Simple Harmonics Compensation Method for Smart Charger with Constant DC-Capacitor Voltage-Control for Electric Vehicles in Single-Phase Three-Wire Distribution Feeders

Abstract

This paper discusses harmonic current compensation of the constant dc-capacitor voltage-control (CDCVC)-based strategy for smart charger for electric vehicles (EVs) in single-phase three-wire distribution feeders (SPTWDFs) under distorted load current conditions. The basic principle of the CDCVC-based harmonics compensation strategy under distorted load current conditions is discussed in detail. The instantaneous power flowing into the three-leg pulse-width modulated (PWM) rectifier, which acts as a smart charger, shows that the CDCVC-based strategy achieves balanced and sinusoidal source currents with a unity power factor (PF). The CDCVC-based harmonics compensation strategy does not require any calculation blocks of fundamental reactive, unbalanced active, and harmonic currents. Thus, the authors propose a simplified algorithm to compensate for reactive, unbalanced active, and harmonic currents. Simulation and experimental results demonstrate that balanced and sinusoidal source currents with a unity PF in SPTWDFs are obtained on the secondary side of the pole-mounted distribution transformer during both the battery-charging and battery-discharging operations in EVs, compensating the reactive, unbalanced active, and harmonic currents.

Constant DC-Capacitor Voltage-Control-Based Reactive Power Control Method of Bidirectional Battery Charger for EVs in Commercial Single-Phase Three-Wire Low-Voltage Feeders

“…In (4), however, only linear loads were connected in SPTWLVFs. The authors dealt with harmonic current compensation with this CDCVC-based method (5) . Simulation and experimental results confirmed that the balanced and sinusoidal source currents with a unity power factor (PF) in SPTWLVFs were achieved using the CDCVC-based method.…”

“…There are four nodes numbered, 1, 2, 3, and 4, in the SPTWLVF on the secondary side of the PMDT. Three domestic consumers are connected at each node while only one domestic consumer is connected in an SPTWLVF in (4), (5), and (6). The commercial SPTWLVF in Fig.…”

“…The commercial SPTWLVF in Fig. 1 means that power quality compensation with the CDCVC-based method in (4), (5), and (6) should be discussed considering the commercial SPTWLVFs, where some domestic consumers are connected at each node. Now, a serious concern of the BBC with the CDCVC-based method for EVs in a commercial SPTWLVF is discussed in detail to demonstrate a technical background and the purpose of this paper.…”

“…Fig. 2(c) shows a schematic diagram of the control circuit for the APLC with the CDCVC-based method proposed in (4), (5), and (6). A calculation block of the unbalanced-active, reactive, and harmonic currents in i SD11 and i SD12 at D1 is not included.…”

“…Thus, no calculation results of those three components of i SD11 and i SD12 is stored in the control circuit of Fig. 2(c based method proposed in (4), (5), and ( 6) never compensate the unbalanced active, reactive, and harmonic currents in i SD21 and i SD22 at D2. Thus, the previously proposed BBC for EVs with CDCVC-based method is applicable in a commercial SPTWLVF.…”