Novel Single Stage Power Factor Corrected LED Driver Topology for Space Constrained Applications of Aircraft Exterior Lighting System

ABSTRACT:

This paper proposes a novel converter topology based on a single stage LED driver with Power Factor  Correction (PFC) which is optimized for weight, volume and cost, for space constrained environments such as Aerospace exterior lighting product. The proposed topology utilizes a single switch to harmonize the input current as well as control the intensity of lighting system.

A typical Power Factor Pre-regulator (PFP) uses a bulk energy storage capacitor, which is subjected to wear out at higher altitudes due to low pressure conditions and freezes at  negative temperatures, resulting in poor reliability converter for Aerospace applications. Unlike a regular Power Factor Pre-regulator (PFP), the proposed topology avoids the use of bulk energy storage capacitor which results in a fast transient response with enhanced reliability, reduced board real estate and weight. The proposed LED driver topology can control the LED current with both Buck and Boost mode of control, making it a good choice for applications with wide input voltage variation.

A 110 W prototype based on proposed converter was built to verify the operation of proposed topology. The experimental results are in line with the predicted performance. The proposed converter is able to achieve a power factor of 0.988 with an input current THD of < 10%.

SOFTWARE: MATLAB/SIMULINK

 BLOCK DIAGRAM:

Figure 1. Proposed LED driver topology with single stage active PFC

 EXPECTED SIMULATION RESULTS:

             

Figure 2. Measured waveforms at 90V AC input (a) Input Voltage (Red) (b) Input current (Blue) (c) Average Voltage drop across LED current sense resistor (green) (Equivalent to LED average current as the sense resistor value is 1ohm.

Figure 3. Measured Linear FFT of input current

 

Figure 4. Start-up transient at 90V AC input (a) Input Voltage (Red) (b) Input current (Blue) (c) Average Voltage drop across LED current sense resistor (Green)(Equivalent to LED average current as the sense resistor value is 1ohm.

Figure 5. Current profiles through various power circuit components (a) LED Current (Green) (b) Current through MOSFET M1 (Red) (c) Current through inductor L2 (Blue) (d) Current through Inductor L1 (Purple)

 

Figure 6. Current profiles through various power circuit components (a) LED Current (Green) (b) Current through MOSFET M1 (Red) (c) Current through inductor L2 (Blue) (d) Current through Inductor L1 (Purple)

Figure 7. Measured waveforms at 132V AC input (a) Input Voltage (Light Blue) (b) Input current (Blue) (c) Average Voltage drop across LED current sense resistor (Red).

Figure 8. LED current profile over one rectified line cycle

CONCLUSION:

This paper presents a novel LED driver topology, capable of input power factor correction, for space constrained applications, such as Aerospace exterior lighting product line. Due to the compact design of the proposed LED driver topology, it can be of great advantage for an integrated power supply solution for Aerospace exterior lighting product offerings. The proposed LED driver topology can control the LED current with both Buck and Boost mode  of control, making it a good choice for applications with wide input voltage variation. The proposed LED driver topology has been verified by mathematical analysis, circuit simulation and performance has been demonstrated experimentally as well. The proposed LED driver topology promises an appreciable amount of savings in term of real estate, power loss, and heat sink requirements while enhancing the power density of the converter and its  reliability. Typically, it’s the bulk output capacitor that wears out with pressure variation (wear out phenomenon accelerates at altitudes more than 8000m due to the reduced pressures); which can be avoided with the proposed topology. Depending upon the load (number of LEDs) and input voltage; in order to protect LEDs, a reverse blocking diode may be required during the Buck operation. For  Boost application, reverse blocking diode will not be required even with today’s technology. Authors have been granted a U.S. Patent 9363291 [8] against the proposed novel LED driver topology.

 

REFERENCES:

[1] L. H. Dixon, "High Power Factor Preregulators for Off- Line Power Supplies," Unitrode Power Supply Design Seminar Manual SEM600, 1988. (Republished in subsequent Manuals)

[2] Spiazzi, G., and Mattavelli, P. (1994) “Design criteria for power factor preregulators based on SEPIC and Cuk converters in continuous conduction mode,” IEEE IAS Conference Record, 1994, 1084-1089.

[3] Z. Ye, F. Greenfeld, and Z. Liang, “Single-stage offline SEPIC converter with power factor correction to drive high brightness LEDs,” in Proc. IEEE Appl. Power Electron. Conf., 2009, pp. 546–553.

[4] C.Zhou and M.Jovanovic, "Design Trade-offs in Continuous Current-Mode Controlled Boost Power-Factor Correction Circuits", HFPC Cod. Proc., 1992, pp. 209-220

[5] L. H. Dixon, "Average Current Mode Control of  Switching Power Supplies," Unitrode Power Supply Design Seminar Manual SEM700, 1990

Reduced Sensor Based PV Array Fed Direct Torque Control Induction Motor Drive for Water Pumping

 ABSTRACT:

This paper aims at the design, control and implementation of a solar photovoltaic (PV) array fed speed sensorless direct torque control (DTC) of an induction motor drive (IMD) for water pumping in standalone as well as battery connected hybrid mode. This stator flux estimated by proposed flux observer, is used for speed estimation. A DC link current sensor is used to reconstruct the motor phase currents by modified active voltage vector. One voltage sensor for DC link voltage sensing and only one current sensor for DC link current sensing, are used in this system for standalone operation of the system. All other required quantities are estimated through these two sensed signals. The IMD is energized by a photovoltaic (PV) array, which is operated at maximum power point (MPP). A perturb and observe control algorithm with additional flow rate controller, is proposed for MPP, which tracks MPP throughout the operating range and provides the facility to control flow rate. The suitability of the system is judged through simulated results in MATLAB/Simulink as well as test results obtained on a prototype developed in the laboratory.

KEYWORDS:

1.      PV Array

2.      Single Stage System

3.      Perturb and Observe (P&O) Algorithm

4.      Direct Torque Control (DTC)

5.      Speed Sensorless

6.      Current Reconstruction

7.      Induction Motor

8.      Submersible Water Pump

SOFTWARE: MATLAB/SIMULINK

BLOCK DIAGRAM:

Fig. 1 Scheme of proposed PV-battery system

EXPECTED SIMULATION RESULTS:

Fig. 2 Bode plot showing the frequency response of flux observer with the

conventional technique

                                                 (a)                                                                                         (b)

Fig. 3 Performance indices: (a) PV array during starting to steady-state at

1000W/m2 (b) IMD indices at 1000W/m2

(a)

(b)

                                             (c)                                                                                               (d)   

                                                                                     

  (e) 

     

                                                                                                        

(f)

Fig. 4 Performance indices during insolation change (a) PV array:1000W/m2-

500W/m2 (b) Induction motor drive:1000W/m2-500W/m2 (c) PV array:

500W/m2-1000W/m2 (d) Induction motor drive: 500W/m2-1000W/m2

(e) PV array:100W/m2-1000W/m2 (f) Induction motor drive:

100W/m2-1000W/m2

                                                               (a)                                                                          (b)

(c)

(d)

Fig. 5 Simulation results at rated insolation and (a) Rated flow rate (b) 80%

of rated flow rate (c) 60% of rated flow rate (d) 40% of rated flow rate

Fig. 6 Stator flux trajectory at rated condition of proposed system

                                                 (a)                                                                                (b)

                                                                                           (c)

Fig. 7 Performance parameters of hybrid system (a) PV parameters (S, Vdc,

Vpv, Ipv) (b) Battery indices (Vdc, SOC, Vbat, Ibat) (c) Motor indices

(a)

(b)

(c)

Fig. 8 Performance parameters during battery charging of hybrid system (a)

PV parameters (S, Vdc, Vpv, Ipv) (b) Battery indices (Vdc, SOC, Vbat, Ibat)

(c) Motor indices

Fig. 9 Starting performance of the drive: (a) 1000W/m2 (b) 500W/m2

CONCLUSION:

The proposed solar PV array fed water pumping system has been modeled and simulated in MATLAB/Simulink in standalone and PV array-battery connected modes, and its suitability is studied experimentally on a prototype in the laboratory. In standalone mode with PV array feeding water pump, the system comprises of one voltage sensor and one current sensor, which are sufficient for the proper operation of proposed system. Moreover, a P&O based MPPT with derating feature technique has been proposed to regulate the flow rate by controlling the PV array power, thereby enabling the user to operate the pump for any discharge and flow rate. The motordrive system performs satisfactorily during starting at various insolations, steady-state, dynamic conditions represented by changing insolation. The speed is estimated in stationary flux components by flux observer, which has been used for DC offset rejection as well as for the satisfactory operation at lower frequency. The flux and torque, are controlled separately. The direct torque control (DTC) is achieved with fixed frequency switching technique for reducing the torque ripple. The line voltages are estimated from this DC link voltage. Moreover, the reconstruction of three phase stator currents, has been successfully carried out from DC link current. In addition, a smooth changeover facility from DTC to scalar control has been provided to ensure the uninterrupted performance of the system even though the current sensor fails. The switching signals are generated by space vector modulation technique (SVM) to drive three phase VSI, which has offered less harmonics distortion (THD) in motor currents as compared with SPWM technique. Simulation results are well validated by experimental results. In the second mode, a successful implementation of bidirectional power flow between PV arraybattery connected systems has been achieved and its suitability has been checked at various conditions. Owing to the virtues of simple structure, control, cost-effectiveness, fairly good efficiency and compactness, it can be inferred that the suitability of the system can be judged by deploying it in the field.

REFERENCES:

[1] G. M. Masters, Renewable and efficient electric power systems, IEEE Press, Wiley and Sons, Inc. 2013, pp. 445-452.

[2] R. Foster, M. Ghassemi and M. Cota, Solar energy: Renewable energy and the environment, CRC Press, Taylor and Francis Group, Inc. 2010.

[3] S. Parvathy and A. Vivek, “A photovoltaic water pumping system with high efficiency and high lifetime,” Int. Conf. Advancements in Power and Energy (TAP Energy), pp.489-493, 24-26 June 2015.

[4] G. M. Shafiullah, M. T. Amanullah, A. B. M. Shawkat Ali, P. Wolfs, and M. T. Arif, Smart Grids: Opportunities, Developments and Trends. London, U.K.: Springer, 2013.

[5] Vimal Chand Sontake and Vilas R. Kalamkar, “Solar photovoltaic water pumping system - A comprehensive review,” Renewable and Sustainable Energy Reviews, vol. 59, pp. 1038-1067, June 2016.

Solar PV Array Fed Direct Torque Controlled Induction Motor Drive for Water Pumping

 ABSTRACT:

This paper deals with the solar photovoltaic (PV) array fed direct torque controlled (DTC) induction motor drive for water pumping system. To extract maximum power from the solar PV array, a DC-DC boost converter is employed. The soft starting of a three-phase induction motor is achieved by controlling the DC-DC boost converter through the incremental conductance maximum power point tracking (MPPT) technique. The induction motor is well matched to drive a type water pump due to its load characteristics. It is well suited to the MPPT of the solar PV array. By using DTC technique, an induction motor exhibits homogeneous or even better response than the DC motor drive. The proposed system is designed and its performance is simulated in MATLAB/Simulink platform. Simulated results are demonstrated to validate the design and control of the proposed system.

KEYWORDS:

1.      Solar Photovoltaic (PV)

2.      Direct Torque Control (DTC)

3.      MPPT Control

4.      Induction Motor

5.      Water Pump

SOFTWARE: MATLAB/SIMULINK

CIRCUIT DIAGRAM:

Fig.l Schematic diagram of proposed system configuration

 EXPECTED SIMULATION RESULTS:

Fig.2 Steady state performance of proposed system

Fig.3 Starting performance of proposed system

Fig.4 Performance of the system at decrease in insolations

Fig.5 Performance of the system at increase in insolations

CONCLUSION:

It has been demonstrated that the solar PV array fed DTC controlled induction motor drive has been found quite suitable for water pumping. A new method for reference speed generation for DTC scheme has been proposed by controlling the voltage at DC bus and pump affinity law has been used to control the speed of an induction motor. Solar PV array has been operated at maximum power during varying atmospheric conditions. This is achieved by using incremental conductance based MPPT algorithm. The speed PI controller has controlled the motor stator current and controlled the flow rate of pump. Simulation results have demonstrated that the performance of the controller has been found satisfactory under steady state as well as dynamic conditions.

REFERENCES:

[I] R. Foster, M. Ghassemi and M. Cota, Solar energy: Renewable energy and the environment, CRC Press, Taylor and francis Group, Inc. 20 I O.

[2] S. Jain, Thopukara, AK. Karampur and V.T. Somasekhar, "A SingleStage Photovoltaic System for a Dual-Inverter-Fed Open-End Winding Induction Motor Drive for Pumping Applications," iEEE Trans. On Power Electro.. vo1.30, no.9, pp.4809-4818, Sept. 2015.

[3] M. A Razzak, A S. K. Chowdhury and K. M. A Salam, "Induction motor drive system using Push-Pull converter and three-phase SPWM inverter fed from solar photovoltaic panel," international Conference on 2014 Power and Energy Systems: Towards Sustainable Energy, 13- 15 March 2014.

[4] J.V. Caracas Mapurunga, G. Farias Carvalho De, L. F. Moreira Teixeira, L.A Ribeiro De Souza, "Implementation of a HighEfficiency, High-Lifetime, and Low-Cost Converter for an Autonomous Photovoltaic Water Pumping System," iEEE Trans. On ind. Appl., vo1.50, no.!, pp.631-641, Jan.-Feb. 2014.