Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
  • H02P29/00—Arrangements for regulating or controlling electric motors, appropriate for both AC and DC motors
  • H02P29/02—Providing protection against overload without automatic interruption of supply
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
  • H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
  • H02P6/08—Arrangements for controlling the speed or torque of a single motor
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
  • H02P6/00—Arrangements for controlling synchronous motors or other dynamo-electric motors using electronic commutation dependent on the rotor position; Electronic commutators therefor
  • H02P6/12—Monitoring commutation; Providing indication of commutation failure

Definitions

• Control unit for an electric motor in particular for a fan motor
• the invention relates to a control unit for an electric motor.
• Such control units are used to control the speed of the motor or regulate.
• the engine speed is reduced as needed to reduce the electrical input power.
• Fig. 1 shows the shaft power of the fan motor (1) and the flow noise of the fan (2) as a function of the speed
• the torque requirement of a fan wheel increases with the second power of the speed. This increases the shaft power of the motor even with the cube of the speed. This means that e.g. at half speed, the output power of the motor reaches only 12.5% of rated power.
• the shaft power drops even below 1% when the speed is less than 21.5% of the rated speed.
• the flow noise (2) decreases according to experience with 15-17 dB (A) when halving the speed.
• the speed of a fan can be influenced differently depending on the motor types used.
• the control unit can specify the motor voltage with a clocked voltage controller (chopper) or through a controlled rectifier.
• chopper clocked voltage controller
• the amplitude of the AC voltage can be adjusted by a phase control.
• a brushless motor also BLDC or electronically commutated motor, called EC motor
• the control unit takes over the electronic commutation.
• the control unit can additionally by appropriate timing of the transistors in the commutation of the motor voltage and thereby the
• Influence engine speed In asynchronous motors either the frequency and the amplitude of the motor voltage are specified with a frequency converter, or in low-cost systems, especially in fan drives, only the motor voltage is changed, for example by a phase control (so-called slip control).
• the desired engine speed is determined by a higher-level control.
• the transmission of the speed setpoint is often done with an analog value (eg 0-10 V) or with a pulse-width-modulated digital signal (PWM).
• Fig. 2 shows an input characteristic typical for fan applications.
• the higher-level controller must output 0-10% control signal (x) so that the motor stops ( so u ⁇ 0).
• the present invention is therefore based on the object to make the input characteristic of the control unit so that the engine continues to operate in such an error case with a predefined speed. In the event of an error such as line break or short in the control line, or if the higher-level control fails, there is a high probability that the control signal x will be 0% or 100%.
• the usual input characteristic of Fig. 2 is changed so that at input values in certain areas, primarily at about 0% or 100%, the control drives the engine from the current setpoint, predefined setpoint.
• the controller also outputs a warning in such an error case.
• This warning may be provided by an optical or acoustic signal, by an analog or digital electronic signal, or by a communication bus, e.g. CAN bus, are output.
• Fig. 1 shows the shaft power of the fan motor and the flow noise of the fan in
• Fig. 2 shows an input characteristic typical of fan applications
• Fig. 3 shows the input characteristic of the control unit in an advantageous embodiment
• Fig. 5 shows the program flow for the realization of the input characteristic
• Fig. 6 shows an exemplary circuit
• FIG. 7 shows a further exemplary circuit with a warning output.
• Fig. 3 shows the input characteristic of the control unit in an advantageous embodiment.
• the superimposed controller must output 5-10% control signal (x) instead of 0-10% to stop the motor.
• control signal 0-1 OV
• this means that the motor is at a control voltage of 0.5 V to 1 V (n so ⁇ 0).
• a control voltage below 0.5 V indicates a fault (eg failure of the higher-level controller, line break or short circuit in the control line).
• the motor should be at a control signal of 5 to 10% PWM.
• a PWM factor below 5% means an error. This is the case, for example, if the control signal has a permanently low level (corresponds to 0% PWM).
• a predefined speed setpoint is used.
• this value is ipl00% for the error case n.
• this ensures safe operation even in the event of an error in the setpoint transfer. In fan applications, no power and noise reduction occur in such an error case, but adequate cooling is ensured.
• the analog control signal can first be converted into a digital value with an analog-to-digital converter. Thereafter, the signal is further processed digitally. This can be done in an advantageous embodiment of the invention by a programmable component such as microprocessor, digital signal processor (DSP) or microcontroller.
• DSP digital signal processor
• FIG. 4 The program sequence for the realization of the input characteristic is shown in FIG.
• the input characteristic is realized by means of an electronic analog circuit.
• FIG. 6 shows an exemplary circuit for this purpose.
• This circuit consists of four analog comparators (Kl to K4), zwe i operational amplifiers (Vl, V2), two digital NAND gates and an analog multiplexer (MUX).
• the comparators compare the control signal X with the voltage values at the discontinuities in the input characteristic according to FIG. 4, ie with 0.5 V 5 1 V, 9 V and 9.5 V. These voltages are produced here with a series of resistances from the 10 V supply voltage ,
• the output signals of the comparators are further processed with the NAND gates and control the analog multiplexer, as the following table shows.
• F is the predefined setpoint for the error case. If this value z. B. 75%, Figure 4 accordingly, 7.5 V must be connected here.
• This circuit can be supplemented with a warning output (W), as shown in Figure 7.
• This output normally supplies a logical "1", in the event of an error a logical "0". This warning is issued if the control signal X assumes values less than 0.5 V or greater than 9.5 V.
• the erf Steuerappelndungsdorfe control unit can form a separate unit, or be integrated in the motor housing or in the terminal box of the engine so that engine and control unit form a mechanical unit.
• the solution according to the invention can also be advantageously used in compact fans, where the control unit and motor are integrated parts of the compact fan.
• the erf ⁇ ndungshiele solution can not only with fans,

Landscapes

• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Control Of Electric Motors In General (AREA)
• Control Of Motors That Do Not Use Commutators (AREA)
• Motor Or Generator Cooling System (AREA)

Priority Applications (7)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

Country Status (7)

Families Citing this family (11)

Citations (3)

Family Cites Families (12)

• 2006
  • 2006-05-04 DE DE202006007136U patent/DE202006007136U1/de not_active Expired - Lifetime
• 2007
  • 2007-05-03 JP JP2009508349A patent/JP5164974B2/ja not_active Expired - Fee Related
  • 2007-05-03 US US12/299,426 patent/US8120298B2/en not_active Expired - Fee Related
  • 2007-05-03 AT AT07728754T patent/ATE476783T1/de active
  • 2007-05-03 DE DE502007004651T patent/DE502007004651D1/de active Active
  • 2007-05-03 CN CN2007800158403A patent/CN101438489B/zh not_active Expired - Fee Related
  • 2007-05-03 WO PCT/EP2007/054301 patent/WO2007128772A1/de not_active Ceased
  • 2007-05-03 EP EP07728754A patent/EP2013966B1/de not_active Not-in-force
• 2012
  • 2012-01-31 US US13/363,028 patent/US20130127386A2/en not_active Abandoned

Patent Citations (3)

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