High voltage Bi-directional flyback converter for capacitive actuator

Abstract

Keywords«High voltage power converters», «Switched-mode power supply », «Energy efficiency», «Actuator», «Electroactive materials». AbstractThis paper presents a high voltage DC-DC converter topology for bi-directional energy transfer between a low voltage DC source and a high voltage capacitive load. The topology is a bi-directional flyback converter with variable switching frequency control during the charge mode, and constant switching frequency control during the discharge mode. The converter is capable of charging the capacitive load from 24 V DC source to 2.5 kV, and discharges it to 0 V. The flyback converter has been analyzed in detail during both charge and discharge modes, by considering all the parasitic elements in the converter, including the most dominating parameters of the high voltage transformer viz., self-capacitance and leakage inductance. The specific capacitive load for this converter is a dielectric electro active polymer (DEAP) actuator, which can be used as an effective replacement for conventional actuators in a number of applications. In this paper, the discharging energy efficiency definition is introduced. The proposed converter has been experimentally tested with the film capacitive load and the DEAP actuator, and the experimental results are shown together with the efficiency measurements.

Design of a high voltage bidirectional DC-DC converter for driving capacitive incremental actuators usable in electric vehicles (EVs)

“…Since the load is purely capacitive, the converter efficiency is defined as energy efficiency, instead of normal power efficiency. The charge and discharge energy efficiency measurement [30] results are provided in Table IV. During the charge process the output energy is the energy stored in the load capacitor, and the input energy is obtained by integrating the input charge current and multiplying it with the input voltage.…”

“…The bidirectional flyback converters are proposed in [26]- [28] to transfer the power in both directions. Prior work on the high voltage drivers for the DEAP actuators demonstrated a low voltage piezoelectric transformer based DEAP solution, and it was inserted inside a coreless DEAP actuator [29], and a bidirectional flyback converter topology to drive the PolyPower Push Inlastor DEAP actuator [30]. In [31] an efficiency optimization technique is proposed for a bidirectional flyback converter used to drive capacitive actuator.…”

Bidirectional flyback converter with multiple series connected outputs for high voltage capacitive charge and discharge applications

“…Several bidirectional flyback converter topolofies have been proposed and implemented in [25]- [29]. The conventional high voltage bidirectional flyback converter [30], [31], for driving (charging and discharging) a DEAP actuator with a certain actuation frequency, is shown in Fig. 3.…”

“…Primary parallel, secondary series flyback converter with multiple transformers is proposed in [36], to reduce the equivalent selfcapacitance on the secondary HV side. The HV converter used in [9], [30], [32], [35] The 4 kV, 300 mA high voltage IXYS MOSFET [37] has the following features:…”

“…The flyback converter is suitable for low power (< 150 W) and high voltage (2.5 kV) applications, due to its simple structure and low component count [16]. In [17], [30], [32]- [36], [44], [45] bidirectional flyback converters with various power stages and control techniques, for charging and discharging DEAP actuators have been proposed and implemented. The proposed converter with multiple series con- nected secondary windings is different from aforementioned converters, since it is aimed for bidirectional operation, by replacing the diode with a MOSFET on the secondary HV side.…”