Single-phase Three-wire Distribution Feeders Research Articles

Research Group Introduction: IKEDA Fuka Laboratory, Dept.of Electrical Engineering, National Institute of Technology, Ube College

Our research focuses on the compensation performance of fundamental reactive, unbalanced active, and harmonics currents with constant dc-capacitor voltage control of the smart charger for electric vehicles in single-phase three-wire distribution feeders.

Simple Power Quality Compensation with Bidirectional Battery Charger for Electric Vehicles in Single-Phase Three-Wire Distribution Feeders

This paper deals with power quality compensation in single-phase three-wire distribution feeders using a constant DC-capacitor voltage-control (CDCVC)-based strategy of the previously proposed bidirectional battery charger (BBC) for electric vehicles under the distorted source-voltage and load-current conditions. Instantaneous active power flowing into the three-leg pulse-width-modulated (PWM) rectifier in the BBC is discussed. The instantaneous power flowing into the three-leg PWM rectifier demonstrates that the CDCVC-based strategy obtains balanced and sinusoidal source currents at a unity power factor, where the source-side active power is balanced with the load-side active power. Simulation and experimental results demonstrate that balanced and sinusoidal source currents at a unity power factor are attained in single-phase three-wire distribution feeders with both battery-charging and -discharging operations for electric vehicles even though both source voltage and load currents are distorted.

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

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 Strategy for Harmonics Compensation in Smart Charger for Electric Vehicles in Single-Phase Three-Wire Distribution Feeders with Reactive Power Control

Constant DC-Capacitor Voltage-Control-Based Strategy for Harmonics Compensation in Smart Charger for Electric Vehicles in Single-Phase Three-Wire Distribution Feeders with Reactive Power Control

Improvement in Harmonic Compensation of a Smart Charger with a Constant DC-Capacitor Voltage-Control-Based Strategy for Electric Vehicles in Single-Phase Three-Wire Distribution Feeders

This paper presents an improvement in harmonic compensation performance of a previously proposed smart charger (SC) with a constant dc-capacitor voltage-control (CDCVC) strategy for electric vehicles (EVs) in single-phase three-wire distribution feeders (SPTWDFs). A controller for 3rd harmonic currents in d-q coordinates is added to the previously proposed SC. This addition improves harmonic compensation performance of the source currents. We briefly introduce harmonic current compensation using the previously proposed CDCVC-based algorithm for the SC. Then, the basic principles of the proposed controller for the 3rd harmonic currents in d-q coordinates are discussed in detail. It is shown that synchronization of the current controllers for both the fundamental and 3rd harmonic components is required. The switching frequency of a three-leg pulse-width modulated rectifier with a bidirectional dc–dc converter, which performs the SC, is determined considering the synchronization of the current controllers. Simulation and experimental results demonstrate that balanced and sinusoidal source currents with a unity power factor are achieved during both battery charging and discharging operations in EVs, improving the harmonic compensation performance of the previously proposed SC. Experimental results also demonstrate that the total harmonic distortion values of source currents are improved by 8.4% and 3.6% with the proposed controller for 3rd harmonic currents, when the SC is discharging, for example.

Constant DC-Capacitor Voltage-Control-Based Harmonics Compensation Strategy of Smart Charger for Electric Vehicles in Single-Phase Three-Wire Distribution Feeders

This paper discusses harmonic current compensation of the constant DC-capacitor voltage-control (CDCVC)-based strategy of smart chargers for electric vehicles (EVs) in single-phase three-wire distribution feeders (SPTWDFs) under nonlinear load conditions. The basic principle of the CDCVC-based harmonics compensation strategy under nonlinear load conditions is discussed in detail. The instantaneous power flowing into the three-leg pulse-width modulated (PWM) rectifier, which performs as a smart charger, shows that the CDCVC-based strategy achieves balanced and sinusoidal source currents with a unity power factor. 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. A digital computer simulation is implemented to confirm the validity and high practicability of the CDCVC-based harmonics compensation strategy using PSIM software. Simulation results demonstrate that balanced and sinusoidal source currents with a unity power factor in SPTWDFs are obtained on the secondary side of the pole-mounted distribution transformer (PMDT) during both the battery-charging and discharging operations in EVs, compensating for the reactive, unbalanced active, and harmonic currents.

Novel Reactive Power Control Strategy Based on Constant DC-Capacitor Voltage Control for Reducing the Capacity of Smart Charger for Electric Vehicles on Single-Phase Three-Wire Distribution Feeders

This paper proposes a novel reactive power control strategy to reduce the capacity of the previously proposed smart charger for electric vehicles (EVs) on single-phase three-wire distribution feeders. The proposed reactive power control strategy is based on the constant dc-capacitor voltage control of the grid-connected pulsewidth-modulated rectifier. Any calculation blocks of the load-side active current are not needed. Thus, we offer the simplest reactive power control strategy. The basic principle of the proposed reactive power control strategy is discussed in detail, and then confirmed by a digital computer simulation using the PSIM software. A prototype experimental model is constructed and tested. Experimental result demonstrates that balanced source currents with a power factor of 0.9, which is an acceptable value in Japanese home appliances, are obtained on the secondary side of the pole-mounted distribution transformer during the battery charging operation in the EVs, reducing the capacity of the smart charger by 36% as compared with that of the smart charger with the previously proposed control strategy.

Reduced-Capacity Smart Charger for Electric Vehicles on Single-Phase Three-Wire Distribution Feeders With Reactive Power Control

In this paper, we propose a new control algorithm to reduce the capacity of a previously proposed smart charger for electric vehicles (EVs) on single-phase three-wire distribution feeders with reactive power control. The basic principle of the proposed control algorithm is discussed in detail. It is shown that controlling the reactive power on the source side reduces the capacity of the previously proposed smart charger. A digital computer simulation is implemented to confirm the validity of the proposed control algorithm using PSIM software. A prototype experimental model is also constructed and tested. Experimental results demonstrate that balanced source currents with a power factor of 0.9, which is acceptable for Japanese home appliances, are obtained on the secondary side of the pole-mounted distribution transformer during both the battery charging and discharging operations in EVs. The capacity of dc capacitor $C_{\rm DC}$ is also reduced by 37% with the proposed reactive power control algorithm.

Reducing Capacity of Smart Charger for Electric Vehicles on Single-Phase Three-Wire Distribution Feeders with Reactive Power Control

Reducing Capacity of Smart Charger for Electric Vehicles on Single-Phase Three-Wire Distribution Feeders with Reactive Power Control

Smart Charger for Electric Vehicles With Power-Quality Compensator on Single-Phase Three-Wire Distribution Feeders

In this paper, we propose a smart charger for electric vehicles with a power-quality compensator. The proposed smart charger consists of four-leg insulated-gate bipolar transistors (IGBTs). Three legs are used for a single-phase full-bridge-based pulsewidth-modulated (PWM) rectifier, which converts power from ac to dc during the battery-charging operation or from dc to ac during the battery-discharging operation. This PWM rectifier can compensate reactive and unbalanced active currents on single-phase three-wire distribution systems because the third leg is connected to the neutral line of single-phase three-wire distribution feeders. The fourth leg is used as a bidirectional dc-dc converter for battery-charging and battery-discharging operations. The three-leg PWM rectifier uses only constant dc-capacitor voltage control, which is commonly used in active power line conditioners. Thus, the authors have developed the simplest possible control method for a single-phase power-quality compensator. The basic principle of the proposed smart charger is discussed in detail and then confirmed by digital computer simulation using PSIM software. A prototype experimental model is constructed and tested. Experimental results demonstrate that balanced source currents are obtained on the secondary side of the pole-mounted distribution transformer for battery-charging and battery-discharging operations.