JP2012074156A - Lighting device, luminaire and lighting system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To measure input power without using a current transformer, and determine input power with sufficient precision even when the ambient temperature of a light source load changes.SOLUTION: A sensing resistor 45 is connected in series with a switching element 42 of a power conversion circuit 4 to sense a current flowing through the switching element 42. A power computing section 83 uses a power setting value output from a power setting section 81 as a determinant of the magnitude of power supplied to an electric discharge lamp 11 and a current sensing value corresponding to the output of the sensing resistor 45 to compensate a fluctuation in the current sensing value caused by a change in the ambient temperature of the electric discharge lamp 11 in determining input power. Specifically, the power computing section 83 computes input power by using a power conditioning value depending on a difference between the power setting value and the current sensing value, a maximum power value that is the power setting value which maximizes power supplied to the electric discharge lamp 11, and the power setting value.

Description

  The present invention relates to a lighting device, a lighting fixture, and a lighting system capable of measuring input power.

  Conventionally, there has been proposed a power supply device that appropriately converts power supplied from an external power supply and supplies it to a load, and measures input power (power consumption) and presents the same to the outside (see, for example, Patent Documents 1 and 2). ). Measurement results of input power obtained from these power supply devices are presented to the user of the power supply device or the manager of the facility to which the power supply device is attached, and can be used for wasteful power consumption reduction (power saving) and the like. .

  As a method for measuring input power, it is generally known to use a current transformer. However, current transformers are difficult to miniaturize and are relatively expensive. The equipment is also large and expensive.

  On the other hand, a lighting device having a configuration capable of measuring input power without using a current transformer has also been proposed. The lighting device includes a power conversion unit that appropriately converts DC power input from a DC power supply unit including a switching element and supplies the light source load, a current detection unit that detects a current flowing through the switching element, and a current detection unit And an arithmetic unit that obtains input power using the detected value.

  Here, the current detection unit includes a detection resistor connected in series with the switching element, and outputs a value that increases as the current flowing through the switching element and the detection resistance increases as a detection value. The calculation unit calculates the input power (power consumption) Win by the expression Win = α × Vs + β using the detection value Vs of the current detection unit and the constants α and β.

  In this configuration, since the current detection unit can be configured by a resistance element connected in series to the switching element, the lighting device (power supply device) can be realized relatively small and inexpensively.

Japanese Utility Model Publication No. 64-13695 Japanese Patent No. 3168842

  By the way, a typical fluorescent lamp as a light source load has an impedance (= lamp voltage / lamp current) that varies depending on the ambient temperature due to its temperature characteristics, and the lamp current increases and lamp power decreases at high and low temperatures. It is known that there is a tendency. Even in a light source using a light emitting diode that has been attracting attention in recent years, the impedance changes depending on the ambient temperature due to its temperature characteristics. For this reason, in lighting devices for lighting these light source loads, the device is devised to improve controllability by feedback control or the like so that the current and voltage flowing through the load have predetermined characteristics against impedance fluctuations of the light source. .

  However, as described above, the input power Win calculated by the equation Win = α × Vs + β cannot cope with a negative characteristic in which the signal integrated value decreases with an increase in input power due to a change in ambient temperature. A relatively large error may occur between That is, there is no problem as long as the ambient temperature of the light source load is constant, but when the ambient temperature changes, the value of the input power Win obtained by the above-described arithmetic expression may not be sufficiently accurate.

  The present invention has been made in view of the above reasons, and can measure input power without using a current transformer, and can obtain input power with sufficient accuracy even if the ambient temperature of the light source load changes. It aims at providing a lighting device, a lighting fixture, and a lighting system.

  The lighting device of the present invention includes a power conversion unit that includes a switching element and adjusts the power supplied to the light source load by using DC power as an input, and determines the magnitude of the power supplied to the light source load. A control unit that inputs a power setting value and controls the operation of the power conversion unit; a current detection unit that detects a current flowing through the switching element; a power estimation unit that estimates input power using a detection value of the current detection unit; Presenting the estimation result of the power estimator, the power estimator using the power setting value and the current detection value corresponding to the output of the current detection unit, resulting from a change in the ambient temperature of the light source load The input power is obtained by correcting the fluctuation of the detected current value.

  In this lighting device, the power estimation unit normalizes the power setting value using the power setting value when the power supplied to the light source load is maximum as the maximum power value, and sets the power setting value and the current detection value. It is desirable to obtain the input power using the power adjustment value corresponding to the difference between the two.

  In this lighting device, the power estimation unit subtracts the power adjustment value from a value obtained by multiplying a ratio of the power setting value to the maximum power value by a coefficient set in advance so as to be larger than the power adjustment value. It is more desirable to obtain a value corresponding to the input power.

  The lighting fixture of this invention is equipped with the fixture main body which comprises the said lighting device, and the light source load hold | maintained at the said fixture main body.

  A lighting system according to the present invention includes a plurality of the above-described lighting fixtures, and a reading device that receives a notification signal transmitted from a presentation unit and reads an estimation result of a power estimation unit.

  The present invention has an advantage that input power can be measured without using a current transformer, and input power can be obtained with sufficient accuracy even if the ambient temperature of the light source load changes.

1 is a schematic circuit diagram illustrating a configuration of a lighting device according to Embodiment 1. FIG. It is a schematic circuit diagram which shows the principal part same as the above. It is a time chart which shows the operation | movement of a frequency generation part same as the above. It is explanatory drawing which shows the relationship between input power same as the above and a current detection value. It is a schematic diagram which shows the relationship between input power same as the above and a current detection value. It is explanatory drawing which shows the relationship between input power same as the above and a current adjustment value. (A) is explanatory drawing which shows the relationship between input power and calculation value when (alpha) = 4.5, (b) is (alpha) = 5, (c) is (alpha) = 6. It is explanatory drawing which shows the relationship between the lamp electric power when α = 5 same as the above, and a calculated value. It is explanatory drawing which shows the relationship between input electric power when (alpha) = 8 same as the above, and a calculated value. FIG. 5 is a schematic circuit diagram illustrating a configuration of a lighting device according to a second embodiment. It is a perspective view which shows the lighting fixture using the lighting device same as the above.

(Embodiment 1)
As shown in FIG. 1, the lighting device 1 of the present embodiment includes a rectifier 2 connected to an AC power supply 100, a DC power supply circuit 3, a power conversion circuit 4, a load circuit 5, a control circuit 6, and a frequency. A calculation unit 7 and an output setting unit 8 are provided. The lighting device 1 does not include the AC power source 100 and the discharge lamp 11 in FIG.

  The DC power supply circuit (DC power supply unit) 3 includes a smoothing capacitor (not shown) and is connected to the output of the rectifier 2 to smooth the full-wave rectified voltage output from the rectifier 2. Therefore, when the AC power supply 100 is turned on, a smoothed DC voltage is output from the DC power supply circuit 3, and this DC voltage is applied to the subsequent power conversion circuit (power conversion unit) 4. Note that the DC power supply circuit 3 may be configured to include at least a smoothing capacitor, and is not limited to a specific specific configuration.

  The power conversion circuit 4 includes a pair of switching elements 41 and 42 connected in series between the output terminals of the DC power supply circuit 3. Each switching element 41, 42 is composed of a MOSFET. The pair of switching elements 41 and 42 alternately turn on and off according to the drive signal output from the control circuit 6, thereby supplying high frequency power to the load circuit 5.

  The load circuit 5 is connected in parallel to the switching element 42, and has a series circuit of a DC cut capacitor 51, a resonance inductor 52, and a resonance capacitor 53. The discharge lamp 11 as a load (light source load) of the lighting device 1 is connected in parallel with the resonance capacitor 53.

  The lighting device 1 further includes a preheating circuit 9 for preheating the filament of the discharge lamp 11, and the preheating circuit 9 is also connected to the switching element 42 in parallel. The preheating circuit 9 includes a preheating transformer 92 in which a primary winding is connected to the output of the power conversion circuit 4 via a capacitor 91. From the secondary winding of the preheating transformer 92, a capacitor 93 and a capacitor 94 are provided. A preheating current is supplied to each filament of the discharge lamp 11.

  Further, in the example of FIG. 1, the control power supply circuit 10 that supplies the control power supply voltage Vcc1 to the control circuit 6 is also connected in parallel to the switching element 42. The control power supply circuit 10 generates a control power supply voltage across the capacitor 101 in accordance with the switching operation of the power conversion circuit 4 and clamps the voltage to a desired level by the Zener voltage of the Zener diode 102. However, the control power supply circuit 10 only needs to have a configuration capable of generating a control power supply in accordance with the switching operation of the power conversion circuit 4, and the specific circuit configuration is not limited to the configuration in FIG.

  The control circuit 6 mainly includes a drive unit 61, a reference power generation unit 62, and a frequency generation unit 63. The reference power supply generation unit 62 receives the control power supply voltage Vcc1 input to the control circuit 6, and generates the power supply voltage Vcc2 to be output to the frequency generation unit 63, the frequency calculation unit 7 and the output setting unit 8 described later. The reference power supply generation unit 62 may be configured to generate a constant voltage (power supply voltage Vcc2) using a Zener diode or a band gap, and is not limited to a specific specific configuration.

  The frequency generation unit 63 determines the frequency of the drive signal output to the switching elements 41 and 42 of the power conversion circuit 4. As shown in FIG. 2, the frequency generation unit 63 includes an operational amplifier 631 that constitutes a constant voltage buffer unit, an output transistor 630, a current mirror 632, and a comparator 633. The current mirror 632 determines the value of the current flowing to the capacitor 635 based on the current flowing to the load unit (here, the resistor 634) through the output transistor 630 according to the output of the operational amplifier 631. The comparator 633 compares the voltage across the capacitor 635 with a predetermined threshold value and controls the charge / discharge current flowing through the capacitor 635.

  When the voltage across the capacitor 635 is lower than the predetermined threshold value Vref2, a current determined by the output voltage Vref1 of the constant voltage buffer unit and the resistance value of the resistor 634 flows through the resistor 634. This current charges the capacitor 635 with a constant current via the current mirror 632 having a predetermined mirror ratio. On the other hand, when the voltage across the capacitor 635 reaches the threshold value Vref2, the “+” input of the comparator 633 is switched to the threshold value Vref3 by the transfer gate unit 636. Further, the switching element 637 is turned off by the output of the comparator 633, and the capacitor 635 starts discharging at a constant current.

  That is, as the output of the comparator 633 is switched between “H” and “L” as shown in FIG. 3B, the voltage across the capacitor 635 is shown in FIG. It becomes such a triangular waveform.

  Here, if the current flowing through the output transistor 630 according to the output of the operational amplifier 631 is large, the charge / discharge current value of the capacitor 635 is also large, the inclination of the triangular wave in FIG. 3A is large, and the frequency of the triangular wave is high. Become. As described above, the frequency generation unit 63 compares the voltage across the capacitor 635 with a predetermined threshold value, and controls the frequency of the triangular wave by the oscillator using the comparator 633 that controls the charge / discharge current flowing through the capacitor 635. is doing.

  The output voltage of the comparator 633 is input to the counter unit 638 and the dead time unit 639 in the subsequent stage. Although a specific circuit is not shown in FIG. 2, the counter unit 638 is configured such that the output is inverted at the falling edge of the input signal, so that a rectangular wave counter signal as shown in FIG. Generate. The counter signal generated by the counter unit 638 is input to the dead time unit 639. In the dead time unit 639, two drive signals having a pause period are generated so that the switching elements 41 and 42 are not simultaneously turned on.

  The dead time unit 639 generates a first drive signal that maintains “L” for a period td from the rising edge of the counter signal, as shown in FIG. 3D, by a combination of a delay element such as a capacitor and a logic element. Generate. The dead time unit 639 outputs the first drive signal to the first drive unit 611 constituting the drive unit 61. The first drive unit 611 receives the first drive signal and drives the switching element 42 via the resistor 43 (see FIG. 1).

  Also, the dead time unit 639 generates a second drive signal that maintains “L” for a period td from the rising edge of the inverted signal, using a signal obtained by inverting the counter signal of FIG. Is output to the second drive unit 612. The second drive unit 612 receives the second drive signal and drives the switching element 41 via the resistor 44 (see FIG. 1). That is, the period td is a driving signal pause period.

  Next, the frequency calculation unit 7 will be described with reference to FIG. As shown in FIG. 2, the frequency calculation unit 7 mainly includes an operational amplifier 71 and a capacitor 72 connected between the inverting input terminal and the output terminal of the operational amplifier 71 to constitute an integrator. Hereinafter, the output voltage of the operational amplifier 71 is referred to as a power adjustment value.

  A pulse signal is output from a power setting unit 81 constituting the output setting unit 8 described later, and a DC voltage obtained by converting the pulse signal into a direct current by a smoothing unit including resistors 73 and 74 and a capacitor 75 is a power set value. Is input to the non-inverting input terminal of the operational amplifier 71. The pulse signal output from the power setting unit 81 corresponds to a dimming rate that is determined inside the power setting unit 81 or determined based on a dimming signal input from a dimming signal generation device that can be operated externally. Have a duty ratio.

  On the other hand, the voltage across the detection resistor (current detection unit) 45 connected in series with the switching element 42 on the low voltage side of the power conversion circuit 4 is input to the inverting input terminal of the operational amplifier 71 via the resistor 76. The detection resistor 45 is inserted between the low voltage side (source) of the switching element 42 and the output terminal on the negative electrode side of the DC power supply circuit 3 so as to detect a current flowing through the switching element 42. As a result, a current detection value corresponding to the current flowing through the switching element 42 (an integral value of the voltage across the detection resistor 45) is input to the inverting input terminal of the operational amplifier 71.

  The output terminal of the operational amplifier 71 is connected to an output transistor 630 connected to the output terminal of the operational amplifier 631 constituting the frequency generation unit 63 via a diode 77 and a resistor 78.

  With the above configuration, when the current detection value input to the inverting input terminal of the operational amplifier 71 is larger than the power setting value input to the non-inverting input terminal, the output voltage (power adjustment value) decreases. When the output voltage (power adjustment value) of the operational amplifier 71 decreases, the current drawn to the output terminal of the operational amplifier 71 through the diode 77 and the resistor 78 increases. Therefore, the current flowing through the output transistor 630 constituting the frequency generation unit 63 is increased, and the frequency of the drive signal supplied to the power conversion circuit 4 is increased and consumed by the load circuit 5 due to the resonance action of the load circuit 5. Electric power decreases.

  On the other hand, when the integrated value of the current detection value is smaller than the power setting value, the output voltage (power adjustment value) of the operational amplifier 71 increases and the frequency of the drive signal supplied to the power conversion circuit 4 decreases. The power consumed by the load circuit 5 increases.

  In this way, the frequency calculation unit 7 changes the operating frequency (switching frequency) of the power conversion circuit according to the increase or decrease of the power adjustment value output from the operational amplifier 71, and the power consumption of the load circuit 5 becomes a desired value. Control as follows. In short, the control circuit 6 and the frequency calculation unit 7 constitute a control unit that inputs a power setting value that determines the amount of power (lamp power) supplied to the discharge lamp 11 and controls the operation of the power conversion circuit 4. To do.

  Next, the output setting unit 8 will be described. As shown in FIG. 1, the output setting unit 8 includes a power setting unit 81 that generates a pulse signal having a duty ratio corresponding to the dimming rate, a maximum power setting unit 82 that stores a maximum power value, and a predetermined calculation. It is comprised from the electric power calculating part 83 which implements.

  The maximum power setting unit 82 stores in advance a maximum power value corresponding to the pulse signal output from the power setting unit 81 when the power value consumed by the load circuit 5 is maximized.

  The power calculation unit 83 inputs the output of the power setting unit 81 (power set value), the output of the maximum power setting unit 82 (maximum power value), and the power adjustment value input from the frequency calculation unit 7 described above. As a result, a predetermined calculation is performed to estimate the input power of the lighting device 1. That is, the power calculation unit 83 functions as a power estimation unit that estimates input power using a detection value of the detection resistor 45 that is a current detection unit.

  Hereinafter, the operation in which the power calculation unit 83 obtains the input power of the lighting device 1 will be described with reference to Tables 1 and 2 and FIGS.

  Tables 1 and 2 show the input power (power consumption), lamp power, current detection value, power adjustment value, and calculation result of the power calculation unit 83 for each ambient temperature of the discharge lamp 11. Here, Tables 1 and 2 show that two fluorescent lamps (FHF63 type) are used as the discharge lamp 11, the input of the lighting device 1 is 200 V, the discharge lamp 11 is dimmed and lit by resonance, and the ambient temperature of the discharge lamp 11 Each value when the temperature changes from −10 ° C. to 60 ° C. is shown. The detected current value here is a numerical value obtained by averaging the voltages at both ends of the detection resistor 45 in FIG. 1, and is a minute value and includes a measurement error. The power adjustment value is an output voltage of the operational amplifier 71 that constitutes the frequency calculation unit 7.

  In Table 1, the dimming rate is 100% (all lighting), the output setting unit 8 outputs a pulse signal with a duty ratio of 100%, and is converted into a power setting value of DC 330 mV in the smoothing unit. In Table 2, dimming lighting with a dimming rate of about 25% is performed, the output setting unit 8 outputs a pulse signal with a duty ratio of 50%, and is converted into a current setting value of DC 165 mV in the smoothing unit. Furthermore, in the maximum power setting unit 82, a power setting value of DC 330 mV corresponding to a pulse signal with a duty ratio of 100% output by the output setting unit 8 when dimming is 100% is preset as a maximum power value.

  FIG. 4 shows the relationship between the input power and the detected current value for each of Table 1 (when the dimming rate is 100%) and Table 2 (when the dimming rate is about 25%). In FIG. 4, the measurement data of Table 1 is indicated by diamond marks, and the measurement data of Table 2 is indicated by square marks.

  Here, FIG. 5 shows a simplified relationship between the input power and the detected current value.

  If the ambient temperature of the discharge lamp 11 is constant, when the dimming rate changes, the signal integral value increases slightly in a curve as the input power increases (positive characteristic). “X” in FIG. 5 represents the relationship between the input power and the current detection value when the dimming rate changes from about 20% to 100% in an environment where the ambient temperature is 25 ° C.

  On the other hand, when the ambient temperature of the discharge lamp 11 changes from −10 ° C. to 75 ° C. with the dimming rate of 100%, the input power increases or decreases depending on the temperature characteristics of the discharge lamp 11, but the detected current value is shown in FIG. As in the region indicated by “Y”, the negative characteristic tends to decrease as the input power increases. Even when the ambient temperature of the discharge lamp 11 is changed from −10 ° C. to 75 ° C. with the dimming rate being about 20%, the detected current value is the input power as shown in the region indicated by “Z” in FIG. There is a tendency for negative characteristics to decrease with increasing.

  In FIG. 5, the relationship between the input power and the current detection value when the dimming rate is 100% or near 20% is indicated by the oval regions “Y” and “Z”. This is because the resistance value is relatively low, the detected current value is very small, and there are many measurement errors. The reason why the detection resistor 45 is low is to avoid an increase in the size of the detection resistor 45 and to prevent the gate drive voltage from becoming insufficient by increasing the source potential when the switching element 42 is turned on. Because.

  The main factor that the relationship between the detected current value and the input power tends to be indicated by “Y” or “Z” in FIG. 5 is that the impedance of the discharge lamp 11 changes depending on the temperature characteristics, and the effective current due to the resonance action. The balance between reactive current and reactive current may change.

  That is, in a high temperature or low temperature environment, the lamp current increases and the lamp power decreases, that is, the lamp voltage decreases. However, since the resonance capacitor 53 is connected in parallel to the discharge lamp 11, it is ineffective when the lamp voltage decreases. The current will be reduced. In other words, the impedance of the discharge lamp 11 is reduced by the temperature characteristics, and the reactive current flowing through the parallel circuit of the discharge lamp 11 and the resonance capacitor 53 is reduced. On the other hand, the effective current increases when the lamp current increases.

  As a result, the combined current of the active current and the reactive current tends to increase, and the loss of circuit components increases. On the other hand, since the lamp power is reduced as described above, the current detection value tends to decrease as the input power increases.

  From the above, when the input power Win is calculated by the equation Win = α × Vs + β as described in the background art section, the calculation is possible if the ambient temperature of the discharge lamp 11 is constant. It is not possible to cope with a decrease in the current detection value with respect to an increase in input power due to. Therefore, when the ambient temperature of the discharge lamp 11 changes, the obtained input power Win value may not be sufficiently accurate.

  In addition, there are various types of lighting fixtures provided with the lighting device 1 in the fixture main body. Even if the lighting fixtures are operated under conditions of, for example, an ambient temperature of 25 ° C., the ambient temperature of the discharge lamp 11 depends on the configuration of the lighting fixtures. It will vary. Therefore, even if the ambient temperature of the lighting fixture is constant, depending on the form of the lighting fixture, the accuracy of the input power may not be sufficient.

  Furthermore, a configuration is conceivable in which a plurality of constants α and β used in the above arithmetic expression are set in advance, and α and β corresponding to the temperature detected by a temperature detection unit (not shown) are appropriately selected. If used, such a configuration can be realized relatively easily. However, as apparent from the above description, since the temperature detection unit does not make sense unless it is arranged in the vicinity of the discharge lamp 11, a structure for attaching the temperature detection unit to the fixture body of the lighting fixture is required. It becomes expensive. Further, in order to store a plurality of constants α and β in advance, it is necessary to use a microcomputer having a relatively large storage capacity.

  On the other hand, in the lighting device 1 of the present embodiment, the power calculation unit 83 uses the power setting value and the current detection value corresponding to the output of the detection resistor 45, and is caused by the change in the ambient temperature of the discharge lamp 11. The input power is obtained by correcting the fluctuation of the detected current value. Furthermore, in the present embodiment, the power calculation unit 83 normalizes the power setting value using the maximum power value that is the power setting value when the power supplied to the discharge lamp 11 is maximized, and also sets the power setting value. The input power is obtained using the power adjustment value corresponding to the difference between the current value and the current detection value.

  Specifically, the power calculation unit 83 uses the power setting value Ws, the coefficient α, and the maximum power value Wmax set by the maximum power setting unit 82, and is expressed by the equation α × Ws / Wmax. 1 operation is executed. Furthermore, the power calculation unit 83 executes a second calculation that subtracts the power adjustment value Vfb from the first calculation result. That is, the power calculation unit 83 performs a calculation represented by the equation (α × Ws / Wmax) −Vfb, and outputs the result as a calculation value (calculation result).

  FIG. 6 shows the relationship between the input power and the power adjustment value for each of Table 1 (when the dimming rate is 100%) and Table 2 (when the dimming rate is about 25%). In FIG. 6, the measurement data of Table 1 is indicated by diamond marks, and the measurement data of Table 2 is indicated by square marks. In the present embodiment, the output voltage Vref1 of the operational amplifier 631 constituting the frequency generation unit 63 is set to 3.5V, and the output voltage (power adjustment value) of the operational amplifier 71 is always set lower than the output voltage Vref1 (3.5V). ing. In the relationship between the input power and the power adjustment value shown in FIG. 6, the same tendency as the tendency of the negative characteristic described in FIG. 5 is observed.

  Here, the calculation result column of Tables 1 and 2 shows the calculation result (calculated value) when the power calculation unit 83 performs the above calculation (first and second calculations) with the coefficient α = 5. Yes.

  Further, the relationship between the calculated value and the input power when the power calculation unit 83 performs the above calculation (first and second calculations) with coefficients α = 4.5, 5, and 6 is shown in FIGS. Each is shown in c).

  When the coefficient α = 4.5, as shown in FIG. 7A, the calculated value is a straight line (hereinafter referred to as “reference line”) connecting 0 [W] and the maximum power value (139.9 [W]). Tend to be lower). On the other hand, when the coefficient α = 6, as shown in FIG. 7C, the calculated value tends to be higher than the reference line. The reference line and the calculated value coincide with each other with relatively high accuracy when the coefficient α is around 5. The input power and the calculated value when the coefficient α = 5 are as shown in FIG. It becomes a relationship.

  In this case, the coefficient α is a target power calculation accuracy, the type of load to be used, a frequency calculation unit among values higher than the output voltage Vref1 (3.5 V in this case) of the operational amplifier 631 constituting the frequency generation unit 63. 7 is selected according to the circuit constant. Since the output voltage (power adjustment value) of the operational amplifier 71 is set to be lower than the output voltage Vref1 of the operational amplifier 631, the coefficient α is set to a value that is at least larger than the power adjustment value.

  Further, the calculated value of the power calculation unit 83 is not only proportional to the input power of the lighting device 1 but also has a substantially proportional relationship to the lamp power as shown in FIG. FIG. 8 shows the relationship between the calculated value and the lamp power when the power calculation unit 83 performs the above calculation with the coefficient α = 5.

  The calculation result (or input power or lamp power estimated from the calculation result) of the power calculation unit 83 obtained as described above is presented from a presentation unit (not shown) of the lighting device 1. The presentation unit presents the calculation result to the user of the lighting device 1 by a method such as display or sound. Thereby, the user or the like can make use of the presented calculation result for wasteful power consumption reduction (power saving) or the like.

  According to the lighting device 1 of the present embodiment described above, the power calculation unit 83 obtains the input power using the current detection value corresponding to the output of the detection resistor 45, so the input power can be obtained without using the current transformer. Can be measured. Furthermore, since the power calculation unit 83 uses the power setting value and the current detection value to correct the fluctuation of the current detection value caused by the change in the ambient temperature of the discharge lamp 11, the input power or the lamp power A calculation result approximately proportional to can be obtained with high accuracy. In short, the power calculation unit 83 uses not only the current detection value but also the power setting value that determines the magnitude of the power supplied to the discharge lamp 11, so that the relationship between the current detection value and the power setting value is The input power can be obtained by correcting the fluctuation of the current detection value caused by the change in the ambient temperature.

  Moreover, the power calculation unit 83 normalizes the power setting value using the maximum power value that is the power setting value when the power supplied to the discharge lamp 11 is maximized, and the power setting value and the current detection value are The input power is obtained using the power adjustment value corresponding to the difference between the two. Therefore, the power calculation unit 83 can obtain the input power with relatively high accuracy while performing a relatively simple calculation.

  That is, the power calculation unit 83 may perform the calculation represented by the formula (α × Ws / Wmax) −Vfb using the maximum power value Wmax, the power set value Ws, and the power adjustment value Vfb. With only simple calculation, a calculation result substantially proportional to the input power can be obtained. Therefore, the power calculation unit 83 can be realized by a combination of simple logic elements or the like without using a microcomputer.

  The calculation performed by the power calculation unit 83 may be a calculation using the maximum power value Wmax, the power set value Ws, and the power adjustment value Vfb, and is not limited to the above-described calculation formula. That is, even if the power calculation unit 83 performs the calculation represented by the equation (Ws / Wmax) − (β × Vfb) using the coefficient β, for example, the power calculation unit 83 reduces the input power or the lamp power to the same value as in the above-described example. It is clear that a proportional calculation result can be obtained.

  Further, FIG. 9 shows the relationship between the input power and the calculation result (calculated value) when the coefficient α is set to 8 using the above formula (α × Ws / Wmax) −Vfb. If it is allowed that the calculated value does not become 0 when the input power is 0 and the calculation accuracy is slightly lowered, the input power and the calculated value are in a substantially linear relationship even in the case of FIG. Therefore, in such a case, if the calculation of (α × Ws / Wmax) −Vfb−A is performed using the predetermined value A, the calculation result is approximately proportional to the input power or the lamp power, as in the above example. Will be obtained.

  In the present embodiment, an example is shown in which the power calculation unit 83 functions as a power estimation unit. However, the power estimation unit can accurately estimate the input power using the detection value of the detection resistor 45 that is a current detection unit. Any configuration is acceptable, and it is not essential to perform the calculation. For example, the power estimation unit includes a table that approximates the input power based on the relationship between the power setting value and the current detection value, and estimates the input power by applying the power setting value and the current detection value to the table. There may be.

  In the present embodiment, the light source load is a discharge lamp, and the lighting device 1 that performs high-frequency lighting by an inverter operation is illustrated. However, the present invention is not limited to this configuration. That is, the lighting device 1 performs frequency control and pulse width control using an operational amplifier based on the detected value of the current flowing through the switching element, and is approximately proportional to input power or lamp power using the same calculation as in this embodiment. Any configuration that can obtain the calculation result may be used. For example, the lighting device 1 may have a configuration in which a light emitting diode for illumination is used as a light source load and the light source load is turned on by a step-down chopper operation.

(Embodiment 2)
As shown in FIG. 10, the lighting device 1 according to the present embodiment is provided with a notification unit 12 that receives a result calculated by the power calculation unit 83 of the output setting unit 8 and notifies the external device of the calculation result as a presentation unit. Yes. Hereinafter, the same configurations as those of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and the description thereof is appropriately omitted.

In the present embodiment, the power calculation unit 83 performs the following calculation using the coefficient α and the coefficient γ, the maximum power value Wmax, the power set value Ws, and the power adjustment value Vfb.
{(Α × Ws / Wmax) −Vfb + Ws} × γ
Tables 3 and 4 below show the input power, lamp power, current detection value, power adjustment value, calculation result of the power calculation unit 83, and error between the input power and the calculation result for each ambient temperature of the discharge lamp 11. . In Tables 3 and 4, two fluorescent lamps (FHF63 type) are used as the discharge lamp 11, the input of the lighting device 1 is set to 200 V, the discharge lamp 11 is dimmed by resonance, and the ambient temperature of the discharge lamp 11 is − Each value when changing from 10 ° C. to 60 ° C. is shown. Here, the calculation result when the power calculation unit 83 calculates with the coefficient α = 4.9 and the coefficient γ = 62 is shown.

  In Table 3, the dimming rate is 100% (all lighting), the output setting unit 8 outputs a pulse signal with a duty ratio of 100%, and is converted into a power setting value of DC 330 mV in the smoothing unit. In Table 4, dimming lighting with a dimming rate of about 25% is performed, the output setting unit 8 outputs a pulse signal with a duty ratio of 50%, and is converted into a current setting value of DC 165 mV in the smoothing unit. Furthermore, in the maximum power setting unit 82, a power setting value of DC 330 mV corresponding to a pulse signal with a duty ratio of 100% output by the output setting unit 8 when dimming is 100% is preset as a maximum power value.

  From Table 3, the calculation result when the dimming rate is 100% is obtained with an error within approximately 1% of the input power. From Table 4, the calculation result when the dimming rate is approximately 25% is approximately 3% of the input power. It can be seen that it is obtained with an error within%.

  Furthermore, since the lighting device 1 of the present embodiment includes the notification unit 12 as a presentation unit, the calculation result of the power calculation unit 83 can be notified from the notification unit 12 to the outside. The notification unit 12 notifies the calculation result to the reading device outside the lighting device 1 by communication.

  Other configurations and functions are the same as those of the first embodiment.

  By the way, as shown in FIG. 11, the lighting device 1 of each of the above embodiments is built in, for example, a ceiling-mounted fixture main body 130, and includes the lighting fixture 13 together with a light source load (discharge lamp 11) held by the fixture main body 130. Constitute. Electrical connection between the lighting device 1 and the discharge lamp 11 is performed through socket portions 131 and 132 provided in the instrument main body 130.

  In such a lighting system including a plurality of lighting fixtures 13, a system administrator or a user can remotely display a notification signal output from the notification unit 12 of the plurality of lighting fixtures 13, a remote control receiver, a personal computer, or the like Is used as a reading device. That is, the system administrator and the user can receive the notification signal from the notification unit 12 by one reading device and can grasp the power consumption amount with relatively high accuracy. Such an illumination system can also be configured at a lower cost than when a current transformer is used.

1 Lighting device 3 DC power supply circuit (DC power supply unit)
4 Power conversion circuit (Power conversion unit)
6 Control circuit 7 Frequency calculator 11 Discharge lamp (light source load)
12 Notification part (presentation part)
13 Lighting equipment 42 Switching element 45 Detection resistance (current detection part)
81 Power setting unit 83 Power calculation unit (power estimation unit)
130 Instrument body

Claims (5)

A power converter that includes switching elements and that receives DC power as input and adjusts the power supplied to the light source load by the on / off operation of the switching elements, and a power setting value that determines the amount of power supplied to the light source load A control unit that controls the operation of the power conversion unit, a current detection unit that detects a current flowing through the switching element, a power estimation unit that estimates input power using a detection value of the current detection unit, and the power A presentation unit that presents an estimation result of the estimation unit,
The power estimation unit uses the power setting value and a current detection value corresponding to the output of the current detection unit to correct a variation in the current detection value caused by a change in ambient temperature of the light source load. And determining the input power.   The power estimation unit normalizes the power setting value using the power setting value when the power supplied to the light source load is maximum as a maximum power value, and the power setting value and the current detection value. The lighting device according to claim 1, wherein the input power is obtained using a power adjustment value corresponding to a difference between the input power and the input power.   The power estimation unit subtracts the power adjustment value from a value obtained by multiplying a ratio of the power setting value to the power maximum value by a coefficient set in advance so as to be larger than the power adjustment value. The lighting device according to claim 2, wherein a value corresponding to the input power is obtained by the following.   An illumination fixture comprising: a fixture main body comprising the lighting device according to any one of claims 1 to 3; and a light source load held by the fixture main body. 5. A lighting system comprising a plurality of lighting fixtures according to claim 4, and further comprising a reading device that receives a notification signal transmitted from the presentation unit and reads an estimation result of the power estimation unit.

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