POWER-CONSUMPTION CALCULATING METHOD OF MOTOR DRIVING DEVICE, AND CONTROL METHOD OF MOTOR DRIVING DEVICE USING THE POWER-CONSUMPTION CALCULATING METHOD

• US 20120112671A1
• Filed: 07/08/2010
• Published: 05/10/2012
• Est. Priority Date: 07/08/2009
• Status: Active Grant

• Current Assignee: Meidensha Corporation
• Original Assignee: Meidensha Corporation
• Inventors: Yamaguchi, Takashi, Kakebayashi, Toru
• Granted Patent: US 8,786,229 B2
• Time in Patent Office: Days
• US Class Current: 318/400.3
• CPC Class Codes: H02P 23/0077 Characterised by the use of a particular software algorithm

Abstract

Accurate power consumption is calculated without raising cost, or making the device bigger. Power consumption (P) upon driving a motor is calculated from an input voltage (Vdc), a switching duty factor of a switching device (Sw1) of a chopper circuit (ch), which is provided with the switching device (Sw1) and a reactor (Ldc), a reactor current (Idc), motor winding reactance (Lm), and motor rotation speed (N), in a motor driving device wherein: the input voltage (Vdc) inputted to the chopper circuit (ch) is stepped down by the chopper circuit (ch); DC power outputted by the chopper circuit (ch) is converted to AC power by driving an inverter (INV) with 120-degree conduction, and outputted to a motor (M); and surge voltage to be generated when the inverter (INV) undergoes commutation is clamped to the input voltage (Vdc), by a diode (D1) connected in inverse-parallel to the chopper circuit (ch).

Claims

1. A power consumption calculating method for a motor driving device configured to step down an input voltage inputted to a chopper circuit by the chopper circuit including a series circuit of a first switching element having one end connected to a positive voltage side of the inputted direct-current voltage, and a reactor having one end connected to the other end of the first switching element, and a second switching element disposed between the connection point between the other end of the first switching element and the one end of the reactor, and a negative voltage side of the input voltage, to convert a direct-current power outputted from the chopper circuit to an alternating-current power by driving an inverter by 120-degree conduction, to output to a motor, and to clamp a surge voltage generated at commutation of the inverter to the input voltage by a diode connected in inverse-parallel to the series circuit, the power consumption calculating method comprising:

calculating a power consumption of the motor driving device at driving of the motor by a following equation (a) from the input voltage to the chopper circuit, a switching duty factor representing a ratio of an ON state of the first switching element to an ON/OFF cycle of the first switching element, a reactor current flowing in the reactor, a winding reactance of the motor, and a rotational speed of the motor,

2. The power consumption calculating method for the motor driving device as claimed in claim 1, wherein a power consumption is calculated by multiplying the power consumption of the motor driving device calculated in the equation (a) by an efficiency of the inverter.

3. A control method for the motor driving device by using the power consumption calculating method as claimed in claim 1, wherein a power control is performed by performing feedback of the power consumption of the motor driving device to an automatic controller.

4. A control method for a motor driving device configured to step down an input voltage inputted to a chopper circuit by the chopper circuit including a series circuit of a first switching element having one end connected to a positive voltage side of the inputted direct-current voltage, and a reactor having one end connected to the other end of the first switching element, and a second switching element disposed between the connection point between the other end of the first switching element and the one end of the reactor, and a negative voltage side of the input voltage, to convert a direct-current power outputted from the chopper circuit to an alternating-current power by driving an inverter by 120-degree conduction, to output to a motor, and to clamp a surge voltage generated at commutation of the inverter to the input voltage by a diode connected in inverse-parallel to the series circuit, the control method comprising:

calculating a current command value by following equations (b) or (c) from the input voltage to the chopper circuit, a switching duty factor representing a ratio of an ON state of the first switching element to an ON/OFF cycle of the first switching element, a reactor current flowing in the reactor, a winding reactance of the motor, a rotational speed of the motor, a power consumption command value of the motor drive device, and an inverter efficiency, and

performing a power control by using this current command value,