to obtain the drive pulse signal T2, which controls the second semiconductor switch to be turned on or off; the drive pulse signal T1 of the first semiconductor switch is low, which means that the first semiconductor switch is in the pulse blocking state.

[0035] In one embodiment of the present invention, when the logic control unit controls the power flow path to be the second path, the logic control unit adopts a current feedback closed-loop control strategy for the load, the current feedback closed-loop control strategy including:

[0036] The logic control unit performs low-pass filtering on the load current to obtain the processed current I. L ;

[0037] Set reference current I L_ref The reference current I L_ref With the processed current I L Subtract them to get the difference;

[0038] The difference obtained after subtraction is subjected to linear control adjustment and amplitude limiting control to obtain the adjusted current I. L_PI ;

[0039] The adjusted current I L_PI The pulse signal is obtained by comparing it with the triangular carrier signal.

[0040] The pulse signal is inverted to obtain the drive pulse signal T2, which controls the second semiconductor switch to be turned on or off; the drive pulse signal T1 of the first semiconductor switch is low, which means that the first semiconductor switch is in the pulse blocking state.

[0041] In one embodiment of the present invention, when the logic control unit controls the power flow path to be a third path, the logic control unit adopts the voltage feedback closed-loop control strategy of the energy storage unit, the voltage feedback closed-loop control strategy including:

[0042] The logic control unit performs low-pass filtering on the voltage of the energy storage unit to obtain the processed voltage V. o ;

[0043] Set reference voltage V o_ref The reference voltage V o_ref With the processed voltage V o Subtract them to get the difference;

[0044] The difference obtained after subtraction is subjected to linear control adjustment and amplitude limiting control to obtain the adjusted voltage V. o_PI ;

[0045] The adjusted voltage V o_PI The pulse signal is obtained by comparing it with the triangular carrier signal.

[0046] The pulse signal is inverted to obtain the drive pulse signal T1, which controls the first semiconductor switch to be turned on or off; the drive pulse signal T2 of the second semiconductor switch is low, which means that the second semiconductor switch is in a pulse blocking state.

[0047] In one embodiment of the present invention, when the logic control unit controls the power flow path to be the fourth path, the logic control unit sets the drive pulse signal T1 of the first semiconductor switch and the drive pulse signal T2 of the second semiconductor switch to a low level, and the first semiconductor switch and the second semiconductor switch are in a pulse blocking state.

[0048] As described above, the space power system and its control method with controllable power flow of the present invention have the following beneficial effects:

[0049] The controllable power flow space power system and its control method of the present invention solve the problems of voltage drop on the primary bus, severe electromagnetic interference, heavy power transmission cables, and high transmission loss caused by the instantaneous large current start-up of the load in traditional space centralized power supply systems. It also features high power density, fast dynamic response, and simple circuit structure, and avoids serious electromagnetic interference to the environment.

[0050] The space power system and control method with controllable power flow of the present invention can improve the dynamic response speed to the millisecond level by performing switching operation on the power electronic converter with controllable power flow, thus meeting the dynamic power supply requirements of pulsed loads.

[0051] The controllable power flow spatial power system and its control method of the present invention configures the controllable power flow power electronic converter near high-power electrical loads, solving the problems of heavy power transmission cables and high transmission loss.

[0052] The space power system and control method with controllable power flow of the present invention have the simplest circuit structure under the premise of satisfying high power, low loss, fast response, high integration and multiple power flow control. Attached Figure Description

[0053] Figure 1 A schematic diagram of the structure of a space power system with controllable power flow provided in an embodiment of this application.

[0054] Figure 2 The schematic diagram of the controllable power flow power electronic converter of the space power system provided in the embodiment of this application.

[0055] Figure 3 The logic control unit of the control method for the controllable power flow space power system provided in the embodiments of this application divides the working mode according to voltage and current.

[0056] Figure 4 The control method for a space power system with controllable power flow direction provided in this application embodiment adopts a voltage feedback closed-loop control strategy block diagram when the control power flow direction path is the first path.

[0057] Figure 5 The control method for the controllable power flow direction of the space power system provided in this application embodiment adopts a current feedback closed-loop control strategy block diagram when the control power flow direction path is the second path.

[0058] Figure 6 The control method for a controllable power flow space power system provided in this application embodiment adopts a voltage feedback closed-loop control strategy block diagram when the control power flow path is the third path.

[0059] Figure 7 When the control power flow path of the control method for the controllable power flow direction of the space power system provided in the embodiments of this application is the fourth path, a control strategy block diagram is adopted.

[0060] Figure 8 The control method for the controllable power flow direction of the space power system provided in this application embodiment is a schematic diagram of the energy storage unit as a primary bus releasing energy when the control power flow direction path is the first path.

[0061] Figure 9 The control method for the controllable power flow direction of the space power system provided in this application embodiment is a schematic diagram of the energy storage unit as a load energy release path when the control power flow direction path is the second path.

[0062] Figure 10 The control method for the controllable power flow direction of the space power system provided in this application embodiment is a schematic diagram of the primary bus as the energy storage unit energy release path when the control power flow direction path is the third path.

[0063] Figure 11 The control method for the controllable power flow direction of the space power system provided in this application embodiment is a schematic diagram of the energy self-sufficiency principle of the energy storage unit when the control power flow direction path is the fourth path.

[0064] Component designation explanation

[0065] 10. Spacecraft primary bus

[0066] 11 Solar cell array

[0067] 12 Power Controller

[0068] 13 Battery Pack

[0069] 20 Power electronic converters with controllable power flow

[0070] 21 First Semiconductor Switch

[0071] 22 Second Semiconductor Switch

[0072] 23 Inductors

[0073] 30 energy storage units

[0074] 40 Logic Control Unit

[0075] 50 load

[0076] 60 Distribution switch

[0077] 70 Primary busbar Detailed Implementation

[0078] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0079] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Therefore, the illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0080] Please see Figure 1 , Figure 1 This is a schematic diagram of the structural principle of a space power system with controllable power flow provided in an embodiment of this application. This invention provides a space power system with controllable power flow, solving problems such as primary bus voltage dip, severe electromagnetic interference, heavy power transmission cables, and high transmission loss caused by the instantaneous high current startup of loads in traditional centralized space power supply systems. It also features high power density, fast dynamic response, and simple circuit structure. Primary bus voltage dip refers to a situation where the primary bus voltage is DC stable, but due to the instantaneous high power consumption of the load, it is pulled down, and then quickly recovers, forming a "dip". The space power system with controllable power flow includes, but is not limited to, the spacecraft primary bus 10, a power electronic converter with controllable power flow 20, an energy storage unit 30, a logic control unit 40, a load 50, and a power distribution switch 60. The positive terminal of the spacecraft primary bus 10 is connected to one end of the power distribution switch 60 and one input terminal of the power electronic converter 20 with controllable power flow, respectively. One end of the load 50 is connected to the other end of the power distribution switch 60. The other input terminal of the power electronic converter 20 with controllable power flow is connected to the other end of the load 50 and the negative terminal of the spacecraft primary bus 10, respectively. The input terminal of the energy storage unit 30 is connected to the output terminal of the power electronic converter 20 with controllable power flow, and the logic control unit 40 is used to collect the voltage of the positive and negative terminals of the spacecraft primary bus 10 and the current of the load 50. The output terminal of the logic control unit 40 is connected to the input terminals of the power electronic converter 20 with controllable power flow and the power distribution switch 60, respectively.

[0081] Specifically, the spacecraft primary bus 10 is connected to the controllable power flow power electronic converter 20, load 50, and power distribution switch 60 via the primary bus 70. The positive and negative terminal voltages of the spacecraft primary bus 10 are the primary bus voltage.

[0082] Specifically, the spacecraft primary bus 10 includes, but is not limited to, a solar array 11, a power controller 12, and a battery pack 13. The output terminal of the solar array 11 is connected to the input terminal of the power controller 12, and the output terminal of the power controller 12 serves as the positive and negative terminals of the spacecraft primary bus 10. The battery pack 13 has a bidirectional communication connection with the power controller 12. The power controller 12 includes an MPPT module and a charge / discharge controller module. The output terminal of the solar array 11 is connected to the input terminal of the MPPT module. The battery pack 13 has a bidirectional communication connection with the charge / discharge controller module. The output terminals of the MPPT module and the charge / discharge controller module are connected together to form the output terminal of the spacecraft primary bus 10. The MPPT module can also be an S3R module or an S4R module.

[0083] Specifically, the logic control unit 40 includes a sampling and processing circuit, a pulse generation circuit, and a drive and protection circuit. The sampling and processing circuit collects and processes information such as primary bus voltage, load current, and energy storage unit voltage. Through the closed-loop feedback control logic of the pulse generation circuit, it generates drive pulse signals for the power switching transistors in the power electronic converter with controllable power flow, and also controls the on / off state of the load distribution switch. The sampling and processing circuit is connected to the output terminals of the primary bus, load 50, and energy storage unit 30. The sampling and processing circuit is connected to the pulse generation circuit, which is connected to the drive and protection circuit. The drive and protection circuit is connected to the power electronic converter 20 with controllable power flow and the distribution switch 60.

[0084] Please see Figure 2 , Figure 2This is the structural schematic diagram of the power electronic converter with controllable power flow direction in the space power system provided by the embodiment of the present application. The power electronic converter 20 with controllable power flow direction includes, but is not limited to, a first semiconductor switch 21, a second semiconductor switch 22, and an inductor 23. The collector of the first semiconductor switch 21 is respectively connected to the positive pole of the spacecraft primary bus 10 and one end of the power distribution switch 60. The source of the first semiconductor switch 21 is respectively connected to the collector of the second semiconductor switch 22 and one end of the inductor 23. The source of the second semiconductor switch 22 is respectively connected to the other end of the load 50, the negative extreme of the spacecraft primary bus 10, and the negative input terminal of the energy storage unit 30. The other end of the inductor 23 is connected to the positive input terminal of the energy storage unit 30. Specifically, the primary bus voltage is V in , the load current is I L ( Figure 2 The direction of the current arrow in is positive), and the energy storage unit voltage is V o .

[0085] The present invention also provides a control method for a space power system with controllable power flow direction, including the above-mentioned space power system with controllable power flow direction. The control method of the space power system with controllable power flow direction of the present invention is integrated in the logic control unit 40. The control method of the space power system with controllable power flow direction includes:

[0086] S1. The logic control unit 40 collects the voltage at the positive and negative extremes of the spacecraft primary bus 10, which is the primary bus voltage, and collects the current of the load 50, which is the load current, and processes the voltage and current to make the voltage value distributed in the interval of [V1, V4] and the current value distributed in the interval of [I1, I3]. Among them, the voltage values are V1 < V2 < V3 < V4, and the current values are I1 < I2 < I3. According to the voltage value and current value, the power flow direction is controlled.

[0087] Specifically, it can be set, but is not limited to, that V1 = 96V, V2 = 98V, V3 = 102V, V4 = 104V; I1 = 0A, I2 = 20A, I3 = 200A. Among them, V1 corresponds to the lowest primary bus voltage of the power system, V4 corresponds to the highest primary bus voltage of the power system; I1 corresponds to the minimum load current, and I3 corresponds to the maximum load current.

[0088] Please refer to Figure 3 , Figure 3 This is the block diagram of the logic control unit 40 of the control method for the space power system with controllable power flow direction provided by the embodiment of the present application, which divides the working mode according to voltage and current.

[0089] S2. When the voltage value is in the range [V1, V2), the control power flow path is the first path.

[0090] Specifically, when detecting the bus voltage V in In [V1,V2) (i.e., 96V≤V) in When the voltage is <98V, the control power flow path is the first path, and the first path corresponds to... Figure 3 ① in the middle.

[0091] S3. When the voltage value is in the range of (V3, V4), the control power flow path is the third path.

[0092] Specifically, when detecting the bus voltage V in In (V3, V4) (i.e., 102V < V) in In the range of ≤104V, the control power flow path is the third path, which corresponds to... Figure 3 ③ in the middle.

[0093] S4. When the voltage value is in the range of [V2, V3] and the current value is in the range of [I2, I3], the power flow path is controlled to be the second path.

[0094] Specifically, when detecting the bus voltage V in In [V2, V3] (i.e., 98V ≤ V), in When the voltage is ≤102V, then adjust according to the load current I. L Divided into:

[0095] When the current is in [I2, I3] (i.e., 20A ≤ I), L When the current is in the range of ≤200A, the control power flow path is the second path, and the second path corresponds to... Figure 3 ② in the middle.

[0096] S5. When the voltage value is in the range of [V2, V3] and the current value is in the range of [I1, I2), the power flow path is controlled to be the third path.

[0097] Specifically, when detecting the bus voltage V in In [V2, V3] (i.e., 98V ≤ V), in When the voltage is ≤102V, then adjust according to the load current I. L Divided into:

[0098] When the current is in [I1, I2) (i.e., 0A ≤ I), L When the range is <20A, the control power flow path is the third path, and the third path corresponds to Figure 3 ③ in the middle.

[0099] It should be specifically noted that when the logic control unit 40 controls the power flow path to be the third path, if the voltage at the positive and negative input terminals of the energy storage unit 30 is greater than the set safety voltage threshold U1, then the power flow path is controlled to switch from the third path to the fourth path, that is, exiting the third path and entering the fourth path. The safety voltage threshold U1 may be, but is not limited to, 80V.

[0100] In addition, when the logic control unit 40 controls the power flow path to be the first path, the logic control unit 40 sends a command to the power distribution switch 60, and the power distribution switch 60 is turned off; when the logic control unit 40 controls the power flow path to be the second path, the third path, or the fourth path, the logic control unit 40 sends a command to the power distribution switch 60, and the power distribution switch 60 is turned on.

[0101] The following details the strategy employed by the logic control unit 40 in controlling the power flow direction:

[0102] Please see Figure 4 , Figure 4 The control method for a controllable power flow space power system provided in this application embodiment employs a voltage feedback closed-loop control strategy block diagram when the control power flow path is the first path. When the logic control unit 40 controls the power flow path to be the first path, the logic control unit 40 uses the voltages of the positive and negative terminals of the spacecraft's primary bus 10, which constitutes a primary bus voltage feedback closed-loop control strategy. This voltage feedback closed-loop control strategy includes:

[0103] S10. The logic control unit 40 performs low-pass filtering on the voltages at the positive and negative terminals of the spacecraft's primary bus 10, i.e., the primary bus voltage, to obtain the processed voltage V. in .

[0104] S20, Set reference voltage V in_ref The reference voltage V in_ref With the processed voltage V in Subtract them to get the difference.

[0105] S30. The difference after subtraction is subjected to proportional integral (PI) control and amplitude limiting control to obtain the regulated voltage V. in_PI .

[0106] S40, the adjusted voltage V in_PI The pulse signal is obtained by comparing it with the triangular carrier signal.

[0107] S50. The pulse signal is inverted to obtain the driving pulse signal T2, which controls the second semiconductor switch 22 to be turned on or off; the driving pulse signal T1 of the first semiconductor switch 21 is low, that is, the first semiconductor switch 21 is in the pulse blocking state.

[0108] S60, Send a disconnect command to the power distribution switch 60.

[0109] Please see Figure 8 , Figure 8 The control method for the controllable power flow direction of the space power system provided in this application embodiment, when the control power flow direction path is the first path, is shown in the schematic diagram of the energy storage unit as the primary bus releasing energy. The arrows in the diagram indicate the direction of energy flow. It can be seen that, in addition to the solar cell array 11 and the battery pack 13 supplying energy to the primary bus 70 through the power controller 12, the energy storage unit 30 also supplies energy to the primary bus 70 through the power electronic converter 20 with controllable power flow direction. During this period, the power distribution switch 60 is disconnected, preventing it from absorbing energy from the primary bus 70.

[0110] Please see Figure 5 , Figure 5 The control method for a controllable power flow space power system provided in this application embodiment employs a current feedback closed-loop control strategy block diagram when the controlled power flow path is the second path. When the logic control unit 40 controls the power flow path to be the second path, the logic control unit 40 uses the current of the load 50, which is a load current feedback closed-loop control strategy. The current feedback closed-loop control strategy includes:

[0111] S110, the logic control unit 40 performs low-pass filtering on the current of the load 50, i.e., the load current, to obtain the processed current I. L .

[0112] S120, Set reference current I L_ref The reference current I L_ref With the processed current I L Subtract them to get the difference.

[0113] S130. The difference after subtraction is subjected to linear control adjustment and amplitude limiting control to obtain the adjusted current I. L_PI .

[0114] S140, the adjusted current I L_PI The pulse signal is obtained by comparing it with the triangular carrier signal.

[0115] S150. The pulse signal is inverted to obtain a drive pulse signal T2, which controls the second semiconductor switch 22 to be turned on or off. The drive pulse signal T1 of the first semiconductor switch 21 is low, which means that the first semiconductor switch 21 is in a pulse blocking state.

[0116] S160, Send the connection command to the power distribution switch 60.

[0117] Please see Figure 9 , Figure 9 When the control power flow path of the control method for the controllable power flow space power system provided in the embodiments of this application is the second path, the energy storage unit is a schematic diagram of the load energy release path. The arrows in the diagram represent the energy flow direction. It can be seen that the solar cell array 11 and the battery pack 13 supply energy to the primary bus 70 through the power controller 12. When the distribution switch 60 is closed, the load current I... L Part of the energy is drawn from the primary bus 70, and the other part is drawn from the power electronic converter 20 supplied by the energy storage unit 30 through the controllable power flow.

[0118] Please see Figure 6 , Figure 6 The control method for a controllable power flow space power system provided in this application embodiment employs a voltage feedback closed-loop control strategy when the controlled power flow path is a third path. When the logic control unit 40 controls the power flow path to be the third path, the logic control unit 40 uses the voltage of the energy storage unit 30, which is the energy storage unit voltage feedback closed-loop control strategy. This voltage feedback closed-loop control strategy includes:

[0119] S1110, The logic control unit 40 performs low-pass filtering on the voltage of the energy storage unit 30, i.e., the energy storage unit voltage, to obtain the processed voltage V. o .

[0120] S1120, Set reference voltage V o_ref The reference voltage V o_ref With the processed voltage V o Subtract them to get the difference.

[0121] S1130. The difference after subtraction is subjected to linear control adjustment and amplitude limiting control to obtain the adjusted voltage V. o_PI .

[0122] S1140, The adjusted voltage V o_PI The pulse signal is obtained by comparing it with the triangular carrier signal.

[0123] S1150. The pulse signal is inverted to obtain a drive pulse signal T1, which controls the first semiconductor switch 21 to be turned on or off; the drive pulse signal T2 of the second semiconductor switch 22 is low, that is, the second semiconductor switch 22 is in a pulse blocking state.

[0124] S1160, Send the connection command to the power distribution switch 60.

[0125] Please see Figure 10 , Figure 10 The control method for the controllable power flow direction of the space power system provided in this application embodiment, when the control power flow direction path is the third path, is shown in the schematic diagram of the primary bus as the energy storage unit's energy release path. The arrows in the diagram represent the energy flow direction. It can be seen that the solar cell array 11 and battery pack 13 supply energy to the primary bus 70 through the power controller 12. When the power distribution switch 60 is closed, the energy from the primary bus 70, in addition to supplying the load 50, also supplies energy to the energy storage unit 30 through the controllable power flow direction power electronic converter 20, until the voltage V across the positive and negative input terminals of the energy storage unit 30 is detected. o If the voltage exceeds the safety voltage threshold U1 (U1 = 80V), exit the third path and enter the fourth path via control.

[0126] Please see Figure 7 , Figure 7 When the control power flow path of the control method for the controllable power flow direction of the space power system provided in this application embodiment is the fourth path, a control strategy block diagram is adopted. When the logic control unit 40 controls the power flow path to be the fourth path, the logic control unit 40 sets the drive pulse signal T1 of the first semiconductor switch 21 and the drive pulse signal T2 of the second semiconductor switch 22 to a low level, and the first semiconductor switch 21 and the second semiconductor switch 22 are in a pulse blocking state. A turn-on command is sent to the power distribution switch 60.

[0127] Please see Figure 11 , Figure 11 The control method for the controllable power flow direction of the space power system provided in this application embodiment, when the control power flow direction path is the fourth path, is illustrated in the energy self-sufficiency principle diagram of the energy storage unit. The arrows in the diagram represent the energy flow direction. It can be seen that the solar cell array 11 and battery pack 13 supply energy to the primary bus 70 through the power controller 12. When the distribution switch 60 is closed, the energy of the primary bus 70 is fully supplied to the load 50. Since the first semiconductor switch 21 and the second semiconductor switch 22 inside the controllable power flow power electronic converter 20 are both in a pulse-blocked state, there is no mutual energy transfer between the primary bus 70 and the energy storage unit 30. Therefore, the energy storage unit 30 is energy self-sufficient.

[0128] Although the present invention has been described in detail through the preferred embodiments described above, it should be understood that the above description should not be considered as a limitation of the present invention. Various modifications and substitutions to the present invention will be apparent to those skilled in the art after reading the above description.

[0129] For example, such as Figure 2 As shown, the power electronic converter 20 with controllable power flow direction, composed of a first semiconductor switch 21, a second semiconductor switch 22, and an inductor 23, proposed in this invention, can also be replaced by other types of bidirectional DC-DC converters with boost and buck functions, but with... Figure 2 Since there is no fundamental change in function or performance, the scope of protection of this invention should be defined by the appended claims.

[0130] In summary, the controllable power flow space power system and its control method of the present invention solve the problems of voltage drop on the primary bus, severe electromagnetic interference, heavy power transmission cables, and high transmission loss caused by the instantaneous large current start-up of the load in traditional space centralized power supply systems. It also features high power density, fast dynamic response, and simple circuit structure, and avoids severe electromagnetic interference to the environment.

[0131] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A control method for a space power system with controllable power flow direction, characterized in that, A space power system with controllable power flow includes: a spacecraft primary bus (10), a power electronic converter (20) with controllable power flow, an energy storage unit (30), a logic control unit (40), a load (50), and a distribution switch (60). Among them, The positive terminal of the spacecraft primary bus (10) is respectively connected to one end of the distribution switch (60) and an input terminal of the power electronic converter (20) with controllable power flow; One end of the load (50) is connected to the other end of the distribution switch (60); The other input terminal of the power electronic converter (20) with controllable power flow is respectively connected to the other end of the load (50) and the negative terminal of the spacecraft primary bus (10); The input terminal of the energy storage unit (30) is connected to the output terminal of the power electronic converter (20) with controllable power flow; The logic control unit (40) is used to collect the voltages at the positive and negative terminals of the spacecraft primary bus (10) and the current of the load (50), and the output terminals of the logic control unit (40) are respectively connected to the input terminals of the power electronic converter (20) with controllable power flow and the distribution switch (60); The control method of the space power system with controllable power flow includes: The logic control unit (40) collects the voltages at the positive and negative terminals of the spacecraft primary bus (10) and the current of the load (50), and processes the voltages and currents to make the voltage values distributed in the interval [V1, V4] and the current values distributed in the interval [I1, I3]. Among them, the voltage values are V1 < V2 < V3 < V4, and the current values are I1 < I2 < I3. The power flow is controlled according to the voltage values and current values; When the voltage value is in the interval [V1, V2), the power flow path is controlled as the first path; When the voltage value is in the interval (V3, V4], the power flow path is controlled as the third path; When the voltage value is in the interval [V2, V3] and the current value is in the interval [I2, I3], the power flow path is controlled as the second path; When the voltage value is in the interval [V2, V3] and the current value is in the interval [I1, I2), the power flow path is controlled as the third path.

2. The control method for a space power system with controllable power flow direction according to claim 1, characterized in that, The spacecraft primary bus (10) includes: a solar array (11), a power controller (12), and a battery pack (13). Among them, The output terminal of the solar array (11) is connected to the input terminal of the power controller (12); The output terminals of the power controller (12) serve as the positive and negative terminals of the spacecraft primary bus (10); The battery pack (13) is in bidirectional communication connection with the power controller (12).

3. The control method for a space power system with controllable power flow direction according to claim 1, characterized in that, The power electronic converter (20) with controllable power flow includes: a first semiconductor switch (21), a second semiconductor switch (22), and an inductor (23). Among them, The collector of the first semiconductor switch (21) is connected to the positive terminal of the primary busbar (10) of the spacecraft and one end of the power distribution switch (60), and the source of the first semiconductor switch (21) is connected to the collector of the second semiconductor switch (22) and one end of the inductor (23). The source of the second semiconductor switch (22) is connected to the other end of the load (50), the negative terminal of the spacecraft primary bus (10), and the negative input terminal of the energy storage unit (30), respectively. The other end of the inductor (23) is connected to the positive input terminal of the energy storage unit (30).

4. The control method for a space power system with controllable power flow direction according to claim 1, characterized in that: When the logic control unit (40) controls the power flow path to be the third path, if the voltage at the positive input terminal and the negative input terminal of the energy storage unit (30) is greater than the set safety voltage threshold, then the power flow path is controlled to be changed from the third path to the fourth path.

5. The control method for a space power system with controllable power flow direction according to claim 4, characterized in that: When the logic control unit (40) controls the power flow path to be the first path, the logic control unit (40) sends a command to the power distribution switch (60), and the power distribution switch (60) is disconnected; When the logic control unit (40) controls the power flow path to be the second path, the third path, or the fourth path, the logic control unit (40) sends a command to the power distribution switch (60), and the power distribution switch (60) is turned on.

6. The control method for a space power system with controllable power flow direction according to claim 1, characterized in that: When the logic control unit (40) controls the power flow path to be the first path, the logic control unit (40) adopts a voltage feedback closed-loop control strategy for the positive and negative terminals of the spacecraft primary bus (10), the voltage feedback closed-loop control strategy including: The logic control unit (40) performs low-pass filtering on the voltages of the positive and negative terminals of the primary bus (10) of the spacecraft to obtain the processed voltage V. in ; Set reference voltage V in_ref The reference voltage V in_ref With the processed voltage V in Subtract them to get the difference; The difference obtained after subtraction is subjected to linear control adjustment and amplitude limiting control to obtain the adjusted voltage V. in_PI ; The adjusted voltage V in_PI The pulse signal is obtained by comparing it with the triangular carrier signal. The pulse signal is inverted to obtain the driving pulse signal T2, which controls the second semiconductor switch (22) to be turned on or off; the driving pulse signal T1 of the first semiconductor switch (21) is low, which means that the first semiconductor switch (21) is in the pulse blocking state.

7. The control method for a space power system with controllable power flow direction according to claim 1, characterized in that: When the logic control unit (40) controls the power flow path to be the second path, the logic control unit (40) adopts the current feedback closed-loop control strategy of the load (50), the current feedback closed-loop control strategy includes: The logic control unit (40) performs low-pass filtering on the current of the load (50) to obtain the processed current I. L ; Set reference current I L_ref The reference current I L_ref With the processed current I L Subtract them to get the difference; The difference obtained after subtraction is subjected to linear control adjustment and amplitude limiting control to obtain the adjusted current I. L_PI ; The adjusted current I L_PI The pulse signal is obtained by comparing it with the triangular carrier signal. The pulse signal is inverted to obtain the driving pulse signal T2, which controls the second semiconductor switch (22) to be turned on or off; the driving pulse signal T1 of the first semiconductor switch (21) is low, which means that the first semiconductor switch (21) is in the pulse blocking state.

8. The control method for a space power system with controllable power flow direction according to claim 1, characterized in that: When the logic control unit (40) controls the power flow path to be the third path, the logic control unit (40) adopts the voltage feedback closed-loop control strategy of the energy storage unit (30), the voltage feedback closed-loop control strategy includes: The logic control unit (40) performs low-pass filtering on the voltage of the energy storage unit (30) to obtain the processed voltage V. o ; Set reference voltage V o_ref The reference voltage V o_ref With the processed voltage V o Subtract them to get the difference; The difference obtained after subtraction is subjected to linear control adjustment and amplitude limiting control to obtain the adjusted voltage V. o_PI ; The adjusted voltage V o_PI The pulse signal is obtained by comparing it with the triangular carrier signal. The pulse signal is inverted to obtain the driving pulse signal T1, which controls the first semiconductor switch (21) to be turned on or off; the driving pulse signal T2 of the second semiconductor switch (22) is low, which means that the second semiconductor switch (22) is in the pulse blocking state.

9. The control method for a space power system with controllable power flow direction according to claim 4, characterized in that: When the logic control unit (40) controls the power flow path to be the fourth path, the logic control unit (40) sets the drive pulse signal T1 of the first semiconductor switch (21) and the drive pulse signal T2 of the second semiconductor switch (22) to a low level, and the first semiconductor switch (21) and the second semiconductor switch (22) are in a pulse blocking state.

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