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This paper is to present a space vector PWM algorithm for four switch three phase inverters (B4, FSTPI) based on the one for six switch three phase inverters (B6, SSTPI) (principle of similarity) where the cX plan is divided into 6 sectors and the formation of the required reference voltage space vector is done in the same way as for B6 by using effective (mean) vectors. This facilitates the calculation for B4 and some studies on B6 can be applied for B4 as well through this proposed similarity, e.g. the problem with PWM in the overmodulation zone due to the complicated non-linear character there. Matlab/ Simulink is used for the simulation of the proposed SVPWM algorithm for undermodulation, overmodulation mode 1 and 2. This SVPWM approach is also validated experimentally using control board TMS eZDSP2812 (Texas Instrument Co.).

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This paper presents the implementation of a two-stage light-emitting diode (LED) driver based on commercial integrated circuits (IC). The presented LED driver circuit topology, which is designed to drive a 150 W LED module, consists of two stages: AC-DC power factor correction (PFC) stage and DC/DC power converter stage. The implementation of the PFC stage uses IC NCP1608, which uses the critical conduction mode to guarantee a unity input power factor with a wide range of input voltages. The DC/DC power converter with soft-switching characteristics for the entire load range uses IC FLS2100XS. Furthermore, the design of an electromagnetic interference (EMI) filter for the LED driver and the dimming control circuit are discussed in detail. The hardware prototype, an LED lighting system, with a rated power of 150 W/32 V from a nominal 220 V/50 Hz AC voltage supply was tested to show the effectiveness of the design. The presented LED driver was tested for street lighting, and the experimental results show that the power factor (PF) was higher than 0.97, the total harmonics distortion (THD) was lower than 7%, and the efficiency was 91.7% at full load. The results prove that the performance of the presented LED driver complies with the standards: IEC61000-3-2 and CIRSP 15:2009. Electronics 2020, 9, 52 2 of 22There are three types of LED driver systems: Single-stage [10,11], two-stage [12][13][14], and integrated LED drivers [15,16]. The single-stage LED driver is an AC/DC converter that provides a constant output current for the LED and a unity power factor. The two-stage system consists of two separate stages, an AC/DC power factor correction (PFC) converter and a DC/DC converter. Recently, some integrated topologies were introduced in order to reduce the size and cost. Single-stage and integrated solutions have some advantages such as low-cost designs and high efficiency due to only one energy conversion. However, the PFC of these topologies causes a high-output voltage ripple due to the absence of electrolytic capacitors. Hence, the low-frequency current ripple makes LEDs flicker. These single-stage and integrated solutions are not suitable LED street lighting systems and are instead used for LED-based replacement lamps where small-size converters are needed. Furthermore, the bridgeless topologies usually generate high electromagnetic interference (EMI) due to large dv/dt and di/dt. The two-stage topology is the most popular topology for LED drivers above 100 W [17]. In the two-stage LED driver, the constant output current regulation is more easily implemented due to the bus voltage. Additionally, an isolated DC-DC stage is needed in the LED driver in order to ensure constant current control.Recently, there have been several commercial analog integrated circuits (ICs) available on the market that are recommended for a high power factor and low cost with a high efficiency. These commercial ICs fulfil the IEC 1000-3-2 Class C, but the total harmonics distortion (THD) is higher than 20% [18]. In reference [19], a reson...

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This paper presents a new switching technique for Direct Torque Control of Induction Motor using Four-Switch Three Phase Inverter (DTC-FSTPI-IM) for low power applications. The modified switching table in this method is based on the principle of similarity between FSTPI and SSTPI (Six-Switch Three Phase Inverter), where the oc4 plan is divided into 6 sectors and the formation of the voltage space vector is done in the same way as for SSTPI by using effective (mean) vectors. This approach allows using the well-knowing established switching table of SSTPI for FSTPI, in order to reduce torque ripples in comparison with the conventional DTC method for FSTPI. The validity of new proposed technique is verified by simulation results using Matlab/Simulink and also experimentally by using DSpace 1104 Card.

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