【摘要】 基于目前三相交流电源过零点检测电路过零点检测不准确或成本高的问题。文中设计了一种经济实用、过零点检测准确且具有相序检测和缺相检测的电路。由于三相三线制电源没有零线,该电路首先构建了一条零线,使线电压变成相电压,利用比例放大器电路降压,然后使用电压比较器电路产生标准的方波,在交流电的正半周期比较器输出零电平,在交流电的负半周期电压比较器输出高电平。该电路多次应用在晶闸管调压电路中,结果证明该电路具有较高的可靠性和准确性。更多还原

【Abstract】 Because the cost of three phase AC power supply pass-zero detect circuit is expensive,and the detection is not accurate nowadays. A novel circuit for three-phase AC voltage zero-point inspecting and phase sequence self-adaptation and phase lack test is proposed in this paper. Firstly,because the three-phase three-wire system power supply hasn’t zero line,this circuit constructs a zero line,the line voltage converts the phase voltage. The purpose of proportional amplifier circuit is to reduce voltage.Then it generates accurate square wave by the voltage comparator circuit. In AC positive half period it generates zero voltage,and in AC negative half period it generates high voltage. This scheme’s time deviation only depends on amplifier ’s voltage jump speed. This circuit was applied in the circuit of thyristor voltage regulation many times,and the results indicate that this circuit has better reliability and accuracy.更多还原