JP2023106511A - power control system - Google Patents

Abstract

To provide a further compact and weight saving power control system of generation power of a power generation device.SOLUTION: A power control system has a power generation device, a bus device, at least a single battery system, and an integrated control device performing a control to the at least single battery system, in which the bus device and the at least single battery system are directly connected to the power generation device in parallel, each battery system includes a bidirectional power conversion device and a battery, each bidirectional power conversion device performs charging/discharging of the battery by converting output voltage of the power generation device to be outputted to the battery side and converting the output voltage of the battery to be outputted to the bus device side, the integrated control device instructs a predetermined charging/discharging control to the at least single battery system, and the at least single battery system performs the control of bus voltage of the bus device.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present invention relates to a power control system, and more particularly to a battery system including a battery, a converter, etc., and a power control system including a power generator.

Surplus power control (shunt control) has traditionally been the basis for power control of artificial satellites, and the basic configuration of power control systems for artificial satellites is generally "shunt circuit + battery charger (+battery discharger)". . In a space environment without a grid power supply, efficient supply of the power generated by the solar cells to the bus equipment is of the highest priority, and the output power of the solar cells can be supplied to the bus equipment without going through a power conversion device such as a converter. Shunt control is recognized as the most suitable power control method for spacecraft.

On the other hand, for spacecraft with limited launch capabilities, it is necessary to reduce the size and weight of the equipment. Reduction in size and weight has been promoted by applying power conversion devices (see Non-Patent Document 1 below). Also, in order to reduce the size of the shunt circuit, techniques have been devised for reducing the power generated by the solar cell when it is not needed (see Patent Documents 1 to 3 below).

JP-A-6-144399 JP-A-7-101400 JP-A-8-258800

M. Iwasa, H. Kusawake, S. Shimada, A. Ishii, Y. Kikuchi, K. Aoki, J. Shimizu and T. Ito, LIGHTWEIGHT POWER CONTROL UNITS AND POWER DISTRIBUTION CONTROL UNIT FOR SATELLITES, the journal of space technology and science, vol.28, no.1, pp.30-36, 2013.

The power required by artificial satellites is on the rise. In particular, communication and broadcasting satellites, which are representative of geostationary satellites, require large power of several tens of kW. there is However, with the conventional basic configuration of "shunt circuit + battery charger (+battery discharger)", there is a limit to reducing the size and weight. Also, it is difficult to eliminate the shunt circuit in the method of reducing the power generated by the solar cell, or even if it is possible, a device larger than the shunt circuit is required, which is not realistic.

Such a situation is the same on the ground, and in the power control system, not only when the power generator is a solar battery, but also when the power generator is a wind power generator, a fuel cell, or the like. It is the same.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a power control system for the power generated by a power generator that is further reduced in size and weight.

One aspect of the present invention includes a power generation device, bus equipment, at least one battery system, and an integrated control device that controls the at least one battery system, wherein the bus equipment and the at least one A battery system is directly connected in parallel to the power generator, each of the at least one battery system including a bidirectional power converter and a battery, each of the bidirectional power converters having an output voltage of the power generator. is converted and output to the battery side, the output voltage of the battery is converted and output to the bus device side to charge and discharge the battery, and the integrated control device controls the at least one battery system and the at least one battery system controls the bus voltage of the bus device.

The power generation device is a solar battery, the power control further includes a solar battery rotation mechanism, and the integrated control device performs charge/discharge control for the at least one battery system and rotation control for the solar battery rotation mechanism. Accordingly, it is possible to control the output power of the solar cell and control the bus voltage of the bus device.

The control of the bus voltage of the bus device may be control to keep the value of the bus voltage within a predetermined range with respect to a predetermined value.

The integrated control device may instruct a first battery system out of the at least one battery system to perform an MPPT (maximum power tracking) mode as the predetermined charge/discharge control during the sunshine mode. can.

When the voltage value of the first battery of the first battery system becomes the first voltage value, the integrated control device, as the charge/discharge control, controls the bus voltage value of the first battery system. A constant bus voltage charging mode, which is a control mode for charging the battery such that V falls within a predetermined range with respect to a predetermined value, can be instructed.

When the voltage value of the first battery of the first battery system becomes a third voltage value, the integrated control device performs the charge/discharge control for the first battery system with the constant bus voltage While instructing the charging mode, the solar cell rotating mechanism is instructed to rotate the solar cell, and the incident angle of sunlight to the solar cell is adjusted to reduce the output power of the solar cell. be able to.

When the voltage value of the first battery of the first battery system reaches the fifth voltage value, the integrated control device, as the charge/discharge control, controls the battery to a constant voltage with respect to the first battery system. A constant voltage charge mode, which is a control mode for charging, can be instructed.

In the shade mode, the integrated control device, as the charging/discharging control, controls the first battery system to discharge the battery so that the value of the bus voltage falls within a predetermined range with respect to a predetermined value. A constant bus voltage discharge mode, which is a mode, may be indicated.

The power control system may further include a reserve battery, and the reserve battery may be connected in series or parallel to the first battery.

The bidirectional power conversion device may be a bidirectional DC/DC converter.

One aspect of the present invention includes a power generation device, bus equipment, at least one battery system, and an integrated control device that controls the at least one battery system, wherein the bus equipment and the at least one A battery system is directly connected in parallel to the power generator, each of the at least one battery system including a bidirectional power converter and a battery, each of the bidirectional power converters having an output voltage of the power generator. and outputting it to the battery side, and converting the output voltage of the battery and outputting it to the bus device side to charge and discharge the battery, wherein the integrated A power control method is provided in which a control device instructs the at least one battery system to perform predetermined charge/discharge control, and the at least one battery system controls the bus voltage of the bus device.

One aspect of the present invention provides a program for causing a computer to execute the power control method.

One aspect of the present invention provides a computer-readable storage medium storing the program.

According to the present invention having the above configuration, it is possible to provide a power control system for power generated by a power generation device that supplies power to a bus device without the intervention of a power conversion device and that is further reduced in size and weight.

It is a figure showing the whole electric power control system composition concerning one embodiment of the present invention. 1 is a diagram showing an example of hardware configuration of an integrated control device 50 of a power control system according to one embodiment of the present invention; FIG. 4 is a flowchart of power control processing in a sunshine mode of the power control system according to one embodiment of the present invention;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing the overall configuration of a power control system 1 according to one embodiment of the invention. The power control system 1 includes a solar cell 10 , a solar cell rotation mechanism 11 , a first battery system 20 , a second battery system 30 , a bus device 40 and an integrated control device 50 .

The first battery system 20 , the second battery system 30 and the bus device 40 are directly connected in parallel to the solar cell 10 .

The solar cell rotation mechanism 11 can change the output power of the solar cell by rotating the solar cell 10 and changing the angle of incidence of sunlight on the solar cell 10 .

The first battery system 20 includes a first bidirectional DC/DC converter 210 and a first battery 230 as a first power conversion device. Similarly, the second battery system 30 comprises a second bidirectional DC/DC converter 310 and a second battery 330 .

The first bidirectional DC/DC converter 210 has a first control section 211 and a first storage section 213 . Similarly, the second bidirectional DC/DC converter 310 has a second control section 311 and a second storage section 313 . The first bidirectional DC/DC converter 210 and the second bidirectional DC/DC converter 310 respectively convert the output voltage of the solar cell 10 by PWM (pulse width modulation) and output it to the battery side. By converting the output voltages of the battery 230 and the second battery 330 and outputting them to the bus device side, the first battery 230 and the second battery 330 are charged and discharged. The first control unit 211 and the second control unit 311 control the PWM duty ratio of each bidirectional DC/DC converter. In each bidirectional DC/DC converter, each voltmeter and ammeter (not shown) measure the operating voltage and output current of the solar cell 10, the input side voltage value (bus voltage value) of the bidirectional DC/DC converter, and the output voltage. A side voltage value (battery voltage value), an input side current value, an output side current value, etc. are measured and input to each control section.

The integrated control device 50 monitors the state of the entire system, including the solar cell 10, the bus device 40, the bi-directional DC/DC converter of each battery system, the voltage and current of the battery, and the state of charge (SOC) of the battery. Then, based on the result of the monitoring and based on which mode is the sunshine mode or the shade mode, it is determined which control mode to instruct which bidirectional DC/DC converter, and each bidirectional DC/DC converter The determined control mode is instructed to the DC converter, and the rotation angle is instructed to the solar cell rotation mechanism 11 as necessary.
In this embodiment, there are six control modes: MPPT (maximum power tracking) mode, constant current charge mode, constant current discharge mode, constant voltage charge mode, constant bus voltage charge mode, and constant bus voltage discharge mode. The MPPT mode performs control to maximize the solar cell output. The constant current charge mode controls constant current charging of the battery. The constant current discharge mode controls constant current discharge of the battery. The constant voltage charging mode controls constant voltage charging of the battery. In the constant bus voltage charge mode, the battery is charged so that the value of the bus voltage falls within a predetermined range with respect to a predetermined value. In the constant bus voltage discharge mode, the battery is discharged so that the value of the bus voltage falls within a predetermined range with respect to a predetermined value.

Here, control of the PWM duty ratio in each bidirectional DC/DC converter is performed by the control unit of each bidirectional DC/DC converter based on the control mode signal transmitted from the integrated control device 50 .

FIG. 2 is a diagram showing an example of the hardware configuration of the integrated control device 50 of the power control system 1 according to this embodiment. The integrated control device 50 includes a CPU 50a, a RAM 50b, a ROM 50c, an external memory 50d, an input section 50e, an output section 50f, and a communication section 50g. The RAM 50b, ROM 50c, external memory 50d, input section 50e, output section 50f, and communication section 50g are connected to the CPU 50a via a system bus 50h. The hardware configuration of the control section of each bidirectional DC/DC converter is the same. Various programs stored in the ROM 50c and the external memory 50d are stored in the CPU 50a, the RAM 50b, the ROM 50c, the external memory 50d, the input section 50e, the output section 50f, and the communication section 50g. etc. as resources. The same applies to the control section of each bidirectional DC/DC converter.

Based on the above system configuration, an example of power control processing of the power control system according to one embodiment of the present invention will be described below.

(1) Control in sunshine mode First, an example of power control processing in sunshine mode will be described. FIG. 3 is a flowchart of power control processing in the sunshine mode of the power control system according to this embodiment.

The integrated control device 50 instructs the MTTP mode to the first battery system 20, instructs the constant current charge mode or the constant current discharge mode to the second battery system 30, and controls the first control unit 211, The second control unit 311 maximizes the output of the solar cell 10 and controls the value of the bus voltage to fall within a predetermined range with respect to the bus reference voltage, which is a predetermined value (S301). The predetermined value is not limited to the bus reference voltage, but may be any other suitable value.

Charging of the second battery 330 progresses, and the integrated control device 50 determines whether the voltage value of the first battery 230 has become the first voltage value or the voltage value of the second battery 330 has become the second voltage value. or the value of the bus voltage is outside the predetermined range with respect to the bus reference voltage (S303), the integrated control device 50 controls the first battery system 20 or the second battery system 30 to The first control unit 211 or the second control unit 311 controls the first battery 230 or the second battery so that the bus voltage falls within a predetermined range with respect to the bus reference voltage. increases or decreases the amount of charge of the battery 330 of . That is, when the bus voltage is lower than the bus reference voltage, the charge amount of the first battery 230 or the second battery 330 is reduced, and when the bus voltage is higher than the bus reference voltage, the first battery 230 or the second battery 330 is charged. The amount of charge of the second battery 330 is increased to control the bus voltage to fall within a predetermined range with respect to the bus reference voltage (S305). The control of the battery charge amount is performed by the integrated control device 50 when the voltage value of the first battery 230 becomes the first voltage value or when the voltage value of the second battery 330 becomes the second voltage value. Alternatively or additionally, detecting that the SOC value of the first battery 230 has become the first SOC value or that the SOC value of the second battery 330 has become the second SOC value You can go if you do.

Charging of the second battery 330 further progresses, and the integrated control device 50 determines whether the voltage value of the first battery 230 has reached the third voltage value or the voltage value of the second battery 330 has reached the fourth voltage value. (S307), the integrated control device 50 instructs the solar cell rotating mechanism 11 to rotate the solar cell 10 and adjust the incident angle of the sunlight to the solar cell 10, so that the solar cell output power is decreased (S309). At this time, the control of the constant bus voltage charging mode started in S305 is continued. The rotation control of the solar cell is performed by the integrated control device 50 when the voltage value of the first battery 230 becomes the third voltage value or when the voltage value of the second battery 330 becomes the fourth voltage value. Alternatively or additionally, detecting that the SOC value of the first battery 230 has become the third SOC value or that the SOC value of the second battery 330 has become the fourth SOC value You can go if you do.

Here, when the power control system 1 is mounted on a moving object such as a spacecraft, the rotation control of the solar cell 10 is related to attitude control, so if the control timing interval is short, the attitude becomes unstable. Therefore, in such a case, it is preferable to increase the time interval of the rotation control timing of the solar cell 10 . For example, the time interval of the rotation control timing itself may be increased, or a plurality of threshold levels (for example, +1 V, +2 V, +3 V, etc. for a bus reference voltage of 50 V) may be set for the bus reference voltage. Then, rotation control may be performed when each threshold level is reached.

Even if the output voltage of the solar cell 10 is reduced by controlling the rotation of the solar cell 10, the integrated control device 50 detects whether the voltage value of the first battery 230 has reached the fifth voltage value or the voltage value of the second battery 330 Upon detecting that the voltage value has reached the sixth voltage value (S311), the integrated control device 50 instructs the first battery system 20 or the second battery system 30 to enter the constant voltage charging mode, The first battery 230 and/or the second battery 330 are protected (S313).

(2) Control in Shade Mode Next, an example of power control processing in the shade mode will be described. The integrated control device 50 instructs the first battery system 20 to operate in the constant bus voltage discharge mode, instructs the second battery system 30 to operate in the constant current discharge mode or the constant bus voltage discharge mode, and instructs the first battery system 20 to operate in the constant current discharge mode or the constant bus voltage discharge mode. The battery system 20 and the second battery system 30 supply electric power to the bus device 40, and control the bus voltage value so that it falls within a predetermined range with respect to the bus reference voltage.

According to this embodiment, the bidirectional DC/DC converter can be constructed by partially improving the battery charger of the basic configuration of the conventional power control system. Electric appliances can be dispensed with, making it possible to significantly reduce equipment. Further, it is possible to reduce the size and weight while maintaining the configuration in which the solar cell is directly connected to the bus device, which is an advantage of the shunt control.

In the above embodiment, since a plurality of bidirectional DC/DC converters are connected in parallel to the solar cell 10, control interference may occur between the bidirectional DC/DC converters. Accordingly, a device may be provided to reduce this control interference. Technology for reducing control interference between multiple bidirectional DC/DC converters, for example, Minoru Iwasa, Hitoshi Naito, Hiromasa Sowake, "Study on Spacecraft Power Supply System Applying Distributed Cooperative Control", Institute of Electronics, Information and Communication Engineers Technical Research Report EE Electronic Communication Energy Technology, The Institute of Electronics, Information and Communication Engineers, January 21, 2016, Vol. 115, No. 429, pp. 115-120, etc. Description is omitted.

Although the number of battery systems was two in the above embodiment, the number of battery systems can be any suitable number greater than or equal to one. Here, the control mode when the number of battery systems is one is the MPPT mode in step 301 of control during sunshine. However, when the bus voltage value is detected to exceed the bus reference voltage, the constant bus voltage charge mode is set, and when it is detected to fall below the constant bus voltage discharge mode, the bus voltage value is set to the predetermined value. When the value is detected, the MPPT mode is set again. Further, in the control in the shade, the bus voltage constant discharge mode is set.

In the above embodiment, each battery may be connected to a spare battery in series or in parallel. According to such a configuration, surplus electric power that has conventionally been wasted by shunt is stored in the spare battery, thereby improving resistance to abnormalities and the like.

In the above embodiment, the integrated control device 50 and the control units of the respective bidirectional DC/DC converters are configured separately, but part or all of the integrated control device 50 includes the bidirectional DC/DC converters may be included in one or more of the controllers.

In the above embodiments, the bidirectional power converters of all the battery systems are bidirectional DC/DC converters, but the present invention is not limited to this, and any other appropriate power converters can be used. can.

In the above embodiments, the power generation device is a solar cell, but the power generation device is not limited to this, and can be any other appropriate power generation device.

Although the present invention has been described with respect to several embodiments for purposes of illustration, the invention is not so limited and may be varied in form and detail without departing from the scope of the invention. It will be apparent to those skilled in the art that variations and modifications can be made.

1 power control system 10 solar cell 11 solar cell rotating mechanism 20 first battery system 30 second battery system 40 bus device 50 integrated control device 210 first bidirectional DC/DC converter 310 second bidirectional DC/DC Converter 211 First control section 311 Second control section 213 First storage section 313 Second storage section 230 First battery 330 Second battery

Claims (16)

a power generator;
a bus device;
at least one battery system;
an integrated controller that controls the at least one battery system;
with
the bus equipment and the at least one battery system are directly connected in parallel to the generator;
each of the at least one battery system includes a bi-directional power converter and a battery;
Each of the bidirectional power conversion devices converts the output voltage of the power generation device and outputs it to the battery side, converts the output voltage of the battery and outputs it to the bus equipment side, thereby charging the battery. Discharge,
A power control system in which the integrated control device instructs the at least one battery system to perform predetermined charge/discharge control, and the at least one battery system controls the bus voltage of the bus device. the power generator is a solar cell,
further comprising a solar cell rotation mechanism;
The integrated control device controls the output power of the solar cell and the bus voltage of the bus device by performing charge/discharge control of the at least one battery system and rotation control of the solar cell rotation mechanism. Item 1. The power control system according to item 1. 3. The power control system according to claim 2, wherein the control of the bus voltage of the bus device is control to keep the value of the bus voltage within a predetermined range with respect to a predetermined value. 4. The integrated control device according to claim 3, wherein the integrated control device instructs a first battery system of the at least one battery system to perform MPPT (maximum power tracking) mode as the predetermined charge/discharge control during the sunshine mode. power control system. the number of the at least one battery system is one;
when the voltage value of the first battery of the first battery system becomes the first voltage value, or when the value of the bus voltage becomes outside the predetermined range with respect to the predetermined value, the integrated control device is a constant bus voltage charging mode, which is a control mode for charging the first battery system as the charging/discharging control so that the value of the bus voltage falls within a predetermined range with respect to a predetermined value; 5. The power control system of claim 4, wherein the . When the voltage value of the first battery of the first battery system becomes a third voltage value, the integrated control device performs the charge/discharge control for the first battery system with the constant bus voltage 6. While instructing the charging mode, instructing the solar cell rotation mechanism to rotate the solar cell and adjust the angle of incidence of sunlight on the solar cell to reduce the output power of the solar cell. The power control system according to . When the voltage value of the first battery of the first battery system reaches the fifth voltage value, the integrated control device, as the charge/discharge control, controls the battery to a constant voltage with respect to the first battery system. 7. The power control system according to claim 6, wherein the constant voltage charging mode, which is the charging control mode, is instructed. the number of the at least one battery system is plural,
The voltage value of the first battery of the first battery system becomes the first voltage value, or the voltage value of the second battery of the second battery system among the at least one battery system becomes the second voltage value. voltage value, or when the value of the bus voltage is outside the predetermined range with respect to the predetermined value, the integrated control device performs the charge/discharge control in the first battery system or the second battery system. 5. The power control according to claim 4, wherein a constant bus voltage charging mode is a control mode for charging the battery so that the value of the bus voltage falls within a predetermined range with respect to a predetermined value. system. When the voltage value of the first battery becomes the third voltage value or the voltage value of the second battery becomes the fourth voltage value, the integrated control device performs the charge/discharge control as the While instructing the constant bus voltage charging mode to the first battery system or the second battery system, instructing the solar cell rotation mechanism to rotate the solar cell, and directing the solar cell to the solar cell 9. The power control system of claim 8, wherein adjusting the angle of incidence reduces the output power of the solar cell. When the voltage value of the first battery becomes the fifth voltage value or the voltage value of the second battery becomes the sixth voltage value, the integrated control device performs the charge/discharge control as the 10. The power control system according to claim 9, wherein the constant voltage charge mode, which is a control mode for constant voltage charging of the battery, is instructed to the first battery system. In the shade mode, the integrated control device, as the charge/discharge control, controls charging of the first battery system so that the value of the bus voltage falls within a predetermined range with respect to a predetermined value. 11. The power control system according to any one of claims 3 to 10, wherein the bus voltage constant discharge mode is indicated. Equipped with a spare battery,
12. The power control system according to any one of claims 1 to 11, wherein said spare battery is connected in series or in parallel with said first battery. The power control system according to any one of claims 1 to 12, wherein said bidirectional power converter is a bidirectional DC/DC converter. a power generator;
a bus device;
at least one battery system;
an integrated controller that controls the at least one battery system;
with
the bus equipment and the at least one battery system are directly connected in parallel to the generator;
each of the at least one battery system includes a bi-directional power converter and a battery;
Each of the bidirectional power conversion devices converts the output voltage of the power generation device and outputs it to the battery side, converts the output voltage of the battery and outputs it to the bus equipment side, thereby charging the battery. discharge,
A power control method in a power control system, comprising:
A power control method, wherein the integrated control device instructs the at least one battery system to perform predetermined charge/discharge control, and the at least one battery system controls the bus voltage of the bus device. A program for causing a computer to execute the power control method according to claim 14. A computer-readable storage medium storing the program according to claim 15.

Images