Improving the area of harmonic pollution and vulnerability to voltage sag for compatible and reliable operation of sensitive harmonic loads

Abstract

Nowadays, sensitive harmonic loads (SHLs) are being increasingly used in the industrial sector. SHLs generate harmonics and may become disconnected from the network when voltage sags occur at the point of common coupling (PCC). Here, a new approach is proposed to reduce harmonics distortion and establish a more reliable annual operation of SHLs by reducing the area of pollution (AOP) with harmonic and the area of vulnerability (AOV) to voltage sag, respectively. The proposed approach includes an innovative optimization problem for planning passive harmonic filters which is solved by the Non‐dominant Sorting Genetic Algorithm (NSGA‐II) on the basis of historical data of the industrial power grid. By doing so, a solution is obtained in which the costs of passive harmonic filters and financial costs due to grid losses and voltage sags are minimized. In order to assess the new proposed approach, an Iranian large copper mine electrical network equipped with SHLs is used. Results of using the new approach show that total harmonic distortion and grid losses decrease by nearly 80% and 15%, respectively and also, the voltage value at the PCC is improved which can assure the secure operation of SHLs. Moreover, decreased financial losses is obtained since voltage sags are reduced by 65%.

Multi‐criteria decision‐making approach for optimal and probabilistic planning of passive harmonic filters in harmonically polluted industrial network with photovoltaic resources

“…The total power losses of the network are obtained by the harmonic load flow and are calculated as follows [8]: $$$$\begin{equation}{P}_{loss}{{}{total}} = \sum_{i = 1}^{{n}_b} {{P}_{loss}{,i}} + \sum\nolimits_{i = 1}^{{n}_b} {\sum\nolimits_{h = {h}0}^{{h}_{\max }} {{P}^{(h)}_{loss,i}} } ,\end{equation}$$$$where P loss,i is the fundamental power losses in the branch i and P (h) loss,i is the losses power of harmonic in the harmonic order of h ;$${n}_b$$, h 0 and $${h}_{\max }$$ are the network branches number, the minimum and maximum values of the network harmonic level, respectively. Note that $$P_{loss,n}^h$$ is calculated as follows [30]: $$$$\begin{equation}P_{loss,n}^h = {R}_n \times I_{n,h}^2 \times \frac{{{{\left( {Y_{l,h}^{ - 1} - Y_{k,h}^{ - 1}} \right)}}^2}}{{{Z}_{h,n}}},\end{equation}$$$$ $$$$\begin{equ...$$…”

“…Additionally, U C and U X are the costs per unit of the capacitor and inductor and are determined as follows: U X = 400 TLkVAr and U C = 100 TL/kVAr . The OC denotes the cost of operations that can be expressed as follows [8]: $$$$\begin{equation}OC = (1750 \times {P}_V \times {F}_V \times {U}_V){F}_{PL}.\end{equation}$$$$…”

“…Additionally, U C and U X are the costs per unit of the capacitor and inductor and are determined as follows: U X = 400 TLk-VAr and U C = 100 TL/kVAr. The OC denotes the cost of operations that can be expressed as follows [8]:…”

“…The F V is the amount of filter use that is believed to be 100% here, U V is the rate of use charge and equals 0.076$ / kWh, and the filter's power loss is F PL . P V is the latest factor of value introduced by (42) [8].…”

Reconfiguration of harmonic polluted distribution network using modified discrete particle swarm optimization equipped with smart radial method

“…Sensitive busses are busses of the network that have served sensitive loads. Sensitive loads are the type of loads with sensitive elements whose operation can be disturbed or stopped by high levels of harmonic distortion, such as power electronic devices, programmable logic controllers (PLC), and computers [40,41].…”