201001864 九、發明說明： 【發明所屬之技術領域】 本發明涉及一種不間斷電源裝置，尤指一種改進 的在線式不間斷電源裝置。 【先前技術】 不間斷電源（UPS)是一種交流電源供應器，其可 以在市電不正常時瞬間提供交流電。目前，習知的在 線式不間斷電源裝置，採用交流_直流、直流_交流的 雙轉換裝置，請參看第4圖所示。市電輸入先由濾波 裝置（ill)進行濾波，再經過保險絲（112)超載保護， 再由一相全橋整流裝置（113 )整流，經電容濾、波裝置 (115)濾成直流電壓，電池裝置（114)也經過三相全橋 整流裝置（113)提供直流電壓，經過保險絲（116)送到 逆變裝置（117)，將直流電壓用SPWM (SINEWAVEpULSE WIDTH MODULATION)控制技術經工頻變壓器隔離升壓 產生正弦波電壓，經過繼電裝置（118)輸出淨化的交 极電源再經過濾、波裝置（1 1 9 )濾波後輸出到用戶端供 電但是習知的（請參看第4圖所示）不間斷電源（ups) 整機滿負荷運行效率約8〇%〜85%，輕载時效率更低， 並且轉換損耗太多功率。 【發明内容】 本發明的一個目的在於提供一種改進的在線式 201001864 不間斷電源裝置，通過直流/直流轉換裝置，將經整 流的直流電壓轉換為正弦波脈寬直流電壓，只在直流 /直流轉換裝置中利用了一次電力轉換實現將輸入電 壓轉換為正弦波脈寬直流電壓，經直流/交流轉換裝 置輸出正弦波脈寬交流電壓。 為實現本發明的上述目的，本發明的在線式不間 斷電源包括： 一父流輸入’搞合於市電輸入端； 父流輸出’輕合於負载端； 整机裝置，其輸入端輕合於交流輸入，用來將 輸入的交流電壓整流輸出； 一直流電源，並聯耦合於該整流裝置的輸出端， 用來在市電停電時提供直流電壓； -矽控開關，電連接於該直流電源的輸出端，該 開關裝置導通時該直流電源供電； 一直流/直流轉換裝置，其輸入端耦合於整流裝 置的輸出端，用來將輸入的直流電壓轉換為正弦波脈 寬直流電麼輸出’該直流/直流轉換裝置包括一升壓 變廢器’該升壓變廢器包括一初級端和-次級端，該 初級端包括兩個繞組， 货、以及分別耦合於該初級端的兩 個繞組的第一功率開關去^每·—丄古 s和第一功率開關，該次級端包 6 201001864 括兩個繞組’以及分別輕合於該次級端的兩個繞組的 第二功率開關和第四功率開關； 一直流/交流轉換裝置，其輸入端耦合於該直流/ 直流轉換裝置的輸出端’輸出端耦合於該交流輸出， 該直流/交流轉換裝置包括四個由處理器控制的功率 開關和一低通濾波器； -繼電器，耦合於交流輸出端，用來切換市電供 電與該不間斷電源裝置供電；以及 八 一處理器，用來控制該第—與第三功率開關交替 導通與關斷、第二與第四功率開關交替導通與關斷； 該直流/直流轉換裝置由該處理器控制，將輸入 的直抓電壓轉換為正弦波脈寬直流電壓，經該直流/ 乂抓轉換裝置輸出正弦波脈寬交流電壓，再進行濾波 後輸出。 由於採用了上述的技術方案，本發明的在線式不 間斷電源裝置利用直流/直流轉換裝置將經整流的直 流電壓轉換為正弦波脈寬直流電壓，經直流/交流轉 換裝置輸出正弦波脈寬交流電麼，只在直流/直流轉 換裝置中彻了電力轉換，減少了轉換功率損耗。 本發明的另一個目的在於提供一種改進的在線 式不間斷電源’其利用直流/直流轉換裝置將負載側 201001864 或者直流/交流轉換裝置產生的多餘能量送回直流電 源儲能。 為實現本發明的上述目的，該直流/直流轉換裝 置還包括一充電電路’該充電電路包括一降壓變壓 器、一電容和一二極管，該降壓變壓器包括一初級端 和一次級端’其中該降壓變壓器初級端即為該升壓變 壓器次級端’該降壓變壓器次級端包括一繞組，該直 流/直流轉換裝置通過該充電電路將負載側或者直流 /交流轉換裝置產生的多餘能量送回直流電源儲能。 由於採用了該技術方案，該在線式不間斷電源裝 置在負載侧或者直流/交流轉換裝置產生的多餘能量 時’可將多餘能量送回直流電源儲能從而達到節能的 目的。 【實施方式】 以下，根據附圖對本發明的最佳實施形態進行說 明。 第1圖是根據本發明一較佳具體實施例的在線式 不間斷電源裝置的結構方塊示意圖。該較佳具體實施 例的在線式不間斷電源裝置包括： 一渡波裝置（1 )，耦合於交流輸入端，用來對輸 入的市電進行濾波； 一整μ裝置（2) ’其輸入端輕合於渡波裝置（1)的 201001864 輸出端，用來將經濾波的市電整流輸出； 一電池裝置（3) ’並聯耦合於該整流裝置（2)的輸 出端，用來在市電停電時提供直流電壓； 一矽控開關（4)，電連接於該電池裝置（3)，該矽 控開關（4)導通時電池裝置（3)供電； 一直流/直流轉換裝置（5)，其輸入端耦合於整流 裝置（2)的輸出端； 直流/父流轉換裝置（6)，其輸入端耦合於直流 /直流轉換裝置（5)的輸出端； 一繼電器（7)，耦合於交流輸出端，用來切換市 電供電與該不間斷電源裝置供電； 一濾波裝置（8)，耦合於該在線式不間斷電源裝 置的輸出知，用來將輸出的電壓經渡波，供給用戶端 設備；以及 一處理器，用來控制直流/直流轉換裝置（5)、直 流/交流轉換裝置（6)及繼電器（7)的切換。 更具體地，該直流/直流轉換裝置（5)包括一升壓 變壓器，由繞組（51)(52)與第一功率開關（56)、第二 功率開關（57)組成推挽式電路初級端，其導通占空比 小於50%，並由繞組（53)(54)與第三功率開關（58)、 第四功率開關（59)組成次級端並聯輸出，用來將輸入 9 201001864 的直流電壓轉換為正弦波脈寬直流電壓輸出。當負載 侧或交流/直流轉換裝置（6)工作時產生多餘能量 時，第三功率開關（58)、第四功率開關（59)導通將能 量送回降壓變壓器次級端繞組（55)經二極管（5〇i)，b 濾波電容（502) ’將能量儲存到電池裝置（3)。由於要 產生的SPWM信號導通占空比大於5〇%，所以由第一功 率開關（56)、第二功率開關（57)各導通一半再經過 (53、54)繞組相加輸出合成spWM信號，當不考慮轉 換效率時，為降低成本也可以用二極管代替第三功率 開關（58)、第四功率開關（59)。可以設定第一功率開 關（56)與第三功率開關（58)同步導通，第二功率開關 (57)與第四功率開關（59)同步導通，降低功率開關導 通時電壓降，提高效率。 該直流/交流轉換裝置（6)，包括四個功率開關 (61 )(62) (63)(64)，以及由一電感（65)與一電容（66) 組成的用來進行濾波的低通濾波器。利用處理器控制 功率開關（61)(62) (63)(64)的導通與關斷，功率開 關（61)(62)導通產生正半周的spwM^壓波形，功率 開關（63) (64)導通產生負半周的spwM電壓波形，將 從直流/直流轉換裝置（5)輸出的正弦波脈寬直流電 壓經四個功率開關（61 )(62)(63)(64)輸出為正弦波 10 201001864 脈寬交流電壓。 本發明的在線式不間斷電源（UPS)，不受市電電 源品質的影響。當市電正常時，市電直接由濾波裝置 (1)濾、波經繼電器（7)、濾波裝置（8 )輸出到用戶端； 當電壓過高或過低時’由該在線式不間斷電源裝置提 供純淨的交流電源；當市電停電時無中斷時間轉由電 池裝置（3)提供能量繼續提供純淨的交流電源。 當市電過高或過低時，矽控開關（4)斷開，由處 理器控制繼電器（7)切換到該在線式不間斷電源供 電。市電輸入從濾波裝置（1)經整流裝置（2)，將交流 電整流成只有正值的市電頻率兩倍的正弦波（請參看 第2圖所示的參考波形丨7)，提供給直流/直流變換器 (5)的升壓變壓器初級端繞組（51)(52)，由處理器控 制第一功率開關（56)、第二功率開關（57)交替導通產 、 生高頻率脈波電壓（請參閱第2圖所示的參考波形 12、13)’為避免變壓器飽合，限制升壓變壓器初級 端繞組（51)(52)的最大占空比不大於50%，經過升壓 變壓器隔離升壓到次級端繞組（53)(54)，將波形相加 合成真正的正弦波脈寬直流電壓（請參看第2圖所示 的參考波形14)(由處理器計算每一正弦波脈寬的值 除以一 ’做為第一功率開關（5 6 )、第二功率開關（5 7 ) 11 201001864 的開關控制信號），再將正弦波脈寬高頻直流電壓經 直流/交流轉換裝置（6)產生低頻（50Hz/60Hz)正弦波 脈寬交流電壓，處理器控制功率開關（61) (62)導通時 產生正半周（請參閱第2圖所示的參考波形6162)，處 理器控制功率開關（63)(64)導通時產生負半周（請參 閱第2圖所示的參考波形6364)，直流/交流轉換裝置 (6)將從直流/直流轉換裝置（5)輸出的正弦波脈寬直 流電壓經四個功率開關（61 )(62)(63) (64)輸出為正 弦波脈寬交流電壓（請參閱第2囷所示的參考波形 15)，然後經過電感器（65)與電容器（66)組成的低通 遽波器濾除南頻成份輸出純淨低頻正弦波交流電壓 (請參閱第2圖所示的參考波形16)，再經過繼電器（7) 輸出，經濾波裝置（8)濾除諧波後提供給用戶設備繼 續供電。其中第三功率開關（58)導通時間與第一功率 f幵1關（56)的導通同步，第四功率開關（59)導通時間與 第二功率開關（57)的導通同步，可降低功率開關能量 損耗’也可以用二極管取代第三功率開關(58)、第四 功率開關（59) ’降低成本。為了將負载侧或直流/交 流轉換裝置（6)產生的多餘能量送回電池端 三功率開關（58)與第四功率開關（59)導通，將能量送 回降壓_次級端繞組(55)經二極管⑽)遽波電 12 201001864 谷（502)將夕餘能罝送回電池儲能，並對電池裝置（3) 充電。 市電停電時，由處理器控制繼電器（7)切換到該 不間斷裝置中的電池裝置（3)供電。矽控開關（4)導 通，電池裝置（3)輸出電壓（請參閱第3圖所示的參考 波形11)，提供給直流/直流變換器（5)的升壓變壓器 初級端繞組（51)(52)，由處理器控制第一功率開關 (56)、第二功率開關（57)交替導通產生高頻脈波電壓 (請參看第3圖所示的參考波形12、13)，為避免變壓 器飽合，限制升壓變壓器初級端繞組（51)(52)的最大 占空比不大於50%，經過升壓變壓器隔離升壓到次級 端繞組（53)(54)，將波形相加合成真正的正弦波脈寬 咼頻直々IL電壓（凊參閱第3圖所示的參考波形14)(由 處理器處理器計算每一正弦波脈寬的值除以二，做為 第一功率開關（56)、第二功率開關（57)的開關控制信 號），再將正弦波脈寬高頻直流電壓經過直流/交流轉 換裝置（6)產生低頻（50Hz/60Hz)正弦波交流電壓，處 理器控制功率開關（61)(62)導通時產生正半周（請參 看第3圖所示的參考波形6162)，處理器控制功率開 關（63)(64)導通時產生負半周（請參看第3圖所示的 參考波形6364)，直流/交流轉換裝置（6)將從直流/ 13 201001864 直流轉換裝置（5)輸出的正弦波脈寬高頻直流電壓經 四個功率開關（61 )(62)(63)(64)輸出為正弦波脈寬 交流電壓（請參看圖示的參考波形丨5)，然後經過電感 器（65)與電容器（66)組成的低通濾波器濾除高頻成 份輸出純淨低頻正弦波交流電壓（請參看第3圖所示 的參考波形16)，再經過繼電器（7)輸出，經濾波裝置 (8 )濾除諧波後提供給用戶設備繼續供電。 可以理解的是’上述實施例的詳細說明是為了闡 述和解釋本發明的原理而不是對本發明的保護範圍 的限定。在不脫離本發明的主旨的前提下，本領域的 一般技術人員通過對上述技術方案的所教導的原理 的理解可以在這些實施例基礎上做出修改，變化和改 動。因此本發明的保護範圍由所附的權利要求以及其 等同來限定。 【圖式簡單說明】 第1圖為本發明一較佳具體實施例的在線式不間 斷電源裝置的結構方塊示意圖。 第2圖為本發明一較佳具體實施例的在線式不間 斷電源裝置在有市電時各點的輸出波形示意圖。 第3圖為本發明一較佳具體實施例的在線式不間 斷電源裝置在電池裝置供電時各點的輸出波形示意 14 201001864 圖。 第4圖為習知的在線式不間斷電源裝置的結構方 框示意圖。 【主要元件符號說明】 (1)濾波裝置 (3)電池裝置 (5)直流/直流轉換裝置 (7)繼電器 (2)整流裝置 (4)矽控開關 (6)直流/交流轉換裝置 (8)濾波裝置 (51 )(52)(53)(54)(55)繞組（56)第一功率開關 (5 7)第二功率開關 (5 9)第四功率開關 (58)第三功率開關 (61)(62)(63)(64)功率開關 (65)電感 (501)二極管 (111)濾波裝置 (113)三相全橋整流裝置 (115)濾波裝置 (117)逆變裝置 (66)電容 (502)濾波電容 (112)保險絲 (114)電池 (116)保險絲 (118)繼電裝置 (119)濾波裝置201001864 IX. Description of the Invention: [Technical Field] The present invention relates to an uninterruptible power supply device, and more particularly to an improved online uninterruptible power supply device. [Prior Art] An uninterruptible power supply (UPS) is an AC power supply that can supply AC power instantaneously when the utility power is abnormal. At present, the conventional on-line uninterruptible power supply unit adopts an AC-DC, DC-AC double conversion device, as shown in Fig. 4. The mains input is first filtered by the filter device (ill), then protected by the fuse (112) overload, and then rectified by a phase full-bridge rectifier (113), filtered by the capacitor filter, wave device (115) into a DC voltage, battery device (114) The DC voltage is also supplied through the three-phase full-bridge rectifier (113), sent to the inverter device (117) via the fuse (116), and the DC voltage is isolated by the SPWM (SINEWAVEpULSE WIDTH MODULATION) control technology by the power frequency transformer. The voltage generates a sinusoidal voltage, and the AC power supply that has been purified by the relay device (118) is filtered, filtered by the wave device (1 19), and output to the user terminal for power supply (known in Figure 4). Uninterruptible power supply (ups) The operating efficiency of the whole machine is about 8〇%~85%, the efficiency is lower at light load, and the conversion loss is too much power. SUMMARY OF THE INVENTION An object of the present invention is to provide an improved on-line 201001864 uninterruptible power supply device that converts a rectified DC voltage into a sinusoidal pulse width DC voltage through a DC/DC converter, only in DC/DC conversion. The device uses a power conversion to convert the input voltage into a sinusoidal pulse width DC voltage, and outputs a sinusoidal pulse width AC voltage through the DC/AC conversion device. In order to achieve the above object of the present invention, the online uninterruptible power supply of the present invention comprises: a parent flow input 'fitted to the mains input; the parent output 'lights to the load end; the whole device, the input of which is lightly coupled An AC input for rectifying and outputting the input AC voltage; a DC power source coupled in parallel to the output of the rectifying device for providing a DC voltage when the mains is powered off; - a control switch electrically connected to the output of the DC power supply The DC power supply is provided when the switch device is turned on; a DC/DC converter device whose input end is coupled to the output end of the rectifying device for converting the input DC voltage into a sinusoidal pulse width DC power and outputting the DC/DC The DC converter includes a boost converter. The booster includes a primary end and a secondary end, the primary end including two windings, and a first of two windings respectively coupled to the primary end The power switch goes to each of the first power switches, and the secondary end package 6 201001864 includes two windings 'and two windings respectively lightly coupled to the secondary end a power switch and a fourth power switch; a DC/AC converter having an input coupled to the output of the DC/DC converter; an output coupled to the AC output, the DC/AC converter comprising four a power switch and a low pass filter; - a relay coupled to the AC output for switching the mains supply and the uninterruptible power supply; and an eighty processor for controlling the first and third powers The switch is alternately turned on and off, and the second and fourth power switches are alternately turned on and off; the DC/DC converter is controlled by the processor to convert the input direct voltage into a sinusoidal pulse width DC voltage, and the DC / Scratch the converter to output a sine wave pulse width AC voltage, and then filter and output. By adopting the above technical solution, the online uninterruptible power supply device of the present invention converts the rectified DC voltage into a sinusoidal pulse width DC voltage by using a DC/DC conversion device, and outputs a sinusoidal pulse width AC power through a DC/AC conversion device. However, the power conversion is only performed in the DC/DC converter, which reduces the conversion power loss. Another object of the present invention is to provide an improved in-line uninterruptible power supply which utilizes a DC/DC converter to return excess energy generated by the load side 201001864 or the DC/AC converter to the DC power source. In order to achieve the above object of the present invention, the DC/DC conversion device further includes a charging circuit. The charging circuit includes a step-down transformer, a capacitor and a diode. The step-down transformer includes a primary end and a primary end end. The primary end of the step-down transformer is the secondary end of the step-up transformer. The secondary end of the step-down transformer includes a winding, and the DC/DC converter device sends excess energy generated by the load side or the DC/AC conversion device through the charging circuit. Back to DC power storage. Due to the adoption of the technical solution, the online uninterruptible power supply device can send excess energy back to the DC power storage to save energy when the load side or the excess energy generated by the DC/AC conversion device is used. [Embodiment] Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a block diagram showing the construction of an in-line uninterruptible power supply unit in accordance with a preferred embodiment of the present invention. The online uninterruptible power supply device of the preferred embodiment comprises: a wave device (1) coupled to the AC input for filtering the input mains; a whole μ device (2) 'the input is lightly coupled The 201001864 output of the Yubo device (1) is used to rectify the filtered mains output; a battery device (3) is coupled in parallel to the output of the rectifying device (2) for providing DC voltage during mains power failure a control switch (4) electrically connected to the battery device (3), the battery device (3) is powered when the switch (4) is turned on; a DC/DC converter (5) whose input is coupled to An output of the rectifier (2); a DC/parent conversion device (6) having an input coupled to the output of the DC/DC converter (5); a relay (7) coupled to the AC output for use Switching the mains power supply and the uninterruptible power supply device; a filtering device (8) coupled to the output of the online uninterruptible power supply device for transmitting the output voltage to the user equipment; and a processor Used to control Switching between DC/DC converter (5), DC/AC converter (6) and relay (7). More specifically, the DC/DC conversion device (5) includes a step-up transformer, and the primary end of the push-pull circuit is composed of a winding (51) (52) and a first power switch (56) and a second power switch (57). The on-duty ratio is less than 50%, and the secondary end of the winding (53) (54) is combined with the third power switch (58) and the fourth power switch (59) to output the DC of the input 9 201001864. The voltage is converted to a sinusoidal pulse width DC voltage output. When excess energy is generated when the load side or the AC/DC converter (6) is operating, the third power switch (58) and the fourth power switch (59) are turned on to return energy to the secondary winding of the step-down transformer (55). Diode (5〇i), b Filter Capacitor (502) 'Save energy to the battery unit (3). Since the SPWM signal to be generated has an on-duty ratio greater than 5〇%, the first power switch (56) and the second power switch (57) are each turned on and then passed through the (53, 54) windings to add and synthesize the spWM signal. When the conversion efficiency is not considered, a diode can be used instead of the third power switch (58) and the fourth power switch (59) in order to reduce the cost. The first power switch (56) can be set to be turned on synchronously with the third power switch (58), and the second power switch (57) and the fourth power switch (59) are turned on synchronously to reduce the voltage drop when the power switch is turned on, thereby improving efficiency. The DC/AC conversion device (6) includes four power switches (61) (62) (63) (64), and a low pass composed of an inductor (65) and a capacitor (66) for filtering filter. The power switch (61) (62) (63) (64) is turned on and off by the processor, and the power switch (61) (62) is turned on to generate a positive half-cycle spwM voltage waveform, power switch (63) (64) The turn-on generates a negative half-cycle spwM voltage waveform, and the sinusoidal pulse width DC voltage output from the DC/DC converter (5) is output as a sine wave 10 through four power switches (61) (62) (63) (64). Pulse width AC voltage. The online uninterruptible power supply (UPS) of the present invention is not affected by the quality of the commercial power supply. When the mains is normal, the mains is directly filtered by the filtering device (1), the wave relay (7), and the filtering device (8) are output to the user terminal; when the voltage is too high or too low, 'the online uninterruptible power supply device provides Pure AC power; when the mains is out of power, no interruption time is transferred to the battery unit (3) to provide energy to continue to provide pure AC power. When the mains is too high or too low, the remote control switch (4) is turned off, and the processor control relay (7) is switched to the online uninterruptible power supply. The mains input is filtered from the filtering device (1) via the rectifying device (2) to rectify the alternating current into a sine wave with twice the positive mains frequency (see reference waveform 丨7 shown in Figure 2) for DC/DC. The primary winding (51) (52) of the step-up transformer of the converter (5) is controlled by the processor to alternately conduct the first power switch (56) and the second power switch (57) to generate a high-frequency pulse wave voltage (please Refer to the reference waveforms 12, 13) shown in Figure 2. To limit the saturation of the transformer, limit the maximum duty cycle of the primary winding (51) (52) of the step-up transformer to no more than 50%, and isolate the boost through the step-up transformer. To the secondary winding (53) (54), add the waveforms to form a true sinusoidal pulse width DC voltage (see reference waveform 14 shown in Figure 2) (the sine wave pulse width is calculated by the processor) The value is divided by a 'switching control signal of the first power switch (5 6 ), the second power switch (5 7 ) 11 201001864), and then the sine wave pulse width high frequency DC voltage is passed through the DC/AC conversion device (6) Generate low frequency (50Hz/60Hz) sine wave pulse width AC voltage, processor control The rate switch (61) (62) generates a positive half cycle when turned on (refer to reference waveform 6162 shown in Figure 2), and the processor controls the power switch (63) (64) to turn on a negative half cycle (see Figure 2). The reference waveform 6364), the DC/AC conversion device (6) outputs a sinusoidal pulse width DC voltage output from the DC/DC conversion device (5) through four power switches (61) (62) (63) (64) The output is a sinusoidal pulse width AC voltage (see reference waveform 15 shown in Figure 2), and then a low-pass chopper consisting of an inductor (65) and a capacitor (66) filters out the south frequency component to output a pure low frequency sine. The wave AC voltage (refer to reference waveform 16 shown in Figure 2) is output through the relay (7), and the harmonics are filtered out by the filtering device (8) to provide power to the user equipment. The conduction time of the third power switch (58) is synchronized with the conduction of the first power f幵1 (56), and the conduction time of the fourth power switch (59) is synchronized with the conduction of the second power switch (57), thereby reducing the power switch. The energy loss can also be replaced by a diode instead of the third power switch (58) and the fourth power switch (59). In order to send the excess energy generated by the load side or the DC/AC conversion device (6) back to the battery terminal, the three power switches (58) and the fourth power switch (59) are turned on, and the energy is returned to the buck_secondary winding (55). ) Via diode (10)) Chopper 12 201001864 Valley (502) will return the energy storage battery back to the battery and charge the battery device (3). When the utility power is cut off, the processor control relay (7) switches to the battery device (3) in the uninterrupted device to supply power. The tamper switch (4) is turned on, and the battery device (3) output voltage (refer to reference waveform 11 shown in Figure 3) is supplied to the step-up transformer primary winding (51) of the DC/DC converter (5) ( 52), the first power switch (56) and the second power switch (57) are alternately turned on by the processor to generate a high frequency pulse wave voltage (refer to the reference waveforms 12 and 13 shown in FIG. 3), in order to avoid the transformer being full. To limit the maximum duty cycle of the primary winding (51) (52) of the step-up transformer to no more than 50%, and boost the boost to the secondary winding (53) (54) through the step-up transformer to add the waveforms to the real The sinusoidal pulse width is directly proportional to the IL voltage (see reference waveform 14 shown in Figure 3) (the value of each sine wave pulse width is divided by two by the processor processor as the first power switch (56). ), the second power switch (57) switch control signal), and then the sine wave pulse width high frequency DC voltage through the DC / AC conversion device (6) to generate low frequency (50Hz / 60Hz) sine wave AC voltage, the processor controls the power The positive half cycle is generated when the switch (61) (62) is turned on (refer to the reference shown in Figure 3). Shape 6162), the processor controls the power switch (63) (64) to generate a negative half cycle when turned on (see reference waveform 6364 shown in Figure 3), and the DC/AC converter (6) will convert from DC / 13 201001864 DC The sine wave pulse width high frequency DC voltage outputted by the device (5) is output as a sinusoidal pulse width AC voltage through four power switches (61) (62) (63) (64) (refer to the reference waveform 丨 5 shown in the figure) Then, a low-pass filter composed of an inductor (65) and a capacitor (66) filters out the high-frequency component to output a pure low-frequency sine wave AC voltage (refer to the reference waveform 16 shown in FIG. 3), and then passes through the relay (7). The output is filtered by the filtering device (8) and then supplied to the user equipment to continue to supply power. It is to be understood that the foregoing detailed description of the embodiments of the present invention Modifications, variations, and modifications can be made in the embodiments of the present invention. The scope of the invention is therefore defined by the appended claims and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a block diagram showing the structure of an in-line uninterruptible power supply unit according to a preferred embodiment of the present invention. Fig. 2 is a schematic diagram showing the output waveform of each point of the online uninterruptible power supply device in the presence of mains according to a preferred embodiment of the present invention. Figure 3 is a diagram showing the output waveform of each point of the online uninterruptible power supply device in the power supply of the battery device according to a preferred embodiment of the present invention. Fig. 4 is a block diagram showing the structure of a conventional online uninterruptible power supply unit. [Description of main component symbols] (1) Filter device (3) Battery device (5) DC/DC converter device (7) Relay (2) Rectifier device (4) Remote control switch (6) DC/AC converter device (8) Filtering device (51) (52) (53) (54) (55) winding (56) first power switch (57) second power switch (59) fourth power switch (58) third power switch (61 ) (62) (63) (64) Power Switch (65) Inductor (501) Diode (111) Filtering Device (113) Three-Phase Full-Bridge Rectifier (115) Filtering Device (117) Inverter (66) Capacitor ( 502) Filter Capacitor (112) Fuse (114) Battery (116) Fuse (118) Relay Device (119) Filter Device