JP2019176687A - 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

  The present invention relates to a power control system, and more particularly to a battery system including a battery, a converter, and the like, and a power control system including a power generator.

  Conventionally, the power control of the satellite is based on the surplus power control (shunt control), and the power control system of the satellite generally has a basic configuration of “shunt circuit + battery charger (+ battery discharger)”. . In space environments where there is no grid power supply, the highest priority is to efficiently supply the power generated by the solar cell to the bus device, and the output power of the solar cell can be supplied to the bus device without going through a power converter such as a converter. Shunt control is recognized as an optimal power control method for spacecraft.

  On the other hand, spacecrafts with limited launch capabilities require equipment to be smaller and lighter, and have high performance based on the basic configuration of “shunt circuit + battery charger (+ battery discharger)” as described above. Reduction in size and weight is being promoted by applying power conversion devices (see Non-Patent Document 1 below). Moreover, the technique which reduces the electric power generated of a solar cell when unnecessary is devised for size reduction of a shunt circuit (refer the following patent documents 1-3 etc.).

JP-A-6-144399 JP 7-101400 A 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 required power of artificial satellites is on the rise. Especially, communication and broadcasting satellites, which are typical geostationary satellites, require high power of several tens of kW, and further reduction in size and weight of power control systems is required. Yes. However, the conventional basic configuration of “shunt circuit + battery charger (+ battery discharger)” has a limit in reducing the size and weight. In addition, it is difficult to eliminate the shunt circuit even in the method of reducing the generated power of the solar cell, or even if possible, a larger-scale device than the shunt circuit is required, which is not practical.

  Such a situation is the same on the ground, and in the power control system, not only when the power generation device is a solar cell, but also when the power generation device is a power generation device such as a wind power generation device or a fuel cell. It is the same.

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

  One aspect of the present invention includes a power generation device, a bus device, at least one battery system, and an integrated control device that controls the at least one battery system, and the bus device 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 being an output voltage of the generator. And the battery is charged and discharged by converting the output voltage of the battery and outputting it to the bus device side, and the integrated control device is configured to output the at least one battery system. Predetermined charge / discharge control is instructed, and the at least one battery system is connected to the bus voltage of the bus device. There is provided a power control system for controlling.

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

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

  The said integrated control apparatus shall instruct | indicate MPPT (maximum power tracking) mode with respect to the 1st battery system of the said at least 1 battery system as said predetermined | prescribed charge / discharge control at the time of sunshine mode. it can.

  When the voltage value of the first battery of the first battery system becomes the first voltage value, the integrated control device determines the value of the bus voltage with respect to the first battery system as the charge / discharge control. May be instructed to be in a constant bus voltage charging mode, which is a control mode for charging the battery so as to fall within a predetermined range with respect to a predetermined value.

  When the voltage value of the first battery of the first battery system becomes the third voltage value, the integrated control device sets the bus voltage constant for the first battery system as the charge / discharge control. Instructing the solar cell rotation mechanism while instructing the charging mode, rotating the solar cell, and adjusting the incident angle of sunlight with respect to the solar cell, thereby reducing the output power of the solar cell. be able to.

  When the voltage value of the first battery in the first battery system becomes the fifth voltage value, the integrated control device supplies a constant voltage to the first battery system as the charge / discharge control. A constant voltage charging mode, which is a control mode for charging, can be indicated.

  In the shade mode, the integrated control device controls the first battery system to discharge the battery so that the bus voltage value falls within a predetermined range with respect to a predetermined value as the charge / discharge control. The mode may indicate a constant bus voltage discharge mode.

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

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

  One aspect of the present invention includes a power generation device, a bus device, at least one battery system, and an integrated control device that controls the at least one battery system, and the bus device 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 being an output voltage of the generator. Is a power control method in a power control system that charges and discharges the battery by converting the output voltage of the battery and outputting it to the bus device side by converting the output voltage of the battery, The control device instructs predetermined charge / discharge control to the at least one battery system, and the at least one battery system Battery system, and provides a power control method for controlling a bus voltage of the bus instrument.

  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-described configuration, it is possible to provide a power control system for generated power of a power generator that supplies power to a bus device without going through a power converter and is further reduced in size and weight.

It is a figure showing the whole power control system composition concerning one embodiment of the present invention. It is a figure which shows the example of the hardware constitutions of the integrated control apparatus 50 of the electric power control system which concerns on one Embodiment of this invention. It is a flowchart of the power control process at the time of the sunshine mode of the power control system which concerns on one Embodiment of this invention.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 is a diagram showing an overall configuration of a power control system 1 according to one embodiment of the present 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 to the solar cell 10 in parallel.

  The solar cell rotating mechanism 11 can change the output power of the solar cell by rotating the solar cell 10 and changing the incident angle of sunlight with respect to the solar cell 10.

  The first battery system 20 includes a first bidirectional DC / DC converter 210 and a first battery 230 that are first power converters. Similarly, the second battery system 30 includes a second bidirectional DC / DC converter 310 and a second battery 330.

  The first bidirectional DC / DC converter 210 includes a first control unit 211 and a first storage unit 213. Similarly, the second bidirectional DC / DC converter 310 includes a second control unit 311 and a second storage unit 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. The first battery 230 and the second battery 330 are charged / discharged by converting the output voltages of the battery 230 and the second battery 330 and outputting them to the bus device side. The 1st control part 211 and the 2nd control part 311 control the duty ratio of PWM of each bidirectional DC / DC converter. Further, in each bidirectional DC / DC converter, an operating voltage and output current of the solar cell 10, an input side voltage value (bus voltage value) of the bidirectional DC / DC converter, and an output by each voltmeter and ammeter (not shown). A side voltage value (battery voltage value), an input side current value, an output side current value, and the like are measured and input to each control unit.

  The integrated control device 50 monitors the state of the entire system, such as the solar cell 10, the bus device 40, the bidirectional DC / DC converter of each battery system, the voltage and current of the battery, and the SOC (State of Charge) of the battery. Then, based on the monitoring result and whether the mode is the sunshine mode or the shade mode, it is determined which control mode is to be instructed to which bidirectional DC / DC converter, and each bidirectional DC / DC The determined control mode is instructed to the DC converter, and the rotation angle is instructed to the solar cell rotating mechanism 11 as necessary. In the present embodiment, there are six control modes: MPPT (maximum power tracking) mode, constant current charging mode, constant current discharging mode, constant voltage charging mode, constant bus voltage charging mode, and constant bus voltage discharging mode. The MPPT mode performs control to maximize the solar cell output. In the constant current charging mode, the battery is controlled to be charged with a constant current. In the constant current discharge mode, control is performed to discharge the battery at a constant current. In the constant voltage charging mode, the battery is controlled to be charged at a constant voltage. In the constant bus voltage charging mode, control is performed to charge the battery so that the value of the bus voltage is within a predetermined range with respect to the predetermined value. In the constant bus voltage discharge mode, control is performed to discharge the battery so that the value of the bus voltage is within a predetermined range with respect to the predetermined value.

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

  FIG. 2 is a diagram illustrating an example of a hardware configuration of the integrated control device 50 of the power control system 1 according to the present embodiment. The integrated control device 50 includes a CPU 50a, a RAM 50b, a ROM 50c, an external memory 50d, an input unit 50e, an output unit 50f, and a communication unit 50g. The RAM 50b, ROM 50c, external memory 50d, input unit 50e, output unit 50f, and communication unit 50g are connected to the CPU 50a via a system bus 50h. The hardware configuration of the control unit of each bidirectional DC / DC converter is the same. Each unit of the control unit of the integrated control device 50 shown in FIG. 1 includes a CPU 50a, a RAM 50b, a ROM 50c, an external memory 50d, an input unit 50e, an output unit 50f, and a communication unit 50g. Etc. are used as resources. The same applies to the control unit 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 the sunshine mode First, an example of the power control process in the 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 the present embodiment.

  The integrated control device 50 instructs the first battery system 20 in the MTTP mode, instructs the second battery system 30 in the constant current charge mode or the constant current discharge mode, and controls the first control unit 211, The second control unit 311 maximizes the output of the solar cell 10 and controls the bus voltage value to be 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, and may be any other appropriate value.

  Charging of the second battery 330 proceeds, and the integrated control device 50 determines whether the voltage value of the first battery 230 becomes the first voltage value or the voltage value of the second battery 330 becomes the second voltage value. Or when it is detected that the value of the bus voltage is out of the predetermined range with respect to the bus reference voltage (S303), the integrated control device 50 detects the first battery system 20 or the second battery system 30. The first control unit 211 or the second control unit 311 instructs the first battery 230 or the second battery so that the bus voltage is within a predetermined range with respect to the bus reference voltage. The amount of charge of the battery 330 is increased or decreased. 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 reduced. The charge amount of the second battery 330 is increased, and control is performed so that the bus voltage is within a predetermined range with respect to the bus reference voltage (S305). In the control of the battery charge amount, the integrated control device 50 determines that 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. In place of or in addition to the detection of the battery, it is detected 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 may go if you do.

  Charging of the second battery 330 further proceeds, and the integrated control device 50 determines that the voltage value of the first battery 230 has become the third voltage value, or the voltage value of the second battery 330 is the fourth voltage value. (S307), the integrated control device 50 instructs the solar cell rotation mechanism 11 to rotate the solar cell 10 and adjust the incident angle of sunlight to the solar cell 10 to thereby adjust the solar cell. Is reduced (S309). At this time, the control in the constant bus voltage charging mode started in S305 is continuously performed. In the rotation control of the solar cell, the integrated control device 50 determines that the voltage value of the first battery 230 has become the third voltage value or the voltage value of the second battery 330 has become the fourth voltage value. In place of or in addition to the detection of the first battery 230, it is detected 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 may go if you do.

  Here, when the power control system 1 is mounted on a mobile body such as a spacecraft, the rotation control of the solar cell 10 is related to the attitude control, so that the attitude becomes unstable if the time interval of the control timing is small. 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, + 1V, + 2V, + 3V,... For the bus reference voltage 50V) 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 decreased by the rotation control on the solar cell 10, the integrated control device 50 determines whether the voltage value of the first battery 230 has reached the fifth voltage value or the second battery 330. When it is detected that the voltage value has become 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, and The first battery 230 and / or the second battery 330 is 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 in the constant bus voltage discharge mode, instructs the second battery system 30 in the constant current discharge mode or the constant bus voltage discharge mode, The battery system 20 and the second battery system 30 supply power to the bus device 40 and control the bus voltage value to be within a predetermined range with respect to the bus reference voltage.

  According to this embodiment, since the bidirectional DC / DC converter can be constructed by partially improving the battery charger having the basic configuration of the conventional power control system, the shunt circuit and the battery discharge having the basic configuration of the conventional power control system can be constructed. Electric appliances can be eliminated, and the equipment can be greatly reduced. And the size and weight reduction can be implement | achieved, maintaining the structure which connects the solar cell which is the advantage of shunt control to bus equipment directly.

  In the above embodiment, since a plurality of bidirectional DC / DC converters are connected in parallel to the solar cell 10, control interference between the bidirectional DC / DC converters may occur. Therefore, an apparatus for reducing this control interference may be provided. Control interference reduction technologies between multiple bidirectional DC / DC converters are, for example, Iwasa Satoshi, Naito Hitoshi, and Sasabe Hiromasa, "Research on spacecraft power supply systems using distributed cooperative control", IEICE technical report The technology disclosed in EE Electronic Communication Energy Technology, The Institute of Electronics, Information and Communication Engineers, January 21, 2016, Vol. 115, No. 429, pp. 115-120, etc. can be used. Description is omitted.

  In the above embodiment, the number of battery systems is two. However, the number of battery systems may be any appropriate number of one or more. Here, the control mode when the number of battery systems is one is the MPPT mode in step 301 of the control at the time of sunshine. However, when it is detected that the bus voltage value exceeds the bus reference voltage, the bus voltage constant charge mode is set. When the bus voltage value is detected to be lower, the bus voltage constant discharge mode is set and the bus voltage value is set to a predetermined value. When the value is detected, the MPPT mode is set again. In shaded control, the bus voltage constant discharge mode is set.

  In the above-described embodiment, a configuration may be employed in which a spare battery is connected to each battery in series or in parallel. According to such a configuration, the surplus power that has conventionally been thrown away by the shunt is stored in the spare battery, thereby improving the resistance to abnormality and the like.

  In the above embodiment, the integrated control device 50 and the control unit of each bidirectional DC / DC converter are configured as separate units. However, part or all of the integrated control device 50 includes each bidirectional DC / DC converter. The configuration may be included in one or more of the control units.

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

  In the said embodiment, although the electric power generating apparatus was a solar cell, it is not limited to this, It can be set as other appropriate arbitrary electric power generating apparatuses.

  Although the present invention has been described above with reference to several embodiments for purposes of illustration, the present invention is not limited thereto and various forms and details may be used without departing from the scope of the present invention. It will be apparent to those skilled in the art that variations and modifications can be made.

DESCRIPTION OF SYMBOLS 1 Power control system 10 Solar cell 11 Solar cell rotation mechanism 20 1st battery system 30 2nd battery system 40 Bus equipment 50 Integrated control apparatus 210 1st bidirectional DC / DC converter 310 2nd bidirectional DC / DC Converter 211 First control unit 311 Second control unit 213 First storage unit 313 Second storage unit 230 First battery 330 Second battery

Claims (16)

A power generator,
Bus equipment,
At least one battery system;
An integrated control device for controlling the at least one battery system;
With
The bus device and the at least one battery system are directly connected in parallel to the power generation device,
Each of the at least one battery system includes a bidirectional power converter and a battery;
Each of the bidirectional power converters converts the output voltage of the power generator and outputs it to the battery side, converts the output voltage of the battery and outputs it to the bus device side, thereby charging the battery. Discharge,
The power control system, wherein the integrated control device instructs predetermined charge / discharge control to the at least one battery system, and the at least one battery system controls a bus voltage of the bus device. The power generator is a solar cell;
A solar cell rotation mechanism;
The integrated control device performs control of output power of the solar cell and bus voltage of the bus device by performing charge / discharge control for the at least one battery system and rotation control for the solar cell rotation mechanism. Item 4. The power control system according to Item 1.   The power control system according to claim 2, wherein the bus voltage control of the bus device is control so that a value of the bus voltage is within a predetermined range with respect to a predetermined value.   The said integrated control apparatus instruct | indicates a MPPT (maximum power tracking) mode with respect to the 1st battery system of the said at least 1 battery system as said predetermined | prescribed charge / discharge control at the time of 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 the value of the bus voltage is out of the predetermined range with respect to the predetermined value, the integrated control device Is a bus voltage constant charge mode which is a control mode for charging the battery so that the bus voltage value falls within a predetermined range with respect to a predetermined value for the first battery system as the charge / discharge control. The power control system according to claim 4, wherein:   When the voltage value of the first battery of the first battery system becomes the third voltage value, the integrated control device sets the bus voltage constant for the first battery system as the charge / discharge control. The output power of the solar cell is reduced by instructing the solar cell rotation mechanism while instructing a charging mode, rotating the solar cell, and adjusting an incident angle of sunlight with respect to the solar cell. Power control system as described in.   When the voltage value of the first battery in the first battery system becomes the fifth voltage value, the integrated control device supplies a constant voltage to the first battery system as the charge / discharge control. The power control system according to claim 6, wherein a constant voltage charging mode that is a control mode for charging is instructed. A plurality of the at least one battery system;
The voltage value of the first battery of the first battery system has become the first voltage value, or the voltage value of the second battery of the second battery system of the at least one battery system is the second voltage value. When the voltage value is reached or the value of the bus voltage is out of the predetermined range with respect to the predetermined value, the integrated control device uses the first battery system or the second battery as the charge / discharge control. 5. The power control according to claim 4, instructing a battery voltage constant charge mode, which is a control mode for charging the battery so that the value of the bus voltage is within a predetermined range with respect to the predetermined value. system.   When the voltage value of the first battery has become the third voltage value or the voltage value of the second battery has become the fourth voltage value, the integrated control device, as the charge / discharge control, While instructing the first battery system or the second battery system in the constant bus voltage charging mode, the solar cell rotating mechanism is instructed to rotate the solar cell, and The power control system according to claim 8, wherein output power of the solar cell is decreased by adjusting an incident angle.   When the voltage value of the first battery has become the fifth voltage value or the voltage value of the second battery has become the sixth voltage value, the integrated control device, as the charge / discharge control, The power control system according to claim 9, wherein the first battery system is instructed in a constant voltage charging mode, which is a control mode for charging the battery at a constant voltage.   In the shade mode, the integrated control device charges the battery so that the bus voltage value falls within a predetermined range with respect to a predetermined value for the first battery system as the charge / discharge control. The power control system according to any one of claims 3 to 10, which indicates a bus voltage constant discharge mode that is a mode. A spare battery,
The power control system according to claim 1, wherein the spare battery is connected in series or in parallel to the first battery.   The power control system according to any one of claims 1 to 12, wherein the bidirectional power converter is a bidirectional DC / DC converter. A power generator,
Bus equipment,
At least one battery system;
An integrated control device for controlling the at least one battery system;
With
The bus device and the at least one battery system are directly connected in parallel to the power generation device,
Each of the at least one battery system includes a bidirectional power converter and a battery;
Each of the bidirectional power converters converts the output voltage of the power generator and outputs it to the battery side, converts the output voltage of the battery and outputs it to the bus device side, thereby charging the battery. Discharge,
A power control method for a power control system, comprising:
The power control method, wherein the integrated control device instructs predetermined charge / discharge control to the at least one battery system, and the at least one battery system controls a 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.

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