Arc quenching device for a solar array

Description of the offer:

The present innovation relates to solar power sources, their regulators and in particular to a circuit to protect against arcing on solar panels or within the solar array drive mechanism (SADM) of a spacecraft. The main innovation allows minimising the risk of significant power loss resulting from failure propagation following an uncontrolled arcing event on the solar array or within the solar array drive mechanism. This objective is achieved by the device to protect from arcing events, solar array panels and control equipment supplying a main power bus. Such control equipment comprises a regulator for controlling a solar array voltage and includes a power dump stage for shunting solar array voltage as a function of a control signal. According to the offer, this device comprises:

• a voltage drop detection circuit to detect voltage drop in the solar array voltage provided by solar array panels. The voltage drop detection circuit generates a voltage drop detection signal;
• an arc-quenching circuit comprising means able to generate an output signal which is applied as a control signal to the power dump stage in order to shunt the solar array voltage when a voltage drop is detected by the voltage drop detection circuit;
• The arc-quenching circuit further comprises means for shaping the output signal to provide a short initial delay without any action subsequent to a voltage drop detection provided by the voltage drop detection signal, and after such initial delay an arc-quenching pulse which triggers the power dump stage to shunt the solar array voltage;
• The arc-quenching circuit also comprises a first monostable controlling the initial delay and a second monostable controlling the width of the arc-quenching pulse, furthermore it comprises means for combining the control signal and output signal before being applied to the power dump stage;
• The initial delay is set to about 19 ms and the arc-quenching pulse has a width set to about 1.7 s;
• The arc-quenching circuit also comprises means to start a new quenching cycle including the initial delay followed by arc-quenching pulse as long as the voltage drop detection circuit detects a voltage drop in the solar array voltage;
• The voltage drop detection circuit comprises means for comparing the solar array voltage to a main bus voltage.

Innovations and advantages:

The major characteristics of this innovation include a protection device associated to the voltage regulator and the power dump stage. Such protection device comprises a voltage drop circuit and an arc-quenching circuit which uses a detection signal provided by the voltage drop detection circuit to generate a pulse which can activate the power dump circuit into the “ON” state for a certain amount of time. The arc-quenching circuit further comprises means to shape the output signal and provides a delay signal after which the pulse triggers the power dump stage to shunt the solar array voltage.

Domain of Application:

The present offer related specifically to solar power sources, their regulators and, in particular, to a circuit to protect against arcing on solar panels or within the solar array drive mechanism (SADM) of a spacecraft. Power Supply and Control, Solar, Electronic devices especially for energy generation and supply.

• Alternative Energy
• Solar energy
• Photovoltaic solar