阅读说明：本技术 一种空间用激光载荷配电器限流控制电路 (Laser load distributor current-limiting control circuit for space ) 是由 李小春 吕锋 徐刚 程新 薛鸿翔 李进 李后春 于 2019-07-26 设计创作，主要内容包括：本发明公开了一种空间用激光载荷配电器限流控制电路,包括：电流环PI、基极电阻、保护电阻、三极管、集电极电阻、软启动电容和PWM控制芯片；电流环PI的输出端通过基极电阻与接三极管的基极连接；集电极电阻的一端接三极管的集电极,另一端接PWM控制芯片的软启动脚；三极管的发射极接地；保护电阻并联接入三极管的基极和发射极；软启动电容一端接PWM控制芯片的软启动脚,另一端接地；在限流控制阶段,PWM控制芯片处于全占空比输出状态,三极管处于深度饱和状态,通过控制三极管的开通时间来控制PWM控制芯片软启动脚的电压,进而控制PWM控制芯片的最大输出占空比,以实现限流输出。本发明实现了对卫星激光载荷配电器的限流控制。(the invention discloses a current-limiting control circuit of a laser load distributor for space, which comprises: the circuit comprises a current loop PI, a base resistor, a protective resistor, a triode, a collector resistor, a soft start capacitor and a PWM control chip; the output end of the current loop PI is connected with the base electrode of the triode through the base electrode resistor; one end of the collector resistor is connected with the collector of the triode, and the other end of the collector resistor is connected with the soft start pin of the PWM control chip; the emitter of the triode is grounded; the protective resistor is connected in parallel with the base electrode and the emitting electrode of the triode; one end of the soft start capacitor is connected with a soft start pin of the PWM control chip, and the other end of the soft start capacitor is grounded; in the current-limiting control stage, the PWM control chip is in a full-duty-ratio output state, the triode is in a deep saturation state, the voltage of a soft start pin of the PWM control chip is controlled by controlling the on-time of the triode, and then the maximum output duty ratio of the PWM control chip is controlled, so that current-limiting output is realized. The invention realizes the current-limiting control of the satellite laser load distributor.)

1. A laser load distributor current limiting control circuit for a space, comprising: the circuit comprises a current loop PI, a base resistor R85, a protective resistor R88, a triode V5, a collector resistor R81, a soft start capacitor C39 and a PWM control chip;

the output end of the current loop PI is connected with a base electrode a connected with a triode V5 through a base electrode resistor R85 so as to control the on and off of the triode;

One end of the collector resistor R81 is connected with the collector c of the triode V5, and the other end is connected with the SOFT start pin SOFT of the PWM control chip;

The emitter b of the triode V5 is grounded;

the protective resistor R88 is connected in parallel to the triode V5, so that the reliability of the triode V5 is improved; one end of the protective resistor R88 is connected with the base electrode a of the triode V5, and the other end is connected with the emitter electrode b of the triode V5;

one end of the SOFT start capacitor C39 is connected with a SOFT start pin SOFT of the PWM control chip, and the other end is grounded;

in the current-limiting control stage, the PWM control chip is in a full-duty-ratio output state, the triode V5 is in a deep saturation state, the voltage of a SOFT start pin SOFT of the PWM control chip is controlled by controlling the on-time of the triode V5, and then the maximum output duty ratio of the PWM control chip is controlled, so that current-limiting output is realized.

2. The space laser load distributor current-limiting control circuit according to claim 1, wherein the current loop PI comprises: the current limiting resistor R83, the current limiting resistor R87, the operational amplifier N2, the proportional resistor R20, the integrating capacitor C8, the compensating capacitor C9, the power supply current limiting resistor R82 and the power supply voltage stabilizing capacitor C44;

The current limiting resistor R83 and the current limiting resistor R87 are respectively connected with the inverting input end d and the non-inverting input end e of the operational amplifier N2 so as to limit the current of the input current limiting reference and current sampling;

the proportional resistor R20 is connected in series with the integrating capacitor C8, and the proportional resistor R20 and the integrating capacitor C8 which are connected in series are connected in parallel to the inverting input end d and the error output end h of the operational amplifier N2;

The compensation capacitor C9 is connected in parallel to the inverting input end d and the error output end h of the operational amplifier N2;

the power supply current limiting resistor R82 is connected to the power supply positive terminal g of the operational amplifier N2 and is used for power supply current limiting of the operational amplifier N2;

the power supply voltage stabilizing capacitor C44 is connected to the power supply positive terminal g of the operational amplifier N2 and is used for power supply voltage stabilization of the operational amplifier N2;

the power supply negative terminal f of the operational amplifier N2 is grounded.

3. The laser load distributor current-limiting control circuit for a space of claim 1, further comprising: a voltage loop PI; the output end of the voltage ring PI is connected with the positive input end IN + of the PWM control chip, and the two input ends of the voltage ring PI are respectively connected with voltage reference and voltage sampling.

4. The space laser load distributor current-limiting control circuit according to claim 1, wherein the inverting input terminal IN-of the PWM control chip is shorted to the error output terminal E/a out.

5. The current-limiting control circuit of the space laser load distributor according to claim 1, wherein the PWM control chip is a PWM control chip with a SOFT start function, and a 9uA constant current source is arranged inside the PWM control chip, and is used for charging a SOFT start pin SOFT when the circuit is powered on.

6. The space laser load distributor current-limiting control circuit according to claim 1, wherein two input terminals of the current loop PI are respectively connected to a current-limiting reference and a current sample.

7. The space laser load distributor current limit control circuit of claim 1,

the soft start capacitor C39 adopts a microfarad capacitor;

the base resistor R85 and the collector resistor R81 both adopt kiloohm resistors;

The protection resistor R88 is a hundred kiloohm resistor.

8. the space laser load distributor current-limiting control circuit according to claim 1, wherein the PWM control chip is a main control chip of the switching power supply circuit, and a voltage Vsoft on a SOFT start pin SOFT of the PWM control chip is proportional to a maximum output duty ratio P of the PWM control chip; wherein the lower the voltage Vsoft, the smaller the maximum output duty cycle P; the higher the voltage Vsoft, the larger the maximum output duty cycle P.

Technical Field

The invention belongs to the technical field of space power supplies, and particularly relates to a current-limiting control circuit of a laser load distributor for a space.

Background

The satellite laser load is a novel satellite load, a large capacitor is arranged in a load power amplifier driver, the laser load needs to release a large amount of energy in a short time, and the laser load can cause large voltage fluctuation to a power supply for power distribution, so that the laser load cannot be directly hung on a platform bus. Novel satellite laser load distributor produced by the method has the functions of: 1. converting the 42V bus of the platform to provide proper bus voltage for the laser load; 2. in order not to cause too much current fluctuation to the platform bus, the power distributor needs the capability of current-limited output, i.e., the capability of current-limited charging of the load's large capacitance.

Currently, the satellite power supply system uses two power topology control methods, i.e., S4R and S3R. The current-limiting charging control principles and their advantages and disadvantages of the two control modes are described below.

When the S4R control technique is applied, the solar array is directly connected to the battery port. Assume a satellite power system with 12 solar arrays, each with an output capacity of 5A. At present, the storage battery pack needs to be charged in a current-limiting mode of 24A, so that 4 solar arrays are in a full-charging state, 7 solar arrays are in a full-off state, and 1 solar array is in a modulation state. By controlling the frequency or duty ratio of the solar array in the modulation state, the effective value of the charging current can be stabilized at 24A, and the ripple of the charging current is the output capacity of one solar array (5A in this example). The current-limiting charging control method is simple, easy to implement and high in charging efficiency, but the charging current ripple is large. The satellite laser load distributor belongs to a secondary power supply, and a constant current source cannot be introduced into a laser load power amplifier driver, so that the technology cannot be applied to the laser load distributor.

When the S3R control technology is applied, the solar array is firstly converted into a stable platform bus through the shunt circuit, and the storage battery pack is hung on the platform bus. The power supply controller carries out current-limiting or voltage-limiting charging on the storage battery through a charging control circuit (BCR). The PI output of the voltage loop and the current-limiting reference are connected in parallel through two diodes to be used as the input of a current loop, and the PI output of the current loop is converted into corresponding PWM waves after UC 1825. When the current limit point is active, the voltage loop is completely inactive. The control mode of the current-limiting charging is simple and is mostly used for average current control, but the charging current ripple is larger, and the diode conduction voltage drop is influenced by high and low temperatures to greatly influence the current-limiting point.

Disclosure of Invention

the technical problem of the invention is solved: the current-limiting control circuit overcomes the defects of the prior art, and provides the current-limiting control circuit of the laser load distributor for the space so as to realize the current-limiting control of the satellite laser load distributor.

in order to solve the technical problem, the invention discloses a current-limiting control circuit of a laser load distributor for a space, which comprises: the circuit comprises a current loop PI, a base resistor R85, a protective resistor R88, a triode V5, a collector resistor R81, a soft start capacitor C39 and a PWM control chip;

the output end of the current loop PI is connected with a base electrode a connected with a triode V5 through a base electrode resistor R85 so as to control the on and off of the triode;

one end of the collector resistor R81 is connected with the collector c of the triode V5, and the other end is connected with the SOFT start pin SOFT of the PWM control chip;

The emitter b of the triode V5 is grounded;

the protective resistor R88 is connected in parallel to the triode V5, so that the reliability of the triode V5 is improved; one end of the protective resistor R88 is connected with the base electrode a of the triode V5, and the other end is connected with the emitter electrode b of the triode V5;

One end of the SOFT start capacitor C39 is connected with a SOFT start pin SOFT of the PWM control chip, and the other end is grounded;

in the current-limiting control stage, the PWM control chip is in a full-duty-ratio output state, the triode V5 is in a deep saturation state, the voltage of a SOFT start pin SOFT of the PWM control chip is controlled by controlling the on-time of the triode V5, and then the maximum output duty ratio of the PWM control chip is controlled, so that current-limiting output is realized.

In the above-mentioned laser load distributor current-limiting control circuit for space, current loop PI includes: the current limiting resistor R83, the current limiting resistor R87, the operational amplifier N2, the proportional resistor R20, the integrating capacitor C8, the compensating capacitor C9, the power supply current limiting resistor R82 and the power supply voltage stabilizing capacitor C44;

the current limiting resistor R83 and the current limiting resistor R87 are respectively connected with the inverting input end d and the non-inverting input end e of the operational amplifier N2 so as to limit the current of the input current limiting reference and current sampling;

The proportional resistor R20 is connected in series with the integrating capacitor C8, and the proportional resistor R20 and the integrating capacitor C8 which are connected in series are connected in parallel to the inverting input end d and the error output end h of the operational amplifier N2;

the compensation capacitor C9 is connected in parallel to the inverting input end d and the error output end h of the operational amplifier N2;

the power supply current limiting resistor R82 is connected to the power supply positive terminal g of the operational amplifier N2 and is used for power supply current limiting of the operational amplifier N2;

the power supply voltage stabilizing capacitor C44 is connected to the power supply positive terminal g of the operational amplifier N2 and is used for power supply voltage stabilization of the operational amplifier N2;

The power supply negative terminal f of the operational amplifier N2 is grounded.

in the above-mentioned laser load distributor current limiting control circuit for space, further include: a voltage loop PI; the output end of the voltage ring PI is connected with the positive input end IN + of the PWM control chip, and the two input ends of the voltage ring PI are respectively connected with voltage reference and voltage sampling.

IN the current-limiting control circuit of the space laser load distributor, the inverting input end IN-of the PWM control chip is IN short circuit with the error output end E/A out.

In the current-limiting control circuit of the space laser load distributor, the PWM control chip is a PWM control chip with a SOFT start function, and a 9uA constant current source is arranged in the PWM control chip and used for charging a SOFT start pin SOFT when the circuit is electrified.

In the current-limiting control circuit of the space laser load distributor, two input ends of a current loop PI are respectively connected with a current-limiting reference and a current sample.

in the above space-use laser load distributor current limit control circuit,

The soft start capacitor C39 adopts a microfarad capacitor;

the base resistor R85 and the collector resistor R81 both adopt kiloohm resistors;

The protection resistor R88 is a hundred kiloohm resistor.

In the current-limiting control circuit of the space laser load distributor, a PWM control chip is a main control chip of a switching power supply circuit, and the voltage Vsoft on a SOFT start pin SOFT of the PWM control chip is in direct proportion to the maximum output duty ratio P of the PWM control chip; wherein the lower the voltage Vsoft, the smaller the maximum output duty cycle P; the higher the voltage Vsoft, the larger the maximum output duty cycle P.

The invention has the following advantages:

the invention discloses a current-limiting control circuit of a laser load distributor for a space, which is firstly used in the field of space power supplies. On one hand, the current limiting control function of the circuit is realized by controlling the voltage of a soft start pin, the current limiting value is slightly influenced by the temperature in a space environment, and the current limiting control precision is high; on the other hand, since the currents for charging and discharging the soft-start capacitor C39 are both small, the current ripple is small during current modulation. The invention realizes the current-limiting control of the satellite laser load distributor, and the circuit has the advantages of excellent performance, high reliability and the like.

drawings

Fig. 1 is a schematic block diagram of power supply and distribution of a satellite laser load distributor according to an embodiment of the present invention;

fig. 2 is a schematic circuit diagram of a current limiting control circuit of a space laser load distributor according to an embodiment of the present invention;

Fig. 3 is a schematic circuit diagram of a current limiting control circuit of a space laser load distributor according to another embodiment of the present invention;

FIG. 4 is a diagram illustrating the results of a Saber simulation in an embodiment of the present invention;

Fig. 5 is a schematic diagram of a measured waveform of a bus bar output current and a bus bar voltage of a laser load distributor according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in fig. 1, an output bus of the laser load distributor is connected with a large capacitor C2 (with a capacitance value of 10mF level) in the load power amplifier driver, the load power amplifier driver discharges the capacitor C2 instantly at a frequency of 20HZ, the discharging time is about 0.3 ms-0.5 ms, the discharging current is about 180A, and the discharging releases a part of energy of the capacitor C2 and pulls down the bus voltage of the distributor. In order to avoid causing too large current fluctuation to the 42V bus of the whole star, the laser load distributor needs to supplement power to a large capacitor C2 inside the load power amplifier driver in a current-limiting charging mode in the rest time, and stabilize the bus output of the distributor at 100V so as to periodically obtain power under the load power amplifier driver.

as shown in fig. 2 to 3, in an embodiment of the present invention, a current limiting control circuit for a space laser load distributor is disclosed, which may specifically include: the circuit comprises a current loop PI, a base resistor R85, a protective resistor R88, a triode V5, a collector resistor R81, a soft start capacitor C39 and a PWM control chip. The output end of the current loop PI is connected with the base a connected with the triode V5 through a resistor base R85 so as to control the on and off of the triode V5; one end of the collector resistor R81 is connected with the collector c of the triode V5, and the other end is connected with the SOFT start pin SOFT of the PWM control chip; the emitter b of the triode V5 is grounded; the protective resistor R88 is connected in parallel to the triode V5, so that the reliability of the triode V5 is improved; one end of the protective resistor R88 is connected with the base electrode a of the triode V5, and the other end is connected with the emitter electrode b of the triode V5; one end of the SOFT start capacitor C39 is connected with a SOFT start pin SOFT of the PWM control chip, and the other end is grounded. In the current-limiting control stage, the PWM control chip is in a full-duty-ratio output state, the triode V5 is in a deep saturation state, the voltage of a SOFT start pin SOFT of the PWM control chip is controlled by controlling the on-time of the triode V5, and then the maximum output duty ratio of the PWM control chip is controlled, so that current-limiting output is realized.

Preferably, as shown in fig. 3, the PWM control chip may specifically be a PWM control chip with a soft start function, and may be used as a main control chip of the switching power supply circuit, and mainly includes: the device comprises an internal 9uA constant current source, a positive phase input end IN +, a negative phase input end IN-, an error output end E/A out and a SOFT start pin SOFT.

And the inverting input end IN-of the PWM control chip is IN short circuit with the error output end E/A out.

the 9uA constant current source can be used for charging the SOFT start pin SOFT when the circuit is powered on.

the voltage Vsoft on the SOFT start pin SOFT of the PWM control chip is in direct proportion to the maximum output duty ratio P of the PWM control chip; wherein the lower the voltage Vsoft, the smaller the maximum output duty cycle P; the higher the voltage Vsoft, the larger the maximum output duty cycle P.

In a preferred embodiment of the present invention, as shown in fig. 3, the current loop PI specifically includes: the current limiting circuit comprises a current limiting resistor R83, a current limiting resistor R87, an operational amplifier N2, a proportional resistor R20, an integrating capacitor C8, a compensation capacitor C9, a power supply current limiting resistor R82 and a power supply voltage stabilizing capacitor C44. The current limiting resistor R83 and the current limiting resistor R87 are respectively connected with the inverting input end d and the non-inverting input end e of the operational amplifier N2 so as to limit the current of the input current limiting reference and current sampling; the proportional resistor R20 is connected in series with the integrating capacitor C8, and the proportional resistor R20 and the integrating capacitor C8 which are connected in series are connected in parallel to the inverting input end d and the error output end h of the operational amplifier N2; the compensation capacitor C9 is connected in parallel to the inverting input end d and the error output end h of the operational amplifier N2; the power supply current limiting resistor R82 is connected to the power supply positive terminal g of the operational amplifier N2 and is used for power supply current limiting of the operational amplifier N2; the power supply voltage stabilizing capacitor C44 is connected to the power supply positive terminal g of the operational amplifier N2 and is used for power supply voltage stabilization of the operational amplifier N2; the power supply negative terminal f of the operational amplifier N2 is grounded.

In a preferred embodiment of the present invention, the space laser load distributor current limiting control circuit may further include: and a voltage loop PI. As shown IN fig. 3, the output end of the voltage loop PI is connected to the positive input end IN + of the PWM control chip, and two input ends of the voltage loop PI are respectively connected to the voltage reference and the voltage sampling.

In a preferred embodiment of the present invention, two input terminals of the current loop PI are respectively connected to the current-limiting reference and the current sample.

in a preferred embodiment of the present invention, the soft start capacitor C39 is a microfarad capacitor; the base resistor R85 and the collector resistor R81 both adopt kiloohm resistors; the protection resistor R88 is a hundred kiloohm resistor.

For ease of understanding, the operation of the space laser load distributor current limit control circuit will be briefly described below.

A. the maximum collector current of the transistor V5 is milliampere, and taking the amplification factor of the transistor V5 equal to 75 times as an example, the current loop PI output can easily cause the transistor V5 to work in a deep saturation region. The soft-start pin voltage Vsoft can then be controlled by controlling the on-time of transistor V5 rather than the base current of the triode. Wherein, the triode V5 is turned on, and Vsoft is decreased; when the transistor V5 is turned off, Vsoft will increase slowly over time due to the presence of the 9uA constant current source inside the PWM control chip. It can be seen that the decrease and increase of Vsoft can be achieved by controlling the on and off of the triode V5.

B. when the voltage loop PI output is relatively large, on one hand, the PWM duty ratio output by the PWM control chip is its maximum output duty ratio, which is determined by the soft start pin voltage Vsoft, that is: when the voltage loop PI enables the PWM control chip to output the full duty ratio, the lower the Vsoft → the smaller the maximum output duty ratio is, and on the contrary, the higher the Vsoft → the larger the maximum output duty ratio is; on the other hand, when the PWM control chip outputs at the full duty ratio, the bus current of the distributor and the maximum output duty ratio have a certain proportional relation. That is, the lower the Vsoft, the lower the bus current that the distributor can output when the PWM control chip is outputting at full duty.

It needs to be known that, after the load power amplifier driver gets electricity from its inside large capacitance, the bus voltage of laser load distributor can be pulled down, and voltage ring PI can make the full duty cycle output of PWM control chip this moment, and bus current can increase rapidly. If the sampling current is larger than the current-limiting reference, the current loop PI controls the transistor V5 to drain the voltage of Vsoft, so that the voltage of Vsoft is reduced → the maximum duty ratio that the PWM control chip can output is reduced → the bus current is reduced → the sampling current is reduced. When the sampling current is smaller than the current-limiting reference, the current loop PI controls the transistor V5 to be turned off, and the 9uA constant current source in the PWM control chip charges the soft-start capacitor C39 → Vsoft increases → bus current increases → sampling current increases → … (enters the modulation process). The modulation process may end after the distributor bus voltage reaches the voltage reference. Finally, the laser load distributor can limit the current output at a current limit value without causing too large current fluctuation to the satellite platform bus. On one hand, since the currents for charging and discharging the soft start capacitor C39 are both relatively small, the current ripple is not too large during current modulation; on the other hand, the current limiting control function is realized by controlling the voltage of the soft start capacitor, so that the current limiting value is not greatly influenced by the temperature. The current-limiting control scheme of the space laser load distributor disclosed by the embodiment of the invention has excellent performances through Saber circuit simulation and actual circuit test, and the circuits can be subjected to current-limiting output according to a current-limiting value.

Based on the above embodiments, the following description will take UC1825 as an example of the PWM control chip, and the examples are combined.

The positive phase input end IN + of the UC1825 is connected with the output of the voltage loop PI controller, and the negative phase input end IN-is IN short circuit with the error output end E/A out. SOFT start pin SOFT of UC1825 is grounded to SOFT start capacitor C39(3 uF-5 uF), and then to collector of triode V5 through collector resistor R81 (kiloohm level).

the UC1825 has a 9uA constant current source inside, and charges its SOFT start pin SOFT when the circuit is powered on. The UC1825 may output a maximum output duty cycle that gradually increases as the soft-start pin voltage Vsoft increases. Generally, Vsoft is about 5V at maximum, and the maximum output duty ratio that UC1825 can output is maximum.

The current loop PI input is current-limiting reference and current sampling, and the current loop PI output is connected with the base of a triode V5 through a base resistor R85 (kiloohm level). The protective resistor R88 (hundred kiloohm level) is used for protecting the triode V5. The current limiting resistor R83 and the current limiting resistor R87 are used for input current limiting, and form a current loop PI controller together with the proportional resistor R20, the integrating capacitor C8 and the compensating capacitor C9. The power supply current limiting resistor R82 is used for power supply current limiting of the operational amplifier N2, and the power supply voltage stabilizing capacitor C44 is used for power supply voltage stabilizing of the operational amplifier N2.

After the bus of the power distributor is established, when the load power amplifier driver takes power from the capacitor C2, the bus of the laser load power distributor is pulled low, so that the voltage ring PI operation amplifier positive voltage > operation amplifier negative voltage → the error is subjected to proportional integration, and then the voltage ring PI maximum output → UC1825 output PWM duty ratio is increased (the maximum output duty ratio is reached) → bus current is increased. Before the bus current does not reach the current limiting point, that is, before the current sample is smaller than the current limiting reference voltage, the output of the current loop PI operational amplifier N2 is 0, the triode V5 does not act, and the soft start pin voltage Vsoft of the UC1825 is about 5V. When the current sampling reaches the current-limiting reference, the operational amplifier N2 outputs a high level → the driving transistor V5 is turned on → the bleeder soft start capacitor C39 voltage → Vsoft is reduced → UC1825 is reduced in the maximum output duty ratio → the bus current is reduced. When the bus current is reduced to the current limiting point and is smaller than the current limiting point, the output of the operational amplifier N2 is 0 → the triode V5 is turned off → the 9uA current limiting source in the UC1825 charges C39 → Vsoft is increased slowly → the bus current is increased. And then, the current limiting circuit enters the repeated process, and the output current of the bus is modulated at a current limiting point, so that the purpose of current limiting output of the laser load distributor is achieved.

Note that transistor V5 should be in deep saturation (which can be achieved by adjusting the magnitude of collector resistance R81) while the soft-start capacitor C39 is drained, and the current loop PI controls Vsoft by controlling the on-time of transistor V5. The purpose of this is: 1. the heating of the triode V5 is minimized, and the circuit loss is minimized; 2. the small current facilitates Vsoft control of the soft start capacitor C39 voltage.

In the case of UC1825 full duty cycle output (before the bus voltage reaches the voltage control point), the soft start voltage Vsoft has a certain proportional relationship with the bus current I as shown in equation (1):

M + Vsoft + n, formula (1)

The operational amplifier N2 is used as an error amplifier of a current loop PI, and is aimed at controlling a current sample (k × I) to be limited in a current-limiting reference V, so as to obtain a formula (2):

k (m Vsoft + n) ═ V current limit · equation (2)

It can be seen that the control method for achieving current limiting by controlling the soft start pin voltage Vsoft is linear control.

K, m and n can be set through an actual circuit and are constant values.

On the basis of the above embodiments, the simulation result of the current limiting control circuit of the space laser load distributor according to the embodiments of the present invention is described.

As shown in fig. 4, a 1-a 4 are a laser load duty cycle, a 1-a 2 are discharge times of the triode V5 to the soft start capacitor C39, and at this time, the triode V5 is in a deep saturation state; A2-A3 are bus current limiting output time, at the moment, a voltage loop PI is fully output, Vsoft is controlled to be a constant voltage value by a current loop, the output current of the laser load distributor is controlled to be a current limiting point, the point A3 is the moment when the bus of the laser load distributor returns to 100V, and then the laser load distributor does not output current; A3-A4 are the constant voltage no current output time intervals of the laser load distributor. In fig. 4, the charging current to the back-end capacitor is also limited to the current-limiting point during the bus-bar set-up phase. It should be noted that: the time Δ t for constant current charging of the large capacitor C2 can be determined by the following equation (3):

Delta t ═ C × delta U/I limit · -formula (3)

Wherein, C is the capacitance value of the capacitor C2, DeltaU is the voltage dropped by the capacitor C2 when the load takes electricity, and I is the current magnitude of the current-limiting charging. When the system is stable, the charging time delta t is less than the working period of the laser load.

it can be seen that the current limiting control circuit for the space laser load distributor according to the embodiment of the present invention is theoretically feasible.

As shown in fig. 5, the working modes of the load power amplifier driver are as follows: 180A discharge for 0.4ms, 50ms dwell. In the figure, the oscilloscope 2 channel is the bus bar output current waveform of a distributor (laser load distributor), and the oscilloscope 1 channel is the bus bar voltage waveform. In each power taking period, 180A discharges for 0.4ms to enable the voltage of a 10mF capacitor array (load large capacitor C2) to be instantly reduced by 9.4V, after 0.4ms, a distributor charges the load large capacitor C2, the current is rapidly increased to 2.94A, and then the charging current is enabled to be constant at 2.5A due to the control of a current limiting control circuit. When the C2 voltage reaches the control voltage, the distributor stops charging.

As can be seen from the actual circuit test result in fig. 5, the current-limiting control circuit for the laser load distributor for the space not only achieves the purpose of current-limiting charging, but also has small current ripple (about 200mA), and simultaneously proves that the current-limiting control circuit for the laser load distributor for the space is effective, feasible and excellent in performance.

The current-limiting control circuit of the space laser load distributor disclosed by the embodiment of the invention is applied to a certain satellite model and belongs to the field of space power supplies for the first time. Through a series of evaluation level environmental tests such as mechanics, calorifics and the like, the current-limiting control circuit of the space laser load distributor is excellent in performance, high in current-limiting control precision, small in current-limiting ripple, feasible and high in reliability, and the current-limiting value is influenced by temperature very little.

The embodiments in the present description are all described in a progressive manner, each embodiment focuses on differences from other embodiments, and the same and similar parts among the embodiments are referred to each other.

The above description is only for the best mode of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention.

Those skilled in the art will appreciate that the invention may be practiced without these specific details.