QUASI-RESONANT BRAKING LOAD

摘要

A method of dissipating electrical energy, the method comprising: switching on a second switching device to cause current to flow in a load resistor under control of a first resonant network and to ensure the voltage across a first switching device is substantially zero, and switching on a first switching device when the voltage across the first switch is substantially zero to cause the current flowing in the load resistor to be maintained while switching off the second switching device; switching off the first switching device to cause the current flowing in the load resistor to reduce under control of a second resonant network. In this way, energy may be transferred from an electric motor to a braking resistor in a manner that reduces the amount of electromagnetic noise produced. In addition this invention reduces the amount of unwanted switching loss associated with the switching devices used to control the energy transfer.