An IFOC-DSVPWM Based DC-Link Voltage Compensation of Z-Source Inverter Fed Induction Motor Drive for EVs

Abstract

The drop in DC-link voltage of adjustable speed drives (ASD) occurs mainly due to the increase in output power demands. This may lead to inefficient operation and eventually the tripping of the drive. This paper presents a Double Space Vector Pulse Width Modulation (DSVPWM) technique for boosting and compensating the DC-link voltage of Z-source inverter (ZSI). The DSVPWM technique estimates the required shoot through period of the Z-source inverter to maintain the DC-link voltage constant at the desired level through capacitor voltage control. The DSVPWM can obtain maximum boost at any given modulation index in comparison to simple boost control (SBC) method. It also utilizes the dead time more effectively. The speed control of the ZSI fed induction motor drive is done by employing indirect field-oriented (IFO) control method. A 32-bit DSP (TMS320F28335) is used to implement the IFOC-DSVPWM method for ZSI. The power structure and the modulation technique are well suited for electric vehicle application. DSP or microcontroller as a control system for the power converter. Selection of electrical (traction) motors for propulsion systems is a very important step that requires special attention. In fact, the automotive industry is still seeking for the most appropriate electric propulsion system for EV. In this case, key issues are efficiency, torque density, weight, cost, cooling, maximum speed, fault-tolerance, safety, and reliability. The types of electric motors adapted for electric vehicles are DC motor, the induction motor, the permanent magnet synchronous motor, and the switched reluctance motor. Of late, the cage induction motors are accepted as the most suitable motors for the electric propulsion of EVs owing to their reliability, ruggedness, low maintenance, low cost, and ability to operate in inimical environments. They are particularly well suited for industrial and traction drive environments. Today, induction motor drive is the most mature technology among various commutatorless motor drives. The high performance control of induction motors can decouple its torque and field control [3,4].In a voltage source inverter fed induction motor for an EV, the speed control techniques are scalar control ( / ), indirect field-oriented control (IFOC), and direct torque

DC-link voltage balancing and control of qZ-source inverter fed induction motor drive

“…The simple boost TSD PWM method is comprehensively based on the dual space vector pulse width modulation (DSVPWM) technique [22]. This SB control method increases the voltage stress and limits the voltage gain due to the switch device voltage rating.…”

High voltage gain reduced current ripple switched coupled inductor quasi‐Z‐source inverter

“…(18), I tot = total magnetizing current referred to winding 1 = P k j = 1 n j n 1 I j A ð Þ, where n = number of turns and j = the number of winding, I M, max = peak magnetizing current referred to winding 1, calculated as per Eqn. (6). The core EPCOS made EE 65 is selected as it was readily available in the laboratory since its K g value satisfies the condition in Eqn.…”

“…(18), I tot = total magnetizing current referred to winding 1 = P k j = 1 n j n 1 I j A ð Þ, where n = number of turns and j = the number of winding, I M, max = peak magnetizing current referred to winding 1, calculated as per Eqn. (6). The results for voltages appearing across the capacitors in simulation and experimental validations are shown in Figure 16A,B, respectively.…”

“…In recent times, the research field of impedance source inverter (ZSI) topologies 1,2 has targeted many application areas such as renewable energy generation, 3,4 EV/HEV, 5,6 microgrid, 7 electric drives, 8 and so on. Table 1 shows the critical literature review of ZSI topological improvements.…”