## 1 Introduction
As for the three-phase induction motor, the phenomena are similar and in addition, as a result of the mechanical torque oscillations and vibrations occurrence, there is an increase in mechanical wear [6; 7]. The voltage balancing of the three-phase low and medium voltage networks containing DERs has become very important, both for the distribution network and the consumers connected to it and from the perspective of the propagation of disturbances in the higher voltage network. In the current specialized literature, there are studies related to a multitude of solutions consisting of new methods and equipment, or the improvement of the known ones. According to [8], the strategies for compensating voltage asymmetries in distribution networks containing DERs can be classified into two broad categories: active strategies and passive strategies. Active strategies use active equipment, based on power electronics technology, with the main or secondary function of voltage asymmetry compensation. This category of equipment, known under the generic name of Switching Power Converters (SPCs), includes: Line Voltage Regulator (LVR) [9], advanced On-Load Tap Changer (OLTC) [10], Reactive Power Compensator (RPC) [11], Zero Sequence Current Compensator (ZSCC) [12], Distribution Static Synchronous Compensator (D-STATCOM) [13], Dynamic Voltage Restorer (DVR) [14], and Unified Power Quality Conditioner (UPQC) [15]. Although this equipment has very good technical performance, it is difficult to implement on a large scale, especially at high nominal unit powers, due to the costs, which are still very high. A distinct category of active strategies is those based on the inverters in the composition of three-phase or single-phase DERs. In the case of three-phase DERs, the inverters can be controlled in such a way as to allow not only different values of active power injection per phase but also the injection or absorption of reactive power of different values per phase, without disturbing the total amount of active power produced by the DER [16]. This control can also be performed in the case of single-phase DERs, but the balancing of power flow on phases requires the coordination of single-phase DERs installed on different phases [17]. The disadvantage of applying these strategies lies in the need for the DERs and the inverters in their composition to be of oversized nominal power to allow the application of the reactive power regulation function with the aim of symmetrizing the voltages on the network phases. The same category of active strategies also includes DER-BESS (Battery Energy Storage System) combinations, the most famous of which is the Photo Voltaic (PV)-Electric Vehicle (EV) combination. They allow the charging or absorption of active powers per phase, so that, by optimizing the control algorithms of the charging and discharging regimes of the batteries, the optimization of the distribution network voltage symmetrization can be obtained [18]. Passive voltage symmetrization strategies, while not as efficient as active ones, are much less expensive and easier to implement on a large scale. The first type of passive strategy is based on methods or techniques for reconfiguring feeders [19], changing load phases [20], optimizing the location of DERs [21], or combinations thereof [22]. Direct, single-phase voltage regulation can also be considered as a passive voltage symmetrization method. For this purpose, special transformers have been designed that allow voltage regulation, through the on-load switching of the taps, individually per phase [10]. One of the most important methods, which belongs to the category of passive strategies, is shunt-reactive compensation. The Balancing-Reactive power Compensator (BRC) originates from [PERSON]'s assembly.