JP2019195261A - Operation device and operation method of lighting means assembly - Google Patents

Abstract

To provide an operation device and an operation method of a lighting means assembly which can easily perform adjustment to low light output without calculating and considering a natural frequency.SOLUTION: The operation device has a control unit 19 that controls a conversion unit 12. In inductor electric current IL flowing through a conversion inductor 32, required electric-current strength Ithat characterizes optical output of a lighting means assembly 17 is previously set in the control unit 19 to form a conversion circuit signal that switches a conversion switch 30 to a conductive state or a cut-off state. If the inductor electric current IL reaches a peak current value that can be previously set, the conversion switch 30 is switched to the cut-off state. When the required electric-current strength Iis smaller than an average current strength in a minimum peak current value, the conversion unit 12 is operated at a discontinuous operating mode of an active phase period and passive phase period.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an actuating device and actuating method for an illumination means assembly connected to an actuating device.

  There is a problem with dimming to low light output. When dimming by pulse width modulation, high frequencies can be reached, but this can increase switching losses and create a critical frequency for electromagnetic compatibility or noise. From German Offenlegungsschrift 10 2013 216 877 (A1), a technique is known in which an OFF time is inserted after each switching cycle of the conversion switch, and as a result, discontinuous operation is performed. During the active phase period, current flows through the illumination means assembly, after which an OFF time is inserted and no current flows until the current flows again in the next switching cycle (passive phase period).

  International Publication No. 2016/050689 (A2) describes a timed electrical energy converter that can be used in dimmable ballasts. However, the known technique of inserting an additional OFF time after each switching cycle has a problem that when the conversion switch is switched in the cut-off state, a voltage fluctuation occurs in the conversion switch, particularly due to a parasitic energy storage element. Therefore, in order to solve this problem, in inserting the OFF time at the end of each switching cycle in the discontinuous operation mode, the next ON time point of the conversion switch is obtained when the voltage fluctuation in the conversion switch is the smallest. In addition, it has been proposed to adjust the OFF time period according to the natural frequency of the circuit. By doing so, when the conversion switch is turned on, the switching load can be reduced almost optimally regardless of the power that should actually be conducted.

  In such a method, it is extremely important to set the ON point of the conversion switch. Therefore, the additional OFF period to be inserted must match the natural frequency of the formed oscillation circuit, and it is assumed that the natural frequency is known. The natural frequency depends specifically on the parasitic effect and the characteristics of the components, but in practice, these are often not easily calculated based on tolerances such as the electrical characteristics of the elements used. Should be calculated empirically. With this method, the OFF time is quantized by the natural frequency.

  It is therefore an object of the present invention to obtain an actuating device and actuating method for a lighting means assembly, which can easily be adjusted to low light output without calculating and taking into account the natural frequency.

  This object is solved by an actuating device having the features of claim 1 and a method having the features of claim 19.

  Specifically, an actuating device according to one aspect of the present invention is configured to actuate an illumination means assembly connected to the actuating device, and includes an input connection for applying a DC voltage, and the illumination means assembly. A conversion unit comprising an electrically connectable output connection, a controllable conversion switch, and a conversion inductor, and controlling the conversion unit based on a desired current intensity of an average value of an inductor current flowing through the conversion inductor A control unit configured to measure, and at least one measurement value characterizing the inductor current, a measurement circuit configured to measure the at least one measurement value transmitted to a conversion circuit device, the conversion The circuit device causes the conversion switch to switch one switching cycle when the at least one measured value indicates a zero crossing of the inductor current. Each time during the switch, the circuit is switched to the conductive state, and when the at least one measured value indicates that the inductor current has reached a preset peak current value, a conversion circuit signal is generated that switches to the cut-off state once. And the control unit is configured to operate the conversion unit in a discontinuous operation mode when the desired current intensity is smaller than an average value of inductor current at a predetermined minimum peak current value. In the discontinuous operation mode, the number of switching cycles indicating the active phase period and the passive phase period are calculated based on the desired current intensity, and the switching of the conversion switch is permitted by the conversion circuit signal during the active phase period, It is configured to prevent the conversion switch from switching to a conductive state during the passive phase period.

  The method according to the present invention is a method for operating a lighting means assembly, and is electrically connected to a conversion switch, a conversion inductor, an input connection to which a DC voltage is applied, and the lighting means assembly. Using an actuating device comprising a conversion unit comprising an output connection and a measurement circuit configured to measure at least one measurement value characterizing the inductor current flowing through the conversion inductor, the desired current intensity of the inductor current is previously determined Setting and converting the conversion switch to a conductive state once each during a switching cycle when the at least one measured value indicates a zero crossing of the inductor current, and the at least one measured value is A conversion circuit that switches to a cut-off state once it indicates that a presettable peak current value has been reached A switching cycle that adjusts discontinuous operation when the desired current strength is less than an average value of the inductor current at a predetermined minimum peak current value and indicates an active phase period based on the desired current strength And the conversion phase signal is allowed during the active phase period, and the conversion circuit signal prevents the conversion switch from being switched to the conductive state during the passive phase period. And including.

  Easily adjust to low light output without calculating and considering natural frequency

FIG. 3 is a block diagram showing an embodiment of an operating device for operating the illumination means assembly. It is a block diagram which shows one Example of the conversion unit and control unit in the actuator of FIG. It is a figure which shows the Example of the conversion unit shown in FIG. 2, and a control unit. FIG. 3 shows an exemplary time course as the inductor current passes through the conversion inductor in the continuous operation mode in the embodiment shown in FIG. 2. FIG. 4 is a diagram illustrating an exemplary time course when the inductor current passes through the conversion inductor in the continuous operation mode in the embodiment shown in FIG. 3. It is a typical principle figure which shows calculation of the active phase period and passive phase period in the continuous operation mode of a conversion unit. FIG. 5 is a schematic diagram showing a discontinuous operation mode when a connected illumination means assembly is activated when the average value of the current intensity of the current flowing through the illumination means assembly is low.

  The operating device in the present invention has a conversion unit including an input connection portion and an output connection portion. For example, a DC voltage may be applied to the input connection unit from a DC power source. An illumination means assembly may be connected to the output connection. The conversion unit includes a conversion switch and a conversion inductor. The conversion switch can be controlled by a control unit. The control unit is configured to control the conversion unit or the conversion switch based on a desired current intensity. This desired current intensity is preset by a signal or set value and indicates the dimming level of the illumination means assembly. The desired current intensity is at least partially related to the average value of the current flowing through the illumination means unit and through the conversion unit. For example, the desired current intensity may indicate an average value of the inductor current IL flowing through the conversion inductor (hereinafter also referred to as an average inductor current).

  The actuating device further comprises a measuring circuit. The measurement circuit is configured to detect at least one measurement value indicative of an inductor current flowing through the conversion inductor. The at least one measured value is transmitted to the control unit.

  The control unit includes a conversion circuit device configured to generate a conversion circuit signal for the conversion switch. The conversion circuit device may be configured as an integrated circuit. For example, a commercially available standard element known as a PFC-IC (“PFC” is an abbreviation of “Power Factor Correction”, that is, an abbreviation for power factor correction) may be used. . The circuit or function realized by the PFC-IS described here is not configured for power factor correction. Rather, the PFC-IC makes it possible to implement the above-described conversion circuit device suitably.

  The conversion circuit signal is switched to a conductive state once in each switching cycle when the conversion switch indicates that the at least one measured value indicates a zero crossing of the inductor current, and the at least one measured value is the inductor current. Indicates that the current limit value that can be set in advance has been reached, each is generated by the conversion circuit device so as to be switched to the cutoff state once. At each zero crossing of the inductor current, the conversion switch is turned on, and is turned off again when the inductor current reaches the predetermined current limit value. In the continuous operation mode, the conversion circuit device may directly connect a plurality of switching cycles to each other.

  When the predetermined desired current intensity reaches a maximum value of a current intensity (peak current value) smaller than the minimum adjustable peak current value, the control unit operates the conversion unit in a discontinuous operation mode. In the discontinuous operation mode, the peak current value of the inductor current is constant and corresponds to the smallest possible adjustable value that is smaller than the minimum peak current value. In this discontinuous operation mode, one total period is divided into an active phase period and a passive phase period. The ratio of the active phase period to the passive phase period is calculated based on the desired current intensity. The active phase period corresponds to the number of switching cycles of the conversion unit. In the active phase period, the conversion switch is switched by the conversion circuit signal. In the passive phase period, switching of the conversion switch is prevented. In the passive phase period, the conversion switch remains in the cut-off state.

  The passive phase period may be set sufficiently long until the voltage variation at the conversion switch is attenuated before the conversion switch is switched back to the conductive state in the next switching cycle in the next active phase period. By doing so, it is not necessary to accurately grasp the phase of the voltage fluctuation in the conversion switch. Therefore, the passive phase period should not be less than the minimum period. The passive phase period and the active phase period may be adapted to each other in consideration of the minimum period of the passive phase period, so that the desired current intensity is achieved. At this time, the frequency in this control (the reciprocal value of the total period of the active phase period and the passive phase period) may be set to at least about 2 to 3 kHz so that flicker does not occur during operation of the illumination means assembly. I know it ’s good.

  The illumination means assembly preferably comprises at least one illumination means, in particular at least one semiconductor illumination means. When multiple semiconductor lighting means are used in the lighting means assembly, they may be connected in series and / or in parallel with each other. For example, an illumination diode may be used as the illumination unit.

  Preferably, the control unit is configured to operate the conversion unit in a continuous operation mode when the average desired current intensity reaches a peak current value at least as large as the minimum peak current value. At this time, a plurality of switching cycles are performed directly and continuously. In other words, the passive phase period is almost zero in the continuous operation mode.

  More preferably, the control unit first switches based on an average desired current intensity and a predetermined desired total period value of the active phase period and the passive phase period and / or a predetermined minimum value of the passive phase period. A calculation period value of an active phase period in which the number of cycle periods is preset is calculated, and the number of switching cycle periods is rounded to an integer in order to obtain the active phase period. Accordingly, the active phase period corresponds to at least one switching cycle period or twice or three times the switching cycle period of the switching cycle.

  In a preferred embodiment, the control unit calculates a first limit value indicated by a total period of the active phase period and the passive phase period based on the desired current intensity and the first boundary condition, and the desired current intensity. And a second boundary condition, the second limit value indicated by the total period of the active phase period and the passive phase period is calculated. The first boundary condition may be a target frequency indicated by the total period. The second boundary condition may be a minimum period of the passive phase period. Depending on both of these boundary conditions, the lower limit value of the actual frequency may be determined as the first limit value, and the upper limit value of the actual frequency may be determined as the second limit value. The actual frequency corresponds to the reciprocal value of the total period, and indicates the switching frequency between the active-passive phase period for each time unit.

  In this case, preferably, the control unit is configured to change an actual frequency in switching between the active and passive phase periods between a plurality of frequency values from the lower limit value to the upper limit value. By doing so, it is possible to influence the noise that can occur without changing the light output.

  The control unit may be further configured to calculate the passive phase period in response to the calculated active phase period, resulting in the average desired current intensity.

  The passive phase period may be calculated and adjusted regardless of the switching cycle period of the switching cycle generated in the active phase period. Therefore, it is not important whether the passive phase period corresponds to an integral multiple of the switching cycle period.

  More preferably, the control unit is configured to measure and store the actual value of the active phase period. The measured actual value may then be used to calculate the passive phase period and adapt it as necessary for so-called fine adjustment. At this time, for example, the average current intensity of the current flowing through the illumination means assembly is preferably adapted to the average desired current intensity, or the passive phase period is a desired frequency or the active phase period and the passive phase. The total length of the periods may be long enough to be obtained.

  In a preferred embodiment, the conversion circuit is configured as a down converter. The down converter is also referred to as a step-down converter or a buck converter.

  In one embodiment, the conversion circuit includes a conversion capacitor arranged in parallel with the output connection. Therefore, the conversion capacitor is connected in parallel to the illumination means assembly in the connected illumination means assembly.

  In one embodiment, the conversion circuit includes a conversion diode. The cathode of the conversion diode is electrically connected to the conversion switch, and the anode of the conversion diode is electrically connected directly to the conversion capacitor.

  In a preferred embodiment, the measurement circuit comprises a measurement coil assigned to the conversion inductor. A measurement voltage used as a measurement value is induced in the measurement coil according to the magnetic field in the conversion inductor. The induced measurement voltage indicates the inductor current flowing through the conversion inductor.

  Additionally / or the measurement circuit may comprise a current measuring resistor. The current measuring resistor is preferably connected in series with the output connection or in series with the illumination means assembly connected thereto. Thus, the voltage at the current measuring resistor indicates the current flowing through the illumination means assembly when activated.

  In order to generate a DC voltage to be supplied to the conversion unit, a DC power source that can be formed in particular by a DC converter may be used. The DC converter may convert a commercial voltage into a rectified DC voltage for supply to the conversion unit.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that each of the embodiments described below shows a comprehensive or specific example of the present disclosure. Accordingly, numerical values, shapes, materials, components, arrangement positions and connection forms of components, and steps and order of steps shown in the following embodiments are merely examples and are not intended to limit the present invention. Absent. Therefore, among the constituent elements in the following embodiments, constituent elements not described in the independent claims are described as arbitrary constituent elements.

  Each figure is a mimetic diagram and is not necessarily illustrated strictly. Accordingly, the scales and the like do not necessarily match in each drawing. Moreover, in each figure, the same code | symbol is attached | subjected to the substantially same structure, The overlapping description is abbreviate | omitted or simplified.

  FIG. 1 is a block diagram showing an embodiment of an operating device for operating the illumination means assembly.

  FIG. 2 is a block diagram showing an embodiment of the conversion unit and the control unit in the actuator of FIG.

  FIG. 3 is a diagram showing the above-described embodiment of the conversion unit and the control unit shown in FIG. 2, and includes a conversion circuit device formed by an integrated circuit for power factor correction.

  4 and 5 show exemplary time courses when the inductor current passes through the conversion inductor in the continuous operation mode in the embodiments shown in FIGS. 2 and 3, respectively.

  FIG. 6 is a schematic principle diagram showing calculation of the active phase period and the passive phase period in the continuous operation mode of the conversion unit.

  FIG. 7 is a schematic diagram showing a discontinuous mode of operation when the connected lighting means assembly is activated when the average value of the current intensity of the current flowing through the lighting means assembly is low.

  FIG. 1 shows a block diagram of an embodiment of the actuator device 10. Actuator 10 is provided with DC power supply 11, and DC voltage UG is supplied to the output side.

  A conversion unit 12 is connected to the DC power source 11. The conversion unit 12 has a first input connection portion 13 and a second input connection portion 14, and a DC voltage UG is supplied between them. The conversion unit 12 further includes a first output connection 15 and a second output connection 16, and the output connections 15, 16 include at least one illumination means, for example, at least one semiconductor illumination. An illumination means assembly 17 with means 18 is connected. If the lighting means assembly 17 is provided with a plurality of semiconductor lighting means 18, they may be connected in series and / or in parallel. Each semiconductor illumination means 18 is formed by an illumination diode, for example.

The conversion unit 12 can be controlled by the control unit 19. A dimming signal D is transmitted from the dimmer 20 to the control unit 19, and the dimming signal D presets the desired current intensity I _soll of the average value of the current flowing through the conversion unit 12. Depending on D, the average value of the illumination means current I1 flowing next through the illumination means assembly 17 is determined. Control unit 19, in response to the dimming signal D, in particular the desired current intensity and controls the conversion unit 12 in response to I _soll, the actual current intensity in accordance with the desired current intensity I _soll required using the transformation unit 12 Adjust.

  As schematically shown in FIG. 1, the DC power supply 11 is formed by, for example, a DC converter 21 that can be controlled by a controller 22. Alternatively, the control unit 19 may be used to control not only the conversion unit 12 but also the DC converter 21. The DC converter 21 converts the commercial voltage UN on the input side into a rectified DC voltage UG.

  FIG. 2 shows a block diagram of the control unit 19 and the conversion unit 12 in the embodiment of the actuator device 10. A DC voltage UG is applied between the first input connection 13 and the second input connection 14. For example, the second input connection unit 14 is connected to a reference potential, for example, the ground potential M. The conversion unit 12 has a controllable conversion switch 30 constituted by a semiconductor switch, in particular a field effect transistor 31 in this embodiment. The drain connection portion of the field effect transistor 31 is connected to the first input connection portion 13. The source connection portion of the field effect transistor 31 is connected to the first output connection portion 15 via the conversion inductor 32. Further, the source connection portion of the field effect transistor 31 is connected to the cathode of the conversion diode 33, and the anode thereof is connected to the second output connection portion 16. A conversion capacitor 34 is further connected between the output connections 15 and 16 and the illumination means assembly 17 connected in parallel thereto.

  In order to generate a conversion circuit signal W for switching the conversion switch 30, the control unit 19 includes a conversion circuit device 35. The conversion circuit device 35 includes a control output unit 36 to which the conversion circuit signal W is supplied. The control output unit 36 is connected to the non-inverting input unit of the AND gate 37. The output part of the AND gate 37 is connected to the control connection part of the conversion switch 30 and, for example, the gate connection part of the field effect transistor 31. The output part of the AND gate 37 is connected to the gate connection part of the field effect transistor 31 via the driver 55, for example.

  Another inverting input part of the AND gate 37 is connected to the output part of the first comparison member 38. The input portion of the first comparison member 38 is connected to the first counting member 39. The counting input unit 40 of the first counting member 39 is connected to the output unit of the AND gate 37. The first counting member 39 and the first comparison member 38 form a first counting unit 41.

  In the control unit 19, for example, a second counting unit 42 including a second counting member 43 and a second comparison member 44 connected to the second counting member 43 is further provided. The second counting member 43 has an internal clock for generating a counting cycle that is transmitted to the second comparison member 44. The second comparison member 44 has an output connection portion connected to the reset input portion 45 of the second counting member 43 and the reset input portion 45 of the first counting member 39. The second comparison member 44 supplies a reset signal R for resetting the first counting member 39 and the second counting member 43 via the output unit.

  The start input unit 46 of the second counting member 43 is connected to the output unit of the first comparison member 38. The first comparison member 38 supplies an operation mode signal B to its output.

  In the embodiment described here, a third counting unit 47 is further provided, and includes a third counting member 48 and a detection member 49 connected to the third counting member 48. The detection input unit 50 of the detection member 49 is connected to the output unit of the first comparison member 38.

  The control unit 19 further includes a measurement circuit 56. The measurement circuit 56 includes, for example, a measurement coil 57 assigned to the conversion inductor 32 so that a voltage can be induced in the measurement coil 57 by the magnetic field of the conversion inductor 32. The voltage induced in the measurement coil 57 indicates the inductor current IL flowing through the conversion inductor 32. The measuring coil 57 is connected to the ground potential M on the one hand and to the first measuring input 59 of the conversion circuit device 35 via the first ohmic resistor 58 on the other hand. The voltage induced in the measurement coil 57 constitutes the first measurement value S1 supplied to the conversion circuit device 35.

  The measurement circuit 56 is further provided with a current measurement resistor 60. The current measuring resistor 60 is connected to the second output connection 16 of the conversion unit 12 and the second measurement input 61 of the conversion circuit device 35 on the one hand and to the ground potential M on the other hand. Therefore, the voltage applied to the current measuring resistor 60 is specific to the inductor current IL flowing through the conversion inductor 32 when the conversion diode 33 is cut off in the conductive state of the conversion switch 30. The voltage applied to the current measuring resistor 60 constitutes the measured value S2 supplied to the conversion circuit device 35. Then, when the conversion diode 33 conducts and the inductor current IL flows through the conversion diode 33 and does not flow through the current measurement resistor 60, the measurement coil 57 can measure the inductor current IL.

In the connected illumination means assembly 17, the inductor current IL flows through a parallel circuit comprising the illumination means assembly 17 and the conversion capacitor 34, the illumination means current I1 passes through the illumination means assembly 17, and the capacitor current I2 passes through the conversion capacitor 34. Flowing. That is, IL = I1 + I2. Therefore, the inductor current IL supplied by the conversion unit 12 is specific to the illumination means current I1, and as a result, in order to adjust the desired light output according to the dimming signal D, it is set to the average inductor current IL. The desired current value _Isoll of the average value of the inductor current IL can be set in advance.

  With reference to FIGS. 4-7, the effect | action of the actuator 10 provided with the control unit 19 and the conversion unit 12 in FIG. 2 is demonstrated.

When the desired current intensity I _soll of the average inductor current IL required for the dimming signal D reaches the maximum value of the current intensity (peak current value IP) at least as large as the minimum adjustable peak current value IP _min Unit 12 operates in a continuous mode of operation as schematically and exemplarily shown in FIGS. The counting units 41, 42, 47 are not active and the operating mode signal B is LOW (digital 0), so that the conversion circuit signal W is connected via the AND gate 37 to the control connection ( Here, it is transferred to the gate of the field effect transistor 31). The conversion circuit device 35 evaluates the first measurement value S1 applied to the first measurement input unit 59 and the second measurement value S2 applied to the second measurement input unit 61. The zero cross of the inductor current IL is calculated from the first measurement value S1. Based on the second measured value S2, it is calculated whether or not the inductor current IL flowing through the conversion inductor 32 has reached a preset or adjustable peak current value IP. When the inductor current IL crosses zero, the conversion circuit signal W becomes HIGH (digital 1), and the conversion switch 30 is switched to the conductive state. Then, the inductor current IL starts to flow and continuously increases. As soon as the inductor current IL reaches the current limit value IG, the conversion circuit device 35 switches the conversion circuit signal W from HIGH to LOW, so that the conversion switch 30 shifts to the cutoff state. The inductor current IL may further flow through the conversion inductor 32, the illumination means assembly 17, and the conversion diode 33, and continuously decreases and finally reaches the numerical value zero. This zero crossing may also be signaled by the conversion circuit device 35 and the conversion switch 30 is turned on again in the next switching cycle.

  In each switching cycle, the conversion switch 30 is turned on during the ON period te and is cut off during the subsequent OFF period ta. The conversion switch 30 is switched to the conductive state when each switching cycle starts, and is switched to the cutoff state when the ON period te ends, and this state is maintained during the OFF period ta until the end of the switching cycle where the inductor current IL indicates zero crossing. maintain. The sum of the ON period te and the OFF period ta corresponds to the switching cycle period TP.

  The operation mode of the conversion unit 12 shown in FIGS. 4 and 5 may be a continuous operation mode or a critical operation mode, and as soon as the zero crossing of the inductor current IL is confirmed, a new inductor current IL is generated by switching the conversion switch 30. Begins to flow. In this continuous operation mode, it is preferable that the interruption period of the inductor current IL between two successive switching cycles is short. This interruption period must be taken into account so that the average inductor current IL can be accurately calculated. Further, for example, a correction count indicating an interruption period may be introduced. Each switching cycle is substantially directly continuous with each other in the continuous mode of operation, and the interruption period is as short as technically possible.

As schematically shown by comparison between FIG. 4 and FIG. 5, the light output can be reduced by reducing the peak current value IP in the continuous operation mode. The peak current value IP may be calculated, for example, in the conversion circuit device 35 on the basis of the desired current intensity I _soll of the average inductor current IL. May be transmitted. As a result, the switching cycle period TP is shortened, and the switching frequency of the conversion switch 30 is increased. If the required light output is quite low, i.e. the peak current value IP is very low, the switching frequency will be quite high and the continuous mode of operation is for stronger dimming, for example with a switching frequency of about 200 kHz or higher. Not suitable or not configured as such. Here, the minimum peak current value IP _min that should not be lower is calculated or preset. Therefore, in the present invention, when the desired current intensity I _soll reaches the peak current value IP smaller than the minimum peak current value IP _min , the continuous operation mode is switched to the discontinuous operation mode.

In this discontinuous operation mode, the peak current value IP does not decrease any more and is kept constant at the minimum peak current value IP _min . By doing so, as shown in FIG. 7, the minimum switching cycle period TP _min (when IP = IP _min ) is obtained. In order to allow the light output of the illumination means assembly 17 to be reduced, in the discontinuous operating mode of the conversion unit 12, the active phase period ts and the passive phase period tn are calculated to correspond to the sum of the total periods TG. Are adjusted alternately. During the active phase period, switching of the conversion switch 30 is permitted in response to continuous operation, while the conversion switch 30 is maintained in the cut-off state during the passive phase period tn. Active phase period ts is the same or the same length as the plurality of minimum switching cycle period _{TP min} the minimum switching cycle period _{TP min.} FIG. 7 exemplarily shows the discontinuous operation mode when the active phase period ts has the same length as the three minimum switching cycle periods TP _min . It is directly followed by a passive phase period tn, during which time the conversion switch is maintained in a non-conducting state.

The passive phase period tn may be calculated and adjusted without depending on the minimum switching cycle period TP _min .

Based on continuous operation with a minimum switching cycle period TP _min , which is a light output limit value for transitioning from continuous operation to discontinuous operation, the ratio of the active phase period ts to the total period TG is a requirement for the light output limit value. It is calculated according to the ratio of the desired light output. As a result, first, a calculation period value tr is obtained. The calculation period value tr corresponds to a calculation factor multiplied by a switching cycle period TP, for example, a minimum switching cycle period TP _min . The calculation factor is rounded down or rounded up to an integer (a natural number including 1 and not 0) (see FIG. 6). Subsequently, the passive period tn is adapted to the calculated active phase period ts so as to satisfy one or more of the following three conditions in an ideal manner as much as possible.

  First condition: The ratio between the active phase period ts and the passive phase period tn is set so that the light output is as close as possible to the desired light output.

  Second condition: the passive phase period tn is at least as long as the predetermined minimum period or within a predetermined desired period range of the passive phase period tn.

  Third condition: The total period TG of the active phase period ts and the passive phase period tn corresponds to a predetermined total desired period as much as possible, or is within a predetermined desired period range of the total period TG.

  Due to the third condition, the desired frequency may be achieved in the discontinuous mode of operation, so that flicker in the illumination means assembly 17 is avoided.

  Furthermore, the passive phase period tn may be set sufficiently long, and as a result, the voltage fluctuation that may occur when the conversion switch 30 is switched from the conduction state to the cutoff state is attenuated by the damper. (See second condition above).

  Below, with reference to FIG. 6, the parameter for implementing discontinuous operation | movement is demonstrated based on an example.

Illustratively, assume that the light output required by the dimming signal D is 25% of the maximum light output. The light output can be reduced to 50% of the maximum light output in continuous operation. Therefore, based on the minimum peak current IP _min , the cycle ratio of the active phase period ts and the passive phase period tn must achieve 50% in order to obtain the desired light output corresponding to 25% of the maximum possible light output. I must.

At this time, as a parameter or a first boundary condition, the target frequency f _zel is _set to 3000 Hz in order to prevent flicker in the illumination means assembly 17.

  At this time, the relational expression represented by the following expression (1) is satisfied.

At this time, PWM is a cycle ratio (for example, 50%), and n is the number of switching cycles in the active phase period ts. The target frequency f _ziel satisfies the relational expression expressed by the following expression (2).

  From the equations (1) and (2), the switching cycle number n in the active phase period ts may be calculated by the following equation (3).

The numerical values assumed as an example here are a cycle ratio PWM = 0.5, a minimum switching cycle period TP _min of, for example, 10 μs, and a target frequency f _ziel of 3000 Hz. As a result of the calculation, the calculated switching cycle number n * in the active period ts is n * = 16.77. Since the switching cycle number n must be an integer, the calculated numerical value n * is rounded up or down, for example, n = 17. In the minimum switching cycle period TP _min , the passive phase period tn is expressed by the following formula (4).

Since the calculated numerical value n * of the number of switching cycles is rounded to an integer value, the predetermined target frequency f _ziel is not _exactly achieved. Based equation (2) may calculate the actual frequency _{f ist} which actually obtained, as a numerical example here is _f ist = 2941Hz. The actual frequency _fist obtained based on the first boundary condition may be used as a limit value, particularly as a lower limit value for defining a frequency range.

  Another second boundary condition may be a minimum period of the passive phase period tn. The minimum period may be set in advance so that the fluctuation of the voltage at the conversion switch 30 that is adjusted after the inductor current IL is zero-crossed by a damper provided in the system can be sufficiently attenuated. The above formulas (1) and (2) apply mutatis mutandis. For example, tn = 56 μs may be set as the minimum period of the passive phase period. By applying the equation (1) and rounding the number n of switching cycles in the active phase period, ts: n = 6.

  Then, based on the number of switching cycles, the passive phase period tn may be calculated according to the equation (4), and here, tn = 60 μs.

As a result, the actual frequency _fist obtained is expressed by the following equation (5) in light of equation (2).

The actual frequency _fist obtained based on the second boundary condition may be used as a limit value, particularly as an upper limit value for defining a frequency range.

Based on the above calculation, the limit value of the frequency range may be calculated on the one hand by the reference value of the target frequency f _ziel and on the other hand by the reference value of the minimum period of the passive phase period tn. For example, the actual frequency _fist may be calculated based on the reference value of the target frequency, and this actual frequency _fist is used as a frequency lower limit value. Furthermore, the actual frequency _fist may be calculated by the reference value of the minimum period of the passive phase period tn, and this may be used as the upper limit value of the frequency. Even if various frequencies in the same duty cycle PWM are adjusted within the range between the lower limit frequency and the upper limit frequency in accordance with the setting of the number n of switching cycles in the active phase period ts in the relationship of the following equation (6). Good.

  At this time, the number n of switching cycles in the active phase period ts can be changed or modulated without changing the optical output, thereby affecting the generated noise. In consideration of the exemplary numerical values calculated as described above, by changing the number of switching cycles n in the active phase period ts between n = 6 and n = 17 at the duty cycle PWM = 50%, Twelve different frequencies f (n) may be obtained in equation (6) and switched between them without changing the light output or brightness of the illumination means assembly.

  It is also possible to change the actual frequency while maintaining it within the full range between the lower limit frequency and the upper limit frequency, which can only be achieved by changing the duty cycle, ie the light output and the brightness. To that end, an algorithm may be used, which uses the discrete possible frequency f (n) in equation (6) as a reference point, so that the frequency f corresponds to the required optical output. Is changed between discrete values f (n), and at this time, the deviation of the light output from the average light output (variation) is minimized.

  During the active phase period ts and / or during continuous operation of the conversion unit 12, when the changing voltage applied to the conversion switch 30 (the drain-source voltage in the field effect transistor 31) exhibits a first minimum value, the conversion switch 30 Turns on (conversion circuit signal W rises). This corresponds to the zero crossing of the inductor current IL.

  The calculated active phase period ts is stored in the first comparison member 38, and the calculated passive phase period tn is stored in the second comparison member 44. The number of switching cycles is acquired by the first counting member 39 via the counting input unit 40. In the first comparison member 38, it is determined whether or not the active phase period ts has reached the corresponding number of switching cycles. In this case, the operation mode signal B is switched from LOW to HIGH at the output portion of the first comparison member 38. The AND gate 37 is thereby interrupted so-called. This may be used as a gate circuit to block the conversion circuit signal W so that it is not transferred to the conversion switch 30.

  The counting member 39 preferably increments as the conversion circuit signal W falls. By doing so, the switching operation of the operation mode signal B from LOW to HIGH can be performed as soon as the conversion circuit signal W falls. This time adjustment can avoid spikes.

  The operation mode signal B is further transmitted to the start input unit 46, and as soon as the operation switching signal B is switched from LOW to HIGH, the second counting member 43 is started. In the second comparison member 44, it is determined whether the calculated or stored passive phase period tn has expired. As soon as this is confirmed, the second comparison member 44 generates a reset signal for the first counting member 39 and the second counting member 43. By doing so, in the first counting unit 41, the operating mode signal B is again switched from HIGH to LOW, which indicates the start of the next active phase period ts. The AND gate 37 may transfer the conversion circuit signal W to the conversion switch 30. Since the inductor current IL is 0, the conversion circuit device 35 switches the conversion switch 30 to the conductive state, and the next active phase period ts starts. As soon as a predetermined number of switching cycles is achieved during the active phase period ts, the AND gate 37 is newly interrupted by the operating mode signal B, the conversion switch 30 is likewise interrupted and the passive phase period tn begins. This process is repeated periodically during discontinuous operation, and this cycle period corresponds to the total period TG.

  The actual active phase period ts may be measured using a third counting unit 47 that is optionally provided. By switching the operation mode signal B from LOW to HIGH, the detection member 49 is operated via the detection input unit 50, and the time is detected based on the counting impulse of the third counting member 48. When the active phase period ts ends, the operation mode signal B is switched from LOW to HIGH, and this is detected by the detection member 49, whereby the exact period of the active phase period ts is calculated. This period may be used to calculate and / or fit the passive phase period tn.

  In the embodiment described here, no adjustment is made to the current through the illumination means assembly. The illumination means current I1 flowing through the illumination means assembly and the light output of the illumination means assembly 17 are adjusted and controlled without returning corresponding measurements.

  In FIG. 3, the feasibility for realizing the control unit 19 using PFC-IC is shown. For example, an MP44014 type IC manufactured by MPS® is used as the PFC-IC forming the conversion circuit device 35. Since the configuration and operation of this IC are known, detailed description is omitted. The IC used here has eight connections. The IC connection unit “ZCS” constitutes a first measurement input unit 59, and the IC connection unit “CS” constitutes a second measurement input unit 61. The IC connection unit “GATE” constitutes the control output unit 36. The IC supply connection “VCC” is connected to the supply voltage UV, and the ground connection “GND” is connected to the ground potential M.

  The first pulse width modulation signal PWM1 is applied to the IC connection “MULTI” via the second ohmic resistor 65. The second pulse width modulation signal PWM2 is supplied via the third ohmic resistor 66. Then, the voltage is applied to the IC input section “FB” and to the IC connection section “COMP” through a series circuit including the third ohmic resistor 66 and the fourth ohmic resistor 67. The first capacitor 68 connects the IC connection “MULTI” to the ground potential M, and the second capacitor 69 connects the IC connections “FB” and “COMP”. Capacitors 68 and 69 limit the bandwidth of pulse width modulation signals PWM1 and PWM2.

  These pulse width modulation signals PWM1 and PWM2 are multiplied by a multiplier in the conversion circuit device 35 to define a current limit value IG. By multiplying two signals that are pulse-width modulated and filtered, in particular low-pass filtered, a quadratic characteristic curve is obtained, which improves the digital quantization, in particular the decomposition at low current intensity.

The invention relates to the actuating device 10 and the actuating method of the illumination means assembly 17. The conversion unit 12 is supplied with a DC voltage UG. On the output side, the illumination means assembly 17 is connected to the conversion unit 12. The control unit 19 controls the conversion switch 30 of the conversion unit 12. The conversion unit 12 includes a conversion inductor 32 arranged in series with the conversion switch 30. Using the measurement circuit 56, at least one measurement value specific to the inductor current IL flowing through the conversion inductor 32 is detected. The control unit 19 is preset with a desired current intensity I _{soll that} is an average value of the inductor current IL. The desired current intensity I _soll characterizes the light output to be adjusted. Peak current IP of the inductor current IL from the desired current intensity I _soll may be calculated so as to adjust the average value of the inductor current IL corresponding to the desired current intensity I _soll. The control unit 19 generates a conversion circuit signal W that switches the conversion switch 30 to the conductive state or the cutoff state. At the start of the switching cycle, if the inductor current IL indicates zero crossing, the conversion switch 30 is switched to the conductive state. Subsequently, the inductor current IL increases and reaches a calculated or predetermined peak current value IP. At this time, the conversion switch 30 is switched to the cut-off state, and the inductor current IL decreases. When the inductor current IL becomes zero, the switching cycle ends and the next switching cycle is started. If the desired current intensity I _soll is lower than the average value of the current flowing through the conversion unit 12 at a predetermined minimum peak current value IP _min that should not be lower, the conversion unit 12 is operated in the discontinuous mode of operation and the active phase period ts includes one or a plurality of full switching cycles, and becomes the passive phase period tn following the active phase period ts. The active and passive phase periods ts, tn are adjusted so that the inductor current IL corresponds at least substantially to the desired current intensity _Isoll . Furthermore, the passive phase period tn may be set to indicate a minimum period. Alternatively / further, while maintaining the ratio of the active phase period ts to the passive phase period tn, the passive phase period tn does not fall below the minimum period and / or at least substantially reaches the desired total period value. In addition, the total period TG may be adjusted or preset.

DESCRIPTION OF SYMBOLS 10 Actuator 11 DC power supply 12 Conversion unit 13 1st input connection part 14 2nd input connection part 15 1st output connection part 16 2nd output connection part 17 Illumination means assembly 18 Semiconductor illumination means 19 Control unit 20 Adjustment Optical device 21 DC converter 22 Controller 30 Conversion switch 31 Field effect transistor 32 Conversion inductor 33 Conversion diode 34 Conversion capacitor 35 Conversion circuit device 36 Control output unit 37 AND gate 38 First comparison member 39 First counting member 40 Count Input unit 41 First counting unit 42 Second counting unit 43 Second counting member 44 Second comparison member 45 Reset input unit 46 Start input unit 47 Third counting unit 48 Third counting member 49 Detection member 50 Detection input section 55 Driver 56 Measurement circuit 57 Measurement carp 58 First Ohm Resistor 59 First Measurement Input 60 Current Measuring Resistor 61 Second Measurement Input 65 Second Ohm Resistor 66 Third Ohm Resistor 67 Fourth Ohm Resistor B Actuation Mode signal D Dimming signal f _fist actual frequency IP peak current value IP _min minimum peak current value IL inductor current M ground potential P _soll desired light output R reset signal S conversion circuit signal UG DC voltage UN commercial voltage UV supply voltage Ta OFF period Te ON period tn Passive phase period TP switching cycle period ts Active phase period TG Total period

Claims (19)

An actuating device (10) configured to actuate a lighting means assembly (17) connected thereto,
An input connection (13, 14) for applying a DC voltage (UG), an output connection (15, 16) electrically connectable to the illumination means assembly (17), and a controllable conversion switch ( 30) and a conversion inductor (32), a conversion unit (12),
A control unit (19) configured to control the conversion unit (12) based on a desired current intensity ( _Isoll ) of an average value of an inductor current (IL) flowing through the conversion inductor (32);
A measurement circuit (56) configured to measure at least one measurement characterizing the inductor current (IL), wherein the at least one measurement value is transmitted to the conversion circuit device (35);
The conversion circuit device (35) switches the conversion switch (30) to a conductive state once each during one switching cycle when the at least one measured value indicates a zero crossing of the inductor current (IL), When at least one measured value indicates that the inductor current (IL) has reached a presettable peak current value (IP), the converter circuit signal (W) is configured to switch to a one-off state. ,
When the desired current intensity (I _soll ) is smaller than the average value of the inductor current (IL) at a predetermined minimum peak current value (IP _min ), the control unit (19) discontinues the conversion unit (12). Configured to operate in operating mode,
In the discontinuous operation mode, the control unit (19) calculates the number of switching cycles indicating the active phase period (ts) and the passive phase period (tn) based on the desired current intensity (I _soll ), and the active unit During the phase period (ts), switching of the conversion switch (30) is permitted by the conversion circuit signal (W), and during the passive phase period (tn), switching of the conversion switch (30) to the conductive state is prevented. Composed of,
Actuator. When the desired current strength (I _soll ) is at least as large as the average value of the inductor current (IL) at a predetermined minimum peak current value (IP _min ), the control unit (19) ) In continuous operation mode,
The actuating device according to claim 1. Based on the desired current intensity (I _soll ), the active phase period, and a predetermined desired total period value of the passive phase period (tn), the control unit (19) first of the active phase period (ts) A calculation period value (tr) is calculated, and the active phase period (ts) is calculated based on the calculation period value (tr).
The actuating device according to claim 1 or 2. Based on the desired current intensity (I _soll ) and a predetermined minimum value of the passive phase period (tn), the control unit (19) first calculates a calculation period value (tr) of the active phase period (ts). And the active phase period (ts) is calculated based on the calculated period value (tr).
The actuating device according to claim 1 or 2. The control unit (19) is configured to set an integer multiple of the switching cycle period (TP, TP _min ) close to the calculation period value (tr) to obtain the active phase period (ts). Features
The actuating device according to claim 3 or 4. The control unit (19) determines the difference between the inductor current (IL) and the desired current intensity ( _Isoll ) as small as possible according to the active phase period (ts). Configured to calculate (tn),
The actuating device according to any one of claims 3 to 5. The control unit (19) is configured to display a first period (TG) indicated by a total period (TG) of the active phase period (ts) and the passive phase period (tn) based on the desired current intensity ( _Isoll ) and the first boundary condition. 1 limit value is calculated, and based on the desired current intensity (I _soll ) and the second boundary condition, a first period (TG) indicated by the total period (TG) of the active phase period (ts) and the passive phase period (tn) is indicated. Configured to calculate a limit value of 2;
The actuator according to any one of claims 1 to 6. The first boundary condition is a target frequency (f _ziel ) indicated by the total period (TG), and / or the second boundary condition is a minimum period of the passive phase period (tn) Characterized by the
8. Actuator according to claim 7. The first limit value corresponds to the lower limit value of the actual frequency at the time of switching between the active phase periods over passive-phase period (f _ist), the second limit value, the upper limit value of the actual frequency (f _ist) Equivalent to,
9. Actuator according to claim 7 or 8. Wherein the control unit (19), it is configured to change the active phase periods over passive-phase period between the actual frequency at the time of switching of (f _ist) between a plurality of frequency values from the lower value to the upper limit value Characterized by the
10. Actuator according to claim 9. The control unit (19) is configured to measure and store an actual value of the active phase period (ts);
The actuating device according to any one of claims 1 to 10. The control unit (19) is configured to calculate the passive phase period (tn) as a function of the actual value of the measured and stored active phase period (ts),
12. Actuator according to claim 11. The conversion circuit (12) is configured as a down converter,
Actuation device given in any 1 paragraph of Claims 1-12. The conversion circuit (12) includes a conversion capacitor (34) connected in parallel to the output connection (15, 16).
The actuating device according to any one of claims 1 to 13. The conversion unit (12) includes a conversion diode (a cathode connected directly to the conversion switch (30) and the conversion inductor (32) and an anode connected directly to the conversion capacitor (34). 33),
15. Actuator according to claim 14. The measurement circuit (56) includes a measurement coil (57) assigned to the conversion inductor (32) and in which a voltage is induced as a measurement value by a magnetic field of the conversion inductor (32).
The actuating device according to any one of claims 1 to 15. The measurement circuit (56) includes a current measurement resistor (60) connected in series to the output connection (15, 16).
The actuator according to any one of claims 1 to 16. A DC converter (21) for generating the DC voltage (UG) is provided,
The actuating device according to any one of claims 1 to 17. A method of operating a lighting means assembly (17) comprising:
A conversion switch (30), a conversion inductor (32), an input connection (13, 14) to which a DC voltage (UG) is applied, and an output connection electrically connected to the illumination means assembly (17) A conversion unit (12) comprising (15, 16) and a measurement circuit (56) configured to measure at least one measurement characterizing the inductor current (IL) flowing through the conversion inductor (32). Using the actuating device (10) comprising,
Presetting the desired current intensity ( _Isoll ) of the inductor current (IL);
The conversion switch (30) is switched to a conductive state once each during one switching cycle when the at least one measured value indicates a zero crossing of the inductor current (IL), and the at least one measured value is the inductor current. Generating a conversion circuit signal (W) that switches to a one-off state when (IL) indicates that a presettable peak current value (IP) has been reached;
The desired current intensity _{(I soll)} is adjusted discontinuously operate when less than the average value of the inductor current (L) at a given minimum peak current _{(IP min),} based on the desired current intensity _{(I soll)} The number of switching cycles indicating the active phase period (ts) and the passive phase period (tn) are calculated, and switching of the conversion switch (30) is permitted by the conversion circuit signal (W) during the active phase period (ts). And, during the passive phase period (tn), preventing the conversion switch (30) from switching to a conductive state by the conversion circuit signal (W);
A method comprising:

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