Research Of Energy-feedback And Constant Voltage Clamp Bipolar Pulse Current Source

In the fields of geophysical exploration and PCB plating process, it is necessary to create a bipolar pulse current source with declining edge of high linearity, high stability, short turn-off time and better positive and negative consistency. However, obtaining an ideal square current especially with high inductor load, small loop resistance and low input voltage is very difficult. This paper uses the idea of circuits in existence for reference, analyses bipolar pulse current circuits in theory, raises two kinds of energy-feedback and constant voltage clamping circuits. A deep discussion is carried on in the research of drive and protection circuits of full-bridge, and the questions fell across in high-power circuits. The achievements of the dissertation are as follows:①In order to solve the energy dissipation problem existing in the circuits in existence, inductance energy-feedback and constant voltage clamping circuit is put forward. The working principle of this circuit is discussed with emphasis on optimizing parameters. By investigating the wave linearity of load current declining edge and permitted fluctuating range of stabilizing voltage capacitor, the method is given to select the optimal capacitor value and optimal inductor value of feedback circuits. The result of Psim simulation proves the proposed circuit meeting the predefined requirements much better than those reported. Design drive and protection circuits which are used for high-power IGBT in experiment specially. At last, high-current inductance and PCB are designed for experiment.The steady voltage part in inductance energy-feedback and constant voltage clamping circuit which consumes energy is smaller than the part raised by literature [1]. This circuit takes on the ability of upgrading rising edge, shorter turn-off time and good linearity in decline edge of load current.②Appearing of late-model energy-feedback and constant voltage clamping circuit is to settle the shortages in anterior circuits, such as the nonideality waveforms of load current's rising edge and changing of flat part with power supply. The paper labors the working principle and design thought of control circuit, at last parameters are calculated in theory and simulation is done to confirm the theoretical analysis.The rising edge and falling edge of load current have the same slope, namely, rising edge holds on the same speed reaching steady current linearly, and it's good for increasing frequency of main circuit. The output current is never influenced by power supply, realizing the invariableness of load current. From the results of simulation, a conclusion is educed that load current closes to ideal pulse aquare current.