Electric driving unit, chopper circuit, DC motor and electric equipment

Abstract

The invention provides an electric driving unit, a chopper circuit, a DC motor and electric equipment equipped with the electric driving unit. The electric driving unit comprises the DC motor, a DC power supply, the chopper circuit used for providing a DC current to the DC motor according to a control signal, and an excitation portion used for providing a work magnetic field, wherein the DC motor has 2j mutually independent armature winding branches composed of M windings, 2j*m commutator segments connected with the windings, and 2 sets of electric brush sets which are respectively connected with two sets of power supply wires of the DC motor and at least contact with the 2j commutator segments, each electric brush set comprises j mutually independent electric brushes, the chopper circuit has 2 leg portions respectively corresponding to the 2 electric brush sets, each leg portion comprises leg units in one-to-one correspondence with the j electric brushes, each leg unit comprises a chopper leg providing a wire current to the corresponding electric brush and a freewheeling diode in reverse parallel connection, and the j and the m are both positive integers greater than 2.

Description

technical field [0001] The invention belongs to the field of DC motors, and in particular relates to an electric driving device, a chopper circuit, a DC motor and electric equipment including the electric driving device. Background technique [0002] With the increase in the number of days and duration of smog in major cities, the country has become more and more strict on the exhaust emission management of fuel equipment; in closed indoor working environments, the use of fuel equipment is basically prohibited; and oil is an energy source. Non-renewable, will face depletion in a few decades. Therefore, electric equipment that uses electricity as energy, such as electric vehicles, electric tools, and indoor electric forklifts, is more and more favored by manufacturers and consumers. Compared with it, it also has the advantages of high energy utilization rate, simple structure, low noise, good dynamic performance and high portability. Under the situation of increasingly tens...

AI Technical Summary

Problems solved by technology

[0010] Affected by various factors, when the switching element turns from the off state to the on state, if the parallel small current switching elements cannot be turned on at the same time, the current sharing will fail, and the single switching element that is turned on in advance will flow for a long time Large motor current, so that the switching element is damaged; the same reason, when the switching element changes from the on state to the off state, if the parallel small current switching elements cannot be turned off at the same time, it will cause the current sharing failure, then the last turn off The switching element will also flow a large motor current, so the switching element will be damaged

[0011] As the number of switching elements connected in parallel increases, it becomes more difficult to ensure the consistency of their switching characteristics, resulting in poorer current sharing effect during switching, resulting in a higher possibility of damage and more serious problems

Since the parallel current sharing technology cannot guarantee that any number of parallel switching elements are turned on and off at the same time, it seriously affects and limits the increase of the current value of the high-current motor, making the high-current motor a difficult obstacle to overcome

[0012] Furthermore, when the voltage of the chopper circuit is powered by a battery, the requirements for personal safety limit the voltage amplitude of the battery, which is far lower than that of the AC rectified power supply, which makes the problem more serious and seriously affects the battery-powered motor. Tools, electric vehicles, especially heavy-duty electric vehicles, electric boats, and even the development of electric chariots, electric warships and electric-driven aircraft carriers for national defense

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