## 1 Introduction
It contains only passive reactive circuit elements, coils, or capacitor banks, which, in order to respond to the load variation, can be controlled or switched with power electronic devices [23; 24], forming the so-called Adaptive Balancing Compensators (ABCs) [25], which are actually a particular form of SVC (Static Var Compensator). For the sizing and control of the component elements of the ABC, the method of symmetrical components [26] or the Current's Physical Components (CPC) concept [11] is usually used. In both cases, the ABC control is completed with the aim of compensating the unwanted components of the currents on the load phases. Comparison based on technical-economic criteria between the two types of equipment designed for the power flow balancing on phases, SVC and SPC, respectively, is favourable to the first type, in the case of a series of applications, including that of distribution networks with a high level of DER penetration. Thus, compared to SVCs, SPCs cause lower active energy losses and therefore have higher energy efficiency, since they contain few passive circuit elements. SPCs also have other clearly superior technical performances, including faster response times, and more compact structures so they demand less space, and generate lower noise. However, most of the SPCs need complicated calculations and high-frequency PWM techniques that reduce the main circuit efficiency, especially in high-power applications [27]. At the same time, in many industrial applications, the reaction speed or the precision of the compensation adjustment are not the main performance criteria, the decisive criterion being the cost of installing and operating the equipment. It is demonstrated that for applications with similar functions such as voltage regulation, power factor correction, load balancing or flicker diminishing, the acquisition and operating costs for an SVC are smaller by about 30-35% than for a SPC [28]. Therefore, not only the SVC type compensators are not being eliminated, but on the contrary, their use is developing, so the world market for such equipment is constantly growing [28]. BRCs (Balancing-Reactive Compensators) and BCCs (Balancing Capacitive Compensators) are also part of the SVC equipment category, known as three-phase load balancing means. These are the subject of the following sections of the article. Thus, the second section is dedicated to the brief presentation of the mathematical relationships for sizing the primary circuits of a BRC (BCC), respectively, of those that allow the demonstration of the energy mechanism of balancing active and reactive inductive loads, by shunt unbalanced-reactive (capacitive) compensation. The fact that these relationships remain valid regardless of the direction of the active and reactive powers through the compensator-controlled section is demonstrated in section three, on a Simulink model of a medium voltage distribution network, for two-way unbalanced power flow operating conditions. This validates the possibility of extending the load balancing function, for which BCC is known until now, to that of balancing the two-way power flow through the sections of the distribution network. The main contributions of the paper are:  
* identification and analysis of unbalanced shunt capacitive compensation as a method of two-way power flow balancing in three-phase networks;
* demonstrating, based on the mathematical model, respectively, by numerical simulation, the ability of the BCC to extend its load balancing function as the two-way power flow balancing function in the controlled section;
* the conception and construction of the Simulink model, respectively, and the interpretation of the operating regimes numerical simulation results of a distribution network containing a high level of renewable distributed sources.