High voltage inverter device and electrical leakage detector thereof

摘要

In a high voltage inverter device switching an input voltage to apply an exciting current to an excitation winding of a transformer and output an alternating-current high voltage from an output winding to supply the high voltage to a load from output lines, a point on the output line is connected to a frame ground. Each of a first and a second winding of the electrical leakage detecting transformer is interposed in series with the output line on a side where current flows out of the point and a side where current flows into the point respectively. A detection voltage Vd outputted from an amplifying winding is compared by a comparison voltage Vref, and an electrical leakage detection signal Sd is outputted when Vd>Vref. The first and second winding are opposite in winding direction to each other and equal in number of turns.

主权项

1. An electrical leakage detector of a high voltage inverter device, said high voltage inverter device being configured to switch an input voltage to apply an exciting current to an excitation winding of a transformer and output an alternating-current high voltage from an output winding of the transformer so as to supply the alternating-current high voltage to a load from a pair of output terminals to which two ends of the output winding are connected via output lines respectively, and one of the output lines between one of the ends of the output winding and one of the output terminals being connected to a frame ground, said electrical leakage detector comprising:
an electrical leakage detecting transformer comprising a first winding interposed in series with said one of the output lines on a side where current flows out of a point connected to the frame ground, a second winding interposed in series with said one of the output lines on a side where current flows into the point connected to the frame ground, and an amplifying winding, said first winding and said second winding being opposite in winding direction to each other and equal in number of turns, and a number of turns of said amplifying winding being larger than the number of turns of said first and second windings by one order or more; and a comparison circuit comparing a detection voltage outputted from between two terminals of said amplifying winding of said electrical leakage detecting transformer to a comparison voltage set in advance, and outputting an electrical leakage detection signal when the detection voltage exceeds the comparison voltage, wherein in said electrical leakage detecting transformer, the number of turns of each of said first winding and said second winding is one turn or two turns and the number of turns of said amplifying winding is one hundred turns to ten thousand turns, and wherein said electrical leakage detecting transformer includes a bobbin made of an insulating material mounted on a core, in which said first winding and said second winding and said amplifying winding are wound to be insulated from each other, furthermore, a space for preventing discharge in said electrical leakage detecting transformer is provided between said first winding and said second winding through the bobbin, and said second winding and said amplifying winding are insulated by the bobbin.