摘要:
An electromechanical system is configured with a variable frequency drive power supply which provides power to both a three-phase motor and to a single-phase motor. In some embodiments, the variable frequency drive also powers one or more additional motors.
摘要:
An HVAC/R system is configured with a variable frequency drive power supply which provides power to both a three-phase motor and to a single-phase motor. In some embodiments, the three-phase motor is a compressor motor and the single-phase motor is a condenser fan motor.
摘要:
Variable speed drives are utilized in refrigerant systems to operate motors of the system components at varying speeds, typically for the purposes of capacity adjustment, efficiency enhancement, reliability improvement or power consumption limitation. However, variable speed controls are expensive. The present invention offers flexibility to utilize a variable speed drive to provide variable speed functionality between compressor and fans (or other rotating components having electric motors) within a refrigerant system depending on operational and environmental conditions and external load demands. The switching device switches the variable speed drive between component motors as indicated by a control for the refrigerant system.
摘要:
Systems and methods for synchronous operation of variable speed drives having active converters include extending the synchronous operation of an active converter to the AC mains voltage during complete line dropout. A phase angle control circuit includes a squaring amplifier, a first phase-lock loop circuit associated and a second phase-lock loop circuit. The squaring amplifier receives the AC power source and outputs a rectangular output signal to a pair of phase lock loop (PLL) circuits. The first PLL circuit with a first lag-lead filter is configured with a high cutoff frequency to provide the converter stage with a phase angle parameter; and the second phase-lock loop circuit including a second lag-lead filter configured to have a low cutoff frequency to provide the lag-lead filter the capability of storing the phase angle of the mains voltage during mains interruption.
摘要:
A method of controlling an air conditioning system of the type having a variable capacity compressor circulating refrigerant through a condenser, an expander, an evaporator and returning to the compressor. Sensors are disposed to sense a refrigerant condition selected from one of pressure and temperature on one or both the compressor high pressure and low pressure side; and, in the event of an overload condition, the sensors generate a control signal that effects operation of an actuator for moving a member in the compressor to vary the compressor capacity to the lowest capacity output. Alternatively, the generated control signal may vary the compressor speed.
摘要:
A scroll compressor is provided with a multiple-speed motor. A control selects a speed for operating the motor, along with selecting between several available options for the system capacity adjustment to meet external load demands in a most efficient and reliable manner. The disclosed embodiment includes an economizer circuit, an unloader function, and an optional suction modulation valve. By utilizing each of these features in combination with the multi-speed motor for the compressor, the present invention is better able to tailor provided capacity to desired capacity.
摘要:
A motor controller (101) according to the invention comprises an inverter circuit (3) for driving a brushless motor (4) and a control unit for controlling the rotational speed of the brushless motor (4) by controlling the phase of the motor current of the brushless motor (4) through the inverter circuit (3).
摘要:
A scroll compressor is provided with a multiple-speed motor. A control selects a speed for operating the motor, along with selecting between several available options for the system capacity adjustment to meet external load demands in a most efficient and reliable manner. The disclosed embodiment includes an economizer circuit, an unloader function, and an optional suction modulation valve. By utilizing each of these features in combination with the multi-speed motor for the compressor, the present invention is better able to tailor provided capacity to desired capacity.
摘要:
Cooling is provided to the power electronics of a compressor speed control system by way of refrigerant that is routed from a refrigeration system, through the power electronics, and then back to the refrigeration system. The amount of refrigerant flowing to the power electronics is automatically regulated to that needed to cool the electronics since both are substantially proportional to compressor speed. The housing for the power electronics is mounted directly to the side of the compressor, and the compressor is resiliently mounted to a support to thereby provide shock protection to the power electronics.
摘要:
A variable speed drive with a converter that is controllable to precharge a DC link is provided. The variable speed drive also includes an inverter. The converter converts a fixed line frequency, fixed line voltage AC power from an AC power source into DC power. The DC link filters the DC power from the converter. Finally, the inverter is connected in parallel with the DC link and converts the DC power from the DC link into a variable frequency, variable voltage AC power. The converter includes a plurality of pairs of power switches, wherein each pair of power switches includes a reverse blocking power switch connected in anti-parallel to another reverse blocking power switch. Alternatively, each pair of power switches includes a reverse blocking power switch connected in anti-parallel with a silicon carbide controlled rectifier.