Current Interactions Mitigation in 3-Phase PFC Modular Rectifier through Differential-Mode Choke Filter Boost Converter

Abstract

In this paper, a new way to mitigate the current interactions is proposed. The problem of current interactions arises when a modular three-phase (3-phase) rectifier (three single-phase modules) with boost converter for power factor correction (PFC) is used. A new differential-mode choke filter is implemented in the developed boost converter. The choke here is a specially made differential inductor in the input of the boost converter that eliminates the known current interactions. To prove the new concept, a study of the level of mitigation of the current interactions is presented. The control is operated in continuous driving mode (CCM), and the popular UC3854B circuit was used for this. The rectifier proposal is validated through a set of simulations performed on the PSIM 12.0 platform, as well as the construction of a prototype. With the results obtained, it is confirmed that the differential-mode choke filter eliminates the current interactions. It is observed that at the input of the rectifier, a sinusoidal alternating current with a low level of harmonic distortion is consumed from the grid. The sinusoidal shape of the phase current proves that a better power factor capable of meeting the international standards is obtained, and that the circuit in its initial version is operational. This proven result promises a good PFC operation, to guarantee the better quality of the electrical energy, being able to be applied in systems that require a high PFC, e.g., in battery charging, wind systems, or in aeronautics and spacecrafts.

Hybrid Three-Phase Rectifiers with Active Power Factor Correction: A Systematic Review

“…In this case, the current loop only has the purpose of imposing the current amplitude (by means of a reference signal of constant value), to allow a certain desired current value (thus allowing a better power distribution in the HTR) and rectangular in shape. Note that some hybrid structures (not all) may have the GRAETZ bridge rectifier 1 and BOOST converter with some minor modifications to allow a correct operation; the modification consists of dividing the BOOST diode and the BOOST inductor, as shown in Figure 4 [2,3,6,21,29,34]. This structure has very interesting characteristics, being robust, simple, reliable, low volume, low financial cost, and widely applied in low power devices; however, it cannot be used for high power levels, because its input currents have a total harmonic distortion current (THDi) of approximately 30% and a PF of 95%, which does not meet the IEC 61000-3-2/61000-3-4 standards [22,27,28].…”

“…Nowadays, this AC power system has become the standard. Since the electrical network is given in AC, and most charges use electrical energy in DC, such as TVs, computers, radios, electric vehicles, etc., an AC-DC rectifier is incorporated into the loads [2,3].…”

“…Of course, these semiconductor elements are not ideal; they have some disadvantages such as thermal losses. Thermal losses cause high heating and can cause the device to burn, but this can be solved by using heat sinks with forced cooling (cooling by deionized water or ventilated air), and water cooling is for high-power converters [2][3][4].…”

“…Examples of wellestablished and internationally known standards used on energy quality are IEC61000-3-2 and IEC61000-3-4, and in relation to the total harmonic distortion (THD) of the current injected into the electrical network, it used IEEE Std 519-2014. With this, the challenge today is to develop a system of medium or high-power converters that are even more efficient and reliable, as is the case with three-phase rectifiers [2][3][4].…”

“…Bidirectional rectifiers, on the other hand, use switching devices (MOSFETs, IGBTs, etc.) activated by means of a control system [2,3]. These rectifiers can achieve good results such as low THD and high Power Factor (PF), and they can even meet international standards.…”