RU17389U1 - DEVICE FOR POWER SUPPLY OF A DISCHARGE LAMP - Google Patents

Abstract

A device for supplying a gas discharge lamp, comprising a ballast capacitor included in the network and connected in series, a voltage multiplier and a polarity reversal switch connected to a lamp, characterized in that a diode voltage divider is connected to the output of the voltage multiplier through a parallel U-shaped RC filter the input of which is connected through a separation capacitor to the network in front of the ballast capacitor and through a blocking capacitor to a polarity reversal switch made in the form of mains contactor connected to the network.

Description

Object - Utility Model

MPK7 NO5V 41/23 device for powering a discharge lamp

The utility model relates to the field of electrical engineering, namely, to ignition and power schemes for gas-discharge lighting lamps of alternating current without an auxiliary starting electrode and can be used in combination with standard ballast equipment (ballasts).

Known electronic starter for discharge lamps, powered from a 50Hz network through a ballast choke (US Pat. No. 5583395, HO5B 41 / 23.39 / 00, publ. 10.12.96), containing a diode bridge, a rectifier, a transistor and a time-delaying RC circuit that controls the operation of the transistor, and the lamp can be connected both to the diagonal of alternating and direct current, and in addition to the lamp, using a relay, an additional capacitor is connected.

The disadvantage of this lamp power supply circuit is the need to control modes using a transistor operating in the key mode to maintain operability in the interval of heating of the electrodes and in the operating mode. In the conditions of fluctuation of the mains voltage, this circuit is unreliable and does not provide stabilization of the light flux. The transistor operates in the active region and limits the lamp current only at a given nominal level, i.e. The circuit imitates the principle of a gas discharge lamp with an active continuous semiconductor ballast. Therefore, traditional disadvantages are observed: the presence of pauses in the current of the lamp, low K.P.D. (60-70%), reduced light output and lamp life.

Known transformerless AC current limiter for powering the lamps (US Pat. No. 4,929,871, HO5B 41/16, publ. 29.05.90) consisting of a bridge rectifier with 4 diodes, the diagonal of the alternating current of which, through a capacitor with a capacity proportional to the load current,

is connected to the mains supply, and the lamp is connected to the diagonal of the rectifier’s direct current, and in order to reduce light ripples, an inductive choke is connected in series with the capacitor.

The disadvantage of this scheme is that the gas discharge lamp serves as an active nonlinear element, therefore, distortions occur in the circuit in the form of higher harmonic components (3,5,7th and others). In this scheme, the most active, with up to 25% of content, is the third harmonic, which is in antiphase with the main current wave, which is expressed in the appearance of current pauses, and a decrease in the light output of the lamp. The current passing through the burner of the discharge lamp immediately after ignition exceeds the steady-state operating current of the lamp by almost a factor of two, therefore, increased wear of the electrodes due to cataphoresis is observed.

In known devices for igniting gas discharge lamps (US Pat. No. 5,225,742, HO5B 41/36, publ. 6.07.93; Czech Pat. No. 280850, HO5B 41/231, HOI J 7/30 publ. 04/17/96) diode a capacitor voltage multiplier connected to the output of the control and starting apparatus, and the output of the device is shunted by a spark gap.

The disadvantages of these devices are the negative effects associated with the operation of the AC lamp at a voltage with a constant component. In this case, the phenomena of cathophoresis occur, leading to a decrease in the luminous flux of the lamp, to accelerated aging and wear of the electrodes.

A known power supply circuit for a discharge lamp (French application No. 2615883, HO5B 41/16 publ. 25.11.88) containing a rectifier according to a half-wave circuit with doubling voltage connected to the lamp through an active ballast.

The disadvantages of the circuit are significant losses in the active resistor ballast, increased wear of the electrodes in lamps not designed for direct current, and a decrease in the luminous flux due to the phenomenon of cathophoresis.

Known devices for powering discharge lamps with direct current (see the journal "Radio, 1997, No. 5, p. 37) containing bridge diode-capacitor doublers-voltage quadruplers, connected in series with an inductive ballast and a lamp.

The disadvantage of these devices is the presence of increased oscillatory processes in the system containing reactive elements (inductor and capacitors) and, in connection with this, the appearance of new additional losses in the ballast, lamp and network, as well as a high pulsation coefficient of the light flux of the lamp. The power supply of a standard AC discharge lamp from this device leads to cathophoresis and accelerated cathode wear, with a decrease in lamp life.

A lighting device is known (AS USSR No. 1809550, HO5V 41/14, publ. 04/15/93) containing a rectifier-voltage quadrupler, a rectifier-doubler and a bridge rectifier connected in parallel to the network, and the connection between the positive and negative points of the three rectifiers, a discharge lamp is connected through a resistor.

The disadvantages of the circuit are increased power losses in the ballast resistor, increased wear of the electrodes in lamps not designed for direct current, and a decrease in the luminous flux of the lamp due to the phenomenon of cathophoresis.

A device for powering a gas discharge lamp (utility model of Russia No. 12495, HO5V 41/23, application 27.08.99) comprising a rectifier with doubling the rectified voltage, consisting of two diodes and two capacitors, while one of the terminals of the rectifier is connected to one of the terminals for connecting to the network and one terminal of the smoothing capacitor, the other terminal of the rectifier is connected to another terminal of the ballast, the output terminals of the rectifier are connected to the terminal of the lamp,

the other terminal of the ballast is connected to another terminal for connection to the network and another terminal of the smoothing capacitor, and the ballast is a capacitive ballast and contains an electrolytic capacitor with a capacity of 60-100 uF.

The disadvantage of this device is the operation of the lamp with a large proportion of the constant component in the current of the lamp, which leads to cataphoresis, rapid aging of the electrodes, and a decrease in the luminous flux of the lamp and the service life.

A device for ignition of gas discharge lamps (utility model of Russia No. 12496, HO5B 41/23, application form. 08.27.99) containing a rectifier with voltage doubling, a capacitive filter and ballast on electrolytic capacitors.

The disadvantage of this device is that the ignition and operation of the lamps occur with the formation of a voltage with a large DC component at the output, and standard lamps are not designed to operate on direct current. In operating mode, the circuit has low energy characteristics due to significant losses in capacitive ballast and due to inefficient operation of the lamp at a current with a high DC component (after several hours of continuous operation, the luminous part of the discharge in the burner will occupy less than half of it due to the phenomenon of cathophoresis long with a decrease in light output of the lamp and its service life due to progressive atomization of the cathode).

A device is known for supplying a gas discharge lamp from an alternating current main (application of Germany No. 4020517, НО5В 41/23, НО2М 7/06, publ. 02.01.92), which contains a ballast reactor and a bridge rectifier connected in series and connected to the network, into the DC diagonal of which , through the L-shaped smoothing LC filter and the switch for periodic polarity reversal, a lamp is connected.

The disadvantages of this device is the presence of high .harmonic vibrations in the PRA-lamp system, due to the presence of reactive elements. The smoothing LC filter creates additional losses that reduce the efficiency power devices. When using inductive-capacitive ballast, the levels of higher harmonics increase - the third (10%) and fifth (1%) two-three times. The presence of higher harmonics in the supply network increases losses in the cores of transformers and the level of interference, and also affects the drive systems of the switch, reducing its reliability.

A device for powering discharge lamps with direct current (US Pat. US No. 5072160, HO5B 41/16, publ. 10.01.91) with a periodic change in the polarity of the supply voltage to the opposite, containing a rectifier with a falling current-voltage characteristic, to the output of which a lamp is connected through a bridge current direction switch assembled using an electromagnetic relay with four pairs of contacts.

The disadvantages of this scheme are the high switching values of current and voltage, additional losses in the electromagnetic relay, the lamp current passing through zero during switching, which leads to current ripple, sputtering of the electrodes and a decrease in lamp life.

The closest analogue to the claimed utility model is a gas discharge lamp power supply device (French application No. 2645393, HO5B41 / 23, publ. 10.05.90) containing a ballast capacitor connected in series and connected in series, a voltage multiplier and a polarity reversal switch connected to the lamp.

The disadvantages of the known device are the low stability of the lamp parameters in the nominal mode when the mains voltage changes and high losses on ballasts. There is a high sensitivity to changes in the mains voltage, leading either to a decrease in the luminous flux, or to overloading the lamp by current and accelerated wear of the electrodes. The lamp itself and the reactive elements of the circuit generate

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harmonic oscillations of high orders, which leads to the appearance of current pauses and a decrease in the luminous flux of the lamp. The semiconductor switching elements of the switch change the polarity of the voltage, to a large extent depends on fluctuations in the mains voltage, which leads to a decrease in the reliability of switching.

The utility model is based on the task of developing such a device for supplying a gas discharge lamp that would ensure stabilization of the lamp parameters in the nominal mode when the voltage in the network changes, while reducing losses on the start-up and control equipment.

The problem is solved in that in the known device for supplying a gas discharge lamp containing a ballast capacitor included in the network and connected in series, a voltage multiplier and a polarity reversal switch connected to the lamp, according to the change, to the output of the voltage multiplier through a parallel U-shaped CRC- filter, a diode voltage divider is encountered, the input of which is connected through an isolation capacitor to the network in front of the ballast capacitor and, through a switching capacitor from the commutator Oromo polarity changes made as a gersikonovogo contactor connected to the network.

The essence of the utility model is illustrated in the drawing, which shows a schematic diagram of a device for powering a discharge lamp.

A device for supplying a gas discharge lamp includes, connected to the terminals 1 and 2 of the AC network, through a ballast capacitor 3, a voltage multiplier, which is a combination of a half-wave bridge circuit and a Delon cascade circuit, and includes four diodes 4,5,6,7 moreover, the diagonal of the alternating current is connected to the terminal 1 of the network and the ballast capacitor 3. Two capacitors 8 and 9 are connected in series to the diagonal of the direct current of the multiplier, and between them and the output to the multiplier from the ballast

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capacitor 3, a capacitor 10 is connected. The multiplier diodes 4 and 5 are shunted by the charging capacitors 11 and 12. The DC diagonal of the multiplier, through a U-shaped CRC filter, consisting of parallel-connected electrolytic capacitors 13 and 14 and a series resistance 15 located between them, is connected counter to the output of the voltage divider, including diodes 16 and 17, connected by a half-bridge circuit. The input of the voltage divider formed by the different-pole electrodes of the diodes 16 and 17 is connected, through a series-connected isolation capacitor 18, to the network terminal 2, and also, through a locking capacitor 19, connected to the Gersikon contactor 20, through its power contact 21. The positive output of the constant diagonal the current of the voltage multiplier is connected to the terminal 22 of the Gersikon contactor 20. The control coil (not shown) of the Gersikon contactor 20 is connected to the terminals 1 and 2 of the network. In the Gersikon contactor 20, the contact pairs 21-23 and 22-24 are normally closed in the absence of voltage on the control coil, and the contact pairs 21-25 and 22-26 are closed when voltage is applied to the control coil. In this case, one terminal of the lamp 27 is connected to the contacts 25 and 24, and the second terminal is connected to the contacts 23 and 26, to ensure a change in polarity.

The supply of the claimed device with a diode voltage divider (diodes 16 and 17), the output of which is connected opposite to the output of the voltage multiplier, and the input through an isolation capacitor 18 with a terminal 2 of the network, in front of the ballast capacitor 3, allows you to adjust the dynamic limitation or expansion of the range of voltage supplied to the lamp voltage fluctuations in the network. This ensures that the lamp remains stable and has a long life.

The connection of the input of the voltage divider, on the diodes 16 and 17, with the switch 20, through a locking capacitor 19, provides a decrease in the DC component in the current, due to partial locking on

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the capacitor 19, which leads to a decrease in higher harmonics in the current of the lamp and increases its service life, with a decrease in the phenomena of cathophoresis.

The use of a U-shaped CRC filter assembled from capacitors 13 and 14 and resistance 15, connected between the output of the voltage multiplier and the output of the voltage divider, allows to increase the efficiency of dynamic ballast due to high-quality filtering of the rectified network voltage, which provides lower losses for ballasts. Using a Gersikon contactor 20 as a switch allows you to change the polarity on the lamp 27, from a current source with a high DC component, without current pauses and interruption of the discharge in the lamp burner 27, with minimal switching costs. A device for powering a discharge lamp works as follows: an alternating mains voltage is applied to terminals 1 and 2. From terminal 1, voltage is supplied to the first input of the voltage multiplier through diodes 6 and 7, and from terminal 2, voltage is supplied through the ballast capacitor 3 to the diodes 4 and 5 of the multiplier and multiplication capacitors 8.9 and 10, as well as to the charging capacitors 11 and 12. V one of the half-periods of the mains voltage, the capacitors 8 and 11 are charged through the capacitor 3, which helps to limit the charging current, and the capacitors 9 and 12 through the capacitor 10. During the next half-cycle, the mains voltage is summed with the voltage of the capacitors 8,9,11,12, as a result what happens is the voltage is multiplied to a value sufficient to "penetrate the interelectrode gap in the lamp 27. In the start-up mode, the increased voltage on the lamp 27 is ensured by superimposing on the alternating voltage of the network a constant component from the voltage multiplier equal to twice or quadruple the amplitude value of this voltage. Moreover, the time constant of the charging circuit of the capacitors 8,9,11i12 determines the time of the lamp 27. The ignition voltage is supplied from the diagonal of the multiplier DC to the normally closed contacts 21-23 and 22-24 of the Gersikon

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the contactor 20 and further to the lamp 27. As a result, the lamp 27 is ignited, the mains voltage decreases, after which the capacitors 11,12,8 and 9 are ignited through the diodes 4, 5, 6, 7 of the multiplier bridge and then do not affect the operation of the device, because they are not able to charge, because the voltage amplitude is less than the voltage drop across the lamp 27. When the discharge is excited, the current in the circuit is determined by the circuit capacitance parameters, and when the discharge in the lamp 27 is lit, the capacitors 8-12 are completely discharged, the current decreases, and during ignition the current increases smoothly, during data charging capacitors, which provides a "soft start, with the limitation of inrush currents through the ballast and lamp 27 during start-up. The half-bridge rectifier circuit on diodes 16 and 17, the input of which is connected through an isolation capacitor 18 to the network terminal 2, acts as a dynamic limiter or expander (voltage expander) supplied to the lamp 27, when the mains voltage fluctuates. In this case, in the case of an increase in the mains voltage, the voltage on the lamp 27 is reduced by a voltage divider, the diodes 16 and 17 of which are controlled from the output side by a voltage multiplier (diodes 4-7). In the event of a decrease in the voltage in the network, the capacitor 18 is discharged to the input of the voltage divider and increases the voltage on the lamp 27. The dynamic range of regulation can be selected in accordance with the minimum and maximum fluctuations in the voltage and rated voltage on the lamp 27. Moreover, the control is closed and therefore devices cannot overshoot. A U-shaped filter containing electrolytic capacitors 13,14, resistance 15 and connected between the outputs of the multiplier and the limiter, provides filtering of low- and high-frequency harmonics from the mains and from the working lamp 27, as well as a smoother increase in voltage on the parts of the rectifier multiplier, in addition , improves the harmonic composition of the input current and increases the power factor. The locking capacitor 19 serves to

reducing the harmonic components of the DC voltage, to damp the oscillatory processes in the device containing capacitive and reactive elements and, as a result, reduces harmonic interference penetrating the network. When supplying a standard lamp designed for alternating voltage from the inventive device having an output voltage with a constant component, to eliminate the negative phenomena associated with cataphoresis, and to reduce the aging processes of the electrodes of the lamp 27, the polarity of the connected lamp 27 is periodically switched using the Gersikon contactor 20 . At the same time, the control coil of the Gersikon contactor 20 (see MG Koblenz, Hermetic switching devices on power reed switches. M .: Energoatoizdat, 1986, p. 30) a timer (not shown) and the Gersikon contactor 20, with a given frequency commutes two pairs of contacts: closure 21-23 and 22-24 gives one polarity of the lamp 27, and the simultaneous closure of contacts 21-25 and 22-26 is designed to change the polarity . Advantages of the Gersikon contactor 20 are small dimensions, stability of operation when the mains voltage changes, inertia-free and non-pause switching. To ensure the safety of service from electric shock, all capacitors with a capacity of more than 0.5 μF (3,8,9,10,11,13,16,18,) must have discharge resistors (not shown in the drawing), connected in parallel with the terminals of the capacitors. The use of electrolytic capacitors 3 and 18 as capacitors with a 50uOmkF capacitance makes it possible to carry out a controlled start of the lamp due to the medium voltage discharge supplemented with higher-order harmonics, which increases the lamp life. The device provides a smooth kindling, operation and switching off of a discharge lamp from an AC source, having a voltage equal to or less than the ignition voltage of the lamp, due to the time delay circuit with storage capacitors 3 and 18. Due to the capacitive nature of the ballast, this

the device is protected against overloads, in the event of emergency not ignition of the lamp 27, from short circuit currents and overvoltage. In addition, the Gersikon contactor 20 allows you to connect (in the drawing not shown) in parallel or in series to the lamp 27 electrolytic capacitors of different capacities (for example, from among 13,15,19), which change the total (apparent), the resistance of the circuit, which will allow you to use them as a capacitive dimmer with step “darkening” (Lighting Engineering, 1998, No. 5, p. 38-39).

In the laboratory, tests were carried out on the inventive device and device taken as a prototype. The measurement of lamp parameters (DRL-250) and ballasts was carried out by devices according to GOST 16809-88 and 6825-70. The start-up parameters of ballasts were determined by the method of equivalent resistors. To account for the higher harmonics in the lamp current, the voltage was measured by an electrostatic voltmeter using the effective value. When measuring the electric and light parameters of the lamp and ballasts, we used exemplary measuring chokes (DPI DPI 250RL / 220) and a rated lamp (LED DRL 250; rated current-2.15A; rated voltage - 130V). The lamp power was measured by an electrodynamic wattmeter with an error of not more than 0.5%. The power loss in the diode-capacitor ballast containing reactive elements was determined by a low-sine wattmeter as the difference between the power consumed from the network and the lamp power. In the circuit of the claimed device, diode bridges KTs405A or KTs402A, diodes of the type KD243G or others designed for current up to 1-2A and reverse voltage of 400V were used. A KERSG contactor of the type KMG18D19 was used. Some ratings of circuit elements: capacitors 3 and 18 -50 μfFkhZOOV; capacitors 8,9,10,11,12, -0,5 μkFkhZOOV; electrolytic capacitors 13-25mkFh750V; capacitor 19 -0.01mkFh750V; resistor 14 -1kOhm. The test results are presented in the table.

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Table

The test results showed that the inventive device increases the stability of the luminous flux of the lamp by 30% compared with the prototype and reaches 90% (according to GOST 16354, at least 72% is normalized), which allows to increase the effective life of the lamp with normalized illumination. The inventive device ensures the normal operating mode of the discharge lamp, stabilizes the current and power during voltage fluctuations, reduces the ripple of the light flux (compared with the prototype, the ripple coefficient of the light flux is 1.5 times less). The device allows to reduce by 2.6 times the time of the lamp ignition period and the time of repeated switching on after shutdown, which increases the efficiency of the lighting system and reduces unproductive energy costs. The inventive device, due to a more effective limitation of the amplitude value of the operating current of the lamp, characterized by the amplitude coefficient of the lamp (9 for the prototype and 6 for the inventive device), which allows to increase the lamp life by 20%. This device maintains a current and power instability coefficient within the nominal range (for DRL lamps - Y and I no more than 2, i.e. when the mains voltage changes by 10%, the power changes by no more than 20%), which guarantees nominal lighting parameters, eliminates excessive illumination, excessive energy consumption and deterioration of the thermal regime of the lamp. The proposed device allows to increase the power factor of the lamp-ballast circuit by 40%, due to a decrease in the reactive component of the lamp current and a greater compensation of the reactive power of higher harmonics in the lamp current by using the compensating ability of the filter capacitors connected in parallel. The tested mercury lamp is designed, when operating on alternating current, for high starting and working current densities, so the electrodes are in difficult working conditions. When using a standard lamp in the DC circuit, to preserve its luminous flux on

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-13 level, which she had when powered by alternating current, the working current can be reduced by 10-20%, compared with the current value of the current when it is working on alternating current. With the combined inclusion of the inventive device and standard ballast (chokes or scattering transformers), losses in ballasts are less, because DC resistance of the inductor is determined only by the active resistance. Thus, the proposed device allows you to maintain a constant luminous flux of the lamp during voltage fluctuations, protects the lamp from overloads, reduces inrush currents and minimizes losses.

Based on the foregoing, we can conclude that the inventive device for powering a discharge lamp is efficient and eliminates the disadvantages that occur in the prototype, which is confirmed by an example of a specific implementation of the device. Accordingly, the inventive device can be used in electrical engineering for ignition and power of gas discharge lamps, and therefore, meets the condition of industrial applicability.

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Claims (1)

A device for supplying a gas discharge lamp, comprising a ballast capacitor included in the network and connected in series, a voltage multiplier and a polarity reversal switch connected to a lamp, characterized in that a diode voltage divider is connected to the output of the voltage multiplier through a parallel U-shaped RC filter the input of which is connected through a separation capacitor to the network in front of the ballast capacitor and through a blocking capacitor to a polarity reversing switch made in the form of mains contactor connected to the network.