Showing papers on "Maximum power point tracking published in 1973"

Power limit and control system

Abstract: A new and improved power limit and control system for determining the power output capability of a group of power sources and limiting the power drawn by a number of loads driven by the power sources to the power capabilities of the sources.

Constant power supply employing a variable frequency inverter

Abstract: A power supply useful for delivering substantially constant power to a plasma arc lamp or other load includes a variable frequency inverter having a substantially fixed pulse width. A constant power control circuit adjusts the inverter frequency to compensate for deviation of the output power away from a linear approximation of a constant power curve. In the control circuit, signals proportional to the output current and voltage are fed to a function generator which implements the linear approximation function. An error signal derived by comparing the function generator output with a reference voltage controls the frequency of an oscillator which in turn establishes the triggering rate of silicon controlled rectifiers (SCRs) in the inverter. The SCRs commutate off after a relatively constant time period, thus inverter output is proportional to the SCR triggering frequency. Cooperation of the control circuit and inverter maintains the supply output power at a constant level.

Power control apparatus for direct-current lines

Abstract: A power control apparatus for controlling the power transmitted over a direct-current line connected between alternating-current lines is disclosed. The direct-current line is connected to the alternating-current lines by a converter and inverter respectively. The power control apparatus includes a converter firing unit connected to the converter, a converter current controller connected to the converter firing unit, and a power regulator connected to the converter current controller for supplying the same with a current reference value. An inverter firing unit is connected to the inverter and a voltage controller and an inverter current controller are provided for setting respective voltages on the direct-current line. One of these voltages is smaller than the other at a given time. A connection circuit connects the last-two mentioned controllers to the inverter firing unit so as to cause the controller corresponding to the one voltage to act upon the inverter firing unit at the given time. The inverter current controller has an input for receiving a current reference value smaller than the current reference value supplied to the converter current controller. The inverter current controller is configured to stabilize the current in the direct-current line to the current reference value supplied to the inverter current controller in a predetermined time interval. A remote transmission arrangement is connected between the power regulator and the inverter current controller for adjusting the current reference value supplied to the inverter current controller in response to a change in the power after the time interval has elapsed.