Source: https://patents.justia.com/patent/7170245
Timestamp: 2020-02-24 19:20:07
Document Index: 599164248

Matched Legal Cases: ['art 201', 'art 201', 'art 20', 'art 10', 'art 20', 'art 80', 'art 80']

US Patent for Motor power supply control apparatus Patent (Patent # 7,170,245 issued January 30, 2007) - Justia Patents Search
Justia Patents Dynamic BrakingUS Patent for Motor power supply control apparatus Patent (Patent # 7,170,245)
Dec 31, 2003 - Samsung Electronics
As shown in FIG. 2, the three-phase motor power supply comprises a AC (Alternating Current) power supply part 201 supplying 110V/220V commercial AC power; a rectifier 203 rectifying the AC power generated from the AC power supply part 201 to a DC power; a capacitor 215 smoothing out the rectified voltage in the rectifier 203; an inverter 216 inverting the DC power from the capacitor 215 to a AC power having various frequencies and generating a three-phase voltage. The inverter 216 has a plural number of transistors 254b turned on/off depending on a PWM (Pulse Width Modulation) control signal, and diodes connected in parallel with each of the plural number of transistors 254b. The three-phase motor power supply further comprises a microprocessor (not shown) turning on/off the transistors 254b of the inverter 216, responding to the PWM control signal and modulating power frequencies to control a rotation speed of an AC motor 217.
FIG. 3A illustrates a circuit of a motor power supply according to an embodiment of the present invention. As illustrated in FIG. 3A, the motor power supply comprises a DC power supply part 20 receiving AC power from an AC power supply part 10 and supplying DC power through a pair of power supply terminals 80a and 80b; and an inverter 30 receiving the DC power from the DC power supply part 20 through a pair of connection terminals 90a and 90b which are, respectively, connected to the pair of power supply terminals 80a and 80b and converting the DC power into AC power having various frequencies so as to supply a three-phase voltage to an AC motor 40.
The motor power supply comprises a braking resistor 56 and a control switching element 58 serially disposed in an additional line connectable with the pair of power supply terminals 80a and 80b of the inverter 30, having series connection with the connection terminal 90 of the inverter 30 each other; a braking switch 60 to connection terminal 90A the connection terminal 90a to the respective power supply part 80a or to the additional line; an over voltage protection resistor 54 connected in series with the control switching element 58, having a side connected to the connection terminal 90a of the inverter 30 and a remaining side connected between the braking resistor 56 and the control switching element 58; a diode 52 connected, in parallel, with the over voltage protection resistor 54, having a cathode connected to the connection terminal 90a of the inverter 30 to which the over voltage protection resistor 54 is connected; a motor speed detector 99 (see FIG. 3B) detecting a speed the of AC motor 40; and a control part (see FIG. 3B) controlling, the control switching element 58 and the braking switch 60.
The inverter 30 has several inverting elements 32 formed in a pair of a transistor 32b and a diode 32a in a parallel connection thereof. Further, each power input terminal U, V and W of the AC motor 40 is, respectively, connected between corresponding pairs of the inverting elements 32 and supplied a three-phase voltage by the inverter 30 so as to input the three-phase voltage from the inverter 30.
The braking switch 60 may be a relay having a first contact point {circle around (1)} and a second contact point {circle around (2)} through which the connection terminal 90a of the inverter 30 is selectively connectable to one of the power supply part 80a (the normal position) and the additional line (i.e., the braking position).
The control part connects the braking switch 60 to the second contact point {circle around (2)} and turns off the transistor 32b of the inverter 30 when the AC motor 40 makes a sudden stop or the AC motor 40 stops driving when power is not applied. The control part enters control signals into a gate of the control switching element 58, and the control signal controls the on-off interval of the control switching element 58 depending on a result of the motor speed detector 99.
Thus, a portion of the current flowing in winding wires around the AC motor 40 flows into the AC motor 40 through the diode 32a of the inverter 30 and the braking resistor 56 resulting in shortening of the power connection terminals, and the braking resistor 56 consumes the current transformed into the heat. A further portion of the current flowing in the winding wires around the AC motor 40, flows in the over voltage protection resistor 54 connected with the braking resistor 56, in parallel, but the over voltage protection resistor 54 generally has a larger resistance value than that of the braking resistor 56, consequently the currents mostly flow through the braking resistor 56, and thereby prevents the AC motor 40 from being damaged and from rotating by external forces to enable the AC motor 40 to make a quick stop.
the DC supply unit comprises: a capacitor connected across the output terminals of the DC supply unit; and
the inrush-current protection circuit comprises: an inrush-current protection resistor reducing the inrush-current into the DC supply unit, and an inrush-current protection relay turned off so that a rectified voltage of the DC supply unit is transferable to the capacitor by passing through the inrush-current protection resistor, or turned on so that the rectified voltage is transferable to the capacitor without passing through the inrush-current protection resistor.
the switching element comprises: a MOS transistor or a field effect transistor and is switchable depending on a gate input signal; and
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Patent Publication Number: 20040227479
Application Number: 10/748,228
Current U.S. Class: Dynamic Braking (318/375); Regenerative (318/376); Locally Closed Armature Circuit (318/379); Closed Through Impedance Or The Like (318/380); With Field Or Secondary Circuit Control (318/381); Braking (318/362); Condition Of Motor Or Driven Device (318/366); Running-speed Control (318/268); With Braking (318/269); Induction Motor Systems (318/727); Braking (318/757); Dynamic Braking (318/759)
International Classification: H02P 3/12 (20060101); H02P 3/14 (20060101); H02P 3/22 (20060101);