Industrial Machine Power Controller Using Torque and Speed
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Solution Overview
Problem
Existing controllers for industrial machines with electric motors lack accuracy in calculating total power consumption, particularly due to neglecting power losses in motors and amplifiers, and require dedicated devices like wattmeters.
Innovation Solution
A controller that calculates motor power consumption by multiplying motor current, rotation speed, and torque constants, and accounts for power losses in motors and amplifiers, integrating these with fixed peripheral consumption to determine total power usage over time without a dedicated wattmeter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a wattmeter is used to measure power consumption, then measurement accuracy is improved, but device complexity and cost increase
Solution Approach 1:
The controller performs self-measurement by utilizing its own existing detection units (current detection unit 7 and rotation speed detection unit 6) to calculate power consumption. The controller calculates motor power consumption using the formula P = Kt × ω × I, where Kt is the torque constant, ω is the rotation speed, and I is the current. This eliminates the need for external measurement devices while maintaining measurement capability within the control system itself.
2Device complexity
If simple calculation methods are used for power consumption, then device complexity is reduced, but measurement precision deteriorates
Solution Approach 1:
The invention converts the harmful effect of power losses (which were previously neglected and caused measurement inaccuracy) into a beneficial factor by explicitly calculating and adding these losses to the power consumption formula. The controller now calculates total power consumption as P_total = P_motor + P_loss, where P_loss includes motor losses and amplifier losses. This transforms the previously problematic unaccounted losses into a measured and compensated parameter, improving accuracy without significantly increasing system complexity.
3Measurement precision
If power losses are included in calculation, then measurement precision is improved, but calculation complexity increases
Solution Approach 1:
The power consumption calculation is segmented into distinct components: motor power consumption (P_motor = Kt × ω × I), motor power losses (P_motor_loss), amplifier power losses (P_amp_loss), and fixed power consumption (P_fixed). Each component is calculated separately using specific formulas and then summed to obtain the total power consumption. This segmentation allows for systematic and manageable calculation while improving overall accuracy.
Solution Approach 2:
The invention introduces additional parameters to the calculation: torque constant (Kt), rotation speed (ω), current (I), and loss coefficients. By changing the calculation from a simple measurement to a multi-parameter formula-based approach, the system achieves higher precision. The controller utilizes existing detection units to obtain these parameters and applies predetermined constants stored in memory to calculate accurate power consumption values.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Accurately calculates total power consumption of industrial machines by considering motor and amplifier losses and peripheral fixed power consumption, eliminating the need for a wattmeter and enhancing cost-effectiveness.
Implementation Method 1
a current detection unit detecting an electric current flowing through the electric motor
Implementation Method 2
a rotation speed detection unit detecting a rotation speed of the electric motor
Implementation Method 3
an electric motor using electric power
Data Source
AI summary
A controller of an industrial machine provided with an electric motor, a peripheral apparatus and an amplifier includes a motor power-consumption calculation section, a power loss calculation section, a fixed power-consumption calculation section, and a total power-consumption calculation section. The motor power-consumption calculation section calculates motor power consumption by decomposing a motor current into a Q-phase current value and a D-phase current value, and multiplying the Q-phase current value with a motor rotation speed and a motor torque constant. The power loss calculation section calculates sum power loss of the motor and amplifier. The fixed power-consumption calculation section calculates fixed power consumption of the peripheral apparatus. The total power-consumption calculation section determines total power consumption of the industrial machine in a predetermined time period by integrating, for the time period, the calculated motor power consumption, sum power loss and fixed power consumption.