Energy management system
The energy management system addresses the need for separate AC and DC communicators by using a power converter and bridge circuit to enable comprehensive communication, reducing the number of required communicators and simplifying installation.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- KAWAMURA ELECTRIC INC
- Filing Date
- 2022-06-08
- Publication Date
- 2026-06-08
AI Technical Summary
The existing energy management systems require separate power line communicators for both AC and DC circuits due to the inability of upper power line communicators on the AC circuit to communicate with those on the DC circuit, leading to an increased number of communicators.
An energy management system with a power converter between AC and DC circuits, a bridge circuit connecting them, and power line communicators on both sides that communicate via the bridge, allowing comprehensive management without separate communicators for each circuit.
Reduces the number of power line communicators needed by enabling communication between AC and DC circuits through a single master unit, simplifying installation and reducing electrical work.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to an energy management system.
Background Art
[0002] Conventionally, an energy management system including a measuring instrument for measuring the power generation amount of a solar panel, a lower power line communicator for monitoring the measuring instrument, and an upper power line communicator for receiving a monitoring result from the lower power line communicator by power line communication has been known (for example, see Patent Document 1). These measuring instruments, lower power line communicators, and upper power line communicators are provided in a DC circuit through which DC power flows.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] Here, the energy management system also has a DC circuit through which DC power flows. A lower power line communicator for monitoring or controlling DC devices is also provided in the DC circuit. Since the upper power line communicator on the AC circuit side cannot perform power line communication with the lower power line communicator on the DC circuit side, it has been necessary to provide upper power line communicators on both the AC circuit and the DC circuit. Therefore, there has been a problem that the number of power line communicators increases.
[0005] An object of the present invention is to provide an energy management system capable of reducing the number of power line communicators.
Means for Solving the Problems
[0006] The energy management system according to the present invention comprises an AC circuit through which AC power flows, a DC circuit through which DC power flows, a power converter provided between the AC circuit and the DC circuit, a first power line communicator provided in the AC circuit, a second power line communicator provided in the DC circuit, and a bridge circuit connecting the AC circuit and the DC circuit in parallel with the power converter, wherein the first power line communicator and the second power line communicator communicate via the bridge circuit.
[0007] The energy management system according to the present invention comprises a power converter installed between an AC circuit and a DC circuit, and a bridge circuit connecting the AC circuit and the DC circuit in parallel with the power converter. Furthermore, a first power line communicator and a second power line communicator communicate via the bridge circuit. In this way, power line communication is possible between the first power line communicator on the AC circuit side and the second power line communicator on the DC circuit side, making it possible to provide a power line communicator that comprehensively manages both the AC circuit side and the DC circuit side. Therefore, it becomes unnecessary to install separate power line communicators for management on both the AC circuit side and the DC circuit side. As a result, the number of power line communicators can be reduced.
[0008] The first power line communication device includes a master unit and a first slave unit that monitors and controls AC equipment installed in an AC circuit, and the second power line communication device includes a second slave unit that monitors and controls DC equipment installed in a DC circuit, and the master unit may communicate with the first and second slave units via power lines. In this case, the master unit can comprehensively manage the first slave unit on the AC circuit side and the second slave unit on the DC circuit side.
[0009] The DC circuit is equipped with multiple solar panels and multiple measuring instruments for measuring the power generation of each solar panel. The first power line communication device has a master unit, and the second power line communication device has slave units that acquire the measurement results of the multiple measuring instruments. The master unit may aggregate the measurement results of each measuring instrument from the slave units via power line communication. In this case, the master unit on the AC circuit side can manage the power generation of the many solar panels on the DC circuit side. [Effects of the Invention]
[0010] According to the present invention, it is possible to provide an energy management system that can reduce the number of power line communication devices. [Brief explanation of the drawing]
[0011] [Figure 1] This is a block diagram showing an energy management system according to an embodiment of the present invention. [Figure 2] Figure 2(a) is a block diagram of the slave unit, and Figure 2(b) is a block diagram of the master unit. [Figure 3] This is a block diagram of a bridge circuit. [Figure 4] This is a block diagram showing an example of an energy management system. [Figure 5] This is a block diagram showing an example of an energy management system. [Modes for carrying out the invention]
[0012] Embodiments of the present invention will be described in detail below with reference to the attached drawings. In the description of the drawings, the same or equivalent elements will be denoted by the same reference numerals, and redundant descriptions will be omitted.
[0013] Figure 1 is a block diagram showing an energy management system 100 according to an embodiment of the present invention. As shown in Figure 1, the energy management system 100 is a system for managing energy within a managed area equipped with predetermined equipment. The energy management system 100 comprises an AC circuit W10, a DC circuit W20, and a power converter 1. The AC circuit W10 is a circuit through which AC power flows. The DC circuit W20 is a circuit through which DC power flows. The power converter 1 is a device installed between the AC circuit W10 and the DC circuit W20 that performs power conversion. The power converter 1 converts DC power to AC power and AC power to DC power.
[0014] The energy management system 100 includes a first power line communication device 2 and AC equipment 3 installed in the AC circuit W10. The AC equipment 3 is equipment that operates on AC power. Examples of AC equipment 3 include lighting and air conditioning. The power converter 1 and the AC equipment 3 are connected via the circuit W11. The energy management system 100 includes a master unit 4 and a slave unit 6 (first slave unit) as the first power line communication device 2. The master unit 4 is equipment that manages the slave units within the energy management system 100. The master unit 4 is connected to the circuit W12 which branches off from the circuit W11. The slave unit 6 is equipment that monitors and controls the AC equipment 3, or at least one of the two. The slave unit 6 is connected to the circuit W13 which branches off from the circuit W11.
[0015] The energy management system 100 includes a second power line communication device 7 and a DC device 8, which are installed in the DC circuit W20. The DC device 8 is a device that supplies DC power or a device that operates using DC power. The power converter 1 and the DC device 8 are connected via the circuit W21. The energy management system 100 also includes a slave unit 9 (second slave unit) as the second power line communication device 7. The slave unit 9 is a device that monitors and controls the DC device 8, or at least one of the latter. The slave unit 9 is connected to the circuit W22, which branches off from the circuit W21.
[0016] In this energy management system 100, information is transmitted between devices using power line communication (PLC). Power line communication is a communication method that transmits and receives communication signals using power lines by, for example, superimposing a communication signal of a different frequency than the commercial frequency onto a power waveform of the commercial frequency and transmitting it, and then separating and receiving the communication signal of a different frequency from this power waveform. Note that power line communication may be subject to the Radio Law depending on its frequency band. However, in the energy management system 100 according to this embodiment, in order to be usable both indoors and outdoors and to achieve a certain amount of data transfer, power line communication in a frequency band of, for example, 100 kHz to 450 kHz may be used. However, power line communication in frequency bands higher or lower than that may also be used. For example, the frequency band may be 10 kHz or lower, or 2 MHz or higher. Furthermore, when using power line communication in a frequency band of 100 kHz to 450 kHz, the modulation method is not particularly limited, and either the OFDM method or the DCSK method may be adopted. The power lines in AC circuit W10 are primarily for supplying AC power at commercial frequency, and serve as transmission lines for power line communication. Specifically, power line communication takes place between the slave unit 6 and the master unit 4. In power line communication, communication signals can be superimposed on AC circuit W10, such as AC100V or AC200V. Communication signals from the slave unit 6 are sent to the master unit 4 via circuits W13, W11, and W12. Communication signals from the master unit 4 are sent to the slave unit 6 via circuits W12, W11, and W13.
[0017] Furthermore, in power line communication, communication signals can be superimposed on the DC circuit W20 in the same way as AC signals. Specifically, power line communication is performed between the slave unit 9 and the master unit 4 by using the bridge circuit 10. The energy management system 100 includes a bridge circuit 10 that connects the AC circuit W10 and the DC circuit W20 in parallel with the power converter 1. The bridge circuit 10 is connected to circuit W31, which branches off from circuit W11 near the power converter 1. The bridge circuit 10 is also connected to circuit W32, which branches off from circuit W21 near the power converter 1. As a result, the bridge circuit 10 connects the AC circuit W10 and the DC circuit W20 via circuits W31 and W32, while straddling the power converter 1. The first power line communicator 2 and the second power line communicator 7 perform power line communication via the bridge circuit 10. Specifically, the communication signal from the slave unit 9 is sent to the master unit 4 via circuits W22, W21, W32, bridge circuit 10, W31, W11, and W12. The communication signal from the master unit 4 is sent to the slave unit 9 via circuits W12, W11, W31, bridge circuit 10, W32, W21, and W22.
[0018] Referring to Figure 2(a), the detailed block configuration of the slave units 6 and 9 will be described. Each slave unit 6 and 9 comprises a communication unit 11, a processing unit 12, and a storage unit 13. The communication unit 11 is a unit that communicates with the master unit 4 and electrical equipment (AC equipment 3 or DC equipment 8). The communication unit 11 has a circuit for receiving signals from the electrical equipment. The communication unit 11 also has a circuit for converting signals from the electrical equipment into signals for power line communication to the master unit 4. The processing unit 12 is a unit that performs at least one of monitoring and control of the electrical equipment. The processing unit 12 is configured to include a microprocessor and its peripheral circuits, etc.
[0019] The storage unit 13 is a unit that stores programs necessary for at least one of the monitoring and control of electrical equipment, information necessary for operations, and the like. The storage unit 13 includes, for example, a non-volatile memory element such as a ROM (Read Only Memory), a rewritable non-volatile memory element such as an EEPROM (Electrically Erasable Programmable Read Only Memory), and a volatile memory element such as a RAM (Random Access Memory) that serves as a working memory. For example, the storage unit 13 stores an address indicating the position of electrical equipment within the energy management system 100.
[0020] Referring to FIG. 2(b), the detailed block configuration of the master unit 4 will be described. The master unit 4 includes a communication unit 21, a processing unit 22, and a storage unit 23. The communication unit 21 is a unit that communicates with the slave units 6 and 9. The communication unit 21 has a circuit for performing power line communication with the slave units 6 and 9. Also, the communication unit 21 has a circuit for performing remote communication with an external communication device using the cloud. That is, the communication unit 21 of the master unit 4 includes a PLC communication unit that controls power line communication with the slave units 6 and 9, and a wireless communication unit such as LTE that controls network communication with the cloud side. The processing unit 22 is a unit that controls the operation of the entire master unit 4. The processing unit 22 is configured to include a microprocessor and its peripheral circuits, etc. The processing unit 22 calculates control information for controlling the ON / OFF switching of each lighting and air conditioning, and the adjustment of the strength of the output.
[0021] The storage unit 23 is a unit that stores programs necessary for the operation of the master unit 4, information necessary for operations, and the like. The storage unit 23 may include the same memory elements as those exemplified in the storage unit 13. For example, the storage unit 23 stores, in a state where the addresses indicating the positions of the master unit 4 and each slave unit 6 and 9 within the energy management system 100 are associated with each other.
[0022] Referring to Figure 3, the detailed block configuration of the bridge circuit 10 will be described. The bridge circuit 10 comprises a high-pass filter 31A and a high-pass filter 31B. The high-pass filter 31A extracts only the power line communication signals from the superimposed AC power, which includes power line communication signals flowing from the AC circuit W10 through circuit W31, and passes them to the DC circuit W20 via circuit W32. The high-pass filter 31A is comprised of equipment 32A, which consists of a transformer and circuitry. The high-pass filter 31B extracts only the power line communication signals from the superimposed DC power, which includes power line communication signals flowing from the DC circuit W20 through circuit W32, and passes them to the AC circuit W10 via circuit W31. The high-pass filter 31B is comprised of equipment 32B, which consists of a transformer and circuitry. Equipment 32A is connected to circuit W31. Equipment 32B is connected to circuit W32. Equipment 32A and equipment 32B are connected via circuit W33. Note that there is no structural difference between high-pass filters 31A and 31B, and the bridge circuit 10 will function even if the AC and DC sides are reversed. The cutoff frequency of the bridge circuit 10 is set to be above the commercial frequency of 50Hz or 60Hz, and below the PLC operating frequency (for example, below 10KHz for low-speed PLCs).
[0023] Referring to Figure 4, a specific example of the use of the energy management system 100 will be described. The DC circuit W20 of the energy management system 100 is equipped with multiple solar panels 40 as DC equipment 8, and multiple measuring instruments 41 for measuring the amount of power generated by each solar panel 40. Each solar panel 40 is connected to a circuit W23 that branches off from the circuit W21. Each measuring instrument 41 is installed in the circuit W23 corresponding to each solar panel 40. The measuring instruments 41 can measure the amount of power generated by the solar panels 40 on a string-by-string basis.
[0024] The slave unit 9 acquires measurement results from multiple measuring instruments 41. The slave unit 9 is connected to all measuring instruments 41 via power lines W30. The slave unit 9 and the multiple measuring instruments 41 are housed together in a connection box 42. The slave unit 9 transmits the acquired measurement results to the master unit 4 via power line communication. As a result, the master unit 4 aggregates the measurement results from each measuring instrument 41 from the slave unit 9 via power line communication. Furthermore, the master unit 4 transmits the aggregated results to the cloud CD. This allows the user to check the amount of power generated by the solar panels 40 on a web screen.
[0025] As shown in Figure 5, the energy management system 100 may be equipped with multiple power converters 1. For example, if multiple junction boxes 42 are provided in parallel on the DC circuit W20 side, a power converter 1 is provided for each junction box 42. In this case, a single master unit 4 provided on the AC circuit W10 side may be provided for multiple sets of slave units 9 and power converters 1. In this case, the master unit 4 can aggregate the measurement results from all the slave units 9 with a single unit. In this case, one bridge circuit 10 is provided for each power converter 1.
[0026] Next, the operation and effects of the energy management system 100 according to this embodiment will be described.
[0027] The energy management system 100 according to this embodiment includes a power converter 1 installed between an AC circuit W10 and a DC circuit W20, and a bridge circuit 10 that connects the AC circuit W10 and the DC circuit W20 in parallel with the power converter 1. Furthermore, a first power line communicator 2 and a second power line communicator 7 communicate via the bridge circuit 10. In this way, power line communication is possible between the first power line communicator 2 on the AC circuit W10 side and the second power line communicator 7 on the DC circuit W20 side, making it possible to provide a power line communicator (master unit 4) that comprehensively manages both the AC circuit W10 side and the DC circuit W20 side. Therefore, it becomes unnecessary to provide a separate power line communicator for management on both the AC circuit W10 side and the DC circuit W20 side. As a result, the number of power line communicators can be reduced.
[0028] As a comparative example, an energy management system in which multiple power converters 1 are provided as shown in Figure 5, but a bridge circuit 10 is not provided, will be described. In this case, in addition to the master unit 4 on the AC circuit W10 side, one master unit is required for each power converter 1 on the DC circuit W20 side. Alternatively, electrical work is required to bridge with a separate DC circuit. In contrast, in this embodiment, the measurement results from multiple slave units 9 on the DC circuit W20 side can also be aggregated by a single master unit 4 on the AC circuit W10 side. In this way, electrical work is not required, and one master unit 4 can handle multiple power converters 1.
[0029] The first power line communication device 2 includes a master unit 4 and a slave unit 6 (first slave unit) that monitors and controls at least one of the AC equipment 3 installed in the AC circuit W10, and the second power line communication device 7 includes a slave unit 9 (second slave unit) that monitors and controls at least one of the DC equipment 8 installed in the DC circuit W20, and the master unit 4 may communicate with the slave units 6 and 9 via power lines. In this case, the master unit 4 can comprehensively manage the slave unit 6 on the AC circuit W10 side and the slave unit 9 on the DC circuit W20 side.
[0030] The DC circuit W20 is equipped with multiple solar panels 40 and multiple measuring instruments 41 for measuring the amount of power generated by each solar panel 40. The first power line communication device 2 has a master unit 4, and the second power line communication device 7 has a slave unit 9 for acquiring the measurement results of the multiple measuring instruments 41. The master unit 4 may collect the measurement results of each measuring instrument 41 from the slave unit 9 via power line communication. In this case, the master unit 4 on the AC circuit W10 side can manage the amount of power generated by the many solar panels 40 on the DC circuit W20 side.
[0031] The present invention is not limited to the embodiments described above. For example, although the energy management system 100 had one master unit, it may have multiple master units as needed. Also, the number of slave units in both the AC circuit W10 and the DC circuit W20 is not particularly limited. [Explanation of symbols]
[0032] 1...Power converter, 2...First power line communication device, 3...AC equipment, 4...Master unit, 6...Slave unit, 7...Second power line communication device, 8...DC equipment, 9...Slave unit, 10...Bridge circuit, 40...Solar panel, 41...Measuring instrument, 100...Energy management system.
Claims
1. AC circuits through which alternating current flows, A DC circuit through which DC power flows, A power converter is provided between the AC circuit and the DC circuit, A first power line communication device installed in the aforementioned AC circuit, A second power line communication device is provided in the aforementioned DC circuit, The system includes a bridge circuit that connects the AC circuit and the DC circuit in parallel with the power converter, The first power line communication device and the second power line communication device perform power line communication via the bridge circuit. The DC circuit is equipped with multiple solar panels and multiple measuring instruments for measuring the amount of power generated by each of the solar panels. The first power line communication device has a master unit, The second power line communication device has a slave unit that acquires the measurement results of a plurality of the measuring instruments, The master unit aggregates the measurement results from each measuring instrument of the slave units via power line communication. Energy management system.
2. The first power line communication device further includes another slave unit that performs at least one of monitoring and controlling AC equipment installed in the AC circuit. The energy management system according to claim 1, wherein the master unit communicates with the other slave unit via power lines.