ELECTRONIC NON-DIFFUSION LOAD Russian patent published in 2010 - IPC G01R31/34 

FIELD: electricity.

SUBSTANCE: invention refers to devices allowing to load various converters with DC output, storage batteries, DC generators during execution of tests of various kind, including life test. Long-term test of various sources and converters relates to large flow of electric power and financial losses for the enterprise producing the like products. Electronic non-diffusion loads (ENDL) essentially (by 4…6 times) reduce the electric power consumption during tests. From the input of the tested converter (TC), being the input voltage source (U_IV), the power is supplied through input throttle to the circuit consisting of two keys, capacitor and resistor, as well as to transistor bridge, to the diagonal of which the primary winding of transformer is connected, and the secondary winding of transformer is connected through bridge rectifier to storage capacitor. Bridge on IGBT transistors of inverter of the second stage is powered from storage capacitor. Throttle and voltage source of the network are connected to the diagonal of that bridge. When connecting the supply voltage through diodes of IGBT transistors of the bridge and through the charging resistor, the storage capacitor is charged to peak voltage of the network. Auxiliary converter provides the required power supply voltages of control circuits of the first and the second stage of ENDL. Certain active clamp is added with the sprocket consisting of transistor key (5) and resistor (6) and one end of which is connected to the connection point of key and capacitor of the clamp, and the other one - to connection point of input throttle, transistor of clamp and to two upper keys of transistor bridge (7, 9). Additional chain allows operation of transistors of the bridge of the inlet stage of ENDL not only in coverage mode, but also in the mode when those transistors operate without coverage. This mode (operation without coverage) is required for providing the boosting of storage capacitor at wide change of voltage at ENDL input and wide change of the network. ENDL operates in two modes: start-up one (storage capacitor is boosted) and operating one when power is supplied from ENDL to the input of the tested converter or to AC network.

EFFECT: improving operating reliability of keys of the first stage in start-up mode and eliminating false actuations of protection at wide change of input constant voltage (for example, U_IV = 20-40 V or U_IV = 40-60 V) and wide range of voltage of the network (for example, U_N = 170-275 V).

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