CN107919667B

CN107919667B - Power controller PCU two-domain low-ripple control method

Info

Publication number: CN107919667B
Application number: CN201710961689.8A
Authority: CN
Inventors: 张博温; 刘青; 朱洪雨; 张艺
Original assignee: Shenzhen Aerospace New Power Technology Ltd; Shenzhen Academy of Aerospace Technology
Current assignee: Shenzhen Aerospace New Power Technology Ltd; Shenzhen Academy of Aerospace Technology
Priority date: 2017-10-16
Filing date: 2017-10-16
Publication date: 2021-04-06
Anticipated expiration: 2037-10-16
Also published as: CN107919667A

Abstract

The invention provides a power supply controller PCU two-domain low ripple control method, which is realized in a SUN domain, wherein a BCR module is charged according to a set current; in the BDR domain, the S3R module is in the full power supply state when the MEA value is setV _{MEA_th_L}AndV _{MEA_th}during the process, the BCR module and the BDR module work simultaneously, the BCR module slowly changes according to the MEA value to realize the slow regulation of the battery charging current from a set value to a non-set value, the BDR module quickly tracks the change of the MEA value, and the bus voltage is stabilized in the process of the slow regulation of the BCR; when the MEA value is less thanV _{MEA_th_L}When this happens, the BCR will not work. According to the invention, through a reasonable control strategy, two-domain control of the power supply controller is realized, and in the bus current load shedding process, under the condition that the BCR module and the BDR module are mutually matched, a loop can realize the requirement of stabilizing the bus voltage.

Description

Power controller PCU two-domain low-ripple control method

Technical Field

The invention belongs to the technical field of power supply controllers, and particularly relates to a two-domain low-ripple control strategy of a power supply controller.

Background

The power controller PCU of the fully regulated bus plays a significant role in the satellite power supply and distribution system, which keeps the bus voltage constant at a certain nominal value whether the satellite is in the illuminated or shadowed area. Namely, the unified management of the power subsystem is realized by the unified MEA bus error amplification signal. When the output power of the solar cell array cannot meet the load requirement, the bus voltage is regulated by a discharge regulator BDR to provide power for an output bus; when the output power of the solar battery array is larger than the load requirement but cannot meet the requirement of the preset battery pack charging current, the bus voltage is regulated by a charging regulator BCR: when the output power of the solar cell array is greater than the load and charging current requirements, the bus voltage is regulated by shunt regulator S3R. The BDR, the BCR and the S3R are dispatched by the MEA, and the aim of stabilizing the bus voltage is fulfilled through three-domain control. However, the three-domain control strategy is complex.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a power supply controller PCU two-domain low-ripple control method, which realizes the two-domain control of the power supply controller through a reasonable design control strategy, and a loop can realize the requirement of stabilizing bus voltage under the mutual cooperation of a BCR module and a BDR module in the bus current load shedding process.

The invention is realized by the following technical scheme:

a Power Controller (PCU) two-domain low-ripple control method comprises the following steps: MEA Module output V_MEASignals are transmitted to the SUN module and the BDR module; the V is_MEAInputting the signal into SUN module to obtain current value I_{bus_SUN}(ii) a The V is_MEAThe signal passes through an LC delay unit to obtain V_{MEA_delay}Signal, said V_{MEA_delay}Signal and preset V_{MEA_th}The value is input to a first arithmetic unit which obtains I according to formula (I)_{bat_BCR}The value of the one or more of,

wherein eta is_BCRIs BCR module efficiency, V_{MEA_th_L}Is the threshold for BCR from active to inactive, I_{bat_BCR_max}Is the maximum charging current of the BCR module; and will I_{bat_BCR}The value is provided to a BCR module, and the BCR module outputs a current value I_{bus_BCR}(ii) a The V is_MEAThe signal is input to a second arithmetic unit which obtains I according to the formula-_{bat_BDR}The value of the one or more of,

wherein eta is_BDRIs BDR Module efficiency, I_{bat_BDR_max}Is the maximum discharge current of the BDR module; and will I_{bat_BDR}The value is provided to a BDR module, and a current value I is output by the BDR module_{bus_BDR}(ii) a Then the solar bus current I_{bus_SUN}Bus current I provided by BCR module_{bus_BCR}Bus current I provided by BDR module_{bus_BDR}Calculating to obtain the bus voltage V_BUS(ii) a Final bus voltage V_BUSAnd a reference voltage V_{bus_ref}As input to the MEA module, closed loop control is implemented.

Further, the control method is realized in the SUN domain, and the BCR module is charged according to the set current; in the BDR domain, the S3R module is in the full power supply state when the MEA value is at the set V_{MEA_th_L}And V_{MEA_th}During the process, the BCR module and the BDR module work simultaneously, the BCR module slowly changes according to the MEA value to realize the slow regulation of the battery charging current from a set value to a non-set value, the BDR module quickly tracks the change of the MEA value, and the bus voltage is stabilized in the process of the slow regulation of the BCR; when the MEA value is less than V_{MEA_th_L}When this happens, the BCR will not work.

Further, the first arithmetic unit also comprises a bus voltage overvoltage protection and battery current overcharge protection subunit.

Further, the first operation unit is implemented by a digital circuit or an analog circuit, and if digital control is adopted, an ADC module is added.

Further, the first operation unit further comprises a constant current charging module, and the constant current charging module outputs a voltage and a set voltage V according to the BCR module_{BAT_max}And realizing constant-current charging control.

Drawings

FIG. 1 is a schematic diagram of MEA domain partitioning;

FIG. 2 is a block diagram of a control strategy of the present invention;

FIG. 3 is a schematic diagram of a time domain simulation model;

FIG. 4 is a waveform diagram of bus voltage and MEA value at 5A for the bus current output by BCR + BDR;

FIG. 5 is a waveform diagram of bus voltage and MEA value at 1A for the bus current output by BCR + BDR;

FIG. 6(a) is a current waveform diagram of bus, BCR, BDR modules when the bus current is stepped from 1A to 5A;

FIG. 6(b) is a waveform of line voltage and MEA voltage when the bus current is stepped from 1A to 5A;

FIG. 7(a) is a waveform diagram of bus, BCR, BDR module current waveforms when the bus current is switched from 5A to 1A;

FIG. 7(b) is a waveform diagram of line voltage and MEA value when the bus current is switched from 5A to 1A;

fig. 7(c) is a waveform diagram of VMEA and VMEA _ delay signals when the bus current is switched from 5A to 1A.

Detailed Description

The invention is further described with reference to the following description and embodiments in conjunction with the accompanying drawings.

The PCU overall control is divided into two regions, i.e., the SUN region and the BDR region, according to the outer ring MEA value, as shown in fig. 1. In the SUN domain, the S3R module is in a shunt regulation state, and the BCR module sets the current I_{BAT_ref_set}Charging; in the BDR domain, the S3R module is in the full power supply state when the MEA value is at the set V_{MEA_th_L}And V_{MEA_th}During the process, the BCR module and the BDR module work simultaneously, the BCR module slowly changes according to the MEA value to realize the slow regulation of the battery charging current from a set value (non-automatic) to a non-set value (automatic), the BDR module quickly tracks the change of the MEA value, and the bus voltage is stabilized in the process of the slow regulation of the BCR; when the MEA value is less than V_{MEA_th_L}When this happens, the BCR will not work.

A specific control strategy block diagram is shown in fig. 2, and in addition to the implementation of the control strategy described above, bus voltage overvoltage protection and battery current overcharge protection are also implemented. The block diagram also shows the control relationship (design values, as shown in formulas (i) and (ii)) between the BCR module and the BDR module controlled by the MEA. The control strategy in the dashed line block diagram can be realized by a digital circuit or an analog circuit, and if digital control is adopted, an ADC module is required to be added.

Specifically, the MEA module output V_MEASignal to SUN module, BDR module, the V_MEAThe signal is input to a second arithmetic unit which obtains I according to the formula-_{bat_BDR}A value of and_{bat_BDR}the value is provided to a BDR module, and a current value I is output by the BDR module_{bus_BDR}(ii) a The V is_MEAInputting the signal into SUN module to obtain current value I_{bus_SUN}(ii) a The V is_MEAThe signal passes through an LC delay unit to obtain V_{MEA_delay}Signal, said V_{MEA_delay}Signal and preset V_{MEA_th}The value is input to a first arithmetic unit which obtains I according to formula (I)_{bat_BCR}A value of and_{bat_BCR}the value is provided to a BCR module, and the BCR module outputs a current value I_{bus_BCR}(ii) a Then the solar bus current I_{bus_SUN}Bus current I provided by BCR module_{bus_BCR}Bus current I provided by BDR module_{bus_BDR}Calculating to obtain the bus voltage V_BUS(ii) a Final bus voltage V_BUSAnd a reference voltage V_{bus_ref}As input to the MEA module, closed loop control is implemented.

A matlab simulation model is built according to the control strategy of fig. 2, and as shown in fig. 3, a battery voltage V is set_BATAt 65V, the BCR module efficiency equals the BDR module efficiency equals 96%. The LC delay module is implemented by an R C circuit, and when a step signal is input when t is 0s, the time domain characteristics include: when t is 50us (20kHz), the output reaches 80% of the input.

Bus voltage stabilization can be realized by adjusting bus current to see different MEA values. Fig. 4 and 5 show bus voltage waveforms of bus currents output by BCR + BDR at 5A and 1A, respectively, and MEA values are 6.2V and 6.8V, respectively, that is, in a range of VMEA from 6V to 8V, the control strategy of the present invention is consistent with the expected variation trend.

Fig. 6(a) and 6(b) show the critical point current and voltage waveforms when the bus current is stepped from 1A to 5A, wherein the bus, BCR and BDR module current waveforms are shown in fig. 6(a), and the bus voltage and MEA value waveforms are shown in fig. 6 (b). Fig. 7(a) to 7(c) show the key point current and voltage waveforms when the bus current is switched from 5A to 1A. It can be seen that in the process of bus current change, the loop can meet the requirement of stabilizing bus voltage under the mutual cooperation of the BCR module and the BDR module.

The foregoing is a more detailed description of the invention in connection with specific preferred embodiments and it is not intended that the invention be limited to these specific details. For those skilled in the art to which the invention pertains, several simple deductions or substitutions can be made without departing from the spirit of the invention, and all shall be considered as belonging to the protection scope of the invention.

Claims

1. A PCU two-domain low ripple control method, characterized in that the control method comprises: MEA Module output V_MEASignals are transmitted to the SUN module and the BDR module; the V is_MEAInputting the signal into SUN module to obtain current value I_{bus_SUN}(ii) a The V is_MEAThe signal passes through an LC delay unit to obtain V_{MEA_delay}Signal, said V_{MEA_delay}Signal and preset V_{MEA_th}The value is input to a first arithmetic unit which obtains I according to formula (I)_{bat_BCR}The value of the one or more of,

wherein eta is_BCRIs the BCR module efficiency; and will I_{bat_BCR}The value is provided to a BCR module, and the BCR module outputs a current value I_{bus_BCR}(ii) a The V is_MEAThe signal is input to a second arithmetic unit which obtains I according to the formula-_{bat_BDR}The value of the one or more of,

wherein eta is_BDRIs BDR Module efficiency, I_{bat_BDR_max}Is the maximum discharge current of the BDR module; and will I_{bat_BDR}The value is provided to a BDR module, and a current value I is output by the BDR module_{bus_BDR}(ii) a Then the solar bus current I_{bus_SUN}Bus current I provided by BCR module_{bus_BCR}Bus current I provided by BDR module_{bus_BDR}Calculating to obtain the bus voltage V_BUS(ii) a Final bus voltage V_BUSAnd a reference voltage V_{bus_ref}As input of the MEA module, closed-loop control is realized;

the control method is realized in the SUN domain, and the BCR module is charged according to the set current; in BDR domain, the S3R module is in full power supply state when V_MEASignal at set V_{MEA_th_L}And V_{MEA_th}In between, the BCR module and the BDR module work simultaneously, and the BCR module works according to V_MEAThe signal changes slowly to realize the slow regulation of the charging current of the battery from a set value to an unset value, and the BDR module tracks V quickly_MEAThe signal changes, and the bus voltage is stabilized in the process of slowly adjusting the BCR; when V is_MEASignal less than V_{MEA_th_L}When this happens, the BCR will not work.

2. The method of claim 1, wherein: the first arithmetic unit also comprises a bus voltage overvoltage protection and battery current overcharge protection subunit.

3. The method of claim 1, wherein: the first operation unit is realized by a digital circuit or an analog circuit, and if digital control is adopted, an ADC module is required to be added.

4. The method of claim 1, wherein: the first operation unit further comprises a constant current charging module, and the constant current charging module outputs a voltage and a set voltage V according to the BCR module_{BAT_max}And realizing constant-current charging control.