Симетpувaння нaпpуги в електpичних меpежaх

Abstract

Ensuring high quality electrical energy is critical for the efficient operation of electrical equipment, as well as for preventing various short circuits. Among the quality indicators, voltage asymmetry in electrical networks occupies an important level. Voltage asymmetry negatively affects the operation of consumers of asynchronous motors, lighting, capacitor units, etc. Balancing voltages in the network is reduced to compensation of the negative sequence current and voltage. With a stable load schedule, reducing the systematic asymmetry of voltages in the network can be achieved by equalizing the phase loads by switching part of the load from the unbiased phase to the underbiased one. Rational load redistribution does not always allow reducing the voltage asymmetry coefficient to an acceptable value (for example, when some of the powerful single-phase electrical consumers operate under the conditions of the technology not all the time, as well as during preventive and major repairs). In these cases, it is necessary to use special balancing devices. A significant number of device balancing schemes are known, some of which are implemented by controllers depending on the nature of the load graph.