Research On Steep Pulse Current Power Source With Inductive Load

In the transient electromagnetic detection and electromagnetic water treatment, etc,the steep-sided pulse current technology has great theoretical significance and practicalvalue. Steep pulse current sources in different applications have different requirements.The current waveform of Transient electromagnetic detection needs higher qualityrequirements, while both needs the current is stable during the constant, linear fallingedge and short-time delay. Because the load character of transient electromagneticdetection inductive, it is very difficult to achieve accurate waveform shape control. Theedge is not able to be symmetrical in the rising and falling, therefore the response signalexcited by rising edge could not be utilized. For the transient electromagneticapplication, this thesis proposes a unipolar trapezoidal pulse current source circuit. Foralternating electromagnetic industrial circulating water scale applications, at presentsingle frequency sinusoidal alternating electromagnetic pulse is generally used. Whiledue to deviate from the optimal scale frequency, it often makes the anti-scaling failure.The thesis put forward that the steep pulse current source contains rich harmonicfrequency; in the electromagnetic water treatment, the current will cover the bestfrequency scale, so as to obtain the good anti-scaling effect. Meanwhile the steeppulse current source technology was applied to electromagnetic anti-scaling.①The topology research of single polarity steep pulse current source. The thesiselaborates the domestic and foreign development of the detection system, analyzes thekey technical issues of the steep pulse current source. Study on the steep pulse currentsource circuit with inductive load, the thesis put forward a unipolar pulse current circuitwith the rising edge fast linearly rising, symmetric linear change, and stable loadcurrent.②The design of constant current and the front-back symmetry about singlepolarity steep pulse current source. The presence of non-ideal increase and overshootproblem of load current that enters the constant phase could be eliminated withcombining the method of constant current power supply and voltage clamp, in designoptimization of the constant current inductor. For the rising and falling edges are notuniformly symmetric, after analyzing the limitation of condition I0R1<<VC, using themethod that the rising and falling edges of load current are separately clamped andsetting the clamp voltage of the former is I0R1higher than the latter’s achieve a real sense of symmetry consistent. For there exists large current ripple, the thesis proposesthe constant current control method of adding freewheeling diode to form the stablefirst-order background field. After introducing the circuit working theory and relevantparameter design in detail, simulation and experiment analysis verifies the correctnessof the circuit.③Study on bipolar steep pulse current source and anti-scaling experiments. Onthe research of alternating electromagnetic descaling、anti-scaling methods, for thesolenoid processing chamber, the thesis designs triangle wave and sawtooth currentgenerator. The current turn-off technology of sawtooth bipolar current generator adoptshigh voltage clamp technique using in single polarity steep pulse current source.Though comparing the anti-scaling effect with the sine wave, triangle wave, sawtoothcurrent field source, under the condition of the same energy and external environment,using EDTA disodium titration verifies that calcium ion concentration in dissolvedsolution processed by the double polarity of sawtooth current source is highest. Thus,the descaling effect of the double polarity sawtooth current is better than conventionalsingle-frequency sinusoidal current’s.