Optimal coordinate control of OLTC, DG, D-STATCOM, and reconfiguration in distribution system for voltage control and loss minimization

Summary Traditional volt‐VAR control (VVC) devices such as on‐load tap changers (OLTC), voltage regulators (VRs), and shunt capacitor banks (SCBs) may not be capable to handle the sudden voltage violations because of slow response and large delay time. The voltage fluctuations may result from various disturbances such as intermittence in power output from distributed energy sources (DERs) such as photovoltaic (PV) and wind generation, change in network configuration, and load demand (especially in the case of flexible loads). Hence, there is a need of fast‐acting voltage regulation device such as smart inverter along with traditional VVC devices to encounter these issues. However, without proper coordination, these devices may cause a detrimental impact on distribution operations and network assets. In order to resolve this issue, a hierarchical coordinated volt‐VAR optimization (VVO) methodology has been introduced in this paper. In the proposed methodology, centralized as well as local control algorithm has been considered. The VVO objective of present study is to minimize the total operating cost considering conservation voltage reduction (CVR) and voltage deviation at all nodes simultaneously. Besides, the impact of battery energy storage (BES) on total operating cost, voltage deviation, and CVR has been examined. The ϵ‐constraint method and fuzzy decision‐making method have been employed for the solution of the abovementioned multi‐objective optimization problem. The performance of the proposed scheme has also been verified considering the forecast errors in PV generation and load demand. The proposed VVO methodology has been validated on a well‐known 33‐bus distribution systems. The test results demonstrate the significance of the proposed scheme on minimization of energy consumption, losses, OLTC switching operations, and voltage deviation.

Section: Simulation Results and Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Optimal coordination of PV smart inverter and traditional volt‐VAR control devices for energy cost savings and voltage regulation

Pamshetti

Singh

2019

“…An investigation on loss of life estimation of distribution transformer through VVO method has been carried out in Kanhaiya et al A bilevel VVO approach has been introduced in Jha et al to coordinate the smart inverter dispatch and VVC devices simultaneously. In order to control the voltage and loss minimization, an optimal coordination scheme for VVC devices and reconfiguration switches through hybrid optimization has been proposed in Murty and Sharma . An integrated VVO approach considering wind and photovoltaic‐based DER has been used to reduce the substation energy demand .…”

Section: Introductionmentioning

confidence: 99%

“…An integrated VVO approach considering wind and photovoltaic‐based DER has been used to reduce the substation energy demand . The methods reported in previous studies have been tested on balanced distributed network with the objective of minimization of system losses. However, full utilization of CVR has not been explored.…”

Section: Introductionmentioning

confidence: 99%

Energy efficiency and peak load management via CVR and distributed energy storage in active distribution grid

Singh

Pamshetti

2020

Summary Energy conservation through voltage reduction and distributed energy storage (DES) technology emerged as a potential candidate for peak load relief in distribution grid. However, lack of coordination between network controls such as conservation voltage reduction (CVR) and assets (DES) may cause detrimental impact on smart grid operations. Therefore, this paper reports on the need for coordination of CVR and DES for maximizing the benefits of both approaches. The impact of integrated operation of CVR devices and DES on energy saving and peak demand reduction have been investigated. The CVR scheme has been implemented using discrete gravitational search algorithm‐driven Volt‐ampere reactive (VAR) optimization (VVO) in the presence of distributed energy sources (DER). Such a smart grid‐enabled centralized CVR scheme has been proposed to be deployed in the grid and integrated with a community energy storage (CES) as DES. The main task of the VVO engine is to minimize the total power demand through optimal settings of Volt‐VAR control (VVC) devices. In order to demonstrate the benefits of integrated operation of CVR and CES, the studies have been carried out in three cases, namely without CVR, VVO‐based CVR, and CVR with CES in presence of both nonrenewable and renewable (wind) type DERs. Moreover, the impact of the proposed method has not only been demonstrated on hourly varying load of the year but during peak load hour also. Besides, the techno‐economic and environmental assessment of combined operation of CES and CVR has been done. The Institute of Electrical and Electronics Engineers (IEEE) 123‐bus unbalanced distribution network with the modification to include the DER and CES system apart from CVR devices has been chosen to corroborate the performance of the proposed method. The test results reveal that the proposed integration method of CVR and CES achieve higher peak sharing and energy saving with reduced carbon emission. In addition, the method assists the demand balancing. Besides, the by‐product of CES control strategy has been demonstrated for mitigation of rise in neutral currents.

“…Recently, renewable distributed generation (DG) has been rapidly deployed in distribution systems, because of their advantages of economy, environmental protection, and flexibility . Meanwhile, responsive loads (RLs) are regarded as an effective asset for shifting peak demands and improving economy of the distribution network.…”

Section: Introductionmentioning

confidence: 99%

Power sensitivity models with wide adaptability in active distribution networks considering loops and DC networks

Liu

Wang

et al. 2019

Summary Because of the high penetration of distributed generation, energy storage systems, and flexible loads, nodal power injections in active distribution networks (ADNs) would vary frequently and significantly. Thus, it becomes crucial to accurately and quickly assess the influence of power injection variations on key operation status of ADNs, such as nodal voltages, line losses, and branch power flows. Meanwhile, modern ADNs may include nonradial and DC network segments, which make power flow analysis more complicated. In this paper, power flow models of ADNs while considering nonradial topologies and hybrid AC/DC networks are analyzed to derive a suite of power sensitivity models with wide adaptability, including a quadratic sensitivity model of nodal power injections to line losses, a linear sensitivity model of nodal power injections to nodal voltages, and a quadratic and a simplified linear sensitivity models of nodal power injections to branch powers. Numerical results evaluate the accuracy and efficiency of the proposed sensitivity models.