【導(dǎo)讀】傳感器等的綜合考量。詳細(xì)討論無機(jī)械傳感器技術(shù)，和減少轉(zhuǎn)矩脈動(dòng)，噪音和振動(dòng)的特殊。方法，敘述在永磁無刷直流電機(jī)驅(qū)動(dòng)控制中使用集成芯片的微電子影響。的改善和成本的減少，其應(yīng)用范圍在日益擴(kuò)大。關(guān)鍵詞永磁無刷直流電機(jī)；傳感器；控制器；無位置傳感器運(yùn)行；轉(zhuǎn)矩脈動(dòng)。最新的無刷直流電動(dòng)機(jī)采用高性能稀土材料制成，應(yīng)用不同的電機(jī)結(jié)構(gòu)，如軸向場(chǎng)、降低成本，提高微電子器件性能。最新的控制理念，如擁有穩(wěn)定性好，適應(yīng)性強(qiáng)的模糊神。經(jīng)網(wǎng)絡(luò)控制器，對(duì)于其在轉(zhuǎn)速為每分鐘幾轉(zhuǎn)到幾千轉(zhuǎn)的范圍內(nèi)的廣泛使用是一個(gè)福音。應(yīng)用這些方面來講，永磁無刷直流電機(jī)的最新進(jìn)展。計(jì)的不同的構(gòu)造使其成為目前最好的電機(jī)。已在永磁電機(jī)中使用，因?yàn)樗鼈儽阋饲胰菀撰@得。磁通密度、抗磁力和低溫度系數(shù)造成的高能量密度，目前也投入使用。在永磁無刷直流電機(jī)中永磁鐵放置于轉(zhuǎn)子內(nèi)。速度限制為會(huì)由電樞反應(yīng)和機(jī)械結(jié)構(gòu)引起的退磁的最大速度。步相電流和軸的位置反饋進(jìn)行閉環(huán)調(diào)節(jié)。

　　

【正文】 n. Current sensors Fast torque control in high performance PMBLDC motor drives is implemented through closed loop regulation of phase winding currents in synchronization with rotor flux position information. Closed loop regulation of winding currents is realized through PWM or hysteresis current controllers of CCVSI over the reference desired currents and sensed winding currents. Therefore, the sensing of winding currents bees indispensable in PMBLDC motor drives. The current sensing is generally carded out using hall effect current sensors. They detect the magnitude and direction of currents and are integrated to provide sensitive and accurate current sensing. Very fast response (less than 1 microsecond) 武漢工程大學(xué)畢業(yè)設(shè)計(jì) (外文文獻(xiàn)翻譯） 21 and accurate current sensors are available from different manufacturers (ABB, LEM etc.) in wide range of current sensing (fractions of amperes to kiloamperes). These hall effect current transducers have galvanic isolation of several kilovolts which is a very desired requirement of these drives in high rating. Generally in 3phase motors two current sensors are required and thirdphase current is estimated from other twophase currents in star connected motors. These current sensing requirements for current regulated rectangular fed PMBLDC motor drive are typically reduced to a single current sensor in the dc link of the inverter. Current shunt resistors with low power dissipation are often used as the current sensor in low power drives for cost effectiveness. In the modem power devices such as MOSFET/IGBT a current sensing feature is provided by many manufacturers which also dispenses with the use of extra current sensors in the control of the inverter/converter feeding the PMBLDCM. Voltage sensors Terminal voltage sensing in modem advanced PMBLDC motor drives is required to estimate the rotor position and speed for the control, resulting in mechanical sensorless drive with a view to reduce size, cost, maintenance and enhanced reliability. Voltage sensing is also required to regulate dc bus voltage during braking or for control of front end converter used for regenerative feature in high rating drives. Terminal voltage sensing is carried out by using electronic isolation amplifier 武漢工程大學(xué)畢業(yè)設(shè)計(jì) (外文文獻(xiàn)翻譯） 22 (AD202 Analog Devices make etc.) and hall effect voltage sensors (ABB make etc.) with galvanic isolation. In small rating drives, voltage is sensed using high valued resistor potential dividers to reduce the cost of the drive. Sometimes, induced voltage in the motor windings is achieved using special windings such as search coils etc. However, ac mains voltages for the control of front end convener are sensed using the potential transformers. 6. Sensors elimination and reduction Recent trends in sensors, their requirement and types of available sensors are already discussed in 167。 5. However, some of these sensors in PMBLDC motor drive may be reduced from the view point of size, cost, maintenance and reliability. Typically mechanical rotor position and speed sensors have the drawbacks of increasing the number of connections between motor and controller, increased interference, limitation in accuracy of sensors due to environmental factors such as temperature, humidity, vibrations etc., increased friction and inertia and additional space in motor housing. Because of these problems recently there has been wide interest and developments in the techniques for elimination of mechanical rotor position/speed sensing by estimating the rotor position and speed using sensed currents and voltages. Moreover, the number of voltage and current sensors may be reduced through using intelligent processors for the control of inverter feeding PMBLDC motors. Various techniques for these sensors elimination and reduction are briefly discussed in the following section. 武漢工程大學(xué)畢業(yè)設(shè)計(jì) (外文文獻(xiàn)翻譯） 23 Mechanical sensors elimination One of the most recent developments in PMBLDC motor drives has been the rapid evolution of new techniques for eliminating the rotor angular position sensor. Elimination of the shaftmounted position sensor is a very desirable feature in a number of applications since this sensor is one of the most expensive and fragile ponents in this drive. Some of the position sensorless schemes are classified in brief. Back EMF based position estimation The most mon methods of rotor flux position sensing is based on deriving the back emf signals. There are many methods for rotor position estimation based on the back emf and are briefly discussed below. Direct back EMF detection: This method is quite popular for rectangular fed PMBLDC motors. In these PM motors, particular phase winding is excited for 2/3 of each electrical period and ideally there is always one phase which is not excited. The direct sensing of back emf of unexcited phases in sequence is used to generate discrete rotor position signal for current synchronization with rotor flux. It has been applied to many industrial applications including disk drives, pact stereo players and room air conditioners. Estimation of back EMF: This method is applied to both sinusoidal fed and 武漢工程大學(xué)畢業(yè)設(shè)計(jì) (外文文獻(xiàn)翻譯） 24 rectangular fed PMBLDC motors. This method is based on the reconstruction of the back emf by using voltage equation of the motor (e = v iRLdi/dt). Reconstruction of the back emf involves either simulating this equation with operational amplifier or solving this equation in online digital processor normally used for control. In this method, the terminal voltage and line current are measured directly and the above equation is used to achieve back emf and rotor position. 武漢工程大學(xué)畢業(yè)設(shè)計(jì) (外文文獻(xiàn)翻譯） 25 武漢工程大學(xué)畢業(yè)設(shè)計(jì) (外文文獻(xiàn)翻譯） 26