Showing papers on "Buck–boost converter published in 1973"

Two-phase solid state power converter

Abstract: A driven two-phase power converter such as a DC-to-AC inverter or boost converter is modified by the incorporation of a unique differential current transductor and transistor pulse drive circuit. The differential current transductor senses any difference in the average current in the two legs of the twophase power converter circuit and produces a voltage proportional to that current difference. This voltage is then used in the pulse drive circuit to control, on a half-cycle basis, the widths of the drive pulse to the switching transistors in a manner which equalizes the currents in the two legs.

ASDTIC control and standardized interface circuits applied to buck, parallel and buck-boost dc to dc power converters

Abstract: Versatile standardized pulse modulation nondissipatively regulated control signal processing circuits were applied to three most commonly used dc to dc power converter configurations: (1) the series switching buck-regulator, (2) the pulse modulated parallel inverter, and (3) the buck-boost converter. The unique control concept and the commonality of control functions for all switching regulators have resulted in improved static and dynamic performance and control circuit standardization. New power-circuit technology was also applied to enhance reliability and to achieve optimum weight and efficiency.

Voltage regulator with controlled current

Abstract: A voltage regulating system for AC generators including a three phase current boost and a voltage responsive control circuit having a full converter type output stage. The three phase boost circuit and the full converter output stage are connected in series with the field winding of the exciter. At high power output levels, the inverting capability of the full converter power stage is used to oppose the voltage generated by the current boost to prevent loss of control over the generator, by diverting excessive boost currents through a load means connected to the current boost circuit.

Voltage-to-current converter and function generator

Abstract: A voltage-to-current converter serving as a function generator or an essential element thereof and producing various output voltages in accordance with an input signal. It comprises a voltage-to-current converter circuit including at least two transistors, one of these transistors being an output transistor carrying current proportional to the potential difference between two input terminals respectively connected to the emitters of the two transistors, and a current-to-current converter providing at an output terminal a current proportional to the current through the afore-mentioned output transistor. With this voltage-tocurrent converter a function generator of a simple circuit construction may be produced inexpensively. Also, it may be readily made as a semiconductor integrated circuit.

Converter station with parallel static converters

Abstract: 1427405 Parallel operation of converters ALLMANNA SVENSKA ELEKTRISKA AB 9 July 1973 [10 July 1972] 32508/73 Heading H2F A converter station, e.g. for HVDC power transmission, comprises two parallel converters, each provided with a current regulator which is adjusted to give a predetermined load distribution between the two converters, each including upper and lower limit circuits for the control angle and each provided with means responsive to the current distribution between the converters arranged to reduce the lower limit of control angle in the least loaded converter when the deviation from the normal current distribution exceeds a certain threshold, e.g. due to a commutation fault in one converter. Fig. 3 shows part of a control system for the two converters, the direct current of which is respectively monitored by transductors 16 and 23 and compared with reference voltages from potentiomerers 26, 27. The system is arranged so that the AND gate 30 or 31 associated with the more lightly loaded converter passes a signal to trigger a monostable flip-flop 32 which temporarily reduces the minimum control angle limit from 18. A further monostable 34 is arranged to increase the current order in the current regulator 13 in order to avoid oscillations in the direct current. The upper limits of control angle may be temporarily limited by way of an OR gate 38 and derivative circuit 39. A further circuit 42 which compares the current or powers on the A.C. and D.C. sides and a circuit 43 as described in Specification 1,228,867 for detecting partial or possible commutation faults may be included to inhibit gate 30 in the event of possible or complete commutation failure in one converter. This inhibition only has effect on the overall system when commutation failure occurs in both converters.

System for controlling the frequency of an alternating current converter in response to load changes

Abstract: Alternating current having a selected frequency is produced by a converter to operate a synchronous motor at a desired speed. The frequency of the alternating current is determined by an accumulating circuit that supplies synchronizing impulses to the converter at a rate determined by the setting of the accumulating circuit and in response to a pilot signal. During failure of power to run the converter, a trigger generator responsive to voltage from the decelerating motor changes the control setting of the circuit so that, upon restoration of power, synchronizing pulses will be produced at a lower repetition rate, causing the frequency of alternating current from the converter to be commensurate with the reduced speed of the motor.

A Three-Phase Inverter with Reactive Power Control

Abstract: A new type of self-commutated inverter for fixed or moderately variable frequency has been developed. The inverter is characterized by an extremely uncomplicated main circuit. In its basic form the inverter contains two converter circuits: a principal converter circuit and an auxiliary converter circuit. The principal converter circuit transfers power from the input dc side to the output ac side, and the auxiliary converter circuit generates an inductive current to balance the reactive current of a three-phase capacitor on the ac side. This capacitor has the combined function of a phase compensator, a filter capacitor, and is also the source of the commutating voltage. Both converter circuits are of the line commutated type, meaning that at power frequencies normal converter thyristors can be employed. This makes it possible to build high-power inverters without series or parallel connected thyristors. All filter reactors are smoothing reactors placed on the dc side of the converter circuits. Thus the inverter has a very good efficiency even at the higher frequencies. The ability of a converter circuit to generate a negative sequence current when unsymmetrically controlled makes the inverter insensitive to unbalanced loads. The transient behavior of the inverter is similar to that obtained from a conventional self-commutated inverter with an output filter.

High-efficiency converter and battery charger for an RTG power source

Abstract: Spacecraft power systems utilizing radioisotope thermoelectric generators CRTGs) as primary power sources present an uncommon set of require ments and limitations for interfacing dc-to-dc converters. A converter configuration is presented that complements these RTG characteristics. The circuit is a variation of the basic flyback regulator modified to provide input regulation. The converter has two isolated outputs. One output provides power directly to the spacecraft equipment, while the second is used for battery charging. Design problems addressed are noise generation in long cable lengths between the RTG source and the converter, regulation of the converter input to obtain maximum power transfer from the RTG to the equipment, and provision for two converter outputs while maintaining high efficiency with a simple design implementation. The design of a converter and battery charger used on the Viking Lander Capsule* is presented as an illustration.