CN103493506B - Load control system, DC load and terminal installation - Google Patents

Abstract

The terminal device (4) includes: a terminal-side communication unit (41) for sending and receiving communication signals via the wiring line (2); and a processing unit (42) for providing control requests to DC loads using the communication signals. Each DC load (3) includes: a load-side communication unit (31) for sending and receiving communication signals via the wiring line (2); and a control unit (32) for communicating according to a control request from the device (4) Control the working status. Each DC load (3) is equipped with an adjustment unit (7), wherein the adjustment unit (7) is used to make the control unit (32) control the working state according to the control request from the device (4) at the control time of multiple DC The loads (3) are staggered.

Description

Load control systems, DC loads and terminal units

technical field

The present invention relates to a load control system configured such that a terminal device controls a plurality of DC loads via a DC supply line, and a DC load and a terminal device.

Background technique

Conventionally, a DC (direct current) power distribution system has been proposed that is configured to convert an alternating current power source such as a commercial power supply via an AC (alternating current)/DC converter disposed in a distribution board such as a residence or the like Convert to DC power, and distribute the DC power from the distribution board to the DC outlets arranged in each room. Regarding this DC power distribution system, a technique is considered in which a DC supply line serving as a feeder line for DC power also serves as a communication line (see, for example, Japanese Patent Application Laid-Open No. 2009-158116 (hereinafter referred to as "Document 1")). This technology is similar to power line transmission technology in which communication signals are superimposed on AC voltage in a power line that supplies AC power.

The system described in Document 1 regards a DC supply line to which a plurality of DC loads (lighting fixtures) are connected as a communication line, and superimposes a communication signal for transmitting data on a DC voltage using a high-frequency carrier wave, thereby enabling Communication between end devices (management devices) and DC loads. With the load control system (lighting control system), one terminal device can control the operating state (lighting state) of a plurality of DC loads connected to the DC supply line using communication signals.

However, in this load control system, when a control request (control instruction) for a plurality of DC loads is generated, since the operating states of the plurality of DC loads change simultaneously, the DC voltage on the DC supply line may be caused by transient Relatively large fluctuations occur in response. As a result, due to fluctuations in DC voltage, the S/N ratio of communication signals transmitted on the same DC supply line decreases and a certain S/N ratio required to keep the bit error rate of communication signals below a specified value may not be ensured.

More specifically, as shown in FIG. 6A, although the amplitude of voltage fluctuations due to changes in the operating states of each DC load is small, if the operating states are simultaneously changed in a plurality of DC loads, these voltage fluctuations are accumulated, and As shown in FIG. 6B , the voltage fluctuation on the DC supply line has a large amplitude. Therefore, although there is no large influence on the S/N ratio of the communication signal when the amplitude of the voltage fluctuation is small as shown in FIG. 6A, the S/N ratio of the communication signal is caused by the voltage fluctuation with a large amplitude as shown in FIG. The /N ratio drops significantly, and a specific S/N ratio cannot be ensured.

Contents of the invention

The present invention has been made in consideration of the above circumstances, and an object of the present invention is to provide a load control system, a DC load, and a terminal device, wherein the load control system is configured to control requests for a plurality of DC loads even when In the case of , a certain S/N ratio is also ensured for the communication signal transmitted on the DC supply line.

A load control system (1) of the present invention, comprising: a plurality of DC loads (3), each of which is configured to receive power supply from a DC power source (5) via a wiring line (2) that doubles as a DC power supply line and a transmission line and a terminal device (4), which includes: a terminal-side communication unit (41) configured to transmit communication signals to the plurality of DC loads (3) via the wiring line (2); and processing A unit (42) configured to provide control requests to the plurality of DC loads (3) using the communication signal. Each DC load (3) of the plurality of DC loads (3) includes: a load-side communication unit (31) configured to receive communication signals from the terminal device (4); and a control unit (32) , which is configured to control the working state of the DC load (3) in response to a control request obtained from a communication signal received by the load-side communication unit (31). The load control system (1) is configured such that each of the control units (32) in two or more DC loads (3) as all or a part of the plurality of DC loads (3) responds to a control When requesting to control the working state of its own DC load (3), the control unit (32) in the two or more DC loads (3) is used to control the two or more DC loads ( 3) The working state is controlled at each moment dispersed.

A load control system (1) of the present invention, comprising: a plurality of DC loads (3), each of which is configured to receive power supply from a DC power source (5) via a wiring line (2) that doubles as a DC power supply line and a transmission line and a terminal device (4), which includes: a terminal-side communication unit (41) configured to transmit communication signals to the plurality of DC loads (3) via the wiring line (2); and processing A unit (42) configured to provide control requests to the plurality of DC loads (3) using the communication signal. Each DC load (3) of the plurality of DC loads (3) includes: a load-side communication unit (31) configured to receive communication signals from the terminal device (4); and a control unit (32) , which is configured to control the working state of the DC load (3) in response to a control request obtained from a communication signal received by the load-side communication unit (31). The load control system (1) is configured to, when the control request for the plurality of DC loads (3) is generated in the terminal device (4), respond to the plurality of DC loads (3) ) changes in the working state of the wiring line (2) that cause voltage fluctuations in the DC voltage to be suppressed, thereby ensuring a bit error rate for the communication signals transmitted on the wiring line (2). Keep the required S/N ratio below the specified value.

In an embodiment, the load control system causes the control unit (32) to stagger the time points at which the control unit (32) controls the working state in response to the control request, so that the time points at the multiple DC loads (3) not repeated in between.

In an embodiment, each DC load (3) in the plurality of DC loads (3) further includes an adjustment unit (7), and the adjustment unit (7) is configured to communicate from the load side communication unit (31 ) causes the control unit (32) to control the working state after an inherent waiting time different among the plurality of direct current loads (3) has elapsed after receiving the communication signal containing the control request.

In an embodiment, each DC load (3) in the plurality of DC loads (3) further includes an adjustment unit (7), and the adjustment unit (7) is configured to communicate from the load side communication unit (31 ) causing the control unit (32) to control the working state after a randomly set waiting time elapses after receiving the communication signal containing the control request.

In an embodiment, the terminal device (4) further includes an adjustment unit (7), and the adjustment unit (7) is configured such that the terminal-side communication unit (41) operates on the plurality of DC loads (3) The communication signals containing the control request are sent at different time points.

The DC load (3) of the present invention is configured for use in said load control system.

The terminal device (4) of the present invention is configured for use in said load control system.

The present invention has an advantage that a certain S/N ratio can be secured for a communication signal transmitted on a DC supply line (wiring line) even when a control request for a plurality of DC loads is generated.

Description of drawings

Preferred embodiments of the present invention will now be described in further detail. Other features and advantages of the present invention will be better understood through the following detailed description and accompanying drawings, in which:

FIG. 1 shows the configuration of a load control system according to Embodiment 1, in which FIG. 1A is an overall system configuration diagram, and FIG. 1B is a block diagram of its main components.

2A and 2B are each an explanatory diagram showing the operation of the load control system according to Embodiment 1. FIG.

3A and 3B are each an explanatory diagram showing the operation of the load control system according to Embodiment 1. FIG.

Fig. 4 is a graph showing the relationship between the S/N ratio and the bit error rate.

5A and 5B are each explanatory diagrams showing other operations of the load control system according to Embodiment 1. FIG.

6A and 6B are each an explanatory diagram showing the operation of the conventional example.

detailed description

The load control systems according to the following embodiments are configured to be used in a DC power distribution system that distributes DC power, such as in a residence or the like. In this DC power distribution system, a plurality of DC loads including electrical machines and equipment are configured to receive supply of DC power from a DC power source via DC power lines to perform operations.

Example 1

As shown in FIGS. 1A and 1B, the load control system 1 of the present embodiment includes a plurality of (four in the example of FIG. 1A ) DC loads 3 (301) connected to wiring lines 2 serving both as DC power lines and transmission lines. , 302, 303 and 304) and terminal device 4. The number of DC loads 3 and the number of terminal devices 4 connected to the wiring line 2 can be changed appropriately and are not limited to the numbers shown in the example of FIG. 1A .

The wiring line 2 is connected to an output of a DC/DC converter 5 as a direct current power supply. The wiring line 2 is, for example, a 2-wire line. The DC/DC converter 5 is housed within the distribution board 6 and is connected to the output of an AC/DC converter (not shown). The AC/DC converter is housed in the distribution board 6 and is configured to convert AC power (commercial power) into DC power. DC power that is the output of a photovoltaic power generation device, a fuel cell, a storage battery, and the like can be input to the DC/DC converter 5 .

The wiring line 2 is connected to a plurality of DC loads 3 and terminal devices 4 configured to receive DC power output from a DC/DC converter 5 for operation. In this embodiment, a downlight having an LED (Light Emitting Diode) as a light source and arranged at an appropriate position in a house is taken as an example of the DC load 3, and is used for ON (connection) and OFF (disconnection) of the DC load 3. ) will be described as the terminal device 4.

Since the wiring line 2 doubles as a DC power supply line and a transmission line, each DC load 3 and terminal device 4 connected to the wiring line 2 can communicate with each other by superimposing communication signals on the DC voltage of the wiring line 2 . This communication signal is a signal for transmitting data using a high-frequency carrier wave.

As shown in FIG. 1B , the terminal device 4 includes a terminal-side communication unit 41 , a processing unit 42 and a storage unit 43 . The terminal-side communication unit 41 is configured to receive and transmit communication signals via the wiring line 2 . The processing unit 42 is configured to provide control requests to (all or a part of) the plurality of DC loads 3 using communication signals. The storage unit 43 is configured to store a unique address. The DC load 3 includes a load-side communication unit 31 , a control unit 32 , a storage unit 33 and a timer 34 . The load side communication unit 31 is configured to receive and transmit communication signals via the wiring line 2 . The control unit 32 is configured to control the operating state of the DC load 3 (for example, turn on or turn off, etc.) in response to a control request obtained from a communication signal received by the load side communication unit 31 . The storage unit 33 is configured to store a unique address. According to this, the terminal device 4 and the plurality of DC loads 3 can bidirectionally communicate with each other by transmitting and receiving communication signals between the terminal side communication unit 41 and each load side communication unit 31 . This communication signal contains the address of the other party as a destination.

More specifically, the terminal device 4 is connected to a wall switch (not shown) including a plurality of operation switches, and stores the correspondence table in the storage unit 43 . The correspondence table makes the following two kinds of information correspond: the operation input received from the operation switch when the operation switch is operated; and the information of one or more DC loads 3 corresponding to the operation switch among the plurality of DC loads 3 one or more addresses. The terminal device 4 is configured to, in the case of receiving an operation input from the operation switch, acquire one or more addresses corresponding to the operation input from the correspondence table and direct to one or more addresses having the one or more addresses. Load 3 provides control requests. Therefore, the operating state of one or more DC loads 3 can be controlled in response to the operation of the operation switch. The DC load 3 is configured to return a control response via a communication signal to the terminal device 4 which is the transmission source of the control request when the control via the operation state of the control unit 32 is completed.

For example, in the case of receiving an operation input corresponding to the DC load 301 from the wall switch, the terminal device 4 provides a control request to the DC load 301 and changes the operation state of the DC load 301 . The DC load 301 is controlled so that the DC load 301 is turned on if the DC load 301 is turned off at the point in time when the control request is received, and the DC load 301 is also controlled so that when the control request is received If the DC load 301 is turned on at the time point of , then the DC load 301 is turned off. The DC load 301 is configured to return the operating state after the control to the terminal device 4 as a control response.

In the correspondence table in the storage unit 43 of the terminal device 4, two or more DC loads 3 can be associated with one operation input. Upon receiving such an operation input, the terminal device 4 simultaneously generates control requests for the two or more DC loads 3 .

That is to say, for example, in the case of receiving operation inputs corresponding to four DC loads 301, 302, 303 and 304, the terminal device 4 simultaneously broadcasts to these four DC loads 301, 302, 303 and 304 Provide control requests. However, if the working states of multiple DC loads 301, 302, 303 and 304 change simultaneously, the DC voltage on the wiring line 2 fluctuates relatively greatly due to the transient response.

At this time, the S/N ratio of the communication signal transmitted on the same wiring line 2 decreases, and a certain S/N ratio required to keep the bit error rate related to the communication signal below a specified value may not be ensured. In this embodiment, as shown in FIG. 1A , the same wiring line 2 is one or more electric wires electrically connected to a terminal device 4 . Communication signals transmitted on the same wiring line 2 include: communication signals sent from the terminal device 4 that has provided control requests to the DC loads 301, 302, 303, and 304 to other DC loads; and communication signals sent from other terminal devices 4. Signal.

Therefore, the load control system 1 is configured such that each control unit 32 in two or more DC loads 3 as all or a part of the plurality of DC loads 3 monitors the operating state of its own DC load 3 in response to a control request. In the case of controlling, the control units 32 in the two or more DC loads 3 are distributed in various moments for controlling the working states of the DC loads 3 . It is expected that each moment is dispersed within a specified time or within a specified time according to unit time (the fluctuation of the DC voltage on the wiring line is reduced to be less than the threshold value, wherein the fluctuation is caused by a change in the working state of a DC load 3) And the number of units of DC load 3 is dispersed within the time period obtained. In the present embodiment, the load control system 1 is configured to: when a control request for two or more DC loads 3 is generated in the terminal device 4, suppress the The voltage fluctuation of the DC voltage on the wiring line 2 ensures a certain S/N ratio required to keep the bit error rate below a specified value for the communication signal transmitted on the wiring line 2 . Therefore, the load control system 1 is configured such that the time points at which the control unit 32 controls its working state in response to the control request can be staggered among the plurality of DC loads 3 without repetition. In this embodiment, as shown in FIG. 1B , each of the plurality of DC loads 3 is provided with an adjustment unit 7 . The adjustment unit 7 is configured to suppress voltage fluctuations generated in the DC voltage when a control request for two or more DC loads 3 is generated in the terminal device 4 .

In FIG. 1B , the adjustment unit 7 is configured to make the time point (control moment) when the control unit 32 controls the working state in response to the control request staggered in a coordinated manner with other DC loads 3, so that more than two DC loads 3 are not repeated, thereby suppressing voltage fluctuations generated in the DC voltage. In other words, even in the case where one control request for two or more DC loads 3 is generated in the terminal device 4, the plurality of adjustment units 7 makes the time point of controlling the operation state in response to the control request to be at two The above DC loads 3 are staggered in a non-repetitive manner. This enables the load control system 1 to avoid simultaneous changes in the operating states of two or more DC loads 3 and to suppress a decrease in the S/N ratio of the communication signal.

In this embodiment, the adjustment unit 7 is respectively installed in a plurality of DC loads 3 . In addition, the storage unit 33 of the DC load 3 pre-stores different inherent waiting times among the plurality of DC loads 3 . The length of the waiting time is set in advance to be different among all the plurality of DC loads 3 belonging to one load control system 1 . In FIG. 1B , the adjusting unit 7 is configured to start, via the timer 34, the inherent waiting time set in its own DC load 3 from the time point when the load-side communication unit 31 receives a communication signal containing a control request. timing; and providing the control unit 32 with an instruction to perform control of the operation state in response to the control request at a point in time when the waiting time has elapsed. As a result, among two or more DC loads 3, even if the terminal device 4 simultaneously transmits a communication signal including a control request to two or more DC loads 3 by multicasting, the control time for actually controlling the operating state is at the two or more DC loads. DC loads are distributed between 3.

The operation of the load control system 1 in this embodiment will now be described with reference to the examples of FIGS. 2A and 2B. FIG. 2A shows voltages fluctuating due to transient responses caused by changes in the respective operating states of DC loads 301 , 302 , 303 , and 304 . FIG. 2B shows voltage fluctuations generated in the wiring line 2 as a final result of accumulation of individual voltage fluctuations.

In the load control system 1, as shown in FIG. 2A , in the case where the terminal device 4 simultaneously transmits a communication signal including a control request, after the inherent waiting times t1, t2, t3, and t4 have elapsed from the reception point of the communication signal , the DC loads 301, 302, 303 and 304 change their working states respectively. In the example of FIG. 2A , the lengths of the waiting times t1 , t2 , t3 , and t4 are set to be sequentially longer in the range of about several tens of milliseconds ( t1 < t2 < t3 < t4 ).

In the DC load 301, its operation state changes after the elapse of the waiting time t1 from the reception point of the communication signal, whereby voltage fluctuation due to transient response is generated in the DC voltage V1 on the wiring line 2 . In the DC load 302, its operation state changes after the elapse of the waiting time t2 from the reception point of the communication signal, whereby a voltage fluctuation due to transient response is generated in the DC voltage V2 on the wiring line 2 . In the DC load 303, its operation state changes after the elapse of the waiting time t3 from the reception point of the communication signal, whereby a voltage fluctuation due to transient response is generated in the DC voltage V3 on the wiring line 2 . In the DC load 304, its operation state changes after the elapse of the waiting time t4 from the reception point of the communication signal, whereby a voltage fluctuation due to transient response is generated in the DC voltage V4 on the wiring line 2 . In the example of FIG. 2A , it is assumed that voltage fluctuations due to changes in the operating state of the DC load 3 have the same amplitude (peak-to-peak) "A1".

Therefore, since the timing at which voltage fluctuations are generated due to transient responses differs from each other among the DC loads 301, 302, 303, and 304, as shown in FIG. Scatter in the direction of the time axis. As a result, unlike the case where the operating states of the DC loads 301, 302, 303, and 304 change simultaneously and the amplitude of the voltage fluctuation is large as a result of the accumulation of the respective transient responses, the voltage generated in the DC voltage V0 on the wiring line 2 The amplitude suppression of fluctuations is "A1".

According to the load control system 1 of the above-described embodiment, even if a control request for two or more DC loads 3 is generated in the terminal device 4, the adjustment unit 7 staggers the control timing for each DC load 3, thereby avoiding the operation of the DC load 3 The state changes at the same time. As a result, the amplitude of the voltage fluctuation of the DC voltage on the wiring line 2 can be suppressed to be smaller compared with the case where the operation states of a plurality of DC loads 3 are changed at the same time, thereby suppressing the communication due to the voltage fluctuation of the DC voltage. The reduction of the S/N ratio of the signal and ensuring a specific S/N ratio. The specific S/N ratio described here is the S/N ratio required to keep the bit error rate related to the communication signal below a specified value, thereby establishing communication between the terminal device 4 and the corresponding plurality of DC loads 3 .

The voltage fluctuation caused by the transient response when the working state of the load changes can be generated not only on the DC voltage but also on the AC voltage. However, in a DC power distribution system, since the power supply capacity of the system is small compared to an AC power distribution system that distributes AC power from such as a commercial power supply, voltage fluctuations due to transient responses may easily occur . Therefore, the load control system 1 of the present embodiment is applied not only to the AC power distribution system but also to the DC power distribution system, thereby having a remarkable effect in suppressing a decrease in the S/N ratio of communication signals due to voltage fluctuations.

In addition, in the load control system of the present embodiment, the adjustment unit 7 is installed in each of the plurality of DC loads 3 . At a point in time when inherent waiting times different among the plurality of DC loads 3 have elapsed from the reception point of the communication signal, the adjustment unit enables the control unit 32 to perform control of an operating state in response to a control request. Therefore, each DC load 3 needs to control the control unit 32 after the lapse of the inherent waiting time in the same manner every time a communication signal is received, and since the adjustment unit 7 does not require complicated arithmetic processing, the structure can be simplified.

In a variant embodiment, the adjusting unit 7 is configured to judge whether the communication signal received via the load-side communication unit 31 is sent by multicast or unicast. In addition, the adjustment unit 7 is configured to enable the counting of the waiting time when the communication signal is transmitted by multicast, and to invalidate the counting of the waiting time when the communication signal is transmitted by unicast (for example, set the waiting time to set to 0). In this case, only when a control request for two or more DC loads 3 is generated from the terminal device 4, the adjustment unit 7 shifts the control timing after the waiting time has elapsed. Furthermore, in the case where a control request is given to only one DC load 3, the DC load 3 that has received the control request disables the function of the adjustment unit 7, and immediately executes the response to the control request without counting the waiting time. control of the working status. Accordingly, when a control request is given to only one DC load 3 , the response speed of the DC load 3 to the control request does not decrease. In addition, the address included in the communication signal can be used to determine whether a control request is given to one DC load 3 .

The point that a specific S/N ratio is ensured by the structure of this embodiment will be described in detail below with reference to FIGS. 3 and 4 .

The communication signal is superimposed on the DC voltage on the wiring line 2 . In FIG. 3A , the amplitude A101 of the voltage fluctuation of the DC voltage 101 is smaller than the amplitude A100 of the communication signal 100 . In this case, even if the two are superimposed, the DC voltage does not have a large influence on the S/N ratio. On the other hand, in FIG. 3B , the amplitude A102 of the voltage fluctuation of the DC voltage 102 is larger than the amplitude A100 of the communication signal 100 . In this case, if the two are superimposed, the S/N ratio of a part of data in the communication signal 100 will be greatly lowered due to the voltage fluctuation of the DC voltage 102 as noise. In short, a part of data in the communication signal 100 is corrupted by the voltage fluctuation of the DC voltage 102 as noise.

FIG. 4 shows the relationship (theoretical value when error correction is omitted) between the S/N ratio (SNR) and the bit error rate (BER) for different types of multi-level modulation schemes. Figure 4 shows the relationship between the five modulation modes of BPSK (Phase Shift Keying), QPSK, 8PSK, 16QAM (Quadrature Amplitude Modulation) and 64QAM. The higher the modulation mode, the larger the amount of data, but the more vulnerable Noise effect. As shown in FIG. 4 , in the case of achieving the same bit error rate, a higher-order modulation scheme has a higher S/N ratio. As can be seen from FIG. 4 , even if the S/N ratio is only slightly lowered, the bit error rate is greatly increased, whereby communication errors are likely to occur.

For example, in the load control system 1 in which the DC load 3 is composed of lighting fixtures, the amount of data to be transmitted is small, so BPSK is sufficient. However, since this system 1 requires a high response speed of the DC load 3 , the condition of the bit error rate required for the system as a whole becomes severe. In the case where the system requires a bit error rate satisfying the condition of BER≦10 ^-7 , that is, a bit error rate with a specified value of 10 ^-7 or less, in BPSK it is necessary to satisfy the condition of SNR≧11dB as shown in Figure 4 S/N ratio. Therefore, in the absence of the condition that the noise level is approximately 1/3.5 or less of the signal level of the communication signal at the receiving end, the specific condition for keeping the bit error rate below a specified value (10 ^-7 ) cannot be realized. S/N ratio. Furthermore, under the same conditions, with error correction applied, even if the bit error rate is improved by, for example, about 6 dB, the noise level exceeds twice the signal level (in short, about 1 /1.75), the specific S/N ratio used to keep the bit error rate below the specified value cannot be achieved.

Therefore, as shown in FIG. 3B, in the case where the amplitude A102 of the voltage fluctuation of the DC voltage 102 is larger than the amplitude A100 of the communication signal 100, even if the frequency of occurrence of the voltage fluctuation is low, it is difficult to realize the error rate based on the bit error rate as described above. Specifies the specific S/N ratio required for the value. In contrast, as shown in FIG. 3A, in the case where the amplitude A101 of the voltage fluctuation of the DC voltage 101 is smaller than the amplitude A100 of the communication signal 100, even if the frequency of occurrence of the voltage fluctuation is high, it is possible to achieve the specified value according to the bit error rate. Specific S/N ratio required. In short, in the load control system 1 of the present embodiment, a certain S/N ratio can be ensured. This is because the amplitude of the voltage fluctuation due to the transient response of the DC voltage is suppressed to be small and the decrease in the S/N ratio of the communication signal is suppressed.

Furthermore, for another example, in the load control system 1 configured to control the air conditioner as the DC load 3 using the measurement result of the temperature sensor, the system does not require high DC load 3 as required in the case of the lighting fixture described above. Response speed. In this case, even if the DC load 3 cannot be controlled due to a communication error, the terminal device 4 can still send a control request again, so the condition of the bit error rate required for the system as a whole becomes less strict. In short, when a bit error rate satisfying the condition of BER≦10 ^-2 is required, that is, a bit error rate with a specified value of 10 ^-2 or less, even if there is no error correction, in BPSK as shown in Fig. 4 A S/N ratio of only about 5 dB is also required.

In addition, in this case, as in the case of the lighting fixture described above, as shown in FIG. 3B , when the amplitude A102 of the voltage fluctuation of the DC voltage 102 is larger than the amplitude A100 of the communication signal 100, it is difficult to maintain the bit error rate. A specific S/N ratio used below the specified value (10 ^-2 ). In contrast, as shown in FIG. 3A, in the case where the amplitude A101 of the voltage fluctuation of the DC voltage 101 is smaller than the amplitude A100 of the communication signal 100, a specific S/N ratio required according to a specified value of the bit error rate can be easily realized.

In this embodiment, the adjustment unit 7 substantially utilizes the preset inherent waiting time among the multiple DC loads 3 to stagger the control timing among the multiple DC loads 3 in a coordinated manner, but the present invention is not limited to this example . For example, the adjusting unit 7 installed in each of the plurality of DC loads 3 may be configured to enable the control unit 32 to Control the working status. In this example, the DC load 3 does not set an inherent waiting time, but a random waiting time is determined in the adjustment unit 7 every time the load-side communication unit 31 receives a communication signal containing a control request. When the load side communication unit 31 receives the communication signal including the control request, the adjustment unit 7 starts to count the randomly determined waiting time. At the point of time when this waiting time has elapsed, the adjustment unit 7 provides the control unit 32 with an instruction to perform control of the operating state in response to the control request.

In the load control system 1 of this configuration, as shown in FIG. 5 , when the terminal device 4 simultaneously transmits a communication signal including a control request, random waiting times t1 and t2 have elapsed from the reception point of the communication signal. After , t3 and t4, the DC loads 301, 302, 303 and 304 change their working states respectively. Same as FIG. 2 , FIG. 5A shows voltage fluctuations that occur due to transient responses caused by changes in the respective operating states of the DC loads 301, 302, 303, and 304, and FIG. 5B shows the accumulated results as the respective voltage fluctuations Finally, voltage fluctuations are generated on the wiring line 2 .

In short, since the waiting times t1, t2, t3, and t4 (t1≠t2≠t3≠t4) are randomly determined between two or more DC loads 3, voltage fluctuations are generated by the transient response as shown in FIG. 5A There is a high probability that the timing of is different among the DC loads 301 , 302 , 303 , and 304 . Therefore, as shown in FIG. 5B , voltage fluctuations finally generated in the DC voltage V0 on the wiring line 2 are dispersed in the direction of the time axis. As a result, the amplitude of the voltage fluctuation generated in the DC voltage V0 on the wiring line 2 can be suppressed to "A1".

According to this configuration, even if the number of DC loads 3 belonging to the same load control system 1 increases, since the waiting time of each DC load 3 is randomly determined, it is possible to reduce the probability of duplication of control timing between different DC loads 3 . Therefore, even if the terminal device 4 transmits the communication signal including the control request to multiple DC loads 3 simultaneously by multicasting, the probability that the operating states of the multiple DC loads 3 change simultaneously can be reduced. Furthermore, since the contractor does not need to set an inherent waiting time for each DC load 3 in the case of installation of the load control system 1 or the like, labor of the contractor can be saved.

Example 2

The difference between the load control system 1 of the present embodiment and the load control system 1 of the first embodiment is that the adjustment unit is not installed in each DC load 3 but in the terminal device 4 . Hereinafter, elements of the same kind are assigned the same reference numerals as in Embodiment 1, and descriptions of these elements are appropriately omitted.

In this embodiment, the adjustment unit is configured to enable the terminal-side communication unit 41 to transmit the communication signal including the control request at different time points (transmission times) between two or more DC loads 3 . Therefore, the control units 32 of the two or more DC loads 3 can stagger the time points (control timing) for controlling the operation state in response to one control request between the two or more DC loads 3 . In short, in the case of receiving an operation input related to these two or more DC loads 3, the terminal device 4 adjusts the transmission timing through the adjustment unit, not at the same time but at different times among the plurality of DC loads 3 Points provide control requests to the plurality of DC loads 3 . For example, whenever a randomly determined waiting time elapses from the reception point of the operation input, the adjustment unit sequentially transmits communication signals to each of the two or more DC loads 3 so that the transmission timing is between the two or more DC loads 3 different.

In the load control system 1 of the above embodiment, since the terminal device 4 has the adjustment unit, the function of the adjustment unit is not required for each DC load 3 and the existing DC load 3 can be applied without change. Furthermore, even if the number of DC loads 3 belonging to the same load control system 1 increases, the probability of duplication of control timing between different DC loads 3 can be reduced. This is because the terminal device 4 randomly determines the waiting time at the time of transmission.

Without being limited to the above configuration, the terminal device 4 may store a waiting time predetermined for each DC load 3 in the storage unit 43 and may be configured to transmit communication signals in the determined order.

Other structures and functions are the same as those in Embodiment 1.

The adjustment unit is not limited to a configuration in which control timings are shifted for all the DC loads 3 that are the targets of the control request. The adjustment unit may also be configured to stagger the control timing for only a part of the two or more DC loads 3 that are objects of the control request. Also, in this case, since the voltage fluctuation of the DC voltage can be suppressed to be small compared with the case where the operating states of all the DC loads 3 are changed simultaneously, it is possible to suppress a decrease in the S/N ratio of the communication signal.

In addition, the adjustment unit can suppress voltage fluctuations in the DC voltage on the wiring line 2 due to changes in the operating state of the DC load 3 by methods other than staggering the control timing, thereby ensuring a specific S/N ratio . Although detailed description is omitted, for example, the adjustment unit may even perform control in such a manner that the adjustment unit performs control to reduce the surge current of at least one of the two or more DC loads 3 that are objects of the control request. Suppresses voltage fluctuations generated in DC voltage.

Although the present invention has been described with reference to certain preferred embodiments, various modifications and changes can be made by those skilled in the art without departing from the true spirit and scope of the present invention, namely claims.

Claims (7)

1. a kind of load control system, including：

Multiple DC loads, it is each configured as via being also used as the wiring route of direct current supply line and transmission line from direct current Source receives power supply to be operated；And

Terminal installation, it includes：End side communication unit, it is configured as negative to the multiple direct current via the wiring route Carry transmission signal of communication；And processing unit, it is configured to, with the signal of communication and provided to the multiple DC load Control data,

Wherein, each DC load in the multiple DC load includes：Load-side communication unit, it is configured as reception and come from The signal of communication of the terminal installation；And control unit, it is configured to respond to from the utilization load-side communication unit The control data that the signal of communication received is obtained is controlled come the working condition to the DC load, and

The load control system also includes adjustment unit, and the adjustment unit is configured as producing pin in the terminal installation To in the case of the control data of the multiple DC load, the change to the working condition due to the multiple DC load Change and cause the voltage pulsation produced in the DC voltage on the wiring route to be suppressed, so that for the wiring route On transmitted the signal of communication, ensure to make the bit error rate remain below designated value needed for S/N ratios,

The adjustment unit is configured in each DC load in the multiple DC load,

The adjustment unit is configured as：The signal of communication is being sent so as to simultaneously to the multiple DC load by multicast In the case of giving the control data, the adjustment unit by the time point that have passed through the stand-by period to the control Unit is provided to the instruction for the control for performing the working condition in response to the control data, and the voltage pulsation is carried out Suppress；The signal of communication is being sent by unicast so as to only give the situation of the control data to a DC load Under, the adjustment unit without indicate immediately in the case of to the stand-by period timing described control unit perform in response to The control of the working condition of the control data.

2. load control system according to claim 1, wherein, the load control system causes described control unit to ring Each time point that control data described in Ying Yu is controlled to working condition staggers, to cause each time point in the multiple direct current Do not repeated between load.

3. load control system according to claim 1 or 2, wherein, the adjustment unit is configured as bearing from described Side communication unit is carried to receive the signal of communication comprising the control data, have passed through between the multiple DC load not After same inherent latency so that described control unit is controlled to the working condition.

4. load control system according to claim 1 or 2, wherein, the adjustment unit is configured as bearing from described Carry side communication unit receive the signal of communication comprising the control data rise, have passed through the stand-by period being randomly provided after, So that described control unit is controlled to the working condition.

5. load control system according to claim 1 or 2, wherein, the terminal installation also includes adjustment unit, described The adjustment unit of terminal installation is configured such that the end side communication unit between the multiple DC load by difference Time point send and include the signal of communication of the control data.

6. a kind of DC load, it is configurable for load control system according to any one of claim 1 to 4 In.

7. a kind of terminal installation, it is configurable in load control system according to claim 5.