Wire and Wireless Linked Remote Control for the Group Lighting System Using Induction Lamps

Transcription

1 PEDS 2007 Wire and Wireless Linked Remote Control for the Group Lighting System Using Induction Lamps Kyu Min Cho*, Jae Eul Yeon**, Ma Xian Chao***, and Hee Jun Kim*** * Dept. of Information and Communications, Yuhan College, Korea ** Visual System Team, Fairchild Korea Semiconductor, Korea *** Div. of Electrical and Computer Engineering, Hanyang University, Korea Abstract--This Paper presents a wire and wireless linked remote control system for the group lighting system using induction lamps. Ethernet based network communication is used for long distance management and 2.4GHz RF network is adopted for the local area communication between the main network and the ballast. For the effective remote control and management including dimming using wire and wireless linked digital communication networks, the control circuit of the ballast is implemented with fully digital circuit using MCU and EPLD. In this paper, the applicable system configuration is proposed for the group lighting-control system and the detailed system configurations including fully digital controlled electronic ballast for the induction lamp are described. frequency is over several hundreds of kilo hertz and up to several Giga hertz. Fig. 2 shows the equivalent circuit of the induction lamp. Since the equivalent resistance is almost infinite before lighting, high voltage must be applied to the primary coil for the ignition. However, the equivalent resistance is rapidly decreased after ignition. Fig. 3 shows a half bridge resonant inverter including all sensing circuit for the control of the ballast. V S1 is used for fuse status monitoring, and over/under voltage protection. V S2 and I S are used to calculate the dc-link power in the case of the closed-loop power control mode. v L is used for protection of switching devices in the ignition stage and also used for detecting the lamp fault. Index Terms wire and wireless linked, remote control, Ethernet, 2.4GHz RF, dimming, induction lamp I. INTRODUCTION Since the induction lamp has no electrodes, it has very long lifetime more than 60,000hours. Therefore, the induction lamp system is usually used in the case where the system maintenance is difficult such as high ceiling lighting system. Induction lamp is driven by using a highfrequency resonant inverter and its driving frequency is over several hundreds of kilo hertz. Therefore, the remote control has to be needed for the dimming of the induction lamp. For the effective management of the group lighting system including the dimming and monitoring, central management system using a personal computer is proper. This paper presents a wire and wireless linked remote control system for the group lighting using induction lamps. Ethernet based network communication is used for the long distance management using personal computer and 2.4GHz digital radio frequency network is adopted for the local area communication between the main network and the ballast. For the effective remote control and management including dimming using wire and wireless linked digital communication networks, control circuit of the ballast is implemented with fully digital circuit using MCU and EPLD. Fig. 1. Configuration of the induction lamp and its lighting principle. Fig. 2. Equivalent circuits of the induction lamp. II. PROPOSED LIGHTING CONTROL SYSTEM A. Electronic Ballast for Induction Lamps Fig. 1 shows the configuration of the induction lamp and its lighting principle. High frequency magnetic flux induces electromotive force in the vessel, and then the discharging is occurred. Normally, the induction lamp is driven by using a high-frequency resonant inverter and its Fig. 3. Main circuit diagrams of the electronic ballast /07/$ IEEE 456

2 A B A B Fig. 4. Block diagrams of the proposed digital controller. Fig. 5. Specific time chart of the proposed average burst PWM method (in the case of 58% duty). B. Digital Controller for the Induction Lamp Ballast Fig. 4 presents block diagrams of the proposed digital controller for the dimming of the induction lamp. Low price 8-bit one-chip MCU can be used for the main controller. Voltage and current of the dc link of the ballast are gathered by using built-in A/D converters of the MCU and digitized data are transferred to the host PC through the wire and wireless communication network kps UART interface is used for all information exchanges between the remote RF modem and the MCU. For the dimming of induction lamp, a novel average burst duty control method is implemented by using an EPLD. A novel average burst duty control method is used for the dimming. The proposed control method can produce variable PWM duty with 1-% of steps. All functions are implemented by using a low cost small size EPLD. Fig. 5 shows the specific time chart of the proposed average burst PWM method and it is in the case of 58-% duty. Since 25-kHz of burst PWM frequency is adopted, the proposed averaging burst PWM method does not produce sound noise caused by PWM. In the ignition mode, the switching frequency is gradually decreased from 500-kHz to 250-kHz during predetermined duration. So the lamp is ignited softly. (a) Circuit diagrams (b) Timing chart Fig. 6. Circuit diagrams and timing chart of the pulse train detector for the ignition status decision and lamp fault decision. 457

3 Fig. 7. Configurations of the proposed wire and wireless linked remote control system using induction lamp. Fig. 8. Data frame structure in the RF communications. Fig. 6(a) shows circuit diagrams of the pulse train detector, which can decide ignition status and lamp fault status. In the case of the successful ignition, the output signal will be low state after ignition, because the voltage of the inductor shown in Fig. 3 is rapidly decreased and then there are no signals at the output of the comparator. Otherwise, the high state of the output of the pulse train detector means ignition fault, no lamp or lamp fault. In that case the driving signal is masked and the switching devise will be protected from high resonant current. Since this lamp status decision method uses the output signal of auxiliary winding, it is useful compare with the other lamp fault detection circuit such as a method using the voltage of the lamp directly. C. Wire and Wireless Linked Remote Control System Since the induction lamp has long life time, it is very useful, especially in the fields of high ceiling and tunnel lighting system. Sometimes those lighting system needs controlling the illumination. For those cases, remote control system must be needed because induction lamps are driven at very high frequency. Therefore the wire and wireless linked remote control system for the group lighting system using induction lamps is proposed. Fig. 7 shows the overall system configurations of the proposed remote lighting control system. In order to use Internet network or local area network for the main long distance communication network, the main network is designed with Ethernet based network. Therefore the system management can be easily achieved by using personal computer to handle the proposed system. And the commercial mobile communication network can be also combined with the proposed system. In that case, the system manager can handle the lighting system with mobile devices such as cellular phone and/or PDA which loaded application soft-ware to control and monitor the system. For the local area communication between the main network and the each ballast, wireless network is more proper than wired network. 2.4GHz RF network is built in the proposed system. We need, therefore, two kinds of RF modem. Ethernet interfaced master modem and 458

4 UART interfaced local modem linking the wireless main network and ballasts. Therefore ballast includes the local modem. In the future, to work with another management system such as IBS, standard protocol like a ZigBee is more proper for the proposed system. In this stage, however, simple user protocol is adopted in the proposed system. Fig. 8 represents the data frame structure, which is adopted in the proposed RF modem. III. EXPERIMENTAL RESULTS For the experimentation, proto lighting system is constructed, which is composed of four sectors. Each sector is composed with four lamps. In actual application system, the number of sectors is not limited and the number of lamps is dependent on addressable capability of the RF modem. In the experimental setup, 150-W and 100-W induction lamps manufactured by OSRAM(they usually call it electrode-less fluorescent lamp). The principal parameters of the experimental setup are as follows: (a) Screen for server and remote modem setting. - DC link voltage, V DC : 400 [V] - Switching frequency, f s : 250 [khz] - Burst PWM frequency, f b : 25 [khz] - Blocking capacitance, C B : 2.2 [nf] - Resonant inductance, L r : 232 [uh] - Resonant capacitance, C r : 2.2 [nf] - Switching devices : IRF840 - Starting frequency : 500 [khz] - Successful ignition determining time : 1 [Sec] - Over voltage protection level : 450 [V] - Under voltage protection level : 200 [V] - Over current protection level : 500 [ma] Fig. 9 shows some images of the prototype server management program screen. Fig. 9(a) is a screen for the parameter settings such as IP address of the center modem, local address of the remote modem, and some gains of the control/monitoring factors. Fig. 9(b) is a screen for overall system control and monitoring screen. Settings constructed in this screen are as follows: (b) Screen for the controlling and system monitoring. - Communication interval - Lamp on/off - Control mode - Lamp power ratings - Reference power level - Minimum PWM duty - Message to the local RF modem Monitoring factors in this screen are as follows: - Source power stauts - Lamp on/off status - Cooling pan staus - PWM duty - DC link voltage - DC link current - DC link power - Message from the local RF modem (c) Screen for the monitoring of each ballast status Fig. 9. Images of the prototype management program screen Fig. 9(c) is a screen for detailed graphical monitoring factors from the each ballast. Since all data can be captured into a file in the PC, system manager can check the past status, especially, when an accident is occurred in the ballast. Moreover, error message is automatically sent to system manager by using SMS(short message service). 459

5 Fig. 10 shows some images of master RF modem with Ethernet interface and local RF modem with UART interface used in the prototype system. The RF modem uses 2.4GHz ISM band radio frequency and the RF power is 10-mW. The data transfer rate of the RF modem is 1-Mbps. The RF modem is worked by using the direct sequence spread spectrum modulation method. Since CSMA/CA, automatic re-transmission, and CCITT- 16bit CRC algorithms are implemented in the MAC protocol level, reliable communication can be achieved. The data transfer rate of UART interface is up to kbps. (a) In case of 100[%] power. (a) Master modem with Ethernet interface (b) In case of 60[%] power. (b) Remote modem with UART interface Fig. 10. Images of 2.4GHz radio frequency data modem. (c) In case of 30[%] power. Fig. 12. Images of the lamp lighting according to the power. (a) In case of the 100-W lamp. (b) In case of the 150-W lamp. Fig. 11. Illumination and Efficiency according to the power. Fig. 11 represents variations of illumination and efficiency according to the various power. Fig. 11(a) and Fig. 11(b) are in the case of 100-W lamp and 150-W lamp, respectively. The trends of illumination and efficiency according to the power percentage are different from each other. The reason for that is minimum power dissipation for exciting the light is nearly same even though the power ratings are different from each other. It can be seen that the case of 150-W lamp is more effective in dimming than the case of 100-W lamp. In actual, the dc link power is not same with the lamp power because the dc link power includes not only the lamp power but also some losses in the resonant inverter. Since the lamp is driven at high frequency, it is nearly impossible to calculate the exact lamp power using by MCU. Therefore, the lamp power is indirectly controlled by controlling the dc link power in the power control mode. If the illumination is directly controlled by using a 460

6 light sensor, the maximum dc power should be controlled to protect the ballast. Normally, the indirect lamp power control is sufficient in the lamp dimming system. Finally, images of the lighting lamp at various powers are shown in Fig. 12. Since the ratings of lamp power is 150-W, 60-% power and 30-% mean 90-W and 45-W, respectively. IV. CONCLUSIONS This paper proposes a wire and wireless linked remote controlled group lighting system using induction lamps, which is driven by fully digital controlled electronic ballast. And a novel average burst PWM duty control algorithm is proposed for dimming. Since the proposed PWM method can produce the output with the 1-% of duty resolution and with the 25-kHz burst frequency, the lamp power is stably controlled without sound noise. For the remote controlling and monitoring the group lighting system, Ethernet based communication and 2.4GHz RF communication are constructed. With the result of experimentation using prototype setup, the usefulness of the proposed remote control system and effectiveness of the proposed dimming method for the induction lamp are confirmed and verified. REFERENCES [1] R. Louis, A Novel Ballast for Electrodeless Fluorescent Lamps, in Conf. Rec. of IEEE Industry Applications, vol. 5, pp , [2] H. Kido, A study of electronic ballast for electrodeless fluorescent lamps with dimming capabilities, in Conf. Rec. of IEEE Industry Applications, vol. 2, pp , [3] H. Y. Wang, A. V. Stankovic, D. Kachmaric, L. Berone, A novel discrete dimming ballast for linear fluorescent lamps, in Conf. Rec. of IEEE PESC, pp , [4] M. K. Kazimierczuk, W. Szaraniec, Electronic Ballast for Fluorescent Lamps, IEEE Trans. on Power Electronics, pp , [5] D. Wharmby, Electrodeless lamps for lighting: a review, in Conf. Rec. IEEE APEC, pp , [6] B. Cook, New developments and future trends in high efficiency lighting, J. of Eng. Science and Educ., , [7] S. Ben-Yaakov, M. Shvartsas, A Behavioral SPICE Compatible Model of and Electrodeless Fluorescent Lamp, in Conf. Rec. of IEEE APEC, pp ,