EP2260682B1 - Method and operating device for minimizing the insulation stress of a high-pressure discharge lamp system - Google Patents

Description

Technical area

The invention relates to a method for minimizing the insulation stress when igniting a high-pressure discharge lamp, with a control gear, generates a high voltage to ignite the high-pressure discharge lamp, and this method Ausführt.

State of the art

The invention is based on a method for minimizing the insulation stress during ignition of a high-pressure discharge lamp according to the preamble of the main claim. Conventional operating devices for high-pressure discharge lamps usually use a fairly simple method to ignite a high-pressure discharge lamp. The high-pressure discharge lamp, also referred to below as a lamp, is supplied with high-voltage pulses which have a sufficient voltage to produce a dielectric breakdown in the discharge lamp between the lamp electrodes. Since not every lamp ignites immediately at the first ignition pulse, the lamp is charged with a large number of ignition pulses, which are combined to form so-called ignition pulse packages. A plurality of these Zündpulspakete is discharged at a predetermined distance to the lamp, as shown in Fig. 3 is apparent. Especially with control gear, which does not allow hot re-ignition of the high pressure discharge lamp, the case may occur that a lamp is turned off, and immediately then switched on again. But then the lamp is too hot to be ignited again with the control gear. Therefore, these operating devices are designed so that they repeatedly deliver ignition pulse packets (so-called bursts) to the lamp for a considerable period of time of approximately 20 minutes to 25 minutes in order to be able to re-ignite a lamp that is being cooled down as quickly as possible (see Fig. 3 ). If such a case occurs, the entire insulation in the high-voltage range of the lamp system is loaded with many hundreds to a thousand unnecessary high-voltage pulses. Of course, this also applies in the case of a non-populated lamp. If the lamp is missing, the entire insulation is particularly stressed. It has been shown that it is precisely the very long bursts of many devices with many high-voltage pulses in rapid succession that are very damaging to the entire high-voltage insulation, and a failure of the insulation over time becomes more and more probable. Under insulation stress, the application of high-voltage pulses to the entire insulation of a high-pressure discharge lamp system from the circuit arrangement which generates the high voltage to the high-pressure discharge lamp burner, which is usually installed in an outer bulb, will be referred to below. Under the entire isolation are all insulating parts of the arrangement of the high voltage source to the high pressure discharge lamp burner to understand. For example, cables, plugs, lamp sockets and outer bulb insulation. High voltage is understood to be anything that generates the high voltage source for the purpose of lamp ignition at high voltage. It is irrelevant whether the high voltage is generated via a pulse ignition method or a resonance ignition method.

task

It is an object of the invention to provide a method for minimizing the insulation stress when igniting a high pressure discharge lamp, which can be performed by an operating device that generates a high voltage to ignite the high pressure discharge lamp.

It is also an object of the invention to provide a control gear that performs this method.

Presentation of the invention

der Zündspannungs-Zeitsumme einer ersten Zeitspanne (t_a|n=0..n1) zur Zündspannungs-Zeitsumme einer zweiten Zeitspanne (t_b|n=n1+1..n2) größer ¼. Die Zündspannungs-Zeitsumme ist die Summe aller Zeitabschnitte Z_i, während derer der Betrag der Zündspannung eine Zündspannungs-Grenze übersteigt. Die Zündspannungsgrenze ist als Faktorbereich eines betragsmäßigen Höchstwertes der angelegten Hochspannungen definiert. Der betragsmäßige Höchstwert ist hierbei der höchste Wert des Betrages der Spannung, der in Summe für mindestens 2µs auftritt, während die Zündspannung anliegt. Wenn das Verhältnis der Zündspannungs-Zeitsummen größer ist als ¼, dann bietet das den Vorteil einer geringen Isolationsbeanspruchung.The object is achieved according to the invention with a method for minimizing the insulation stress of a high-pressure discharge lamp system, with an operating device that generates a high voltage to ignite the high-pressure discharge lamp, wherein a voltage applied at lamp start ignition voltage time is minimized, the ratio $\frac{{\displaystyle \underset{i=0}{\overset{n1}{\Sigma }}}{Z}_i}{{\displaystyle \underset{i=n1+1}{\overset{n2}{\Sigma }}}{Z}_i}$

the ignition voltage time sum of a first time period (t _a | n = 0..n1) to the ignition voltage time sum of a second time period (t _b | n = n1 + 1..n2) greater than ¼. The ignition voltage time sum is the sum of all time periods Z _i , during which the amount of the ignition voltage exceeds an ignition voltage limit. The ignition voltage limit is defined as the factor range of an absolute maximum value of the applied high voltages. The maximum value in this case is the highest value of the amount of voltage that occurs in total for at least 2μs while the ignition voltage is applied. If the ratio of the ignition voltage time sums greater than ¼, then this offers the advantage of a low insulation stress.

der Zündspannungs-Zeitsumme einer ersten Zeitspanne (t_a|n=0..n1) zur Zündspannungs-Zeitsumme einer zweiten Zeitspanne (t_b|n=n1+1..n2) größer als ½ ist der Vorteil einer geringen Isolationsbeanspruchung besonders groß.At a ratio $\frac{{\displaystyle \underset{i=0}{\overset{n1}{\Sigma }}}{Z}_i}{{\displaystyle \underset{i=n1+1}{\overset{n2}{\Sigma }}}{Z}_i}$

the ignition voltage time sum of a first time period (t _a | n = 0..n1) for Zündspannungs-time sum of a second period (t _b | n = n1 + 1..n2) greater than ½, the advantage of low insulation stress is particularly large.

The factor range is preferably between 0.6 and 0.95, more preferably between 0.8 and 0.9. As a result, only voltages applied to the high-pressure discharge lamp are counted for the method according to the invention, which on the one hand really also contribute to the ignition, but on the other hand also claim the insulation to a significant extent.

The duration of the first period (t _a ) is preferably between 1 s and 2 min, more preferably between 30 s and 1 min. The duration of the second time interval (t _b ), however, is preferably between 15 minutes and 25 minutes, more preferably 20 minutes.

If in the first period (t _a ) Zündpulspakete with a packet duration of 0.5 s - 1.5 s with a distance between two Zündspulets from 7s - 35s are generated, a cold high-pressure discharge lamp can be particularly well ignited. The ignition pulse packets generated in the second time period (t _b ) with a packet duration of 0.05 s - 0.15 s with a distance between two ignition pulse packets of 30 s - 7 min are hot on the ignition High pressure discharge lamp optimized. If a lamp breakdown is detected in the second period (t _b ), the generation of an ignition pulse packet with a packet duration of 0.5 s - 1.5 s can start the high-pressure discharge lamp even better. With this measure, a safe lamp ignition can be generated from a first dielectric breakthrough.

If a preceding measured switch-off duration of the high-pressure discharge lamp is> = 20 min, ignition coil packets with a packet duration of 0.5 s-1.5 s are preferably generated for a first time interval (t _a ), which have a spacing between two ignition pulse packets of 7 s - 35 s , Thus, a cold high-pressure discharge lamp can be started optimally, further ignition pulses are not necessary.

Ignition pulse packets for a first time period (t _a ) with a packet duration of 0.5 s - 1.5 s and for a second time period (t _b ) with a packet duration of 0.05 s - 0 at a preceding measured turn-off duration of less than 20 min , 15s generated. The distance between two Zündpulspaketen for the first period (t _a ) is 7s - 35s, the distance between two Zündpulspaketen for the second period (t _b ) is 30s - 7min. These values offer the advantage that, on the one hand, hot lamps can be ignited well while sparing insulation, and on the other hand, in the event of a lamp replacement, a cold lamp, which is then recognized as being hot, nevertheless starts up well.

Further advantageous developments and refinements of the method according to the invention for minimizing the insulation stress during the ignition of a high-pressure discharge lamp result from further dependent claims and from the following description.

Short description of the drawing (s)

Fig. 1a

die Darstellung eines ersten erfindungsgemäßen Verfahrens zur Minimierung der Isolationsbeanspruchung beim Zünden einer Hochdruckentladungslampe für den Fall einer kalten Lampe.

Fig. 1b

die Darstellung eines ersten erfindungsgemäßen Verfahrens zur Minimierung der Isolationsbeanspruchung beim Zünden einer Hochdruckentladungslampe für den Fall einer heißen Lampe.

Fig. 2a

die Darstellung eines zweiten erfindungsgemäßen Verfahrens zur Minimierung der Isolationsbeanspruchung beim Zünden einer Hochdruckentladungslampe in einer ersten Variante.

Fig. 2b

die Darstellung eines zweiten erfindungsgemäßen Verfahrens zur Minimierung der Isolationsbeanspruchung beim Zünden einer Hochdruckentladungslampe in einer zweiten Variante.

Fig. 2c

die Darstellung eines zweiten erfindungsgemäßen Verfahrens zur Minimierung der Isolationsbeanspruchung beim Zünden einer Hochdruckentladungslampe in einer dritten Variante.

Fig. 3

die Darstellung eines Verfahrens zum Zünden einer Hochdruckentladungslampe nach dem Stand der Technik.

The invention will be explained in more detail below with reference to embodiments. Show it:

Fig. 1a

the representation of a first method according to the invention for minimizing the insulation stress when igniting a high-pressure discharge lamp in the case of a cold lamp.

Fig. 1b

the representation of a first method according to the invention for minimizing the insulation stress when igniting a high-pressure discharge lamp in the case of a hot lamp.

Fig. 2a

the representation of a second method according to the invention for minimizing the insulation stress when igniting a high-pressure discharge lamp in a first variant.

Fig. 2b

the representation of a second method according to the invention for minimizing the insulation stress when igniting a high-pressure discharge lamp in a second variant.

Fig. 2c

the representation of a second method according to the invention for minimizing the insulation stress when igniting a high-pressure discharge lamp in a third variant.

Fig. 3

the representation of a method for igniting a high-pressure discharge lamp according to the prior art.

Preferred embodiment of the invention

Fig. 1a shows a graphical representation of a first method according to the invention for minimizing the insulation stress when igniting a high-pressure discharge lamp in the case of a cold lamp. On the vertical axis, the voltage applied to the lamp ignition voltage is applied, on the transverse axis of the elapsed time since the first ignition pulse z. Since a cold lamp can be ignited immediately, only a few Zündpulspakete should be applied one behind the other to the lamp. If the lamp does not light until then, it must be assumed that it is defective or no lamp is present. In the present embodiment, there are two Zündpulspakete executed in succession, but have a fairly long packet duration to overcome the poor ionization of the lamp in the cold state. In summary, for a predetermined first period of time, an ignition voltage having a first intensity IN _{ta is applied} to the lamp to start it. After this predetermined first time no ignition pulses are applied to the lamp. In this case, the intensity is the sum of all the ignition pulses Z applied to the lamp in this time period per unit of time or the absolute duration of the time during the first period of time applied to the high pressure discharge lamp ignition voltage per unit time.

Z sind dabei wie oben schon erwähnt die Zeitabschnitte, während derer der Betrag der Zündspannung eine Zündspannungs-Grenze übersteigt, und die Zündspannungsgrenze als Faktorbereich eines betragsmäßigen Höchstwertes der angelegten Hochspannungen definiert. Die Anzahl der einzelnen Zeitabschnitte in dieser Periode ist n1. Für die vorbestimmte zweite Zeitspanne gilt dann analog: ${\mathit{IN}}_{\mathit{tb}}=\frac{{\displaystyle \sum _{i=n1+1}^{n2}}{Z}_i}{t_b}$

Fig. 1b shows a graphical representation of a first method according to the invention for minimizing the insulation stress when igniting a high-pressure discharge lamp in the case of a hot lamp. In this condition, the lamp must first cool to be ignited, so continuous exposure of the ignition pulse lamp from the beginning, as described in the prior art, is not optimal. Therefore, an optimized method is used which provides longer time periods between the ignition pulses. Since the lamp state measurement implemented in the operating device may be very inaccurate, it may be that the lamp has already cooled down a long way, and therefore it is ready to ignite after a short time. Therefore, ignition pulses are still generated from the beginning to cover this case. Even in the event that a burning old lamp is switched off to be replaced by a new cold lamp shortly thereafter, must be covered for such a case, because the control gear does not know whether a lamp has been replaced. Therefore, as with a cold lamp, an ignition voltage having a first intensity IN _{ta is} applied to the lamp for a predetermined first time period t _a . Then, an ignition voltage having a predetermined second intensity IN _{tb is applied} to the lamp for a predetermined second time period t _b . The predetermined second time interval t _b is significantly longer than the predetermined first time period t _a . For this, the predetermined second intensity IN _{tb of} the ignition voltage is lower than the predetermined first intensity IN _ta . If ignition pulses are applied to the lamp, then the predetermined first intensity IN _{ta can be} regarded as the sum of all time periods of the ignition voltage (ignition voltage time sum) applied in this time period per this period of time: ${\mathit{IN}}_{\mathit{ta}}=\frac{{\displaystyle \underset{i=0}{\overset{n1}{\Sigma }}}{Z}_i}{t_a}\mathrm{,}$

Z are, as already mentioned above, the time periods during which the magnitude of the ignition voltage exceeds an ignition voltage limit, and the ignition voltage limit is defined as the factor range of an absolute maximum value of the applied high voltages. The number of individual time periods in this period is n1. For the predetermined second period then applies analogously: ${\mathit{IN}}_{\mathit{tb}}=\frac{{\displaystyle \underset{i=n1+1}{\overset{n2}{\Sigma }}}{Z}_i}{t_b}$

wobei n2 die Summe der Pulse aus der ersten Zeitspanne t_a und der Pulse aus der zweiten Zeitspanne t_b ist. Fig. 2a shows the representation of a second method according to the invention for minimizing the insulation stress when igniting a high-pressure discharge lamp in a first variant. The second method according to the invention is a simplified variant in which no measurement of the state of the lamp is made. As a result, the operating device can be made much simpler and thus cheaper. However, since the control gear does not know the condition of the lamp, the procedure must be suitable for both cold and hot lamps. Since it has been shown that cold lamps require ignition pulse packages with a longer package duration for optimal ignition due to their low tendency to ionise, at the beginning as in the first method according to the invention with hot lamps, a few long ignition pulse packages are generated for the period t _a . If the lamp has not ignited despite the long packages, the lamp is probably not cold, but still too hot, therefore, the inventive method changes the strategy and extends the pauses between the Zündpulspaketen in the subsequent period t _b . It has also been found that for hot lamps due to their temperature, ignition pulse packages with a short package duration are sufficient to ignite the lamp. Therefore, not only the breaks are extended, but also greatly reduced the package duration. These measures ensure a significant reduction in the amount of ignition voltage applied to the lamp ${\displaystyle \underset{i=0}{\overset{n2}{\Sigma }}}{Z}_i.$

where n2 is the sum of the pulses from the first time period t _a and the pulses from the second time period t _b .

Fig. 2b shows the representation of a second method according to the invention for minimizing the insulation stress when igniting a high-pressure discharge lamp in a second variant. The second variant is similar to the first variant, only the strategy for the ignition of a hot lamp is another. In the second variant, a Zündpulspaket is applied to the lamp for the ignition of a hot lamp at very large intervals for the period t _b , which is similar to that for the cold ignition. The fact that the distances between the Zündpulspaketen are even greater than in the first variant, the Zündspannungs-time total during the period t _b compared to the prior art also be significantly reduced. This variant is suitable for high-pressure discharge lamps, which have a bad ignitability even when hot, which is why this second variant compared to the first variant also defined for the hot ignition Zündpulspakete with a longer package duration.

In a third variant, the in Fig. 2c is shown, the methods are combined according to the first and the second variant. Again, the cold ignition already described above for the period t _{a is first performed} with a few long Zündpulspaketen. Then it switches to an ignition strategy as in the first variant. At short intervals, short ignition pulse packets are applied to the lamp for the time t _b . Detects the operating device has a breakdown between the lamp electrodes at time t _i, the Zündpulspaket is significantly prolonged in order to ignite the lamp in the further course safely. With this strategy, one achieves a significant reduction of the ignition voltage time sum while improving the lamp ignition. The entire insulation in the high voltage range, including the lamp socket and the creepage distances in the operating device, are thus protected.

For both methods and variants according to the invention, it has been shown that there are certain optimum values for both time periods t _a and t _b . The duration of the first time period t _a is then between 1 s and 2 min, particularly advantageously between 30 s and 1 min. The duration of the second period is thereafter 15min to 25min, more preferably about 20min.

The limit for which a high voltage applied to the lamp is still regarded as the ignition voltage pulse z is defined as the ignition voltage limit. The ignition voltage limit is in the range of 60% to 95%, advantageously in the range of 80% to 90% of the maximum value of all amounts of the high voltages applied to the lamp in the period t _a and in the time period t _b . The maximum value in this case is the highest value of the amount of voltage that occurs in total for at least 2μs while the ignition voltage is applied.

der Zündspannungs-Zeitsummen der ersten und zweiten Zeitabschnitte in einem bestimmten Bereich bewegt. Gut ist ein Verhältnis von ¼ wobei ein Verhältnis von ½ besonders vorteilhaft ist.In order to optimize the ignition voltage behavior of the lamp, it is advantageous if the ratio $\frac{{\displaystyle \underset{i=0}{\overset{n1}{\Sigma }}}{Z}_i}{{\displaystyle \underset{i=n1+1}{\overset{n2}{\Sigma }}}{Z}_i}$

the ignition voltage time sums of the first and second periods moved in a certain range. Good is a ratio of ¼ where a ratio of ½ is particularly advantageous.

The ratio of ignition voltage sums of the prior art is in the range of 1/10 to 1/40, which entails a significantly higher isolation stress than the method according to the invention.

Claims (14)

1. Method for minimizing the insulation stress of a highpressure discharge lamp system, with an operating device, which generates a high voltage for starting the highpressure discharge lamp, characterized in that a starting voltage time sum applied during lamp starting is minimized, the starting voltage time sum is the sum of all time segments Z_i during which the magnitude of the starting voltage exceeds a starting voltage limit, and the starting voltage limit is defined as the factor range of a maximum value, in terms of magnitude, of the applied high voltages, the ratio $\frac{{\displaystyle \sum _{i=0}^{n1}}{Z}_i}{{\displaystyle \sum _{i=n1+1}^{n2}}{Z}_i}$

   

   of the starting voltage time sum of a first time span (t_a|n=0..n1) to the starting voltage time sum of a second time span (t_b|n=n1+1..n2) being greater than ¼.
2. Method according to Claim 1, characterized in that the factor range is between 0.6 and 0.95, in particular between 0.8 and 0.9.
3. Method according to either of Claims 1 and 2, characterized in that the ratio $\frac{{\displaystyle \sum _{i=0}^{n1}}{Z}_i}{{\displaystyle \sum _{i=n1+1}^{n2}}{Z}_i}$

   

   of the starting voltage time sum of a first time span (t_a|n=0..n1) to the starting voltage time sum of a second time span (t_b|n=n1+1..n2) is greater than ½.
4. Method according to one of Claims 1 to 3, characterized in that the duration of the first time span (t_a) is between 1 s and 2 min, preferably between 30 s and 1 min.
5. Method according to one of Claims 1 to 4, characterized in that the duration of the second time span (t_b) is between 15 min and 25 min, preferably 20 min.
6. Method according to Claim 5, characterized in that, in the first time span (t_a), starting pulse bursts with a burst duration of 0.5 s - 1.5 s with an interval between two starting pulse bursts of 7 s - 35 s are generated.
7. Method according to Claim 6, characterized in that, in the second time span (t_b), starting pulse bursts with a burst duration of 0.05 s - 0.15 s with an interval between two starting pulse bursts of 30 s - 7 min are generated.
8. Method according to Claim 7, characterized in that, when a lamp breakdown is detected in the second time span (t_b), a starting pulse burst with a burst duration of 0.5 s - 1.5 s is generated.
9. Method according to Claim 5, characterized in that, in the case of a preceding, measured switch-off duration, the longer the measured, preceding switch-off duration is, the greater the ratio $\frac{{\displaystyle \sum _{i=0}^{n1}}{Z}_i}{{\displaystyle \sum _{i=n1+1}^{n2}}{Z}_i}$

   

   of the starting voltage time sums is set to be.
10. Method according to Claim 9, characterized in that, after a certain switch-off duration in the range of from 15 min to 25 min, the ratio $\frac{{\displaystyle \sum _{i=0}^{n1}}{Z}_i}{{\displaystyle \sum _{i=n1+1}^{n2}}{Z}_i}$

    

    of the starting voltage time sums reaches a maximum.
11. Method according to Claim 9 or 10, characterized in that, in the case of a preceding, measured switch-off duration ≥ 20 min, starting pulse bursts with a burst duration of 0.5 s - 1.5 s are generated for a first time span (t_a), and the interval between two starting pulse bursts is 7 s - 35 s.
12. Method according to Claim 5, characterized in that, in the case of a measured, preceding switch-off duration < 20 min, starting pulse bursts with a burst duration of 0.5 s - 1.5 s are generated for a first time span (t_a) and starting pulse bursts with a burst duration of 0.05 s - 0.15 s are generated for a second time span (t_b).
13. Method according to Claim 12, characterized in that the interval between two starting pulse bursts is 7 s - 35 s for a first time span (t_a), and the interval between two starting pulse bursts is 30 s - 7 min for a second time span (t_b).
14. Circuit arrangement with a high-voltage part, which generates starting pulse bursts for starting a highpressure discharge lamp, characterized by reduced insulation stress in the high-voltage part as a result of the application of a method according to one or more of Claims 1 to 13.

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