CN104917461B - A kind of Satellite vapour image Orbital detection circuit - Google Patents

Abstract

An on-orbit test circuit for a satellite solar cell array is used for the on-orbit IV curve test of a satellite solar cell array, including on-board electronic equipment, an on-board information processing unit, and a satellite-ground communication unit. When the IV test circuit is connected, the on-orbit real-time data such as the voltage, current and temperature of the solar cell array can be obtained in real time through the electronic equipment on the star. Complete solar array IV characteristic curve. The invention solves the defect that the existing method can only count the voltage and current of the working point of the satellite busbar, but cannot directly and comprehensively reflect the defect of the IV curve, improves the accuracy and comprehensiveness of the performance monitoring of the solar cell array, and provides a basis for the performance evaluation of the solar cell array It provides complete IV curve information, improves the efficiency of satellite life assessment, and provides more concise and intuitive data support for on-orbit management of satellite solar arrays.

Description

A satellite solar cell array on-orbit test circuit

technical field

The invention relates to an on-orbit test circuit of a satellite solar battery array, belonging to the field of satellite solar battery array testing.

Background technique

All existing satellites have adopted the combined topology of solar cell arrays combined with storage battery packs. As the power generation equipment of the satellite, the solar cell array provides the conversion of solar energy to electric energy for the satellite when it is in orbit. Due to the influence of attenuation factors such as space ion radiation attenuation factor, ultraviolet radiation attenuation factor, microfluidic collision and cold and heat alternation when operating in space, the on-orbit power of the solar cell array will be attenuated . In addition, the earth's albedo and star occlusion will also affect the on-orbit power of the solar array.

The on-orbit test results of the solar array output power can provide accurate on-orbit measurement basis for satellite design, and provide detailed and reliable data guarantee for satellite on-orbit use. The attenuation coefficient obtained from the analysis of on-orbit data provides reliable data support for the design of solar arrays in the design of long-life satellites, especially when the satellite life is required to be longer and longer, accurate and reliable analysis of solar array data in orbit is more important .

Existing satellites do not have a dedicated on-orbit test circuit for the IV curve, but use the existing solar array current, bus voltage, and solar array temperature telemetry data (as shown in Figure 1) for analysis and processing. The output current of the solar cell array collected by the output section of the solar cell array, the bus voltage collected at the primary power bus, and the related telemetry collected by the thermistor arranged on the solar cell array. When sunlight shines on the solar cell array, the microprocessor collects the telemetry of the solar cell array current, bus voltage, and solar cell array temperature and packs them into a telemetry package, which is sent to the communication module every 1s, through the on-board processing module, satellite-ground communication The unit passes to the ground. The ground personnel calculate according to the current telemetry data, temperature telemetry data and attitude data of the solar cell array in different modes in orbit, and eliminate the influence of the incident angle and the sun-earth distance factor on the solar cell array through the normalization method, so as to obtain the attenuation coefficient.

To sum up, a complete IV curve (as shown in Figure 2) should include all data from the open circuit voltage point to the short circuit current point. However, the existing method has few data sampling points, and the voltage and current at the working point are basically stable. The data obtained are only a few isolated points on the IV curve, which cannot directly and comprehensively reflect the IV curve of the entire solar cell, let alone provide All data required for quantitative analysis of solar array performance degradation.

In Figure 5, the abscissa is the output voltage of the solar cell array, the ordinate is the output current of the solar cell array, the dotted line is a schematic diagram of the entire IV curve, and the dots are the output voltage and current data of the on-orbit solar cell array. The measurement result obtained according to the existing method in Fig. 5 is not a complete test curve, but the voltage and current of the working point when the solar cell array works at the primary bus voltage, which changes slightly with the change of the load. Because the primary bus voltage is regulated within the range of 28.5V±1V by the power controller, the range pointed to by M in Figure 5 is the position of the corresponding part of the curve on the IV curve when the output voltage of the solar cell array is within the range of 28.5V±1V . This part of the curve is only a part of the entire IV curve, and cannot display the changes in short-circuit current and open-circuit voltage, let alone the overall drift of the IV curve caused by changes in temperature and on-orbit life of the solar cell array. For example, when the temperature changes, the constant current section of the IV curve will become shorter, and at the same time the open circuit voltage point will move to the left, but since the design of the solar cell array ensures that the operating point can work in the constant current section at different temperatures, then in Figure 5 The data represented by M cannot represent the left shift of the IV curve.

Contents of the invention

The technical solution problem of the present invention is: overcome the deficiencies in the prior art, propose a kind of satellite solar cell array on-orbit test circuit, obtain the solar cell array on-orbit change data in real time, the obtained IV curve (Fig. 3) can reflect covering short circuit All parameters of current, open circuit voltage, and operating point voltage/current can be used to visually evaluate the on-orbit performance of solar arrays, and obtain long-term on-orbit flight attenuation data.

The technical solution of the present invention is: an on-orbit test circuit of a satellite solar battery array, including a solar battery array, on-board electronic equipment, an on-board information processing unit, and a satellite-ground communication unit.

The solar cell array includes a first solar cell array and a second solar cell array.

Electronic equipment on the star, including switch switching circuit, temperature measurement circuit, IV test circuit, analog-to-digital converter, microprocessor, communication module.

The IV test circuit includes a voltage acquisition circuit, a current acquisition circuit, and a load regulation circuit.

The external on-board electrical equipment is connected in series with the first solar battery array through the primary power bus.

When the satellite is in orbit, the first solar battery array supplies power to the primary power bus after being irradiated by sunlight, and the second solar battery array supplies power to the primary power bus under the control of the switch circuit after being irradiated by sunlight. The initial state is to connect the second solar cell array to the primary power bus, that is, the initial state of the switching circuit enables both the first solar cell array and the second solar cell array to supply power to the primary power bus;

When the switch circuit is in the initial state, the current collected by the current collection circuit from the second solar cell array through the switch switching circuit is 0, the voltage collected by the corresponding voltage collection circuit is 0, and the temperature measurement circuit collects the temperature of the second solar cell array , convert the temperature into a voltage value and convert the voltage value into a 0-5V analog quantity Vo and pass it to the analog-to-digital converter, and the analog-to-digital converter converts the voltage Vo into a digital quantity D1, and then sends it to the microprocessor;

When the communication module receives the turn-on command of the IV test circuit sent by the information processing unit on the star, the microprocessor sends an instruction pulse to the switch circuit to switch the switch circuit to the test state. When the switch circuit is in the test state, the first The second solar battery array is connected to the current acquisition circuit in the IV test circuit. At this time, the second solar battery array, that is, the test solar array, is connected to the IV test circuit to supply power to the load regulation circuit.

After the voltage acquisition circuit is switched from the initial state to the test state, the voltage Vin of the second solar cell array is the initial moment when the second solar cell array is just connected to the IV test circuit, and Vin gradually increases from 0V , until the charging of the load regulating circuit is completed, at this time Vin rises to the maximum voltage value, and the maximum voltage value is the open circuit voltage of the second solar cell array;

After switching from the initial state to the test state, the current acquisition circuit collects the current Iin of the second solar cell array, that is, the moment when the second solar cell array is just connected to the IV test circuit is the initial moment, and Iin starts from the maximum value, that is, the first 2. The short-circuit current of the solar battery array starts to decrease until the charging of the load regulation circuit ends, and at this time Iin decreases to 0;

After switching from the initial state to the test state, the voltage acquisition circuit converts Vin from 0V to the maximum voltage value into 0-5V analog Vout and transmits it to the analog-to-digital converter. The analog-to-digital converter converts the voltage Vout to digital value D2 and sends it to To the microprocessor; the current acquisition circuit collects the current in the load regulation circuit, converts the current value into a 0-5V analog quantity and transmits it to the analog-to-digital converter, and the analog-to-digital converter converts the analog quantity into a digital quantity D3; temperature measurement The circuit collects the temperature of the second solar cell array, converts the temperature into a voltage value and converts the voltage value into a 0-5V analog quantity Vo and transmits it to the analog-to-digital converter, and the analog-to-digital converter converts the voltage Vo to a digital quantity D1, then sent to the microprocessor;

The microprocessor sends out instruction pulses to switch the switching circuit from the initial state to the test state and starts timing. The microprocessor composes the digital quantities D1, D2, and D3 into a device telemetry packet in each program cycle, and then sends it through the communication module. To the on-board information processing unit;

The information processing unit on the star identifies and judges the telemetry packet of the device, and then sends it to the ground test equipment through the satellite-ground communication unit. After the ground test equipment receives the telemetry packet of the device, it decodes and obtains the temperature, output voltage, Output current, select the continuous data collected from temperature, output voltage, and output current at multiple temperatures, and draw the IV curve of the solar cell array.

Each program cycle is 1s.

The selected multiple temperatures include 0°C, 20°C, 60°C, and 90°C.

The temperature measuring circuit includes a thermistor RT and a voltage dividing resistor R5, one end of the voltage dividing resistor R5 of the temperature measuring circuit is connected to the +5V voltage input, and the other end of the voltage dividing resistor R5 is used as the output terminal Vo of the temperature measuring circuit, and is connected with the +5V voltage input. One end of the thermistor RT is connected, the other end of the thermistor RT is connected to the signal ground, and the output terminal Vo is connected to the analog-to-digital converter;

The switch switching circuit includes a switch K1, which is a single-pole double-throw switch; the fixed end of the switch K1 is connected to the positive pole of the second solar cell array; the second moving end of the switch K1 is respectively connected to the first The positive pole of the solar cell array and the positive pole of the electrical equipment on the external star; the negative pole of the electrical equipment on the external star is respectively connected to the negative pole of the first solar cell array and the negative pole of the second solar cell array;

The current acquisition circuit includes a sampling resistor R1 and an operational amplifier, one end of R1 is connected to the first moving end of the switch K1, the other end of R1 is connected to one end Vin of the resistor R2 in the voltage acquisition circuit, and the two ends of R1 are respectively connected to the input end of the operational amplifier Connected, the output of the operational amplifier is connected to the analog-to-digital converter; the positive terminal V+ of the operational amplifier is connected to +12V, and the negative terminal V- of the power supply is connected to -12V;

The voltage acquisition circuit includes a resistor R2 and a resistor R3; one end Vin of the voltage acquisition circuit resistor R2 is connected to the other end of R1, and the other end Vout of the resistor R2 is respectively connected to one end of the resistor R3 and the analog-to-digital converter; the other end of the resistor R3 is respectively connected to One end of the resistor R4 is connected to the negative pole of the second solar cell array;

The load regulation circuit includes a resistor R4, a capacitor C1, and a capacitor C2. One end of the capacitor C1 and one end of the capacitor C2 are connected to one end Vin of the resistor R2, and the other end of the capacitor C1 and the other end of the capacitor C2 are connected to the other end of the resistor R4.

The current acquisition circuit is selected from the high-precision operational amplifier of Xi'an Microelectronics Technology Research Institute, the model is OP07.

The sampling resistor R1 selected by the current acquisition circuit is selected from 2mΩ to 10mΩ. The resistance values of resistors R2 and R3 selected by the voltage acquisition circuit should meet the requirement that the maximum voltage obtained by dividing the voltage across R3 should not exceed 5V. The resistor R4 of the load regulating circuit is selected from 0.5Ω to 2Ω.

The capacitors C1 and C2 of the load regulation circuit are both selected to be 470 μF.

The second solar cell array is composed of a string of solar cells, and the total number of solar cells is the same as that of a single string of solar cells in the first solar cell array; the solar cell monomers selected by the first solar cell array and the second solar cell array are the same , which can meet the requirement of directly supplying power to the primary busbar.

The advantage of the present invention compared with prior art is:

(1) The present invention utilizes on-board electronic equipment such as microprocessors, temperature measuring circuits, and telemetry transmission channels, combined with voltage acquisition, current acquisition and load regulation circuits, to provide a solar cell array on-orbit test circuit design method. The electronic equipment used has high acquisition accuracy and controllable input and output. After the second solar cell array is connected to the IV test circuit through the switch, the charging characteristics of the capacitor in the load regulation circuit are used to realize the collection of various points (short circuit current, open circuit voltage, operating point voltage and current) on the IV curve of the solar cell array.

(2) The IV test circuit of the present invention can be connected and withdrawn through a switch switching circuit controlled by a remote control command. That is, in order to ensure the main mission of the satellite, the second solar cell array is connected to the busbar through the remote control command issued independently on the ground or on the satellite to provide the maximum solar cell array current for the load; only when the load does not work, or the solar cell array current has When there is a surplus, the second solar cell array is connected to the on-orbit test circuit through the remote control command issued independently on the ground or on the satellite, and the IV curve test is performed.

(3) The present invention utilizes the change characteristics of load regulation circuit capacitors C1 and C2 to be turned on to open circuit instantaneously during charging and discharging, so as to realize the collection of the whole IV curve from short-circuit current to open circuit voltage, without additionally adding adjustable electronic loads as the method for obtaining IV The curved solar array load saves equipment space, the control circuit principle is simple, safe and reliable, and the cost is low. It is suitable for all kinds of satellites equipped with solar arrays.

(4) The on-orbit change data of the solar cell array acquired in real time by the present invention includes the output voltage, current and temperature of the solar cell array. The obtained IV curve can reflect all parameters including short-circuit current, open-circuit voltage, and operating point voltage/current. It is a complete IV curve, which can directly evaluate the on-orbit performance of the solar cell array and obtain the attenuation data of long-term on-orbit flight.

(5) In the present invention, the switching circuit K1 is controlled by the microprocessor to issue instructions to realize the connection and exit of the solar battery array test circuit. Only when the load is not working, or the current of the solar battery array is sufficient, the second solar battery array is connected to the on-orbit test circuit through the remote control command issued independently on the ground or on the satellite, and the IV curve test is performed.

(6) The first solar cell array and the second solar cell array of the present invention are two independent parts, the first solar cell array is specially used for power supply, and the second solar cell array realizes both power supply and on-orbit testing through the switch switching circuit K1 Purpose. In order to ensure the main mission of the satellite, when the load is working, the two solar cell arrays are connected to the busbar to provide the maximum solar cell array current for the load.

Description of drawings

Fig. 1 is the topological structure schematic diagram of existing solar cell current and voltage acquisition circuit for satellites;

Fig. 2 is the ideal solar cell array IV curve diagram of the solar cell on-rail test circuit of the present invention;

Fig. 3 is a schematic diagram of the topological structure of the solar cell on-orbit test circuit of the present invention;

Fig. 4 is a schematic diagram of the solar cell on-rail test circuit design of the present invention;

Fig. 5 is a schematic diagram of the position of the data collected by the prior art on the IV curve;

Fig. 6 is a schematic diagram of the variation of IV curve with temperature.

detailed description

The present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments.

As shown in Fig. 3, the on-orbit test circuit of the satellite solar cell array of the present invention includes a solar cell array, electronic equipment on the star, an information processing unit on the star, and a satellite-ground communication unit; the solar cell array includes a first solar cell array, a second Solar battery array; on-board electronic equipment, including switch switching circuit, temperature measurement circuit, IV test circuit, analog-to-digital converter, microprocessor, communication module. The IV test circuit includes a voltage acquisition circuit, a current acquisition circuit, and a load regulation circuit, and the external on-board electrical equipment is connected in series with the first solar battery array through the primary power bus. The electronic equipment used in the invention has high collection precision and controllable input and output. After the second solar cell array is connected to the IV test circuit through the switch, the charging characteristics of the capacitor in the load regulation circuit are used to realize the collection of various points (short circuit current, open circuit voltage, operating point voltage and current) on the IV curve of the solar cell array.

After the communication module receives the instruction from the on-board information processing unit, the microprocessor sends an instruction to turn on the switch of the IV test circuit first, and switch the test solar battery from the bus to the IV test circuit. The load capacitance is charged by the IV test circuit; the voltage acquisition circuit collects the voltage value between the positive and negative bus bars of the IV test circuit power supply, and the analog-to-digital converter converts the voltage into a digital quantity; the current acquisition circuit collects the current value of the IV test circuit power supply path, The analog-to-digital converter converts the current quantity into a digital quantity; the microprocessor continuously stores the voltage and current digital quantity in the data memory. When the voltage digital quantity collected by the microprocessor drops to 0V and remains unchanged, an instruction is issued to disconnect the IV test circuit switch, and the test solar cell is connected to the bus bar. The above-mentioned digital quantities are packaged in the microprocessor, and the telemetry packet is sent to the on-board information processing unit through the communication module; the on-board information processing unit performs packet processing on the telemetry packet containing the original voltage value sent by the device, and sends To the satellite-ground communication unit, the satellite-ground communication unit sends the telemetry packet output by the information processing unit on the star to the ground test equipment. The positive line of the second solar cell array is connected to the positive end of the power supply of the test capacitor circuit through the switching circuit, the negative line of the second solar cell array is directly connected to the negative end of the power supply of the test capacitor circuit, and the voltage acquisition circuit is connected between the positive and negative lines. The current acquisition circuit is connected in series on the positive line.

As shown in FIG. 4 , the solar cell array includes a first solar cell array and a second solar cell array, the first solar cell array is used for powering satellites, and the second solar cell array is used for satellite power supply and IV curve testing. In the present invention, the first solar cell array and the second solar cell array are two independent parts. The first solar cell array is specially used for power supply, and the second solar cell array realizes the purpose of both power supply and on-track testing through the switch switching circuit K1. Its purpose is to ensure the main mission of the satellite. When the load is working, the two solar cell arrays are connected to the busbar to provide the maximum solar cell array current for the load.

The temperature measuring circuit includes a thermistor RT and a voltage dividing resistor R5, one end of the voltage dividing resistor R5 of the temperature measuring circuit is connected to the +5V voltage input, and the other end of the voltage dividing resistor R5 is used as the output terminal Vo of the temperature measuring circuit, and is connected with the +5V voltage input. One end of the thermistor RT is connected, the other end of the thermistor RT is connected to the signal ground, and the output terminal Vo is connected to the analog-to-digital converter; the temperature measurement circuit realizes the real-time collection of temperature data and provides the temperature of the solar cell drawn by the IV curve. The data can detect the performance data of the solar cell array at different temperatures.

The switch switching circuit includes a switch K1, which is a single-pole double-throw switch; the fixed end of the switch K1 is connected to the positive pole of the solar battery array 2; the second moving end of the switch K1 is respectively connected to the solar battery array through the primary power bus 1 and the positive pole of the external on-board electrical equipment; the negative pole of the external on-board electrical equipment is respectively connected to the negative pole of the solar cell array 1 and the negative pole of the solar cell array 2. The switching circuit realizes the switching between the two modes of the second solar battery array for power supply and testing, effectively utilizes the limited resources of the satellite, and takes into account the functions of power supply and testing. That is, in order to ensure the main mission of the satellite, the second solar cell array is connected to the busbar through the remote control command issued independently on the ground or on the satellite to provide the maximum solar cell array current for the load; only when the load does not work, or the solar cell array current has When there is a surplus, the second solar cell array is connected to the on-orbit test circuit through the remote control command issued independently on the ground or on the satellite, and the IV curve test is performed.

The current acquisition circuit includes a sampling resistor R1 and an operational amplifier, one end of R1 is connected to the first moving end of the switch K1, the other end of R1 is connected to one end Vin of the resistor R2 in the voltage acquisition circuit, and the two ends of R1 are respectively connected to the input end of the operational amplifier The output of the operational amplifier is connected to the analog-to-digital converter, the positive terminal V+ of the operational amplifier is connected to +12V, and the negative terminal V- of the power supply is connected to -12V; the current acquisition circuit realizes the high-speed and high-precision acquisition of the power supply current of the solar cell array.

The voltage acquisition circuit includes a resistor R2 and a resistor R3; one end Vin of the voltage acquisition circuit resistor R2 is connected to the other end of R1, and the other end Vout of the resistor R2 is respectively connected to one end of the resistor R3 and the analog-to-digital converter; the other end of the resistor R3 is respectively connected to One end of the resistor R4 is connected to the negative pole of the solar battery array 2; the voltage acquisition circuit realizes high-speed and high-precision acquisition of the power supply voltage of the solar battery array.

The load regulation circuit includes a resistor R4, a capacitor C1, and a capacitor C2. One end of the capacitor C1 and one end of the capacitor C2 are connected to one end Vin of the resistor R2, and the other end of the capacitor C1 and the other end of the capacitor C2 are connected to the other end of the resistor R4. As the load regulation part of the IV test circuit, the load regulation circuit realizes the whole output change process of the solar cell array from the short-circuit current to the open-circuit voltage. Utilize the change characteristics of the capacitors C1 and C2 of the load regulation circuit from conduction to open circuit instantaneously when charging and discharging, to realize the collection of the entire IV curve from short-circuit current to open circuit voltage, without adding additional adjustable electronic loads as solar cell arrays for obtaining IV curves Load, saving equipment space, simple control circuit principle, safe and reliable, low cost, suitable for all kinds of satellites equipped with solar arrays.

The course of work of the circuit of the present invention is:

When the satellite is in orbit, the solar cell array 1 supplies power to the primary power bus after being irradiated by sunlight, and the solar cell array 2 supplies power to the primary power bus under the control of the switch circuit after being irradiated by sunlight, and the initial state of the switch circuit is In order to connect the solar battery array 2 to the primary power bus, that is, switch the initial state of the switch circuit to realize that both the solar battery array 1 and the solar battery array 2 supply power to the primary power bus.

When the switch circuit is in the initial state, the current collected by the current acquisition circuit from the solar cell array 2 through the switch switching circuit is 0, the voltage collected by the corresponding voltage acquisition circuit is 0, and the temperature measurement circuit collects the temperature of the solar cell array 2, and the The temperature is converted into a voltage value and the voltage value is converted into a 0-5V analog quantity Vo and passed to the analog-to-digital converter. The analog-to-digital converter converts the voltage Vo into a digital quantity D1, and then sends it to the microprocessor.

When the communication module receives the turn-on instruction of the IV test circuit sent by the information processing unit on the star, the microprocessor sends an instruction pulse to the switch circuit to switch the switch circuit to the test state. When the switch circuit is in the test state, the sun The battery array 2 is connected to the current acquisition circuit in the IV test circuit. At this time, the solar battery array 2, that is, the test solar array, is connected to the IV test circuit to supply power to the load regulation circuit.

After the voltage acquisition circuit is switched from the initial state to the test state, the voltage Vin of the solar cell array 2, that is, the moment when the solar cell array 2 is just connected to the IV test circuit is the initial moment, and Vin gradually increases from 0V until After the charging of the load regulation circuit ends, Vin rises to the maximum voltage value at this time, and the maximum voltage value is the open circuit voltage of the solar cell array 2 .

After switching from the initial state to the test state, the current acquisition circuit collects the current Iin of the solar cell array 2, that is, the moment when the solar cell array 2 is just connected to the IV test circuit is the initial moment, and Iin starts from the maximum value, that is, the solar cell array The short-circuit current of 2 starts to decrease until the charging of the load regulation circuit ends, and Iin decreases to 0 at this time.

After switching from the initial state to the test state, the voltage acquisition circuit converts Vin from 0V to the maximum voltage value into 0-5V analog Vout and transmits it to the analog-to-digital converter. The analog-to-digital converter converts the voltage Vout to digital value D2 and sends it to To the microprocessor; the current acquisition circuit collects the current in the load regulation circuit, converts the current value into a 0-5V analog quantity and transmits it to the analog-to-digital converter, and the analog-to-digital converter converts the analog quantity into a digital quantity D3; temperature measurement The circuit collects the temperature of the solar cell array 2, converts the temperature into a voltage value and converts the voltage value into a 0-5V analog quantity Vo and transmits it to the analog-to-digital converter, and the analog-to-digital converter converts the voltage Vo into a digital quantity D1, and then sent to the microprocessor.

The microprocessor sends out instruction pulses to switch the switch circuit from the initial state to the test state and starts timing. The microprocessor composes the digital quantities D1, D2, and D3 in each program cycle to form a device telemetry packet, and then sends it to the On-board information processing unit.

The information processing unit on the star identifies and judges the telemetry packet of the device, and then sends it to the ground test equipment through the satellite-ground communication unit. After the ground test equipment receives the telemetry packet of the device, it decodes and obtains the temperature, output voltage, Output current, select the continuous data collected from temperature, output voltage, and output current at multiple temperatures, and draw the IV curve of the solar cell array.

The IV curve effect that the present invention gathers is as shown in Figure 2, can gather no less than 1000 points continuously, thereby obtain the whole output variation process IV curve from short circuit current to open circuit voltage, compared with the measurement data that existing method obtains (such as Figure 5) is more detailed.

In Fig. 2, the abscissa is the output voltage of the solar cell array, and the ordinate is the output current of the solar cell array. The starting point of the curve is the leftmost short-circuit current point, that is, the output voltage of the solar cell array is 0V, and the output current of the solar cell array is the maximum value. After that, the output voltage of the solar cell array gradually increases until it reaches the open circuit voltage point on the far right of the curve, that is, the output voltage of the solar cell array is the maximum value, and the output current of the solar cell array is 0. From the IV curve obtained in Figure 2, the short-circuit current and open-circuit voltage points can be displayed. By reading the data, the operating point voltage, current, maximum power point voltage, and current can be calculated to characterize the characteristic points of the IV curve of the solar cell array. The number of sampling points and feature point information contained in the curve are more than those in the prior art. When the performance of the solar array is degraded by temperature, on-orbit running time, and space environment, the above characteristic points (short-circuit current point, open-circuit voltage point, operating point voltage, operating point current, maximum power point voltage, maximum power point current ) can completely characterize the drift trend of IV curve. On the one hand, a large amount of detailed data is obtained, on the other hand, the performance change of the solar array is visually evaluated, and the attenuation data of long-term in-orbit flight is obtained.

Taking the IV curve drift with temperature as an example, since the solar cell array is designed to ensure that the operating point voltage and current remain constant at different temperatures, but the open circuit voltage will shift to the left as the temperature rises, and the position of the maximum power point will move to the left. shift. Fig. 6 is a schematic diagram of the variation of the IV curve of the solar cell with temperature. In Figure 6, the abscissa is the output voltage of the solar cell array, the ordinate is the output current of the solar cell array, T represents the working temperature of the solar cell, and the direction of the arrow of T represents the gradual increase in temperature. As the IV curve shown in Figure 6 increases with temperature, the constant current section becomes shorter and the open circuit voltage point moves to the left. Only methods that characterize the complete IV curve can show such changes, which is not possible with existing methods (as shown in Figure 5).

The content that is not described in detail in the description of the present invention belongs to the well-known technology of those skilled in the art.

Claims (8)

1. A satellite solar cell array on-orbit test circuit is characterized in that: it comprises a solar cell array, electronic equipment on the star, an information processing unit on the star, and a satellite-ground communication unit; The solar cell array includes a first solar cell array and a second solar cell array; On-board electronic equipment, including switch switching circuits, temperature measurement circuits, IV test circuits, analog-to-digital converters, microprocessors, and communication modules; The IV test circuit includes a voltage acquisition circuit, a current acquisition circuit, and a load regulation circuit; The external on-board electrical equipment is connected in series with the first solar battery array through the primary power bus; When the satellite is in orbit, the first solar battery array supplies power to the primary power bus after being irradiated by sunlight, and the second solar battery array supplies power to the primary power bus under the control of the switch circuit after being irradiated by sunlight. The initial state is to connect the second solar cell array to the primary power bus, that is, the initial state of the switching circuit enables both the first solar cell array and the second solar cell array to supply power to the primary power bus; When the switch circuit is in the initial state, the current collected by the current collection circuit from the second solar cell array through the switch switching circuit is 0, the voltage collected by the corresponding voltage collection circuit is 0, and the temperature measurement circuit collects the temperature of the second solar cell array , convert the temperature into a voltage value and convert the voltage value into a 0-5V analog quantity Vo and pass it to the analog-to-digital converter, and the analog-to-digital converter converts the voltage Vo into a digital quantity D1, and then sends it to the microprocessor; When the communication module receives the turn-on command of the IV test circuit sent by the information processing unit on the star, the microprocessor sends an instruction pulse to the switch circuit to switch the switch circuit to the test state. When the switch circuit is in the test state, the first The second solar battery array is connected to the current acquisition circuit in the IV test circuit, and at this time the second solar battery array, that is, the test solar array, is connected to the IV test circuit to supply power to the load regulation circuit; After the voltage acquisition circuit is switched from the initial state to the test state, the voltage Vin of the second solar cell array is the initial moment when the second solar cell array is just connected to the IV test circuit, and Vin gradually increases from 0V , until the charging of the load regulating circuit is completed, at this time Vin rises to the maximum voltage value, and the maximum voltage value is the open circuit voltage of the second solar cell array; After switching from the initial state to the test state, the current acquisition circuit collects the current Iin of the second solar cell array, that is, the moment when the second solar cell array is just connected to the IV test circuit is the initial moment, and Iin starts from the maximum value, that is, the first 2. The short-circuit current of the solar battery array starts to decrease until the charging of the load regulation circuit ends, and at this time Iin decreases to 0; After switching from the initial state to the test state, the voltage acquisition circuit converts Vin from 0V to the maximum voltage value into 0-5V analog Vout and transmits it to the analog-to-digital converter. The analog-to-digital converter converts the voltage Vout to digital value D2 and sends it to To the microprocessor; the current acquisition circuit collects the current in the load regulation circuit, converts the current value into a 0-5V analog quantity and transmits it to the analog-to-digital converter, and the analog-to-digital converter converts the analog quantity into a digital quantity D3; temperature measurement The circuit collects the temperature of the second solar cell array, converts the temperature into a voltage value and converts the voltage value into a 0-5V analog quantity Vo and transmits it to the analog-to-digital converter, and the analog-to-digital converter converts the voltage Vo to a digital quantity D1' , and then sent to the microprocessor; The microprocessor sends out instruction pulses to switch the switch circuit from the initial state to the test state and starts timing. The microprocessor forms the digital quantities D1', D2, and D3 into the equipment telemetry package in each program cycle, and then passes the communication module Send to the on-board information processing unit; The information processing unit on the star identifies and judges the telemetry packet of the device, and then sends it to the ground test equipment through the satellite-ground communication unit. After the ground test equipment receives the telemetry packet of the device, it decodes and obtains the temperature, output voltage, Output current, select the continuous data collected from temperature, output voltage, and output current at multiple temperatures, and draw the IV curve of the solar cell array. 2. The on-orbit test circuit of a satellite solar cell array according to claim 1, characterized in that: each program cycle is 1s. 3. An on-orbit test circuit for a satellite solar cell array according to claim 1, wherein the selected temperatures include 0°C, 20°C, 60°C, and 90°C. 4. The on-orbit test circuit of a satellite solar cell array according to claim 1, characterized in that: the temperature measuring circuit comprises a thermistor RT and a voltage dividing resistor R5, and one end of the voltage dividing resistor R5 of the temperature measuring circuit is connected to The +5V voltage input is connected, and the other end of the voltage dividing resistor R5 is used as the output end Vo of the temperature measuring circuit, which is connected to one end of the thermistor RT, and the other end of the thermistor RT is connected to the signal ground, and the output end Vo is connected to the modulus connected to the converter; The switch switching circuit includes a switch K1, which is a single-pole double-throw switch; the fixed end of the switch K1 is connected to the positive pole of the second solar cell array; the second moving end of the switch K1 is respectively connected to the first The positive pole of the solar cell array and the positive pole of the electrical equipment on the external star; the negative pole of the electrical equipment on the external star is respectively connected to the negative pole of the first solar cell array and the negative pole of the second solar cell array; The current acquisition circuit includes a sampling resistor R1 and an operational amplifier. One end of R1 is connected to the first moving end of the switch K1, the other end of R1 is connected to one end Vin of the resistor R2 in the voltage acquisition circuit, and one end of R1 is connected to the reverse input of the operational amplifier. The other end of R1 is connected to the same input terminal of the operational amplifier, the output of the operational amplifier is connected to the analog-to-digital converter, the positive terminal V+ of the power supply of the operational amplifier is connected to +12V, and the negative terminal V- of the power supply is connected to -12V; The voltage acquisition circuit includes a resistor R2 and a resistor R3; one end Vin of the voltage acquisition circuit resistor R2 is connected to the other end of R1, and the other end Vout of the resistor R2 is respectively connected to one end of the resistor R3 and the analog-to-digital converter; the other end of the resistor R3 is respectively connected to One end of the resistor R4 is connected to the negative pole of the second solar cell array; The load regulation circuit includes a resistor R4, a capacitor C1, and a capacitor C2. One end of the capacitor C1 and one end of the capacitor C2 are connected to one end Vin of the resistor R2, and the other end of the capacitor C1 and the other end of the capacitor C2 are connected to the other end of the resistor R4. 5. The on-orbit test circuit of a satellite solar cell array according to claim 4, characterized in that: the operational amplifier selected by the current acquisition circuit is a high-precision operational amplifier of Xi'an Microelectronics Technology Research Institute, and the model is OP07. 6. The on-orbit test circuit of a satellite solar cell array according to claim 4, characterized in that: the sampling resistance R1 selected by the current acquisition circuit is 2mΩ～10mΩ, and the resistance R2 and R3 resistance selections selected by the voltage acquisition circuit should be The maximum voltage obtained by dividing the voltage across R3 does not exceed 5V, and the resistor R4 of the load regulation circuit is selected from 0.5Ω to 2Ω. 7. The on-orbit test circuit of a satellite solar cell array according to claim 4, characterized in that: the capacitors C1 and C2 of the load regulation circuit are both selected to be 470 μF. 8. The on-orbit test circuit of a satellite solar cell array according to claim 1 or 4, characterized in that: the second solar cell array consists of multiple solar cells connected in series to form a string of solar cells, and the first solar cell array consists of multiple Strings of solar cells are connected in parallel, and each string of solar cells is composed of multiple solar cells in series; the total number of solar cells in the second solar cell array is the same as the number of solar cells in a string of the first solar cell array; the first solar cell array and the second solar cell array The solar cells selected by the second solar cell array are exactly the same, so that the output voltages of the first solar cell array and the second solar cell array are consistent, meeting the requirement of directly supplying power to the primary power bus.