可程控双向直流电源通过SCPI(Standard Commands for Programmable Instruments)指令动态调整负载率的核心机制,在于利用SCPI命令实时控制输出电压/电流参数,结合双向能量流动特性实现负载率的动态调节。以下是具体实现方法与技术要点:
SOURce:VOLTage
指令设置输出电压,电源自动维持电压稳定,电流随负载变化。
SOURce:VOLTage 24rn
(设置输出电压24V)
SOURce:CURRent
指令设置输出电流,电源自动维持电流稳定,电压随负载调整。
SOURce:CURRent 3rn
(设置输出电流3A)
SOURce:POLarity
指令切换输出极性(正/负),实现能量双向流动。
SOURce:POLarity NEGativern
(切换为负电压输出)
python
# 初始设置:24V/3A(负载率=72W/100W=72%)
source.write("SOURce:VOLTage 24rn")
source.write("SOURce:CURRent 3rn")
# 动态调整至12V/6A(负载率=72W/100W=72%,但电流增大)
source.write("SOURce:VOLTage 12rn")
source.write("SOURce:CURRent 6rn")
SOURce:FUNCtion
指令设置电源为“双向模式”,允许能量从负载回馈至电源(如电池测试中的充电阶段)。
SOURce:FUNCtion BIDirectionalrn
SOURce:VOLTage
和
SOURce:CURRent
指令,实现充电/放电过程的动态控制。
python
# 放电阶段:电源输出24V/3A(负载率72%)
source.write("SOURce:VOLTage 24rn")
source.write("SOURce:CURRent 3rn")
# 充电阶段:切换为回馈模式,设置输入电流限制
source.write("SOURce:FUNCtion BIDirectionalrn")
source.write("SOURce:CURRent:LIMit -2rn")# 负号表示能量回馈
LIST
模式或
TRIGger
指令实现复杂负载曲线模拟。
python# 定义电压序列(0s:12V, 10s:24V, 20s:12V)source.write("SOURce:LIST:VOLTage "12,24,12"rn")source.write("SOURce:LIST:TIME "10,10"rn") # 每步持续时间source.write("SOURce:LIST:ACTrn") # 激活序列
SOURce:CURRent:LIMit
指令设置电流上限,防止过载损坏。
SOURce:CURRent:LIMit 5rn
(限制电流5A)
SYSTem:ERR?
指令查询错误状态,实现故障自动处理。
pythonerror = source.query("SYSTem:ERR?rn")if "OVERLOAD" in error:source.write("OUTPut OFFrn") # 过载时关闭输出
MEASure
指令查询实际输出电压/电流,验证负载率。
pythonvoltage = source.query("MEASure:VOLTage?rn")current = source.query("MEASure:CURRent?rn")print(f"实际负载率: {float(voltage)*float(current)/100*100}%") # 假设额定功率100W
python
# 恒流充电(1A)至4.2V
source.write("SOURce:FUNCtion BIDirectionalrn")
source.write("SOURce:VOLTage 4.2rn")
source.write("SOURce:CURRent 1rn")
# 恒压充电(4.2V)至电流降至0.1A
source.write("SOURce:FUNCtion VOLTagern")
source.write("SOURce:VOLTage 4.2rn")
while
float(source.query("MEASure:CURRent?rn")) >
0.1:
pass
python
# 启动阶段:高电流(5A)
source.write("SOURce:CURRent 5rn")
# 稳态运行:低电流(2A)
source.write("SOURce:CURRent 2rn")
time.sleep(0.03)
),避免缓冲区溢出。
SYSTem:ERR?
指令,直至返回
0,"No error"
,确保命令执行成功。